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Biomedical subjects

M Walker

Publications and source records attributed to M Walker.

At least 37 records · Page 2Linked to original sources
PubMed1997

Identification and management of stroke risk in older people: a national survey of current practice in primary care.

The current practice of stroke prevention was assessed among UK general practitioners (GPs) using a postal questionnaire. A random sample of 583 GPs (response rate 60%) in practice throughout the UK was examined. Main outcomes were the reported practice in the identification of stroke risk, management of hypertension, and use of other interventions (particularly aspirin treatment) to reduce the risk of stroke. Most respondents (451, 77%) reported that they specifically identified patients at high risk of stroke. However, of these only 301 (67%) used more than one major risk factor to do this and less than one-third used either age or pre-existing cardiovascular disease as an indicator. Thresholds for drug treatment of hypertension increased markedly with patient age with only 68%, 23% and 9% of respondents reporting treating elevated systolic, diastolic and isolated systolic pressures respectively, in accord with the British Hypertension Society (BHS) guidelines for patients aged 70-79 years. Thresholds for blood pressure (BP) treatment in older patients did not differ by region but were higher among respondents who had been in general practice for more than 10 years. The value of aspirin in preventing stroke in patients with pre-existing cardiovascular disease was recognized by almost all (560, 96%) respondents. The results suggest that there is scope for increasing the benefits of stroke prevention in primary care, by focusing on the management of patients at high absolute risk, in whom the greatest treatment benefits are likely to be obtained.

Aged↗
PubMed1997

Dynamic variations in plasma corticosteroid-binding globulin and basal HPA activity following acute stress in adult rats.

We report on dynamic changes in plasma corticosteroid-binding globulin (CBG) binding and basal hypothalamic-pituitary-adrenal (HPA) activity following acute stress in adult rats. Plasma CBG binding was significantly reduced at 24 and 48 h following a single 60 min period of restraint. Basal levels of plasma ACTH and total corticosterone (B) during the light phase of the cycle were elevated at 24 h following restraint. These effects occurred only when animals were stressed in the light phase of the cycle; animals exposed to restraint stress during the dark phase of the cycle showed no change in plasma CBG binding or in basal HPA activity. Pituitary intracellular transcortin, which is derived from circulating CBG, was also decreased by restraint stress. The decrease in CBG binding was also associated with a significant increase in resting-state free B levels. Together, these effects produced a substantially (i.e. approximately 10-fold) increased 'basal' glucocorticoid signal 24 h following acute stress. These data suggest that the increase in the circulating glucocorticoid signal associated with acute stress endures well beyond the period of increased total B levels.

Adrenal Glands↗
PubMed1997

Rapid geographic spread of a methicillin-resistant Staphylococcus aureus strain.

In May 1993, an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) was identified at our tertiary care teaching center. The epidemic MRSA strain was transmitted efficiently in the hospital environment. Subsequent investigations indicated that the strain had been introduced into western Canada by a patient who had recently been hospitalized for 3 months in the Punjab, India, and had been admitted to a hospital in rural British Columbia shortly after his arrival in Canada. Transfer of the patient to a hospital in Vancouver and subsequent transfer of a colonized patient contact to a hospital in Winnipeg, Manitoba, resulted in major outbreaks of MRSA at these two large tertiary care centers within 6 weeks of the arrival of the index case in Canada. Epidemiological typing of the S. aureus coagulase gene with use of a polymerase chain reaction method and pulsed-field gel electrophoresis documented clonality of this strain. These outbreaks again illustrate both the propensity of certain strains of S. aureus to produce epidemic disease, including rapid spread within the institutional setting, and the global nature of problems with antimicrobial resistance.

Bacterial Typing Techniques↗
PubMed1997

Dietary carbohydrates and insulin sensitivity: a review of the evidence and clinical implications.

Insulin resistance is associated with diabetes mellitus, ischemic heart disease, and hypertension both independently and as part of syndrome X. Environmental influences on SI are incompletely understood. Exercise has a strong beneficial effect and obesity a strong adverse effect. The balance of evidence suggests that a high-fat diet is likely to reduce insulin sensitivity but the effects of dietary carbohydrates are more controversial. Extensive studies in animals showed a detrimental effect of diets very high in fructose or sucrose, particularly in association with induction of hypertriglyceridemia. The more limited studies in humans had conflicting results, partly because of heterogeneity of design. Certain groups of subjects may be more sensitive to adverse effects of high intakes of dietary sucrose or fructose. More carefully controlled studies in humans are needed to provide evidence on which to base public health policies with respect to dietary carbohydrates and SI.

