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K Boudjema

Publications and source records attributed to K Boudjema.

At least 91 records · Page 5Linked to original sources
PubMed1991

Effects of method of preservation on functions of livers from fed and fasted rabbits.

Livers from fed, fasted (48 h) and glucose-fed rabbits were preserved for 24 and 48 h by either simple cold storage (CS) or continuous machine perfusion (MP) with the University of Wisconsin preservation solutions. After preservation liver functions were measured by isolated perfusion of the liver (at 37 degrees C) for 2 h. Fasting caused an 85% reduction in the concentration of glycogen in the liver but no change in ATP or glutathione. Glucose feeding suppressed the loss of glycogen (39% loss). After 24 h preservation by CS livers from fed or fasted animals were similar including bile production (6.2 +/- 0.5 and 5.6 +/- 0.4 ml/2 h, 100 g, respectively), hepatocellular injury (LDH release = 965 +/- 100 and 1049 +/- 284 U/liter), and concentrations of ATP (1.17 +/- 0.15 and 1.18 +/- 0.04 mumol/g, glutathione (1.94 +/- 0.51 and 2.35 +/- 0.26 mumol/g, respectively), and K:Na ratio (6.7 +/- 1.0 and 7.7 +/- 0.5, respectively). After 48 h CS livers from fed animals were superior to livers from fasted animals including significantly more bile production (5.0 +/- 0.9 vs 2.0 +/- 0.3 ml/2 h, 100 g), less LDH release (1123 +/- 98 vs 3701 +/- 562 U/liter), higher concentration of ATP (0.50 +/- 0.16 vs 0.33 +/- 0.07 mumol/g) and glutathione (0.93 +/- 0.14 vs 0.30 +/- 0.13 mumol/g), and a larger K:Na ratio (7.4 vs 1.5). Livers from fed animals were also better preserved than livers from fasted animals when the method was machine perfusion. The decrease in liver functions in livers from fasted animals preserved for 48 h by CS or MP was prevented by feeding glucose. Glucose feeding increased bile formation after 48 h CS preservation from 2.0 +/- 0.3 (fasted) to 6.9 +/- 1.2 ml/2 h, 100 g; LDH release was reduced from 3701 +/- 562 (fasted) to 1450 +/- 154 U/liter; ATP was increased from 0.33 +/- 0.07 (fasted) to 1.63 +/- 0.18 mumol/g; glutathione was increased from 0.30 +/- 0.01 (fasted) to 2.17 +/- 0.30 mumol g; and K:Na ratio was increased from 1.5 +/- 0.9 to 5.3 +/- 1.0. This study shows that the nutritional status of the donor can affect the quality of liver preservation. The improvement in preservation by feeding rabbits only glucose suggests that glycogen is an important metabolite for successful liver preservation. Glycogen may be a source for ATP synthesis during the early period of reperfusion of preserved livers.

Adenosine Triphosphate↗
PubMed1991

[Glycogen storage of the liver: a determining factor of initial function of the hepatic graft].

In this study we have investigated the effects of hepatocytes glycogen storage on the quality of livers for transplantation. Rats were fed or fasted for 24 h and hepatocytes isolated and cold stored in UW solution for 24 and 48 hours. Viability of the cells was analyzed by LDH release after 2 hours incubation in L15 with O2. Also, rabbits were fed, fasted (48 h) or glucose fed (48 h) and livers cold stored for 6, 24 and 48 h in UW solution. Functions of the livers were analyzed by isolated perfusion for 2 hours. Hepatocytes from fasted rats released significantly more LDH than hepatocytes from fed rats after 24 and 48 h cold storage. In rabbit livers, fasting depleted glycogen by 85% but had no effect on ATP or glutathione concentration. Livers from fasted rabbits produced similar amount of bile, released similar concentrations of lactate dehydrogenase and aspartate transaminase into the perfusate, maintained similar concentrations of glutathione after 24 hours preservation when compared to fed animals. After 48 h preservation livers from fasted animals were less viable than livers from fed animals and the decrease of liver functions in livers from fasted animals preserved for 48 hours was prevented by feeding glucose. This study shows that liver glycogen storage in hepatocyte is an important metabolite for successful liver preservation. Glycogen may be a source for ATP and antioxydant synthesis during the early period of reperfusion.

