Biomedical subjects

D Calise

Publications and source records attributed to D Calise.

24 records · Page 2Linked to original sources

PubMed1990

[Development of a model of combined liver-intestinal transplantation in rats for the study of immune tolerance].

The aim of a combined liver/intestinal transplantation experimental model in rats is the study of the liver-induced tolerance of a solid, vascularized and highly immunogenic organ. Animals. Inbred Lewis rats were divided in two syngenic groups: 1. small intestine grafting (n = 10); 2. combined liver/intestinal grafting (n = 10). Intestinal grafting was performed 15 days after liver transplantation. Results. 10/10 animals were alive after 60 days in the first group and 7/10 in the second. Intestinal graft viability was good and 3 intestinal biopsies were done without any complication in each animal. All samples were histologically normal. Our study using syngenic animals prove that combined liver/intestinal transplantation is technically possible and reliable.

Animals↗

PubMed1989

[Anastomoses of the small intestine in a septic environment protected by polyglactin 910-collagen mesh. Experimental study in rats].

An experimental study was carried out in rats to evaluate the outcome of small bowel anastomoses in the presence of peritonitis with and without protection by a polyglactin 910 mesh. One hundred and thirty rats were operated. 1) Thirty small bowel anastomoses were performed in a sterile environment to evaluate the morbidity and mortality due to the surgical procedure itself. All these animals had an uneventful course. 2) Forty anastomoses were performed in a septic environment without protection. Twelve rats died immediately after the procedure. Six rats developed an anastomotic fistula and 22 had an uneventful course. 3) Sixty anastomoses were performed in a septic environment and protected by a polyglactin 910 mesh. Seventeen rats died immediately after the procedure. There were no anastomotic disruptions. Seventeen rats had an uneventful course, and 28 (65%) developed stenosis of the anastomosis. Protection of small bowel anastomoses by a polyglactin 910 mesh appears to effectively prevent disruptions (no anastomotic fistulae or locoregional infections were recorded). However, the mesh is responsible for an intense inflammatory reaction, that often results in intestinal obstruction.

Anastomosis, Surgical↗

PubMedDate not supplied

Use of human mesenteric arteries to study chronic vascular rejection in SCID/beige mice reconstituted with human spleen cells.

We wanted to establish a preclinical model of chronic vascular rejection (CVR) by transplanting small arteries from the mesentery of cadaveric organ donors by the rapid "sleeve" technique into SCID/beige mice reconstituted with human allogeneic spleen cells. After institutional authorization and with informed consent from relatives, we obtained tissues and cells from cadaveric organ donors. A piece of mesentery was recovered from the donor and kept in buffered solution at 4 degrees C until use. After dissection of the mesentery, small arteries of suitable size were transplanted in place of the infrarenal aorta of the mice. Cells for the immunological reconstitution of the mice were spleen cells from the same or other organ donors. Twenty-three suitable arterial segments were obtained from the mesentery of three cadaveric donors. Ten of the mice received 3 x 10(7) human spleen cells intraperitoneally 1 week after the arterial graft and they all showed circulating human CD3+ and CD19+ cells 2 weeks after injection. The mice were sacrificed 5 weeks after the arterial graft. SCID/beige mice reconstituted with allogeneic spleen cells showed a typical CVR, whereas mice that received no cells had a normal vascular anatomy. We believe our model is well suited for the study of treatment of CVR under human allograft conditions.

Animals↗

PubMedDate not supplied

Chronic vascular rejection: histologic comparison between two murine experimental models.

