Longitudinal genetic analysis of brain volumes in normal elderly male twins.

This study investigated the role of genetic and environmental influences on individual differences in brain volumes measured at 2 time points in normal elderly males from the National Heart, Lung, and Blood Institute Twin Study. The magnetic resonance imaging (MRI) scans were conducted 4 years apart on 33 monozygotic and 33 dizygotic male twin pairs, aged 68 to 77 years when first scanned. Volumetric measures of total brain and total cerebrospinal fluid were significantly heritable at baseline (over 70%).

Prospective assessment after pediatric cardiac ablation: fate of intracardiac structure and function, as assessed by serial echocardiography.

Background: Catheter ablation puts cardiac valves at risk of damage, and children are of particular concern.

Methods: A multicenter prospective study was performed to assess the results and risks associated with radiofrequency (RF) ablation in children. Patients were aged 0 to 16 years with supraventricular tachycardia due to accessory pathway or atrioventricular node reentry, excluding patients with more than trivial congenital heart disease.

Longitudinal genetic analysis of executive function in elderly men.

The objective of this study was to characterize the relative contribution of genetic and environmental influences to individual differences in longitudinal performance and decline of executive function (EF) using a population-based prospective study of male, WWII veteran twins (NHLBI twin study). Three tests of EF were administered when the twins were 59-70 years old, with 9- and 13-year follow-up. APOE epsilon4 allele status was incorporated in the genetic models to determine its contribution to longitudinal genetic variability.

Apolipoprotein E epsilon4 and change in cognitive functioning in community-dwelling older adults.

The relationship between apolipoprotein E (APOE) epsilon4 and change in cognition was examined in older men (n = 247; age = 75.0 +/- 3.5 years) and women (n = 79; age = 70.

Association of sex steroid hormones with brain morphology and cognition in healthy elderly men.

Background: There is inconsistent evidence of the presence and direction of the relationship between sex hormone concentrations and cognitive function in older men, and there is little published literature on the relationship of sex hormone concentrations and brain volume as measured by MRI.

Objective: To examine the hypothesis that midlife total serum concentrations of testosterone (T), estradiol, estrone, and sex hormone binding globulin (SHBG) predict cognitive task performance and regional brain volumes at 10- to 16-year follow-up, in a longitudinal sample of World War II veteran twin men.

Methods: Treating twins as individuals, linear regression models were used, adjusting analyses for age, education, depressive symptomatology, blood pressure, alcohol consumption, years of cigarette smoking, and APOE epsilon4 allele status.