Animals↗
PubMed1997

Effect of fresh fruit consumption on lung function and wheeze in children.

BACKGROUND: Fresh fruit consumption and vitamin C intake have been associated with improved lung function in adults. Whether this is due to enhancement of lung growth, to a reduction in lung function decline, or to protection against bronchospasm is unclear. METHODS: In a cross-sectional school based survey of 2650 children aged 8-11 from 10 towns in England and Wales the main outcome measure was forced expiratory volume in one second (FEV1) standardised for body size and sex. Exposure was assessed by a food frequency questionnaire to parents and by measurement of plasma levels of vitamin C in a subsample of 278 children. RESULTS: FEV1 was positively associated with frequency of fresh fruit consumption. After adjustment for possible confounding variables including social class and passive smoking, those who never ate any fresh fruit had an estimated FEV1 some 79 ml (4.3%) lower than those who ate these items more than once a day (95% CI 22 to 136 ml). The association between FEV1 and fruit consumption was stronger in subjects with wheeze than in non-wheezers (p = 0.020 for difference in trend), though wheeze itself was not related to fresh fruit consumption. Frequency of consumption of salads and of green vegetables were both associated with FEV1 but the relationships were weaker than for fresh fruit. Plasma vitamin C levels were unrelated to FEV1 (r = -0.01, p = 0.92) or to wheeze and were only weakly related to fresh fruit consumption (r = 0.13, p = 0.055). CONCLUSIONS: Fresh fruit consumption appears to have a beneficial effect on lung function in children. Further work is needed to confirm whether the effect is restricted to subjects who wheeze and to identify the specific nutrient involved.

Ascorbic Acid↗
PubMed1997

Nuclear DNA content of fine needle aspirates of invasive ductal carcinomas of the breast.

Patients with aggressive breast cancers benefit from chemotherapy prior to surgery. If the biology of the breast cancers were better characterised pre-operatively, more patients at risk could be offered chemotherapy. We have assessed nuclear DNA content of fine needle aspirates (FNA) of 103 invasive ductal breast cancers and compared this to tumour size, node status and histological grade. Median follow-up was 18 months so no prognostic studies were made. Diploid and non-diploid tumours were distributed equally in node negative and positive patients. However non-diploidy status increased in line with known prognostic markers of tumour size and histological grade. This suggests that ploidy might contribute to the pre-operative assessment of prognosis. We conclude that nuclear DNA of breast cancer FNAs may be of value in the pre-operative biological assessment of breast cancer patients.

Adult↗
PubMed1997

Do labor medications affect breastfeeding?

Do labor medications affect breastfeeding? Few studies examine breastfeeding as an outcome of labor medication. While parents may be told that labor medications and epidurals have no effect on newborns, the literature reports significant neurobehavioral effects of these medications on the newborn and the mother-infant relationship.

Analgesia, Epidural↗
PubMed1997

Breastfeeding the sleepy baby.

Sleepy babies can be a source of frustration to both mothers and health care providers during the early days of breastfeeding. This paper looks at some reasons for excessive sleepiness and offers suggestions for helping sleepy babies to breastfeed using the baby as a guide.

Age Factors↗
PubMed1997

Quantitative measurement of estrogen and progesterone receptors in breast lumps using image cytometry.

OBJECTIVE: To evaluate image cytometry for detecting estrogen (ER) and progesterone receptors (PR) in breast lumps quantitatively. STUDY DESIGN: Fifty consecutive breast lumps were analyzed for ER and PR using the avidin-biotin complex on tissue sections. RESULTS: Mean ER-positive nuclear area percentage (PA%) for 25 invasive ductal carcinomas was 47.81% and for PR was 57.83%. Mean ER PA% was 40.78% and PR 58.91% for seven invasive lobular carcinomas. There were two papillary carcinomas and one in situ ductal carcinoma. Fourteen of 15 benign breast lumps were benign breast lesions. Mean ER PA% was 65.95% and PR 73.43% for 10 fibroadenomas and for 4 fibrocystic lesions was 51.57% and 44.13%, respectively. CONCLUSION: Quantitative detection of ER and PR can be achieved by image cytometry. We aim in the future to assess this method in prognostic studies and the preoperative cytology of breast cancers.

