Highly sensitive and selective visual detection of Cr(VI) ions based on etching of silver-coated gold nanorods

We report a visual detection of Cr(VI) ions using silver-coated gold nanorods (AuNR@Ag) as sensing probes. Au NRs were prepared by a seed-mediated growth process and AuNR@Ag nanostructures were synthesized by growing Ag nanoshells on Au NRs. Successful coating of Ag nanoshells on the surface of Au NRs was demonstrated with TEM, EDS, and UV–vis spectrometer. By increasing the overall amount of the deposited Ag on Au NRs, the localized surface plasmon resonance (LSPR) band was significantly blue-shifted, which allowed tuning across the visible spectrum. The sensing mechanism relies on the redox reaction between Cr(VI) ions and Ag nanoshells on Au NRs. As the concentration of Cr(VI) ions increased, more significant red-shift of the longitudinal peak and intensity decrease of the transverse peak could be observed using UV–vis spectrometer. Several parameters such as concentration of CTAB, thickness of the Ag nanoshells and pH of the sample were carefully optimized to determine Cr(VI) ions. Under optimized condition, this method showed a low detection limit of 0.4 μM and high selectivity towards Cr(VI) over other metal ions, and the detection range of Cr(VI) was tuned by controlling thickness of the Ag nanoshells. From multiple evaluations in real sample, it is clear that this method is a promising Cr(VI) ion colorimetric sensor with rapid, sensitive, and selective sensing ability.This research was supported under the framework of Nano Material Technology Development Program (NRF-2015M3A7B6027970) and Basic Science Research Program (NRF-2018R1D1A1B07051249) by National Research Foundation, South Korea. Also, this work was supported by the Center of Integrated Smart Sensors funded by the Ministry of Science, ICT and Future Planning, South Korea, as Global Frontier Project (CISS-012M3A6A6054186

Sclerosing encapsulating peritonitis in a long-term propranolol user

Sclerosing encapsulating peritonitis (SEP) is a rare cause of bowel obstruction that is characterized by the encasement of the small bowel by a thick, whitish, and fibrous membrane. The pathophysiology of SEP is poorly understood and preoperative diagnosis is difficult. Previous reports suggest that SEP may be linked to the chronic use of β-adrenergic blockers. A 46-year-old man with liver cirrhosis and end-stage renal disease on hemodialysis presented with recurrent abdominal pain and borborygmi. He had been taking propranolol to prevent bleeding from gastroesophageal varices for the past 15 years. Abdominal computed tomography showed ileal loops encapsulated by soft tissue with dilatation of the proximal small bowel on the right side of the abdomen. Barium follow-through showed conglomerated distal ileal loops with a cauliflower-like appearance. Explorative laparotomy revealed a thick, fibrous, whitish capsule encapsulating the ileal loops. The covering membrane was dissected and excised, resulting in an improvement in symptoms after surgery. Accordingly, a final diagnosis of SEP was made. Due to the lack of other apparent causes for SEP, we conclude that in this case, the long-term use of propranolol may be associated with the development of SEP

Magnetic and near-infrared derived heating characteristics of dimercaptosuccinic acid coated uniform Fe@Fe3O4 core–shell nanoparticles

Among the number of hyperthermia materials, magnetic nanoparticles have received much attention. In this work, we studied the heating characteristics of uniform Fe@Fe3O4 core–shell nanoparticle under near-infrared laser irradiation and external AC magnetic field applying. The Fe@Fe3O4 core–shell nanoparticles were prepared by thermal decomposition of iron pentacarbonyl and followed by controlled oxidation. The prepared uniform particles were further coated with dimercaptosuccinic acid to make them well dispersed in water. Near-infrared derived photothermal study of solutions containing a different concentration of the core–shell nanoparticles was made by using 808 nm laser Source. Additionally, magnetic hyperthermia ability of the Fe@Fe3O4 nanoparticle at 150 kHz and various oersted (140–180 Oe) condition was systemically characterized. The Fe@Fe3O4 nanoparticles which exhibited effective photo and magnetic hyperthermia are expected to be used in biomedical application.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2018R1D1A1B07051249), Nano Material Technology Develop‑ment Program (NRF-2015M3A7B6027970) of MSIP/NRF and Center for Inte‑grated Smart Sensors funded by the Ministry of Science, ICT, and Future Plan‑ning, Republic of Korea, as Global Frontier Project (CISS-012M3A6A6054186)

