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Biomedical subjects

B M Kapur

Publications and source records attributed to B M Kapur.

At least 91 records · Page 5Linked to original sources
PubMed1983

delta 9-Tetrahydrocannabinol and cannabidiol: dose-dependent effects on evoked potentials in the hippocampal slice.

The effects of (-) trans-delta 9-tetrahydrocannabinol (THC) and its metabolite cannabidiol (CBD) were investigated on evoked responses in the CA1 and dentate gyrus regions of the guinea pig transverse hippocampal slice. In both areas orthodromically evoked responses were enhanced by 10(-7) M THC, while 10(-6) M THC caused depression. Antidromic responses were not significantly affected. Antidromically-evoked inhibition in the CA1 region was decreased at low doses and unaffected at higher doses, while the facilitation by orthodromic interaction was unaffected at both dose ranges. The early part of the orthodromic field potential corresponding to the excitatory postsynaptic potential (EPSP) was enhanced at 10(-7) M in both areas. CBD (10(-6) M) decreased facilitation in CA1, and caused delayed excitation in the dentate granule layer. This study supports the conclusion that the biphasic effects of THC are dose dependent.

Anesthetics↗
PubMed1983

Distribution of morphine in the eye tissues and fluids of rabbits after systemic administration and after transfer via corneal grafting.

To determine whether corneas from animals receiving morphine could be used for grafting, rabbits were given a single intravenous injection of tritium-labelled morphine and killed 10 minutes later. Of the drug entering the eye, 12% was found in the cornea, 36% in the retina and optic nerve, 29% in the uveal tissues, 8% in the aqueous humour, 8% in the choroid, 4% in the vitreous humour and 2% in the lens. Another group of rabbits then received full-thickness corneal grafts from rabbits treated with morphine. The grafts contained the drug for up to 21 days after transplantation. From the graft bed the agent dispersed into the different solid ocular tissues and intraocular fluids. None of the grafts failed, and none of the recipients' eyes showed any adverse reaction. In-vitro tests showed that the amount of morphine found in the cornea and the aqueous humour of the donor did not have any significant effect on cell division or protein synthesis of the corneal cells. Higher concentrations of the drug, however, decreased both cell division and protein synthesis.

Animals↗
PubMed1981

Low-molecular-weight polyethylene glycol as a probe of gastrointestinal permeability after alcohol ingestion.

Gastrointestinal permeability has been assessed previously by the excretion of PEG-400, which consists of inert molecules that are neither degraded nor metabolized and are excreted intact in the urine. We report here the effects of alcohol on gastrointestinal permeability using PEG-400. Ten grams of PEG-400 dissolved in 60 ml of water were given to 12 intoxicated alcoholics (mean blood alcohol: 2406 mg/liter). The mean urinary excretion of PEG-400 in the following 6 hr was 3.75 +/- 0.3 g SEM. When repeated after sobering up (mean elapsed time: 45 hr), all except one subject showed a decrease in PEG-400 excretion (mean: 2.08 +/- 0.2 g) (P less than 0.001). Similar experiments were conducted in two series with 12 normal controls. (1) In 7 subjects the administration on consecutive days of (a) PEG-400 (10 g) alone, (b) 10.2 g (0.42 mol) of ethanol plus PEG-400 (10 g), (c) PEG-400 (10 g) alone, and (d) PEG-400 (10 g) plus a diuretic (40 mg furosemide) resulted in the following values of PEG-400 excretion in urine: (a) 2.12 +/- 0.3 g; (b) 3.5 +/- 0.3 g, P less than 0.005; (c) 2.02 +/- 0.4, NS; and (d) 2.2 +/- 0.2 g, NS. (2) In the second experiment (5 subjects) the administration on subsequent days of (a) PEG-400 (10 g) + 0.42 mol of urea; (b) PEG-400 (10 g) + 19.2 g ethanol; (c) PEG-400 (10 g) + 0.42 mol of urea resulted also, as in the previous experiment, in increased urinary excretion of PEG-400 after the solution (b) containing ethanol (P less than 0.001). Peak serum levels of PEG-400 were (a) 0.094 +/- 0.01 g/liter; (b) 0.152 +/- 0.02 g/liter (P less than 0.05); and (c) 0.095 +/- 0.01 (P less than 0.05). The ratio of urea--creatinine clearance and urinary volumes were the same in the three periods. Therefore, PEG-400 excretion was not related to changes in urinary clearance or in volume, since the furosemide increased the volume but not PEG-400 excretion. It is concluded that ethanol increases the permeability of the gastrointestinal tract as measured by the PEG-400 test, both in chronic alcoholics during intoxication and in nonalcoholics after a small dose of ethanol. The permeability alteration is transient once ethanol ingestion stops.

Adult↗
PubMed1981

High-density lipoprotein cholesterol in male alcoholics with and without severe liver disease.

