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Biomedical subjects

W Miller

Publications and source records attributed to W Miller.

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

Increases in HDL-cholesterol and the HDL/LDL cholesterol ratio during prolonged endurance exercise.

The influence of prolonged, low-intensity exercise (45% VO2max) until exhaustion on plasma lipid levels, in particular high-density lipoprotein cholesterol (HDL-C), and the time sequence associated with changes in these blood constituents was investigated in 10 trained subjects. The exercise consisted of walking on a motor-driven treadmill until exhaustion. Blood samples were drawn before, at 30 and 60 minutes after the beginning of exercise, at each hour thereafter until exhaustion, immediately before exhaustion, and after a 30-minute recovery period. At exhaustion the total cholesterol concentration was significantly elevated by 3% and rose another 3% during the recovery period. The HDL-C level was significantly elevated within two hours after the start of exercise and by exhaustion (about 4.5 hours of exercise) had risen to 52.5 +/- 2.3 mg X dL-1, which represented a 10.8% increase above the pre-exercise concentration (47.4 +/- 1.8 mg X dL-1). The HDL/LDL cholesterol ratio followed a pattern similar to that described for HDL-C. Plasma free fatty acids (FFA) also increased linearly during the exercise period but were not significantly correlated with HDL-C during exercise (r = 0.14). These results suggest that prolonged, low-intensity exercise can acutely improve the lipid profile of humans.

Adult↗
PubMed1983

Human peritoneal macrophage cytotoxicity mediated by cytophilic IgG.

Cells of the human mononuclear phagocyte system have recently been shown to possess cytophilic IgG molecules that promote phagocytosis of staphylococci bearing cell-wall protein A. In the present study, the possible mediation of a cytotoxic response to 51Cr-labeled sheep erythrocytes coated with protein A by cytophilic antibodies on human peritoneal macrophages was evaluated. The target cells were readily lysed by peritoneal macrophages. Cytotoxicity was blocked by pretreatment of macrophages with soluble protein or with anti-Fc F(ab')2 fragments. In contrast, cytotoxicity was not affected by cytochalasin B; this finding suggests that cytolysis is an extracellular event. Perturbation of cytophilic IgG with particle-bound protein A elicited a chemiluminescent response from peritoneal macrophages; however, experiments with scavengers of reactive oxygen species indicated that toxic oxygen radicals may not be required for cytotoxicity. The results indicate that cytophilic antibody-mediated cytotoxicity may contribute to cellular injury as well as host-defense aspects of the inflammatory process.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1983

Red cell cation transport: differences between black and white school children.

Differences in red cell sodium content and sodium-lithium countertransport were studied in black and white children with a mean age of 12 years. For both boys and girls red cell sodium content was higher in blacks and countertransport lower (P less than 0.05). For both ethnic groups red cell sodium was lower in girls than boys and a consistent positive relationship was noted between body mass index and countertransport. Despite the lower red cell Na-Li countertransport values in black compared to white children, a significant positive correlation with systolic blood pressure was found independent of adiposity. In contrast, no correlation was evident between Na-Li countertransport and blood pressure in the white children. If red cell cation transport is confirmed as a marker for hypertension, study of racial differences may help explain the twofold higher prevalence of this disease among blacks.

Adolescent↗
PubMed1983

Transplantation of T-lymphocyte-depleted bone marrow between HLA-mismatched individuals.

Four patients with acute leukemia received transplants from HLA-mismatched, related donors. Marrow cells that had been depleted of T lymphocytes using a monoclonal anti-T-lymphocyte antibody and rabbit complement were used. In vitro studies showed that 80-97% of the mature T lymphocytes were removed using this procedure. Infusion of the treated marrow was accomplished without complications, and engraftment occurred in each case. Graft-versus-host disease occurred in 3 of the 4 patients. These results show that additional manipulations of the marrow will be required to allow complete T lymphocyte removal from the marrow before the feasibility of this approach in HLA-mismatched patients can be determined.

