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Biomedical subjects

S Chandrasekar

Publications and source records attributed to S Chandrasekar.

At least 19 recordsLinked to original sources

Drug related crisis in myasthenia gravis.

Myasthenia gravis is an autoimmune disorder where antibodies against the nicotinic Ach receptor resulting in impaired transmission at the NM junction. A number of drugs have been reported to cause neuromuscular blockade and/or to increase weakness in myasthenia gravis. We report a case of myasthenia gravis in which the calcium channel blocker-nifedipine caused the worsening of the symptoms.

Adult↗

Effect of granulocyte macrophage colony stimulating factor on hepatitis-B vaccination in haemodialysis patients.

OBJECTIVES: Haemodialysis patients often fail to respond to hepatitis B vaccination. There are various agents that can be used as vaccine adjuvant in chronic renal failure patients on haemodialysis. In this study, the adjuvant effect of granulocyte macrophage colony stimulating factor (GMCSF) is compared with that of control subjects. METHODS: In this study, eight patients were started on 150 mcg of GMCSF subcutaneously 24 hours prior to intramuscular hepatitis B vaccination (20 mcg of genetically engineered vaccine at the same site). The antibody response to surface antigen (anti HBsAg) in these patients were compared with those of eight control subjects who received standard three doses of monthly 40 mcg of same hepatitis B vaccine. RESULTS: In the control study, only two patients developed significant antibody response to surface antigen whereas seven of eight patients in GMCSF group developed significant antibody titres (> 10 IU/L). The sero-protection rate was 87.5% in GMCSF group and 25% in control group. CONCLUSION: This study shows that GMCSF offers significantly better seroprotection against hepatitis B compared to standard dose of vaccination in patients with chronic renal failure on haemodialysis.

Adjuvants, Immunologic↗

Pharmacokinetics of single dose oral digoxin in patients with uncomplicated type II diabetes mellitus.

Digoxin pharmacokinetics was studied in eight patients with uncomplicated type II diabetes mellitus and seven healthy volunteers. After a single oral dose of digoxin (1 mg), the drug concentration was measured in the serum collected at different time intervals, using a radioimmunoassay method. The diabetics had a higher serum concentration of drug when compared to control. The clearance rate of digoxin was significantly reduced in diabetics when compared to healthy volunteers. The elimination half-life of about 22 hours in both groups is much less than that reported in Western data. Possible reasons for this discrepancy are discussed.

Administration, Oral↗

Short term anti-tubercular drug therapy and hepatic microsomal enzyme activity. Antipyrine metabolism as an index.

The effect of short course chemotherapy on the drug metabolising capacity of the liver was studied in 7 newly diagnosed pulmonary tuberculosis patients, using antipyrine as a model drug. Antipyrine elimination half-life and plasma clearance rate were not significantly altered by 3 weeks of therapy. It is concluded that short course chemotherapy does not affect antipyrine metabolising enzyme activity.

Adult↗

Coxsackie virus and rheumatic fever. A correlative study.

Twenty-one patients of whom 13 had acute rheumatic fever and 8 had recurrence of rheumatic fever were studied for the evidence of coxsackie B viral infection using neutralisation test. A significant rise was noted in 17 cases (81%) and two cases had very high initial titre of neutralising antibodies to coxsackie B viruses type 1 to 6. Mixed infection with more than one serotype was seen in 11 cases. Coxsackie B2 was the commonest type and 14 patients had antistreptolysin 'O' anti-bodies. The high incidence of coxsackie B viral infection in rheumatic fever and the coexistent streptococcal infection and their relationship are discussed.

Adolescent↗

Differential effect of type I and type II diabetes mellitus on serum ampicillin levels.

Ampicillin elimination was studied in 10 poorly controlled, 6 well controlled type I and 14 poorly controlled type II diabetic patients. Two groups of age-matched healthy volunteers served as controls. After oral administration of ampicillin (500 mg), the poorly controlled type I diabetics had significantly lower serum concentration of the drug when compared to their corresponding healthy controls. The elimination half-life (t1/2) remained unaltered. Their creatinine clearance rate and urinary excretion of the drug were significantly reduced. There was no difference in these parameters between well controlled diabetics and healthy volunteers. The bioavailability data calculated from the urinary recovery of the drug, after oral and i.v. administration, suggested reduced oral absorption in poorly controlled type I diabetic patients. Ampicillin kinetics data of poorly controlled type II diabetic patients were not significantly different from that of the control group. Serum ampicillin levels and urinary excretion of the drug were similar in these groups. It is concluded that serum ampicillin level may be lower in poorly controlled type I diabetics which may be due to reduced absorption of the orally administered drug.

Adult↗

Differential effect of type I and type II diabetes mellitus on antipyrine elimination.

