摘要:

Background.The cell surface carbohydrate moiety, Gal(α1,3)Galactose (αGal), has been implicated as the major determinant recognized by more than 80% of human anti-porcine natural antibodies (NAb). An ELISA system was developed for the detection of this subpopulation of porcine cell-reactive NAb using synthetic αGal conjugated to bovine serum albumin.Methods.A screen of 95 human serum samples by this method demonstrated marked variability in the αGal reactivity of unrelated donors. The percentage of αGal-reactive NAb relative to total immunoglobulin was determined for 10 donors.Results.αGal-reactive NAb comprised 1.0-2.4% of total serum IgG, whereas the range was from 3.9% to 8.0% for IgM.Conclusions.The higher level of αGal-reactive IgM suggests that xenoreactive NAbs may be the product of germ-line genes. Two-dimensional gel analysis of affinity-purified αGal-reactive NAb from two donors provided evidence suggesting that IgM from this subpopulation of NAb were restricted in protein charge heterogeneity.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Feline bone marrow cells treated with the soybean agglutinin (SBA) lectin are separated into two populations, the agglutinated SBA(+) fraction containing predominantly cells of myeloid origin and the nonagglutinated SBA(-) fraction consisting of cells primarily of the erythroid lineage. FACScan analyses revealed a clear distinction of the cells based on their light scattering properties, i.e., large cells and cells with high granularity were found in the SBA(+) fraction, whereas cells having a low forward light scatter and side light scatter were found in the SBA(-) fraction. Colony-forming assays showed colony-forming unit-granulocyte/monocyte (CFU-GM) cells to have a strong affinity for SBA because these were found almost entirely in the SBA(+) fraction; in contrast, burst-forming unit-erythroid (BFU-E)-forming cells were concentrated in the SBA(-) fraction. When the marrow was fractionated by counterflow centrifugal elutriation (CCE), a differential binding to SBA among the CFU-GM forming cells was found. The SBA(-) fractions of cells collected at 21 and 25 ml/min contained primarily BFU-E forming cells, similar to that observed with whole marrow; the later CCE fractions, those collected at 32 ml/min and the rotor off fraction, when treated with SBA showed a small but significant number of CFU-GM cells in the SBA(-) fraction. T lymphocytes were found predominantly in the SBA(+) fractions of whole bone marrow and the CCE fractions. Successful autologous marrow transplants were performed with the early CCE SBA(-) fractions. The latter cells were used for our initial transplant attempts because ongoing studies in our laboratory had shown these cells to be free of any viral-containing cells when the marrow had been obtained from animals infected with the feline immunodeficiency virus. In summary, although SBA treatment of feline marrow yields a marked separation of CFU-GM and BFU-E progenitors, select CCE SBA(-) fractions contain stem cells capable of providing hematopoietic reconstitution of lethally irradiated animals.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background.Graft-versus-host disease (GVHD) occurs in the recipient after small bowel transplantation (SBT). Proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and interleukin 6 (IL-6), may be important mediators of GVHD. Increased expression of these cytokines might precede the clinical manifestations of GVHD induced by SBT.Methods.Heterotopic SBT was performed using Lewis donors into Lewis × Brown Norway F1 (LBN-F1) recipients. The isograft control was performed from LBN-F1 into LBN-F1. Animals were killed on the 5th and 11th postoperative day (POD). mRNA was isolated from recipient native small bowel, colon, spleen, liver, and mesenteric lymph nodes and from nonsurgical controls as baseline. Semiquantitative reverse transcriptase polymerase chain reaction was performed to amplify mRNA transcripts for TNF-α, IFN-γ, and IL-6 using α32P-dATP incorporation. Clinical signs, histologic assessment, and cytokine expression were correlated.Results.On POD 5, there were neither clinical signs nor histologic features of GVHD, but mRNA expression of TNF-α and IL-6 in small bowel, IL-6 in spleen, and IFN-γ in mesenteric lymph nodes were significantly increased in allograft animals when compared with normal and isograft tissues. On POD 11, both the clinical signs and histologic features of GVHD were seen, and TNF-α and IL-6 in native small bowel, TNF-α in colon, IFN-γ in spleen, and IL-6 in mesenteric lymph nodes were significantly increased in allograft animals when compared with that in normal and isograft tissues.Conclusions.In conclusion, TNF-α, IFN-γ, and IL-6 expression precede clinical onset and histologic evidence of GVHD in specific tissues. Therefore, increased expression of these cytokines is correlated with the development of GVHD in this model of SBT.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background.Antibodies targeting recipient major histocompatibility complex (MHC) class II molecules have been demonstrated to be effective at prolonging allograft survival. However, antigen-presenting cell depletion would explain this effect and has not been definitively excluded as the mechanism of action of such antibodies. We have studied an anti-MHC class II antibody (OX6) proven to be noncytotoxic in the recipient strain used.Methods.Antibody was administered the day before, 2 hr before, and the day after grafting.Results.Antibody administration on the day before, 2 hr before, and the day after grafting significantly prolonged vascularized cardiac allograft survival. Importantly, treatment recognizing recipient MHC was effective, whereas a similar regimen recognizing donor MHC was not.Conclusions.Noncytotoxic recipient MHC class II-specific antibodies modify allograft rejection. Possible mechanisms for this therapeutic effect are discussed.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background.The present study evaluates the effects of long-term immunosuppression after cardiac transplantation on the risk for adenomatous polyps.Methods.The endoscopic procedures performed at LDS and University Hospitals in cardiac transplant recipients were reviewed and compared with results from a previously studied control group.Results.A total of 123 endoscopic procedures were performed in 98 heart transplant patients (59% for cancer screening and 41% for gastrointestinal complaints). Eighty-five percent of patients were male and 15% were female; their mean age was 57 years. In the group <3 years posttransplant, adenomatous polyps were present in 25%, hyperplastic polyps were present in 10%, and synchronous lesions in 3 patients. In the group >3 years posttransplant, adenomatous polyps were present in 16% hyperplastic polyps were present in 22%, and synchronous lesions in were evident in 3 patients. No significant difference with results from a previously studied control group.Conclusions.Long-term immunosuppression does not increase the risk for adenomatous polyps of the colon.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

