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Biomedical subjects

R Taylor

Publications and source records attributed to R Taylor.

At least 505 records · Page 28Linked to original sources
PubMed1988

Effect of marathon training on the plasma lactate response to submaximal exercise in middle-aged men.

Twenty-one previously sedentary male volunteers (aged 35-50 years) undertook a defined marathon training programme lasting 30 weeks. At weeks 0 (T1), 15 (T2) and 30 (T3) they underwent measurement of maximal oxygen uptake (VO2 max), submaximal VO2 and submaximal plasma lactate concentration during cycle ergometry. No exercise was taken for 24-48 hours prior to testing. During training aerobic power increased significantly (p less than 0.001) from an initial VO2 max at T1 of 33.9 +/- 6 (mean +/- sd) ml.kg-1min-1 to 39 +/- 5.6 ml.kg-1min-1 at T2 but the T3 value of 39.2 +/- 5.2 ml.kg-1min-1 was not significantly different from that at T2. Plasma lactate concentration of 4 mmol.l-1 (OBLAw) occurred at a significantly (P less than 0.05) higher workload (155 +/- 28 w) at T2 compared with T1 (132 +/- 30 w) but the T3 figure was 137 +/- 34 w. OBLA VO2 at T1 was 2.04 +/- 0.42 l.min-1, at T2 was 2.24 +/- 0.04 l.min-1 but at T3 was 2.03 +/- 0.30 l.min-1 (T1:T2 P less than 0.05, T1:T3 NS). OBLA % VO2 max at T1 was 75 +/- 12%, at T2 was 73 +/- 11% but at T3 was 62 +/- 10% (T1:T2 NS, T1:T3 P less than 0.01).

Adult↗
PubMed1988

Four DNA polymorphisms in the LDL receptor gene: their genetic relationship and use in the study of variation at the LDL receptor locus.

We have studied four different restriction fragment length polymorphisms (RFLPs) for the LDL receptor gene, detected using the restriction enzymes StuI, PvuII, ApaLI, and NcoI, in normal subjects and in patients with familial hypercholesterolaemia (FH) from London. Significant linkage disequilibrium was detected between all four RFLPs. Used together they give a polymorphism information content (PIC) of greater than 0.7 which makes them useful for studying the inheritance of the LDL receptor gene in more than 70% of families with FH. The NcoI and ApaLI RFLPs were found to be the most useful, giving a combined PIC value of 0.6. The allele frequencies of all four polymorphisms were compared in the normal and FH groups and the frequency of the rarer N2 allele of the NcoI RFLP was found to be significantly higher in the FH group. This suggests that a mutation has occurred on the rare NcoI N2 allele and that it may be making a significant contribution to the defects causing FH in this patient group. We have also used these RFLPs to look for evidence that variation at the LDL receptor gene locus contributes to the determination of cholesterol levels in the normal population. People with different RFLP genotypes do not have significantly different levels of serum total or LDL cholesterol. At present we have no evidence that variation at this locus may be determining cholesterol levels in the non-FH population.

Alleles↗
PubMed1988

Intermediary metabolism, insulin sensitivity and insulin receptor status under comparable long-term therapy with insulin injections and continuous subcutaneous insulin infusion.

We have compared metabolic parameters, insulin sensitivity and insulin receptor status in 12 patients with insulin-dependent diabetes after 6 months treatment with insulin injection therapy and continuous subcutaneous insulin infusion therapy (CSII) in random order. Mean 24-h blood glucose, intermediary metabolite, plasma free insulin and counter-regulatory hormone concentrations were equivalent on the two regimes despite a significantly lower insulin dose on CSII (49.8 +/- 4.0 vs 39.3 +/- 2.2 U/24 h, P less than 0.01). When compared with a group of matched normal subjects, mean blood glucose and M-value, blood 3-hydroxybutyrate and free insulin concentrations were significantly higher on both regimes whilst blood alanine levels were depressed. Peripheral insulin sensitivity as assessed by the euglycemic clamp, basal hepatic glucose output, glucose carbon recycling, adipocyte insulin binding, adipocyte insulin sensitivity and lipogenesis were all similar after the two treatments. Insulin-stimulated initial rates of glucose uptake by adipocytes were higher after CSII (1.78 +/- 0.16 vs 2.35 +/- 0.27 pmol per cm2 cell membrane per 20 sec, P less than 0.005).

Adipose Tissue↗
PubMed1988

Effects of BAYm 1099, new alpha-glucosidase inhibitor, on acute metabolic responses and metabolic control in NIDDM over 1 mo.

