Rapid chiral discrimination of oncometabolite dl-2-hydroxyglutaric acid using derivatization and field asymmetric waveform ion mobility spectrometry/mass spectrometry.

2-Hydroxyglutaric acid is a chiral metabolite whose enantiomers specifically accumulate in different diseases. An enantiomeric excess of the d-form in biological specimens reflects the existence of various pathogenic mutations in cancer patients, however, conventional methods using gas or liquid chromatography and capillary electrophoresis had not been used for large clinical studies because they require multiple analytical instruments and a long run time to separate the enantiomers. Here, we present a rapid separation method for dl-2-hydroxyglutaric acid using a chiral derivatizing reagent and field asymmetric waveform ion mobility spectrometry/mass spectrometry, which requires a single analytical instrument and <1 s for the separation. We compared three derivatization methods and found that a method using (S)-1-(4,6-dimethoxy-1,3,5-triazin-2-yl)pyrrolidin-3-amine enables the separation. In addition, we were able to detect dl-2-hydroxyglutaric acid in standard solution at lower concentrations than that previously reported for the serum. These results show the potential of the method to be used in clinical analysis.

Prevention of Image Quality Degradation in Wider Field Optical Coherence Tomography Angiography Images Via Image Averaging.

Purpose: To evaluate the mutual effect of widening the field of view and multiple en face image averaging on the quality of optical coherence tomography angiography (OCTA) images. Methods: This prospective, observational, cross-sectional case series included 20 eyes of 20 healthy volunteers with no history of ocular or systemic disease. OCTA imaging of a 3 × 3-mm, 6 × 6-mm, and 12 × 12-mm area centered on the fovea was performed nine times using the PLEX Elite 9000. We acquired averaged OCTA images generated from nine en face OCTA images. The corresponding areas in the three scan sizes were evaluated for the original single-scanned OCTA images and averaged OCTA images both qualitatively and quantitatively. Quantitative measurements included vessel density (VD), vessel length density (VLD), fractal dimension (FD), and contrast-to-noise ratio (CNR). Results: Significant differences in VD, VLD, FD, and CNR (P < 0.001) were observed due to the mutual effect of averaging and differences in scan size. Both qualitative and quantitative evaluations indicated that the quality of 6 × 6-mm averaged images was equal to or better than that of 3 × 3-mm single-scanned images. However, the quality of 12 × 12-mm averaged images did not reach that of 3 × 3-mm single-scanned images. Conclusions: To some extent, multiple en face OCTA image averaging can compensate for the deterioration in image quality caused by widening the field of view. Translational Relevance: Multiple en face OCTA image averaging can be a technique for acquiring wider field OCTA images with good quality.

Nitric oxide production inhibitory activity of flavonoids contained in trunk exudates of Dalbergia sissoo.

Methanolic extracts of trunk exudates of Dalbergia sissoo yielded two new open-chain neoflavonoids (1, 2), a new flavonoid (3), a new flavanone (4), and 26 known compounds. Their structures were elucidated by detailed spectroscopic analyses. The ability of the isolated compounds to prevent nitric oxide (NO) production by LPS-stimulated J774.1 cells was also studied. All of the isolated compounds except 4, formononetin, and zenognosin B exhibited significant activity in a concentration-dependent manner. Compounds 2 and 3 were among the most potent NO production inhibitors, with IC50 values of 3.19 and 6.22 microM, respectively, and compound 1 had an IC50 of 31.6 microM.