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With advances in diagnostic endoscopy, the detection of rectal neuroendocrine tumors (NETs) has increased. However, clinical outcomes, especially after endoscopic treatment, are still unclear. The aim of this study was to determine the long-term clinical outcomes of endoscopically resected rectal NETs according to the pathologic status after initial resection.In this large, multicenter, retrospective cohort study, we analyzed the medical records of patients who underwent endoscopic resection of rectal NETs and were followed for ≥24 months at 16 university hospitals. The outcomes of interest were local or distant recurrence and metachronous lesions.On the pathologic assessment of 407 patients, the resection margin status was positive in 76 (18.7%) and indeterminate in 72 (17.7%) patients. Patients whose rectal NETs were diagnosed or suspected as NETs before resection showed a much higher complete resection rate than those whose tumors were resected as polyps and then diagnosed (P0.001). Fourteen patients received salvage treatment at 1.9±2.8 months after initial treatment. During a median follow-up period of 45.0 months, local recurrence occurred in 3 (0.74%) patients, but there was no recurrence in the lymph nodes or distant organs. Metachronous rectal NETs were diagnosed in 3 (0.74%) patients. According to the pathologic status after initial resection, local recurrence and metachronous lesions occurred in 1 (0.4%) and 2 (0.8%) patients, respectively, in the pathologic tumor-free group, whereas they occurred in 2 (1.4%) and 1 (0.7%) patients, respectively, in the indeterminate group.Considering the long-term prognosis including that for recurrences or metachronous lesions, endoscopic resection is an efficient and a safe modality for the treatment of rectal NETs. This treatment may result in favorable clinical outcomes in patients with tumors of indeterminate pathology, as well as in pathologic tumor-free cases after initial resection.

Although adenoma detection rate (ADR) has been proposed as a quality indicator of colonoscopies, adenomas per colonoscopy (APC) is a promising alternative to ADR, as it reflects inspection over the entire length of the colon. This study investigated the correlation between ADR and APC, and compared the efficacy of ADR and APC based on the correlation of each with the advanced adenoma detection rate (AADR).Two prospectively collected databases, including the 1142 subjects who underwent screening colonoscopies by 28 colonoscopists, were retrospectively reviewed. AADR1 were definded as the proportion of participants having advanced neoplasms, and AADR2 were definded as the proportion of participants having advanced neoplasms or three or more adenomas. Pearson correlation and Steiger's z-test was used to evaluate the relationship between ADR-APC, ADR-AADR and APC-AADR.The ADRs ranged from 16.67 to 66.67% (mean, 37.29%) and APCs ranged from 0.22 to 1.28 (mean, 0.65). The ADR and APC showed a significant correlation (R = 0.82; p 0.001). The screening ADR was significantly correlated with AADR1/AADR2 (R = 0.60; p = 0.001 and R = 0.64; p 0.001, respectively). APC was also significantly correlated with AADR1/AADR2 (R = 0.65; p 0.001 and R = 0.77; p 0.001, respectively). The correlation coefficient for APC-AADR2 was higher than ADR-AADR2 (0.77 versus 0.64, p = 0.04).Colonoscopists' ADRs and APC were significantly correlated. Moreover, as the correlation coefficient for AADR was higher with APC than it was with ADR, APC might be a better quality indicator of colonoscopy than ADR.

Purpose To elucidate the brain's intrinsic response to injury, we tracked the response of neural stem/progenitor cells (NSPCs) located in ventricular-subventricular zone (V-SVZ) to hypoxic-ischemic brain injury (HI). We also evaluated whether transduction of V-SVZ NSPCs with neurogenic factor NeuroD1 could enhance their neurogenesis in HI. Materials and methods Unilateral HI was induced in ICR neonatal mice. To label proliferative V-SVZ NSPCs in response to HI, bromodeoxyuridine (BrdU) and retroviral particles encoding LacZ or NeuroD1/GFP were injected. The cellular responses of NSPCs were analyzed by immunohistochemistry. Results Unilateral HI increased the number of BrdU+ newly-born cells in the V-SVZ ipsilateral to the lesion while injury reduced the number of newly-born cells reaching the ipsilateral olfactory bulb, which is the programmed destination of migratory V-SVZ NSPCs in the intact brain. These newly-born cells were directed from this pathway towards the lesions. HI significantly increased the number of newly-born cells in the cortex and striatum by the altered migration of V-SVZ cells. Many of these newly-born cells differentiated into active neurons and glia. LacZ-expressing V-SVZ NSPCs also showed extensive migration towards the non-neurogenic regions ipsilateral to the lesion, and expressed the neuronal marker NeuN. NeuroD1+/GFP+ V-SVZ NSPCs almost differentiated into neurons in the peri-infarct regions. Conclusion HI promotes the establishment of a substantial number of new neurons in non-neurogenic regions, suggesting intrinsic repair mechanisms of the brain, by controlling the behavior of endogenous NSPCs. The activation of NeuroD1 expression may improve the therapeutic potential of endogenous NSPCs by increasing their neuronal differentiation in HI.

The aims of this study were to demonstrate the trends in seropositivity and the eradication therapy rate for Helicobacter pylori (H. pylori) over an 18-year period in an asymptomatic Korean population and to explore the factors associated with H. pylori seropositivity and its eradication therapy. In total, 23,770 subjects (aged 17–97 years) from a health examination center participated in this cross-sectional study from January 2016 to June 2017. Questionnaires that included questions about the participants’ H. pylori eradication therapy history were collected, and anti-H. pylori IgG antibodies were measured. Among the eligible subjects, the seroprevalence of H. pylori infection was 41.5%. The H. pylori eradication therapy rate increased continuously from 2005 (13.9%) to 2011 (19.3%) and then increased again until the first half of 2017 (23.5%) (P < 0.001). After exclusion of subjects with a history of gastric surgery, gastric cancer, H. pylori eradication therapy, or gastric symptoms, H. pylori seropositivity was 43.9% in 16,885 subjects, which was significantly lower than the seropositivities in 1998 (66.9%), 2005 (59.6%), and 2011 (54.4%). The risk factors associated with H. pylori seropositivity according to multivariable analysis were male sex (odds ratio (OR) 1.34, 95% confidence interval (CI): 1.23–1.46), medium educational level (OR 1.17, 95% CI: 1.05–1.31), medium household income level (OR 1.10, 95% CI: 1.03–1.19), and age of 60–69 years (OR 8.78, 95% CI: 6.41–11.85). The observed downward trend in H. pylori seroprevalence and increase in H. pylori eradication over the 18-year period will affect upper gastrointestinal disorders in South Korea.

