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Biomedical subjects

V S Mathur

Publications and source records attributed to V S Mathur.

At least 37 records · Page 2Linked to original sources
PubMed1988

Disposition of sulphadiazine in young rhesus monkeys with protein calorie malnutrition.

Disposition of sulphadiazine was assessed in young rhesus monkeys under three stages of nutritional manipulations i.e. control, protein calorie malnutrition (PCM) state and following nutritional rehabilitation. There was no alteration in the absorption kinetics except a delayed peak in the malnourished group. A decrease in volume of distribution of drug in the peripheral compartment was noted. The most significant changes observed was in the elimination kinetic parameter. The (Ke) elimination rate constant and the clearance rate showed a significant decrease which could be either because of decreased rate of acetylation or a decrease volume of distribution.

Animals↗
PubMed1988

A scoring system for selection of essential drugs.

A scoring system is presented for selection of essential drugs, using criteria of efficacy, safety, cost of a course of therapy, compliance, multiple usage and storage, ease of administration and local availability. Such a system allows for different weighting of factors whose relative importance varies from country to country and would help in choosing the most appropriate and cost-effective drugs for use in developing countries. The importance of such factors as cost and compliance has been illustrated with suitable examples. This approach could also be used for individual patient decisions with the aid of a computer program.

Anti-Bacterial Agents↗
PubMed1987

Effect of tolbutamide treatment on the pharmacokinetics of intravenously administered sulphamethoxazole in rabbits.

Fifteen days of tolbutamide treatment significantly decreased the elimination half life (t1/2), area under the curve (AUC0----infinity) and increased the clearance of sulphamethoxazole (SMZ) in rabbits. No significant difference was observed in the volume of distribution. The percentage of plasma protein binding to SMZ was not altered, while N-acetyltransferase activity in liver and kidney was significantly increased after tolbutamide therapy. The changes observed in the pharmacokinetic parameters of SMZ after tolbutamide treatment is due to the induction of liver N-acetyltransferase activity.

Animals↗
PubMed1986

Steroid therapy in Bell's palsy.

The effect of steroid therapy was studied on twenty-eight cases of Bell's palsy. Complete and partial recovery was obtained in twenty-five cases. Delay in starting the therapy with steroids seems to be a major factor responsible for the failures.

Adolescent↗
PubMed1986

Disposition of chloramphenicol in young rhesus monkeys with protein-energy malnutrition.

The disposition of chloramphenicol was studied in young rhesus monkeys at three levels of nutrition: control, protein-energy deficiency, and following nutritional rehabilitation. During the malnutrition phase, the plasma elimination half-life was prolonged and the plasma clearance was reduced. Simultaneously there was a decrease in the activity of chloramphenicol-specific UDP-glucuronyl transferase. These changes were reversible following nutritional rehabilitation.

Animals↗
PubMed1986

Effect of Rumex nepalensis extracts on histamine, acetylcholine, carbachol, bradykinin, and PGs evoked skin reactions in rabbits.

The antihistaminic, anticholinergic, antibradykinin, and/or antiprostaglandin activity of aqueous and the alcoholic leaf extracts of the plant Rumex nepalensis were tested on the prepared site on the back of rabbits, using a control and a test site. Aqueous extract was found to reduce the mean size of the wheal produced by histamine, acetylcholine, carbachol, and bradykinin. The alcoholic extract reduced the size of the wheal produced by histamine, acetylcholine and carbachol. The results indicate that Rumex nepalensis may have antihistaminic, anticholinergic, and/or antibradykinin activity.

Acetylcholine↗
PubMed1986

Comparative pharmacokinetic study of four different sulfonamides in combination with trimethoprim in human volunteers.