The presence of antibodies against human leukocyte antigens (HLA) in recipients of cryopreserved, nontissue-antigen-matched human meniscal allografts was evaluated. Serological HLA typing was performed for both class I and class II antigens. The results showed that 11 of 18 recipients became sensitized.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background.Bronchiolitis obliterans (BO) is the most important long-term complication of lung transplantation. Treatment of this condition is often unsuccessful.Methods.A patient presented with early BO. Despite OKT3 and the addition of methotrexate, the patient needed persistently high doses of prednisone to maintain lung function at a moderate level. Only the substitution of azathioprine by mycophenolate mofetil (MMF, 3 g/day) made it possible to reduce the dose of prednisone.Results.Reduction of the dose of MMF to 2 g/day resulted in a deterioration of lung function, which improved impressively after MMF was increased again to 3 g/day.Conclusions.MMF may be a valuable therapy for lung transplant BO. However, the use of a high dose, i.e., 3 g/day, may be crucial.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

A bile duct stricture caused by an inadvertent ligation or suture during donor operation is rare, but not a negligible complication after living-related liver transplantation (LRLT). We present here a simple technique to prevent this kind of complication. Before bilioenteric anastomosis, a rod-shaped surgical probe was introduced into the bile ducts of the graft to examine their patency. The position of the surgical probe and the liver segment in which the probe proceeded was checked using ultrasonography. Using this technique in all of our 60 cases of LRLT, we have had no experience of this bile duct complication. We recommend this technique to be adopted in LRLT and split-liver transplantation to diminish the risk of biliary complications.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background.We investigated the prevalence, risk factors, and consequences of hepatitis G virus (HGV) infection in 87 kidney transplant recipients.Methods.Infection was diagnosed with reverse transcriptase polymerase chain reaction using primers in the NS3 region of the viral genoma.Results.Twenty-four patients (27.5%) were HGV RNA positive (HGV+ group) and 63 patients (72.5%) were HGV RNA negative (HGV- group). No statistically significant differences were found between the two groups for age, sex, transplantation and hemodialysis duration, number of kidney transplantations, serum creatinine, history of transfusions, hepatitis B and C virus infections, and percentage of patients having suffered from acute rejection. Acute and chronic hepatitis were not more prevalent in the HGV+ group than in the HGV- group.Conclusions.HGV infection is highly prevalent in kidney transplant recipients but does not alter liver or kidney functions. HGV contamination may be linked to nosocomial transmission during long-term hemodialysis.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background.Replication-deficient adenovirus, one of the most efficient vectors in gene therapy, has been limited by transient transgene expression due to its episomal location and loss during cell division, as well as a host immune response against viral proteins.Methods.Murine pancreatic islets were infected ex vivo with ad5-cytomegalovirus (CMV)-β-galactosidase and transplanted into diabetic recipients with normalization of glucose metabolism.Results.High levels of β-galactosidase activity were detectable histologically for at least 20 weeks after transplant, and β-galactosidase and viral mRNA were also present that long. Sera from transplanted animals did not significantly inhibit ad5-CMV-interleukin-2-Ig infection of HeLa cells in vitro, whereas sera from intravenously delivered ad5-CMV-β-galactosidase drastically diminished HeLa cell infection, suggesting the presence of reduced levels of antibodies in transplanted animals as compared with intravenously infected animals. Immunofluorescent staining of islet isografts infected with ad5-CMV-β-galactosidase revealed the presence of CD8+and CD4+T lymphocytes at all time points, however, no islet destruction was seen.Conclusions.Treatment of islet isografts ex vivo with ad5-CMV-β-galactosidase results in prolonged transgene expression, possibly due to an attenuated immune response against adenovirus.

ISSN:0041-1337    

出版商:OVID    

年代:1997

数据来源: OVID