Clinical significance of distal colon polyps for the prediction of an advanced proximal neoplasm: the KASID prospective multicenter study

Background/aims The possibility of proximal lesion without distal polyps is a weak point of sigmoidoscopic colon cancer screening, but the clinical significance of distal findings for advanced proximal neoplasm (APN) is uncertain. The aim of this study was to assess the significance of a distal finding as a predictor of APN. Materials and methods Asymptomatic patients ≥50 years old were enrolled from among patients who underwent polypectomy at 11 tertiary medical centers during the Korean Association for the Study of Intestinal Disease prospective study conducted between July 2003 and March 2004. Polyps located distal to the splenic flexure were defined as distal polyps. An advanced neoplasm was defined as a polyp of ≥10 mm in size, and/or with villous features, and/or with high-grade dysplasia, or invasive cancer. Age, gender, and distal polyp size, appearance, and histology were analyzed as risk factors of APN. The sensitivity and positive predictive value of distal polyps for APN were calculated. Results Data from 826 patients were analyzed. Mean patient age was 60.1 years (range 50–86), and 71.3% were men. APN was found in 98 patients, and 45 (45.9%) patients had no distal polyps. Risk factors of APN were a male gender, distal polyp size, and an advanced distal neoplasm. Sensitivities of a distal polyp of ≥10 mm and of an advanced distal neoplasm for APN were both 38.8% with positive predictive values of 13.3 and 14.4%, respectively. Conclusions Although distal colon findings were found to be helpful for predicting APN in asymptomatic patients aged ≥50 years, APN without distal polyps requires careful consideration.     

Analysis of PTEN Gene Mutations in Korean Patients With Cowden Syndrome and Polyposis Syndrome

PURPOSE PTEN (phosphatase and tensin homologue deleted in chromosome 10) is a candidate tumor suppressor gene. Mutations of this gene are responsible for PTEN hamartoma tumor syndromes, including Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, Proteus syndrome, and Proteus -like syndromes. Recently, PTEN mutations were identified in several human neoplasms. We analyzed the DNA of various organs and lesions in Korean patients with Cowden syndrome, their family members, and patients with familial adenomatous polyposis for germline or somatic PTEN mutations.METHODS The 11 patients included in this study were 5 patients with Cowden syndrome, 4 of their family members, and 2 patients with familial adenomatous polyposis. Deletions and mutations in exons 1 to 9 of the PTEN gene were evaluated by polymerase chain reaction-single strand conformation polymorphism and sequencing analysis in esophageal acanthosis, gastric polyps, colonic polyps, skin lesions, and peripheral blood mononuclear cells. To exclude common polymorphisms, 240 controls were tested.RESULTS All patients with Cowden syndrome showed several to numerous polyps in the gastrointestinal tract. A missense mutation at codon 217 (GTC to GAC, Val to Asp) in exon 7 was identified in one Cowden syndrome patient, and a nonsense mutation at codon 211 (TGC to TGA, Cys to stop) in exon 6 was identified in a second patient. Identical mutations were found in all tissue samples, including colonic polyps, from each patient. No PTEN mutations were found in their family members or in any patient with familial adenomatous polyposis. None of tested controls contained a mutation.CONCLUSIONS We have identified two new germline PTEN mutations in Korean patients with Cowden syndrome. Mutations in the introns and regulatory regions of the PTEN gene may be present in additional patients with Cowden syndrome and polyposis syndrome.Supported by a grant (Grant number 2003-261) from the Asan Institute for Life Sciences, Seoul, Korea.Reprints are not available.Presented at the meeting of International Gastrointestinal Bioregulation Conference, Hyogo, Japan, March 27, 2004.     

Mechanical properties of composite resins light-cured using a blue DPSS laser

Lasers have many favorable features as a light source owing to their monochromaticity and coherence. This study examined the mechanical properties of composite resins that were light-cured using a diode-pumped solid state (DPSS) laser. Eight composite resins were light-cured using four different light sources (one quartz–tungsten–halogen (QTH), two light-emitting diodes (LEDs), and one DPSS laser with a wavelength of 473 nm). The light intensity of the DPSS laser and remaining light-curing units were approximately 500 and 900 mW/cm², respectively. The microhardness, flexural properties, and compressive properties were evaluated using the Vickers hardness test, three-point bending test, and compression test, respectively. In most cases, the microhardness, flexural properties, and compressive properties of the specimens light-cured using the DPSS laser were similar to those obtained using the other light-curing units. Within the limits of the study, the microhardness, flexural modulus, and compressive strength were linearly correlated with the filler content (in weight percent). The flexural modulus and compressive modulus were also linearly correlated with the microhardness. Even with a much lower light intensity, the DPSS laser with a wavelength of 473 nm can polymerize composite resins and give comparable mechanical properties to those obtained using the other light-curing units.     

