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Biomedical subjects

L Bang

Publications and source records attributed to L Bang.

27 records · Page 2Linked to original sources

Glibenclamide blocks the relaxant action of pinacidil and cromakalim in airway smooth muscle.

Concentration-relaxation curves for pinacidil and cromakalim were obtained in isolated guinea-pig tracheas contracted by histamine. Pinacidil produced complete relaxation with an EC50 value of 2.8 microM. The antidiabetic sulfonylurea, glibenclamide (0.1, 1, 10 microM), caused concentration-dependent rightward shifts (3- to 16-fold) of the concentration-relaxation curve for pinacidil without changing the maximal relaxant response. Cromakalim produced 85% relaxation with an EC50 value of 1.1 microM. Glibenclamide (0.1 microM) displaced the concentration-relaxation curve to the right and at higher concentrations (1-10 microM) caused nearly complete suppression of the maximal relaxant response to cromakalim. Glibenclamide not only prevented the effects of pinacidil and cromakalim but also produced a concentration-dependent and complete reversal of submaximal relaxations produced by these drugs. Glibenclamide was a selective antagonist of the relaxation of airway smooth muscle induced by pinacidil and cromakalim. Concentration-relaxation curves for theophylline, terbutaline and verapamil were unaffected by glibenclamide.

Animals↗

Smooth muscle neoplasms of the stomach.

We reviewed the records of 31 patients with smooth muscle tumors of the stomach seen at the First Surgical Department, Medical School, University of Athens, Greece, between the years 1961 and 1981 with special emphasis on the clinical data, diagnosis, and pathology. The majority of patients were symptomatic and were preoperatively diagnosed by radiology and/or endoscopy, but accurate histologic diagnosis was obtained in only three cases. The tumors varied in size, were relatively equally distributed throughout the stomach, and their management required 35 operations, consisting of 18 Billroth II gastrectomies, 15 local excisions, and two total gastrectomies. Histologically, the tumors proved to be leiomyoma in 23 cases, leiomyosarcoma in ten, and leiomyoblastoma in two. The difficulty of histologic classification in the absence of metastasis is clearly shown by the fact that three tumors recurred and were subsequently characterized as leiomyosarcoma one to three years after they were initially classified as leiomyoma.

Adult↗

The biosynthetic pathway of ecdysone: studies with vitellogenic ovaries of Locusta migratoria (Orthoptera).

Ovaries of adult females of Locusta migratoria synthesize impressive amounts of the steroid hormone ecdysone (and related ecdysteroids) during the late phases of vitellogenesis. The present study, aimed at elucidating the sequence of the biosynthetic steps that lead from cholesterol to ecdysone, has taken benefit of this remarkable biological model by using a double approach: (1) isolation and physico-chemical identification of endogenous biogenetic intermediates; (2) metabolic study of labelled putative precursor molecules. The data presented in this paper lead us to propose the following sequence of events: conversion of cholesterol to 3 beta-hydroxy-5 beta-cholest-7-en-6-one (via several intermediates not identified in this study) followed by 14 beta-hydroxylation to 3 beta, 14 alpha-dihydroxy-5 beta-cholest-7-en-6-one; hydroxylation on the side-chain at C-25 and C-22 (in this order) to 2-deoxyecdysone; hydroxylation at C-2 to ecdysone.

Animals↗