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Biomedical subjects

M J Lewis

Publications and source records attributed to M J Lewis.

At least 307 records · Page 17Linked to original sources
PubMed1976

The uptake of tritiated delta 1-tetrahydrocannabinol by the isolated vas deferens of the rat.

1 Weighed stripped vasa deferentia were incubated in Holman's solution containing (a) [14C]-sorbitol 0.014 mm, (b) [3H]-noradrenaline ([3H]-NA) 12.31 nM, (c) [3H]-tetrahydrocannabinol ([3H]-delta1-THC) 1 mug/ml for 5, 10, 20 and 30 minutes. 2 Tissues were washed, dissolved in Protosol, counted by standard scintillation counting technique and 'drug space' expressed as ct min-1 mg-1 tissue/ct min-l mul-1 bathing fluid. 3 Vasa incubated for 30 min with [14C]-sorbitol were washed for varying lengths of time; 82% clearance had taken place after 2 washes of 5 minutes. 4 The uptake of [3H]-NA was inhibited by the presence of desmethylimipramine (DMI) 10 nM in the bath or by pretreatment of rats with 6-hydroxydopamine (6-OHDA). 5 The uptake of [3H]-delta 1-THC was not inhibited by the presence of DMI. It was reduced but not abolished by 6-OHDA pretreatment.

Animals↗
PubMed1976

Global surveillance of antibiotic sensitivity of Vibrio cholerae.

Strains of Vibrio cholerae-1156 from various parts of the world-were examined by standardized antibiotic sensitivity tests in one centre, to determine the global incidence of antibiotic resistance in this organism and to assess the extent to which differences in methods of sensitivity testing might be responsible for discrepancies in the reported incidence of resistant strains. Of the strains examined, 1127 were fully sensitive to ampicillin, chloramphenicol, tetracycline, furazolidone, and three different sulphonamides, 27 showed stable and reproducible resistance to one or more of these agents, and 2 proved to contain a minority of cells with unstable, presumably plasmid-borne, resistance to chloram-phenicol. Unstable resistance to antibiotics may be common in V. cholerae but rarely recognized, and may account for some of the discrepancies in the reported incidence of resistant strains.

Anti-Bacterial Agents↗
PubMed1975

Opioid-reinforced operant behavior: selective suppression by alpha-methyl-para-tyrosine.

Morphine-addicted rats performed operant responses for opioid or milk rewards. When rats were then denied access to opioids, abstinence symptoms developed. Responding under extinction conditions 2 wk. after opioid withdrawal provided a measure of the "relapse" tendency. Systemic administration of DL-alpha-methyl-para-tyrosine, an inhibitor of catecholamine synthesis, suppressed these responses if they had been reinforced by an opioid but not if they had been established with milk reinforcement. This indicates that the integrity of the catecholamine systems is vital for relapse to occur.

Administration, Oral↗
PubMed1975

Mouth lesions in iron-deficient anemia: relationship to Candida albicans in saliva and to impairment of lymphocyte transformation.

The atrophic glossitis and angular chilosis in patients with iron-deficient anemia are associated with infection of the mouth by Candida albicans. Saliva from these patients contained more Candida and supported the growth of Candida better than did saliva from a control group. The possibility that growth of Candida may be due to impaired lymphocyte function was investigated by measuring transformation of lymphocytes stimulated with phytohemagglutinin. Transformation was depressed in iron-deficient subjects and returned to normal after correction of their iron status. The lymphocyte count in the peripheral blood was also depressed and corrected by additional iron. Impaired lymphocyte function did not explain the mouth lesions and growth of Candida in saliva since lymphocyte transformation was equally depressed in patients with and without mouth lesions. A local factor, such as an effect of lack of iron on the resident vacterial flora of the mouth, may be important.

Adolescent↗
PubMed1975

Changes in erythroblast morphology as an index of response to cyanocobalamin in patients with megaloblastic anaemia.

Fifty-three patients with megaloblastic anaemia treated with cyanocobalamin and folic acid have been studied. Repeat marrow examination was found to be of value in assessing response to treatment. The early improvement in marrow morphology in patients with pernicious anaemia was greater with 1000 mug than with 5 mug doses of cyanocobalamin. The effect of folate deficiency in delaying marrow response to cyanocobalamin in patients with pernicious anaemia is described and combined cyanocobalamin and folic acid treatment was found to be more effective than either alone. The response to large doses of cyanocobalamin in folate deficient patients was unrelated to the initial serum vitamin B12 level.

Adult↗
PubMed1974

The effect of delta1-tetrahydrocannabinol on the release of (3H-(-)-noradrenaline from the isolated vas deferens of the rat.

1 The amount of tritium released upon transmural stimulation of the isolated vas of the rat incubated with [(3)H]-Delta(1)-tetrahydrocannabinol (THC) (2.8 muM) was significantly greater than the non-stimulated overflow.2 There was no difference between non-stimulated overflow and the effect of transmural stimulation of vasa equilibrated with [(14)C]-sorbitol (6.5 mg/ml).3 The difference between non-stimulated and stimulated efflux from vasa equilibrated with [(3)H]-Delta(1)-THC was abolished in rats pretreated for 24 h with 6-hydroxydopamine (250 mg/kg).4 The amount of tritium released upon transmural stimulation of the vas incubated with [(3)H]-noradrenaline (6 muM) was significantly greater than the non-stimulated overflow.5 Delta(1)-THC (560 nM and 14 muM) caused a significant dose-dependent reduction of both non-stimulated and stimulated tritium efflux, especially the latter.

Animals↗
PubMed1974

The effect of delta1-tetrahydrocannabinol on the uptake of [3H]-(minus)-noradrenaline by the isolated perfused heart of the rat.

Forty-eight isolated rat hearts were perfused with Krebs solution and with [(3)H]-(-)-noradrenaline ([(3)H]-NA) containing 4.5 nCi/ml in 50 ng/ml, as described by Iversen (1963). To groups of six, cocaine was added to [(3)H]-NA in concentrations of 400 nM, 2 and 10 muM. To the rest Tween 80, 25 mug/ml was added to [(3)H]-NA and in three groups Delta(1)-THC additionally in concentrations of 560 nM and 2.8 or 14 muM. Cocaine caused a linear concentration-related inhibition of uptake; Tween caused a 38.7% inhibition; THC caused additionally a linear concentration-related inhibition.

Animals↗