To examine the clinical role of BAYm 1099, 15 diet-treated non-insulin-dependent diabetic (NIDDM) subjects were randomized to start drug (50 mg 3 times/day) or placebo after a 4-wk run-in period in a double-blind crossover study. Treatment periods (4 wk) were separated by a 2-wk washout period. During the last week of each treatment period, three test meals (TMs) were administered: 60 g starch (TM1), 25 g sucrose (TM2), and combined 60 g starch and 25 g sucrose (TM3). Twelve subjects completed the study. The peak postprandial blood glucose, lactate, and pyruvate levels (means +/- SE) were significantly lower with active drug after all test meals, particularly TM2 (11.3 +/- 1.0 vs. 14.3 +/- 1.4 mM, P less than .001; 1.53 +/- 0.20 vs. 2.48 +/- 0.17 mM, P less than .001; and 105.1 +/- 17.6 vs. 147.6 +/- 11.1 microM, P less than) less than .001; and 105.1 +/- 17.6 vs. 147.6 +/- 11.1 microM, P less than .05, respectively. Peak blood glucose levels were significantly delayed. However, fasting blood glucose, HbA1, fructosamine, and cholesterol did not change during active treatment (10.0 +/- 1.0 vs. 9.9 +/- 1.0 mM, 10.0 +/- 0.7 vs. 9.4 +/- 0.7%, 2.44 +/- 0.10 vs. 2.37 +/- 0.07 mmol/100 g protein, and 6.7 +/- 0.3 vs. 6.5 +/- 0.3 mM, P NS). Flatulence and diarrhea were severe in 2 subjects, requiring termination of study. Thus, in NIDDM, BAYm 1099 was effective in diminishing and delaying postprandial excursions of blood glucose, lactate, and pyruvate after high- and low-sucrose meals, but overall metabolic control remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Deoxynojirimycin↗
PubMed1988

[Monitoring of mosquito vectors at international airports of the South Pacific region].

A survey conducted in eight airports of the South pacific, yielded 2,044 larvae and 136 adult forms, belonging to 25 Culicidae species. Breeding places were found in every airport, either within the perimeter (6 airports) or in the protective zone. Some potentially dangerous vectors were identified: Aedes aegypti (4 airports), Ae. polynesiensis, Ae. vigilax, Anopheles farauti (2 airports), Culex annulirostris, C. p. quinquefasciatus. Vector control measures should be strengthened to suppress every breeding place within the airport perimeter.

Aedes↗
PubMed1988

Hypertension and diabetes mellitus: erythrocyte electrolytes and the effect of captopril treatment.

Erythrocyte sodium, potassium and water contents and sodium fluxes were measured in both normotensive and hypertensive patients with either insulin dependent or non-insulin dependent diabetes mellitus. Hypertensive patients were studied again after two months' treatment with captopril. There were no differences in erythrocyte ion contents or concentrations but sodium fluxes may have been lower in insulin dependent patients and in hypertensive patients. The most marked erythrocyte defects associated with hypertension were low erythrocyte water content and increased potassium concentration in non-insulin dependent diabetic patients. Treatment with captopril caused an increase in erythrocyte water and a decrease in ion content and concentration. In non-insulin dependent diabetic patients, who had the greatest increases in erythrocyte water and falls in potassium concentration, frusemide-sensitive sodium-potassium co-transport activity was reduced. The reduction in blood pressure with captopril treatment was related to the initial erythrocyte sodium content.

Biological Transport↗
PubMed1987

Mortality in Niue, 1978-82.

This report is an analysis of mortality in the population of Niue Island over the years 1978-82. The overall level of mortality in Niue is low. Life expectancy at birth is correspondingly high (66.5 years). Because of the extensive migration of Niueans during the period of study the death rate may be underestimated and the life expectancy correspondingly overestimated. Infant mortality has dropped from over 200 deaths per 1000 live births during the 1940s to around 10 per 1000 during the period under study. The major causes of premature mortality in Niuean males were injury/poisoning followed by cardiovascular disease. In females infection, injury/poisoning and neoplasia were the major causes of mortality. The 1980 epidemic of dengue fever had an appreciable effect on mortality in this small population. Except for dengue fever, the pattern of mortality in Niue is similar to that in many developed countries. Preventive efforts against metabolic and cardiovascular disease (including hypertension and diabetes) should continue in order to control mortality from these causes, Mosquito programmes, and emergency measures if epidemics threaten, are required so that deaths from haemorrhagic dengue are prevented.

Adolescent↗
PubMed1987

Insulin-like and insulin-inhibitory effects of monoclonal antibodies for different epitopes on the human insulin receptor.

