Biomedical subjects
R Wilson
Publications and source records attributed to R Wilson.
HIV and contact lens wear.
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The HIV-infected optometrist.
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Effects of long-term vasodilator therapy on electrocardiographic abnormalities in chronic aortic regurgitation.
Electrocardiographic abnormalities develop in patients with chronic aortic regurgitation (AR). Although vasodilator drugs may reduce left ventricular (LV) volume overload, the effects of such therapy on electrocardiographic abnormalities have not been previously evaluated. Accordingly, electrocardiograms were analyzed before and after double-blind, randomized administration of either hydralazine or placebo in 54 patients with chronic AR. These patients were without limiting symptoms and had preserved ejection fraction on entry in the study. The magnitude of ST-segment depression and Romhilt-Estes point score for LV hypertrophy were assessed. Baseline ST depression and LV hypertrophy scores in the placebo and hydralazine groups were not significantly different. At follow-up, after a mean of 19 +/- 6 months, there was a significant reduction in ST depression in patients taking hydralazine (n = 28) compared with patients given placebo (n = 26): -0.023 +/- 0.044 vs 0.029 +/- 0.055 mV, respectively (p = 0.0001); and in the LV hypertrophy score (-1.1 +/- 2.2 vs 0.9 +/- 2.3 points, respectively; p = 0.002). Hydralazine-treated patients also had significant decreases in LV end-diastolic and end-systolic volume indexes, and a significant increase in ejection fraction. These results suggest that such vasodilator therapy may be beneficial in patients with chronic AR.
Measurement of the inclusive B* cross section above the Upsilon (4S).
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Inclusive chi (2P) production in Upsilon (3S) decay.
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Clinical analysis in intact erythrocytes using 1H spin echo NMR.
A new method of clinical analysis based on 1H spin echo NMR spectroscopy is presented. It is capable of providing information on six metabolites within viable erythrocytes, directly and without any preparative procedures prior to analysis except for cell separation and washing. Erythrocytes from patients with rheumatoid arthritis and Graves' disease are compared with cells obtained from healthy volunteers. The NMR detectable species in the cytosol of the cells are glutathione, ergothioneine, choline, creatine, glycine, lactate and to a lesser extent alanine and valine. Significant differences are observed between the ergothioneine pools in the rheumatoid group (P less than 0.01) compared to the control group. The glutathione: di-glutathione ratio can be assessed from the ratio, g2 to g4, taken from different signals in the glutathione molecule. The total concentration of glutathione present is easily assessed qualitatively but is more difficult to quantitate.
Inclusive production of the charmed baryon Lambda c+ from e+e- annihilations at sqrt s =10.55 GeV.
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Study of D0 decays into final states with a pi 0 or eta.
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Recurrent abortion.
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Study of pi + pi - transitions from the Upsilon (3S) and a search for the hb.
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Visualization of altered myocardial lipids by 1H NMR chemical-shift imaging following ischemic insult.
Acute myocardial infarction is associated with an accumulation of lipids. Spectroscopic and chemical-shift imaging strategies which can depict the spatial distribution of these chemical species are evolving. The present study was undertaken to test whether the Dixon method could detect spatially lipids known to accumulate in myocardium after an ischemic insult. Seven dogs underwent a 24-h coronary artery occlusion (LAD = 4, Cx = 3). Post mortem, hearts were removed and imaged ex vivo. Myocardial samples were also evaluated by high-resolution 1H NMR spectroscopy. Lipid images revealed regions of increased signal intensity, in the regions corresponding to the myocardial infarction, particularly in the periphery of the infarction. An increase in mobile lipids was observed by 1H NMR spectroscopy of myocardial samples with moderately reduced blood flow and corresponding to regions with increased signal intensity on the lipid image. This study shows that chemical-shift imaging may be useful for detecting alterations in myocardial lipid levels following an ischemic insult.
In vivo and in vitro studies into the immunological changes following iodine 131 therapy for Graves' disease.
Radio-iodine therapy for Graves' disease is followed by immunological changes in addition to effects on thyroid hormone production. The present study examined these changes and the mechanisms responsible for them. Of the 15 patients enrolled in the study, 10 became hypothyroid in the first year after iodine 131 therapy. Patients who became hypothyroid had a tendency to show a rise in serum thyrotropin receptor antibody levels (30 +/- 14 to 40 +/- 9 units; NS) and a significant rise in immunoglobulin production (324 +/- 153 to 740 +/- 200 ng/ml; P less than 0.0005) from mitogen-stimulated peripheral blood lymphocytes (a measure of B-cell activity) 2 months after iodine 131 therapy. The increases were not seen in the patients who remained euthyroid at 1 year. In vitro studies suggested that the rise in B-cell activity is due to a fall in suppressor T cell numbers, a change shown to occur following iodine 131 therapy in previous studies. Our results indicate that immunological changes do arise after iodine 131 therapy for Graves' disease but appear to be confined to patients who subsequently became hypothyroid. It is not possible from this study to determine whether the immunological changes appear as a consequence of thyroidal destruction leading to hypothyroidism or whether they contribute directly to it.
