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Objective:To study the distribution and antibiotics resistance of the main pathogens of neonatal purulent meningitis in different regions of China.Methods:A retrospective descriptive clinical epidemiological study was conducted in children with neonatal purulent meningitis which admitted to 18 tertiary hospitals in different regions of China between January 2015 to December 2019. The test results of blood and cerebrospinal fluid, and drug sensitivity test results of the main pathogens were collected. The distributions of pathogenic bacteria in children with neonatal purulent meningitis in preterm and term infants, early and late onset infants, in Zhejiang Province and other regions outside Zhejiang Province, and in Wenzhou region and other regions of Zhejiang Province were analyzed. The chi-square test was used for statistical analysis.Results:A total of 210 neonatal purulent meningitis cases were collected. The common pathogens were Escherichia coli ( E. coli)(41.4%(87/210)) and Streptococcus agalactiae ( S. agalactiae)(27.1%(57/210)). The proportion of Gram-negative bacteria in preterm infants (77.6%(45/58)) with neonatal purulent meningitis was higher than that in term infants (47.4%(72/152)), and the difference was statistically significant ( χ2=15.54, P=0.001). There were no significant differences in the constituent ratios of E. coli (36.5%(31/85) vs 44.8%(56/125)) and S. agalactiae (24.7%(21/85) vs 28.8%(36/125)) between early onset and late onset cases (both P>0.05). The most common pathogen was E. coli in different regions, with 46.7%(64/137) in Zhejiang Province and 31.5%(23/73) in other regions outside Zhejiang Province. In Zhejiang Province, S. agalactiae was detected in 49 out of 137 cases (35.8%), which was significantly higher than other regions outside Zhejiang Province (11.0%(8/73)). The proportions of Klebsiella pneumoniae, and coagulase-negative Staphylococcus in other regions outside Zhejiang Province (17.8%(13/73) and 16.4%(12/73)) were both higher than those in Zhejiang Province (2.9%(4/137) and 5.1%(7/137)). The differences were all statistically significant ( χ2=14.82, 12.26 and 7.43, respectively, all P<0.05). The proportion of Gram-positive bacteria in Wenzhou City (60.8%(31/51)) was higher than that in other regions in Zhejiang Province (38.4%(33/86)), and the difference was statistically significant ( χ2=6.46, P=0.011). E. coli was sensitive to meropenem (0/45), and 74.4%(32/43) of them were resistant to ampicillin. E. coli had different degrees of resistance to other common cephalosporins, among which, cefotaxime had the highest resistance rate of 41.8%(23/55), followed by ceftriaxone (32.4%(23/71)). S. agalactiae was sensitive to penicillin, vancomycin and linezolid. Conclusions:The composition ratios of pathogenic bacteria of neonatal purulent meningitis are different in different regions of China. The most common pathogen is E. coli, which is sensitive to meropenem, while it has different degrees of resistance to other common cephalosporins, especially to cefotaxime.
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Detection of moving objects is an essential skill for animals to hunt prey, recognize conspecifics and avoid predators. The zebrafish, as a vertebrate model, primarily uses its elaborate visual system to distinguish moving objects against background scenes. The optic tectum (OT) receives and integrates inputs from various types of retinal ganglion cells (RGCs), including direction-selective (DS) RGCs and size-selective RGCs, and is required for both prey capture and predator avoidance. However, it remains largely unknown how motion information is processed within the OT. Here we performed in vivo whole-cell recording and calcium imaging to investigate the role of superficial interneurons (SINs), a specific type of optic tectal neurons, in motion detection of larval zebrafish. SINs mainly receive excitatory synaptic inputs, exhibit transient ON- or OFF-type of responses evoked by light flashes, and possess a large receptive field (RF). One fifth of SINs are DS and classified into two subsets with separate preferred directions. Furthermore, SINs show size-dependent responses to moving dots. They are efficiently activated by moving objects but not static ones, capable of showing sustained responses to moving objects and having less visual adaptation than periventricular neurons (PVNs), the principal tectal cells. Behaviorally, ablation of SINs impairs prey capture, which requires local motion detection, but not global looming-evoked escape. Finally, starvation enhances the gain of SINs' motion responses while maintaining their size tuning and DS. These results indicate that SINs serve as a motion detector for sensing and localizing sized moving objects in the visual field.
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Objective To investigate the effects of olfactory bulb(OB) lesion on neural stem cells proliferation and expression of NMDA receptor subunit 2B in subventricular zone(SVZ) of rats.Methods Sixty adult female SD rats were randomly divided into normal group,saline group and OB lesion group.OB lesion was induced by N-methyl-D-aspartic acid (NMDA) injection.Each group was respectively divided into four time points including 3 d,7 d,14 d and 28 d.Immunohistochemistry staining was used to detect the number of Nestin,Ki67 and NR2B-positive cells in the SVZ.Results (1) Nestin positive cells in the SVZ were shown at the different time of three groups.Seven days after OB lesion,IOD value of nestin-positive cells began to increase((29601± 1788)/0.01 mm2,P＜0.05),reached the maximum at 14 d((49800±3701)/0.01 mm2,P＜0.05) and still sustained a high level at 28 day((27600±3209)/0.01 mm2,P＜0.05).(2)Ki67 positive cells in the SVZ were shown at the different time of three groups.The number of Ki67-positive cells was increased significantly at 7 d,14 d and 28 d after OB lesion compared to normal group and saline group (P＜0.05).(3)NR2B immune expression in the SVZ was shown at the different time of three groups.The NR2B-positive cells increased at 3 d after OB lesion(58.80±2.95,P＜0.05),reached the maximum at 14 d(68.40±4.04,P＜0.05).At 28 d of OB lesion,the number of positive cells was reduced,but still sustained a high level(62.20±3.56,P＜0.05).(4)The positive cells of NR2B and Ki67 were highly positive correlation at different time after OB lesion(r=0.968,P＜0.05).Conclusions OB lesion can stimulate neural stem cell proliferation and increases the expression of NR2B.The increased mode of NR2B is in accordance with the schedule of the neural stem cells increase induced by OB lesion.Therefore,it indicates that the NMDA receptor subunit 2B may be involved in neural stem cell proliferation.
