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This paper reports a wirelessly powered ionic polymer-metal composite (IPMC) soft actuator operated by external radio frequency (RF) magnetic fields for targeted drug delivery. A 183 μm thick IPMC cantilever valve was fitted with an embedded LC resonant circuit to wirelessly control the actuator when the field frequency is tuned to its resonant frequency of approximately 25 MHz. Experimental characterization of the fabricated actuator showed a cumulative cantilever deflection of 160 μm for three repeated RF ON-OFF cycles at 0.6 W input power. The device was loaded with a dye solution and immersed in DI water to demonstrate wireless drug release. The qualitative result shows the successful release of the dye solution from the device reservoir. The release rate can be controlled by tuning the RF input power. We achieved a maximum average release rate of ∼0.1 μl s-1. We further conducted an in vitro study with human tumor cells (HeLa) to demonstrate the proof of concept of the developed device. The experiments show promising results towards the intended drug delivery application.

Immunoglobulin G4 (IgG4)-related disease (IgG4RD) is a relatively recently recognized entity that is histopathologically characterized by an extensive infiltration of lymphocytes and IgG4-positive plasma cells with dense fibrosis. IgG4RD is now known to affect any organ system, and a few cases of gastrointestinal lesions have also been reported. However, solitary IgG4RD of the stomach is still very rare. Furthermore, as it can mimic malignant conditions, it is important to recognize this disease to avoid unnecessary surgery. Herein, we present a case of IgG4RD presenting as an isolated subepithelial mass in the stomach.

Aim: To investigate the difference in magnifying endoscopic findings of gastric epithelial dysplasias (GEDs) according to the morphologic characteristics., Methods: This study included 46 GED lesions in 45 patients who underwent magnifying endoscopy using narrow band imaging (ME-NBI) before endoscopic resection. During ME-NBI, the microvascular and microsurface (MS) patterns and the presence of light blue crest (LBC) and white opaque substance were investigated. GEDs were categorized as adenomatous, foveolar, and hybrid types, and their mucin phenotype was evaluated., Results: Of the 46 lesions, 27 (59%) were categorized as adenomatous, 15 (32%) as hybrid, and the remaining 4 (9%) as foveolar. All adenomatous GEDs showed the round pit and/or tubular MS patterns, all foveolar GEDs showed the papillary pattern, and hybrid GEDs showed mixed patterns (P < 0.001). LBC was more frequently observed in adenomatous GEDs than in hybrid or foveolar GEDs (52%, 33%, 0%, respectively), although this difference was not significant (P = 0.127). The papillary MS pattern was associated with MUC5AC and MUC6 expression, and the round pit and/or tubular MS patterns were associated with CD10 expression., Conclusion: The MS pattern in ME-NBI findings is useful for predicting the morphologic category and mucin phenotype of GEDs, and ME-NBI findings may guide decisions regarding GED treatment.

Background/aims: The combination therapy of peginterferon (PEG-IFN) and ribavirin is the standard treatment for hepatitis C virus (HCV) infection. However, few trials have involved patients with cirrhosis. The purpose of this study was to elucidate the efficacy and safety of treatment with PEG-IFN and ribavirin in patients with cirrhosis associated with HCV infection., Method: A total of 65 patients were treated with PEG-IFN alpha-2a/ribavirin (n=32) or PEG-IFN alpha-2b/ribavirin (n=33). PEG-IFN alpha-2a and PEG-IFN alpha-2b were administered at doses of 180 microg/week and 1.5 microg/kg/week, respectively, and ribavirin was administered orally at doses of 800-200 mg. Patients with HCV genotype 1 and genotype non-1 were treated for 48 and 24 weeks, respectively. The treatment response was assessed based on the sustained virologic response (SVR)., Results: The early virologic response (EVR), end-of-treatment response (ETR), and SVR were 70.0%, 52.0%, and 24.0%, respectively, in genotype 1 (n=50). In genotype non-1 (n=15), the ETR was 53.3% and the SVR was 33.3%. The overall SVR did not differ with genotype (1 vs non-1, 24.0% vs. 33.3%; P=0.471) or between decompensated cirrhosis and compensated cirrhosis (20.0% vs. 27.3%, P=0.630). Ten patients developed cirrhotic complications during the treatment, and 11 stopped treatment due to treatment-related adverse events., Conclusion: The combination therapy of PEG-IFN and ribavirin exhibited a low efficacy in cirrhotic patients with HCV infection and was associated with frequent serious complications. However, with careful management of complications, the therapy may have a considerable efficacy in some patients with cirrhosis and HCV infection.

Background/aims: In order to identify microsatellite instability (MSI), the test based on the polymerase chain reaction (PCR) can be used. However, PCR is not routinely performed in all hospital laboratories. Recently, immunohistochemistry (IHC) for MLH1 and MSH2 proteins has been reported as a rapid and useful method for MSI. However, the efficacy of IHC in the detection of the MSI has not been well established. The aim of this study was to evaluate the usefulness of IHC in the detection of the MSI by comparing it with the test results using PCR in colorectal cancer (CRC)., Methods: Paraffin-embedded normal and tumor tissues from seventy-five patients who underwent surgical resection of CRC were used. Abnormal expression of MLH1 and MSH2 protein was determined by IHC using MLH1 and MSH2 antibodies. Normal and tumor DNAs were obtained from thirty CRC tissues that showed abnormal expression of MLH1 and MSH2 proteins by IHC. The MSI status was confirmed by PCR using five markers., Results: Thirty tumors showed abnormal expression of MLH1 and MSH2 proteins by IHC, but only three tumors out of them were confirmed to have MSI by PCR., Conclusions: This result suggests that IHC with MLH1 and MSH2 antibodies does not seem to be a useful method to identify MSI in CRC, therefore PCR is required for detection of the MSI.