Altered cellular membrane fluidity levels and lipid peroxidation during experimental pancreas transplantation.

Although the pathogenesis of ischemia reperfusion (IR) injury is based on complex mechanisms, free radicals play a central role. We evaluated membrane fluidity and lipid peroxidation during pancreas transplantation (PT) performed in 12 pigs (six donors and six recipients). Fluidity was measured by fluorescence spectroscopy, and malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations were used as an index of lipid oxidation. Pancreatic tissues were collected as follows: (A) donor, immediately before vascular clamping; (B) graft, following perfusion lavage with University of Wisconsin preservation fluid; (C) graft, after 16 h of cold ischemia; and (D) recipient, 30 min vascular postreperfusion. Fluidity and MDA and 4-HDA concentrations were similar in cases A, B, and C. However, there was significant membrane rigidity and increased lipid peroxidation after reperfusion (D). These findings suggest that reperfusion exaggerates oxidative damage and may account for the rigidity in the membranes of allografts during PT.

Cystatin C level as a predictor of death and cardiovascular events after liver transplantation.

BACKGROUND: The diagnosis of renal failure is important in cirrhosis. Cystatin C (Cys) has been suggested not only to be a sensitive marker of renal function, but also a stronger predictor of the risk of death and cardiovascular events in heart failure. Our aims were to investigate plasma Cys concentrations for the detection of moderately impaired renal function and its association with mortality and cardiovascular events among cirrhotic patients after liver transplantation (OLT). METHODS: Clinical and biochemical data, including Cys levels, were analyzed in 99 cirrhotic candidates for OLT. We recorded cardiovascular events. RESULTS: Receiver-operator characteristics curves showed a similar efficiency to detect a creatinine clearance <60 mL/min per 1.73m(2) (Cys = 0.753; creatinine [Cr] = 0.799; glomerular filtration rate [GFR, Cockcroft-Gault formula] = 0.842; urea = 0.823; P = .001). However, at cutoff concentrations of 1.3 mg/dL, Cr showed great specificity (96%) but poor sensitivity (13%), while the sensitivity of Cys was superior (83%) with moderate specificity (55%) at a cutoff of 1400 ng/mL. Over a median follow-up of 2.7 years, 14 patients developed a cardiovascular event, including, 11 who displayed Cys levels >1400 ng/mL before OLT, showing a significant difference (P < .05) compared to patients who showed no cardiovascular event. Kaplan-Meier analysis Cys discriminated significantly better than the Model for End-Stage Liver Disease score between survivors and nonsurvivors (P < .05). CONCLUSION: Cys determinations could be a valuable tool for early diagnosis of renal dysfunction among cirrhotic patients. Furthermore, it may predict the risk of death and cardiovascular events after OLT.

Inter-alpha-trypsin inhibitor heavy chain 4 as a marker of acute rejection in pancreas allotransplantation in pigs.

BACKGROUND/AIMS: An early, simple, and reliable marker for acute pancreatic allograft rejection is not available. Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) is an interleukin-6-dependent acute-phase positive protein that can act as an anti-inflammatory protein. We studied the response of the ITIH4 in pigs undergoing pancreas allotransplantation (PT) and evaluated this protein as a biomarker for acute graft rejection. METHODS: PT with enteric drainage of the exocrine secretion and systemic venous drainage was performed on 12 Landrace pigs. No immunosuppression was administered. Serum concentrations of glucose, amylase, lipase, insulin, C-peptide, and ITIH4 were determined daily. RESULTS: The response of ITIH4 to PT was early, intense, and prolonged, with 2 peaks in serum concentration. The first peak, which started on day 1 and reached maximum (around 6 mg/dL) on day 3, was attributed to the systemic acute phase response to surgical stress. The second peak, which exceeded the first peak and reached maximum (>8 mg/dL) on day 6, began when the recipients were still normoglycemic, and preceded onset of the diabetic state caused by acute graft rejection by an average of 4 days. CONCLUSION: Serum ITIH4 could help to predict subclinical acute graft rejection after PT in pigs.

