Wan Sik Lee

Epigallocatechin-3-gallate Inhibits LPS-Induced NF-κB and MAPK Signaling Pathways in Bone Marrow-Derived Macrophages

Background/Aims Epigallocatechin-3-gallate (EGCG), the primary catechin in green tea, has anti-inflammatory and anti-oxidative properties. The aim of the current study was to characterize the impact of EGCG on lipopolysaccharide (LPS)-induced innate signaling in bone marrow-derived macrophages (BMMs) isolated from ICR mice. Methods The effect of EGCG on LPS-induced pro-inflammatory gene expression and nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling was examined using reverse transcription-polymerase chain reaction, Western blotting, immunofluorescence, and the electrophoretic mobility shift assay. Results EGCG inhibited accumulation of LPS-induced IL-12p40, IL-6, MCP-1, ICAM-1, and VCAM-1 mRNA in BMMs. EGCG blocked LPS-induced IκBα degradation and RelA nuclear translocation. EGCG blocked the DNA-binding activity of NF-κB. LPS-induced phosphorylation of ERK1/2, JNK, and p38 was inhibited by EGCG. U0126 (an inhibitor of MEK-1/2) suppressed the LPS-induced IL-12p40, IL-6, MCP-1, ICAM-1, and VCAM-1 mRNA accumulation in BMMs. Conclusions These results indicate that EGCG may prevent LPS-induced pro-inflammatory gene expression through blocking NF-κB and MAPK signaling pathways in BMMs.

Lymph node metastases in esophageal carcinoma: An endoscopist’s view

One of the most important prognostic factors in esophageal carcinoma is lymph node metastasis, and in particular, the number of affected lymph nodes, which influences long-term outcomes. The esophageal lymphatic system is connected longitudinally and transversally; thus, the pattern of lymph node metastases is very complex. Early esophageal cancer frequently exhibits skipped metastasis, and minimal surgery using sentinel node navigation cannot be performed. In Korea, most esophageal cancer cases are squamous cell carcinoma (SCC), although the incidence of adenocarcinoma has started to increase recently. Most previous reports have failed to differentiate between SCC and adenocarcinoma, despite the fact that the Union for International Cancer Control (7th edition) and American Joint Committee on Cancer staging systems both consider these separately because they differ in cause, biology, lymph node metastasis, and outcome. Endoscopic tumor resection is an effective and safe treatment for lesions with no associated lymph node metastasis. Esophageal mucosal cancer confined to the lamina propria is an absolute indication for endoscopic resection, and a lesion that has invaded the muscularis mucosae can be cured by local resection if invasion to the lymphatic system has not occurred.

Expression of E- and N-cadherin and clinicopathology in hepatocellular carcinoma

Loss or reduced E‐cadherin expression and aberrant expression of N‐cadherin have been associated with invasiveness of human carcinoma cells and poor prognosis. The role of E‐ and N‐cadherin, however, in hepatocellular carcinoma (HCC) has not yet been elucidated. The aim of the present study was to investigate the expression pattern of E‐ and N‐cadherin in surgically resected HCC specimens according to their relationship with clinicopathological features. The expression patterns of E‐ and N‐cadherin were evaluated on immunohistochemistry in 68 specimens of HCC and adjacent non‐tumor tissue. The most different expression pattern between HCC and non‐tumor tissue was the decreased staining intensity of E‐cadherin (nu2003=u200337, 54%) and the dot‐like discontinuous staining of N‐cadherin (nu2003=u200335, 55%). Decreased intensity of E‐cadherin and discontinuous staining of N‐cadherin in HCC was correlated with advanced stage. The risk factors for expression patterns related to recurrence were loss of E‐cadherin expression (odds ratio (OR)u2003=u20033.6; 95% confidence interval (CI): 1.1–12.4) and discontinuous staining of N‐cadherin (ORu2003=u20031.6; 95% CI: 0.8–3.2). In conclusion, discontinuous staining of N‐cadherin and loss of E‐cadherin expression in HCC predicts a high risk of recurrence after surgical treatment.

