[Phenolic constituents of Ampelopsis grossedentata from zhangjiajie].

OBJECTIVE: To study the phenolic constituents from Ampelopsis grossedentata. METHODS: Compounds were isolated using column chromatographic techniques (silica gel, polyamide gel, Sephadex LH-20) and semi-preparative HPLC. Structures were elucidated on the basis of spectral data (NMR and HR-MS). RESULTS: Eight compounds were isolated and identified as ampelopsin (I), 5, 7, 3',4',5'-pentahydroxyflavanone (II), galloyl-beta-D-glucopyranoside (III), gallic acid (IV), ethyl gallate (V), myricitrin (VI), (2R, 3S)-5,7,3',4',5'-pentahydroxyflavanonol (VII) and myricetin (VIII). CONCLUSION: Compounds II and VII are obtained from this genus for the first time.

Reduction of miR-29a-3p induced cardiac ischemia reperfusion injury in mice via targeting Bax.

The current study mainly aimed to evaluate the expression and the potential mechanism of miR-29a-3p in the hearts of mice after cardiac ischemia reperfusion (CIR) injury. Quantitative PCR was carried out to assess the relative levels of miR-29a-3p in the hearts of a CIR injury mouse model. To the best of our knowledge, the current study is the first to show that the level of miR-29a-3p was significantly decreased in the hearts of CIR injury mouse models compared with that of sham controls. Moreover, the authors found that decreased miR-29a-3p levels enhanced the production of reactive oxygen species in cardiomyocytes. Meanwhile, the inhibition of miR-29a-3p induced substantial cardiomyocyte apoptosis. Further study showed that the inhibition of miR-29a-3p decreased the activation of Akt and p38, suggesting a stress-induced self-regulatory mechanism after CIR injury in primary cardiomyocytes. A dual luciferase assay and western blot analysis showed that Bax was a target gene of miR-29a-3p. The authors also measured the level of miR-29a-3p in the plasma of 100 acute myocardial infarction (AMI) patients and found that circulating miR-29a-3p was significantly decreased in AMI patients. Receiver operating characteristic curve analysis showed that miR-29a-3p could be used to screen AMI patients from healthy controls. Hence, the authors of the current study propose that reduced miR-29a-3p levels in primary cardiomyocytes contribute to CIR injury-related apoptosis mainly by targeting Bax.

Expression of MMIF, HIF-1α and VEGF in Serum and Endometrial Tissues of Patients with Endometriosis.

The aim of this study was to investigate the expression of macrophage migration inhibitory factor (MMIF), hypoxia-inducible factor-1 a (HIF-1α) and vascular endothelial growth factor (VEGF) in the serum and endometrial tissues of patients with endometriosis (EM) and the clinical significance. Eighty EM patients [American Reproductive Association stage I (n=20), stage II (n=22), stage III (n=21) and stage IV (n=17)] were enrolled and divided into mild (10-14 points, n=28), moderate (16-24 points, n=27) and severe (26-30 points, n=25) dysmenorrhea groups. The control group included 40 healthy women of childbearing age who underwent routine healthcare examinations in the enrolment period. The expression of MMIF, HIF-1α and VEGF in the serum and endometrial tissues was measured by enzyme-linked immunosorbent assay and Western blotting, respectively. Meanwhile, the sensitivity and specificity of serum MMIF, HIF-1α, and VEGF when separately used as single indexes or jointly used as one index were examined as well. The results showed that serum concentrations of MMIF, HIF-1α, and VEGF were significantly higher in EM patients than in controls (P<0.05). The expression of all three proteins in both serum and endometrial tissues increased significantly with the R-AFS stage (P<0.05) and with dysmenorrheal severity (P<0.05). The sensitivity and specificity of the combined detection of serum MMIF, HIF-1α, and VEGF levels were significantly higher than those of single index detection (P<0.05). In conclusion, the expression of MMIF, HIF-1α, and VEGF in the serum and endometrial tissues may be used to assess the stage of EM and the severity of dysmenorrhea. Combined evaluation of MMIF, HIF-1α, and VEGF significantly improves the diagnostic sensitivity and specificity.

Antibacterial Activity of Stenotrophomonas maltophilia Endolysin P28 against both Gram-positive and Gram-negative Bacteria.

Maltocin P28 is a phage-tail like bacteriocin produced by Stenotrophomonas maltophilia P28. The ORF8 of maltocin P28 gene cluster is predicted to encode an endolysin and we name it endolysin P28. Sequence analysis revealed that it contains the lysozyme_like superfamily conserved domain. Endolysin P28 has the four consensus motifs as that of Escherichia coli phage lambda gpR. In this study, endolysin P28 was expressed in E. coli BL21 (DE3) and purified with a C-terminal oligo-histidine tag. The antibacterial activity of endolysin P28 increased as the temperature rose from 25 to 45°C. Thermostability assays showed that endolysin P28 was stable up to 50°C, while its residual activity was reduced by 55% after treatment at 70°C for 30 min. Acidity and high salinity could enhance its antibacterial activity. Endolysin P28 exhibited a broad antibacterial activity against 14 out of 16 tested Gram-positive and Gram-negative bacteria besides S. maltophilia. Moreover, it could effectively lyse intact Gram-negative bacteria in the absence of ethylenediaminetetraacetic acid as an outer membrane permeabilizer. Therefore, the characteristics of endolysin P28 make it a potential therapeutic agent against multi-drug-resistant pathogens.

Highly efficient transformation of Stenotrophomonas maltophilia S21, an environmental isolate from soil, by electroporation.

Stenotrophomonas maltophilia is an emerging opportunistic pathogen, which also exhibits potential of wide applications in industry, environment and agriculture. An efficient transformation method for S. maltophilia would be convenient to its genetic studies. In this report, we focused on developing an efficient transformation protocol for S. maltophilia. Gene transfer by three different methods (chemical transformation, conjugation and electroporation) indicated that electroporation was the most efficient method to transform S. maltophilia S21. Then, the entire electroporation process from competent-cell preparation to post-pulse incubation was optimized to get higher efficiencies. Utilizing competent cells prepared at optical density (600 nm) of 1.0, the maximal transformation efficiency of S. maltophilia S21 reached 1.53 × 10(8) transformants/µg of pBBR1MCS DNA at a field strength of 18 kV/cm, a time constant of 4.8 ms (200 Ω), a DNA amount of 100 ng and a cell concentration of 2.4 × 10(8) CFU/ml after 3 h incubation. Moreover, we successfully transformed the other four isolates of S. maltophilia using this protocol. To date, this is the first report about electroporation of S. maltophilia and it will facilitate the further study of this species.