University of Pittsburgh

About: University of Pittsburgh is a education organization based out in Pittsburgh, Pennsylvania, United States. It is known for research contribution in the topics: Population & Transplantation. The organization has 87042 authors who have published 201012 publications receiving 9656783 citations. The organization is also known as: Pitt & Western University of Pennsylvania.

Prospective study of obstructive sleep apnea and incident coronary heart disease and heart failure: The sleep heart health study

Abstract: Background— Clinic-based observational studies in men have reported that obstructive sleep apnea is associated with an increased incidence of coronary heart disease. The objective of this study was to assess the relation of obstructive sleep apnea to incident coronary heart disease and heart failure in a general community sample of adult men and women. Methods and Results— A total of 1927 men and 2495 women ≥40 years of age and free of coronary heart disease and heart failure at the time of baseline polysomnography were followed up for a median of 8.7 years in this prospective longitudinal epidemiological study. After adjustment for multiple risk factors, obstructive sleep apnea was a significant predictor of incident coronary heart disease (myocardial infarction, revascularization procedure, or coronary heart disease death) only in men ≤70 years of age (adjusted hazard ratio 1.10 [95% confidence interval 1.00 to 1.21] per 10-unit increase in apnea-hypopnea index [AHI]) but not in older men or in women of...

Entrepreneurship and the concept of fit: A model and empirical tests

Abstract: This paper reports the results of a study designed to investigate entrepreneurship and 'fit' in small and medium sized high technology manufacturing firms. A normative model of fit has been developed, which including the variables of entrepreneurial style, organizational structure, and mission strategy, determines a measure of the firm's fit with its environment. The normative model of fit proposed here is based on variables and relationships found to be important in previous empirical studies. Data on environmental turbulence, entrepreneurial style, organization structure, mission strategy, and financial performance were collected from 82 manufacturing firms. A measure of fit was calculated for each firm. Findings indicate that performance among firms was positively related to the measurement of fit. In short, fit is an important construct for firm success. Implications include prescriptive guidance to assist practitioners in diagnosing and correcting 'misfit' for individual firms.

Lack of effect of induction of hypothermia after acute brain injury.

Abstract: Background Induction of hypothermia in patients with brain injury was shown to improve outcomes in small clinical studies, but the results were not definitive. To study this issue, we conducted a multicenter trial comparing the effects of hypothermia with those of normothermia in patients with acute brain injury. Methods The study subjects were 392 patients 16 to 65 years of age with coma after sustaining closed head injuries who were randomly assigned to be treated with hypothermia (body temperature, 33°C), which was initiated within 6 hours after injury and maintained for 48 hours by means of surface cooling, or normothermia. All patients otherwise received standard treatment. The primary outcome measure was functional status six months after the injury. Results The mean age of the patients and the type and severity of injury in the two treatment groups were similar. The mean (±SD) time from injury to randomization was 4.3±1.1 hours in the hypothermia group and 4.1±1.2 hours in the normothermia group, a...

Oxidized arachidonic and adrenic PEs navigate cells to ferroptosis

Abstract: Enigmatic lipid peroxidation products have been claimed as the proximate executioners of ferroptosis-a specialized death program triggered by insufficiency of glutathione peroxidase 4 (GPX4). Using quantitative redox lipidomics, reverse genetics, bioinformatics and systems biology, we discovered that ferroptosis involves a highly organized oxygenation center, wherein oxidation in endoplasmic-reticulum-associated compartments occurs on only one class of phospholipids (phosphatidylethanolamines (PEs)) and is specific toward two fatty acyls-arachidonoyl (AA) and adrenoyl (AdA). Suppression of AA or AdA esterification into PE by genetic or pharmacological inhibition of acyl-CoA synthase 4 (ACSL4) acts as a specific antiferroptotic rescue pathway. Lipoxygenase (LOX) generates doubly and triply-oxygenated (15-hydroperoxy)-diacylated PE species, which act as death signals, and tocopherols and tocotrienols (vitamin E) suppress LOX and protect against ferroptosis, suggesting a homeostatic physiological role for vitamin E. This oxidative PE death pathway may also represent a target for drug discovery.

Prognosis and Outcomes of Patients With Community-Acquired Pneumonia: A Meta-analysis

Abstract: Objective. —To systematically review the medical literature on the prognosis and outcomes of patients with community-acquired pneumonia (CAP). Data Sources. —A MEDLINE literature search of English-language articles involving human subjects and manual reviews of article bibliographies were used to identify studies of prognosis in CAP. Study Selection. —Review of 4573 citations revealed 122 articles (127 unique study cohorts) that reported medical outcomes in adults with CAP. Data Extraction. —Qualitative assessments of studies' patient populations, designs, and patient outcomes were performed. Summary univariate odds ratios (ORs) and rate differences (RDs) and their associated 95% confidence intervals (Cls) were computed to estimate a summary effect size for the association of prognostic factors and mortality. Data Synthesis. —The overall mortality for the 33148 patients in all 127 study cohorts was 13.7%, ranging from 5.1% for the 2097 hospitalized and ambulatory patients (in six study cohorts) to 36.5% for the 788 intensive care unit patients (in 13 cohorts). Mortality varied by pneumonia etiology, ranging from less than 2% to greater than 30%. Eleven prognostic factors were significantly associated with mortality using both summary ORs and RDs: male sex (OR=1.3; 95% Cl, 1.2 to 1.4), pleuritic chest pain (OR=0.5; 95% Cl, 0.3 to 0.8), hypothermia (OR=5.0; 95% Cl, 2.4 to 10.4), systolic hypotension (OR=4.8; 95% Cl, 2.8 to 8.3), tachypnea (OR=2.9; 95% Cl, 1.7 to 4.9), diabetes mellitus (OR=1.3; 95% Cl, 1.1 to 1.5), neoplastic disease (OR=2.8; 95% Cl, 2.4 to 3.1), neurologic disease (OR=4.6; 95% Cl, 2.3 to 8.9), bacteremia (OR=2.8; 95% Cl, 2.3 to 3.6), leukopenia (OR=2.5; 95% Cl, 1.6 to 3.7), and multilobar radiographic pulmonary infiltrate (OR=3.1; 95% Cl, 1.9 to 5.1). Assessments of other clinically relevant medical outcomes such as morbid complications (41 cohorts), symptoms resolution (seven cohorts), return to work or usual activities (five cohorts), or functional status (one cohort) were infrequently performed. Conclusions. —Mortality for patients hospitalized with CAP was high and was associated with characteristics of the study cohort, pneumonia etiology, and a variety of prognostic factors. Generalization of these findings to all patients with CAP should be made with caution because of insufficient published information on medical outcomes other than mortality in ambulatory patients. ( JAMA . 1995;274:134-141)