thiourea and Hemolysis

Ufmylation was proved to play a crucial role in hematopoietic stem cell (HSC) survival and erythroid differentiation, ufmylation deficiency induces acute anemia and lethality of embryos and adults in mouse models. To screen some compounds to rescue phenotypes induced by gene deletion, in this study, we used DDRGK1

Topics: Anemia; Animals; Cinnamates; Erythrocytes; Erythropoiesis; Eukaryotic Initiation Factor-2; Fetus; Hemolysis; Liver; Male; Mice, Inbred C57BL; Mice, Knockout; Models, Biological; Phenotype; Phenylhydrazines; Phosphorylation; Protein Processing, Post-Translational; Thiourea; Up-Regulation

Success of synthetic interfering nucleic acids (siRNAs)-based therapy relies almost exclusively on effective, safe and preferably nanometric delivery systems which can be easily prepared, even at high concentrations. We prepared by chemical synthesis various self-assembling polymers to entrap siRNAs into stable polyplexes outside cells but with a disassembly potential upon sensing endosomal acidity. Our results revealed that pyridylthiourea-grafted polyethylenimine (πPΕΙ) followed the above-mentioned principles. It led to above 90% siRNA-mediated gene silencing in vitro on U87 cells at 10 nM siRNA concentration and did not have a hemolytic activity. Assembly of siRNA/πPΕΙ at high concentration was then studied and 4.5% glucose solution, pH 6.0, yielded stable colloidal solutions with sizes slightly below 100 nm for several hours. A single injection of these concentrated siRNA polyplexes into luciferase-expressing human glioblastoma tumors, which were subcutaneously xenografted into nude mice, led to a significant 30% siRNA-mediated luciferase gene silencing 4 days post-injection. Our results altogether substantiate the potential of self-assembling cationic polymers with a pH-sensitive disassembly switch for siRNA delivery in vitro and also in vivo experiments.

Topics: Animals; Cell Line, Tumor; Cell Survival; Erythrocytes; Gene Silencing; Hemolysis; Humans; Hydrophobic and Hydrophilic Interactions; Male; Mice; Mice, Nude; Neoplasm Transplantation; Neoplasms; Polyethyleneimine; RNA, Small Interfering; Sheep; Thiourea

We found that rats subjected to thermal skin injury (burn) had increased serum hydrogen peroxide (H2O2) scavenging activity, serum catalase activity, erythrocyte (RBC) fragility, and edematous lung injury (lung leak) when compared to sham-treated rats. Serum H2O2 scavenging activity was inhibited by addition of sodium azide, a catalase inhibitor. Treatment of rats with the oxygen radical scavenger, dimethylthiourea (DMTU), decreased RBC fragility and lung leak but did not alter increased H2O2 scavenging or catalase activity of serum from rats subjected to skin burn. We conclude that increased serum catalase activity is a consequence of thermal skin injury and that increased serum catalase activity may be a mechanism that modulates H2O2-dependent processes following skin burn.

Topics: Animals; Burns; Catalase; Erythrocytes; Free Radical Scavengers; Hemolysis; Hydrogen Peroxide; Lung; Permeability; Rats; Skin; Thiourea

The photohaemolytic potentials of the quinolones oxolinic acid, pipemidic acid, rosoxacin, norfloxacin, ciprofloxacin and M-193324 (synthesis intermediary) were evaluated and compared with the photohaemolysis induced by nalidixic acid. Quinolones with a piperazine group in position 7 (pipemidic acid, norfloxacin and ciprofloxacin) did not induce photohaemolysis. However, oxolinic acid, rosoxacin and M-193324 produced a concentration- and oxygen-dependent photohaemolysis. Ascorbic acid, histidine and thiourea inhibited the photohaemolysis induced by oxolinic acid, rosoxacin and M-193324, suggesting a photodynamic mechanism similar to that found with nalidixic acid. In addition, deuterium oxide increased the photohaemolysis induced by photohaemolytic quinolones, indicating that this process is mediated by singlet oxygen.

Topics: Ascorbic Acid; Hemolysis; Histidine; Humans; Light; Photolysis; Quinolones; Radiation-Sensitizing Agents; Structure-Activity Relationship; Thiourea

Topics: Ascorbic Acid; Hemolysis; Histidine; Humans; In Vitro Techniques; Nalidixic Acid; Naphthyridines; Photolysis; Thiourea

Desferrioxamine a well-known iron chelator was found to decrease hydrogen peroxide and phenylhydrazine induced lipid peroxidation of red blood cell membranes assessed by hydrocarbon gas release and loss of polyunsaturated fatty acids. Hydroxyl radical scavengers like mannitol and thiourea and proteins like albumin were unable to reduce peroxidative reactions to our system. Addition of uric acid (in an unphysiological concentration of 5 mM) to the incubation medium resulted in a slight reduction in H2O2/phenylhydrazine mediated break-down of arachidonic (20:4) and docosahexaenoic acid (22:6) in the erythrocyte membrane and consequently in a decreased alkane release and haemolysis.

