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Biomedical subjects

J R Wilson

Publications and source records attributed to J R Wilson.

At least 217 records · Page 12Linked to original sources
PubMed1983

Effect of hydralazine on perfusion and metabolism in the leg during upright bicycle exercise in patients with heart failure.

The aerobic exercise capacity of patients with chronic heart failure is frequently impaired because of inadequate O2 transport to working skeletal muscle. To determine whether hydralazine improves O2 transport to working muscle, we examined the effect of intravenous hydralazine on blood flow (measured by thermodilution) and metabolism in the leg during maximal upright bicycle exercise in 10 patients with chronic heart failure. Hydralazine increased maximal exercise cardiac output (5.6 +/- 0.7 to 6.7 +/- 0.6 l/min; p less than .01) and decreased systemic O2 extraction (79 +/- 3% to 65 +/- 2%; p less than .01) but did not alter maximal O2 uptake (787 +/- 105 vs 779 +/- 82 ml/min). Leg blood flow at maximal exercise increased from 1.6 +/- 0.2 to 2.1 +/- 0.4 l/min (p less than .03); the proportion of cardiac output delivered to the leg remained unchanged (59 +/- 3% vs 57 +/- 9%). This increase in flow was associated with a decrease in O2 extraction in the leg (84 +/- 2% to 79 +/- 2%; p less than .01) and no change in peak femoral venous lactate (59.1 +/- 7.4 vs 54.1 +/- 5.3 mg/dl), suggesting that there is functional or anatomic shunting of the augmented limb flow rather than delivery to metabolizing muscle. These data suggest that hydralazine augments flow to the exercising limb in patients with heart failure but that this augmented flow does not increase oxygen availability within working muscle.

Aged↗
PubMed1982

An electron microscopic comparison of the medial interlaminar nucleus and the A laminae in the dorsal lateral geniculate nucleus of the cat.

The medial interlaminar nucleus (MIN) of the cat's dorsal lateral geniculate nucleus was studied under the light and electron microscopes and compared with the A laminae. At the light level, MIN has more axons and a lesser cell packing density than the A laminae. Examined at the electron microscopic level, MIN could not qualitatively be distinguished from the A laminae. When quantitative counts of the profiles containing synaptic vesicles were made, MIN had less F profiles and more RSD profiles per unit area than the A laminae. Structure/function correlations suggest that additional F terminals may mediate nondominant eye inhibition and/or a greater amount of inhibition on X-cells versus Y-cells.

Animals↗
PubMed1982

An overview of consumer ergonomics in the United Kingdom.

Consumer ergonomics has emerged as one of the mainstream areas of ergonomics research and application. This paper discusses the background to this development and provides a framework for the three special issues of Applied Ergonomics devoted to this topic. The main aspects of current consumer ergonomics research, for example the fields of application, available techniques and relevant criteria, are reviewed by drawing on papers from this special series and other complementary published work. Some criticisms are made relating to the failure to achieve the systematic application of ergonomics in the design process, and a series of recommendations is made as to how the contribution of ergonomics could be made more effective. Finally, the future of consumer ergonomics in considered in the light of three major trends - the increased complexity of products, changes in social climate and forthcoming changes in consumer legislation.

Journal Article↗
PubMed1982

Lack of association between preference for and dependence on ethanol.

Tests were performed on 60 HS mice to determine preference for ethanol before and after a period of forced ethanol ingestion via a liquid diet treatment. Seizure scores measured 4, 5 and 6 h after the end of the liquid diet treatment showed that moderate degrees of physical dependence had developed. Statistical analyses revealed a significant sex difference only for the amount of ethanol consumed during the liquid diet treatment, with females drinking more than males (on a g/kg basis). Correlation analyses indicated that preference for ethanol was not related to seizure severity or to amount consumed during the liquid diet treatment. A significant drop in preference after ethanol withdrawal was observed when pre- and post-withdrawal preference ratios were compared. These findings are discussed in the context of the usefulness of preference for ethanol as a predictor of alcoholism.

Alcoholism↗
PubMed1982

Handedness and spatial ability.

Data from a large-scale study of cognitive abilities were used to test the hypothesis that there are handedness-related differences in spatial visualization. The spatial factor score of the cognitive test battery provided a measure of spatial visualization. Analyses revealed a sex X handedness X ethnicity interaction on the spatial factor, and no significant handedness-related differences on verbal factor. In all ethnic groups strongly left-handed males had higher spatial scores than strongly right-handed males, whereas strongly left-handed females had lower spatial scores than strongly right-handed females. Among subjects of Japanese or Chinese ancestry, strongly left-handed subjects differed from ambidextrous subjects as well as from right-handed subjects, and these differences, too, were of opposite sign for males and females. It is suggested that the use of spatial ability measures which are relatively insensitive to differences in right hemisphere ability, as well as the failure to attend to degree of handedness, ethnicity, and particularly gender, may be responsible for the negative findings in this area of research.

