Mast cell degranulation promotes ischemia-reperfusion injury in rat liver.

BACKGROUND: Mast cells (MCs) play a role in ischemia-reperfusion (I/R) injury in many organs. However, a recent study found that MCs are not involved in I/R injury in isolated rat livers that were perfused only for 1 h. The purpose of this study is to reevaluate the role of MCs in hepatic I/R injury in rat. MATERIALS AND METHODS: A warm hepatic I/R injury model of 1 h ischemia followed by 24 h of reperfusion was used. MC modulation was induced via cromolyn injection or a method called MC depletion using compound 48/80. The effects of MC modulation were evaluated by toluidine blue staining and assessment of mast cell tryptase in sera. The role of MCs in I/R injury was evaluated by hematoxylin and eosin staining graded by Suzuki criteria, alanine aminotransferase and aspartate aminotransferase levels in sera, and malondialdehyde levels in liver homogenates. RESULTS: First, MC degranulation peaked after 2 h of reperfusion and liver damage peaked after approximately 6 h of reperfusion. Second, a method called MC depletion previously used in the skin with repeated injections of compound 48/80 worked similarly in the hepatic setting. Third, stabilization of MCs with cromolyn or depletion of MCs with compound 48/80 each decreased hepatic I/R injury. The most noticeable effects of cromolyn and compound 48/80 treatment were observed after approximately 6 h of reperfusion. CONCLUSIONS: MC degranulation promotes hepatic I/R injury in rats.

[Differential gene expression profiles of gastric cancer].

OBJECTIVE: To explore the different gene expressions of normal versus tumor tissues of gastric cancer at molecular levels. METHODS: Gene chip technology was used to determine the differentially expressed genes between gastric cancer (n = 12) and normal tissues (n = 12) from December 2009 to June 2010 of Xinhua Hospital of Shanghai Jiaotong University School of Medicine. And reverse transcriptase (RT)-PCR was performed to validate the results of gene chip analysis. RESULTS: Sixty-nine up-regulated genes and 80 down-regulated genes were identified by significance analysis of microarrays (SAM). And these genes were correlated with cell adhesion, angiogenesis, cell proliferation and apoptosis, et al. They were also closely correlated with the signaling pathways of Wnt (1/151, 0.66%) and vascular endothelial growth factor (VEGF) (2/76, 2.63%). The differential expressions of ATP4A, CLDN10, OLFM4, SAA1 and PROK2 were confirmed by RT-PCR (0.94 ± 0.19 vs 4.33 ± 0.39, 1.00 ± 0.14 vs 3.04 ± 0.26, 5.37 ± 0.30 vs 1.02 ± 0.14, 4.37 ± 0.30 vs 0.95 ± 0.29, 2.62 ± 0.54 vs 1.35 ± 0.35, all P < 0.05). CONCLUSION: The classifier genes identified in this study may be closely correlated with the carcinogenesis of gastric cancer.

Characteristic gene expression profiles in the progression from normal gastric epithelial cells to moderate gastric epithelial dysplasia and to gastric cancer.

BACKGROUND: Gastric cancer ranks high among the most common causes of cancer-related death worldwide. This study was designed to explore key genes involved in the progression of normal gastric epithelial cells to moderate gastric epithelial dysplasia (mGED) and to gastric cancer. METHODS: Twelve pairs of mGED tissues, gastric cancer tissues, and normal gastric tissues were collected by gastroscopy. Total RNA was then extracted and purified. After the addition of fluorescent tags, hybridization was carried out on a Gene chip microarray slide. Significance analysis of microarrays was performed to determine significant differences in gene expression between the different tissue types. RESULTS: Microarray data analysis revealed totally 34 genes that were expressed differently: 18 highly expressed (fold change > 2; P < 0.01) and 16 down-regulated (fold change > 2; P < 0.01). Of the 34 genes, 24 belonged to several different functional categories such as structural molecule activity, extracellular regions, structural formation, cell death, biological adhesion, developmental processes, locomotion, and biological regulation that were associated with cancer. The remaining 10 genes were not involved in cancer research. Of these genes, the expression levels of Matrix metalloproteinase-12 (MMP12), Caspase-associated recruitment domain 14 (CARD14), and Chitinase 3-like 1 (CHI3L1) were confirmed by semi-quantitative RT-PCR. A two-way clustering algorithm divided the 36 samples into three categories and the overall correct classification efficiency was 80.6% (29/36). Almost all of these genes (31/34) showed constant changes in the process of normal gastric epithelial cells to mGED to gastric cancer. CONCLUSIONS: The results of this study provided global gene expression profiles during the development and progression from normal gastric epithelial cells to mGED to gastric cancer. These data may provide new insights into the molecular pathology of gastric cancer which may be useful for the detection, diagnosis, and treatment.

The hepatic protective mechanism of Ginkgo biloba extract in rats with obstructive jaundice.

The objective of our study was to examine the hepatic protective mechanism of Ginkgo biloba extract (GBE) in rats with obstructive jaundice (OJ). Twenty rats underwent bile duct ligation and received daily intraperitoneal injections of either control saline or Ginkgo biloba extract for 14 days. Ten sham-operated rats had their bile duct exposed but not ligated or sectioned. Serum alanine transaminase (ALT) was analyzed for liver function tests and liver damage was further assessed by histologic examination. The levels of endothelin 1 (ET-1) and nitric oxide (NO) in blood and liver homogenate were measured. The serum alanine transaminase was elevated in the bile duct ligation rats (BDL rats); GBE could significantly lower serum transaminase level and ameliorate liver histological damage. ET-1 and NO levels in both plasma and liver tissue were also elevated in common bile duct (CBD)-ligated rats, but this increase was significantly decreased by GBE treatment. Moreover, the degree of liver damage severity positively correlates with high levels of ET-1 and NO. GBE mediated the liver protective effect at least in part by suppressing overproduction of ET-1 and NO and restoring a proper balance between ET-1 and NO to some extent.