Multivariate prognostic study on node-positive gastric cancer: is tumor size a prognostic indicator?

BACKGROUND/AIMS: We analyzed the clinicopathological factors of patients with node-positive gastric cancer, evaluated the prognostic factors associated with long-term survival and clarified the effect of tumor size on long-term survival. METHODOLOGY: The study included 591 patients who underwent curative resection for node-positive gastric cancer. Clinicopathological prognostic variables were evaluated as predictors of long-term survival by univariate and multivariate analyses. RESULTS: The 5-year survival rate was influenced by tumor size, tumor location, depth on invasion, level of lymph node metastasis, Borrmann classification, histological type, liver metastasis, peritoneal dissemination and disease stage. Of these, independent prognostic factors were depth on invasion and lymph node metastasis. Tumor size is an influence but not independent factor for the prediction of long-term survival in patients with node-positive gastric cancer. CONCLUSIONS: In patients with node-positive gastric cancer, two independent prognostic factors were depth on invasion and the status of lymph node metastasis.

Impaired PI3K/Akt signal pathway and hepatocellular injury in high-fat fed rats.

AIM: to determine whether mitochondrial dysfunction resulting from high-fat diet is related to impairment of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt, also known as PKB) pathway. METHODS: rat models of nonalcoholic fatty liver were established by high-fat diet feeding. The expression of total and phosphorylated P13K and Akt proteins in hepatocytes was determined by Western blotting. Degree of fat accumulation in liver was measured by hepatic triglyceride. Mitochondrial number and size were determined using quantitative morphometric analysis under transmission electron microscope. The permeability of the outer mitochondrial membrane was assessed by determining the potential gradient across this membrane. RESULTS: after Wistar rats were fed with high-fat diet for 16 wk, their hepatocytes displayed an accumulation of fat (103.1 ± 12.6 vs 421.5 ± 19.7, P < 0.01), deformed mitochondria (9.0% ± 4.3% vs 83.0% ± 10.9%, P < 0.05), and a reduction in the mitochondrial membrane potential (389.385% ± 18.612% vs 249.121% ± 13.526%, P < 0.05). In addition, the expression of the phosphorylated P13K and Akt proteins in hepatocytes was reduced, as was the expression of the anti-apoptotic protein Bcl-2, while expression of the pro-apoptotic protein caspase-3 was increased. When animals were treated with pharmacological inhibitors of P13K or Akt, instead of high-fat diet, a similar pattern of hepatocellular fat accumulation, mitochondrial impairment, and change in the levels of PI3K, Akt, Bcl-2 was observed. CONCLUSION: high-fat diet appears to inhibit the PI3K/Akt signaling pathway, which may lead to hepatocellular injury through activation of the mitochondrial membrane pathway of apoptosis.