Patient Descriptions of Rectal Effluents May Help to Predict the Quality of Bowel Preparation With Photographic Examples

Background/AimsPrevious studies have suggested a weak correlation between self-reported rectal effluent status and bowel preparation quality. We aim to evaluate whether photographic examples of rectal effluents could improve the correlation between patient descriptions of rectal effluents and bowel preparation quality.MethodsBefore colonoscopy, patients were asked to describe the nature of their last three rectal effluents. Photographic examples of rectal effluents were provided as a reference for scoring. Bowel preparation was subsequently assessed by a single endoscopist using a global preparation assessment scale. Preparation outcomes were grouped into two levels (excellent to good vs. fair to inadequate). Both univariate and multivariate logistic regression models were used to find any association between bowel preparation quality and patient characteristics.ResultsA total of 138 patients completed the questionnaires. The mean age was 56.5±10.4 years. The mean sum of the last three rectal effluent scores was 5.9±2.0. Higher rectal effluent scores (odds ratio [OR], 0.82; P=0.043) and the presence of diverticula (OR, 0.16; P<0.001) were risk factors for suboptimal preparation.ConclusionsPhotographic example-guided patient descriptions of rectal effluents showed a statistically significant association with bowel preparation quality. However, clinical significance seemed to be low. The presence of diverticula was an independent predictive factor for suboptimal bowel preparation quality

Guidewire Impaction in the Main Pancreatic Duct in a Patient with Chronic Pancreatitis: A Case Report

The guidewire is an essential accessory in ERCP. Although rare, guidewires can cause complications, such as subcapsular hepatic hematoma, perforation, knotting, fracture, and impaction, during ERCP. This report describes a guidewire impaction during the endoscopic treatment of a patient with symptomatic chronic pancreatitis. The methods used to treat guidewire impaction are not well known. In the present case, the impacted guidewire was retrieved by inserting another guidewire and dilating the space adjacent to it. Endoscopists should check for the free movement of the guidewire before stent deployment. Additionally, it is important to ask for help from experienced senior staff to overcome any challenges during the procedure. In conclusion, endoscopists should be aware of the possibility of a guidewire impaction during ERCP

Impact of 5-Year Endoscopic Surveillance Intervals with Biopsy following Endoscopic Papillectomy for Ampullary Adenoma

Background: Endoscopic snare papillectomy (ESP) has been established as a safe and effective treatment for ampullary adenomas. However, little is known about the optimal post-procedure follow-up period and the role of routine endoscopic surveillance biopsy following ESP. We aimed to evaluate patient adherence to a 5-year endoscopic surveillance and routine biopsy protocol after ESP of ampullary adenoma. Methods: We reviewed our prospectively collected database (n = 98), all members of which underwent ESP for ampullary lesions from January 2011 to December 2016, for the evaluation of long-term outcomes. The primary outcome was the rate of patient adherence to 5-year endoscopic surveillance following ESP. The secondary outcomes were the diagnostic yield of routine endoscopic biopsy, recurrence rate, and adverse events after endoscopic surveillance in the 5-year follow-up (3-month, 6-month, and every 1 year). Results: A total of 19 patients (19.4%) experienced recurrence during follow-up, all of these patients experienced recurrence within 3 years of the procedure (median 217 days, range 69&ndash;1083). The adherence rate for patients with sporadic ampullary adenoma were 100%, 93.5%, and 33.6% at 1, 3, and 5 years after ESP, respectively. The diagnostic yield of routine endoscopic biopsy without macroscopic abnormality was 0.54%. Pancreatitis occurred in four patients (4%, 3 mild, 1 moderate) after surveillance endoscopic biopsy without macroscopic abnormality. Conclusions: Given the low 5-year adherence rate and diagnostic yield of routine endoscopic biopsy with risk of pancreatitis, optimal surveillance intervals according to risk stratification (low grade vs. high grade adenoma/intramucosal adenocarcinoma) may be required to improve patient adherence, and routine biopsy without macroscopic abnormality may not be recommended

