pyrophosphate and sodium-pyrophosphate

Tetrasodium and/or tetrapotassium pyrophosphate (Ppi) is the anticalculus component of most tartar control dentifrices on the market today. While pyrophosphates alone are not responsible for hypersensitivity reactions, several modifications which may lead to adverse oral manifestations may occur when pyrophosphates are added to a dentifrice. First, tetrasodium pyrophosphate in a dentifrice forms a slightly alkaline solution upon oral use which could irritate oral membranes. Second, increased concentrations of flavoring agents, known to be sensitizers, are needed to mask the strong bitter taste of pyrophosphates. Third, increased concentrations of detergents, capable of producing hypersensitivity reactions, are necessary to allow the pyrophosphates to become soluble in the dentifrice. Fourth, a pre-existing condition of reduced salivary flow may augment hypersensitivity to tartar control toothpastes. While pyrophosphates have been approved as additives in dentifrices, these compounds along with the increased concentrations of flavorings and detergents and their higher intraoral alkalinity are strongly implicated as the causative factor in certain hypersensitivity reactions.

Topics: Adult; Alkalies; Dental Calculus; Detergents; Diphosphates; Female; Flavoring Agents; Humans; Hypersensitivity; Irritants; Mouth Mucosa; Potassium Compounds; Stomatitis; Toothpastes; Xerostomia

To assess the effects for controlling extrinsic tooth stain of a whitening toothpaste containing 10% high cleaning silica, 0.5% sodium phytate and 0.5% sodium pyrophosphate, in comparison with a negative control toothpaste.. A total of 86 adults who met with the inclusion and exclusion criteria were invited to take part in the study. They were distributed into test and control groups randomly. At baseline, 4 weeks and 8 weeks, the same examiner provided the clinical examinations, including evaluations of oral soft and hard tissues and measurements of tooth stain of the anterior teeth using the Lobene Stain Index. Adverse events and any changes in general health conditions of the patients were monitored.. When the study was completed, comparisons between patients in test and control groups yielded statistically significant differences in Lobene stain adjusted mean area score [0.83 (0.05) vs. 1.13 (0.05)], Lobene stain adjusted mean intensity score [0.99 (0.06) vs. 1.32 (0.06)] and Lobene stain adjusted mean composite score [1.45 (0.13) vs. 2.50 (0.13)] (All, P < 0.001). Patients in the test group exhibited reductions of 26.55%, 25% and 42%, respectively in Lobene stain area, intensity and composite scores, relative to patients in the control group. Comparisons within groups showed that all three Lobene scores at 8 weeks in both groups were lower than those at baseline (All, P < 0.001).. This study demonstrates that 8-week use of a toothpaste containing 10% high cleaning silica, 0.5% sodium phytate and 0.5% sodium pyrophosphate can effectively reduce extrinsic tooth stain. Trial registration NCT04238429 (before enrollment of the first participant). Data register: March 4, 2018.

Topics: Adult; Dentifrices; Diphosphates; Humans; Phytic Acid; Silicon Dioxide; Sodium Fluoride; Tooth Bleaching; Tooth Discoloration; Toothpastes; Treatment Outcome

It is challenging to find an iron compound that combines good bioavailability with minimal sensory changes when added to seasonings or condiments. Ferric pyrophosphate (FePP) is currently used to fortify bouillon cubes, but its bioavailability is generally low. Previously, the addition of a stabilizer, sodium pyrophosphate (NaPP), improved iron bioavailability from a bouillon drink.. We assessed whether there is a dose-response effect of added NaPP on iron bioavailability from local meals prepared with intrinsically labeled FePP-fortified bouillon cubes in young Nigerian women using iron stable isotope techniques.. In a double-blind, randomized, cross-over trial, women (n = 24; aged 18-40 y; mean BMI 20.5 kg/m2) consumed a Nigerian breakfast and lunch for 5 d prepared with bouillon cubes containing 2.5 mg 57Fe (as FePP) and 3 different molar ratios of NaPP: 57Fe (0:1, 3:1, and 6:1). Iron bioavailability was assessed by measuring 57Fe incorporation into erythrocytes 16 d after each 5 d NaPP: 57Fe feeding period. Data were analyzed using a linear regression model of log iron absorption on NaPP ratio, with body weight and baseline body iron stores as covariates and subject as a random intercept.. Of the women included, 46% were anemic and 26% were iron deficient. Iron bioavailability was 10.8, 9.8, and 11.0% for the 0:1, 3:1, and 6:1 NaPP:57Fe treatments, respectively. There was no dose-response effect of an increasing NaPP:57Fe ratio (β ± SE: 0.003 ± 0.028, P = 0.45).. In this study, the addition of NaPP did not increase iron bioavailability from FePP-fortified bouillon cubes. However, iron bioavailability from the Nigerian meals prepared with FePP-fortified bouillon cubes was higher than expected. These results are encouraging for the potential of bouillon cubes as a fortification vehicle. Further studies are needed to assess the effect of FePP-fortified bouillon cubes on improving iron status in low-income populations. This trial was registered at clinicaltrials.gov as NCT02815449.

Topics: Adult; Anemia; Anemia, Iron-Deficiency; Biological Availability; Cross-Over Studies; Diphosphates; Double-Blind Method; Erythrocytes; Female; Food, Fortified; Humans; Intestinal Absorption; Iron; Iron Isotopes; Meals; Nigeria; Young Adult

Fe fortification of centrally manufactured and frequently consumed condiments such as bouillon cubes could help prevent Fe deficiency in developing countries. However, Fe compounds that do not cause sensory changes in the fortified product, such as ferric pyrophosphate (FePP), exhibit low absorption in humans. Tetra sodium pyrophosphate (NaPP) can form soluble complexes with Fe, which could increase Fe bioavailability. Therefore, the aim of this study was to investigate Fe bioavailability from bouillon cubes fortified with either FePP only, FePP+NaPP, ferrous sulphate (FeSO4) only, or FeSO4+NaPP. We first conducted in vitro studies using a protocol of simulated digestion to assess the dialysable and ionic Fe, and the cellular ferritin response in a Caco-2 cell model. Second, Fe absorption from bouillon prepared from intrinsically labelled cubes (2·5 mg stable Fe isotopes/cube) was assessed in twenty-four Fe-deficient women, by measuring Fe incorporation into erythrocytes 2 weeks after consumption. Fe bioavailability in humans increased by 46 % (P<0·005) when comparing bouillons fortified with FePP only (4·4 %) and bouillons fortified with FePP+NaPP (6·4 %). Fe absorption from bouillons fortified with FeSO4 only and with FeSO4+NaPP was 33·8 and 27·8 %, respectively (NS). The outcome from the human study is in agreement with the dialysable Fe from the in vitro experiments. Our findings suggest that the addition of NaPP could be a promising strategy to increase Fe absorption from FePP-fortified bouillon cubes, and if confirmed by further research, for other fortified foods with complex food matrices as well.

Topics: Adolescent; Adult; Biological Availability; Caco-2 Cells; Digestion; Diphosphates; Erythrocytes; Female; Ferritins; Ferrous Compounds; Food, Fortified; Humans; Intestinal Absorption; Iron; Solubility; Young Adult

Processed meat intake has been associated with increased colorectal cancer risk. We have shown that cured meat promotes carcinogen-induced preneoplastic lesions and increases specific biomarkers in the colon of rats.. We investigated whether cured meat modulates biomarkers of cancer risk in human volunteers and whether specific agents can suppress cured meat-induced preneoplastic lesions in rats and associated biomarkers in rats and humans.. Six additives (calcium carbonate, inulin, rutin, carnosol, α-tocopherol, and trisodium pyrophosphate) were added to cured meat given to groups of rats for 14 d, and fecal biomarkers were measured. On the basis of these results, calcium and tocopherol were kept for the following additional experiments: cured meat, with or without calcium or tocopherol, was given to dimethylhydrazine-initiated rats (47% meat diet for 100 d) and to human volunteers in a crossover study (180 g/d for 4 d). Rat colons were scored for mucin-depleted foci, putative precancer lesions. Biomarkers of nitrosation, lipoperoxidation, and cytotoxicity were measured in the urine and feces of rats and volunteers.. Cured meat increased nitroso compounds and lipoperoxidation in human stools (both P < 0.05). Calcium normalized both biomarkers in rats and human feces, whereas tocopherol only decreased nitro compounds in rats and lipoperoxidation in feces of volunteers (all P < 0.05). Last, calcium and tocopherol reduced the number of mucin-depleted foci per colon in rats compared with nonsupplemented cured meat (P = 0.01).. Data suggest that the addition of calcium carbonate to the diet or α-tocopherol to cured meat may reduce colorectal cancer risk associated with cured-meat intake. This trial was registered at clinicaltrials.gov as NCT00994526.

Topics: Abietanes; Acetylcysteine; Adult; Aged; alpha-Tocopherol; Animals; Biomarkers; Blood Glucose; C-Reactive Protein; Calcium, Dietary; Carcinogenesis; Carcinogens; Cholesterol; Colon; Colorectal Neoplasms; Creatinine; Cross-Over Studies; Dimethylhydrazines; Diphosphates; Feces; Female; Healthy Volunteers; Humans; Inulin; Meat Products; Middle Aged; Rats; Rats, Inbred F344; Rutin; Single-Blind Method; Thiobarbituric Acid Reactive Substances

To evaluate the erosive potential of orange juice modified by food additives in enamel and dentine.. Calcium lactate pentahydrate (CLP), xanthan gum (XG), sodium linear polyphosphate (LPP), sodium pyrophosphate tetrabasic (PP), sodium tripolyphosphate (STP) and some of their combinations were added to an orange juice. Pure orange juice and a calcium-modified juice were used as negative (C-) and positive (C+) controls, respectively. In phase 1, 15 modified orange juices were tested for erosive potential using pH-stat analysis. In phase 2, the additives alone and the combination with good results in phase 1 and in previous studies (CLP+LPP) were tested in an erosion-remineralization cycling model. In phase 3, the erosion and remineralization episodes were studied independently. Enamel was analysed by surface microhardness (SMH) and profilometry, whilst dentine by profilometry.. In phase 1, reduction of the erosive potential was observed for all additives and their combinations, except XG alone. In phase 2, no detectable enamel loss was observed when CLP, LPP and CLP+LPP were added to the juice. XG, STP and PP had enamel loss similar to C- (p>0.05). Amongst additives, the combination CLP+LPP showed the highest SMH values followed by CLP (p<0.05). All the other groups presented SMH values similar to C- (p>0.05). For dentine, only CLP+LPP lead to surface loss values lower than C- (p<0.05). In phase 3, CLP, LPP and CLP+LPP seemed to protect against erosion; whilst none of the tested compounds seemed to interfere with the remineralization process.. CLP and LPP reduced erosion on enamel and this effect was enhanced by their combination. For dentine, only the combination CLP+LPP reduced erosion.

Topics: Animals; Beverages; Calcium; Calcium Compounds; Cattle; Citrus sinensis; Dental Enamel; Dentin; Diphosphates; Food Additives; Fruit; Hardness; Humans; Hydrogen-Ion Concentration; Lactates; Polyphosphates; Polysaccharides, Bacterial; Protective Agents; Saliva, Artificial; Temperature; Time Factors; Tooth Erosion; Tooth Remineralization

This study was carried out to compare the effects of the combination of ionomycin with a H1-histone kinase inhibitor (dimethylaminopurine, DMAP) or cdc2 kinase inhibitor (sodium pyrophosphate, SPP) on the development of reconstituted bovine eggs. For this study, the enucleated bovine oocytes were injected with a presumptive primordial germ cell pre-treated with 1% sodium citrate, and randomly allocated into three activation groups: Group 1 (ionomycin 5 microm, 5 min), Group 2 (ionomycin + DMAP 1.9 mm, 3 h), and Group 3 (ionomycin + SPP 2 mm, 3 h). The reconstituted eggs were compared on the rates of cleavage and development with the blastocyst stage and the ploidy of embryos at 96 h post-activation. Cleavage rates and blastocyst development in Groups 1, 2 and 3 were 7 and 0%, 63 and 17%, and 53 and 14%, respectively. The chromosomal composition differed significantly (p < 0.05) among treatments. Although the embryos in Group 1 had significantly lower developments, 60% of embryos evaluated had diploid chromosomal sets. In contrast, approximately 60% of embryos in Group 2 had abnormal ploidy (21% polyploid and 38% mixoploid). In Group 3, the appearance of abnormal chromosome sets was reduced with the proportion of diploid embryos being increased to 86% (19 of 22), significantly higher (p < 0.05) than in Group 2. It can be concluded that the use of SPP with ionomycin reduces greatly the incidence of chromosomal abnormalities, and may be applicable for the activation of nuclear transplant bovine embryos.

Topics: Adenine; Animals; Blastocyst; Cattle; CDC2 Protein Kinase; Clone Cells; Diphosphates; Female; Ionomycin; Pregnancy; Protamine Kinase; Treatment Outcome

The objective of this double-blind clinical study, conducted in harmony with the Volpe-Manhold design for studies of dental calculus, was to compare the effect on supragingival calculus formation of a dentifrice containing pyrophosphate, tripolyphosphate and a copolymer in a 0.243% sodium fluoride/silica base (Test Dentifrice), to that of a commercially available calculus-inhibiting dentifrice containing tetrapotassium pyrophosphate, disodium pyrophosphate and tetrasodium pyrophosphate in a 0.243% sodium fluoride/silica base (Positive Control Dentifrice). Adult male and female subjects from the Buffalo, New York area were entered into the study, provided a full oral prophylaxis, and assigned the use of a placebo (non-calculus-inhibiting) dentifrice for fourteen weeks. At the completion of this initial period, subjects were assessed for baseline Volpe-Manhold Calculus Index scores, provided another full prophylaxis, and stratified into two treatment groups which were balanced for age, sex and baseline calculus. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice, using a soft-bristled toothbrush. Examinations for dental calculus were again performed after twelve weeks' use of the study dentifrices. Ninety-one (91) subjects complied with the protocol and completed the entire study. At the three-month examination, the Test Dentifrice group exhibited a statistically significant 27.3% reduction in mean Volpe-Manhold Calculus Index score as compared to the Positive Control Dentifrice group. The results of this clinical study support the conclusion that a new calculus-inhibiting dentifrice, containing pyrophosphate, tripolyphosphate and a copolymer in a 0.243% sodium fluoride/silica base, is efficacious for the control of the development of supragingival calculus, and provides a level of benefit greater than that provided by a commercially available calculus-inhibiting dentifrice containing tetrapotassium pyrophosphate, disodium pyrophosphate and tetrasodium pyrophosphate in a 0.243% sodium fluoride/silica base.

Topics: Adult; Aged; Analysis of Variance; Complex Mixtures; Dental Calculus; Dentifrices; Diphosphates; Double-Blind Method; Female; Humans; Male; Middle Aged; Polyphosphates; Potassium Compounds; Silicic Acid; Silicon Dioxide; Sodium Fluoride; Toothpastes; Treatment Outcome

The objective of this double-blind clinical study, conducted in harmony with the Volpe-Manhold design for studies of dental calculus, was to compare the effect on supragingival calculus formation of a dentifrice containing pyrophosphate, tripolyphosphate and a copolymer in a 0.243% sodium fluoride/silica base (Test Dentifrice), to that of a commercially available calculus-inhibiting dentifrice containing tetrapotassium pyrophosphate, disodium pyrophosphate, and tetrasodium pyrophosphate in a 0.243% sodium fluoride/silica base (Positive Control Dentifrice). Adult male and female subjects from the Northern New Jersey area were entered into the study, provided a full oral prophylaxis and assigned the use of a placebo (non-calculus-inhibiting) dentifrice for eight weeks. At the completion of this initial period, subjects were assessed for baseline Volpe-Manhold Calculus Index scores, provided another full prophylaxis and stratified into two treatment groups which were balanced for age, sex and baseline calculus. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice, using a soft-bristled toothbrush. Examinations for dental calculus were again performed after twelve weeks' use of the study dentifrices. Eighty-nine (89) subjects complied with the protocol and completed the entire study. At the three-month examination, the Test Dentifrice group exhibited a statistically significant 31.0% reduction in the mean Volpe-Manhold Calculus Index score compared to the Positive Control Dentifrice group. The results of this clinical study support the conclusion that a new calculus-inhibiting dentifrice containing pyrophosphate, tripolyphosphate, and a copolymer in a 0.243% sodium fluoride/silica base is efficacious for the control of the development of supragingival calculus, and provides a level of benefit greater than that provided by a commercially available calculus-inhibiting dentifrice containing tetrapotassium pyrophosphate, disodium pyrophosphate, and tetrasodium pyrophosphate in a 0.243% sodium fluoride/silica base.

Topics: Adult; Aged; Analysis of Variance; Complex Mixtures; Dental Calculus; Dentifrices; Diphosphates; Double-Blind Method; Female; Humans; Male; Middle Aged; Polyphosphates; Potassium Compounds; Silicic Acid; Silicon Dioxide; Sodium Fluoride; Toothpastes; Treatment Outcome

The objective of this double-blind clinical study, conducted using the Volpe-Manhold evaluation method for dental calculus, was to compare the effect on supragingival calculus formation of a dentifrice containing tetrasodium pyrophosphate, sodium tripolyphosphate, and a copolymer in a 0.243% sodium fluoride/silica base (Test Dentifrice), to that of a commercially available calculus-inhibiting dentifrice containing tetrasodium pyrophosphate and a copolymer in a 0.243% sodium fluoride/silica base (Positive Control Dentifrice). Adult male and female subjects from the northern New Jersey area were entered into the study based on a pre-test (baseline) Volpe-Manhold Calculus Index score of 7.0 or greater, provided a full oral prophylaxis, and stratified into two treatment groups which were balanced for age, sex and baseline calculus scores. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice, using a soft-bristled toothbrush. Examinations for dental calculus were again performed after twelve weeks' use of the study dentifrices. Seventy-three (73) subjects complied with the protocol, and completed the entire study. At the twelve-week examination, the Test Dentifrice group exhibited a statistically significant 43.5% reduction in mean Volpe-Manhold Calculus Index scores compared to the Positive Control Dentifrice group. The results of this clinical study support the conclusion that a new calculus-inhibiting dentifrice, containing tetrasodium pyrophosphate, sodium tripolyphosphate, and a copolymer in a 0.243% sodium fluoride/silica base, is efficacious for the control of the development of supragingival calculus, and provides a level of benefit greater than that provided by a commercially available calculus-inhibiting dentifrice containing tetrasodium pyrophosphate and a copolymer in a 0.243% sodium fluoride/silica base.

Topics: Adult; Aged; Analysis of Variance; Complex Mixtures; Dental Calculus; Dentifrices; Diphosphates; Double-Blind Method; Female; Humans; Male; Middle Aged; Oral Hygiene Index; Polyphosphates; Potassium Compounds; Silicic Acid; Silicon Dioxide; Sodium Fluoride; Toothpastes; Treatment Outcome

1. The effect of three iso-osmotic pharmaceutical excipient solutions on gastrointestinal transit were investigated in eight healthy male volunteers. Each subject received 200 ml radiolabelled purified water, or a 200 ml solution of sodium acid pyrophosphate ((SAPP) 1.1 g/200 ml), mannitol (2.264 g/200 ml) or sucrose (4.08 g/200 ml) in a four way cross over design. On each of the study days the volunteers also received five 6 mm diameter non-disintegrating tablets. Dual isotope gamma scintigraphy was used to assess the transit behaviour of the tablets and solutions. 2. There were no significant differences between the gastric emptying times of the four solution formulations. Rapid gastric emptying was observed in all cases (mean t 50% varied from 11-14 min). 3. Small intestinal transit (SIT) times for the SAPP and mannitol solutions were reduced by 39 and 34%, respectively, when compared with the control solution (purified water = 240 min; SAPP = 147 min; mannitol = 158 min). The 95% confidence limits for the mean differences in SIT time between the control and SAPP solutions was 39-94-149 min, and 40-82-124 min between the mannitol and the control. Intestinal transit for the sucrose solution was similar to that for the control solution (sucrose = 229 min). 4. There were no significant differences in the transit times of the non-disintegrating tablet preparations, when co-administered with each solution.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Cross-Over Studies; Diphosphates; Excipients; Gastric Emptying; Gastrointestinal Transit; Humans; Intestine, Small; Isotope Labeling; Male; Mannitol; Radionuclide Imaging; Sucrose; Water

A double blind, seven month clinical study was conducted to determine the effects of three Triclosan containing test dentifrices on supragingival plaque, gingivitis and supragingival calculus formation compared to a 0.8 per cent monofluorophosphate-silica control dentifrice. Each test dentifrice contained 0.3 per cent Triclosan; additionally one contained 0.75 per cent zinc citrate, the second contained 2 per cent Gantrez and the third contained 5 per cent pyrophosphate. Subjects were assigned to one of the three test groups or to the control group according to random allocation within nine strata. Subjects were evaluated for supragingival plaque and calculus formation and for gingivitis after one, four and seven months' use of the dentifrices. After seven months, the Triclosan/Gantrez and the Triclosan/pyrophosphate dentifrices each provided a statistically significant reduction of approximately 25 per cent in gingival bleeding compared to the control. Neither dentifrice gave statistically significant reductions in supragingival plaque or calculus formation. In contrast, the Triclosan/zinc citrate dentifrice provided statistically significant reductions of 33 per cent in supragingival plaque, 51 per cent in gingival bleeding and 67 per cent in supragingival calculus formation. The reductions in gingival bleeding and calculus formation were statistically superior to those of the Triclosan/Gantrez and the Triclosan/pyrophosphate products. The results demonstrate that use of the Triclosan/zinc citrate dentifrice over a seven month period provided statistically significant and clinically relevant reductions in supragingival plaque and calculus formation, and control of gingivitis as compared to a control dentifrice.

Topics: Adult; Citrates; Citric Acid; Dental Calculus; Dental Plaque; Dental Plaque Index; Dentifrices; Diphosphates; Double-Blind Method; Drug Combinations; Female; Fluorides; Gingival Hemorrhage; Gingivitis; Humans; Male; Maleates; Oral Hygiene; Periodontal Index; Phosphates; Polyvinyls; Silicon Dioxide; Tooth; Triclosan; Zinc

A double-blind, cross-over study was carried out to assess the anti-calculus effectiveness of a pyrophosphate containing cleaning gel. 2 groups of 30 heavy calculus formers were followed up comparing conventional clinical scoring systems (Volpe-Manhold-Index and Marginal-Line-Calculus-Index) and micromorphologic SEM criteria of calculus formation and inhibition. The results indicated that after a 3-month period, there was a significant reduction of calculus formation compared to a placebo gel. The proposed SEM calculus index (SEMCI) objectively reflects the reduction of supragingival calculus formation.

Topics: Adult; Dental Calculus; Dentifrices; Diphosphates; Double-Blind Method; Drug Combinations; Female; Fluorides; Gels; Humans; Incisor; Male; Microscopy, Electron, Scanning; Middle Aged; Phosphates; Placebos; Potassium; Potassium Compounds; Replica Techniques

Anticalculus dentifrices containing pyrophosphate salts have been shown to reduce calculus formation. The purpose of this double-blind, cross-over study was to compare the effects of a pyrophosphate dentifrice with a placebo on supragingival calculus formation in highly calculus-prone subjects. 60 volunteers completed a compliance period during which meticulous full-mouth scaling was performed. Subjects were randomly assigned either to placebo (F-Antibelag Gel) or to the test group (F-Antibelag Gel + K4P2O7/Na4P2O7). Participants were told to brush twice daily with their assigned dentifrice, use only the brushes provided and to abstain from any other oral hygiene procedures. After a three month period a second full-mouth scaling was performed, and according to the cross-over design of this study the participants used the alternative placebo or, respectively, dentifrice for another three months. Baseline scores and control scores after 1, 2 and 3 months were obtained using the Volpe-Manhold-Index and the Marginal-Line-Calculus-Index. A micromorphological SEM Calculus Index was introduced using replicas from interdental areas of mandibular incisors (score 0-3). Both test groups showed significantly less accumulation of supragingival calculus of 25.5% (VMI) and 19.5% (MLCI) and significantly less SEM detectable calculus (24%) with the pyrophosphate dentifrice than with the placebo. It is concluded that the test dentifrice inhibits the formation of calculus.

Topics: Adult; Dental Calculus; Dentifrices; Diphosphates; Double-Blind Method; Female; Gels; Humans; Male; Middle Aged; Oral Hygiene Index

A double-blind clinical study was conducted to evaluate the effect of a tartar-control dentifrice containing 1% sodium polyphosphate as tartar control agent compared with dentifrice A containing 5% sodium pyrophosphate and a placebo dentifrice. One hundred forty-eights who continued to have a degree of calculus formation after using a regular dentifrice containing no tartar control agent for 1 month in the pretest, were stratified randomly on the basis of pretest, calculus score, age and sex into 3 homogeneous groups. All subjects who received initial prophylaxis were provided the assigned dentifrice and toothbrush. No instructions regarding frequency or method of toothbrushing were allowed. Assessment of supragingival calculus was made at 4 and 12 weeks using the calculus scoring procedure proposed by Volpe et al. Side effects such as oral irritation, ablation of oral mucosa and discoloration of teeth caused by dentifrices were also diagnosed after 12 weeks of use. The following results were obtained in this study. 1. The test dentifrice had reduced (P less than 0.01) supra-gingival calculus significantly more than dentifrice A and the placebo at 12 weeks. 2. A significant reduction (P less than 0.01) was observed when dentifrice A was compared with the placebo dentifrice. 30.1% reduction was obtained using the test dentifrice and 9.0% reduction using dentifrice A when assessed in subjects who had a pretest VMI score of more than 6.0. 3. No side effects caused by the dentifrice which contained sodium polyphosphate were observed.

Topics: Dental Calculus; Dentifrices; Diphosphates; Double-Blind Method; Humans

Topics: Adult; Chlorides; Clinical Trials as Topic; Dental Calculus; Dentifrices; Diphosphates; Double-Blind Method; Female; Humans; Male; Middle Aged; Placebos; Zinc; Zinc Compounds

A sodium fluoride dentifrice, containing a mixture of soluble pyrophosphates, was used ad libitum in an adult population for 6 months after receiving a dental prophylaxis. In comparison with the control group, who used the sodium fluoride formula without the pyrophosphates, the test group had significantly less calculus by occurrence and severity. Thus, a significant reduction in newly forming calculus was obtained with the experimental dentifrice when used as an adjunct to regular professional care and personal oral hygiene procedures.

Topics: Adolescent; Adult; Aged; Clinical Trials as Topic; Dental Calculus; Dentifrices; Diphosphates; Double-Blind Method; Female; Fluorides; Humans; Male; Middle Aged; Oral Hygiene; Solutions

The present study attempted to investigate the interactive roles of protein oxidation (0-20 mM H

Topics: Actomyosin; Catalysis; Diphosphates; Hydrogen Peroxide; Oxidative Stress; Transglutaminases

To improve the gel properties of duck egg white gel and increase the industrial value of duck egg white, the mechanisms of ultrasound and synergetic phosphorylation/ultrasound treatments were examined in this study. It was found that as the ultrasound power increased, the surface hydrophobicity, hardness, and cohesiveness of the gel system increased, and the ζ-potential and water mobility decreased. Of the two treatments, phosphorylation/ultrasound had the strongest impact on the conformation and crystallinity of the gel system and promoted the formation of high molecular polymers. Both gel systems displayed enhanced compactness, stability, and gel strength because of the enhanced protein-protein interactions via hydrogen bonds and protein aggregation, and increased the content of intramolecular β-sheets following ultrasound treatment, and synergetic phosphorylation/ultrasound further improved the stability, water binding and gel properties. This experiment showed that ultrasound and, particularly, phosphorylation/ultrasound are effective methods to improve the gel properties of duck egg white. This study enhanced our understanding of the interactions of sodium pyrophosphate and egg white under ultrasound treatment, and promote the potential application of sodium pyrophosphate and ultrasound treatment of novel food products.

