[Show abstract][Hide abstract] ABSTRACT: Aims/IntroductionInsulin has been associated with the risk of colorectal cancer (CRC). However, few studies have evaluated the association between insulin and colorectal adenoma. We investigated the relationship between fasting serum insulin levels or homeostasis model assessment of insulin resistance (HOMA-IR) and colorectal adenoma. Materials and Methods
We retrospectively enrolled 15,427 participants who underwent both fasting serum insulin measurement and colonoscopy for a routine health examination at Asan Medical Center from January 2007 to December 2008. Participants with a history of any cancer, previous colectomy or polypectomy, those taking antidiabetic medications, and inflammatory bowel disease, non-specific colitis, non-adenomatous polyps only or CRC on colonoscopic findings were excluded. Finally, 3,606 participants with histologically confirmed colorectal adenoma and 6,019 controls with no abnormal findings on colonoscopy were included. Participants were categorized into quartiles (Q) based on fasting serum insulin levels and HOMA-IR. ResultsFasting serum insulin and HOMA-IR were significantly higher in participants with colorectal adenomas compared with controls. Multivariate regression analysis adjusting for age, sex, smoking habits, drinking habits and family history of CRC showed that participants with higher quartiles of fasting serum insulin levels (odd ratio [OR] 1.17 for 2nd Q, 1.19 for 3rd Q, and 1.42 for 4th Q, P < 0.05) or HOMA-IR (OR 1.18 for 2nd Q and 1.45 for 4th Q, P < 0.05) showed significantly increased ORs of colorectal adenoma compared with the lowest quartiles. Conclusions
These findings showed that increased serum insulin levels and insulin resistance were significantly associated with the presence of colorectal adenoma.
[Show abstract][Hide abstract] ABSTRACT: Studies on seroconversion and its reversion rate in Korean adults with Helicobacter pylori infection are very rare. The purpose of this study was to evaluate the overall seroprevalence, seroconversion rate, and seroreversion rate of H. pylori infection in an adult population.
We performed this retrospective cohort study on healthy adults who had visited our health screening center at Asan Medical Center more than twice between January 2000 and December 2010. We reviewed the anti- H. pylori Ab IgG profiles of the enrolled people and their family members and the results of esophagogastroduodenoscopies and a self-reported questionnaire.
A total of 67,212 people were enrolled in this study. The mean follow-up duration was 4.6 years, and each participant visited the center for a mean of 3.8 visits. The overall proportions of participants demonstrating persistent seropositivity, persistent seronegativity, seroconversion, and seroreversion were 53.1%, 32.5%, 4.3%, and 10.1%, respectively. The annual seroconversion rate was 2.79%. The annual crude and spontaneous seroreversion rates of the entire study population were 3.64% and 2.42%, respectively. According to multivariate logistic regression, old age (HR = 1.015), smoking (HR = 1.216), alcohol consumption more than four times per week (HR = 1.263), marriage (HR = 2.735), and living with H. pylori-infected family members (HR = 1.525) were identified as statistically significant risk factors associated with seroconversion.
The annual seroconversion rate was 2.79% in our study population. Marriage and living with H. pylori-infected family members were important risk factors affecting seroconversion in our adult population.
[Show abstract][Hide abstract] ABSTRACT: Researchers have not clearly described the clinical and pathogenetic features of hypoganglionosis and adult-onset Hirschsprung's disease, which cause pseudo-obstruction or intractable constipation. We conducted this study to explore these features of hypoganglionosis and adult-onset Hirschsprung's disease in Korean patients.
We enrolled 24 patients pathologically confirmed as having hypoganglionosis and 11 as having adult-onset Hirschsprung's disease. We recruited 26 subjects who had undergone operation for nonobstructive colon cancer and 45 healthy volunteers as controls. We described their clinical features, investigated ganglion cells and interstitial cells of Cajal (ICC), and analyzed RET, EDNRB, EDN3, and SOX10 genes.
We classified hypoganglionosis patients into two groups: type I (focal type, n = 13), with focally narrowed transition zone (TZ); and type II (diffuse type, n = 11), without transition zone. Hypoganglionosis patients had significantly fewer ganglion cells than the controls, and those cells were scarcer in the transition zone than in the proximal dilated area (P < 0.05). The ICC numbers in both diseases were significantly lower than in controls; however, they were similar between transition zone and the proximal dilated area in hypoganglionosis. In adult-onset Hirschsprung's disease, two significant intronic RET polymorphic variants, IVS14-24G>A and IVS19+47T>C, were significantly associated with adult-onset Hirschsprung's disease (P = 0.0122 and 0.0295, respectively), but not with hypoganglionosis.
