Duquesne University

About: Duquesne University is a education organization based out in Pittsburgh, Pennsylvania, United States. It is known for research contribution in the topics: Population & Health care. The organization has 3615 authors who have published 7169 publications receiving 180066 citations. The organization is also known as: Duquesne University of the Holy Spirit.

Interleukin-4 Is Essential for Microglia/Macrophage M2 Polarization and Long-Term Recovery After Cerebral Ischemia

Abstract: Background and Purpose— Interleukin-4 (IL-4) is a unique cytokine that may contribute to brain repair by regulating microglia/macrophage functions. Thus, we examined the effect of IL-4 on long-term recovery and microglia/macrophage polarization in 2 well-established stroke models. Methods— Transient middle cerebral artery occlusion or permanent distal middle cerebral artery occlusion was induced in wild-type and IL-4 knockout C57/BL6 mice. In a separate cohort of wild-type animals, IL-4 (60 ng/d for 7 days) or vehicle was infused into the cerebroventricle after transient middle cerebral artery occlusion. Behavioral outcomes were assessed by the Rotarod, corner, foot fault, and Morris water maze tests. Neuronal tissue loss was verified by 2 independent neuron markers. Markers of classically activated (M1) and alternatively activated (M2) microglia were assessed by real-time polymerase chain reaction, immunofluorescence, and flow cytometry. Results— Loss of IL-4 exacerbated sensorimotor deficits and impaired cognitive functions ≤21 days post injury. In contrast to the delayed deterioration of neurological functions, IL-4 deficiency increased neuronal tissue loss only in the acute phase (5 days) after stroke and had no impact on neuronal tissue loss 14 or 21 days post injury. Loss of IL-4 promoted expression of M1 microglia/macrophage markers and impaired expression of M2 markers at 5 and 14 days post injury. Administration of IL-4 into the ischemic brain also enhanced long-term functional recovery. Conclusions— The cytokine IL-4 improves long-term neurological outcomes after stroke, perhaps through M2 phenotype induction in microglia/macrophages. These results are the first to suggest that immunomodulation with IL-4 is a promising approach to promote long-term functional recovery after stroke.

Evidence of validity for the hip outcome score in hip arthroscopy.

Abstract: Purpose: The purpose of this study was to provide evidence of validity for the Hip Outcome Score (HOS) as an outcome instrument in hip arthroscopy. Methods: We mailed the short form 36 (SF-36) and HOS questionnaires, as well as questionnaires regarding self-reported current activity level (normal, nearly normal, abnormal, or severely abnormal) and self-reported surgical outcome (excellent/good or fair/poor), to 337 subjects. Medical records were used to collect surgical and demographic information. Two groups were formed for those above and below the median age. Pearson correlation coefficients were used to assess the relation between the SF-36 scores and HOS scores. One-way analysis of variance was used to determine whether HOS scores differed according to current level of function, surgical outcome, and age. Results: Of the subjects, 116 (34%) returned the questionnaire material. Nine of these subjects reported having surgery after August 2003 and were excluded. The data analysis was therefore performed on 107 subjects (32%). Within this group, there were 56 female patients (52%) and 51 male patients (48%), with a mean age of 42 years (median, 44.2 years; range, 14 to 79 years; SD, 14) and mean time to follow-up of 3.1 years (range, 2 to 4.6 years; SD, 0.49). The HOS activities of daily living (ADL) and sports subscales had a high correlation to the SF-36 physical function subscale ( r = 0.86 and r = 0.84, respectively) and physical component summary score ( r = 0.80 and r = 0.81, respectively) and a significantly ( P r = 0.41 and r = 0.43, respectively) and mental component summary score ( r = 0.17 and r = 0.18, respectively). HOS ADL and sports subscale scores were significantly different based on current activity level, surgical outcome, and age ( P Conclusions: This study provides evidence of validity for the HOS in a sample of subjects at a mean of 3 years after hip arthroscopy. As hypothesized, the HOS scores had a high correlation to measures of physical function and a low correlation to measures of mental health. The HOS scores were different based on subjects' reported current activity level, reported surgical outcome, and age. The results of this study support the use of the HOS ADL and sports subscales as a self-report outcome instrument for hip arthroscopy. Level of Evidence: Level III, development of diagnostic criteria in a study of nonconsecutive patients.

Dual role of mitochondria in producing melatonin and driving GPCR signaling to block cytochrome c release

Abstract: G protein-coupled receptors (GPCRs) are classically characterized as cell-surface receptors transmitting extracellular signals into cells. Here we show that central components of a GPCR signaling system comprised of the melatonin type 1 receptor (MT1), its associated G protein, and β-arrestins are on and within neuronal mitochondria. We discovered that the ligand melatonin is exclusively synthesized in the mitochondrial matrix and released by the organelle activating the mitochondrial MT1 signal-transduction pathway inhibiting stress-mediated cytochrome c release and caspase activation. These findings coupled with our observation that mitochondrial MT1 overexpression reduces ischemic brain injury in mice delineate a mitochondrial GPCR mechanism contributing to the neuroprotective action of melatonin. We propose a new term, "automitocrine," analogous to "autocrine" when a similar phenomenon occurs at the cellular level, to describe this unexpected intracellular organelle ligand-receptor pathway that opens a new research avenue investigating mitochondrial GPCR biology.

From Groundnuts to Globalization: A Structural Estimate of Trade and Growth

Abstract: Starting with Romer [1987] and Rivera-Batiz-Romer [1991] economists have been able to model how trade enhances growth through the creation and import of new varieties. In this framework, international trade increases economic output through two channels. First, trade raises productivity levels because producers gain access to new imported varieties. Second, increases in the number of varieties drives down the cost of innovation and results in ever more variety creation. Using highly disaggregate trade data, e.g. Gabon's imports of Gambian groundnuts, we structurally estimate the impact that new imports have had in approximately 4000 markets per country. We then move from groundnuts to globalization by building an exact TFP index that aggregates these micro gains to obtain an estimate of trade on productivity growth for each country. We find that in the typical country in the world, new imported varieties account for 15 percent of its productivity growth. These effects are larger in developing countries where the median impact of new imported varieties equals a quarter of national productivity growth.