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Biomedical subjects

P K Ray

Publications and source records attributed to P K Ray.

At least 163 records · Page 9Linked to original sources
PubMed1970

An assessment of the Coulter counter model S.

An assessment of the Coulter model S automatic blood counter has been carried out. The standard deviations for the haemoglobin concentration, haematocrit, red cell count, and white cell count are, respectively, +/- 0.15 g/100 ml, +/- 0.45%, +/- 0.04 m/c mm, and +/- 0.47 thous/c mm. These results are clearly more accurate than careful manual estimates, performed for comparison on the same samples. Details of the comparisons are presented. A comparison is also made with routine daily estimations.;Carryover' from one sample to the next was found to be about 2%, and tests in the ranges likely to be found in practice showed good linearity for the haemoglobin estimation, haematocrit, red cell count, and white cell count. A brief account of instrument failures is given.The performance of the Coulter model S compares well with that of other automated equipment for which detailed evaluations are available.

Blood Cell Count↗
PubMedDate not supplied

Membrane alterations in health and disease with particular reference to immune function and cancer.

Ever since the early microscopists and experimental biologists distinguished the fundamental differences between the animal and plant cells, investigations on the structure and function of the cell membrane have become a fascinating field of biomedical research. The membranes of all types of cells provide the biological border, and maintain the integrity of the cell by protecting it from toxic insult rendered by chemicals, biochemicals, toxins etc. The toxic damage of the cell membrane results in an alteration of the transport mechanism or transmits a message for altered DNA, RNA and protein synthesis, vis-a-vis altered cell division which ultimately leads to death of the cell. In fact, the ligand receptor binding, with particular reference to toxicants of different kinds, may alter the normal physiological function of the cell. If the damaged cell is involved in immune function, the host becomes more susceptible to infection. Prolonged immunosuppression may predispose the host to develop cancer, although cancer cells themselves originate as a result of genetic damage caused by environmental toxicants, endocytosed after binding with membrane receptors, finally reaching the genomic material to cause carcinogenic alteration. The phenomena of membrane binding, transmission of message, processing of message and eventual alteration of biomolecular structure consequently resulting in a disorder or disease process are described in the present communication.

Animals↗
PubMedDate not supplied

Aflatoxin induces depletion of activities of phase I biotransformation enzymes in growing rats.

Aflatoxins are suspected human carcinogens and are also known to possess diverse toxicological activities. In the present communication an attempt has been made to evaluate the effects of aflatoxin B1 (AFB1) on hepatic microsomal drug metabolizing enzymes in growing rats. The weanling rats were exposed to 60, 300 or 600 micrograms AFB1/kg body weight, per os, on alternate days for 4 weeks, in 0.2 ml corn oil. A significant depression in the activities of aryl hydrocarbon hydroxylase (AHH), aniline hydroxylase (AH) and aminopyrene-N-demethylase (AND) was observed at 300 micrograms and 600 micrograms doses of AFB1. However, no significant change was recorded in glutathione-S-transferase (GST) activity and total sulphydryl (SH) content upon AFB1 exposure in weanling rats. Thus, AFB1 appears to have more pronounced effect on the phase I, rather than phase II, biotransformation enzyme system in weanling rats. The depression of drug metabolizing enzymes together with suppression of immunity by AFB1, as reported earlier by us, may increase the susceptibility of the host to toxic chemicals, drugs and infectious agents, particularly during the post-natal period.

Aflatoxin B1↗
PubMedDate not supplied

Clinical and biochemical changes in chronically exposed organophosphate workers.

Health effects of occupational organophosphate exposure were investigated by subjecting 22 workers chronically exposed to an organophosphate pesticide, fenthion (O,O-dimethyl-O-(4-methylmercapto-3-methylphenyl)-phosphorothioate) to clinical evaluation, estimation of serum cholinesterase, serum alkaline phosphatase (SAP), serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT). The mean age of the workers was 31 years and the mean duration of fenthion exposure 8.2 years. Headache (59%), giddiness (50%), ocular symptoms (27%) and paresthesia (18%) were the commonest symptoms. Serum acetylcholinesterase and butyrylcholinesterase levels were significantly lower than in controls. After withdrawing the workers from organophosphate exposure for 3 weeks, the follow-up study revealed absence of transient symptoms. There was no change in their neurological status, and serum acetylcholinesterase and butyrylcholinesterase levels were raised significantly, whereas the other serum enzymes showed no significant change. For monitoring of occupational organophosphate exposure, the importance of both clinical and biochemical parameters is emphasised.

Adult↗