The prevalence of upper gastrointestinal disease is expected to change following advances in socioeconomic status and improved hygiene in Korea. The aim of this study was to investigate the recent trends in upper gastrointestinal diseases based on endoscopic findings and Helicobacter pylori (H. pylori) seroprevalence in subjects undergoing health check-up at tertiary centers in Korea.A multicenter cross-sectional study was conducted at nine healthcare centers between September 2016 and June 2017. The subjects were evaluated using questionnaires, upper endoscopy and H. pylori serology tests. The results were compared with previous data in our study group obtained from eight tertiary healthcare centers in 2011 (n = 4023).In total, we prospectively enrolled 2504 subjects undergoing health check-up. The prevalence of reflux esophagitis (RE) was 9.7%, which showed an increasing but insignificant trend since 2011 (8.8%). The prevalence of active and healing-stage benign gastric ulcer and duodenal ulcer (DU) was 1.6% and 1.2%, respectively, which confirmed a significant decrease since 2011 (4.1%; p .001 and 2.2%; p = .005, respectively). The prevalence of gastric cancer was 0.5%, representing an increasing trend since 2011 (0.12%; p = .003). H. pylori seroprevalence was 51.3%, which significantly decreased from 2011 (59.8%; p .001). In multivariate analysis, H. pylori seropositivity was a significant risk factor for DU (p .001), whereas a significant protective factor against RE (p .001).The significant decrease of H. pylori seroprevalence in the past five years altered the incidence of upper gastrointestinal disease.

Background/aims Functional dyspepsia (FD) is one of the most common gastrointestinal disorders, and FD imposes social and economic burden worldwide. The aim of this study is to identify the prevalence and risk factors of FD in health check-up population in tertiary centers in Korea. Methods A nationwide multicenter prospective study was performed at 9 tertiary healthcare centers in Korea between September 2016 and June 2017. A total of 2525 subjects were investigated based on endoscopic findings and questionnaires with the Rome III criteria, and Helicobacter pylori serology (IgG). Results A total of 1714 subjects without organic disease were enrolled. The mean (± SD) age was 51.5 (± 12.7) years, and 917 patients (53.5%) were female. The proportion of H. pylori seropositivity was 51.0% (874/1714). The prevalence of FD was 10.3% (176/1714), and the subtypes of postprandial distress syndrome alone, epigastric pain syndrome alone, and postprandial distress syndrome-epigastric pain syndrome overlap were 4.8%, 3.0%, and 2.5%, respectively. Multivariate analysis showed that female gender (OR, 1.58; 95% CI, 1.14-2.21) and education below college level (OR, 1.45; 95% CI, 1.01-2.07) were related to FD. Multivariate analysis based on age 60 showed female gender as a significant (OR, 2.90; 95% CI, 1.06-7.94) factor in the group ≥ 60 years. Conclusions The prevalence of FD was 10.3% in the health check-up population in Korea. Female sex and education below college level were risk factors for FD. Female sex is a risk factor for FD in old age, underscoring the need for close attention in this age group.

Hypoxic-ischemic (HI) brain injury and spinal cord injury (SCI) lead to extensive tissue loss and axonal degeneration. The combined application of the polymer scaffold and neural progenitor cells (NPCs) has been reported to enhance neural repair, protection and regeneration through multiple modes of action following neural injury. This study investigated the reparative ability and therapeutic potentials of biological bridges composed of human fetal brain-derived NPCs seeded upon poly(glycolic acid)-based scaffold implanted into the infarction cavity of a neonatal HI brain injury or the hemisection cavity in an adult SCI. Implantation of human NPC (hNPC)–scaffold complex reduced the lesion volume, induced survival, engraftment, and differentiation of grafted cells, increased neovascularization, inhibited glial scar formation, altered the microglial/macrophage response, promoted neurite outgrowth and axonal extension within the lesion site, and facilitated the connection of damaged neural circuits. Tract tracing demonstrated that hNPC–scaffold grafts appear to reform the connections between neurons and their targets in both cerebral hemispheres in HI brain injury and protect some injured corticospinal fibers in SCI. Finally, the hNPC–scaffold complex grafts significantly improved motosensory function and attenuated neuropathic pain over that of the controls. These findings suggest that, with further investigation, this optimized multidisciplinary approach of combining hNPCs with biomaterial scaffolds provides a more versatile treatment for brain injury and SCI., Tissue engineering: Repairing brain and spinal injuries Biodegradable scaffolds seeded with human fetal brain cells can help repair neurological injuries in rodents. A team led by Kook In Park and Il-Shin Lee from the Yonsei University College of Medicine in Seoul, South Korea, created a mesh of plastic fibers that they bathed in neural progenitor cells. Over the course of several days, these cells differentiated into different types of brain cells, including neurons and glia. The researchers implanted these cell-scaffold complexes into the sites of injury in two rodent models: newborn mice with oxygen deprivation to the brain, and adult rats with severed spinal cords. In both cases, the treatment helped the injured tissues heal and improved the neurological or motor function of the animals. The authors suggest these tissue-engineered structures could also help people with brain or spine injuries.

A light-activated genome editing platform based on the release of enzymes from a plasmonic nanoparticle carrier when exposed to biocompatible near-infrared light pulses is described. The platform relies on the robust affinity of polyhistidine tags to nitrilotriacetic acid in the presence of copper which is attached to double-stranded nucleic acids self-assembled on the gold nanoparticle surface. A protein fusion of the Cre recombinase containing a TAT internalization peptide sequence to achieve endosomal localization is also employed. High-resolution gene knock-in of a red fluorescent reporter is observed using a commercial two-photon microscope. High-throughput irradiation is described to generate useful quantities of edited cells.

