BACKGROUND/AIMS: Colorectal cancer (CRC) with microsatellite instability (MSI) has a better prognosis than CRC with microsatellite stable (MSS). Recent studies have reported biological differences according to tumor location in CRC. In this study, we investigated the clinical significance of MSI in patients with right-sided CRC. METHODS: The medical records of 1,009 CRC patients diagnosed at our institute between October 2004 and December 2016 with MSI test results were retrospectively reviewed. The long-term outcomes of CRC patients with MSI were assessed with respect to tumor location using Kaplan-Meier curves and Cox regression models. RESULTS: The median follow-up duration for all 1,009 study subjects was 25 months (interquartile range, 15–38). One hundred twenty-four of the study subjects had MSI (12.3%) and 250 had right-sided CRC (24.8%). The patients with MSI and right-sided CRC had better disease-free survival (DFS) than those with MSS as determined by the log-rank test (p=0.013), and this result was significant in females (p=0.035) but not in males with right-sided CRC. Multivariate Cox regression analysis showed MSS significantly predicted poor DFS in patients with right-sided CRC (hazard ratio 3.97, 95% CI 1.30–12.15, p=0.016) and in female patients (hazard ratio 4.69, 95% CI 1.03–21.36, p=0.045). CONCLUSIONS: The study shows MSI is a useful predictor of DFS in patients with right-sided CRC, especially in female patients.
Colorectal Neoplasms ; Disease-Free Survival ; Female ; Follow-Up Studies ; Gender Identity ; Humans ; Male ; Medical Records ; Microsatellite Instability ; Microsatellite Repeats ; Prognosis ; Retrospective Studies

Background/Aims: This study aimed to develop a rehabilitation program for musculoskeletal pain experienced by gastrointestinal endoscopists and to investigate its usefulness. Methods: This was a multicenter cohort study. During the first 2 weeks, a questionnaire regarding daily workload and musculoskeletal symptoms was administered. Then, a rehabilitation program including equipment/posture correction and stretching was conducted during the remaining 6 weeks. Follow-up daily workload and musculoskeletal symptom surveys were distributed during the last 2 weeks. The program satisfaction survey was performed at the 6th and 8th weeks. Results: Among 118 participants (69 men), 94% (n=111) complained of musculoskeletal pain at baseline. Various hospital activities at baseline were associated with multisite musculoskeletal pain, whereas only a few workloads were correlated with musculoskeletal pain after the rehabilitation program. Follow-up musculoskeletal pain was negatively correlated with equipment/ posture program performance; arm/elbow pain was negatively correlated with elbow (R=–0.307) and wrist (R=–0.205) posture; leg/foot pain was negatively correlated with monitor position, shoulder, elbow, wrist, leg, and foot posture. Higher performance in the scope position (86.8% in the improvement vs 71.3% in the aggravation group, p=0.054) and table height (94.1% vs 79.1%, p=0.054) were associated with pain improvement. An increased number of colonoscopy procedures (6.27 in the aggravation vs 0.02 in the improvement group, p=0.017) was associated with pain aggravation. Most participants reported being average (32%) or satisfied (67%) with the program at the end of the study. Conclusions Our rehabilitation program is easily applicable, satisfactory, and helpful for improving the musculoskeletal pain experienced by gastrointestinal endoscopists.

