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Biomedical subjects

W B Strong

Publications and source records attributed to W B Strong.

At least 55 records · Page 3Linked to original sources
PubMed1993

Determinants of left ventricular mass in normotensive children.

Left ventricular hypertrophy has been shown to be an independent predictor of cardiovascular morbidity and mortality. Few studies have examined the determinants of left ventricular mass (LVM) in normotensive children. Eight-four healthy children, blacks and whites, girls and boys, between 6 and 18 years of age, all with positive family histories of essential hypertension, participated in the study. Demographic and anthropometric characteristics, physical activity, and hemodynamic responses at rest and in response to the stress of forehead cold stimulation and a challenging video game were related to M-mode echocardiographic determined LVM indexed by two indices of body habitus. Hierarchical stepwise multiple regression analysis indicated that the significant independent correlates of LVM per body surface area were gender (boys were greater), baseline systolic blood pressure and heart rate, a physical activity index (sweat episodes per week) and peak systolic blood pressure responses to the forehead cold stressor (final model r2 = 0.49). For LVM/height2.7 significant independent correlates were adiposity index (weight z score--height z score), gender (boys were greater), age, resting systolic pressure, and systemic vascular resistance reactivity to forehead cold stimulation (final model r2 = 0.42). These findings with normotensive children corroborate other findings that have typically involved hypertensive children, indicating that resting heart rate and systolic pressure, gender, and adiposity are early determinants of LVM indices in children. In addition, the current findings indicate that hemodynamic responses to stress also appear to play a role in the early development of LVM.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Hostility: relationship to lifestyle behaviors and physical risk factors.

The relationship between hostility and coronary artery disease may be partially mediated by unhealthy lifestyle behaviors. This study examined the relationship between hostility, lifestyle behaviors, and physical risk factors in 138 adult men and women. Subjects completed the Cook and Medley Hostility Scale (Ho scale) and self-reports of their dietary habits, consumption of alcohol and cigarettes, and physical activity. Recent findings indicated that a composite hostility score from three rationally derived subscales of the Ho scale tapping the dimensions of cynicism, hostile affect, and aggressiveness was a better predictor of mortality than the total Ho score. Thus, this composite measure of hostility and the total Ho score were used in data analyses. Measures of resting blood pressure, height, weight, and adiposity were also obtained. In men and women, both measures of hostility were positively associated with cholesterol intake and vigorous physical activity. Among women, both hostility measures were positively related to animal fat intake and negatively related to fiber intake. The composite measure was positively related to their resting systolic pressures. Among men, both hostility measures were positively related to cigarette smoking and sugar intake and negatively associated with systolic blood pressure and calcium intake. Findings are discussed in terms of previous research linking hostility to lifestyle behaviors and CAD.

Adult↗
PubMed1992

Complications of polycythemia in patients who have cyanotic congenital heart disease.

A 13-mo-old child is brought to his pediatrician following sudden onset of left-sided hemiplegia. The pediatrician accompanies the child and family to the emergency room. The pediatrician has been following the child, who has a diagnosis of possible cyanotic congenital heart disease. The child has never been known to have had a hypercyanotic episode. Oxygen saturation determinations by pulsed oximeter had been in the range of 84% to 88%. On one occasion, when the child was very upset, a reading of 78% was observed. At his 1-year visit, his hemoglobin level was 13 g/dL. On admission to the emergency department, a computed tomographic scan of the head was ordered. It demonstrated a right-sided nonhemorrhagic cerebrovascular lesion.

Cerebrovascular Disorders↗
PubMed1991

Family history of myocardial infarction and hemodynamic responses to exercise in young black boys.

The influence of family history of coronary artery disease on children's hemodynamic responses to exercise was examined with 25 black boys aged 7 to 10 years. Blood pressure, heart rate, cardiac output, stroke volume, and total peripheral resistance were evaluated during preexercise, peak exercise, and recovery stages. Children with a family history of CAD exhibited greater systolic blood pressure and total peripheral resistance during preexercise and peak exercise stages than did those without a family history of coronary artery disease. After controlling for preexercise differences, the group with a family history of coronary artery disease exhibited greater increases in systolic blood pressure and less attenuation of total peripheral resistance to peak exercise than the group without a family history of coronary artery disease. Cardiac output indexed by body surface area and stroke volumes were higher at all times in the group without a family history compared with the group with a family history of coronary artery disease. Findings are compared with those of adult studies in terms of influence of family history of coronary artery disease on cardiovascular reactivity to stress.

Black People↗
PubMed1991

Social support for exercise: relationship to physical activity in young adults.

BACKGROUND: Physical inactivity is an independent risk factor for cardiovascular disease, yet little is known concerning factors which influence participation in physical activity or exercise. Two studies assessed the relationships between self-reported physical activity and social support for exercise. METHOD: One study involved a biracial sample of middle-class male and female teachers (mean age = 38.5 +/- 8.9 years) and one involved a biracial sample of lower- to middle-class males and females (mean age = 35.8 +/- 5.1 years). RESULTS: In both studies the social support scales had high internal consistencies and a two-component solution identical to the original validation study. In both studies, social support for exercise positively correlated with physical activity, but the relationships were mediated by race, gender, specific types of support (i.e., family, friend), and dimensions of physical activity (i.e., global, work, sports, and leisure). In both studies, regardless of work status and race, women's overall activity, particularly during leisure time, was positively related to family support for exercise. In both studies white women's overall activity levels, especially sports and leisure activities, were positively related to friend support. In both studies, black women's sports activity was positively associated with family support. Among white men in both studies, sports activities and total energy expenditure were positively related to family and friend support. Black men's sports-related activity was positively related to family support among the teachers and to friend support among subjects in the second study. CONCLUSION: Findings are discussed in terms of future research directed toward identification of other familial and sociocultural variables which might influence individuals' involvement in physical activity.

