A Novel Model of Mouse-to-Rat Kidney Xenotransplantation.

Transplantation animal models require 2 animals for each experiment, 1 as a donor and 1 as a recipient. At the present time, developing microsurgical instruments and refining surgical techniques should allow us to reduce the number of animal used for transplantation research. In this study, we aimed to harvest 2 kidneys from 1 donor to be able to minimize the number of animals needed for transplantation studies. For this purpose, we developed a kidney xenotransplantation model from mouse to rat, in which only 1 animal was used as the donor for 2 kidney recipients. Ten male Balb/c mice weighing from 25 to 30 g were used as donors, and 20 male Sprague-Dawley rats weighing from 150 to 200 g were used as recipients. In this study, the harvesting of 2 kidneys from a mouse as well as the recipient operation were described with technical detail. Although harvesting 2 kidneys from a mouse and mouse-to-rat kidney xenotransplantation is a highly challenging microsurgical procedure, we believe that every experienced surgeon should be capable of performing this surgery with some practice. This model allows us to reduce the number of animals in transplantation studies without compromising the graft quality. We strongly recommend our refined harvesting technique to researchers, particularly in terms of animal rights.

Acute Rejection Pattern of an Outbred Strain Combination on Mouse-to-Rat Heterotopic Heart Xenotransplantation.

OBJECTIVES: This study aimed to investigate the acute rejection patterns of outbred mice and rats on a xenotransplantation model. MATERIALS AND METHODS: Thirty male Balb/c mice weighing from 30 to 40 g were used as donors, and 30 male outbred Sprague-Dawley rats weighing from 150 to 200 g were used as recipients for heterotopic heart xenotransplantation models. Animals were allocated into 5 groups according to their killed days, and each group had 6 animals. Animals in group 1 were followed for 1 day and then killed; animals in groups 2, 3, 4, and 5 were followed up 2, 3, 4, and 5 days after transplantation, respectively. Operative findings, the appearance and heartbeat strength of the grafts, and histopathologic examinations of the grafts were evaluated to determine acute rejection. RESULTS: There were no mortalities during the study period, and the animal survival rate was 100%. Heartbeat strengths were strong (4.5 ± 0.5) and graft appearances were normal in group 1 animals. The heartbeat scores of the xenografts dramatically declined thereafter. Histopathologically, there were inflammation patterns in all xenografts. The infiltration of neutrophils and the formation of platelet and fibrin thrombi were seen in the first postoperative day and gradually increased daily. CONCLUSIONS: This study concluded that outbred Balb/c mouse to Sprague-Dawley rat combination has reliable acute xenograft rejection patterns microscopically and macroscopically in the heterotopic heart xenotransplantation model.

The value of computed tomography in the diagnosis of acute necrotising pancreatitis in a renal transplant patient.

BACKGROUND: The incidence of acute pancreatitis after renal transplantation ranges around 1%, and the mortality rate is nearly 65%. Dynamic computed tomography (CT) scan and amylase levels are valuable in the diagnosis of this rare complication. CASE OUTLINE: A 29-year-old man was hospitalised with cytomegalovirus (CMV) pancreatitis after renal transplantation. An initial CT scan showed an enlarged pancreas with hypodense, heterogeneous consistency and with peripancreatic, perihepatic, mesenteric and pelvic fluid collections. After initial conservative management, follow-up CT revealed pancreatic necrosis and abscess formation. The patient underwent necrosectomy and repeated drainage of abscess facilitated by a Bogota bag, but he died 60 days after admission and five surgical procedures. DISCUSSION: CMV pancreatitis after renal transplantation is rare and frequently fatal. In the presence of an acute abdomen after renal transplantation, the diagnosis of pancreatitis should be considered. Dynamic CT scan and measurement of amylase levels are recommended.

Evaluation of the outcomes of short bowel syndrome and indications for intestinal transplantation.

Long-term parenteral nutrition (PN) and intestinal transplantation (IT) are life-saving therapies for patients with short bowel syndrome (SBS). However, indications and timing of these therapies are controversial. In this study we aimed to evaluate the indications for IT. Forty-two patients, each with <100 cm of small bowel, were divided into three groups according to the length of remnant: group I patients (n = 18): colon plus 50 to 100 cm of small bowel (SB); group II patients (n = 14): colon plus <50 cm of SB; and group III patients (n = 10): <50 cm of SB without colon. One-year mortality rates for groups I, II, and III were 50%, 72%, and 100%, respectively. All group I survivors developed intestinal adaptation, returning to regular oral feedings at 1 year. Interestingly, three of four surviving patients in group II developed adaptation and were fed an oral short bowel diet (SBD) at 1 year. None of the group III patients survived >1 year, dying due to multiorgan failure in the early postoperative period or from sepsis within 1 year. We conclude that patients with a very short bowel are candidates for IT when stable. If the colon is intact, however, regardless of small bowel remnant length, the patient should be given a chance to develop intestinal adaptation before making the decision for permanent PN or IT.

Value of computed tomography in addition to ultrasound for preoperative staging of gastric cancer.

