Adult ; Humans ; Male ; Occupational Exposure ; Sodium Azide ; poisoning

The effects of dimethyl sulfoxide (DMSO) were studied in two groups of Xenopus oocytes, one expressing ATP sensitive K+ (KATP) channel comprised of sulfonylurea receptor SUR1 and inwardly rectifying K+ channel subunit Kir6.2, and the other expressing renal KATP channel ROMK2. At concentrations of 0.3~10% (vol/vol) DMSO inhibited whole cell Kir6.2/SUR1 currents elicited by bath application of sodium azide (3 mM) in a concentration-dependent manner. The inhibition constant and Hill coefficient were 2.93% and 1.62, respectively. ROMK2 currents, however, was not affected significantly by DMSO. The results support the idea that DMSO inhibits KATP channel expressed in Xenopus oocyte through a protein-specific mechanism(s) that remains to be further elucidated.
Adenosine Triphosphate ; Baths ; Dimethyl Sulfoxide* ; Oocytes* ; Sodium Azide ; Xenopus*

Astrocytes are reported to have critical functions in ischemic brain injury including protective effects against ischemia-induced neuronal dysfunction. Na-K ATPase maintains ionic gradients in astrocytes and is suggested as an indicator of ischemic injury in glial cells. Here, we examined the role of the Na-K ATPase in the pathologic process of ischemic injury of primary cultured astrocytes. Chemical ischemia was induced by sodium azide and glucose deprivation. Lactate dehydrogenase assays showed that the cytotoxic effect of chemical ischemia on astrocytes began to appear at 2 h of ischemia. The expression of Na-K ATPase alpha1 subunit protein was increased at 2 h of chemical ischemia and was decreased at 6 h of ischemia, whereas the expression of alpha1 subunit mRNA was not changed by chemical ischemia. Na-K ATPase activity was time-dependently decreased at 1, 3, and 6 h of chemical ischemia, whereas the enzyme activity was temporarily recovered to the control value at 2 h of chemical ischemia. Cytotoxicity at 2 h of chemical ischemia was significantly blocked by reoxygenation for 24 h following ischemia. Reoxygenation following chemical ischemia for 1 h significantly increased the activity of the Na-K ATPase, while reoxygenation following ischemia for 2 h slightly decreased the enzyme activity. These results suggest that the critical time for ischemia-induced cytotoxicity of astrocytes might be 2 h after the initiation of ischemic insult and that the increase in the expression and activity of the Na-K ATPase might play a protective role during ischemic injury of astrocytes.
Adenosine Triphosphatases ; Astrocytes ; Brain Injuries ; Glucose ; Ischemia ; L-Lactate Dehydrogenase ; Neuroglia ; Neurons ; RNA, Messenger ; Sodium Azide

BACKGROUND: It is reported by rnany t,hat UVB and large coses of UVA damage epidermal Langerhans cells. UVA irradiated skin produces reactive oxygen soecies such as superoxide anion(O ), hydrogen peroxide(H O), hydroxyl radical( OH) and singlet oxigen(O ). Reactive oxygen species such as O are invnlved in the process of decreasing the number if epidermal Langerhans cells after irradiation with UVB. However, no well established studies have been carried out after irradiation with UVA. OBJECTIVES: We wished to find out whether the UVA-induced decrease in the number of Ia Langerhans cells would be protected by scavengers of reactive oxiygen species. METHODS: We irradiated 200J/cm and 400J/cm of UVA on thi ears of C3H mice with or without intravenous injectior. of SOD, catalase, and sodium azide which are the scavengers of O , HO and O, respectively. We biopsied the ears of mice 2 days after irradiaion, stained them with immunope-roxidase technique, and counted the number of Langerhans cells. RESULTS: 1, There was significant decrease in the number of Ia Langerhans cells in the 200J/cm or 400J/cm of UVA irradiated group compared to the normal control group. 2. The pretreatment groups with SOD, catalase, and sodium to before irradiation with 200J/cm or 400J/cm of UVA showed less decrease in the number of la Langerhans cells compared to the 200J/cm or 400J/cm irradiated group with UVA only. CONCLUSION: Frorn the above result, we can deduce that reactive oxygen species are involved in the decrease in the number of Ia Langerhans cells induced by 200J/cm. or 400J/cm of UVA irradiation.
Animals ; Catalase ; Ear ; Hydrogen ; Langerhans Cells* ; Mice ; Mice, Inbred C3H ; Oxygen ; Reactive Oxygen Species* ; Skin* ; Sodium ; Sodium Azide ; Superoxides