The Need for Second-Look Endoscopy to Prevent Delayed Bleeding after Endoscopic Submucosal Dissection for Gastric Neoplasms: A Prospective Randomized Trial

Background/Aims Many authors recommend performing a second-look endoscopy (SLE) to reduce the frequency of delayed bleeding after endoscopic submucosal dissection (ESD) for gastric neoplasms, but these recommendations have been made despite a lack of reliable evidence supporting the effectiveness of SLE. Methods From January 2012 to May 2013, we investigated 441 gastric neoplasms treated by ESD to assess the risk factors for delayed bleeding. Delayed bleeding occurred in four of these lesions within 1 postoperation day. Therefore, we enrolled the patients with the remaining 437 lesions to determine the utility of SLE performed on the morning of postoperative day 2. All lesions were randomly assigned to SLE (220 lesions) groups or non-SLE (217 lesions) groups. Results Delayed bleeding occurred in 18 lesions (4.1%). A large tumor size (>20 mm) was the only independent risk factor for delayed bleeding (p=0.007). The chance of delayed bleeding was not significantly different between the patients receiving a SLE (eight cases) and those patients not receiving a SLE (six cases, p=0.787). Furthermore, SLE for lesions with a large tumor size did not significantly decrease delayed bleeding (p=0.670). Conclusions SLE had little or no influence on the prevention of delayed bleeding, irrespective of the risk factors.

Reflux episode reaching the proximal esophagus are associated with chronic cough.

Background/Aims Gastroesophageal reflux (GER) has been implicated in the pathogenesis of chronic cough. The aims of this study were to evaluate the diagnostic usefulness of multichannel intraluminal impedance combined with pH monitoring (MII/pH monitoring) in patients with suspected symptoms of gastroesophageal reflux disease (GERD) and to assess the correlation between GER symptoms and reflux nature. Methods Seventy patients with suspected symptoms of GERD (such as heartburn, acid regurgitation, non-cardiac chest pain, globus and chronic cough) were enrolled. All patients were asked to discontinue medications that would influence esophageal motor function and gastric acid secretion at least one week ago. All subjects underwent MII/pH monitoring. Results Forty-five patients (64.3%) were diagnosed with GERD. Among these patients, eleven patients (15.7%) had pathologic acid reflux by pH data and thirty-four patients (48.6%) had pathologic bolus exposure by impedance. Subjects with chronic cough had a higher DeMeester score (p=0.009), percentage of acid exposure time (p=0.007), acid bolus exposure % time (p=0.027), distal acid reflux episodes (p=0.015) and proximal acid reflux episodes (p=0.030) than subjects without chronic cough. Conclusions The results of this study showed that the impedance monitoring enhanced diagnostic sensitivity than pH-monitoring alone by 48.6%. In addition, reflux episodes at the distal and proximal esophagus were noted to be important factors associated with chronic cough.

Short-Term Outcomes of Endoscopic Submucosal Dissection in Patients with Early Gastric Cancer: A Prospective Multicenter Cohort Study

Background/Aims Endoscopic submucosal dissection (ESD) is an effective treatment for early gastric cancer (EGC) that has demonstrated a minimal risk of lymph node metastasis in retrospective studies. We sought to prospectively evaluate the short-term outcomes of ESD treatment in EGCs. Methods A prospective multicenter cohort study of neoplasms 3 cm or less in diameter at endoscopic size evaluation was performed in 12 Korean ESD study group-related university hospitals and the National Cancer Center. Resected specimens were evaluated by the central pathologic review board. Results A patient cohort (n=712) with a total of 737 EGCs was analyzed. The margin-freeen bloc resection rate was 97.3%, and curative resection of 640 lesions (86.8%) was achieved. Lower curative resection rates were associated with lesions 2 to 3 cm in size prior to ESD compared with lesions 2 cm or less in size (78.6% vs 88.1%, respectively, p=0.009). Significant factors associated with noncurative resection were moderately or poorly differentiated histological type, posterior wall tumor location, tumor size larger than 3 cm, ulceration, and submucosal invasion. Delayed bleeding occurred in 49 patients (6.9%), and 12 patients (1.7%) exhibited perforations. Conclusions ESD is an effective treatment with a high curative resection rate for EGCs that meets relatively conservative pre-ESD indications. Long-term survival outcomes should be evaluated in follow-up studies.

Quality of Life after Endoscopic Submucosal Dissection for Early Gastric Cancer: A Prospective Multicenter Cohort Study.

