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Biomedical subjects

J Duff

Publications and source records attributed to J Duff.

At least 55 records · Page 3Linked to original sources
PubMed1992

Surgical technique for combined liver/intestine transplantation in rats.

Simultaneous liver transplantation may reduce the risk of intestinal transplant rejection. We have recently developed two new models of combined liver/intestine transplantation (LIT) in the rat to study this phenomenon. Herein, we report our experience with LIT using a single donor (SD) or multiple donors (MD). Large volumes of fluid were required to prevent a drop in the mean arterial pressure during the anhepatic phase in the SD recipients. Many of the SD recipients died of intraoperative hypovolemic shock (57%). The MD recipients had a shorter anhepatic time (12 +/- 1 minutes vs. 17 +/- 2 minutes; P less than 0.01) and a shorter warm intestinal ischemia time (15 +/- 1 minutes vs. 32 +/- 2 minutes; P less than 0.01). Operative mortality rates were much lower in the MD recipients (10% vs. 68%; P less than 0.01). The long-term survival rate using MD was 71% at 1 month. Graft function was normal in the long-term survivors. LIT with MD provides a good model to study the immunological effects of multivisceral grafting.

Animals↗
PubMed1991

Refined technique for intestinal transplantation in the rat.

Unlike other solid organ transplants, intestinal transplantation (IT) remains a highly experimental procedure. Rejection, sepsis, and graft-versus-host disease have been the major barriers to successful IT in humans. These problems can be studied in the rat model, but this requires a reliable surgical technique that will produce high survival rates and excellent graft function. Herein, we review 400 consecutive IT in rats and describe important technical aspects of surgery. Technical modifications that have helped to reduce the morbidity after IT in rats include 1) minimizing mechanical and ischemic injuries to grafts during the donor procedure, 2) marking the portal vein and aortic conduit with sutures to ensure correct orientation of the graft, 3) using a macaroni noodle to stent the intestinal anastomosis, and 4) administering large volumes of crystalloid to maintain a normal blood pressure during the donor and recipient surgeries. The survival rate in 298 rats with accessory, heterotopic grafts was 90%. The survival rate in 102 rats with orthotopic (in continuity) graft (OIT) was 86%. Rats have survived more than 500 days after OIT, maintaining normal weights, intestinal function, and intestinal histology.

Anastomosis, Surgical↗
PubMed1991

A comparison of heterotopic and orthotopic intestinal transplantation in rats.

Two surgical techniques are commonly used for small intestinal transplantation: heterotopic (accessory) intestinal grafting (HIT), where the small bowel is initially defunctioned with restoration of intestinal continuity at a later date, and orthotopic (in continuity) intestinal grafting (OIT), where the small bowel is immediately anastomosed to the native intestine. The present experiments were undertaken to compare the advantages and disadvantages of these two surgical models. Graft barrier function (intestinal permeability), intestinal histology, and graft survival were evaluated after heterotopic and orthotopic intestinal transplantation in the following groups of rats: group 1: isografts, group 2: untreated allografts, group 3: low-dose cyclosporine-treated allografts (subcutaneous CsA 2 mg/kg/day), and group 4: high-dose CsA-treated allografts (subcutaneous CsA 4 mg/kg/day). Intestinal permeability was consistently higher after HIT than OIT in all of the groups (ANOVA; P less than 0.01). Histological evidence of rejection appeared earlier after HIT than OIT (HIT 5th postoperative day (POD); OIT 7th POD; P less than 0.05). The mean survival of untreated allografts was longer after HIT than OIT (HIT 15.7 +/- 6 days, OIT 9.2 +/- 1 days, P less than 0.05). The rats treated with low-dose CsA after OIT lost weight and died of rejection after a mean survival time of 17.7 +/- 2 days, while the rats treated with low-dose CsA after HIT remained well until sacrifice on POD 28 (P less than 0.01). The rats with isografts and rats with allografts treated with high-dose CsA remained well after HIT and OIT until sacrifice on the 28th POD. These data suggest that nutrients and other factors in the succus entericus may improve gut barrier function and delay the onset of rejection after OIT. However, rejection of the orthotopic intestinal graft is usually fatal, while rejection of the heterotopic graft is often surprisingly well tolerated. These factors must be taken into consideration when choosing a surgical technique for intestinal transplantation in humans.

Animals↗
PubMed1991

Intestinal permeability and bacterial translocation following small bowel transplantation in the rat.

In addition to its role in absorbing nutrients, the intestinal mucosa provides an important barrier against toxins and bacteria in the bowel lumen. The present study evaluated gut barrier function following orthotopic (in continuity) intestinal grafting in rats. Graft histology, intestinal permeability, and bacterial translocation to the grafted mesenteric lymph nodes, the host's liver, and the host's spleen were assessed on the 3rd, 5th, and 7th postoperative days. The study group received no immunosuppression after allotransplantation. The two control groups included rats with isografts and rats with cyclosporine-treated allografts. On the 7th POD, the study animals had moderate transmural inflammation due to rejection, with normal histology in the isografts and CsA-treated allografts; increased intestinal permeability, measured by urinary excretion of oral 51Cr-EDTA (P less than 0.01); and increased number of bacteria in the MLN and spleen (P less than 0.05). The number of bacteria in the MLN and spleen of the study group positively correlated with the changes in intestinal permeability (P less than 0.05). Rejection of the orthotopic intestinal graft leads to increased intestinal permeability and bacterial translocation from the lumen of the graft to the host's reticuloendothelial system. Measures to improve gut barrier function and antibiotic therapy during rejection episodes may help reduce the incidence of septic complications after intestinal grafting.

Animals↗
PubMed1990

Successful small-bowel/liver transplantation.

A patient with the short-gut syndrome and antithrombin III deficiency underwent small bowel and liver grafting a year ago. Transient, mild graft-versus-host disease and intestinal rejection occurred within 2 months of grafting and were easily managed. Parenteral nutrition was discontinued 8 weeks after surgery. The patient has maintained normal nutritional indices while on an unrestricted oral diet. Small-bowel/liver grafting is feasible for patients with the short-gut syndrome and associated liver disorders. Further experience is needed to determine the specific risks, benefits, and general applicability of this procedure.

Adult↗
PubMed1990

Nutrition and public health: division of labour in the study of nutrition.

This article draws inferences from changes in the style of a nutrition journal which was originally published by the Commonwealth Department of Health, and is now published by the Australian Dietitians' Association. The changes reflect developments in the field of nutrition, towards more 'scientific' styles of inquiry and publishing, against the backdrop of a division of labour in which (mainly male) laboratory scientists produced scientific knowledge which was then communicated by (mainly female) dietitians and nutritionists. Consistent with the approach of the 'new public health', this paper argues that reliance upon 'scientific' methods alone diverts attention from the social, economic and political conditions which help explain not only the improvements earlier in the century, but current difficulties in bringing about further improvements.

Australia↗