Determination of l-tryptophan and l-kynurenine derivatized with (R)-4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole by LC-MS/MS on a triazole-bonded column and their quantification in human serum.

The concentrations of l-tryptophan (Trp) and the metabolite l-kynurenine (KYN) can be used to evaluate the in-vivo activity of indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO). As such, a novel method involving derivatization of l-Trp and l-KYN with (R)-4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole (DBD-PyNCS) and separation by high-performance liquid chromatography (HPLC) with tandem mass spectrometric (MS/MS) detection on a triazole-bonded column (Cosmosil HILIC®) was developed to determine their concentrations. The optimized mobile phase, CH3 CN/10 mm ammonium formate in H2 O (pH 5.

Japanese features of native valve endocarditis caused by coagulase-negative staphylococci: case reports and a literature review.

Although coagulase-negative staphylococci (CoNS) is a frequent cause of prosthetic valve endocarditis, native valve endocarditis (NVE) caused by CoNS is not commonly seen. Its high mortality is well known; however, there are no systematic reports published in Japan. We herein report the cases of two Japanese patients with CoNS NVE who were admitted to our hospital located in Tokyo and conduct literature searches on CoNS NVE in Japan from 1983 to March 2012 using PubMed and ICHUSHI WEB (Japan Medical Abstract Society).

Red blood cell distribution width as an effective tool for detecting fatal heart failure in super-elderly patients.

Objective: Red blood cell distribution width (RDW) is a numerical measure of erythrocyte size variation. It has been recently reported to be an independent prognostic marker of heart failure (HF). Previous studies on RDW were mostly designed for middle-aged and elderly patients (60-79 years old), therefore, there is no established limit for super-elderly patients (≥ 80 years old).