Observation of an "extended" Van Hove singularity in YBa2Cu4O8 by ultrahigh energy resolution angle-resolved photoemission.
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Biomedical subjects
Publications and source records attributed to M Lindroos.
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The purpose of this study was to measure the frequency of left ventricular (LV) hypertrophy in old age. Random subjects born in 1904, 1909, and 1914 (n = 501), and 76 born in 1920 to 1935 were studied. All subjects underwent clinical and echocardiographic investigation. An electrocardiogram was obtained in 449 subjects. Complete data for calculation of LV mass corrected for body size were available in 422 of the studied subjects (73%). LV hypertrophy was defined as calculated LV mass exceeding either an internal standard of the Helsinki Aging Study, earlier published limits from the Framingham Heart Study, or criteria from Devereux et al. LV wall thickness and mass were positively related to age. Hypertrophy was present in both sexes, the rate even exceeding 70% in the oldest cohort aged 85 to 86 years using the Framingham and Devereux limits. LV hypertrophy (LV mass exceeding defined limits after correction for body height) was significantly and independently related to age, systolic blood pressure, body mass index, and mitral regurgitation. A sustained apex beat, third heart sound, and electrocardiographic changes were significantly more frequent in the group with echocardiographic hypertrophy, although with considerable overlapping. The fourth heart sound was unrelated to hypertrophy. Use of age-independent criteria result in an extremely high prevalence of LV hypertrophy in old age. This is partly due to age-related diseases increasing LV mass, but also partly to an independent effect of age. The usefulness of clinical signs for detecting LV hypertrophy is limited in old age.
The potential predictors of left ventricular mass in old age were studied in a random sample of people born in 1904, 1909, 1914 (n = 501) and 1920-35 (n = 76). Data on the left ventricle with mass calculation, quantitative data on valve disorders and biochemical data were collected. Left ventricular mass (corrected for height) was positively related to male gender, age, body mass index and systolic blood pressure. It was also significantly higher in the presence of aortic valve calcification, a low velocity ratio (indicating aortic valve obstruction), and aortic or mitral regurgitation. In men, left ventricular mass was higher in the presence of coronary artery disease and inversely related to serum high density lipoprotein cholesterol. In multivariate analysis, independent predictors of left ventricular mass without sex interaction were age (standardized coefficient beta = 0.23, P = 0.000), male gender (beta = 0.38, P = 0.000), body mass index (beta = 0.22, P = 0.000), systolic blood pressure (beta = 0.21, P = 0.000), velocity ratio (beta = -0.11, P = 0.010), detectable aortic regurgitation (beta = 0.11, P = 0.014) and moderate-to-severe mitral regurgitation (beta = 0.21, P = 0.000). Thus, the increase in left ventricular mass with age can largely be related to discrete predictors. The impact of valve disorders is substantial.
This study aimed at identifying factors influencing aortic valve calcification in old age. Echocardiographic and Doppler characteristics of the aortic valve were compared with possible clinical and biochemical predictors in 501 people aged 75-86 years and in 76 aged 55-71. Slight calcification was seen in 222 people (40%) and severe calcification in 72 (13%); 21 people had moderate or severe aortic stenosis. Age (P = 0.000) and serum parathyroid hormone (P = 0.015) were higher and body mass index lower (P = 0.002) in the presence of aortic valve calcification. In multivariate analysis, age (P = 0.000), hypertension (P = 0.005) and body mass index (P = 0.005) were independent predictors of aortic valve calcification, and age (P = 0.022) and serum ionized calcium (P = 0.037) of valve stenosis. The odds ratio (95% confidence interval) for valve calcification was 1.89 (1.42-2.50) for a 10-year increase in age, 1.74 (1.19-2.55) in the presence of hypertension, and 1.39 (1.10-1.76) for a 5 kg.m-2 decrease in body mass index. Sex, smoking, diabetes, serum lipids and insulin were unrelated to valvular calcification. These data suggest that leanness and a history of hypertension increase the likelihood of senile aortic valve calcification. Calcium metabolism may also be of significance. The mechanisms of these associations deserve further study.
