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Biomedical subjects

J A Lewis

Publications and source records attributed to J A Lewis.

At least 163 records · Page 9Linked to original sources
PubMed1977

Deanol in minimal brain dysfunction.

The literature on minimal brain dysfunction is confused, confusing and controversial. The statements that the condition exists, needs treatment, and that treatment may be pharmacological, are more expressions of faith than accepted fact. We believe they are true (within limits not discussed in the article). Furthermore, there is evidence that some patients with MBD are hypo-aroused, while others are not. The role of deanol in the treatment of MBD is still unclear, because of the complexities of identifying appropriate patients in terms of levels of arousal, as well as identifying appropriate measures of response. There is sufficient support for an effect of deanol in the literature to justify further investigation. Further studies should attend to important methodological problems as discussed.

Attention Deficit Disorder with Hyperactivity↗
PubMed1976

Methyldopa and propranolol or practolol in moderate hypertension.

The effect of a low dose of methyldopa combined with (a) a non-selective and (b) a selective beta-adrenoceptor antagonist was studied in a double-blind crossover trial in 24 carefully selected patients with moderate hypertension (mean initial lying blood pressure 189/117 mm Hg). Each patient received methyldopa 750 mg/day, propranolol 240 mg/day, practolol 600 mg/day, methyldopa 750 mg/day combined with propranolol 240 mg/day, methyldopa 750 mg/day combined with practolol 600 mg/day, and placebo for four weeks each according to a random sequence. After four weeks of therapy the most effective treatment, methyldopa combined with propranolol, reduced lying and standing blood pressures by 36-5/21-4 mm Hg and 44-7/25 mm Hg respectively. Thic combination had similar effects to those of the combination of methyldopa with the cardioselective agent practolol except that it reduced lying diastolic pressure further. The combination was more effective than either treatment alone. No significant differences were found between the effects of propranolol, practolol, or methyldopa at the doses used.

Adult↗
PubMed1976

Propranolol in hypertension: a dose-response study.

The effect of propranolol was studied in a double-blind crossover trial in 24 carefully selected hypertensive outpatients. Each patient received propranolol 60 mg/day, 120 mg/day, 240 mg/day, and placebo for four weeks each according to a randomised sequence. Propranolol 60 mg/day was no better than placebo in reducing blood pressure. The effects of propranolol 120 mg/day and 240 mg/day were not significantly different. Both doses reduced lying blood pressure by about 20/10 mm Hg from an initial level of 173/104 mm Hg. No difference was detected between the effects of the different doses of propranolol and placebo on weight or on the occurrence of adverse reactions.

Adult↗
PubMed1976

Morphological and biochemical changes in the hepatic endoplasmic reticulum and golgi apparatus of male Xenopus laevis after induction of egg-yolk protein synthesis by oestradiol-17 beta.

This report describes morphological and biochemical changes accompanying oestrogen induced synthesis of the egg-yolk protein precursor, vitellogenin, in male Xenopus liver. Extensive proliferation of the rough and smooth endoplasmic reticulum and the Golgi apparatus occurs between 3 and 9 days after administration of oestradiol-17 beta. Subcellular fractionation showed that microsomal fractions have an increased number of ribosomes available for protein synthesis, hormone treatment enhances the in vitro protein synthetic capacity per unit of RNA; both in microsome and ribosome preparations. Polypeptides synthesized in vitro by ribosome preparations show an enrichment in serine content after hormone treatment and an increased proportion of ribosomes can be immunoprecipitated by antibodies directed against vitellogenin. Our data are consistent with the proposal that vitellogenin is synthesized on the ribosomes of the rough endoplasmic reticulum and processed and packaged for secretion in the smooth endoplasmic reticulum and Golgi apparatus. Response to hormonal induction of vitellogenin involves an early phase in which membrane proliferation occurs in order to increase the cellular capacity to synthesize, process and secrete large quantities of egg-yolk protein precursor.

Animals↗
PubMed1976

Production of volatiles from decomposing plant tissues and effect of these volatiles on Rhizoctonia solani in culture.

Volatiles, of which NH3 is a major component, were evolved from decomposing immature corn tissue (c:n9) and affected R. solani in culture two ways: they supplied additional nitrogen to the growth medium so that fungal mycelial growth increased; and they raised substrate pH from 5.5 to 8.2 which induced melanization of mycelium. Volatiles increased fungus growth and pigmentation within 2 weeks of amendment addition to soil. Increases were concomitant with NH3 production from corn tissue. More NH3 evolved from decomposing corn tissues of C:N9 and 17 than from those of C-N 33 and 81. More growth and pigmentation occurred in flasks through which volatiles from decomposing corn (C:N9) were passed than in flasks through which volatiles from nonamended soil or decomposing corn (C:N81) were passed. Carbon dioxide from decomposing tissues did not affect growth or pigmentation. Twice as much NH3 evolved from corn tissue (C:N9) which decomposed in saturated soil than from tissue which decomposed in soil at 50% of its water-holding capacity. Pigment production doubled under saturated conditions.

Ammonia↗
PubMed1975

Atenolol and bendrofluazide in hypertension.

The effect of atenolol, a new beta-1-adrenergic receptor blocking agent, was studied in a double-blind cross-over trial in 24 carefully selected hypertensive outpatients. After a four-week run-in period on matching placebo each patient received atenolol 200 mg/day, atenolol 400 mg/day, a combination of atenolol 200/mg day with bendrofluazide 5 mg/day, and bendrofluazide 5 mg/day alone, according to a random sequence. Atenolol at either dose produced a significantly greater reduction in all blood pressure levels except standing systolic pressure than bendrofluazide alone. There was no statistically significant difference between the effects of the two atenolol doses on either blood pressure or pulse rate. The addition of bendrofluazide to atenolol resulted in a further significant lowering of the blood pressure. A significant effect of thiazide on weight was noted. The study shows that atenolol, a cardioselective beta-blocker of similar potency to propranolol in animals but without membrane-stabilizing or partial agonist acitivity, is an effective and well-tolerated hypotensive agent.

Adult↗
PubMed1975

Deanol and methylphenidate in minimal brain dysfunction.

Deanol, a putative acetylcholine precursor, has been used as a treatment for childhood hyperactivity for years. Efficacy has not been satisfactorily established, however. Seventy-four children referred for problems with learning, including many with hyperactivity, were screened for neurological or psychiatric illness, then given deanol, methylphenidate, or placebo in a double-blind fashion for 3 months. Maintenance dose for methylphenidate was 40 mg daily; for deanol, 500 mg. Behavior rating forms, reaction time, and a series of standard psychometric tests were given before and after treatment. Both drugs showed significant improvement on a number of tests; the pattern and degree of change differed slightly for the two. In this paradigm, deanol thus appeared to improve performance in children with learning and behavior disorders. The mechanism of action remains speculative; proof that deanol increases acetylcholine is scanty, and there is a theoretical basis for actually assuming an anticholinergic effect. Further clinical studies on deanol are indicated.

Analysis of Variance↗