Topics: Animals; Diphosphates; Ducks; Egg White; Gels; Phosphorylation; Polymers; Protein Aggregates; Water

Topics: Aminopyridines; Benzimidazoles; Biological Transport; Cell Cycle; Cell Line, Transformed; Chlamydomonas reinhardtii; Cilia; Diphosphates; Humans; Imidazoles; Oximes; Taxoids

As antibiotic resistance is being a threat to public health worldwide, bacteriophages are re-highlighted as alternative antimicrobials to fight with pathogens. Various wild-type phages isolated from diverse sources have been tested, but potential mutant phages generated by genome engineering or random mutagenesis are drawing increasing attention. Here, we applied a chelating agent, sodium pyrophosphate, to the staphylococcal temperate Siphoviridae phage SA3821 to introduce random mutations. Through 30 sequential sodium pyrophosphate challenges and random selections, the suspected mutant phage SA3821

Topics: Anti-Bacterial Agents; Diphosphates; Genome, Viral; Host Specificity; Mutagenesis; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus Phages

In this study, sodium tripolyphosphate (STP) and tetrasodium pyrophosphate (TSPP) were utilized to modify duck egg white protein (EWP). The phosphorylated EWP was prepared as egg white gel (EWG) by adding sodium hydroxide. The phosphorus content of EWP reached 2.18 mg/g and 2.07 mg/g with the addition of STP and TSPP, respectively, after 2 h phosphorylation. The average particle size, absolute zeta potential value, and surface hydrophobicity of EWP increased significantly during phosphorylation. FTIR results indicate that phosphorylation reduced the random structure and α-helical content while increasing the content of β-sheets and β-turn. The mechanical and rheological properties of EWG decreased obviously after phosphorylation. A three-dimensional porous network microstructure was formed, and the gel with added TSPP had larger pores. Adding STP and TSPP to EWG weakened its salt and solvent sensitivity. The findings provide a direction for the exploration of gel properties after protein modification.

Topics: Alkalies; Animals; Diphosphates; Ducks; Egg Proteins; Gels; Hydrophobic and Hydrophilic Interactions; Particle Size; Phosphorylation; Rheology; Sodium Chloride; Sodium Hydroxide

Myofibrillar protein isolated from beef muscles were treated with 3 phosphates (Sodium Hexametaphosphate, sodium tripolyphosphate, sodium pyrophosphate) with different concentrations of 0.3%, 0.6%, 0.9%, 1.2% respectively. Protein solubility, surface hydrophobicity and reactive sulfhydryl group was determined. Atomic force microscopy was used to observe the microscopic protein surface. SDS-PAGE was carried out to determine the proteolysis of myofibrillar protein. The solubility and surface hydrophobic bond of myofibrillar protein was highly increased and the diameter decreased by SHMP, TSPP, STPP. Reactive sulfhydryl groups increased after SHMP addition, but slightly decreased in STPP and TSPP treated MP. TSPP and STPP had the same effect on myofibrillar microstructure and was different from SHMP. Three phosphates all caused MP unfolding. The MP gel complexity was increased, and roughness was decreased after phosphates addition, indicating phosphates helped to construct a more ordered and smoother gel microcosmic surface.

Topics: Animals; Cattle; Diphosphates; Hydrophobic and Hydrophilic Interactions; Microscopy, Atomic Force; Muscle Proteins; Phosphates; Polyphosphates; Red Meat; Solubility

A dynamic model was developed to predict growth of Clostridium perfringens in cooked ground pork supplemented with salt (0-3% wt/wt) and sodium pyrophosphate (0-0.3% wt/wt) under varying temperatures. C. perfringens (NCTC 8238, NCTC 8239, and NCTC 10240) spores were heat shocked, cooled, and inoculated into ground pork. Isothermal bacterial growth was quantified with variable salt and phosphate concentrations at temperatures ranging from 15 to 51 °C. The primary Baranyi model was fitted to all C. perfringens growth profiles and gave a satisfactory fit (R

Topics: Animals; Clostridium perfringens; Cooking; Diphosphates; Food Handling; Food Microbiology; Meat Products; Models, Biological; Sodium Chloride; Spores, Bacterial; Swine; Temperature

The objective of this research was to investigate the influence of various levels (0.0, 0.1, 0.2, 0.3, 0.4, 0.5%) of added encapsulated polyphosphates (sodium tripolyphosphate; sodium pyrophosphate) combined with unencapsulated polyphosphate to total 0.5% on the inhibition of lipid oxidation in cooked ground meat (beef, chicken) during refrigerated storage (0, 1, 7 d). The use of sodium tripolyphosphate (encapsulated sodium tripolyphosphate, unencapsulated sodium tripolyphosphate) led to lower cooking loss compared to sodium pyrophosphate in both meat species (p < 0.05). Increasing encapsulated sodium tripolyphosphate up to 0.3% decreased cooking loss in ground beef (p < 0.05). Added encapsulated polyphosphate at 0.5% had the same effect on pH as 0.5% unencapsulated polyphosphate in the cooked ground beef and chicken. A higher accumulation of orthophosphate was determined in the samples with sodium tripolyphosphate compared to those with sodium pyrophosphate (p < 0.05). Inclusion of a minimum of 0.1% encapsulated polyphosphate decreased thiobarbituric acid reactive substances and lipid hydroperoxides on 7 d. Increasing encapsulated sodium tripolyphosphate and encapsulated sodium pyrophosphate up to 0.2% in beef decreased thiobarbituric acid reactive substances at 7 d. Addition of 0.4% encapsulated sodium tripolyphosphate and 0.3% encapsulated sodium pyrophosphate in chicken prevented any increase in TBARS during storage. Incorporating encapsulated sodium pyrophosphate at 0.3% inhibited lipid hydroperoxide formation in beef and chicken. The meat industry could achieve enhanced lipid oxidation inhibition by replacing some of the unencapsulated polyphosphate with encapsulated polyphosphate in their product formulations.

Topics: Animals; Antioxidants; Capsules; Cattle; Chickens; Cooking; Diphosphates; Food Handling; Food Preservation; Food Preservatives; Food Storage; Humans; Hydrogen-Ion Concentration; Lipid Peroxidation; Meat; Phosphates; Polyphosphates; Red Meat; Refrigeration; Thiobarbituric Acid Reactive Substances

Porcine myofibrillar proteins (MP) with or without sodium pyrophosphate (PP) were oxidatively stressed in hydroxyl radical (˙OH)-generating systems (10 μM FeCl

Topics: Amino Acids; Animals; Diphosphates; Gels; Humans; Hydroxyl Radical; Lipid Peroxidation; Muscle Proteins; Myofibrils; Oxidative Stress; Solubility; Swine

The utility of plasma-treated winter mushroom powder (PWMP) as an alternative to synthetic nitrite and phosphate in ground ham was evaluated. Treatment of atmospheric non-thermal plasma generated nitrite in winter mushroom homogenate, and PWMP contained 4.87 g/kg of nitrite. Canned ground ham samples without nitrite and phosphate (NC), with sodium nitrite and sodium pyrophosphate (PC), and with PWMP (PWM) were manufactured, sterilized (F

Topics: Animals; Color; Diphosphates; Flammulina; Food Handling; Meat Products; Sodium Nitrite; Swine; Thiobarbituric Acid Reactive Substances

Formation of a gel matrix, involving interactions between proteins, lipids, and water, plays an essential role in the textural properties of processed meats. This study investigated the effects of sodium pyrophosphate (SPP) on the textural properties and oxidative stability of myofibrillar protein (MP)-stabilized emulsion gels under different pH conditions (5.0-9.0). The SPP-modified MP emulsion gels showed an improved elasticity, strength, water-holding capacity, and oxidative stability at pH 6.0 and 7.0. This improvement should be mainly attributed to the enhanced protein-protein crosslinks via ionic interaction between phosphate groups and -NH3+ of amino acids, which were homogeneously formed among adsorbed and/or unadsorbed proteins, entrapping fractions of MPs (myosin heavy chain, actin, and troponin T) within the network. Therefore, the oil droplets were better adherent to the gel matrix. Nevertheless, increased electrostatic repulsion between protein molecules due to excessive phosphates attached to MPs at pH 8.0 and 9.0, as well as protein precipitation at pH 5.0, caused the collapse of the MP-stabilized emulsion gel structure, and thus, overall decreased the gel properties and oxidative stability. LC-MS/MS results confirmed that phosphate groups were successfully introduced to MPs through C-O-P bonds at pH 6.0, and the phosphorylation sites were found to be on serine residues (Ser14, Ser79, Ser96, Ser148, Ser2427, and Ser5272), threonine residues (Thr118 and Thr926), and tyrosine residues (Tyr215 and Tyr425). The results provided a new aspect for better understanding the effect of polyphosphates in meat protein/oil composite systems.

Topics: Animals; Chickens; Diphosphates; Emulsions; Gels; Hydrogen-Ion Concentration; Meat Products; Muscle Proteins; Myofibrils; Oxidation-Reduction; Phosphorylation

The objective was to examine shelf stability, cooked product yield, and sensory characteristics of beef patties that had no binder (Control), incorporated soy flour (Textured Vegetable Protein; TVP) or one of three dry potato extracts: X-TRATOS™ (potato extract), X-TRATOS™ O (potato extract with mustard), or X-TRATOS™ W (potato extract with sodium acid pyrophosphate). In retail display patties, all binders decreased discoloration and lipid oxidation compared to Control, and X-TRATOS™ O was superior (P < 0.05) to all other treatments. Cooking yield was higher (P < 0.05) in patties containing potato extracts compared with patties containing TVP, which had higher yield than Control patties. Beef patties with potato extracts were juicier (P < 0.05) than Control and TVP patties and had higher (P < 0.05) overall acceptability than Control patties. We conclude that potato extracts are effective binders for use in fresh or precooked beef patties because they improve retail shelf life, cooked product yield, and sensory characteristics.

Topics: Animals; Cattle; Color; Consumer Behavior; Cooking; Diphosphates; Food Storage; Glycine max; Humans; Lipid Peroxidation; Meat Products; Mustard Plant; Plant Extracts; Solanum tuberosum; Water

Cryoprotective saccharides are widely accepted antifreeze additives that reduce thawing loss, maintain texture, and retard protein denaturation in frozen seafood. In this study, the inhibition effects of trehalose and alginate oligosaccharides on ice growth were investigated and compared with sodium pyrophosphate (Na

Topics: Alginates; Animals; Diphosphates; Freezing; Hydrogen Bonding; Hydrophobic and Hydrophilic Interactions; Ice; Molecular Docking Simulation; Molecular Dynamics Simulation; Oligosaccharides; Penaeidae; Static Electricity; Trehalose

The ability of polyvalent anions to influence protein-protein interactions and protein net charge was investigated through solubility and turbidity experiments, determination of osmotic second virial coefficients ( B

Topics: Chemical Precipitation; Chlorides; Citric Acid; Diphosphates; Muramidase; Polyphosphates; Protein Binding; Protein Multimerization; Scattering, Radiation; Sulfates

The food additives sodium acid pyrophosphate (SAPP), sodium acetate (SA), and citric acid (CA) were evaluated for their hemato-immunotoxic effects. Forty adult Sprague-Dawley rats were distributed into four groups and were orally administered water, SAPP (12.6 mg/kg), CA (180 mg/kg), or SA (13.5 mg /kg) daily for 90 days. Erythrogram and leukogram profiles were evaluated. The levels of lysozyme, nitric oxide, immunoglobulin, and phagocytic activity were measured. Histologic and immunohistochemical evaluations of splenic tissues were performed. Changes in the mRNA expression levels of peroxisome proliferator-activated receptor α and γ (PPAR-α and PPAR-γ), and tumor necrosis factor α (TNF-α) genes were assessed. A significant leukopenic condition was observed with SAPP, while CA induced marked leukocytosis, and SA showed a lymphocytosis condition. Both the innate and humoral parameters were significantly depressed. Various pathological lesions were observed, including diffuse hyperplasia of the red pulp, depletion of the white pulp, and capsular and parenchymal fibrosis. A marked decrease in CD3 T-lymphocyte and CD20 B-lymphocyte immunolabeling in rats treated with SAPP and SA was evident. Marked downregulation of PPAR-α and PPAR-γ together with upregulation of TNF-α was recorded. These results indicate that high doses of SAPP, SA and CA exert hematotoxic and immunotoxic effects with long-term exposure.

Topics: Animals; B-Lymphocytes; Biomarkers; Citric Acid; Diphosphates; Down-Regulation; Food Additives; Male; PPAR alpha; PPAR gamma; Rats, Sprague-Dawley; RNA, Messenger; Signal Transduction; Sodium Acetate; Spleen; T-Lymphocytes; Tumor Necrosis Factor-alpha

The present study examined the impacts of sodium acetate (SA), sodium acid pyrophosphate (SAPP), and citric acid (CA) on the viability, proliferation, and DNA damage of isolated lymphocytes in vitro. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release assays were adopted to evaluate cell viability, while comet assay was employed to assess the genotoxic effects. The cells were incubated with different levels of SA (50, 100, and 200 mM), SAPP (25, 50, and 100 mM/L), or CA (100, 200, and 300 μg/mL). The lymphocytes treated with the tested food additives showed concentration-dependent decreases in both cell viability and proliferation. A concentration-dependent increase in LDH release was also observed. The comet assay results indicated that SA, SAPP, and CA increased DNA damage percentage, tail DNA percentage, tail length, and tail moment in a concentration-dependent manner. The current results showed that SA, SAPP, and CA are cytotoxic and genotoxic to isolated lymphocytes in vitro.

Topics: Animals; Cell Proliferation; Cell Survival; Citric Acid; Comet Assay; Diphosphates; DNA Damage; Dose-Response Relationship, Drug; Food Additives; L-Lactate Dehydrogenase; Limit of Detection; Lymphocytes; Male; Rats, Sprague-Dawley; Sodium Acetate

Rodents consume solutions of phosphates and pyrophosphates in preference to water. Recently, we found that the preference for trisodium pyrophosphate (Na3HP2O7) was greater in T1R3 knockout (KO) mice than wild-type (WT) controls, suggesting that T1R3 is a pyrophosphate detector. We now show that this heightened Na3HP2O7 preference of T1R3 KO mice extends to disodium phosphate (Na2HPO4), disodium and tetrasodium pyrophosphate (Na2H2PO4 and Na4H2PO4), a tripolyphosphate (Na5P3O10), a non-sodium phosphate [(NH4)2HPO4], and a non-sodium pyrophosphate (K4P2O7) but not to non-P salts with large anions (sodium gluconate, acetate, or propionate). Licking rates for Na3HP2O7 are higher in T1R2 KO mice than WT controls; Na3HP2O7 preference scores are increased even more in T1R2 KO mice and T1R2+T1R3 double KO mice than in T1R3 KO mice; preference scores for Na3HP2O7 are normal in T1R1 KO mice. These results implicate each subunit of the T1R2+T1R3 dimer in the behavioral response to P-containing taste compounds.

Topics: Animals; Diphosphates; Food Preferences; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptors, G-Protein-Coupled; Taste

We studied activation of macrophages with humic acids extracted from peat of large deposits in the Tomsk region by two extraction methods: by hydroxide or sodium pyrophosphate. Humic acid of lowland peat types containing large amounts of aromatic carbon, phenolic and alcohol groups, carbohydrate residues and ethers, irrespectively of the extraction methods contained LPS admixture that probably determines their activating properties. Humic acid of upland peat types characterized by high content of carbonyl, carboxyl, and ester groups enhance NO production and reduce arginase expression, but these effects were minimized when sodium hydroxide was used as an extraction solvent. Pyrophosphate samples of the upland peat types were characterized by aromaticity and diversity of functional groups and have a significant advantage because of they induce specific endotoxin-independent stimulating action on antigen presenting cells.

Topics: Animals; Arginase; Carbon; Complex Mixtures; Diphosphates; Female; Humic Substances; Lipopolysaccharides; Liquid-Liquid Extraction; Macrophages, Peritoneal; Male; Mice; Mice, Inbred C57BL; Nitric Oxide; Phenols; Polymyxin B; Primary Cell Culture; Sodium Hydroxide; Soil

Mutations in the proximal tubular sodium-dependent phosphate co-transporters NPT2a and NPT2c have been reported in patients with renal stone disease and nephrocalcinosis, however the relative contribution of genotype, dietary calcium and phosphate, and modifiers of mineralization such as pyrophosphate (PPi) to the formation of renal mineral deposits is unclear. In the present study, we used Npt2a-/- mice to model the renal calcifications observed in these disorders. We observed elevated urinary excretion of PPi in Npt2a-/- mice when compared to WT mice. Presence of two hypomorphic Extracellular nucleotide pyrophosphatase phosphodiesterase 1 (Enpp1asj/asj) alleles decreased urine PPi and worsened renal calcifications in Npt2a-/- mice. These studies suggest that PPi is a thus far unrecognized factor protecting Npt2a-/- mice from the development of renal mineral deposits. Consistent with this conclusion, we next showed that renal calcifications in these mice can be reduced by intraperitoneal administration of sodium pyrophosphate. If confirmed in humans, urine PPi could therefore be of interest for developing new strategies to prevent the nephrocalcinosis and nephrolithiasis seen in phosphaturic disorders.

Topics: Animals; Diphosphates; Disease Models, Animal; Female; Humans; Injections, Intraperitoneal; Kidney Calculi; Male; Mice; Mice, Knockout; Mutation; Phosphoric Diester Hydrolases; Pyrophosphatases; Sodium-Phosphate Cotransporter Proteins, Type IIa; Treatment Outcome

Natural organic matter is often associated with Fe(III) oxyhydroxides, and may be stabilized as a result of coprecipitation or sorption to their surfaces. However, the significance of this association in relation to Fe and C dynamics and biogeochemical cycling, and the mechanisms responsible for organic matter stabilization as a result of interaction with minerals under various environmental conditions (e.g., pH, Eh, etc.) are not entirely understood. The preservation of mineral-bound OM may be affected by OM structure and mineral identity, and bond types between OM and minerals may be central to influencing the stability, transformation and composition of both organic and mineral components under changing environmental conditions. Here we use bulk and submicron-scale spectroscopic synchrotron methods to examine the in situ transformation of OM-bearing, biogenic ferrihydrite stalks (Gallionella ferruginea-like), which formed following injection of oxygenated groundwater into a saturated alluvial aquifer at the Rifle, CO field site. A progression from oxidizing to reducing conditions during an eight-month period triggered the aging and reductive transformation of Gallionella-like ferrihydrite stalks to Fe (hydroxy)carbonates and Fe sulfides, as well as alteration of the composition and amount of OM. Spectromicroscopic measurements showed a gradual decrease in reduced carbon forms (aromatic/alkene, aliphatic C), a relative increase in amide/carboxyl functional groups and a significant increase in carbonate in the stalk structures, and the appearance of organic globules not associated with stalk structures. Biogenic stalks lost ∼30% of their initial organic carbon content. Conversely, a significant increase in bulk organic matter accompanied these transformations. The character of bulk OM changed in parallel with mineralogical transformations, showing an increase in aliphatic, aromatic and amide functional groups. These changes likely occurred as a result of an increase in microbial activity, or biomass production under anoxic conditions. By the end of this experiment, a substantial fraction of organic matter remained in identifiable Fe containing stalks, but carbon was also present in additional pools, for example, organic matter globules and iron carbonate minerals.

Topics: Carbon; Carbonates; Chemical Precipitation; Diphosphates; Ferric Compounds; Groundwater; Hydroxylamine; Iron; Minerals; Oxidation-Reduction; Particle Size; X-Ray Absorption Spectroscopy; X-Ray Diffraction

The effect of levels (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) of added encapsulated (e) phosphate (sodium tripolyphosphate, STP; sodium hexametaphosphate, HMP; sodium pyrophosphate, SPP) on lipid oxidation inhibition during storage (0, 1, and 7 d) of ground meat (chicken, beef) was evaluated. The use of eSTP and eSPP resulted in lower and higher cooking loss (CL) compared to eHMP, respectively (P < 0.05). Increasing encapsulated phosphate level (PL) enhanced the impact of phosphates on CL in both chicken and beef samples (P < 0.05). Encapsulated STP increased pH, whereas eSPP decreased pH (P < 0.05). pH was not affected by PL. The highest orthophosphate (OP) was obtained with eSTP, followed by eSPP and eHMP (P < 0.05). The level of OP determined in both chicken and beef samples increased (P < 0.05) during storage. Increasing PL caused an increase in OP (P < 0.05). The highest reduction rate in the formation of thiobarbituric acid reactive substances (TBARS) and LPO for both meat species were obtained with eSPP, followed by eSTP and eHMP (P < 0.05). Increasing PL resulted in lower TBARS and LPO (P < 0.05). Findings suggest that encapsulated phosphates can be a strategy to inhibit lipid oxidation for the meat industry and the efficiency of encapsulated phosphates on lipid oxidation inhibition can be enhanced by increasing PL.

Topics: Animals; Capsules; Cattle; Chickens; Cooking; Diphosphates; Food Handling; Food Preservation; Food Storage; Humans; Lipid Metabolism; Lipid Peroxidation; Lipids; Meat; Oxidation-Reduction; Phosphates; Polyphosphates; Thiobarbituric Acid Reactive Substances

We studied substrate specificity of Na

Topics: Adenosine Diphosphate; Adenosine Monophosphate; Adenosine Triphosphatases; Adenosine Triphosphate; Aniline Compounds; Animals; Chloride-Bicarbonate Antiporters; Cytidine Triphosphate; Diphosphates; Guanosine Triphosphate; Organophosphorus Compounds; Rabbits; Substrate Specificity; Uridine Triphosphate

As suppression of Streptococcus mutans in young children may prevent or delay colonisation of the oral cavity, toothbrushing with dentifrices containing anti-S. mutans activity may aid in preventing caries. The aims of this study were to compare the effects of children's dentifrices on the growth of S. mutans and non-mutans bacteria (Streptococcus sanguinis and Lactobacillus acidophilus).. The agar diffusion assay at neutral pH was used to examine the antibacterial activity of commercial dentifrices and their major constituents.. Dentifrices containing 1,450 ppm fluoride produced greater growth inhibition of both S. mutans and S. sanguinis than those with <500 ppm. No inhibition was seen for pure solutions of sodium fluoride or sodium monofluorophosphate at fluoride concentrations up to 100,000 ppm. Stannous fluoride exerted antibacterial effects at concentrations above 10,000 ppm. Significant growth inhibition of both S. mutans and S. sanguinis was seen with sodium lauryl sulphate at 2,500 ppm and with triclosan at 100 ppm. No inhibitory effects were seen for xylitol, sorbitol, sodium pyrophosphate or polyethylene glycol at concentrations up to 80,000 ppm.. Sodium lauryl sulphate is the major bacterial inhibitory compound in children's dentifrices.

Topics: Anti-Bacterial Agents; Anti-Infective Agents, Local; Cariostatic Agents; Child; Dentifrices; Diphosphates; Fluorides; Humans; Lactobacillus acidophilus; Phosphates; Polyethylene Glycols; Sodium Dodecyl Sulfate; Sodium Fluoride; Sorbitol; Streptococcus mutans; Streptococcus sanguis; Surface-Active Agents; Sweetening Agents; Tin Fluorides; Toothpastes; Triclosan; Xylitol

Laboratory rats and mice prefer some concentrations of tri- and tetrasodium pyrophosphate (Na3HP2O7 and Na4P2O7) to water, but how they detect pyrophosphates is unknown. Here, we assessed whether T1R3 is involved. We found that relative to wild-type littermate controls, Tas1r3 knockout mice had stronger preferences for 5.6-56mM Na3HP2O7 in 2-bottle choice tests, and they licked more 17.8-56mM Na3HP2O7 in brief-access tests. We hypothesize that pyrophosphate taste in the intact mouse involves 2 receptors: T1R3 to produce a hedonically negative signal and an unknown G protein-coupled receptor to produce a hedonically positive signal; in Tas1r3 knockout mice, the hedonically negative signal produced by T1R3 is absent, leading to a heightened avidity for pyrophosphate.

Topics: Animals; Choice Behavior; Diphosphates; Food Preferences; Genotype; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptors, G-Protein-Coupled; Sodium Chloride; Taste

To evaluate the anti-erosive potential of solutions containing sodium fluoride (NaF, 225 ppm F) and different film-forming agents.. In Phase 1, hydroxyapatite crystals were pre-treated with solutions containing NaF (F), linear sodium polyphosphate (LPP), sodium pyrophosphate tetrabasic (PP), sodium tripolyphosphate (STP), sodium caseinate (SC), bovine serum albumin (BSA), stannous chloride (Sn) and some combinations thereof. Deionized water was the control (C). The pH-stat method was used to evaluate hydroxyapatite dissolution. In Phase 2, the most effective solutions were tested in two independent experiments. Both consisted of an erosion-remineralization cycling model using enamel and dentine specimens with three solution treatments per day. In Phase 2a, the challenge was performed with 0.3% citric acid (pH=3.8). In Phase 2b, 1% citric acid (pH=2.4) was used. Hard tissue surface loss was determined profilometrically. Data were analyzed with two-way ANOVA and Tukey tests.. In Phase 1, F, LPP, Sn and some of their combinations caused the greatest reduction in hydroxyapatite dissolution. In Phase 2a, C showed the highest enamel loss, followed by LPP. There were no differences between all other groups. In Phase 2b: (F+LPP+Sn) < (F+LPP) = (F+Sn) < (F) = (LPP+Sn) < (LPP) < (Sn) < C. For dentine, in both experiments, only the fluoride-containing groups showed lower surface loss than C, except for LPP+Sn in 2a.. F, Sn, LPP reduced enamel erosion, this effect was enhanced by their combination under highly erosive conditions. For dentine, the F-containing groups showed similar protective effect.. The addition of LPP and/or Sn can improve the fluoride solution protection against erosion of enamel but not of dentine.

Topics: Cariostatic Agents; Diphosphates; Humans; Sodium Fluoride; Tooth Erosion; Tooth Remineralization

Amino-functionalized fluorescent carbon dots have been prepared by hydrothermal treatment of glucosamine with excess pyrophosphate. The produced carbon dots showed stabilized green emission fluorescence at various excitation wavelengths and pH environments. Herein, we demonstrate the surface energy transfer between the amino-functionalized carbon dots and negatively charged hyaluronate stabilized gold nanoparticles. Hyaluronidase can degrade hyaluronate and break down the hyaluronate stabilized gold nanoparticles to inhibit the surface energy transfer. The developed fluorescent carbon dot/gold nanoparticle system can be utilized as a biosensor for sensitive and selective detection of hyaluronidase by two modes which include fluorescence measurements and colorimetric analysis.

Topics: Animals; Biosensing Techniques; Carbon; Cattle; Colorimetry; Diphosphates; Gold; Green Fluorescent Proteins; Humans; Hyaluronic Acid; Hyaluronoglucosaminidase; Hydrogen-Ion Concentration; Metal Nanoparticles; Nanotubes, Carbon; Quantum Dots; Quantum Theory; Spectrometry, Fluorescence

Chronic kidney disease (CKD) is generally associated with disturbances of mineral and bone metabolism. They contribute to the development of vascular calcification (VC), a strong, independent predictor of cardiovascular risk. Pyrophosphate (PPi), an endogenous inhibitor of hydroxyapatite formation, has been shown to slow the progression of VC in uremic animals. Since in patients with CKD treatment is usually initiated for already existing calcifications, we aimed to compare the efficacy of PPi therapy with that of the phosphate binder sevelamer, using a uremic apolipoprotein-E knockout mouse model with advanced VCs. After CKD creation or sham surgery, 12-week-old female mice were randomized to one sham group and four CKD groups (n = 18-19/group). Treatment was initiated 8 weeks after left nephrectomy allowing prior VC development. Uremic groups received either intraperitoneal PPi (high dose, 1.65 mg/kg or low dose, 0.33 mg/kg per day), oral sevelamer (3 % in diet), or placebo treatment for 8 weeks. Both intima and media calcifications worsened with time in placebo-treated CKD mice, based on both quantitative image analysis and biochemical measurements. Progression of calcification between 8 and 16 weeks was entirely halted by PPi treatment, as it was by sevelamer treatment. PPi did not induce consistent bone histomorphometry changes. Finally, the beneficial vascular action of PPi probably involved mechanisms different from that of sevelamer. Further studies are needed to gain more precise insight into underlying mechanisms and to see whether PPi administration may also be useful in patients with CKD and VC.

Topics: Animals; Apolipoproteins E; Diphosphates; Disease Models, Animal; Disease Progression; Infusions, Parenteral; Mice; Mice, Knockout; Renal Insufficiency, Chronic; Uremia; Vascular Calcification

The content of ATP, ADP, AMP, sodium phosphate and sodium pyrophosphate were determined by 31P NMR, the linear range of ATP, ADP and AMP were found to be 0.004-0.080 mol x L(-1), sodium phosphate and sodium pyrophosphate were 0.005-0.100 mol x L(-1). The RSD were 0.40%-1.30%, the recovery were 96.9% - 105.2%. The method has been applied to the determination of ATP injection. The impurities of ATP injection were ADP and sodium phosphate. The content of ATP is in line with the requirement of the pharmacopoeia. The results indicated that the method is of good reproducibility, high accuracy, rapid and simple operation, without pretreatment and interference of other elements, 31P NMR is a new and reliable method of analyzing ATP, ADP, AMP and phosphate.

