Search

• Energy Conversion System to compensate for reactivity loss due to fuel burn-up. • Determination of the contribution of an ECS to the reactor core control. • KGH steady-state method for evaluating the core power evolution. This study focuses on an Energy Conversion System (ECS) designed to fully compensate the reactivity swing during reactor operation. A methodology is proposed to assess the contribution of the ECS to the core reactivity and to propose a core with produced power uniquely driven by the control of the ECS. The aim is to control the core inlet and mean temperatures in order to take advantage of reactivity feedbacks in the core. PWR and SFR cores, connected to Rankine and Brayton cycles, are analysed. A static method is proposed to take into account the reactivity feedback effects on the core and the CYCLOP code (a software package developed by CEA) is used to model the Energy Conversion Cycles. The conclusion proposes a control of the ECS and the associated cycle efficiency to compensate the reactivity loss and to drive the reactor produced power. [ABSTRACT FROM AUTHOR]

• This Phase II study evaluated the tolerability and safety of a clofarabine and treosulfan conditioning regimen before allogeneic hematopoietic stem cell transplantation. • We found a low incidence of severe hepatic toxicities such as veno-occlusive disease. • Disease relapse represent a major issue, mainly for patients with poor prognostic risk factors. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be curative for patients with hematologic malignancies. The ideal conditioning regimen before allo-HSCT has not been established. We conducted a Phase II study to evaluate the tolerability and efficacy of clofarabine and treosulfan as conditioning regimen before allo-HSCT. The primary objective was to evaluate the cumulative incidence of nonrelapse mortality (NRM) on day +100. Forty-four patients (36 with acute myelogenous leukemia, 5 with acute lymphoblastic leukemia, 3 with myelodysplastic syndromes) were enrolled. The median patient age was 47 years, and the median duration of follow-up was 27 months. The conditioning regimen was based on clofarabine 40 mg/m2 (days -6 to -2) and treosulfan 14 g/m2 (days -6 to -4). Allogeneic hematopoietic stem cells were derived from a sibling (n = 22) or a well-matched unrelated donor (n = 22). Graft-versus-host disease (GVHD) prophylaxis consisted of antithymocyte globulin, rituximab, cyclosporine, and a short-course of methotrexate. The regimen allowed for rapid engraftment and a 100-day NRM of 18%, due mainly to bacterial infections. The incidences of grade II-IV acute GVHD and chronic GVHD were 16% and 19%, respectively. The rates of overall survival (OS), progression-free survival, and relapse at 2 years were 51%, 31%, and 50%, respectively. Significantly different outcomes were observed between patients with low-intermediate and patients with high-very high Disease Risk Index (DRI) scores (1-year OS, 78% and 24%, respectively). Our findings show that the use of treosulfan and clofarabine as a conditioning regimen for allo-HSCT is feasible, with a 78% 1-year OS in patients with a low-intermediate DRI score. However, 1-year NRM was 18%, and despite the intensified conditioning regimen, relapse incidence remains a major issue in patients with poor prognostic risk factors. [ABSTRACT FROM AUTHOR]

Background: Extracorporeal photopheresis (ECP) is a recognized second-line treatment for steroid-refractory chronic graft-versus-host disease (cGVHD). Treatment course is usually long, expensive, and demanding for patients, so predictors for response are needed. We carried out a retrospective study on cGVHD patients treated at our institution with the aim to identify a possible correlation between apheretic yields composition and probability of response.Study Design: Patients treated for at least 6 months were eligible for the study. Flow cytometry data, including absolute counts of lymphocytes and their subpopulations in ECP products from cGVHD patients, were collected. For each cell population 1) the median dose per procedure harvested during the first 3 months of treatment and 2) the cumulative dose collected in the same period were compared with clinical response.Results: A total of 726 ECP procedures were performed in 15 patients. Overall response, defined as either a complete response (CR) or a partial response according to National Institutes of Health criteria, was obtained in 10 of 15 patients (66.7%), and CR, in eight of 15 (53.3%). According to Cox regression analysis, the probability of achieving an overall response is significantly correlated with the median number of CD3+, CD3+CD4+, and CD3+CD8+ lymphocytes collected during the early treatment phase (first 3 months).Conclusion: Our data suggest that CD3+ cell evaluation in ECP during the early phase of treatment course could predict response and help identify patients who deserve further treatment. [ABSTRACT FROM AUTHOR]

Background: Transplantation of hematopoietic stem cells from partially matched family donors is a promising therapy for patients who have a hematologic cancer and are at high risk for relapse. The donor T-cell infusions associated with such transplantation can promote post-transplantation immune reconstitution and control residual disease. Methods: We identified 43 patients who underwent haploidentical transplantation and infusion of donor T cells for acute myeloid leukemia or myelodysplastic syndrome and conducted post-transplantation studies that included morphologic examination of bone marrow, assessment of hematopoietic chimerism with the use of short-tandem-repeat amplification, and HLA typing. The genomic rearrangements in mutant variants of leukemia were studied with the use of genomic HLA typing, microsatellite mapping, and single-nucleotide–polymorphism arrays. The post-transplantation immune responses against the original cells and the mutated leukemic cells were analyzed with the use of mixed lymphocyte cultures. Results: In 5 of 17 patients with leukemia relapse after haploidentical transplantation and infusion of donor T cells, we identified mutant variants of the original leukemic cells. In the mutant leukemic cells, the HLA haplotype that differed from the donor's haplotype had been lost because of acquired uniparental disomy of chromosome 6p. T cells from the donor and the patient after transplantation did not recognize the mutant leukemic cells, whereas the original leukemic cells taken at the time of diagnosis were efficiently recognized and killed. Conclusions: After transplantation of haploidentical hematopoietic stem cells and infusion of donor T cells, leukemic cells can escape from the donor's antileukemic T cells through the loss of the mismatched HLA haplotype. This event leads to relapse. N Engl J Med 2009;361:478-88. [ABSTRACT FROM AUTHOR]