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.

Reducing Suicidal Ideation and Depressive Symptoms in Depressed Older Primary Care Patients: A Randomized Controlled Trial

Abstract: ContextSuicide rates are highest in late life; the majority of older adults who die by suicide have seen a primary care physician in preceding months. Depression is the strongest risk factor for late-life suicide and for suicide's precursor, suicidal ideation.ObjectiveTo determine the effect of a primary care intervention on suicidal ideation and depression in older patients.Design and SettingRandomized controlled trial known as PROSPECT (Prevention of Suicide in Primary Care Elderly: Collaborative Trial) with patient recruitment from 20 primary care practices in New York City, Philadelphia, and Pittsburgh regions, May 1999 through August 2001.ParticipantsTwo-stage, age-stratified (60-74, ≥75 years) depression screening of randomly sampled patients; enrollment included patients who screened positive and a random sample of screened negative patients. This analysis included patients with a depression diagnosis (N = 598).InterventionTreatment guidelines tailored for the elderly with care management compared with usual care.Main Outcome MeasuresAssessment of suicidal ideation and depression severity at baseline, 4 months, 8 months, and 12 months.ResultsRates of suicidal ideation declined faster (P = .01) in intervention patients compared with usual care patients; at 4 months, in the intervention group, raw rates of suicidal ideation declined 12.9% points (29.4% to 16.5%) compared with 3.0% points (20.1% to 17.1% in usual care [P = .01]). Among patients reporting suicidal ideation, resolution of ideation was faster among intervention patients (P = .03); differences peaked at 8 months (70.7% vs 43.9% resolution; P = .005). Intervention patients had a more favorable course of depression in both degree and speed of symptom reduction; group difference peaked at 4 months. The effects on depression were not significant among patients with minor depression unless suicidal ideation was present.ConclusionsEvidence of the intervention's effectiveness in community-based primary care with a heterogeneous sample of depressed patients introduces new challenges related to its sustainability and dissemination. The intervention's effectiveness in reducing suicidal ideation, regardless of depression severity, reinforces its role as a prevention strategy to reduce risk factors for suicide in late life.

Oxaliplatin Combined With Weekly Bolus Fluorouracil and Leucovorin As Surgical Adjuvant Chemotherapy for Stage II and III Colon Cancer: Results From NSABP C-07

Abstract: Purpose This phase III clinical trial evaluated the impact on disease-free survival (DFS) of adding oxaliplatin to bolus weekly fluorouracil (FU) combined with leucovorin as surgical adjuvant therapy for stage II and III colon cancer. Patients and Methods Patients who had undergone a potentially curative resection were randomly assigned to either FU 500 mg/m2 intravenous (IV) bolus weekly for 6 weeks plus leucovorin 500 mg/m2 IV weekly for 6 weeks during each 8-week cycle for three cycles (FULV), or the same FULV regimen with oxaliplatin 85 mg/m2 IV administered on weeks 1, 3, and 5 of each 8-week cycle for three cycles (FLOX). Results A total of 2,407 patients (96.6%) of the 2,492 patients randomly assigned were eligible. Median follow-up for patients still alive is 42.5 months. The hazard ratio (FLOX v FULV) is 0.80 (95% CI, 0.69 to 0.93), a 20% risk reduction in favor of FLOX (P < .004). The 3- and 4-year disease-free survival (DFS) rates were 71.8% and 67.0% for FULV and 76.1% and 73.2% for FLOX, resp...

A durable and energy efficient main memory using phase change memory technology

Abstract: Using nonvolatile memories in memory hierarchy has been investigated to reduce its energy consumption because nonvolatile memories consume zero leakage power in memory cells One of the difficulties is, however, that the endurance of most nonvolatile memory technologies is much shorter than the conventional SRAM and DRAM technology This has limited its usage to only the low levels of a memory hierarchy, eg, disks, that is far from the CPUIn this paper, we study the use of a new type of nonvolatile memories -- the Phase Change Memory (PCM) as the main memory for a 3D stacked chip The main challenges we face are the limited PCM endurance, longer access latencies, and higher dynamic power compared to the conventional DRAM technology We propose techniques to extend the endurance of the PCM to an average of 13 (for MLC PCM cell) to 22 (for SLC PCM) years We also study the design choices of implementing PCM to achieve the best tradeoff between energy and performance Our design reduced the total energy of an already low-power DRAM main memory of the same capacity by 65%, and energy-delay2 product by 60% These results indicate that it is feasible to use PCM technology in place of DRAM in the main memory for better energy efficiency

