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Biomedical subjects

S Lal

Publications and source records attributed to S Lal.

At least 253 records · Page 14Linked to original sources
PubMed1981

Effect of choline on central dopaminergic function in normal subjects.

Oral administration of choline (10 g) had no effect on basal serum growth hormone or prolactin concentrations in normal subjects (N = 5). Choline significantly enhanced the increase in growth hormone secretion induced by apomorphine HCl (0.5 mg s.c.). These data suggest that cholinergic mechanisms may enhance hypothalamic-pituitary dopaminergic function in man in contrast to their inhibitory effect on dopaminergic function in the basal ganglia.

Adult↗
PubMed1981

Effect of sleep deprivation on dopamine receptor function in normal subjects.

Twenty-four hours sleep deprivation significantly decreased the growth hormone response to the dopamine receptor agonist, apomorphine HCl, in five normal men (0.5 mg s.c.) and one woman (0.75 mg s.c.) but had no effect on basal or post-apomorphine prolactin concentrations. These results suggest that sleep deprivation decreases the sensitivity of certain central dopamine receptors. The relevance of this finding to the antidepressant effect of sleep deprivation is unclear.

Adult↗
PubMed1981

Effect of manganese and copper interaction on behavior and biogenic amines in rats fed a 10% casein diet.

Manganese chloride (1 mg manganese/ml drinking water) and copper sulphate (250 mg copper/kg diet) were administered daily for 30 days to growing rats maintained on a 10% casein diet. Manganese in combination with copper produced impairment in the learning ability and memory of rats in either dietary group, with greater alterations in those receiving a 10% casein diet. Hyperactivation due to the combined effects of the metal ions was identical in both dietary groups. The behavioral aberrations were associated with a marked accumulation of Cu in the brain of rats receiving the 10% casein diet. Combined exposure of Mn and Cu also produced a greater elevation in the levels of dopamine (DA) and norepinephrine (NE) and a depression of 5-hydroxytryptamine (5-HT) in the brain of animals fed with a 10% casein diet compared to the animals receiving the 21% casein diet. Thus the animals receiving the 10% casein diet appear to be more vulnerable to the neurotoxic effects of a combined exposure to manganese and copper. However rats maintained on the 21% casein diet and receiving both manganese and copper showed almost identical changes to those observed after manganese administration alone.

Animals↗
PubMed1981

Effect of L-tryptophan on spasmodic torticollis.

The effect of L-tryptophan, a precursor of serotonin, and placebo were studied in eight patients with spasmodic torticollis. L-Tryptophan (5 g po as a single dose) which increased free plasma tryptophan 20-53 fold improved only one out of six patients. Two out of three patients, including the subject who improved following an oral load of tryptophan, improved with L-tryptophan combined with nicotinamide, a tryptophan pyrrolase inhibitor, when administered for 1-3 weeks. However, the magnitude of clinical improvement was not impressive. Our findings suggest that impairment of serotonergic function is not a general finding in spasmodic torticollis though it may play a minor role in the manifestation of this movement disorder in some patients. The present study emphasizes therapeutic response, namely, the intrinsic variability of the disorder, the response to placebo in some subjects and the limitations of methods for measuring change.

Drug Therapy, Combination↗
PubMed1981

Effect of clonidine on growth hormone and glucagon secretion.

The effect of clonidine (0.15 mg i.v.) on circulating GH, glucagon and glucose concentrations was measured in six normal subjects. GH and glucose increased but glucagon secretion remained unchanged. These data indicate that in man clonidine-induced GH secretion is not mediated by a stimulatory effect of clonidine on glucagon secretion and that alpha-adrenergic mechanisms have little role in the regulation of basal glucagon secretion.

Adult↗
PubMed1981

Quantitative DNCB epicutaneous sensitization in leprosy patients and controls.

Status of non-specific cell mediated immunity in 49 leprosy patients classified according to Ridley & Jopling scale and 16 non leprous controls was studied using epicutaneous sensitization with DNCB and quantitatively grading the degree of sensitization with DNCB and quantitatively grading the degree of sensitization and Mx. test with 1 TU PPD. The effect of dapsone administration on CMI responses was also observed. There was no gross depression of CMI responses as made out by epicutaneous sensitization to DNCB but quantitative grading of responses revealed a subtle depression of CMI responses progressively increasing from II to LL end of spectrum. Mx. testing with 1 Tu PPD did not appear to be a good parameter to study the CMI status. Dapsone administration did not alter the CMI responses.

Dapsone↗
PubMed1981

Knowledge about leprosy among leprosy patients.

A study on "Knowledge of Leprosy in Leprosy patients" was conducted in the Dermatology outpatient department of JIPMER. The study has shown that a good percentage of leprosy patients possess proper knowledge of leprosy in respect of its awareness, nature of treatment, consequences of lack of treatment and prevention of disease. Knowledge regarding the cause and mode of spread of disease and duration of treatment was lacking in majority of patients These areas should be given more concentration in educating the leprosy patients. It was found that literate patients possessed better knowledge than illiterate patients.

Adolescent↗
PubMed1981

Gastro-intestinal side effects of clofazimine.

Three out of 30 patients of leprosy getting clofazimine therapy developed severe gastrointestinal side effects following the therapy in the dose of 100 mg after one month, eight months and five weeks respectively. One of the patients died due to the side effects. Indian patients appear to be more prone to severe gastrointestinal side effects of clofazimine and may develop the same after shorter duration of therapy with smaller doses of the drug.

