Publications by authors named "Krishnakumari M"

Polyhydroxyalkanoates (PHAs) are natural polyesters produced by microbes, a potential alternative to synthetic plastics. Various methods ranging from gravimetry to spectrophotometry are routinely used for qualitative analysis of extracted PHA. There is a great need for accurate quantification of intracellular PHA during bioprocess.

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Exposure of the cyclodiene insecticide heptachlor at 1/8 and 1/4 LD50 to male and female albino rats before mating affected fertility in both sexes. A decrease in implantations, serum oestrogen and progesterone levels and increase in resorptions in the females was observed. However, no histological changes were observed except for few atretic follicles in the treated females.

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1. Technical hexachlorocyclohexane (HCH) depleted hepatic stores of vitamin A in male albino rats to cause secondary vitamin A deficiency. 2.

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The haematotoxicity of technical hexachlorocyclohexane (HCH) (1000 ppm) was investigated in male albino rats fed with diet free of vitamin A or containing vitamin A at 2000 or 10(5) I.U./kg.

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The reproductive toxicity of the organochlorine insecticide, hexachlorocyclohexane (HCH), was investigated in male albino rats fed a diet free of vitamin A or containing vitamin A at 2000 or 100,000 IU/kg diet. Diets containing 1000 ppm HCH for 7 weeks did not cause testicular toxicity in the vitamin-A-deficient and supplemented rats. However, reproductive toxicity was clearly manifested 2 weeks after withdrawing HCH from the diets and was more pronounced in the vitamin A deficient rats compared to their vitamin A supplemented counterparts.

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Activities of Acetylcholinesterase (AChE) in brain and erythrocytes, pseudocholinesterase (PChE) in plasma and non-specific carboxylesterase (NSE) in brain, liver, plasma and kidney were assayed at weekly intervals in growing male rats fed dietary pirimiphos-methyl at dosages of 1000, and 1500 ppm for a period of 28 days. Significant inhibition of tissue esterases were observed at the end of 7 days at both the dosages and the enzyme activities remained markedly inhibited at subsequent intervals. Activities of all enzymes (excepting Brain AChE) returned to normal levels following a 7-day maintenance on the insecticide-free diet implicating that pirimiphos-methyl induced little or no permanent tissue damage.

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Responses of Paramecium caudatum, a ciliated protozoan, to acute exposures of certain organic solvents and organophosphorus insecticides (OPI) were studied by determining their lethal concentration (10 min-LC100) and median lethal concentration (4 h-LC50). The solvents and OPI evoked a distinct sequence of responses. Among the five solvents tested, acetone proved most toxic [LC-2.

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Growing male rats were fed dietary Pirimiphos-methyl at 0, 500, 1000 and 1500 ppm for 28 days and selected blood and urine constituents were measured at weekly intervals. Dietary intake of Pirimiphos-methyl induced an initial, transient hypoglycemia and a marked elevation in blood urea at all dosages. Though it did not produce any significant change in the urine output initially, marked oliguria was observed after 12 days of feeding.

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In an acute study, albino rats of both sexes were orally administered graded doses of Pirimiphosmethyl, and the statistically computed median lethal dose (LD-50) were 1861 and 1667 mg/kg body weight for male and female rats respectively. No treatment related changes were discernible with regard to food intake, growth, gross or histopathology of the organs. In a time-course study, the correlation between symptoms and degree of esterase inhibition was examined in rats administered the minimum lethal dose (MLD: 1000 mg/kg b.

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Response of cholinesterase to dermal exposure of acute, single and multiple doses of Bromophos in the female rat has been studied. Dose-response studies (50-4000 mg/kg body weight, 24 h exposure) showed that plasma cholinesterase was most sensitive to inhibition in vivo, followed by the brain and erythrocyte acetylcholinesterase. The ID50 values for the in vivo cholinesterase inhibition were 10.

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Dichlorvos (O, O-dimethyl O-(2,2-dichlorovinyl phosphate: DDVP 76.6 X EC) an organophosphate pesticide had a profound effect on cardiac activity of albino rats. Adult male rats anesthetized with pentobarbitone were administered 30, 50, 70 and 90 mg/kg body weight of dichlorvos.

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The effect of L-ascorbic acid supplementation on Pirimiphos-methyl induced toxicity was studied in albino rats. Biochemical estimations were made in rats administered orally the insecticide at 100 and 200 mg/kg body weight with or without oral supplementation of L-ascorbic acid at 200 mg/kg b.w.

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Acute oral toxicity of the copper fungicides, copper sulphate and copper oxychloride, were studied in male Gallus domesticus. The median lethal dose for copper sulphate and copper oxychloride determined were 693 and 1263 mg/kg body weight, respectively. Severe diarrhea and delayed mortality (3 to 6 days) was characteristic of copper oxychloride.

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Eighty male weanling rats were fed dietary levels of Technical X-factor (beta-isomer free BHC, a by-product obtained during the separation of lindane from Tech. BHC) at dosages of 10,50,250,750,1500 and 3000 ppm for 90 days. No overt signs of toxicity or mortality were observed at any of the dietary levels.

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Weanling male albino rats were fed 100, 750 and 1500 p.p.m.

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Intragastric administration of acute doses of Technical X-factor (beta-isomer free BHC, a byproduct obtained during separation of Lindane from Tech. BHC) carried in peanut oil elicited typical signs of central nervous system depression in adult rats. The computed oral LD50 values of X-factor were 4174 and 5673 mg/kg.

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The algae Scenedesmus acutus and Spirulina platensis have been considered for use as a supplementary protein in feed and food. This Institute has developed the technology of production and utilization of such algae. It is essential to demonstrate their safety in view of their public health aspects, the interest of the producers and image of these new sources of foods.

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Twelve week old male birds (Gallus domesticus) were intragastrically administered technical grade samples of Benzene hexachloride (gamma-isomer: 13%) and X-factor (gamma-isomer: 16%) [a by-product obtained during separation of gamma-isomer from (BHC)] in capsules with a view of establishing oral LD50 values. The computed oral LD50 values for BHC and X-factor were 596.8 and 589.

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