Adult↗
PubMed1997

Subcutaneous recombinant hirudin (HBW 023) versus intravenous sodium heparin in treatment of established acute deep vein thrombosis of the legs: a multicentre prospective dose-ranging randomized trial. International Multicentre Hirudin Study Group.

The aim of this multicentre, prospective, randomised, dose-ranging study was to compare the safety and efficacy of subcutaneous recombinant hirudin (HBW 023) against intravenous sodium heparin in acute lower limb deep venous thrombosis (DVT). Patients were randomized to treatment with either HBW 023 or heparin for 5 +/- 1 days. HBW 023 was given according to body-weight in three dose groups. Thromboembolic disease was assessed by phlebography and ventilation/perfusion (V/Q) scanning on Day 1 and Day 5 +/- 1. One hundred and fifty-five patients were enrolled, of these 121 were evaluable for efficacy analysis. Significantly fewer patients on HBW 023 developed new V/Q abnormalities during the treatment period, (p = 0.006). There was no difference between the groups in thrombus extension or regression, major bleeding complications or serious adverse events. There were significantly fewer findings of new V/Q mismatch after treatment with HBW 023, and anticoagulant control was superior in these patients.

Adult↗
PubMed1997

Aspirin use in middle-aged men with cardiovascular disease: are opportunities being missed?

BACKGROUND: Since the 1980s, clinical trial evidence has supported aspirin use in the secondary prevention of cardiovascular disease (CVD). AIM: To explore aspirin use among British men with known CVD in a population-based study. METHOD: Longitudinal study (British Regional Heart Study), in which subjects have been followed up for cardiovascular morbidity and mortality since 1978-1980. Aspirin use was assessed by questionnaires to study participants in November 1992 (Q92); cardiovascular diagnoses are based on general practice notifications to October 1992. A total of 5751 men aged 52-73 years (87% of survivors) completed questions on aspirin use. RESULTS: Overall, 547 men (9.5%) were taking aspirin daily, of whom 321 (59%) had documented CVD. Among men with pre-existing disease, 153 out of 345 (44%) men with myocardial infarction, 42 out of 109 (39%) with stroke, and 75 out of 247 (29%) with angina were taking aspirin daily. Among men with angina (54% versus 26%) or myocardial infarction (59% versus 42%), those who had undergone coronary artery bypass surgery (CABG) or angioplasty were more likely to be receiving aspirin. Higher rates of aspirin use were also found in those whose last major event occurred after January 1990 (47% versus 34%). There was no association between aspirin use and social class or region of residence. CONCLUSION: Despite strong evidence of its effectiveness, many patients with established CVD were not receiving aspirin. Daily aspirin treatment was less likely in men with less recent major CVD events and in those who had not received invasive treatment.

Aged↗
PubMed1997

Bowel obstruction in a pregnant patient with ileal pouch-anal anastomosis.

Bowel obstruction is a rare but serious complication of pregnancy for both the mother and the developing fetus. This report describes the case of 17-year-old girl with ileal pouch-anal anastomosis (IPAA). She presented at 36 weeks' gestation with a complete small-bowel obstruction. Because conservative management was unsuccessful, labour was induced to relieve the obstruction or simplify surgery. Soon after spontaneous vaginal delivery she began to pass copious amounts of flatus and stool. The bowel obstruction resolved within hours. This report illustrates how IPAA alters the anatomy of the gastrointestinal tract, placing the ileal pouch at risk from compressive obstruction by the gravid uterus. Induction of labour in a near-term fetus is a reasonable initial method of management in such women.

Adenomatous Polyposis Coli↗
PubMed1996

Influence of fathers' social class on cardiovascular disease in middle-aged men.

