Ho-Seok Ki

Black tea extract prevents lipopolysaccharide-induced NF-κB signaling and attenuates dextran sulfate sodium-induced experimental colitis.

BackgroundBlack tea has been shown to elicit anti-oxidant, anti-carcinogenic, anti-inflammatory and anti-mutagenic properties. In this study, we investigated the impact of black tea extract (BTE) on lipopolysaccharide (LPS)-induced NF-κB signaling in bone marrow derived-macrophages (BMM) and determined the therapeutic efficacy of this extract on colon inflammation.MethodsThe effect of BTE on LPS-induced NF-κB signaling and pro-inflammatory gene expression was evaluated by RT-PCR, Western blotting, immunofluorescence and electrophoretic mobility shift assay (EMSA). The in vivo efficacy of BTE was assessed in mice with 3% dextran sulfate sodium (DSS)-induced colitis. The severity of colitis was measured by weight loss, colon length and histologic scores.ResultsLPS-induced IL-12p40, IL-23p19, IL-6 and IL-1β mRNA expressions were inhibited by BTE. LPS-induced IκBα phosphorylation/degradation and nuclear translocation of NF-κB/p65 were blocked by BTE. BTE treatment blocked LPS-induced DNA-binding activity of NF-κB. BTE-fed, DSS-exposed mice showed the less weight loss, longer colon length and lower histologic score compared to control diet-fed, DSS-exposed mice. DSS-induced IκBα phosphorylation/degradation and phosphorylation of NF-κB/p65 were blocked by BTE. An increase of cleaved caspase-3 and poly (ADP-ribose) polymerase (PARP) in DSS-exposed mice was blocked by BTE.ConclusionsThese results indicate that BTE attenuates colon inflammation through the blockage of NF-κB signaling and apoptosis in DSS-induced experimental colitis model.

Knockdown of RON Inhibits AP-1 Activity and Induces Apoptosis and Cell Cycle Arrest Through the Modulation of Akt/FoxO Signaling in Human Colorectal Cancer Cells

Background/AimsAltered Recepteur d’Origine nantais (RON) expression transduces signals inducting invasive growth phenotype that includes cell proliferation, migration, matrix invasion, and protection of apoptosis in human cancer cells. The aims of the current study were to evaluate whether RON affects tumor cell behavior and cellular signaling pathways including activator protein-1 (AP-1) and Akt/forkhead box O (FoxO) in human colorectal cancer cells.MethodsTo study the biological role of RON on tumor cell behavior and cellular signaling pathways in human colorectal cancer, we used small interfering RNA (siRNA) to knockdown RON gene expression in human colorectal cancer cell line, DKO-1.ResultsKnockdown of RON diminished migration, invasion, and proliferation of human colorectal cancer cells. Knockdown of RON decreased AP-1 transcriptional activity and expression of AP-1 target genes. Knockdown of RON activated cleaved caspase-3, -7, -9, and PARP, and down-regulated the expression of Mcl-1, survivin and XIAP, leading to induction of apoptosis. Knockdown of RON induced cell cycle arrest in the G2/M phase of cancer cells by an increase of p27 and a decrease of cyclin D3. Knockdown of RON inhibited the phosphorylation of Akt/FoxO signaling proteins such as Ser473 and Thr308 of Akt and FoxO1/3a.ConclusionsThese results indicate that knockdown of RON inhibits AP-1 activity and induces apoptosis and cell cycle arrest through the modulation of Akt/FoxO signaling in human colorectal cancer cells.

Cap-assisted ERCP in patients with difficult cannulation due to periampullary diverticulum

Selective biliary cannulation is an essential prerequisite for therapeutic endoscopic retrograde cholangiopancreatography (ERCP). The cap-fitted forward-viewing endoscope has been used for ERCP in patients with surgically altered anatomy. In this case series, 12 patients with periampullary diverticulum underwent ERCP using the cap-assisted forward-viewing endoscope due to failure of biliary cannulation using the standard technique. Successful ERCP was achieved in all patients with no serious complications.

Feasibility of Cap-Assisted Endoscopic Retrograde Cholangiopancreatography in Patients with Altered Gastrointestinal Anatomy

