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Biomedical subjects

R D Watson

Publications and source records attributed to R D Watson.

17 recordsLinked to original sources
PubMed1992

Patients with suspected myocardial infarction: effect of mode of referral on admission time to a coronary care unit.

The aim of this prospective study was to determine the delay between the onset of symptoms and arrival in the coronary care unit of patients with suspected acute myocardial infarction, and the relative contribution to the total delay of patient delay, method of referral (self referral or general practitioner referral) and delay in the hospital before reaching the coronary care unit. All patients admitted with chest pain to the coronary care unit at Dudley Road Hospital, Birmingham, over the six month period April-September 1989 were included in the study. Ninety five patients were referred by their general practitioner and 107 patients attended the accident and emergency department directly or arrived by ambulance without contacting their general practitioner. The proportion of self referred and general practitioner referred patients with acute myocardial infarction, angina and non-cardiac chest pain were not significantly different. The total delay was significantly longer for patients who had been referred by their general practitioner (median 5.3 hours) than for self referrals (3.2 hours, P less than 0.001), with a significantly higher proportion of self referrals arriving at the coronary care unit within six hours of the onset of symptoms (77% versus 54%, P less than 0.01). Among general practitioner referrals, initial patient delay accounted for a median of 2.5 hours and the general practitioner's response time for a median of 1.1 hours. The delay in hospital was similar for both groups of patients. In inner city areas, self referral may result in considerably less delay than general practitioner referral allowing a greater proportion of patients to receive effective thrombolytic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Care Units↗
PubMed1991

Computer graphics representation of a statistical model used with computer-aided diagnosis.

A description of computer graphics of a multidimensional model that is used with computer-aided diagnosis or prognosis is presented. The model is discussed and computer graphics of the model are developed. The computer graphics are suitable as visual supplements for presenting the computer-aided diagnostic model to individuals who may be inexperienced in multivariate statistics.

Animals↗
PubMed1991

Influence of racial origin on admission rates of patients with suspected myocardial infarction in Birmingham.

All patients with suspected myocardial infarction admitted to hospital in four Birmingham health districts were studied to test the hypothesis that Asian patients would be overrepresented and Caribbean patients underrepresented compared with the indigenous population. One thousand four hundred and ninety six patients had a final diagnosis of myocardial infarction or severe angina pectoris. The relative risk of admission for Asian men compared with white men aged 45-64 years was 2.65 (95% confidence interval 2.20 to 3.19) and the risk for Asian men was high for both myocardial infarction and ischaemia when analysed separately. The relative risk of admission for Caribbean men compared with white men was 0.53 (95% CI 0.33 to 1.20). The relative risk for Asian women compared with white women in the same age group was 2.58 (95% CI 1.68 to 3.96), but this was due to an excess of admissions diagnosed as ischaemia rather than infarction in the Asian women. For Caribbean and white women the risk of admission was the same, although significantly fewer Caribbean women were admitted with myocardial infarction. The study was undertaken in 1986-87 and population data had to be derived from the 1981 census. The resident population changed in those five years and so the results were recalculated making allowances for these changes in the health districts involved. Based on these data the admission rate for Asian men with suspected myocardial infarction aged 45-64 was nearly twice that for white men (1.8): the relative risk of admission for Asian men compared with white men was 2.04 (95% CI 1.53 to 2.18). For Caribbean men the relative risk compared with white men was 0.45 (95% CI 0.29 to 0.71). For Asian women the relative risk of admission calculated from the adjusted census data resemble that in white women aged 45-64 years. The relative risk for admission with coronary heart disease in Asians is higher than expected work; one possible explanation for this is that the Asian population resident in the area under study was larger than estimated. The single major difference in risk factors was the high prevalence of diabetes mellitus in Asians (19.5% compared with 8.3% for white residents) but this did not wholly account for the excess of admissions from the Asian community.

Asia↗
PubMed1979

Cold-pressor test.

Explore the source record for details and available documents.

Cardiomyopathies↗
PubMed1979

Influence of once-daily administration of beta-adrenoceptor antagonists on arterial pressure and its variability.

Intra-arterial pressure was recorded over 24 h in hypertensive patients before and during long-term treatment with beta-adrenoceptor antagonists given once daily under standardised conditions. Arterial pressure was reduced throughout the 24 h after the last dose as was variability of pressure during physical activity; variability during sleep and rest did not change significantly.

Acebutolol↗
PubMed1979

Effects of beta-adrenoreceptor antagonists on sino-aortic baroreflex sensitivity and blood pressure in hypertensive man.