Adenosine Triphosphate↗
PubMed1991

[Changes in glutathione levels in the renal cortex of dogs during preservation by continuous hypothermic pulsatile perfusion].

A loss of glutathione (GT) from the kidney can cause increased sensitivity to oxygen free radical-induced injury. In this study we investigated the effects of kidney preservation on GT concentration in the cortex tissue, and how various GT precursors affect GT concentration in the dog kidney. During five day continuous machine perfusion of the kidney at 5 degrees C, there was a loss of GT from the cortex tissue (524 +/- 1% GT remained after 5 days). Perfusion with reduced glutathione (GSH, 3 mM) suppressed this loss (77 +/- 11% of GT remained after 5 days). Oxidized glutathione (GSSG) did not prevent the loss of GT. The addition of the three amino acids that make up GT (glycine, glutamic acid, and cysteine, 3 mM each) stimulated the synthesis of GT in the kidney during hypothermic perfusion (137 +/- 23% of control values at 5 days). The increase in tissue GT stimulated by GSH or other precursors was sensitive to the GT synthetase inhibitor, buthionine sulfoximine. This indicated active GT metabolism even at 5 degrees C in perfused kidneys. This study showed that in kidney preservation there was a loss of GT that could be suppressed by the addition of various precursors for GT synthesis. The loss of GT from preserved kidneys may be one cause of post-transplant renal injury which could be prevented by utilization of the appropriate GT precursors.

Animals↗
PubMed1991

[En bloc transplantation of liver, stomach, pancreas and small intestine in an infant. Apropos of a case].

The now common practice of joint kidney and pancreas or heart or lung transplantation is being completed by other combinations. This is shown by our case of en bloc liver-pancreas-stomach-duodenum-small bowel transplantation in an 18-month-old infant with small bowen atresia complicated by biliary cirrhosis secondary to total parenteral feeding, after the failure of an intraperitoneal visceral transplant at 1 year of age. The graft was taken from an 8-year-old donor and was not pretreated. Being made of the whole intraperitoneal visceral mass, it had to be adapted to the recipient's size by ex vivo exeresis of the right liver, of the spleen, of the terminal ileon and of the colon. Following intraperitoneal visceral exenteration in the recipient, the graft was inserted in an orthoptic position with a digestive reconstruction by esogastric anastomosis and terminal ileostomy. Immunosuppression combined steroids, azathioprine, ciclosporine, and the biological and immunological follow-up regarded the hepatic and pancreatic functions. The intestinal graft was controlled by repeated biopsies through the stomy. Rectal biopsies and lymphocyte typing in the peripheral blood allowed watching for the occurrence of a possible graft-versus-host disease. The outcome was marked by the persistence of massive lymphorrhea during three months and severe central neurological disorders caused by the difficulties to adapt the level of ciclosporine. The hepatic and pancreatic functions became normal within a few days, and the intestinal function allowed progressively suppressing parenteral feeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1991

Changes in glutathione concentration in hypothermically perfused dog kidneys.

A loss of glutathione from the kidney can cause increased sensitivity to oxygen free radical-induced injury. In this study we investigated the effects of kidney preservation on glutathione and how various glutathione precursors affect glutathione concentration in the dog kidney. During 5-day continuous machine perfusion of the kidney at 5 degrees C, a loss of glutathione from the cortex tissue was seen (24% +/- 1% glutathione remained after 5 days). Perfusion with reduced glutathione (GSH, 3 mmol/L) suppressed this loss (77% +/- 11% of glutathione remained after 5 days). Oxidized glutathione (GSSG) did not prevent the loss of glutathione. The addition of the three amino acids that make up glutathione (glycine, glutamic acid, and cysteine, 3 mmol/L each) also suppressed the loss of glutathione (82% +/- 13% remained at 5 days). The glutathione precursor, thioproline, a cysteine delivery compound, in combination with glycine and glutamic acid (3 mmol/L each), stimulated the synthesis of glutathione in the kidney during hypothermic perfusion (137% +/- 23% of control values at 5 days). The increase in tissue glutathione stimulated by GSH or other precursors was sensitive to the glutathione synthetase inhibitor, buthionine sulfoximine. This indicated the existence of active glutathione metabolism even at 5 degrees C in perfused kidneys. This study showed that in kidney preservation a loss of glutathione occurred that could be suppressed by the addition of various precursors for glutathione synthesis. The loss of glutathione from preserved kidneys may be one cause of posttransplant renal injury that could be prevented by use of the appropriate glutathione precursors.

