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Biomedical subjects

J Steinberger

Publications and source records attributed to J Steinberger.

At least 19 recordsLinked to original sources

Comparison of body fatness measurements by BMI and skinfolds vs dual energy X-ray absorptiometry and their relation to cardiovascular risk factors in adolescents.

OBJECTIVE: To compare estimates of adiposity by dual emission X-ray absorptiometry (DXA), skinfolds and body mass index (BMI); and to evaluate the relation of these measures to cardiovascular risk in adolescents. DESIGN: In a cohort of adolescents participating in a longitudinal study of insulin resistance, Slaughter formulas were used to estimate adiposity from skinfolds and DXA was used to estimate adiposity as % body fat (%BF) and fat mass (FBM). BMI, blood pressure, lipids and insulin resistance were measured. SUBJECTS: Male and female, 11-17 y old (n=130). MEASUREMENTS: To compare DXA with two office-based methods of assessing fatness and cardiovascular risk. RESULTS: Slaughter estimates were highly correlated with DXA (%BF r=0.92, P=0.0001; FBM r=0.96, P=0.0001). Correlations were similar in heavy and thin children. BMI was also highly correlated with DXA (%BF r=0.85, P=0.0001; FBM r=0.95, P=0.0001), and these relations were stronger in heavy than thin children. BMI and the Slaughter formulas were similar to DXA in their relations to cardiovascular risk factors. CONCLUSIONS: Adiposity by BMI and Slaughter formulas are highly correlated with DXA and similarly related to cardiovascular risk factors. BMI is easy to obtain and is an acceptable method for initial office estimation of body fatness. BMI and skinfolds compare well with DXA in predicting adverse cardiovascular risk profile.

Absorptiometry, Photon↗

Association of physical activity with insulin sensitivity in children.

BACKGROUND: Physical activity (PA) has been shown to improve insulin resistance and other cardiovascular disease risk factors in normal and diabetic adults and in obese youth, but not in non-diabetic, normal-weight children. METHODS: Data from 357 non-diabetic children (10-16 y) were used to examine cross-sectional associations with PA. Insulin sensitivity was assessed with a euglycemic hyperinsulinemic clamp and expressed as M(ffm) (glucose utilization/kg of fat-free mass/min). RESULTS: Correlations were adjusted for age, sex, race and Tanner stage. PA was significantly correlated with fasting insulin and insulin sensitivity (r=-0.12, P=0.03 and r=0.13, P=0.001, respectively), more strongly in children with above-median systolic blood pressure (r=-0.17, P=0.03 and r=0.35, P=0.0001, respectively). Further adjustment for body mass index, body fat percentage, waist circumference or lipids did not alter these observations. CONCLUSIONS: Physical activity is correlated with lower fasting insulin and greater insulin sensitivity in childhood. These results are consistent with the hypothesis that increasing physical activity among youth may reduce the incidence of type 2 diabetes in children and adolescents.

Adipose Tissue↗

Insulin resistance and cardiovascular risk in the pediatric patient.

The insulin resistance syndrome, a cluster of potent risk factors for atherosclerotic cardiovascular disease and type 2 diabetes in adults, is composed of hyerinsulinemia, obesity, hypertension and hyperlipidemia. In addition, left ventricular hypertrophy and its precursor increased left ventricular mass, is known to be a powerful predictor of adverse cardiovascular events, both as an independent risk factor and by association with the insulin resistance syndrome. Obesity appears to have a major role in the relations between the components of the insulin resistance syndrome, and their association with increased heart mass. Of significant impact in the adult population, atherosclerotic cardiovascular disease and death are rarely seen in the young, but the pathologic processes and risk factors associated with its development have been shown to begin during childhood. Recent studies revealed the presence of components of the insulin resistance syndrome also in children and adolescents, however, their associations are not well understood. A direct link between obesity and insulin resistance has also been reported in the young, as has the link between insulin resistance and abnormal lipid profile. There is an increasing amount of data to show that being overweight during childhood and adolescence is significantly associated with insulin resistance, abnormal lipids and elevated blood pressure in young adulthood. Weight loss in these situations results in a decrease in insulin concentration and an increase in insulin sensitivity toward normalcy. Moreover, it has been determined that increased left ventricular mass is present in childhood, and is related to other risk factors, namely obesity and insulin resistance. Based on current knowledge, it is reasonable to suggest that weight control, and lifestyle modification, could alter the incidence of the syndrome of insulin resistance, and improve the risk profiles for cardiovascular disease as children make the transition toward adolescence and young adulthood.