The pharmacokinetics of four different sulfonamides i. e., sulfamethoxazole (SMZ). Sulfamoxole (SMO), Sulfadiazine (SDZ) and Sulfadimidine (SDD) in combination with trimethoprim (TMP) were studied in 12 healthy volunteers. Plasma and urine concentrations of sulfonamides were measured at different time intervals. No significant difference was observed in the area under the plasma curve (AUC) of SMZ, SMO and SDZ, while AUC of SMO was significantly higher than SDD only. Free (unmetabolized) SDZ urinary excretion during a 10-25 h period was significantly higher than SMZ, SMO and SDD. The results suggest that SDZ alone or in combination with TMP would be more effective in urinary tract infections as compared to other sulfonamides studied.

Adult↗
PubMed1986

Assessment of bio(in)equivalence of deriphyllin-digoxin in human volunteers. II. Evaluation of rabbits as qualitative animal model.

In rabbits, a three way cross-over test was carried out to assess bioavailability of digoxin from commercially available 'Deriphyllin-Digoxin' tablets. The in vitro dissolution test showed that these tablets had low dissolution even at the end of 4 hr. The in vivo tests in rabbits compared bioavailability of digoxin from Deriphyllin-Digoxin tablets with that from Lanoxin tablets and intravenous digoxin injection. The treatments were given in randomized order with a minimum of 14 days wash-out period between the treatments. After the drug administrations, periodic blood samples were collected and plasma digoxin concentrations were analysed using radioimmunoassay. As indicated by the results of in vitro dissolution tests, Deriphyllin-Digoxin tablets showed poor and delayed absorption of digoxin in vivo. A parallel study on comparative bioavailability for the same batches of digoxin tablets was also carried out in human volunteers. The study in human volunteers involved 14 subjects and had a cross-over dosing. The bioavailability results in rabbits were qualitatively similar to human bioquivalence studies. This is the first report showing digoxin bioavailability in rabbits corresponding to that in humans. The importance of the rabbit as a secondary model for bioequivalence testing of digoxin formulations has been emphasized.

Administration, Oral↗
PubMed1986

Assessment of bio(in)equivalence of deriphyllin-digoxin in human volunteers.

Bioavailability of digoxin from the formulations of a fixed dose combination of the glycoside with xanthines was compared with that of "Lanoxin". The in vitro analysis of the fixed dose "Deriphyllin-Digoxin" tablets showed that these tablets had low dissolution even at the end of four hours. The in vivo study had a randomized cross-over design with a 14 days wash-out period. The formulations were administered to 14 healthy adult volunteers and periodic blood samples were collected up to 24 hours. The samples were analyzed for digoxin concentration using radioimmunoassay. Results indicate poor and delayed absorption of digoxin from the fixed dose combination. It is concluded that a multiple dose study with pharmacodynamic assessment, in patients or in volunteers, would be adequate to critically reassess the need for the marketed fixed dose combination.

Adult↗
PubMed1985

Collateral circulation in coronary artery disease.

The coronary arteriograms and left ventriculograms of 202 consecutive patients were reviewed. All had at least 75% diameter reduction of 1 or more major coronary arteries. In 127 patients (63%), at least 1 major branch was totally occluded. Collateral circulation was seen in 125 of these 127 patients (190 of 192 totally occluded arteries). Of the 75 patients without total occlusion, only 2 with 99% (or near-total) occlusion had demonstrable collateral circulation (2 of 208 arteries). In no patient with 75 to 98% diameter narrowing was collateral circulation demonstrated (0 of 164 arteries). An analysis was made of the relation between left ventricular (LV) segmental wall motion and the quality of collateral circulation in 190 totally occluded arteries among 125 patients. Of 126 arteries with good collateral circulation, LV contraction was normal in 21%, hypokinetic in 48% and akinetic/dyskinetic in 29%. Of 64 arteries with poor collateral circulation, LV contraction was normal in 23%, hypokinetic in 55% and akinetic/dyskinetic in 20%. There was no statistically significant difference between the effect of good or poor collateral circulation on LV function. These data indicate that collateral circulation cannot be seen angiographically unless there is total or near-total occlusion, and that the presence of collateral circulation does not correlate with LV wall motion abnormalities, i.e., akinetic area, despite good collateral flow or normal wall motion despite absent or poor collateral flow.

