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Biomedical subjects

A B Miller

Publications and source records attributed to A B Miller.

At least 253 records · Page 14Linked to original sources
PubMed1986

Lung cancer mortality (1950-80) in relation to radon daughter exposure in a cohort of workers at the Eldorado Beaverlodge uranium mine.

A cohort study of 8,487 workers employed between 1948 and 1980 at a uranium mine in Saskatchewan, Canada, has been conducted. A total of 65 lung cancer deaths was observed (34.24 expected, P less than 10(-5)). There was a highly significant linear relationship between dose and increased risk of lung cancer giving estimates for the relative and attributable risk coefficients of 3.28% per working level month (WLM) and 20.8 per WLM per 10(6) person-years. Age at first exposure had a significant modifying effect on risk. The interaction of exposure with age at observation fits a relative risk model well. The similarity of these results to a recent study of Swedish iron miners with similar levels of relatively low exposure suggests that exposure to radon daughter products may be a major contributory factor to lung cancer occurring among nonsmokers in the general population. The results also reinforce concerns as to the appropriateness of present occupational exposure standards.

Age Factors↗
PubMed1985

Reproducibility of left ventricular area and volume measurements using a computer endocardial edge-detection algorithm in normal subjects.

The variability of serially recorded 2-dimensional echocardiograms in normal subjects was determined. During a 2-week period, 10 normal subjects underwent echocardiography 5 times, in 2 laboratories, with use of different ultrasonographs. The video recordings were analyzed using a computer image analysis system (Quantic 1200) to provide standardized left ventricular short-axis areas and area ejection fraction (EF). Left ventricular volumes and volume EF were calculated. The 95% confidence limits of the percent difference for end-diastolic area and volume between 2 samples in a given subject were +/- 16.8 and +/- 16.7%, respectively. The limits for end-systolic area and volume were +/- 15.8 and +/- 17.0%, respectively. The 95% confidence limits for differences of area and volume EF between 2 recordings were +/- 12.8 and +/- 9.7%, respectively. No correlation was found between clinical grade (image quality) and the variability of area measurements. A good correlation (r = 0.98) was found between area and volume EF for any given subject over the 5 observations. These confidence limits are narrower than those previously recorded.

Adult↗
PubMed1985

Mixed ischemic subsets. Comparison of the mechanisms of silent ischemia and mixed angina.

The traditional concept of myocardial ischemia precipitated by increases in the myocardial demand for oxygen is well accepted for patients with fixed coronary atherosclerosis. Recently, however, observations of abnormal vasomotor tone in the coronary artery bed have suggested that vasoconstriction at an atherosclerotic site may be a primary cause of decreases in the myocardial supply of oxygen. This has led to a classification of mixed ischemic subsets characterized by the superimposition of an increased myocardial oxygen demand on a decreased myocardial oxygen supply. The subsets are defined by several clinical parameters, including unstable angina pectoris, acute myocardial infarction, malignant ventricular arrhythmias, mixed angina pectoris, and asymptomatic or silent ischemia. Holter monitoring, electrocardiography, and evaluations of wall motion have confirmed the existence of asymptomatic ischemic episodes that far outnumber episodes of angina in patients with stable angina pectoris. This concept has considerable diagnostic and therapeutic implications.

Angina, Unstable↗
PubMed1985

Sublingual nifedipine: acute effects in severe chronic congestive heart failure secondary to idiopathic dilated cardiomyopathy.

Nine patients with chronic, severe (New York Heart Association class III to IV) congestive heart failure were studied to determine the acute effects of 10 mg of sublingual nifedipine on left ventricular (LV) function. Hemodynamic and echocardiographic data were obtained at rest and 30 minutes, 1, 2, 4 and 6 hours after nifedipine. Measurements at rest reflected LV dysfunction with elevation of end-diastolic volume index (102 +/- 46 ml/m2), pulmonary capillary wedge pressure (17 +/- 8 mm Hg), systemic vascular resistance (1,547 +/- 439 dynes s cm-5) and reduction of cardiac index (2.8 +/- 0.5 liters/min/m2). There were no adverse effects noted with administration of sublingual nifedipine. Initial changes through 1 hour reflected an unloading effect of nifedipine with reduction in pulmonary capillary wedge pressure (11 +/- 5 mm Hg) (p less than 0.05), systemic vascular resistance (1,179 +/- 289 dynes s cm-5) (p less than 0.01), end-diastolic volume index (91 +/- 37 ml/m2 [difference not significant]) and an increase in cardiac index (3.6 +/- 0.7 ml liters/min/m2) (p less than 0.01). Subsequently the cardiac index, systemic vascular resistance and end-diastolic volume index returned toward baseline. Only the pulmonary capillary wedge and pulmonary artery pressures demonstrated a sustained reduction through the 6-hour study period suggesting an effect of nifedipine on LV relaxation. Thus, sublingual nifedipine administered acutely to patients with clinical congestive heart failure is a safe and efficacious vasodilator.