Journal Article↗

Adiposity in childhood predicts obesity and insulin resistance in young adulthood.

OBJECTIVE: To determine whether adiposity in children predicts adiposity, insulin resistance, and abnormal lipid levels in young adults. STUDY DESIGN: Children (n = 31) were recruited into an epidemiologic study at age 13.3 +/- 0.3 years and had blood pressure, weight, and height measured. They were reevaluated at age 21.8 +/- 0.3 years at which time the measurements were repeated, a euglycemic insulin clamp was performed, and fasting lipid levels were measured. All values are expressed as mean +/- SEM. Data were analyzed by analysis of variance and linear regression analysis. RESULTS: Body mass index (BMI) in childhood (22.6 +/- 0.6) was highly correlated with BMI in young adulthood (26.9 +/- 0.9). Childhood BMI was also inversely correlated with young adult glucose utilization (r = -0.5, P = .006) and positively correlated with total cholesterol (r = 0.37, P = .05), and low-density lipoprotein (LDL) cholesterol (r = 0.48, P = .01). CONCLUSIONS: These data confirm that adiposity in childhood is a strong predictor of young adult adiposity. In addition, these results demonstrate that cardiovascular risk in young adulthood is highly related to the degree of adiposity as early as age 13.

Adolescent↗

Insulin resistance syndrome in childhood: associations of the euglycemic insulin clamp and fasting insulin with fatness and other risk factors.

OBJECTIVE: Our objective was to describe in children the relation of fatness and insulin resistance to the risk factors associated with the insulin resistance syndrome and to compare fasting insulin with the euglycemic insulin clamp as a measure of insulin resistance in children. STUDY DESIGN: This was a random selection of participants after blood pressure screening of 12,043 students in the fifth through eighth grades. Euglycemic insulin clamp studies with an insulin infusion rate of 1 mU/kg/min and a variable infusion of 20% glucose to maintain euglycemia, that is, plasma glucose at 5.6 mmol/L. Insulin sensitivity (M(lbm)) is defined as the amount of glucose required to maintain euglycemia (milligrams of glucose infused per kilogram lean body mass per minute). RESULTS: Body mass index was significantly correlated with fasting insulin and significantly inversely correlated with M(lbm). Fasting insulin was significantly correlated with systolic blood pressure in both sexes, all lipids, except high-density lipoprotein-cholesterol in males and triglycerides and high-density lipoprotein-cholesterol in females, but after adjustment was done for body mass index, it was significantly related only to triglycerides. M(lbm) was significantly correlated only with triglycerides and high-density lipoprotein-cholesterol, and this did not change after adjustment was done for body mass index. A clustering effect for the risk factors was seen in children in the lowest quartile of M(lbm) (highest degree of insulin resistance) compared with children in the highest quartile of M(lbm) (lowest degree of insulin resistance). CONCLUSIONS: As defined by M(lbm), there is an early association of insulin resistance, independent of body fat, with the risk factors. There is a significant relation between fasting insulin, as an estimate of insulin resistance, and the risk factors, but this is significantly influenced by body fatness. The clustering of risk factors according to level of M(lbm) suggests that adult cardiovascular disease is more likely to develop in children with the greatest degree of insulin resistance.

Adolescent↗

Echocardiographic diagnosis of heart disease in apparently healthy adolescents.

