Screening and identification of marine fungi against bacterial quorum sensing / 生物工程学报

The discovery of quorum sensing (QS) system and its critical role in bacterial virulence have revealed a new way to attack pathogenic bacterium. The pathogenecity of QS deletion mutants decreases significantly. Targeting bacterial QS system is a promising therapeutic approach to control infections and anti-microbial resistance. To obtain natural QS inhibitors from marine organisms, marine fungi (69 strains) were isolated from marine mollusca, and their extracts were screened using improved QSIS2 (Quorum Sensing Inhibitor Selector 2) assay and Chromobacterium violaceum CV026. To improve the efficiency of QSIS2 screening, 2,3,5-triphenyltetrazolium chloride (TTC) staining method was used. Extract from strain QY013 was found to have QS inhibitory activity. Further experiment indicated that pyocyanin in Pseudomonas aeruginosa PAOI and violacein in C. violaceum CV026 were reduced by QY013 extract, without affecting bacterial growth. Morphological and 18S rDNA sequence analysis revealed that strain QY013 was most closely related to Penicillium species. The above results suggest that active constituents from QY013 may be used as novel antimicrobial agents against bacterial infection.

Comparison of the effects of midazolam and propofol on heart rate variability during operation in patients with type Ⅱ diabetes / 中华麻醉学杂志

Objective To compare the effects of sedation induced with midazolam and propofol on blood pressure(BP), heart rate(HR) and heart rate variability (HRV) during operation on lower extremity preformed under continuous epidural anesthesia in patients with the type Ⅱ diabetes. Methods Forty patients with type Ⅱ diabetes scheduled for lower limb surgery were randomized to receive either midazolam (group M n - 20) for propofol (group P n = 20) for sedation during operation, all patients were classified as ASA physical status Ⅱ or Ⅲ . The patients were unpremeditated. Epidural catheter was inserted at L2-3 or L3-4 . The local anesthetic used was 2% lidocaine. MAP,HR,HRV and SpO2 were monitored during anesthesia and operation. After onset of epidural analgesia a loading dose of midazolam(0.03 mg?kg-1 ) or propofol (0.7 mg?kg-1 ) was given i.v. followed by intermittent i.v. boluses of 1 /4-1 /2 loading dose to maintain the depth of sedation at OAA/S score of 3 (respond to name outer if called repeatedly) . Changes in HRV before and during sedation were recorded and compared between the two groups. Results The demographic data including sex, age and body weight were comparable between the two groups. LF and TP decreased significantly during sedation as compared with baseline in both groups ( P