Guidelines for the management of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disorder characterized by a relapsing and remitting course. The quality of life can decreases significantly during exacerbations of the disease. The incidence and prevalence of UC in Korea are still lower than those of Western countries, but have been rapidly increasing during the past decades. Various medical and surgical therapies are currently used for the management of UC. However, many challenging issues exist and sometimes these lead to differences in practice between clinicians. Therefore, Inflammatory Bowel Diseases (IBD) Study Group of Korean Association for the Study of Intestinal Diseases (KASID) set out the Korean guidelines for the management of UC. These guidelines are made by the adaptation using several foreign guidelines and encompass treatment of active colitis, maintenance of remission and indication for surgery in UC. The specific recommendations are presented with the quality of evidence. These are the first Korean treatment guidelines for UC and will be revised with new evidences on treatment of UC.     

The Prevalence and Clinical Characteristics of Reflux Esophagitis in Koreans and Its Possible Relation to Metabolic Syndrome

The prevalence of reflux esophagitis is increasing in Korea. To estimate the prevalence and clinical characteristics of reflux esophagitis in healthy subjects, we retrospectively examined the medical records of healthy subjects undergoing a routine check-up from October 2004 to September 2005. A total of 6,082 (3,590 men, mean age 44±10 yr) subjects were enrolled in this study. The prevalence of reflux esophagitis in healthy subjects was 10.5%. According to the univariate analysis, male sex (odds ratio [OR] 3.49, 95% confidence interval [CI] 2.84-4.30), smoking history (OR 1.91, 95% CI 1.60-2.28), body mass index (BMI) >30 kg/m² (OR 2.13, 95% CI 1.37-3.33), total cholesterol >250 mg/dL (OR 1.50, 95% CI 1.05-2.14), low-density lipoprotein (LDL) cholesterol ≥160 mg/dL (OR 1.52, 95% CI 1.08-2.14), triglyceride ≥150 mg/dL (OR 1.92, 95% CI 1.61-2.30), high blood pressure (BP) (OR 1.46, 95% CI 1.20-1.76), and fasting glucose ≥110 mg/dL (OR 1.45, 95% CI 1.13-1.86) were significantly associated with reflux esophagitis (all p<0.05). However, age, alcohol drinking and Helicobacter pylori infection were not associated with reflux esophagitis. In conclusiosn, significant relationships of reflux esophagitis with obesity, low high-density lipoprotein (HDL) cholesterol, high triglyceride, high BP, and elevated fasting glucose suggested that reflux esophagitis might represent the disease spectrum of the metabolic syndrome.     

Emerging need for vaccination against hepatitis A virus in patients with chronic liver disease in Korea

Vaccination against hepatitis A virus (HAV) is recommended for patients with chronic liver disease (CLD), but this has been deemed unnecessary in Korea since the immunity against HAV was almost universal in adults. However, this practice has never been reevaluated with respect to the changing incidence of adult acute hepatitis A. We retrospectively reviewed the medical records of 278 patients with acute hepatitis A diagnosed from January 1995 to November 2005 and prospectively tested 419 consecutive CLD patients from July to December 2005 for the presence of IgG anti-HAV. The number of patients with acute hepatitis A has markedly increased recently, and the proportion of adult patients older than 30 yr has been growing from 15.2% during 1995-1999, to 28.4% during 2000-2005 (p=0.019). Among 419 CLD patients, the seroprevalences of IgG anti-HAV were 23.1% for those between 26 and 30 yr, 64% between 31 and 35 yr, and 85.0% between 36 and 40 yr. These data demonstrate that immunity against HAV is no more universal in adult and substantial proportion of adult CLD patients are now at risk of HAV infection in Korea. Therefore, further study on seeking proper strategy of active immunization against HAV is warranted in these populations.