Hepatology : official journal of the American Association for the Study of Liver Diseases
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It has been reported that upstream components of the insulin-like growth factor (IGF) signaling axis could be overexpressed during hepatocarcinogenesis in humans and rodents. However, the signal transduction pathways activated downstream have been poorly studied. Here, we examined whether glycogen synthase kinase-3beta (GSK-3beta) could be a target in human hepatoma cell lines and transgenic ASV mice with hepatic expression of the SV40 large T antigen. ⋯ Finally, we observed that reexpression of IGF-2 in tumoral livers from ASV mice was associated with a marked phosphorylation of GSK-3beta. In conclusion, our results identify GSK-3beta as a molecular target of the constitutive activation of the IGF axis in in vitro and in vivo models of hepatocarcinogenesis. Persistent phosphorylation of GSK-3beta could be critical for regulation of glycogen metabolism and cell growth in hepatoma cells.
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Clinical Trial
Terlipressin therapy with and without albumin for patients with hepatorenal syndrome: results of a prospective, nonrandomized study.
Vasopressin analogues associated with albumin improve renal function in hepatorenal syndrome (HRS). The current study was aimed at assessing the efficacy of the treatment, predictive factors of response, recurrence of HRS, and survival after therapy. Twenty-one consecutive patients with HRS (16 with type 1 HRS, 5 with type 2 HRS) received terlipressin (0.5-2 mg/4 hours intravenously) until complete response was achieved (serum creatinine level < 1.5 mg/dL) or for 15 days; 13 patients received intravenous albumin together with terlipressin. ⋯ In conclusion, terlipressin therapy reverses HRS in a high proportion of patients. Recurrence rate after treatment withdrawal is uncommon. Albumin appears to improve markedly the beneficial effects of terlipressin.
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Livers can be preserved only for a short period without jeopardizing the transplantation outcome. Heat shock proteins (HSPs) protect against ischemia and reperfusion injury. We studied whether their induction and, in particular, the induction of heme oxygenase 1 (HO-1), improves transplantation survival after an extended time of cold storage. ⋯ Preconditioning tended to reduce the number of positive cells and to stimulate the expression of antiapoptotic Bcl-X(L). In conclusion, heat preconditioning and, specifically, overexpression of HO-1 improve posttransplantation survival and graft function after prolonged cold ischemia preservation. The mechanism underlying these beneficial effects does not appear to be prevention of apoptosis.
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Meta Analysis Comparative Study
Endoscopic treatment versus endoscopic plus pharmacologic treatment for acute variceal bleeding: a meta-analysis.
Endoscopic therapy, involving either injection sclerosis or band ligation, is considered the intervention of first choice for acute variceal bleeding (AVB). Pharmacologic agents have also been shown to be highly effective in the control of the bleeding episode. The purpose of this meta-analysis was to assess whether vasoactive drugs may improve the efficacy of endoscopic therapy (injection sclerosis or band ligation) in the control of AVB and thus increase survival rates. ⋯ Mortality was not significantly decreased by combined therapy (RR, 0.73; 95% CI, 0.45-1.18). Severe adverse events were similar in both groups. In conclusion, in patients with AVB, pharmacologic agents improve the efficacy of endoscopic therapy to achieve initial control of bleeding and 5-day hemostasis, yet fail to affect mortality.
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Activation of endothelial nitric oxide synthase (eNOS) in portal hypertensive (PHT) gastric mucosa leads to hyperdynamic circulation and increased susceptibility to injury. However, the signaling mechanisms for eNOS activation in PHT gastric mucosa and the role of TNF-alpha in this signaling remain unknown. In PHT gastric mucosa we studied (1) eNOS phosphorylation (at serine 1177) required for its activation; (2) association of the phosphatidylinositol 3-kinase (PI 3-kinase), and its downstream effector Akt, with eNOS; and, (3) whether TNF-alpha neutralization affects eNOS phosphorylation and PI 3-kinase-Akt activation. ⋯ Neutralizing anti-TNF-alpha antibody significantly reduced p85 phosphorylation, phosphorylation and activity of Akt, and eNOS phosphorylation in PHT gastric mucosa to normal levels. Furthermore, TNF-alpha stimulated eNOS phosphorylation in human microvascular endothelial cells. In conclusion, these findings show that in PHT gastric mucosa, TNF-alpha stimulates eNOS phosphorylation at serine 1177 (required for its activation) via the PI 3-kinase-Akt signal transduction pathway.