Relevance of epidermal growth factor to improve steatotic liver preservation in IGL-1 solution.

AIM: Static preservation solution is critical for liver graft outcomes, especially when steatosis is present. Institut Georges Lopez (IGL)-1 solution protects fatty livers effectively against cold ischemia reperfusion injury. Its benefits are mediated by nitric oxide and prevention of oxidative stress. The supplementation of IGL-1 with epidermal growth factor (EGF) enhances steatotic graft preservation by increasing adenosine triphosphate content, thereby mitigating oxidative stress and mitochondrial damage. METHODS: After steatotic livers were preserved for 24 hours in IGL-1 solution with or without EGF supplements, they were perfused ex vivo for 2 hours at 37°C. The benefits of EGF were assessed by evidences of hepatic damage and function--transaminases, bile production, and flow rate--as well as by other factors presumably associated with the poor tolerance of fatty livers toward cold ischemia-reperfusion injury (IRI)--energy metabolism, mitochondrial damage, oxidative stress, eNOS activity and proinflammatory interleukin (IL) beta content. RESULTS: Steatotic livers preserved in IGL-1 solutions supplemented with EGF (10 µg/L) showed lower transaminase levels, greater bile production, and ameliorated flow rates when compared to IGL-1 alone. In addition, energy metabolism deterioration, mitochondrial damage, oxidative stress, and cytokine IL-1 beta release were prevented. CONCLUSION: EGF addition to IGL-1 increased fatty liver graft preservation, thereby reducing steatotic liver damage against cold IRI.

Effects of tryptophan and 5-hydroxytryptophan on the hepatic cell membrane rigidity due to oxidative stress.

The ability of several indoleamines to scavenge free radicals is well documented. Our aim was to evaluate the ability of 0.01-3 mM tryptophan (Trp) and 0.1-5 mM 5-hydroxytryptophan (5-OH-Trp) to protect hepatic cell membranes against 0.1 mM FeCl(3) plus 0.1 mM ascorbic acid-induced lipid peroxidation and increases in membrane rigidity. Membrane fluidity was evaluated using fluorescence spectroscopy. Lipid and protein oxidation were estimated by quantifying malondialdehyde (MDA) plus 4-hydroxyalkenals (4-HDA) concentrations and carbonyl group content, respectively. Exposure to FeCl(3) plus ascorbic acid increased hepatic cell membrane rigidity, MDA + 4-HDA and carbonyl content. The presence of 5-OH-Trp, but not Trp, attenuated these changes. In the absence of oxidative stress, neither indoleamine modified fluidity, MDA + 4-HDA or carbonylation. These results suggest that C5 hydroxylation determines the ability of Trp to preserve membrane fluidity in the presence of oxidative stress.

Effects of premedication with tiletamine/zolazepam/medetomidine during general anesthesia using sevoflurane/fentanyl in swine undergoing pancreas transplantation.

