174 resultados para Graft Rejection

em Queensland University of Technology - ePrints Archive


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Objectives: To describe longitudinal height, weight, and body mass index changes up to 15 years after childhood liver transplantation. Study design: Retrospective chart review of patients who underwent liver transplant from 1985-2004 was performed. Subjects were age <18 years at transplant, survived ≥5 years, with at least 2 recorded measurements, of which one was ≥5 years post-transplant. Measurements were recorded pre-transplant, 1, 5, 10, and 15 years later. Results: Height and weight data were available in 98 and 104 patients, respectively; 47% were age <2 years at transplant; 58% were Australian, and the rest were from Japan. Height recovery continued for at least 10 years to reach the 26th percentile (Z-score -0.67) 15 years after transplant. Australians had better growth recovery and attained 47th percentile (Z-score -0.06) at 15 years. Weight recovery was most marked in the first year and continued for 15 years even in well-nourished children. Growth impaired and malnourished children at transplant exhibited the best growth, but remained significantly shorter and lighter even 15 years later. No effect of sex or age at transplant was noted on height or weight recovery. Post-transplant factors significantly impact growth recovery and likely caused the dichotomous growth recovery between Australian and Japanese children; 9% (9/98) of patients were overweight on body mass index calculations at 10-15 years but none were obese. Conclusions: After liver transplant, children can expect ongoing height and weight recovery for at least 10-15 years. Growth impairment at transplant and post-transplant care significantly impact long-term growth recovery. Copyright © 2013 Mosby Inc. All rights reserved.

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Objective: To review the outcome of acute liver failure (ALF) and the effect of liver transplantation in children in Australia. Methodology: A retrospective review was conducted of all paediatric patients referred with acute liver failure between 1985 and 2000 to the Queensland Liver Transplant Service, a paediatric liver transplant centre based at the Royal Children's Hospital, Brisbane, that is one of three paediatric transplant centres in Australia. Results: Twenty-six patients were referred with ALF. Four patients did not require transplantation and recovered with medical therapy while two were excluded because of irreversible neurological changes and died. Of the 20 patients considered for transplant, three refused for social and/or religious reasons, with 17 patients listed for transplantation. One patient recovered spontaneously and one died before receiving a transplant. There were 15 transplants of which 40% (6/15) were < 2 years old. Sixty-seven per cent (10/15) survived > 1 month after transplantation. Forty per cent (6/15) survived more than 6 months after transplant. There were only four long term survivors after transplant for ALF (27%). Overall, 27% (6/22) of patients referred with ALF survived. Of the 16 patients that died, 44% (7/16) were from neurological causes. Most of these were from cerebral oedema but two patients transplanted for valproate hepatotoxicity died from neurological disease despite good graft function. Conclusions: Irreversible neurological disease remains a major cause of death in children with ALF. We recommend better patient selection and early referral and transfer to a transplant centre before onset of irreversible neurological disease to optimize outcome of children transplanted for ALF.

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Post-liver transplant cytomegalovirus (CMV) infection (seroconversion or virus isolation) and CMV disease (infection plus clinical signs and symptoms) were studied in relation to pretransplant recipient and donor serology, age, nutritional status and the effect of paediatric versus adult (reduced size) grafts. Of 70 children receiving 79 transplants, 26 (37%) had evidence of CMV infection, and eight (11.5%) had evidence of CMV disease, four of whom died. The primary infection rate (where the recipients were CMV negative) was 71% with mortality of 7% with most receiving a CMV-positive graft. The active secondary infection rate (reactivation or reinfection, where the recipients were CMV positive) was 60% with mortality of 12.5%. No significant differences in infection on disease rates were found comparing malnourished versus well-nourished patients, or between those who received whole or reduced-size grafts. The high prevalence of CMV infections supports the view that clinical signs alone are inadequate to direct investigations for CMV. Both primary and active secondary CMV infection can result in serious morbidity and mortality in children receiving liver transplants. These data do not support the strategy of providing immunoprophylaxis to seronegative recipients only, at least in paediatric liver transplantation.

