M. Hema Prasad

Free radicals antioxidant enzymes and lipid peroxidation in different types of leukemias

Free radicals are highly reactive species that have been implicated in the pathogenesis of many diseases. Reactive oxygen species can initiate lipid peroxidation and DNA damage leading to mutagenesis, carcinogenesis and cell death, if the antioxidant system is impaired. This study was undertaken to examine the prevalence of oxidative stress and the role of antioxidant defence in untreated leukemia patients. The generation of superoxide anion and hydrogen peroxide by leukocytes, plasma malondialdehyde levels, red cell copper zinc superoxide dismutase (Cu-Zn SOD) and glutathione peroxidase (GSH-PX) activities were determined in 30 patients with different types of leukemias prior to therapy. The superoxide anion generation by polymorphonuclear leukocytes was found to be significantly increased in leukemia patients especially those with acute lymphocytic and nonlymphocytic leukemias, while the hydrogen peroxide levels were comparable to the control values. Plasma lipid peroxidation products in untreated leukemia patients were in the normal range. Red cell Cu-Zn SOD and GSH-PX activities were significantly increased and showed no correlation with the hemoglobin content. Although superoxide generation was high, lipid peroxide levels were normal in these patients. This might be due to the increased activities of the antioxidant enzymes (SOD, GSH-PX) which counteract lipid peroxidation. Increased free radical generation, especially superoxide anion in leukemia patients and increased antioxidant defence enzymes, which is an adaptive protective response, are indicative of mild oxidative stress. There were no significant differences for the parameters cited above between different types of leukemias, suggesting that the changes are not specific to the type of leukemia.

Role of glutathione S‐transferase Mu‐1 (GSTM1) polymorphism in oligospermic infertile males

The aim of this study was to examine whether an association exists between glutathione S‐transferase Mu‐1 (GSTM1) gene polymorphism and idiopathic male infertility. Forty‐two men with infertility and 43 fertile men were recruited for this study. GSTM1 gene was analysed using PCR technique. The frequency of GSTM1 null (−) genotype was observed to be 45.2% in infertile men as against 20.09% in fertile men. Subjects with the GSTM1 null genotype had lower sperm concentrations and motility when compared with the subjects with GSTM1‐positive genotype in both the groups. This study shows that the frequency of GSTM1 null (−) genotype is significantly high in infertile males when compared with the frequency in fertile males (OR = 0.32, P = 0.017, 95% CI = 0.124–0.831).

The effect of thiram on the germ cells of male mice

The effects of thiram or tetramethylthiuram disulphide on the germ cells of Swiss albino male mice were evaluated by analysing spermatocytes (derived from treated spermatogonia) for chromosomal aberrations and by the sperm-head morphology assay. The total doses tested were 80, 200 and 320 mg/kg body weight given by gavage in three consecutive daily doses, the top dose being slightly below the LD50 of thiram. There was a significant increase in the frequency of numerical chromosomal aberrations and abnormal sperms in mice treated with thiram at all dose levels. Such results could have implications for man in that they suggest that undue exposure to thiram could result in the birth of human infants with numerical chromosomal aberrations.

Cytogenetic damage in lymphocytes of rubber industry workers

Cytogenetic investigations were conducted in workers who are occupationally exposed to rubber chemicals such as tetramethylthiuram disulfide, zinc dimethyldithiocarbamate, and tetraethylthiuram disulfide using lymphocytes of peripheral blood. A significant increase in the frequency of chromosomal breaks and gaps was recorded regardless of the duration of exposure to these chemicals.

Analysis of Chromosomal Aberrations in the Peripheral Lymphocytes of Workers Exposed to Diagnostic X-rays

Abstract The incidence of chromosomal aberrations were evaluated in the lymphocytes of peripheral blood of 70 persons working in different hospitals at Hyderabad and occupationally exposed to X-rays. The age range of the workers was 25-54 years and their duration of service ranged from 3-25 years. For comparison blood samples were also collected from 50 subjects (controls) who belonged to same age and socioeconomic status and not exposed to any chemical agents. Subjects in the both groups were nonsmokers and nonalcoholics. The radiographers showed a significant increase of chromosomal aberrations (8.18%) when compared to controls (0.44%). Further the incidence of chromosomal aberrations increased significantly with duration of exposure when compared to controls.

