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Biomedical subjects

K Krishnaswamy

Publications and source records attributed to K Krishnaswamy.

100 records · Page 6Linked to original sources
PubMedDate not supplied

Influence of dietary restriction and protein deficiency on plasma half-life and tissue distribution of tetracycline in rats.

1. The effects of dietary restriction and protein deficiency on plasma half-life and tissue distribution of tetracycline were studied in rats by feeding either a 20% protein diet in restricted quantity or a 9% protein diet ad lib and compared with rats given a 20% protein diet ad lib (control group). 2. It was observed that half-life of tetracycline was shortened and that plasma and tissue Cmin levels at steady-state were lower in undernourished rats. Tissue concentrations in liver, kidney, muscle and bone correlated well with plasma levels. A high degree of correlation was also observed between plasma and tonsillar concentrations of tetracycline in human subjects. 3. These studies indicate that undernourished subjects may require an altered dosage regimen of tetracycline to maintain effective steady-state concentrations of the drug.

Adolescent↗
PubMedDate not supplied

The effect of malnutrition on the pharmacokinetics of phenylbutazone.

The pharmacokinetics of phenylbutazone were studied after a single oral dose of 6 mg/kg bodyweight in 35 adult male subjects with differing nutritional status. The elimination half-life was significantly shorter and plasma clearance accelerated in undernourished patients who had significant weight deficit and low serum albumin concentration. Plasma protein binding was only 86% compared with 95 to 96% in normal subjects (smokers and non-smokers). The apparent volume of distribution was also higher in undernourished patients. Significant correlations were observed between serum albumin, protein binding and bodyweight. Multiple regression analysis of the data indicated that altered drug protein binding partially contributed towards variation in half-life and clearance; and the plasma albumin concentration significantly influenced the amount of drug bound in plasma. The results indicate that nutritional status is one of the important environmental variables that can alter drug kinetics and disposition in man. Further studies, including measurement of steady-state plasma concentrations of various other drugs, are necessary to elucidate drug kinetics in malnourished subjects.

Adult↗
PubMedDate not supplied

Fibrinogen and homocysteine levels in coronary artery disease.

Conventional risk factors like high serum cholesterol, smoking and hypertension do not explain all the mortality and morbidity due to coronary artery disease in Indian population. Novel factors like plasma fibrinogen and homocysteine have been currently recognised as independent risk factors for coronary artery disease. A case-control study was carried out to examine the role of plasma fibrinogen, homocysteine, lipid profile and anthropometric parameters in angiographically established coronary artery disease patients. The relationship between the biochemical and anthropometric parameters was also examined. Fifty-eight male patients in the age range of 35-60 years with angiographically established coronary artery disease and equal number of matched-controls were the subjects of this study. Cases with coronary artery disease had significantly higher waist-to-hip ratio, waist-to-thigh ratio, plasma fibrinogen and total cholesterol. Mean plasma total homocysteine levels were not significantly different between cases and controls. In Indian population, elevated plasma fibrinogen and abdominal obesity appear to be significantly associated with coronary artery disease.

Adult↗
PubMedDate not supplied

Hepatic dysfunction in undernourished patients receiving isoniazid and rifampicin.

Adult undernourished tuberculous patients receiving isoniazid, rifampicin and ethambutol were evaluated clinically and biochemically for hepatic dysfunction. The nutritional status was assessed by body-mass index, serum albumin and haemoglobin. While only 11% of the patients developed jaundice, the majority of the patients had a significant elevation of the serum hepatic enzymes suggesting subclinical hepatotoxicity. A significant downward trend during the 3-6 months period was seen in patients with multiple estimations of SGOT and SGPT indicating a self-limiting toxic process. However, the continued elevation of GGT suggests enzyme induction by rifampicin. Undernutrition contributes to drug toxicity by various mechanisms. Therefore, it is important to evaluate the nutritional status of the tuberculous patients receiving drugs, which are potentially hepatotoxic.

Adolescent↗
PubMedDate not supplied

Food restriction and short-term effects of aflatoxin B1 feeding on putative preneoplastic biochemical markers.

The susceptibility of experimental rats to Aflatoxin B1, a well known hepatocarcinogen, during chronic food restriction was studied, using a few putative preneoplastic biochemical markers. Gamma-Glutamyl transpeptidase was the most sensitive among the various enzymes studied, at the dose of 10 micrograms/day/100 gm body weight of Aflatoxin B1 fed over a period of three weeks after a twelve chronic food restriction in experimental rats. It was significantly elevated in the underfed untreated group, thus suggesting that preneoplastic changes may be precipitated during chronic undernutrition and carcinogen exposure.

Aflatoxin B1↗