This study describes the purification and characterization of type II restriction endonuclease of Helicobacter pylori in order to understand the DNA restriction and modification of H. pylori. H. pylori cell extract was subjected to polyethyleneimine treatment, salt precipitation, heparine-sepharose column chromatography, and fast protein liquid chromatography (FPLC) using Resource Q column and Mono Q column to purify the type II restriction endonuclease. Hpy51-I was characterized to recognize the sequneces 5`-GT(G/C)AC-3`, yielding 5-base 5` protruding ends. The restriction sequence was identical to that of Tsp 45 I. The enzyme exhibited its maximal activity in the presence of 10-20 mM LaCl, but was inhibited completely in the presence of more than 80 mM NaCl. The enzyme showed its maximal activity in the presence of 1-10 mM MgC1(2). The optimal pH and temperature for enzyme activity was pH 9.0 and 37 degrees C, respectively. MnC1(2) could not substitute for MgC1(2) in reaction mixture. And addition of j3-mercaptoethanol and bovine serum albumin in reaction mixture led to loss of enzyme activity of Hpy51-I. The whole cell extract of H. pylori strain 51 was confirmed to carry the enzyme activity for methylation of Hpy51-I-recognised sequence. Hpy51-I digested genomic DNAs of enteric bacteria to less than I kb while it could not cut the genomic DNAs of H. pylori isolates. In this study, the type II restriction enzyme (Hpy51-I) of H. pylori was identified and characterized its biochemical properties, demonstrating that Hpy51-I might be one of the barriers for preventing the introduction of foreign DNAs into H. pylori.
Chromatography ; Chromatography, Liquid ; DNA ; DNA Restriction Enzymes* ; Enterobacteriaceae ; Helicobacter pylori* ; Helicobacter* ; Hydrogen-Ion Concentration ; Methylation ; Polyethyleneimine ; Serum Albumin, Bovine

BACKGROUND/AIMS: Polyethylene glycol (PEG) solution is the most widely used bowel preparation agent for colonoscopy because of its safety and efficacy in colon cleansing. It has been hypothesized that the timing of colon preparation may influence the quality of colon cleansing, and therefore affect the diagnostic yield of colonoscopy. The aim of this study was to determine the optimal interval of time between complete ingestion of PEG and performing colonoscopy. METHODS: We prospectively enrolled 1,355 patients who had undergone a PEG-based bowel preparation on the day of colonoscopy in 11 tertiary hospitals in Korea between March 2008 and February 2009. All colonoscopies were performed in the afternoon. The start time of PEG ingestion, completion time of PEG ingestion, dose of PEG ingested, start time of colonoscopy, and the quality of bowel cleansing were recorded. RESULTS: There was no difference of cleansing quality of bowel preparation between three groups of less than 7 hours of elapsed time (2< or = and <3 hours, 3< or = and <5 hours, 5< or = and <7 hours). However, group of more than 7 hours of elapsed time presented poor cleansing quality than others (P<0.01). CONCLUSIONS: If>7 hours elapses after ingestion of PEG, the quality of bowel preparation is poor. Therefore, depending on the time colonoscopy is scheduled, the start time of PEG ingestion may need to be adjusted.
Colon ; Colonoscopy ; Eating ; Humans ; Korea ; Polyethylene ; Polyethylene Glycols ; Prospective Studies ; Tertiary Care Centers

BACKGROUND/AIMS: Polyethylene glycol (PEG) solution is the most widely used bowel preparation agent for colonoscopy because of its safety and efficacy in colon cleansing. It has been hypothesized that the timing of colon preparation may influence the quality of colon cleansing, and therefore affect the diagnostic yield of colonoscopy. The aim of this study was to determine the optimal interval of time between complete ingestion of PEG and performing colonoscopy. METHODS: We prospectively enrolled 1,355 patients who had undergone a PEG-based bowel preparation on the day of colonoscopy in 11 tertiary hospitals in Korea between March 2008 and February 2009. All colonoscopies were performed in the afternoon. The start time of PEG ingestion, completion time of PEG ingestion, dose of PEG ingested, start time of colonoscopy, and the quality of bowel cleansing were recorded. RESULTS: There was no difference of cleansing quality of bowel preparation between three groups of less than 7 hours of elapsed time (2< or = and <3 hours, 3< or = and <5 hours, 5< or = and <7 hours). However, group of more than 7 hours of elapsed time presented poor cleansing quality than others (P<0.01). CONCLUSIONS: If>7 hours elapses after ingestion of PEG, the quality of bowel preparation is poor. Therefore, depending on the time colonoscopy is scheduled, the start time of PEG ingestion may need to be adjusted.
Colon ; Colonoscopy ; Eating ; Humans ; Korea ; Polyethylene ; Polyethylene Glycols ; Prospective Studies ; Tertiary Care Centers