Biomedical subjects
Publications and source records attributed to A C Edwards.
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This report documents the adjustment to prison life by individuals with schizophrenia and compares their adaptation with a control group with no known mental illness matched for age, race, sex, most serious crime, and security level. On all outcome variables, number of infractions, number of "lock-ups", days in "lock-up," ability to obtain a job in prison, and ability to obtain release from prison, the group with schizophrenia was inferior to the control group. That inmates with schizophrenia may require special assistance in prison and the need for future investigation are discussed.
One hundred and thirty six healthy white females within 30 months of their last menstrual period (mean age 52 years) were examined to determine the usefulness of a risk factor questionnaire in predicting bone density and subsequent loss. Bone density was assessed at baseline and at 12 monthly intervals. None of the proposed risk factor variables with the exception of nulliparity correlated with the baseline spinal or femoral bone density. As a predictor of bone loss only drinking alcohol (more than four units/day) was significant. A risk factor score derived from the questionnaire before its administration did not correlate with baseline bone density or subsequent bone loss. In most normal women questioned soon after a natural menopause, an estimate of bone density and subsequent bone loss and hence osteoporotic risk cannot be reliably made using a simple risk factor questionnaire.
Using the population of St John's, Newfoundland, we did a constructive replication of previous studies testing the association between health practices and health status. A telephone questionnaire was applied to all adults in a probabilistic sample of households (3300 subjects, 85% response rate). Several health practices and preventive behaviours indexes were developed and tested. An additive index of six practices (breakfast, sleeping, drinking, smoking, weight and exercise) using the Alameda County definitions, and an additive score of five practices (excluding breakfast and with revised definitions for smoking, drinking and exercise) were analysed using log-linear models; there was association between the indexes and self-assessed health status when controlling for sex, age and education, with the exception of the six-practice index in males. The association between these two indexes and several variables and constructs of health status showed that the best relationships were with self-assessed health status and with a construct including variables measuring subjective health.
Prevention of postmenopausal osteoporosis is now possible with current therapy, if initiated soon after the menopause and continued for at least 10 years. Simple ways of detecting those at risk of subsequent osteoporosis are urgently needed. This study investigated the hypothesis that certain serum sex hormones could predict bone mineral content (BMC) as measured by dual photon densitometry, soon after the menopause. The subjects included 136 healthy white females within 30 months of their last menstrual period with a mean age of 52 years. Of the sex hormones, the adrenal androgen dehydroepiandrosterone sulphate (DHEAS) correlated best with spinal BMC, a relationship which was significant using multiple regression (P = 0.02), although the correlation was weak (r = +0.19). A direct physiological role for DHEAS has yet to be found, despite being present in large quantities in serum, although it may act as a marker for other processes. No association was seen between testosterone, sex hormone binding globulin, oestradiol, oestrone and oestrone sulphate and spinal BMC. No significant correlations with any hormones were seen with femoral BMC. The data suggest that serum sex hormones are not useful markers of current bone mineral status soon after the menopause, although further work is needed to explore the relationship with DHEAS.
Primary coronary angioplasty was attempted in 288 patients (206 men and 82 women) who presented with stable (50%) or unstable (50%) angina pectoris. The success rates of angioplasty and the subsequent revascularization requirements in these two angina categories were compared during a one year prospective follow-up. The site and distribution of coronary artery stenoses did not differ between the categories. Three hundred and five dilatations were attempted (149 in 144 patients with unstable angina and 156 in 144 patients with stable angina). Of these procedures, 265 (87%) were technically successful--133 (89%) in 128 patients with unstable angina and 132 (85%) in 120 patients with stable angina. Lower success rates were achieved in 29 attempted dilatations of vessels with chronic total occlusion (19 successful [66%], P = 0.002) and in 19 patients who presented with unstable angina after recent (within two weeks) infarction (10 patients with successful angioplasty, [53%], P less than 0.0001). Subsequent revascularization requirements after an initially successful angioplasty in 57 patients were greater in unstable (36 patients) than in stable angina (21 patients; P = 0.05) and reflected the greater frequency of repeat angioplasty in patients with unstable angina (22 patients) compared with those with stable angina (10 patients; P = 0.04) among patients with recurrent symptoms. At one year, 245 patients (85%)-121 treated for unstable angina and 124 treated for stable angina--experienced no angina during normal daily activities. We conclude that a primary angioplasty success rate of 89% can be achieved in patients with unstable angina pectoris but this rate is significantly lower in patients presenting after recent infarction. Repeat angioplasty for recurrent symptoms after a successful primary procedure is required more frequently in patients presenting with unstable angina.
