Continuous recycling of homogeneous Pd/Cu catalysts for cross-coupling reactions.

Given the importance of homogeneous catalysts recycling in organic chemistry, we have developed a unique microfluidic loop system for automated continuous recirculation of a soluble polymer supported metal catalyst for novel isocyanide cross-coupling reactions under thermomorphic multicomponent solvent (TMS) conditions. Our system provides an innovative approach for the chemical library synthesis of quinazolinone derivatives as well as an important intermediate of Merck's LTD4 antagonist "Singulair" with efficient continuous homogeneous catalyst recycling.

Chitosan-microreactor: a versatile approach for heterogeneous organic synthesis in microfluidics.

Microreactors have been proven to be efficient tools for a variety of homogeneous organic transformations due to their mixing efficiency, which results in very fast reactions, better heat and mass transfer, and simple scale-up. However, in heterogeneous catalytic reactions each catalyst needs an individual substrate as support. Herein, a versatile approach to immobilize metal catalysts on chitosan as a common substrate is presented. Chitosan, accommodating many metal catalysts, is grafted onto the microchannel surface as nanobrush. The versatility, catalytic efficiency, and stability/durability of the microreactor are demonstrated for a number of organic transformations involving various metal compounds as catalysts.

A rare case of "rosai-dorfman disease".

Sinus histiocytosis with massive lymphadenopathy (SHML) is a benign proliferating histiocytic disorder, predominantly of lymphnodes with extranodal involvement also seen. We present a case of 35 years old female with history of multiple swellings in neck since 1 month duration. On examination patient had painless bilateral cervical lymphadenopathy. No other ENT manifestations noted. Lymphnode biopsy revealed SHML. Abdominal scan and chest X-ray was done which was normal. This case report highlights the clinical, histological aspects of SHML, Rosai-Dorfman disease.

Patient acceptance and clinical impact of Bravo monitoring in patients with previous failed catheter-based studies.

BACKGROUND: Standard pH monitoring is performed over 24 h with a naso-oesophageal catheter (C-pH). Limitations include naso-pharyngeal discomfort, nausea and social embarrassment resulting in reduced reflux-provoking activities. Recently a catheter-free pH-monitoring technique has become available. The tolerability and diagnostic yield of this system in patients who failed standard monitoring remain unknown. AIM: To examine the tolerability and diagnostic outcome of catheter-free pH-monitoring technique in patients who failed standard monitoring. METHODS: Patients referred for C-pH and catheter-free pH monitoring completed a tolerability questionnaire. Acid exposure in the distal oesophagus and symptom index (SI) were reviewed. RESULTS: Over 4 years, 883/1751 (50%) of patients with typical reflux symptoms referred for C-pH were diagnosed with gastro-oesophageal reflux disease (GERD) based on a pathological percentage time acid exposure (%time pH <4);134 (8%) patients failed C-pH and, of these, 129 successfully completed 2-day catheter-free pH monitoring. Ninety-eight (76%) of these patients had a pathological percentage pH <4 on either day compared with 49/102 (49%) of contemporaneous C-pH patients (P < 0.01). There was no difference in SI for heartburn (35% vs. 42%; P = 0.49). The questionnaire demonstrated a preference for catheter-free pH monitoring (96%) with less restriction in activities of daily living, naso-pharyngeal discomfort, dysphagia and chest pain. CONCLUSIONS: Tolerance and satisfaction with catheter-free pH monitoring are high in patients who had previously failed C-pH; catheter-free pH monitoring assists the definitive diagnosis of GERD in this group.

Eosinophilic oesophagitis: a common cause of dysphagia in young adults?

Eosinophilic oesophagitis (EO) is an increasingly recognised chronic, relapsing inflammatory condition of the oesophagus. There has been a mini-epidemic of EO in the last decade. The incidence of this condition is higher in children and is commoner in males. There is either a family or personal history of atopic conditions present in a significant number of patients and can also be familial in up to 10%. The classical symptom in an adult is chronic, intermittent solid-food dysphagia and food impaction, often necessitating emergency endoscopic removal. Despite the history of dysphagia for a number of years, patients remain well with no weight loss, which can mislead clinicians to diagnose a functional problem with a resulting delay in the diagnosis. There are various endoscopic features of EO; commonly multiple rings and linear furrows, though these can be subtle and the mucosa may be macroscopically normal. The hallmark of this condition is the histological presence of > or =15 eosinophils/high power field (HPF) in the oesophageal mucosa. Therapeutic options include avoidance of dietary allergens, topical or systemic steroids, Montelukast, Mepolizumab (anti-IL-5 antibody) and endoscopic dilation of strictures unresponsive to medical therapy.