Search PubMed⌕ Search

Biomedical subjects

R Taylor

Publications and source records attributed to R Taylor.

At least 559 records · Page 31Linked to original sources
PubMed1985

Insulin secretion, adipocyte insulin binding and insulin sensitivity in thyrotoxicosis.

The pattern of insulin secretion following an oral glucose load and the insulin receptor status and insulin sensitivity of adipocytes have been studied in patients with thyrotoxicosis and in matched controls. Thyrotoxic subjects showed normal basal and peak levels of serum immunoreactive insulin (peak, 69.0 +/- 6.8 vs 54.3 +/- 8.8 mU/l) and serum C-peptide (peak, 1.95 +/- 0.13 vs 1.71 +/- 0.12 nmol/l for thyrotoxic and control subjects, respectively). Peak serum proinsulin was higher in the thyrotoxic group (64.8 +/- 7.3 vs 39.0 +/- 3.7 pmol/l; P less than 0.01). Maximum specific insulin binding to adipocytes was decreased in the thyrotoxic group (1.80 +/- 0.18 vs 2.62 +/- 0.27%; P less than 0.025) and half-maximum displacement of tracer insulin was similar in the two groups, suggesting that reduced receptor number rather than reduced affinity accounted for the difference. However, adipocyte insulin sensitivity was normal as judged by half-maximal stimulation values of 13.9 +/- 3.6 vs 11.4 +/- 2.1 pmol/l, respectively for lipogenesis and 24.3 +/- 2.2 vs 24.6 +/- 3.6 pmol/l, respectively for glucose transport. Hence, thyroid hormone excess appears to affect adipocyte insulin receptor number directly, but change in receptor number is not associated with change in adipocyte insulin sensitivity in hyperthyroidism. The normal insulin secretion together with the failure to demonstrate abnormal insulin sensitivity of one of the major peripheral tissues suggests that disturbed hepatic rather than peripheral insulin responsiveness may be responsible for the glucose intolerance of hyperthyroidism.

Adipose Tissue↗
PubMed1985

Mortality patterns in the modernized Pacific Island nation of Nauru.

Nauru is a small phosphate-rich independent island country situated in the Central Pacific. The population is Micronesian and was estimated to be 4,680 in mid-1981. An analysis of mortality data for the years 1976-81 indicates a high adult male mortality due to accidents, injuries, cardiovascular disease, and diabetes. The life expectancy estimate at birth for men was 49 years, and for women 62 years. The male life expectancy is among the lowest in the region. The considerable adult male mortality appears to be related to the rapidly acquired affluence and the ready availability of motorcycles, cars, imported foods, tobacco, and alcohol. The data suggest that modernization of the economy in Pacific Island nations can lead to new and serious public health problems.

Accidents↗
PubMed1985

Medicine as social science: Rudolf Virchow on the typhus epidemic in Upper Silesia.

Rudolf Virchow's Report on the 1848 typhus epidemic is one of the neglected classics of "social medicine"--a term he did much to popularize. His analysis of the epidemic emphasized the economic, social, and cultural factors involved in its etiology, and clearly identified the contradictory social forces that prevented any simple solution. Instead of recommending medical changes (i.e., more doctors or hospitals), he outlined a revolutionary program of social reconstruction; including full employment, higher wages, the establishment of agricultural cooperatives, universal education, and the disestablishment of the Catholic Church. This article includes the first English translation of these long-term recommendations. It also locates Virchow's Report within the context of the Medical Reform Movement of 1848 and traces his influence on the subsequent development of social medicine. Parallels are drawn between Virchow's attempts to reform health care and current developments in the political economy of health.

Germany↗
PubMed1985

Assessment of initial hexose uptake in adipocytes using the physiological substrate D-glucose. Particular relevance to human adipocytes.

The characteristics of U-[14C]D-glucose uptake into human and rat adipocytes have been examined. The initial rates of U-[14C]D-glucose uptake were found to be linear during the first 30 s, both basally and with maximum insulin stimulation. Phloretin was shown to be effective in stopping glucose flux for human adipocytes, although rapid separation of cells from medium was found to be necessary for accurate measurement of initial rate of glucose uptake into rat adipocytes. The pH and temperature dependency of U-[14C]D-glucose uptake were found to be similar to those reported for 3-0-methylglucose. The use of U-[14C]D-glucose for assessment of initial rate of glucose uptake into human adipocytes provides results directly relevant to D-glucose metabolism, in addition to being technically less demanding and much less expensive than methods using the non-physiological sugar analogue 3-0-[14C]methylglucose.

