Histopathological changes in liver of Heteropneustes fossilis exposed to cypermethrin.

Cypermethrin was administered to Heteropneustes fossilis in chronic concentration to determine lesion of liver as indicators of tissue damage. The cypermethrin dose used was 1/4 of 96 hr LC50. Histopathological changes in liver ranged from vacuolization, necrosis, fibrosis of perivascular region and disposition of yellow brown grains at different time of exposure viz; 20th, 30th, 40th and 60th days.

Effects of bleomycin and Staphylococcus protein-A on lungs of mice.

Fibrosis of organs and tissues are major causes of morbidity and mortality in human. The currently available pharmacologically based treatments are unsatisfactory. As an experimental animal model antitumor antibiotic drug bleomycin (BLM) is widely used to produce lung fibrosis. The present study has been undertaken to investigate the possible role of a potent immunomodulator Staphylococcus protein-A (SpA) in the modulation of lung lesions caused by treatment of BLM. In mice BLM, 0.5 mg in 200 microliters of normal saline and SpA, 6 micrograms in 200 microliters of normal saline was administered singly or in combination twice a week for 4 weeks. The fibrotic lesions in the lungs were observed after 4 weeks of BLM treatment. After 4 weeks treatment of SpA, the hyperreactive changes in bronchi and bronchioles were observed. In the co-treatment group of BLM and SpA, the effects observed were in the form of enhanced lesions in the lung parenchyma. Moreover, the pleural lesions were also observed in co-treatment group (BLM + SpA). Opposite to the assumption, SpA being a potent immunomodulator was not able to reduce the lung lesions produced by BLM.

Enhanced translocation of particles from lungs by jaggery.

Because industrial workers in dusty or smoky environments seemed to experience no discomfort if they consumed the sugar cane product jaggery, experimental studies were undertaken to observe the effects of jaggery on dust-exposed rats. Rats with and without a single intratracheal instillation of coal dust (50 mg/rat) were orally gavaged with jaggery (0.5 g/rat, 5 days/week for 90 days). The enhanced translocation of coal particles from lungs to tracheobronchial lymph nodes was observed in jaggery-treated rats. Moreover, the jaggery reduced the coal-induced histological lesions and hydroxyproline contents of lungs. The lesions induced in omental tissue and regional lymph nodes by a single intraperitoneal injection of 50 mg each of coal and silica dust were modified by jaggery (0.5 g/rat, 5 days/week for 30 days). These findings along with the preventive action of jaggery on smoke-induced lung lesions suggest the potential of jaggery as protective agent for workers in dusty and smoky environments.

Effect of Staphylococcus protein-A on adrenal gland in mice.

Staphylococcus protein-A (SpA) was administered (ip) to Balb/c male mice for two weeks, twice a week at the dose level of 1, 6 and 12 micrograms in 200 microliters of normal saline. A significant change in the relative weights of liver, spleen, thymus, tracheobronchial lymph node, lung and testis was observed in 1 microgram SpA treatment group. In the adrenal, marked changes at the dose level of 1 microgram SpA treatment after 2 weeks were observed in the form of cellular proliferation on zona glomerulosa (ZG) and zona fasciculata (ZF) of adrenal cortex. With 6 and 12 micrograms SpA, adrenocortical masses were observed outside the capsule of adrenal gland. The enhanced effects of SpA at 4 weeks after treatment with the dose level of 6 and 12 micrograms were in the form of adrenal cell masses outside adrenal gland and histological changes in the adrenal cortex. The results suggest that long term and high doses therapy with SpA may be a risk factor to sensitive endocrine glands.

Excess choline availability: a transient effect on spermatogenesis in the rat.

The reproductive effects of choline (trimethyl-beta-hydroxyethylammonium) are unknown. Excess dietary intake of choline may occur in humans. Adult male rats were administered i.p. aqueous choline chloride (25 mg/rat, daily for 12 or 24 days). Administration of excess choline for 12 days did not significantly alter spermatogenesis. Administration for 24 days depleted pachytene spermatocytes until posttreatment day 5, while slight proliferation of spermatogonia was noted from day 5 onwards. By day 12, the tubules showed almost normal cellular associations. It is suggested that perhaps a prolonged administration of excess choline may prove to be toxic to male reproduction.

Effect of choline and mineral fibres (chrysotile asbestos) on guinea-pigs.