OBJECTIVE: Comprehensive data are currently unavailable on the prevalence of cardiac abnormalities in children after the newborn/infant period. The present report describes the prevalence of echocardiographically detected cardiac disease in a cohort of randomly selected healthy junior high school children. METHODS: The cohort for this report consists of 357 children (mean age: 13 years) randomly selected after blood pressure screening of 12 043 fifth through eighth grade students and having an echocardiographic examination as part of a study of insulin resistance in childhood. RESULTS: A physical examination performed by a board-certified pediatrician reported no cardiac abnormalities. However, echocardiography and Doppler studies identified 13 (3.6%) children (7 males and 6 females), with previously unknown cardiac abnormalities, as follows: abnormal mitral valve with mitral regurgitation (4), bicuspid aortic valve (2), atrial septal defect (2), coronary artery to pulmonary artery fistula (1), patent ductus arteriosus (1), pulmonary hypertension (1), cardiomyopathy (1), and pulmonary artery stenosis (1). Physical examination performed by a pediatric cardiologist detected abnormal cardiac findings in 7 (54%) of the children. Cardiac catheterization was required in 3 for additional diagnostic evaluation and in 2 for therapeutic intervention; 1 patient underwent open-heart surgery. Bacterial endocarditis prophylaxis was recommended in 8 (62%) of the 13 children. CONCLUSIONS: The results suggest that: 1) clinically significant cardiac disease in childhood is more prevalent than previously reported; and 2) improved screening methods should be considered to detect asymptomatic but significant cardiac abnormalities that may result in long-term complications. echocardiography, prevalence, incidence, heart disease, children.

Adolescent↗

Precision Timing of Two Anomalous X-Ray Pulsars.

We report on long-term X-ray timing of two anomalous X-ray pulsars, 1RXS J170849.0-400910 and 1E 2259+586, using the Rossi X-Ray Timing Explorer. In monthly observations made over 1.4 and 2.6 yr for the two pulsars, respectively, we have obtained phase-coherent timing solutions which imply that these objects have been rotating with great stability throughout the course of our observations. For 1RXS J170849.0-400910, we find a rotation frequency of 0.0909169331(5) Hz and frequency derivative -15.687&parl0;4&parr0;x10-14 Hz s-1 for epoch MJD 51215.931. For 1E 2259+586, we find a rotation frequency of 0.1432880613(2) Hz and frequency derivative -1.0026&parl0;7&parr0;x10-14 Hz s-1 for epoch MJD 51195.583. The rms phase residuals from these simple models are only approximately 0.01 cycles for both sources. We show that the frequency derivative for 1E 2259+586 is inconsistent with that inferred from incoherent frequency observations made over the last 20 yr. Our observations are consistent with the magnetar hypothesis and make binary accretion scenarios appear unlikely.

Journal Article↗

Insulin resistance during puberty: results from clamp studies in 357 children.

Insulin resistance may be an important cause of a constellation of cardiovascular risk factors in adults, and onset of this syndrome may occur in childhood. However, children normally experience transient insulin resistance at puberty. There were 357 normal children (159 girls, 198 boys) age 10-14 years who underwent euglycemic clamp studies to assess the effects of Tanner stage (T), sex, ethnicity, and BMI on insulin resistance. Insulin resistance increased immediately at the onset of puberty (T2), but returned to near prepubertal levels by the end of puberty (T5). Its peak occurred at T3 in both sexes, and girls were more insulin resistant than boys at all T stages. White boys appeared to be more insulin resistant than black boys; no difference was seen between white and black girls. Insulin resistance was strongly related to BMI, triceps skinfold thickness, and waist circumference, and this relationship was independent of Tanner stage or sex. Differences in BMI and adiposity did not, however, entirely explain the insulin resistance of puberty. These results demonstrate that 1) significant differences in insulin resistance are present between boys and girls; 2) insulin resistance increases significantly at T2, T3, and T4, but decreases to near prepubertal levels at T5; and 3) while insulin resistance is related to BMI and anthropometric measures of fatness, these factors do not completely explain the insulin resistance that occurs during the Tanner stages of puberty.