Adipose Tissue↗
PubMed1985

Environmental setting and early drug involvement among inner-city junior high school youths.

This study explores the drug use of a sample of inner-city junior high school youths by examining a hypothesized, interactive relationship between perceived toughness/drug use in their neighborhood and the youths' demographic, neighborhood orientation/involvement, and drug use context factors in regard to their involvement with drugs. The results dramatically showed that the youths' views of their environmental setting operate as a conditioning factor in understanding the correlates of their drug involvement. In supporting the hypothesis, prosocial correlates of drug use are stressed in settings characterized by high toughness/drug use settings. Our findings urge that serious consideration be given to examining social contextual effects on drug taking as a means to understanding this behavior among different sociocultural groups.

Adolescent↗
PubMed1985

The elderly as underconsulters: a critical reappraisal.

This paper reconsiders the evidence for underconsultation among the elderly. Earlier evidence from studies of unreported illness is reassessed and new data are presented for the ratio of self-reported illness to number of consultations. It is concluded that underconsultation among the elderly is exaggerated and that there are implications for screening and case-finding. It is suggested that attention should be directed towards a combination of self-referral and multi-tiered screening for low contact and high risk groups.

Aged↗
PubMed1984

Impaired glucose tolerance in Kiribati.

Subjects with impaired glucose tolerance have been shown to have a higher risk for subsequent diabetes and increased susceptibility to atherosclerosis. Data obtained from a cross-sectional medical survey in Kiribati in 1981 have been studied for evidence as to whether impaired glucose tolerance is a truly separate category of glucose intolerance. Subjects in the impaired glucose tolerance category were compared to both normal and diabetic subjects with respect to the mean values of certain variables including plasma glucose, body mass index, plasma cholesterol, plasma triglycerides, and systolic blood pressure. Differences between impaired glucose tolerant and normal subjects, and between impaired glucose tolerant and diabetic subjects were assessed. The most important differences between groups occurred with respect to plasma glucose concentration, body mass index, and plasma lipids. The results of this study provide further support for the validity of the impaired glucose tolerance category.

Adult↗
PubMed1984

Glucose tolerance and ancestral genetic admixture in six semitraditional Pacific populations.

Population-based data on 1,842 subjects from six semitraditional Pacific communities, collected in the years 1978-1983, have been compared in order to examine the hypotheses that differences in the distribution of plasma glucose concentration between populations are to some extent genetically determined, and that non-Austronesian (NAN) Melanesians are relatively resistant to glucose intolerance. Semitraditional communities were chosen for study so that the comparison would be minimally confounded by either known or as yet undetermined environmental factors associated with nontraditional living, the effects of which may vary between populations. The samples were also selected so as to provide a gradient of proportional NAN and AN admixture. They were drawn from the following regions: the highlands of Papua New Guinea, New Caledonia, Fiji, the Wallis Islands, Western Samoa, and Kiribati (formerly the Gilbert Islands). The Papua New Guinea highlanders, of entirely NAN ancestry, were regarded as the baseline population. A gradient of increasing mean 2-hr plasma glucose concentration was observed across the six populations and differences persisted between populations, after controlling for age and obesity. Variations in diet, physical activity, and degree of sociocultural modernization were not considered a sufficient or consistent explanation of these findings and they therefore lend tentative support to the hypothesis of a genetic component to variability in glucose tolerance. The relationship between population estimates of glucose tolerance and estimates of the genetic distance from the baseline NAN Melanesian sample was examined. With the notable exception of Fiji, there was evidence of a linear correlation between the two parameters.

Female↗
PubMed1984

Differential binding of sulphated insulin to adipocytes and hepatocytes.

