Jong Hoon Lee

Long-term outcomes of endoscopic submucosal dissection in gastric neoplastic lesions at a single institution in South Korea

Abstract Objective. Although endoscopic treatment for early gastric cancer (EGC) is an accepted therapy in South Korea and Japan, long-term outcomes remain unknown. We evaluated the clinical outcome of endoscopic submucosal dissection (ESD) for gastric dysplasia and EGC. Material and methods. A total of 402 patients with gastric dysplasia and EGC were treated with ESD at a single hospital from January 2004 to December 2007. The patients underwent ESD and then received periodic endoscopic follow-up and metastatic surveys for 9–49 months (median 30 months). Resectability (en bloc or piecemeal resection), curability (complete or incomplete), local recurrence, and disease-free survival rates were estimated. Results. There were 107 patients with low-grade dysplasia (LGD), 97 with high-grade dysplasia (HGD) and 198 with EGC. In EGC patients, en bloc resection was achieved in 89.7% (177/198), the complete resection rate was 87.9% (174/198), and the local recurrence rate was 5.1% (10/198). Tumor size >20 mm was significantly associated with local recurrence (odds ratio 6.45; 95% CI 1.20–20.11; p=0.001). There were significant correlations between the incidences of a piecemeal or incomplete resection and that of local recurrence (odds ratio 5.23; 95% CI 1.02–18.34; p=0.001; and odds ratio 6.99; 95% CI 1.22–21.65; p=0.002, respectively). The 3-year cancer-free survival rate was 94.9%. Conclusions. Curative treatment with successful en bloc resection can reduce the local recurrence of gastric neoplastic lesions after ESD. Clinical outcome may be excellent, although longer follow-up studies are warranted.

Risk factors for immediate and delayed bleeding associated with endoscopic submucosal dissection of gastric neoplastic lesions

Abstract Objective. Endoscopic submucosal dissection (ESD) of gastric neoplasia has been reported to have a higher bleeding rate than conventional endoscopic mucosal resection (EMR). The aim of this study was to identify the risk factors for bleeding associated with ESD. Material and methods. The records of consecutive patients who underwent ESD for gastric adenoma/early gastric cancer were reviewed. Potential risk factors included patient age, lesion size, gross findings, location, and histology of the tumor. The primary end-point was the incidence of immediate or delayed bleeding related to ESD. Results. A total of 144 patients were studied; bleeding occurred in 32 cases (22.2%) with immediate bleeding in 29 cases. Delayed bleeding (3 cases) occurred at day 2 (2 patients) and at day 7 in 1 patient. In all cases of immediate bleeding, immediate hemostatic therapy was successful. The histology of tumor was the only factor that was statistically significantly associated with bleeding (adjusted hazard ratio 6.770, 95% confidence interval 1.830–25.048, p=0.004). Conclusions. The only factor that correlated with an increased risk of bleeding with ESD was the presence of gastric malignancy. We found no factor that would, prospectively, be amenable to prevention of bleeding.

Prognostic values of KAI1 and survivin expression in an infiltrating ductal carcinoma of the breast

Aims: To investigate KAI1 and survivin expression in infiltrating ductal carcinomas, and to evaluate the relationship between clinicopathological factors and KAI1 and survivin expression levels in breast cancers. Methods and Results: KAI and survivin expression levels were measured in 62 patients, using immunohistochemical staining. Western blot analysis was performed on eight frozen cases. DNA ploidy was determined by flow cytometry. The results of the KAI1 expression analyses were as follows: in 14 cases (22.6%) levels were preserved (++), in 30 cases (48.4%) levels were reduced (+), in 18 cases (29.0%) no KAI1 expression was detected, so these were designated “lost’ (−). Results of assessments of survivin expression were as follows: six cases (9.7%) were strong positive (++), 28 cases (45.15%) were positive (+), and 28 cases (45.15%) were negative. Survivin (p=50.0009) and KAI1 (p=50.0091) expression levels were directly correlated with survival rate. However, no significant difference was determined to exist between survivin and KAI1 expression levels and the clinicopathological factors. DNA ploidy did not correlate with survivin and KAI1 expression levels and survival rate. Four different groups, according to their survivin and KAI1 expression levels, correlated with the clinical stage and survival rate. Conclusion: KAI1 and survivin expression levels might be prognostic factors in breast cancers.

The effects of antibiotics on the biofilm formation and antibiotic resistance gene transfer

AbstractRecently, a number of microcontaminants were found in aquatic environment and it raises the concerns about their effects to ecosystem. This study investigated if low levels of antibiotics can trigger the biofilm formation and result in the enhanced antibiotic gene transfer. For this purpose, the biofilm formation of enteric bacteria (Escherichia coli), environmental micro-organism (Pseudomonas aeruginosa), and their mixture by ppb level of antibiotics were investigated. In addition, the effects on the conjugation of E. coli with P. aeruginosa in the biofilm structure were also evaluated using biofilm colony-forming unit assay in 96-well plates and ELISA. Interestingly, at 100–1000 ppb, the mixed culture was able to reach its highest biofilm biomass and also form the highest number of transconjugants, which is greater than negative controls. This experiment shows that ppb levels of tetracycline and cephradine can alter the transfer rate of the pB10 plasmid among the biofilm biomass at rates 2–5 tim...