Primary Histiocytic Sarcoma of the Central Nervous System

Histiocytic sarcoma is a type of lymphoma that rarely involves the central nervous system (CNS). Its rarity can easily lead to a misdiagnosis. We describe a patient with primary CNS histocytic sarcoma involving the cerebral hemisphere and spinal cord, who had been initially misdiagnosed as demyelinating disease. Two biopsies were necessary before a correct diagnosis was made. A histologic examination showed bizarre shaped histiocytes with larger nuclei and nuclear atypia. The cells were positive for CD68, CD163, and S-100 protein. As a resection was not feasible due to multifocality, he was treated with highdose methotrexate, but showed no response. As a result, he was switched to high dose cytarabine; but again, showed no response. The patient died 2 months from the start of chemotherapy and 8 months from the onset of symptoms. Since few patients with this condition have been described and histopathology is difficult to diagnose, suspicion of the disease is essential. Key words Histiocytic sarcoma, Central nervous system

Primary histiocytic sarcoma of the central nervous system

© 2015 by the Korean Cancer Association. Histiocytic sarcoma is a type of lymphoma that rarely involves the central nervous system (CNS). Its rarity can easily lead to a misdiagnosis. We describe a patient with primary CNS histocytic sarcoma involving the cerebral hemisphere and spinal cord, who had been initially misdiagnosed as demyelinating disease. Two biopsies were necessary before a correct diagnosis was made. A histologic examination showed bizarre shaped histiocytes with larger nuclei and nuclear atypia. The cells were positive for CD68, CD163, and S-100 protein. As a resection was not feasible due to multifocality, he was treated with highdose methotrexate, but showed no response. As a result, he was switched to high dose cytarabine; but again, showed no response. The patient died 2 months from the start of chemotherapy and 8 months from the onset of symptoms. Since few patients with this condition have been described and histopathology is difficult to diagnose, suspicion of the disease is essential

Efficacy of Precut Endoscopic Mucosal Resection for Treatment of Rectal Neuroendocrine Tumors

Background/Aims Endoscopic resection is the first-line treatment for rectal neuroendocrine tumors (NETs) measuring <1 cm and those between 1 and 2 cm in size. However, conventional endoscopic resection cannot achieve complete resection in all cases. We aimed to analyze clinical outcomes of precut endoscopic mucosal resection (EMR-P) used for the management of rectal NET. Methods EMR-P was used to treat rectal NET in 72 patients at a single tertiary center between 2011 and 2015. Both, circumferential precutting and EMR were performed with the same snare device in all patients. Demographics, procedural details, and histopathological features were reviewed for all cases. Results Mean size of the tumor measured endoscopically was 6.8±2.8 mm. En bloc and complete resection was achieved in 71 (98.6%) and 67 patients (93.1%), respectively. The mean time required for resection was 9.0±5.6 min. Immediate and delayed bleeding developed in six (8.3%) and 4 patients (5.6%), respectively. Immediate bleeding observed during EMR-P was associated with the risk of delayed bleeding. Conclusions Both, the en bloc and complete resection rates of EMR-P in the treatment of rectal NETs using the same snare for precutting and EMR were noted to be high. The procedure was short and safe. EMR-P may be a good treatment choice for the management of rectal NETs

Chronic intractable diarrhea caused by gastrointestinal mastocytosis

As mast cells have been highlighted in the pathogenesis of diarrhea-predominant irritable bowel syndrome, a new term "mastocytic enterocolitis" was suggested by Jakate and colleagues to describe an increase in mucosal mast cells in patients with chronic intractable diarrhea and favorable response to treatment with antihistamines. Although it is not an established disease entity, two cases have been reported in the English medical literature. Here, for the first time in Asia, we report another case of chronic intractable diarrhea caused by gastrointestinal mastocytosis. The patient was a 70-year-old male with chronic intractable diarrhea for 3 months; the cause of the diarrhea remained obscure even after exhaustive evaluation. However, biopsy specimens from the jejunum were found to have increased mast cell infiltration, and the patient was successfully treated with antihistamines