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Biomedical subjects

H Chandra

Publications and source records attributed to H Chandra.

At least 37 records · Page 2Linked to original sources

GC-NPD and GC-MS analysis of preserved tissue of Bhopal gas disaster: evidence of methyl carbamylation in post-mortem blood.

Twenty-five preserved autopsy blood samples of Bhopal toxic gas exposed victims were analysed by gas chromatography (GC) coupled with either Nitrogen-Phosphorous detector (NPD) or mass spectrometer (MS) for the presence of methyl carbamyl valine in terms of valine methyl hydantoin (VMH). 84% of these samples showed a positive test for VMH on GC-NPD and the identity of the peaks were further confirmed on GC-MS. The concentration of VMH in the gas-affected positive blood samples ranged from 2.56 to 51.28 nanomoles. These results indicate entry of methyl isocyanate (MIC), one of the constituents of the toxic cloud caused by the disaster, into the blood stream of victims who had inhaled gas.

Accidents, Occupational↗

GC-MS identification of MIC trimer: a constituent of tank residue in preserved autopsy blood of Bhopal gas victims.

Based on the external and internal findings of Bhopal gas disaster victims, it was apparent that the gases and particulate matter came out as an aerosol. This was possibly the pyrolysed, reformulated, reconjugated suspension of constituents of the tank E-610 of Union Carbide India Limited, Bhopal, while it was claimed to be methyl isocyanate (MIC) only. It was postulated by the manufacturer of MIC, that the material inhaled by the victims of the Bhopal gas disaster does not cross the lung barrier (UCC press conference on 14th December 1984). It was observed that the more the victims ran, the more aerosol they inhaled and the fatalities were observed in such victims. The tissues, which were preserved in the deep freeze, were randomly selected and analysed by GC coupled with MS (ITD) Finnigan MAT, UK. 14 out of 34 autopsy cases showed MIC trimer peak in extracts of blood. This was one of the constituents of the aerosol and was also located in the tank residue, thereby proving that the trimer had passed the lung barrier.

Accidents, Occupational↗

High performance liquid chromatographic method for the analysis of organophosphorus and carbamate pesticides.

A method has been developed for the rapid quantitative analysis of organophosphorous and carbamate pesticides using HPLC. Good separation was obtained among the four major groups of organophosphorus pesticides [i.e. aryl phosphorothionate (methyl parathion), alkyl phosphorothionate (malathion), enolphosphate (phosphomidon, monocrotophos, dichlorvos), heterocyclic phosphorothionates (quinalphos)] and carbamates [viz. Carbaryl (Sevin) and Baygon (Dalf)] with a detection limit of 100 ng for all the pesticides. Separation was measured in terms of capacity factor (k') resolution (R) and selectivity factor (alpha ii). The method described can be used for the analysis of biological samples for the presence of organophosphorus and carbamate pesticides in the cases of poisoning. Recovery studies were made in the blood, lung and liver and found to be 85-97% with reproducibility at greater than 95%.

Autopsy↗

Repair of prostatomembranous urethral strictures by a bulboprostatic intussusception technique.

The repair of post-traumatic strictures of the prostatomembranous urethra in 22 patients by a bulboprostatic intussusception technique is described. Minor wound infection occurred in 12 patients. No other complications were encountered in up to 5 years of follow-up. This operation is a useful and relatively easy technique for dealing with all but the very long strictures of this region.

Adolescent↗

Time since death. An entomological study on corpses.

After death, during disintegration, various environmental conditions and fauna play an important role, indicating "time since death." The natural openings of the host body provide the most important breeding place for an agent which could consume the body very quickly, e.g., flies. Wounds are preferred over the natural openings by this agent. In such cases, antemortem wounds become unidentifiable. This paper presents the study of 25 cases in which inferences relating to the maturation of blow fly life stages and the total developmental time of an adult blow fly in breeding experiments in the prevailing environment are drawn. These can be used to help estimate the "time since death" of infested bodies.

Animals↗

The uptake of cadmium from a dietary and soluble source by the crustacean Daphnia magna.

Daphnia were exposed to radioactively labeled cadmium in solution and in the presence of Chlorella which had been preloaded with the metal to varying extents. Illuminated algal cells retained the cadmium and greatly reduced its availability to the daphnids. Autoradiographic evidence was obtained which implicated the exoskeleton as a major sink for the cadmium taken up from solution. Cadmium in solution at a concentration close to the 48 hr LC50 level did not affect respiration during the first 6 hr of exposure. Retention patterns were similar, regardless of the source of cadmium, but ecdysis resulted in a considerable loss of body burden provided that this had been acquired via a predominantly soluble route.

