chloramine-t and chloramine

PURPOSE：The purpose of this study was to evaluate the effect of various storage methods on shear bond strength of enamel of bovine teeth and find the storage condition that could preserve the similar bond strength as the freshly extracted teeth.. One hundred and thirty freshly extracted bovine teeth were divided into 13 groups. One was the reference group and 12 were the experimental group. Each group contained 10 teeth. Teeth in the reference group were operated on the same day as the teeth were extracted, while teeth in the experimental groups were stored in different methods (4% formaldehyde solution at 4 ℃, 23 ℃, 1% chloramine T at 4 ℃, 23 ℃, distilled water at 4 ℃, 23 ℃). After stored for 30 days and 90 days, the bovine teeth were taken out and then the shear bond strength was tested. The data were analyzed with SPSS 20.0 software package.. The bovine teeth stored in 4% formaldehyde and 1% chloramine T at 23 ℃ and in distilled water at 4 ℃ achieved similar bond strength as freshly extracted teeth at 30 days and 90 days, and the bond strength did not change over time. The bovine teeth stored in 4% formaldehyde solution and 1% chloramine T at 4 ℃ at 30 days had higher shear bond strength than freshly extracted bovine teeth, but over time the bond strength reduced and reached the similar level at 90 days. The bovine teeth stored in distilled water at 23 ℃ obtained similar bond strength as freshly extracted teeth at 30 days but over time the bond strength reduced until 90 days.. Bovine teeth stored in 4% formaldehyde solution and 1% chloramine T at 23 ℃ and in distilled water at 4 ℃ achieved similar bond strength as freshly extracted teeth and does not change over time. These three methods are recommended for storing bovine teeth.

Topics: Animals; Cattle; Dental Bonding; Dental Enamel; Dental Stress Analysis; Formaldehyde; Materials Testing; Resin Cements; Shear Strength; Water

Recently, we showed that monochloramine (NH2 Cl) has a significantly stronger bactericidal and fungicidal activity than chloramine T despite its lower oxidizing power. This phenomenon was explained by increased penetration because of the higher lipophilicity and smaller bulk of NH2 Cl. As iodine (I2 ) has an even fivefold higher bulk than NH2 Cl, a comparison of both compounds regarding their microbicidal activity became the aim of this study. Aqueous solutions of I2 at a concentration of 10·7 μmol l(-1) killed 10(6) colony forming units per millilitre (CFU ml(-1) ) of Escherichia coli, Staphylococcus aureus or Pseudomonas aeruginosa to the detection limit of 10(2) CFU ml(-1) within 1 min at 20°C and pH 7·1, while a concentration of 36-355 μmol l(-1) of NH2 Cl was needed to achieve the same effect. Aspergillus fumigatus was inactivated within 5 min by 36 μmol l(-1) I2 and by 355 μmol l(-1) NH2 Cl, Candida albicans within 1 min by 10·7 μmol l(-1) I2 and by 355 μmol l(-1) NH2 Cl. The lipophilicity of I2 , determined with the octanol/water method, was three powers of 10 higher than that of NH2 Cl. The at least 10-fold stronger microbicidal activity of iodine suggests that the hindrance of penetration of the bulky molecule is outweighed by enhanced lipophilicity.. The microbicidal activity of active halogen compounds increases not only with their reactivity, but also with higher lipophilicity and lower bulk, as shown recently. In this study, iodine showed a higher microbicidal activity than monochloramine and a 1000-fold higher lipophilicity. Therefore, the lipophilicity of a disinfectant may be more important than the bulk for bactericidal activity. These facts should be considered upon the design of new antiseptics and their clinical application.

Topics: Anti-Bacterial Agents; Anti-Infective Agents, Local; Aspergillus fumigatus; Candida albicans; Chloramines; Disinfectants; Escherichia coli; Iodine; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Staphylococcus aureus; Tosyl Compounds

The activity of oxidants, such as halogens and active halogen compounds, decreases generally in the presence of proteinaceous material. A quantification of consumption effects was performed to judge the suitability of different representatives as antiseptics and their compatibility with pharmaceutical additives.. An iodometric approach served to assess the temporal loss of oxidation capacity in the presence of peptone and fetal calf serum (FCS). The tested agents comprised active halogen compounds, well-known and in particular novel chloramine-based agents indicated for the topical treatment of infections.. The decrease in oxidation capacity was higher in the presence of FCS than of peptone and correlated with the reactivity of the oxidants in both cases. The highest consumption rates were for active bromine compounds followed by hypochlorous acid and heterocyclic chlorimides, such as dichloro-isocyanuric acid, while N-chlorotaurine and related amine-based analogues were least consumed. The pH dependence was only remarkable for chloramine T.. The observed consumption effects are the result of the differing oxidizing (chlorinating) potencies. Since consumption and irritation are founded on the very same reactions, representatives with low reactivity (N-chloro amino acids) are regarded as more tolerable and retain more oxidative capacity, which provides a more sustained antimicrobial activity.