목적: 이물 섭취에 의한 합병증은 드물고, 대부분의 식도 이물은 내시경으로 제거가 가능하다. 그러나 만약 천공과 같은 중증 합병증이 발생한다면 심각한 결과를 초래할 수 있다. 본 연구는 식도 이물 환자에서 중증 합병증을 일으킬 수있는 위험요인을 찾고자 시행되었다. 방법: 2001년 1월부터 2014년 12월까지 단국대학교병원에서 식도 이물 제거를 성공적으로 시행 받은 298명의 환자를 대상으로 그들의 내시경 영상 및 진료기록을 후향적으로 검토하였다. 중증 합병증은 식도열상, 단순세척에도 멈추지 않는 출혈, 그리고 천공으로 정의하였다. 다변량 로지스틱 회귀분석을 통해 중증 합병증의 위험요인을 분석하였다. 결과: 성인과 소아에서 가장 호발하는 식도 이물은 각각 생선 가시(52.0%)와 동전(61.0%)이었다. 식도이물에 의한 합병증은 미란, 궤양, 열상, 출혈, 천공이었다. 다변량 분석에서 식도열상, 출혈, 천공을 포함하는 중증 합병증의 위험요인은 이물의 모양(생선 가시, OR 2.306, p = 0.004), 크기(25 mm 이상, OR 2.614, p = 0.001), 이물 섭취 후 경과한 시간(24시간 이상, OR 1.887, p = 0.035)이었다. 천공은 9명의 환자에서 발생하였고, 이물 섭취 후 24시간이 경과한 경우에 위험요인으로 나타났다(OR 41.700, p = 0.005). 천공 환자 중 2명은 이물제거 후 8시간과 12시간이 경과한 이후에 지연성 천공이 발생하였다. 결론: 식도 이물 환자에서 이물이 생선 가시이거나, 이물의 크기가 25 mm 이상, 이물을 섭취한 후 24시간이 경과한 경우에는 중증 합병증의 위험이 있음으로 치료 시보다 세심한 주의가 필요하다. 특히, 이물 섭취 후 24시간이 경과하면 천공의 위험이 증가하는데, 이물 제거 이후에도 지연성 천공의 가능성이 있음으로 주의 깊게 관찰하여야 한다.

TNF-α는 항산균에 대한 인체의 면역학적 방어기전에서 중요한 역할을 한다. Mycobacterium gordonae는 독성이 낮아임상 검체에서 검출되면 대부분 오염균으로 간주되고 있다. 저자들은 TNF-α 길항제로 치료 중인 궤양성 대장염 환자에서 M. gordonae 폐질환으로 진단되어 적절한 약물 치료 후-호전된 증례를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity lung disease due to bronchial colonization of Aspergillus fumigatus that occurs in susceptible patients with asthma or cystic fibrosis. A 10-year-old girl was referred to the Department of Pediatric Pulmonology for persistent consolidations on chest radiography. Pulmonary consolidations were observed in the right upper and left lower lobes and were not resolved with a 4-week prescription of broad-spectrum antibiotics. The patient had a history of atopic dermatitis and allergic rhinitis but no history of asthma. She had no fever but produced thick and greenish sputum. Her breathing sounds were clear. On laboratory testing, her total blood eosinophil count was 1,412/mm(3) and total serum IgE level was 2,200 kU/L. Aspergillus was isolated in the sputum culture. The A. fumigatus-specific IgE level was 15.4 kU/L, and the Aspergillus antibody test was also positive. A chest computed tomography scan demonstrated bronchial wall thickening and consolidation without bronchiectasis. An antifungal agent was added but resulted in no improvement of pulmonary consolidations after 3 weeks. Pulmonary function test was normal. Methacholine provocation test was performed, revealing bronchial hyperreactivity (PC20=5.31 mg/mL). Although the patient had no history of asthma or bronchiectasis, ABPA-seropositivity was suspected. Oral prednisolone (1 mg/kg/day) combined with antifungal therapy was started. Pulmonary consolidations began decreasing after 1 week of treatment and completely resolved after 1 month. This is the first observed and treated case of seropositive ABPA in Korean children without previously documented asthma.

Background/Aims Metformin use has been associated with decreased colorectal cancer risk and mortality among diabetic patients. Recent research suggests that metformin use may decrease the incidence of colorectal adenomas in diabetic patients with previous colorectal cancer. This study aimed to assess the clinical effect of metformin use on the development of colorectal adenomas in diabetic patients without previous colorectal cancer. Methods Among 604 consecutive diabetic patients who underwent colonoscopic surveillance after initial colonoscopy between January 2002 and June 2012, 240 patients without previous colorectal cancer were enrolled in this study and were divided in two groups: 151 patients receiving metformin and 89 patients not receiving metformin. Patient demographics and clinical characteristics as well as the colorectal adenoma incidence rate were retrospectively analyzed. Results The incidence rate of total colorectal adenomas was not different according to metformin use (P=0.349). However, the advanced adenoma incidence rate was significantly lower in the metformin group compared with the non-metformin group (relative risk [RR], 0.09; P=0.011). Metformin use was independently associated with a decreased incidence of advanced colorectal adenomas after adjustment for clinically relevant factors (RR, 0.072; P=0.016). In addition, the cumulative development rate of advanced adenomas during follow-up was significantly lower in the metformin group compared with the non-metformin group (P=0.007). Conclusions Metformin use in diabetic patients without previous colorectal cancer is associated with a lower risk of advanced colorectal adenomas.