Adolescent↗

Cardiovascular function in children following bone marrow transplant: a cross-sectional study.

Sixty-three patients who had undergone a BMT at age < or = 18 years were evaluated cross-sectionally to determine cardiac function as well as the long-term prevalence, types, severity, and risk factors of cardiac abnormalities. Patients were > or = 1 year post-BMT and were evaluated by history, resting ECG, echocardiography (ECHO), exercise treadmill test, chest X-ray, pulmonary function tests and review of past cardiac studies. Patients were assigned a New York Heart Association (NYHA) class based on an activity and cardiac symptoms questionnaire. Pretransplant preparative regimens included high-dose cyclophosphamide (CY) and total body/lymphoid irradiation (n = 38), CY in combination with other chemotherapy (n = 22), and other drug combinations (n = 3). Forty patients (63.5%) had received prior anthracyclines (median 307 mg/m2). Patients' ages ranged from 1.9 to 32 years (median 10.9 years) with median follow-up of 3.3 years (range 1-16.3 years). Twenty-six patients (41.3%) had a cardiac abnormality detected at follow-up. In 21 patients the abnormal finding had not been present at the pre-BMT evaluation. Ten patients (16.4%) had resting ECG abnormalities. Left ventricular ejection fraction (LVEF) by ECHO was mildly decreased to 50-54% in three patients and markedly decreased to 40% in one patient. Only one patient (1.7%) developed a mildly abnormal shortening fraction of 27%. All patients with ECHO abnormalities were asymptomatic. Twenty-three of 31 patients > or = 9 years of age (74%) who underwent a treadmill exercise test had a borderline or abnormal response to exercise. There was no correlation between demographic factors, previous therapy, preparative regimen or length of follow-up with the post-BMT ECG, ECHO and treadmill abnormalities. Overall, eight patients (12.7%) were symptomatic and NYHA class II or III, and all had abnormal exercise tests. The presence of symptoms and NYHA class were predictors for oxygen consumption during exercise (P = 0.03 and 0.02, respectively) and tended to predict overall treadmill results also. Late cardiac abnormalities do occur following BMT in childhood and thus, there is a clear need for continued, serial long-term cardiac evaluation in transplant survivors. Evaluations should include exercise stress testing to detect inadequate cardiac output as well as oxygen consumption during exercise.

Adolescent↗

Causes of sudden unexpected cardiac death in the first two decades of life.

Sudden, unexpected cardiac death in the age group 1 to 21 years usually is due to myocarditis, hypertrophic cardiomyopathy, aortic valvar stenosis, and coronary arterial abnormalities. The hearts of 70 patients <21 years of age who died suddenly were reviewed. Twenty patients were <1 year of age and 50 were 1 to 21 years old. The cardiac findings were compared with those in 68 age-matched controls with known cardiac disease who did not die suddenly. Significant cardiac abnormalities were present in 13 (65%) of the 20 infants; 10 (50%) had anomalies of the aortic origin of the coronary arteries. Among the 50 older patients, cardiac abnormalities were found in 40 (80%), among whom coronary arterial anomalies existed in 12 (24%). Anomalies of aortic origin more frequently involved the left main than the right coronary artery in both groups.

Adolescent↗

Monosomy 9p24-->pter and trisomy 5q31-->qter: case report and review of two cases.

Partial deletion of the short arm of chromosome 9 (p24-->pter) and partial duplication of the long arm of chromosome 5 (q32-->qter) were observed in an abnormal boy who died at age 8 weeks of a complex cyanotic cardiac defect. He also had minor anomalies, sagittal craniosynostosis, triphalangeal thumbs, hypospadias, and a bifid scrotum. Two other infants with similar cytogenetic abnormalities were described previously. These patients had severe congenital heart defect, genitourinary anomalies, broad nasal bridge, low hairline, apparently low-set ears, short neck, and triphalangeal thumbs, in common with our patient. We suggest that combined monosomy 9p23,24-->pter and trisomy 5q31,32-->qter may constitute a clinically recognizable syndrome.

