Colonoscopy decreases mortality in colorectal cancer patients compared with fecal immunochemical test.

BACKGROUND AND AIM: Colonoscopy and fecal immunochemical test (FIT) are commonly used screening methods for the detection of colorectal cancer (CRC), but their effects on survival have not been compared. We compared survival outcomes in patients with CRC according to the exposure history to colonoscopy or FIT before diagnosis of CRC. METHODS: We performed a nationwide population-based retrospective cohort study using Korean national-insurance claims data. In total, 24 875 patients with CRC diagnosed in 2012 were included. The patients were divided into three groups in terms of examinations performed during the 10 years prior to CRC diagnosis: the colonoscopy group, the FIT group, and the never-screened group. Survival outcomes were compared among the three groups. The colonoscopy group and FIT group were matched using propensity score-matching method. RESULTS: The cohort consisted of 9619 patients in the colonoscopy group, 6936 patients in the FIT group, and 8320 patients in the never-screened group. The 5-year overall survival rates were 74.1% in the colonoscopy group, 65.9% in the FIT group, and 59.6% in the never-screened group (P < 0.001). The adjusted hazard ratios for death were 0.56 (95% confidence interval [CI], 0.53-0.59) in the colonoscopy group and 0.78 (95% CI, 0.74-0.82) in the FIT group compared with the never-screened group. In the matched cohort, the adjusted hazard ratios for death was 0.76 (95% CI, 0.72-0.81) in the colonoscopy group compared with the FIT group. CONCLUSION: Colonoscopy is a more effective method for reducing mortality in patients with CRC compared with FIT.

Stool-Based miR-92a and miR-144* as Noninvasive Biomarkers for Colorectal Cancer Screening.

OBJECTIVES: Current noninvasive screening tests for colorectal cancer (CRC) have insufficient sensitivity. MicroRNA (miRNA) levels in stool have potential as markers for noninvasive screening of CRC. We evaluated the diagnostic value of stool miRNA levels and determined the optimal miRNA subtypes for detecting CRC. METHODS: Stool samples were collected from 29 patients with CRC and 29 healthy controls. The stool levels of miR-21, miR-92a, miR-200c, miR-144*, miR-135a, miR-135b, miR-106a, and miR-17-3p were determined by real-time quantitative reverse transcription polymerase chain reaction. The sensitivity and specificity of the miRNAs for CRC were determined by receiver operating characteristics analysis. RESULTS: Among the eight tested miRNAs, the mean stool levels of miR-21, miR-92a, miR-144*, and miR-17-3p differed significantly between the CRC group and the control group (p =0.014, 0.001, <0.001, and 0.008, respectively). The sensitivities and specificities of miR-21, miR-92, miR-144*, and miR-17-3p were 79.3 and 48.3%, 89.7 and 51.7%, 78.6 and 66.7%, and 67.9 and 70.8%, respectively. In a multivariate analysis, miR-92a and miR-144* were significantly associated with the presence of CRC (p = 0.03 and 0.011, respectively). CONCLUSIONS: The stool levels of miR-92a and miR-144* showed good sensitivity and fair specificity for detection of CRC, and thus may be useful as noninvasive biomarkers for this disease.

Diagnostic value of magnetic resonance cholangiopancreatography to detect bile duct stones in acute biliary pancreatitis.