AIM: The aim of this study was to assess the added value of computed tomography (CT) with ultrasound in identifying unresectable or incurable gastric cancer. METHODS: One hundred and eighteen patients with various types of gastric cancer were preoperatively staged with ultrasound and CT between January 1999 and October 2000. Each individual was evaluated for ascites, liver metastasis and peritoneal metastases. The observations were compared to findings at surgery. RESULTS: Both techniques were highly specific (93-99%) for all conditions except retroperitoneal invasion (85%). The sensitivities of ultrasound and CT were 64 and 36% for ascites, 50 and 62% for liver metastasis, 9 and 13% for peritoneal metastasis and 18 and 41% for retroperitoneal invasion. Ultrasonography was more sensitive than CT for detecting ascites, and CT was better for detecting retroperitoneal invasion. CONCLUSIONS: Both techniques allowed more accurate identification of liver metastasis and ascites than peritoneal metastasis and retroperitoneal invasion. In order to simplify scanning of patients with gastric cancer, we recommend that CT investigation should be done only in cases where the ultrasound findings are suspicious.

Budesonide, a locally acting steroid, prevents graft rejection in a rat model of intestinal transplantation.

BACKGROUND: The requirement for potent systemic immunosuppression to prevent intestinal graft rejection has resulted in high rates of infection and post-transplant lymphoproliferative disease. Budesonide (BUD) is a locally acting steroid that is almost completely metabolized during its first pass through the intestinal wall and liver. The present study examined whether BUD could prevent small bowel allograft rejection without causing the adverse systemic effects associated with prednisolone. METHODS: Orthotopic Brown Norway to Lewis rat small bowel allotransplants were randomly assigned to treatment with low-dose BUD (0.1 mg/kg/day, p.o.) and high-dose BUD (1.0 mg/kg/day, p.o.) with and without cyclosporine (CsA; 2 mg/kg/day s.c.). The following parameters were assessed: allograft survival, recipient plasma adrenocorticotrophic hormone (ACTH) levels, recipient adrenal, splenic and thymic weights, recipient CsA levels, and graft histopathology. RESULTS: Low- and high-dose BUD alone did not prolong graft survival compared with the untreated group (9.1+/-0.4 days vs. 11+/-0.8 days vs. 9.7+/-0.4 days, respectively). However, when low-dose BUD and high-dose BUD were given in combination with CsA, the mean graft survival times were prolonged to 27.6+/-5.3 and 36.6+/-8.0 days, respectively (P<0.01). ACTH levels, adrenal weights, and thymic weights were not significantly different in the treatment and control groups receiving intestinal transplants. CONCLUSIONS: BUD enhances the immunosuppressive effects of CsA and prolongs small bowel allograft survival in rats without inhibiting normal ACTH release. These data suggest that BUD may be a useful immunosuppressive agent for clinical intestinal transplantation.

Pattern of liver, kidney, heart, and intestine allograft rejection in different mouse strain combinations.

With advances in microsurgery and molecular biology, the mouse model for organ transplantation has become increasingly popular. However, knowledge about these models is limited, as only a small number of centers have experience with murine models. In this study, we compared the rejection pattern after liver, kidney, heart, and small bowel transplantation in the three different mouse strain combinations: (1) C57BL/6 (H2b)-->BALB/c (H2d), (2) BALB/c (H2d)-->CBA (H2k), and (3) C57BL/6-->C3H/HeN (H2k). Our study demonstrated that mouse allograft survival varies depending on the organ graft and on the donor-recipient strain combinations. The majority of liver allografts were spontaneously accepted despite complete MHC disparity. A mixed pattern of acute rejection and acceptance occurred in kidney recipients depending on the donor-recipient strain combination. All the heart grafts developed rejection and all the intestinal grafts were rapidly rejected with no spontaneous acceptance. The criteria for rejection, the potential applications, and the limitations of each model are discussed. The models described in this article provide a number of useful choices for organ transplantation research.

Influence of macrophage depletion on bacterial translocation and rejection in small bowel transplantation.

Rejection and sepsis can be intimately related following small bowel transplantation when rejection compromises normal intestinal barrier mechanisms and bacterial translocation results. Macrophages play a role in controlling the egress of intestinal luminal bacteria--and they have also been implicated in allograft rejection. In this study, the role of macrophages in rejection and bacterial translocation was evaluated by depleting macrophages in donors and/or recipients of rat small bowel allografts with injection of liposome-encapsulated dichloromethylene diphosphonate (CL2MDP). In preliminary studies, we demonstrated that a single intraperitoneal injection of liposome-encapsulated CL2MDP (350 mg/kg) depleted ED2-positive macrophages by > 90% in the liver mesenteric lymph nodes and proximal and distal small bowel, and by approximately 50% in the spleen. ED1-positive macrophages were depleted by > 90% in the liver and by approximately 50% at the other sites. ED3-positive macrophages were completely depleted. Dendritic cells were > 90% depleted in the spleen and mesenteric lymph nodes, but were not depleted in the small bowel. Macrophage depletion in the donor resulted in increased translocation of bacteria to the peritoneal cavity (P = 0.03) if recipient macrophages were present. With histopathologic analysis, a significantly milder rejection with less arteritis was seen in the allografts of the recipient macrophage-depleted group compared with nondepleted controls (P = 0.045). This suggests that recipient macrophages play an important role in rejection. With macrophage depletion in both the donor and the recipient, graft survival was prolonged significantly (13.2 +/- 1.9 days) compared with non-macrophage-depleted controls (9.2 +/- 1.3 days) (P = 0.003). These studies suggest that strategies targeting recipient macrophages may be useful in controlling small bowel allograft rejection without increasing bacterial translocation.