1. Sensitivity of the sino-aortic baroreflex was investigated before and after acute (23 patients) and chronic (23 patients) beta-adrenoreceptor antagonism in patients with essential hypertension. 2. Sensitivity was inversely related to age (r = -0.60) and systolic blood pressure (r = -0.46); a positive relationship was noted between sensitivity and initial pulse intervals (r = 0.40). 3. Sensitivity increased significantly in patients less than 40 years of age after chronic treatment. No change occurred after acute treatment or in older patients treated chronically. 4. The fall in ambulatory intra-arterial blood pressure after chronic treatment was unrelated to alteration of baroreflex sensitivity.

Acebutolol↗
PubMed1979

Plasma noradrenaline concentrations at different vascular sites during rest and isometric and dynamic exercise.

1. Blood samples were obtained simultaneously from femoral artery and vein, pulmonary artery and antecubital vein at rest and during isometric and dynamic exercise in six patients during cardiac catheterization and plasma noradrenaline was measured radioenzymatically. 2. Analysis of variance indicated that differences between vascular sites were not significant, whereas differences between patients (P less than 0.001) and differences between activities (P less than 0.001) were significant. 3. Mean systemic arterial concentrations tended to be lower than pulmonary arterial concentrations during each activity, although the difference was not significant. 4. We conclude that forearm venous plasma noradrenaline concentrations are representative of those from other sites.

Adult↗
PubMed1979

Factors determining the variability of arterial pressure in hypertension.

1. Intra-arterial pressure was recorded continuously in 26 patients with uncomplicated essential hypertension under standardized conditions. Pressure was analysed beat by beat by computer and variability measured as the standard deviation of the normally distributed frequency histogram. 2. Variability was strongly influenced by physical activity, being least during sleep and increasing progressively with bed rest and ambulation. Variability during daytime was not related to time. 3. Systolic variability correlated directly with systolic pressure. An independent inverse relationship with baroreflex sensitivity was observed. Systolic variability tended to increase with obesity. 4. None of the following were related independently with variability: age; race; sex; plasma renin activity; plasma angiotensin II; plasma noradrenaline; plasma adrenaline.

Adolescent↗
PubMed1979

Onset and duration of beta-adrenergic receptor blockade following single oral dose acebutolol hydrochloride (Sectral).

1. The onset and duration of action of once daily acebutolol (400 mg) on resting and exercise heart rate and blood pressure were studied in normal subjects in a double-blind, cross-over trial against placebo. Subjects were studied 1.5, 3, 8 and 24 h after the first dose and 24 h after the fifth dose. 2. Resting and exercise heart rate and blood pressure were significantly reduced within 90 min of the first dose. 3. A significant reduction in these variables persisted throughout 24 h after the fifth daily dose. However, at 24 h the effects were considerably attenuated, the falls in resting and exercise systolic blood pressure being only 5%. 4. A linear relationship was noted between log serum drug level and percentage reduction of exercise heart rate.

Acebutolol↗
PubMed1975

The detection by immunodiffusion of tumour associated antigenic components in extracts of human bronchongenic carcinoma.

Antisera to extracts of a variety of bronchogenic carcinoma were raised in rabbits and extensively absorbed with immunoadsorbents prepared with normal lung extracts cyanogen bromide linked to Sepharose 4B, and glutaraldehyde insolubilized normal lung extracts. The antisera were tested by immunodiffusion against a panel of extracts from a variety of bronchogenic carcinoma, foetal lung extracts and pools of normal lung extracts. The results indicate that two distinct antigenic components are associated with bronchogenic carcinoma; one which is present in a high percentage of the tumour extracts tested and appears to have partial identity with a foetal lung component, and one (or more) which is not foetal and appears to have higher cross-reactivity (but not exclusively) with tumours of the same pathological type. Attempts to detect either antibody or antigens relating to these components in the serum of patients with bronchogenic carcinoma by these techniques were unsuccessful. The foetal cross-reacting component was neither carcinoembryonic antigen and alpha1-foetoprotein.

Antigens, Neoplasm↗
PubMedDate not supplied

Changes in plasma norepinephrine, blood pressure and heart rate during physical activity in hypertensive man.

We have investigated the changes in plasma norepinephrine and blood pressure and heart rate during a range of physical activities in eight hypertensive subjects in order to determine whether changes in plasma norepinephrine reflect changes in sympathetic activity. Blood pressure was recorded over 24 hours from an intra-arterial cannula. Plasma norepinephrine, measured by a sensitive radioenzymatic method, increased progressively with increasing levels of physical activity. In each subject a statistically significant linear relationship was observed between the logarithm of plasma norepinephrine and systolic blood pressure. Analysis of variance showed that 66% of the variance of plasma norepinephrine was associated with changes in blood pressure and heart rate. These observations support the hypothesis that plasma norepinephrine reflects short-term changes in sympathetic activity. Use of the quantitative relationship described, in conjunction with measurements of norepinephrine metabolism, may help to determine the significance of increased levels of plasma norepinephrine observed in some hypertensive patients.

Adult↗