Topics: Alkanes; Antioxidants; Deferoxamine; Erythrocytes; Fatty Acids; Free Radicals; Hemolysis; Humans; Mannitol; Phenylhydrazines; Thiourea

Human neutrophils (PMN), when stimulated with such chemotaxins as phorbol myristate acetate (PMA), destroy erythrocytes and other targets. Cytotoxicity depends on PMN-generated reactive oxygen metabolites, yet the exact toxic specie and its mode of production is a matter of some dispute. Using 51Cr-labeled erythrocytes as targets, we compared various reactive-O2 generating systems for their abilities to lyse erythrocytes as well as to oxidize hemoglobin to methemoglobin. PMA-activated PMNs or xanthine oxidase plus acetaldehyde were added to target erythrocytes in amounts that provided similar levels of superoxide. PMNs lysed 68.3 +/- 2.9% (SEM) of targets, whereas the xanthine oxidase system was virtually impotent (2.3 +/- 0.8%). In contrast, methemoglobin formation by xanthine oxidase plus acetaldehyde was significantly greater than that caused by stimulated PMNs (P less than 0.001). A similar dichotomy was noted with added reagent H2O2 or the H2O2-generating system, glucose plus glucose oxidase; neither of these caused 51Cr release, but induced 10-70% methemoglobin formation. Thus, although O2- and H2O2 can cross the erythrocyte membrane and rapidly oxidize hemoglobin, they do so evidently without damaging the cell membrane. That a granule constituent of PMNs is required to promote target cell lysis was suggested by the fact that agranular PMN cytoplasts (neutroplasts), although added to generate equal amounts of O2- as intact PMNs, were significantly less lytic to target erythrocytes (P less than 0.01). Iron was shown to be directly involved in lytic efficiency by supplementation studies with 2 microM iron citrate; such supplementation increased PMN cytotoxicity by approximately 30%, but had much less effect on erythrocyte lysis by neutroplasts (approximately 3% increase), and no effect on lysis in the enzymatic oxygen radical-generating systems. These results suggest a critical role for an iron-liganding moiety that is abundantly present in PMN, marginally so in neutroplasts, and not at all in purified enzymatic systems--a moiety that we presume catalyzes very toxic O2 specie generation in the vicinity of juxtaposed erythrocyte targets. The obvious candidate is lactoferrin (LF), and indeed, antilactoferrin IgG, but not nonspecific IgG, reduced PMN cytotoxicity by greater than 85%. Re-adding 10(-8) M pure LF to neutroplasts increased their ability to promote hemolysis by 48.4 +/- 0.9%--to a level near that of intact PMNs. We conclude that O-2 and H2O2

Topics: Cytoplasmic Granules; Erythrocytes; Free Radicals; Hemolysis; Humans; Hydroxides; Hydroxyl Radical; Lactoferrin; Mannitol; Methemoglobin; Neutrophils; Oxygen; Tetradecanoylphorbol Acetate; Thiourea

The mechanism of cetomacrogol 1000-induced hemolysis was investigated. Previous conclusions that peroxides are involved in the hemolytic process were confirmed. The possibility that hydrogen peroxide, superoxide, hydroxyl radical, or singlet oxygen, which are known to induce hemolysis, are involved in cetomacrogol 1000-induced hemolysis was tested by using specific inhibitors and inactivators. The hydroxyl radical (OH.) was shown to be the only apparent oxygen species involved in cetomacrogol 1000-induced hemolysis. Its contribution to the hemolytic potency of the surfactant is approximately 30%.

Topics: Animals; Catalase; Cetomacrogol; Free Radicals; Hemolysis; Histidine; Hydroxides; Hydroxyl Radical; In Vitro Techniques; Light; Mannitol; Polyethylene Glycols; Rats; Saponins; Superoxide Dismutase; Thiourea