Topics: Amines; Animals; Anti-Infective Agents, Local; Bromine; Cattle; Chloramines; Drug Interactions; Halogens; Hydrogen-Ion Concentration; Hypochlorous Acid; Oxidants; Oxidation-Reduction; Peptones; Serum; Taurine; Tosyl Compounds; Triazines

Chloramine T (CAT) and monochloramine (NH2Cl) are active chlorine compounds and well-known biocides. CAT has stronger oxidative activity than NH(2)Cl, which is a smaller, more lipophilic molecule. The question arises whether lower oxidative activity can be compensated by higher lipophilicity. To address this problem, we investigated the bactericidal and fungicidal activity of pure NH(2)Cl compared to CAT. Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus fumigatus, A. flavus, and Candida albicans were subjected to quantitative killing assays at 20 degrees C and pH 7.1 in equimolar solutions of CAT or NH2Cl. NH2Cl was superior to CAT against all test strains at all test concentrations. At a concentration of 0.036 mM, NH2Cl reduced the count of E. coli (S. aureus) by 3log10 within 1 min (5 min), whereas CAT needed 120 min (30 min) for the same effect. At 0.107 mM NH2Cl, a 3log10 reduction of P. aeruginosa was achieved after 5 min compared to 20 min using CAT. NH2Cl (0.355 mM) caused a 2log10 reduction of C. albicans within 30 s, whereas 60 min were necessary for the same reduction with 0.355 mM CAT. The difference between the antiseptics was even more pronounced when tested on aspergilli. NH2Cl had a significantly stronger bactericidal and fungicidal activity than CAT despite its lower oxidative activity. This phenomenon can be attributed to its lipophilicity and smaller bulk, and it should be taken into account when developing and using chloramine antiseptics.

Topics: Anti-Bacterial Agents; Antifungal Agents; Aspergillus flavus; Aspergillus fumigatus; Bacteria; Candida albicans; Chloramines; Escherichia coli; Fungi; Humans; Microbial Sensitivity Tests; Oxidation-Reduction; Pseudomonas aeruginosa; Staphylococcus aureus; Tosyl Compounds

The effect of oxidants on voltage-dependent K+ currents was examined in mouse colonic smooth muscle cells. Exposure to either chloramine-T (Ch-T), an agent known to oxidize both cysteine and methionine residues, or the colon-specific oxidant monochloramine (NH2Cl) completely suppressed the transient outward K+ current (Ito) while simultaneously enhancing the sustained delayed rectifier K+ current (Idr). In contrast, the cysteine-specific oxidants hydrogen peroxide (H2O2) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) exhibited partial and slow suppression of Ito by inducing a shift in channel availability of -18 mV without affecting Idr. After enhancement by NH2Cl or Ch-T, Idr was sensitive to 10 mM tetraethylammonium but not to other K+ channel blockers, suggesting that it represented activation of the resting Idr and not a separate K+ conductance. Extracellular dithiothreitol (DTT) partially reversed the effect of H2O2 and DTNB on Ito but not the actions of NH2Cl and Ch-T on either Idr or Ito. Dialysis of myocytes with GSH (5 mM) or DTT (5 mM) prevented suppression of Ito by H2O2 and DTNB but did not alter the effects of NH2Cl or Ch-T on either Idr or Ito. Ch-T and NH2Cl completely blocked Ito generated by murine K(v)4.1, 4.2, and 4.3 in Xenopus oocytes, an effect not reversible by intracellular DTT. In contrast, intracellular DTT reversed the effect of H2O2 and DTNB on the cloned channels. These results suggest that I(to) is suppressed via modification of both methionine and cysteine residues, whereas enhancement of Idr likely results from methionine oxidation alone.

Topics: Animals; Chloramines; Colon; Dithionitrobenzoic Acid; Dithiothreitol; Hydrogen Peroxide; Ion Channel Gating; Membrane Potentials; Mice; Mice, Inbred C57BL; Muscle, Smooth; Oxidants; Oxidation-Reduction; Patch-Clamp Techniques; Potassium Channels, Voltage-Gated; Sulfhydryl Reagents; Tosyl Compounds