Simultaneous determination and analysis of amino acids and nucleosides in Dendrobium by UHPLC-QTRAP-MS/MS / 中国中药杂志

By using multivariate statistical analysis to evaluate essential quality, and provide scientific basis for their comprehensive utilization, we established an UHPLC-QTRAP-MS/MS method for the fast, precise, efficient determination of 21 kinds of amino acids and 10 kinds of nucleosides in different species of Dendrobium. The analysis was performed on a Waters XBridge Amide column(2.1 mm×100 mm,3.5 μm) with elution by mobile phase of 0.2% formic acid in water-0.2% formic acid in acetonitrile at a flow rate of 0.2 mL·min~(-1) with the column temperature at 30 ℃. The target compounds were analyzed by the positive ion multiple reaction monitoring(MRM) mode. The comprehensive evaluation of different species of Dendrobium was carried out by PCA and TOPSIS analysis. All 21 kinds of amino acids and 10 nucleosides showed good linearity among certain concentration range(r>0.999), the RSDs of the stability, precision, and repeatability tests were less than 3.0%. The recovery rate was in the range from 93.31% to 107.5%, and RSD was in the range of 1.1%-3.7%. The comprehensive evaluation index obtained with PCA showed that D. huoshanense was significantly higher than others regarding amino acids and D. officinale has higher nucleosides than other species. The biggest C_i difference of TOPSIS was 68.7%, and comprehensive evaluation showed that D. huoshanense produced the highest comprehensive quality. The method is precise, fast and efficient and can provide reliable basis for further researches and intrinsic quality control of Dendrobium.

Cloning and quantitative expression analysis of GMPP gene from Dendrobium huoshanense / 中国中药杂志

In order to understand the function of GDP-mannose pyrophosphorylase(GMPP) function and its regulation in polysaccharide biosynthesis mechanism in Dendrobium. D. huoshanense was used to clone GMPP gene. GMPP gene expression in D. huoshanense,D. officinale and D. moniliforme was also determined by qPCR. The results showed that the length of D. huoshanense GMPP gene c DNA sequence is 1 867 bp,containing 1 245 bp open reading frame(ORF),encoding 415 amino acids. Phylogenetic tree analysis showed that D. huoshanense,D. officinale and D. moniliforme are closely related with GMPP taken into consideration. Bioinformatics analysis demonstrated that GMPP sequence similarity among the three species reached as high as 99%. qPCR results indicated that GMPP genes was highly expressed in stem of D. huoshanense compared with its leaf,flower and root. According to GMPP gene expression profile in D. huoshanense,D. officinale and D. moniliforme grown in Huoshan area,it was clear that GMPP in D. huoshanense showed the highest expression level. Furthermore,our findings of GMPP gene expression profile will facilitate future researches into its polysaccharide biosynthetic mechanism.

Analysis of the protein expression and gene amplification of HER2 in gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the clinical significance of protein expression and gene amplification of HER2 in gastric cancer.</p><p><b>METHODS</b>Immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) method were used to detect protein expression and gene amplification of HER2 in 80 specimens of gastric cancer patients.</p><p><b>RESULTS</b>Protein expression of HER2 was negative in 51 cases, (+) in 12 cases, (++) in 12 cases, (+++) in 5 cases, and the positive expression rate was 21.3% (17/80). Seven (8.8%) cases had gene amplification of HER2, including gene critical amplification in 3 (3.8%) cases. The result of IHC was positively correlated with CISH (P<0.05), and the coincidence rate was 85.0% (68/80). HER2 positive expression rate was higher in the gastroesophageal junction carcinoma, poorly differentiated and stage III-IIII gastric cancer (all P<0.05).</p><p><b>CONCLUSION</b>The gastric cancer tissue has high positive rate of protein expression and gene amplification of HER2, which is closely correlated to the development of gastric cancer.</p>

Effects of arsenic trioxide on apoptosis of peripheral T-lymphocytes from asthmatic patients and normal subjects in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of arsenic trioxide on apoptosis of peripheral T-lymphocytes from asthmatic patients and normal subjects in vitro.</p><p><b>METHODS</b>The T-lymphocytes were isolated from the blood of 21 asthmatic patients and 20 healthy controls and treated with arsenic trioxide and dexamethasone. Cell apoptosis was observed by fluorescence microscope and measured with flow cytometry and Cytochrome C ELISA kit.</p><p><b>RESULTS</b>The T-lymphocytes from the asthmatic patients, when compared to those from of the healthy control, exhibited decelerated spontaneous apoptosis after a 24-hour incubation in vitro. Dexamethasone treatment significantly increased the percentage of apoptotic T-lymphocytes from both asthmatic patients and normal subjects in comparable magnitude. Arsenic trioxide treatment, in contrast, significantly increased the percentage of apoptotic T-lymphocytes from asthmatic patients, but slightly affected the cells from the control group.</p><p><b>CONCLUSIONS</b>Spontaneous apoptosis of T-lymphocytes can be decelerated in asthmatic patients, whose T-lymphocytes are more sensitive to arsenic trioxide-induced apoptosis than those of normal subjects, but the T-lymphocytes from normal subjects and asthmatic patients are equally sensitive to dexamethasone.</p>