Objective To explore a rapid diagnostic method in neonatal sepsis and bacterial me- ningitis. Methods The primers and TaqMan probes were designed and synthesized based on the sequences of bacterial 16S rRNA gene. Nineteen bacterial strains, 3 different viruses, fungus and human genomic DNA were tested by FQ-PCR assay. Blood specimens and CSF from 195 cases of suspected septicemia were detected with both TaqMan PCR assay and blood or/and CSF culture. Results The FQ-PCR showed very high sensitivity and specificity and was able to detect at least 10 copies of 16S rRNA gene equivalent to 1~2 copies bacterium. No cross-reaction was found with human genomic DNA, other fungus and viruses. Among the 195 cases, the positive rate by FQ-PCR was 12.8%(25 cases) and 7.1%(15 cases) by blood culture ( P

Objective To investigate the distribution and sequence conservation of Hap adhensin encoding gene (hap) in clinical isolates of nontypeable Haemophilus influenzae (NTHi), to screen out and identify the predominant T-and B-cell (T-B) combined antigenic epitopes on Hap protein and to analyze their immunogenicity.Methods Sequence conservation of hap genes in NTHi strains and T-B combined antigenic epitopes were predicted using bioinformatic softwares.PCR was used to amplify the 156 bp segment at 5′-end and the 855 bp segment at 3′-end of hap gene (hap-5′-156 and hap-3′-855) and the amplified products were sequenced.Phage display systems of seven T-B combined antigenic epitopes located on the 55 aa segment at N-terminal and the 285 aa segment at C-terminal of Hap protein (Hap-N52 and Hap-C285) were constructed.Western blot assay and ELISA were performed to detect the antigenicity and immunoreactivity of different T-B combined epitopes displayed by recombinant phage PⅢ protein (rPⅢ).Results Hap protein encoded by the hap gene in NTHi was located on membrane surface.Sequences of the 156 bp segment at 5′-end and the 855 bp segment at 3′-end of hap genes extracted from different NTHi strains were relatively conservative, but many mutations were found in sequences at the middle regions of these hap genes.All of the 56 NTHi strains carried hap-5′-156 and hap-3′-855 segments and shared 92.3％-100％ identities in nucleotide and amino acid sequences of these segements.Hap-N5-24 in the Hap-N52 segment as well as Hap-C4-27, Hap-C28-47, Hap-C114-129, Hap-C150-173, Hap-C200-227 and Hap-C241-267 in the Hap-C285 segment was predicted as the T-B combined antigenic epitope with a higher score and less mutations.Results of Western blot assay and ELISA confirmed that the rPⅢ-displayed Hap-C4-27 and Hap-C150-173 epitopes presented clear hybridization bands with NTHi antisera, and 96.9％ (63/65) and 92.3％ (60/65) of serum samples from children with NTHi infection were positive for antibodies against Hap-C4-27 and Hap-C150-173 epitopes, respectively.Conclusion The gene of hap is widely distributed in clinical isolates of NTHi.Moreover, sequences of the 156 pb segment at 5′-end and the 855 bp segment at 3′-end of hap gene are conservative.Hap-C4-27 and Hap-C150-173 are the predominant T-B combined antigenic epitopes on Hap protein, suggesting that they can be used as epitope candidates for developing multiple antigenic peptide vaccines against NTHi.

