Diffusion tensor imaging of deep gray matter in children treated for brain malignancies.

Purpose: Previous DTI studies reported microstructural changes in white matter of patients receiving treatment for brain malignancies. The primary aim of this prospective pilot longitudinal study was to examine if DTI can detect microstructural changes in deep gray matter (as evaluated by the apparent diffusion coefficient, ADC) between pediatric patients treated with cranial radiation therapy and typically developing healthy children. The relationship between ADC and neurobehavioral performance was also examined.

Screening for prostate cancer using multivariate mixed-effects models.

Using several variables known to be related to prostate cancer, a multivariate classification method is developed to predict the onset of clinical prostate cancer. A multivariate mixed-effects model is used to describe longitudinal changes in prostate specific antigen (PSA), a free testosterone index (FTI), and body mass index (BMI) before any clinical evidence of prostate cancer. The patterns of change in these three variables are allowed to vary depending on whether the subject develops prostate cancer or not and the severity of the prostate cancer at diagnosis.

Antibody dynamics and spontaneous viral clearance in patients with acute hepatitis C infection in Rio de Janeiro, Brazil.

Background: The anti-HCV antibody response has not been well characterized during the early phase of HCV infection and little is known about its relationship to the clinical course during this period.

Methods: We analyzed serial anti-HCV antibodies longitudinally obtained from a prospective cohort of 65 patients with acute HCV infection by using a microparticle enzyme immunoassay AxSYM HCV 3.0 (Abbott Diagnostics) during the first 12 months from HCV acquisition in Rio de Janeiro, Brazil.

Gender differences in the accuracy of time-dependent blood pressure indices for predicting coronary heart disease: A random-effects modeling approach.

Background: Previous studies on blood pressure (BP) indices as a predictor of coronary heart disease (CHD) have provided equivocal results and generally relied on Cox proportional hazards regression methodology, with age and sex accounting for most of the predictive capability of the model.

Objective: The aim of the present study was to use serially collected BP measurements to examine age-and gender-related differences in BP indices for predicting CHD.

Methods: The predictive accuracy of time-dependent BP indices for CHD was investigated using a method of risk prediction based on posterior probabilities calculated from mixed-effects regression to utilize intraindividual differences in serial BP measurements according to age changes within gender groups.

Prospective study of the association of serum gamma-glutamyltransferase with cervical intraepithelial neoplasia III and invasive cervical cancer.

Epidemiologic studies indicate that elevated levels of gamma-glutamyltransferase (GGT), a key enzyme of glutathione metabolism, might be associated with increased cancer risk. Furthermore, preclinical studies support a role for GGT in tumor invasion and progression. However, the relationship between GGT and risks of cervical intraepithelial neoplasia III (CIN-III) and invasive cervical cancer (ICC) have not been evaluated.

Examining heterogeneity of functional recovery among older adults with hip fractures.

Objective: To examine heterogeneity in 1-year functional recovery following postacute rehabilitation among older adults with hip fracture.

Methods: Two hundred twenty-five community-dwelling older adults with hip fracture who received postacute rehabilitation in 5 rehabilitation facilities in Baltimore, Maryland, were recruited during postacute rehabilitation (baseline) and follow-up at 2, 6, and 12 months following postacute rehabilitation discharge. Functional recovery was measured by the activities of daily living (ADL) and instrumental activities of daily living (IADL) scores.

Model choice can obscure results in longitudinal studies.

Background: This article examines how different parameterizations of age and time in modeling observational longitudinal data can affect results.

Methods: When individuals of different ages at study entry are considered, it becomes necessary to distinguish between longitudinal and cross-sectional differences to overcome possible selection biases.

Results: Various models were fitted using data from longitudinal studies with participants with different ages and different follow-up lengths.

Age, sex, and race influence single-strand break repair capacity in a human population.