BACKGROUND: We previously developed an experimental model to study chronic vascular rejection (CVR) in mice, the orthotopic aortic allograft. More recently we performed human arterial grafts into SCID/Beige mice reconstituted with human spleen cells. We report herein the differences in CVR lesions. MATERIAL AND METHODS: In the first model, recipient mice were C57BL/6 (H-2b), and donor mice were DBA/2 (H-2d). In the second model, terminal branches of the human superior mesenteric artery were transplanted into SCID/Beige mice in the infrarenal aorta. Human immune reconstitution was achieved by a single intraperitoneal injection of 30 x 10(6) human spleen cells. The presence of human lymphocytes and IgG was verified weekly. In both models, the vascular grafts were inserted in the infrarenal aortic position using the sleeve technique. The transplanted mice were sacrificed at 35 days after the operation. The grafts were analyzed by histology and morphometry. The mean intimal thickening was calculated based on transverse sections at 0.1-mm intervals. RESULTS: Typical CVR lesions developed with neointimal thickening, T-cell infiltration, and smooth muscle cell (SMC) proliferation in both models. In the mouse aortic model, disappearance of SMC in the media was noted in contrast to human arterial transplants, where the media remained intact. CONCLUSION: Other groups have noted that arteries conserve their media in clinical organ transplants. From this point of view, the lesions in the second experimental model (human arteries) better reflect the pathology of CVR in clinical transplantation than the murine aortic transplant model.

Animals↗

PubMedDate not supplied

Human immune reconstitution with spleen cells in SCID/Beige mice.

BACKGROUND: We developed an original experimental model to study chronic vascular rejection (CVR) consisting of a graft of human mesenteric artery followed by human immune reconstitution into CB.17 SCID/Beige mice. Human immune reconstitution achieved after human PBMC injection has often been variable and incomplete. The aim of this work was to develop an alternative method to achieve a complete, functional human immune reconstitution. METHOD: After institutional authorizations, spleen cells were recovered from cadaveric organ donors. Single intraperitoneal injections of various doses of spleen cells were made into 70 CB.17 SCID/Beige mice. Reconstitution of the human immune system was monitored by flow cytometry (circulating human cells) and ELISA (human IgG). Colonization of murine lymphoid organs by human cells was studied by immunohistochemistry and flow cytometry. Evaluation of the immune function consisted of examination of CVR lesions in human arterial grafts. The animals were humanely killed at day 28. RESULTS: After injection of 30 to 40 x 10(6) spleen cells, the mice showed significant human CD3(+), CD19(+), and CD56(+) populations in peripheral blood. The mean human cells levels were, respectively, 8.2% +/- 5.4%, 2.9% +/- 1.2%, and 5.3% +/- 5.1%. Murine spleen and mesenteric lymph nodes were colonized by human T and B cells, while the murine thymus was only colonized by human T cells. Human IgG was detected in murine serum (65.9 +/- 63.3 mg/L) and typical CVR lesions were observed within the allogeneic grafts. CONCLUSION: Intraperitoneal injection of 30 to 40 x 10(6) human spleen cells into CB.17 SCID/Beige mice induces complete and functional human immune reconstitution allowing the study of CVR under human allogeneic conditions.

Aged↗

PubMedDate not supplied

[Intrasplenic transplantation of hepatocytes in spf-ash mice with congenital ornithine transcarbamylase deficiency].

The only curative treatment for enzymatic deficiency such as Ornithine transcarbamylase (OTC) deficiency is liver transplantation. We have studied hepatocyte transplantation as alternative therapy in spfash mouse, the animal mode of OTC deficiency. Hepatocytes were obtained from C57BL/6J strain mice (normal OTC activity). About 2 x 10(6) hepatocytes in 0.1 ml were injected in the spleen of recipient mouse. We then studied: ammonemia, urinary orotate, spleen OTC activity, liver OTC activity, histological presence of hepatocytes in the spleen, immunohistochemical OTC staining in liver and spleen hepatocytes. In syngeneic hepatocyte transplantation (C57 > C57) functional transplanted hepatocytes were found in the spleen over 5 months after transplantation. In allogeneic transplantation (C57 > spfash) without immunosuppression, hepatocytes were rejected in 3 days. With cyclosporine immunosuppression, hepatocyte survived 12 days and showed OTC activity. A few transplanted hepatocytes with OTC activity migrated from spleen of liver. Metabolic disorder were not corrected. This technically easy method (compared to whole liver transplantation) demonstrated 2 problems: reject in allogeneic transplantation and the small amount of injected enzyme.

Animals↗