Three years clinical experience with intestinal transplantation

BACKGROUND: After the successful evolution of hepatic transplantation during the last decade, small bowel and multivisceral transplantation remains the sole elusive achievement for the next era of transplant surgeons. Until recently, and for the last thirty years, the results of the sporadic attempts of intestinal transplantation worldwide were discouraging because of unsatisfactory graft and patient survival. The experimental and clinical demonstration of the superior therapeutic efficacy of FK 506, a new immunosuppressive drug, ushered in the current era of small bowel and multivisceral transplantation with initial promising results. STUDY DESIGN: Forty-three consecutive patients with short bowel syndrome, intestinal insufficiency, or malignant tumors with or without associated liver disease, were given intestinal (n=15), hepatic and intestinal (n=21), or multivisceral allografts that contained four or more organs (n=7). Treatment was with FK 506 based immunosuppression. The ascending and right transverse colon were included with the small intestine in 13 of the 43 grafts, almost evenly distributed between the three groups. RESULTS: After six to 39 months, 30 of the 43 patients are alive, 29 bearing grafts. The most rapid convalescence and resumption of diet, as well as the highest three month patient survival (100 percent) and graft survival (88 percent) were with the isolated intestinal procedure. However, this advantage was slowly eroded during the first two postoperative years, in part because the isolated intestine was more prone to rejection. By the end of this time, the best survival rate (86 percent) was with the multivisceral procedure. With all three operations, most of the patients were able to resume diet and discontinue parenteral alimentation, and in the best instances, the quality of life approached normal. However, the surveillance and intensity of care required for these patients for the first year, and in most instances thereafter, was very high, being far more than required for patients having transplants of the liver, kidney or heart. CONCLUSIONS: Although intestinal transplantation has gone through the feasibility phase, strategies will be required to increase its practicality. One possibility is to combine intestinal transplantation with contemporaneous autologous bone marrow transplantation

Abdominal multivisceral transplantation

Under FK506-based immunosuppression, 13 abdominal multivisceral transplantations were performed in 6 children and 7 adults. Of the 13 recipients, 7 (53.8%) are alive and well with functioning grafts after 9 to 31 months. Six recipients died: Three from PTLD, one from rejection, one from sepsis, and one from respiratory failure. In addition to rejection, postoperative complications occurring in more than isolated cases included PTLD (n=6), abdominal abscess formation (n=5), pancreatitis (n=3), and ampullary dysfunction (n=2). In addition, infection by enteric microorganisms was common during the early postoperative period. Currently, all 7 survivors are on an oral diet and have normal liver function. Two recipients (one insulin-dependent) require antidiabetes treatment, in one case following distal pancreatectomy and in the other after two episodes of pancreatic rejection. Thus, abdominal multivisceral transplantation is a difficult but feasible operation that demands complex and prolonged posttransplantation management. It is not yet ready for application and awaits a better strategy of immune modulation. © 1995 by Williams & Wilkins

Mechanism of Microwave Assisted Hydrodistillation Studied Through Heat Analysis

In this study, the efficiency of heating mechanism of microwave assisted hydrodistillation (MAHD) in the extraction of cinnamon bark oil was investigated. The optimum conditions used to analyse the heating performance were 8:1 ratio of water to cinnamon bark powder and fixed 250 W of irradiation power. The increasing temperature in the cinnamon bark matrix was dependent on the solvent, physical, dielectric and heating properties of the cinnamon matrix. Due to the high dielectric properties of water it accelerated the process of extraction. However, after the cinnamon matrix reached the boiling point, the density of solvent decreased which led to decrease in the dielectric properties. Volume rate of heat generation and penetration depth of microwave was also evaluated. The rate of volume heat generation reduced when the exposure time increase which is related to the reducing dielectric properties of cinnamon matrix. The penetration depth was calculated to support the data of dielectric properties. This study therefore produced an in depth justification necessary to understand the heating mechanism of MAHD in extraction of cinnamon bark essential oil

Rejection of human intestinal allografts: Alone or in combination with the liver

The current results of the present series demonstrate that intestinal allografts are more vulnerable to rejection and continue to be at a significantly higher risk long after transplantation compared with isolated liver allograft recipients. Unexpectedly, a combined liver allograft does not protect small bowel from rejection. The necessarily continuous heavy immunosuppression for these unique recipients is potentially self-defeating. This is clearly demonstrated by their high susceptibility to early and late infectious complications after transplantation as reported in this issue. With the minimal graft-versus-host disease threat in this clinical trial, our revised protocol for future intestinal transplantation is to maximize the passenger leukocyte traffic with supplementary bone marrow from the same intestinal donor in an attempt to augment the development of systemic chimerism and the gradual induction of donor-specific nonreactivity

Photorespiration: metabolic pathways and their role in stress protection

Photorespiration results from the oxygenase reaction catalysed by ribulose-1,5-bisphosphate carboxylase/ oxygenase. In this reaction glycollate-2-phosphate is produced and subsequently metabolized in the photorespiratory pathway to form the Calvin cycle intermediate glycerate-3-phosphate. During this metabolic process, CO2 and NH3 are produced and ATP and reducing equivalents are consumed, thus making photorespiration a wasteful process. However, precisely because of this ine¤ciency, photorespiration could serve as an energy sink preventing the overreduction of the photosynthetic electron transport chain and photoinhibition, especially under stress conditions that lead to reduced rates of photosynthetic CO2 assimilation. Furthermore, photorespiration provides metabolites for other metabolic processes, e.g. glycine for the synthesis of glutathione, which is also involved in stress protection. In this review, we describe the use of photorespiratory mutants to study the control and regulation of photorespiratory pathways. In addition, we discuss the possible role of photorespiration under stress conditions, such as drought, high salt concentrations and high light intensities encountered by alpine plants

Technical aspects of intestinal transplantation.

Since the advent of the potent immunosuppressive agent FK 506, intestinal transplantation has become a feasible therapeutic option for patients with irreversible intestinal failure. In this chapter, we present our clinical experience with intestinal transplantation, focusing on the technical aspects of both the donor and recipient operations. The logistics of the operative procedure have been described previously