OBJECTIVES: This study aims to evaluate the diagnostic value of magnetic resonance cholangiopancreatography (MRCP) in detecting common bile duct (CBD) stones in acute biliary pancreatitis (ABP). METHODS: The medical records of patients presenting with ABP from January 2008 to July 2013 were reviewed to assess the value of MRCP in detecting CBD stones in ABP. Endoscopic retrograde cholangiopancreatography (ERCP) was used as the reference standard to assess the diagnostic yield of MRCP in detecting choledocholithiasis. When ERCP was unavailable, intraoperative cholangiography or clinical follow-up was used as the reference standard. RESULTS: Seventy-eight patients who underwent MRCP were diagnosed with ABP, and thirty of the 78 patients (38%) were confirmed to have CBD stones per the study protocol. The sensitivity of MRCP in detecting CBD stones in ABP was 93.3% compared to 66.7% for abdominal CT (P < 0.008). The overall accuracy of MRCP in detecting choledocholithiasis was 85.9% compared to 74.0% for abdominal CT (P < 0.041). The area under the receiver operating characteristic curve (AUC) of MRCP in detecting CBD stones was 0.882, which was more accurate than the AUC of 0.727 for abdominal CT (P = 0.039). In 38 patients who underwent ERCP, the sensitivity and negative predictive value of MRCP in detecting CBD stones were both 100% regardless of the dilatation of the bile duct (≥7 mm versus < 7 mm). CONCLUSION: MRCP is an effective, noninvasive modality to detect CBD stones in ABP and can help identify patients who require ERCP.

Clinical outcome of endoscopic management of duodenal Dieulafoy's lesions: endoscopic band ligation versus endoscopic hemoclip placement.

BACKGROUND: The most appropriate type of endoscopic hemostasis for bleeding due to duodenal Dieulafoy's lesions (DLs) is not yet established. The aim of this study was to assess the efficacy of mechanical endoscopic hemostasis for duodenal DLs and long-term outcome after successful hemostasis, as well as to compare the efficacy and safety of endoscopic band ligation (EBL) and endoscopic hemoclip placement (EHP). METHODS: Patients admitted to the emergency unit with acute upper gastrointestinal bleeding from duodenal DLs were enrolled in this study. The data were collected prospectively, but data analysis was performed retrospectively. Twenty-four patients with duodenal DLs were treated with EBL (n = 11) or EHP (n = 13). RESULTS: There were no significant differences between groups with respect to clinical or endoscopic characteristics, apart from the number of epinephrine (three cases with EBL vs. 11 cases with EHP; p = 0.011). Primary hemostasis was achieved in all patients. Recurrent bleeding was observed in one patient (9.1 %) from the EBL group and in five patients (38.5 %) from the EHP group (p = 0.166). The recurrent bleeding in the patient from the EBL group was treated by EHP. In the EHP group, all five patients achieved successful secondary hemostasis by endoscopic treatment (EBL in two patients and EHP in three patients). There were no differences in secondary outcomes between the two groups, including the number of endoscopic sessions required, need for angiographic embolization or emergent surgery, transfusion requirements, or length of hospital stay. No complications occurred, and there was no recurrence of bleeding in either group during the follow-up period. CONCLUSIONS: Mechanical endoscopic treatments are effective and safe for the treatment of bleeding duodenal DLs. A large-scale, randomized, controlled study is required to confirm the efficacy and safety of EBL and EHP for the management of bleeding duodenal DLs.

Circumferential submucosal incision prior to endoscopic mucosal resection provides comparable clinical outcomes to submucosal dissection for well-differentiated neuroendocrine tumors of the rectum.

BACKGROUND: Small rectal neuroendocrine tumors (NETs) can be treated with endoscopic resection. Endoscopic submucosal dissection (ESD) has been accepted as a reliable technique, but it is difficult. We evaluated the feasibility and efficacy of precut and endoscopic mucosal resection (CSI-EMR) for rectal NETs compared to ESD. METHODS: Patients with rectal NETs were enrolled consecutively. ESD or CSI-EMR was performed at operator's discretion. Histological and clinical outcomes were measured and compared between the two treatment modalities. RESULTS: Thirty-three patients were enrolled in the study. Seventeen NETs were treated by the ESD method and 16 were treated by CSI-EMR. Both groups had similar mean tumor diameters (ESD 7.53 ± 1.94 vs. CSI-EMR 6.63 ± 1.99 mm; p = 0.197). En bloc resection was achieved in 100 % of ESD group and 87.5 % of CSI-EMR group. Lateral margin involvement occurred in one patient in ESD group and two in CSI-EMR group. The histologically complete resection rate was 88.2 % (15 of 17) in the ESD group and 81.2 % (13 of 16) in CSI-EMR group (p = 0.592). One case of perforation occurred in both groups. Delayed bleeding did not occur. None of the measured outcomes were different between the two groups. Operating time was significant shorter in CSI-EMR group than in ESD group (9.69 vs. 20.12 min, respectively; p value = 0.004). CONCLUSIONS: CSI-EMR results in reliable clinical outcomes for small rectal NETs comparable to those of ESD. CSI-EMR is technically feasible and more time saving.