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OBJECTIVES: This study was undertaken to elucidate the prevalence of aortic valve abnormalities in the elderly. BACKGROUND: The age of persons treated actively for valve disorders is increasing. More information is needed about the prevalence of aortic valve disease in old age. METHODS: Randomly selected men and women in the age groups 75 to 76, 80 to 81 and 85 to 86 years (n = 501) participating in the Helsinki Ageing Study were studied with imaging and Doppler echocardiography. Additionally, 76 persons 55 to 71 years of age were included. The systolic aortic valve area was calculated by the continuity equation. The velocity ratio (peak velocity in the left ventricular outflow tract/peak velocity across the aortic valve) was a supplementary criterion for aortic stenosis. Valve regurgitation and cusp calcification were assessed visually. RESULTS: Evaluation of the aortic valve was possible in 552 persons (96%). Mild calcification was found in 222 (40%) and severe calcification in 72 (13%). Two persons (0.4%) had an aortic valve prosthesis. Critical native valve stenosis (calculated aortic valve area < or = 0.8 cm2 and velocity ratio < or = 0.35) was found in 12 persons (2.2%). Six of these were symptomatic and potentially eligible for valvular surgery. All persons with aortic valve stenosis were in the three oldest age groups. The prevalence of critical aortic valve stenosis was 2.9% (95% confidence interval 1.4% to 5.1%) in the group 75 to 86 years of age. Aortic regurgitation, mostly mild, was found in 29% of the entire study cohort. CONCLUSIONS: Calcific aortic valve stenosis constitutes a significant health problem in the elderly. Only a minority of those with potentially operable aortic valve stenosis undergo surgery.
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In many patients with valvular aortic stenosis (AS), management decisions may be possible without invasive studies if coexistent coronary artery disease (CAD) can be ruled out noninvasively. The use of thallium-201 single-photon emission computed tomography to the exclusion of CAD was studied in 44 patients aged 41 to 78 years with AS. In addition to cardiac catheterization and selective coronary angiography, patients underwent a cardiac ultrasound study and thallium-201 myocardial perfusion imaging at rest and after bicycle ergometer exercise. Two thirds of the patients had critical AS (valve area index less than or equal to 0.5 cm2/m2) but none had left ventricular systolic dysfunction. Twenty-one patients had angiographically significant CAD (greater than or equal to 50% diameter stenosis in greater than or equal to 1 coronary artery), whereas 23 had either a fully normal angiogram (n = 17) or mild (less than 50%) stenoses (n = 6). Each patient with significant CAD had an abnormal thallium-201 tomogram, either a strictly segmental perfusion defect (n = 19), or a patchy nonsegmental abnormality (n = 2); however, 10 of 23 patients free of significant CAD had similar results. Thus, the sensitivity and specificity of an abnormal scintigram were 100 and 57%, respectively. If only segmental perfusion defects typical of CAD had been considered abnormal, then the sensitivity of the test would have been 90% and the specificity 70%. Patients with false abnormal scintigrams had more severe AS and more angiographically nonsignificant CAD than those with true normal findings.(ABSTRACT TRUNCATED AT 250 WORDS)
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The skin reactivity of 46 ICU patients was tested against recall antigens: mumps, candidin, streptokinase-streptodornase, and purified protein derivative of tuberculin. At the same time, the intravascular catheters used in these patients were cultured with a semiquantitative method. Twelve patients did not react to any of the antigens. There was a statistically significant association between anergy in skin testing and lethal outcome of the current illness. Catheter cultures from 11 patients yielded over 15 colony-forming units of bacteria. No association was found between positive catheter cultures and skin reactivity to any of the antigens. This indicates that catheter colonization is independent of host factors reflected by skin testing and supports the view that transmission of microorganisms into catheters is more important than poor host defense in the initiation of catheter-related infections.
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Functions of cell-mediated immunity were studied from 11 patients after cardiovascular resuscitation and from matched controls who were simultaneously under observation. The resuscitated patients were anergic to recall skin antigens (93% negative) as compared to the controls (62%) (p less than 0.01). The anergic state correlated with the outcome of the patients. Lymphocyte numbers did not differ between these groups, but the number of T cells was significantly decreased, and B cells and granulocytes was increased in resuscitated patients. Lymphocytes from resuscitated patients responded to mitogenic stimulation although the responses were lower than those of the controls. Decreased lymphocyte responses were partly due to serum factor(s) which were not attributable to serum cortisol concentration. In addition the findings favour a change in the compartmentalization of lymphocyte subsets resulting in increased number of suppressor cells and/or increased sensitivity of lymphocytes to suppressive humoral factor(s) in the circulation. The anergy in skin evidently represents the final outcome of the dysfunction of several arms of cell mediated immunity.
The antihypertensive effects of timolol administered once daily and a combination diuretic were compared in 45 young and middle-aged hypertensive patients. Both treatments significantly reduced lying and standing systolic and diastolic blood pressures as compared to placebo. There were no significant differences between blood pressure reductions after treatment with timolol or with the diuretic. There was a slight negative correlation between the decrease of diastolic blood pressure during timolol treatment and patient age. Serum potassium decreased slightly but significantly during treatment with the diuretic.
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