Topics: Adenosine Diphosphate; Adenosine Monophosphate; Adenosine Triphosphate; Chemistry, Pharmaceutical; Diphosphates; Magnetic Resonance Spectroscopy; Perfusion; Pharmaceutical Preparations; Phosphates; Quality Control; Reproducibility of Results

Effects of 0.5% encapsulated (e) phosphates (sodium tripolyphosphate, STP; sodium hexametaphosphate, HMP; sodium pyrophosphate, SPP) on lipid oxidation during storage (0, 1, and 7 d) of ground meat (chicken, beef) after being cooked to 3 end-point cooking temperatures (EPCT; 71, 74, and 77 °C) were evaluated. The use of STP or eSTP resulted in lower (P < 0.05) cooking loss (CL) compared to encapsulated or unencapsulated forms of HMP and SPP. Increasing EPCT led to a significant increase in CL (P < 0.05). Both STP and eSTP increased pH, whereas SPP and eSPP decreased pH (P < 0.05). The higher orthophosphate (OP) was obtained with STP or SPP compared to their encapsulated counterparts (P < 0.05). The lowest OP was determined in samples with HMP or eHMP (P < 0.05). A 77 °C EPCT resulted in lower OP in chicken compared to 74 and 71 °C (P < 0.05), dissimilar to beef, where EPCT did not affect OP. In encapsulated or unencapsulated form, using STP and SPP enhanced reduction in TBARS and lipid hydroperoxides (LPO) compared with HMP (P < 0.05). Regardless of the phosphate type, more effective lipid oxidation inhibition was achieved by the use of encapsulated forms (P < 0.05). Increasing EPCT resulted in lower TBARS in beef and higher LPO values in both beef and chicken samples (P < 0.05). Findings suggest that encapsulated phosphates can be a strategy to inhibit lipid oxidation for meat industry and the efficiency of encapsulated phosphates on lipid oxidation inhibition can be enhanced by lowering EPCT.

Topics: Animals; Capsules; Cattle; Chickens; Cooking; Diphosphates; Food Handling; Food Preservation; Food Preservatives; Hot Temperature; Lipid Metabolism; Lipid Peroxidation; Lipid Peroxides; Meat; Oxidation-Reduction; Phosphates; Polyphosphates; Temperature; Thiobarbituric Acid Reactive Substances

The dynamic hydrolysis of tetrasodium pyrophosphate (TSPP), sodium tripolyphosphate (STPP) and polyphosphate compound, which was catalyzed by purified pyrophosphatase (PPase) and myosin- tripolyphosphatase (TPPase) from the silver carp dorsal muscle, was studied using (31) P NMR spectroscopy. In the PPase + TSPP system, the pyrophosphate (PP) was hydrolyzed quickly and completely within 8 h and the hydrolysis rate of PP was 12.51%/h. In the TPPase + STPP system, the first-order hydrolysis of tripolyphosphate (TPP) was not yet complete after 48 h, and the derived PP accumulated progressively. Given the coexistence of PPase and TPPase, only 1.20% of TPP in STPP alone remained after 48 h. However, the generation rate of Pi in the polyphosphate compound (TSPP: STPP: sodium hexametaphosphate = 1: 8: 1) was 0.76%/h, which was less than 0.88%/h in STPP alone. In the presence of polyphosphatases, the decrease of PP or TPP content in the polyphosphate compound was not as rapid as that in TSPP or STPP alone due to the inhibitory effect of PP on TPPase and the effect of low system pH on PPase. The understanding of polyphosphates hydrolysis mechanism was capable of developing the advanced polyphosphate mixture in order to reduce the phosphate residue in fish products.. Processors appreciate the proven value of phosphates to increase the yield and functionality of the fish meat products. Our studies showed that the hydrolysis rate of PP or TPP in the blend was slower than that of polyphosphate alone. Thus, it is likely that the addition of PP and TPP in a polyphosphate blend had a prolonged interaction with proteins in fish meat processing and the effectiveness of polyphosphates was enhanced.

Topics: Acid Anhydride Hydrolases; Animals; Carps; Diphosphates; Fish Products; Food Additives; Hydrogen-Ion Concentration; Hydrolysis; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Meat; Muscle, Skeletal; Myosins; Phosphates; Polyphosphates

A 63-year-old woman presented with intestinal disorder, alternating between obstipation and diarrhoea. Sodium phosphate/diphosphate (Fleet®) was used in preparation for colonoscopy. Within 24 h the patient developed severe hyperphosphatemia and oliguric acute kidney failure with the need of renal replacement therapy. This case illustrates the rare event of phosphate nephropathy after colonoscopy.

Topics: Acute Kidney Injury; Colonoscopy; Diphosphates; Female; Humans; Hyperphosphatemia; Laxatives; Middle Aged; Premedication; Renal Replacement Therapy; Treatment Outcome

The objective of this study was to describe the dependence of textural properties (hardness, cohesiveness, and relative adhesiveness) of processed cheese spreads on the proportion of disodium phosphate (DSP), tetrasodium diphosphate (TSPP), and sodium salts of polyphosphate in ternary mixtures of emulsifying salts. Sodium salts of polyphosphate with different mean lengths (n ≈ 5, 9, 13, 20, and 28) were used. Pentasodium triphosphate (PSTP) was used instead of TSPP in the second part of the study. Products with and without pH adjustment were tested (the target pH value was 5.60-5.80). Textural properties of the processed cheese were observed after 2, 9, and 30 d of storage at 6°C. Hardness of the processed cheese with a low content of polyphosphate increased at a specific DSP:TSPP ratio (~1:1 to 3:4). This trend was the same for all the polyphosphates used; only the absolute values of texture parameters were different. The same trends were observed in the ternary mixtures with PSTP, showing lower final values of hardness compared with samples containing TSPP. Hardness and cohesiveness decreased and relative adhesiveness increased in the samples with increased pH values and vice versa; the main trend remained unchanged.

Topics: Animals; Cheese; Diphosphates; Emulsions; Food Handling; Food Storage; Hardness; Hydrogen-Ion Concentration; Phosphates; Polyphosphates; Salts

Sodium ion batteries offer promising opportunities in emerging utility grid applications because of the low cost of raw materials, yet low energy density and limited cycle life remain critical drawbacks in their electrochemical operations. Herein, we report a vanadium-based ortho-diphosphate, Na7V4(P2O7)4PO4, or VODP, that significantly reduces all these drawbacks. Indeed, VODP exhibits single-valued voltage plateaus at 3.88 V vs. Na/Na(+) while retaining substantial capacity (>78%) over 1,000 cycles. Electronic structure calculations reveal that the remarkable single plateau and cycle life originate from an intermediate phase (a very shallow voltage step) that is similar both in the energy level and lattice parameters to those of fully intercalated and deintercalated states. We propose a theoretical scheme in which the reaction barrier that arises from lattice mismatches can be evaluated by using a simple energetic consideration, suggesting that the presence of intermediate phases is beneficial for cell kinetics by buffering the differences in lattice parameters between initial and final phases. We expect these insights into the role of intermediate phases found for VODP hold in general and thus provide a helpful guideline in the further understanding and design of battery materials.

Topics: Crystallography; Diphosphates; Electric Power Supplies; Electrochemistry; Kinetics; Models, Theoretical; Vanadium Compounds; X-Ray Diffraction

Effects of encapsulated sodium tripolyphosphate (STP), sodium hexametaphosphate (HMP) and sodium pyrophosphate (SPP) on lipid oxidation in uncooked (0, 2, 24h) and cooked (0, 1, 7 d) ground chicken and beef during storage were determined. Ten phosphate treatments included a control (no phosphate), three unencapsulated (u) at 0.5% and three encapsulated (e) phosphates (0.5%) each at a low (e-low) and high (e-high) coating level. Two heating rates (slow, fast) were investigated. Cooking loss (CL), pH, color, orthophosphate (OP), TBARS and lipid hydroperoxides (LPO) were determined. A fast heating and uSTP resulted in lower CL (p<0.05). Orthophosphate increased with phosphate incorporation, slow heating and storage (p<0.05). Encapsulated phosphates and increased coating level reduced OP (p<0.05). Unencapsulated STP increased CIE a* and pH, whereas uSPP decreased CIE a* and pH (p<0.05). Encapsulated phosphates and the greater coating level had no effect on the pH in cooked samples. Not increased coating level but encapsulated phosphates decreased lipid oxidation in cooked samples (p<0.05).

Topics: Animals; Cattle; Chickens; Color; Cooking; Diphosphates; Hydrogen-Ion Concentration; Lipid Metabolism; Meat; Oxidation-Reduction; Phosphates; Polyphosphates; Thiobarbituric Acid Reactive Substances

The aim of this study was to evaluate the effect of sintered dicalcium pyrophosphate (SDCP) on fracture healing in an osteoporotic rat model. Female Sprague-Dawley rats (8 weeks old) were randomly allocated into five groups: sham-operated group, and bilateral ovariectomized group treated with SDCP, alendronate, calcitonin, or no treatment. Rats were sacrificed at 6 or 16 weeks after fracture. Fracture sites were examined by microcomputed tomography (microCT), histology, and mechanical testing. The results showed that SDCP mildly suppressed callus remodeling at 6 weeks, but not at 16 weeks. The lamellar bone in the callus area and new cortical shell formation in SDCP-treated group were similar to that of the sham group at 16 weeks after fracture, indicating there was no delayed callus remodeling into lamellar bone. At both 6 and 16 weeks after fracture, ultimate stress and elastic modulus were similar between the SDCP and sham groups, and the mechanical strength in these groups was better than that in other groups. Finally, analysis of the serum bone markers CTX-1 and P1NP suggested that SDCP decreased the bone turnover rate and promoted proper fracture healing. The effect of SDCP is superior to that of alendronate and calcitonin in the healing of osteoporotic fractures.

Topics: Animals; Calcium Pyrophosphate; Diphosphates; Drug Combinations; Female; Femoral Fractures; Fracture Healing; Mechanical Phenomena; Osteoporosis; Rats, Sprague-Dawley; X-Ray Microtomography

Ground beef with 1% NaCl was incorporated with 0.5% unencapsulated sodium tripolyphosphate (uSTP), 0.5% encapsulated sodium tripolyphosphate (eSTP), 0.5% unencapsulated sodium acid pyrophosphate (uSAPP), or 0.5% encapsulated sodium acid pyrophosphate (eSAPP) prior to being cooked and stored (0 or 6 d, 3 °C). The pH was higher (P<0.05) for sodium tripolyphosphate samples (6 d: uSTP 5.98; eSTP 5.89) and lower (P<0.05) for sodium acid pyrophosphate (6 d: uSAPP 5.31, eSAPP 5.33) samples than control sample (6 d, 5.50). Overall, samples with uSTP had the least cooking loss and lowest TBARS values. TBARS (mg/kg) for the phosphate treatments were lower (P<0.05; ave. 1.78, 0 d; 3.49, 6 d) than for the control samples (3.07, 0 d; 22.85, 6 d). Therefore, phosphate incorporation into ground beef prior to cooking aids in the reduction of oxidation in the cooked, stored product, although a longer period of time before thermal processing may be necessary for the encapsulated phosphate to have significant benefits.

Topics: Animals; Antioxidants; Cattle; Cooking; Diphosphates; Hot Temperature; Hydrogen-Ion Concentration; Lipid Metabolism; Meat; Oxidation-Reduction; Phosphoric Monoester Hydrolases; Polyphosphates; Thiobarbituric Acid Reactive Substances

Chlamydomonas reinhardtii, a bi-flagellated green alga, is a model organism for studies of flagella or cilia related activities including cilia-based signaling, flagellar motility and flagellar biogenesis. Calcium has been shown to be a key regulator of these cellular processes whereas the signaling pathways linking calcium to these cellular functions are less understood. Calcium-dependent protein kinases (CDPKs), which are present in plants but not in animals, are also present in ciliated microorganisms which led us to examine their possible functions and mechanisms in flagellar related activities. By in silico analysis of Chlamydomonas genome we have identified 14 CDPKs and studied one of the flagellar localized CDPKs--CrCDPK3. CrCDPK3 was a protein of 485 amino acids and predicted to have a protein kinase domain at the N-terminus and four EF-hand motifs at the C-terminus. In flagella, CrCDPK3 was exclusively localized in the membrane matrix fraction and formed an unknown 20 S protein complex. Knockdown of CrCDPK3 expression by using artificial microRNA did not affect flagellar motility as well as flagellar adhesion and mating. Though flagellar shortening induced by treatment with sucrose or sodium pyrophosphate was not affected in RNAi strains, CrCDPK3 increased in the flagella, and pre-formed protein complex was disrupted. During flagellar regeneration, CrCDPK3 also increased in the flagella. When extracellular calcium was lowered to certain range by the addition of EGTA after deflagellation, flagellar regeneration was severely affected in RNAi cells compared with wild type cells. In addition, during flagellar elongation induced by LiCl, RNAi cells exhibited early onset of bulbed flagella. This work expands new functions of CDPKs in flagellar activities by showing involvement of CrCDPK3 in flagellar biogenesis in Chlamydomonas.

Topics: Algal Proteins; Calcium; Cell Membrane; Chlamydomonas reinhardtii; Diphosphates; Egtazic Acid; Flagella; Gene Expression Regulation, Plant; Genome; Isoenzymes; Lithium Chloride; Plant Development; Protein Kinases; Protein Structure, Tertiary; RNA, Small Interfering; Signal Transduction; Sucrose

Gelation is a significant operation in dairy processing. Protein gelation can be affected by several factors such as temperature, pH, or enzyme addition. Recently, the use of ultrasonication has been shown to have a significant impact on the formation of whey protein gels. In this work, the effect of ultrasonication on the gelation of casein systems was investigated. Gels were formed by the addition of 7.6 mm Tetra Sodium Pyro Phosphate (TSPP) to 5 wt% micellar casein (MC) solutions. Sonication at 20 KHz and 31 W for up to 30 min changed the surface hydrophobicity of the proteins, whereas surface charge was unaltered. Sonication before the addition of TSPP formed a firm gel with a fine protein network and low syneresis. Conversely, sonication after TSPP addition led to an inconsistent weak-gel-like structure with high syneresis. Gel strength in both cases increased significantly after short sonication times, while the viscoelastic properties were less affected. Overall, the results showed that ultrasonication can have a significant effect on the final gel properties of casein systems.

Topics: Caseins; Chemical Phenomena; Diphosphates; Elasticity; Gels; Hydrophobic and Hydrophilic Interactions; Micelles; Rheology; Sonication; Surface Properties; Viscosity

The optimization of analytical procedures for the quantification of free and total microcystins (MCs) in natural sediments was systematically examined based on solvent extraction and Lemieux oxidation. In this optimized analytical procedure, a sequential solvent extraction using 50% (v/v) methanol and EDTA-sodium pyrophosphate was selected as the optimal extraction solvent for free MCs analysis, after which the purified extracts and sediment residuals were applied to the optimized Lemieux oxidation for determination of total MCs in lake sediments. The optimized procedures were shown to be efficient and reliable for the routine analysis of both free and total MCs in lake sediment samples, as indicated by the minimal adverse impact of sediment organic matter on the recovery of free MCs and yield of MMPB (2-methyl-3-methoxy-4-phenylbutyric acid). Finally, the developed procedures were applied to field sediment samples collected from Lake Dianchi during a bloom season and seven of thirty samples showed positive results.

Topics: Chromatography, High Pressure Liquid; Diphosphates; Edetic Acid; Geologic Sediments; Lakes; Liquid-Liquid Extraction; Methanol; Microcystins; Oxidation-Reduction; Phenylbutyrates; Soil Pollutants

This work focuses on the remediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soil using modified Fenton (MF) treatment coupled with a novel chelating agent (CA), a more effective technique among currently available technologies. The performance of MF treatment to promote PAH oxidation in artificially contaminated soil was investigated in a packed column with a hydrogen peroxide (H(2)O(2)) delivery system simulating in-situ soil flushing which is more representative of field conditions. The effectiveness of process parameters H(2)O(2)/soil, Fe(3+)/soil, CA/soil weight ratios and reaction time were studied using a 2(4) three level factorial design experiments. An optimised operating condition of the MF treatment was observed at H(2)O(2)/soil 0.05, Fe(3+)/soil 0.025, CA/soil 0.04 and 3h reaction time with 79.42% and 68.08% PAH removals attainable for the upper and lower parts of the soil column respectively. The effects of natural attenuation and biostimulation process as post-treatment in the remediation of the PAH-contaminated soil were also studied. In all cases, 3-aromatic ring PAH (phenanthrene) was more readily degraded than 4-aromatic ring PAH (fluoranthene) regardless of the bioremediation approach. The results revealed that both natural attenuation and biostimulation could offer remarkable enhancement of up to 6.34% and 9.38% in PAH removals respectively after 8 weeks of incubation period. Overall, the results demonstrated that combined inorganic CA-enhanced MF treatment and bioremediation serves as a suitable strategy to enhance soil quality particularly to remediate soils heavily contaminated with mixtures of PAHs.

Topics: Biodegradation, Environmental; Chelating Agents; Chromatography, Gas; Diphosphates; Fluorenes; Hydrogen Peroxide; Iron; Oxidation-Reduction; Phenanthrenes; Soil; Soil Pollutants

(99m)Tc-Sn-PYP (Technetium-99(m) labeled tin pyrophosphate) has been widely used as a radiopharmaceutical for bone scanning as well as in nuclear cardiology. It is also found in the body in trace amounts. (177)Lu is presently considered as an excellent radionuclide for developing bone pain palliation agents. PYP is an analogue of MDP and MDP has been labeled with (177)Lu. No study on preparing a complex of (177)Lu with PYP has been reported yet. Based on these facts, it was hypothesized that a bone-seeking (177)Lu-PYP (Lutetium-177 labeled Pyrophosphate) radiopharmaceutical could be developed as an agent for palliative radiotherapy of bone pain due to skeletal metastases.. (177)Lu was produced by irradiating lutetium foil (11 mg) natural target at a flux ∼1.0×10(14)n/cm(2)/s for 12 h in the swimming pool type reactor. (177)Lu in the form of (177)LuCl(3) was labeled with PYP. The radiochemical purity and labeling efficiencies were determined by paper chromatography. Labeling of (177)Lu with PYP was optimized and a labeled sample was subjected to HPLC analysis. To determine the charge on the (177)Lu-PYP complex, radio-electrophoresis was conducted for 1 h under a voltage of 300 V and 45 mA current using 0.025 M phosphate buffer (pH 6.9). Bioevaluation studies with rabbit under γ-camera were also performed to verify the skeletal uptake.. The quality control using paper radio-chromatography has shown >99% radiochemical purity of (177)Lu-PYP complex. Radio-chromatography also showed maximum labeling at ligand/metal ratio=60:1. HPLC analysis showed 1.42±0.01 min retention time of (177)Lu-PYP complex. No decrease in labeling was observed at higher temperatures. Gamma-camera images of (177)Lu-PYP in normal rabbit at 24 h post injection also showed high skeletal uptake.. The study demonstrated that sodium pyrophosphate could be labeled with (177)Lu with high radiochemical yields (>99%). Negatively charged (177)Lu-PYP complex retained stability for a day and at high temperatures too. Gamma-camera images of (177)Lu-PYP in normal rabbit at 24 h post injection showed high skeletal uptake, suggesting that it may be useful as a bone-pain palliation agent for the treatment of bone metastases.

Topics: Animals; Bone and Bones; Diphosphates; Feasibility Studies; Isotope Labeling; Lutetium; Pain Management; Palliative Care; Rabbits; Radiochemistry; Radioisotopes; Radionuclide Imaging; Radiopharmaceuticals; Temperature

Osteocytes are terminally differentiated osteoblasts which reside in a mineralized extracellular matrix (ECM). The factors that regulate this differentiation process are unknown. We have investigated whether ECM mineralization could promote osteocyte formation. To do this we have utilised MLO-A5 pre-osteocyte-like cells and western blotting and comparative RT-PCR to examine whether the expression of osteocyte-selective markers is elevated concurrently with the onset of ECM mineralization. Secondly, if mineralization of the ECM is indeed a driver of osteocyte formation, we reasoned that impairment of ECM mineralization would result in a reversible inhibition of osteocyte formation. Supplementation of MLO-A5 cell cultures with ascorbic acid and phosphate promoted progressive ECM mineralization as well as temporally associated increases in expression of the osteocyte-selective markers, E11/gp38 glycoprotein and sclerostin. Consistent with a primary role for ECM mineralization in osteocyte formation, we also found that inhibition of ECM mineralization, by omitting phosphate or adding sodium pyrophosphate, a recognized inhibitor of hydroxyapatite formation, resulted in a 15-fold decrease in mineral deposition that was closely accompanied by lower expression of E11 and other osteocyte markers such as Dmp1, Cd44 and Sost whilst expression of osteoblast markers Ocn and Col1a increased. To rule out the possibility that such restriction of ECM mineralization may produce an irreversible modification in osteoblast behaviour to limit E11 expression and osteocytogenesis, we also measured the capacity of MLO-A5 cells to re-enter the osteocyte differentiation programme. We found that the mineralisation process was re-initiated and closely allied to increased expression of E11 protein after re-administration of phosphate or omission of sodium pyrophosphate, indicating an ECM mineralization-induced restoration in osteocyte formation. These results emphasise the importance of cell-ECM interactions in regulating osteoblast behaviour and, more importantly, suggest that ECM mineralization exerts pivotal control during terminal osteoblast differentiation and acquisition of the osteocyte phenotype.

Topics: Adaptor Proteins, Signal Transducing; Animals; Calcification, Physiologic; Cell Differentiation; Cells, Cultured; Diphosphates; Extracellular Matrix; Extracellular Matrix Proteins; Gene Expression Regulation, Developmental; Glycoproteins; Hyaluronan Receptors; Intercellular Signaling Peptides and Proteins; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Osteoblasts; Osteocytes; PHEX Phosphate Regulating Neutral Endopeptidase; Skull

Calcium is a mineral naturally present in water and may be included into meat products during processing thereby influencing meat quality. Phosphates improve myofibril swelling and meat water-holding capacity (WHC) but can be sensitive to calcium precipitation. In this study, pork shoulder meat was used to investigate the impact of calcium at 0, 250, and 500 ppm and phosphate type [sodium pyrophosphate (PP), tripolyphosphate (TPP), and hexametaphopshate (HMP)] at 10 mM on nitrite-cured protein extract color at various pH levels (5.5, 6.0, and 6.5) and crude myofibril WHC at pH 6.0. Neither calcium nor phosphates present in the curing brines significantly affected the cured color. Increasing the pH tended to promote the formation of metmyoglobin instead of nitrosylmyoglobin. The ability of PP to enhance myofibril WHC was hampered (P < 0.05) by increasing the calcium concentration due to PP precipitation. Calcium also decreased the solubility of TPP but did not influence its enhancement of WHC. On the other hand, HMP was more tolerant of calcium but the soluble Ca-HMP complex was less effective than free HMP to promote water binding by myofibrils. The depressed muscle fiber swelling responding to added calcium as evidenced by phase contrast microscopy substantiated, to a certain extent, the deleterious effect of calcium, suggesting that hardness of curing water can significantly affect the quality of cured meat products.. Although not affecting nitrite-cured color, calcium hampers the efficacy of phosphates to promote water binding by muscle proteins, underscoring the importance of water quality for brine-enhanced meat products.

Topics: Animals; Calcium; Color; Diphosphates; Food Handling; Hydrogen-Ion Concentration; Meat Products; Muscle Proteins; Myofibrils; Myoglobin; Nitrites; Phosphates; Polyphosphates; Salts; Solubility; Solutions; Swine; Water; Water Quality

The role of different types of emulsifying salts-sodium citrate (TSC), sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP) and tetrasodium pyrophosphate (TSPP)-on microstructure and rheology of "requeijão cremoso" processed cheese was determined. The cheeses manufactured with TSC, TSPP, and STPP behaved like concentrated solutions, while the cheese manufactured with SHMP exhibited weak gel behavior and the lowest values for the phase angle (G"/G'). This means that SHMP cheese had the protein network with the largest amount of molecular interactions, which can be explained by its highest degree of fat emulsification. Rotational viscometry indicated that all the spreadable cheeses behaved like pseudoplastic fluids. The cheeses made with SHMP and TSPP presented low values for the flow behavior index, meaning that viscosity was more dependent on shear rate. Regarding the consistency index, TSPP cheese showed the highest value, which could be attributed to the combined effect of its high pH and homogeneous fat particle size distribution.

Topics: Cheese; Citrates; Diphosphates; Emulsions; Food Handling; Hydrogen-Ion Concentration; Phosphates; Polyphosphates; Rheology; Salts; Viscosity

The aim of this study was to investigate the effect of different types and concentrations of emulsifying salts (trisodium citrate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, and disodium orthophosphate) on the physicochemical properties of processed cheese. The physicochemical composition, texture profile, degree of casein dissociation, fat particle size, color, and nuclear magnetic resonance profile (NMR) of processed cheese were determined. Hardness, degree of casein dissociation, and pH increased as the concentration of emulsifying salts increased. The fat particle size of processed cheese was significantly influenced by the type of emulsifying salts, with processed cheese made with sodium hexametaphosphate having larger particles (4.68 µm) than cheeses made with the other salts (from 2.71 to 3.30 µm). The processed cheese prepared with trisodium citrate was whiter than those prepared with the other emulsifying salts. The NMR analysis showed that the relaxation time of processed cheese of 10 to 100 ms accounted for a major proportion, indicating that the moisture in processed cheese was mainly bound water combined with the fat globule and hydrated casein.

Topics: Cheese; Citrates; Diphosphates; Emulsifying Agents; Food Handling; Phosphates; Polyphosphates

After-cooking darkening (ACD) is an inherent and undesirable trait that develops in cooked potatoes. The objective of this study was to evaluate the effectiveness of sodium acid sulfate (SAS) dip treatments compared to other antigraying treatments and a control to reduce ACD in boiled, Katahdin potatoes. Dip treatments were applied for 3 min prior to boiling and included: 3% SAS, 3% citric acid (CA), 3% sodium acid pyrophosphate (SAPP), along with a distilled water control. SAS- and CA-treated potatoes had slightly, but significantly (P ≤ 0.05) higher b* and chroma values, which indicates a more intense yellow potato color, with less graying, compared to the control. SAS- and CA-treated potatoes also had significantly (P≤ 0.001) lower pH values for inner and outer potato surfaces than the control. No significant (P > 0.05) differences were detected for total phenolic or mineral contents among treatments. CA and SAPP samples had slightly, but significantly (P≤ 0.05) higher moisture contents than the control. Sensory test results showed no significant differences for color, aftertaste, or overall acceptability. However, CA-treated samples were rated significantly (P≤ 0.05) lower for flavor than all other treatments and panelists commented on sour notes. CA- and SAS-treated potatoes were scored slightly, but significantly lower for texture than other treatments due to a waxy outer layer. However, SAS was the most acidic dip treatment, but did not significantly affect flavor. Overall, results suggest that SAS was similarly accepted by consumers in comparison to CA and SAPP, which is the industry standard to reduce ACD.. After-cooking darkening (ACD) is an undesirable potato trait that occurs after potatoes have been processed. Sodium acid pyrophosphate (SAPP) has been used as the industry standard to reduce ACD. Sodium acid sulfate (SAS) treatments prior to boiling appeared to be comparable to SAPP and citric acid in effectiveness to reduce ACD. SAS did not negatively affect the flavor of boiled potato samples according to sensory results. The SAS treatment may be more beneficial for potatoes intended for potato salad products.

