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BACKGROUND: Several interventions can cure posttransplant lymphoproliferative disease (PTLD); a sequential approach is usual, starting with reduction in immunosuppressives (RI). The efficacy of RI remains poorly defined, particularly in adults. We assessed an algorithm starting with a defined course of RI in all patients, escalating to interferon (IFN) alpha2b, and finally to chemotherapy, in a prospective multicenter phase II study of adult solid organ transplant recipients. The design predated rituximab. METHODS: Reduction in immunosuppressives: cyclosporine or tacrolimus reduction by 50% for 2 weeks; a further 50% reduction for 1 week if not in complete remission (CR). Intravenous acyclovir was given for the duration of all RI. Patients with less than CR, or any rejection, resumed immunosuppressives and proceeded to IFN 3 MIU/m(2)/day for up to 3 months; if less than CR, ProMACE-CytaBOM chemotherapy. RESULTS: Twenty patients were registered over 60 months; 16 patients with biopsy-proven PTLD were eligible (13 heart, 3 kidney recipients). Median age was 47 (24-75) years. Reduction in immunosuppressives resulted in only 1 of 16 partial responses (12.5%), no CR. Progressive disease occurred in 8 of 16 (50%) and 6 of 16 (38%) experienced rejection. Only 1 of 13 (7%) patients achieved durable CR with IFN. Seven eligible patients received ProMACE-CytaBOM chemotherapy, five of seven (67%) achieving CR, four of five durable beyond 2 years. CONCLUSIONS: Reduction in immunosuppressives produced no CR, progressive disease and rejection were frequent; response to IFN was rare. A strong case can be made for adding rituximab to RI as initial therapy. Chemotherapy resulted in 57% durable CR, data that are relevant for the up to two thirds of PTLD patients who are refractory to rituximab.  相似文献   
85.
Development and progression of cancer is accompanied by marked changes in the expression and activity of enzymes involved in the cellular homeostasis of fatty acids. One class of enzymes that play a particularly important role in this process are the acetyl-CoA carboxylases (ACC). ACCs produce malonyl-CoA, an intermediate metabolite that functions as substrate for fatty acid synthesis and as negative regulator of fatty acid oxidation. Here, using the potent ACC inhibitor soraphen A, a macrocyclic polyketide from myxobacteria, we show that ACC activity in cancer cells is essential for proliferation and survival. Even at nanomolar concentrations, soraphen A can block fatty acid synthesis and stimulate fatty acid oxidation in LNCaP and PC-3M prostate cancer cells. As a result, the phospholipid content of cancer cells decreased, and cells stopped proliferating and ultimately died. LNCaP cells predominantly died through apoptosis, whereas PC-3M cells showed signs of autophagy. Supplementation of the culture medium with exogenous palmitic acid completely abolished the effects of soraphen A and rescued the cells from cell death. Interestingly, when added to cultures of premalignant BPH-1 cells, soraphen A only slightly affected cell proliferation and did not induce cell death. Together, these findings indicate that cancer cells have become dependent on ACC activity to provide the cell with a sufficient supply of fatty acids to permit proliferation and survival, introducing the concept of using small-molecule ACC inhibitors as therapeutic agents for cancer.  相似文献   
86.
The present study explored the effect of different movement orientations on the arm end-effector kinematic features, levels of muscle activity and intermuscular coordination between shoulder and elbow muscles during cyclical movement. Subjects were instructed to trace cyclical lines with their dominant arm along vertical, horizontal, and right (low inertia) or left diagonal (high inertia) orientations. EMG activity from the biceps, triceps and anterior and posterior deltoids were monitored along with the displacements of the end-effector of the arm. The results suggested a differential role for the shoulder versus elbow muscles in the manipulation of the hand end-effector trajectory. The activity in the shoulder flexors was predominantly in anti-phase with that of the shoulder extensors and was therefore presumed to manipulate the global features of the trajectory. Biceps and triceps tended to show less orchestrated activity and were therefore assumed to be responsible for making the fine adjustments and to compensate for intersegmental interactions. The most pronounced differences in kinematics and EMG features among the four principal movement orientations were observed between the two diagonal orientations, which differed profoundly in arm inertial resistance. The findings converged upon the principle of 'inertial anisotropy,' as previously identified for discrete movement, suggesting that the central nervous system did not fully preplan the actual kinematic requirements of cyclical task performance. Moreover, inertial anisotropy was evident in spite of the fact that movement was performed under temporal constraints (metronome pacing) and with availability of a visual template of the task, suggesting that enhancement of the feedback loop did not fully eliminate these effects.  相似文献   
87.