The Effect of Intervention for Improving Colonoscopy Quality Is Associated with the Personality Traits of Endoscopists.

Background/Aims: This study investigated whether the personality traits of endoscopists are associated with the effect of interventions for the improvement of colonoscopy quality. Methods: This prospective, multicenter, single-blind study was performed with 13 endoscopists in three health screening centers over a 12-month period. Quality indicators (QIs), including adenoma detection rate (ADR), polyp detection rate (PDR), and withdrawal time, were measured every 3 months. Consecutive interventions for the improvement of colonoscopy quality were conducted every 3 months, which included the personal notification of QIs, the in-group notification of QIs, and finally a targeted "quality education" session. The personality traits of each endoscopist were evaluated for perfectionism, fear of negative evaluation, and cognitive flexibility after the last QI assessment. Results: A total of 4,095 colonoscopies were evaluated to measure the QIs of the individual endoscopists for 12 months. The mean ADR, PDR, and withdrawal time of the 13 endoscopists were 32.3%, 47.7%, and 394 seconds at baseline and increased to 39.0%, 55.1%, and 430 seconds by the end of the study (p=0.003, p=0.006, and p=0.004, respectively). Among the three interventions, only quality education significantly improved QIs: ADR, 36.0% to 39.0% (odds ratio, 1.28; 95% confidence interval, 1.01 to 1.63). The improvement of ADR and PDR by education was significantly associated with perfectionism (r=0.617, p=0.033 and r=0.635, p=0.027, respectively) and fear of negative evaluation (r=0.704, p=0.011 and r=0.761, p=0.004, respectively). Conclusions: Education can improve colonoscopy quality, and its effect size is associated with an endoscopist's personal traits such as perfectionism and fear of negative evaluation (Clinical-Trials.gov Registry NCT03796169).

Antimigration property of a newly designed covered metal stent for esophageal stricture: an in vivo animal study.

BACKGROUND: Covered self-expandable metal stents (SEMSs) are associated with a higher migration rate than uncovered SEMSs. OBJECTIVE: The antimigration property of a novel covered SEMS was investigated in a canine esophageal stricture model. DESIGN: The new stent (80 mm in length, 20 or 24 mm in diameter) has multiple protuberances on its body that were designed to be separated from the inner silicone membrane so that they could be embedded into the mucosa after deployment. Twenty-two beagle dogs were subjected to circumferential EMR in the middle esophagus for stricture formation. After 2 weeks, conventional covered stents were inserted in a control group (n = 11), and the newly designed covered SEMSs were inserted in a study group (n = 11). SETTING: Animal laboratory. INTERVENTIONS: Circumferential EMR of the middle esophagus for stricture formation, followed by endoscopic placement of a conventional or newly designed stent. MAIN OUTCOME MEASUREMENTS: Migration, complications, survival, and esophageal histopathology. RESULTS: There was no significant difference in the diameter of the esophageal stricture between the control and study groups (10 mm vs 11 mm, P = .52). Within 3 days, all stents in the control group had migrated, whereas 6 had migrated in the study group (100% vs 55%, P = .035). There were no significant complications directly associated with stent insertion. LIMITATIONS: Complications, survival, and esophageal histopathology could not be compared because all of the conventional stents migrated in the control group within 3 days. CONCLUSIONS: The newly designed covered SEMS is more resistant to migration than the conventional covered SEMS.

A novel technique using endoscopic band ligation for removal of long-stalked (>10 mm) pedunculated colon polyps: A prospective pilot study.