Acute Disease↗
PubMed1983

Endurance improved by ingestion of a glucose polymer supplement.

The effect of glucose polymer (GP) ingestion upon endurance performance during walking exercise at 45% VO2max was examined. Also, performance on a battery of psychomotor tests was assessed to determine if exhaustion from endurance exercise was related to central nervous system dysfunction. Ten trained male subjects ingested approximately 120 g of GP in four equally-divided dosages 60, 90, 120, and 150 min following the start of exercise. This treatment significantly increased time to exhaustion by 11.5% as compared to the control (C) group (GP=299.0 +/- 9.8 min; C=268.3 +/- 11.8 min). No difference in VO2 (1 X min-1) or perceived exertion was noted between treatments. As a result of the GP feedings the rate of carbohydrate utilization during the GP trial was 0.53 g X min-1 greater than during the C trial. However, during the GP trial plasma glucose did not fall below the pre-exercise level and was significantly higher than the C plasma glucose concentration at exhaustion. No differences in psychomotor performance between treatments or between rested and exhausted states for either the C or GP treatments were noted. These data suggest that exhaustion was not a result of hypoglycemia or central nervous system dysfunction and that glucose polymer supplements may enhance endurance capacity.

Blood Glucose↗
PubMed1983

Lack of effect of nitroglycerin on the transmural variation of tissue pH during fixed coronary stenosis.

A new MpH-measuring system was used to investigate the mechanism of action of intravenous NTG on pacing-induced myocardial ischemia during critical stenosis. In ten anesthetized open-chest dogs, two MpH electrodes were placed in a segment supplied by the CCA, one superficial and one deep. Atrial pacing at a rate 50 beats/min higher than baseline was instituted for a period of 10 min (Pacing I). Critical stenosis was then applied to the CCA. Three more similar periods of atrial pacing were instituted during critical stenosis. Pacing II was without any intervention, Pacing III was after the intravenous administration of a bolus of NTG, and Pacing IV was after the intravenous administration of NTG + A. NTG (metamarinol) during critical stenosis and atrial pacing did not alter preload and did not reduce afterload more than critical stenosis and atrial pacing alone. It did not significantly alter flow in the CCA measured by an electromagnetic flow meter. Consequently, the magnitude of fall in both endo- and epicardial MpH during critical stenosis and atrial pacing was no different with or without the administration of NTG. That under these conditions NTG failed to reduce the degree of myocardial ischemia suggests that the beneficial effects of NTG during fixed critical stenosis are determined primarily by its ability to reduce the determinants of myocardial oxygen demand, and not by a direct effect on the ischemic myocardium per se. The study also demonstrates for the first time a significant transmural gradient in MpH in the canine heart, even in the normal resting state.

Animals↗
PubMed1982

A candidate reference method for uric acid in serum. II. Interlaboratory testing.

We describe the interlaboratory testing of a candidate Reference Method (Part I) for uric acid in serum. The method is based on the ultrasound spectrophotometric quantitation of uric acid before and after incubation with uricase. A comprehensive investigation involving 12 laboratories was organized to document the transferability, intra- and interlaboratory precision, and general reliability of the candidate Reference Method. The interlaboratory CV with this method was about 2 to 6% for uric acid concentrations ranging from 0.12 to 0.60 mmol/L. The results detailed here demonstrate that the method can be successfully duplicated among different laboratories.

Evaluation Studies as Topic↗
PubMed1981

Dietary sodium, erythrocyte sodium concentration, sodium-stimulated lithium efflux and blood pressure.

1. There was a significant positive relationship between sodium-stimulated lithium efflux and systolic blood pressure (r = 0.512) in erythrocytes of black school children. Weight was also positively and significantly correlated with blood pressure. Although erythrocyte sodium concentration did not bear any significant relationship with blood pressure, it did bear significant inverse relationship with urinary sodium excretion. 2. High-school students were randomly assigned to either the experimental or the control group. In the former a reduction of about 70% in salt intake was achieved. After 24 days, the erythrocyte sodium concentration was significantly reduced in the experimental group. A non-significant decline in systolic blood pressure was observed in the experimental group; no change was detectable in the control group for either erythrocyte sodium concentration or systolic blood pressure.

