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Biomedical subjects

R S Cooper

Publications and source records attributed to R S Cooper.

At least 145 records · Page 8Linked to original sources
PubMed1992

Comparability of risk factors for coronary heart disease among blacks and whites in the NHANES-I Epidemiologic Follow-up Study.

The incidence of new coronary events and the predictive strength of the major coronary risk factors were evaluated in a biracial sample drawn from the general U.S. population. In this cohort of 12,599 persons, free of reported coronary heart disease (CHD) at baseline, both hospitalizations and deaths coded to this cause were recorded prospectively. Based on CHD as the underlying cause of death, black men and women experienced higher age-adjusted mortality than their white counterparts (BM = 6.15, WM = 5.59, BW = 3.72 and WW = 2.58 [cumulative deaths, percent]), while having lower hospitalization rates than did whites. In a univariate logistic regression model, with all incident events as the endpoint, the predictive strength of the coronary risk factors was remarkably similar for the four sex-race groups. Notable exceptions included smoking, where the data from this study are problematic, and body mass index, where a relationship was noted only among white women. In a multivariate model, the beta coefficients were similar for age, systolic blood pressure, cholesterol, and income; the statistical significance varied among the groups. Within the power of this study to examine between-race differences, the predictive strength of the standard risk factors are very similar. None of the within-sex, between-race differences in the multivariate relationships were significant, although sizable percentage differences were noted. Blacks appeared to receive less hospital care for CHD, despite higher rates of fetal events.

Black or African American↗
PubMed1991

Bedside diagnosis of preserved versus impaired left ventricular systolic function in heart failure.

The importance of recognizing symptomatic heart failure with preserved left ventricular (LV) systolic function has only recently been appreciated. To determine its frequency and identify clinical features that make the bedside diagnosis likely, 82 patients admitted for decompensated heart failure were classified into 2 groups based on their LV systolic performance, as defined by fractional shortening (FS): group I (n = 59), with impaired systolic function (fractional shortening less than 24%), and group II (n = 23) with preserved systolic function (fractional shortening greater than or equal to 24%). Mean fractional shortening was 15 +/- 5% and 39 +/- 1% for groups I and II, respectively. Female gender (p less than 0.05), obesity (p less than 0.01) and diastolic blood pressure greater than or equal to 105 mm Hg (p less than 0.05) predominated in group II. Jugular venous distention was identified more frequently in group I (p less than 0.05). No statistically significant difference between the 2 groups was noted among various demographic variables (age, duration of symptoms, history of hypertension, ischemic heart disease and heavy alcohol drinking) or physical findings (S3 gallop, edema, cardiomegaly, pulmonary congestion and pulmonary edema). Echocardiographic mean left ventricular dimension measured 6.6 +/- 1 versus 5.0 +/- 1 cm (p less than 0.01) and mean posterior wall thickness 1.1 +/- 0.3 versus 1.4 +/- 0.4 cm (p less than 0.01) in group I and II, respectively. The combination of diastolic blood pressure greater than or equal to 105 mm Hg and an absence of jugular venous distention had a high specificity and positive predictive value (100%) for identifying group II patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Impact of left ventricular hypertrophy on ventricular arrhythmias in the absence of coronary artery disease.

Left ventricular hypertrophy has a grave prognosis. Ventricular arrhythmias may account for a large portion of this poor prognosis, but the contribution of coronary artery disease has not been excluded. The occurrence of ventricular arrhythmias was investigated by 24 h ambulatory electrocardiographic (ECG) monitoring in 49 hypertensive patients who had normal findings on coronary arteriography. The presence of left ventricular hypertrophy was assessed by both ECG and echocardiography. The frequency and complexity of ventricular arrhythmias were significantly related to the presence of left ventricular hypertrophy whether it was defined by wall thickness (interventricular septum or posterior wall greater than or equal to 1.2 cm) or by left ventricular mass indexed to height (left ventricular mass/height greater than or equal to 163 g/m in men and greater than or equal to 121 g/m in women). The relation between left ventricular mass or wall thickness to ventricular arrhythmia was graded and continuous; for every 1 mm increase in the thickness of interventricular septum or posterior wall there was an associated two- to threefold increase, respectively, in the occurrence and complexity of ventricular arrhythmias. In conclusion, left ventricular hypertrophy is associated with an increase in the frequency and complexity of ventricular arrhythmias in the absence of coronary artery disease, and the relation is graded and continuous.

