Prevalence and risk factors of bowel symptoms in Korean patients with ulcerative colitis in endoscopic remission: a retrospective study.

BACKGROUND: Many patients with ulcerative colitis (UC) in clinical remission frequently complain of bowel symptoms such as increased stool frequency (SF) and rectal bleeding (RB). However, studies on these patient-reported outcomes in patients with inactive UC are limited, especially in Korea. Therefore, we investigated the prevalence and risk factors of bowel symptoms in Korean patients with inactive UC. METHODS: We investigated the prevalence of bowel symptoms in patients with endoscopically quiescent UC between June 1989 and December 2016 using a well-characterized referral center-based cohort. The Mayo clinic score (MCS) was used to evaluate bowel symptoms at the most recent visit near the date of endoscopy. Clinical characteristics of the patients were compared based on the presence or absence of bowel symptoms. RESULTS: Overall, 741 patients with endoscopically quiescent UC were identified, of whom 222 (30%) and 48 (6.5%) had an SF and RB subscore of ≥ 1, respectively. Patients with bowel symptoms (SF + RB ≥ 1; n = 244 [32.9%]) had higher rates of left-sided colitis (E2) or extensive colitis (E3) than patients without bowel symptoms (SF + RB = 0; n = 497 [67.1%]; P = 0.002). Multivariate analysis revealed that female sex (odds ratio [OR]: 1.568; 95% confidence interval [CI]: 1.023-2.402; P = 0.039) and E2 or E3 (OR 1.411; 95% CI 1.020-1.951; P = 0.038) were the significant risk factors for increased SF. CONCLUSIONS: This study revealed that one-third of patients with endoscopically quiescent UC reported increased SF. Female sex and disease extent may be associated with bowel symptoms.

The Clinical Significance of Anastomotic Ulcers After Ileocolic Resection to Predict Postoperative Recurrence of Crohn's Disease.

BACKGROUND: The Rutgeerts score is used to predict postoperative recurrence in CD patients after ileocolic resection and is primarily based on endoscopic findings at the neoterminal ileum. However, the optimal assessment of anastomotic ulcers (AUs) remains subject to debate. AIMS: We aimed to investigate the association between anastomotic ulcers (AUs) and endoscopic recurrence in postoperative Crohn's disease (CD) patients. METHODS: This single-center retrospective study, conducted between 2000 and 2016, evaluated postoperative CD patients with endoscopic remission at the first ileocolonoscopy within 1 year after ileocolic resection and those who underwent subsequent ileocolonoscopic follow-up. The study outcome was the clinical significance of AUs in predicting endoscopic recurrence. RESULTS: Among 116 patients who were in endoscopic remission defined as the RS of i0 to i1 at the index postoperative ileocolonoscopy, 84.5% (98/116) underwent subsequent ileocolonoscopies. During the median 30.0 months (interquartile range, 21.3-53.3) of follow-up after the first ileocolonoscopy, 56.1% (55/98) of patients showed endoscopic recurrence. Furthermore, 65.8% (48/73) with AUs and 75.5% (40/53) with major AUs, defined as either an ulcer occupying ≥ 1/4 of the circumference, ≥ 3 ulcers confined to anastomotic ring, or any ulcers extending to the ileocolonic mucosa, showed endoscopic recurrence. On multivariable analysis, AUs (adjusted hazard ratio [aHR], 4.33; 95% confidence interval [CI], 1.87-10.0; P < 0.001) and major AUs (aHR, 3.64; 95% CI, 1.95-79; P < 0.001) were associated with endoscopic recurrence. CONCLUSIONS: AUs are associated with a significantly high risk of endoscopic recurrence in postoperative CD patients who are in endoscopic remission.

Tip-in versus conventional endoscopic mucosal resection for flat colorectal neoplasia 10 mm or larger in size.