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Keratinocytes expressing tumor or viral antigens can be eliminated by antigen-primed CD8 cytotoxic T cells. CD4 T-helper cells help induction of CD8 cytotoxic T cells from naive precursors and generation of CD8 T-cell memory. In this study, we show, unexpectedly, that CD4 cells are also required to assist primed CD8 effector T cells in rejection of skin expressing human growth hormone, a neo-self-antigen, in keratinocytes. The requirement for CD4 cells can be substituted by CD40 costimulation. Rejection of skin expressing ovalbumin (OVA), a non-self-antigen, by primed CD8 cytotoxic T cells can in contrast occur without help from antigen-specific CD4 T cells. However, rejection of OVA expressing keratinocytes is helped by antigen-specific CD4 T cells if only low numbers of primed or naive OVA-specific CD8 T cells are available. Effective immunotherapy directed at antigens expressed in squamous cancer may therefore be facilitated by induction of tumor antigen-specific CD4 helper T cells, as well as cytotoxic CD8 T cells.

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Adoptive T cell therapy uses the specificity of the adaptive immune system to target cancer and virally infected cells. Yet the mechanism and means by which to enhance T cell function are incompletely described, especially in the skin. In this study, we use a murine model of immunotherapy to optimize cell-mediated immunity in the skin. We show that in vitro - derived central but not effector memory-like T cells bring about rapid regression of skin-expressing cognate Ag as a transgene in keratinocytes. Local inflammation induced by the TLR7 receptor agonist imiquimod subtly yet reproducibly decreases time to skin graft rejection elicited by central but not effector memory T cells in an immunodeficient mouse model. Local CCL4, a chemokine liberated by TLR7 agonism, similarly enhances central memory T cell function. In this model, IL-2 facilitates the development in vivo of effector function from central memory but not effector memory T cells. In a model of T cell tolerogenesis, we further show that adoptively transferred central but not effector memory T cells can give rise to successful cutaneous immunity, which is dependent on a local inflammatory cue in the target tissue at the time of adoptive T cell transfer. Thus, adoptive T cell therapy efficacy can be enhanced if CD8+ T cells with a central memory T cell phenotype are transferred, and IL-2 is present with contemporaneous local inflammation. Copyright © 2012 by The American Association of Immunologists, Inc.

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Bone graft is generally considered fundamental in achieving solid fusion in scoliosis correction and pseudarthrosis following instrumentation may predispose to implant failure. In endoscopic anterior-instrumented scoliosis surgery, autologous rib or iliac crest graft has been utilised traditionally but both techniques increase operative duration and cause donor site morbidity. Allograft bone and bone- morphogenetic-protein alternatives may improve fusion rates but this remains controversial. This study's objective was to compare two-year postoperative fusion rates in a series of patients who underwent endoscopic anterior instrumentation for thoracic scoliosis utilising various bone graft types. Significantly better rates of fusion occurred in endoscopic anterior instrumented scoliosis correction using femoral allograft compared to autologous rib-heads and iliac crest graft. This may be partly explained by the difficulty obtaining sufficient quantities of autologous graft. Lower fusion rates in the autologous graft group appeared to predispose to rod fracture although the clinical consequence of implant failure is uncertain.

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Bone graft is generally considered fundamental in achieving solid fusion in scoliosis correction and pseudarthrosis following instrumentation may predispose to implant failure. In thoracoscopic anterior-instrumented scoliosis surgery, autologous rib or iliac crest graft has been utilised traditionally but both techniques increase operative duration and cause donor site morbidity. Allograft bone and bone morphogenetic protein (BMP) alternatives may improve fusion rates but this remains controversial. This study's objective was to compare two-year postoperative fusion rates in a series of patients who underwent thoracoscopic anterior instrumentation for thoracic scoliosis utilising various bone graft types.

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This study sought to improve understanding of the persuasive process of emotion-based appeals not only in relation to negative, fear-based appeals but also for appeals based upon positive emotions. In particular, the study investigated whether response efficacy, as a cognitive construct, mediated outcome measures of message effectiveness in terms of both acceptance and rejection of negative and positive emotion-based messages. Licensed drivers (N = 406) participated via the completion of an on-line survey. Within the survey, participants received either a negative (fear-based) appeal or one of the two possible positive appeals (pride or humor-based). Overall, the study's findings confirmed the importance of emotional and cognitive components of persuasive health messages and identified response efficacy as a key cognitive construct influencing the effectiveness of not only fear-based messages but also positive emotion-based messages. Interestingly, however, the results suggested that response efficacy's influence on message effectiveness may differ for positive and negative emotion-based appeals such that significant indirect (and mediational) effects were found with both acceptance and rejection of the positive appeals yet only with rejection of the fear-based appeal. As such, the study's findings provide an important extension to extant literature and may inform future advertising message design.