Objective To provide reference for anti-infection drugs in Zunyi area by analyzing the etiological characteristics of children with severe pneumonia.Methods The sputum, throat swabs and serum of children with severe pneumonia in pediatric intensive care unit of our hospital from January 2014 to December 2015 were collected in this study.The pathogen species which caused severe pneumonia were detected and identified by the method of pathogen culture,and typical pathogens were detected by RT-PCR and indirect immunofluorescence.Results A total of 337 children with severe pneumonia were included,the pathogen positive rate was 86.65%(292/337).The rate of viral infection(37.32%)was the highest,followed by bacterial infection accounting for 28.42%,then the mixed infection accounting for 27.74%,and the mycoplasma pneumoniae infection accounting for 6.50%.The respiratory syncytial virus type B accounting for 28.44% was the most common in viral infection,and there were significant differences in age distribution(P<0.05),the children under 3-years-old,especially the infants under 1-year-old had the highest susceptibility.Viral infection had certain seasonality,compared with spring and winter,autumn and winter(November to April) had higher viral detection rate and the difference was statistically significant(x2=29.28,P=0.001).The escherichia coli was the most common in bacterial infection,accounting for 21.69%.Klebsiella pneumoniae,Escherichia coli were more common in neonates and infants under 1-year-old,Haemophilus influenzae occured in 1~3 years old children,Streptococcus pneumoniae infection could occur in any age.Conclusion Viral infection is the most common pathogen in children with severe pneumonia in Zunyi area followed by bacterial infection,which is more common in children under 1-year-old,and with the high incidence in autumn and winter.Bacterial infection is more common in children over 3 years of age.Bacterial and viral mixed infection is common in children under 3 years of age,especially in children under 1-year-old.

Objective:Explore the hydrogen-nuclear magnetic resonance ( 1H-NMR) application potential of metabolomics in early screening of vitamin A deficiency(VAD). Methods:From January to June 2019, 40 cases of left-behind children with confirmed VAD <1 year old were enrolled in Zunyi area as VAD group, and 40 healthy children were selected as healthy control group.Urine from the 2 groups of children was collected and 1H-NMR spectrum was measured.By combining metabonomics technology and multivariate statistical analysis, the 2 groups of metabolites were compared, and the differential metabolites of children with VAD were screened out. Results:Compared with VAD group [(0.56±0.10)μmol/L], the difference in the serum retinol concentration of healthy control group [(1.35±0.18)μmol/L] was statistically significant ( t=23.93, P<0.001). Compared with healthy group, VAD group showed higher level of methylmalonate, 2-ketoisovalerat, N-acetyl glycoprotein signal, dimethylglycine and betaine, with statistically significant differences (| r|>0.602, all P<0.05). The level of Isovalerylglycine, 2-hydroxyisobutyrate, creatine, phosphate choline/glycerophosphocholine, 4-PY and Hippurate were significantly decreased, with statistically significant differences (| r|>0.602, all P<0.05). Conclusions:Compared with healthy children, children with VAD have differences in urine Metabolites.Differential metabolites are closely correlated with intestinal microecological ba-lance, digestive system diseases, respiratory system diseases, immune-related diseases, energy metabolism, growth and development.Urine 1H-NMR metabolomics analysis has potential application value in the early screening of VAD.

Objective To study the effect of caffeine on hyperoxic lung injury of premature rats and its relationship with p38 motigen-activated protein kinase( MAPK) signal pathway. Methods Sixty Wistar premature rats were divided into 4 groups(n＝15) according to the random number table:air + normal sa-line group(A+N group),air + caffeine group( A+C group),hyperoxia + normal saline group( H+N group),and hyperoxia + caffeine group(H+C group). Among them,H+N group and H+C group were continually exposed to hyperoxia ( oxygen concentration was 60% ~70%). For A + C group and H + C group,the premature rats were injected with caffeine of 29 mg/(kg·d) into their peritoneal cavities every day after birth. For A+N group and H+N group,the premature rats were injected with normal saline of the same volume into their peritoneal cavities. In each group,the lung tissues of 5 premature rats were randomly select-ed on the third, seventh and fourteenth day respectively. The pathological changes of lung tissue, radiated alveolar count(RAC) and collagen content in lung tissue were observed under a light microscope. The wet/dry ratio ( W/D) was measured. Two-step immunohistochemistry was used to detect the distribution of p38MAPK in lung tissue. The content of phosphorylated p38MAPK( p-p38MAPK) protein was detected by western blot. Results Compared with the air groups,the lung tissues of premature rats in high oxygen expo-sure groups showed different degree of inflammatory changes on the third,seventh,and fourteenth day. The changes were more obvious with the prolonged exposure to hyperoxia. Pulmonary fibrosis was visible on the fourteenth day,which was improved after caffeine intervention. The RAC value of premature rats in hyperoxia exposure groups was significantly lower than that in air-exposure groups(P<0. 05),and the W/D ratio and collagen content in lung tissue increased significantly (P<0. 05),which were improved after caffeine inter-vention(P<0. 05). The results of two-step immunohistochemistry showed that the number of p-p38MAPK positive cells in the lung tissue of premature rats in hyperoxia exposure groups increased and widely distribu-ted, but decreased after caffeine intervention. The results of western blot showed that the content of p-p38MAPK protein in lung tissue of premature rats in hyperoxia exposure groups was significantly higher than that of air groups(P<0. 05),but it decreased after caffeine intervention(P<0. 05). Conclusion Hy-peroxia can promote the formation of pulmonary fibrosis by activating p38MAPK signal pathway. Caffeine can interdict the expression of p38MAPK to alleviate the fibrosis of lung tissue exposed to hyperoxia and thus protects the lung tissue.