Soluble histamine added to mouse peritoneal macrophages in culture suppressed the synthesis of the functional and antigenic complement component C5. Synthesis of intracellular C5 antigen by resident macrophages was suppressed by 16 to 80%, and functional C5 activity by 13.6 to 87.2% at concentrations of histamine ranging from 10(-6) M to 10(-3) M, respectively; secretion of C5 protein was depressed by 18.3 to 85.5% and hemolytic C5 by 8 to 80%. In thioglycollate-stimulated exudates, intracellular synthesis of C5 protein was reduced by 3.3 to 72.3% and functional C5 activity by 7.6 to 73.5% using similar concentrations of histamine; secreted C5 protein was inhibited by 8.9 to 75.7% and functional activity by 4 to 78%. The suppression of C5 activity in resident and thioglycollate-stimulated cultures was dependent on the dose of histamine with maximal suppression occurring at a concentration of 10(-3) M. Experiments in which specific histamine agonists were used confirmed that the action was mediated by the H2 receptor. The inhibition of C5 antigenic protein synthesis paralleled that detected for functional C5. Immunochemical analysis of C5 antigen synthesized under the influence of histamine indicated that suppression of synthesis of pro-C5 was the major mechanism responsible for the depression of C5 produced under these conditions. The inhibitory effects produced by histamine were shown to be mediated by histamine type 2 receptors as indicated by abrogation of the inhibition by cimetidine (H2 antagonist).

Topics: Animals; Antigens; Bucladesine; Cimetidine; Complement C5; Complement Inactivator Proteins; Dimaprit; Guinea Pigs; Hemolysis; Histamine; Histamine H2 Antagonists; Humans; Macrophages; Male; Mice; Mice, Inbred C57BL; Protein Precursors; Receptors, Histamine H2; Thiourea; Tripelennamine

Topics: Animals; Antibody Formation; Cells, Cultured; Cimetidine; Guanidines; Hemolysis; Lymphocytes; Male; Metiamide; Mice; Mice, Inbred BALB C; Spleen; Thiourea

The effect of several free-radical scavengers on the radiation-induced haemolysis of bovine erythrocytes (50 krad, 60Co, cell concentration: 0.05 v/v) was studied. A two-phase effect of the additives was found with a maximum of the protective action in the millimolar concentration range. A correlation was established between the degree of protection at a fixed concentration (5mM) and the rate constants of reactions of respective compounds with OH. A radiosensitizing effect of diethyldithiocarbamate, an inhibitor of superoxide dismutase (SOD) was not confirmed and no specific protective effect of SOD was seen.

Topics: Animals; Azides; Cattle; Cobalt Radioisotopes; Dimethyl Sulfoxide; Ditiocarb; Dose-Response Relationship, Radiation; Erythrocytes; Free Radicals; Hemolysis; Radiation-Protective Agents; Thiourea

1 Changes in the osmotic fragility and critical haemolytic volume of human erythrocytes produced by S-n-decylthiouronium (S-10) and related compounds have been studied. 2 S-10 had a biphasic action on osmotic fragility, protecting erythrocytes against lysis in low concentrations but producing lysis in a concentration of 1 mM or higher. 3 Some lower homologues of S-10 also protected erythrocytes against osmotic lysis, the degree of protection depending on the length of the alkyl chain. 4 Critical haemolytic volume was increased by antihaemolytic concentrations of procaine and chlorpromazine but not by antihaemolytic concentrations of S-10 and related amidines. 5 It is concluded that S-10 and its near homologues penetrate and stabilize erythrocyte membranes, potency increasing with the number of methylene groups in the side-chain up to about ten. The stabilization produced by S-10 apparently differs from that produced by many other lipid-soluble depressant drugs. It may be related to a drug-induced change in the ionic permeability of the membrane.

Topics: Chlorpromazine; Erythrocyte Membrane; Erythrocytes; Hemolysis; Humans; In Vitro Techniques; Osmotic Fragility; Procaine; Thiourea

The osmotic swelling to haemolysis of individual red blood cells by isosmotic thiourea has been studied using microcine photography. 2. Crenation occurs immediately upon addition of isosmotic thiourea. The cell becomes a crenated sphere without volume decrease. 3. Subsequently, the cell volume increases linearly with time with maximum swelling occurring at about 102 sec which is 81% of the total haemolysis time. 4. At maximum swelling, the cell volume is 92% greater than the initial cell volume. This volume increase is about double that measured with other permeating substances. 5. The much larger maximum volume implies that thiourea increases the area of the cell membrane. This increase varies from 0 to 75% for individual cells, with a mean of 22%. 6. Membrane expansion varies inversely as the initial cell membrane area and cell volume (r=0-790). 7. Using the increased surface area, increased maximum volume and the swelling time, the mean permeability is calculated to be 5-52 X 10(-7) cm/sec (S.D. of mean=+/-1-19 X 10(-7) cm/sec). The distribution of permeabilities represents a normal distribution. 8. The pre-lytic potassium loss ranged from 0 to 36% with a mean value of 16-5%. This is consistent with values reported in the literature for slow haemolysis. As with other permeants the distribution is skewed towards lower values. 9. Membrane permeability of individual cells varies with the amount of membrane expansion observed. Coefficient of correlation between permeability and expansion index is 0-674. 10. There is no correlation between permeability and the reciprocal of the haemolysis time (r=-0-035). The correlation between permeability and the reciprocal of the swelling time is also poor (r=0-303), probably owing to the variability in membrane expansion by thiourea in individual cells. 11. As has been shown previously for faster permeants, the permeability coefficient cannot be calculated from the haemolysis time. Because thiourea alters the membrane area and the haemolytic volume, the coefficient cannot be calculated from the swelling time unless the changes in the membrane area are also taken into account.