BACKGROUND: The independent effect of early life circumstances on adult cardiovascular risk is still unresolved. We assessed the associations of father's social class with cardiovascular risk factors and with risk of ischaemic heart disease and stroke in adult life. METHODS: We did a longitudinal study of cardiovascular disease in 5934 men aged 40-59 years at enrollment. A cross-sectional measurement survey was done between 1978 and 1980 and a follow-up questionnaire was completed in 1992. The main endpoints were non-fatal myocardial infarction and stroke based on general practitioners' reports obtained between screening and 1992 and on recall of physician-diagnosed ischaemic heart disease in the 1992 questionnaire. FINDINGS: Father's social class was strongly associated with social class in adulthood (fathers' occupation was manual for 41.3% of professionals [I] vs 89.1% for unskilled manual workers [V]) and was significantly related to height (non-manual vs manual 175.4 cm [SE 0.2] vs 172.9 cm [0.1], p < 0.0001) and obesity (213 [14.1%] vs 804 [20.1%], p < 0.0001) irrespective of adult social class; no association was found with blood glucose (log, 1.69 [0.005] vs 1.70 [0.003], p = 0.22) or cholesterol (6.34 [0.03] vs 6.29 mmol/L [0.02], p = 0.16. Men whose fathers' social class was manual had significantly higher rates of non-fatal myocardial infarction (342/4006 vs 92/1510) and self-reported physician-diagnosed ischaemic heart disease (686/4006 vs 192/1510) than men whose fathers' social class was non-manual, even after adjustment for adult social class and other established risk factors (relative odds 1.3 [95% Cl 1.0-1.7], p < 0.05 and 1.3 [1.1-1.6], p < 0.01, respectively). The influence of father's social class on non-fatal myocardial infarction and ischaemic heart disease was only seen in men whose adult social class was non-manual. No association was seen between father's social class and non-fatal stroke. INTERPRETATION: Father's social class is strongly associated with adult social class. The higher risk of non-fatal myocardial infarction and self-reported physician-diagnosed ischaemic heart disease seen in men whose father's social class was manual suggests that socioeconomic status early in life has some persisting influence on ischaemic heart disease risk in adult life.

Adult↗
PubMed1996

Heart failure in a macaw with atherosclerosis of the aorta and brachiocephalic arteries.

A female severe macaw (Ara severa) that was at least 11 years old was evaluated for sudden onset of exercise intolerance and dyspnea. Radiography revealed a large heart silhouette, an increase in prominence of the brachiocephalic arteries, and a diffuse increase in opacity of the lungs. Lateral nonselective angiography revealed dilatation of both chambers of the right side of the heart and incomplete emptying of the right atrium. Alterations in the shape and position of the left-side heart chambers and reduction in blood flow through the brachiocephalic arteries and aorta were identified. Despite treatment, the bird died suddenly 2.5 months after the first episode of dyspnea. At necropsy, severe atherosclerosis of the aorta and brachiocephalic arteries, dilatation of all heart chambers, pulmonary edema, and severe hepatic centrolobular atrophy and fibrosis were identified. Correlation between the angiography and necropsy findings suggested that angiography could be an important diagnostic tool for the detection of cardiovascular disease in birds.

Angiography↗
PubMed1996

Life expectancy in men who have never smoked and those who have smoked continuously: 15 year follow up of large cohort of middle aged British men.

OBJECTIVE: To estimate the life expectancy in a representative sample of men who have never smoked and of those who have smoked all their adult lives. DESIGN: 15 year follow up of a large representative cohort of British men in the British regional heart study and use of national mortality statistics for 1992. SUBJECTS: 7735 middle aged British men aged 40-59 at the time of screening (between 1978 and 1980). MAIN OUTCOME MEASURES: Mortality from all causes and from smoking related causes. RESULTS: 1624 men had never smoked at the time of screening and did not take up smoking during the study. 127 of them died during follow up. 3151 men began smoking before they were 30 and were still smoking at the time of screening. Of these, 751 had stopped smoking five years after screening; they were excluded from the analysis five years after the date they had stopped. 560 of the lifelong smokers died during follow up. When study estimates were combined with those from national mortality statistics for men aged 20-40, only an estimated 42% (95% confidence interval 36% to 50%) of lifelong smokers alive at the age of 20 would be alive at 73, compared with 78% (74% to 82%) of lifelong non-smokers. CONCLUSION: These estimates present the effects of smoking on mortality in a way that is easily communicated to patients and the general public in health promotion initiatives.

Adult↗