Objective To inquire into the molecular epidemiology of enterovirus 71 ( EV71 ) in our region by analyzing the whole genome characteristics and genetic evolution of EV 71 strains isolated from Guizhou area. Methods The throat swabs samples of hospitalized children with hand,foot and mouth disease in Guizhou province from 2013 to 2015 were collected,the virus nucleic acid were extracted,then the whole genome of virus were piecewise amplified by reverse transcription polymerase chain reaction( RT-PCR) and sequenced. Sequencing results were edited and spliced by DNAMAN8. 0 software,then the viral genome se-quences were compared with genome sequences of other EV71 strains in the genebank by Blastn,the phyloge-netic tree was constructed by the Neighbor-Joining method in MEGA5. 2 software. Results The whole ge-nome sequences of 17 EV71 strains were successfully isolated and amplified,the whole genome length of 17 EV71 isolates was 7405 base pair,encoded about 2193 amino acids. The 17 isolates were divided into ten species of amino acid sequences by 12 differences of amino acid among the strains,different sequences and clinical types had not shown regularity and correlation. The nucleotide homology in VP1 region,5′untranslat-ed region(5′UTR) and 3′untranslated region (3′UTR) were high among 17 EV71 isolates. The results that the whole genome of 17 EV71 isolates was compared with representative strains of EV71 A,B,C genotype and coxsakievirus A 16 ( CA16) showed that 17 EV71 isolates had higher homology with EV71 C4a sub-type,95. 3%-98. 1%,and the lowest homology with CA16. The phylogenetic tree was constructed based on nucleotide sequence of the whole genome,VP1 region and 5′untranslated region of 17 isolates showed that the 17 isolates were clustered into one cluster,and were clustered in the same branch with C4a isoforms,the phy-logenetic relationships among different regions were different. Conclusion The popular genotype of EV71 strains in Guizhou area for 2013-2015 was C4a subtype,consistenting with the genotype of popular EV71 in other regions of China. EV71 strains hasn′t the antigen transformation and input of a new subtype temporari-ly,but exist nucleotide and amino acid changes,so need be chronically and dynamically monitored. There is no correlation between the amino acid sequence difference of 17 EV71 isolates and the state of an illness.

Objective: To explore the characteristic changes in urinary metabolites in left-behind children with vitamin D deficiency under 1 year old in Zunyi area by metabolomic nuclear magnetic resonance (NMR) in order to provide new biomarkers for early diagnosis of vitamin D deficiency. Methods: From January to August 2018, blood tests and urine collection were carried out on the left-behind children under 1 year old in Fenggang county, Bozhou district and Zheng′an county under Zunyi city by stratified sampling.Forty children diagnosed as a vitamin D deficiency were selected as a vitamin D deficiency group, and 40 children with normal urine test were selected as a healthy control group.For urine sampling, SIMCA-P+ software was applied to analyze the integral value of hydrogen spectrogram by principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) was used to distinguish the difference in urine metabolites between two groups of the left-behind children.Orthogonal partial least squares discriminant analysis (OPLS-DA) was used to screen different metabolites. Results: The serum level of 25-hydroxy vitamin D[25-(OH)D][(32.0±3.6) nmol/L ] in the healthy control group was higher than that in the vitamin D deficiency group[(15.8±2.3) nmol/L], and the difference was statistically significant (P<0.05). PCA and PLS-DA analysis showed significant differences in urine metabolites between the healthy control group and the vitamin D deficiency group (P<0.05). OPLS-DA indicated R²X=0.365, Q²=0.978, which further verified the difference of metabolites.Compared with the healthy control group, the urine of methyl malonic acid, 3-hydroxy butyrate, N-acetyl glycoprotein signal, glutamic acid, dimethyl glycine, 2-ketone glutaric acid, taurine, fumaric acid salt level increased significantly in the vitamin D deficiency group, and the differences were statistically significant (|r|>0.602, all P<0.05, df=39). However, the levels of ethyl malonic acid, creatine, choline, glycerophosphalocholine and equine were significantly decreased, and the differences were statistically significant (|r|>0.602, all P<0.05, df=39). Conclusions The left-behind children under 1 year old with vitamin D deficiency in Zunyi region are mainly characterized by disorder in energy metabolism, lipid metabolism, amino acid metabolism and intestinal microbial meta-bolism disorders, and their differential metabolites have potential application value in early diagnosis and pathogenesis of vitamin D deficiency.