Search PubMed⌕ Search

Biomedical subjects

M Weinstock

Publications and source records attributed to M Weinstock.

At least 145 records · Page 8Linked to original sources
PubMed1971

Bradford's Law.

Explore the source record for details and available documents.

Letter↗
PubMed1971

Role of adrenergic neurone blockade in the hypotensive action of propranolol.

1. Propranolol, in doses of 25-100 mug/kg, blocks contractions of the nictitating membrane to nerve stimulation but not to injected noradrenaline.2. This adrenergic neurone blocking action of propranolol is antagonized by amphetamine.3. It is also reversed by raising the dose of propranolol to amounts exceeding 0.5 mg/kg.4. Still larger amounts potentiate the responses of the nictitating membrane to both submaximal stimulation of the cervical sympathetic nerve and to injected noradrenaline.5. The (+) isomer of propranolol produced adrenergic nerve blockade and some degree of hypotension without blocking cardiac beta-adrenoceptors.6. The relevance of adrenergic neurone blockade to the hypotensive effect of propranolol is discussed.

Adrenergic beta-Antagonists↗
PubMed1970

Brush border development in the intestinal absorptive cells of Xenopus during metamorphosis.

The differentiation of the brush border which makes up the apical free surface of intestinal absorptive cells has been studied by electron microscopy. Specimens of Xenopus small intestine were fixed at various stages during metamorphosis, the time when a new intestinal epithelium forms. The interpretation of details described herein emphasizes the role of "surface-forming" vesicles. These vesicles are thought to provide membrane both for the initial expansion of the apical surface and for the later elongation of the microvilli. The latter are believed to be "molded" around filamentous cores that appear early in differentiation. The cores are attached to the apical membrane and extend vertically into the supranuclear cytoplasm. This interpretation rests chiefly on (a) the resemblance, both in morphology and in staining properties with colloidal thorium, between the membrane that limits the vesicles and that which limits the microvilli and (b) the distribution and time of appearance of the vesicles with respect to development of the microvilli. According to this view, the specific properties of surface membrane reside in preformed units that arise within the supranuclear cytoplasm. This morphogenetic process probably involves participation of the Golgi region as the site where the complex macromolecular architecture of the cell surface is assembled.

Animals↗