Collateral Circulation↗
PubMed1985

Myocardial infarction associated with cocaine abuse.

We report a patient who sustained a myocardial infarction after inhaling cocaine. He developed a persistent wall motion defect that was present 18 months after the acute event despite resolution of electrocardiographic evidence of infarction.

Journal Article↗
PubMed1985

Pharmacokinetic profile of antipyrine in young rhesus monkeys (Macaca mulatta) with protein energy malnutrition.

An experimental model of protein energy malnutrition was produced in five young rhesus monkeys and the pharmacokinetics of antipyrine were studied at three points, initially, during protein energy malnutrition and following nutritional rehabilitation. In a separate group of animals, the estimation of hepatic enzyme aminopyrine N-demethylase was performed. There was a significant decrease in the elimination kinetics, the half life was increased, and the clearance rate was decreased in the malnourished animals, which correlated with a corresponding decrease in aminopyrine N-demethylase activity.

Aminopyrine N-Demethylase↗
PubMed1985

Disposition of acetaminophen in children with protein calorie malnutrition.

Acetaminophen disposition was studied in 11 children suffering from Protein Calorie Malnutrition (PCM) and 5 (age matched) control subjects using the time plasma concentration curve obtained after a single oral administration of 10 mg/kg of the drug. Absorption rate constant (Ka) was not altered in PCM. Elimination rate constant (Ke) was decreased significantly. PCM children had Ke 0.108 +/- 0.015 h-1 in comparison to the control value of 0.170 +/- 0.022 h-1. Plasma half-life (t1/2) was increased in PCM (8.14 +/- 1.30 h) in comparison of the control (4.33 +/- 0.52 h). Area under the curve (AUC) was also significantly increased in PCM (88.88 +/- 21.36 ug h/ml/kg) compared to the control (25.05 +/- 2.99 ug h/ml/kg). Time of drug disappearance was 44.7 +/- 7.1 hours in PCM compared to 24.6 +/- 3.3 hours in the control. Five PCM subjects could be restudied after rehabilitation and they demonstrated the return of elimination parameters towards control values. Drug therapy needs revision in light of these findings.

Acetaminophen↗
PubMed1985

GABAergic, dopaminergic and cholinergic interactions in perphenazine-induced catatonia in rats.

Anticatatonic effects of systemic and intracerebroventricularly administered GABAergic agents (GABA, muscimol piracetam, sod. valproate) were studied in rats against perphenazine-induced catatonia. All GABAergic agents, except piracetam, were found to posses anticatatonic actions as they significantly blocked perphenazine-induced catatonia. When these GABAergic agents were administered simultaneously with anticholinergic (scopolamine) or dopaminergic (bromocriptine) substances there was potentiation of the anticatatonic effect. The protective effect of GABAergic agonists and GABA antagonist and its modification by anticholinergic and dopaminergic agents has been explained on the basis of neurotransmitter interaction.

Animals↗
PubMed1985

Impairment of drug elimination in patients with liver disease.

An attempt has been made to investigate drug elimination in patients with liver disease. Antipyrine was chosen as a model drug. The patients were divided into three groups depending upon clinical, biochemical, radiologic and histologic findings; (1) mild (Idiopathic portal hypertension, extrahepatic portal vein obstruction and Gilbert's syndrome); (2) moderate (Budd-Chiari syndrome and amoebic liver abscess); (3) severe (acute hepatitis, chronic active hepatitis and cirrhosis). A prolongation in antipyrine half-life (t1/2) was observed in 108 patients with liver disease (24.59 +/- 1.72 h) as compared to 12 controls (11.63 +/- 0.86 h). Similarly, metabolic clearance rate was decreased in all liver disorders. Among liver function tests, antipyrine t1/2 showed a significant correlation with serum albumin and prothrombin time index. After phenobarbitone administration, antipyrine clearance studied in 37 patients showed a significant decrease in t1/2 and an increase in MCR. Antipyrine t1/2 in 26 patients after recovery was comparable to those of controls.

Adult↗