Rush University Medical Center

About: Rush University Medical Center is a healthcare organization based out in Chicago, Illinois, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 13915 authors who have published 29027 publications receiving 1379216 citations. The organization is also known as: Rush Presbyterian St. Luke's Medical Center.

Maintaining Mobility in Late Life. I. Demographic Characteristics and Chronic Conditions

Abstract: To assess the role of demographic factors and chronic conditions in maintaining mobility in older persons, this study utilized longitudinal data collected as part of the Established Populations for Epidemiologic Studies of the Elderly between 1981 and 1987 on 6,981 men and women aged 65 years and older in East Boston, Massachusetts; Iowa and Washington counties, Iowa; and New Haven, Connecticut. Results are presented for those who at baseline reported intact mobility, defined as the ability to climb stairs and walk a half mile without help, and who were followed annually for up to 4 years for changes in mobility status. Age, income, education, and chronic conditions present at baseline and occurring during follow-up were evaluated for their association with loss of mobility. Over the follow-up period, 55.1% of subjects maintained mobility, 36.2% lost mobility, and 8.7% died without evidence of mobility loss prior to death. In both men and women, increasing age and lower income levels were associated with increased risk of losing mobility, even after controlling for the presence of chronic conditions at baseline. After adjustment for age, income, and chronic conditions, lower education levels were a significant risk factor for mobility loss in men, but not in women. Baseline reports of previous heart attack, stroke, high blood pressure, diabetes, dyspnea, and exertional leg pain were associated with small but significant risks for mobility loss. There was a stepwise increase in the risk of mobility loss according to the number of chronic conditions present at baseline that was very consistent between men and women. The occurrence during the study of a new heart attack, stroke, cancer, or hip fracture was associated with a substantially greater risk of mobility loss than was associated with the presence of these conditions at baseline.

In vivo corrosion of modular hip prosthesis components in mixed and similar metal combinations. The effect of crevice, stress, motion, and alloy coupling

Abstract: One hundred forty-eight retrieved modular hip prostheses of both mixed (Ti-6Al-4V/Co-Cr) and similar (Co-Cr/Co-Cr) metal combinations were examined and positive evidence of corrosive attack was found in the conical taper region between head and stem. Significant corrosion was observed in both mixed and similar metal combinations with 16% of necks and 35% of heads (for mixed-metal cases), and 14% of necks and 23% of heads (for similar-metal cases) showing moderate to severe corrosive attack. There was a significant correlation between the percentage of prostheses with moderate to severe corrosion and the duration of implantation for both mixed and similar metal cases, indicating that this corrosion process is progressive in time. Moderate to severe corrosion was seen as early as 2.5 and 11 months (mixed and similar metals, respectively). Scanning electron microscopy and x-ray analysis identified several forms of corrosive attack in the cobalt-based component of the taper. These included, for both mixed and same metal combinations: preferential dissolution of cobalt, fretting, and pitting; mixed metals only: the formation of a Ti-Cr-Mo interfacial phase and interdendritic corrosion; and for similar metals: intergranular attack adjacent to grain boundaries enriched in molybdenum and silicon. It is hypothesized that the restricted crevice environment, coupled with high cyclic stresses which cause repeated fracture of the passive oxide films in the taper, result in an unstable electrochemical environment within the crevice for both the cobalt alloy and Ti-alloy passive films. The passivity of these alloys is subsequently lost and active attack of the taper results. Also, the repeated fracturing of the passive films will result in large amounts of corrosion products being formed. This corrosion and particulate accumulation could result in loss of mechanical integrity of the implants in vivo, create particles for third body wear, and release particles into the surrounding tissues.

The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study

Abstract: Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHRadjBMI in four strata (men ≤50y, men >50y, women ≤50y, women >50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR<5%) age-specific effects, of which 11 had larger effects in younger (<50y) than in older adults (≥50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape.

Prognostic factors in early‐stage uterine sarcoma: A gynecologic oncology group study

Abstract: Background. A clinicopathologic evaluation of clinical Stage I and II uterine sarcoma was done by the Gynecologic Oncology Group from 1979-1988. Methods. After all eligibility criteria were met, 453 cases were evaluable and analyzed for prognostic factors. Results. Of the 301 mixed mesodermal tumors (MMT), 167 were homologous (HO), and 134 were heterologous (HE). Fifty-nine tumors were leiomyosarcomas (LM). The remaining 93 sarcomas were predominantly stromal cell and adenosarcomas. For this study, only the MMT or LM tumors were analyzed