Abstract Background Community-acquired pneumonia (CAP) is a leading infectious cause of hospitalisation and death worldwide. The knowledge about the incidence and aetiology of CAP in China was fragmented. Methods A multicenter study performed at four hospitals in four regions in China and clinical samples from CAP patients were collected and used for pathogen identification from July 2016 to June 2019. Results A total of 1,674 patients were enrolled and the average annual incidence of hospitalized CAP was 18.7 cases per 10,000 people (95% confidence interval 18.5–19.0). The most common viral and bacterial agents found in patients were respiratory syncytial virus (19.2%) and Streptococcus pneumoniae (9.3%). The co-infections percentage was 13.8%. Pathogen distribution displayed variations within age groups, and seasonal and regional differences. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was not detected. Respiratory virus detection was significantly positively correlated with air pollutants, including PM2.5, PM10, NO2 and SO2; and significantly negatively correlated with ambient temperature and O3 content; bacteria detection was opposite. Conclusion The hospitalized CAP incidence in China was higher than previously known. CAP etiology showed differences in age, seasons, regions, and respiratory viruses were detected at a higher rate than bacterial infection overall. Air pollutants and temperature have influence on the detection of pathogens.
Background Neuregulin1 (NRG1) is a member of family of epidermal growth factors,which play an important effect in the development and immigration of neuron and glial cells,but not clear in the mature nerve system and chronic pain.Objective This article reviewed the newest research about NRG1 in the chronic pain and looked forward to the value of NRG1 in the chronic pain in the future.Content The text states the function and role of NRG1 and its receptors in the chronic pain and neuropathic pain.Trend NRG1 has a great role in the generation and development of the chronic pain through complex mechanisms and will offer a new target point for the treatment of chronic pain.
Key words:
Neuregulin1 ; Chronic pain; Neuropathic pain; Demyelination; Microgliosis; Synaptic plasticity
High accurate NURBS interpolation algorithm based on Runge-Kutta method was proposed to solve the problem of low precision and efficiency during NURBS machining. The algorithm plans desired feed rate according to the constraint of the tolerant maximum chord error, and calculates the interpolation parameters through the classical fourth-order Runge-Kutta method during real-time interpolation process, which only needs the first derivative of NURBS curve. Then we can quickly get the high accurate interpolation parameters, which greatly reduces the error between the actual feed rate and desired feed rate. Namely, the feed rate fluctuation rate has been effectively controlled. The feasibility of the algorithm was verified by MATLAB simulation.
Abstract Background Salmonella typhimurium is an important intracellular pathogen that poses a health threat to humans. The key to studying the pathogenesis of Salmonella is to clarify the mechanisms responsible for its survival and reproduction in macrophages. In this study, RNA was extracted from S. typhimurium reference strain (ATCC 14028) and S. typhimurium isolated from the spleen of infected mice for RNA high-throughput sequencing analysis, based on the BGISEQ-500 platform. Results A total of 1,340 significant differentially expressed genes ( DEGs ) were screened through quantitative gene analysis and various analyses based on gene expression. Of these, 16 genes were randomly selected for fluorescence quantitative PCR verification. Two pairs of primers, 16S and pyridoxol 5ʹ-phosphate synthase ( pdxJ ), were used as internal references. The coincidence rate was determined to be 93.75%, which was consistent with the RNA-seq data, proving the reliability of the RNA-seq data. Functional annotation revealed DEGs associated with regulation, metabolism, transport and binding, pathogenesis, and motility. Through data mining and literature retrieval, 26 of the 58 upregulated DEGs (FPKM >10) were not reported to be related to the adaptation to intracellular survival, and were classified as candidate key genes ( CKGs ) for survival and proliferation in vivo . Among the CKGs, five were biotin synthetic bio family proteins. BioF is one of the first enzymes in the protein synthesis pathway. To evaluate the potential role of bioF in survival and proliferation, bioF mutants of Salmonella were constructed, and the virulence/attenuation was evaluated in vivo . Through the infection of BALB/c mice, bioF deficiency was found to significantly reduce the bacterial load and the fatality rate of mice. Conclusions Our results indicated that the bioF gene plays an important role in the survival and proliferation of S. typhimurium in vivo . These data contribute to our understanding of the mechanisms used by Salmonella to regulate virulence gene expression whilst replicating inside mammalian cells.
Objective To establish a gold immuneochromatography assay(GICA) using expressed and purified recombinant F1 antigen(rF1) of Yersinia pestis and to evaluate its field application effect.Methods rF1 was purified by Ni-NTA affinity chromatography column and desalting column and the GICA was established using purified rF1.Plague F1 antibody of one immune rabbit serum and 1 685 field serum samples(including 94 human,939 dog,34 cat,609 rat and 9 Marmot serums) were detected using GICA,double antigen sandwich enzymelinked immunosorbent assay (ELISA) and indirect hemagglutination assay (IHA).Results rF1 was expressed efficiently and purified effectively.The F1 antibody of one immune rabbit serum was positive for the three assays and the rank of antibody titer was ELISA ＞ GICA ＞ IHA(1 ∶ 10 × 211 vs 1 ∶ 10 × 29 vs 1 ∶ 10 × 2s).Among 1 685 field serum samples detected,89 serums(5.28％) werepositive for GICA,53(3.15％) were positive for IHA and 101 (5.99％) were positive for ELISA.General coincidence rates for GICA,IHA and ELISA were 97.3％ and 97.9％,respectively.Chi-square test for paired data showed that the positive rate of GICA was higher than that of IHA(x2 =26.63,P ＜ 0.05),but the difference between GICA and ELISA was not statistically significant(x2=3.36,P＞ 0.05).Conclusions rF1 protein is successful expressed and purified.The specificity and sensitivity of the GICA established using rF1 are higher than those of IHA and ELISA.When GICA is combined with IHA and ELISA,the time and quality of plague diagnosis may be improved effectively.
Key words:
Plague; Recombinant F1 antigen; Gold immuneochromatography assay; Field evaluation
Abstract Background Rapid phage enumeration/quantitation and viable bacteria determination is critical for phage application and treatment of infectious patients caused by the pathogenic bacteria. Methods In the current study, a direct phage DNA detection-based Taqman qPCR methodology for quantification of phage P53 and rapid ultrasensitive identification of Acinetobacter baumannii ( A. baumannii ) was evaluated. Results The assay was capable of quantifying P53 phage DNA without DNA extraction and the detection limit of the assay was 550 PFU/mL. The agreement bias between the quantitative results of three different phage concentrations in this assay and double agar overlay plaque assay were under 3.38%. Through the built detection system, down to 1 log CFU/mL of viable A. baumannii can be detected within 4 h in A. baumannii spiked swab and bronchoalveolar lavage fluid samples. Compared with the Taqman qPCR that targets the conserved sequence of A. baumannii , the sensitivity of the assay built in this study could increase four orders of magnitude. Conclusions The methodology offers a valid alternative for enumeration of freshly prepared phage solution and diagnosis of bacterial infection caused by A. baumannii or other bacterial infection in complicated samples through switching to phages against other bacteria. Furthermore, the assay could offer drug adjustment strategy timely owing to the detection of bacteria vitality.
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