Topics: Adult; Citric Acid; Colorimetry; Consumer Behavior; Cooking; Diphosphates; Female; Humans; Hydrogen-Ion Concentration; Hydroxybenzoates; Linear Models; Maillard Reaction; Male; Solanum tuberosum; Sulfates; Taste; Vegetables

The potential of liposomes as a drug delivery system for use in the oral cavity has been investigated. Specifically targeting for the teeth, the in vitro adsorption of charged liposomal formulations to hydroxyapatite (HA), a common model substance for the dental enamel, has been conducted. The experiments were performed in human parotid saliva to simulate oral-like conditions. It was observed, however, that precipitation occurred in tubes containing DPPC/DPTAP or DPPC/DPPG-liposomes in parotid saliva with no HA present, indicating that constituents of parotid saliva reacted with the liposomes. The aggregation reactions of liposome-parotid saliva mixtures were examined by turbidimetry and by atomic force microscopy. Negatively charged DPPC/DPPS and DPPC/PI-liposomes were additionally included in these experiments. The initial turbidity of positive DPPC/DPTAP-liposomes in parotid saliva was very high, but decreased markedly after 30 min. AFM images showed large aggregates of micelle-like globules known to be present in saliva. The turbidity of the various negatively charged liposome and parotid saliva mixtures stayed relatively constant throughout the measuring time; however, their initial turbidities were different; mixtures with DPPC/DPPG-liposomes were the most turbid and DPPC/DPPA-liposomes the least. Pyrophosphate (PP) was added to the various liposome-parotid saliva mixtures to examine the effect of Ca(2+) on the interactions. The effect of PP treatment of the negatively charged liposome-parotid saliva mixtures was most pronounced with DPPC/DPPG-liposome mixtures where it caused a sudden drop in turbidity. For positive DPPC/DPTAP liposome and parotid saliva mixtures, the effect of PP was minimal. These experiments showed that saliva constituents may interact with liposomes. An appropriate liposomal drug delivery system intended for use in the oral cavity seems to be dependent on the liposomal formulation. Based on the present results, negatively charged DPPC/DPPA-liposomes seem to be most suitable for use in the oral cavity as they were found to be the least reactive with the components of parotid saliva.

Topics: 1,2-Dipalmitoylphosphatidylcholine; Adsorption; Chelating Agents; Chemical Phenomena; Dental Care; Diphosphates; Drug Carriers; Drug Delivery Systems; Female; Humans; Hydroxyapatites; Liposomes; Microscopy, Atomic Force; Mouth; Nephelometry and Turbidimetry; Pharmaceutical Preparations; Saliva; Surface Properties; Time Factors

The reaction in water of Cu(NO(3))(2)·2.5H(2)O with 2,2'-bipyridine (bipy), 1,10-phenanthroline (phen), or 1,10-phenanthroline-5-amine (phenam), and sodium pyrophosphate (Na(4)P(2)O(7)), at various pHs, afforded three new copper(II)-pyrophosphate complexes, namely, {[Cu(bipy)(cis-H(2)P(2)O(7))](2)}·3H(2)O (1a), {[Cu(phen)(H(2)O)](4)(HP(2)O(7))(2)}(ClO(4))(2)·4H(2)O (2), and {[Cu(2)(phenam)(2)(P(2)O(7))](2)·25H(2)O}(n) (3). A solvent free crystalline phase of 1a was also isolated with formula {[Cu(bipy)(trans-H(2)P(2)O(7))](2)} (1b), which can be regarded as a pseudo-polymorph of 1a. Single crystal X-ray analyses revealed these compounds to have uncommon molecular architectures, with 3 being an unprecedented pyrophosphate-containing two-dimensional (2D) polymer. Compounds 1a/1b and 2 are discrete di- and tetra-nuclear complexes, respectively. The cationic {[Cu(phen)(H(2)O)](4)(HP(2)O(7))(2)}(2+) unit in 2 presents a unique quasi-flat structure, held together by solely in-plane pyrophosphate bridging modes (short O(eq)-P-O(eq) and long O(eq)-P-O-P-O(eq) pathways), a coordination arrangement also not previously reported. A different tetranuclear copper(II)-pyrophosphate arrangement is found in 3, with two classically bridged dimers (O(eq)-P-O(eq) pathway) joined together by auxiliary equatorial-axial μ-O pyrophosphate bridges. Here, the bidimensionality is reached through bridging phenam ligands, which provide further inter-"tetramer" metal-metal connections [(N,N')(eq)-(N'')(ax) pathway], leading to the formation of an expanded covalent network based on the [Cu(2)(phenam)(2)(P(2)O(7))](2) moiety. Variable-temperature magnetic susceptibility measurements on polycrystalline samples of 2 and 3 revealed net antiferromagnetic coupling between metal centers with J(2a) = -7.9(2) cm(-1), J(2b) = -46.9(3) cm(-1), J(2c) = 0 cm(-1) in 2 (H = -J(2a)[S(Cu(1))·S(Cu(2)) + S(Cu(1a))·S(Cu(2a))] - J(2b)[S(Cu(1))·S(Cu(2a)) + S(Cu(1a))·S(Cu(2))] - J(2c)S(Cu(2))·S(Cu(2a))), and J(3a) = -87.9(2) cm(-1), J(3b) = -5(1) cm(-1) and J(3c) = +5(3) cm(-1) in 3 (H = -J(3a)[S(Cu(1))·S(Cu(2)) + S(Cu(1a))·S(Cu(2a))] - J(3b)[S(Cu(1))·S(Cu(2a)) + S(Cu(1a))·S(Cu(2))] - J(3c)S(Cu(2))·S(Cu(2a))). For 1a, a net ferromagnetic coupling is observed with J(1a) = +0.86(1) cm(-1) (H = -J S(A)·S(B) + S(A)·D· S(B) + βH (g(A)S(A) + g(B)S(B)). This is the first example of ferromagnetic coupling in pyrophosphate-complexes reported to date. A structure-function correlation study focusing on magnetic exchang

Topics: 2,2'-Dipyridyl; Coordination Complexes; Copper; Crystallography, X-Ray; Dimerization; Diphosphates; Hydrogen-Ion Concentration; Magnetics; Mathematical Computing; Models, Molecular; Molecular Structure; Phenanthrolines; Polymers; Structure-Activity Relationship; Thermodynamics

Pyrophosphate, which may be deficient in advanced renal failure, is a potent inhibitor of vascular calcification. To explore its use as a potential therapeutic, we injected exogenous pyrophosphate subcutaneously or intraperitoneally in normal rats and found that their plasma pyrophosphate concentrations peaked within 15 min. There was a single exponential decay with a half-life of 33 min. The kinetics were indistinguishable between the two routes of administration or in anephric rats. The effect of daily intraperitoneal pyrophosphate injections on uremic vascular calcification was then tested in rats fed a high-phosphate diet containing adenine for 28 days to induce uremia. Although the incidence of aortic calcification varied and was not altered by pyrophosphate, the calcium content of calcified aortas was significantly reduced by 70%. Studies were repeated in uremic rats given calcitriol to produce more consistent aortic calcification and treated with sodium pyrophosphate delivered intraperitoneally in a larger volume of glucose-containing solution to prolong plasma pyrophosphate levels. This maneuver significantly reduced both the incidence and amount of calcification. Quantitative histomorphometry of bone samples after double-labeling with calcein indicated that there was no effect of pyrophosphate on the rates of bone formation or mineralization. Thus, exogenous pyrophosphate can inhibit uremic vascular calcification without producing adverse effects on bone.

Topics: Animals; Calcification, Physiologic; Calcinosis; Diphosphates; Male; Osteogenesis; Rats; Rats, Sprague-Dawley; Uremia; Vascular Diseases

Pyrophosphate, a ubiquitous small-molecule inhibitor of mineralization abundantly present in the extracellular environment, binds to calcium and mineral surfaces to inhibit crystal growth. O'Neill and colleagues show in uremic rats that systemic administration of pyrophosphate prevents or reduces uremia-related vascular calcification, without overt negative consequences for bone and without calcium pyrophosphate deposition disease. These findings prompt further research into the potential of pyrophosphate as treatment for vascular calcification in chronic kidney disease patients.

Topics: Alkaline Phosphatase; Animals; Calcinosis; Diphosphates; Humans; Osteopontin; Rats; Uremia; Vascular Diseases

The high rate of cardiovascular mortality in patients with end-stage renal disease (ESRD) is a significant barrier to improved life expectancy. Unique in this population is the marked development and aggressive worsening of vascular calcification (VC). Pyrophosphate (PPi), an endogenous molecule, appears to naturally inhibit soft tissue calcification, but may be depressed in chronic kidney disease (CKD) and ESRD. Although once thought to be a promising therapeutic, PPi's very short half-life in circulation curtailed earlier studies. We tested the possibility that a slow, continuous entry of PPi into the circulation and prevention of VC might be achieved by daily peritoneal dialysis (PD).. Pharmacokinetic studies were first carried out in rats with renal impairment resulting from a 5/6 nephrectomy. Efficacy studies were then performed in the apolipoprotein E gene knockout mouse model overlaid with CKD. PPi was delivered by means of a permanent peritoneal catheter in a solution simulating PD, but without the timed removal of spent dialysate. von Kossa's staining followed by semiquantitative morphological image processing, with separation of inside (intimal) and outside (presumed medial) lesions, was used to determine aortic root calcification.. In comparison to an intravenous bolus, delivery of PPi in a PD solution resulted in a slower, extended delivery over >4 h. Next, the efficacy studies showed that a 6-day/week PD-simulated administration of PPi resulted in a dose-dependent inhibition of aortic calcification in both intimal and medial lesions. A dose-response effect on total aortic calcification was also documented, with a full inhibition seen at the highest dose. A limited peritoneal catheter-related inflammation was observed, as expected, and included the placebo-treated control groups. This inflammatory response could have masked a lower level PPi-specific adverse effect, but none was observed.. Our findings suggest potential for PPi, administered during PD, to prevent the development of VC and to potentially extend the life of ESRD patients.

Topics: Animals; Apolipoproteins E; Calcium; Dialysis Solutions; Diphosphates; Female; Half-Life; Male; Mice; Mice, Knockout; Peritoneal Dialysis; Rats; Rats, Sprague-Dawley; Renal Insufficiency; Tissue Distribution; Uremia; Vascular Calcification

Ground beef products are susceptible to contamination with Escherichia coli O157:H7. The objective of this study was to examine the effect of salt, sodium pyrophosphate (SPP), and sodium lactate on the probability of growth of E. coli O157:H7 in ground beef under a temperature abuse condition. Ground beef containing 0 to 2.25% salt, 0 to 0.5% SPP, and 0 to 3% lactate was inoculated with a four-strain mixture of E. coli O157:H7, vacuum packaged, and stored at 10°C for 15 days. A total of 25 combinations of the three additives, each with 20 samples, were tested. A logistic regression was used to model the probability of growth of E. coli O157:H7 (with a 1.0-log CFU/g increase during storage) as a function of salt, SPP, and lactate. The resultant probability model indicated that lactate at higher concentrations decreased the probability of growth of E. coli O157:H7 in ground beef, and the effect was more pronounced at higher salt concentrations. At salt concentrations below 1.3%, the increase of SPP concentration marginally increased the growth probabilities of E. coli O157:H7. The model illustrated the effect of salt, SPP, and lactate on the growth probabilities and growth or no-growth behavior of E. coli O157:H7 in ground beef and can be used to improve the microbial food safety of ground beef products.

Topics: Animals; Cattle; Colony Count, Microbial; Consumer Product Safety; Diphosphates; Dose-Response Relationship, Drug; Escherichia coli O157; Food Contamination; Food Preservation; Food Preservatives; Humans; Meat Products; Sodium Lactate; Temperature

Current studies in plants suggest that the content of the coenzyme NAD is variable and potentially important in determining cell fate. In cases that implicate NAD consumption, re-synthesis must occur to maintain dinucleotide pools. Despite information on the pathways involved in NAD synthesis in plants, the existence of a mitochondrial nicotinamide mononucleotide adenylyltransferase (NMNAT) activity which catalyses NAD synthesis from nicotinamide mononucleotide (NMN) and ATP has not been reported. To verify the latter assumed pathway, experiments with purified and bioenergetically active mitochondria prepared from tubers of Jerusalem artichoke (Helianthus tuberosus L.) were performed. To determine whether NAD biosynthesis might occur, NMN was added to Jerusalem artichoke mitochondria (JAM) and NAD biosynthesis was tested by means of HPLC and spectroscopically. Our results indicate that JAM contain a specific NMNAT inhibited by Na-pyrophosphate, AMP and ADP-ribose. The dependence of NAD synthesis rate on NMN concentration shows saturation kinetics with K (m) and V (max) values of 82 ± 1.05 μM and 4.20 ± 0.20 nmol min(-1) mg(-1) protein, respectively. The enzyme's pH and temperature dependence were also investigated. Fractionation studies revealed that mitochondrial NMNAT activity was present in the soluble matrix fraction. The NAD pool needed constant replenishment that might be modulated by environmental inputs. Thus, the mitochondrion in heterotrophic plant tissues ensures NAD biosynthesis by NMNAT activity and helps to orchestrate NAD metabolic network in implementing the survival strategy of cells.

Topics: Adenosine Diphosphate Ribose; Adenosine Monophosphate; Adenosine Triphosphate; Cell Fractionation; Chromatography, High Pressure Liquid; Diphosphates; Helianthus; Heterotrophic Processes; Hydrogen-Ion Concentration; Kinetics; Mitochondria; NAD; NADP; Nicotinamide Mononucleotide; Nicotinamide-Nucleotide Adenylyltransferase; Oxygen; Plant Tubers; Substrate Specificity; Temperature

Double-rotation (DOR) is the only technique generally capable of yielding high-resolution NMR spectra of half-integer quadrupolar nuclei in one dimension for solids without the need for sophisticated coherence pathway selection. Unfortunately, due to the low outer rotor spinning frequencies currently available, the spectra often contain a large number of spinning sidebands which may overlap with the resonances of interest. We implement a simple, robust, and easy to use family of pulse sequences, which in practice are fully analogous to the 'total suppression of sidebands' (TOSS) sequences, to suppress all sidebands arising from the spinning of the outer rotor in DOR experiments. By removing the rotor phase dependence of the evolution of the sidebands, the sidebands destructively interfere with one another during the course of signal averaging to yield 'solution-like' spectra of half-integer quadrupolar nuclei in solids. Advantages and shortcomings of the method compared to other DOR sideband suppression methods are explored with the aid of simulations.

Topics: Algorithms; Artifacts; Computer Systems; Crystallography; Diphosphates; Electromagnetic Fields; Magnetic Resonance Spectroscopy; Sodium Radioisotopes

Newly synthesized Zn(II) and Cd(II)-based complexes show unique selectivity towards inorganic pyrophosphate (PPi) in 100% aqueous medium at pH = 7.4 and act as a "turn-on" and "turn-off" real-time assay, respectively, for the evaluation of the enzymatic activity of alkaline phosphatase.

Topics: Alkaline Phosphatase; Cadmium; Diphosphates; Enzyme Assays; Fluorescent Dyes; Humans; Hydrogen-Ion Concentration; Hydrolysis; Organometallic Compounds; Zinc

In this study, we investigated the tripolyphosphatase (TPPase) activity responsible for the hydrolysis of tripolyphosphates (TPP) in rabbit Psoas major muscle tissue. After a series of extraction and purification steps, myosin was identified to be a TPPase. Optimum pH and temperature for myosin-TPPase activity were 6.0 and 35°C, respectively. We also found that myosin-TPPase activity was significantly influenced by Mg(2+) and Ca(2+) levels, whose optimal concentrations were determined to be 3 and 6mM, respectively. Furthermore, myosin-TPPase was strongly inhibited by EDTA-4Na(+) and KIO(3), and was slightly activated by EDTA-2Na(+). These results suggest that it may be useful to regulate tripolyphosphate hydrolysis to enhance its function in meat processing.

Topics: Acid Anhydride Hydrolases; Animals; Calcium; Diphosphates; Electrophoresis, Polyacrylamide Gel; Enzyme Inhibitors; Female; Hydrogen-Ion Concentration; Hydrolysis; Magnesium; Muscle Proteins; Myosins; Polyphosphates; Psoas Muscles; Rabbits; Temperature

Acid birnessite was treated with Na4P2O7 at pH 2, 4, 5 respectively. After the treatments, the species and content of manganese ion in the complex solution, and the variation of average oxidation state (AOS) of Mn in birnessite, and the amount of adsorbed Pb2+ and released Mn2+, H+ during the Pb2+ adsorption were investigated. The results indicate that after acid birnessite, the AOS of Mn is 3.670 which is treated by Na4P2O7 at different pH, Mn( III) located in the layer edge and part of Mn(III) located in the interlayer are released to the solution through complexation with Na4P2O7. The content of Mn(III) in the structure of original birnessite is very low. Small amount of Mn(II), which accounts for 4.70%-7.46% in the molar percentage of total released Mn, is also released simultaneously. The AOS of Mn of birnessites after treatment increases to 3.783 (pH 2), 3.786 (pH 4), 3.824 (pH 5) respectively. While the crystal structure of birnessite does not change after treatment, the amount of Mn(III) located above or below vacant cation sites decreases, and the amount of H+ located above or below vacant cation sites goes up in the structure of birnessites. The amount of vacant cation sites responsible for Pb2+ adsorption increases, which lead to the increase of the maximum amount of adsorbed Pb2+. Additionally, the distribution of Mn(III) in the structure of acid birnessite is deduced. About one sixth of Mn(III) locates in the layer edge, and five sixths of Mn(III) locates in the interlayer and the non layer edge.

Topics: Adsorption; Diphosphates; Hydrogen-Ion Concentration; Lead; Manganese; Manganese Compounds; Oxides; Soil Pollutants

The effect of phosphate blends and pork meat type (pale, soft, and exudative [PSE]; normal; and dark, firm, and dry [DFD]) on the germination and outgrowth of Clostridium perfringens during abusive exponential chilling times was evaluated. Two phosphates were used: tetrasodium pyrophosphate (TSPP) and sodium acid pyrophosphate (SAPP; from two different sources, SAPP(1) and SAPP(2)). The pork loins representing each meat type were ground (1/8-in. [0.3-cm] plate), and one of the three phosphate blends (SAPP(1)+SAPP(2), TSPP+SAPP(1), or TSPP+SAPP(2)) was added (0.3% total, equal proportions of 0.15% each type) with salt (1.0%). The pork was then mixed with a three-strain C. perfringens spore cocktail to obtain a final concentration of ca. 2.0 to 2.5 log spores per g. The inoculated product was heat shocked for 20 min at 75 degrees C and chilled exponentially from 54.4 to 4 degrees C in a period of 6.5, 9, 12, 15, 18, or 21 h. In control samples (PSE, normal, and DFD), the increase in C. perfringens population was <1 log CFU/g within the 6.5-h chilling period, and longer chilling times resulted in greater increases. C. perfringens population increases of 5.95, 4.73, and 5.95 log CFU/g of meat were observed in normal, PSE, and DFD pork, respectively, during the 21-h abusive chilling period. The combination of SAPP(1)+SAPP(2) was more effective than the other treatments for inhibiting C. perfringens. The types of phosphate and their blends and the meat type affected the germination and outgrowth of C. perfringens spores in cooked pork during abusive chilling periods.

Topics: Animals; Clostridium perfringens; Colony Count, Microbial; Diphosphates; Food Contamination; Food Handling; Food Preservation; Food Preservatives; Humans; Meat Products; Phosphates; Spores, Bacterial; Swine; Temperature

We investigated the genotoxicities or mutagenicities of 2 chemicals (octane and tetrasodium pyrophosphate) with limited toxicological data in spite of their common usage based on Ames reverse mutation test. In this test, treatment of 2 chemicals at each five dose did not induce mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537, and in Escherichia coli WP2uvrA with and without metabolic activation. These results indicate that 2 chemicals do not have mutagenic potentials under the conditions examined in each study. Despite these results, it can affect by inducing inhalation, skin or eye contact, ingestion, and have affected central nervous system as a target organ. It is thus necessary to prepare the local exhaust system and personal protective equipments. Based on this study, we suggest that future studies should be directed toward chronic inhalation, carcinogenic test and so on.

Topics: Diphosphates; Escherichia coli; Mutagenicity Tests; Mutagens; Octanes; Salmonella typhimurium

Protein hydrolysate from salted egg white (PHSEW) with different degrees of hydrolysis (DH) (3%, 6%, and 9%) was produced using pepsin. Disappearance of proteins with molecular weight (MW) of 108 and 85 kDa with the concomitant formation of proteins with MW of 23, 20, 13, and 5 kDa was observed in PHSEW. The use of PHSEW for quality improvement of Pacific white shrimp (Litopenaeus vannamei) was investigated. Shrimp soaked in 4% NaCl containing 7% PHSEW and 2.5% mixed phosphates (0.625% sodium acid pyrophosphate [SAPP] and 1.875% tetrasodium pyrophosphate [TSPP]) had the highest cooking yield with the lowest cooking loss (P < 0.05), compared with shrimps with other treatments. Nevertheless, no difference in weight gain was obtained in comparison with those treated with 4% NaCl containing 3.5% mixed phosphate (P > 0.05). Cooked shrimp treated with 4% NaCl containing 7% PHSEW and 2.5% mixed phosphate or those treated with 4% NaCl containing 3.5% mixed phosphate had the higher score of appearance, texture, and overall likeness but less shear force, in comparison with the control (no treatment) (P < 0.05). Microstructure study revealed that muscle fibers of cooked shrimp from both treatments had the swollen fibrils and gaps, while the control had the swollen compact structure. Therefore, use of PHSEW could reduce phosphate residue in shrimps without an adverse effect on sensory properties.

Topics: Animals; Cooking; Diphosphates; Ducks; Egg Proteins, Dietary; Egg White; Food Additives; Food Analysis; Food Handling; Food Preservation; Microscopy, Electron, Scanning; Penaeidae; Pepsin A; Phosphates; Protein Hydrolysates; Quality Control; Salts; Sensation; Shear Strength; Shellfish

Efficient detachment and purification of bacterial cells associated with streambed sediments are required in order to quantify cell abundance and to assess community composition through the application of epifluorescence microscopy techniques. We applied chemical (i.e., sodium pyrophosphate and polysorbate) and physical treatments (i.e., shaking and sonication), followed by Nycodenz density gradient centrifugation to efficiently recover benthic bacteria. This procedure resulted in a highly purified cell suspension allowing for a precise cell quantification through the application of fluorescent dyes. About 93% of total cells were recovered from the original sediment, with higher recovery from the finer grain-size class (90%) in comparison to the coarse fraction (69%). The potential damaging effects of the applied procedures on cell integrity were assessed on planktonic bacteria in a pre-filtered water control. As a consequence of the high purity of the extracted bacteria, flow cytometry was successfully applied as counting method for sediment cell suspension. However, a significant decrease of protein synthesis in purified samples was measured by estimating the (3)H-Leucine incorporation rates, rising uncertainties on the possibility to apply potential metabolic assays after Nycodenz purification.

Topics: Bacteria; Bacteriological Techniques; Centrifugation, Density Gradient; Diphosphates; Flow Cytometry; Fresh Water; Geologic Sediments; Microscopy, Fluorescence; Polysorbates; Sonication

Functional properties of pasteurized process cheese (PPC) made with different types of emulsifying salts (ES) (2%, wt/wt) were investigated as a function of different pH values (from 5.3 to approximately 5.9). The ES investigated were trisodium citrate (TSC), disodium phosphate (DSP), sodium hexametaphosphate (SHMP), and tetrasodium pyrophosphate (TSPP). Meltability and textural properties were determined using UW-MeltProfiler and uniaxial compression, respectively. All PPC samples exhibited an increase in degree of flow (DOF) determined at 45 degrees C when the pH was increased from 5.3 to 5.6, presumably reflecting greater Ca binding by the ES, increased charge repulsion and therefore greater casein dispersion. When the pH of PPC was increased from 5.6 to approximately 5.9, 2 types of ES (DSP and SHMP) exhibited no further increase in DOF at 45 degrees C; while DOF increased in 1 type of PPC (made with TSC) but decreased in another (made with TSPP). TSPP is able to form crosslinks with casein especially in the vicinity of pH 6, which likely restricted melt; in contrast TSC does not crosslink caseins and the increase in pH helped cause greater casein dispersion. Low pH samples (5.3) were not significantly harder than higher pH samples for all ES types but exhibited fracture. The PPC with the highest hardness values at pHs 5.3 and 5.6 were made with TSPP and TSC, respectively. The pH-dependent functional behavior of PPC was strongly influenced by the type of ES and its physicochemical properties including its ability to bind Ca, the possible creation of crosslinks with casein and casein dispersion during cooking.

Topics: Calcium; Cheese; Chemical Phenomena; Citrates; Diphosphates; Emulsifying Agents; Food Handling; Hydrogen-Ion Concentration; Salts; Sensation

The effect of tetrasodium pyrophosphate (TSPP) on the properties of yogurt gels was investigated. Various concentrations (0.05 to 0.2%) of TSPP were added to preheated (85 degrees C for 30 min) reconstituted skim milk, which was readjusted to pH 6.50. Milk was inoculated with 2% starter culture and incubated at 42 degrees C until the pH reached 4.6. Acid-base buffering profiles of milk and total and soluble calcium levels were measured. Turbidity measurements were used to indicate changes in casein dispersion. Storage modulus (G') and loss tangent (LT) values of yogurts were monitored during fermentation using dynamic oscillatory rheology. Large deformation properties of gels were also measured. Microstructural properties of yogurt were observed using fluorescence microscopy. The addition of TSPP resulted in the disappearance of the buffering peak during acid titration at pH approximately 5.1 that is due to the solubilization of colloidal calcium phosphate (CCP), and a new peak was observed at lower pH values (pH 4.0-4.5). The buffering peak at pH 6.0 during base titration virtually disappeared with addition of TSPP and a new peak appeared at pH approximately 4.8. The addition of TSPP reduced the soluble Ca content of milk and increased casein-bound Ca values. The addition of up to 0.125% TSPP resulted in a reduction in turbidity because of micelle dispersion but at 0.15%, turbidity increased and these samples exhibited a time-dependent increase in turbidity because of aggregation of casein particles. Gels made with 0.20% TSPP were very weak and had a very high gelation pH (6.35), probably due to complete dispersion of the micelle structure in this sample. The LT value of gels at pH 5.1 decreased with an increase in TSPP concentration, probably due to the loss of CCP with the addition of TSPP. The G' values at pH 4.6 of gels made with or=0.125% TSPP significantly decreased G' values. The addition of 0.05 to 0.125% TSPP to milk resulted in a reduction in the yield stress values of yogurt compared with yogurt made without TSPP. Greater TSPP levels (>0.125%) markedly reduced the yield stress values of yogurt. Lowest whey separation levels were observed in yogurts made with 0.10% TSPP. High TSPP levels (>0.10%) greatly increased the apparent pore size of gels. Addition of very low levels of TSPP to milk for yogurt manufacture may be useful in reducing the whey separation defect, but at TSPP c

Topics: Calcium; Caseins; Diphosphates; Gels; Micelles; Particle Size; Rheology; Titrimetry; Yogurt

The objective of this study was to investigate the influence of several types of emulsifying salts (ES) on the texture of nonfat process cheese (NFPC). Improperly produced nonfat cheese tends to exhibit several problems upon baking including stickiness, insufficient or excessive melt, pale color upon cooling, formation of a dry skin (skinning) often leading to dark blistering, and chewy texture. These attributes are due to the strength and number of interactions between and among casein molecules. We propose to disrupt these interactions by using suitable emulsifying salts (ES). These ES chelate Ca and disperse caseins. Stirred curd cheese bases were made from skim milk using direct acidification with lactic acid to pH values 5.0, 5.2, and 5.4, and ripened for 1 d. Various levels of trisodium citrate (TSC; 0.5, 1, 1.5, 2, 2.5, 3, and 5%), disodium phosphate (DSP; 1, 2, 3, and 4%), or trisodium phosphate (TSP; 1, 2, 3, and 4%) were blended with the nonfat cheese base. Cheese, ES, and water were weighed into a steel container, which was placed in a waterbath at 98 degrees C and then stirred using an overhead stirrer for 9 min. Molten cheese was poured into plastic containers, sealed, and stored at 4 degrees C for 7 d before analysis. Texture and melting properties were determined using texture profile analysis and the UW-Melt-profiler. The pH 5.2 and 5.4 cheese bases were sticky during manufacture and had a pale straw-like color, whereas the pH 5.0 curd was white. Total calcium contents were approximately 400, 185, and 139 mg/100 g for pH 5.4, 5.2, and 5.0 cheeses, respectively. Addition of DSP resulted in NFPC with the lowest extent of flow, and crystal formation was apparent at DSP levels above 2%. The NFPC manufactured from the pH 5.0 base and using TSP had reduced melt and increased stickiness, whereas melt was significantly increased and stickiness was reduced in NFPC made with pH 5.4 base and TSP. However, for NFPC made from the pH 5.4 cheese and with 1% TSP, the pH value was >6.20 and crystals were observed within a few days. Use of TSC increased extent of flow up to a maximum with the addition of 2% ES for all 3 types of cheese bases. Addition of high levels of TSC to the pH 5.2 and 5.4 cheese bases resulted in increased stickiness. Similar pH trends for attributes such as extent of flow, hardness, and adhesiveness were observed for both phosphate ES but no consistent pH trends were observed for the NFPC made with TSC. These initial trials suggest t

Topics: Calcium; Cheese; Citrates; Diphosphates; Emulsifying Agents; Food Technology

A phosphate-hydrolyzing activity from Glycine max embryo axes was purified by a series of chromatographic steps and electroelution from activity gels, and demonstrated to be an inositol-1 (or 4)-monophosphatase by partial internal amino acid sequence. This enzyme hydrolyzed ATP, sodium pyrophosphate (NaPPi), inositol hexakisphosphate, and inositol 1-monophosphate, but not p-nitrophenyl phosphate, ADP, AMP or glucose 6-P. Using NaPPi as substrate, the highly purified protein hydrolyzed up to 0.4 mmol phosphate min(-1) mg(-1) protein and had a Km(avg) of 235 microM for NaPPi. Since NaPPi is relatively inexpensive and readily available, we used this as substrate for the subsequent characterization. We observed the following: (a) specific inhibition by Li and NaF but not by butanedione monoxime, or orthovanadate; (b) activation by Cu(2+) and Mg(2+); (c) optimum activity at pH 7.4; and (d) temperature stability after 1-h incubations at 37-80 degrees C, with maximum activity at 37 degrees C. The partially purified protein was detected by in-gel activity assays and the band was electroeluted to yield a highly purified protein. Analysis by SDS-PAGE and native IEF-PAGE yielded a single major polypeptide of 29 kDa and pI approximately 5.9, respectively. In addition, in-gel activity from embryo axes and whole hypocotyls at early germination times revealed one high and one intermediate molecular weight isoform, but only the intermediate one corresponded to IMPase. Throughout the post-imbibition period, the activity of the high molecular weight isoform disappeared and IMPase increased, indicating an increasing expression of the enzyme as germination and growth proceeded. These data indicate that the inositol-1 (or 4)-monophosphatase present in the embryo axis of G. max has a wide phosphate substrate specificity, and may play an important role in phosphate metabolism during the germination process.

