M Iappelli

Measurement of oxysterols and α-tocopherol in plasma and tissue samples as indices of oxidant stress status

Oxidant stress seems to play a role in several setting of human pathology, such as atherosclerosis, cancer, and aging. The study of oxidant stress in human disease should be based on the evaluation of either sensitive and specific markers of enhanced oxidant stress, such as oxysterols, or antioxidant defense, by measuring alpha-tocopherol. We have developed a rapid method to measure the oxysterols 7beta-hydroxycholesterol and 7-ketocholesterol in plasma (50 healthy subjects) and tissue as an index of oxidant stress in vivo, and from the same sample alpha-tocopherol content. The mean plasma concentration of 7beta-hydroxycholesterol and 7-ketocholesterol was 4.6+/-1.1 and 13.4+/-7.6 ng/mL, respectively. Plasma alpha-tocopherol concentration was 5.8+/-1.0 micromol/mol cholesterol. Samples from atherosclerotic plaques contained 20 times more cholesterol, about 45 times higher oxysterols levels, and 600 times more alpha-tocopherol compared to normal arteries. No significant difference in cholesterol and oxysterol content was observed between cirrhotic and normal liver. However, cirrhotic liver contained significantly smaller concentration of alpha-tocopherol compared to normal liver. In conclusion, we have developed a rapid and reliable method for the assay of cholesterol oxidation products and alpha-tocopherol in plasma and tissue useful for estimation of oxidant stress/antioxidant balance.

High preoperative recipient plasma 7β‐hydroxycholesterol is associated with initial poor graft function after liver transplantation

Oxidative stress is implicated in the pathogenesis of hepatic ischemia‐reperfusion injury, a major determinant of initial poor graft function (IPGF) after orthotopic liver transplantation (OLT). We prospectively investigated the association between the recipient plasma preoperative oxidative stress and the occurrence of IPGF after deceased‐donor OLT and indirectly studied the source—hepatic or extra‐hepatic—of systemic oxidative stress in vivo in cirrhosis. We used a recently developed specific and sensitive mass spectrometry assay to measure 7β‐hydroxycholesterol and 7‐ketocholesterol (oxysterols), markers of oxidative stress, in biological matrices. At univariate analysis, preoperative recipient 7β‐hydroxycholesterol plasma concentration was significantly higher in transplants with subsequent IPGF (n = 9) compared with those with initial good graft function (IGGF; n = 23) [mean ± SD: 30.63 ± 26.42 and 11.57 ± 15.76 ng/mL, respectively] (P = 0.017). In a logistic regression model, which included also the Model for End‐Stage Liver Disease (MELD) score, 7β‐hydroxycholesterol plasma concentration was an independent predictor of IPGF with an odds ratio of 1.17 (95% CI, 1.02‐1.33, P = 0.028). Patients with cirrhosis (n = 32) had increased oxysterol plasma levels compared with healthy controls (n = 49); livers with cirrhosis (n = 21), however, had oxysterol content comparable with normal livers obtained from organ donors (n = 19). Oxysterols persisted elevated in plasma 1 month after OLT (n = 23). In conclusion, cirrhosis presents upregulated systemic oxidative stress likely of extrahepatic source that is associated with graft failure after OLT. (Liver Transpl 2005.)

Preharvest donor hyperoxia predicts good early graft function and longer graft survival after liver transplantation

A total of 44 donor/recipient perioperative and intraoperative variables were prospectively analyzed in 89 deceased‐donor liver transplantations classified as initial good graft function (IGGF) or initial poor graft function (IPGF) according to a scoring system based on values obtained during the 1st 72 postoperative hours from the serum alanine aminotransferase (ALT) concentration, bile output, and prothrombin activity. The IGGF compared with the IPGF group showed: 1) longer graft (P = .002) and patient (P = .0004) survival; 2) at univariate analysis, a higher (mean [95% confidence interval]) preharvest donor arterial partial pressure of oxygen (PaO2) (152 [136‐168] and 104 [91‐118] mmHg, respectively; P = .0008) and arterial hemoglobin oxygen saturation (97.9 [97.2‐98.7] and 96.7 [95.4‐98.0]%, respectively; P = .0096), a lower percentage of donors older than 65 years (13 and 33%, respectively; P = .024), a lower percentage of donors treated with noradrenaline (16 and 41%, respectively; P = .012). At multivariate analysis, IGGF was associated positively with donor PaO2 and negatively with donor age greater than 65 years and with donor treatment with noradrenaline. Independently from the grouping according to initial graft function, graft survival was longer when donor PaO2 was >150 mmHg than when donor PaO2 was ≤150 mmHg (P = .045). In conclusion, preharvest donor hyperoxia predicts IGGF and longer graft survival. (Liver Transpl 2005;11:140–151.)

Giant hemangiomas of the liver: surgical strategies and technical aspects

The incidence of hemangiomas is 2-7% in the general population. We evaluated more than 300 patients with hepatic hemangiomas. Surgical removal of hepatic hemangiomas was performed in 48 cases due to uncertain diagnosis (2 cases), intractable symptoms (26 cases), size increase (18 cases), and liver failure in 2 cases that were treated by hepatic transplantation. In all, 26 patients underwent enucleation of hemangiomas or segmentectomies, while the remaining 20 patients underwent right lobectomies or left lateral segmentectomies. Blood transfusions were required in four cases (including two liver transplants); mean post-resection hospital stay was 6.3 days. We observed no perioperative mortality and only two cases of major morbidity (bile leaks not requiring reoperation). Our experience confirms that, after adequate patient selection, surgical treatment of hepatic hemangiomas is a very effective therapeutic choice with no mortality and low morbidity.