Purpose Atopic dermatitis (AD) is a chronic inflammatory relapsing skin disorder. Vitamin D plays a pivotal role in the development of AD, and interleukin (IL) 31 is known to be related to pruritus in AD. The aim of our study was to determine whether 25-hydroxyvitamin D (25(OH)D) levels are related to IL-31 levels or to the severity of AD. Methods We enrolled 91 children with AD and 32 control subjects without history or symptoms of allergic diseases. Blood was drawn to evaluate complete blood cell count, total eosinophil count (TEC), and total IgE, specific IgE to common allergens, 25(OH)D, and IL-31 levels. Serum 25(OH)D and IL-31 levels were measured using high-performance liquid chromatography and enzyme-linked immunosorbent assay, respectively. The scoring atopic dermatitis (SCORAD) index was used to evaluate the severity of AD. Results The mean 25(OH)D level was significantly lower in the AD group than in the control group; 25(OH)D decreased greatly in the moderate and severe AD groups compared with the mild AD group. Children with atopic sensitization showed significantly lower 25(OH)D levels than nonatopic children. However, serum IL-31 levels were not related to AD group, SCORAD index, or 25(OH)D levels. The SCORAD index was inversely correlated with serum 25(OH)D level and positively correlated with TECs and total IgE levels. Children with moderate and severe AD had significantly higher TECs than children with mild AD. Conclusion Vitamin D is related to the severity of AD independently of IL-31.

Background/Aims We investigated gut flora characteristics in patients with functional constipation (FC) and influences of short-term treatment with VSL#3 probiotic on flora and symptom improvement. Methods Thirty patients fulfilling Rome III criteria for FC and 30 controls were enrolled. Fecal samples were obtained before and after VSL#3 intake (one sachet twice daily for 2 weeks) and flora were examined by quantitative real-time polymerase chain reaction (qRT-PCR). Symptom changes were also investigated. Results The fold differences in Bifidobacterium and Bacteroides species were significantly lower in feces from FC, compared to in controls (P = 0.030 and P = 0.021). After taking VSL#3, the fold differences in Lactobacillus, Bifidobacterium and Bacteroides species increased in controls (P = 0.022, P = 0.018, and P = 0.076), but not in FC. Mean Bristol scores and complete spontaneous bowel movements (CSBMs)/week increased significantly in FC after ingesting VSL#3 (both P < 0.001). Relief of subjective CSBM frequency, stool consistency and abdominal bloating were reported in 70%, 60%, and 47% of patients. After VSL#3 cessation, 44.4% of patients with symptom improvement experienced constipation recurrence mostly within one month. Conclusions Bifidobacterium and Bacteroides species might be quantitatively altered in FC. A short-term VSL#3 treatment can improve clinical symptoms of FC. Further studies are needed to investigate VSL#3’s additional effects beyond altering gut flora to allevate constipation.

Few prior reports exist that address the appropriate colonoscopy surveillance interval for individuals 50 years old. We compared the risk of metachronous neoplasia between younger (20-49 years) and older (50-54 years) cohorts.This multicenter retrospective cohort study compared the incidence of metachronous neoplasia in younger and older cohorts according to baseline risk stratification. Subjects were eligible if they underwent their first colonoscopy between June 2006 and May 2010 and had at least 1 or more surveillance colonoscopy up to June 2015.Among a total of 10,477 subjects who underwent baseline colonoscopy, 9722 were eligible after excluding 755 subjects. Of those 9722 subjects, 43% underwent surveillance colonoscopy. In the baseline high-risk adenoma group (n = 840), the 3-year risk of metachronous advanced neoplasia was 10.7% in the younger patients on screening colonoscopy and 8.9% in the older patients (P.1). In the baseline low-risk adenoma group (n = 1869), the 5-year risk of metachronous advanced neoplasia was 4.9% in the younger patients on screening colonoscopy and 5.1% in the older patients (P.1). Similarly, in the baseline no neoplasia group (n = 7013), the 5-year risk of metachronous advanced neoplasia was 4.1% in the younger patients on screening colonoscopy and 5.6% in the older patients (P.1).Considering the similar risk of metachronous advanced neoplasia in younger and older individuals, we suggest a 3-year surveillance interval for high-risk adenoma and a 5-year surveillance interval for low-risk adenoma in young individuals without a strong family history.

Peutz-Jeghers syndrome is an autosomal dominant inherited disease that manifests as a combination of mucocutaneous pigmentation and gastrointestinal hamartomatous polyps that usually cause intussusception and intestinal hemorrhage. We report the case of a 40-year-old male patient who was diagnosed 20 years ago and had previously undergone 3 intestinal resection surgeries. This time, with the use of combined operative and endoscopic polypectomy, more than 100 polyps were removed. This technique is useful for providing a "clean" small intestine that allows the patient a long interval between laparotomies and reduces the complications associated with multiple laparotomies and resections.

Background/Aims It is essential that clinicians have an understanding of patients’ perceptions of constipation as well as constipation mis-perception (CM), which can be defined as failure to recognize the six constipation symptoms (infrequency, straining, hard stool, incomplete evacuation, anorectal obstruction or manual maneuver). The aims of our study were to identify the prevalence of CM and its association with demographics and clinical features. Methods This nationwide survey included 625 self-reported constipated subjects (431 females; mean age, 41.2 years) among random participants in the National Health Screening Program. The prevalence of CM for each constipation symptom was estimated, and the participants were classified into nil (0), low (1–2), mid (3–4) and high (5–6) level CM subgroups according to the number of misperceived symptoms. Results The highest rate of CM was observed for manual maneuver (48.3%), followed by anorectal obstruction (38.4%), stool infrequency (34.6%), incomplete evacuation (32.2%), hard stool (27.2%) and straining (25.4%). Among the nil (n = 153), low (n = 242), mid (n = 144) and high level (n = 86) subgroups, there were significant differences in the proportions of males (18.3%, 34.3%, 39.6% and 30.2%; P = 0.001, respectively), never-married status (25.7%, 38.2%, 36.8% and 45.9%; P = 0.030, respectively) and those who did not receive treatment for constipation (41.8%, 47.5%, 58.3% and 66.3%; P < 0.001, respectively). There was a significant linear trend of increasing degree of CM with decreasing symptoms experienced (P < 0.001). Conclusions CM is significantly associated with gender, marital status, treatment utilization and the range of constipation symptoms experienced.

