Decoding glycome of Astragalus membranaceus based on pressurized liquid extraction, microwave-assisted hydrolysis and chromatographic analysis.

Carbohydrates in herbs are a relatively untapped source of new drugs and health beneficial ingredients. Their analysis has been developed as a novel aspect in quality control and herbal glycomics. In this study, glycome of Astragalus membranaceus was decoded based on optimized pressurized liquid extraction (PLE), microwave-assisted acidic hydrolysis (MAAH) and comprehensive chromatographic approaches. Twelve saccharides including sucrose, galacturonic acid, mannitol, fructose, rhamnose, ribose, arabinose, fucose, xylose, mannose, glucose and galactose were quantitatively analyzed by GC-MS and HPLC-CAD (charged aerosol detectors). Different columns, including Prevail Carbohydrate ES, XBridge Amide and CARBOSep CHO-820 CA for HPLC-CAD analysis, were compared for evaluation of oligosaccharides. The polysaccharides in water extract of Astragalus membranaceus were characterized by high performance size exclusive chromatography (HPSEC) combined with multiple angle light scattering detection (MALSD) and refractive index detection (RID). The results showed that A. membranaceus contained more than 108.5mgg(-1) free sucrose and small amounts of glucose 9.6-26.0mgg(-1) and fructose 8.7-22.9mgg(-1). While its polymeric carbohydrates were composed of glucose 71.0-162.3mgg(-1), galacturonic acid 52.0-113.4mgg(-1), arabinose 22.8-54.4mgg(-1) and small amounts of galactose, rhamnose, xylose and mannose. CARBOSep CHO-820 CA showed its potential in simultaneously analyzing oligosaccharides and uronic acid, especially only the environment-friendly water mobile phase was used. HPSEC-MALSD-RID showed that there were three different molecular weight distributions of polysaccharides in A. membranaceus and the average molecular weight were 21901.1, 2038.5, and 353.4kDa. Hierarchical clustering analysis and principal component analysis demonstrated that A. membranaceus from different regions showed variations both in free and polymeric carbohydrates, which indicated that carbohydrates should be evaluated for the proper quality control of A. membranaceus. Rha, Ara, Xyl, Man and Gal were found to be the main elements for quality evaluation of polymeric carbohydrates in A. membranaceus by factor analysis. The strategy for decoding the glycome based on chromatographic approaches including GC-MS, HPLC-CAD and HPSEC-MALSD-RID after pressurized liquid extraction and microwave-assisted hydrolysis could be applied for carbohydrates profiling in herbs and beneficial for their quality control.

Preparation of inulin-type fructooligosaccharides using fast protein liquid chromatography coupled with refractive index detection.

A fast protein liquid chromatography coupled with refractive index detection (FPLC-RID) method was firstly developed for preparation and purification of fructooligosaccharides with different degree of polymerization from burdock, Arctium lappa. After extraction with 60% ethanol and decolorization with MCI gel CHP20P, total fructooligosaccharides were purified on Bio-Gel P-2 column eluted with water at the flow rate of 0.3 ml/min, which was the optimized conditions. The obtained fructooligosaccharides with degree of polymerization of 3-9 were identified based on their methylation analysis, MS and NMR data. This method has the advantages of high automation, good recovery and easy performance, which could be used for preparation of FOS from other sources, as well as other targeted compounds without UV absorbance.

Quality evaluation of lentinan injection produced in China.

Lentinan is a ß-(1→6) branched ß-(1→3)-glucan derived from Lentinula edodes mushroom. It has been developed as an adjuvant to cancer chemotherapy and clinically used in Japan and China. Up to date, six lentinan injections or powders for injection produced by individual manufacturers were widely used in clinic in China. Since antitumor effect of lentinan is highly related to its structure, conformation and molecular weight, quality evaluation of lentinan injection produced in China is crucial to ensure its efficacy, which has never been performed. In this study, absolute molecular weights and their distributions of lentinan in multiple batches of injections from different manufacturers in China were firstly determined through a high performance size exclusive chromatography (HPSEC) combined with multiple angle light scattering detection (MALSD) and refractive index detection (RID). Enzymatic (ß-1,3-D-glucanase) digestion characters and triple helical conformation of lentinan were also investigated. The results showed that quality consistency of lentinan injections from different manufacturers in China was poor, which should be greatly improved to ensure their safety and efficacy.

Periodic lateralized epileptiform discharges in neuropsychiatric lupus: association with cerebritis in magnetic resonance imaging and resolution after intravenous immunoglobulin.

A 13-year-old girl with a known diagnosis of systemic lupus erythematosus presented with seizures and psychosis. An electroencephalogram (EEG) revealed continuous, non-evolving periodic lateralized epileptiform discharges (PLEDs) in the left temporal region, which did not resolve with benzodiazepine. A magnetic resonance imaging (MRI) brain scan demonstrated a focal hyperintensity in the left medial temporal and left occipital lobes, left thalamus and bilateral cerebellar white matter, with evidence of vasculitis in the magnetic resonance angiography. Intravenous immunoglobulin was given because of failed steroid therapy, which resulted in a full resolution of clinical, EEG and MRI abnormalities. Lupus cerebritis should be considered as a possible aetiology in PLEDs, and immunoglobulin can be effective in neuropsychiatric lupus.

The yield for colorectal cancer and adenoma by indication at colonoscopy.

Colonoscopy is an integral part of the clinician armamentarium in the diagnosis of colorectal cancer and its precursor, the adenoma. Polypoid lesions when identified can be excised at colonoscopy and in turn reduce the risk of colorectal cancer. We prospectively evaluated the yield of colorectal cancer and adenomatous polyps by indication for colonoscopy over a one-year period. A total of 375 colonoscopies were carried out. The more common indications of colonoscopy were rectal bleeding, abdominal pain, surveillance of colorectal cancer and altered bowel habit. The highest yield for cancer was for rectal bleeding with 12.5% while surveillance of patients with a history of polyps yielded the highest percentage of new polyps. We conclude that rectal bleeding as an indication for colonoscopy yielded the highest number of cancers.

Investigation of certain diffraction effects in an optical disk.

We report certain diffraction effects that are pertinent to the operation of double-layer optical recording media. For simulating cross-talk effects for double layers, the diffraction of light from the out-of-focus layer and the resulting distribution on the in-focus layer are studied by use of computer simulations. The findings are then verified qualitatively by direct measurements. We also describe a technique for analyzing (by computer simulation) the focus-error signal (FES), taking into account the cross talk between two layers, in systems that use the astigmatic method in conjunction with the double-layer disk. The results of our computer simulations of the FES give us a 10% cross-talk contribution to the original signal. The results of the FES evaluation are compared with those measured in an actual disk drive; good agreement between computation and measurement is obtained.