PubMed Health⌕ Search

Biomedical subjects

M Whyte

Publications and source records attributed to M Whyte.

18 recordsLinked to original sources
PubMed2006

Exercise training reduces fatty acid availability and improves the insulin sensitivity of glucose metabolism.

AIMS/HYPOTHESIS: It is not known whether the beneficial effects of exercise training on insulin sensitivity are due to changes in hepatic and peripheral insulin sensitivity or whether the changes in insulin sensitivity can be explained by adaptive changes in fatty acid metabolism, changes in visceral fat or changes in liver and muscle triacylglycerol content. We investigated the effects of 6 weeks of supervised exercise in sedentary men on these variables. SUBJECTS AND METHODS: We randomised 17 sedentary overweight male subjects (age 50 +/- 2.6 years, BMI 27.6 +/- 0.5 kg/m(2)) to a 6-week exercise programme (n = 10) or control group (n = 7). The insulin sensitivity of palmitic acid production rate (Ra), glycerol Ra, endogenous glucose Ra (EGP), glucose uptake and glucose metabolic clearance rate were measured at 0 and 6 weeks with a two-step hyperinsulinaemic-euglycaemic clamp [step 1, 0.3 (low dose); step 2, 1.5 (high dose) mU kg(-1) min(-1)]. In the exercise group subjects were studied >72 h after the last training session. Liver and skeletal muscle triacylglycerol content was measured by magnetic resonance spectroscopy and visceral adipose tissue by cross-sectional computer tomography scanning. RESULTS: After 6 weeks, fasting glycerol, palmitic acid Ra (p = 0.003, p = 0.042) and NEFA concentration (p = 0.005) were decreased in the exercise group with no change in the control group. The effects of low-dose insulin on EGP and of high-dose insulin on glucose uptake and metabolic clearance rate were enhanced in the exercise group but not in the control group (p = 0.026; p = 0.007 and p = 0.04). There was no change in muscle triacylglycerol and liver fat in either group. CONCLUSIONS/INTERPRETATION: Decreased availability of circulating NEFA may contribute to the observed improvement in the insulin sensitivity of EGP and glucose uptake following 6 weeks of moderate exercise.

Blood Glucose↗
PubMed2000

Gender differences in Ayrshire teenagers' attitudes to sexual relationships, responsibility and unintended pregnancies.

Disadvantages and risks related to teenage pregnancy, together with a recent increase in Scottish conception rates among teenagers aged 13-15 years old, give cause for concern. Using an illustrated short story and questionnaire, attitudes of 129 Ayrshire teenagers aged 14-15 years old were examined to teenage pregnancy, and more generally to early sex. Seventy-three percent of girls advocated joint responsibility for contraceptive protection compared with only 46% of boys (p<0.01). Also, significantly more boys than girls saw nothing wrong with casual sex (21%vs. 5%, p<0.01), and significantly less boys than girls upheld the virtue of commitment in sexual relationships (27%vs. 54%, p<0.01). Sex education programmes should explore these gender-related disparities.

Adolescent↗
PubMed2000

Increased risk of fibrosing alveolitis associated with interleukin-1 receptor antagonist and tumor necrosis factor-alpha gene polymorphisms.