Patients with Crohn's disease (CD) are frequently exposed to diagnostic radiation, mainly as a result of abdominopelvic computed tomography (APCT) examinations. However, there are limited data on the impact of APCT on clinical management in this population.To investigate clinical predictors of urgent findings on APCT in patients with CD who presented to the emergency department (ED).A retrospective study was performed among patients with CD presenting to 11 EDs with a gastrointestinal complaint. The primary outcome, OPAN (obstruction, perforation, abscess, or non-CD-related urgent findings), included new or worsening CD-related urgent findings or non-CD-related urgent findings that required urgent or emergency treatment. Variables with P0.1 in univariate analyses were included in a multivariable logistic regression model.Of the 266 APCTs performed, 103 (38.7 %) had OPAN and 113 (42.5 %) required changes in treatment plan. Stricturing or penetrating disease (odds ratio [OR] 2.72, 95 % confidence interval [CI] 1.21-6.13), heart rate100 beats/min (OR 2.33, 95 % CI 1.10-4.93), leukocyte count10,000/mm(3) (OR 4.38, 95 % CI 2.10-9.13), and CRP2.5 mg/dL (OR 3.11, 95 % CI 1.23-7.86) were identified as the independent predictors of OPAN, whereas biologic agent use (OR 0.37; 95 % CI 0.15-0.90) was identified as the negative predictor in patients with CD.Only 39 % of the APCTs performed in the ED among patients with CD showed urgent findings. Stricturing or penetrating disease, tachycardia, leukocytosis, and high CRP level were predictors of urgent CT findings, while biologic agent use was a negative predictor. To reduce unnecessary radiation exposure, the selection process for CD patients referred for APCT must be improved.

Background/Aims Infliximab was introduced recently as a rescue therapy for ulcerative colitis (UC) patients refractory to conventional treatments such as therapy with 5-amiono salicylic acids (5-ASA), immune modulators, and corticosteroids. However, there is insufficient data about its efficacy and safety in Korea. Methods From 7 tertiary referral hospitals, 33 patients who were treated with infliximab for moderate to severe (Mayo score 6-12) UC refractory to conventional treatment were recruited to this study. Clinical remission was defined as a total Mayo score of 2 or lower and every subscore less than 2. Partial response was defined as a decrease of Mayo score at least 3 points from baseline. Results Twenty-three patients (69.7%) showed clinical remission and 29 patients (87.8%) showed partial response in the observation period. When the remission and non-remission groups were compared in univariate analysis, only a higher total Mayo score at base line (11.0±0.9 vs. 9.9±1.5; P=0.04) was related to remission. The remission maintenance rate decreased with time in the Kaplan-Meier analysis. Two patients experienced re-remission after the first remission followed by aggravation during infliximab treatment. Three patients stopped infliximab treatment owing to adverse events including rhabdomyolysis, pneumonia, and fever of unknown origin. Conclusions If there is no choice except surgery for UC patients refractory to conventional treatment, infliximab is an effective and relatively safe treatment option for these patients in Korea.

Purpose Newborn screening (NBS) programs are important for appropriate management of susceptible neonates to prevent serious clinical problems. Neonates admitted to neonatal intensive care units (NICU) are at a potentially high risk of false-positive results, and repetitive NBS after total parenteral nutrition is completely off results in delayed diagnosis. Here, we present the usefulness of a targeted next-generation sequencing (TNGS) panel to complement NBS for early diagnosis in high-risk neonates. Materials and Methods The TNGS panel covered 198 genes associated with actionable genetic and metabolic diseases that are typically included in NBS programs in Korea using tandem mass spectrometry. The panel was applied to 48 infants admitted to the NICU of Severance Children's Hospital between May 2017 and September 2017. The infants were not selected for suspected metabolic disorders. Results A total of 13 variants classified as likely pathogenic or pathogenic were detected in 11 (22.9%) neonates, including six genes (DHCR7, PCBD1, GAA, ALDOB, ATP7B, and GBA) associated with metabolic diseases not covered in NBS. One of the 48 infants was diagnosed with an isobutyl-CoA dehydrogenase deficiency, and false positive results of tandem mass screening were confirmed in two infants using the TNGS panel. Conclusion The implementation of TNGS in conjunction with conventional NBS can allow for better management of and earlier diagnosis in susceptible infants, thus preventing the development of critical conditions in these sick infants.

Background and Aim Although differences in genetic susceptibility and the clinical features of Crohn's disease (CD) have been reported between Asian and Caucasian patients, the disease course and predictors of CD in Asians remains poorly defined. The study therefore aimed to investigate factors predictive of the clinical outcomes of patients with CD in a Korean population. Methods This retrospective multicenter cohort study included 728 Korean CD patients from 13 university hospitals. The first CD-related surgery or need for immunosuppressive or biological agents were regarded as the clinical outcomes of interest. Results A total of 126 (17.3%) CD patients underwent CD-related surgery, while 473 (65.0%) and 196 (26.9%) were prescribed thiopurine drugs and infliximab, respectively. Multivariate Cox regression analysis identified current (hazard ratio [HR] = 1.86; P = 0.018) and former smoking habits (HR = 1.78; P = 0.049), stricturing (HR = 2.24; P

Although transplantation of microencapsulated islets has been proposed as a therapy for the treatment of diabetes mellitus, limited retrievability of the cells has impeded its medical usage. To achieve retrieval of microencapsulated islets, capsules were attached to polydimethylsiloxane (PDMS) with a biocompatible adhesive. Because the hydrophobic nature of the PDMS surface prevents attachment, surface modification is essential. Alginate microcapsules were attached to modified PDMS sheets, and the mechanical stability of the resulting constructs was determined. Acrylic acid (AA) and acrylamide (AM) mixtures were grafted on the surfaces of PDMS sheets using a two-step oxygen plasma treatment (TSPT). TSPT-PDMS was characterized according to water contact angle and zeta-potential measurements. The contact angle was altered by changing the ratio of AM to AA to generate hydrophilic surface. Evaluation of the surface charge at pH 2, 7, and 12 confirmed the presence of polar groups on the modified surface. Microcapsules were attached to TSPT-PDMS using Histoacryl® and shown to be in a monolayered and half-exposed state. The shear stress resistance of alginate capsules attached to the PDMS sheet indicates the possibility of transplantation of encapsulated cells without scattering in vivo. This method is applicable to retrieve microencapsulated porcine islets when required.

