A method has been developed for culturing cardiac myocytes in a collagen matrix to produce a coherently contracting 3-dimensional model heart tissue that allows direct measurement of isometric contractile force. Embryonic chick cardiomyocytes were mixed with collagen solution and allowed to gel between two Velcro-coated glass tubes. During culture, the cardiomyocytes formed spontaneously beating cardiac myocyte-populated matrices (CMPMs) anchored at opposite ends to the Velcro-covered tubes through which they could be attached to a force measuring system. Immunohistochemistry and electron microscopy revealed a highly organized tissue-like structure of alpha-actin and alpha-tropomyosin-positive cardiac myocytes exhibiting typical cross-striation, sarcomeric myofilaments, intercalated discs, desmosomes, and tight junctions. Force measurements of paced or unpaced CMPMs were performed in organ baths after 6-11 days of cultivation and were stable for up to 24 h. Force increased with frequency between 0.8 and 2.0 Hz (positive "staircase"), increasing rest length (Starling mechanism), and increasing extracellular calcium. The utility of this system as a test bed for genetic manipulation was demonstrated by infecting the CMPMs with a recombinant beta-galactosidase-carrying adenovirus. Transduction efficiency increased from about 5% (MOI 0.1) to about 50% (MOI 100). CMPMs display more physiological characteristics of intact heart tissue than monolayer cultures. This approach, simpler and faster than generation of transgenic animals, should allow functional consequences of genetic or pharmacological manipulation of cardiomyocytes in vitro to be studied under highly controlled conditions.
Epstein-Barr virus (EBV)-induced posttransplant lymphoproliferative disease (PTLD) continues to be a serious complication following transplantation. The aim of the present study was to evaluate the EBV load as a parameter for the prediction and monitoring of PTLD. The EBV load was analyzed by a quantitative competitive PCR with 417 whole-blood samples of 59 patients after allogeneic stem cell transplantation (SCT). The EBV load was positive for all 9 patients with PTLD and for 17 patients without PTLD. The viral loads of patients with manifest PTLD differed from the loads of those without PTLD (median loads, 1.4 ؋ 10 6 versus 4 ؋ 10 4 copies/g of DNA; P < 0.0001). A threshold value of 10 5 copies/g of DNA showed the best diagnostic efficacy (sensitivity, 87%; specificity, 91%). However, in patients with less than three major risk factors for PTLD, the positive predictive value of this threshold was rather low. One week prior to the manifestation of PTLD, the EBV load was as low in patients who developed PTLD as in patients without disease (median, 2.2 ؋ 10 4 copies/g of DNA; P was not significant). EBV DNA tested positive first at 20 to 71 days prior to the clinical manifestation of PTLD and occurred with the same delay after transplantation regardless of disease (median delay, 52 versus 63 days; P was not significant). EBV DNA was detected earlier in patients with primary infections than in those with reactivations (33 versus 79 days; P ؍ 0.01), but the peak levels were similar in the two groups. EBV primary infection or EBV reactivation is frequent in patients after allogeneic SCT but results in PTLD only in a subgroup of patients. Although evaluation of the EBV load has limitations, the EBV load represents a valuable parameter to guide therapy.
ObjectiveTo assess and compare the value of split-liver transplantation (SLT) and living-related liver transplantation (LRT). Summary Background DataThe concept of SLT results from the development of reducedsize transplantation. A further development of SLT, the in situ split technique, is derived from LRT, which itself marks the optimized outcome in terms of postoperative graft function and survival. The combination of SLT and LRT has abolished deaths on the waiting list, thus raising the question whether living donor liver transplantation is still necessary. MethodsOutcomes and postoperative liver function of 43 primary LRT patients were compared with those of 49 primary SLT patients (14 ex situ, 35 in situ) with known graft weight performed between April 1996 and December 2000. Survival rates were analyzed using the Kaplan-Meier method. ResultsAfter a median follow-up of 35 months, actual patient survival rates were 82% in the SLT group and 88% in the LRT group. Actual graft survival rates were 76% and 81%, respectively. The incidence of primary nonfunction was 12% in the SLT group and 2.3% in the LRT group. Liver function parameters (prothrombin time, factor V, bilirubin clearance) and surgical complication rates did not differ significantly. In the SLT group, mean cold ischemic time was longer than in the LRT group. Serum values of alanine aminotransferase during the first postoperative week were significantly higher in the SLT group. In the LRT group, there were more grafts with signs of fatty degeneration than in the SLT group. ConclusionsThe short-and long-term outcomes after LRT and SLT did not differ significantly. To avoid the risk for the donor in LRT, SLT represents the first-line therapy in pediatric liver transplantation in countries where cadaveric organs are available. LRT provides a solution for urgent cases in which a cadaveric graft cannot be found in time or if the choice of the optimal time point for transplantation is vital.Living-related liver transplantation (LRT) and split-liver transplantation (SLT) are surgical strategies that have led to a reduction in the pretransplant death rate in children from 20% to nearly 0%.1-5 LRT provides a graft of excellent quality by minimizing the cold ischemic time. Primary nonfunction (PNF) after LRT is rare. In addition, this procedure is elective and thus allows flexibility in choosing the optimal time for transplantation with regard to the recipient's clinical status. Because of these advantages, worldwide long-term results of LRT are equal or even superior to those obtained with cadaveric full-size or reduced-size techniques. The actual 1-year graft and patient survival rate after LRT exceeds 80%.6 -10 The expansion of LRT for adult recipients reflects the great expectations of this procedure despite the higher risks for the donor associated with major hepatectomy.Split-liver transplantation (SLT) is technically comparable to LRT. However, as in other cadaveric procedures, it is theoretically susceptible to potential negative effects resulting from...
Summary. Allogeneic stem cell transplantation (allo‐SCT) after reduced‐intensity conditioning was evaluated in 22 patients (median age 53, range 36–66 years) with multiple myeloma with progression after an autologous SCT. Seven patients received a transplant from a human leucocyte antigen (HLA)‐identical sibling and 15 patients (68%) from an unrelated donor [including 3/22 (14%) from a HLA‐mismatched unrelated donor]. Graft‐versus‐host disease (GVHD) prophylaxis consisted of serotherapy with antithymocyte globulin (ATG) and cyclosporine (CSA) (n = 12) or CSA plus mycophenolate mofetil (n = 10). Despite of heavy pretreatment, the transplant‐related mortality (TRM) for all grafted patients was acceptable at 5/22 patients (23%). Seven of 21 patients (33%) that were evaluated developed grade II GVHD and one (5%) patient developed grade III/IV acute GVHD. Seven patients developed chronic GVHD (cGVHD), but only one was extensive. Eleven patients died of progressive disease within a median of 7 months (2–19 months) post transplant. Thirteen of all 22 patients (59%) achieved a partial or complete remission with six of these 13 patients (46%) remaining event free at a median of 24 months (range 8–36 months) post allografting. Estimated 2 year overall and event‐free survival was, respectively, 25·5% and 22·0% for the whole patient group, and 62·5% and 57·1% for patients with chemosensitive disease. Chemorefractory disease prior to allogeneic stem cell transplantation (P = 0·0182) and absence of cGVHD (P = 0·069) were associated with shorter event‐free survival. Thus long‐term disease control can be achieved, but is restricted to patients responding to prior salvage chemotherapy.
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