Search PubMed⌕ Search

Biomedical subjects

W C Orr

Publications and source records attributed to W C Orr.

137 records · Page 8Linked to original sources
PubMed1975

Variant angina and sleep: a case report with therapeutic considerations.

A 33 year old male with three years of increasingly frequent nocturnal angina pectoris was found on ECG tape monitoring to develop marked ST segment elevation followed by coarse ventricular tachycardia with subsequent spontaneous termination of the arrhythmia. Further evaluation included normal maximal exercise tolerance test, normal coronary arteriography and left ventricular angiography. Continuous nocturnal EEG, ECG, and blood pressure recordings on nitrate therapy revealed normal sleep patterns, development of sinus tachycardia with minimal muscular movement and a normal circadian decline in blood pressure. Therapy with progressive doses of 2% Nitroglycerin ointment has prevented further breakthrough in nocturnal angina pectoris. The association of nocturnal angina and sleep stages and the possibility of altering the coronary vasospasm by approaching the central neurophysiologic trigger rather than the peripheral coronary arteries is discussed.

Adult↗
PubMedDate not supplied

CuZn-SOD promoter-driven expression in the Drosophila central nervous system.

The aim of this study was to ascertain the status of CuZn superoxide dismutase (CuZn-SOD) expression in the central nervous system of Drosophila melanogaster. Immunoblot analysis of dissected tissue extracts revealed low levels of the CuZn-SOD protein in adult brains relative to other adult and larval tissues. To explore further this observation, three different reporter constructs containing different elements of the CuZn-SOD promoter domain were used for the generation of transgenic flies. A high level of reporter gene expression occurred during the second wave of neurogenesis (third instar and early pupal stages) in scattered, proliferating neuroblasts (NBs) and in proliferation centers of the optic lobe. In mature, postmitotic neurons, this expression was lower relative to other tissues. In adult flies, at all ages examined, there was little if any detectable reporter gene expression in cells of the central nervous system. These results suggest that one of the key components of the antioxidant defenses, CuZn-SOD, is quite low in postmitotic neural tissue, rendering it particularly susceptible to oxidative damage during aging.

Aging↗
PubMedDate not supplied

Psychological and physiological responses to postprandial mental stress in women with the irritable bowel syndrome.

OBJECTIVE: To investigate the psychological (affective and symptomatic) and physiological (autonomic and cortisol) responses to postprandial mental stress in women with irritable bowel syndrome (IBS). It was hypothesized that patients with IBS would show exaggerated autonomic and cortisol responses to the psychological stressor and that the stressor would enhance gastrointestinal symptoms. METHOD: Twenty-four women with IBS and 20 healthy women participated in the two-day study protocol. Both days were identical, with the exception that on one day, a stressful mental task was completed after ingestion of a standard meal. Heart rate variability, cortisol, affective, and symptomatic responses were measured before and after application of the stressor. RESULTS: Patients with IBS demonstrated increased negative affect at baseline and in response to the stressor. Gastrointestinal symptoms were not affected by the stressor. Appraisal of the stressor by patients with IBS was not different from that of controls. There were no group differences in the autonomic response to the stressor. There was no overall cortisol response to the stressor in either group. CONCLUSIONS: Patients with IBS respond with greater negative affect to postprandial psychological stress as well as to food intake alone, and they can be distinguished from controls on the basis of self-report data. Patients with IBS cannot be differentiated from controls on the basis of the pattern of changes in sympathetic activation after the mental stressor. The stressor used in this study did not elicit a cortisol response in either group.

Adult↗
PubMedDate not supplied

The assessment of time-dependent changes in human performance.

This paper discribes a series of experiments to illustrate the use of various methods of time series analysis in the delineation of the effects of circadian and ultradian cycles on human performance. These experiments are concerned with measures of both human performance and physiology. They illustrate how the parameters of these time series analytic techniques can be used to postulate physiological mechanisms where time-dependent changes have been shown to be significant. The use of analytic techniques in both the time and frequency domain is illustrated.

Circadian Rhythm↗