BACKGROUND: Endoscopic removal of large and thick-stalked pedunculated colonic polyps, often leads to massive hemorrhage. Several techniques to minimize this complication have not been widely adopted due to some caveats. In order to prevent postpolypectomy bleeding, we invented a novel technique to dissect long-stalked pedunculated colonic polyps using endoscopic band ligation (EBL) by laterally approaching the stalk. METHODS: In this prospective single-center study, 17 pedunculated polyps in 15 patients were removed between April 2012 and January 2016. We targeted pedunculated polyps with a long stalk length (>10 mm) and a large head (>10 mm) located in the distal colon. After identifying lesions with a colonoscope, we reapproached the middle part of the stalk of the targeted polyp with an EBL-equipped gastroscope to ligate it. Snare polypectomy was performed just above the ligation site of the stalk. RESULTS: EBL-assisted polypectomy removed all of the lesions successfully, which were confirmed pathologically. There was little technical difficulty associated with the endoscopic procedures, regardless of polyp size and stalk thickness, except for one case with a very large polyp that impeded the visualization of the ligation site. We observed a positive correlation between procedure time and the diameter of the head (spearman ρ = 0.52, P = 0.034). After dissection of the polyp, the EBL bands remained fastened to the dissected stalks in all cases. There was no complication associated with polypectomy for 1 month. CONCLUSION: EBL-assisted polypectomy is an easy, safe, and effective technique to remove long-stalked pedunculated colonic polyps without postpolypectomy bleeding.

LY294002 may overcome 5-FU resistance via down-regulation of activated p-AKT in Epstein-Barr virus-positive gastric cancer cells.

BACKGROUND: As EBV-associated gastric cancer has unique features that are different from EBV (-) gastric cancer, EBV is considered to have a key role in gastric carcinogenesis. It has been reported that viral latent membrane protein 2A (LMP2A) in EBV-transformed tumor cells activates the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which provides a survival signal and chemo-resistance to cytotoxic anti-cancer drugs. This study was to evaluate anti-proliferative effect and cell cycle change when 5-FU and LY294002 (LY), a selective inhibitor of PI3K, were treated separately or combined with different schedules in EBV positive gastric cancer cell line, SNU-719. METHODS: After single treatment and sequential combination of 5-FU and LY, cytotoxic activity was measured by MTS assay. When 5-FU and LY were treated in single and sequential combinations, the expression of p-AKT, p-NFkB, p-p53 and bcl-2 was observed on different concentrations by Western blot analysis. We also investigated the effect on apoptosis and cell cycle distribution using flow cytometry. The LMP2A siRNA inhibition was done to confirm the reversal of decreased 5-FU activity and p-AKT. RESULTS: When 5-FU was sequentially combined with LY, the combination index (CI) value indicated synergistic anti-proliferative effect. The expression of p-AKT and p-NF kappaB was upregulated by 5-FU alone but sequential treatment of 5-FU and LY decreased the expression of both p-AKT and p-NF kappaB. When 5-FU was combined with LY, G0/G1 and sub G1 cell population (%) increased. When 5-FU was added to the cells transfected with LMP2A siRNA, its anti-proliferative effect increased and the expression of p-AKT decreased. In sequential combination of 5-FU and LY, the expression of p-p53 was increased and bcl-2 expression was diminished compared to 5-FU alone. CONCLUSION: These data suggest that sequential combination of 5-FU and LY induce synergistic cytotoxicity and overcome intrinsic and acquired resistance of 5-FU via downregulation of activated p-AKT and mitochondria-dependent apoptosis in EBV gastric cancer cell line, SNU-719.

Clinical trial: inhibitory effect of revaprazan on gastric acid secretion in healthy male subjects.