Recently, we developed an improved comet assay protocol for evaluating single-strand break repair capacity (SSB-RC) in unstimulated cryopreserved human peripheral blood mononuclear cells (PBMCs). This methodology facilitates control of interexperimental variability [A.R.

Use of penalized splines in extended Cox-type additive hazard regression to flexibly estimate the effect of time-varying serum uric acid on risk of cancer incidence: a prospective, population-based study in 78,850 men.

Purpose: We sought to investigate the effect of serum uric acid (SUA) levels on risk of cancer incidence in men and to flexibly determine the shape of this association by using a novel analytical approach.

Methods: A population-based cohort of 78,850 Austrian men who received 264,347 serial SUA measurements was prospectively followed-up for a median of 12.4 years.

Longitudinal change in serum gamma-glutamyltransferase and cardiovascular disease mortality: a prospective population-based study in 76,113 Austrian adults.

Objective: The purpose of this study was to investigate the association of longitudinal change in serum gamma-glutamyltransferase (GGT) with mortality from cardiovascular disease (CVD).

Methods And Results: A population-based cohort of 76,113 Austrian men and women with 455,331 serial GGT measurements was prospectively followed-up for a median of 10.2 years after assessment of longitudinal GGT change during an average period of 6.

Association of gamma-glutamyltransferase and risk of cancer incidence in men: a prospective study.

Although several epidemiologic studies have shown that gamma-glutamyltransferase (GGT) is independently associated with cardiovascular disease and all-cause mortality, its relationship with cancer incidence remains widely unexplored. In several experimental models, the ability of cellular GGT to modulate crucial redox-sensitive functions has been established, and it thus may play a role in tumor progression, as has been repeatedly suggested. We prospectively investigated the association between GGT and risk of overall and site-specific cancer incidence in a large population-based cohort of 79,279 healthy Austrian men with serial GGT measurements.

Serum uric acid is an independent predictor for all major forms of cardiovascular death in 28,613 elderly women: a prospective 21-year follow-up study.

Background: The role of serum uric acid (SUA) as a risk factor for cardiovascular disease (CVD) remains controversial. Little is known about its predictive value for mortality from congestive heart failure (CHF) and stroke, particularly in elderly, post-menopausal women.

Methods: The relation of SUA to risk of death from total CVD, CHF, stroke and coronary heart disease (CHD) was examined prospectively in a large cohort of 28613 elderly Austrian women (mean age 62.

Serum uric acid and risk of cardiovascular mortality: a prospective long-term study of 83,683 Austrian men.

Background: The role of serum uric acid (SUA) as an independent risk factor for cardiovascular disease (CVD) remains controversial, and little is known about its prognostic importance for mortality from congestive heart failure (CHF) and stroke. Few large-scale epidemiologic studies with sufficient follow-up have addressed the association of SUA and CVD mortality in apparently healthy men across a wide age range.

Methods: A cohort of 83 683 Austrian men (mean age, 41.

Proton magnetic resonance spectroscopic imaging to differentiate between nonneoplastic lesions and brain tumors in children.

Purpose: To investigate whether in vivo proton magnetic resonance spectroscopic imaging (MRSI) can differentiate between 1) tumors and nonneoplastic brain lesions, and 2) high- and low-grade tumors in children.

Materials And Methods: Thirty-two children (20 males and 12 females, mean age = 10 +/- 5 years) with primary brain lesions were evaluated retrospectively. Nineteen patients had a neuropathologically confirmed brain tumor, and 13 patients had a benign lesion.

Hierarchical linear modeling analyses of the NEO-PI-R scales in the Baltimore Longitudinal Study of Aging.

The authors examined age trends in the 5 factors and 30 facets assessed by the Revised NEO Personality Inventory in Baltimore Longitudinal Study of Aging data (N=1,944; 5,027 assessments) collected between 1989 and 2004. Consistent with cross-sectional results, hierarchical linear modeling analyses showed gradual personality changes in adulthood: a decline in Neuroticism up to age 80, stability and then decline in Extraversion, decline in Openness, increase in Agreeableness, and increase in Conscientiousness up to age 70. Some facets showed different curves from the factor they define.