Background/Aims Endoscopic retrograde cholangiopancreatography (ERCP) is technically challenging in patients with altered gastrointestinal (GI) anatomy. We evaluated the feasibility of cap-assisted ERCP in patients with altered GI anatomy. Methods The outcome of ERCP procedures (n=136) was analyzed in 78 patients with Billroth II (B-II) gastrectomy (n=72), Roux-en-Y total gastrectomy (n=4), and hepaticoduodenostomy (n=2). The intubation rate for reaching the papilla of Vater (POV), deep biliary cannulation rate, therapeutic interventions and procedure-related complications were analyzed. All of the procedures were conducted using a cap-fitted forward-viewing endoscope. Results The rate of access to the POV was 97.1% (132/136). In cases with successful access, selective biliary cannulation was achieved in 98.5% (130/132) of the patients. The successful biliary cannulation rates were 100% (125/125) for B-II gastrectomy, 50% (2/4) for Roux-en-Y gastrectomy and 100% (3/3) for hepaticoduodenostomy. After selective biliary cannulation, therapeutic interventions, including stone extraction (n=57), sphincterotomy (n=54), stent placement (n=37), nasobiliary drainage (n=20), endoscopic papillary balloon dilatation (n=7) and mechanical lithotripsy (n=15), were performed successfully. The procedure-related complication rate was 8.8% (12/136), including immediate bleeding (5.9%, 8/136), pancreatitis (2.2%, 3/136), and perforation (0.7%, 1/136). There were no procedure-related deaths. Conclusions Cap-assisted ERCP is efficient and safe in patients with altered GI anatomy.

Low Pepsinogen I Level Predicts Multiple Gastric Epithelial Neoplasias for Endoscopic Resection

Background/Aims Synchronous/metachronous gastric epithelial neoplasias (GENs) in the remaining lesion can develop at sites other than the site of endoscopic resection. In the present study, we aimed to investigate the predictive value of serum pepsinogen for detecting multiple GENs in patients who underwent endoscopic resection. Methods In total, 228 patients with GEN who underwent endoscopic resection and blood collection for pepsinogen I and II determination were evaluated retrospectively. Results The mean period of endoscopic follow-up was 748.8±34.7 days. Synchronous GENs developed in 46 of 228 (20.1%) and metachronous GENs in 27 of 228 (10.6%) patients during the follow-up period. Multiple GENs were associated with the presence of pepsinogen I <30 ng/mL (p<0.001). Synchronous GENs were associated with the presence of pepsinogen I <30 ng/mL (p<0.001). Conclusions Low pepsinogen I levels predict multiple GENs after endoscopic resection, especially synchronous GENs. Cautious endoscopic examination prior to endoscopic resection to detect multiple GENs should be performed for these patients.

Cap-assisted gastroscope versus cap-assisted colonoscope for examination of difficult sigmoid colons in a nonsedated Asian population: a randomized study

BACKGROUND Studies have estimated that cecal intubation failure occurs with conventional colonoscopy in about 10% of cases. Various methods have been adopted to improve the cecal intubation rate, including a transparent cap and special colonoscopes. OBJECTIVE To assess the efficacy of using a cap-assisted gastroscope (E-cap) compared with a cap-assisted colonoscope (C-cap) for the complete examination of the colon in nonsedated patients with technically difficult sigmoid colons. DESIGN Randomized, controlled study. SETTING Tertiary-care referral center. PATIENTS One hundred thirty-nine patients with technically difficult sigmoid colons were studied. INTERVENTION Colonoscopy with either an E-cap (n = 69) or a C-cap (n = 70). MAIN OUTCOME MEASUREMENTS Cecal intubation rate, cecal intubation time, patient-assessed pain score, and endoscopist-assessed pain score. RESULTS The cecal intubation rate was significantly higher in the E-cap (65/69, 94.2%) than in the C-cap group (50/70, 71.4%; P < .0001). Patient-assessed pain (moderate to severe) was more frequently reported in the C-cap (14/70, 20.0%) than in the E-cap group (5/69, 7.2%; P = .029). Endoscopist-assessed pain (moderate to severe) was more frequently reported in the C-cap (13/70, 18.6%) than in the E-cap group (3/69, 7.2%; P = .009). For patients with a low body mass index (≤ 22 kg/m(2)), the cecal intubation rate was significantly higher in the E-cap (37/38, 97.4%) than in the C-cap group (15/29, 51.7%; P < .0001). LIMITATIONS Single-center experience, lack of a gastroscope control group without a cap. CONCLUSION The cap-assisted gastroscope is more tolerable and effective than cap-assisted colonoscope for the complete examination of the colon in patients with technically difficult sigmoid colons. ( CLINICAL TRIAL REGISTRATION NUMBER KCT0000744.).

Various applications of endoscopic scissors in difficult endoscopic interventions

Endoscopic scissors offer a benefit over other devices by avoiding potential complications related to thermal and mechanical injury of surrounding structures. We describe our experience with endoscopic scissors in three difficult endoscopic interventions. A fishbone embedded in the esophageal wall penetrated very close to the pulsating aorta and the bronchus. The fishbone was cut in half by endoscopic scissors and removed without injury to adjacent organs. A gastric submucosal tumor with an insulated core that could not be resected by electrosurgical devices was cut using endoscopic scissors following endoloop placement. Extravascular coil migration after transcatheter arterial embolization resulted in a duodenal ulcer. The metallic coil on the duodenal ulcer was cut by endoscopic scissors without mechanical or thermal injury.