Administration, Oral↗
PubMed1985

Evaluation of screening programmes for gynaecological cancer.

A workshop of the Project on Evaluation of Screening Programmes of the International Union against Cancer (UICC) was held in Lyon, France. on November 20-22, 1984. The focus of the workshop was on screening for gynaecological cancer, especially for cancer of the cervix uteri. This report summarizes the presentations, conclusions and recommendations from the workshop.

Adult↗
PubMed1985

Cigarette smoking and breast cancer: a case-control study of screening program participants.

A case-control study of Canadian women aged 40-59 years (n = 123; 369) has been conducted on the relationship of cigarette-smoking and initial visit breast cancer detection within a multicenter screening program. Among premenopausal women, a relative risk of 2.1 (1.1, 4.0) was found for ever-smokers versus never-smokers. There was a dose-response gradient with relative risks of 1.0, 1.3, 2.5, and 3.5 among women with 0, 1-200, 201-500, and greater than 500 cigarette-years of exposure, respectively. No overall association was detected among postmenopausal women but a significant interaction with parity was present in this group. When menopausal status was ignored, there was a nonsignificantly elevated risk of 1.4 (0.9, 2.1) for ever- versus never-smokers but the dose-response was significant with relative risks of 1.0, 0.9, 1.7, and 2.0 in the above four exposure categories, respectively. These results persisted despite adjustment for several important variables. These data are consistent with an interaction of smoking and participation in the screening study or with a possible etiologic role for smoking. Even if smoking is not related to breast cancer etiologically, these data still suggest that smokers who visit screening centers have an elevated risk of breast cancer detection on initial visit, especially among premenopausal women. They do not support the hypothesis of a protective effect of smoking and underscore the need for further study into this important relationship.

Adult↗
PubMed1985

Dietary factors and the incidence of cancer of the stomach.

A case-control study of diet and stomach cancer was conducted during 1979-1982 in Toronto, Winnipeg, and St. John's Canada. Two hundred forty-six histologically verified cancer cases were individually matched by age, sex, and area of residence to 246 randomly selected population controls. Daily nutrient consumption values were calculated from quantitative diet history questionnaire data through use of the US Department of Agriculture Food Composition Data Bank, which was extended and modified for Canadian items. For the analysis, continuous conditional logistic regression methods were used. It was found that consumption of dietary fiber was associated with decreased risk of gastric cancer; the odds ratio estimate of trend was 0.40/10 g average daily intake of fiber (i.e., 0.40(1.5)/15 g, etc.) (p less than 10(-8)). Also, average daily consumption of nitrite, chocolate, and carbohydrate was associated with increasing trends in risk, with odds ratio estimates, respectively, 2.6/mg (p less than 10(-4)), 1.8/10 g (p less than 10(-4)), and 1.5/100 g (p = 0.015). While citrus fruit intake appeared to be somewhat protective (odds ratio = 0.75/100 g daily average, p = 0.0056), vitamin C intake was less so, and vitamin E not at all. Thus, a number of dietary components seem to be implicated in the pathogenesis of stomach cancer.

Adult↗
PubMed1985

Age at first pregnancy and risk of colorectal cancer: a case-control study.

Results from a case-control study of colorectal cancer conducted in Toronto and Calgary, Canada, are reported with respect to pregnancy-related variables. A total of 158 female "ever-married" colon cancer cases, 71 rectum cancer cases, 242 neighborhood controls, and 257 hospital controls were interviewed to obtain a complete pregnancy history. The results indicate a strong protective effect of early age at first pregnancy for both colon and rectum cancers, with little or no effect noted for the total number of pregnancies. There is a suggestion that age at first pregnancy may have a greater effect on right colon cancer than on left colon cancer. In addition, there also is a suggestion that non-live-birth outcomes may be a risk factor for both colon and rectum cancer. The similarity of these results to those of other studies on large bowel cancer and on breast cancer support the hypothesis that carcinogenesis in the large bowel may be at least partly mediated by female sex hormones.

Colonic Neoplasms↗