Gamma-glutamyltransferase as a risk factor for cardiovascular disease mortality: an epidemiological investigation in a cohort of 163,944 Austrian adults.

Background: There is evidence from recent studies that gamma-glutamyltransferase (GGT) is likely to be associated with cardiovascular disease (CVD). However, few studies to date with sufficient sample size and follow-up investigated the association of GGT with CVD mortality.

Methods And Results: The relation of GGT to the risk of death from CVD was examined in a cohort of 163,944 Austrian adults that was monitored for up to 17 years.

Serum erythropoietin and aging: a longitudinal analysis.

Objectives: To determine the changes in serum erythropoietin with age in patients with and without anemia and to assess the importance of certain comorbidities on changes in erythropoietin level and the development of anemia.

Design: Clinical history, hematological parameters, and serum erythropoietin levels were examined at 1- to 2-year intervals for 8 to 30 years.

Setting: Baltimore Longitudinal Study on Aging (BLSA), National Institute on Aging.

Accelerated longitudinal decline of aerobic capacity in healthy older adults.

Background: The ability of older persons to function independently is dependent largely on the maintenance of sufficient aerobic capacity and strength to perform daily activities. Although peak aerobic capacity is widely recognized to decline with age, its rate of decline has been estimated primarily from cross-sectional studies that may provide misleading, overly optimistic estimates of aging changes.

Methods And Results: To determine longitudinal rate of change in aerobic capacity and the influence of age, gender, and physical activity on these changes, we performed serial measurements of peak treadmill oxygen consumption (peak VO2) in 375 women and 435 men ages 21 to 87 years from the Baltimore Longitudinal Study of Aging, a community-dwelling cohort free of clinical heart disease, over a median follow-up period of 7.

Data from a longitudinal study provided measurements of cognition to screen for Alzheimer's disease.

Background: This article presents a computerized method to help predict individuals at risk for developing Alzheimer's disease (AD). This would be a valuable tool for clinicians in developing treatment plans for potential AD patients. Using the initial level and rates of change in visual memory performance, such a method could predict potential AD patients in a fast and inexpensive manner.

Living with achondroplasia: quality of life evaluation following cervico-medullary decompression.

Achondroplasia is the most common of the heritable skeletal dysplasias. Cervico-medullary compression is a frequently encountered and potentially lethal neurological complication. Cervico-medullary decompression (CMD) at the foramen magnum is often employed to relieve the pressure on the emerging cervical cord.

Asymmetry and gender effect in functionally lateralized cortical regions: a proton MRS imaging study.

Purpose: to compare metabolite concentrations and ratios in gray matter regions known for their anatomical/functional asymmetry and evaluate gender effect.

Materials And Methods: Proton MRS imaging was performed at 1.5 T with TR/TE 2300/280 msec in 20 healthy right-handed subjects (mean age 29.

Estimates of future physical functioning by seriously ill hospitalized patients, their families, and their physicians.

Objectives: To compare prognostic estimates made by seriously ill hospitalized patients, their surrogates, and their physicians about the patients' activities of daily living (ADLs) 2 months after admission; compare the accuracy of their estimates; and identify factors associated with the optimism and accuracy of these estimates.

Design: Prospective cohort study.

Setting: Five teaching hospitals.

In vivo quantitative proton MRSI study of brain development from childhood to adolescence.

Purpose: To quantify regional variations in metabolite levels in the developing brain using quantitative proton MR spectroscopic imaging (MRSI).

Materials And Methods: Fifteen healthy subjects three to 19 years old were examined by in vivo multislice proton MRSI. Concentrations of N-acetyl aspartate (NAA), total choline (Cho), total creatine (Cr), and peak area ratios were determined in selected frontal and parietal gray and white matter regions, basal ganglia, and thalamus.