PURPOSE: A modified endoscopic mucosal resection (EMR) technique, Tip-in EMR, was recently introduced to enhance the complete resection of colorectal neoplasia (CRN). We aimed to evaluate the feasibility of Tip-in EMR for flat CRNs. METHODS: From January to September 2018, conventional or Tip-in EMR was consecutively performed for 112 flat CRNs ≥ 10 mm in diameter. Tip-in EMR was performed when en bloc snaring was impossible with conventional EMR or when a lesion was inadequately lifted owing to a previous forceps biopsy. We retrospectively collected the clinical, procedural, and histologic data of the conventional and Tip-in EMR groups and compared the en bloc resection rate, complete resection rate, and complications between the two groups. RESULTS: Among 112 flat CRNs of 80 patients, conventional EMR and Tip-in EMR were performed for 74 and 38 lesions, respectively. The median lesion size was 12 (10-27) mm. Tip-in EMR was superior to conventional EMR in terms of en bloc resection (94.7% vs. 77.0%, p = 0.018) and histologic complete resection (76.3% vs. 54.1%, p = 0.022). There was no difference in postprocedural bleeding between the two groups; however, overall adverse events, including bleeding and postpolypectomy electrocoagulation syndrome, were more frequent in the Tip-in EMR group. CONCLUSIONS: Tip-in EMR is a feasible technique for flat colorectal lesions ≥ 10 mm and is superior to conventional EMR with respect to en bloc and complete resection rates. The safety profiles of Tip-in EMR and conventional EMR should be compared via large-scale prospective studies.

Concordance regarding disease type and phenotypic characteristics among patients with familial inflammatory bowel disease.

BACKGROUND AND AIMS: The phenotypic concordance among familial cases of inflammatory bowel disease (IBD) has been rarely reported. Thus, the present study aimed to evaluate the concordance regarding disease type and phenotypic features in a large cohort of Korean patients with IBD. METHODS: A total of 6647 patients with IBD who visited the Asan Medical Center between June 1989 and September 2016 were enrolled in the study. When at least two familial cases existed in our cohort, they were included in the concordance analysis (κ index). The concordance between younger and older members for IBD type [Crohn's disease (CD) and ulcerative colitis (UC)] and phenotypic characteristics such as disease extent and location, disease behavior, the use of medication, and need for surgery were evaluated. RESULTS: A positive family history of IBD was noted in 216 patients with CD (7.0%) and in 238 patients with UC (6.7%). Of all patients, 167 consanguineous pairs in 146 families were identified. The crude concordance rate for IBD type was 82.6% with a κ index of 0.656 [95% confidence interval (CI): 0.545-0.768, good concordance]. There was mild concordance for disease location in CD (κ = 0.256; 95% CI: 0.007-0.505) and for the use of antitumor necrosis factor agents in UC (κ = 0.354; 95% CI: -0.049-0.757). The concordance for IBD type and several phenotypes in first-degree relative pairs was better than that in the entire pairs. CONCLUSIONS: Disease type and phenotypic characteristics of patients with familial IBD may be anticipated.

Incidence and risk factors of Pneumocystis jirovecii pneumonia in Korean patients with inflammatory bowel disease.

BACKGROUND AND AIM: Little is known whether routine prophylaxis against Pneumocystis jirovecii pneumonia (PJP) is needed in patients with inflammatory bowel disease (IBD) on immunosuppression, especially in Asian populations. We, therefore, sought to investigate the incidence and risk factors of PJP in patients with IBD in Korea. METHODS: We investigated the incidence of PJP in patients with IBD and compared the characteristics of IBD patients with PJP episodes (IBD-PJP group) with those of matched controls (IBD-only group) using a large, well-characterized referral center-based cohort. RESULTS: Among the 6803 IBD patients (3171 with Crohn's disease and 3632 with ulcerative colitis) enrolled in the Asan IBD Registry between June 1989 and December 2016, six patients (0.09%) were diagnosed with PJP. During the 57 776.0 patient-years of follow-up (median 7.2 years per patient), the incidence of PJP was 10.4 cases per 100 000 person-years, and none of these patients had received PJP prophylaxis. In case-control analysis, the IBD-PJP group (n = 6) showed significantly higher C-reactive protein level at diagnosis of IBD (P = 0.006), as well as higher exposure to corticosteroids (P = 0.017), than did controls (n = 24). In addition, the IBD-PJP group showed higher rates of double (50% vs 12.5%) or triple (33.3% vs 4.2%) immunosuppression than did controls, although these are not statistically significant. CONCLUSIONS: Although the incidence of PJP in Korean patients with IBD is low, careful monitoring is necessary for the early detection of PJP. In addition to the patients receiving double or triple immunosuppression, PJP prophylaxis should be considered especially in patients with severe disease activities requiring corticosteroids.

Synthesis of TaZnO thin films using combinatorial magnetron sputtering and its electrical, structural and optical properties.