Fibrosing alveolitis (FA) is characterized by persistent inflammation and elevated production of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1beta), and interleukin-1 receptor antagonist (IL-1ra) in the lung. Single base variations at position +2018 in the IL-1ra gene (IL-1RN) and position -308 in the TNF-alpha gene (TNF-A) are overrepresented in other chronic inflammatory disease populations. We have tested the hypothesis that predisposition to FA may also be influenced by these polymorphisms by genotyping 88 cases and matched controls from England and 61 cases and 103 unmatched controls from Italy. The rarer allele for IL-1RN and TNF-A was designated allele 2 in each case. For IL-1RN allele 2, in the English group, the relative odds of FA were increased in homozygous subjects by an odds ratio (OR) of 10.2 (95% confidence intervals [CI], 1.26 to 81.4; p = 0.03) and for carriers by an OR of 1.85 (95% CI, 0.94 to 3.63; p = 0.075). In the Italian population, the risk of FA was increased, in IL-1RN allele 2 homozygotes (OR, 2.54; 95% CI, 0.68 to 9.50; p = 0.2) and in carriers (OR 2.40; 95% CI, 1.26 to 4.60; p = 0.008). Carriage of TNF-A allele 2 was also associated with increased risk of FA in the English (OR, 1.85; 95% CI, 0.94 to 3.63; p = 0.075) and Italian (OR, 2.50; 95% CI, 1.14 to 5.47; p = 0.022) populations. These data suggest IL-1RN (+2018) allele 2 and TNF-A (-308) allele 2 confer increased risk of developing FA and, therefore, that unopposed IL-1beta and/or excessive TNF-alpha may play a pathophysiologic role in this condition.

Aged↗
PubMed1997

Protection against Dictyocaulus viviparus in second year cattle after first year treatment with doramectin or an ivermectin bolus.

Forty-five calves were assigned randomly to three groups of 15 at turnout (day 0) in the spring of their first grazing season on to separate paddocks on a pasture known to carry infective larvae of Dictyocaulus viviparus. Group 1 calves were left as untreated controls, group 2 were injected with doramectin at 200 micrograms/kg at turnout and again on day 56, and group 3 were treated with an intraruminal bolus containing ivermectin. From day 42 onwards group 1 calves developed parasitic bronchitis which required repeated treatment with levamisole. The two endectocide regimes controlled lungworm infection, although some calves in group 2 developed some coughing during the week before the second dose of doramectin. After the end of the grazing season and again in May of the following year, five cattle from each group were infected experimentally with lungworm larvae and slaughtered 28 days later for lungworm counts and measurements of length to be made. At both times group 1 calves were found to be largely resistant to reinfection; group 2 were slightly more susceptible although the differences from group 1 were not statistically significant. Group 3 calves were more susceptible with no significant difference in worm counts from naive infection controls.

Animal Husbandry↗
PubMed1996

ICE/CED-3 proteasesin apoptosis.

An expanding family of cysteine proteases, of which interleukin-1beta-converting enzyme (ICE) is the prototype, has been shown to play a key role in mammalian cell apoptosis. ICE is both a structural and functional homologue of the nematode 'death gene' ced-3. Here, Moira Whyte discusses how functional characterization of these ICE-like proteases and identification of their substrates is helping to elucidate the biochemical processes underlying the stereotyped morphology of apoptosis and to identify potential targets for therapy.

Journal Article↗
PubMed1995

Apoptosis and the cell cycle.

Apoptosis is an evolutionarily conserved 'suicide' programme present in all metazoan cells. Despite its highly conserved nature, it is only recently that any of the molecular mechanisms underlying apoptosis have been identified. Several lines of reasoning indicate that apoptosis and cell proliferation coincide to some degree: many oncogenes that promote cell cycle progression also induce apoptosis; damage to the cell cycle or to DNA integrity is a potent trigger of apoptosis; and the key tumour suppressor proteins, p105rb and p53, exert direct effects both on cell viability and on cell cycle progression. There is less evidence, however, to indicate that apoptosis and the cell cycle share common molecular mechanisms. Moreover, the interleukin-1 beta converting enzyme (ICE) family of cysteine proteases is now known to play a key role in apoptosis but has no discernible role in the cell cycle, arguing that the two processes are discrete.

Animals↗
PubMed1995

Hypercalciuria in osteogenesis imperfecta: a follow-up study to assess renal effects.

