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Biomedical subjects

M Brown

Publications and source records attributed to M Brown.

At least 775 records · Page 43Linked to original sources
PubMed1980

Chronic heart failure in the guinea pig increases cardiac alpha 1- and beta-adrenoceptors.

Compared with sham-operated guinea pigs, chronic heart failure produced by aortic constriction resulted in a 79% increase in alpha 1-adrenoceptor density as measured by [3H]prazosin binding (73 +/- 15 vs. 131 +/- 20 fmol/mg protein, P < 0.05); beta-adrenoceptor number, measured by (-)-[3H]dihydroalprenolol binding, increased by 93% (28 +/- 3.4 vs. 54 +/- 5.2 fmol/mg protein, P < 0.01). For each radioligand KD values were unchanged. Thus, congestive heart failure due to chronic pressure overload results in compensatory augmentation of alpha 1- and beta-adrenoceptor numbers.

Animals↗
PubMed1980

Thyrotropin-releasing hormone--CNS action to stimulate gastric acid secretion.

Much physiological and pharmacological evidence has accumulated to suggest that the autonomic nervous system has an important role in the peripheral modulation of gastric secretion, although the neurochemical mediators in the brain which initiate or modulate autonomic input are poorly understood. Recently, the demonstration that some oligopeptides present in mammalian brain act in the central nervous system (CNS) to influence profoundly glucoregulation, thermoregulation, blood pressure, sympathetic outflow, muscular activity of gut and stress-induced gastric haemorrhagic lesions have led us to examine a possible role for some of these endogenous brain oligopeptides as chemical messengers involved in the CNS modulation of gastric secretion. We report here that thyrotropin-releasing hormone (TRH) acts within the CNS to elicit a vagus-dependent stimulation of gastric acid secretion.

Animals↗
PubMed1980

Bombesin-induced poikilothermy in rats.

The effect of ambient temperature (Ta) on the rectal temperature (Tre) response to intraventricular injection of bombesin has been evaluated in conscious adult male rats. At Ta = 4 degrees C, bombesin (50 ng-1 microgram) caused a marked hypothermia which was dose-dependent both in terms of the magnitude and of the duration of the response. The bombesin-induced hypothermia was reduced at Ta = 24 degrees C, whereas at Ta = 31 or 33 degrees C, the peptide (1 microgram) failed to affect Tre.AtTa = 36 degrees C, bombesin 1-10 micrograms induced an elevation in Tre. The hyperthermia observed at high Ta could be reversed to hypothermia by transferring rats to cold. The analogs [d-Trp8]bombesin or [d-Leu13]bombesin, tested under the same conditions, failed to produce significant changes in Tre. These findings demonstrate that bombesin appears to act in the brain as a poikilothermic agent by disrupting thermoregulation at temperatures below or above thermoneutrality.

Animals↗
PubMed1980

Brain regulation of gastric secretion: influence of neuropeptides.

Several neuropeptides injected intracisternally were assessed for their effects on gastric secretion in rats. Bombesin (1 microgram) completely suppressed gastric acid secretion, produced the volume of gastric secretion, and partially blocked insulin- or 2-deoxy-D-glucose-induced stimulation of gastric acid output. The inhibitory effect of this peptide is dose-dependent, long-acting, reversible, and specific. Bombesin response appears to be central nervous system-mediated; its expression is not dependent on the vagus nerve or the adrenal glands, and does not rely on a decrease in gastrin secretion. Among seven other peptides tested, only beta-endorphin and a potent gonadotropin releasing-factor (gonadoliberin) agonist significantly reduced gastric acid secretion, with an activity ca. 100 times less than that of bombesin. The presence of bombesin-like material in rat brain and the high potency of bombesin to inhibit gastric secretion suggest that this peptide may be of physiologic significance as a chemical messenger involved in brain modulation of gastric secretion.

Adrenalectomy↗
PubMed1980

Walking efficiency before and after total hip replacement.

The energy cost of walking and gait characteristics of patients with hip disease were studied to determine changes in walking efficiency following total hip replacement. Twenty-nine patients, 24 with unilateral hip disease and 5 with bilateral hip disease, were tested preoperatively and at various times postoperatively. Oxygen uptake was measured by a modified Douglas bag procedure. The temporal and distance characteristics of gait were measured with contact closing heel switches. Results showed postoperative increases in velocity, cadence, and stride length in patients with unilateral disease and with bilateral disease with bilateral replacement. After surgery, energy cost tended toward more normal levels, but the subjects were not within normal limits for oxygen uptake per minute, oxygen uptake per distance walked, or percent of predicted maximum aerobic capacity. Comparison of energy expenditure data with temporal and distance factors of gait indicated that all subjects became more physiologically efficient after hip replacement.

Adult↗
PubMed1980

Sexual dysfunction associated with urinary incontinence.

208 female patients attending an incontinence clinic gave information about their marital lives and sexual habits. 90 women (43%) maintained that their urinary disorder had adversely affected sexual relations. Women with bladder instability had a significantly higher incidence of sexual dysfunction than women with pure stress incontinence.

Adult↗
PubMed1980

The sleeping giant stirs: growth in multihospital systems.

Because their future is interwoven with the Church's broader role, Catholic multihospital systems must not grow solely for efficiency's sake. On the following pages the authors analyze data showing a direct shift toward a new form of health care delivery and suggest that system types, organization structures, and objectives should reflect and enhance Gospel values.

Catholicism↗
PubMed1980

Trends in multihospital systems: a multiyear comparison.

Although data suggest that multihospital systems are growing rapidly, more in-depth investigation is necessary to truly monitor the success of the systems approach. Cost effectiveness, quality of services and access are major factors in determining if the trend toward systems configurations should be encouraged or discouraged.

Costs and Cost Analysis↗