Endoscopic resection for early gastric cancer: current status in Korea

Endoscopic mucosal resection (EMR) was introduced in the 1990s, and endoscopic submucosal dissection (ESD) in 2003. Currently, ESD is becoming the main procedure for the resection of early gastric cancer (EGC), and provides safer and curative outcomes. Endoscopic resection (ER) showed excellent long-term survival in Korea. The number of ESD has doubled over 5 years. ESD might be better than EMR in terms of en bloc resection, complete resection and long-term outcome. Novel techniques including endoscopic full-thickness resection with lymph node dissection will be positioned for some EGC.     

Pasteurella multocida endocarditis

Pasteurella multocida is a Gram-negative rod that forms part of the natural oral flora of cats and dogs. It is usually associated with skin and soft tissue infections, as a result of bites and scratches. Although invasive and serious infections by P. multocida are rare, there are limited reports of pneumonia and sepsis. Infective endocarditis (IE) is extremely rare. The case is reported of an 82-year-old male who presented with a productive cough, fever, and shortness of breath, and who was initially diagnosed with pneumonia. Further work-up revealed P. multocida bacteremia and an aortic valve lesion consistent with endocarditis. The patient was treated with antibiotics, and showed significant clinical recovery on follow up.     

Cryptogenic pyogenic liver abscess as the herald of colon cancer

Background and Aim: Colonic mucosal defects might be a route for bacterial invasion into the portal system, with subsequent hematogenous spread to the liver. We retrospectively investigated the results of colonoscopy and the clinical characteristics of patients with pyogenic liver abscess of colonic origin. Methods: A total of 230 consecutive patients with pyogenic liver abscess were reviewed between 2003 and 2010. The 230 patients were categorized into three groups (pancreatobiliary [n = 135], cryptogenic [n = 81], and others [n = 14]). Of the 81 cryptogenic patients, 37 (45.7%) underwent colonoscopy. Colonic lesions with mucosal defects were considered colonic causes of abscess. Results: In the 37 colonoscopic investigations, colon cancer was found in six patients (16.2%), laterally‐spreading tumor (LST) in two patients (5.4%), multiple colon ulcers in one patient (2.7%), colon polyps in 17 patients (45.9%), and diverticula in four patients (10.8%). Nine (11%) of 81 cryptogenic abscesses were therefore reclassified as being of colonic origin (colon cancer = 6, LST = 2, ulcer = 1). Three cases were stage III colon cancer, and the others were stage I. Two LST were high‐grade dysplasia. The percentage of patients with Klebsiella pneumoniae (K. pneumoniae) and diabetes mellitus (DM) of colonic origin was 66.7%, which was significantly higher than the 8.6% for other causes (P < 0.001). Conclusions: Of the 37 patients with cryptogenic pyogenic liver abscess who underwent colonoscopy, nine (24.3%) were diagnosed with a colonic cause. Colonoscopy should be considered for the detection of hidden colonic malignant lesions in patients with cryptogenic pyogenic liver abscess, especially for patients with K. pneumoniae and DM.     

Resistance of Helicobacter pylori strains to antibiotics in Korea with a focus on fluoroquinolone resistance

Background and Aim: New regimens, including those with new fluoroquinolones, have been developed to overcome the antibiotic resistance of Helicobacter pylori. We aimed to assess the antibiotic resistance rates, as well as the molecular mechanisms of fluoroquinolone resistance, of the clinical isolates obtained in Korea. Methods: The minimal inhibitory concentration (MIC) values of ciprofloxacin, amoxicillin, clarithromycin, metronidazole and tetracycline were determined by the agar dilution method for 185 treatment‐naïve Helicobacter pylori isolates. The resistant strains were evaluated for the presence of point mutations in the quinolone resistance‐determining region (QRDR) of the gyrA and gyrB genes by direct nucleotide sequencing. Results: Twenty‐nine (29/185, 15.7%) of the strains were found to be resistant to ciprofloxacin. The resistance rates to amoxicillin, clarithromycin, metronidazole and tetracycline were 2.2% (four of 185), 10.8% (20 of 185), 30.3% (56 of 185) and 0.5% (one of 185), respectively. The most common mutations in the H. pylori gyrA gene were found at codons corresponding to Asp87 (16/29, 55.2%) and Asn91 (10/29, 34.5%). Conclusions: Primary H. pylori resistance to ciprofloxacin occurred at a high frequency. The fluoroquinolone resistance is most likely mediated through amino acid point mutation in the gyrA gene at Asn87 and Asp91.     

A Case of Acute Thrombotic Occlusion of an Anomalous Origin of the Right Coronary Artery From the Left Coronary Sinus: Focus on the Importance of Dual-Source Computed Tomography for Failed Emergency Coronary Angiography

Coronary artery anomalies in patients undergoing coronary angiography are often technically challenging for invasive cardiologists and may delay revascularization time. We report a patient who underwent successful bailout revascularization using dual-source computed tomography after failed emergency angiography. This case emphasizes the utility of dual-source computed tomography, especially in an urgent clinical setting, for allowing interventional cardiologists to rapidly identify and effectively treat the aberrant coronary artery.     

Estimating the origin and evolution characteristics for Korean HIV type 1 subtype B using Bayesian phylogenetic analysis

The majority of Korean human immunodeficiency virus type 1 (HIV-1) isolates are composed of the Korean clade B strain that is distinct from the subtype B prevalent in North America and Europe. However, it is still not clear how HIV-1 was introduced, transmitted, and evolved within the Korean population. To identify the evolutionary characteristics of Korean HIV-1, we estimate the molecular epidemic history of HIV-1 subtype B gp120 env in Korea in comparison with sequences isolated from other geographic locations. A Bayesian Markov chain Monte Carlo (MCMC) statistical inference was used to estimate the time of divergence of subtype B. The estimated time of divergence of subtype B and the distinct monophyletic Korean B cluster was estimated to be in the early and mid-1960s, respectively. Substitution rates were estimated at 7.3×10(-3) and 8.0×10(-3) substitutions per site per year for HIV-1 subtype B and Korean clade B, respectively. The demographic dynamics of two Korean data sets showed that the effective number of infections in Korea increased rapidly until the early 1980s, and then the rate only slowly increased until the mid-1990s when the population growth approached a steady-state. These results suggest that the growth rate of prevalent HIV-1 strains in Korea was lower than in other countries, suggesting that the evolution of HIV-1 Korean clade B was relatively slow. Furthermore, the limited transmission of HIV-1 within the Korean population likely led to the independent evolution of this virus to form the HIV-1 Korean clade B.