1.Histomorphological and Histochemical Alterations Following Short-term Inhalation Exposure to Sulfur Mustard on Visceral Organs of Mice
Biomedical and Environmental Sciences 1999;12(3):201-213
Toxic effects of inhaled sulfur mustard (SM) on the histology of visceral organs was investigated by exposing mice to 84.6mg/m3 for 1 h duration, using controlled single exposure conditions. A progressive fall in body weight from third day onwards was noticed. Light microscopic examination of the pulmonary tissue of these animals at 6 h post exposure revealed that the tracheobronchial epithelium remained intact, but was infiltrated by inflammatorv cells. By 24 h post exposure, the mucosecretory cells were destroyed. The inflammatory reaction was maximum at 48 h. Bv 7th day post exposure there was swelling and vacuolation of lung parenchymal cells and thrombi formation. In addition SM caused congestion and hemorrhage at alveolar level. SM also caused granulovacuolar degeneration with perinuclear clumping of the cytoplasm of hepatocytes and renal parenchymal cells. Renal lesions were characterized by congestion and hemorrhage. Among visceral tissues, maximum atrophy was observed in spleen. Distribution of lesions increased with post exposure period. The maximum lesions were observed at 7th day post-exposure.
2.Acute Inhalation Toxicity Study of 2-Fluoroacetamide in Rats
SINGH MANINDER ; R.VIJAYARAGHAVAN ; S.C.PANT ; K.SUGENDRAN ; KUMAR PRAVIN ; SINGH RAM ; PURNANAND
Biomedical and Environmental Sciences 2000;13(2):90-96
One of the most potent rodenticides is 2-fluoroacetamide (2-FA). Toxicity of this chemical is well documented. However, its inhalation toxicity data is not available in the literature. Hence, acute inhalation toxicity study was carried out by exposing male and female rats to aerosols of 2-FA at different concentrations for 4 h in a dynamically operated whole body inhalation exposure chamber. During and after the inhalation exposure the rats were less active, and showed mild tremors and convulsions. At higher concentrations the rats died after 2-3 days. The estimated 4-h LC50 for male and female rats was 136.6 and 144.5 mg·m-3 respectively. Exposure to 0.7 LC50 for 4 h duration showed an increase in the liver weight of male and female rats 7 days after exposure. Various haematological and biochemical variables determined were within the normal limits. However, histological findings showed injured lung as indicated by desquamation and necrosis of the epithelium of the respiratory tract. Marked hypertrophy of hepatocytes displaying strong acidophilic granulated cytoplasm was observed. Focal dilatation of renal proximal tubules in kidney with cytoplasmic vacuolation, and irregularly placed pyknotic nuclei were seen. The present study shows that 2-FA is a highly toxic chemical through the inhalation route based on the LC50 value. Consequently necessary precautions should be taken during its handling.
3.Subacute (90 Days) Oral Toxicity Studies of Kombucha Tea
R.VIJAYARAGHAVAN ; SINGH MANINDER ; P.V.L.RAO ; BHATTACHARYA ; KUMAR PRAVIN ; K.SUGENDRAN ; KUMAR OM ; S.C.PANT ; SINGH RAM
Biomedical and Environmental Sciences 2000;13(4):293-299
Kombucha tea (KT) is a popular health beverage and is used as an alternative therapy. KT is prepared by placing the kombucha culture in solution of tea and sugar and allowing to ferment. The inoculum is a fungus consisting of symbiotic colony of yeast and bacteria. KT is consumed in several countries and is believed to have prophylactic and therapeutic benefits in a wide variety of ailments, viz., intestinal disorders, arthritis, ageing and stimulation of immunological system. Though KT is used in several parts of the world its beneficial effects and adverse effects have not been scientifically evaluated. Since there are no animal toxicological data on KT, subacute oral toxicity study was carried out. Five groups of rats were maintained: (a) control group given tap water orally, (b) KT given 2 ml/kg orally, (c) plain tea (PT) given 2 ml/kg orally, (d) KT given in drinking water, 1% (v/v) and (e) PT given in drinking water, 1% (v/v). The rats were given this treatment daily for a period of 90 days. Weekly records of weight, feed intake, water intake and general behaviour were monitored. There was no significant difference in the growth of the animals as evidenced by the progressive body weight change. The organ to body weight ratio and histological evaluation did not show any toxic signs. The haematological and biochemical variables were within the clinical limits. The study indicates that rats fed KT for 90 days showed no toxic effects.