The polymerization and precipitation of highly purified insulins which causes major problems in portable infusion systems does not occur with sulphated insulin. To compare the biological behaviour of sulphated insulin with that of a neutral highly purified monocomponent insulin, insulin receptor studies were performed on human and rat adipocytes and rat hepatocytes. Sulphated insulin displayed a lower affinity for binding to both human and rat adipocytes compared with neutral insulin, approximately four times the concentration being required to achieve half-maximal displacement of monoiodoinsulin (p less than 0.05 and 0.01, respectively). A 20-fold higher concentration of sulphated insulin was required for half-maximal displacement from rat hepatocytes (p less than 0.025). However, sulphated insulin bound to liver membranes with an affinity more closely resembling that for adipocytes rather than hepatocytes. Differences in the intracellular processing of the negatively charged insulin could account for the observed lower affinity of binding to hepatocytes.

Adipose Tissue↗
PubMed1984

Adipocyte insulin binding and insulin sensitivity in 'brittle' diabetes.

Adipocyte insulin binding and insulin sensitivity to stimulation of lipogenesis were assessed in a group of extremely 'brittle' diabetic patients who were resistant to subcutaneous insulin therapy and had required frequent and prolonged hospital admission. These patients had significantly lower maximum adipocyte insulin binding (1.78 +/- 0.18%) than age-, sex- and weight-matched stable diabetic control subjects (2.57 +/- 0.36%; p less than 0.05). Scatchard analysis suggested that the decreased binding was secondary to reduced receptor affinity with no change in receptor number. Adipocytes from the brittle subjects displayed resistance to insulin stimulation of lipogenesis compared with those from diabetic or normal control groups (half-maximal stimulation at 34 +/- 4, 15 +/- 3 and 13 +/- 2 pmol/l respectively; p less than 0.01 between brittle and stable diabetic groups). In the one subject who was treated with intraperitoneal insulin, the changes in insulin binding and sensitivity were found to have reverted towards normal. The peripheral tissue abnormalities of brittle diabetes may exacerbate the clinical syndrome although the relationship of these changes to the primary cause of the syndrome is uncertain.

Adipose Tissue↗
PubMed1984

Physical activity and prevalence of diabetes in Melanesian and Indian men in Fiji.

In Fiji Melanesian and Indian men, prevalence of diabetes is more than twice as high in those graded as sedentary or undertaking light activity as in those classed as performing moderate or heavy exercise. This difference was present in both ethnic groups, and maintained when age, obesity, and urban/rural- status were taken into account. It is concluded that, in the population under study, there is epidemiological evidence for the role of physical inactivity as an independent risk factor for Type 2 (non-insulin-dependent) diabetes.

Adult↗
PubMed1984

Hyperlipemia and arteriosclerotic cardiovascular disease in the Polynesian population of Rarotonga.

Total cholesterol, total triglyceride and high density lipoprotein (HDL) cholesterol and their relation to arteriosclerotic cardiovascular disease (ASCVD) were investigated in a population of Polynesian Maoris in Rarotonga who are becoming increasingly westernized. 8.5% of the population had plasma triglyceride elevations (triglyceride greater than or equal to 200 mg/dl), and the occurrence of hypertriglyceridemia was significantly higher in males than females. 5.8% of the population had elevations of total cholesterol (cholesterol greater than or equal to 250 mg/dl), and the proportion with elevation of total cholesterol was similar for males and females. 3.2% of the population had elevations of both triglyceride and cholesterol. HDL cholesterol concentrations were relatively low, and no sex differences were observed at any age. Analysis of lipoprotein cholesterol and triglyceride in a subset of those who had hyperlipemia indicated that the elevations of total cholesterol and triglyceride were mainly due to elevations of low density lipoprotein (LDL) cholesterol and very low density lipoprotein (VLDL) triglyceride, respectively; furthermore, elevations of VLDL triglyceride and LDL cholesterol were significantly correlated with increase in VLDL apolipoprotein B (apo B) and LDL apo B, respectively. Although an appreciable prevalence of diabetes was observed in this population (male: 6.7%, female: 8.4%), the diabetes could not account for the hyperlipemia. Among 693 subjects between the ages of 30 and 59 years, approx. 3% of males and 1% of females had Q-wave changes, and 16% of females and 4% of males had ST-T changes. Among males with Q-wave abnormalities, hyperlipemia was more frequent. There was also increased frequency of hypertension in those with elevated lipids. The data indicate the occurrence of some hyperlipemia in this population which could be of the familial-combined type; the elevated plasma lipids may contribute to the increased frequency of coronary heart disease.

Adult↗