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Biomedical subjects

S K Garg

Publications and source records attributed to S K Garg.

At least 163 records · Page 9Linked to original sources
PubMed1989

Serum growth hormone, insulin and blood sugar responses to oral glucose in protein energy malnutrition.

Blood sugar (BS), serum immunoreactive insulin (IRI) and growth hormone (GH) were measured in 5 normal children and 15 with varying grades of protein energy malnutrition (PEM) during a standard oral glucose tolerance test (OGTT). Impaired glucose tolerance was noted in grade III and IV PEM but not in grade II. Serum insulin responses were low but appropriate to blood glucose in grade II and grade III PEM and were lower (p less than 0.001) in Grade IV PEM subjects. Higher basal GH was observed in most cases of grade III and IV PEM (p less than 0.001) and the elevated GH was not suppressed following the oral glucose load. Further, a paradoxical rise in GH during OGTT was seen in 3 of the 5 subjects with grade-IV PEM.

Blood Glucose↗
PubMed1989

Comparative pharmacokinetic and pharmacodynamic study of four different brands of propranolol in normal volunteers.

The pharmacokinetic and pharmacodynamic studies of four different brands of propranolol (Inderal, Ciplar, Corbeta and Propal) were carried out after single and multiple dosing on six normal adult healthy volunteers in a randomized crossover fashion to determine any inter-brand variations in bioavailability and pharmacodynamic effects. No significant difference was observed in any of the pharmacokinetic and pharmacodynamic parameters of four different brands of propranolol studied.

Adult↗
PubMed1989

Theophylline pharmacokinetics in well-nourished and malnourished asthmatic children.

The influence of age, sex and nutritional status on theophylline pharmacokinetics was studied in stable asthmatic children. Theophylline was given at a dose of 6 mg/kg orally on an empty stomach and the pharmacokinetic parameters were calculated from the estimated plasma concentration of theophylline. No significant difference in the elimination half-life (t1/2), volume of distribution (Vd), clearance (cl) and area under the time plasma curve (AUC) could be observed between the three pediatric age groups. Also, there was no influence of sex and nutritional status on the pharmacokinetic parameters. The notable observation was a 5-fold interindividual difference in the peak plasma concentration (Cmax) after a single dose.

Adolescent↗
PubMed1988

Effect of defolliculation and 17 alpha-hydroxy, 20 beta-dihydroprogesterone on cyclic AMP level in full-grown oocytes of the rainbow trout, Salmo gairdneri.

The changes in cAMP were followed in trout oocytes incubated in vitro after defolliculation performed by either enzymatic or manual dissection. Both defolliculation methods induced a highly significant rise in oocyte cAMP level (4.5 times the basal level of control [follicle-enclosed oocytes], after 6 h). Treatment of defolliculated oocytes with 17 alpha-hydroxy, 20 beta-dihydroprogesterone (17 alpha, 20 beta-OH-P) (10(-6) M), which induced oocyte maturation (germinal vesicle breakdown [GVBD]) was able, first, to interrupt the increase of oocyte cAMP level promoted by defolliculation and then to lower this level significantly down to values that still remained higher than folliculated controls. Very low concentrations of 17 alpha, 20 beta-OH-P (1.38-55.6 10(-9) M), or physiological doses of testosterone (0.35 10(-6) M, in the range found in vivo before ovulation) were able to induce a similar decrease of oocyte cAMP level without inducing GVBD. Under the same experimental conditions estradiol (0.35 10(-6) M) exhibited no action. These results suggest that some factor(s) originating in the follicle (FIF), inhibit the oocytes' tendency to accumulate cAMP before the final surge of 17 alpha, 20 beta-OH-P. This factor might be a follicular steroid such as testosterone or nonmaturing concentrations of 17 alpha, 20 beta-OH-P. Moreover our data favour the hypothesis that the final surge of 17 alpha, 20 beta-OH-P could induce distinct intraoocyte mechanisms: the first induces an irreversible blockage of cAMP level before the inhibitory action of the FIF is suppressed by ovulation, and the second mechanism leads to GVBD.

Animals↗
PubMed1988

Role of pineal and eyes in the regulation of ovarian activity and vitellogenin levels in the catfish exposed to continuous light or continuous darkness.

