Yil Sik Hyun

Role of IL-17A in the development of colitis-associated cancer

A close relationship between inflammation and colon cancer has been widely accepted, and interleukin (IL)-17A plays an important role in controlling colonic inflammation. However, the role of IL-17A has not yet been validated in colitis-associated cancer (CAC). This study aims to identify the effects of IL-17A in tumorigenesis utilizing IL-17A-deficient mice in an experimental CAC model. CAC was induced in both the IL-17A-deficient and the C57BL/6 (wild-type, WT) mice by injection of 12.5 mg/kg azoxymethane followed by three rounds of 1.7% dextran sodium sulfate exposure to elicit colitis. On day 63 after the start of the study, mice were sacrificed. Colonic inflammation, proliferation and tumorigenesis were evaluated. Tumor numbers per mouse (1.43 versus 5.80; P = 0.02) and mean tumor size (1.17 versus 3.58 mm; P = 0.01) were significantly decreased in IL-17A-deficient mice compared with WT mice. Furthermore, the inflammation and the proliferation scores of IL-17A-deficient mice were significantly lower than WT mice. In the analysis of inflammatory mediators, IL-6, interferon-γ, tumor necrosis factor-α and IL-17A were markedly decreased in IL-17A-deficient mice compared with WT mice. In the western blot analysis, p-STAT3, cyclin D1, cyclin-dependent kinase 2, cyclin E, Glycogen synthase kinase 3-β and p-Akt were downregulated in IL-17A-deficient mice. Immunohistochemical staining with p-STAT3, Ki-67 and β-catenin revealed lower number of stained cells in IL-17A-deficient mice compared with WT mice. IL-17A ablation significantly decreases CAC tumorigenesis and thus may play an important role associated with chronic colitis.

Endoscopic ultrasound-guided choledochoduodenostomies with fully covered self-expandable metallic stents.

AIM To investigate the long-term outcomes of endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) with a fully covered self-expandable metallic stent (FCSEMS). METHODS From April 2009 to August 2010, 15 patients with distal malignant biliary obstructions who were candidates for alternative techniques for biliary decompression due to a failed endoscopic retrograde cholangiopancreatography (ERCP) were included. These 15 patients consisted of 8 men and 7 women and had a median age of 61 years (range: 30-91 years). The underlying causes of the distal malignant biliary obstruction were pancreatic cancer (n = 9), ampulla of Vater cancer (n = 2), renal cell carcinoma (n = 1), advanced gastric cancer (n = 1), lymphoma (n = 1), and duodenal cancer (n = 1). RESULTS The technical success rate of EUS-CDS with an FCSEMS was 86.7% (13/15), and functional success was achieved in 100% (13/13) of those cases. In two patients, the EUS-CDS failed because an FCSEMS with a delivery device could not be passed into the common bile duct. The mean duration of stent patency was 264 d. Early adverse events developed in three patients (3/13, 23.1%), including self-limited pneumoperitoneum in two patients and cholangitis requiring stent reposition in one patient. During the follow-up period (median: 186 d, range: 52-388 d), distal stent migration occurred in four patients (4/13, 30.8%). In 3 patients, the FCSEMS could be reinserted through the existing choledochoduodenal fistula tract. CONCLUSION EUS-CDS with an FCSEMS is technically feasible and can lead to effective palliation of distal malignant biliary obstructions after failed ERCP.

A fatal case of hepatitis B virus (HBV) reactivation during long-term, very-low-dose steroid treatment in an inactive HBV carrier

Hepatitis B virus (HBV) may be reactivated after chemotherapy or immunosuppressive therapy, and therefore administration of antiviral agents before such treatment is recommended. Most reported cases of reactivation are associated with high doses of immunosuppressive agents or combination therapy. We present a case of a previously inactive HBV carrier with an acute severe flare-up during a long-term, very-low-dose (2.5 mg/day) steroid treatment for rheumatoid arthritis. We suggest that even a minimal dose of single-regimen oral steroid can cause reactivation of indolent, inactive HBV.

Graduated injection needles and snares for polypectomy are useful for measuring colorectal polyp size

BACKGROUND Accurate measurement of polyp size during colonoscopy is important; however, visual estimation of polyp size is inaccurate, and it is cumbersome to use additional accessories to measure polyp size whenever polyps are detected. AIMS To evaluate the accuracy and usefulness of graduated devices that can also be used for polypectomy. METHODS The ends of the outer sheath of the injection needles and snares were marked at intervals of 5mm (total 30mm). Four endoscopists measured 53 polyps of 36 patients in the following manner: visual estimation, estimation with biopsy forceps, and measurement with graduated devices. Actual size of all polyps measured through a calliper was used as reference standard. RESULTS The difference between actual size and size measured by visual estimation was statistically significant (1.27mm, P<0.001), whilst the differences between actual size and size measured by biopsy forceps (0.06mm, P=1.00) or graduated devices (0.15mm, P=0.620) were not. The linear correlation between the estimates and the actual sizes showed that the graduated device gave the largest positive linear correlation (0.986, P<0.001) of the three measurement methods tested. CONCLUSIONS The graduated devices are efficient methods when measuring polyp size and performing polypectomy in a single step.