Topics: Adenosine Triphosphate; Amino Acid Sequence; Cations, Divalent; Diphosphates; Enzyme Induction; Enzyme Stability; Germination; Glycine max; Hot Temperature; Hydrolysis; Inositol Phosphates; Kinetics; Lithium Chloride; Molecular Sequence Data; Molecular Weight; Phosphoric Monoester Hydrolases; Phosphorylation; Phytic Acid; Protein Denaturation; Seeds; Sodium Fluoride; Substrate Specificity; Time Factors

A selective and rapid capillary zone electrophoresis method for determination of the multicomponent aminoglycoside antibiotic gentamicin is described. Baseline separation of gentamicin C1, C1a, C2, C2a and C2b components was achieved with a background electrolyte containing 0.35 mM cetyl trimethylammonium bromide, 3% methanol and 90 mM sodium pyrophosphate (pH 7.4) and detected directly with UV detection without derivatization. Quantitative analysis was performed and illustrated the potential use of capillary electrophoresis for the identification and quantitation of gentamicin components, but the application of this method is limited to a gentamicin concentration range of 2-6 mg/ml.

Topics: Anti-Bacterial Agents; Cetrimonium; Cetrimonium Compounds; Diphosphates; Electrolytes; Electrophoresis, Capillary; Gentamicins; Hydrogen-Ion Concentration; Methanol; Molecular Structure; Sensitivity and Specificity; Spectrophotometry, Ultraviolet; Time Factors

A novel two-step process was developed to prepare ssDNA templates for pyrosequencing. First, PCR-amplified DNA templates modified with an acrylamide group and acrylamide monomers were copolymerized in 0.1 M NaOH solution to form polyacrylamide gel spots. Second, ssDNA templates for pyrosequencing were prepared by removing electrophoretically unbound complementary strands, unmodified PCR primers, inorganic pyrophosphate (PPi), and excess deoxyribonucleotides under alkali conditions. The results show that the 3-D polyacrylamide gel network has a high immobilization capacity and the modified PCR fragments are efficiently captured. After electrophoresis, gel spots copolymerized from 10 microL of the crude PCR products and the acrylamide monomers contain template molecules on the order of pmol, which generate enough light to be detected by a regular photomultiplier tube. The porous structure of gel spots facilitated the fast transportation of the enzyme, dNTPs and other reagents, and the solution-mimicking microenvironment guaranteed polymerase efficiency for pyrosequencing. Successful genotyping from the crude PCR products was demonstrated. This method can be applied in any laboratory; it is cheap, fast, simple, and has the potential to be incorporated into a DNA-chip format for high-throughput pyrosequencing analysis.

Topics: Acrylamide; Base Sequence; Diphosphates; DNA Primers; DNA, Single-Stranded; Electrophoresis, Polyacrylamide Gel; Gels; Indicators and Reagents; Luciferases; Luminescent Measurements; Polymerase Chain Reaction; Sequence Analysis, DNA

We investigated the properties of gels that were formed by adding emulsifying salts, such as tetrasodium pyrophosphate (TSPP), to reconstituted milk protein concentrate solution. The pH of a 51 g/L milk protein concentrate solution was adjusted to 5.8 after adding TSPP. Milk protein concentrate solutions were placed in glass jars and allowed to stand at 25 degrees C for 24 h. Gels with the highest breaking force were formed when TSPP was added at a concentration of 6.7 mM, whereas no gel was formed when TSPP was added at concentrations of < or =2.9 or > or =10.5 mM. Several other phosphate-based emulsifying salts were tested but for these emulsifying salts, gelation only occurred after several days or at greater gelation temperatures. No gelation was observed for trisodium citrate. Gelation induced by TSPP was dependent on pH, and the breaking force of gel was greatest at pH 6.0. Furthermore, when the concentration of milk protein concentrate in solution was increased to 103 g/L, the breaking force of the gel increased, and a clearly defined network between caseins could be observed by using confocal scanning laser microscopy. These results suggest that TSPP-induced gelation occurs when the added TSPP acts with calcium as a cross-linking agent between dispersed caseins and when the balance between (a reduced) electrostatic repulsion and (enhanced) attractive (hydrophobic) interactions becomes suitable for aggregation and eventual gelation of casein molecules.

Topics: Calcium Chloride; Caseins; Diphosphates; Emulsifying Agents; Food Handling; Gels; Hydrogen-Ion Concentration; Microscopy, Confocal; Milk Proteins; Phosphates; Sodium Chloride

Organic acids, hot water (HW), and chlorine have been commonly used in carcass decontamination for years. However, it has been observed that organic acids have adverse effects on color and are corrosive, while HW is discoloring. On the other hand, glucose fermentation by lactic acid bacteria in meat during the rigor period might be effective in microbial inhibition, without producing an adverse effect on the organoleptic quality of meat. Therefore, this study has aimed at finding an alternative meat decontamination procedure without any adverse effects. In this study, briskets were treated with 6 different applications: D (+) glucose monohydrate (GM) (16.51 g/100 mL, 15%) dip, HW dip, sodium pyrophosphate (SPP) and HW dip, GM + SPP + HW, and GM + HW combined dip. Then, the results of these applications were compared. First, GM + HW and GM + SPP + HW applications indicated more inhibition on Pseudomonas spp., Coliform and total Mesophile Aerob Bacteria growth, resulting in lower acidity loss (P < 0.01). Second, additional use of SPP with GM and HW did not enhance microbial inhibition (P < 0.01). Finally and most importantly, GM, 15%, improved a and b Hunter values significantly (P < 0.01), producing a very intense red meat color that can be very attractive for meat producers and consumers.

Topics: Animals; Bacteria; Cattle; Colony Count, Microbial; Consumer Product Safety; Diphosphates; Disinfectants; Dose-Response Relationship, Drug; Drug Synergism; Food Contamination; Glucose; Hot Temperature; Humans; Meat; Pigmentation; Water

Glomalin, a glycoprotein produced by arbuscular mycorrhizal (AM) fungi, is a major component of the humus fraction of soil organic matter. Glomalin is extracted from soil and hyphae of AM fungi by using sodium citrate at 121 degrees C in multiple 1-h cycles, but extensive extraction does not solubilize all glomalin in all soils. Efficacies of 100 mM sodium salts of citrate, borate or pyrophosphate (pH 9.0, 121 degrees C) were tested for two 1-h cycles for hyphae from four AM fungal isolates and four 1-h cycles for seven soils from four US geographic regions. Residual soil glomalin was examined by pyrophosphate extraction of soils previously extracted with citrate or borate followed by extraction of all soils after treatment with NaOH. Hyphal extracts were compared using Bradford-reactive total protein (BRTP) values, and extracts from soils were compared using BRTP, percentage C and C weight. No difference among extractants was detected for AM fungal isolates or across soils. The residual glomalin across soils for extractants contained the following percentages of the total BRTP: pyrophosphate, 14%; borate, 17%; and citrate, 22%. Comparisons among individual soils indicated that pyrophosphate extracted significantly more BRTP (10-53%) than borate or citrate in six soils and borate was equal to pyrophosphate in one soil. Extraction with borate should be compared with pyrophosphate before initiating an experiment. For routine extractions of ca. 85% of the glomalin across a variety of soils, sodium pyrophosphate appears to be equal to or better than borate and better than citrate.

Topics: Borates; Carbon; Citrates; Diphosphates; Fungal Proteins; Glycoproteins; Hyphae; Mycorrhizae; Sodium Citrate; Soil; Zea mays

Effects of polyamine and metal ions on the new type of acid phosphatase purified from potato (Solanum tuberosum L. Irish Cobbler) tubers were analyzed. The enzyme belongs to nonspecific acid phosphatase family (EC 3.1.3.2), which hydrolyzes various phosphorylated substrates. The enzyme hydrolyzed inorganic pyrophosphate as a preferred substrate, and exhibited the hyperbolic kinetics with respect to the substrate, inorganic pyrophosphate in the absence of metal cations. Polyamine activated the enzyme effectively by lowering the K(m) value without appreciable changes in the maximal velocity. The most effective polyamines as activators were spermine and spermidine. Mg(2+) ion increased the K(m) value without affecting the maximal velocity of the enzyme, but Ca(2+) ion decreased both the K(m) and V(max) values. Increasing concentrations of spermine also decreased the K(m) value irrespective of Mg(2+) ion included, but gave a constant K(m) and V(max) values in the absence and presence of Ca(2+) ion. Action of spermine and metal ions can be explained by the complex formation with the substrate pyrophosphate. The acid phosphatase from potato can utilize the pyrophosphate-spermine or pyrophosphate-Ca(2+) complex as the preferred substrates. However, the enzyme can use the pyrophosphate-Mg complex with a weak affinity for the active site. Polyamine activates acid phosphatase in the absence and presence of metal cations, and activation by polyamine of the enzyme may contribute to the stimulation of starch biosynthesis and the control of glycolysis/gluconeogenesis by regulating PPi levels in growing potato tubers.

Topics: Acid Phosphatase; Calcium; Diphosphates; Kinetics; Magnesium; Polyamines; Solanum tuberosum; Spermidine; Spermine

We examined the biodegradation and desorption of a set of 15 polycyclic aromatic hydrocarbon (PAH) compounds in coal tar-contaminated soil at a former manufactured gas plant site to evaluate the feasibility of in situ bioremediation. Experiments were conducted in well-mixed aerobic soil suspensions containing various additives over a 93- to 106-d period. In general, both biotransformation and desorption decreased with PAH ring size, becoming negligible for the six-ring PAH compounds. Biodegradation by indigenous microorganisms was strongly accelerated by addition of inorganic nutrients (N, P, K, and trace metals). The rates of biotransformation of PAH compounds by indigenous microorganisms in nutrient-amended flasks outpaced their maximum (i.e., chelate-enhanced) rates of desorption to an infinite sink (Tenax) in sterilized systems run in parallel, suggesting that indigenous organisms facilitated desorption. Biodegradation by indigenous organisms in nutrient-amended flasks appeared to be unaffected by the addition of a site-derived bacterial enrichment culture, resulting in approximately 100-fold higher aromatic dioxygenase levels, and by the addition of 0.01 M chelating agent (citrate or pyrophosphate), although such chelating agents greatly enhanced desorption in microbially inactivated flasks. The strong ability of nutrients to enhance degradation of the bioavailable PAHs indicates that their persistence for many decades at this site likely results from nutrient-limited natural biodegradation, and it also suggests that an effective strategy for their bioremediation could consist simply of adding inorganic nutrients.

Topics: Adsorption; Biodegradation, Environmental; Chelating Agents; Citrates; Coal Tar; Colony Count, Microbial; Diphosphates; Evaluation Studies as Topic; Gasoline; Industrial Waste; Metals; Polycyclic Aromatic Hydrocarbons; Sodium Citrate; Soil Pollutants

Micellar casein particles (submicelles) are formed by removing calcium phosphate from native casein. The submicelles aggregate and eventually form a gel with a rate that increases strongly with increasing temperature and casein concentration. At low casein concentrations the gel is very weak and collapses under its own weight so that a precipitate is formed. The structure of the aggregates is studied using light scattering and cryo-electron microscopy. It is found that the aggregates have a self-similar structure with fractal dimension 2. The viscoelastic properties of the gel are studied by frequency scans of the loss and storage moduli during the gelation process. The bonds between the submicelles probably involve calcium phosphate complexes.

Topics: Calcium Phosphates; Caseins; Cryoelectron Microscopy; Diphosphates; Gels; Light; Micelles; Multiprotein Complexes; Particle Size; Rheology; Scattering, Radiation; Viscosity

Influence of emulsifying salts (ES) on some physical properties of casein micelles was investigated. A reconstituted milk protein concentrate (MPC) solution (5% wt/wt) was used as the protein source and the effects of ES [0 to 2.0% (wt/wt)] were estimated by measuring turbidity, acid-base titration curves and amount of casein-bound Ca and inorganic P (P(i)). Various ES, trisodium citrate (TSC), or sodium phosphates (ortho-, pyro-, or hexameta-) were added to MPC solution, and all samples were adjusted to pH 5.8. Acid-base buffering curves were used to observe changes in the amount and type of insoluble Ca phosphates. An increase in the concentration of TSC added to MPC solution decreased turbidity, buffering at pH approximately 5 (contributed by colloidal Ca phosphate), and amount of casein-bound Ca and P(i). Addition of up to 0.7% disodium orthophosphate (DSP) did not significantly influence turbidity, buffering curves, or amount of casein-bound Ca and P(i). When higher concentrations (i.e., > or =1.0%) of DSP were added, there was a slow decrease in turbidity. With increasing concentration of added tetrasodium pyrophosphate (TSPP), turbidity and buffering at pH approximately 5 decreased, and amount of casein-bound Ca and P(i) increased. When small concentrations (i.e., 0.1%) of sodium hexameta-phosphate were added, effects were similar to those when TSPP were added but when higher concentrations (i.e., > or =0.5%) were added, the buffering peak shifted to a higher pH value, and amount of casein-bound Ca and P(i) decreased. These results suggested that each type of ES influenced casein micelles by different mechanisms.

Topics: Animals; Buffers; Calcium; Caseins; Diphosphates; Emulsifying Agents; Hydrogen-Ion Concentration; Micelles; Milk Proteins; Nephelometry and Turbidimetry; Phosphates; Solutions

Effects of 2 types of emulsifying salts (ES) on the functionality of nonfat pasta filata cheese were examined. Nonfat pasta filata cheese was made from skim milk by direct acidification. Trisodium citrate (TSC) and tetrasodium pyrophosphate (TSPP) were added to curds (at 1, 3, and 5%, wt/wt) at the dry-salting step, together with glucono-delta-lactone to maintain a constant pH. When TSC was added, there were no significant compositional differences, although insoluble Ca and P contents significantly decreased with the addition of TSC. When TSPP was added, fat content was not significantly different, but protein content decreased with increasing concentrations of TSPP. Both insoluble Ca and P contents increased with the addition of 1% TSPP. The addition of ES affected textural and functional properties. With increasing concentrations of TSC, meltability increased, whereas increasing the TSPP content decreased meltability. Cheese made with 1% TSC had better stretchability compared with control cheese. However, the addition of more than 3% TSC decreased stretchability. Addition of TSPP caused a considerable decrease in stretchabilty. Scanning electron microscopy revealed that the size and number of serum pockets decreased and protein appeared more hydrated with the addition of both ES. These results suggested that TSC and TSPP influenced the functionality of nonfat pasta filata cheese differently; that is, the effects of TSC were probably caused by a decrease in the number of colloidal calcium phosphate cross-links and an increase in electrostatic repulsion, whereas the effects of TSPP may have been related to the formation of new TSPP-induced casein-casein interactions.

Topics: Calcium; Caseins; Cheese; Chemical Phenomena; Chemistry, Physical; Citrates; Colloids; Diphosphates; Emulsifying Agents; Fats; Gluconates; Hydrogen-Ion Concentration; Lactones; Phosphorus; Sodium Citrate; Solubility; Static Electricity

1. An experiment was conducted to assess the effect of tetrasodium pyrophosphate and sodium bicarbonate on colour and sensory attributes of pre- and post-chilled breast meat. 2. Three groups of 6 halves of breasts (pre-chill) immediately after slaughter were treated with 3% tetrasodium pyrophosphate, 3% sodium bicarbonate in 2% NaCl or 2% NaCl alone (control); the remaining 6 halves (post-chill) were stored overnight at 4 degrees C and then treated similarly. Both the pre- and post-chill samples were held at 4 degrees C for 24 h and pH, water holding capacity, cooking loss, CIE colour values and sensory attributes were recorded. 3. Chilling had few effects on the meat characteristics measured in this study. 4. Treatment with phosphate and bicarbonate increased pH in both the pre- and post-chill groups. Treated breasts exhibited lower L* and higher a* value (more red) than controls. 5. A sensory evaluation study revealed improvements in colour and other sensory attributes of cooked broiler breast meat in all treated samples compared to the control. 6. The findings suggest that tetrasodium pyrophosphate and sodium bicarbonate, when injected post mortem, will have beneficial effects on several physico-chemical (pH, colour, WHC %, cooking loss) and sensory attributes of broiler meat. However, phosphate had a smaller effect than bicarbonate.

Topics: Animals; Chickens; Cold Temperature; Cooking; Diphosphates; Female; Food Preservation; Hydrogen-Ion Concentration; Male; Meat; Sodium Bicarbonate; Sodium Chloride

Phototropin (phot) is a UV/blue- light receptor mediating phototropic reactions of plants as a response to unilateral irradiation. Using an antiserum directed against the N-terminal part of Arabidopsis phot1, we show here cross-reaction with phototropin from Avena sativa, Eruca sativa, Glycine max, Lepidium sativum, Lycopersicon esculentum, Pisum sativum, Sinapis alba, and Zea mays. In all investigated plants, blue light irradiation led to a gel mobility shift of phototropin corresponding to an apparent increase in size of 2-3 kDa. This increase is transient: the apparent size of the phototropin band reverted back to the original size in the dark within 60-90 min. The capacity for in vitro phosphorylation increased to 350% ( A. sativa) and 200% ( L. sativum) at 90 min after a blue light pulse without an increase in the amount of phototropin protein. Starting from coleoptile tips of monocots that contained the highest concentration of phototropin, we found an exponential decrease in basipetal sections of equal size while a linear decrease was determined for dicots in basipetal sections starting from the section below the hypocotyl hook. We confirmed the membrane association of all phototropin in dark-grown seedlings; after a 2-min blue light pulse, however, 20% of phototropin was found in the cytosolic fraction and only 80% in the membrane fraction. Both fractions showed the gel mobility shift indicating light-dependent autophosphorylation. Detergent-free solubilization of phototropin with chaotropic reagents was investigated with etiolated A. sativa seedlings. Up to 95% of phototropin was solubilized with a mixture of sodium bromide and sodium diphosphate, and subsequently subjected to affinity purification using Cibachron Blue 3GA-agarose as a dinucleotide analogue. Immediately after solubilization, soluble phototropin still showed blue-light-dependent autophosphorylation but lost its activity within less than 1 h.

Topics: Arabidopsis Proteins; Avena; Bromides; Cryptochromes; Darkness; Diphosphates; Drosophila Proteins; Eye Proteins; Flavoproteins; Immunoblotting; Light; Membrane Proteins; Phosphoproteins; Photoreceptor Cells, Invertebrate; Protein Serine-Threonine Kinases; Receptors, G-Protein-Coupled; Sodium Chloride; Sodium Compounds

Reduction of the antimicrobial efficacy of lysozyme-chelator combinations against two Escherichia coli O157:H7 strains on addition of mineral salts was studied. The objective of the study was to determine the effect of type and concentration of mono-, di-, and trivalent mineral salts on the antimicrobial effectiveness of lysozyme and various chelators against E. coli O157:H7. Seven salts (Al3+, Ca2+, Fe2+, Fe3+, K+, Mg2+, and Na+) at 1 to 10 mM were added to aqueous solutions of lysozyme and disodium ethylenediamine tetraacetic acid (EDTA), disodium pyrophosphate (DSPP), or pentasodium tripolyphosphate (PSTPP) at pH 6, 7, or 8 and applied to cultures of E. coli O157:H7 strains 932 and H1730. Inhibitory activity of lysozyme chelator combinations against both strains was completely lost after addition of > or = 1 mM Ca2+ and Mg2+ at pH 7 and 8. At pH 6, antimicrobial activity of lysozyme-EDTA against both strains was retained in the presence of calcium or magnesium cations. DSPP-lysozyme inhibited strain H1730 at pH 6 despite the presence of Mg2+. Concentrations above 4 mM Fe2+ neutralized activity of all lysozyme-chelator combinations. Reversal of inhibition by lysozyme-chelator complexes by the monovalent Na+ and K+ ions depended on E. coli O157:H7 strain type. Neither monovalent cation reversed inhibition of strain 932. However, Na+ and K+ reversed lysozyme-chelator inhibition of strain H1730. The addition of > or = 1 mM Fe3+ or Al3+ was effective in reversing inhibition of both strains by lysozyme and EDTA at pH 6, 7, and 8. Isothermal titration calorimetry was used to determine the amount of ion-specific competitive binding of free cations by EDTA-lysozyme combinations. A mechanistic model for the antimicrobial functionality of chelator-lysozyme combinations is proposed.

Topics: Anti-Infective Agents; Cations; Chelating Agents; Diphosphates; Dose-Response Relationship, Drug; Drug Synergism; Edetic Acid; Escherichia coli O157; Food Microbiology; Hydrogen-Ion Concentration; Kinetics; Microbial Sensitivity Tests; Models, Biological; Muramidase

The degradation of phenol (100-2800 mg/L) by cells Pseudomonas putida CCRC14365 in an extractive hollow-fiber membrane bioreactor (HFMBR) was studied, in which the polypropylene fibers were prewetted with ethanol. The effects of flow velocity, the concentrations of phenol, and the added dispersive agent tetrasodium pyrophosphate on phenol degradation and cell growth were examined. It was shown that about 10% of phenol was sorbed on the fibers at the beginning of the degradation process. The cells P. putida fully degraded 2000 mg/L of phenol within 73 h when the cells were immobilized and separated by the fibers. Even at a level of 2800 mg/L, phenol could be degraded more than 90% after 95-h operation. At low phenol levels (< 400 mg/L) where substrate inhibition was not severe, it was more advantageous to treat the solution in a suspended system. At higher phenol levels (> 1000 mg/L), however, such HFMBR-immobilized cells could degrade phenol to a tolerable concentration with weak substrate-inhibition effect, and the degradation that followed could be completed by suspended cultures due to their larger degradation rate. The process development in an HFMBR system was also discussed.

Topics: Algorithms; Bacteriological Techniques; Biodegradation, Environmental; Biofilms; Bioreactors; Biotransformation; Cell Proliferation; Diphosphates; Kinetics; Microscopy, Electron, Scanning; Phenol; Polypropylenes; Pseudomonas putida

Inexpensive, high-throughput genotyping methods are needed for analyzing human genetic variations. We have successfully applied the regular bioluminometric assay coupled with modified primer extension reactions (BAMPER) method to single-nucleotide polymorphism (SNP) typing as well as the allele frequency determination for various SNPs. This method includes the production of single-strand target DNA from a genome and a primer extension reaction coupled with inorganic pyrophosphate (PPi) detection by a bioluminometric assay. It is an efficient way to get accurate allele frequencies for various SNPs, while single-strand DNA preparation is labor intensive. The procedure can be simplified in the typing of SNPs. We demonstrate that a modified BAMPER method in which we need not prepare a single-strand DNA can be carried out in one tube. A PCR product is directly used as a template for SNP typing in the new BAMPER method. Generally, tremendous amounts of PPi are produced in a PCR process, as well as many residual dNTPs, and residual PCR primers remain in the PCR products, which cause a large background signal in a bioluminometric assay. Here, shrimp alkaline phosphatase (SAP) and E. coli exonuclease I were used to degrade these components prior to BAMPER detection. The specific primer extension reactions in BAMPER were carried out under thermocycle conditions. The primers were extended to produce large amounts of PPi only when their bases at 3'-termini were complementary to the target. The extension products, PPis, were converted to ATP to be analyzed using the luciferin-luciferase detection system. We successfully demonstrated that PCR products can be directly genotyped by BAMPER in one tube for SNPs with various GC contents. As all reactions can be carried out in a single tube, the method will be useful for realizing a fully automated genotyping system.

Topics: Alleles; Base Pair Mismatch; Diphosphates; DNA; DNA Mutational Analysis; DNA Primers; Genes; Genome; Genotype; Humans; Luminescent Measurements; Myocardium; Nucleic Acid Amplification Techniques; Polymorphism, Single Nucleotide

Some metabolic inhibitors, mevastatin (MVS), chlorocholine chloride (CCC), sodium pyrophosphate (NaPP) and D,L-glyceraldehyde (DLG), were respectively added into the suspension cultures of the yew Taxus chinensis var. mairei at the late phase of cell growth to study isopentenyl pyrophosphate (IPP) biosynthesis. The content of total taxanes decreased in the cases of MVS, NaPP and DLG addition, regardless of the inhibitor concentration, whereas it increased in the case of CCC addition. It was thus presumed that a mevalonate pathway might exist in IPP biosynthesis at the late growth phase of Taxus cells and that some IPP might transfer from the cytoplasm to the plastids. This presumption was also confirmed by analysing the effects of the inhibitors on taxane content. It was further demonstrated that IPP in the biosynthesis of taxol, baccatin III and 10-deacetylbaccatin III might transfer from the cytoplasm to the plastids, whereas the translocation of IPP might be not involved in cephalomannine biosynthesis. Furthermore, in combination with the results of previous studies, it is very probable that different IPP biosynthesis pathways exist during different growth phases in Taxus cells.

Topics: Bridged-Ring Compounds; Cells, Cultured; Chlormequat; Culture Media; Diphosphates; Enzyme Inhibitors; Glyceraldehyde; Hemiterpenes; Lovastatin; Organophosphorus Compounds; Species Specificity; Taxoids; Taxus

The effects and interactions of 27 combinations of heating temperature (57.5 to 62.5 degrees C), sodium pyrophosphate (SPP) level (0 to 0.5%, wt/vol), and salt (NaCl) level (0 to 6%, wt/vol) on the thermal inactivation of starved Listeria monocytogenes ATCC 19116 in pork slurry were investigated. A split-split plot experimental design was used to compare all 27 combinations. L. monocytogenes survivors were enumerated on tryptic soy agar supplemented with 0.6% yeast extract. The natural logarithm (loge) of the means of decimal reduction times (D-values) were modeled as a function of temperature, SPP level, and NaCl level. Increasing concentrations of SPP or NaCl protected starved L. monocytogenes from the destructive effect of heat. For example, D-values for the pathogen at 57.5 degrees C in pork slurry with 0, 3, and 6% NaCl were 2.79, 7.75, and 14.59 min, respectively. All three variables interacted to affect the thermal inactivation of L. monocytogenes. A mathematical model describing the combined effect of temperature, SPP level, and NaCl level on the thermal inactivation of starved L. monocytogenes was developed. There was strong correlation (R2 = 0.97) between loge D-values predicted by the model and those observed experimentally. The model can predict D-values for any combination of variables that falls within the range of those tested. This predictive model can be used to assist food processors in designing thermal processes that include an adequate margin of safety for the control of L. monocytogenes in processed meats.

