PubMed Health⌕ Search

Biomedical subjects

B S Alpert

Publications and source records attributed to B S Alpert.

At least 19 recordsLinked to original sources
PubMed2003

Cardiovascular hemodynamics: relationships with insulin resistance in obese children.

We investigated blood pressure (BP), cardiac output (CO), and systemic vascular resistance (SVR) and their relationships with insulin and glucose blood levels in a group of 24 obese children (mean age, 11.9 +/- 2.1 years; 19 males). The data were compared to those obtained from a group of 19 healthy controls of the same age (12.4 +/- 2.1 years; p = NS; 13 males). BP at rest was measured and all subjects underwent an exercise testing on the treadmill (Bruce Prot.), time of exercise, maximal heart rate, maximum systolic blood pressure, CO, and SVR at rest and at peak exercise were considered. Only in the OC group were an oral glucose tolerance test were performed to calculate insulin sensitivity index (ISI) and echocardiography performed to determine the left ventricular mass (LVM). The relationships between cardiovascular and metabolic parameters were investigated. Student's t-test and linear regression analysis were used when appropriate. OC had a significant reduction in TE and higher BP, and linear regression analysis showed significant correlations between BP, ISI, and LVM. We speculate that OC need a regular cardiovascular and metabolic screening to prevent the development of early cardiovascular damage.

Cardiac Output↗
PubMed2000

Racial differences in hemodynamic responses to environmental thermal stress among adolescents.

BACKGROUND: Previous studies by our laboratory and others have shown that blood pressure (BP) responses to many short-term laboratory stressors are greater in black than in white children. We sought to determine the cardiac and vascular contributions to these differences in BP reactivity and whether racial differences in vascular reactivity involve excessive vasoconstriction or deficient vasodilation. METHODS AND RESULTS: We evaluated BP, heart rate, and impedance cardiographic measures of preejection period (PEP) and total peripheral resistance (TPR) in healthy black (n=76) and white (n=60) adolescents (mean age, 14.8 years) during passive exposure to a vasoconstrictive cold chamber (8 degrees C to 10 degrees C) and a vasodilatory heat chamber (40 degrees C to 42 degrees C). Results indicated greater decreases in PEP and increases in TPR in blacks than whites during cold exposure (P<0.05) but no group differences during heat exposure. Covariance analyses indicated that the racial differences during cold exposure probably reflected greater beta-adrenergic cardiac reactivity and alpha-adrenergic vasoconstrictive reactivity in blacks than whites. CONCLUSIONS: Blacks and whites exhibited comparable myocardial and vasodilatory responses to heat stress, but blacks exhibited heightened myocardial and vasoconstrictive reactivity to cold stress. These results suggest that the locus of racial differences in vascular reactivity involves vasoconstrictive rather than vasodilatory function. The pattern of racial differences during cold stress raises the possibility that both myocardial and vasoconstrictive mechanisms may contribute to the increased risk of hypertension in blacks.

Adolescent↗
PubMed2000

Ambulatory blood pressure monitoring in children with aortic coarctation and kidney transplantation.

BACKGROUND: Ambulatory blood pressure monitoring (ABPM) has been found to be of significant importance in clinical practice because numerous blood pressure (BP) measurements may be made throughout the 24-hour period. OBJECTIVE: To assess the clinical utility of ABPM in children with secondary hypertension. METHODS: We studied 37 patients (21 boys and 16 girls), with a mean age of 16.4 +/- 4.1 years, after kidney transplantation and 38 patients (27 boys and 11 girls), with a mean age of 10.2 +/- 2.1 years, after surgical correction of aortic coarctation. Data, expressed as mean +/- SD, were analyzed after dividing the patients into 4 groups. Group A consisted of 25 patients receiving antihypertensive therapy; group B included 12 patients not receiving antihypertensive therapy. Group C included 25 patients operated on before 3 years of age (8 +/- 7 months of age); group D included 13 patients operated on after 3 years of age (74 +/- 29 months of age). RESULTS: In groups A and B, casual BP measurement showed that 16 of 37 patients (43%) were hypertensive; 24-hour ABPM detected a larger number of patients who were hypertensive (23 of 37, 62%); there were 18 in group A and 5 in group B. In groups C and D, casual BP measurement identified 6 of 38 (15%) patients as hypertensive, whereas 24-hour ABPM again identified a higher number (13 of 38, 34%). CONCLUSIONS: Our findings confirm that 24-hour ABPM is more sensitive than casual BP in detecting abnormal BP in patients at high risk for secondary hypertension.

Adolescent↗
PubMed2000

Racial differences in adolescents' perceived vulnerability to disease and injury.

This study examined gender and racial differences in adolescents' risk perceptions of major diseases and motor vehicle injury and whether these perceptions agree with national mortality rates and parental health history. Adolescent (N = 135; 55% African-American) boys and girls reported on their chances compared to other adolescents of developing specific diseases or experiencing a motor vehicle injury and their knowledge of parental health history. Logistic regression models revealed that girls' risk perceptions were similar to boys' ratings even though females are at less risk than males per national figures. Caucasian adolescents inaccurately perceived that they were at significantly greater risk than African-American peers for motor vehicle injury, stroke, cancer, and heart attack. Adolescents' knowledge of a father's diabetes was predictive of greater perceived vulnerability to diabetes.