The structural, electrical, and optical properties of tantalium zinc oxide (TaZnO) thin films grown using combinatorial magnetron sputtering system were investigated. To explore the effects of film thickness and post annealing treatment on the properties of the films, we have fabricated TaZnO sample libraries having different thicknesses and carried out post annealing treatment. Sample libraries fabricated at room temperature showed the resistivity ranged 2.1 to approximately 7.1 x 10(-3) Omega cm, while the films post annealed at 200 degrees C under 1 mTorr exhibited the resistivity as low as 1.2 x 10(-3) Omega cm. XRD measurements revealed that the film structure was strongly depended on the film thickness, showing that the structure was changed from amorphous to polycrystalline with increasing the film thickness. Furthermore, it was found that figure of merit (0TC), which was determined by T% and Rs of the TaZnO films, showed maximum value as the films with a thickness of 230 nm was post-annealed at 200 degrees C under vacuum of 1 mTorr.

Effect of zinc content on the refractive index of Co-sputtered Zn-doped ITO films.

In this study, we investigated the possibility of using Zn-doped ITO film as an alternative material for conventional SiO2 waveguides used in optical communication. The Zn-doped ITO films were deposited on quartz substrates using a combinatorial sputtering system, which yielded composition spread Zn-In-Sn-O (ZITO) films by co-sputtering two targets of ITO and ZnO. The Zn-doped ITO films deposited at room temperature exhibited an amorphous phase in the Zn content [Zn/(Zn+In+Sn)] range of 39-54 at%. The Zn-doped ITO films deposited at low oxygen partial pressure showed resistivity below 10(-3) ohms cm and optical transmittance of approximately 85% at 550 nm. The refractive index calculated by the Swanepoel method was found to be dependent on the Zn content in the Zn-doped ITO films. The calculated bending loss from the refractive index indicated that Zn-doped ITO could be utilized as a new waveguide material for various optical devices, such as optical splitters, wavelength division multiplexers (WDMs), optical modulators, and optical switches.

Concerns and breakthroughs of combining ionic liquids with microwave irradiation for the synthesis of Ru nanoparticles via decarbonylation.

HYPOTHESIS: Combination of microwave irradiation (MWI) and ionic liquids (IL) is widely used for the synthesis of nanoparticles (NP) via decarbonylation of zero-valent metal carbonyl precursors. However, we carefully raise a question as to whether this combination is always beneficial. Upon MWI, highly-absorbing materials such as ILs would be subject to local intense heating, likely resulting in the occurrence of localized chemical decomposition. The decomposition is expected to influence the growth mechanism of NPs due to changes in the electrostatic and steric effects. If the assumption is valid, it should be possible to decompose IL and destabilize the NPs by modifying the amplitude of the incident microwaves. In other words, it should also be possible to control the particle aggregation by circumventing the decomposition of the IL. EXPERIMENTS: A series of comparative studies were conducted using a model system (i.e. [BMIm][BF4] and Ru3(CO)12). Variables were systematically controlled. After MWI, the decrease in colloidal stability of NPs was identified. FINDINGS: In the formation of Ru NPs via decarbonylation, the association between incident microwave intensity, chemical decomposition of IL, and initiation of particle aggregation has been demonstrated. Conditions that can accelerate or alleviate the decomposition and the aggregation are also corroborated.

Biosimilars: concept, current status, and future perspectives in inflammatory bowel diseases.

The inflammatory bowel diseases (IBD), which consist of Crohn's disease and ulcerative colitis, are chronic, incurable immunemediated inflammatory disorders of the intestine. As IBD incidence continues to increase globally and its mortality is low, prevalent cases of IBD are rapidly increasing, thereby leading to a substantial increase in health care costs. Although the introduction of biologic agents for IBD management has revolutionized the armamentarium of IBD therapy, the high cost of this therapy is concerning. With the expirations of patents for existing biologic agents (originals), biosimilars with cheaper costs have been highlighted in the field of IBD. Despite concerns regarding their short- and long-term efficacy, safety, immunogenicity, and interchangeability, increasing evidence via prospective observations and phase III or IV clinical trials, which aim to prove the "biosimilarity" of biosimilars to originals, has partly confirmed their efficacy, safety, and interchangeability. Additionally, although patients and physicians are reluctant to use biosimilars, a positive budget impact has been reported owing to their use in different countries. In the near future, multiple biosimilars with lower costs, and efficacy and safety profile similar to originals, could be used to treat IBD; thus, further consideration and knowledge dissemination are warranted in this new era of biosimilars.

Association of Faecal Calprotectin Level and Combined Endoscopic and Radiological Healing in Patients With Crohn's Disease Receiving Anti-tumour Necrosis Factor Therapy.