Electroretinographic and electro-oculographic studies were made in pigmented rabbits after the administrations of chloroquine hydrochloride (Aralen). Systemic administration of chloroquine, 15 mg/kg daily for 20 days, induced marked general weakness, weight loss and even death of animals. EOG and ERG data obtained in survived 6 animals showed nothing abnormal. Azide sensitive DC potential of the eye increased as normal animals did b- intravenous administration of 1 mg sodium azide. Histopathological studies revealed slight thickening of ganglion cell and nerve fiber layers, with slight irregularity of pigment distribution in pigment epithelium of the retina, photoreceptors and bipolar cells being undisturbed. Acute experiment in 4 animals with intravitreal injection of 5 mg chloroquine in 0.1 ml saline produced marked reduction of scotopic b- potential during the first 2-3 days and this subnormal state remained thereafter. Scotopic a-potential also decreased with lesser degree. Photopic ERG extinguished on the next day, and showed slight recovery after 5 days. EOG data revealed general flattening of EOG curves and reduced light peak/dark trough ratio throughout the experimental period Azide reaction, however, was within normal limits 20 days after the treatment. Histological section disclosed marked destruction of ganglion cell and nerve fiber layers, depigmentation and pigment clumping in pigment epithelium, pigment migration into the inner retinal layers, degeneration of visual cells and bipolar cells. These findings suggest direct toxic action of chloroquine on the retinal tissues with little impairment of functions of pigment epithelium of the retina.
Administration, Intravenous ; Animals ; Chloroquine* ; Electrooculography ; Epithelium ; Ganglion Cysts ; Intravitreal Injections ; Nerve Fibers ; Rabbits* ; Retina ; Retinaldehyde ; Sodium Azide ; Weight Loss

Sodium azide (NaN3) is a white to colorless, crystalline powder that is highly water soluble, tasteless, and odorless. It is used mainly as a preservative in aqueous laboratory reagents and biologic fluids and also as an automobile airbag gas generant. Although it has caused deaths for decades, the toxic properties and effects of sodium azide in humans remains unknown. A 31-year-old comatose female was transported to the emergency department with an empty bottle labeled sodium azide. She developed cardiac arrest 15 minutes after arrival and expired in spite of 30 minutes of resuscitative effort. Subsequently, resuscitation team members incidentally suffered from sodium azide's exposure and developed eye discomfort, skin rashes parasthesias, pruritus, sore throat, and headache.
Adult ; Air Bags ; Automobiles ; Coma ; Crystallins ; Eating ; Emergencies ; Exanthema ; Eye ; Female ; Headache ; Heart Arrest ; Humans ; Indicators and Reagents ; Pharyngitis ; Pruritus ; Resuscitation ; Sodium ; Sodium Azide