Monoclonal antibodies previously shown to react with five distinct epitopes on the human insulin receptor were tested for their metabolic effects on isolated human adipocytes. Two antibodies which reacted with receptor alpha-subunit and completely inhibited 125I-insulin binding mimicked the actions of insulin to stimulate lipogenesis from [14C]glucose and to inhibit catecholamine-induced lipolysis. On a molar basis, these antibodies were comparable in potency with insulin itself. Two other antibodies which decreased insulin binding only slightly or not at all also mimicked these metabolic effects of insulin. One of these antibodies reacted with receptor beta-subunit. In contrast, a further antibody which reacted with alpha-subunit and inhibited insulin binding did not affect basal lipogenesis or catecholamine-induced lipolysis, but was able to antagonize the effects of insulin on these processes. The same antibody antagonized the insulin-like effect of another antibody with which it competed in binding to insulin receptor, but not the effect of an antibody which bound independently to the receptor. It is concluded that binding of ligand at or close to the insulin-binding site is neither necessary nor sufficient to trigger insulin-like metabolic effects, which may rather depend on some general property of antibodies, such as their ability to cross-link and aggregate receptor molecules.

Adipose Tissue↗
PubMed1987

Hypertension and indicators of coronary heart disease in Wallis Polynesians: an urban-rural comparison.

A comparative study of hypertension, and indicators of and risk factors for coronary heart disease was undertaken in samples of rural Wallisians of Wallis Island, and first generation Wallisian migrants in the urban centre of Noumea, New Caledonia. Approximately 20% of the adult population of the two communities was included in the study. Higher mean blood pressure and hypertension prevalence in Wallisians in Noumea compared to those in Wallis was documented. There was no significant rise in blood pressure with age in rural Wallisian males. Wallisians in Noumea tended to be more obese than those in Wallis (particularly females). Although differences in the extent of obesity appeared to explain some of the differences in blood pressure between populations of Wallis and Noumea, other environmental factors (such as salt intake) are probably important. There was a trend for a higher prevalence of Q wave changes on the ECG in urbanized Wallisians compared to their rural counterparts. There was no significant or consistent differences in plasma lipid concentrations between the two groups. The prevalence of diabetes was 7 and 4 times higher in Noumea compared to Wallis for males and females respectively. Differences in diabetes and hypertension prevalence are more likely to account for the variation in ischaemic heart disease than plasma lipid levels.

Adult↗
PubMed1987

Endometrial carcinoma occurring in patients under the age of 45 years.

Endometrial adenocarcinoma is frequently unsuspected in women under the age of 45 years by the gynecologist or the pathologist, but it does occur. Twenty-seven cases of endometrial adenocarcinoma in this age group, from 1980 to 1985, were reviewed clinically and pathologically. Five cases were excluded by histologic examination. Obesity and abnormal vaginal bleeding were shown to be risk factors. Endometrial screening is to be encouraged. This cancer may arise de novo rather than from a premalignant precursor. Implications of this neoplasm for the premenopausal woman are considered.

Adult↗
PubMed1987

Ten year experience with the negatively charged glutaraldehyde-tanned vascular graft in peripheral vascular surgery. Initial multicenter trial.

The negatively charged glutaraldehyde-tanned vascular graft was developed to determine the utility of grafts of biologic origin to provide satisfactory revascularization for ischemic limbs with advanced arteriosclerotic peripheral vascular disease. The bovine carotid artery was modified under a number of conditions using a large number of variables and evaluated in the carotid artery and aorta of dogs. Eventually ficin-digested carboxylated glutaraldehyde-tanned grafts were selected as being most antithrombotic and most resistant to aneurysm formation. Under an Investigational Device Exemption with the Food and Drug Administration, 146 grafts were evaluated in 108 patients with patency approaching 67 percent for all grafts at 5 years and 59 percent at 9 years plus. Total aneurysm formation has been 4 percent (six grafts) occurring only in hypertensive patients. The graft is now undergoing clinical use and evaluation worldwide.

Adult↗
PubMed1987

Use of adipose tissue for metabolic studies.

Open biopsy of adipose tissue from volunteer subjects has led to a greater understanding of the mechanisms of adipose-tissue insulin resistance in various clinical states. Studies of adipose tissue obtained during surgical operations have allowed development of techniques and exploration of adipocyte physiology. This has been particularly valuable in examining the relationship between cellular insulin binding and action. Examination of the lipid stores and of enzyme activities has been possible by using the more convenient technique of needle biopsy. Regional differences in adipose tissue metabolism have been identified and must be considered in experimental design. It is now clear that the insulin sensitivity of any one metabolic pathway does not necessarily reflect that of others, and care must be taken to avoid inappropriate extrapolation of data both between metabolic pathways in the adipocyte itself and from the adipocyte to the whole body.

Adipose Tissue↗