Topics: Animals; Colony Count, Microbial; Diphosphates; Food Microbiology; Hot Temperature; Kinetics; Listeria monocytogenes; Manure; Models, Biological; Models, Theoretical; Sodium Chloride; Swine

The aim of this study was to overcome the analytical problems encountered during the detection of protozoans by flow cytometry resulting from particle compaction.. Malvern Mastersizer (Malvern Instruments, Malvern, UK) was used to characterize the particle distribution of four different water samples and/or particle concentrates incubated with (i) low ionic strength solution or sequestring agent, (ii) anionic or non-ionic surfactants (iii) industry detergent formulations and (iv) physical treatment. The recovery of oocysts and cysts in seeded and treated particle concentrates was estimated by cytometry and microscopy. The decrease in ionic strength of the aqueous solution was most efficient in particle dispersion for different types of water. Moreover, samples treated with deionized water or tetrasodium pyrophosphate showed the highest recovery with more than 80% of the oocysts and cysts recovered.. Chemical treatments that act by altering the ionic strength of the medium are the most efficient for all water types tested here but the overall detergency performance cannot be predicted for all water types.. Flow cytometric detection has been replaced largely by immunomagnetic separation but the data recorded still have relevance in this technique as well as in molecular techniques requiring DNA or RNA extraction.

Topics: Animals; Cryptosporidium; Diphosphates; Flow Cytometry; Giardia; Hydrophobic and Hydrophilic Interactions; Microscopy, Fluorescence; Particle Size; Surface-Active Agents; Water; Water Purification

Analyses of survival data of a mixture of Salmonella spp. at fixed temperatures between 55 degrees C (131 degrees F) and 71.1 degrees C (160 degrees F) in ground beef matrices containing concentrations of salt between 0 and 4.5%, concentrations of sodium pyrophosphate (SPP) between 0 and 0.5%, and concentrations of sodium lactate (NaL) between 0 and 4.5% indicated that heat resistance of Salmonella increases with increasing levels of SPP and salt, except that, for salt, for larger lethalities close to 6.5, the effect of salt was evident only at low temperatures (<64 degrees C). NaL did not seem to affect the heat resistance of Salmonella as much as the effects induced by the other variables studied. An omnibus model for predicting the lethality for given times and temperatures for ground beef matrices within the range studied was developed that reflects the convex survival curves that were observed. However, the standard errors of the predicted lethalities from this models are large, so consequently, a model, specific for predicting the times needed to obtained a lethality of 6.5 log(10), was developed, using estimated results of times derived from the individual survival curves. For the latter model, the coefficient of variation (CV) of predicted times range from about 6 to 25%. For example, at 60 degrees C, when increasing the concentration of salt from 0 to 4.5%, and assuming that the concentration of SPP is 0%, the time to reach a 6.5-log(10) relative reduction is predicted to increase from 20 min (CV = 11%) to 48 min (CV = 15%), a 2.4 factor (CV = 19%). At 71.1 degrees C (160 degrees F) the model predicts that more than 0.5 min is needed to achieve a 6.5-log(10) relative reduction.

Topics: Animals; Bacteriological Techniques; Cattle; Diphosphates; Meat; Models, Biological; Poultry; Regression Analysis; Salmonella; Serotyping; Sodium Chloride; Sodium Lactate; Swine; Temperature; Thermodynamics

To evaluate whether nuclear activity as measured by the disodium phosphate 32P (32P) uptake test for uveal melanoma is of prognostic value and corresponds to known prognostic factors.. A retrospective analysis of 121 patients with choroidal and/or ciliary body melanoma, tested with the 32P uptake test before enucleation between January 1, 1973, and December 31, 1976, at the Leiden University Medical Center. We obtained the 25-year follow-up information of this group of patients and compared the 32P test results and histopathological variables with the long-term survival rates.. The cumulative 5-, 10-, and 20-year survival for melanoma-related death was 81.4%, 73.3%, and 63.9%, respectively. The results of the 32P uptake test were not significantly correlated with survival (P =.35). Of all prognostic factors under study, tumor diameter, cell type, and mitotic count were identified as the most important prognostic markers for uveal melanoma in this group.. The 32P isotope uptake test has no prognostic value for uveal melanoma. Moreover, the results of this study indicate that it is unlikely that cell activity as determined by 32P uptake involves mitotic activity of the tumor.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Diphosphates; Eye Enucleation; Female; Humans; Male; Melanoma; Middle Aged; Phosphorus Radioisotopes; Prognosis; Retrospective Studies; Survival Rate; Uveal Neoplasms

Cryptosporidium is a zoonotic coccidian parasite associated with diarrhea, and the disinfectant-resistant oocysts are threats to public health even in industrialized countries. In order to make an accurate assessment of the risk to public health, a detection method that has a high recovery rate of oocysts in water is required. In this study, we developed a new filter-eluting solution that facilitates more efficient recovery of Cryptosporidium oocysts from different kinds of water samples. The filter-eluting solution, referred to as PET, consists of sodium pyrophosphate (0.02%), Tween 80 (0.01%) and trisodium EDTA (0.03%). By using PET instead of conventional filter-eluting solutions, the average recovery rate significantly increased from 25.5+/-15.1% to 43.1+/-13.9% (p<0.05). The improved oocyst recovery was likely due to the increased separation of the oocysts from debris trapped on the filter membrane as well as increased capture of the oocysts by immunomagnetic beads. We recommend that PET be used as the filter-eluting solution for detection of Cryptosporidium oocysts in environmental water.

Topics: Animals; Cryptosporidium; Diphosphates; Edetic Acid; Filtration; Humans; Immunomagnetic Separation; Oocysts; Polysorbates; Public Health; Water; Water Purification

The aim of this paper was to investigate the electrostatic interactions between multivalent phosphates (phosphate (Phos), pyrophosphate (Pyro) and tripolyphosphate (TPP)) and chitosan, as well as the influence of electrostatic interactions on the properties of chitosan films ionically cross-linked by the above mentioned phosphates. The charge number of Phos was too low to interact with chitosan, while Pyro and TPP with more negative charges showed a significant ability to ionically cross-link chitosan. Solution pH played an important role on the charge numbers carried by Pyro, TPP and chitosan, especially for Pyro/chitosan. For instance, at pH less than 2.0 the interaction between Pyro and chitosan disappeared, while for TPP/chitosan even in solutions at pH less than 0.5 it still existed. Media pH and ionic strength also had a significant influence on the properties of cross-linked chitosan film with multivalent phosphates. Usually these films swelled and drug was released quickly in acidic conditions (such as in simulated gastric fluid) while under neutral conditions (such as in simulated intestinal fluid) they remained in a shrinkage state and drug was released slowly. Compared to TPP/chitosan films, Pyro/chitosan films exhibited much better pH-sensitive swelling and controlled release properties due to their relatively weak electrostatic interaction. The same reasoning was used to explain the significant acceleration of Pyro/chitosan film swelling and model drug release observed on adding sodium chloride. These films may be promising for site-specific drug delivery in the stomach.

Topics: Anions; Biocompatible Materials; Chitin; Chitosan; Cross-Linking Reagents; Delayed-Action Preparations; Diphosphates; Hydrogen-Ion Concentration; Nephelometry and Turbidimetry; Osmolar Concentration; Pharmaceutic Aids; Phosphates; Polyphosphates; Potentiometry; Riboflavin; Rosaniline Dyes; Time Factors

The aim of this paper is to study possible synergic effects between crystallization-inhibitor molecules of low molecular weight on the hydroxyapatite and brushite crystal nucleation. Kinetic-turbidimetric measurements were performed to follow the nucleation process in synthetic urine at 37 degrees C. Only pyrophosphate + phytate mixture manifested synergic effects on the brushite nucleation, whereas the mixture pyrophosphate + citrate exhibited synergic effects only on the hydroxyapatite nucleation. It seems clear that synergic effects between the crystallization inhibitory capacity of some substances in urine can take place and as a consequence, the high crystallization inhibitory capacity of healthy urine could be assigned not only to the individual inhibitory capacity of each product but also to the synergic effects between different products.

Topics: Calcium Phosphates; Citrates; Crystallization; Diphosphates; Drug Synergism; Durapatite; Humans; Kidney Calculi; Molecular Weight; Phytic Acid; Sodium Citrate

The small Japanese "firefly squid," Watasenia scintillans, emits a bluish luminescence from dermal photogenic organs distributed along the ventral aspects of the head, mantle, funnel, arms and eyes. The brightest light is emitted by a cluster of three tiny organs located at the tip of each of the fourth pair of arms. Studies of extracts of the arm organs show that the light is due to a luciferin-luciferase reaction in which the luciferase is membrane-bound. The other components of the reaction are coelenterazine disulfate (luciferin), ATP, Mg(2+), and molecular oxygen. Based on the results, a reaction scheme is proposed which involves a rapid base/luciferase-catalyzed enolization of the keto group of the C-3 carbon of luciferin, followed by an adenylation of the enol group by ATP. The AMP serves as a recognition moiety for docking the substrate molecule to a luciferase bound to membrane, after which AMP is cleaved and a four-membered dioxetanone intermediate is formed by the addition of molecular oxygen. The intermediate then spontaneously decomposes to yield CO(2) and coelenteramide disulfate (oxyluciferin) in the excited state, which serves as the light emitter in the reaction.

Topics: Adenosine Triphosphate; Animals; Decapodiformes; Diphosphates; Enzyme Activation; Female; Firefly Luciferin; Imidazoles; Luciferases; Luminescent Measurements; Models, Chemical; Organ Specificity; Oxygen; Pyrazines

This paper presents composting of the organic fraction of municipal solid waste containing 50,000 mg/kg of cellucotton and 7980 mg/kg of zinc carried out under laboratory conditions. In the initial material as well as the compost obtained, zinc, cadmium, copper, nickel, and lead were analyzed, and their forms were determined by means of sequential extraction. It was found that 65% of zinc occurs in the organically bound form. Removal of zinc from the waste through leaching and subsequent electrochemical separation from the leaching solution was also examined. A double extraction of the waste with sodium diphosphate(V) enables a reduction of zinc content to 1240 mg/kg. As a result of electrolysis of the leaching solution, 90.2% of Zn is separated on the cathode. This paper suggests a method for processing municipal solid waste with high zinc content based on extraction of the waste with sodium diphosphate(V) and composting. The leaching solution is recovered electrochemically.

Topics: Antineoplastic Agents; Diphosphates; Electrochemistry; Environmental Pollution; Organic Chemicals; Refuse Disposal; Zinc

Raf-1 activation is a complex process which involves plasma membrane recruitment, phosphorylation, protein-protein and lipid-protein interactions. We now show that PP1 and PP2A serine-threonine phosphatases also have a positive role in Ras dependent Raf-1 activation. General serine-threonine phosphatase inhibitors such sodium fluoride, or ss-glycerophosphate and sodium pyrophosphate, or specific PP1 and PP2A inhibitors including microcystin-LR, protein phosphatase 2A inhibitor I(1) or protein phosphatase inhibitor 2 all abrogate H-Ras and K-Ras dependent Raf-1 activation in vitro. A critical Raf-1 target residue for PP1 and PP2A is S259. Serine phosphatase inhibitors block the dephosphorylation of S259, which accompanies Raf-1 activation, and Ras dependent activation of mutant Raf259A is relatively resistant to serine phosphatase inhibitors. Sucrose gradient analysis demonstrates that serine phosphatase inhibition increases the total amount of 14-3-3 and Raf-1 associated with the plasma membrane and significantly alters the distribution of 14-3-3 and Raf-1 across different plasma membrane microdomains. These observations suggest that dephosphorylation of S259 is a critical early step in Ras dependent Raf-1 activation which facilitates 14-3-3 displacement. Inhibition of PP1 and PP2A therefore causes plasma membrane accumulation of Raf-1/14-3-3 complexes which cannot be activated.

Topics: 14-3-3 Proteins; Amino Acid Substitution; Animals; Binding Sites; Carrier Proteins; Cell Membrane; Chlorocebus aethiops; COS Cells; Diphosphates; Enzyme Activation; Enzyme Inhibitors; Genes, ras; Glycerophosphates; Intracellular Signaling Peptides and Proteins; Isoenzymes; Macromolecular Substances; Marine Toxins; Microcystins; Models, Biological; Mutation, Missense; Peptides, Cyclic; Phosphoprotein Phosphatases; Phosphorylation; Protein Phosphatase 2; Protein Processing, Post-Translational; Protein Structure, Tertiary; Proteins; Proto-Oncogene Proteins c-raf; Proto-Oncogene Proteins p21(ras); RNA-Binding Proteins; Sodium Fluoride; Transfection; Tyrosine 3-Monooxygenase

Micrurgically isolated interphasal nuclei of Amoeba proteus, which preserve F-actin cytoskeletal shells on their surface, shrink after perfusion with imidazole buffer without ATP, and expand to about 200% of their cross-sectional area upon addition of pyrophosphate. These changes in size may be reproduced several times with the same nucleus. The shrunken nuclei are insensitive to the osmotic effects of sugars and distilled water, whereas the expanded ones react only to the distilled water, showing further swelling. The shrinking-expansion cycles are partially inhibited by cytochalasins. They are attributed to the state of actomyosin complex in the perinuclear cytoskeleton, which is supposed to be in the rigor state in the imidazole buffer without ATP, and to dissociate in the presence of pyrophosphate. Inflow of external medium to the nuclei during dissociation of the myosin from the perinuclear F-actin may be due to colloidal osmosis depending on other macromolecular components of the karyoplasm.

Topics: Actins; Actomyosin; Amoeba; Animals; Antineoplastic Agents; Cell Nucleus; Cytochalasin B; Cytoskeleton; Diphosphates; Imidazoles; Microscopy, Fluorescence

Sintered bovine cancellous bone exhibited excellent biocompatiblity, high porosity and have an interconnecting porous structure allowing for bone ingrowth. However, the main mineral constitution of sintered bovine bone-hydroxyapatite (Ca10(PO4)6(OH)2, HAP) seems to be too stable in vivo. For improving its bioactivity, the calcined bovine bone removing the organic substance by burning process-with different quantities of sodium pyrophosphate (Na4P2O7.10H2O, NP) addition was heated to a high temperature to transform its crystalline phase constitution from HAP into TCP/HAP biphasic or other multiphasic structures. Results revealed that the calcined bovine bone without NP addition, exhibited a pure form of HAP characterized pattern during heating. Its thermal behavior was similar to stoichiometric HAP, it gradually lost its OH- ions and transformed into oxyhydroxyapatite at high temperature. After being doped into calcined bovine bone, NP would react with HAP to form betaBTCP and NaCaPO4 around 600 degrees C. At 900 degrees C, doped NP would completely react with HAP and the NaCaPO4 would further react with HAP to form more betaBTCP in the system. With NP increasing in the calcined bovine bone, HAP would gradually convert into different crystalline phase compositions of TCP/HAP, TCP/HAP/NaCaPO4 or TCP/NaCaPO4 at high temperature. By heating calcined bovine cancellouse bone with different quantities of NP we could obtain different crystalline phase compositions of natural porous bioceramic in this study.

Topics: Animals; Biocompatible Materials; Bone and Bones; Bone Transplantation; Cattle; Ceramics; Crystallization; Crystallography, X-Ray; Diphosphates; Durapatite; Hot Temperature; Humans; Materials Testing; Microscopy, Electron, Scanning; Spectroscopy, Fourier Transform Infrared; Transplantation, Heterologous

Fungal laccases are extracellular multinuclear copper-containing oxidases that have been proposed to be involved in ligninolysis and degradation of xenobiotics. Here, we show that an electrophoretically homogenous laccase preparation from the white rot fungus Trametes versicolor oxidized Mn2+ to Mn3+ in the presence of Na-pyrophosphate, with a Km value of 186 microM and a Vmax value of 0.11 micromol/min/mg protein at the optimal pH (5.0) and a Na-pyrophosphate concentration of 100 mM. The oxidation of Mn2+ involved concomitant reduction of the laccase type 1 copper site as usual for laccase reactions, thus providing the first evidence that laccase may directly utilize Mn2+ as a substrate.

Topics: Diphosphates; Dose-Response Relationship, Drug; Fungi; Hydrogen-Ion Concentration; Kinetics; Laccase; Manganese; Oxidoreductases; Sodium Fluoride; Time Factors

The effects and interactions of heating temperature (55 to 65 degrees C), pH (4 to 8), salt (NaCl; 0 to 6%, wt/vol), and sodium pyrophosphate (SPP; 0 to 0.3%, wt/vol) on the heat inactivation of a four-strain mixture of Listeria monocytogenes in beef gravy were examined. A factorial experimental design comparing 48 combinations of heating temperature, salt concentration, pH value, and SPP content was used. Heating was carried out using a submerged-coil heating apparatus. The recovery medium was plate count agar supplemented with 0.6% yeast extract and 1% sodium pyruvate. Decimal reduction times (D-values) were calculated by fitting a survival model to the data with a curve-fitting program. The D-values were analyzed by second-order response surface regression for temperature, pH, NaCl, and SPP levels. Whereas increasing the NaCl concentration protected L. monocytogenes against the lethal effect of heat, high SPP concentrations increased heat sensitivity. Also, low pH values increased heat sensitivity of L. monocytogenes. The four variables interacted to affect the inactivation of the pathogen. Thermal resistance of L. monocytogenes can be lowered by combining these intrinsic factors. A predictive model that described the combined effect of temperature, pH, NaCl, and SPP levels on thermal resistance of L. monocytogenes was developed. The model can predict D-values for any combination of temperature, pH, NaCl, and SPP that are within the range of those tested. Using this predictive model, food processors should be able to design adequate thermal regimes to eliminate L. monocytogenes in thermally processed foods.

Topics: Animals; Cell Survival; Diphosphates; Food Microbiology; Hot Temperature; Hydrogen-Ion Concentration; Listeria monocytogenes; Meat Products; Models, Biological; Sodium Chloride

A group of 26 2,6-dimethyl-3,5-disubstituted and 2,6-dimethyl-3,4, 5-trisubstituted-1,4-dihydropyridines (1,4-H(2)Py=1,4-DHPs) and five related pyridines were studied as inhibitors of rat liver mitochondrial swelling and O(2) uptake by ascorbic acid-dependent lipid peroxidation (LP) and as modulators of mitochondrial swelling induced by Na(+)-linoleate or Na(+)-pyrophosphate. 1,4-DHPs studied include 4-unsubstituted and 4-methyl- and 4-phenyl-substituted 3, 5-dialkoxycarbonylderivatives of 2,6-dimethyl-1,4-DHP with variations in alkoxy chain length and composition, 4-unsubstituted and 4-methyl-, 4-aryl- and 4-pyridyl-substituted 3, 5-dianilidocarbonylderivatives, and a structurally related group of 3,5-dipyridylamidocarbonylderivatives. Many 1,4-DHPs possess marked antioxidant (AO) and membrane stabilizing activity, expressed as the mitochondrial swelling (deltaA(520)/t) and/or O(2) uptake rate decrease (V(0)/V) as well as prolongation of the induction period (tau/tau(0)) of mitochondrial swelling and/or O(2) uptake at ascorbic acid-dependent LP of rat liver mitochondria. 4-Unsubstituted 3,5-dialkoxycarbonyl-2,6-dimethyl-1,4-DHPs, as well as 4-unsubstituted or those possessing lipophylic 4-aryl- groups 3, 5-diamido-2,6-dimethyl-1,4-DHPs, reveal marked AO and membrane stabilizing properties. Oxidized (heteroaromatized) derivatives have minimal activity. Perhaps 1,4-DHPs preferably act as antioxidants on stages of initiation and prolongation of LP chain reactions at low concentrations: IC(50) (when V(0)/V or tau/tau(0)=2) are 0.1 microM to 100 microM. At 100 microM 3,5-di-p-hydroxyphenoxycarbonyl- and 3, 5-di-p-tolyloxycarbonyl-2,6-dimethyl-1,4-DHPs, as well as 3, 5-diethoxycarbonyl-2,6-dimethylpyridine (oxidized form of Hantzsch ester) and 3,5-diamyloxycarbonyl-2,6-dimethylpyridine, alter the mitochondrial swelling rate in the presence of natural protonophore Na(+)-linoleate (0.063 mM and 0.125 mM). 3,5-Di-n-butyloxycarbonyl-2, 6-dimethyl-1,4-DHP at 100 microM completely stops mitochondrial swelling in the presence of 0.8 mM Na(+)-pyrophosphate. In the presence of many of the 1,4-DHPs, the lipid peroxidation process was inhibited. However, the swelling process could be prolonged, promoted, accelerated or inhibited-depending on 1,4-DHPs structure, concentration, the type of initiators of the swelling process and the medium composition.

Topics: Animals; Antioxidants; Ascorbic Acid; Calcium Channel Blockers; Dihydropyridines; Diphosphates; Linoleic Acid; Lipid Peroxidation; Male; Mitochondrial Swelling; Molecular Structure; Rats; Rats, Wistar

The 23Na magic-angle spinning (MAS), double rotation (DOR) and multiple-quantum magic-angle spinning (MQMAS) NMR spectra of anhydrous sodium pyrophosphate, Na4P2O7, measured at five different Larmor frequencies (nuL) ranging from 105.8 MHz (corresponding to 400 MHz 1H frequency) to 211.6 MHz (800 MHz) are analysed and the complete set of NMR parameters (C(qcc), etaQ and delta(iso)) of the four crystallographically inequivalent sodium sites were determined with high accuracy. Different approaches of spectra evaluation are discussed and their results are compared. The most reliable results are obtained from a combined evaluation of five DOR and three MQMAS spectra but also from two DOR and one MAS spectra or even from a single MQMAS spectrum all data can be derived. It is shown that Na4P2O7 may serve as a useful reference material for experimental set-up and reliability tests of the various NMR experiments.

Topics: Crystallography; Diphosphates; Magnetic Resonance Spectroscopy

Calcium phosphate cements can be handled in paste form and set in a wet medium after precipitation of calcium phosphate crystals in the implantation site. Depending on the products entering into the chemical reaction leading to the precipitation of calcium phosphates, different phases can be obtained with different mechanical properties, setting times and injectability. We tested a cement composed of a powder, containing beta-tricalcium phosphate (beta-TCP) and sodium pyrophosphate mixed with a solution of phosphoric and sulphuric acids. The cement set under a dicalcium phosphate dihydrate (DCPD)-based matrix containing beta-TCP particles. This was injected with a syringe into a defect drilled in rabbit condyles, the control being an identical defect left empty in the opposite condyle. The condyles were analysed histologically 2, 6 and 18 weeks after implantation. After injection into the bone defect the cement set and formed a porous calcium phosphate structure. Two different calcium phosphate phases with different solubility rates could be identified by scanning electron microscopy (SEM) observation. The less-soluble fragments could be degraded by cell phagocytosis in cell compartments of low pH or integrated in the newly formed bone matrix. The degradation rate of the material was relatively high but compatible with the ingrowth of bone trabeculae within the resorbing material. The ossification process was different from the creeping substitution occurring at the ceramic contact. Bone did not form directly at the cement surface following the differentiation of osteoblasts at the material surface. The trabeculae came to the material surface from the edges of the implantation site. Bone formation in the implantation site was significantly higher than in the control region during the first week of implantation. In conclusion, this material set in situ was well tolerated, inducing a mild foreign-body reaction, which did not impair its replacement by newly formed bone within a few weeks.

Topics: Animals; Biocompatible Materials; Bone Cements; Calcium Phosphates; Diphosphates; Female; Mandibular Condyle; Microscopy, Electron, Scanning; Osteoblasts; Prostheses and Implants; Prosthesis Implantation; Rabbits; Surface Properties; Time Factors

In this paper, the high-temperature stabilized beta-tricalcium phosphate (betaTCP, beta-Ca3(PO4)2) were prepared by heating the deficient HAP (d-HAP, Ca10-x(HPO4)x(PO4)6-x(OH)2-x) with tetra-sodium diphosphate decahydrate (NP, Na4P2O7 x 10H2O) addition. The betaTCP, d-HAP and d-HAP doped with 2.5, 5, 7.5 and 10 wt % NP were heated to different temperatures and were investigated by X-ray diffraction analysis (XRD) and Fourier-transformed infrared spectroscopy (FTIR). The results demonstrated that the HPO4(2-) of d-HAP condensed into P2O7(4-) occurred before 650 degrees C. The P2O7(4-) ions could be traced in the FTIR spectrum when the d-HAP was heated up to 750 degrees C. The reaction of P2O7(4-) with OH- did not occur instantly but over a wide range of temperatures. The d-HAP doped with NP would decrease the decomposition temperature of d-HAP. NP doped into d-HAP not only induced the d-HAP decomposition at lower temperature but also stabilized the betaTCP crystal structure at higher-temperature. It could also increase the conversion temperature of betaTCP to alphaTCP from 1180 degrees C up to 1300 degrees C. We could successfully prepare high-temperature (up to 1300 C) stabilized ffTCP by heating NP doped d-HAP.

Topics: Calcium Phosphates; Diphosphates; Durapatite; Hot Temperature; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction

Autogenous bone transfer is an important part of reconstructive plastic surgery. Presently available techniques have the disadvantages of limitation of available donor site, loss of donor tissue and the possibility of donor defect or deformity. In the present study, a vascularized bone graft was created and cultured in the groin area of the New Zealand rabbit. The cylindrical ceramic chambers, 15 mm in length, 6 mm in outer diameter and 3 mm in inner diameter, were prepared by the addition of sintered porous beta-Ca2P2O7 with 5 wt% Na4P2O7.10H2O. In the first group, the chambers impregnated with autogenous bone fragments and allogenous demineralized bone matrix with volume ratio 1:1 were cultured in the rabbit's groin area with saphenous vessels passing through. In the second group, the chambers were treated by the same procedures as the first group but without saphenous vessels passing through. In the third group, the chambers were not impregnated, and were cultured in the groin area with saphenous vessels. After 2, 4, 6, 8 and 12 wk of operation, the animals were killed with an overdose of intravenous pentobarbital. The viability of the osseous tissue in the chamber was evaluated by histological examination, microangiograms and fluorochrome incorporation for the three groups. The autogenous bone chips could survive and retain their osteogenic properties while packed into the sintered porous beta-Ca2P2O7 (with 5 wt% Na4P2O7.10H2O addition) ceramic chamber and implanted in the rabbit groin area up to 12wk. However, even at the longest time periods, considerable amounts of dead bone were present in the chambers. In addition, we observed bone resorption in the three groups up to 12 wk, which might be attributed to lack of physiological stress. There were significant differences in new bone formation and osseous cell viability among the three groups. The prevascularized vessels and autogenous bone chips were both necessary for the formation of new bone and osteogenic property in the chamber under these heterotopic circumstances. The biodegradable ceramic used in this study was gradually absorbed and dissolved in the physiological environment. However, the degradation debris of the ceramic caused no injury to the new bone formation. These findings support the concept of creating a preformed vascularized bone graft to reconstruct segmental bone defects.

Topics: Animals; Biocompatible Materials; Bone and Bones; Bone Demineralization Technique; Bone Transplantation; Calcium Pyrophosphate; Cell Survival; Ceramics; Diphosphates; Histocytochemistry; Male; Rabbits

The addition of divalent cations such as Mg(2+) and Ca(2+) ions markedly reduced binding of a radiolabeled double stranded oligonucleotide probe for the transcription factor c-Myc in the presence of 100 mM KCl in nuclear extracts of the mouse whole brain. Irrespective of the addition of MgCl(2), binding was selectively competed with the unlabeled probe for c-Myc having a double stranded conformation. Treatment with V8 protease differentially modulated binding of the probe for c-Myc determined in the presence and absence of added MgCl(2). Introduction of irreversible covalent bonding between the radiolabeled probe and nuclear proteins led to retarded mobility of the radioactive probe/protein complex in the presence of MgCl(2) on sodium dodecyl sulfate electrophoresis regardless of treatment with DNase. However, an antibody against the c-Myc protein affected neither mobility nor intensity of the radioactive band on gel retardation electrophoresis. Moreover, regional distribution was different from each other in mouse brain when determined in the presence and absence of added MgCl(2). These results suggest that magnesium ions may have an ability to differentiate between nuclear c-Myc family proteins with different affinities for the consensus core nucleotide element CACGTG in murine brain.