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The objective of this study is to verify empirically the existence of separate dimensions in the overall concept of health status by analyzing 10 variables included in a questionnaire that was applied to all adults in a simple random sample of households in St John's, Newfoundland. The response rate was 85% for a total of 3300 subjects. These data were analyzed by frequencies and by associations with sex, age and education. Nonparametric correlation, factor and cluster analyses on variables were used to verify if health status had identifiable dimensions. All these methods produced similar results showing five distinct factors. The first factor is composed of variables related to disease (disability/chronic conditions/worry about health); the second, to happiness (happiness/emotional); the third, to subjective appraisal of health (physical condition/comparative level of energy/self-rated health status). Finally, the fourth and fifth factors were single variables; restriction of normal activities and social contacts. An interesting finding was that self-rated health status was distributed with almost equal weight in both the first and third factors. A validation of the 10 variables and the 5 factors was undertaken by studying their association with health care utilization. Two measures of utilization were used; number of physicians' visits in a year and number of hospital days in a 4-year period. Number of chronic conditions, disability and self-rated health status were associated with both measures of utilization; factor 1 was the only summary construct showing association with utilization. This paper demonstrates that self-rated health status is valid as a single measure of overall health status in this sample, being associated with both disease and subjective assessment components.
A cross-sectional survey of the work force at an iron ore surface mine and beneficiation plant in Labrador identified cases with a radiologic diagnosis compatible with simple pneumoconiosis by the International Labour Organization (ILO) classification (1980). Their distribution by ILO categories 1, 2, and 3, after excluding those with confounding diagnoses for pneumoconiosis, was 30, 10, and 2 cases, respectively. ILO category was related to age, duration of current employment, and cumulative respirable dust and quartz levels, as well as to decrement in ventilatory function.
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Left ventricular mass (LV mass) and function were assessed in 16 acromegalic patients by echocardiography, and rest and exercise gated blood pool scanning (GBPS) respectively. At the time of study, five patients had active acromegaly, five were hypertensive and three had coexisting coronary artery disease. Increased LV mass was found in six (38%) patients, of whom four were hypertensive and two others had active acromegaly of long duration. One normotensive patient, who did not have coronary disease, had increased LV mass associated with persistently elevated growth hormone (GH) levels for the previous 11 years. Abnormal LV function, as detected by GBPS, occurred only in the three patients with coronary disease. Thus, acromegaly is associated with increased LV mass in hypertensive patients and normotensive patients who have prolonged elevation of GH levels prior to adequate treatment. We found no detectable impairment of LV function, at rest or exercise unless other cardiac disease was present.
Sixty-five patients with angiographically documented coronary artery disease were investigated by thallium-201 (201Tl) scintigraphy to determine the role of the collateral circulation during dynamic exercise. Fifty-three patients had complete proximal occlusion of at least one major coronary artery. One patient had total occlusion of all three major coronary arteries. Sixty-four collateral channels were identified, graded, and compared with corresponding regions of the myocardial scintigram. Tracer uptake was also graded and classified as various degrees of protection from ischaemia. A significant correlation between good collaterals with complete protection and poor or absent collaterals with no protection was noted. Seventeen patients (20 occluded vessels) had total coronary occlusion without myocardial infarction. Collaterals conferred protection in 9/15 occlusions whereas no protection was seen in five occlusions without collaterals. There was no difference in the protective role of homocoronary and heterocoronary collateral vessels. Hypertrophy of the first septal left anterior descending perforator conferred significant protection from ischaemia in contrast to bridging collaterals and ghosting. During exercise the right coronary bed is preferentially protected from ischaemia, in contrast to the left anterior descending territory. This probably reflects the direction of a transmural flow gradient between left and right ventricles during exercise.
A 27-year-old man had inferior myocardial infarction following superficial chest trauma. Coronary arteriography documented an isolated total occlusion of the right coronary artery, probably caused by localized extra-coronary compression, and no other evidence of intrinsic coronary disease. The left anterior descending artery later developed a localized proximal stenosis, most likely due to mural thrombus, which progressed rapidly to cause anterior myocardial infarction despite coronary artery surgery. The etiology of this lesion is discussed and support given to the "encrustation" hypothesis of human atherosclerosis. Exercise thallium scintigraphy proved helpful in the management of this case.
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