S. K. Kashyap

In vitro cytological and cytogenetic effects of an Indian variety of chrysotile asbestos

Abstract The cytotoxic and cytogenetic effects of chrysotile asbestos (Indian Variety, AP-I) in vitro on Chinese hamster ovary cells were investigated. Chrysotile asbestos (AP-I) produces high vacuolization of cytoplasm, flattening of cells with increased size, and chromosomal aberrations. Both cytological and cytogenetic studies were dependent upon the dose and the period of exposure to chrysotile asbestos.

Dominant-lethal study of technical-grade hexachlorocyclohexane in Swiss mice.

Male Swiss mice, 6-8 weeks old, were given a diet containing technical-grade hexachlorocyclohexane (BHC) at 500 ppm continuously for 4, 6 and 8 months. After the completion of the scheduled exposure period, the males were sequentially mated with 2-3 untreated virgin females at weekly intervals for 8 weeks. The females were autopsied at mid-term pregnancy for evaluation of dominant-lethal mutation. The number of dead implants, including deciduomas and dead embryos, showed a significant increase. Similarly, the percentage fertility and live embryos per female showed a decline when compared with the control

Protection against "green symptoms" from tobacco in Indian harvesters: a preliminary intervention study

Two types of gloves were provided to 85 non-Virginia tobacco harvesters who complained of having green symptoms. Results show that the use of gloves causes a significant reduction in nicotine absorption as reflected by the nicotine and cotinine excretion rates and also the reduction in the prevalence of green symptoms, since contact with the leaves and leaf-sap and the abrasions of the palms was avoided by their use. It was found that the use of rubber gloves afforded protection among 93% of the subjects, while with cotton gloves the proportion was somewhat less (78.5%). Cotton gloves were more comfortable but nondurable while the rubber ones were durable but not so comfortable.

Effect of chrysotile asbestos (AP-I) on sister chromatid exchanges in Chinese hamster ovary cells

Abstract In vitro effect of an Indian variety of chrysotile asbestos from Andhra Pradesh (AP-I) is evaluated using sister chromatid exchanges (SCEs) in Chinese hamster ovary (CHO) cells. Cultures were treated for 24 hr with different concentrations of asbestos fibers, i.e., 0.1, 1, 10, and 100 μg/ml of medium. Sister chromatid exchanges were elevated even with the lowest concentration used. However, the linear relationship between SCEs and asbestos concentration is not seen.

Intervention studies against green symptoms among indian tobacco harvesters

The use of rubber gloves reduced nicotine and cotinine absorption among 29 tobacco harvesters, as evidenced by the urinary excretion rate of nicotine and cotinine. Approximately 20% (n = 6) of the subjects reported that symptoms disappeared when they used gloves, but the remaining 23 workers complained of an occasional headache even when using gloves. Wearing of boots and socks as well as gloves prevented the symptoms and significantly decreased nicotine and cotinine excretion. This suggests that nicotine is absorbed through the feet.

Experimental studies on insecticides commonly used in India

SummaryUsing hexachlorocyclohexane (BHC) as a model histopathological, histoenzymological, biochemical, and electrophoretic studies were undertaken to find out certain parameters for early diagnosis of liver cancer. In addition, cytogenetic studies were carried out to evaluate the effect of BHC feeding on mitotic and meiotic divisions. The results of these investigations suggest that there is a significant change in liver weight in experimental group. Histologically, liver cells follow a definite sequential cellular alteration ultimately leading to liver tumor. Histochemically, well defined pattern of glycogen accumulation and iron distribution in hepatocytes was observe. The electron-microscopic observation demonstrated prominently the proliferation of agranular endoplasmic reticulum in early stages. The distribution of certain enzymes linked with plasma membrane, lysosomes, and mitochondria showed the functional alteration of these organelles both in neoplastic nodules and tumours induced by BHC. The biochemical changes observed in gluconeogenic enzymes (G6Pase and F1,6dipase) and dehydrogenases (LDH, ICDH, and MDH) at different duration of exposure to BHC indicated decrease in enzyme activity of both gluconeogenic pathway and tricarboxylic acid cycle, linked with energy metabolism. These changes tend to recover with discontinuation of BHC but 8 months continuous feeding produces irreversible changes in G6Pase activity. Using polyacrylamide gel electrophoresis technique a change in serum proteins and LDH isoenzymes was observed. However, extrapolation of these findings to human situation needs more extensive studies, taking into account all possible variables, such as the DDT and BHC load in our environment and the body burden resulting there from.

Changes in Serum Hexachlorocyelohexane (HCH) Residues in Malaria Spraymen after Short-Term Occupational Exposure

The use of organochlorine insecticides for public health programs is indisputably necessary in developing countries. Thus, there is a need to evaluate human response to these chemicals under local field conditions. The effects of a short-term, 16-wk exposure to hexachlorocyclohexane has been evaluated and compared in malaria spraymen with and without any previous occupational exposure to this insecticide by measuring the pre- and post-exposure serum hexachlorocyclohexane concentration. A significant increase in original serum hexachlorocyclohexane concentration. A significant increase in original serum hexachlorocyclohexane concentration was observed in subjects on their first occupational exposure (5X), compared to those with previous exposure (3X). All workers reached approximately the same serum levels within 16 wk, regardless of their history of previous exposure.

Early changes in serum protein and liver LDH isoenzymes in mice exposed to technical grade hexachlorocyclohexane (BHC) and their possible relationship to liver tumours

Mice were exposed to hexachlorocyclohexane (BHC) in order to study the changes in the serum protein pattern and in the LDH isoenzymes of the liver. After 2 months of exposure the protein pattern showed a new band which persisted even after the development of a tumour. The LDH isoenzymes pattern showed a gradual decrease of the faster moving LDH-1 and LDH-2 bands which later disappeared completely when hepatic tumours formed. The significance of these results is discussed.