Animals↗
PubMed1990

Prolonged survival of murine thyroid allografts after 7 days of hyperbaric organ culture in the UW preservation solution at hypothermia.

Organ culture of murine thyroid allografts in hyperbaric oxygen (95% O2 at 25 psi, 37 degrees C) for 48 hr, results in prolonged allograft survival. Endocrine tissues can be cultured at 37 degrees C--however, this method may not be applicable to vascularized organs at normothermia. The aim of this study was to apply hyperbaric oxygen culture (HOC) under organ preservation conditions (hypothermia, UW solution) that have been shown to be successful in clinical organ transplantation. B10BR/SGSNJ murine thyroid lobes were transplanted beneath the kidney capsule of C57BL/10J recipients. Thyroids were cultured in Eagle's MEM at 37 degrees C (controls) and at 5 degrees C, under hyperbaric conditions (95% O2:5% CO2, 25 psi). Alternatively, thyroids were cultured in UW solution (+/- allopurinol/GSH) at 5 degrees C, for up to 7 days. Graft survival was determined 21 days posttransplant by 125I uptake and by histology. In Eagle's MEM, HOC at 37 degrees C/48 hr and 5 degrees C/7 days, resulted in 93% and 20% allograft survivals, respectively. In UW solution (- allopurinol/glutathione [GSH]), HOC at 5 degrees C/7 days resulted in 83% allograft survival: immunoperoxidase staining showed a decrease of MHC class I alloantigen expression. Oxygen free radical scavenger (allopurinol/GSH) addition to the UW solution diminished this effect and suggested an oxygen free radical-mediated mechanism in immunoalteration. These results demonstrate that HOC for 7 days reduced the antigenicity and immunogenicity of murine thyroid grafts under conditions that simulate organ preservation. Hypothermic hyperbaric oxygen culture conditions require testing in a higher animal species and in vascularized grafts to determine if this method can be applied to whole-organ transplantation.

Adenosine↗
PubMed1990

The effects of fasting on the quality of liver preservation by simple cold storage.

Although livers can be successfully preserved for 24 hr or more, often the transplanted livers have poor or no (primary nonfunction) function. The quality of the liver does not appear dependent upon the time of preservation but may be dependent upon the condition of the donor. In this study we have investigated the effects of fasting on the quality of livers for transplantation. Rabbits were fasted (48 hr) and livers preserved in the UW solution for 6-8 hr. Functions of the liver were analyzed by isolated perfusion for 2 hr. Also, pigs were fasted for 72 hr, livers preserved for 12 hr, and viability determined by orthotopic transplantation. Fasting depleted the liver glycogen by 85% but had no effect on ATP or glutathione concentrations. Rabbit livers from fasted animals produced similar amounts of bile, released similar concentrations of lactate dehydrogenase (LDH) and aspartate amino transaminase (AST) into the perfusate, maintained similar concentrations of ATP and glutathione in the tissue, and had a similar intracellular K:Na ratio after 24-hr preservation when compared to livers from fed animals. After 48-hr preservation, livers from fasted animals were less viable than livers from fed animals, including: reduced bile production (2.0 +/- 0.3 vs. 5.0 +/- 0.9 ml/2 hr, 100 g), greater release of LDH (3701 +/- 562 units vs. 1123 +/- 98 units) and AST, less ATP (0.326 +/- 74 vs. 0.802 +/- 160 nmol/g), less glutathione (0.303 +/- 13 vs. 0.933 +/- 137 nmol/g), and a lower K:Na ratio (1.5 +/- 0.9 vs. 7.4 +/- 0.6). Pigs receiving livers from fed animals preserved for 12 hr had better survival (5/6, 83%) than livers from fasted animals (3/6, 50%). The results show that the nutritional status of the donor can affect the outcome of liver preservation and transplantation. Increased injury in livers from fasted animals may be due to the loss of glycogen that may be an essential source of energy in the initial posttransplant period. In clinical liver transplantation the nutritional status of the donor may be an important factor in the initial function of the liver, and methods to increase the nutritional status of the donor may be important in increasing the quality of livers.

