Acute myeloid leukemia (AML) induces bone marrow (BM) failure in patients, predisposing them to life-threatening infections and bleeding. The mechanism by which AML mediates this complication is unknown but one widely accepted explanation is that AML depletes the BM of hematopoietic stem cells (HSCs) through displacement. We sought to investigate how AML affects hematopoiesis by quantifying residual normal hematopoietic subpopulations in the BM of immunodeficient mice transplanted with human AML cells with a range of genetic lesions. The numbers of normal mouse HSCs were preserved whereas normal progenitors and other downstream hematopoietic cells were reduced following transplantation of primary AMLs, findings consistent with a differentiation block at the HSC-progenitor transition, rather than displacement. Once removed from the leukemic environment, residual normal hematopoietic cells differentiated normally and outcompeted steady-state hematopoietic cells, indicating that this effect is reversible. We confirmed the clinical significance of this by ex vivo analysis of normal hematopoietic subpopulations from BM of 16 patients with AML. This analysis demonstrated that the numbers of normal CD34 + CD38− stem-progenitor cells were similar in the BM of AML patients and controls, whereas normal CD34 + CD38+ progenitors were reduced. Residual normal CD34+ cells from patients with AML were enriched in long-term culture, initiating cells and repopulating cells compared with controls. In conclusion the data do not support the idea that BM failure in AML is due to HSC depletion. Rather, AML inhibits production of downstream hematopoietic cells by impeding differentiation at the HSC-progenitor transition.ematopoiesis is tightly regulated under normal circumstances to ensure adequate production of mature blood cells. At steady state hematopoietic stem cells (HSCs) are relatively quiescent and the majority of proliferation occurs downstream of HSCs. Hematopoietic stresses such as bleeding or bone marrow (BM) damage from chemotherapy induce HSCs to enter the cell cycle to replenish mature blood cells (1-3).BM failure (reduced production of neutrophils, red cells, and platelets) is almost universal at diagnosis of acute myeloid leukemia (AML) and contributes significantly to morbidity and mortality by inducing severe infections and bleeding. These complications often compromise the delivery of intensive chemotherapy and lead to a high frequency of induction death (4).A common assumption is that marrow failure occurs due to displacement of normal hematopoietic cells from the marrow by AML cells, resulting in depletion of normal hematopoietic cells. However, AML has a more profound impact on BM function than many other types of hematologic malignancy (e.g., chronic lymphocytic leukemia, follicular lymphoma) even where there is a similar degree of diffuse infiltration of BM by leukemia/ lymphoma cells.To clarify how AML suppresses normal hematopoiesis, we investigated the impact of AML on residual normal hematopoietic subpopul...

Background: There is uncertainty in deferred active treatment (DAT) programmes, regarding patient selection, follow-up and monitoring, reclassification, and which outcome measures should be prioritised. Objective: To develop consensus statements for all domains of DAT. Design, setting, and participants: A protocol-driven, three phase study was undertaken by the European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy and Oncology (ESTRO)-European Association of Urology Section of Urological Research (ESUR)-International Society of Geriatric Oncology (SIOG) Prostate Cancer Guideline Panel in conjunction with partner organisations, including the following: (1) a systematic review to describe heterogeneity across all domains; (2) a two-round Delphi survey involving a large, international panel of stakeholders, including healthcare practitioners (HCPs) and patients; and (3) a consensus group meeting attended by stakeholder group representatives. Robust methods regarding what constituted the consensus were strictly followed. Results and limitations: A total of 109 HCPs and 16 patients completed both survey rounds. Of 129 statements in the survey, consensus was achieved in 66 (51%); the rest of the statements were discussed and voted on in the consensus meeting by 32 HCPs and three patients, where consensus was achieved in additional 27 statements (43%). Overall, 93 statements (72%) achieved consensus in the project. Some uncertainties remained regarding clinically important thresholds for disease extent on biopsy in low-risk disease, and the role of multiparametric magnetic resonance imaging in determining disease stage and aggressiveness as a criterion for inclusion and exclusion. Conclusions: Consensus statements and the findings are expected to guide and inform routine clinical practice and research, until higher levels of evidence emerge through prospective comparative studies and clinical trials. Patient summary: We undertook a project aimed at standardising the elements of practice in active surveillance programmes for early localised prostate cancer because currently there is great variation and uncertainty regarding how best to conduct them. The project involved large numbers of healthcare practitioners and patients using a survey and face-to-face meeting, in order to achieve agreement (ie, consensus) regarding best practice, which will provide guidance to clinicians and researchers.

