摘要:

Background.Protection against complement activation may reduce acute islet damage in pig-to-human islet xenotransplantation. Expression of the human complement regulatory proteins decay-accelerating factor (DAF, CD55) or CD59 was induced on intact adult porcine islets (APIs) by adenoviral transduction. The functional capacity of the transgenes was examined in vitro after exposure to fresh human serum.Methods.Intact APIs were transduced with adenoviral vectors Ad.hDAF or Ad.hCD59 or a control vector. After 3 days, the islets were trypsin dissociated to a single-cell suspension. A cytotoxicity assay was performed in which the islet cells were incubated with human complement active AB serum. Flow cytometry and immunohistochemistry were used to evaluate transgene expression.Results.APIs could be transduced to express hDAF or hCD59. Flow cytometry analysis of islet single cells revealed that only a fraction of the cells expressed the transgene; immunohistochemical staining of transduced islets demonstrated that mainly cells located in the periphery of the islets were expressing the protein. Cells from nontransduced islets or islets expressing the control protein were sensitive to lysis in human sera (66±4.0% and 73±3.7% cytotoxicity, respectively). Single cells from islets transduced with hDAF and hCD59 were partially protected from lysis. Islet cells expressing hCD59 were slightly less sensitive to lysis (33±3.3%) than cells expressing hDAF (45±3.5%).Conclusions.These data show that intact pig islets can be transduced to express human regulators of complement activation on the surface and that pig islet cells expressing hDAF or hCD59 are less sensitive to complement-mediated lysis.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.It is still controversial whether a major mode of cell death during hepatic ischemia-reperfusion (I/R) injuries is apoptosis or necrosis. Moreover, the correlation between these cell deaths and the effects of a novel inducible nitric oxide synthase inhibitor (ONO-1714) has not been studied before.Methods.Pigs were subjected to 180 min of hepatic warm I/R under extracorporeal circulation. The control group was not administered ONO-1714. In the ONO-1714 group, ONO-1714 was administered 5 min before ischemia at a dose of 0.05 mg/kg through a portal vein catheter. The apoptotic and necrotic changes after reperfusion were examined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and hematoxylin-eosin staining. Nitrotyrosine, active caspase-3, and cytochrome c were examined by immunohistochemistry. The plasma NO2-+ NO3-, aspartate aminotransferase, and lactate dehydrogenase levels were also examined.Results.In the control group, the frequency of apoptotic cells was only 2.6%; nevertheless, that of necrotic cells was 37% at 24 hr after reperfusion. ONO-1714 significantly attenuated apoptosis and necrosis, the expression of nitrotyrosine, and the increases of the plasma aspartate aminotransferase, lactate dehydrogenase, and NO2-+ NO3-levels in the reperfusion phase.Conclusions.A major mode of cell death during hepatic warm I/R injury was necrosis, and apoptosis was not dominant. These necrotic changes were caused by the excess production of peroxynitrite, and ONO-1714 greatly attenuated I/R injuries as the result of inhibition of the peroxynitrite production.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.Genetic variations in the interleukin (IL)-10 gene promoter have been associated with levels of induced production of IL-10, disease susceptibility, and allograft rejection. Small amounts of this cytokine are constitutively produced and are important in maintaining the physiologic function of the cytokine network. In this study, we evaluated the distribution of IL-10 basal levels and its genetic regulation in a healthy Spanish population.Methods.Polymorphisms at the −1082, −819, and −512 positions of the IL-10 promoter were analyzed by polymerase chain reaction amplification and hybridization with fluorescent-labeled allele-specific probes in 183 Spanish people. Levels of IL-10 messenger (m)RNA were tested by real-time reverse transcription-polymerase chain reaction in 123 healthy donors. Serum concentrations of IL-10 were measured by a highly sensitive ELISA, whereas protein amounts in lipopolysaccharide culture supernatants were quantified by an in-house ELISA.Results.The frequency of IL-10 promoter alleles and haplotypes in our population showed remarkable differences from other Caucasian populations. Large interindividual variations were found in mRNA and protein constitutive levels of IL-10, which allowed its classification in low and intermediate/high producers. We found statistical differences in mRNA concentration between the polymorphic variant GCC/GCC and the low producer genotypes. The G allele at position −1082 was the most important genetic factor in the regulation of constitutive IL-10 mRNA levels. Similarly, we also found an association of this polymorphic position with serum concentration greater than 2 pg/mL.Conclusions.Constitutive levels of IL-10 (mRNA and serum protein) displayed remarkable interindividual variations, which are genetically controlled by polymorphic variants at the cytokine gene promoter.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.Although class II human leukocyte antigen (HLA) DR mismatching has been shown to demonstrate a significant effect on kidney regraft survival, it has not generally been clinically emphasized.Methods.We examined 2,574 kidney retransplants performed in Southeastern Organ Procurement Foundation centers between January 1988 and December 1997 in which there was ABDR typing on both donor and recipient and pretransplant panel reactive antibody (PRA) data.Results.Cox regression of multiple variables demonstrated that the most important risk factors in descending order were DR mismatching, non-white recipient, female donor, PRA as a continuous variable, and cold ischemia time. Although DR mismatching demonstrated a significant effect in white recipients, the impact was much greater in non-white recipients. In both groups, zero to four AB mismatches demonstrated no significant effect on regraft survival if DR was matched and only a minimal effect when DR was mismatched. The discrepancy of these findings with reports that demonstrate a stepwise decrease in regraft survival on the basis of the total zero to six ABDR mismatches was explained by the fact that the zero to six ABDR mismatches are a combination of AB mismatches with little effect and DR mismatches with a major effect. Regraft survival decreased progressively in association with increasing PRA.Conclusions.DR matching is critically important in kidney retransplantation. There was no significant difference in survival of zero ABDR mismatched retransplants compared with one to four AB and zero DR mismatched retransplants. On the other hand, kidney graft survival of all one to four AB and zero DR mismatches exceeded that of one or two DR mismatched retransplants. We propose that the association of decreasing regraft survival with increasing PRA reflects undetected sensitization to class II, and possibly class I, antigens.