BACKGROUND AND AIM: Revaprazan is a novel acid pump antagonist. The aim of this study was to investigate the inhibitory effect of revaprazan on gastric acid secretion in healthy male subjects. METHODS: In a double-blind, three-way cross-over study, 30 healthy male volunteers were randomized to 100, 150 or 200 mg of oral revaprazan daily for 7 days. Serum gastrin concentration was measured, and 24-h intragastric pH was recorded at baseline and on days 1 and 7 of each administration period. Serial blood samples were processed for pharmacokinetics. RESULTS: Median intragastric pH over 24 h and mean percentage time that pH was > 4 increased in a dose-dependent manner and were significantly higher on days 1 and 7 compared with baseline in all groups (P < 0.05). The antisecretory effect of revaprazan was rapid and nearly maximal on day 1 in all groups. Serum gastrin levels were rapidly normalized by 100 and 150 mg/day of revaprazan on days 1 and 7, but were significantly higher in the 200 mg/day revaprazan group. The pharmacokinetic effect was rapidly absorbed and eliminated on days 1 and 7 in all groups. CONCLUSIONS: Revaprazan rapidly and effectively inhibits gastric acid secretion in healthy male subjects. Therefore, revaprazan can be used as an effective drug for acid-related disease.

Intestinal helminthic infections diagnosed by colonoscopy in a regional hospital during 2001-2008.

The present study investigated characteristics of 24 parasite infection cases detected during colonoscopy in a regional hospital from January 2001 to December 2008. Sixteen patients were confirmed with Trichuris trichiura infection, 6 patients were with Ascaris lumbricoides infection, 1 patient with Enterobius vermicularis infection, and 1 patient with Anisakis infection. Among them, 7 patients (43.8%) were asymptomatic. Colonoscopy findings were normal in 18 patients (75.0%). Among the patients with T. trichiura infection, colonoscopy showed several erosions in 2 patients (8.3%) and non-specific inflammation of the affected segment of the colon in 3 patients (12.5%). In 1 patient with anisakiasis, colonoscopy revealed a markedly swollen colonic wall. Stool examinations were performed before treatment in 7 patients (29.2%) and were all negative for parasite eggs or worms. These results suggest that colonoscopy is a useful diagnostic approach for parasitic infections even for asymptomatic patients and for patients with negative stool examinations.

[Influence of long-term gastric acid suppression therapy on the expression of serum gastrin, chromogranin A, and ghrelin].

BACKGROUND/AIMS: Long-term use of proton pump inhibitor (PPI) induces hypergastrinemia, which results from the suppression of gastric acid secretion. Hypergastrinemia causes enterochromaffin-like (ECL) cell hyperplasia, which is a predisposing factor of carcinoid tumor of stomach. The aim of this study was to identify the effect of long-term gastric acid suppression on the gastric peptides levels, such as gastrin, chromogranin A, or ghrelin. METHODS: Control group included patients who had no medication over six months. Both H(2)RA (H(2) receptor antagonist) and PPI groups had medication at least for six months. Fasting blood was taken from each patient to assay serum gastrin, chromogranin A, and ghrelin by RIA and ELISA techniques. RESULTS: The patients with the above reference range of serum gastrin and chromogranin A were more commonly found in PPI group compared to control and H(2)RA group. However, serum ghrelin level was within the reference range in all the patients regardless of groups. There was no difference in the ratio of serum gastrin/chromogranin A among three groups. Both average serum levels of gastrin and chromogranin A were significantly elevated in PPI group compared to control and H(2)RA group. There was a significant correlation between the level of serum gastrin and chromogranin A. CONCLUSIONS: Long-term administration of H(2)RA does not affect the serum gastrin and chromogranin A level. However, long-term administration of PPI increases serum gastrin and chromogranin A. Ghrelin may influence gastric acid secretion in other pathway than ECL cell-mediated pathway such as gastrin or chromogranin A.

Efficacy of Endobiliary Radiofrequency Ablation using a Novel Endoluminal Radiofrequency Ablation Catheter in a Swine Model.