Glass dust esophagitis: an unusual cause of chest pain

H Y n H A 29-year-old man who had worked as a glass grinder for 6 months presented with 2 days of chest pain that began after drinking a glass of water at his workplace. The pain was worsened by the intake of both food and liquids. Physical examination, chest radiography, and electrocardiography findings all were normal. Hematologic examination was normal except for mild eosinophilia (white blood count 7900/mm; eosinophils, 8.4%). EGD revealed fine whitish granular elevations with mucosal erythema scattered throughout the entire esophagus (A and B). Pathologic examination of esophageal biopsy specimens showed diffuse surface epithelial erosion associated with active inflammatory infiltrates including eosinophils (C, H&E, orig. mag. 40). On higher power view, numerous tiny fragments of refractile foreign body–like material were present over the surface squamous epithelium with occasional impaction into the erosive foci (D, H&E, orig. mag. 200). Considering his d

Education and imaging. Gastrointestinal: Sigmoidocecal fistula diagnosed with colonoscopy.

A 42–year–old woman underwent a colonoscopy for evaluation of abdominal bloating of three months’ duration. Colonoscopic view revealed a large collapsed fistulous opening of the sigmoid colon. The ileocecal valve was identified when the colonoscope was passed through the fistulous opening connecting with the sigmoid colon. When the colonoscope reached the cecum through the conventional intra-luminal technique, white numbers corresponding to the colonoscope insertion length markings could be seen through the fistulous opening (Fig. 1). The appendiceal orifice opening was normal. To confirm the fistulous opening, indigocarmine dye was sprayed into the cecum. The blue dye was found in the sigmoid colon confirming the fistulous connection (Fig. 2). Double contrast barium enema and abdominal computed tomography (CT) scan were also performed. The barium enema also demonstrated the fistulous opening with contrast connecting the mid sigmoid colon and the cecum. Abdominal CT scan also demonstrated an air–filled fistulous tract that extended from the mid sigmoid colon to the cecal pole. However, there were no pericolic inflammation, mesenteric infiltration or bowel wall thickening around the lesion. Colocolonic fistulas are usually a complication of an inflammatory or neoplastic process. However, she had no prior history of any of the predisposing factors related to colocolonic fistulas. A thorough search of English literatures revealed only two cases of sigmoidocecal fistula due to sigmoid diverticulitis or granulomatous colitis. A radiologic study with contrast media is usually used to diagnose intra-abdominal fistulas. In addition, the primary role of colonoscopy may directly visualize the lesion that caused the fistula, and if needed, confirm through histopathologic review. In this case, chromoendoscopy was utilized to prove the presence of the sigmoidocecal fistula during the colonoscopy.

Gastrointestinal: Sigmoidocecal fistula diagnosed with colonoscopy

A 42–year–old woman underwent a colonoscopy for evaluation of abdominal bloating of three months’ duration. Colonoscopic view revealed a large collapsed fistulous opening of the sigmoid colon. The ileocecal valve was identified when the colonoscope was passed through the fistulous opening connecting with the sigmoid colon. When the colonoscope reached the cecum through the conventional intra-luminal technique, white numbers corresponding to the colonoscope insertion length markings could be seen through the fistulous opening (Fig. 1). The appendiceal orifice opening was normal. To confirm the fistulous opening, indigocarmine dye was sprayed into the cecum. The blue dye was found in the sigmoid colon confirming the fistulous connection (Fig. 2). Double contrast barium enema and abdominal computed tomography (CT) scan were also performed. The barium enema also demonstrated the fistulous opening with contrast connecting the mid sigmoid colon and the cecum. Abdominal CT scan also demonstrated an air–filled fistulous tract that extended from the mid sigmoid colon to the cecal pole. However, there were no pericolic inflammation, mesenteric infiltration or bowel wall thickening around the lesion. Colocolonic fistulas are usually a complication of an inflammatory or neoplastic process. However, she had no prior history of any of the predisposing factors related to colocolonic fistulas. A thorough search of English literatures revealed only two cases of sigmoidocecal fistula due to sigmoid diverticulitis or granulomatous colitis. A radiologic study with contrast media is usually used to diagnose intra-abdominal fistulas. In addition, the primary role of colonoscopy may directly visualize the lesion that caused the fistula, and if needed, confirm through histopathologic review. In this case, chromoendoscopy was utilized to prove the presence of the sigmoidocecal fistula during the colonoscopy.

Gastrointestinal: Sigmoidocecal fistula diagnosed with colonoscopy: Images of Interest

A 42–year–old woman underwent a colonoscopy for evaluation of abdominal bloating of three months’ duration. Colonoscopic view revealed a large collapsed fistulous opening of the sigmoid colon. The ileocecal valve was identified when the colonoscope was passed through the fistulous opening connecting with the sigmoid colon. When the colonoscope reached the cecum through the conventional intra-luminal technique, white numbers corresponding to the colonoscope insertion length markings could be seen through the fistulous opening (Fig. 1). The appendiceal orifice opening was normal. To confirm the fistulous opening, indigocarmine dye was sprayed into the cecum. The blue dye was found in the sigmoid colon confirming the fistulous connection (Fig. 2). Double contrast barium enema and abdominal computed tomography (CT) scan were also performed. The barium enema also demonstrated the fistulous opening with contrast connecting the mid sigmoid colon and the cecum. Abdominal CT scan also demonstrated an air–filled fistulous tract that extended from the mid sigmoid colon to the cecal pole. However, there were no pericolic inflammation, mesenteric infiltration or bowel wall thickening around the lesion. Colocolonic fistulas are usually a complication of an inflammatory or neoplastic process. However, she had no prior history of any of the predisposing factors related to colocolonic fistulas. A thorough search of English literatures revealed only two cases of sigmoidocecal fistula due to sigmoid diverticulitis or granulomatous colitis. A radiologic study with contrast media is usually used to diagnose intra-abdominal fistulas. In addition, the primary role of colonoscopy may directly visualize the lesion that caused the fistula, and if needed, confirm through histopathologic review. In this case, chromoendoscopy was utilized to prove the presence of the sigmoidocecal fistula during the colonoscopy.