Accidents, Traffic↗
PubMed2000

Exercise as a therapy to control hypertension in children.

Hypertension is not uncommon in childhood and adolescence; vascular and renal causes predominate. Non-pharmacologic therapy, including exercise, may lower blood pressure (BP). There are several articles relating to the use of exercise as a therapy for high BP. Most of these show a beneficial effect. The "dose" of exercise remains undetermined. There are no known data stating that dynamic exercise is of significant risk in childhood or adolescence. A multicenter trial of exercise is proposed to define the intensity, duration, and frequency of sessions needed to obtain optimal BP control.

Child↗
PubMed2000

Validation of the CAS Medical Systems, inc. OscilloMitt, hand-blood-pressure cuff.

BACKGROUND: There are technical difficulties in accurately measuring blood pressure of individuals with varying arm and body sizes. OBJECTIVE: To perform validation testing with 109 children of a novel cuff that occludes the palm rather than the upper arm. METHODS: This cuff, the OscilloMitt made by CAS Medical Systems, Inc. , was used in conjunction with a commercially available monitor. Readings of blood pressure taken by trained auscultatory observers were compared with those of the OscilloMitt monitor. The mean difference in systolic blood pressure was 1.13mmHg and the mean difference in diastolic blood pressure was 0.94mmHg. The OscilloMitt was tolerated very well, especially by the young children (those aged <5years). CONCLUSION: The OscilloMitt is accurate and its use should be preferable to traditional upper-arm placement of cuffs for assessing many specific groups of patients. We recommend its use for persons aged 2 years and more.

Adolescent↗
PubMed2000

Consistency of hemodynamic responses to cold stress in adolescents.

Laboratory research on hypertension often is performed with cold stress to elicit vasoconstriction and increases in blood pressure. Several studies have shown that cardiovascular responses to the cold pressor test predict the development of hypertension. We extended this research by comparing cardiovascular responses to a traditional forehead cold pressor test and a naturalistic whole-body cold exposure. We evaluated blood pressure and impedance cardiographic measures of cardiac output and total peripheral resistance in healthy black (n=69) and white (n=47) adolescents (mean age, 14.7 years) during forehead cold pressor (3 degrees C to 4 degrees C) and passive whole-body exposure to a cold chamber (8 degrees C to 10 degrees C). Both tasks elicited increases in vascular resistance and blood pressure, but forehead cold elicited an increase in cardiac output, whereas whole-body cold elicited a decrease in cardiac output (P<0.05). Consistent with previous research, there was a tendency toward greater vasoconstrictive reactivity to cold stress in blacks than in whites, particularly during whole-body cold exposure (P<0.05). Cardiovascular reactivity correlated significantly between tasks, but substantial intertask consistency occurred only for cardiac and vascular reactivity in male subjects (r>0.30) but not in female subjects (r<0.15). These gender differences might reflect diminished adrenergic receptor function in female subjects. We conclude that whole-body cold exposure offers a viable, relatively naturalistic alternative to traditional cold pressor tests for the assessment of cardiovascular reactivity.

Adolescent↗
PubMed2000

Racial differences in the influence of body size on ambulatory blood pressure in youths.

BACKGROUND: African Americans have higher night-time blood pressures than Caucasians do despite their having similar daytime blood pressures. It is well established that body size is related to casual blood pressure. OBJECTIVE: To examine the influence of body size on racial differences in patterns of ambulatory blood pressure. METHODS: Ambulatory blood pressure recordings were performed on 292 healthy children and adolescents (148 African Americans and 144 Caucasian) aged 10-18 years (mean 13+/-2 years). These blood pressures were related to height, weight, body surface area, and body mass index in separate regression models that also included race, sex, and age as factors. RESULTS: The race-by-height interaction was significant for night-time systolic blood pressure (P<0.02), with a significant relationship for African Americans (P<0. 0001), but not for Caucasians. The race-by-weight interaction was significant for night-time systolic blood pressure (P<0.04), also with a greater relationship for African Americans (P<0.0001) than for Caucasians (P<0.03). In addition, the race-by-weight interaction was significant for night-time diastolic blood pressure (P<0.04), with a significant relationship for African Americans (P<0.01), but not for Caucasians. Finally, the race-by-body-surface-area interaction was significant for night-time diastolic blood pressure (P<0.05), again with a significant relationship for African Americans (P<0.02) but not for Caucasians. CONCLUSION: Differences in the relationship between body size and blood pressure contribute to the racial differences in patterns of ambulatory blood pressure and should be considered when evaluating patterns of blood pressure in African American youths.

Adolescent↗
PubMed1998

Double patch closure of ventricular septal defect with increased pulmonary vascular resistance.