Design of HTS Modular Magnets for a 2.5 MJ Toroidal SMES: ReBCO vs. BSCCO

A 2.5 MJ HTS SMES is being developed as a national program in Korea. This paper presents design results of modular HTS magnets for the 2.5 MJ toroidal SMES. We considered a choice of BSCCO-2223 or ReBCO tapes as the conductors for the HTS magnets of the SMES. Operating temperature was decided to be 20 K which could be accomplished by conduction cooling with a couple of GM cryo-coolers. Key design factors may include minimization of total conductor requirement and low AC loss.

L-phenylalanine production by auxotrophic regulatory mutants ofEscherichia coli—L-phenylalanine production by mutants ofE. coli

Various regulatory mutants ofEscherichia coli have been isolated using phenylalanine and tyrosine analogues. It has been found that the growth of wild type strain ofE. coli W3110 was strongly inhibited by phenylalanine analogues. Regulatory mutants resistant to phenylalanine analogue could accumulate b-phenylalanine at concentrations of 5–6 g/l. However, L-phenylalanine accumulation was increased significantly up to 11.4 g/1 using a tyrosine auxotrophic mutant resistant to phenylalanine analogue such as β-2-thienyl-DL-alanine.

[Clinical features of gas-forming liver abscesses: comparison between diabetic and nondiabetic patients].

BACKGROUND/AIMS Patients with diabetes mellitus (DM) are more likely to have a pyogenic liver abscess with gas formation, which is associated with higher morbidity and mortality. The morbidity and mortality in pyogenic liver abscess are also higher in DM patients than in non-DM patients. This study evaluated the morbidity, mortality, and clinical features in patients with gas-forming liver abscesses associated with DM. METHODS Among 379 cases of pyogenic liver abscess excluding malignancy from January 2001 through December 2009, 25 patients treated for pyogenic-gas-forming liver abscesses were reviewed retrospectively. We compared the morbidity, mortality, and clinical findings in patients with pyogenic-gas-forming liver abscesses between DM and non-DM patients. RESULTS Gas formation was present in 25 (6.6%) of 379 cases with pyogenic liver abscess. DM was combined with gas-forming liver abscesses in 19 cases (76%). The most common organism responsible for the gas formation was Klebsiella pneumoniae (82%). Complications were present in 23 cases (92%) of gas-forming liver abscesses, with pulmonary complications (especially pleural effusion) being the most common (n=14, 61%). Four patients (16%) died of sepsis. CONCLUSIONS Gas-forming liver abscesses are not uncommon in cases of pyogenic liver abscesses and are associated with high morbidity and mortality rates. The clinical manifestations and complications do not differ significantly between DM and non-DM patients.

Expressions of matrix metalloproteinase-7 and -9 and their prognostic significances in rectal cancer.

PURPOSE The matrix metalloproteinases (MMPs) are a family of proteolytic enzymes. MMPs are known to be involved in tumor invasion, and several have been implicated in tumor prognosis. The aim of this study was to evaluate the prognostic significances of the expressions of MMP-7 and -9 in rectal cancer. MATERIALS AND METHODS The tumor tissues of 87 patients with stage II or III rectal carcinoma that underwent potentially curative resection followed by postoperative adjuvant chemoradiation and 5-fluorouracil based chemotherapy, were investigated immunohistochemically using monoclonal antibodies against MMP-7 and MMP-9. Clinical information, including tumor grades, carcinoembryonic antigen (CEA) levels, and disease-free survival and overall survival were evaluated with respect to the expressions of MMP-7 and -9. RESULTS Median follow-up duration was 53.2 months, and median patient age was 55±11 years (range 32~75). MMP-7 expression in tumor tissue was found to be significantly correlated with the presence of nodal metastasis (p=0.029), whilst MMP-9 expression correlated with depth of tumor invasion (p=0.019). No relationships were found between the expressions of MMP-7 or -9 and age, sex, tumor size, tumor grade, or CEA level. Univariate analysis showed that MMP-7 expression was associated with poor 5-year overall survival (12.8 months vs. 65.3 months, p=0.0405). Multivariate analysis confirmed that MMP-7 was independently associated with an adverse outcome (Relative risk: 1.415, p=0.027). However, MMP-9 expression was not found to be related to clinical outcome. CONCLUSION MMP-7 expression in tumor tissue is associated with lymph node metastasis and a poor 5-year overall survival in rectal cancer patients.

Chemistry and product quality of an NH3–CO2 forward osmosis desalination system

AbstractThis study examined the chemistry of a forward osmosis (FO) desalination system, which employs ammonium bicarbonate as the draw solute. The Indophenol blue photometric technique and a total carbon analyzer were used to determine the ammonia concentration and carbonate species concentration, respectively. The equilibrium relationships of the concerned species in water were used to analyze the distribution of ionic and gaseous species present in the solution at different stages of the process. The results can be used to evaluate the economic and environmental feasibility of the FO desalination process for water supply.

Delayed Viral Clearance of Chronic Hepatitis C in Patients after Treatment Failure

Hepatitis C virus (HCV) infection usually progresses to chronic hepatitis, with rare cases of spontaneous viral eradication. We present herein four cases involving patients that were initially declared to have failed to respond to treatments, based on the presence of HCV RNA that was still detectable after completion of the standard treatment for chronic hepatitis C with genotype 2. However, the HCV RNA became undetectable, with a delayed response, after discontinuation of therapy. Two of the four patients were diagnosed as treatment failures after extended treatment, and the other two received no further treatment after the standard treatment. All four patients maintained a sustained virological response during the periodic follow-up after delayed viral clearance.