Adult↗
PubMed1980

Lumped and population stochastic models of skeletal muscle: implications and predictions.

Lumped models of skeletal muscle have been assumed a) in the design of experiments and the interpretation of experimental findings, b) in theoretical studies. In this paper, a population model that takes into account the differing properties and separate (independent) activation of motor units is presented as the most appropriate for muscle. A realistic (for muscle) transformation, population leads to lumped model, resulting in the lumping of motor unit neural signals or system responses, is proposed. On this basis, the possibility of modelling muscle as a single system is examined; and the consequences of treating muscle as a lumped system, in experiments or theoretical studies, are discussed. Also, the advantages of lumping, in models of muscle, are reviewed. Predictions of a computer population model, together with actual recordings from a hand muscle, are used to confirm the results of the analysis.

Axons↗
PubMed1980

CNS tryptamine metabolism in hepatic coma.

Lumbar CSF indoleacetic acid (IAA) was higher in patients with cirrhosis of the liver than in controls. It was also higher in CSF of patients in coma than in those with hepatic cirrhosis but not in coma. There was a strong correlation (r = 0.89, p less than 0.01) between the grade of hepatic coma and CSF IAA. These data indicate that there is an association between elevated CNS tryptamine metabolism and hepatic coma. How far changes in the metabolism of tryptamine and other trace amines are relevant to the induction of hepatic coma or are simply a reflection of advanced liver dysfunction is unclear.

Adult↗
PubMed1980

The effect of manganese administration, alone or combined with zinc, mercury and cadmium, on the tissue levels of these elements in rats.

Manganese chloride was administered alone or in combination with zinc chloride, mercuric chloride and cadmium chloride i.p. to rats for 30 days to investigate the effect of interaction of these elements on their content in brain, liver and kidney. Significant changes in the accumulation of these metals after combined exposure indicated that metabolic interactions occur. Alterations in the tissue contents of manganese, zinc, mercury and cadmium after combined administration may reflect changes at the absorptive sites or in excretory pattern.

Animals↗
PubMed1980

Effect of L-tryptophan on apomorphine-induced growth hormone secretion in normal subjects.

Oral administration of the serotonin precursor, L-tryptophan, to normal male volunteers (n = 7) in a dose (3 g) sufficient to increase free plasma tryptophan concentrations more than 12-fold had no significant effect on basal growth hormone secretion or on apomorphine HCL-induced (0.75 mg sc) peak growth hormone concentrations. These data suggest that, in man, tryptophan administration has little effect on central dopaminergic function, at least in the hypothalamic-pituitary axis and that serotonergic mechanisms have no major modulatory effect on dopamine-mediated growth hormone secretion.

Adult↗
PubMed1980

Beclomethasone dipropionate aerosol compared with dry powder in the treatment of asthma.

In a double-blind trial, beclomethasone dipropionate inhaled as a dry powder in doses of 200 micrograms three times a day was compared with the conventional aerosol of 100 micrograms three times a day, each for a period of 4 weeks. Neither the dry powder nor the aerosol showed any significant advantage over each other in terms of ventilatory function. Plasma cortisol levels were unaltered with the two medications in spite of the doubled dose of the corticosteroid powder. Choice of one or the other method of administration of medication depended on patient preference and the ease with which he could familiarize himself with either technique.

Administration, Intranasal↗
PubMed1980

Further evidence of the efficacy of co-trimoxazole in granuloma venereum.

One hundred and sixteen patients with granuloma venereum were treated with cotrimoxazole two tablets twice daily. All the patients responded; most of them required treatment for 10-15 days. Only two patients had recurrences, which were probably due to reinfections. No side effects of the drug occurred. Co-trimoxazole is considered to be the treatment of choice for granuloma venereum because of its high efficacy, few side effects, easy administration, and absence of any risk of masking concomitant syphilis.

Drug Combinations↗
PubMed1980

Combined light- and electron-microscopic study of the rat saphenous nerve.

Using light- and electron-microscopic techniques, a quantitative histological study of the rat saphenous nerve has been carried out. The distribution of myelinated fibre diameters was bimodal; while that of the unmyelinated axons was unimodal. The variation of myelin sheath thickness with axon diameter was non-linear; two straight lines were found to fit the data best. The variation of g (axon diameter/total fibre diameter) with total fibre diameter was also nonlinear, being best fitted by two lines -- one straight, the other slightly curved. The number of unmyelinated axons per Schwann cell process was examined. the ration of unmyelinated axons to myelinated fibres was 3.42:1.

Animals↗
PubMed1980

Transient abolition of generalized photosensitive epileptic discharge in humans by apomorphine, a dopamine-receptor agonist.

Apomorphine, an agonist of dopamine receptors, blocks or significantly reduces photically induced seizures in the baboon (Papio papio). We therefore studied the effect of subcutaneously administered apomorphine in 11 patients with generalized photosensitive epilepsy. Visual evoked potentials were not altered by apomorphine, but in nine patients apomorphine transiently blocked the epileptic photosensitivity for an average of 45 minutes. Therefore, dopaminergic mechanisms play a role in the pathophysiology of human generalized photosensitive epilepsy.

Adolescent↗