In 1991, we reported that hypercalciuria is a common finding in our pediatric patient population with osteogenesis imperfecta (OI) (17 of 47 = 36%). Here, we prospectively screened 12 of these hypercalciuric children, on average 4 years subsequent to the discovery of elevated urine calcium levels, for adverse effects on renal function. Despite an ad libitum decrease since initial investigation of about 30% in their previously normal dietary calcium intake (adjusted for body weight), 8 of the 12 patients remained hypercalciuric (urine calcium/creatinine > 0.62 mmol/mmol). We found, once again, that urinary calcium levels significantly correlated with the severity of the skeletal disease as assessed by z-score for height (r = -0.75, p = 0.005). Evaluation of kidney function, however, revealed: (i) normal routine urinalysis in all but 1 subject who had transient microscopic hematuria; (ii) unremarkable concentrating ability determined by fasting urine osmolality; (iii) normal creatinine clearance, and (iv) unremarkable ultrasonography to measure renal size and to screen for nephrocalcinosis or nephrolithiasis. Although no significant renal compromise was detected with these studies in our hypercalciuric pediatric OI patients, investigation of affected adults, especially those severely affected, will be important to assess whether this is a long-term problem and if adverse effects on the kidneys do develop.

Adolescent↗
PubMed1995

New moms and self medication.

"Is there any reason why healthy women should not have access to simple pain medication when they require it?" This is the question pharmacists at the Salvation Army Grace Hospital in Ottawa were asked in addressing the needs of new mothers. And, while post-partum self-medication programs have existed for over a decade in Canada, the Grace has developed and implemented a comprehensive, patient-focused, multidisciplinary system with an innovative and user-friendly approach that benefits patients and staff.

Christianity↗
PubMed1978

Lifestyle, health and disease: a comparison between Papua New Guinea and Australia.

The proposition that lifestyle is a major determinant of community health is explored by contrasting the features of a rural subsistence community in the highlands of Papua New Guinea and the features of the community in urbanized, industrialized Australia. Reference is made to differences in physical environment, housing, work, social situation, human relationships, patterns of disease, population statistics, diet, growth, obesity, physical fitness, blood lipid concentrations, blood pressure, salt intake and the occurrence of hypertension, diabetes, cardiovascular disease and signs of degenerative changes in various tissues. The Papua New Guinea community is seen as a self-reliant, self-contained, socially cohesive subsistence society whose members are well adapted to their physical and social environment, free from major degenerative cardiovascular diseases, with little overt psychiatric illness, but with a heavy burden of infectious disease, with marginal nutritional levels of degenerative disease and disease from psychological stress. It is clear that health, in its fullest sense, is not the prerogative of any one type of society.

Adolescent↗
PubMed1977

National views: Australia.

The Austrialian scene in this area would seem to show the same features, and haze, as are found in many other countries. There is general recognition of atherosclerotic problems, of the common risk factors and of the need for prevention. Learned and informed bodies such as The Australian Academy of Science and The National Heart Foundation of Australia have made recommendations along familiar lines, involving especially dietary changes, as preventive measures. The basis for these recommendations has been a general review of the subject and doses not include anything uniquely Australian. The admission of uncertainty about causes and prevention, awareness of controversy, confusion, ignorance and a natural reluctance to change habits no doubt contribute to popular disregard for the recommendations at the present time.

Arteriosclerosis↗
PubMed1977

Cholesterol metabolism in Papua New Guineans.

Cholesterol metabolism has been studied in a group of healthy males drawn from a New Guinea highland population whose plasma cholesterol concentration is low by Western standards and does not rise with age. Mean values from compartmental studies in six subjects were: pool A mass 289 mg/kg; production rate 1069 mg/day or 17.4 mg kg-1 day-1. The average rate of endogenous synthesis measured by sterol balance in twelve men was 751 mg/day or 12.4 mg kg-1 day-1. There was evidence of probable suppression of synthesis by about 500 mg/day when 1 g/day of egg yolk cholesterol was added to the diet of six subjects for 5 weeks. In the latter group, mean cholesterol absorption was 39% (390 mg/day) but the plasma cholesterol concentration did not rise, possibly reflecting compensatory redution in synthesis. It is suggested that these results were unexceptional, except possibly for the failure of the plasma cholesterol concentration to rise when cholesterol was ingested, despite gross differences in diet and many other factors.

Adult↗