Animals↗

Effect of long-term centchroman treatment on some estrogen-sensitive biochemical constituents in the genital organs of female rhesus monkeys (Macaca mulatta).

Effect of long-term Centchroman (3,4,-trans-2,2-dimethyl-3-phenyl-4-p-(beta-pyrrolidinoethoxy)-phe nyl)-7-methoxy chroman) treatment on some estrogen-sensitive biochemical parameters in the genital organs of female rhesus monkey was studied. Centchroman treatment did not demonstrate any consistent pattern of stimulation or inhibition in any of the estrogen-sensitive biochemical parameters. However, glycogen recorded a gradual decline in uterus, cervix and vagina. The results thus indicate that Centchroman evoked a mixed response probably due to manifestations of both estrogenic and antiestrogenic properties.

Alkaline Phosphatase↗

Effect of long-term centchroman treatment on plasma steroid and peptide hormones in female rhesus monkeys (Macaca mulatta).

Effect of weekly oral administration of Centchroman (3,4-trans-2, 2-dimethyl-3-phenyl-4-(p-(beta-pyrrolidinoethoxy)-phenyl)-7-met hoxychroman) at 1 and 2.5 mg/kg for 12 months on plasma estradiol, progesterone, luteinizing hormone and follicle stimulating hormone of female rhesus monkeys was studied. Centchroman administration at both doses did not disturb the menstrual pattern of rhesus monkeys except for a prolongation of the first treatment cycle. The subsequent cycles were of normal duration. The general pattern of plasma estradiol, progesterone, luteinizing hormone and follicle stimulating hormone was not affected by Centchroman treatment. The basal and peak levels were similar in pretreatment, control and treatment cycles. The results clearly indicate that Centchroman treatment up to 1 year does not affect the hypothalamo-pituitary-ovarian axis in female rhesus monkeys.

Administration, Oral↗

Antimycotic activity of some amino acids against dermatophytes.

20 amino acids were assayed at 1% concentration for their toxicity against the mycelial growth of two dermatophytes viz., Microsporum gypseum and Trichophyton mentagrophytes. L-Cysteine hydrochloride exhibited absolute toxicity against both the test pathogens while DL-aspartic acid was found active against Microsporum gypseum only. The minimum inhibitory concentrations of L-cysteine hydrochloride was found to be 0.5 and 0.4% against M. gypseum and T. mentagrophytes, respectively, at which it showed mycostatic nature. However, the amino acid exhibited mycocidal activity at 0.9 and 0.8% against M. gypseum T. mentagrophytes, respectively. The spectrum of L-cysteine hydrochloride was studied at 1 and 0.5% concentrations against 24 human and animal pathogenic fungi and it was found to possess broad range of activity. The mycotoxicity of amino acid remained unaltered at high temperature, on autoclaving and against high inoculum density. Besides, it showed stronger activity in comparison to four antimycotic drugs viz., griseofulvin, 5-bromosalicyl-4-chloranilidine, acidum undecylenicum and nystatin.

Amino Acids↗

Histomorphologic evidence of fracture healing after direct electrical stimulation in dogs.

A histomorphologic study was done at intervals up to 10 days after causing a fracture in both hindleg tibiae in dogs and giving direct electrical stimulation in one tibia, the other being used as control (20 microns ampere of direct current were passed in 28 limbs and the current was maintained with the help of a simple regulator developed by the authors). The radiologic and histomorphologic study showed definite evidence of early start and completion of healing processes in the electrically stimulated hindlegs. Negative potentials induced at the fracture sites appeared to be the cause of improved healing. The incidence of infection and focal necrosis at the anode was minimal in this experiment.

Animals↗

Zinc in the epididymal and vasal spermatozoa of rhesus monkey (Macaca mulatta).

Zinc level in maturing spermatozoa collected from caput, corpus, and cauda regions of the epididymis and vas deferens of rhesus monkey was measured. Spermatozoa collected from the caput epididymis have the highest concentration of zinc (36 micrograms/10(8) spermatozoa). There was a marked reduction in the zinc content of corpus spermatozoa and a further decrease in the spermatozoa of cauda epididymis. Thus the zinc content of spermatozoa gradually decreases as they migrate from the caput to cauda epididymis. There was a significant increase in the zinc content of vasal spermatozoa as compared to those collected from the cauda region of epididymis.

Animals↗