OBJECTIVE: To assess cardiac and hemodynamic responses and body temperature during long-term general anesthesia using sevoflurane/fentanyl after premedication with a tiletamine/zolazepam/medetomidine combination in swine undergoing experimental pancreas transplantation. MATERIALS AND METHODS: Twelve Landrace female pigs of means weight 46.4 +/- 5.1 kg were premedicated by intramuscular administration of tiletamine/zolazepam (3.5 mg/kg), medetomidine (0.03 mg/kg), and atropine (0.02 mg/kg), before anesthesia with 0.75 minimum alveolar concentration sevoflurane and continuous intravenous fentanyl infusion (5.7 +/- 0.7 microg/kg/h). Assessment of heart rate, arterial blood pressure, and temperature in pigs undergoing allogenic pancreas transplant surgery were registered at the start of anesthesia (T0), as well as at 60 (T60), 120 (T120), and 180 (T180) minutes after T0, and finally at the end of anesthesia (T anesthesia end), when we switched off the sevoflurane vaporizer. Analysis of variance was used to determine differences between times with P < .05 considered significant. Results are given as mean values +/- standard deviations. RESULTS: Arterial blood pressure significantly decreased from T120 to the end of anesthesia, while a significantly decreased heart rate was only evident at T60. Body temperature decreased significantly from T60 to the end of anesthesia. These decreases, however, lacked clinical relevance; all parameters were within normal range. No major anesthetic complications were observed in this study. CONCLUSIONS: The administration of a tiletamine/zolazepam/medetomidine combination as premedication in swine subjected to pancreas transplantation allowed for a safe reduction of sevoflurane/fentanyl requirements during long-term general anesthesia. Despite arterial blood pressure and body temperature evidencing a decrease during anesthetic maintenance, all parameters remained within normal range values.

Preservation of the liver graft with Celsior solution.

INTRODUCTION: We studied the evolution of the liver graft with preservation in Celsior (CS) compared with University of Wisconsin solution (UW). MATERIAL AND METHODS: A randomized prospective clinical study in 80 liver transplants (OLTs) from May 2001 to October 2003, compared CS (group I; n = 40) and UW (group II; n = 40). The characteristics of the donors were homogeneous, with no significant differences in 15 variables. CS was perfused with 4 L through the aorta, 2 L through the portal vein, and 1 L, through the portal vein on the back table; and the UW, as 3 L, 2 L, and 1 L, respectively. All OLTs were performed using the piggyback technique. RESULTS: Group I experienced reperfusion syndrome (n = 2; 5.9%), primary graft nonfunction (n = 0); vascular complications (n = 0); biliary anastomosis stenosis (n = 8; 22.9%), intensive care unit (ICU) days (n = 4.1 +/- 1), death within 30 days (n = 1; 3.1%). The patient and graft survivals at 1, 3, 6, 12, and 24 months were 93.7%, 93.7%, 90.2%, 85.7%, 85.7%, and 94.3%, 88.5%, 85.2%, 78%, 78%, respectively. For group II; the reperfusion syndrome occured in 6 patients (17.6%); primary graft nonfunction (n = 0); vascular complications (n = 0), biliary anastomosis stenosis (n = 3; 8.6%), ICU days (n = 4.9 +/- 2.4) and death within 30 days (n = 1; 3.1%); The patient and graft survival at 1, 3, 6, 12, and 24 months were 96.9%, 93.5%, 89.8%, 79.8%, 79.8% and 94.3%, 88.3%, 84.9%, 75.5%, 66.1%, respectively. CONCLUSIONS: CS offers the similar safety to UW for preservation of liver grafts within these ischemia times.

Liver transplant, in emergency 0 (UNOS Status 1).

INTRODUCTION: The emergency 0 (UNOS status 1) liver transplant (OLT) constitutes a challenge to the transplant team. The precarious condition of the patient and the use, sometimes forced by the instability of the patients, of marginal or different blood type grafts leads to worse results than in nonemergency OLT. Herein we have presented our experience with emergency 0 OLT in the first 5 years of our program. PATIENTS AND METHODS: Among the 167 OLTs performed in the first 5 years of our program, 10 were emergency 0 OLTs. The patients were transplanted within 72 hours of inclusion on the waiting list, seven within 24 hours. The indications for emergency OLT were fulminant liver failure (FLF) in six and graft failure in the first week post-OLT in four. RESULTS: All OLTs were performed with preservation of the vena cava (piggyback) and without venovenous bypass. There was 100% patient survival of those who required an emergency 0 OLT (follow-up period of 3 to 7 years). The graft survival in FLF was 50%. Emergency retransplant was necessary because of acute rejection due to ABO incompatibility in two patients, and due to arterial ischemia in another patient. The emergency retransplants were all successful. CONCLUSION: In our experience the emergency 0 OLT is a formidable challenge for the team, but we achieved a patient survival comparable to or even better than that of OLT for chronic liver disease.