The aim of this study was to describe reproductive decisions in mutation carriers after predictive testing for Huntington's disease (HD) and to identify factors that play a role in decision-making. In 1987-2004, 245 individuals received a predictive test result; 89 of them were carriers and seven received an equivocal result. Quantitative data on reproductive behaviour have been collected during all follow-up contacts. The follow-up time in this study was 1-16 years (mean: 7.1 years). Qualitative data on reproductive decision-making have been collected by the means of semistructured interviews during the 5-year follow-up study. For 46 carriers and two persons with an equivocal result, family planning was one of the motives for predictive testing. In this group, slightly more than half of the carriers (58%) had chosen to have children with prenatal diagnosis or preimplantation genetic diagnosis and about one in three (35%) decided to have no children anymore after the test. A minority (7%) was undecided or had no children for other reasons. Factors playing a role in the decision-making process were the carrier's sex, ethical issues about PD and PGD, the strength of the desire to have children, illness representations including personal experiences with HD in the family and the technological imperative. Some of these elements were in conflict and induced ambivalence towards reproductive choices. The results illustrate the complexity of the decision-making process and the necessity of in-depth counselling. Counselling should pay special attention to conflicting values and beliefs and to all kinds of pressure.  相似文献   
88.
The results of blood or marrow transplantation in patients with chemorefractory aggressive lymphoma, that is, those not responding to conventional-dose chemotherapy at the time of transplant, have been poor. The relapse rate has been high after autologous bone marrow transplant, whereas allogeneic transplantation has been associated with excessive transplant-related toxicity. Administration of cyclosporine after autologous transplantation can induce an autoreactive syndrome that resembles graft-versus-host disease (GVHD). This syndrome, named autologous graft-versus-host disease, has clear antitumor activity in animal models that can be enhanced by the addition of cytokines such as gamma-interferon and interleukin-2. A randomized, prospective study was conducted to evaluate the antitumor effect of autologous graft-versus-host disease induced with cyclosporine, and augmented by the administration of gamma-interferon and interleukin-2 in patients with chemorefractory Hodgkin and aggressive non-Hodgkin lymphomas. Fifty-one patients were randomized, 24 to the autologous GVHD induction arm, and 27 to the noninduction arm after autologous transplant using mobilized peripheral blood stem cell (PBSC) grafts. There were no differences in treatment-related mortality, overall and event-free survival (OS, EFS) between both groups; however, in the induction arm, GVHD developed only in 4 patients. The administration of oral cyclosporine followed by interleukin-2 and gamma-interferon is generally not well tolerated, and does not appear to be an effective method to induce autologous GVHD in patients receiving autologous PBSC grafts.  相似文献   
89.
This article provides a quantitative evaluation of Varian Medical Systems' beam matching procedure. A one-dimensional y analysis is employed to investigate the level of agreement of matched beams. A customized concept of one-dimensional gamma evaluation was designed. Our algorithm first performs a "local" fit of the reference and the evaluated datasets. For a particular point on the fitted evaluated curve, the y is derived as the shortest distance between the point and the fitted reference curve. This approach removes variations of the obtained y value related to the discrete character and noise in the original datasets. Criteria of 1 mm distance-to-agreement and 1% dose difference were used to evaluate the level of agreement of according profiles. Relative point and profile measurements were performed for all photon and electron beams of two Varian Clinacs 2100C/D. Matched beams show a good level of agreement. 70% of profiles completely pass the chosen criteria. The analysis of remaining 30% of the profiles demonstrates that measurement error becomes a limiting factor in achieving a better score. The highest obtained y value was 1.70. The quality of beam matching allowed us to treat according beams of both treatment units as "identical" and to use the reference beam data for the new unit. Nevertheless, the vendor's acceptance criteria of beam matching are much more benevolent. It might happen that the acceptance criteria are met, however, resulting quality of beam matching does not allow full interchangeability of beams.  相似文献   
90.
Normal physiological changes of pregnancy warrant the need to employ gestation specific reference ranges for the interpretation of thyroid function tests. Thyroid hormones play crucial roles in foetal growth and neurodevelopment which are dependent on adequate supply of maternal thyroid hormones from early gestation onwards. The prevention of significant adverse obstetric and neurodevelopmental outcomes from hypothyroidism requires a strategy of empirical levothyroxine dose increases and predictive dose adjustments in pregnancy combined with regular thyroid function testing, starting before pregnancy and until the postpartum period. Subclinical hypothyroidism has been associated with an increased risk of pregnancy loss and neurocognitive deficits in children, especially when diagnosed before or during early pregnancy. Whilst trials of levothyroxine replacement for mild hypothyroidism in pregnancy have not indicated definite evidence of improvements in these outcomes, professional guidelines recommend treatment, especially if evidence of underlying thyroid autoimmunity is present. Studies of isolated hypothyroxinaemia in pregnancy have shown conflicting evidence with regards to adverse obstetric and neurodevelopmental outcomes and no causative relationships have been determined. Treatment of this condition in pregnancy may be considered in those with underlying thyroid autoimmunity. Whilst the evidence for a link between the presence of anti‐TPO antibodies and increased risks of pregnancy loss and infertility is compelling, the results of ongoing randomized trials of levothyroxine in euthyroid women with underlying autoimmunity are currently awaited. Further studies to define the selection of women who require levothyroxine replacement and to determine the benefits of a predictive dose adjustment strategy are required.  相似文献   
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