Purpose: Endobiliary radiofrequency ablation (RFA) is a new endoscopic ablative technique. However, the ideal power setting for RFA has not yet been clarified. Therefore, we intended to evaluate the effects of endobiliary RFA according to time variations using novel RFA. Materials and methods: Nine female pigs were divided into three groups according to ablation time (60, 90, and 120 seconds) with the same setting (10 watts, 80 °C). All pigs underwent endoscopic retrograde cholangiography (ERC) and endobiliary RFA in the common bile duct. Gross and histologic examinations were performed after 24 hours. Results: The ERC and application of the endobiliary RFA were 100% successful, and the post-RFA cholangiogram did not show contrast leakage. The median depth of microscopic ablation was significantly different among the three groups (60 vs. 90 vs. 120 seconds = 1.90 (1.17-2.23) vs. 2.44 (2.31-2.60) vs. 2.52 (2.47-2.64) mm, p = 0.018). There was also a linear relationship between ablation time and microscopic ablation depth (r2 = 0.552, p = 0.002). However, no significant differences in macroscopic or microscopic ablation length were observed. In addition, there were focal ablation injuries in adjacent liver tissue in five of the nine pigs (2/3 in 60, 1/3 in 90, and 2/3 in 120 seconds). Conclusion: Endobiliary RFA using a novel RFA catheter resulted in controlled ablation with a linear relationship between microscopic ablation depth and ablation time in a swine model. Clinical studies are needed to validate the safe energy condition of endobiliary RFA in malignant biliary obstruction.

Prolapse gastropathy syndrome may be a predictor of pathologic acid reflux.

AIM: To assess the occurrence of gastric acid reflux into the esophagus in endoscopically confirmed prolapse gastropathy syndrome (PGS). METHODS: Using ambulatory esophageal pH measurement (BRAVO(TM) wireless esophageal pH monitoring system), twenty-six patients with PGS were compared with twenty-one patients with erosive esophagitis (EE) as controls. We assessed several reflux parameters, including the percentage of total time at pH < 4, and the DeMeester score. RESULTS: There were no statistical differences between the PGS group and the EE group as to mean age, sex ratio and pH recording time. The EE group showed more severe reflux than the PGS group, as evaluated in terms of the longest duration of reflux, the number of reflux episodes, the number of reflux episodes lasting > 5 min, the total time with pH < 4 during acid reflux episodes, and the DeMeester score, but none of these parameters showed statistically significant difference. Although 53.8% (14/26) of the PGS group and 76.2% (16/21) of the EE group demonstrated pathologic acid reflux (DeMeester score > 14.72), there was no statistically significant difference between the two groups in the incidence of pathologic acid reflux (P = 0.11). CONCLUSION: There was no statistically significant difference in pathologic acid reflux between the PGS and EE group. These data suggest that endoscopically diagnosed PGS might be a predictor of pathologic acid reflux.

Extraction and clipping repair of a chicken bone penetrating the gastric wall.

We report a case of gastric penetration caused by accidental ingestion of a chicken bone in a 42-year old woman with a partially wearing denture. Three days ago, she accidentally swallowed several lumps of poorly-chewed chicken. Physical examination disclosed mild tenderness in the periumbilical area. Abdominal Computed tomography (CT) showed a suspicious penetration or perforation of the stomach wall measuring about 3 cm, by a linear radiopaque material at the lesser curvature of the antrum. The end of a chicken bone was very close to but did not penetrate the liver. Endoscopic examination revealed a chicken bone that penetrated into the prepyloric antrum. The penetrating chicken bone was removed with grasping forceps. Five endoscopic clips were applied immediately at the removal site and the periumbilical pain resolved promptly. After removal of the chicken bone, the patient was treated with conservative care for three days, after which she was completely asymptomatic and discharged without complication. To treat gastric penetration by a foreign body, endoclipping can be a useful method in patients with no signs or symptoms of peritoneal irritation.

Endoscopic band ligation and endoscopic hemoclip placement for patients with Mallory-Weiss syndrome and active bleeding.