BACKGROUND: Closure of a large ventricular septal defect (VSD) in children with elevated pulmonary vascular resistance is associated with significant morbidity and mortality. Pulmonary hypertensive episodes continue to be a major cause of postoperative morbidity and mortality. We designed a fenestrated flap valve double VSD patch in an effort to decrease the morbidity and mortality associated with the closure of a large VSD with elevated pulmonary vascular resistance. METHODS: Eighteen children (mean age, 5.7 years) with a large VSD and elevated pulmonary vascular resistance (mean, 11.4 Wood units) underwent double patch VSD closure using moderately hypothermic cardiopulmonary bypass and cardioplegic arrest. The routine VSD patch was fenestrated (4 to 6 mm) and on the left ventricular side of the patch, a second, smaller patch was attached to the fenestration along its superior margin before closure of the VSD. RESULTS: All children survived operation and were weaned from inotropic and ventilator support within 48 hours postoperatively. Postoperative pulmonary artery pressures were significantly lower than preoperative values. One child died 9 months postoperatively. CONCLUSIONS: Closure of a large VSD in children with elevated pulmonary vascular resistance can be performed with low morbidity and mortality when a flap valve double VSD patch is used.

Adolescent↗
PubMed1998

Syncope recurrence in children: relation to tilt-test results.

OBJECTIVES: To examine the intermediate-term outcome of children with syncope and its relationship to tilt test. DESIGN: This was a retrospective study of 45 children. In 20, the tilt test was negative. Follow-up with respect to the recurrence of syncope was obtained via chart review, a mailed questionnaire, or telephone interview. RESULTS: Follow-up data were available on 15 children whose tilt test was negative and on all 25 tilt-test positive children. Recurrent syncope was significantly greater in the positive-tilt children (13 of 25) than the negative-tilt children (2 of 15). There was no difference between the syncope-free group and the recurrent syncope group or between the tilt-positive and tilt-negative groups with respect to age at initial syncope, duration of symptoms, age at tilt test, and duration of follow-up. Children with a positive tilt test and those with recurrent syncope had more syncopal episodes before their evaluation than either the group with a negative tilt test or the group with no recurrent syncope, respectively. CONCLUSIONS: Syncope may recur after either a negative or a positive tilt test. The recurrence rate, however, is higher for the tilt-positive children.

Adolescent↗
PubMed1998

Tall stature.

Explore the source record for details and available documents.

Aorta↗
PubMed1996

The PAPERCUFF, a new disposable blood pressure cuff.

We demonstrated the accuracy of a new disposable BP cuff (CAS PAPERCUFF) compared with 2 widely used cuffs. The PAPERCUFF should limit the possibility of spread of infection and reduce costs.

Blood Pressure Determination↗
PubMed1996

Fibromuscular proliferation in finger arteries after hand replantation: a case report.

We report on a case where a digit of a previously replanted hand was amputated 3 years after injury. Histologically, the finger arteries demonstrated a marked intimal thickening due to fibromuscular proliferation, with narrowing of the lumen. The media showed muscular hyperplasia and fibrosis, whereas the adventitia was normal. These changes are probably a consequence of ischemia and reperfusion injury and might explain the persistent vasomotor insufficiency found in replantation patients.

Adult↗
PubMed1996

Contour restoration of large defects of the trunk and extremities.

Advances in reconstructive techniques have led to the ability to provide coverage of wounds previously considered inoperable. Severe deformities of the trunk from trauma, tumor extirpation, and congenital causes have been demonstrated to be manageable using local and distant flaps. This article presents a series of cases of severe contour deformities of the trunk and extremities treated with tissue transplantation.

Adult↗
PubMed1995

Contribution of superior vena caval flow to total cardiac output in children. A Doppler echocardiographic study.

BACKGROUND: After a cavopulmonary anastomosis, the superior vena caval flow, by virtue of being the effective pulmonary blood flow, is the most important factor influencing the systemic arterial saturation. Determination of the amount of this blood flow will allow a better understanding of the physiology of the circulation after this anastomosis. The purposes of this study were to determine the volumetric flow in the superior vena cava and to evaluate its contribution to the cardiac output as children grow. METHODS AND RESULTS: Using two-dimensional and Doppler echocardiography, we measured the diameter of and mean flow velocities in the superior venae cavae and the pulmonary arteries of 145 healthy children. We calculated the volumetric flow in each vessel and determined the ratio of superior vena caval flow to total cardiac output. Cardiac output and superior vena caval flow increased with increasing age and body surface area. The superior vena caval flow accounted for 49% of cardiac output in newborn infants. This contribution increased to a maximum of 55% at the age of 2.5 years. Afterward, there was a slow decline in the ratio of superior vena caval-pulmonary arterial flow; it reached the adult value of 35% by 6.6 years of age. CONCLUSIONS: There is a maturational change in the superior vena caval contribution to total cardiac output in children. This is most likely related to somatic growth and changes in body segment proportions. This flow maturation may explain the higher systemic saturation in infants compared with older children after cavopulmonary anastomosis.

Blood Flow Velocity↗