Both short-term and long-term, low and high doses of parenterally administered choline produce pathological lesions in lungs and lymph-nodes of rats and guinea-pigs. Male guinea-pigs given choline by intraperitoneal injection, 40 doses of 50 mg of choline chloride, 5 days per week for 8 weeks, developed lung lesions consisting of peripheral nodules of small cells, neoplastic bronchiolar epithelium, carcinomatous lesions and changes in the pleural surface by the end of the experiment (680 days). In a second group, a single intraperitoneal injection of 15 mg of chrysotile asbestos given after 210 days of choline administration resulted in the early onset of pulmonary lesions at 570 days but there was, in addition, evidence of enhancement of cancerous lesions both in lung and in lymph-nodes at 570 days and 680 days as compared with choline alone. It is clear from the present experiment that the parenteral administration of carcinogenic mineral fibres (chrysotile asbestos) and availability of excess choline act synergistically in producing cancerous lesions in lungs and other organs.

Effect of mica dust and choline on the lymph nodes of rats.

Male albino rats given choline alone by intraperitoneal injection (40 doses of 25 mg/5 days a week over a period of 10 weeks), developed atypical lymphadenopathy at the end of the experiment (330 days). In a second group, the intratracheal instillation of single dose of 25 mg of respirable mica provoked proliferation of reticular cells and macrophages in the tracheobronchial lymph nodes. However, in a third group, the combined action of choline and mica caused marked lymphadenopathy with abnormal cells. The role of choline, an essential component of cell membrane, in enhancing the reaction to mica in the lymph nodes, is discussed.

Type IV collagen is a heteropolymer with the formula C2D.

Native type IV collagen was purified from bovine kidney cortex homogenate by a method involving pepsin-solubilization and heat gelation. The near homogenous protein has a molecular weight of approximately 380K and the chain composition C2D. The subunits are linked by disulfide bridges.

Pulmonary response to kaolin, mica and talc in mice.

Following intratracheal inoculation the pulmonary fibrogenic response of kaolin, mica and talc was investigated in mice over a period of 210 days. All the three dusts incited acute inflammatory reaction at early periods but with mica dust the acute reaction persisted longer. Subsequently there was gradual increase in the fibroblastic activity in the focal areas and mica produced, in addition, many cholesterol cleft-like structures together with marked fibroblastic activity and lymphocytic infiltration. Towards the termination of experiment at 210 days the fibrosis, in general, remained restricted to grade II with kaolin and mica while talc produced thickened interalveolar septa. The transport of dust from lungs to lymph nodes occurred earlier with mica than with kaolin or talc dust accompanied with little fibrotic reaction. The significance of the findings has been discussed.

Experimental manganese lymphadenopathy in guinea pigs.

Experimental manganese lymphadenopathy was produced by guinea pigs by intratracheal inoculation of manganese dioxide (50 mg/300 g body weight) and histopathologic changes in the tracheobronchial lymph nodes were studied up to 180 days. There was slow extracellular transport of manganese dust into the nodes, which did not provoke any significant reaction at early periods. However, at later periods the nodes exhibited a significant increase in the density of dust particles and the reaction consisted of phagocytosis, degeneration of dust laden macrophages, slight proliferation of fibroblasts, together with some reticulinosis corresponding to deposits of dust particles. The significance of these findings have been discussed from the chronic toxicity viewpoint.

Effect of intratracheal injection of mica dust on the lymph nodes of guinea pigs.

Histopathological changes in the tracheo-bronchial lymph nodes were studied up to 365 days in guinea pigs following intratracheal injection of a suspension of mica dust. In general, the cytotoxic effect provoked by dust was not pronounced as the majority of the swollen dust-laden macrophages retained their normal structure at the termination of the experiment and fibrotic lesions were limited to the formation of thick reticulin fibers. The poor fibrogenic response of mica dust has been attributed to its low cytotoxicity.

Fibrogenic response in murine lungs to asbestos.

Pulmonary fibrogenic response was investigated in mice following intratracheal inoculation of amosite, anthophylite and tremolite varieties of Indian asbestos and studies were made over a period of 150 days. At early periods all the varieties produced acute inflammatory reaction in the lungs. Thick reticulum fibers were encountered at later periods with amosite, while only thin reticulum fibers developed with anthophyllite or tremolite variety. The formation of asbestos bodies did not take place with any of the asbestos varieties even at 150 days. The deviation in the pulmonary fibrogenic response in mice has been attributed to species difference.