Abnormalities, Multiple↗

Relationship between insulin resistance and abnormal lipid profile in obese adolescents.

OBJECTIVE: To determine whether the lipid abnormalities observed in obese adolescents are associated with insulin resistance. METHODS: We evaluated the relationship between lipid levels and insulin resistance in 82 obese adolescents. Insulin resistance was assessed by fasting insulin level and sum of the insulin values after an oral glucose tolerance test in all 82, and were compared with data from 40 nonobese adolescents. Whole-body glucose uptake during euglycemic hyperinsulinemia (M value) was performed in 19 of the obese adolescents and compared with that of 24 nonobese young adults. RESULTS: The obese adolescents had significantly elevated low-density lipoprotein cholesterol (LDL-C) (3.09 +/- 0.73 mmol/L; 119 +/- 28.2 mg/dl) and triglycerides (1.22 +/- 0.62 mmol/L; 108 +/- 54.6 mg/dl) and low high-density lipoprotein cholesterol (HDL-C) levels (0.94 +/- 0.24 mmol/L; 36 +/- 9.1 mg/dl) when compared with values in the nonobese subjects. M values were significantly depressed in the obese compared with the nonobese subjects. Adiposity significantly correlated with low HDL-C and elevated triglyceride values. From the variables representing insulin resistance, the strongest correlation with the abnormal lipid profile was found for the M value. A stepwise multiple regression analysis revealed that the M value was the only step entered into the relationship for triglycerides and LDL-C, and both M value and fasting insulin were entered for HDL-C. CONCLUSION: In obese adolescents the degree of insulin resistance explains a significant portion of the variance in the levels of triglycerides, LDL-C, and HDL-C.

Adolescent↗

Once daily cefixime compared with twice daily trimethoprim/sulfamethoxazole for treatment of urinary tract infection in infants and children.

We conducted a randomized prospective multicenter study to compare the safety and efficacy of once daily oral cefixime (8 mg/kg) to twice daily oral trimethoprim/sulfamethoxazole (TMP/SMX) (8/40 mg/kg/day) for the treatment of acute urinary tract infection in children ages 6 months to 13 years. Seventy-six patients (38 in each group) were studied. Thirty-seven percent were younger than 3 years of age. Escherichia coli was the most common isolate in both groups (85%). Eighty-five percent of all Gram-negative organisms were susceptible to TMP/SMX and all were susceptible to cefixime. Seventy-two percent of all patients were febrile at the time of diagnosis. Both groups were treated for 7 to 10 days. Peripheral white blood cell counts, erythrocyte sedimentation rate, body temperature and urinalysis returned to normal at the same rate in both groups. No failures were observed and relapse occurred in 3 cases within the 4 weeks after treatment (2 in the cefixime group and one in the TMP/SMX group). Side effects were observed in 14% of the cefixime group and 16% of the TMP/SMX group and were all mild enough not to necessitate discontinuation of therapy. We conclude that the efficacy and safety of cefixime administered once daily compared favorably with TMP/SMX administered twice daily for acute uncomplicated urinary tract infection.

Administration, Oral↗

Results of a right ventricular outflow patch for pulmonary atresia with intact ventricular septum.