Background/Aims Atrophic gastritis (AG) and intestinal metaplasia (IM) are premalignant gastric lesions. The aims of this study were to evaluate the prevalence of endoscopic AG and IM and to document the risk factors for these lesions. Methods In total, 4,023 subjects were enrolled at eight hospitals in Korea. AG and IM were diagnosed by endoscopy. Helicobacter pylori immunoglobulin G antibodies were measured. Results The prevalences of endoscopic AG and IM were 40.7% and 12.5%. In a multivariate analysis, the risk factors for AG were age groups of 40 to 59 years and >60 years, male sex, positive H. pylori serology, IM, and education below the college level (odds ratio [OR], 2.55, 5.00, 1.38, 1.41, 4.29, and 1.35, respectively). The risk factors for IM were age groups of 40 to 59 years and >60 years, male sex, positive H. pylori serology, AG, having relatives with gastric cancer, education below the college level and consumption of dairy products (OR, 3.16, 3.25, 1.88, 2.17, 3.68, 1.48, 1.47, and 1.40, respectively). Conclusions A nationwide survey regarding the prevalence of endoscopic AG and IM and their risk factors in Korea supports the hypothesis that endoscopic diagnosis of these premalignant lesions could be helpful to describe a group at high risk for gastric cancer.

Background and study aims: Post-polypectomy coagulation syndrome (PPCS) is a well known complication of colonoscopic polypectomy. However, no previous studies have reported on the clinical outcomes or risk factors of PPCS. The aim of the current study was to analyze the clinical outcomes and risk factors of PPCS developing after a colonoscopic polypectomy. Patients and methods: Data for all patients who underwent colonoscopic polypectomies and required hospitalization in nine university hospitals were analyzed retrospectively. The incidence, clinicopathological characteristics, and clinical outcomes of PPCS cases were examined. Additionally, patients who developed PPCS were compared with controls who were matched by age and sex, in order to assess for possible risk factors. Results: The rate of PPCS that required hospitalization after colonoscopic polypectomy was 0.7/1000. All patients with PPCS were treated medically without the need for surgical interventions. The median durations of therapeutic fasting, hospitalization, and antibiotic use were 3 days, 5.5 days, and 7 days, respectively. The rates of major PPCS and mortality were 2.9 % and 0 %, respectively. On multivariate analysis, hypertension (OR = 3.023, 95 %CI 1.034 – 8.832), large lesion size (OR = 2.855, 95 %CI 1.027 – 7.937), and non-polypoid configuration (OR = 3.332, 95 %CI 1.029 – 10.791) were found to be independent risk factors related to the development of PPCS. Conclusions: In this study, the rates of major PPCS and mortality were only 2.9 % and 0 %, respectively. Hypertension, large lesion size, and non-polypoid configuration of the lesion were independently associated with PPCS. Therefore, patients may be reassured by the excellent prognosis of PPCS, while endoscopists should be especially careful when performing colonoscopic polypectomies in patients with hypertension or large and non-polypoid lesions.

Background/Aims Researches on the potential risk factors for the development of erosive esophagitis have been conducted extensively, however, the results are conflicting. The aim of this multicenter study was to identify the prevalence rate and risk factors of erosive esophagitis and their interactions with residency status. Methods A total of 4,023 eligible subjects at 8 tertiary health care centers were evaluated using questionnaires, laboratory tests and endoscopy. Univariate and multivariate analyses were conducted to identify independent risk factors for erosive esophagitis. Results The prevalence rate of reflux esophagitis was 8.8%. Los Angeles grade A was common type of erosive esophagitis. Residence in a large urban areas was negatively associated with the development of erosive esophagitis (OR, 0.60; 95% CI, 0.40-0.90). The high body mass index (≥ 25 kg/m2) was more frequent in residents of small and medium-sized cities than those in big cities (38.8% and 26.9%, respectively; P < 0.001). Seronegativity of Helicobacter pylori was associated with increased erosive esophagitis (OR, 1.91; 95% CI, 1.48-2.46). Triglyceride ≥ 150 mg/dL (OR, 1.65; 95% CI, 1.08-2.07), fasting glucose level ≥ 126 mg/dL (OR, 1.73; 95% CI, 1.06-2.81), and hiatal hernia (OR, 3.11; 95% CI, 1.87-5.16) were also associated with erosive esophagitis. Conclusions The prevalence rate of erosive esophagitis and its risk factors in this study were similar to the result of 8.0% of nationwide study in 2006. Residency and obesity are more important independent risk factors than H. pylori infection status for development of erosive esophagitis in Korea. These results suggest that the prevalence rate of erosive esophagitis in Korea might not increase as in the Western countries.

Background/Aims: The inflammatory bowel disease disability index (IBD-DI) was recently developed for IBD to assess the functional consequences and disease burden. We applied the IBD-DI to a Korean population and identified predictive factors influencing IBD-related disability. Methods: Between March and August 2015, 322 consecutive patients with IBD were prospectively recruited. Patients completed the IBD-DI questionnaire and Crohn`s and Ulcerative Colitis Questionnaire (CUCQ-8) for assessing quality of life. We examined the relationships between IBD-DI and disease activity or quality of life and analyzed predictive factors in Korean IBD patients. Results: Enrolled patients completed both questionnaires. Total IBD-DI was correlated with CUCQ-8 scores in both ulcerative colitis (r=0.636, p