Adult↗
PubMed1990

Purification and properties of serine hydroxymethyltransferase and C1-tetrahydrofolate synthase from L1210 cells.

Serine hydroxymethyltransferase and the trifunctional enzyme C1-tetrahydrofolate synthase have been purified to near homogeneity from L1210 cells. Kinetic constants (Km and kcat) have been determined for both folate and non-folate substrates. The effect of increasing glutamate chain length on affinity and catalytic efficiency were determined for the four activities. The studies show that the structural and catalytic properties of the two L1210 enzymes are very similar to the corresponding enzymes purified from rabbit liver. Antibodies to both rabbit serine hydroxymethyltransferase and C1-tetrahydrofolate synthase cross-react with the corresponding L1210 enzymes. The intracellular concentration of active sites of serine hydroxymethyltransferase and C1-tetrahydrofolate synthase in L1210 cells are both 9 microM. The combined concentration of these two enzymes exceeds the previously reported concentration of 10 microM for total intracellular folates. A network thermodynamic computer model of one carbon metabolism (Seither, R. L., Trent, D. F., Mikulecky, D. C., Rape, T. J., and Goldman, I. D. (1989) J. Biol. Chem. 264, 17016-17023) suggests that complete inhibition of cytosolic serine hydroxymethyltransferase would neither significantly decrease the rates of biosynthesis of purines and thymidylate nor significantly alter the rate of interconversion of tetrahydrofolate cofactors to dihydrofolate with subsequent inhibition of dihydrofolate reductase.

Aminohydrolases↗
PubMed1990

Noninvasive assessment of cardiac output in children using impedance cardiography.

This study evaluated the effect of intracardiac shunting on the accuracy of thoracic bioimpedance-derived cardiac output determinations. Twenty-six patients, ranging in age from 3 months to 17 years, underwent cardiac catheterization during which simultaneous Fick and impedance measurements of cardiac output were obtained. The subjects were divided into three groups: 10 children with no intracardiac shunts, nine children with predominant left-to-right intracardiac shunts, and seven children with predominant right-to-left intracardiac shunts. Positive correlations between impedance and Fick-derived cardiac output determinations were obtained in the non-shunt group (r = 0.84), with lower correlations in the left-to-right shunt group (r = 0.70). In the right-to-left shunt group, the impedance derived cardiac output correlated with Fick pulmonary flow (r = 0.82), but the variability was unacceptably large. Although further study is needed, impedance cardiography appears to have validity as a methodology in pediatric critical care and cardiovascular health research.

Adolescent↗
PubMed1990

Family history of hypertension and cardiovascular reactivity to forehead cold stimulation in black male children.

The effects of family history of hypertension on cardiovascular reactivity to forehead cold stimulation was examined in 16 black males from 11 to 14 years of age. Measures of blood pressure, heart rate, cardiac output, stroke volume and systemic vascular resistance were obtained during baseline, forehead cold stimulation and recovery phases. Diastolic blood pressure and systemic vascular resistance increases to the forehead cold stimulation were significantly greater in subjects with positive family histories of hypertension than in those with negative family histories. These findings are compared with the results of adult studies and discussed in terms of racial differences in alpha and beta-adrenergically mediated cardiovascular reactivity.

Adolescent↗
PubMed1990

Individual and cross-spouse correlations of perceptions of family functioning, blood pressure and dimensions of anger.

Individual and cross-spouse correlations of perceptions of family cohesiveness, emotional expressiveness and conflict with blood pressure and five dimensions of anger were examined in 85 couples. Wives' perceptions of family cohesiveness were negatively related to their diastolic blood pressure, whereas husbands' perceptions of all three dimensions of family functioning were unrelated to their blood pressure. Cross-spouse correlations showed that both husbands' and wives' perceptions of emotional expressiveness were negatively related to their spouses' blood pressure, and husbands' perceived family cohesiveness was negatively related to wives' diastolic blood pressure. Individual and cross-spouse correlations with dimensions of anger were also obtained. These findings are discussed in terms of prior cross-spouse correlational research, and gender differences in the pattern of relationships are discussed.

Adaptation, Psychological↗
PubMed1990

Primary prevention of coronary artery disease through a family-oriented cardiac risk factor clinic.

Primary prevention of coronary artery disease in children and young adults is important and can be instituted through a family-oriented cardiac risk factor clinic. Such a clinic was initiated at the Medical College of Georgia in March 1988. Children whose total cholesterol level (TC) exceeded 200 mg/dL when screened by their primary care physician were referred with their siblings and parents for fasting lipid profile and further evaluation. Data are available for the initial 21 families, including 30 children and 36 adults. The mean TC level was 258 mg/dL for index cases, 195 mg/dL for siblings, and 233 mg/dL for parents. Follow-up data obtained after therapy at a mean of 6 months are available for 12 families, including 14 children and 14 adults. The mean change in TC was from 265 to 246 mg/dL; 82% of the patients had a decrease in TC. Only one index case was documented as having neither a sibling nor a parent with an elevated cholesterol level. Family-oriented cardiac risk factor clinics are important for the identification and treatment of hypercholesterolemia in asymptomatic young people when primary prevention is possible.

Adolescent↗