Arrhythmias, Cardiac↗
PubMed1991

Risk factors for hypertension in a national cohort study.

Hypertension continues to be a major public health problem in the United States. We used data from the National Health and Nutrition Examination Survey Epidemiologic Followup Study (1971-1984) to examine predictors of hypertension for the 7,073 participants free from hypertension at the baseline examination. The follow-up period averaged 10 years. Body mass index was positively related to the probability of hypertension developing among white men (n = 2,370), white women (n = 3,949), black men (n = 231), and black women (n = 523). Education was inversely associated with the probability of hypertension developing among white women and was of borderline significance among white men and black women. In a subanalysis of white men (n = 1,790) and white women (n = 3,063) who completed the 24-hour recall dietary questionnaire, dietary consumption of sodium, calcium, and potassium did not predict the development of hypertension. The failure of our study to support findings relating intake of dietary cations to the development of hypertension may be attributable to imprecision in the measurement of dietary data and misclassification of hypertension status. These data reinforce the importance of weight control in the primary prevention of hypertension.

Adult↗
PubMed1991

Age-related differences in case-fatality rates among diabetic patients with myocardial infarction. Findings from National Hospital Discharge Survey, 1979-1987.

OBJECTIVE: To determine age-related differences in case-fatality rates among diabetic patients with myocardial infarction (MI). Published studies have demonstrated 60% higher case-fatality rates during acute MI among diabetic patients compared with those without diabetes. However, many previous reports have been of insufficient size to examine the effect of age on mortality and have not been drawn from a representative sample of hospitals. The National Hospital Discharge Survey provides data on discharge diagnosis and vital status from a random sample of approximately 500 short-stay American hospitals. RESEARCH DESIGN AND METHODS: In this analysis, people with acute MI listed as the first diagnosis on the discharge sheet were studied. Any mention of diabetes mellitus on the discharge sheet was used to stratify the patients into those with and without diabetes. RESULTS: Age-adjusted case-fatality rates were identical in patients with and without diabetes for both sexes: 16.1 vs. 16.3 in men and 18 vs. 18.2 in women, respectively. Mortality rates were, however, higher among the younger patients with diabetes. Ratios of the case-fatality percentage by 10-yr age-groups (age 35-75 yr) and greater than or equal to 75 yr old for diabetes versus no diabetes were 1.7, 1.8, 1.2, 0.9, and 0.9 for men and 2.4, 1.2, 1.1, 1, and 0.9 for women. CONCLUSIONS: Diabetes thus appears to increase the in-hospital mortality risk with acute MI disproportionately in the younger age-groups, particularly among men, and does not appear to be a marker of increased risk among the elderly.

Adult↗
PubMed1991

A library for the fifteenth through the twenty-first centuries.

The University of California, San Francisco (UCSF), began developing a program for a new library in 1977, started the design in 1985, began construction in 1988, and opened the library in September 1990. The primary objectives were to design and build a facility that would house print collections under optimal conditions, allow for ten years' growth, be flexible enough to permit future reconfiguration, support present and future technologies, and provide beautiful spaces in which to study. The planning process is summarized, planning concepts are outlined, and considerations for the electronic library are briefly reviewed.

Computer Systems↗
PubMed1991

Coronary heart disease: black-white differences.

