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Biomedical subjects

R Singh

Publications and source records attributed to R Singh.

At least 793 records · Page 44Linked to original sources
PubMed1976

Enzymatic conversion of sterigmatocystin into aflatoxin B1 by cell-free extracts of Aspergillus parasiticus.

A cell-free extract, prepared from Aspergillus parasiticus ATCC 15517 grown in synthetic medium, was active in converting [14C]sterigmatocystin into aflatoxin B1 in the presence of reduced nicotinamide adenine dinucleotide phosphate. The activity was demonstrated by the time course of conversion and the linear dependence of the yield of product on enzyme concentrations. Optimum activity was obtained at pH 7.5 to 7.8 at 27 C. The results confirm sterigmatocystin as a biogenetic precursor of aflatoxin B1. Techniques were developed for enzymatic studies on aflatoxin biosynthesis.

Aflatoxins↗
PubMed1976

Alcohol dehydrogenase activities of wine yeasts in relation to higher alcohol formation.

Alcohol dehydrogenase activities were examined in cell-free extracts of 10 representative wine yeast strains having various productivities of higher alcohols (fusel oil). The amount of fusel alcohols (n-propanol, isobutanol, active pentanol, and isopentanol) produced by the different yeasts and the specific alcohol dehydrogenase activities with the corresponding alcohols as substrates were found to be significantly related. No such relationship was found for ethanol. The amounts of higher alcohols formed during vinification could be predicted from the specific activities of the alcohol dehydrogenases with high accuracy. The results suggest a close relationship between the control of the activities of alcohol dehydrogenase and the formation of fusel oil alcohols. Also, new procedures for the prediction of higher alcohol formation during alcoholic beverage fermentation are suggested.

Journal Article↗
PubMed1976

Effect of prolactin administration on ovarian and thyroidal activity in relation to gonadotropic and thyrotropic potency in a freshwater catfish, Heteropneustes fossilis (Bloch).

Radiophosphorus incorporation by ovary was the criterion used for the assessment of ovarian activity in H. fossilis. Prolactin administration at different dose levels failed to elicit any obvious change in ovarian 32P uptake. From the findings of this experiment it appears that prolactin has no influence on ovarian activity. However, it exerted an inhibitory effect on the thyroid activity in intact H. fossilis. It was evident by retarded thyroidal 131I uptake. But the declension in serum PB131I was less pronounced. TSH content of the pituitary gland in response to prolactin administration was also reduced. It seems that prolactin interferes in thyroidal iodine accumulation perhaps by retarding the synthesis of TSH, but apparently does not prevent thyroxine output to a perceptible level.

Animals↗
PubMed1975

Traumatic left ventricular aneurysm. Two cases with normal coronary angiograms.

Two young males had traumatic left ventricular aneurysm and normal coronary angiograms. Trauma was penetrating (bullet) in one and nonpenetrating (fist blow) in the other. Recurrent ventricular tachycardia in one and a systemic embolus in the other required aneurysmectomy. The patients are free of symptoms 42 and 21 months after surgery. The presence of traumatic ventricular aneurysm and normal coronary angiograms suggests that myocardial necrosis following chest trauma is often caused by direct injury to the myocardium rather than by injury to occlusion of the coronary arteries. Therefore, coronary artery bypass surgery may be unnecessary or even hazardous in persons with chest trauma and evidence of early myocardial necrosis.

Adolescent↗
PubMed1975

Experience with homologous lyophilised nerve grafts in the treatment of peripheral nerve injuries.

Report of a series of 18 late secondary nerve grafts using lyophilised (disantigenised and disenzymatised) homografts of the Braun Melsungen Company. In contrast to the publication of Kuhlendahl et al. (1972) 32% of the cases showed definitive signs of regeneration. Therefore, in spite of the fact that autografts give better results, further research into the possibilities of homografts seems desirable. Their potential usefulness obviously is restricted to cases in which from any reasons autologous nerve grafts are not available.

Adolescent↗
PubMed1975

Microbiology of cutaneous tuberculosis.

Detailed bacteriological characteristics including drug sensitivity of 12 mycobacteria isolated from 51 cases of different types of cutaneous tuberculosis were studied; no mycobacterium could be isolated from remaining 39 cases. Nine were identified as M. tuberculosis and 3 as 'anonymous' mycobacteria. Acquired resistance to one or more than one drug (streptomycin, isoniazid, PAS and thiacetazone) was observed in 3 out of 9 strains of M. tuberculosis. All the 'anonymous' strains were resistant to all the drugs except ethionamide and ethambutol.

Aminosalicylic Acids↗
PubMed1975

Personal evaluations, laughter, and affective judgments.

Fifty-six subjects read positive or negative evaluations of their personality made by a bogus same-sex peer and then rated their immediate feelings. A second group of 22 subjects rated their feelings after reading the evaluations of a third person. It was found that personal evaluations evoked more spontaneous laughter than did the evaluation of a third person (p less than .001). Inclusion of the factor of laughter in the experimental design disclosed that subjects who laughed felt more pleasant than those who did not laugh (p less than .008) and that laughter was associated with affective state only in the negative evaluation condition (p less than .003).. Also, positive evaluations made the subjects feel good, and negative ones made them feel bad (p less than .001). Results seemed to suggest that extreme affective arousal engenders laughter which, in turn, alters the judgments of one's affective state.

Adolescent↗
PubMed1975

Nutritional anthropometric measurements of male Tamil clerks in Madras (sea coast plains) and Ooty (hills).

The mean values and standard deviations of height, weight, bicristal diameter, arm girth and skinfold measurements at triceps and biceps of 315 Tamilian adult men from Madras (South India) and 318 adult men of the same ethnic, linguistic, socioeconomic and age groups from the Hill Station of Ooty (South India) are compared. Intercorrelations between age and six anthropometric parameters have also been presented separately for Madras and Ooty subjects. Body weight, arm girth and skinfold measurements were significantly higher in Madras subjects, and bicristal diameter measurements were significantly higher in Ooty subjects. Stature measurements were lower in Ooty subjects than Madras subjects but the difference was not statistically significant. In both Madras and Ooty subjects, highest positive correlations were observed between arm girth and body weight. The next highest correlation observed was between triceps-biceps skinfolds.

Adult↗