Antipyrine elimination was studied in 11 type I and 10 type II diabetic patients and 2 age-matched control groups. After oral administration of antipyrine (15 mg/kg), salivary concentration of the drug was measured at various time intervals by high performance liquid chromatography method. In type I diabetics the clearance rate (CL) and apparent volume of distribution (V) of the drug were significantly higher when compared to corresponding controls. The elimination half-life (t 1/2) remained unaltered. In type II diabetics, the t 1/2 of the drug was increased due to increase in V. There was no significant difference in CL. It is concluded that antipyrine elimination is enhanced in type I diabetics while in type II patients it is unaltered.

Adolescent↗

Effect of type II diabetes mellitus on theophylline elimination.

Theophylline elimination was studied in poorly-controlled and well-controlled type II diabetic patients, seven in each group. Eight healthy volunteers served as a control group. After a single oral dose of theophylline (200 mg) the drug concentration was measured in plasma, collected at different time intervals, using a high pressure liquid chromatography method. The poorly-controlled diabetics had significantly longer elimination half-life (t1/2) due to increased apparent volume of distribution (V) of the drug when compared to well-controlled diabetics. Their clearance rate (Cl) remained unaltered. There was no significant difference in these parameters between healthy volunteers and diabetic patients, although poorly-controlled diabetics had a tendency for higher t1/2 and V. It is concluded that theophylline clearance is unaltered in type II diabetic patients.

Adult↗

Effect of diabetes mellitus on salivary paracetamol elimination.

1. Salivary elimination of paracetamol was studied in nine type I and ten type II diabetics. Ten healthy volunteers served as a control group. 2. A significant increase in the elimination half-life (t1/2) and apparent volume of distribution was observed in type I diabetics compared with controls. Clearance rate (CL) was not significantly altered. 3. In type II diabetics paracetamol elimination t1/2 was significantly increased with a corresponding decrease in CL. Apparent volume of distribution of the drug was not significantly different. 4. Paracetamol elimination t1/2 had significant correlation with fasting blood sugar values.

Acetaminophen↗

Specific heart muscle disease in diabetes mellitus--a functional structural correlation.

We report the morphology of diabetic myocardium obtained by endomyocardial biopsy in 16 diabetics. The material was divided into three groups. The first comprised six patients with unexplained cardiomegaly and obscure congestive cardiac failure. The second group, also of six patients, had no cardiac signs and symptoms but exhibited abnormal systolic time intervals. The third group, of 4 patients, was without any cardiac symptoms or signs and had normal systolic time intervals. The vascular and extravascular changes observed were more pronounced in the symptomatic group, intermediate in the asymptomatic patients with abnormal intervals and least in those without symptoms and normal intervals. This provides supporting evidence for the existence of a specific primary myocardial disease in diabetes with good functional structural correlation.

Adolescent↗

Salivary paracetamol elimination in patients with congestive cardiac failure.

1. Salivary paracetamol elimination was studied in nine patients with congestive cardiac failure (CCF). Six healthy volunteers served as the control group. 2. Paracetamol elimination t1/2 and apparent volume of distribution were significantly higher in patients with CCF compared with controls. There was no significant change in the clearance rate. 3. Drug therapy of failure for a period of 15 days returned the t1/2 and V values to normality.

Acetaminophen↗

A study on the neurotoxicity of broxyquinoline and brobenzoxaldine combination in therapeutic doses.

The neurotoxicity of a combination of broxyquinoline and brobenzoxaldine (Intestopan Forte, containing 500 mg and 100 mg of the drugs respectively per capsule) was investigated by prospective clinical and electrophysiological studies in patients and volunteer subjects given the drugs in therapeutic doses (two capsules three times a day for 5 days). Of 16 patients with intestinal amoebiasis given the drugs (study A), 13 (81.25%) were cured. Adverse effects were mild and did not affect treatment. No neurological adverse effect was reported. Neurological examinations revealed no abnormality in any patient after treatment. Seven volunteer subjects underwent medical, neurological and ophthalmological examinations, and electrophysiological studies of ulnar and peroneal nerve conduction before and after treatment with the drugs in therapeutic doses (study B). Transient paresthesias were reported by one subject on the fourth day of treatment. No medical, neurological or ophthalmological abnormality was detected in any subject after treatment. There was no significant change in motor nerve conduction velocities. There was a significant (P less than 0.001) increase in the stimulus strength for distal ulnar stimulation and a significant (P less than 0.01) decrease in stimulus duration for proximal and distal ulnar stimulation. No significant changes were seen in the peroneal nerves in these parameters. No qualitative abnormality was seen in the oscilloscopic patterns of nerve conduction after treatment. Literature on the neurotoxicity of the halogenated hydroxyquinolines is reviewed. It is concluded that broxyquinoline and brobenzoxaldine (and probably other halogenated hydroxyquinolines as well) are safe and effective in therapeutic doses; neurotoxicity is unlikely to occur when these drugs are used according to therapeutic recommendations.

Adult↗