Important features of the racial patterns in CHD at the present time are summarized in Table 15-10. Many of these conclusions follow inevitably from the economic disadvantage suffered by blacks, and the overwhelming importance of hypertension in this population. More knowledge is needed regarding the value of standard diagnostic tools in distinguishing noncoronary from coronary chest pain symptoms. A hard look is also needed at questions of access for blacks, particularly to angioplasty and thrombolytic therapy. There is additional growing evidence that the gains against CHD have been concentrated primarily among the educated and affluent. New strategies will need to be developed if we are to repeat the kind of gains against cardiovascular disease among blacks in the 1990s that were made in the 1970s and 1980s.

Black or African American↗
PubMed1990

Left ventricular hypertrophy is associated with worse survival independent of ventricular function and number of coronary arteries severely narrowed.

Left ventricular (LV) hypertrophy has been repeatedly shown to be associated with a marked increase in mortality risk. Available data, however, do not provide evidence that the risk associated with the increase in cardiac muscle mass is independent of the severity of preexistent coronary artery disease. In a cohort of predominantly black patients with a high prevalence of hypertension and LV hypertrophy, LV mass as estimated by echocardiography was found to be a powerful prognostic factor independent of ejection fraction and obstructive coronary disease. After excluding patients with either a dilated LV cavity (diastolic internal diameter greater than 5.8 cm) or asymmetric septal hypertrophy (septal:posterior wall ratio greater than 1.5) LV mass/height remained significantly increased in decedents compared to survivors (116 +/- 38 vs 131 +/- 47 g/m, p = 0.014), while the thickness of the ventricular septum and the posterior wall were even more highly predictive of a fatal outcome (p = 0.003 and 0.001, respectively). After exclusion of patients with eccentric LV hypertrophy, differences in LV muscle mass in survivors and decedents were due entirely to increased thickness of the ventricular wall, and no differences in cavity dimensions or LV ejection fraction were noted. Stepwise regression analysis was used to demonstrate that measures of LV hypertrophy were the most important predictors of survival and eliminated the contribution of all other prognostic factors to the model except the number of stenotic vessels. The relative risk associated with a 100-g increase in mass was 2.1, while a 0.1-cm increase in posterior wall thickness was associated with approximately a 7-fold increase in the risk of dying.(ABSTRACT TRUNCATED AT 250 WORDS)

Black People↗
PubMed1990

Serum lipids, lipoproteins and apolipoproteins in black patients with angiographically defined coronary artery disease.

The association between angiographically defined coronary artery disease (CAD) and serum lipids, lipoproteins, and apolipoproteins was evaluated in 151 black men and 245 black women. Patients with 70% or greater narrowing of at least one coronary artery or greater than or equal to 50% stenosis of the left main coronary artery (n = 179) were compared to those with lesions of less than 50% stenosis (n = 217) for total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), LDL-C/HDL-C, triglycerides, apolipoprotein A-I, apolipoprotein B, and apolipoprotein A-I/B. A consistently more atherogenic pattern of lipids, lipoproteins, and apolipoproteins occurred only among the women. Using stepwise selection multiple logistic regression analysis, the ratio of apolipoprotein A-I/B (odds ratio = 0.38, 95% confidence limits 0.24-0.61) was the only statistically significant association of CAD in women, after adjusting for the effects of age, body mass index, and histories of smoking, hypercholesterolemia, hypertension, and diabetes. When stratified by median of total cholesterol, the ratio of apolipoprotein A-I/B was the most strongly associated with the presence of CAD in the lower half of the total cholesterol distribution (less than 208 mg/dl), whereas in the upper half of the total cholesterol distribution the total cholesterol/HDL-C ratio was more strongly associated with CAD. None of the variables studied was associated with CAD in men. These results support other studies suggesting that apolipoproteins may be better predictors of CAD.

Angiography↗
PubMed1990

Test characteristics of self-reported hypertension among the Hispanic population: findings from the Hispanic Health and Nutrition Examination Survey.

