Akihisa Kato

Comparison of intraductal ultrasonography findings between primary sclerosing cholangitis and IgG4-related sclerosing cholangitis

Comparisons of intraductal ultrasonography (IDUS) findings between primary sclerosing cholangitis (PSC) and IgG4‐related sclerosing cholangitis (IgG4‐SC) have not been elucidated. We aimed to clarify the differences in transpapillary IDUS findings between PSC and IgG4‐SC.

Chemopreventive effect of resveratrol and apocynin on pancreatic carcinogenesis via modulation of nuclear phosphorylated GSK3β and ERK1/2

Despite progress in clinical cancer medicine in multiple fields, the prognosis of pancreatic cancer has remained dismal. Recently, chemopreventive strategies using phytochemicals have gained considerable attention as an alternative in the management of cancer. The present study aimed to evaluate the chemopreventive effects of resveratrol (RV) and apocynin (AC) in N-Nitrosobis(2-oxopropyl)amine-induced pancreatic carcinogenesis in hamster. RV- and AC-treated hamsters showed significant reduction in the incidence of pancreatic cancer with a decrease in Ki-67 labeling index in dysplastic lesions. RV and AC suppressed cell proliferation of human and hamster pancreatic cancer cells by inhibiting the G1 phase of the cell cycle with cyclin D1 downregulation and inactivation of AKT-GSK3β and ERK1/2 signaling. Further, decreased levels of GSK3βSer9 and ERK1/2 phosphorylation and cyclin D1 expression in the nuclear fraction were observed in cells treated with RV or AC. Nuclear expression of phosphorylated GSK3βSer9 was also decreased in dysplastic lesions and adenocarcinomas of hamsters treated with RV or AC in vivo. These results suggest that RV and AC reduce phosphorylated GSK3βSer9 and ERK1/2 in the nucleus, resulting in inhibition of the AKT-GSK3β and ERK1/2 signaling pathways and cell cycle arrest in vitro and in vivo. Taken together, the present study indicates that RV and AC have potential as chemopreventive agents for pancreatic cancer.

The efficacy of transcatheter arterial embolization as the first‐choice treatment after failure of endoscopic hemostasis and endoscopic treatment resistance factors

Aim:  The aim of this retrospective study was to evaluate the efficacy of transcatheter arterial embolization (TAE) as the first‐choice treatment in patients with bleeding peptic ulcer after the failure of endoscopic hemostasis. An additional objective was to clarify endoscopic treatment resistance factors.

Predictive factors for positive diagnosis of malignant biliary strictures by transpapillary brush cytology and forceps biopsy

The diagnostic yields of endoscopic transpapillary brush cytology and forceps biopsies for malignant biliary strictures (MBS) remain unclear and predictive factors for diagnosis have not been established. We aimed to clarify the diagnostic yields of both methods and the predictive factors

Stent under-expansion on the procedure day, a predictive factor for poor oral intake after metallic stenting for gastric outlet obstruction.

Self‐expandable metallic stents (SEMS) have been widely accepted as palliation therapy for malignant gastric outlet obstruction (GOO). However, the factors predictive of poor oral intake after SEMS placement have not been elucidated sufficiently. We aimed to clarify both the patient and stent‐related predictive factors.

Connexin 32 and luteolin play protective roles in non-alcoholic steatohepatitis development and its related hepatocarcinogenesis in rats

Non-alcoholic steatohepatitis (NASH) has the potential to lead to the development of cirrhosis and hepatocellular carcinoma (HCC). Connexin (Cx) 32, a hepatocyte gap-junction protein, plays a preventive role in hepatocarcinogenesis. However, the precise contribution of Cx32 in the development of NASH has not been established. In this study, we aimed to clarify the role of Cx32 and the chemopreventive effect of luteolin, an antioxidant flavonoid, on the progression of NASH and NASH-related hepatocarcinogenesis. Cx32 dominant negative transgenic (Cx32ΔTg) and wild-type (Wt) rats at 10 weeks of age were given diethylnitrosamine and fed methionine-choline-deficient diet (MCDD) or MCDD with luteolin for 12 weeks. MCDD induced steatohepatitis and fibrosis along with increased inflammatory cytokine expression and reactive oxygen species in the liver. These effects were more severe in Cx32ΔTg rats as compared with Wt rats, and significantly suppressed by luteolin in both genotypes. Concerning NASH-related hepatocarcinogenesis, the number of glutathione S-transferase placental form (GST-P)-positive foci was greater in Cx32ΔTg versus Wt rats, and significantly reduced by luteolin in Cx32ΔTg rats. Microarray analysis identified brain expressed, X-linked 1 (Bex1) as an upregulated gene in Cx32ΔTg rat liver. Quantitative RT-PCR and in situ hybridization revealed that increased Bex1 mRNA was localized in GST-P-positive foci in Cx32ΔTg rats, and the expression level was significantly decreased by luteolin. Moreover, Bex1 knockdown resulted in significant growth inhibition of the rat HCC cell lines. These results show that Cx32 and luteolin have suppressive roles in inflammation, fibrosis and hepatocarcinogenesis during NASH progression, suggesting a potential therapeutic application for NASH.