AIM: To compare the hemostatic efficacy and safety of two mechanical endoscopic methods: endoscopic band ligation (EBL) and endoscopic hemoclip placement (EHP) in patients with actively bleeding Mallory-Weiss syndrome (MWS). METHODS: A prospective randomized study to compare the efficacy and safety of EHP with EBL was performed from January 2002 to August 2005. Forty-one patients with active bleeding from MWS were treated with EHP (n = 21) or EBL (n = 20). RESULTS: There were no significant differences between groups with respect to clinical and endoscopic characteristics. The mean number of hemoclips applied was 3.2 +/- 1.5 and the mean number of bands applied was 1.2 +/- 0.4. Primary hemostasis was achieved in all patients. Recurrent bleeding was observed in one patient from the EHP group and two from the EBL group. Patients with recurrent bleeding were treated by the same modality as at randomization and secondary hemostasis was achieved in all. There were no significant differences between the two groups in total transfusion amount or duration of hospital stay. No complications or bleeding-related death resulted. CONCLUSION: EHP and EBL are equally effective and safe for the management of active bleeding in patients with Mallory-Weiss syndrome, even in those with shock or comorbid diseases.

Thalidomide effect in endothelial cell of acute radiation proctitis.

AIM: To determine whether thalidomide prevents microvascular injury in acute radiation proctitis in white rats. METHODS: Fourteen female Wistar rats were used: six in the radiation group, six in the thalidomide group, and two in normal controls. The radiation and thalidomide groups were irradiated at the pelvic area using a single 30 Gy exposure. The thalidomide (150 mg/kg) was injected into the peritoneum for 7 d from the day of irradiation. All animals were sacrificed and the rectums were removed on day 8 after irradiation. The microvessels of resected specimens were immunohistochemically stained with thrombomodulin (TM), von Willebrand Factor (vWF), and vascular endothelial growth factor (VEGF). RESULTS: The microscopic scores did not differ significantly between the radiation and thalidomide groups, but both were higher than in the control group. Expression of TM was significantly lower in the endothelial cells (EC) of the radiation group than in the control and thalidomide groups (P<0.001). The number of capillaries expressing vWF in the EC was higher in the radiation group (15.3+/-6.8) than in the control group (3.7+/-1.7), and the number of capillaries expressing vWF was attenuated by thalidomide (10.8+/-3.5, P<0.001). The intensity of VEGF expression in capillaries was greater in the radiation group than in the control group and was also attenuated by thalidomide (P=0.003). CONCLUSION: The mechanisms of acute radiation-induced proctitis in the rats are related to endothelial cell injury of microvessel, which may be attenuated with thalidomide.

A squamous metaplasia in a gastric ulcer scar of the antrum.

An 81-year-old man presented with epigastric pain and weight loss for one month. He had a past history of pulmonary tuberculosis, 10 years ago. We performed a gastroscopy, which showed a linear depressed whitish gastric ulcer scar (0.8 cm in length) in the posterior wall of the prepyloric antrum. The result of biopsy was reported as squamous epithelium. Immunohistochemical staining using an antibody to high molecular weight cytokeratin (HMC) revealed positive staining in the squamous epithelium. Two years later, the lesion was followed up. The lesion remained at same site endoscopically, but no squamous epithelium could be seen microscopically.

Endoscopic resection of asymptomatic, colonic, polypoid arteriovenous malformations: Two case reports and a literature review.

A colonic arteriovenous malformation (AVM) is a significant vascular lesion of the gastrointestinal tract and a common cause of lower gastrointestinal bleeding. AVMs are usually identified endoscopically as bright red, flat lesions. AVMs with a polypoid appearance are extremely rare in the large intestine. We present two cases of colonic polypoid AVM, which were detected incidentally during screening colonoscopy. Both the patients had no history of gastrointestinal bleeding such as melena or hematochezia. Colonoscopy revealed pedunculated polyps overlaid by hyperemic mucosa in the ascending colon and proximal sigmoid colon. Microscopic examination showed aberrant vessels with thickened, hypertrophic walls in the mucosa and the submucosa, and arteries were directly connected to veins without capillary beds. These features were compatible with a diagnosis of AVM with a polypoid appearance. No immediate or delayed bleeding was noted after polypectomy.