Alignment of Lyotropic Liquid Crystalline Conjugated Polymers in Floating Films.

Directed alignment of polymer chains plays an indispensable role in charge transport properties. We focus not only on a specific method to induce the alignment but also on the design of a liquid crystalline (LC) conjugated polymer to take advantage of an intrinsic self-assembly characteristic. We synthesized a lyotropic LC conjugated polymer, CP1-P, having o-nitrobenzyl (ONB) esters as photocleavable side chains and adopted a floating film transfer method to induce the polymer chain alignment through a lyotropic LC phase transition. An optimum amount of a high boiling point solvent (1,2-dichlorobenzene) in chloroform turned out to be an important factor to maximize the polymer chain alignment. The hole transport mobility along the polymer chain alignment direction was 13-14 times higher than that in the direction perpendicular to the alignment. In addition, the removal of side chains resulted in the solvent resistivity while maintaining the alignment feature in organic thin-film transistors.

Technical skills and training of upper gastrointestinal endoscopy for new beginners.

The incidence of gastric cancer remains high in South Korea. Upper gastrointestinal (GI) endoscopy, i.e., esophagogastroduodenoscopy (EGD), has a higher diagnostic specificity and sensitivity than the upper GI series. Additionally, EGD has the ability to biopsy, through taking a tissue of the pathologic lesion. Successful training of EGD procedural skills require a few important things to be learned and remembered, including the posture of an examinee (e.g., left lateral decubitus and supine) and examiner (e.g., one-man standing method vs one-man sitting method), basic skills (e.g., tip deflection, push forward and pull back, and air suction and infusion), advanced skills (e.g., paradoxical movement, J-turn, and U-turn), and intubation techniques along the upper GI tract (e.g., oral cavity, pharynx, larynx including vocal cord, upper and middle and lower esophagus, gastroesophageal junction, gastric fundus, body, and antrum, duodenal bulb, and descending part of duodenum). In the current review, despite several limitations, we explained the intubation method of EGD for beginners. We hope this will be helpful to beginners who wish to learn the procedure.

Comparison of the efficacy and safety of sodium phosphate tablets and polyethylene glycol solution for bowel cleansing in healthy Korean adults.

PURPOSE: Bowel cleansing is generally regarded as time-consuming and unpleasant among patients. Patients commonly state that bowel preparation provokes more discomfort than the actual colonoscopic examination. The purpose of this study was to compare two regimens of sodium phosphate (NaP) tablets versus polyethylene glycol (PEG) solution for bowel preparation in healthy Korean adults. MATERIALS AND METHODS: This was a single center, prospective, open-label, investigator-blinded, randomized, controlled-pilot study. A total of 62 healthy Korean subjects were randomly assigned to two groups (NaP vs. PEG). Efficacy, safety, and patient-related outcomes, as well as procedural parameters, were evaluated. RESULTS: Although there were no significant differences in total Ottawa bowel quality score, fluid scores and the rate of adequate bowel preparation were significantly better in the NaP group than the PEG group. Additionally, the NaP group showed better results regarding patient tolerance, satisfaction, preference, and rate of adverse events than the PEG group. Significant fluctuations in specific serum electrolytes were common and of a greater magnitude in the NaP group than the PEG group. However, these abnormalities were transient and did not result in serious complications and side effects. CONCLUSION: In this study, NaP tablets were shown to be an effective, well-tolerated, and acceptable regimen for bowel preparation. Also, our study suggests that NaP tablets may be safe and can be used as a bowel cleansing agent in healthy adults undergoing elective colonoscopy. Further multicenter, large scale studies are needed to confirm these findings.

Ectopic sebaceous glands in the oesophagus: a case report and review of literature.

INTRODUCTION: Most ectopic sebaceous glands have been reported in the tissues of ectodermal origin. However, there are relatively a few reports of ectopic sebaceous glands in the oesophagus, an organ of endodermal origin. CASE PRESENTATION: We report the case of an asymptomatic 54-year-old man with ectopic oesophageal sebaceous glands. These lesions were incidentally observed in the distal oesophagus during screening endoscopy of gastric neoplasm and confirmed by histologic analysis. CONCLUSION: Surveillance or resection with regard to ectopic sebaceous glands in the oesophagus is generally not required since there is no known malignant potential. However, anti-reflux treatment may be sometimes needed, if such symptoms are present in patients. Also, these lesions should be differentiated from other pathologic lesions of oesophagus that need to be treated. Thus, greater attention of endoscopists is required for detection and differential diagnosis of these lesions. The narrow-band imaging mode and/or endoscopic biopsy may be helpful.

Colonic mucosa-associated lymphoid tissue lymphoma identified by chromoendoscopy.

Colonic mucosa-associated lymphoid tissue (MALT) lymphomas are a rare occurrence and the definitive treatment has not been established. Solitary or multiple, elevated or polypoid lesions are the usual appearances of MALT lymphoma in the large intestine and sometimes the surface may reveal abnormal vascularity. Herein, we report a case of MALT lymphoma and review the relevant literature. Upon colonoscopy, a suspected pathologic lesion was observed in the proximal transverse colon. The lesion could be distinguished more prominently after using narrow-band imaging mode and indigo carmine-dye spraying chromoendoscopy. Histopathologic examination of this biopsy specimen revealed lymphoepithelial lesions with diffuse proliferation of atypical lymphoid cells effacing the glandular architecture and centrocyte-like cells infiltrating the lamina propria. Immunohistochemical analyses showed that tumor cells were positive for CD20 and Bcl-2e, and negative for CD10, CD23, and Bcl-6. According to Ann-Arbor staging system, the patient had stage IIE. A partial colectomy with dissection of the paracolic lymph nodes was performed. Until now, there is no recurrence of lymphoma at follow-up.

Effect of acute auditory stress on gastric motor responses to a meal in healthy volunteers.

BACKGROUND AND AIM: Stress is believed to play a role in the pathogenesis of functional gastrointestinal disorders. The aim of the present study was to investigate the effect of acute auditory stress on gastric motor responses to a meal in healthy subjects. METHODS: A total of eight healthy volunteers (seven men and one woman; median age, 33.4 years [30-35 years]) who had no recurrent gastrointestinal symptoms participated in the prospective, randomized, crossover study. Gastric half-emptying time and meal-induced proximal gastric accommodation were measured using gastric scintigraphy under the auditory stress and control conditions in a randomized crossover design. RESULTS: The gastric half-emptying time under the stress condition was significantly longer than that under the control condition (130.8 ± 16.6 vs. 105.0 ± 13.1 min; P = 0.005 by paired t-test). Under the stress and control conditions, the proximal gastric volume significantly increased after a meal (P < 0.001 by repeated measures analysis of variance). The degree of the postprandial increase in proximal gastric volume did not significantly differ between both conditions (P = 0.598 by tests of between-subjects effects using repeated measures analysis of variance). The severity scores of postprandial epigastric discomfort and fullness were significantly higher under the stress condition than under the control condition (P = 0.001 and P = 0.039, respectively, by paired t-test). CONCLUSIONS: Acute auditory stress delays gastric emptying and increases the severity of postprandial symptoms in the healthy subjects, suggesting the relevance of psychological stress to the pathophysiological mechanism of functional dyspepsia.