A benchmark study on the thermal conductivity of nanofluids

Abstract: This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or “nanofluids,” was measured by over 30 organizations worldwide, using a variety of experimental approaches, including the transient hot wire method, steady-state methods, and optical methods. The nanofluids tested in the exercise were comprised of aqueous and nonaqueous basefluids, metal and metal oxide particles, near-spherical and elongated particles, at low and high particle concentrations. The data analysis reveals that the data from most organizations lie within a relatively narrow band (±10% or less) about the sample average with only few outliers. The thermal conductivity of the nanofluids was found to increase with particle concentration and aspect ratio, as expected from classical theory. There are (small) systematic differences in the absolute values of the nanofluid thermal conductivity among the various experimental approaches; however, such differences tend to disappear when the data are normalized to the measured thermal conductivity of the basefluid. The effective medium theory developed for dispersed particles by Maxwell in 1881 and recently generalized by Nan et al. [J. Appl. Phys. 81, 6692 (1997)], was found to be in good agreement with the experimental data, suggesting that no anomalous enhancement of thermal conductivity was achieved in the nanofluids tested in this exercise.

Therapy of murine tumors with tumor peptide-pulsed dendritic cells: dependence on T cells, B7 costimulation, and T helper cell 1-associated cytokines.

Abstract: Antigen presentation by host dendritic cells (DC) is critical for the initiation of adaptive immune responses. We have previously demonstrated in immunogenic murine tumor models that bone marrow (BM)-derived DC pulsed ex vivo with synthetic tumor-associated peptides, naturally expressed by tumor cells, serve as effective antitumor vaccines, protecting animals against an otherwise lethal tumor challenge (Mayordomo, J.I., T. Zorina, W.J. Storkus, C. Celluzzi, L.D. Falo, C.J. Melief, T. Ildstad, W.M. Kast, A.B. DeLeo, and M.T. Lotze. 1995. Nature Med. 1:1297-1302). However, T cell-defined epitopes have not been identified for most human cancers. To explore the utility of this approach in the treatment of tumors expressing as yet uncharacterized epitopes, syngeneic granulocyte/macrophage colony-stimulating factor-stimulated and BM-derived DC, pulsed with unfractionated acid-eluted tumor peptides (Storkus, W.J., H.J. Zeh III, R.D. Salter, and M.T. Lotze. 1993. J. Immunother. 14:94-103) were used to treat mice bearing spontaneous, established tumors. The adoptive transfer of 5 x 10(5) tumor peptide-pulsed DC dramatically suppressed the growth of weakly immunogenic tumors in day 4 to day 8 established MCA205 (H-2b) and TS/A (H-2d) tumor models, when applied in three biweekly intravenous injections. Using the immunogenic C3 (H-2b) tumor model in B6 mice, tumor peptide-pulsed DC therapy resulted in the erradication of established d14 tumors and long-term survival in 100% of treated animals. The DC-driven antitumor immune response was primarily cell mediated since the transfer of spleen cells, but not sera, from immunized mice efficiently protected sublethally irradiated naive mice against a subsequent tumor challenge. Furthermore, depletion of either CD4+ or CD8+ T cells from tumor-bearing mice before therapy totally suppressed the therapeutic efficacy of DC pulsed with tumor-derived peptides. Costimulation of the host cell-mediated antitumor immunity was critical since inoculation of the chimeric fusion protein CTLA4-Ig virtually abrogated the therapeutic effects of peptide-pulsed DC in vivo. The analysis of the cytokine pattern in the draining lymph nodes and spleens of tumor-bearing mice immunized with DC pulsed with tumor-eluted peptides revealed a marked upregulation of interleukin (IL) 4 and interferon (IFN) gamma production, as compared with mice immunized with DC alone or DC pulsed with irrelevant peptides. DC-induced antitumor effects were completely blocked by coadministration of neutralizing monoclonal antibody directed against T helper cell 1-associated cytokines (such as IL-12, tumor necrosis factor alpha, IFN-gamma), and eventually, but not initially, blocked by anti-mIL-4 mAb. Based on these results, we believe that DC pulsed with acid-eluted peptides derived from autologous tumors represents a novel approach to the treatment of established, weakly immunogenic tumors, and serves as a basis for designing clinical trials in cancer patients.