ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Pigs appear to be a suitable biological and logistical animal donor of islets for xenotransplantation in human diabetic type I recipients. To improve the islet isolation technique in this species, to evaluate the islet function in vivo, and to assess the toxic effects of various immunosuppressive regimens on transplanted islets will necessitate a model of the pancreatectomized pig suitable for islet autotransplantation.We describe three techniques of total pancreatectomy in pigs. The first removed the pancreas in order to study postoperative management and pig survival; no attempt was made to preserve the pancreas for islet isolation. The second consisted of a pancreatectomy in a surviving pig, with careful preservation of the whole pancreas for subsequent islet isolation. The third was rapid en bloc procurement of the pancreas and duodenum, to obtain a pancreas solely for the purpose of islet isolation.We conclude that pigs tolerate and survive a total pancreatectomy—they are suitable animals for islet isolation and possible autotransplantation. The result of islet isolation does not appear related to the pancreas procurement technique; however, the islet yield must be improved before autotransplantation can be functionally successful.

ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The aim of this study was to determine the mechanisms responsible for concordant xenograft rejection using the hamster-to-rat heart graft model. Even though it was known that rat CD4 positive T cells proliferated to hamster stimulators in mixed lymphocyte reactions, the depletion of CD4 positive T cells in rat recipients did not lead to an extension of xenograft survival. Suppression of T cell immunity using other monoclonal antibodies or cyclosporine also failed to improve survival. Only by depleting complement with cobra-venom factor could hamster xenograft survival be prolonged, and long-term survival was achieved by combining CsA with COF. High-antibody titers to hamster cells were found after transplantation of hamster hearts, and evidence is presented that rejection of these “concordant” xenografts is mediated primarily by antibody-complement mechanisms. The antihamster antibodies were produced in the absence of T cell help, which suggests that antibody-mediated graft destruction cannot be inhibited by suppression or depletion of T cells. Pharmacologic depletion of complement for the clinical application of concordant xenografts is a promising avenue of future research.

ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The development of a successful method to preserve the heart for relatively long periods (24–48 hr) requires demonstrating successful orthotopic transplantation and long-term survival after preservation. There are however, multiple variables that may affect the quality of heart preservation, and it is nearly impossible to systematically study all the variables in this complicated model. One model that may be useful to study how preservation parameters affect heart cell preservation is the isolated myocyte preparation. In this study myocytes were isolated from the rabbit heart and the effects of up to 24 hr cold storage on viability measured to determine if this would be a suitable preservation model. Myocytes were stored in various preservation solutions including; EuroCollins (EC), two cardioplegic solutions (Stanford[ST] and Bretschneider solution [HTK]) and the University of Wisconsin solution (UW) with or without the addition of polyethylene glycol. The viability of myocytes was judged by measuring the effects of preservation and rewarming after preservation on cellular morphology (percent rod-shaped cells), ATP concentration, and LDH release. Myocytes preserved in the cardioplegic solutions were least well preserved after 12 and 24 hr storage, as judged by the loss of rod-shaped morphology and lower ATP concentration. Preservation in EC resulted in a decrease in the percent rod-shaped cells after 12 hr and 24 hr storage that was greater than obtained in the UW solutions. The best preservation of myocyte morphology and highest content of ATP was

ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The effects of pretreatment with cyclosporine, allopurinol, or methylprednisolone on ischemia-reperfusion injury of the liver were investigated. A total of 32 adult mongrel dogs that received one of the pretreatments were divided into four groups and were subjected to 90 min liver ischemia. Serum activities of aspartate aminotransferase (s-AST) and lactate dehydrogenase, (s-LDH) as well as animal survivals were used as indicators of liver injury. The elevation of both s-AST and s-LDH was significantly suppressed by pretreatment with cyclosporine as much as by allopurinol. However a significant improvement in animal survival was obtained only in the cyclosporine-pretreated group. Pretreatment with methylprednisolone did not affect either the activities of s-AST and s-LDH or animal survivals when compared with the control group. These data suggest that cyclosporine is a potent protector against ischemic liver injury—as effective as allopurinol or methylprednisolone. Although the precise mechanism of the effect of cyclosporine on liver ischemia still remains unknown, these observations may be of use in liver transplantation.

ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The influence of UW preservation fluid in comparison with that of Euro-Collins and Bretschneider solutions on collagen, adenosine diphosphate and ristocetin-induced platelet aggregation was investigated in vitro using platelet-rich plasma of 4 healthy volunteers. The concentrations of the solutions tested were comparable to those that may be used in the transplant situation. 2UW solution inhibited ADP and collagen-induced platelet aggregation—an effect that could be attributed mainly to adenosine and secondarily to penicillin in UW solution—whereas ristocetin-induced aggregation was not affected. Euro-Collins and Bretschneider solutions did not alter platelet aggregation. The inhibition of platelet aggregation by UW may, on the one hand, contribute to bleeding complications after reperfusion and, on the other hand, be responsible for the observed lower incidence of hepatic artery thrombosis.

ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The value of colloid in preservation of the liver by cold storage has not yet been fully clarified. Therefore, we studied the effects of colloid on cell swelling, liver weight, and bile production after cold storage in rat liver tissue slices and isolated rabbit liver. In rat liver tissue slices cold-stored for 24 hr in UW solution, total tissue water (TTW) was the same as in the control freshly unpreserved tissue and omitting the colloid (hydroxyethyl starch) from the UW solution did not affect the TTW. However, after cold storage for 24 hr in Perfadex, TTW was markedly increased (by 100%, P<0.001). Omitting the colloid in this solution, dextran, or replacing it with hydroxyethyl starch, did not affect this increase in TTW. Thus, the hypothermia-induced cell swelling evident after preservation in Perfadex was not prevented by colloid. Rabbit liver cold-stored in UW solution for 24 hr lost 15.4±4.7% of weight, but omitting the colloid from UW solution decreased this weight loss to 3.1±3% (P<0.01). In contrast, rabbit livers cold-preserved in colloid-free Perfadex gained 23.3±5.7% in weight. Adding colloid, either dextran or hydroxyethyl starch, decreased significantly this weight gain, to 9± 3.7% and 10.4±1.8%, respectively (P<0.01), probably as a result of colloid osmotic pressure, preventing the interstitial edema. Rabbit livers preserved for 24 hr in UW solution, with or without colloid, produced the same amount of bile as control unpreserved livers. In contrast, livers preserved in colloid-free Perfadex for 24 hr had a markedly impaired bile production (3.9±0.9 ml/100 g) as compared with control livers (15.5±2.6 ml/100 g,P<0.01). Colloid partially restored this impaired bile production, to 8±1.4 mg/100 g by dextran and to 8.5± 1.7 ml/100 g by hydroxyethyl starch, respectively (P<0.01). Thus, although colloids do not prevent the hypothermia-induced cell swelling, they prevent the development of interstitial edema, and, hence, improve the liver function.

ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Livers from normal porcine donors were preserved by surface cooling only, without flushing or perfusion, for periods up to 24 hr. All recipients of livers stored for 6 hr survived until sacrifice at 7 days. In a separate, similar group, survival up to 21 days was noted. Only 2 of 6 recipients survived after 9-hr liver storage, but one of these lived for > 120 days. No animals survived longer than 2 days after transplantation of livers stored for 12 or 24 hr. The changes in plasma levels of aspartate aminotransferase of recipients of 6-hr surface-cooled livers were not significantly different from AST levels of recipients of livers stored in University of Wisconsin or Euro-Collins solution as observed in previous studies in this laboratory. At sacrifice after 7 days, there was no histologic evidence of damage after surface cooling.In the light of recent reports of evidence of endothelial and reticuloendothelial damage caused by flushing solutions, it is suggested that surface cooling of the liver may provide adequate preservation for 6 hr in appropriate circumstances. Further studies will be needed to confirm that this method of preservation is applicable to livers removed from brain-dead donors and that it does not cause endothelial damage.

ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Organ transplantation has made tremendous strides in the last decade. The demand for transplantable organs has far outstripped the supply; waiting lists have grown long and patients are dying for want of vital organs. Therefore policies and criteria that guide the allocation of transplantable organs become ever more important. Over the years, allocation policies have evolved by including both medical and ethical considerations, and much work has gone into defining and analyzing components of such policies. However, they have often grown by accretion, and a parallel analysis of both sets of approaches did not occur. This article attempts to integrate medical and ethical considerations, and to develop a schema that will permit review, redefinition, and—it is hoped—development of a fairer, more equitable and responsive allocation system.

ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Transplantation is the treatment of choice for children with end-stage renal disease. However, the long-term quality of life and socioprofessional outcome for those with successful transplants have not previously been reported. We studied these factors in patients transplanted when<18 years old who currently have ≥10 years of graft function. A total of 57 questionnaires were sent out; 57 (100%) responded [24 female and 33 male patients; average (±SD) age at tx = 10±5 years (0.9–17.7); average f/u = 15.6±3 years (10–26); current age = 26±5 years (12–38); 26 had < 1 transplant]. Of the 57 respondents, 9 are<18 (all are in school); 48 are ≥18 (7 in school, 37 employed, 4 unemployed); 12 are married, 1 engaged, and 2 divorced; and 9 have children.While in school, 43 (75%) had participated in sports, 37 (65%) in other extracurricular activities; 7 (12%) were A and 33 (58%) B students; 15 (26%) received awards or scholarships. For those working, the range of occupations is broad (average work week = 41±5 hr). Health-related absence from work has been nonexistent for 93%. Health is rated as good to excellent by 91% and fair by 9%. The future is regarded as hopeful or promising by 80%. Similarly, 89% are satisfied with life in general; 95% said health never or seldom interferes with family life; 95% feel health and drug side effects are of no or minor concern in sexual relationships. Only 3% feel health is a problem in maintaining a sexual relationship (41% are not sexually active).Only 4% stated that health often interferes with social life; 98% meet with friends on a regular basis; 76% are satisfied with personal relationships and 8% dissatisfied; 91% are satisfied with their ability to perform at work or school and 5% dissatisfied. Of note, 32% are dissatisfied with body appearance. Major concerns are short stature and brittle bones. Major suggestions include education/support groups to deal with teasing at school and peer problems. We conclude that transplanted children with long-term graft function have a favorable social and professional outcome. Overall, quality of life seems excellent.

ISSN:0041-1337    

出版商:OVID    

年代:1991

数据来源: OVID