Adolescent↗
PubMed1982

Regional coronary anatomy in rest angina. Comparison of patients with rest and exertional angina using quantitative coronary angiography.

To determine if patients with rest angina have more severe regional ischemia than patients with exertional angina, we compared the severity of left coronary artery (LCA) stenosis in 29 patients with transient anterior ischemic ST-T changes at rest, and 30 patients with anterior ST changes only during exertion. The percentage diameter stenosis was measured with Vernier calipers as (2 x lesion diameter x 100 percent)/(prestenotic + poststenotic diameter). There was no difference between the two groups in the mean diameter stenosis of unoccluded LCA vessels either when all vessels were compared (rest: 69 +/- 12 percent; exertional: 70 +/- 13 percent [p = NS]) or when only the maximal stenosis in each patient was compared (rest: 74 +/- 10 percent; exertional: 75 +/- 12 percent [p = NS]). Total occlusion of at least one major vessel of the LCA also occurred with similar frequency in patients with rest (6/29) and exertional (12/30) angina (p = NS). However, collateral development distal to 76-100 percent LCA lesions was significantly less frequent in rest angina (4/21 vessels [19 percent]) than in exertional angina (21/30 vessels [70 percent]), (p less than .03). We conclude that patients with rest angina do not have more severe coronary stenosis than patients with exertional angina, but frequently may have more severe regional ischemia due to reduced collaterization of jeopardized myocardium.

Aged↗
PubMed1982

Effect of isosorbide dinitrate on submaximal exercise capacity of patients with chronic left ventricular failure.

The effect of chewable isosorbide dinitrate on submaximal bicycle exercise capacity was evaluated in a double-blind randomized study involving 13 patients with chronic heart failure. All patients had impaired maximal exercise capacity (VO2 max = 12.0 +/- 2.6 ml/kg/min) due to fatigue and dyspnea but not angina. The administration of isosorbide dinitrate lowered the resting mean blood pressure (82 +/- 9. mm Hg to 78 +/- 10 mm Hg, (p less than 0.03)) and the resulting pulmonary wedge pressure (26 +/- 5 mm Hg to 12 +/- 6 mm Hg, (p less than 0.01)). Isosorbide dinitrate acutely improved exercise duration during upright bicycle exercise at a workload fixed at 50 percent of the maximal workload (placebo): 21.8 +/- 14.1 min vs isosorbide dinitrate: 31.4 +/- 13.6 min, (p less than 0.003)) due to reduced exertional dyspnea. Administration of chewable isosorbide dinitrate acutely improved submaximal exercise tolerance in patients with chronic heart failure.

Double-Blind Method↗
PubMed1982

Selective breeding in mice for severity of the ethanol withdrawal syndrome.

Starting with a foundation population of 200 genetically heterogeneous mice (HS/Ibg), selective breeding has been initiated for a multivariate index of the ethanol withdrawal syndrome. This paper discusses the advantages of using multivariate indices to define pharmacological concepts. The seven variables included in our multivariate index are described. Because five of the seven variables showed a significant sex difference, separate principal component analyses were performed to establish selection indices appropriate for each sex. The study employs within-family mating to minimize inbreeding and includes replicate high, low, and control lines. These selectively bred lines should eventually provide a useful animal model for studying physiological and neurological mechanisms that may be involved in the ethanol withdrawal syndrome.

Alcohol Withdrawal Delirium↗
PubMed1982

Development of the electrophysiological properties of Y-cells in the kitten's medial interlaminar nucleus.

Single unit, extracellular recordings were made in the medial interlaminar nucleus (MIN) of adult cats and of kittens at 2, 4, 6, 8, 12, and 16 weeks of age. MIN is part of the dorsal lateral geniculate nucleus, and nearly all of its recorded neurons are Y-cells in adult cats. We find that Y-cells in the MIN of younger kittens have long latencies to optic chiasm stimulation, large receptive fields without surrounds, low spatial and temporal resolutions, and nearly absent spontaneous activity. Responses to hand-held light stimuli are typically poor and inconsistent. Also, most of these immature Y-cells exhibit only linear response properties when tested with a counterphased modulated grating pattern. All of the above characteristics gradually develop to adult values over several months of the postnatal period. The percentage of cells with nonlinear response properties becomes adult-like near 8 weeks of age, while both spatial and temporal resolutions are still developing at 16 weeks of age. Latencies and receptive field center sizes achieve adult values at about 12 weeks of age. The immature properties of these neurons are similar to those recorded from abnormal cells in the area of the medial interlaminar nucleus innervated by the deprived eye of monocularly deprived adult cats. This indicates that the adult deprived Y-cells probably fail to develop and thus retain their immature properties.

Aging↗