Hypoganglionosis and adult-onset Hirschsprung's disease have different pathophysiologic characteristics, although their clinical presentations are similar. We suggest that there are two subgroups of hypoganglionosis: those with or without a focally narrowed transition zone with a profoundly diminished number of ganglion cells.
No preview · Article · Jun 2011 · Digestive Diseases and Sciences
[Show abstract][Hide abstract] ABSTRACT: Early tumor detection is crucial for the prevention of colon cancer. Near-infrared fluorescence (NIRF) imaging using a target-activatable probe may permit earlier disease detection. Matrix metalloproteinases (MMPs) participate in tumorigenesis and tumor growth. The aim of this study was to determine whether NIRF imaging using an MMP-activatable probe can detect colon tumors at early stages.
WE UTILIZED TWO MURINE COLON CANCER MODELS: a sporadic colon cancer model induced by azoxymethane (AOM), and a colitis-associated cancer model induced by a combination of AOM and dextran sodium sulfate (DSS). Colonic lesions were analyzed by histologic examination, Western blotting, immunohistochemical staining, and NIRF imaging using an MMP-activatable probe.
Multiple variable-sized tumors developed in both models and progressed from adenomas to adenocarcinomas over time. At the early stage of the AOM/DSS model, diffuse inflammation was observed within the tumors. MMP expression increased progressively through normal, inflammation, adenoma, and adenocarcionoma stages. NIRF signal intensities were strongly correlated with each tumor stage from adenoma to adenocarcinoma. NIRF imaging also distinguished tumors from inflamed mucosa.
NIRF imaging using a protease-activatable probe may be a useful tool for early tumor detection. This approach could translate to improve the endoscopic detection of colon tumors, especially in patients with inflammatory bowel disease.
[Show abstract][Hide abstract] ABSTRACT: A Western-style diet (WD) is known to play an important role in inflammatory bowel disease and colon carcinogenesis. The purpose of this study was to understand the role of macrophages in WD-induced colitis associated with carcinogenesis.
Male BALB/c mice were fed a WD or a control diet (CD) for 4 weeks and exposed to azoxymethane (AOM) followed by 2% dextran sulfate sodium (DSS) for 7 days.
The WD increased susceptibility to DSS-induced inflammation and accelerated the infiltration of macrophages. The incidence and multiplicity of colon tumors were higher in mice fed the WD than in those fed the CD (P < 0.05). Levels of prostaglandin-endoperoxide synthase (PTGS) 2 and prostaglandin (PG) E(2) in the colon were higher after treatment with AOM and DSS in mice fed the WD than in those fed the CD. In addition, WD consumption increased the DNA binding activity of nuclear factor-kappaB and the serum concentration of tumor necrosis factor (TNF)-α. Mice fed the WD had higher numbers of F4/80-positive cells surrounding cancer cells compared with mice fed the CD. These cells expressed PTGS2, TNF-α and β-catenin, which are up-regulated by the WD. We also found that the WD increased unphosphorylated β-catenin accumulation in the cytoplasm and nucleus of colon cancer cells.
A WD increases the susceptibility to DSS-induced inflammation and accelerates the infiltration of macrophages. In turn, this resulted in the development and progression of colon cancer.
No preview · Article · Nov 2010 · Journal of Gastroenterology and Hepatology
[Show abstract][Hide abstract] ABSTRACT: Double balloon endoscopy (DBE) is a new endoscopic method with the capability for complete observation of whole small bowel. This study evaluated the feasibility and usefulness of DBE for the diagnosis and therapy of small bowel diseases in patients with distorted intestinal anatomy by previous surgeries.
From January 2005 to August 2007, 15 patients with Roux-en-Y anastomosis underwent DBE in Asan Medical Center. Eight were men and the median age was 57 years (range, 40 to 68 y). Indications of DBE were suspected small bowel bleeding, chronic diarrhea, and recurrent acute pancreatitis. The main outcome measurements included completeness of the observation of afferent loop and DBE findings.
Because 1 patient underwent DBE twice separately owing to recurrent bleeding, a total of 16 cases were analyzed. The observation of afferent loop was complete in 13 (81%) of 16 cases. The overall diagnostic yield of DBE was 69% (11/16). Out of 11 cases in which DBE detected abnormalities, 6 (55%) showed definite lesions and 5 (45%) probable lesions. Of the 11 cases in which abnormalities were found, 7 (64%) showed lesions in afferent loop. Of the 6 cases in which definite lesions were found, 4 (67%) showed lesions in afferent loop. Therapeutic endoscopic procedures were performed in 4 cases, which include argon plasma coagulation, foreign body removal, and endoscopic nasobiliary drainage.
DBE in patients with distorted intestinal anatomy such as Roux-en-Y anastomosis is a useful tool for the management of small bowel lesions, especially those in the afferent loop.
No preview · Article · Apr 2009 · Journal of clinical gastroenterology