To investigate the relative importance of pineal and eyes in ovarian activity, catfish subjected to pinealectomy, binding, or both were exposed to continuous light (LL) or continuous darkness (DD) during the different phases of the annual reproductive cycle. Pineal or eyes have no influence on ovarian activity during the preparatory, prespawning, and spawning periods of the annual reproductive cycle under these photoregimes. However, the pineal accelerated ovarian activity under LL and DD during the postspawning period. Blinding alone has no effect on ovarian recrudescence under these regimes. However, combined surgery (blinded-pinealectomy) inhibited ovarian development under both these conditions, indicating that the pineal organ is more important than the eyes. Ovarian recrudescence occurred even in the absence of both pineal and eyes, indicating the involvement of extrapineal and extraocular photoreception in the regulation of reproductive activity in the catfish.

Animals↗
PubMed1988

GABAergic, dopaminergic and cholinergic interaction in tremorine-induced tremors in mice.

Antitremor effects of systemically administered GABA agonists (GABA and sodium valproate) and GABA antagonists (bicuculline and picrotoxin) were studied in mice against tremorine-induced tremors. None of the GABA agonists were found to possess any antitremor effect, whereas GABA antagonists were found to possess protective effect against tremorine-induced tremors. Simultaneous administration of GABA agonists with sub-effective doses of anticholinergic agent (scopolamine) did not potentiate antitremor effect of scopolamine, whereas GABA antagonists and effective doses of scopolamine when administered simultaneously resulted in antagonism of protective effect of scopolamine. Similarly, when GABA agonists and sub-effective doses of dopaminergic agent, bromocriptine, were administered simultaneously, the protective effect of bromocriptine was potentiated. When GABA antagonists and effective doses of bromocriptine were administered simultaneously, the protective effect of bromocriptine was antagonized. The modification of the protective effect of anticholinergic and dopaminergic agents by GABAergic agents has been explained on the basis of neurotransmitter interaction.

Animals↗
PubMed1988

Pharmacokinetic study of a new sustained release preparation of propranolol in normal healthy volunteers.

The pharmacokinetics of a sustained release (SR) propranolol (Betalong) were compared with conventional propranolol (Inderal) after single and multiple dosing in 8 normal healthy volunteers. The study was designed in a crossover fashion. SR propranolol 80 mg in a single dose maintained the plasma concentration of propranolol above the minimum therapeutic concentration up to 25 h. The steady-state propranolol concentration after 80 mg conventional propranolol twice daily and SR propranolol 80 mg daily was almost similar. The results indicate that Betalong (SR propranolol) satisfies the pharmacokinetic criteria expected of a sustained release preparation of propranolol and may be useful in single daily dose.

Adult↗
PubMed1988

Single dose kinetics of rifampicin and isoniazid in well-nourished and malnourished patients of tuberculosis.

A single dose kinetics of isoniazid and rifampicin alone, and combination was studied in well-nourished and malnourished patients of tuberculosis. The elimination half-life of isoniazid was significantly increased when administered in combination with rifampicin in well-nourished and malnourished patients, while no significant difference was observed in any of the pharmacokinetic parameters of rifampicin in combination with isoniazid or alone in both groups of patients. Results are discussed on the basis of pharmacokinetic drug interaction.

Acetylation↗
PubMed1988

Plasma dapsone and its metabolite monoacetyldapsone levels in leprotic patients.

Dapsone (DDS) is a drug of choice in the treatment of leprosy. The DDS and MADDS levels and different pharmacokinetic parameters after a single dose of dapsone and at steady state in leprotic patients have been studied. At steady state, all the patients showed plasma DDS and MADDS levels above 0.5 micrograms/ml throughout the 24-h duration. There was no significant difference in the elimination half-lives of DDS and MADDS after a single dose as compared to at steady state, but AUC0-alpha for both DDS and MADDS were significantly increased at steady state. From these results, it could be concluded that 100 mg daily dose is sufficient to maintain plasma therapeutic concentration in leprotic patients in Indian population.

Adult↗
PubMed1988

Pharmacokinetics of aspirin and chloramphenicol in normal and leprotic patients before and after dapsone therapy.

Pharmacokinetics of aspirin and chloramphenicol was studied in 16 normal and 16 patients suffering from leprosy. A significant increase (p less than 0.05) in the elimination half-life of chloramphenicol was observed before and after dapsone treatment in leprotic patients as compared with the normal volunteers, while no significant difference was observed in any of the pharmacokinetic parameters with aspirin.

Adult↗