Learning Curves for Colonoscopy: A Prospective Evaluation of Gastroenterology Fellows at a Single Center

BACKGROUND/AIMS: Colonoscopy training programs and the minimal experience with colonoscopy required to be considered technically competent are not well established. The aim of this study was to determine the colonoscopy learning curves and factors associated with this difficult procedure at a single center. METHODS: A total of 3,243 colonoscopies were performed by 12 first-year gastroenterology fellows, and various clinical factors were assessed prospectively for 22 months. Acquisition of competence (success rate) was evaluated based on two objective criteria: (i) the adjusted completion rate (>90%) and (ii) cecal intubation time (20 minutes). Surgery of the uterus and ovaries was significantly correlated with delayed cecal intubation time, but not after sufficient colonoscopy experience. CONCLUSIONS: The minimum number of procedures to reach technical competence was 200. The cecal intubation time was longer in female and older patients.

Fabrication of tissue engineered myo-mucosal flap by grafting the complex of autologous oral keratinocytes and platelet rich plasma (prp) in a rat model

BACKGROUNDS: To overcome limited amount of autogenous mucosa for the reconstruction of various mucosal defect including oral mucosal defect, tissue engineered mucosa has been recently introduced. However, introduced conventional technique of tissue engineered mucosa still have serious pitfalls such as long fabrication time, fragility of the reconstructed mucosa, and complexity of the technique. AIM OF THE STUDY: To examine whether the complex of preconfluent autologous keratinocytes and autologous PRP (Platelet rich plasma) can reconstruct oral mucosa on the muscular flap with easier and faster way compared to conventional mucosal tissue engineering technique. MATERIALS AND METHODS: One day before the operation, oral mucosa (3mm in diameter) were taken and treated for extraction of oral keratinocytes according to the routine manner. The day of operation, oral keratinocytes were prepared in the laboratory and then moved to the operating theater. Autologous PRP was also prepared and then mixed with oral keratinocytes just before grafting on the prepared muscular flap. After keratinocyte-PRP complex was seated, then a sterilized rubber sheet was placed on the graft and the elevated skin flap was replaced and sutured. Biopsies were proceeded at 3,5,7,14 and 21 days. Tissue samples were evaluated clinically, histologically, and immunohistochemically. RESULTS: All of the oral keratinocyte-PRP complexes were successfully grafted on the recipient sites (100%). On 3 days after the operation, 1-2 continuous epithelial layer and many inflammatory cells were observed. On 5 days after the operation, increase of layers of keratinocyte was observed with less inflammatory response. Thickness of the layers was gradually increased from 7 to 21 days after the operation. Cytokeratin confirms epithelium in every specimen. CONCLUSIONS: Preconfluent graft of autogenous oral keratinocytes mixed with autogenous PRP have successfully reconstructed myo-mucosal flap. This technique could be a useful alternative for oral mucosal reconstruction in the near future.

The Prevalence of Peripheral Iron Overload and the Presence of HFE gene (H63D) Mutation among the Korean Patients with Nonalcoholic Fatty Liver Disease / 대한간학회지

BACKGROUNDS/AIMS: There are controversies on the role of iron overload in the mechanism of liver injury in nonalcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate the prevalence of peripheral iron overload, and to study the presence of HFE mutations (C282Y, H63D, S65C) in a cohort of Korean NAFLD patients. METHODS: 255 patients with NAFLD were included. The patients had been diagnosed as having NAFLD by the criteria of elevated aminotransferase levels, compatible ultrasonographic findings and exclusion of other etiologies. Blood samples were tested for chemistry, iron profile, and mutational analysis for HFE gene (C282Y, H63D, S65C). RESULTS: Of the 255 NAFLD patients, the prevalence of peripheral iron overload was 19.2% according to the cutoff level of transferrin saturation (TS) > 45%, and 3.9% of NAFLD patients were having hyperferritinemia over 400 ng/mL. Hyperferritinemia was significantly associated with elevated serum levels of fasting glucose, AST and TS. We found the presence of H63D mutation, either heterozygote or homozygote, among the NAFLD patients with peripheral iron overload. CONCLUSIONS: The prevalence of peripheral iron overload in the Korean NAFLD patients was not rare, and the presence of H63D mutation among NALFD patients was identified. Further studies on the significance of iron overload or HFE mutation in the pathogenesis of NAFLD are needed.

Recent Etiology and Clinical Features of Acute Viral Hepatitis in a Single Center of Korea / 대한간학회지

BACKGROUND AND AIMS: The etiology of acute viral hepatitis in Korea has been dynamically changing during the recent years. The aim of this study was to investigate the recent etiology and the clinical features of acute viral hepatitis in a single center of Korea. METHODS: We performed a retrospective analysis of a prospective cohort of 55 patients who were diagnosed with acute viral hepatitis A to E during the period from May 2005 to August 2006. In addition to the clinically acute manifestations, the confirmatory serological tests were performed for the diagnosis of acute hepatitis A, B, C and E. RESULTS: The proportion of patients with acute viral hepatitis A, B, C, E and others were 56.4% (n=31), 12.7% (n=7), 18.2% (n=10), 9.1% (n=5) and 3.6% (n=2), respectively. The mean age of the patients with acute hepatitis A, B, C and E were 29.1+/-4.38, 38.7+/-11.72, 45.3+/-17.62 and 32.4+/-6.58 years, respectively. There was no fatal case. All cases of acute hepatitis B and six out of ten cases of acute hepatitis C recovered spontaneously. Four out of the five patients with acute hepatitis E had no history of travel to endemic area. CONCLUSIONS: The most common etiology of acute viral hepatitis in Korea is hepatitis A virus, and hepatitis C and B virus were the next most common causes. The sporadic cases of acute hepatitis E were not rare, and coinfection of HAV and HEV was observed. A multicenter, prospective study is warranted in the future.

Multiple langerhans cell histiocytosis at the lung and mandible: Case report

Hitiocytosis X, recently termed Langergans cell histiocytosis, is a rare disease histologically characterized by an abnormal proliferation of histiocytes, and of which the pathophysiology is still ambiguous. The clinical presentation is highly varied. Typically, there is a solitary or multiple bony involvements, and less frequently, lesions are found in other organs such as the lungs, liver, lymph nodes, skin, and mucosae. Interestingly, so far, there has been no report which shows multiple developments in both soft and hard tissues. In this report, we present a case of hitiocytosis X in both mandible and lung. This may provide some information for understanding the pathophysilogy of the histiocytosis X.