Infection diseases induced by bacteria continue to be one of the greatest health problems worldwide. In this framework, nanotechnology-based solutions, and in particular silver nanoparticles ( AgNPs) , have recently emerged as promising candidates in the market as new antibacterial agents because of the enhanced broad-range antibacterial/antiviral properties and low cost.Here we analyze the experimental conclusions on the bactericidal effects of AgNPs, and discuss the safety issues.

Objective To investigate the clinical curative effect of Prepenem for pathogen from cranial neu-rosurgieal patients with lower respiratory tract infection after traeheotomy and to provide basis for treatment of such pa-tients. Methods Thirty-two cranial neurosurgical patients with lower respiratory tract infection after tracheotomy were enrolled in the study with original empiric therapy with Prepenem. And the pathogenic bacteria in sputum from patients with lower respiratory tract infection after traeheotomy were stricdy identified and analyzed by automatic mi-croorganism analyzers. The clinical efficacy of Prepenem was identified after treatment. Results The straim of bacte-rial species(48) and funni(5) from 32 specimens were isolated. 15 strains were infected by one kind of bacteria and 38 strains were infected by two kinds of bacteria. Among the pathogen, gram-negative bacilli were about 64. 1% and Klebsiela pneumoniae (18. 8%)was the most predominant, gram-positive coccobacteria were about 26. 4% and Staph-ylococcus aureus(13.2%)was the most predominant,funni were about 9.4% and C. albicans (5.7%)was the most predominant. The drug sensitivity test showed that the ratio of drug resistance of bacteria isolated from sputum was high,but gram-negative bacilli were highly sensitive to imipenem. Staphylococcus aurens was sensitive to Nitrofuran-toin and Rifampicin. Satisfied clinical curative effect was shown by the de-escalation therapy for all patients. Conclu-sions Gram-negative bacili in cranial neurosurgical patients with lower respiratory tract infection after tracheotomy are the main pathogenic bacteria from lower respiratory tract infection, and Staphylococcus aureus are the main gram-positive cocci. So the drug sensitivity test of sputum should be done more often and antibiotics must be selected ac-cording to the drug sensitivity test. In general, this kind of infection can be controlled by prepenem effectively.

Objective To explore the action mechanism of tauroursodeoxycholic acid(TUDCA)promoting intracellular clearance of Burkholderia pseudomallei(B.pseudomallei)in RAW264.7 macrophages.Methods After TUDCA of different concentrations were used to treat RAW264.7 cells pre-infected with B.pseudomallei for 8 h or not,flow cytometry was applied to detect the apoptosis of the infected and control cells.In addition,another endoplasmic reticulum stress(ERS)inhibitor 4-PBA was used to detect the apoptosis and proliferation of host cells after B.pseudomallei infection with Annexin-V/PI double staining and MTT cell proliferation assay.Furthermore,after transfected with CHOP siRNA,Western blotting and flow cytometry were employed to detect the effect of TUDCA on the expression levels of Caspase-3 and Caspase-12 and the changes in apoptotic rate after B.pseudomallei infection,respectively.Finally,the effect of TUDCA on intracellular multiplication of infected RAW264.7 cells were observed to estimate the CFU value in the presence and absence of CHOP siRNA.Results Under different concentrations of TUDCA,100 or 200 μmol/L TUDCA significantly reduced B.pseudomallei-induced apoptosis in RAW264.7 cells(P＜0.05).Meanwhile,both TUDCA and 4-PBA treatment could decrease the apoptosis induced by B.pseudomallei infection by ERS(P＜0.05).Further,the expression levels of Caspase-3 and Caspase-12 were obviously increased after B.pseudomallei infection compared with uninfected groups,but their expression levels in the siCHOP group was significantly lower than that in the siC group.Besides,flow cytometry also showed that TUDCA could reduce apoptosis induced by B.pseudomallei infection(P＜0.05),but no significant effect of TUDCA on apoptosis was observed under CHOP knockdown.Finally,intracellular CFU assay indicated that TUDCA treatment promoted the host cell clearance of B.pseudomallei(P＜0.05),but no such effect was observed in siCHOP group.Conclusion In B.pseudomallei infected RAW264.7 cells,TUDCA promotes the intracellular clearance of the bacteria by inhibiting ERS-induced apoptosis.

OBJECTI VE To optimize the extraction technology of the leaves of Dimocarpus longan according to flavonoids and phenolic acids. METHODS The contents of gallic acid ，protocatechuic acid ，ethyl gallate ，quercetin，luteolin and kaempferol in the leaves of D. longan were determined by HPLC. Based on single factor test ，with the ethanol volume fraction ，solid-liquid ratio and extraction time as factors ，using comprehensive scores of the contents of above six components as indexes ，the extraction technology of the leaves of D. longan was optimized by Box-Behnken response surface methodology. RESULTS The optimal extraction technology included ethanol volume fraction of 100％，solid-liquid ratio of l ∶ 7（g/mL），extraction time of 90 min， extraction temperature of 80 ℃. After 3 times of validation tests ，the average comprehensive score was 97.54（RSD＝0.33％，n＝ 3），relative error of which with predicted score （99.05）was 1.55％. CONCLUSIONS Box-Behnken response surface methodology combined with multi-index comprehensive score can be used for the extraction technology of the leaves of D. longan ，and the optimized extraction technology is stable and feasible.

OBJECTIVE To study the metabolites derived from the ethanol extract from the leaves of Dimocarpus longan preliminarily in rats in vivo ，and to provide reference for elucidating the possible metabolic mechanism of the leaves of D. longan in lowering blood glucose . METHODS Ultra high performance liquid chromatography quadrupole time -of-flight mass spectrometry （UPLC-Q-TOF-MS/MS） was adopted by taking ethanol extract of D. longan leaves，the feces and urine of rats at 0-72 h and 0-48 h after intragastric administration of 33.8 g/kg ethanol extract of D. longan leaves（by extract ），the feces and urine of rats at the corresponding time after intragastric administration of normal saline （blank control ） as samples . The accurate relative molecular weight ，formula and fragment information of the compounds were collected ， and the compounds were speculated and i dentified by matching with the database and spectrum library of the instrument ，and comparing with the reference substance and relevant literature . RESULTS A total of eight compounds were identified in urine and feces of rats ，including 2 prototype components and 6 metabolites. Three compounds （including two prototype components as quercetin ，luteolin and one metabolite as luteolin or kaempferol） in feces of rats were identified ；five compounds （all metabolites ） in urine of rats were identified ，involving metabolites of quercetin ，luteolin or kaempferol . Metabolites mainly included the products of methylation ，glucuronidation and oxidation. CONCLUSIONS After intragastric administration ，the ethanol extract from the leaves of D. longan is mainly metabolized in rats through methylation ，glucuronidation and other pathways . The identified compounds are mostly metabolites of quercetin and luteolin .

Humans ; Aged ; Lung Diseases ; Pneumonia/drug therapy* ; Adrenal Cortex Hormones/therapeutic use* ; Pulmonary Disease, Chronic Obstructive/drug therapy* ; Administration, Inhalation ; Community-Acquired Infections/drug therapy*