In a study of 26 male alcoholics, the subgroup without severe liver disease showed significant elevation in high-density lipoprotein cholesterol (HDL) in the immediate post-intoxication period: HDL levels decreased to control levels after one to two weeks of abstinence. Those patients with advanced liver disease failed to show this ethanol-induced rise in HDL. We were not able to correlate these observations with any variation in sex hormone levels, nutritional indices, age or quantity of alcohol intake. We concluded that ethanol consumption in alcoholics is associated with an increase in HDL levels, which is offset by the development of alcoholic liver disease.

Adult↗
PubMed1981

Acute and chronic drug abuse emergencies in Metropolitan Toronto.

From 3,548 drug overdose or abuse cases presenting at 21 Metropolitan Toronto hospitals' Emergency departments, data concerning demographic and medical characteristics, investigative and management procedures, drug analysis services, and disposition of patients were collected. Of the 3,548 cases, 2,723 (77%) were acute overdose and 816 (23%) were drug abuse. Drug overdose was more common than drug abuse for both sexes, but was more characteristic of females. The drugs most frequently alleged ingested were benzodiazepines (34%), ethanol (32%), salicylates (16%), and barbiturates (14%). The frequency with which particular classes of drugs are alleged in overdose corresponds closely to the frequency of prescribing these drugs in Ontario.

Adult↗
PubMed1980

A study of malabsorption in intestinal tuberculosis: stagnant loop syndrome.

A study was carried out in the patients with intestinal tuberculosis and obstruction requiring surgery to determine the pathogenesis of malabsorption in this condition. Fifteen of the 20 patients studied had malabsorption, nine of 17 (53%) had intestinal bacterial overgrowth and 10 of 16 (62.6%) had free bile acids in their jejunal aspirates. In a comparable group of nontuberculus intestinal obstruction requiring surgery, six of seven (85.7%) had malabsorption, and four of five (80%) had both the bacterial overgrowth as well as bile salt deconjugation. Among a group of 10 patients with intestinal tuberculosis without significant obstruction, four were found to have malabsorption but only one had evidence of bacterial overgrowth and bile salt deconjugation. In contrast, only one of the 10 patients with extraintestinal tuberculosis and none of the 12 healthy, normal subjects had malabsorption. None had bacterial overgrowth or bile salt deconjugation in either group. Resection of the obstructing lesion corrected the malabsorption as well as the bacterial overgrowth and the bile salt deconjugation in all four patients tested with intestinal tuberculosis. Malabsorption in intestinal tuberculosis thus appears to be associated with obstruction rather than with the tuberculous process. Demonstration of bacterial overgrowth and bile salt deconjugation in the upper small intestine of patients with intestinal tuberculosis with obstruction and malabsorption indicate the presence of a stagnant loop syndrome.

Adolescent↗
PubMed1979

Intravenous phenobarbital therapy in barbiturate and other hypnosedative withdrawal reactions: a kinetic approach.

Phenobarbital (0.03 to 0.04 mg/kg/min) was infused intravenously in 7 patients with clinical hypnosedative withdrawal reaction until patients slept but were arousable. The infusion time to reach this clinical end point was 7.8 +/- 1.1 hr (mean +/- SEM), the total dose was 992 +/- 144 mg, and the peak serum phenobarbital concentration was 26.1 +/- 5.1 micrograms/ml. A user of minimal hypnosedatives required 54% less phenobarbital and 65% lower concentration than any of the abusers to reach an equivalent state of intoxication. The mean serum half-life (t 1/2) was 57.5 +/- 4.9 hr for hypnosedative abusers and 86 +/- 3 hr for 8 normal volunteers (p less than 0.001). Only the patient with the shortest t 1/2 (36.4 hr) required oral phenobarbital supplements to prevent withdrawal symptoms. Dosage supplements required can be calculated from the postinfusion rate of fall of serum phenobarbital. Slow infusion of large amounts of phenobarbital provides a safe, efficacious single-dose treatment.

Adult↗
PubMed1979

Massive rectal bleeding due to intestinal tuberculosis.

Two cases of massive rectal bleeding due to tuberculosis of the intestine are described and 24 reported cases of massive rectal bleeding in intestinal tuberculosis are reviewed. Tuberculosis of the intestine, though uncommon should be considered as a cause for rectal bleeding.

Adult↗
PubMed1979

Does a barbiturate drug given in lethal dose enter the cornea?

We wished to see whether sodium phenobarbital (one of the commonest drugs used to commit suicide) given in a lethal dose would enter the cornea. Guinea pigs and rabbits were killed with an overdose of the drug. Using gas chromatography we were able to detect the drug not only in the vascular ocular tissues and the intraocular fluids but also in the avascular tissues such as the cornea.

Animals↗