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Objective To prepare polyclonal antibody of transactivated protein 5 of hepatitis C virus nonstructural 5A (NA5ATP5) and to explore its expression in the liver tissues. Methods In Escherichia coil BL21, the prokaryotic expression vector pET32a(+)-NS5ATP5 was induced by isopropyl-β-D-thiogalactoside (IPTG), and it was analyzed with sodium dodecyl sulfate-polyaerylamide gel electrophoresis (SDS-PAGE) and Western blotting. And the purified protein was used to immunize the rabbit to prepare polyelonai antibody, with which we studied the function of NSSATP5 by determining the different liver tissues with the streptavidin-perosidase (SP) immunohistochemistry method. Results Recombinant NS5ATP5 (molecular weight: 65 kD) and polyclonal antibody were successfully prepared. NS5ATP5 expression in the liver of patients with chronic HCV infection was much higher than that of a normal person, and it was detected mainly in the cytoplasm. Conclusion The findings of the expression difference between HCV patients and normal people led to a novel diagnostic marker to detect HCV infection.
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group pACT-apoA Ⅰ and pBIND-core was higher than that in the negative control.Conclusion HCV core protein and apoA Ⅰ can interact in vivo.This study provides new theory for the mechanism of chronicity hepatitis C in fatty liver.
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Objective To investigate the effect of xenon intervention on delayed neuropsychologic sequelae (DNS)in acute carbon monoxide(CO)poisoning.Method Adult Wistar rats were randomly divided into sustained group,early intervention group,and control group.CO(150 ml/kg)was infused by intraperitoneal injection to produce DNS model.In sustained intervention group(S-group),xenon(150 ml/kg/d)was infilsed by intraperitoneal injection for 2 weeks;in control group(C-group),xenon was replaced by equal volume air;and in early intervention group(E-tvoup),xenon(150 ml/kg/d)was,employed in the first 3 days and air(150 ml/kg/d)was substituted for xenon in the following days until 2 weeks after CO poisoning.Morris maze test was used to evaluate the intelligence of rats.The long-term potentiation(LTP)of hippocampus Was detected by neuroelectricity recording.The apoptosis rates in brain was detected by TUNEL staining.The data were expressed as(x±s)and analyzed with student's test and analysis of variance.A P value less than 0.05 indicated statisfical significance.Results After exposure to CO,poisoned rats showed intelligence decline,demyeliation ofwater matler and cell apoptosis increased,which were consistent with DNS.In S-group and E-group,the rates of DNS and apoptosis were significantly lower than those in C-group,whereas the rote of LTP in S-group and E-group Was significantly higher than those in C-group.Conclusions Early xenon intervention can effectively decrease the rates of DNS occurred after acute CO poisoning.
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OBJECTIVE To study the distribution and drug resistance of coagulase negative Staphylococcus(CNS)that leads to nosocomial infection.METHODS Nosocomial CNS was identified and then drug resistance test was performed by K-B method.Nitrocefin method and the Congo red method were utilized to detect ?-lactamase and the slime,respectively.RESULTS Of all 162 CNS strains isolated,there were 102 strains of MRCNS and 60 strains of MSCNS including 83 S.epidermidis strains,accounting for 51.2%.Among all the MRCNS and MSCNS strains above,the positive rates of the ?-lactamase were 100.0% and 5.0%,respectively,and the positive rates of the slime were 17.6% and 1.7%,respectively.The resistance rates of MRCNS to 12 types of antibiotics were higher than those of MSCNS(P
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Objective To study the interaction between HCV core protein and HCBP6 in mammlian cells using CheckMateTM Mammalian Two-Hybrid System.Methods cDNA fragments encoding HCV core protein and HCBP6 were amplified by PCR and subsequently cloned into pGEM-T vector.After verified by sequencing,the target fragments were subcloned into mammalian two-hybrid plasmids,pBIND and PACT,respectively.The recombinant plasmids,pBIND-core and pACT-HCBP6 were co-transfected into HepG2 cells with reporter plasmid pG5luc.pBIND+pACT were induced as background controls,pBIND-Myod+pACT-Id as positive controls,and pBIND-core+pACT,pBIND+pACT-HCBP6 as blank controls.The expression of G5luc,which indicated the interaction between HCV core protein and HCBP6 in mammlian HepG2 cells,was assayed through Dual-Luciferase Report Assay System and Turner Biosystems Veritas Microplate Lunimometer.Results The recombinant vectors pBIND-core and pACT-HCBP6 were successfully constructed.When co-transfected into HepG2 cells with reporter plasmid pG5luc,there were significant differences in the luciferase activity in the pBIND-core and pACT-HCBP6 groups compared with every control group.Conclusions HCBP6 can interact with HCV core protein in HepG2 cells,which provides clues for further study on the function of HCBP6 and core proteins,and on the mechanism of HCV core in cell apoptosis and cancer transformation.