Treatment of cutaneous infection by Alternaria alternata with voriconazole in a liver transplant patient.

Alternaria alternata is a dematiaceous mold capable of causing systemic and dermatological infections in immunosuppressed patients. We present a case of a liver transplant patient with cutaneous alternariosis and no response to amphotericin B lipid or surgical debridement of the lesions. Treatment with intravenous voriconazole was initiated, followed by the oral protocol, with complete resolution of the lesions. Voriconazole is an efficient alternative for the treatment of cutaneous lesions produced by A alternata.

Lipid peroxidation in ischemia-reperfusion oxidative injury of the graft preserved in Celsior and University of Wisconsin solutions on a pig pancreas transplantation model.

BACKGROUND: Graft pancreatitis (GP) is one the main technical problems associated with pancreas transplant (PT). It occurs in 20% of patients representing a risk factor for thrombosis and cause of graft loss. GP is related to oxidative effects from oxygen-derived free radicals (OFR) in ischemia-reperfusion injury. We evaluated lipid peroxidation by the OFR in the PT of pig organs preserved with either Celsior or Wisconsin solutions. METHODS: In Landrace pigs we performed 24 pancreas allografts, which were preserved 18 or 24 hours: 12 with Celsior solution (CS) and 12 with Wisconsin solution (UW). No immunosuppression was administered. The oxidative effects were determined by quantification of malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) and of the carbonyl groups of proteins in our pancreatic tissue samples and measured at different times: (A) baseline in the donor, (B) after perfusion of the graft, (C) after the ischemia period, and (D) 30 minutes after ischemia-reperfusion of the graft. RESULTS: The MDA and 4-HDA values were similar in conditions A, B, and C, but showed an extraordinary increase after ischemia-reperfusion in D, among both the 18- or 24-hour preserved grafts and in the same proportion with CS and UW. The carbonyl groups of the proteins rose in conditions B and C (cold ischemia), but less so in state D (reperfusion). CONCLUSIONS: The oxidative injury of a pancreatic graft preserved for 18 or 24 hours occurs during reperfusion, with an extraordinary intensity, but similarly with CS and UW, an observation that may help to explain graft pancreatitis.

[Cancer of the surgically treated stomach: 46 cases. II: Therapeutic and survival aspects]. / Cáncer en el estómago operado: 46 casos. II parte: Aspectos terapéuticos y de supervivencia.

We made a retrospective study of stomach cancer operated in 46 cases between 1971 and 1988, based on therapeutic aspects and survival, observing that due to the generally late diagnosis of this neoplasm, the treatment, which is mainly surgical, produces a low 5-year survival rate in the majority of patients. In our series, partial gastrectomy was more predominant than total gastrectomy, and the overall 5-year survival is 11% and 13%, depending on whether postoperative mortality is included or not. We recommend the follow-up of all patients operated for benign gastric pathology, basically by endoscopy five years after the operation and throughout life, for the early diagnosis and improved prognosis of this neoplasm.

[Cancer of the surgically treated stomach: 46 cases. Etiopathogenic, diagnostic and anatomopathologic aspects]. / Cáncer en el estómago operado: 46 casos. Aspectos etiopatogénicos, diagnósticos y anatomopatológicos.

A retrospective study was made of 46 patients with operated stomach cancer (CEO) between 1971 and 1988, with respect to etiopathogenic diagnostic and pathologic aspects; it occurs most often in stomachs previously submitted to Billroth II type partial gastrectomy and there is a highly variable symptom-free interval, from 6 and 46 years in our series. The diagnosis, which unfortunately is usually late, is based mainly on gastroscopy with biopsy and/or cytology. On pathological study epithelial tumors predominate, particularly Lauren's intestinal type.