New concept of traction force applied to biliary self-expandable metallic stents

BACKGROUND AND STUDY AIMS Various mechanical properties of self-expandable metallic stents (SEMSs) have been reported. They can be classified into the device behavior during and after deployment. While there have been several reports on the latter, information on the former is insufficient. During deployment, the position is maintained by retracting the delivery catheter. We propose that this pulling force be called the traction force and that the magnitude of traction force is termed the traction momentum. The aim of this study was to measure these parameters in order to clarify the properties of SEMSs in terms of their deployment. MATERIAL AND METHODS The traction force, traction momentum, and shortening rate of 10 different SEMSs were measured. Traction force was measured using in-house equipment, and the shortening rate was determined by measuring the stents. RESULTS The shortening rate was closely related to the stent structure. The traction force varied between 1.5 N and 9.4 N, and the traction momentum was significantly elevated in covered and braided stents. A high traction force did not imply a high traction momentum. CONCLUSIONS A low or constant traction force and a minimal shortening rate significantly facilitated SEMS deployment to optimal positions. Traction force could be an important element for new ideal SEMS design.

Correlation between long-term outcome and steroid therapy in type 1 autoimmune pancreatitis: relapse, malignancy and side effect of steroid

Abstract Objectives. Autoimmune pancreatitis (AIP) responds well to corticosteroid therapy (CST), and CST is essential to induce remission. However, the correlation between long-term outcome and CST has not been evaluated. We aimed to clarify the correlation between long-term outcome of AIP and CST. Material and methods. We retrospectively evaluated relapse, risk of malignancy and side effects of CST by focusing on the correlation with CST in 84 patients with type 1 AIP. Results. The incidence of relapse was 23.8%. The frequency of relapse after CST administration was significantly lower in patients taking CST for >6 months than in those who did not (22% versus 67%; p = 0.036). The incidence of malignancy was 10.7%. The standardized incidence ratio of malignancy was 2.14 [95% confidence interval 0.74–3.54]. There were no significant correlations between development of malignancy and CST. The incidences of total and serious side effects due to CST were 75% and 19.1%, respectively. Relapse was the only significant independent predictive risk factor for serious side effects in a multivariate analysis (odds ratio 4.065; 95% confidence interval 1.125–14.706; p = 0.032). The cumulative dose of corticosteroid was significantly higher in patients with serious side effects than in those without (12,645 mg versus 7322 mg; p = 0.041). Conclusions. CST reduces relapse of AIP. However, CST causes serious side effects, particularly in relapsing patients. Alternative maintenance therapy to prevent relapse is needed.

8-mm versus 10-mm diameter self-expandable metallic stent in bilateral endoscopic stent-in-stent deployment for malignant hilar biliary obstruction

We aimed to clarify the clinical benefits of using 8‐mm versus 10‐mm diameter self‐expandable metallic stent (SEMS) in bilateral endoscopic stent‐in‐stent (SIS) deployment for malignant hilar biliary obstruction (MHBO).

Efficacy of pancreatic stenting prior to extracorporeal shock wave lithotripsy for pancreatic stones

BACKGROUND Extracorporeal shock wave lithotripsy is the first-line therapy for large pancreatic duct stones; however, it requires a long duration of therapy. AIMS To clarify the effect of pancreatic stenting prior to extracorporeal shock wave lithotripsy on shortening the duration of therapy and reducing complications. METHODS We retrospectively compared 45 patients who underwent pancreatic stenting prior to extracorporeal shock wave lithotripsy (stenting group) and 35 patients who did not undergo stenting prior to extracorporeal shock wave lithotripsy (non-stenting group) with regard to the cumulative number of shock waves required for stone fragmentation (stone size <3mm) and the rate of complications. RESULTS The stenting group was associated with a significantly lower cumulative number of shock waves in univariate analysis (log-rank, p=0.046) and multivariate Cox proportional hazard analysis (hazard ratio, 1.88; 95% confidence interval, 1.13-3.14; p=0.015) than the non-stenting group. The frequency of pancreatitis tends to be lower in the stenting group than the non-stenting group (2.2% [1/45] vs 11.4% [4/35]; p=0.162). CONCLUSIONS Pancreatic stenting prior to extracorporeal shock wave lithotripsy reduced the cumulative number of shock waves required for pancreatic stone fragmentation, and could be useful to shorten the duration of therapy.