The number of patients with10 adenomas is relatively small, and few studies have investigated the risk of colorectal neoplasm (CRN) in these patients. Thus, we aimed to investigate the risk of developing CRN in patients with10 adenomas and to compare their risk with that of patients with 3-10 adenomas.A retrospective multicenter cohort study that included 214 patients with10 adenomas on index colonoscopy performed between January 2009 and December 2011, and underwent follow-up colonoscopy until December 2015 was conducted. The risk of developing advanced CRN (cancer or advanced adenoma with a diameter of ≥10 mm or with a villous component, or high-grade dysplasia) was investigated and compared with that in patients with 3-10 adenomas (n = 975).Among the 214 patients with10 adenomas, the mean age was 62.9 years and the mean number of adenomas on index colonoscopy was 14.2. Overall, 57 patients (26.6%) developed an advanced CRN after a mean of 4.3 years from baseline colonoscopy. The respective 3- and 5-year cumulative risks of advanced CRN were 6.8% (95% confidence interval [CI] 2.9-10.7) and 28.7% (95% CI 20.8-36.5), higher than those in the group with 3-10 adenomas (n = 975, P = 0.001). Having10 adenomas on index colonoscopy was an independent risk factor for developing advanced CRN (odds ratio 2.25, 95% CI 1.49-3.38).The risk of developing advanced CRN in patients with10 adenomas was high and statistically higher than that in patients with 3-10 adenomas. Further prospective studies are needed to investigate whether a more intensive surveillance is needed in this group.

Shared decision-making may increase the effectiveness of inflammatory bowel disease (IBD) treatment, as different anti-tumor necrosis factor (anti-TNF) administrations may have different effects on the quality of life (QOL). Patient preference is integral to the selection of anti-TNFs and their routes of administration, however, previous studies on the patient preference to anti-TNFs are inconsistent and limited. We evaluated the predictive factors for preferences to anti-TNF administrations in IBD patients between March and August in 2015. Consecutive adult IBD patients who received care at one of four university hospitals in Korea were invited to participate in this study. Patients were administered questionnaires about their preferences regarding anti-TNF therapy and QOL. During the study period, 322 IBD patients completed the questionnaires. IBD patients preferred intravenous anti-TNFs to subcutaneous anti-TNFs (2.4:1), and 58.4% of patients preferred shared decision-making. When comparing subcutaneous anti-TNF therapy with intravenous anti-TNF therapy, patients with higher income levels, patients who experienced adverse events with prior medication and patients with a longer disease duration preferred subcutaneous anti-TNF therapy over intravenous anti-TNF therapy (P = 0.043, P = 0.000, and P = 0.029, respectively). In a logistic regression analysis, high income level (odds ratio [OR] 2.0; 95% confidence interval [CI] 1.1-3.5; P = 0.026) and an adverse event with prior medication (OR 4.0; 95% CI 2.2-7.2; P = 0.000) and were found to be independent predictors for preference to subcutaneous anti-TNF therapy. Therefore, physicians should share decision-making with their IBD patients regarding the mode of anti-TNF administration.

Aim Neonatal arterial ischaemic stroke (AIS) is an important cause of severe neurological disability. This study aimed to analyse the clinical manifestations and outcomes of AIS patients. Methods We enrolled neonates with AIS admitted to Severance Children's Hospital and Gangnam Severance Hospital between 2008 and 2015. AIS was confirmed using magnetic resonance imaging (MRI). We retrospectively reviewed the clinical manifestations, MRI findings, electroencephalography (EEG) findings and neurodevelopmental outcomes. Results The study comprised 29 neonates (18 boys). The mean follow-up period was 15.4 months (range 6–44 months) and the mean age at diagnosis was 8.1 days. Seizure was the most common symptom (66%). Bilateral involvement was more common than unilateral involvement (52%). The middle cerebral artery was the most commonly identified territory (79%). Abnormal EEG findings were noted in 93% of the cases. Neurodevelopment was normal in 11 (38%) patients, while cerebral palsy and delayed development were noted in eight (28%) and six (21%) patients, respectively. Patients with bilateral involvement were very likely to have abnormal neurodevelopmental outcomes. Conclusion Our study showed that abnormal neurodevelopmental outcomes were very likely after cases of neonatal AIS with bilateral involvement and clinicians should consider early and more effective interventions in such cases. This article is protected by copyright. All rights reserved.

Constipation is a digestive symptom that is frequently seen in clinical practice. Its prevalence has been reported to be 2% to 20%, depending on geographical region. Despite the rapid development of medical science, systematic studies on constipation have been rarely conducted in Korea. Recently, guidelines on the diagnosis and treatment of functional gastrointestinal disorders, including constipation, were proposed by The Korean Society of Neurogastroenterology and Motility. These guidelines are expected to reflect the current situation regarding treatment of constipation in Korea. In this paper, practical constipation treatment methods that are in current use will be reviewed with reference to these recent guidelines.

The process conditions for high efficiency industrial crystalline Si solar cells with selective emitter were optimized. In the screen printed solar cells, the sheet resistance must be 50–60 Ω/sq. because of metal contact resistance. But the low sheet resistance causes the increase of the recombination and blue response at the short wavelength. Therefore, the screen printed solar cells with homogeneous emitter have limitations of efficiency, and this means that the selective emitter must be used to improve cell efficiency. This work demonstrates the feasibility of a commercially available selective emitter process, based on screen printing and conventional diffusion process. Previous work, we announced about 18.5% efficient selective emitter solar cell by variation of heavy emitter pattern width. Now, we improved cell efficiency from 18.5% to 19% by transition of heavy emitter pattern and shallow emitter doping condition. A maximum cell efficiency of 19.05% is obtained on a 156 mm × 156 mm crystalline silicon solar cell.

