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In addition to being the primary organ involved in redox cycling, the liver is one of the most highly innervated tissues in mammals. The interaction between hepatocytes and sympathetic, parasympathetic, and peptidergic nerve fibers through a variety of neurotransmitters and signaling pathways is recognized as being important in the regulation of hepatocyte function, liver regeneration, and hepatic fibrosis. However, less is known regarding the role of the sympathetic nervous system (SNS) in modulating the hepatic response to oxidative stress. Our aim was to investigate the role of the SNS in healthy and oxidatively stressed liver parenchyma. Mice treated with 6-hydroxydopamine hydrobromide were used to realize chemical sympathectomy. Carbon tetrachloride (CCl4) injection was used to induce oxidative liver injury. Sympathectomized animals were protected from CCl4induced hepatic lipid peroxidation-mediated cytotoxicity and genotoxicity as assessed by 4-hydroxy-2-nonenal levels, morphological features of cell damage, and DNA oxidative damage. Furthermore, sympathectomy modulated hepatic inflammatory response induced by CCl4-mediated lipid peroxidation. CCl4induced lipid peroxidation and hepatotoxicity were suppressed by administration of anα-adrenergic antagonist. We conclude that the SNS provides a permissive microenvironment for hepatic oxidative stress indicating the possibility that targeting the hepaticα-adrenergic signaling could be a viable strategy for improving outcomes in patients with acute hepatic injury.

Aim. To analyze the risk factors for pancreatic stent migration, dislocation, and fracture in chronic pancreatitis patients with pancreatic strictures.Materials and Methods. Endoscopic stent placements (total 386 times) were performed in 99 chronic pancreatitis patients with pancreatic duct stenosis at our institution between April 2006 and June 2014. We retrospectively examined the frequency of stent migration, dislocation, and fracture and analyzed the patient factors and stent factors. We also investigated the retrieval methods for migrated and fractured stents and their success rates.Results. The frequencies of stent migration, dislocation, and fracture were 1.5% (5/396), 0.8% (3/396), and 1.2% (4/396), respectively. No significant differences in the rates of migration, dislocation, or fracture were noted on the patient factors (etiology, cases undergoing endoscopic pancreatic sphincterotomy, location of pancreatic duct stenosis, existence of pancreatic stone, and approach from the main or minor papilla) and stent factors (duration of stent placement, numbers of stent placements, stent shape, diameter, and length). Stent retrieval was successful in all cases of migration. In cases of fractured stents, retrieval was successful in 2 of 4 cases.Conclusion. Stent migration, fracture, and dislocation are relatively rare, but possible complications. A good understanding of retrieval techniques is necessary.

Objectives. Endoscopic submucosal dissection (ESD) is a promising technique to treat early colorectal neoplasms by facilitating en bloc resection without size limitations. Although ESD for early gastrointestinal epithelial neoplasms has been popular in Japan, clinical experience with colorectal ESD has been rarely reported in Taiwan.Methods. From March 2006 to December 2011, 92 consecutive patients with early colorectal neoplasms resected by ESD at Tri-Service General Hospital were included. ESD was performed for colorectal epithelial neoplasms with a noninvasive pit pattern which had the following criteria: (1) lesions difficult to remove en bloc with a snare, such as laterally spreading tumors-nongranular type (LST-NG) ≧20 mm and laterally spreading tumors-granular type (LST-G) ≧30 mm; (2) lesions with fibrosis or which had recurred after endoscopic mucosal resection with a nonlifting sign.Results. The mean age of the patients was66.3±12.9years, and the male-female ratio was 1.8 : 1. The mean tumor size was37.2±17.9 mm. The en bloc resection rate was 90.2% and the R0 resection rate was 89.1%. Perforations during ESD occurred in 11 patients (12.0%) and all of them were effectively treated by endoscopic closure with hemoclips. No delayed perforation or postoperative bleeding was recorded. There were no procedure-related morbidities or mortalities.Conclusion. ESD is an effective method for en bloc resection of large early colorectal neoplasms and those with a nonlifting sign. An endoscopic technique to close perforations is essential for colorectal ESD.