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.Pancreas-kidney transplant recipients are at high risk for cytomegalovirus (CMV) disease despite prophylactic ganciclovir therapy. Because the impact of antiviral therapy on anti-CMV immune reactions is unknown, CMV-specific T-cell subsets in primary and recurrent CMV infection were analyzed in a pancreas-kidney transplant case study.Methods.Major histocompatibility complex class I tetramers were used to detect peripheral CMV pp65-specific CD8+T cells. Intracellular cytokine staining was used to determine the frequency of CMV-specific CD4+T cells. Conventional virologic parameters and routine laboratory parameters were monitored. For ganciclovir resistance testing, CMV-UL97 genotyping was performed.Results.Despite prophylactic ganciclovir therapy, primary CMV infection induced in vivo expansion of activated CMV-specific CD8+T cells. Interestingly, viral dissemination during recurrent CMV disease was a result of partially ganciclovir-resistant CMV. Recovery after discontinued ganciclovir treatment was associated with the expansion of CMV-specific CD4+T cells.Conclusion.Immunologic monitoring may contribute to clinical management of recurrent CMV disease.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Veno-occlusive disease (VOD) can develop in association with the administration of cytotoxic chemotherapeutic agents and irradiation. In solid-organ transplant settings, azathioprine has been implicated as a predisposing factor. VOD with fatal outcome occurred in a postliver-transplant recipient who had never been exposed to any agents that have the potential to induce VOD. At onset, the disease manifested clinically as gross ascites and progressive jaundice and was observed after clinically diagnosed acute graft rejection. The disease was confirmed by histologic examinations. Histologic studies of biopsy samples from this patient revealed that most small hepatic veins less than 300 &mgr;m in diameter were affected, exhibiting concentric intimal thickening with sparse inflammatory cells. A few of the hepatic veins exhibited active endotheliitis with occasional extension of inflammation to neighboring centrilobular areas. Despite intensified immunosuppression, the observed fibrous obliterative changes were irreversible. Although the cause of VOD in this patient is tentative, the damage to the endothelium, associated with acute rejection, is likely to be attributable. VOD deserves recognition as one of the causes for liver dysfunction and persistent ascites after liver transplantation.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Isolated visceral angioedema is an extremely rare complication of angiotensin-converting enzyme inhibitors (ACEIs). We report the first known case of ACEI-associated visceral angioedema occurring in a liver transplant recipient who presented with acute-onset abdominal pain, nausea, vomiting, diarrhea, radiologic findings of small bowel edema, and ascites. Heightened awareness of the phenomenon of isolated ACEI-associated visceral angioedema is necessary given the increasing use of these medications for treating hypertension related to calcineurin inhibitors and the need to avoid unnecessary surgical or diagnostic interventions in solid-organ transplant recipients.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Graft-versus-host disease (GVHD) is a rare complication that occurs after living-related liver transplantation (LRLT). This condition usually occurs early after transplantation and is fatal. Although one-way matching between a human leukocyte antigen (HLA)-homozygous donor and a haploidentical recipient has been shown to be a significant risk factor for the development of acute GVHD, chronic GVHD has not been clarified. A 50-year-old woman underwent LRLT for primary biliary cirrhosis with her 32-year-old HLA-homozygous son as the donor. The patient developed chronic GVHD 114 days posttransplant, presenting with a skin rash only. Her atypical onset included neither fever nor gastrointestinal symptoms. The patient responded to corticosteroid therapy and is now doing well at home. Careful donor selection and HLA matching before LRLT should be performed to prevent GVHD. However, the risks associated with grafts from homozygous donors may be unavoidable at present because of the shortage of cadaveric donors in Japan.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.Pancreatic islets are avascular immediately after transplantation and depend on revascularization. Recently, the authors found decreased vascular density in mouse islets 1 month after implantation into nondiabetic recipients. This study investigated possible differences in revascularization between islets implanted into nondiabetic and diabetic recipients, and also evaluated changes in vascular density up to 6 months posttransplantation.Methods.Islets were syngenically transplanted beneath the renal capsule of normoglycemic or alloxan-diabetic C57BL/6 mice. One to 6 months later, the animals were killed and the grafts removed. Histologic slides were prepared and stained withBandeiraea simplicifolia.Results.The vascular density in all transplanted islets was decreased compared with native islets. There were no differences in the islet graft vascular density between nondiabetic and diabetic animals. No improvement over time occurred.Conclusions.The vascular density is decreased in islets implanted to cure diabetic recipients. No improvement occurs in transplanted islets after 1 month posttransplantation.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID