Katsutaka Watanabe

Inchinkoto, an herbal medicine, exerts beneficial effects in the rat liver under stress with hepatic ischemia-reperfusion and subsequent hepatectomy.

Objective:To investigate the beneficial effects of inchinkoto (ICKT) in the liver after 70% hepatectomy following ischemia reperfusion. Methods:Wistar rats were divided into 3 groups: simple laparotomy and 70% hepatectomy (Hx), 70% hepatectomy following ischemia reperfusion (IR) with vehicle (IRHxV), 70% hepatectomy following IR with ICKT (1 or 2 g/kg of body weight; IRHxK). Vehicle or ICKT was administered for 3 days preoperatively. The hepatoduodenal ligament was clamped for 15 minutes before hepatectomy in the IRHx groups. Rats were killed 1 hours after hepatectomy. In other experiments, the hepatoduodenal ligament was clamped for 30 minutes, with or without ICKT treatment, to evaluate the effect of ICKT on IR injury-induced mortality. Serum transaminase levels and the gene expression of inflammatory cytokines and inducible nitric oxide synthase in the remnant liver were determined. Furthermore, the expression of antioxidant genes was evaluated by PCR array. Results:The elevation of serum transaminase levels, the upregulation of genes for inflammatory cytokines and inducible nitric oxide synthase, and the increased formation of nitrotyrosine observed in the remnant livers of the IRHxV group were all significantly attenuated by preoperative administration of ICKT in the IRHxK group. The expression of antioxidant genes was also higher in the IRHxK group compared with that of the IRHxV group. Moreover, administration of ICKT significantly reduced the mortality induced by IRHx after 30-minute ischemia. Conclusions:Preoperative administration of ICKT provides beneficial effects through attenuating inflammatory responses and oxidative stress in the liver following IR and subsequent hepatectomy.

Segmental cholangitis impairs hepatic regeneration capacity after partial hepatectomy in rats.

BACKGROUND Patients with hilar cholangiocarcinoma or hepatolithiasis often develop segmental cholangitis (SC), but it is unclear whether hepatectomy for patients with SC can be performed safely. METHODS Rats were subjected to segmental bile duct ligation (SBDL) with LPS (SC group) or a saline (Sham group) infusion into the bile duct of the ligated lobes. The rats were sacrificed at 3, 24 and 48 h after the SBDL. For another experiment, the rats were subjected to partial hepatectomy (PHx) for the ligated lobes. Hepatic regeneration rates and the expression of regeneration-associated genes were evaluated. RESULTS In the SC group, severe parenchymal damage was observed in the acute phase (3 h). Altered gene expression in the liver in response to biliary infection occurred not only in the infected lobes but also in the non-infected lobes. In the rats of the SC group, both the hepatic regeneration rate and serum HGF levels were significantly lower than in the Sham group. CONCLUSION These results clearly demonstrate that SC impairs the regeneration capacity of the contralateral remnant liver. Therefore, hepatectomy should be avoided for patients with SC even if it occurs in the part of the liver to be resected.

Estrogen promotes hepatic regeneration via activating serotonin signal.

The aim of this study was to determine if estrogen plays any role in the process of hepatic regeneration of nonligated lobe after portal vein branch ligation (PBL). We also investigated whether estrogen has any association with serotonin action during liver regeneration. Ovariectomized female rats with (E group) or without (non-E group) estrogen pellet were subjected to PBL on the left and middle lobes. Thereafter, the rats were killed, and blood, liver, and small intestine were sampled and analyzed. Sham animals underwent only ovariectomy and laparotomy. The E group showed a significantly greater regeneration rate than the non-E group at days 1, 2, and 7 after PBL. The activation of hepatic regeneration-related genes (such as IL-6, TNF-&agr;, hepatic growth factor, c-fos, and c-myc) was also significantly higher in the E group as compared with the non-E group. Gene expression of serotonin receptor (5-HT2A) in the liver and tryptophan hydroxylase 1 in the small intestine were also up-regulated in the E group, indicating an activation of serotonin system in the E group. Additionally, total intestinal flow, portal venous flow, and hepatic arterial flow determined by fluorescent microsphere were significantly higher in the E group compared with the non-E group. Moreover, serotonin receptor antagonist (ketanserin) significantly attenuated liver regeneration rate in the E group. These results indicated that estrogen plays an important role in the process of liver regeneration after PBL. Our results also indicated that estrogen is at least partly related to the activation of serotonin system, which is also important in the process of liver regeneration.

15-Deoxy-Δ12,14-Prostaglandin J2 prevents inflammatory response and endothelial cell damage in rats with acute obstructive cholangitis

Acute obstructive cholangitis is a common disease with a high mortality rate. Ligands for peroxisome proliferator-activated receptor-gamma (PPARgamma), such as 15-deoxy-Delta(12,14)-prostaglandin J(2) (15D-PGJ(2)), have been proposed as a new class of anti-inflammatory compounds. This study investigated the effect of 15D-PGJ(2) treatment on lipopolysaccharide (LPS)-induced acute obstructive cholangitis. The rats were randomly assigned to five groups: sham operation (Sham; simple laparotomy), sham operation with intraperitoneal saline infusion (Sham+Saline), sham operation with intraperitoneal LPS infusion (Sham+LPS), bile duct ligation (BDL) with saline infusion into the bile duct (BDL+Saline), and BDL with LPS infusion into the bile duct (BDL+LPS). Biochemical assays of blood samples, histology of the liver, portal venous pressure, hyaluronic acid clearance, and expression of inflammation-associated genes in the liver were evaluated. Furthermore, the Sham+LPS and the BDL+LPS group were divided into two groups (with and without 15D-PGJ(2) treatment), and their survival rates were compared. Biochemical assays of blood samples, portal venous pressure, hyaluronic acid clearance, and expression of inflammation-associated genes in the liver were all significantly higher in the BDL+LPS group compared with those in the BDL+Saline group, indicating the presence of increased liver damage in the first group. However, preoperative administration of 15D-PGJ(2) significantly improved these outcomes. Furthermore, the survival rate after establishment of cholangitis was significantly improved by the administration of 15D-PGJ(2) in the BDL+LPS group. These results clearly demonstrate that 15D-PGJ(2) inhibits the inflammatory response and endothelial cell damage seen in acute obstructive cholangitis and could contribute to improve the outcome of this pathology.

Laparoscopic surgery for the treatment of a ruptured aneurysm of the right gastric artery: a case report.

Laparoscopic surgery for the treatment of a ruptured visceral artery aneurysm is recognized as a challenging procedure. Here, we describe our experience with laparoscopic surgery to treat a ruptured aneurysm of the right gastric artery. A 72‐year‐old woman was diagnosed with intra‐abdominal hemorrhage caused by a ruptured aneurysm of the right gastric artery. Transcatheter arterial embolization failed because the right gastric artery could not be cannulated. Therefore, we performed laparoscopic surgery. Using laparoscopy, we detected that the bleeding from the aneurysm had ceased; thus, the planned procedure was successful. The operative time and intraoperative blood loss were 100 min and 5 mL, respectively. The patient was discharged 7 days after surgery. Laparoscopic surgery after the failure of transcatheter arterial embolization is a suitable and safe procedure for ruptured visceral artery aneurysms, provided the circulatory dynamics are stable as a result of the temporary cessation of bleeding from the ruptured aneurysm.

Nek2 siRNA therapy using a portal venous port–catheter system for liver metastasis in pancreatic cancer

Nek2 (NIMA‐related kinase 2) is a serine‐threonine kinase and human homolog of the mitotic regulator NIMA of Aspergillus nidulan. We reported the efficiency of Nek2 siRNA in several cancer xenograft models using cholangiocarcinoma, breast cancer and colorectal cancer. Pancreatic cancer is difficult to treat due to its rapid progression and resistance to chemotherapy. Novel treatments are urgently required to improve survival in pancreatic cancer, and siRNA are a promising therapeutic option. However, finding an in vivo drug delivery system of siRNA remains a major problem for clinical application. In this study, the overexpression of Nek2 was identified in pancreatic cancer cell lines. Nek2 siRNA inhibited tumor growth in a subcutaneous xenograft mouse model of pancreatic cancer, prolonged the survival time in an intraperitoneal xenograft mouse model and efficiently prevented the progression of liver metastasis using a portal venous port–catheter system. Taken together, Nek2 is an effective therapeutic target in pancreatic cancer. An adequate delivery system is considered important in treating advanced pancreatic cancer, such as peritoneal dissemination and liver metastasis. Further investigations are required on the safety and side effects of the portal venous port–catheter system. We hope that Nek2 siRNA will be a novel therapeutic strategy for pancreatic cancer with liver metastasis and peritoneal dissemination.