Topics: Animals; Antibodies, Monoclonal; Binding, Competitive; Brain; Consensus Sequence; Diphosphates; Hydrolysis; Magnesium; Male; Mice; Mice, Inbred Strains; Nuclear Proteins; Oligonucleotide Probes; Proto-Oncogene Proteins c-myc; Transcription Factors; Ultraviolet Rays

The ultimate goal of implantation of biomaterials in the skeleton is to reach full integration of the non-living implant with the living bone. The biomaterial can be used much as a bone graft, resorbing or dissolving as bone growth occurs, and the end result is a new remoulded bone. Calcium pyrophosphate, Ca2P2O7, is one of the intermediate products of bone mineralization. beta-Dicalcium pyrophosphate (beta-DCP) doped with certain amounts of Na4P2O7.10H2O was prepared as the developed material. Na4P2O7.10H2O was used as a liquid-phase additive to improve the sintering process and promote physiological bioresorbability. Compressive strength and four-point bending strength were measured by the Bionix test system 858. The mechanical strength of the sintered beta-DCP increased with the addition of Na4P2O7.10H2O up to 5 wt%, but thereafter decreased. The microstructure and crystal structure were analysed by the techniques of SEM, EPMA, TEM and XRD. The relationship between the mechanical strength of the sintered bioceramics and the Na4P2O7.10H2O dopant was examined in terms of the presence of NaCa(PO3)3, grain growth and abnormal grain coalescence while the dopant increased. Preliminary in vivo evaluation was studied by rabbit femur condyle implantation. There was no inflammation or any toxic sign during the experimental period. The histological section of intraosseous implantation revealed that the new bone deposited directly on the surface of the material in the fourth week after operation. The implant gradually decreased in volume and was replaced by the surrounding regenerated bone in the rabbit condyle in vivo environment. The results led us to conclude that the developed material has great potential as a biodegradable bone substitute.

Topics: Animals; Bone and Bones; Bone Substitutes; Calcification, Physiologic; Calcium Pyrophosphate; Ceramics; Diphosphates; Femur; Male; Materials Testing; Microscopy, Electron; Microscopy, Electron, Scanning; Rabbits; Stress, Mechanical; Tensile Strength

Transfer RNA-guanine ribosyltransferase (TGRase) irreversibly incorporates queuine into the first position in the anticodon of four tRNA isoacceptors. Rat brain protein kinase C (PKC) was shown to stimulate rat liver TGRase activity. TGRase preparations derived from rat liver have been observed to decrease in activity over time in storage at -20 or -70 degrees C. Contamination of the samples by phosphatases was indicated by a p-nitrophenylphosphate conversion test. The addition of micromolar concentrations of the phosphatase inhibitors sodium pyrophosphate and sodium fluoride into TGRase isolation buffers resulted in a greater return of TGRase activity than without these inhibitors. Inactive TGRase preparations were reactivated to their original activity with the addition of PKC. In assays combining both TGRase and PKC enzymes, inhibitors of protein kinase C (sphingosine, staurosporine, H-7 and calphostin C) all blocked the reactivation of TGRase, whereas activators of protein kinase C (calcium, diacylglycerol and phosphatidyl serine) increased the activity of TGRase. None of the PKC modulators affected TGRase activity directly. Alkaline phosphatase, when added to assays, decreased the activity of TGRase and also blocked the reactivation of TGRase with PKC. Denaturing PAGE and autoradiography was performed on TGRase isolates that had been labelled with 32P by PKC. The resulting strong 60 kDa band (containing the major site for phosphorylation) and weak 34.5 kDa band (containing the TGRase activity) are suggested to associate to make up a 104 kDa heterodimer that comprises the TGRase enzyme. This was corroberated by native and denaturing size-exclusion chromatography. These results suggest that PKC-dependent phosphorylation of TGRase is tied to efficient enzymatic function and therefore control of the queuine modification of tRNA.

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Alkaloids; Animals; Brain; Buffers; Diphosphates; Enzyme Activation; Enzyme Reactivators; Enzyme Stability; Isoquinolines; Liver; Naphthalenes; Pentosyltransferases; Phosphoric Monoester Hydrolases; Piperazines; Protein Kinase C; Rats; Rats, Sprague-Dawley; Sodium Fluoride; Sphingosine; Staurosporine

Seven chemicals, three buffers, and a salt solution known to affect bacterial attachment were tested to quantify their abilities to enhance the penetration of Alcaligenes paradoxus in porous media. Chemical treatments included Tween 20 (a nonionic surfactant that affects hydrophobic interactions), sodium dodecyl sulfate (an anionic surfactant), EDTA (a cell membrane permeabilizer that removes outer membrane lipopolysaccharides), sodium PPi (a surface charge modifier), sodium periodate (an oxidizer that cleaves surface polysaccharides), lysozyme (an enzyme that cleaves cell wall components), and proteinase K (a nonspecific protease that cleaves peptide bonds). Buffers included MOPS [3-(N-morpholino)propanesulfonic acid], Tris, phosphate, and an unbuffered solution containing only NaCl. Transport characteristics in the porous media were compared by using a sticking coefficient, alpha, defined as the rate at which particles stick to a grain of medium divided by the rate at which they strike the grain. Tween 20 reduced alpha by 2.5 orders of magnitude, to alpha = 0.0016, and was the most effective chemical treatment for decreasing bacterial attachment to glass beads in buffered solutions. Similar reductions in alpha were achieved in unbuffered solutions by reducing the solution ionic strength to 0.01 mM. EDTA, protease, and other treatments designed to alter cell structures did not reduce alpha by more than an order of magnitude. The number of bacteria retained by the porous media was decreased by treatments that made A. paradoxus more hydrophobic and less electrostatically charged, although alpha was poorly correlated with electrophoretic mobility and hydrophobicity index measurements at lower alpha values.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Alcaligenes; Bacterial Adhesion; Buffers; Diphosphates; Edetic Acid; Endopeptidase K; Glass; Microspheres; Muramidase; Periodic Acid; Polysorbates; Serine Endopeptidases; Sodium Dodecyl Sulfate; Soil Microbiology; Water Microbiology

Topics: Aluminum Oxide; Citrates; Dentin Sensitivity; Diphosphates; Fluorides; Humans; Oxidants; Papain; Sodium Dodecyl Sulfate; Surface-Active Agents; Toothpastes

It is proposed that aging is induced by somatic replication of transposable elements (TEs). Most transposable elements in Drosophila reproduce by reverse transcription. Therefore inhibitors of reverse transcriptase were tested for their ability to retard aging in Drosophila melanogaster. Two inhibitors, phosphonoformic acid (PFA) and dideoxyinosine (ddI), were capable of prolonging life span when administered for the first half of the adult life. PFA was investigated further. It also produced a reduction in the rate of decline of behavior. PFA appeared not to act on an infectious agent in these experiments, nor did it alter the food intake. Analogues unable to inhibit RT had no life span prolonging effect at similar concentrations to that of PFA.

Topics: Aging; Animals; Dideoxyadenosine; Diphosphates; DNA Transposable Elements; Drosophila melanogaster; Feeding Behavior; Foscarnet; Life Expectancy; Oxalates; Reverse Transcriptase Inhibitors

F5 was identified originally as an interleukin-2-regulated gene in the murine helper T-lymphocyte clone L2. Subsequent studies demonstrated high levels of F5 mRNA and protein in mature neurons in adult mouse central and peripheral nervous systems. The F5 protein was present in dendrites and perikarya but not in axons. In the present studies, the intracellular localization of the F5 protein in adult mouse brain was determined by subcellular fractionation and Western blotting. Although the deduced F5 sequence predicts a soluble protein, virtually no F5 immunoreactivity was found in the cytosol. The F5 protein was restricted to the P2 crude mitochondrial and P3 crude microsomal particulate fractions. Within the P2 fraction, F5 protein was enriched in the P2B synaptosomal subfraction. The results of temperature-dependent phase separation with Triton X-114 and alkaline extraction with sodium carbonate of the P2 and P3 fractions were consistent with the F5 protein being an extrinsic membrane-associated protein. Although essentially all of the F5 protein in the P3 fraction was membrane-associated, a substantial proportion of P2-associated F5 protein and nearly all of the synaptosomal F5 protein was detergent-insoluble. Direct isolation and subfractionation of brain cytoskeleton confirmed colocalization of F5 immunoreactivity with the membrane-associated cytoskeleton and postsynaptic densities. These studies suggest that the F5 protein, which has a large number of potential phosphorylation sites, plays a role in membrane-cytoskeletal interactions and in dynamic aspects of synaptic structure or function.

Topics: Animals; Blotting, Western; Brain; Brain Chemistry; Cell Membrane; Cytoskeletal Proteins; Diphosphates; Mice; Mitochondria; Nerve Tissue Proteins; Neurons; Subcellular Fractions; Temperature

The availability and stability of the active ingredients in a Sensitive/Tartar Control dentifrice have been evaluated in this study. The Sensitive/Tartar Control dentifrice contains 5% potassium nitrate as the anti-hypersensitivity agent, 0.243% sodium fluoride as the anti-caries agent, 2% tetrasodium pyrophosphate and 1.5% polyvinylmethyl ether/maleic acid (PVM/MA) copolymer as the antitartar system. The availability of potassium and fluoride from this dentifrice was tested and found to be acceptable in both freshly prepared and aged samples. Fluoride and potassium availability were also tested at dilutions similar to in vivo brushing levels, and the ability of the Sensitive/Tartar Control dentifrice to provide fluoride to enamel and reduce enamel solubility was measured. In these tests the Sensitive/Tartar Control dentifrice performed similarly to commercial fluoride dentifrices. Potassium availability was equal to Crest Sensitivity Protection, a product shown to be clinically effective against tooth sensitivity; fluoride availability and activity was shown to be equal to Crest Tartar Control, a product with published clinical anti-caries effectiveness.

Topics: Analysis of Variance; Biological Availability; Dental Enamel; Dental Enamel Solubility; Dentifrices; Diphosphates; Drug Combinations; Drug Stability; Fluorides; Humans; Maleates; Nitrates; Polyethylenes; Potassium; Potassium Compounds; Sodium Fluoride; Solubility

Genetic and biochemical studies have established that the sole function of the Escherichia coli DnaJ, DnaK, and GrpE heat shock proteins in plasmid P1 DNA replication is to convert RepA dimers to monomers. Monomers bind avidly to oriP1 DNA and initiate DNA replication. However, with purified heat shock proteins, only DnaJ, DnaK, and ATP were required for the monomerization of RepA; GrpE was not required. We have found reaction conditions that mimic the physiological situation. GrpE function is absolutely necessary for RepA activation in vitro with DnaJ and DnaK when the free Mg2+ concentration is maintained at a level of approximately 1 microM by a metal ion buffer system. EDTA or physiological metabolites, including citrate, phosphate, pyrophosphate, and ATP, all elicit the GrpE requirement. With these metal ion-buffering systems, GrpE specifically lowers the concentration of Mg2+ required for the RepA activation reaction. The absence of Mg2+ blocks activation and high levels of Mg2+ in solution bypass the requirement for GrpE but not for the other two heat shock proteins. Our results imply that GrpE facilitates the utilization of Mg2+ for an essential step in RepA activation.

Topics: Bacterial Proteins; Diphosphates; DNA Helicases; DNA Replication; DNA-Binding Proteins; Edetic Acid; Escherichia coli; Escherichia coli Proteins; Heat-Shock Proteins; HSP40 Heat-Shock Proteins; HSP70 Heat-Shock Proteins; Kinetics; Macromolecular Substances; Magnesium; Magnesium Chloride; Plasmids; Proteins; Trans-Activators

Oral delivery and clearance of Triclosan and zinc were studied following use of three commercially available Triclosan-containing toothpastes. One paste contained 0.3 per cent Triclosan and 2 per cent PVM-MA copolymer, one contained 0.3 per cent Triclosan and 5 per cent sodium pyrophosphate and the third contained 0.3 per cent Triclosan and 0.75 per cent zinc citrate trihydrate. Each gave similar total oral retention of Triclosan (37 per cent-46 per cent of the dose). However, clinically important product differences were observed in the salivary clearance of Triclosan and in Triclosan delivery to plaque. The Triclosan/zinc paste delivered more Triclosan to oral reservoirs (as measured by the area under the salivary clearance curve) than either the Triclosan/PVM-MA or the Triclosan/pyrophosphate paste (p < 0.001). The Triclosan/zinc paste produced higher Triclosan levels in plaque than the Triclosan/PVM-MA paste (109 micrograms/g versus 78 micrograms/g, p < 0.05). Zinc was effectively delivered to oral surfaces by the Triclosan/zinc paste, and was cleared more slowly than Triclosan (single-reservoir t1/2 = 50 min). After use of the Triclosan/zinc paste the zinc level in plaque was 153 micrograms/g, a seven-fold increase over the control. These results demonstrate that good delivery of Triclosan requires a highly optimised formulation. Furthermore, they suggest that the superior clinical effects of the Triclosan/zinc paste are due to a combination of superior delivery of Triclosan to oral sites of action together with effective delivery of a second, complementary antiplaque agent, zinc.

Topics: Adult; Citrates; Citric Acid; Dental Plaque; Dentifrices; Diphosphates; Female; Humans; Male; Maleates; Middle Aged; Mouth; Polyvinyls; Saliva; Triclosan; Zinc

The environment of the multi-manganese center in the O2-evolving complex (OEC) of plant photosystem II (PS II) under conditions of Ca2+ depletion has been probed using pulsed electron paramagnetic resonance (EPR) spectroscopy, and the following results are reported: (1) In Ca(2+)-depleted PS II membranes treated with the chelator [ethylenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA), the modified Mn EPR signal arising from the OEC in the S2 state and the split EPR signal from the S3 state could be detected in the absorption mode by recording the amplitude of a two-pulse echo as a function of the external magnetic field. The formation of the S3 signal (g approximately 2.004; delta Hpp = 164 G) is not accompanied by the disappearance of the Mn EPR signal, although the signal becomes difficult to detect in CW EPR. This result supports the previous interpretation of the split S3 EPR signal as arising from the interaction of an organic radical with the Mn cluster [Boussac, A., Zimmermann, J. L., Rutherford, A. W., & Lavergne, J. (1990) Nature 347, 303-306]. (2) The two-pulse electron spin echo envelope modulation (ESEEM) spectra of the S2 state formed in Ca(2+)-depleted PS II membranes obtained from 14N- and 15N-labeled material are different. This indicates that nitrogen nuclei from nitrogen-containing protein residues are coupled to the Mn center in the S2 state of the inhibited enzyme. In addition, comparison with the two-pulse ESEEM data obtained for the S2 state in the untreated enzyme suggests that the coupling may be altered by the Ca2+ depletion and/or EGTA treatment. (3) The treatment of Ca(2+)-depleted PS II membranes with sodium pyrophosphate also induced a stable S2 state characterized by a modified multiline EPR signal that is similar to that obtained in EGTA-treated PS II membranes. Comparison of the ESEEM data obtained for the pyrophosphate and 14N and 15N samples treated with EGTA suggests that the modification induced by the EGTA treatment is accompanied by the binding of (an) EGTA molecule(s) to or near the Mn center. (4) ESEEM data obtained for the S3 state formed in the pyrophosphate or EGTA-treated enzyme are quite similar to those obtained for the corresponding S2 state. The data are also compared with ESEEM data obtained on oxidized 4(5)-methylimidazole obtained by UV irradiation. These results are discussed with respect to the current assignment of the S3 radical as arising from oxidation of a histidine residue.

Topics: Calcium; Diphosphates; Egtazic Acid; Electron Spin Resonance Spectroscopy; Histidine; Manganese; Metalloproteins; Nitrogen Isotopes; Oxidation-Reduction; Oxygen; Photosynthetic Reaction Center Complex Proteins; Photosystem II Protein Complex; Plants, Edible

During development of a ranitidine effervescent oral solution dosage form, a marked decrease was observed in the extent of ranitidine absorption relative to the conventional oral tablet. Two studies were conducted in healthy volunteers to confirm the involvement of an excipient, SAPP (sodium acid pyrophosphate), and the mechanism of interaction, altered gastrointestinal transit. The first study (n = 12) involved single-dose crossover comparisons of (A) 150 mg ranitidine with 1132 mg SAPP versus (B) 150 mg ranitidine and (C) 150 mg ranitidine with all the effervescent tablet excipients except SAPP versus (D) a 150-mg ranitidine effervescent tablet, all administered as oral solutions. Serum ranitidine AUC, Cmax, and tmax were compared using two one-sided t test 90% confidence intervals (CI). Comparing treatments A to B and D to C, all 90% CI were below the 80-120% range, indicating significantly less extensive ranitidine absorption (54% based on AUC) from the oral solutions containing SAPP. The second study (n = 12) was a single-dose crossover comparing 50 microCi 111 InCl solutions with and without 1132 mg SAPP. Gastrointestinal transit times, determined by scintigraphic imaging, were compared between treatments. Gastric emptying time was unchanged, but small intestinal transit time was decreased to 56% in the presence of SAPP. More rapid small intestinal transit associated with an excipient of a solution dosage form apparently resulted in a decreased extent of ranitidine absorption. This observation contradicts the conventional wisdom that oral solutions are unlikely to fall short of bioequivalence relative to solid oral formulations.

Topics: Adult; Biological Availability; Chromatography, High Pressure Liquid; Diphosphates; Gastrointestinal Transit; Humans; Indium Radioisotopes; Intestinal Absorption; Male; Ranitidine; Solutions; Spectrophotometry, Ultraviolet; Tablets

Membranes of cultured newborn rat cardiomyocytes contain enzymatic activities that regulate the formation and the breakdown of inositol 1,4,5-trisphosphate (1,4,5-IP3). GTP gamma S increased the rate of exogenous [3H]phosphatidyl 4,5-bisphosphate ([3H]PIP2) hydrolysis (EC50: 40 microM). This effect was dependent on the presence of deoxycholate and maximal at 2 mM deoxycholate. GTP gamma S increased the efficacy of phospholipase C (PLC) (by 2.3-fold), but did not alter the apparent affinity of the enzyme for PIP2. Other nucleotides, GDP beta S and ATP gamma S, and pyrophosphate also stimulated PIP2 hydrolysis, while AlF4- was ineffective. The effect of GTP gamma S was not inhibited by GDP beta S. The agonists norepinephrine and thrombin, which by themselves had no effect, did not potentiate the response to GTP gamma S. In contrast, 1,4,5-IP3 hydrolysis was decreased by GTP gamma S (EC50: 100 microM) as well as by other nucleotides and by pyrophosphate, but not by AlF4-. GDP beta S did not antagonize the GTP gamma S-induced inhibition of IP3 hydrolysis. These results suggest that GTP can stimulate the hydrolysis of exogenous PIP2 by an action on membrane-bound PLC at a site beyond the G protein activating PLC and inhibit the hydrolysis of 1,4,5-IP3 by a mechanism common to all nucleotides. Thus, GTP can regulate 1,4,5-IP3 metabolism by stimulating its formation and inhibiting its breakdown.

Topics: Adenosine Triphosphate; Aluminum; Animals; Animals, Newborn; Cell Membrane; Cells, Cultured; Diphosphates; Fluorine; Guanine Nucleotides; Guanosine Triphosphate; Heart; Hydrolysis; Inositol 1,4,5-Trisphosphate; Inositol Phosphates; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Rats; Rats, Inbred Strains; Type C Phospholipases

In vivo NMR spectroscopy is often complicated with problems of low signal-to-noise, poor resolution, undefined peak shapes, and nonlinear baselines despite the efforts of investigators to optimize their experiments. Several data processing options are available to spectroscopists to enhance resolution and signal-to-noise and/or to flatten baselines. There is some question about how these processing protocols affect quantitative information. This paper evaluates five different processing protocols for their ability to extract quantitative information from a set of nonideal spectra. Three of the protocols involve recently developed statistical signal processing methods, maximum entropy Fourier spectral deconvolution, linear prediction singular value decomposition, and baseline deconvolution. These protocols are compared with the conventional processing methods of convolution difference and zeroing initial data points of the FID. The methods are evaluated by use of a quantitative 31P model sample and also are demonstrated on surface coil 31P data.

Topics: 2,3-Diphosphoglycerate; Adenosine Triphosphate; Animals; Brain Chemistry; Diphosphates; Diphosphoglyceric Acids; Image Enhancement; Image Processing, Computer-Assisted; Liver; Magnesium Chloride; Magnetic Resonance Spectroscopy; Models, Biological; Muscles; Phosphocreatine; Phosphorus; Rats

This paper reports the effectiveness of 0.1% (W/V) quinoline-8-ol, 0.5% (V/V) phosphoric acid and 0.5% (W/V) sodium pyrophosphate as stabilizers of stock solutions on peracetic acid. The three solutions were put separately as stabilizers into stock solutions of peracetic acid in the laboratory. They were stored at room temperature for approximately one year, and the percent of peracetic acid content was determined at regular intervals. Also, we made studies on different concentrations of phosphoric acid for different prescriptions of peracetic acid. The results show that 0.1%, 0.3% and 0.5% (V/V) phosphoric acid and 0.5% (W/V) sodium pyrophosphate were not effective stabilizers for the stock solutions of peracetic acid. Therefore, phosphoric acid or sodium pyrophosphate is not an effective stabilizer in stockpiling stock solutions of peracetic acid.

Topics: Diphosphates; Drug Stability; Excipients; Oxyquinoline; Peracetic Acid; Phosphoric Acids

The enzyme reverse transcriptase (RT) is crucial in the early steps of the life cycle of retroviruses. We have expressed in bacteria the RTs from human immunodeficiency viruses (HIV) types 1 and 2 in order to study the structural-functional relationships of these two multifunctional enzymes that share a relatively high degree of amino acid sequence homology. For comparison purposes, we have analyzed several catalytic functions of both enzymes. The two HIV RTs show a high similarity in many aspects studied but exhibit profound differences in several other properties. For instance, the specific RNase H activity of HIV-2 RT is about 10 times lower than the corresponding activity of HIV-1 RT. There are also significant dissimilarities between some of the apparent Km values calculated for the DNA polymerizing functions of both enzymes. Furthermore, the heat stability of the DNA polymerizing activity of HIV-2 RT is about 15-fold higher than that of HIV-1 RT. On the other hand, the susceptibility of the RNase H activities of the two enzymes to heat inactivation was found to be similar. Other treatments also enable discrimination between the RNase H and DNA polymerizing catalytic properties of the two enzymes (although both reverse transcriptases respond similarily). Thus, the RNase H activity was inactivated by N-ethylmaleimide, suggesting the possible involvement of cysteine residues in performing this activity, whereas the DNA polymerizing functions of the two enzymes were fully resistant to this chemical modification. The zinc chelator 1,10-phenanthroline affected the DNA polymerase activities of both enzymes to a significantly higher extent than the RNase H activity. In all, the two HIV RTs were shown to be substantially different one from the other in several of their properties and also distinct from other RTs thus far studied.

Topics: Catalysis; Diphosphates; DNA-Directed DNA Polymerase; Endoribonucleases; Escherichia coli; Ethylmaleimide; Gene Expression Regulation, Bacterial; Genes, Bacterial; HIV-1; HIV-2; Hot Temperature; Hydrogen-Ion Concentration; Phenanthrolines; Pyridoxal Phosphate; Reverse Transcriptase Inhibitors; Ribonuclease H; RNA-Directed DNA Polymerase; Rose Bengal

A restriction map of phi A7 DNA (46.7 kb) was established for nine endonucleases (BclI, ClaI, EcoRI, EcoRV, HpaI, PvuI, SacII, SphI and XbaI) which cut the phage genome up to 11 times. There was no sites for BamHI, BglII, HindIII, PstI, PvuII, SacI or SalI. phi A7 DNA, circularized through its cohesive ends, could integrate into the genome of several Streptomyces hosts, to form stable lysogens. Integration occurred by recombination between unique attachment sites on the phage (attP) and the host (attB) genomes. The attP site has been located on the phi A7 restriction map. Deletion mutants of phi A7 DNA were obtained by selecting for pyrophosphate- or EDTA-resistant clones. The deletions occurred either near the left-hand end of the conventional restriction map, or about 18 kb from the right-hand end, close to, but not affecting the unique SacII site. Together, the deletions defined at least 7.9 kb of DNA (16.9% of the phage genome) non-essential for plaque formation. phi A7 DNA was introduced into S. lividans protoplasts by liposome-assisted transfection. Since the phage does not adsorb to intact cells of this strain, and therefore does not form plaques, an overlay of S. antibioticus spores was used to detect the infectious progeny released by the protoplasts. Using this technique, phi A7 could be introduced into S. antibioticus with an efficiency of about 6 x 10(6) p.f.u. per micrograms DNA (equivalent to 3 x 10(-4) p.f.u. per DNA molecule).

Topics: Attachment Sites, Microbiological; Bacteriophages; Diphosphates; DNA, Viral; Edetic Acid; Lysogeny; Mutation; Restriction Mapping; Streptomyces; Streptomyces antibioticus; Transfection; Viral Plaque Assay

Calculus plays an important role in chronic inflammatory periodontal diseases. Currently, there is much interest in dentifrices that have the capacity to reduce the formation of calculus. Recent clinical studies have indicated that dentifrices containing soluble pyrophosphate and sodium fluoride can reduce the formation of supragingival calculus. The purpose of this study was to compare the effect on supragingival calculus of a dentifrice containing soluble pyrophosphate and 0.24% sodium fluoride to a placebo dentifrice. Thirty five subjects were stratified into balanced groups based on initial calculus scores. They then received an oral prophylaxis and were assigned to the use of either the placebo or soluble pyrophosphate/sodium fluoride dentifrice for the next 3 months. The results from the 3-month examinations indicated that the dentifrice containing the soluble pyrophosphate and sodium fluoride did not significantly reduce supragingival calculus as compared to the placebo dentifrice. However, both dentifrices reduced the calculus significantly.

Topics: Dental Calculus; Dentifrices; Diphosphates; Humans; Sodium Fluoride

Soluble pyrophosphate (PP) has been introduced in dentifrices to inhibit the formation of dental calculus. The mechanism of inhibition is probably an adsorption of the pyrophosphate ions to the Ca-sites on the enamel surfaces and a blocking of the active sites for crystal growth. It has been shown in a recently published study that PP reduced the protein adsorption to hydroxyapatite (HA) in vitro and also inhibited the pellicle formation in vivo. The aim of the present study was to examine the desorption potential of pyrophosphate on the acquired enamel pellicle in vivo. Enamel fragments were carried in the mouth to collect pellicle material and some of the enamel surfaces were then treated with PP. Pellicle formation was examined by SEM of the enamel surfaces. The results showed that pyrophosphate desorbed the acquired enamel pellicle effectively. The clinical consequences of this effect is unknown, but it could possibly explain some aspects of hypersensitivity of teeth observed in some individuals using dentifrices containing PP.

Topics: Adsorption; Binding, Competitive; Calcium; Dental Deposits; Dental Enamel; Dental Pellicle; Diphosphates; Humans; Microscopy, Electron, Scanning; Mouthwashes; Salivary Proteins and Peptides

Longissimus muscle sections were excised from eight pork carcasses 1 h postmortem and sectioned into six .5-kg roasts to determine the effects of glucose, salt and polyphosphates (aqueous solution to 110% of fresh weight) on palatability of hot-boned pork. Treatments were hot-boned control (HB) with no infusion or infusions of 2% KCl and 3% of a 1:1 mixture of sodium hexametaphosphate and sodium pyrophosphate (PP) plus either 8% NaCl; 2% glucose (G) plus 6% NaCl; 6% G plus 2% NaCl; or 8% G. Another muscle section was chilled at 0 degrees C for 24 h on each carcass as a cold-processed control (CP). The roasts were frozen until cooked and evaluated by a sensory panel. The infused groups were more tender, juicy and salty and higher in moisture and ash but lower in protein content than either the CP or HB controls (P less than .05). The fat content of the infused groups was lower than of the HB control but was not different from that of the CP control. Either 2% NaCl plus 6% G or equal amounts (4%) of NaCl and G produced the most tender and juicy product. The substitution of 4% glucose for NaCl not only reduced the NaCl content of the infusion solution, but also improved the palatability of the meat. This substitution allows production of a hot-boned, lower-sodium precooked pork that is tender and juicy.