Adenosine Triphosphate↗
PubMed1990

Effect of oxidized and reduced glutathione in liver preservation.

Glutathione spontaneously oxidizes in the UW solution for organ preservation and reduced glutathione (GSH) is converted to oxidized (GSSG) glutathione. To determine the effects of the oxidized or reduced forms of glutathione on liver preservation dog livers were preserved for 24 and 48 hr with the UW solution containing either GSH or GSSG. After 24 hr of preservation the form of glutathione did not affect survival or the postoperative course of the animals. All animals survived (three per group) with near-normal liver functions by the third to fifth postoperative day. When preservation was extended to 48 hr survival was 100% (6/6) with GSH and 29% (2/7) with GSSG. The dogs that died developed primary nonfunction of the liver. This study shows that GSH is an important component of the UW solution for 48-hr preservation of the dog liver. The presence of GSSG does not prevent successful 24-hr preservation of the liver, which has been confirmed in clinical studies. However, for 48-hr preservation GSH is required and GSSG is not suitable.

Adenosine↗
PubMed1990

Organ preservation: experience with University of Wisconsin solution and plans for the future.

Transplantation of organs continues to be a primary therapeutic modality for treatment of end-stage organ disease, and 1-year graft survival rates show increasing improvements for most organs. A number of transplant centers show 1-yr graft survival rates approaching 90% or more for the kidney, liver and pancreas. Rejection continues to be the major cause for loss of organs and there is still a major shortage of organs for transplantation. Additionally, many organs showed delayed graft function (or primary nonfunction) which may be related to either donor factors or preservation factors. The University of Wisconsin solution for organ preservation has increased the safe time of preservation for the liver, kidney, and pancreas and helped to increase the quality and number of organs available for transplantation. However, the long-range goal of organ preservation (unlimited preservation) is still far from being reached. In the past, preservation could accurately be categorized as an art and preservation solutions were developed based upon theoretical rationales about the mechanisms of organ injury at hypothermia and what agents would suppress injury. The utility and success of this approach is exemplified by the developments of Collins solution and the UW solution. However, further developments in methods to increase the quality and duration of preservation of all transplantable organs would appear to be dependent upon defining, systematically, how organs are injured and what can be done to suppress the injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Forecasting↗
PubMed1990

[Is Trendelenburg's procedure still useful in 1990? Apropos of 3 cases of massive pulmonary embolism surgically treated successfully in a general surgery department].

The authors report about 3 cases of massive pulmonary embolism operated successfully in a context of general surgery. As they discuss the data given by the literature, they establish the remaining indications of Trendelenburg's procedure, as well as the problems encountered today to perform it without the help of extracorporeal circulation.

Emergencies↗
PubMed1990

[Experience in hepatic transplantation. Report of 118 cases].

From February 1978 to November 1989, 118 orthotopic liver transplantations were performed in 106 patients, including 100 adults and 6 children; 11 of these grafts were performed before 1984. The study of this series emphasizes the casuistical peculiarities, with high incidence of alcoholic cirrhosis, 24/106 (22.6%) and of fulminating hepatitis, 17/106 (16%). The study of the results yields a real survival rate of 61% in the total series, 78% for the recent period including the past 3 years, and 86% if excluding the emergent cases. The comments also deal with the changes in the procedure and in postoperative complications, with some immunological issues and with the peculiar features connected with the insertion of this operation into a combined medical and surgical program of multi-organ transplantation.

Adult↗