BACKGROUND: Although overall outcome has improved, pulmonary atresia with intact septum remains a difficult surgical and clinical problem. To determine whether an early right ventricular outflow patch will result in biventricular repair for this lesion, we reviewed the long-term follow-up (5.8 +/- 0.8 years) of 19 newborns who underwent repair between 1979 and 1990. METHODS AND RESULTS: An early right ventricular outflow patch was placed in 15 of 19 newborns; in the remaining four, this was preceded by an aortopulmonary shunt. Prostaglandin E1 infusion postoperatively eliminated the need for shunt in 14 of 15. Coronary sinusoids were ligated in three newborns. Based on right ventricular morphology, the newborns were divided into two groups: group 1 (tripartite, n = 9) and group 2 (bipartite and monopartite, n = 10). Before surgery, group 1 had significantly larger right ventricular volumes (23.6 +/- 3.7 versus 5.2 +/- 1.1 ml/m2, p < 0.002). Five-year survival was 79% for the entire series. Four infants, all group 2, died within 12 months of their initial surgery. Fourteen of 15 survivors (nine group 1 and five group 2) currently are acyanotic and New York Heart Association functional class I. A biventricular repair was achieved in 12 of 15, and three other children are awaiting evaluation. All 15 survivors had significant right ventricular and tricuspid annulus growth. CONCLUSIONS: Our data suggest that early placement of a right ventricular outflow patch in infants with pulmonary atresia and intact ventricular septum, regardless of right ventricular anatomy, results in an excellent chance for biventricular repair.

Alprostadil↗

Stimulation characteristics of a steroid-eluting electrode compared with three conventional electrodes.

Stimulation thresholds of a steroid-eluting electrode (Medtronic CapSure 4003, 9 patients) were compared with three conventional electrodes (carbon-tipped lead, Siemens-Elema 423 S/60, 10 patients; Elgiloy-tipped lead, Cordis Encor, 10 patients; platinum-tipped lead, Telectronix Laserdish 030-276, 9 patients). Voltage thresholds were determined during implantation, 1-3 days, 6 weeks, and 6 months postimplantation. No significant difference among the four electrodes was found in regard to stimulation and sensing behavior during implantation. Compared to intraoperative measurements, mean increase in voltage threshold and absolute voltage thresholds were substantially less for the steroid-eluting electrode than for the other tested electrodes 6 weeks and 6 months after implantation. The rheobasechronaxie product, a parameter of the stimulation performance of electrodes, underlined the superior pacing characteristics of the steroid-eluting electrode. To achieve low chronic stimulation threshold by pharmacological means is an attractive direction for future electrode technology.

Adult↗

Interstitial deletion 2q14q21.

A girl with multiple congenital anomalies and a tendency to severe pyogenic infections was found to have an interstitial deletion of chromosome band 2q14----q21. Unusual facial manifestations included enophthalmos, long philtrum, micrognathia, narrow forehead, prominent glabella, and depressed nasal bridge. Unilateral corneal clouding, with Peters-like anomaly; agenesis of the corpus callosum; brain atrophy; and heart, kidney, hand, and dermatoglyphic anomalies were additional findings. Eye anomalies were observed in five of 22 patients with deletions of chromosome 2q. In comparing these cases, it seems that deletions of bands 2q21 and 2q31 are variably associated with microphthalmia, corneal clouding, cataracts, and Peters anomaly. Measurement of protein C and interleukin-1 (IL-1) did not show a gene dose effect, but the pyogenic infections and low IgA found in this patient may reflect an abnormality of IL-1 not detectable by our methods.

Abnormalities, Multiple↗

Interstitial 7q deletion [46,XY,del (7) (pter----cen::q112----qter)] in a retarded quadriplegic boy with normal beta glucuronidase.

A 14-year-old severely retarded male with deletion of chromosomal band 7 cen----q112 is described. Clinical features include short stature, microcephaly, unusual facies with narrow forehead, short nose, malar hypoplasia, protruding alveolar ridges and incisors, receding chin, relatively long philtrum, and large ears. In addition, he had bilateral inguinal herniae cryptorchidism with hypogonadism, pulmonic stenosis, and spastic quadriplegia. Normal activity of beta-glucuronidase was found in the patient's leukocytes. This finding suggests that the gene is not in the deleted region, narrowing the smallest region of overlap to 7q112----q22.

Abnormalities, Multiple↗