Protective effects of carnosic acid against aging in a premature cellular senescence model and in a D-galactose induced mouse model / 药学学报

This study aimed to investigate the effect and possible mechanism of carnosic acid (CA) on delaying aging. The effects of CA on senescence-related β-galactosidase (SA-β-Gal) activity and expressions of p53, p21 and p16 were evaluated by an oxidative challenge induced premature 2BS cell senescence model. Meanwhile, the animal experiment was approved by the Ethics Committee of Zhejiang Hospital. Male C57 BL/6J mice were injected with 100 mg·kg-1·d-1 D-galactose (D-gal) for 8 weeks to establish an aging model in vivo, and CA at 5 and 10 mg·kg-1·d-1 were given ig administration at the same time. Morris water maze test was used to test the spatial memory ability. Then the serum and tissue samples were collected for the detections of malondialdehyde (MDA), total superoxide dismutase (T-SOD), interleukin-6 (IL-6), tumor necrosis factor α (TNFα) and advanced glycation end products (AGEs) as well as the protein expression of p53, p21 and p16 in hippocampus of brain. The results showed that H2O2 induced increment of SA-β-Gal activity (95%) was prevented by CA treatment (35%) and the enhanced protein expressions of p53, p21 and p16 in H2O2 exposed 2BS cells were alleviated by CA treatment, suggesting a potent protective role of CA against premature senescence induced by oxidative challenge. For in vivo study, D-gal induced declined spatial memory ability was partly reversed by CA administration. Besides, the serum and cerebral levels of MDA, IL-6, TNFα and AGEs were attenuated by CA treatment when compared to those in model mice. And the protein expressions of p53, p21 and p16 in mice hippocampus were suppressed by CA in D-gal treated mice. Taken together, our results showed that CA protects premature senescence induced by oxidative stress and D-gal, which is related to its antioxidative, antiinflammatory roles and inhibition on non-enzymatic glycosylation.

Plasmid-mediated quinolone resistance in clinical isolates of gram-negative bacilli / 中国感染与化疗杂志

Objective To investigate the importance of plasmid-mediated quinolone resistance in the development of quinolone resistance in clinical isolates of gram-negative bacteria.Methods A total of 541 consecutive clinical isolates of gram-negative ba- cilli resistant or intermediate to ciprofloxacin were screened for the qnrA gene by PCR.Conjugation experiments were carried out with azide-resistant E.coli J53 as a recipient.The aac(6')-Ib-cr gene was detected.The mutations in the quinolone-resist- ance-determining region (QRDR) of the gyrA and parC genes were identified in qnrA positive strains.Results qnrA was identi- fied in 7 of the 541 strains.Among the qnrA positive strains,5 were Enterobacter cloacae.No qnrA was detected in nonfer- menters.Quinolone resistance was transferred in 4 of 7 qnrA positive strains.Transconjugants had 12-to 125-fold increases in MIC of ciprofloxacin relative to that of the recipient.Seven strains contained qnrA with a nucleotide sequence identical to that originally reported.Two transconjugants with higher ciprofloxacin MICs contained aac(6')-Ib-cr gene.Mutations occurred in the QRDR of the gyrA and parC genes in 5 PCR-positive clinical strains.Conclusions Transferable plasmid-mediated quinolone resistance associated with qnrA is highly prevalent in clinical strains of Enterobacter spp.aac(6')-Ib-cr gene and mutations in the quinolone targets may co-exist with qnrA,which may contribute to the further increase of resistance to quinolones.

Effect of heartbeat perception on heartbeat evoked potential waves / 神经科学通报·英文版

<p><b>OBJECTIVE</b>Early researches found that different heartbeat perceivers have different heartbeat evoked potential (HEP) waves. Two tasks were considered in our experiments to get more details about the differences between good and poor heartbeat perceivers at attention and resting state.</p><p><b>METHODS</b>Thirty channels of electroencephalogram (EEG) were recorded in 22 subjects, who had been subdivided into good and poor heartbeat perceivers by mental tracking task. Principal component analysis (PCA) was applied to remove cardiac field artifact (CFA) from the HEP.</p><p><b>RESULTS</b>(1) The good heart-beat perceivers showed difference between attention and resting state in the windows from 250 ms to 450 ms after R wave at C3 location and from 100 ms to 300 ms after R wave at C4 location; (2) The difference waveforms between good and poor heartbeat perceivers was a positive waveform at FZ from 220 ms to 340 ms after R wave, which was more significant in attention state.</p><p><b>CONCLUSION</b>Attention state had more effect on the HEPs of good heartbeat perceivers than that of poor heartbeat perceivers; and perception ability influenced HEPs more strongly in the attention state than in the resting state.</p>

Study on the ?-lactamases in eight pan-drug-resistant citrobacter freundi isolates / 中华传染病杂志

Objective Study the production of the?-lactamases in eight pan-resistant citrobact- er freandi and their epidemic characteristics.Methods Modified Hodge test and EDTA-disk syner- gy test were used to screen Metallo-?-lactarnases,and isoelectric focusing to estimate the production of ESBLs and AmpC enzymes.ESBLs,AmpC,MBL genes were amplified and analyzed by PCR and DNA sequencing.Molecular epidemics were investigated by PFGE.Results All the 8 strains pro- duced TEM-1,CTX-M-14,4 of them at the same time producing CTX-M-3.No Plasmid mediated AmpC was found.Furthermore,a new subtype of MBL with one amino acid different from IMP-8 was de- tected.All the 8 strains belong to the same PFGE type.Conclusions Pan-drug-resistant citrobacter freundi produced more than one kind of?-lactamases.All these isolates were clonally related.

Bio-oss combined with fibrin glue in reconstruction of canine mandibular defects / 第二军医大学学报

Objective:To evaluate the osteogenic activities of Bio-oss after combining with fibrin glue in reconstruction of canine mandibular defects.Methods:The second and fourth premolar teeth and the second molar teeth were extracted bilaterally, in 9 hibrid canines,resulting in 6 bone defects(1 cm?1 cm)in each canine.Bio-oss,Bio-oss+FG and FG were implanted into the bone defects of the second,fourth premolar teeth and the second molar teeth,respectively.Canines were executed in group of 3 after 4,8,and 12 weeks to observe the healing of soft tissues.The bone density was assessed by X-ray,the property of Bio-oss were observed via gross specimen,and the morphology of the newly-formed bone was observed by tissue sections.The proportion of newly-formed bone was obtained by computer image analysis(SAS software,analysis of variance).Results:StageⅠhealing of soft tissues was achieved in all animals.The bone densities were not significantly different between Bio-oss+FG and Bio-oss groups.The bone in FG group had transparent area.We also found that the bone in Bio-oss+FG group was closely combined and there were sccatered Bio-oss dusts in the soft tissues of the Bio-oss group.The newly-formed bone in the FG group was only found in the border between the defects and FG.The proportion of newly-formed bone was less in the Bio-oss+ FG group than in the Bio-oss group at 4,8,and 12 weeks after extraction(P