BACKGROUND AND AIMS: Combined endoscopic and radiological healing, or deep healing, is associated with favourable outcomes in patients with Crohn's disease; thus, a non-invasive biomarker for predicting deep healing would be invaluable. We evaluated the usefulness of faecal calprotectin for predicting deep healing in patients with Crohn's disease receiving anti-tumour necrosis factor [TNF] therapy. METHODS: We analysed the records of patients with Crohn's disease who received anti-tumour necrosis factor therapy and underwent endoscopic evaluation, radiological evaluation, and faecal calprotectin measurement within a period of 3 months between August 2017 and November 2018. Results of endoscopic and radiological studies were independently reviewed by two gastrointestinal endoscopists and a gastrointestinal radiologist, respectively. Serum C-reactive protein and albumin were also measured. RESULTS: Out of 268 patients analysed, 77 [28.7%] had deep healing, 36 [13.4%] had endoscopic healing only, 36 [13.4%] had radiological healing only, and 119 [44.4%] had neither. The median duration of anti-TNF treatment was 40.0 months. The deep healing group had the lowest median faecal calprotectin level [56.5 mg/kg] among the four groups [p <0.001]. The faecal calprotectin cutoff level of 81.1 mg/kg showed a sensitivity of 0.623 and a specificity of 0.817 in predicting deep healing (area under the receiver operating characteristic curve [AUROC], 0.767; 95% confidence interval, 0.702-0.832). Adding serum C-reactive protein and serum albumin to faecal calprotectin further increased the AUROC to 0.805 [95% confidence interval, 0.752-0.858]. CONCLUSIONS: Faecal calprotectin, when combined with serum C-reactive protein and albumin, showed acceptable performance in predicting deep healing in patients with Crohn's disease.

Novel nomogram for screening the risk of developing diabetes in a Korean population.

AIMS: We propose a novel nomogram, which graphically expresses the numerical relationship between type 2 diabetes (T2D) and disease-related risk factors. METHODS: Data of 8999 patients from the 2013-2014 Korean National Health and Nutrition Examination Survey were analyzed. Multiple logistic regression analysis was performed to assess risk factors for T2D and a nomogram was constructed based on screened risk factors. A receiver operating curve (ROC) and calibration plot were created to evaluate the accuracy of the nomogram. RESULTS: The risk factor with the greatest impact on the prevalence of T2D was age over 60 years (95% CI 5.97-15.00, OR = 9.46), followed by presence of dyslipidemia and cardiovascular disease (95% CI 5.90-13.68, OR = 8.98), family history of T2D (95% CI 2.33-3.64, OR = 2.92), abdominal obesity (OR = 1.76), hypertension (OR = 1.75), male gender (OR = 1.55), current-smoking status (OR = 1.52), lower education level (OR = 1.42), and lower income (OR = 1.30). The area under the ROC curve (AUC) showed statistically significant determination (AUC = 0.83). The equation of the calibration plot was drawn along the ideal line; coefficient of determination was 0.864. CONCLUSION: Our proposed nomogram could accurately predict the risk of T2D from nationwide data. The novel nomogram can be a useful tool for screening patients with T2D risk in a Korean population.

Characteristics of AZO electrode with high transmittance in near infrared range.

We studied Al2O3-doped ZnO (AZO) thin film as a transparent conducting layer for photovoltaic cell operated in wide range of solar spectrum. Effects of substrate temperature on the optical, structural, and electrical properties of thin AZO film were investigated. AZO films were deposited on glass substrates by RF magnetron sputtering system using a 2 wt.% Al2O3 doped target at different temperature conditions. The grown AZO films at low deposition temperatures ranged from 100 degrees C to 300 degrees C show relatively low resistivity, while the samples deposited at 400 degrees C or room temperature are with higher resistivity of -8 x 10(-4) Ω x cm. The measurement by atomic force microscopy reveals that all AZO films possess very smooth surface morphologies with RMS values below 1 nm regardless of substrate temperature. Optical transmittance of the AZO films increases from 81% to 95% as the substrate temperature increases. The AZO films deposited at 200 degrees C condition shows the optimum value of figure-of-merit of 43.7 x 10(-3) Ω(-1), showing the resistivity of 3.4 x 10(-4) Ω x cm and the transmittance of 94%. Additionally, it is noted that the transmittance of the films at near infrared wavelength of 1250 nm exceeds 90%, demonstrating the feasibility as a transparent electrode for thin film solar cell with narrow band gap.