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Biomedical subjects

R Raveendran

Publications and source records attributed to R Raveendran.

14 recordsLinked to original sources
PubMed1999

Objective structured practical examination in pharmacology for medical laboratory technicians.

The objective structured practical examination (OSPE) is a useful evaluation method for testing psychomotor skills. Students for the degree in medical laboratory technology require to learn certain skills which will make them useful in any research or teaching laboratory in experimental pharmacology. We outline an OSPE which can be used for evaluating students in experimental pharmacology.

Educational Measurement↗
PubMed1996

A computer program for calculation of sample size.

Sample size must be determined while planning a study to ensure that valid conclusions can be drawn when the study is over. different formulae for calculating the required size of the sample are used for different study designs and situations. A computer program is described here to ease the complexity of calculation of sample size for studies designed to use students 't' test.

Sample Size↗
PubMed1994

Ascorbic acid delays the development of tolerance to amphetamine induced anorexia but does not affect the reverse tolerance which develops to the locomotor activity.

Ascorbic acid (1 g/kg) accentuated anorectic and locomotor effects of amphetamine (5 mg/kg) and delayed development of tolerance to anorectic effect. On the contrary, it did not alter the pattern of reverse tolerance to increased locomotor activity. The results suggest that modulation of dopamine receptor sensitivity by ascorbic acid may be the reason for the delay in development of tolerance to amphetamine induced anorexia.

Amphetamine↗
PubMed1992

Indomethacin and protein binding of methotrexate.

Indomethacin, a non-steroidal anti-inflammatory drug is known to increase the efficacy and toxicity of methotrexate, the widely used anti-cancer drug in man. The mechanism for this interaction has not been clearly established. However, since these drugs bind with albumin, a possible displacement of methotrexate by indomethacin from albumin might explain this interaction. To investigate the possible interaction an in-vitro protein-binding displacement study was carried out in 17 normal volunteers and in two groups of eight cancer patients. One group of patients had active disease and the other was in complete clinical remission. Serum samples were obtained and protein levels estimated. The protein binding of methotrexate was measured alone and with indomethacin using equilibrium dialysis. Statistical analysis of results suggested that the binding of methotrexate is not influenced by indomethacin, confirming that methotrexate is not displaced by indomethacin.

Adult↗
PubMed1992

Protein binding of indomethacin, methotrexate and morphine in patients with cancer.

The in vitro protein binding of indomethacin, morphine and methotrexate has been studied in two groups of ten patients each suffering from different types of cancers and compared with twenty normal adult subjects. One group of patients had active disease and the other group was in complete clinical remission. Serum samples were obtained from each subject and the concentrations of albumin and alpha-1 acid glycoprotein (AGP) were measured. Protein binding of drugs was determined using equilibrium dialysis. Alpha-1 acid glycoprotein levels were increased in patients and this effect was more pronounced in active disease (1802 +/- 1025 mg/l) than in remission (931 +/- 273 mg/l). Albumin levels were reduced in active disease (47.67 +/- 15.91 milligrams), but not in remission (61.86 +/- 6.62 milligrams), as compared to control values (58.98 +/- 9.9 milligrams). The protein binding of methotrexate and indomethacin were both reduced in active disease (34.17 +/- 7.12% and 96.26 +/- 0.93% respectively) in comparison with normal subjects (39.33 +/- 4.68% and 96.89 +/- 0.47% respectively), but that of morphine was not changed. In patients there was a strong negative correlation between albumin and alpha-1 acid glycoprotein levels (r = -0.75, p < 0.01) but the correlation in controls was not significant. This study found only weak association between the binding of the drugs studied and the protein levels. It is concluded that reduction in methotrexate dose levels may reduce toxicity in patients with active cancer.

Adult↗
PubMed1992

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↗
PubMed1990

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↗
PubMed1990

Ampicillin pharmacokinetics in Indian geriatric subjects.

Ampicillin elimination was studied in geriatric and younger subjects, 10 in each group. The geriatric subjects had higher serum concentration and elimination half-life of the drug. The plasma clearance and urinary excretion of the drug were significantly reduced in them when compared to younger subjects. Urinary excretion of the drug had significant correlation with creatinine clearance of the subjects.

Adult↗
PubMed1985

Alphamethyldopa analgesia: its possible mechanism of action.

The analgesic activity of alphamethyldopa (MD) was studied in mice using the acetic acid writhing test and the hot plate method. In the writhing test, MD produced a dose-dependent analgesic effect with an ED 50 of 26.5 mg/kg. The results of the hot plate test confirmed the analgesic activity of MD. Yohimbine, but not naloxone, antagonized the analgesic effect of MD in the writhing test. Atropine antagonized MD analgesia while physostigmine potentiated it. The study suggests that MD analgesia is of the nonopioid type involving both adrenergic and cholinergic systems.

Analgesics↗