Reproductive Epidemiology in Radiographers Exposed to Diagnostic X-rays

Abstract In the present study reproductive performance of 195 workers employed in various hospitals in Hyderabad was evaluated using standard questionnaire. The workers were exposed to X-rays while handling the patients for diagnostic purposes. 210 individuals belonging to same age and socioeconomic group but not exposed to radiation and toxic chemicals were studied for control data. Statistical analysis revealed a significant increase in the frequency of stillbirths and neonatal deaths in the offspring of the exposed group when compared to the controls. There was an increase in the incidence of congenital defects but the increase was not statistically significant. A decrease in the frequency of live births was observed in the offspring of the exposed group when compared to the data from controls. The increase in abortions among the wives of exposed workers was significant.

Reproductive Outcome in the Wives of Traffic Policemen Exposed to Automobile Exhaust

Abstract Adverse health effects and reproductive hazards at the workplace are an issue of increasing health concern and more than 1000 chemicals at workplace have been demonstrated to have adverse effects in animals. However such studies are limited in humans. Since data on reproductive epidemiology in traffic policemen exposed to automobile exhaust is limited, a study on the reproductive endpoints of traffic policemen exposed to vehicular exhaust was undertaken. Information on age, sex, medical history, occupational health problems, reproductive outcome, possible exposure to mutagens, etc was collected and clinical investigations were undertaken. A significant increase in neonatal deaths and abortions in the wives of traffic police and a decrease in live births was observed. The findings suggest that exposure to vehicular exhaust induce adverse reproductive outcome in the traffic police.

Serum Adenosine Deaminase Estimation in Petrol Filling Station Workers

Abstract The activity of adenosine deaminase (ADA), a measure of cell mediated immune response was determined in serum of 65 male workers employed in different petrol filling stations in Hyderabad and Secunderabad, Andhra Pradesh, over a period of 2 years (July 1999-July 2001). The mean ADA activity in the study group was found to be 18.48 units/liter compared to 17.89 units/liter among controls. There was only a marginal increase in the ADA activity in the study group compared to controls. The increase in the ADA activity in the workers was found to be statistically insignificant. The results indicate that serum ADA activity in petrol filling station workers remains unaltered.

Analysis of chromosomal aberrations in the peripheral blood lymphocytes of aluminium foundry workers

Abstract Cytogenetic effects were evaluated by analysing various types of chromosomal aberrations in the peripheral blood lymphocytes of 97 male employees involved in the manufacture of aluminium wire rods and aluminium conductors. The age range of the subjects was 20-52 years and their service in the factory ranged from 1 to 24 years. The workers were occupationally exposed to aluminium fumes and burnt gases. For comparison, 54 healthy controls belonging to the same age group and socio-economic status were also studied. Peripheral blood lymphocyte cultures were carried out for all the samples and various structural and numerical type of chromosomal aberrations were analysed. A statistically significant increase in total chromosomal aberrations was observed in the exposed group when compared to the control group.

Reproductive Epidemiology of Aluminium Foundry Workers

Abstract 160 non-smoking male workers engaged in the production of aluminium alloys were studied for their reproductive performance. The reproductive parameters studied included number of pregnancies, stillbirths, abortions in their wives and number of neonatal deaths, premature births, congenital abnormalities in their offspring. For comparison, 150 controls belonging to the same age group and socio-economic status and with no occupational exposure to any known physical or chemical agent were also studied. A significant increase in the percentage of abortions, congenital defects and a significant decrease in the percentage of livebirths were observed in the exposed group when compared with the control group. This could be due to occupational exposure to fumes of aluminium at the workplace.