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International audience; Acute Graft-Versus-Host Disease (aGVHD), mediated by CD4(+) and CD8(+) effector T cells, is a life-threatening complication in hematopoietic stem cell (HSC) transplantation. Naturally-occurring CD4(+)CD25(hi)(Foxp3(+)) regulatory T cells (T(reg)) have been shown to modulate tolerance to aGVHD in murine graft models. In this report, we investigated their role in the prevention of aGVHD in patients transplanted with bone-marrow-derived HSC. When CD4(+)CD25(hi)Foxp3(+) T cells were isolated from bone-marrow grafts, they showed no suppressive activity. The analysis of their function in patients suffering from aGVHD after transplantation revealed a gain of suppressive activity indicating their inability to control the aGVHD induction. Thus, our findings clearly demonstrate that CD4(+)CD25(+) and CD4(+)CD25(hi)Foxp3(+) T cells, when administered in steady-state physiological conditions, do not influence the outcome of aGVHD after bone-marrow transplantation.

This research tested a structural equation model of educational outcomes for three socioeconomic status (SES) groups of African American students enrolled in a community college. The structural model, which was based on a variant of Tinto's (1987) model, contained two exogenous constructs, educational intentions/commitment and external commitments, and three endogenous constructs, academic integration, social integration, and educational outcomes. The study demonstrated that higher levels of academic and social engagement had positive direct effects on educational outcomes for all students regardless of SES background. Other paths that were supported included the positive direct effects of educational intentions/commitment on academic and social integration and the negative impact of external commitments on social integration. Significant structural differences were not present in the measurement of model constructs or the process of educational outcomes among lowest, lower to middle, and middle to upper ...

The primary purpose of this study was to explore the differential persistence impact of the components of the Tinto model, preentry characteristics, initial goals and commitments, integration, subsequent goals and commitments, and external commitments, to the process of younger and older student persistence. The sample (N=449) included first-time students enrolled full- or part-time at a large, urban community college. The study design was longitudinal with questionnaire data gathered at the beginning and end of the spring 1989 semester. Persistence was measured from the spring to the following fall semester. Discriminant function analysis was used to study multivariate differences between short-term persisters and nonpersisters. Younger (17 to 24 years) and older (25+ years) student data were analyzed separately. Findings indicated (1) integration was more important to the persistence of younger students than it was for the older cohort; (2) self-assessed study skills were the most important discriminator for older students; (3) student perceptions of cognitive and personal development were important to persistence in both groups; and (4) goal commitment was important to the persistence of both age groups.

SummaryHaematopoietic stem cell transplantation is often complicated by the life-threatening graft-versus-host disease (GVHD) which consists of an allogeneic reaction of the graft cells against the host organs. The aim of this study was to investigate the putative involvement of soluble human leucocyte antigen (sHLA) class I molecules, and particularly sHLA-G molecules, in the occurrence and/or prevention of acute GVHD (aGVHD) in allogeneic peripheral blood stem cell (PSC) transplantation. Whole sHLA class I molecules seem to be involved in aGVHD pathogenesis because detection of a high concentration of these molecules in the first month post allograft is correlated with aGVHD occurrence. Conversely, a high level of sHLA-G molecules before and after allograft could indicate good prognosis in PSC allograft transplantation. sHLA-G molecules seem to be involved in aGVHD prevention, not only because they are enriched in plasma of patients without aGVHD, but also because: (i) a positive correlation has been found between sHLA-G level and CD4+ CD25+ CD152+ natural regulatory T cell (Treg) frequency in the blood of transplanted patients; and (ii) the presence of CD4+ CD25+ CD152+ natural Treg is correlated with increased sHLA-G expression in in vitro mixed leucocyte reaction cultures. Altogether, these results support the immunomodulatory function of sHLA-G molecules that might create a regulatory network together with the natural Treg to foster the induction of a tolerogenic environment and improve PSC transplantation favourable outcome.

Patients who require oral anticoagulation usually receive warfarin. We used an indanedione drug, anisindione, in two patients who were intolerant of warfarin but who needed long-term oral anticoagulation. The use of this alternative oral anticoagulant is reviewed. © 1994 Wiley-Liss, Inc.

Although unfractionated heparin (UFH) is standard therapy for venous thromboembolism, there is a clinical failure rate of up to 10%. Newer treatment strategies include low-molecular-weight heparins (LMWH). As part of an international study comparing the efficacy and safety of enoxaparin, a LMWH versus UFH in patients with venous thromboembolism, we studied the effects of enoxaparin and UFH on the plasma concentrations of two activation peptides, fragment 1 + 2 (F1 + 2), and thrombin-antithrombin III (TAT) complexes. We hypothesized that enoxaparin would be more effective in suppressing activation of coagulation. Intravenous heparin was given by bolus injection followed by infusion. There were 2 enoxaparin treatment groups (1 mg/kg s.c., bid and 1.5 mg/kg s.c. daily). Plasma samples were obtained from 11 patients in the enoxaparin group and 6 patients in the heparin group prior to and at 6 hour intervals after initiating therapy. Clinical characteristics of the enoxaparin and UFH patient groups were similar. TAT concentrations were not statistically different between groups at any treatment interval. However, plasma F1 + 2 concentrations differed significantly (p < 0.05); concentrations in the enoxaparin group were consistently lower over time than in the UFH group. These results suggest that this LMWH is more effective in suppressing ongoing thrombosis in vivo than UFH in patients with venous thrombosis.

This Artificial Intelligence program, combined with a computerized data base, comprises an expert system for the selection/development of wire enamels and other electrical insulating materials. This program could be an indispensable tool and aid for the scientist, freeing him from the necessity of redundant experimentation, due to the vast network of information sharing and the system's ability to suggest promising pathways. This artificial intelligence approach would provide the scientist with sophisticated modeling and complex interactive simulation of chemical reactions and physical properties of potentially useful materials, which would be exceptionally rapid, efficient and cost-effective. Modeling of materials through techniques of artificial intelligence differs from prior computer modeling by creating a unique, accurate conceptual representation of a specific material, as opposed to statistical and purely numerical methods.