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Aim Low anterior resection syndrome (LARS) is pragmatically defined as disordered bowel function after rectal resection leading to a detriment in quality of life. This broad characterization does not allow for precise estimates of prevalence. The LARS score was designed as a simple tool for clinical evaluation of LARS. Although the LARS score has good clinical utility, it may not capture all important aspects that patients may experience. The aim of this collaboration was to develop an international consensus definition of LARS that encompasses all aspects of the condition and is informed by all stakeholders. Method This international patient–provider initiative used an online Delphi survey, regional patient consultation meetings, and an international consensus meeting. Three expert groups participated: patients, surgeons and other health professionals from five regions (Australasia, Denmark, Spain, Great Britain and Ireland, and North America) and in three languages (English, Spanish, and Danish). The primary outcome measured was the priorities for the definition of LARS. Results Three hundred twenty‐five participants (156 patients) registered. The response rates for successive rounds of the Delphi survey were 86%, 96% and 99%. Eighteen priorities emerged from the Delphi survey. Patient consultation and consensus meetings refined these priorities to eight symptoms and eight consequences that capture essential aspects of the syndrome. Sampling bias may have been present, in particular, in the patient panel because social media was used extensively in recruitment. There was also dominance of the surgical panel at the final consensus meeting despite attempts to mitigate this. Conclusion This is the first definition of LARS developed with direct input from a large international patient panel. The involvement of patients in all phases has ensured that the definition presented encompasses the vital aspects of the patient experience of LARS. The novel separation of symptoms and consequences may enable greater sensitivity to detect changes in LARS over time and with intervention.

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Allogeneic hematopoietic stem-cell transplantation can cure some patients with high-risk B-cell malignancies, but disease relapse following transplantation remains a significant problem. One approach that could be used to augment the donor T-cell-mediated antitumor effect is the infusion of allogeneic donor-derived T cells expressing a chimeric antibody receptor (CAR) specific to the B-cell antigen CD19. However, the use of such cells might result in toxicity in the form of graft-versus-host disease mediated by CD19-specific (CD19-CAR) T cells possessing alloreactive endogenous T-cell receptors. We therefore investigated whether nonalloreactive tumor-specific human T cells could be generated from peripheral blood mononuclear cells of healthy donors by the combination of CD19 redirection via CAR expression and subsequent alloanergization by allostimulation and concomitant blockade of CD28-mediated costimulation. Alloanergization of CD19-CAR T cells resulted in efficient and selective reduction of alloresponses in both CD4 + and CD8 + T cells, including allospecific proliferation and cytokine secretion. Importantly, T-cell effector functions including CARdependent proliferation and specific target cytolysis and cytokine production were retained after alloanergization. Our data support the application of CD19 redirection and subsequent alloanergization to generate allogeneic donor T cells for clinical use possessing increased antitumor activity but limited capacity to mediate graft-versus-host disease. Immunotherapy with such cells could potentially reduce disease relapse after allogeneic transplantation without increasing toxicity, thereby improving the outcome of patients undergoing allogeneic transplantation for high-risk B-cell malignancies. Cancer Res; 70(10); 3915-24. ©2010 AACR.

Diurnal sampling of a transect across a shallow, eutrophic gravel pit suggested that a diurnal horizontal migration was present in Daphnia hyalina lacustris, in which it remained in the littoral zone during the day and moved out into the open water at night. The avoidance of fish predation seemed the most likely ultimate cause of this migration.

Ex vivo alloanergization of human immune cells, via allostimulation in the presence of costimulatory blockade with either a combination of anti-B7.1 and anti-B7.2 antibodies or first-generation cytotoxic T-lymphocyte antigen 4-immunoglobulin (CTLA4-Ig), induces alloantigen-specific hyporesponsiveness and expands alloantigen-specific regulatory T cells (Treg). We have successfully used this approach in the clinical setting of haploidentical hematopoietic stem cell transplantation. Recently, the in vivo use of a new second-generation CTLA4-Ig, belatacept, has shown promise in controlling alloresponses after transplantation of both human kidneys and islet cells. We therefore compared the efficiency of first- and second-generation CTLA4-Ig in alloanergizing human peripheral blood mononuclear cells (PBMCs) and investigated whether ex vivo alloanergization with belatacept could be used to engineer an alloantigen-specific immunoregulatory population of autologous cells suitable for administration to recipients of cellular or solid organ transplant recipients. Alloanergization of HLA-mismatched human PBMCs with belatacept resulted in a greater reduction in subsequent alloresponses than alloanergization with first generation CTLA4-Ig. Moreover, subsequent ex vivo re-exposure of alloanergized cells to alloantigen in the absence of belatacept resulted in a significant expansion of Tregs with enhanced alloantigen-specific suppressive function. Alloanergized PBMCs retained functional Epstein-Barr virus (EBV)-specific T-cell responses, and expanded Tregs did not suppress EBV-specific proliferation of autologous cells. These results suggest that ex vivo alloanergization with belatacept provides a platform to engineer populations of recipient Treg with specificity for donor alloantigens but without nonspecific suppressive capacity. The potential advantages of such cells for solid organ transplantation include (1) reduction of the need for nonspecific immunosuppression, (2) retention of pathogen-specific immunity, and (3) control of graft rejection, if used as an intervention.