Topics: Cell Membrane; Cell Membrane Permeability; Erythrocytes; Female; Hemolysis; Humans; Male; Osmosis; Thiourea

The distribution of a random variable is determined by the probability density functions (PDF) of all other random variables with which the variable in question is jointly distributed. If the PDF of the random variable of interest is normal, or skewed normal, then the distributions with which it is jointly distributed determine its mean and standard deviation. In the case described here (where hemolysis time of the red blood cell is a function of the permeability coefficient and geometric variables of the cell) the mean and standard deviation of the permeability coefficient and the known distributions of the geometric variables on which the hemolysis time depends determine a predicted distribution of hemolysis time. An observed distribution of the hemolysis time is obtained spectrophotometrically. By choosing the mean and standard deviation of the permeability coefficient so that the predicted PDF of the hemolysis time matches the observed PDF best by least-squares criterion, the complete distribution of the permeability coefficient is determined.

Topics: Cell Membrane; Cell Membrane Permeability; Erythrocytes; Ethylenes; Glycerol; Glycols; Hemolysis; Mathematics; Probability; Propylene Glycols; Spectrophotometry; Thiourea; Time Factors

Topics: Analgesia; Aniline Compounds; Animals; Antifungal Agents; Blood Cell Count; Blood Coagulation; Blood Pressure; Body Temperature; Brain; Carbamates; Cholinesterases; Electrocardiography; Erythrocyte Count; Fungicides, Industrial; Heart Rate; Hemolysis; Hypnotics and Sedatives; In Vitro Techniques; Lethal Dose 50; Leukocyte Count; Male; Mice; Muscle, Smooth; Mydriatics; Rabbits; Rats; Respiration; Thiourea

Topics: Cell Membrane; Cell Membrane Permeability; Child; Erythrocytes; Glycerol; Hemolysis; Humans; Kwashiorkor; Phosphatidylcholines; Phosphatidylethanolamines; Phospholipids; Serum Albumin; Sphingomyelins; Thiourea

Topics: Amino Acid Sequence; Anhydrides; Barbiturates; Bees; Buffers; Electrophoresis; Furans; Hemolysis; Humans; Hydrogen-Ion Concentration; Nitrobenzenes; Peptides; Phosphates; Radiation Effects; Surface-Active Agents; Thiourea; Tryptophan; Venoms

Topics: Animals; Dietary Fats; Erythrocytes; Fatty Acids; Hemolysis; Linoleic Acids; Lipids; Male; Rats; Thiourea; Vitamin E; Vitamin E Deficiency

Topics: Animals; Blood; Erythrocytes; Hemolysis; Rats; Sodium Chloride; Thiourea

Topics: Animals; Cell Membrane Permeability; Copper; Erythrocytes; Fatty Acids; Glycerol; Glycols; Hemolysis; Intestine, Small; Liver; Male; Mitochondria; Osmosis; Phospholipases; Rats; Sodium; Thiourea

Topics: Alcohols; Animals; Cell Membrane Permeability; Erythrocytes; Glycerol; Glycols; Hemolysis; In Vitro Techniques; Mice; Rats; Thiourea

The exposure of erythrocytes from the elasmobranch, Squalus acanthias, to solutions isosmotic with plasma (IM) but containing urea or hydroxyurea as the sole solute does not produce hemolysis. Exposure of these cells to IM methylurea, thiourea and acetamide does produce hemolysis. Low concentrations of urea, which are associated with hemolysis, protect dogfish red cells against hemolysis by methylurea and thiourea. Dogfish red cells exposed to mediums containing high concentrations of urea, or no urea, reach 95 percent of their equilibrium concentration in less than 5 minutes.

Topics: Acetamides; Amides; Animals; Biological Transport; Dogfish; Erythrocytes; Facilitated Diffusion; Hemolysis; Metabolism; Methylurea Compounds; Pharmacology; Research; Sharks; Thiourea; Urea

Topics: Butter; Castor Oil; Chromatography; Cocos; Dietary Fats; Electrolytes; Erythrocytes; Fatty Acids; Fatty Acids, Essential; Glycerol; Glycols; Hemolysis; Linoleic Acid; Lipids; Oils; Permeability; Pharmacology; Phospholipids; Rats; Research; Thiourea; Zea mays

Topics: Cell Death; Hemolysis; Humans; Radiation Protection; Thiourea