Background/Aims A two-year, prospective, nationwide multicenter study was undertaken to evaluate the effect of Helicobacter pylori eradication on the development of reflux esophagitis (RE) and gastroesophageal reflux disease (GERD) symptoms in the Korean population. Methods In total, 1,489 subjects without RE were enrolled at the outpatient clinics of 12 tertiary hospitals nationwide, and 452 subjects underwent follow-up (F/U) for 2 years to evaluate the development of RE and GERD symptoms. Results RE was found in 33 subjects (7.3% of 452 subjects) and 14 subjects (7.3% of 192 subjects) during the first and second year of F/U, respectively. H. pylori status was not associated with the development of RE. RE was found in six (9.0%) of 67 H. pylori-negative patients, in 26 (11.2%) of 233 eradicated subjects and in eight (7.0%) of 114 noneradicated subjects (p=0.532). Multivariate analysis showed that age ≥60 years (odds ratio [OR], 7.11; 95% confidence interval [CI], 1.92 to 26.41), alcohol consumption (OR, 4.43; 95% CI, 1.03 to 19.19) and F/U cholesterol levels ≥200 mg/dL (OR, 5.03; 95% CI, 1.32 to 19.17) were significant risk factors for the development of RE. There was no significant difference in the development of GERD symptoms or weight according to H. pylori status during the 2-year F/U. Conclusions Eradication of H. pylori did not affect the development of reflux esophagitis or GERD symptoms among patients in outpatient gastroenterology clinics in South Korea.

No reported prospective, randomized study has evaluated the impact of an endoscopy nurse participating as a second observer during colonoscopy.To determine whether the participation of an endoscopy nurse enhanced the polyp detection rate (PDR) and adenoma detection rate (ADR) during screening colonoscopy.Multicenter, prospective, randomized study.Academic hospitals.A total of 844 consecutive patients undergoing screening colonoscopy.Single observation by colonoscopist or dual observation by colonoscopist and endoscopy nurse during colonoscope withdrawal.PDR and ADR.No significant difference in patient demographic data, adequacy of bowel preparation, or mean withdrawal time was observed between the 2 groups. In total, 1153 polyps, including 762 adenomas, were detected in 791 patients. Seven nonpolypoid, depressed neoplastic lesions (0-IIc or combined types) were only detected in the dual observation group. A multivariate analysis revealed that experienced (≥ 2 years) endoscopy nurse participation significantly increased the PDR and ADR compared with those in the single observation group by a colonoscopist alone (adjusted odds ratio [OR] 1.58 [95% CI, 1.07-2.32]; adjusted OR 1.47 [95% CI, 1.01-2.12], respectively). Additionally, the PDR was significantly higher in the dual-observation group with fellows (500 colonoscopies) and an experienced endoscopy nurse versus that in the single observation group (adjusted OR 2.07 [95% CI, 1.15-3.74]). There was no significant benefit of experienced nurse participation in the subgroup with experienced colonoscopists.Absence of colonoscopist blinding.Experienced endoscopy nurse participation increased the PDR and ADR during screening colonoscopy. However, the benefit of participation by experienced nurses appears to be exclusively with inexperienced colonoscopists.

Background and study aim Rectal carcinoids are low-grade malignancies that are usually treated by endoscopic resection. However, on pathologic examination, resection margins that are positive for carcinoid cells are frequently found. Patient outcomes were reviewed after endoscopic resection of rectal carcinoids and the clinical significance of possible residual disease, as defined by pathologic and endoscopic examination, was evaluated. Patients and methods The medical records and endoscopic findings of 347 patients presenting with rectal carcinoids to 14 university hospitals in Korea between January 1999 and June 2007 were retrospectively analyzed. Results A total of 304 patients were treated with endoscopic resection, and 43 patents were treated with surgery. In the endoscopic resection group, the complete resection rate was 88.2% based on endoscopic appearance (CR-E) and 60.2% based on pathologic evaluation (CR-P). The agreement between CR-E and CR-P was low (κ=0.192). No residual tumors were found in 77 of 85 patients (90.6%) who were CR-E but not CR-P and who had endoscopic biopsy taken at 24-month follow-up. The receiver-operating characteristic curve identified an optimal cut-off value of 10.5 mm, at which the sensitivity and the specificity for metastasis were 100% and 89%, respectively. The risk factors for metastasis by multivariate analysis were tumor size, increased mitotic rate, and lymphovascular invasion. Conclusions Endoscopic resection is a safe and effective modality for treating well-differentiated rectal carcinoids smaller than 10 mm in diameter. Discrepancies were observed between CR-E and CR-P. The risk factors for metastasis were tumor size, increased mitotic rate, and lymphovascular invasion.

Background Glycosaminoglycans (GAGs) have various structural and physiological regulatory functions in skin, including tissue water maintenance, due to their high water-holding capacity. Objective To investigate changes of GAGs during intrinsic aging and photoaging of human skin and their correlations with water content. Methods Samples of sun-protected buttock and sun-exposed forearm skin were obtained from young male (21–30years, n =8) and female (20–33years, n =8) subjects, as well as old male (70–78years, n =8) and female (70–80years, n =8) subjects, and their epidermal and dermal contents of hyaluronic acid (HA), total sulfated GAG (tsGAG), total uronic acid (tUA), and tissue water were measured. HA content was determined by enzyme-linked immunosorbent assay using HA-binding protein, tsGAG by the sulfated GAG assay kit using 1,9-dimethylmethylene blue, tUA by carbazole reaction, and tissue water by subtraction of tissue dry weight from wet weight. Results In the buttock, HA was higher in dermis than in epidermis, while tsGAG and tUA were higher in epidermis. In intrinsically aged buttock, epidermal HA and dermal tsGAG and tUA decreased. However, when analyzed for each gender, epidermal tsGAG, tUA, and tissue water decreased only in females. Forearm/buttock ratios of each molecule were compared for determination of photoaging-dependent changes. Forearm/buttock ratios of HA, tsGAG, tUA, and tissue water increased in aged dermis, but showed no change in aged epidermis. When analyzed for each gender, ratios of epidermal HA and tissue water increased only in aged females, while ratios of epidermal tsGAG, tUA, and tissue water decreased only in aged males. Correlations of water content with HA, tsGAG, and tUA were found in epidermis, but not with tsGAG in dermis. Conclusion These intrinsic aging- and photoaging-dependent GAG changes and their correlations with water content provide new insights into the pathophysiology of dry skin in the elderly.

A well-defined styrenic block copolymer was prepared through controlled/“living” radical polymerization technique and evaluated as a polymeric surface modifier for multiwalled carbon nanotube (MWCN...