Data from the Hispanic Health and Nutrition Examination Survey conducted from 1982 to 1984 were analyzed for the sensitivity, specificity, and positive and negative predictive value of self-reported hypertension in 5195 Hispanics of both sexes between the ages of 18 and 74 years. On the basis of a hypertension definition of 140/90 mmHg or of the use of antihypertensive medications, overall sensitivity of self-reported hypertension was 56% for Mexican-Americans, 71% for Cuban-Americans and 72% for Puerto Ricans. Sensitivity was higher among women, among the obese, and among those with access to a regular place for medical care; increased with increasing age; and decreased with education and the time interval since last medical visit. Independent associations for sensitivity were noted for sex, body mass index (BMI), and time interval since last medical visit among Mexican-Americans; and for time interval since last medical visit and for being divorced or separated for Cuban-Americans. Overall positive predictive value reached 49% among Mexican-Americans, 53% among Cuban-Americans, and 39% among Puerto Ricans. Raising the hypertension-threshold to 160/95 mmHg tended to increase the sensitivity but reduced the positive predictive value.

Adolescent↗
PubMed1990

Cell cations and blood pressure in US whites, US blacks, and west African blacks.

Differences in cell cation metabolism have been previously demonstrated between blacks and whites in the US. To investigate a potential racial/genetic basis for these differences we studied red cell sodium content (Nai) and platelet cytosolic calcium (Cai) in a group of US whites (n = 26), US blacks (n = 20) and West African blacks (n = 26) residing in Chicago, IL. Participants in all groups were primarily health professionals. The West Africans had lived in Africa until at least age 21 and subsequently resided in the US for an average of 19 months. Immunological markers were used to estimate European gene admixture among the US blacks. Red cell Nai was significantly lower in US whites (7.72 +/- 2.49 mEq/l cells) compared to both the US blacks and West African blacks (9.98 +/- 2.36 and 10.60 +/- 2.80, respectively; P less than 0.01) and Cai was higher in whites than among US blacks (P less than 0.05). No differences were noted in blood pressure (BP) levels among the three racial groups. A linear correlation existed between Nai and both systolic (SBP) and diastolic (DBP) (r = 0.378 and 0.339, respectively; P less than 0.01), which was strongest among the blacks, particularly the US blacks (SBP vs. Nai, r = 0.716, P less than 0.01). Approximately 20% European gene admixture was present among the US blacks. Based on these findings, it would appear that, compared to US whites, higher levels of RBC Nai are common to black persons native to the US and West Africa.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Enhancement of sensitivity of fluorescence line narrowing spectrometry for detection of carcinogen-DNA adducts.

Fluorescence line narrowing (FLN), is a method by which highly characteristic spectra have been obtained for a large number of polycyclic aromatic hydrocarbon (PAH)-DNA adducts and is well suited for the analysis of exposures to complex mixtures of PHA. The basic method is described and recent improvements discussed which overcome one of the major limitations of the method to its wider application to biological samples, that is its sensitivity.

Animals↗
PubMed1987

Angioplasty for coarctation of the aorta: long-term results.

Balloon coarctation angioplasty (BCA) was performed in seven consecutive patients (five boys and two girls) 18 months to 18 years old (mean 9.5) with isolated discrete unoperated coarctation of the aorta. A No. 8F or 9F catheter was chosen with balloon lengths of 30 or 40 mm and maximum inflation diameters 1 mm less than the smallest measured aortic diameter determined 1 cm proximal to the coarctation site. A 10 sec inflation-deflation cycle of 6 to 8 atmospheres (90 to 120 psi) was performed. The peak systolic pressure gradient (PSG) before BCA ranged from 35 to 70 mm Hg (mean 58), and immediately after BCA it decreased to 0 to 20 mm Hg (mean 7). One to two year follow-up (mean 14 months) of the seven patients revealed a PSG range of 10 to 30 mm Hg (mean 19). Repeat angiography was performed immediately proximal to the coarctation site. Three patients (43%) had evidence of aneurysm formation at or immediately distal to the balloon dilatation site. One patient had coarctation restenosis. While initial results with BCA for unoperated coarctation were encouraging, current data raise serious concerns about its long-term safety and efficacy.

Adolescent↗