Turmeric has long been used as a spice and food colouring agent in Asia. In the present investigation, the antimutagenic potential of curcumin was evaluated in Allium cepa root meristem cells. So far there is no report on the biological properties of curcumin in plant test systems. The root tip cells were treated with sodium azide at 200 and 300 microg/ml for 3 h and curcumin was given at 5, 10 and 20 microg/ml for 16 h, prior to sodium azide treatment. The tips were squashed after colchicine treatment and the cells were analyzed for chromosome aberration and mitotic index. Curcumin induces chromosomal aberration in Allium cepa root tip cells in an insignificant manner, when compared with untreated control. Sodium azide alone induces chromosomal aberrations significantly with increasing concentrations. The total number of aberrations was significantly reduced in root tip cells pretreated with curcumin. The study reveals that curcumin has antimutagenic potential against sodium azide induced chromosomal aberrations in Allium cepa root meristem cells. In addition, it showed mild cytotoxicity by reducing the percentage of mitotic index in all curcumin treated groups, but the mechanism of action remains unknown. The antimutagenic potential of curcumin is effective at 5 microg/ml in Allium cepa root meristem cells.
Antimutagenic Agents ; pharmacology ; Chromosome Aberrations ; drug effects ; Curcumin ; pharmacology ; Meristem ; drug effects ; genetics ; Mutagens ; toxicity ; Onions ; drug effects ; genetics ; Sodium Azide ; toxicity

Amyloid beta-Peptides ; analysis ; Animals ; Frontal Lobe ; drug effects ; physiology ; Hippocampus ; drug effects ; physiology ; Learning ; drug effects ; Memory ; drug effects ; Rats ; Rats, Wistar ; Sodium Azide ; pharmacology ; Space Perception

The first purpose of present study was to compare the anticariogenic effect of compomer, resin modified glass ionomer cement and composite (RMGIC). The second purpose was to evaluate the recently introduced methods, which use confocal scanning microscope, in detecting initial caries around restoration. 2x4x1.5mm cavities were prepared from the recently extracted 50 human teeth on the buccal or lingual surface. The prepared teeth were randomly devided into 5 groups and restored with each filling material. Group 1: Dyract AP, Group 2: compoglass F, Group 3: F2000, Group 4: Z100, Group 5:Fuji II LC. The teeth were stored for 30 days in the distilled water, then stored in the buffer solution for artificial caries development; pH 4.3, lactic acid 100 mM, calcium 16 mM, phosphate 8mM, sodium azide 3mM. Then, the samples were sectioned longitudinally and examined with confical scanning microscope. The results showed that the use of compomer and resin modified glass ionomer cement showed caries inhibition zone whereas the composite did not. There was no difference in the width of caries inhibition zone between compomers and RMGIC. The confocal scanning microscope was useful in detecting initial caries around restoration.
Acrylic Resins ; Calcium ; Compomers ; Composite Resins ; Fluorides ; Glass Ionomer Cements ; Humans ; Hydrogen-Ion Concentration ; Lactic Acid ; Silicon Dioxide ; Sodium Azide ; Tooth ; Water

Hemolytic property is a specific feature of bacteria to obtain iron which is essential for its survival in host tissues. Therefore, it is thought to be one of several factors of virulence. The purpose of this study was to investigate the hemolytic properties of Prevotella nigrescens isolated from the teeth diagnosed as pulp necrosis and apical periodontitis under the presence of hemolysin inhibitors such as NaN3 and dithiothreitol, heat, various pH and cultural conditions. The results were as follows; 1. Clinically isolated P. nigrescens strains and standard P. nigrscens ATCC 33563 showed hemolytic activity. 2. P. nigrescens showed higher hemolytic activity against human erythrocytes than sheep or horse erythrocytes. 3. NaN3 and dithiothreitol (DTT) reduced the hemolytic activity of P. nigrescens in a dose dependent manner (p < 0.05). 4. Optimal pH for the maximum hemolytic activity of P. nigrescens was 4.0 and the hemolysin was stable under the 50degrees C, but the hemolytic activity was significantly decreased at 95degrees C. 5. P. nigrescens cultured in 10% CO2 condition showed higher hemolytic activity than the bacteria cultured in the anaerobic condition.
Bacteria ; Dental Pulp Necrosis ; Dithiothreitol ; Erythrocytes ; Horses ; Hot Temperature ; Humans ; Hydrogen-Ion Concentration ; Iron ; Periapical Periodontitis ; Prevotella nigrescens* ; Prevotella* ; Sheep ; Sodium Azide ; Tooth ; Virulence