Objective To investigate whether the nod-like receptor (NLR) pathway is involved in protection of hydrogen sulfide (H2S) preconditioning during renal ischemia reperfusion.Methods Male Wistar rats were randomly divided into 3 groups:sham operation (Sham) group,renal ischemia/ reperfusion (I/R) group subjected to occlusion of left renal pedicle for 45 min then reperfusion for 24 hours,and sodium hydrosulfide (NaHS) preconditioning group with continuous infusion of NaHS (300 nmol/min) by left renal artery for 15 min before I/R treatment.Renal injuries were evaluated by HE staining.The protein levels of NOD1,NOD2,nuclear NF-κB P65 and caspase-1 were analyzed by Western blot assay.The protein level of MCP-1 and IL-1β expressions was determined by immunohistochemical staining assay.Cell apoptosis were evaluated by Tunel staining assay.Results In I/R group,the renal NOD1 and NOD2 protein expressions were upregulated.Moreover,the nuclear NF-κB P65 expression was also elevated with an increase in its target genes-MCP-1 and IL-1β (All P ＜ 0.01).HE staining revealed the existence of acute tubular necrosis in I/R kidney.TUNEL staining revealed more apoptotic cells in risk zone with the activation of caspase-1 of I/R-treated kidney(P ＜0.01).NaHS preconditioning reversed I/R-induced increase in the expression of NOD1 and NOD2(P ＜0.05).NaHS preconditioning also reduced I/R-induced activation of NF-κB P65 (P ＜ 0.05) and upregulation of MCP-1 and IL-1β (P ＜ 0.01).Moreover,NaHS preconditioning attenuated inflammation,repressed caspase-1 activation and reduced apoptotic cells after I/R.Conclusion Hydrogen sulfide preconditioning can alleviate renal ischemia/reperfusion injury by Nod-like receptor dependent on inflammatory pathway.

Objective:Evidence on potential cardiovascular benefits of personal-level intervention among the elderly exposed to high levels of particulate matter(PM)remains limited.We aimed to assess improvements in surrogate markers of cardiovascular injury in vulnerable populations at risks by using indoor air filtration units.Methods:We conducted a randomized crossover trial for 2 separate 2-week air filtration interventions in 20 households of patients with stable chronic obstructive pulmonary disease and their partners in the winter of 2013,with concurrent measurements of indoor PM.The changes in biomarkers indicative of cardiac injury,atherosclerosis progression and systemic inflammation following intervention were evaluated using linear mixed-effect models.Results:In the analysis,average levels of indoor PM with aerodynamic diameters＜2.5 μm(PM2.5)decreased significantly by 59.2％(from 59.6 to 24.3 μg/m3,P＜0.001)during the active air filtration.The reduction was accompanied by improvements in levels of high-sensitivity cardiac troponin I by-84.6％(95％confidence interval[CI]:-90.7 to-78.6),growth differentiation factor-15 by-48.1％(95％CI:-31.2 to-25.6),osteoprotegerin by-65.4％(95％CI:-56.5 to-18.7),interleukin-4 by-46.6％(95％CI:-62.3 to-31.0)and myeloperoxidase by-60.3％(95％CI:-83.7 to-3.0),respectively.Conclusion:Indoor air filtration intervention may provide potential cardiovascular benefits in vulnerable popu-lations at risks.

Objective:The exact biological mechanism whereby exposure to ambient ozone(O3)may contribute to clinical onset of cardiovascular events remains unclear.In this study,we aim to examine the impacts of O3 exposure on cardiac arrhythmias and potential pathways involved through autonomic dysfunction and myocardial injury.Methods:Seventy-three non-smoking healthy adults were followed with 4 repeated measurements of 24-hour ambulatory arrhythmias,heart rate variability,ST-segment deviation,and blood pressure(BP)in Beijing,China,2014-2016.Generalized additive mixed models coupled with distributed lag nonlinear models were constructed to evaluate the associations and potential interlinks between O3 exposure and outcome measurements.Results:During the study period,24-hour average concentrations of ambient O3 were 47.4 μg/m3(ranging from 1.0 to 165.9 μg/m3).Increased risks of premature ventricular contraction and ventricular tachycardia were associated with interquartile range increases in O3 exposure during the last 5 days before each participant's clinic visit,with relative risks of 2.14(95％confidence interval[CI]:1.95 to 2.32)and 5.47(95％CI:3.51 to 7.43),respectively.Mediation analyses further showed that sympathetic activation,parasympathetic inhibition,and elevated BP levels,as well as heightened risks of ST-segment depression could mediate up to 47.74％of the risks of arrhythmias attributable to O3 exposure.Conclusion:Our results suggest that short-term exposure to ambient O3 could prompt the genesis of arrhythmias partially through worsening autonomic function and myocardial burden.