Background/Aims Endoscopic submucosal dissection (ESD) has been an established treatment for indicated early gastric cancer (EGC) without deterioration of quality of life (QOL) compared with surgical resection. The aim of this study was to evaluate long-term QOL in patients undergoing ESD for EGC. Methods Patients scheduled to undergo curative ESD for EGC were prospectively enrolled from 12 institutions between May 2010 and December 2011. Assessments of QOL with Korean versions of the European Organization for Research and Treatment of Cancer (EORTC) QOL questionnaire-core (QLQ-C30) and a gastric cancer-specific questionnaire (STO22) were performed at baseline and at 7 days, 3 months, and 6 months after ESD. Results A total of 666 subjects were assessed for QLQ-C30 and QLQ-STO22. The mean QLQ-C30 score was 69.5 at baseline, 68.8 at 7 days, 73.1 at 3 months, and 73.2 at 6 months. The global health status on the EORTC QLQ-C30 was significantly improved after 3 and 6 months (p=0.0003 and p<0.0001, respectively). The QLQ-C30 and STO22 scores were not significantly different, or they only slightly deteriorated between before and immediately after ESD, but they were significantly improved after 3 and 6 months (p<0.05). Conclusions QOL did not deteriorate immediately after ESD, and it improved more significantly at up to 6 months in patients who underwent curative ESD for EGC without significant complications.

Autoamputation of a Giant Colonic Lipoma

Most colonic lipomas are asymptomatic and need no treatment, whereas lesions larger than 2 cm can cause acute abdominal pain, changes in bowel habits, gastrointestinal bleeding, intussusception or bowel obstruction. Autoamputation of polypoid lesions in the gastrointestinal tract is indeed a rare phenomenon, and its precise mechanism remains unknown. It presumably occurs due to ischemic necrosis of the polyp by peristalsis-induced torsion or tension. Here, we report a case of autoamputation of a giant colonic lipoma in a 48-year-old man. In our case, colonoscopic examination showed a huge autoamputated mass in the rectum and a remnant long stalk in the transverse colon. The autoamputated mass in the rectum was completely removed after fragmentation using an electrosurgical snare, and the remnant long stalk located in the transverse colon was also resected safely by endoscopic snare polypectomy. To our knowledge, these endoscopic treatments for removal of an autoamputated mass and a remnant long stalk of colonic lipoma have not been reported previously.

Risk Factors for Food Residue after Distal Gastrectomy and a New Effective Preparation for Endoscopy: The Water-Intake Method

Background/Aims Food residue is frequently observed in the gastric remnant after distal gastrectomy, despite adequate preparation. We devised a water-intake method to reduce food residue in the gastric remnant by drinking large quantities of water in a short time. The aims of this study were to identify the risk factors for food residue and to study the effectiveness of this new method for endoscopy preparation. Methods A cohort of 708 patients who underwent distal gastrectomy for gastric cancer was reviewed prospectively. Sixty patients with large amounts of food residue were randomly divided into two groups: a water-intake group (n=40) and a prolonged fasting group (n=20). Results The incidences of a large amount of food residue were 15.7%, 5.8%, 7.5%, and 2.8% at 3, 12, 24, and 36 months, respectively, after distal gastrectomy. Independent risk factors for food residue were endoscopy at 3 months, diabetes mellitus, a body mass index of <19.5, and laparoscopic surgery. The proportion of successful preparations at follow-up endoscopy was higher for the water-intake group (70%) than for the prolonged fasting group (40%, p=0.025). Conclusions The water-intake method can be recommended as a preparation for endoscopy in patients who have had repetitive food residue or risk factors after distal gastrectomy.

Prevalence of and risk factors for endogenous endophthalmitis in patients with pyogenic liver abscesses

Background/Aims Although pyogenic liver abscesses (PLAs) can be successfully treated, the visual prognosis of patients with endogenous endophthalmitis (EE) associated with a PLA is poor. Early diagnosis and prompt intervention may salvage useful vision. Therefore, we investigated risk factors for EE in patients with PLA, to facilitate early diagnosis. Methods Data from 626 patients diagnosed with PLA between January 2004 and July 2013 were analyzed retrospectively. Patients were divided into two groups: those with liver abscess-associated endogenous endophthalmitis (LAEE) and non-LAEE. Results The prevalence of EE in PLA patients was 1.92%. The mean age for all patients (373 males, 59.6%) was 62.8 years. Upon multivariate logistic regression, a liver abscess or another systemic infection (odds ratio [OR], 5.52; p = 0.005), an abscess in the right superior segment (OR, 5.26; p = 0.035), and Klebsiella pneumoniae infection (OR, 3.68; p = 0.039), were risk factors for LAEE. The final visual outcomes of patients with LAEE included no light perception in seven, hand motion only in three, and decreased visual acuity in two. Vitrectomy and early intravitreal injections of antibiotics improved visual acuity and preserved useful vision. Conclusions PLA patients with other systemic infections, abscesses in the right superior segment, and K. pneumoniae infection require close monitoring and early intervention to treat LAEE. Intravitreal antibiotic injections or early vitrectomy may salvage useful vision.