Lipid and fatty acid composition is altered in plaque tissue from multiple sclerosis brain compared with normal brain white matter.
Plaques and white matter from brains of multiple sclerosis (MS) patients were analyzed for lipid content, class composition, and fatty acid composition of total lipid, together with the fatty acid composition of plaque glycerophospholipids, and the results were compared with white matter from normal brain. Plaques contained less than 30% of the lipid present in normal white matter. Plaque lipid was characterized by significantly increased proportions of glycerophospholipids and decreased cerebrosides and sulfatides. In addition, a subacute plaque contained approximately 10 times the proportion of steryl esters observed in chronic plaques or normal white matter. Total lipid from all the MS plaques showed significantly increased percentages of saturated fatty acids, n-6, n-3 and total polyunsaturated fatty acids and decreased percentages of monoenes and alk-l-enyl ethers in comparison with normal brains. These results were consistent with increased cellularity and astrogliosis associated with MS plaques. However, analysis of plaque glycerophospholipids showed that the fatty acid changes observed in total lipid were not simply due to the increased proportion of glycerophospholipids and decreased myelin lipids, but that the fatty acid composition of the individual glycerophospholipids was different.
Antioxidant systems in normal pregnancy and in pregnancy-induced hypertension.
Increased free radical activity has been implicated in the pathogenesis of pregnancy-induced hypertension. This article investigates whether changes in antioxidant systems contribute to this condition. Two extracellular (plasma thiols and ceruloplasmin) and two intracellular (red blood cell lysate thiols and red blood cell superoxide dismutase) antioxidant markers were assayed in 25 nonpregnant women, 16 pregnant women with normal blood pressure, 19 women with pregnancy-induced hypertension, and 13 women with proteinuric pregnancy-induced hypertension. In the normotensive pregnant group (in comparison with the nonpregnant group) the plasma thiol level was reduced (p less than 0.001) and the ceruloplasmin level raised (p less than 0.005), suggesting increased free radical activity. The lysate thiol level increased (p less than 0.005), which may reflect a compensatory protective response. In the hypertensive pregnant groups the lysate thiol rise was not present. These red blood cells may be more prone to oxidative stress. Whether this situation is a cause or an effect of oxidative stress in pregnancy-induced hypertension has yet to be elucidated.
Changes in immunologic parameters in normal pregnancy and spontaneous abortion.
To study the immunologic characteristics of miscarriage, 40 nonpregnant control subjects, 40 primigravid women in the first trimester of pregnancy, and 18 patients admitted with a spontaneous abortion were investigated. The total white blood cell count was raised significantly in normal pregnancy and spontaneous abortion (p less than 0.0005). The lymphocyte count was unchanged. The total T-cell number fell significantly in normal pregnancy and abortion (p less than 0.01). No change was seen in the cytotoxic suppressor or helper/inducer T-cell numbers. The number of activated T cells fell significantly in both groups of patients (p less than 0.0005). The response to mitogens was greatly increased in both normal patients and those with miscarriage. A marked rise in interleukin-2 receptor levels was noted in patients with spontaneous abortion (p less than 0.005). The changes in white blood cell count, total T-cell number, activated T-cell number, and mitogen activity were thought to be a direct result of pregnancy. The rise in interleukin-2 receptor levels was seen only in the miscarriage group. Although it is not known if these changes are cause or effect, it would appear that immunologic abnormalities are associated with spontaneous abortion.
Northern Ireland: political violence and self-reported physical symptoms in a community sample.
In order to investigate the possible relationship between physical health and political violence in Northern Ireland a random sample of residents of four electoral areas (two with relatively high violence and two with relatively low violence) was interviewed at home. Each person was asked to rate their health in terms of common physical symptoms, to indicate their use of family doctor and hospital services, and to rate the level of political violence in their neighbourhood. Analysis of covariance (with a measure of psychological well-being, a measure of trait neuroticism plus age and socioeconomic status as covariates) revealed that women reported more physical symptoms than did men, people in the 'high' violence areas reported more symptoms than did those in the 'low' violence areas, while those who rated their own neighbourhood most highly in terms of perceived violence also reported the greatest number of physical symptoms. However, a series of chi 2 tests revealed no association between political violence or perceived political violence and uptake of services.