Topics: Animals; Chlorides; Diphosphates; Food Handling; Glucose; Male; Meat; Muscles; Phosphates; Polyphosphates; Potassium Chloride; Sodium Chloride; Swine; Taste

Hypophosphatemia complicating parathyroidectomy for secondary hyperparathyroidism in renal failure is usually corrected by the oral or intravenous routes. We present a case in which those methods of treatment were not possible, and the phosphate was administered intraperitoneally. Phosphate was added as one molar sodium diphosphate solution to the dialysis fluid. In our case the procedure was well tolerated, phosphate blood levels were rapidly corrected, no alterations in calcium, magnesium or other parameters were detected and the patient was discharged in good condition. In selected cases of hungry bone syndrome after parathyroidectomy, intraperitoneal phosphate can be used safely.

Topics: Adult; Chronic Kidney Disease-Mineral and Bone Disorder; Dialysis Solutions; Diphosphates; Female; Humans; Hyperparathyroidism, Secondary; Kidney Failure, Chronic; Parathyroidectomy; Peritoneal Dialysis; Phosphates

Sorbitol dehydrogenase (EC 1.1.1.14) was isolated from bovine brain and purified 3,000-fold to apparent homogeneity, as judged by polyacrylamide gel electrophoresis. The purified enzyme had a specific activity of 36 units/mg of protein; a molecular weight of 39,000 for each of the four identical subunits and 155,000 for the intact enzyme were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel exclusion chromatography, respectively. The presence of one Zn2+ per subunit was confirmed by atom absorption spectroscopy; inactivation of the enzyme by metal-chelating agents points to the essential role that Zn2+ plays in the catalytically competent enzyme. The enzyme is also inactivated by thiol-blocking reagents; with respect to inactivation by sodium pyrophosphate, sorbitol dehydrogenase is different from closely related alcohol dehydrogenase.

Topics: Aldehyde Reductase; Animals; Brain; Cattle; Chelating Agents; Chromatography, Gel; Diphosphates; Electrophoresis, Polyacrylamide Gel; Hydrogen-Ion Concentration; Kinetics; L-Iditol 2-Dehydrogenase; Macromolecular Substances; Molecular Weight; NAD; Spectrophotometry, Atomic; Sugar Alcohol Dehydrogenases; Sulfhydryl Reagents; Zinc

Calcium-containing crystals and elevated levels of calcium chloride (CaCl2) and lanthanum chloride (LaCl3) have been previously reported to enhance the proliferative activity of cultured fibroblasts. We have investigated the relative mitogenicity of these agents, whether they function via precipitation on the cell surface and whether they interact with one another. Confluent cultures of newborn foreskin fibroblasts provided with fresh medium containing 10% fetal bovine serum (FBS) in the presence of hydroxyapatite (HA), pyrophosphate (PPi), LaCl3 (La), or additional CaCl2 (Ca) were all stimulated more than control cultures provided with fresh medium and 10% FBS alone as assessed by cell counts 5 days later. Increases in cell yield above the original confluent cell density were 316% for La, 271% for Ca, 189% for HA, 131% for PPi, and 45% for controls. Addition of fresh medium containing 10% FBS and epidermal growth factor or fresh medium containing 20% FBS as additional points of reference yielded increases of 204 and 107%, respectively, over original confluent density. Stimulation induced by La or Ca was significantly greater (P less than 0.001) than the stimulation induced by each of the other treatments. The same treatments added to confluent cultures without a change of medium also renewed mitotic activity, with La and Ca again the most mitogenic and approximately doubling the pretreatment cell yields. Cultures incubated in an inverted position to avoid cell contact with precipitates in the medium were also stimulated by La and Ca, but not by HA and PPi. When added to confluent cultures simultaneously supplemented with optimal additional Ca, La decreased Day 5 cell yields in a dose-dependent manner at low concentrations (0.03-0.2 mM) but increased cell yields over those obtained with 0.2 mM LaCl3 again in a dose-dependent manner at higher concentrations. Thus, while HA and PPi act via precipitation on the cell surface, the more mitogenic agents La and Ca function in solution and appear to stimulate cell division by different nonadditive mechanisms. These findings suggest multiple mechanisms of membrane participation in mitogen responsiveness and in density-dependent inhibition of growth.

Topics: Calcium Chloride; Cell Division; Cells, Cultured; Diphosphates; Durapatite; Fibroblasts; Humans; Hydroxyapatites; Infant, Newborn; Lanthanum; Male; Mutagens; Skin

Tubulin phosphorylation was analyzed during the different phases of platelet activation. Platelets preloaded with [32P]-phosphate were stimulated with collagen. Tubulin was immunoprecipitated from serial samples obtained during the activation process. The immunoprecipitates were resolved by SDS-polyacrylamide gel electrophoresis and autoradiographs analyzed by laser densitometry. Agonist induced dephosphorylation of platelets occurred after the onset of shape change at the time of initiation of the secretory release. The dephosphorylation was selective affecting specific peptides.

Topics: Adenosine Triphosphate; Autoradiography; Blood Platelets; Collagen; Cyanogen Bromide; Densitometry; Diphosphates; Electrophoresis, Polyacrylamide Gel; Humans; Immunosorbent Techniques; Kinetics; Phosphates; Phosphorylation; Platelet Aggregation; Tubulin

The inhibitory capacity of pyrophosphate, citrate, magnesium and chondroitin sulphate was investigated, using the urine of 21 calcium oxalate stone-forming patients without metabolic alterations. The inhibitory effect of these substances was assessed by a combination of nephelometry (light scattering) and optical microscopy. The results showed that citrate and magnesium had an inhibitory effect in a significant number of cases. Pyrophosphate and chondroitin sulphate had a less marked effect. The main urinary lithogenic biochemical parameters of the patients were also studied to see if there was a relationship between them and the inhibitory capacity of the compounds.

Topics: Calcium Oxalate; Chondroitin; Chondroitin Sulfates; Citrates; Citric Acid; Crystallization; Diphosphates; Humans; Magnesium; Urinary Calculi

Phospholipase A2 activity is raised in non-lesional psoriatic epidermis compared with normal epidermis. It has been shown that the activity of this enzyme is controlled by an inhibitory protein the inhibitory effect of which is increased by dephosphorylation. Treatment of epidermal extracts with alkaline phosphatase reduced the phospholipase A2 activity, both in normal and in lesion-free psoriatic epidermis. Inclusion of pyrophosphate, a protein phosphatase inhibitor, in the homogenizing medium caused the activity of phospholipase A2 in epidermal extracts from normal and lesion-free epidermis to be raised to the same high level. These results are consistent with the hypothesis that the raised phospholipase A2 activity in psoriatic epidermis is due to hyperphosphorylation of an endogenous inhibitor as a result of defective control of a phosphorylation/dephosphorylation mechanism. The relevance of these findings to other work is discussed.

Topics: Alkaline Phosphatase; Diphosphates; Epidermis; Humans; Phospholipases; Phospholipases A; Phospholipases A2; Phosphoprotein Phosphatases; Psoriasis; Skin

In the course of muscle differentiation, changes in fibre-type population and in myosin composition occur. In this work, the expression of native myosin isoforms in developing fast-twitch (posterior latissimus dorsi; PLD) and slow-tonic (anterior latissimus dorsi; ALD) muscles of the chick was examined using electrophoresis under nondissociating conditions. The major isomyosin of 11-day-old embryonic PLD comigrated with the adult fast myosin FM3. Two additional components indistinguishable from adult fast FM2 and FM1 isomyosins appeared successively during the embryonic development. The relative proportion of these latter isoforms increased with age, and the adult pattern was established by the end of the 1st month after hatching. Between day 11 and day 16 of embryonic development, PLD muscle fibres also contained small amounts of slow isomyosins SM1 and SM2. This synthesis of slow isoforms may be related to the presence of slow fibres within the muscle. At all embryonic and posthatch stages, ALD was composed essentially of slow isomyosins that comigrated with the two slow components SM1 and SM2 identified in adult. Several studies have reported that the SM1:SM2 ratio decreases progressively throughout embryonic and posthatching development, SM2 being predominant in the adult. In contrast, we observed a transient increase in SM1:SM2 ratio at the end of embryonic life. This could reflect a transitional neonatal stage in myosin expression. In addition, the presence in trace amounts of fast isomyosins in developing ALD muscle could be related to the presence of a population of fast fibres within this muscle.

Topics: Animals; Chick Embryo; Chickens; Diphosphates; Electrophoresis, Polyacrylamide Gel; Muscle Contraction; Muscle Development; Muscles; Myosins

Experimentally adsorbed bacteriophage f2 was eluted from clay particles in estuarine water using 1% Tween, 80.3% beef extract, and 0.3 M NaNO3 with 54% recovery. Replacing sodium nitrate with tetrasodium pyrophosphate (0.4 M) increased the recovery to 81%. Estuarine sediments treated with 1% Tween 80 revealed significantly higher male-specific phage elutions.

Topics: Adsorption; Animals; Bentonite; Cattle; Coliphages; Diphosphates; Kaolin; Meat Products; Nitrates; Polysorbates; Water Microbiology

The aim of the present study was to examine a sodium fluoride anticalculus dentifrice product containing soluble pyrophosphate for its ability to promote remineralization and/or inhibit demineralization of dental enamel in a pH cycling model in vitro. Enamel crowns with windows were subjected to 14 days of alternating demineralization and remineralization periods at 37 degrees C. Teeth were immersed 5 min daily in one of the test dentifrice systems (1:3 slurry in deionized water) between the demineralization and remineralization cycles. Test dentifrices included (1) sodium fluoride (NaF; 1,100 ppm F)/silica abrasive (Crest) and (2) NaF (1,100 ppm F) with 3.3% soluble pyrophosphate/silica abrasive (Crest Tartar Control). Controls included a placebo dentifrice (silica abrasive) with no added fluoride and a group which received no treatment at all, i.e., demineralization/remineralization only. Overall, both of the NaF dentifrices were very effective in limiting in vitro caries progression and were not significantly different from each other. Inclusion of pyrophosphate in the NaF dentifrice did not affect the net outcome of the cycling demineralization/remineralization processes which is in agreement with recent clinical and in situ studies of these products.

Topics: Dental Calculus; Dental Caries; Dental Enamel; Dental Enamel Solubility; Dentifrices; Diphosphates; Hardness; Humans; Hydrogen-Ion Concentration; Sodium Fluoride; Tooth Remineralization

Topics: Animals; Dental Calculus; Diphosphates; Polyphosphates; Rats

The self-assembly of myosin in the presence of sodium pyrophosphate was studied in the pH range between 7.0 and 8.5. As evidenced by sedimentation velocity (S0(20,w) = 6.30 S) and light-scattering measurements (molecular weight of 470 000; radius of gyration = 45 nm), myosin existed in a predominantly monomeric form in the presence of 5 mM sodium pyrophosphate at pH 8.5 and above. The concentration-dependent monomer-dimer equilibrium could be easily shifted toward dimeric species at pH 8.0 in the presence of 5 mM sodium pyrophosphate and 5 mM 2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)-1,3-propanediol. The estimated parameters of the dimeric particles were S0(20,w) between 10 and 11 S, molecular weight of 1.1 X 10(6), and radius of gyration = 52 nm. These results are consistent with a head to tail (parallel) arrangement of staggered myosin molecules in the dimer. At lower pH values (7.5), and in the presence of 10 mM sodium pyrophosphate, the monomer-dimer species were in dynamic equilibrium with myosin minifilaments. At pH 7.0, the minifilaments appeared to be the only detectable species present in solutions of myosin in 5 mM sodium pyrophosphate. The molecular parameters of these minifilaments, including sedimentation and viscosity coefficients, molecular weight, radius of gyration, and morphological appearance, were almost indistinguishable from those obtained for myosin minifilaments prepared in 10 mM citrate-tris(hydroxymethyl)aminomethane at pH 8.0 [Reisler, E., Smith, C., & Seegan, G. (1980) J. Mol. Biol. 143, 129-145]. The equilibrium polymerization reactions of myosin in sodium pyrophosphate are discussed in the context of minifilament assembly.

Topics: Animals; Diphosphates; Hydrogen-Ion Concentration; Kinetics; Macromolecular Substances; Muscles; Myosins; Rabbits; Scattering, Radiation; Viscosity

Topics: Dental Calculus; Dental Caries; Dental Enamel; Dentifrices; Diphosphates; Fluorides; Humans; Sodium Fluoride

The effects of two pH levels (5.55 or 5.85) in combination with 0.4% sodium acid pyrophosphate (SAPP), NaH2PO4 X H2O, Na2HPO4 X 7H2O, or NaCl on the growth and toxicity of Clostridium botulinum 52A were studied. Absorbancy measurements at 630 nm, microscopic observations, and the mouse bioassay procedure were used to observe the effects. At pH 5.55 and 5.85 most control cultures exhibited toxicity when cell lysis began. Vegetative cell development was normal (4 micron long; 1 micron wide). SAPP-containing (0.4%) treatment cultures displayed similar growth and lysis but no or delayed (48 h) toxicity. Cells grown in the SAPP treatment culture were longer and wider (6 micron long; 1.5 micron wide) than in most other treatment cultures. Trypsinization of nontoxic supernatants from 0.4% SAPP resulted in toxicity. Addition of 0.4% SAPP to toxic C. botulinum supernatant delayed but did not prevent death of mice. The addition of various levels of SAPP to toxic supernatants resulted in a decrease in zone size with an increase in the level of SAPP (9 mm with 0.4% SAPP to 7 mm with 1.0% SAPP), using a dual substrate protease assay. A decrease in the zone size also occurred with the supernatant from cultures grown in the presence of SAPP and with Bacillus polymyxa protease dilutions containing 0.4% SAPP. Results suggest that the actual production or function of the protease responsible for toxin activation may have been inhibited by the presence of SAPP.

Topics: Botulinum Toxins; Clostridium botulinum; Diphosphates; Hydrogen-Ion Concentration; Microscopy, Phase-Contrast; Phosphates; Protease Inhibitors; Sodium Chloride; Trypsin

Treatment with phosphates, thiazides and allopurinol was undertaken in 54 idiopathic calcium oxalate stone formers, 38 of whom were recurrent stone formers. The patients were followed up for 1 1/2 to 4 years (mean 2.6). During the same period at the pre-treatment stage the patients formed 80 stones, but during therapy only one stone was formed. A dynamic scheme of therapy was used. Each patient was tested before the start of drug treatment by the discriminant index (DI) method, which measures the overall inhibitory potential to calcium oxalate crystallisation. About 10 days after the start of treatment the DI was tested again. If the response was positive, therapy was continued; if not, the patient was given another drug. Adjustments were made as required. The stopping of stone formation correlated well with the DI prediction but less well with the hypocalciuric effect of the drugs.

Topics: Adult; Aged; Allopurinol; Calcium; Calcium Oxalate; Chlorothiazide; Diphosphates; Female; Follow-Up Studies; Humans; Kidney Calculi; Male; Middle Aged; Recurrence; Uric Acid

Four chemical buffers were evaluated with in vitro rumen fermentation studies using both an 80% concentrate and a 50% roughage diet. Treatments included a positive control (PC), negative control (NC) and four buffered diets in which 500 mg of either CaHPO4, CaCO3, NaHCO3 or Na4P2O7 were added. The PC consisted of unbuffered diet with one part rumen fluid and four parts McDougall's artificial saliva. In the unbuffered NC and buffered treatments, three-fourths of the artificial saliva was replaced by iso-osmotic saline. In the concentrate-based diet, NaHCO3 and Na4P2O7 elevated (P less than .05) pH above the NC. Starch digestion and total VFA were increased (P less than .05) by NaHCO3 compared with the NC while the molar proportion of individual VFA was not altered. Tetrasodium pyrophosphate had no effect on starch digestion or total VFA, but did increase (P less than .05) the molar proportion of acetic acid. Regarding the 50% roughage diet, both NaHCO3 and Na4P2O7 elevated (P less than .05) starch and cellulose digestion and total VFA compared with the NC. Both NaHCO3 and Na4P2O7 increased (P less than .05) the molar proportion of acetate to equal that of the PC. Tetrasodium pyrophosphate decreased (P less than .05) apparent starch digestion compared with the NC, but increased (P less than .05) the molar proportion of acetate. Compared with the NC, CaHPO4 and Na4P2O7 increased the quantity of microbial alpha-amino N in both diets. Soluble P was highly correlated with microbial protein synthesis in both the concentrate- and roughage-based diets (.92 and .90, respectively).

Topics: Ammonia; Animals; Bacteria; Bacterial Proteins; Bicarbonates; Buffers; Calcium Carbonate; Calcium Phosphates; Cattle; Cellulose; Dietary Fiber; Dietary Proteins; Digestion; Diphosphates; Fatty Acids, Volatile; Fermentation; Hydrogen-Ion Concentration; In Vitro Techniques; Nitrogen; Rumen; Sodium Bicarbonate; Starch

Incubation of the simian virus 40 (SV40) large tumor antigen (T) from either transformed or lytically infected cells with adenosine [8-3H]-, [alpha-32P]-, or [alpha-[35S]thio]-triphosphate in the presence of Mg2+ resulted in its labeling as defined by the appearance of an intact, appropriately immunoreactive band in NaDodSO4/polyacrylamide gels. Radioactivity remained associated with the protein after boiling in buffer containing 3% NaDodSO4, and 2-mercaptoethanol as well as after heating in 0.1 M HCl, 0.1 M NH4OH, or hydroxylamine, but it was dissociated after incubation in 0.1 M NaOH at 37 degrees C. After limited boiling of gel-purified [alpha-32P] ATP + T complex in 5.6 M HCl, o-[32P]phosphoserine was released, and snake venom phosphodiesterase or 0.5 M piperidine treatment of such a complex resulted in the liberation of [alpha-32P]AMP. The reaction proceeded when either purified, soluble T or insoluble, specifically immunoprecipitated antigen was used as substrate. ATP and dATP were the preferred nucleotide substrates by comparison with the other six standard ribonucleoside or deoxynucleoside triphosphates. Partial tryptic digests of T + [alpha-32P]ATP complexes revealed the presence of a single labeled peptide of Mr approximately equal to 12 - 14 X 10(3), and after exhaustive digestion, there was a single radioactive spot in the fingerprint. These data indicate that T can be adenylylated at a specific seryl residue(s) in a limited portion of the protein surface. Furthermore, adenylylation appears to be reversible and to proceed by a pyrophosphorylytic mechanism, since the nucleotide was released from the protein following incubation of adenylylated T with Mg2+, sodium pyrophosphate, and poly(dT).

Topics: Adenosine Triphosphate; Antigens, Viral, Tumor; Cell Line; Cell Transformation, Viral; Deoxyadenine Nucleotides; Diphosphates; Humans; Immunosorbent Techniques; Magnesium; Peptide Fragments; Poly T; Simian virus 40; Trypsin

Crystalline complexes of tyrosyl-tRNA synthetase from Bacillus stearothermophilus were prepared with adenosine, AMP, ATP and PPi, all in the presence of tyrosinol, which binds strongly to the tyrosine binding site but cannot be adenylated by ATP. The hydrolysis of ATP in the presence of crystalline tyrosyl-tRNA synthetase (or redissolved crystals) was checked in the absence of tyrosine or with tyrosinol. No ATPase activity due to the enzyme was detected under these conditions. Difference Fourier analysis shows that tyrosinol binds to the tyrosine binding site with the same occupancy as the amino acid. Comparison between tyrosine and tyrosinol shows the location of the extra oxygen atom of the tyrosine carboxylate. Adenosine, AMP and ATP are weakly bound to the enzyme in the presence of tyrosinol. Even when ATP is present at a concentration greater than Km for adenylation, it is not sufficiently strongly bound to give a recognizable density for adenine. However, some significant peaks of density are present near the tyrosine binding site. One of them is at the usual ribose binding site, and may possibly represent ribose binding with a low occupancy. When AMP is bound a similar but not identical arrangement of density is observed.

Topics: Adenosine; Adenosine Monophosphate; Adenosine Triphosphatases; Adenosine Triphosphate; Amino Acyl-tRNA Synthetases; Autoradiography; Binding Sites; Chromatography, Thin Layer; Crystallization; Diphosphates; Geobacillus stearothermophilus; Hydrolysis; Tyrosine; Tyrosine-tRNA Ligase; X-Ray Diffraction

Resident peritoneal macrophages of the mouse, cultivated for 3 d, have been studied by quantitative subcellular fractionation using differential centrifugation and density equilibration in linear gradients of sucrose. Density equilibration experiments were carried out on untreated cytoplasmic extracts, on cytoplasmic extracts treated with digitonin or sodium pyrophosphate, and on cytoplasmic extracts derived from cells cultivated for 24 h in the presence of Triton WR-1339. The enzyme distributions obtained distinguished six typical behaviors characteristic of distinct subcellular entities. Acid alpha-galactosidase and other acid hydrolases displayed the highest average velocity of sedimentation and equilibrium density. Culturing in a medium that contained Triton WR-1339 markedly decreased their density, most likely as a result of Triton WR-1339 accumulation within lysosomes. Cytochrome c oxidase and the sedimentable activity of malate dehydrogenase showed a narrow density distribution centered around 1.17, very similar under all the experimental situations; their rate of sedimentation fell within the range expected for mitochondria. Catalase was particle-bound and exhibited structure-linked latency (80 percent); it was released in soluble and fully active form by digitonin, but this required a much higher concentration than in the case of lysosomal enzymes. Differences relative to all the other enzymes studied suggest the existence of a particular species of organelles, distinctly smaller than mitochondria, and possibly related to peroxisomes. Many enzymes were microsomal in the sense that the specific activities, but not the yields, were greater in microsomes than in other fractions obtained by differential centrifugation. These enzymes were distinguished in three groups by their properties in density equilibration experiments. NAD glycohydrolase, alkaline phosphodiesterase I, and 5'-nucleotidase had low equilibrium densities but became noticeably more dense after addition of digitonin. The other microsomal enzymes were not shifted by digitonin, in particular N-acetylglucosaminyltransferase and galactosyltransferase, which otherwise equilibrated at the same position in the gradient. We assign the digitonin-sensitive enzymes to plasma membranes and possibly to related endomembranes of the cells, and the two glycosyltransferases to elements derived from the Golgi apparatus. Finally, alpha-glucosidase, sulphatase C, NADH cytochrome c reductase, NADPH cytoch

Topics: Animals; Ascitic Fluid; Cell Fractionation; Cells, Cultured; Centrifugation; Centrifugation, Isopycnic; Cytoplasm; Diphosphates; Macrophages; Mice; N-Glycosyl Hydrolases; NAD+ Nucleosidase; NADH Dehydrogenase; NADPH-Ferrihemoprotein Reductase; Polyethylene Glycols; Subcellular Fractions

The pyruvate dehydrogenase complex from Escherichia coli shows an appreciable lag phase (tau) of some minutes when its overall reaction rate was tested with very limiting amounts of thiamin diphosphate. tau depends on the concentration of thiamin diphosphate in a nonlinear fashion. Sodium diphosphate, a competitive inhibitor with respect to thiamin diphosphate (Ki = 5.2 . 10(-4) M) prolongs the lag, while the strongly binding transition state analog thiamin thiazolone diphosphate has no effect. tau is independent of the enzyme concentration, thus no dissociation-association step is involved. Incubation of the pyruvate dehydrogenase complex with thiamin diphosphate, Mg2+, and pyruvate leads to a shortening of the lag phase, as well as to a decrease of the intrinsic tryptophan fluorescence in a time-dependent process, which evinces the same characteristics as tau. Dependence of pyruvate, as well as of the substrate analog methylacetylphosphonate, can be established by measurements of fluorescence quenching, thus ruling out an essential role of hydroxyethyl thiamin diphosphate in the process reflected by the lag phase. The results demonstrate that the lag phase is induced after the binding of both thiamin diphosphate . Mg2+ and pyruvate to the catalytic site to form a ternary enzyme complex, which undergoes subsequently a slow conformational change to an active enzyme form. This change is confined to single subunits, and no interactions between neighboring monomers could be observed. A model is proposed to describe the mechanism represented by the lag phase.

Topics: Diphosphates; Escherichia coli; Kinetics; Mathematics; Protein Binding; Pyruvate Dehydrogenase Complex; Thiamine Pyrophosphate

Topics: Copper; Diagnosis, Differential; Diphosphates; Humans; Melanoma; Phosphorus Radioisotopes; Skin Neoplasms

Topics: Acetates; Bacteria; Corrosion; Diphosphates; Drug Combinations; Hydrogen Peroxide; Peracetic Acid; Sulfuric Acids

Captan (N-trichloromethylthiocyclohex-4-ene-1,2-dicarboximide) was shown to inhibit RNA synthesis in vitro catalysed by Escherichia coli RNA polymerase. Incorporation of [gamma-32P]ATP and [gamma-32P]GTP was inhibited by captan to the same extent as overall RNA synthesis. The ratio of [3H]UTP incorporation to that of [gamma-32P]ATP or of [gamma-32P]GTP in control and captan-treated samples indicated that initiation was inhibited, but the length of RNA chains being synthesized was not altered by captan treatment. Limited-substrate assays in which re-initiation of RNA chains did not occur also showed that captan had no effect on the elongation reaction. Studies which measured the interaction of RNA polymerase with template DNA revealed that the binding of enzyme to DNA was inhibited by captan. Glycerol-gradient sedimentation of the captan-treated RNA polymerase indicated that the inhibition of the enzyme was irreversible and did not result in dissociation of its subunits. These data are consistent with a mechanism in which RNA polymerase activity was irreversibly altered by captan, resulting in an inability of the enzyme to bind to the template. This interaction was probably at the DNA-binding site on the polymerase and did not involve reaction of captan with the DNA template.

Topics: Binding Sites; Captan; Diphosphates; DNA-Directed RNA Polymerases; DNA, Viral; Escherichia coli; Kinetics; RNA; Templates, Genetic

Topics: Actins; Animals; Diphosphates; Electrophoresis, Polyacrylamide Gel; Muscle Contraction; Myofibrils; Myosins; Protein Binding; Rabbits; Trypsin

Cation chelators cause flagellar shortening in Chlamydomonas reinhardii. Most effective are EDTA and EGTA (1 mM) but pyrophosphate (10 mM) also is effective. Addition of 5 mM Ca2+ after shortening caused by 4 mM EGTA results in flagellar regeneration. Other divalent cations can replace Ca2+ with the following relative activities: Ca2+ greater than Sr2+ = Mn2+ much greater than Ba2+ = Mg2+. Although the specific ion requirement to reverse shortening is not clear, it is possible that all of the ions act by displacing one bound cation, presumably Ca2+. A specific requirement for Ca2+ in flagellar regeneration could be demonstrated, however, because as little as 50 microM EGTA in the presence of 500 microM Mg2+ delayed regeneration and prevented full regeneration. Ca2+ at 100 microM overcame this inhibition.

Topics: Calcium; Cations, Divalent; Chelating Agents; Chlamydomonas; Diphosphates; Flagella; Regeneration

Topics: Animals; Diphosphates; Lymphoma, Non-Hodgkin; Mice; Phosphoric Acids; Sarcoma, Experimental; Sodium

The structure of sodium imidodiphosphate has been determined by single crystal x-ray diffraction. The P-N-P bond angle (127.2 degrees) and P-N bond distance (1.68 angstroms) are remarkably similar to newly refined values for the P-O-P bond angle (128.6 degrees) and the bridging P-O bond distance (1.63 angstroms) of sodium pyrophosphate. This close similarity may explain why P-N-P linkages in algal "polyphosphates" escaped detection until recently and why adenosine triphosphate analogs with this linkage mimic adenosine triphosphate so closely.

Topics: Adenosine Triphosphate; Chemical Phenomena; Chemistry, Physical; Crystallography, X-Ray; Diphosphates; Diphosphonates; Models, Chemical

Topics: 4-Aminobenzoic Acid; Acetylation; Aminosalicylic Acid; Diphosphates; Leadership; Protein Processing, Post-Translational

Topics: Diphosphates; Humans; Hydrolysis; Inorganic Pyrophosphatase; Magnesium; Phosphoric Monoester Hydrolases

Topics: Diphosphates; Fibroblasts; Quinones; Sodium Chloride, Dietary; Tissue Culture Techniques; Vitamin K

Topics: Diphosphates; Sodium Chloride, Dietary; Vitamin K

Topics: Biochemical Phenomena; Diphosphates; Phosphates; Thiamine Pyrophosphate

Topics: Alcohols; Diphosphates; Humans; Hydrolysis; Male; Phenolphthalein; Phenolphthaleins; Prostate; Sodium