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Biomedical subjects

A Hunaiti

Publications and source records attributed to A Hunaiti.

3 recordsLinked to original sources

Lead concentration and the level of glutathione, glutathione S-transferase, reductase and peroxidase in the blood of some occupational workers from Irbid City, Jordan.

Blood samples were collected from 263 lead-exposed suspected males living in Irbid area in the northern part of Jordan. The blood lead concentrations in the samples were determined by atomic absorption and were related to the type of work performed by the workers. The blood lead concentration was higher in metal casters, 41.6, and radiator welders, 32,8 micrograms/dl, compared to non-suspected lead-exposed university students, 5.7 micrograms/dl. Workers such as mechanics, bus drivers, car painters and gas station workers showed slightly higher but not significant blood lead. The blood glutathione content and the activities of glutathione reductase, glutathione peroxidase and glutathione S-transferase were also determined in non-suspected subjects and in those with occupational exposure to lead. With increasing blood lead concentration, glutathione content decreases as well as the activities of the glutathione utilizing enzymes.

Adult↗

Radial diffusion as a simple and rapid method for screening superoxide dismutase activity.

Superoxide dismutases are of great interest due to their increasing medical applications in therapy and diagnosis of some diseases. The radial diffusion assay was evaluated for its usefulness as a simple, cheap and accurate assay for screening superoxide dismutase activity. In this assay O2- radicals were generated from the interaction of reduced riboflavin with molecular oxygen upon exposure of agar gel containing riboflavin and N,N,N,N-tetramethylethylene diamine (TEMED) to light. If nitrotetrazolium dye is also present, it will be reduced to the blue insoluble formazan, whilst if superoxide dismutase is present it will prevent this blueing. The developed assay was found to give reproducible estimates of pure samples of superoxide dismutase with a lower limit of measurements of about 10 mg. It can be adapted to measure the levels of superoxide dismutase in various crude biological samples.

Animals↗

Activation of sodium cyanide to a toxic but non-mutagenic metabolite in Salmonella typhimurium.

Salmonella typhimurium strains (OASS-positive) synthesize a toxic but non-mutagenic metabolite from cyanide and O-acetylserine. Salmonella typhimurium mutant DW379 (OASS-deficient) is neither able to carry out this reaction in vitro nor produce the toxic metabolite in vivo. L-Cysteine reverses the cyanide metabolite mediated inhibition and thus allows OASS-positive strains to grow in medium containing cyanide and O-acetylserine. The results suggest that the enzyme O-acetylserine sulfhydrylase catalyzes the reaction of cyanide and O-acetylserine to form the toxic metabolite. This metabolite is ninhydrin-positive, adheres strongly to the cation-exchange column, and migrates in TLC to an Rf value similar to that of beta-cyanoalanine.

Biotransformation↗