Adolescent↗
PubMed1981

Racism, society, and disease: an exploration of the social and biological mechanisms of differential mortality.

Racial differentials in mortality provide important insight into the nature of mass disease in capitalist society. Not only are the differentials sizable in magnitude, they are consistent for multiple causes of death and appear to evolve in response to social development. The relationships among social factors and the biological and physical agents of disease can be identified through racial contrasts and a pattern of causation which applies to both the minority and majority populations described. Furthermore, the impact of exploitation as the primary disease-mediating factor under capitalist social relations can be estimated. This paper attempts to combine an analysis of bio-medical mechanisms with Marxist social theory in a comprehensive framework for the study of the social origins of racial differentials.

Black or African American↗
PubMed1981

Improved mortality among U.S. Blacks, 1968-1978: the role of antiracist struggle.

A marked improvement in health status for black adults took place over the last decade in the United States. Life expectancy for black men increased 4.6 years between 1968 and 1978, while for black women the increase was 5.7 years. Death rates for the age group 35-74 decreased approximately 25 percent for blacks over the same period. The largest contribution to this improvement was made by cardiovascular diseases (coronary heart disease and stroke). Although similar improvement was observed in the white population, on both a percentage and absolute basis the change was greater for blacks. For the first time in the U.S., important progress was made in the effort to narrow the gap in mortality rates between black and white adults. Hypertension detection and control appears to have played the key role in this positive public health trend. The community-based demand for greater access to medical care, which emerged from the social struggle of the 1960s, also can be accorded a major social role. The current policies of the Reagan Administration pose a serious threat to these antiracist programs, as well as to the effort to close the gap in black-white mortality.

Adult↗
PubMed1981

Human T-cell lymphoma with suppressor effects on the mixed lymphocyte reaction (MLR). I. Morphological and cytogenetic analysis.

The aggressive clinical course and the distinctive histologic, cytochemical, and cytogenetic features of an adult non-Sézary T-cell lymphoma with suppressor activity have been investigated. Morphological and ultrastructural analysis of neoplastic cells from peripheral blood and involved lymph nodes revealed cells with convoluted nuclei, prominent cytoplasmic azurophilic granules, well developed Golgi apparatus, short strands of endoplasmic reticulum, and moderate numbers of ribosomes and mitochondria. Cytochemical reactions showed acid phosphatase (ACP) positivity in virtually all of the neoplastic cells; and a substantial percentage of the cells, the tartrate-resistant acid phosphatase (T-ACP) isoenzyme was observed. Granular naphthyl acetate esterase (A-EST) reactivity was not present. The histological and cytochemical features of these neoplastic suppressor cells were compared with those recently described for the suppressor T-cell fraction isolated from normal peripheral blood T-cell by Fc gamma-rosette formation. The aneuploid clone had 47 chromosomes with multiple complex abnormalities, including a 14q + chromosome formed by the tandem translocation of two no. 14 chromosomes and translocations involving the long arms of no. 2 and no. 9 at band 9q34. These latter changes are particularly common in T-cell disorders. The extensive analysis of this histologic, cytochemical, and cytogenetic features of this adult T-cell suppressor lymphoma should help to clarify the criteria for distinguishing among the subsets of T-cell neoplasms with definable immunologic function.

Cytogenetics↗
PubMed1980

The treatment of haemorrhoids by rubber band ligation at St Mark's hospital.

Two hundred and ninety-five patients with symptomatic haemorrhoids were treated by rubber band ligation as out-patients at St Mark's Hospital, London, between April 1972 and December 1975. Follow-up was possible in 260 patients of whom two-thirds were satisfied with the outcome: 69 patients had residual symptoms for which no treatment had been sought. Nineteen patients eventually required a haemorrhoidectomy.

Ambulatory Care↗