Objective:To investigate the histone acetylation of interleukin-4(IL-4) gene and its roles in immunological pathogenesis of Kawasaki disease (KD).Methods:Thirty-six children with KD and 28 age-matched healthy children in Shenzhen Children′s Hospital from October 2016 to December 2018 were recruited in this study.Peripheral venous blood samples were collected from healthy controls (28 cases) and patients with KD during acute phase and 4 to 5 days after effective intravenous immunoglobulin (IVIG) treatment.Co-immunoprecipitation followed by real-time PCR was used to assess histone H4 acetylation levels of IL-4 promoter and Va enhancer, and binding abilities of p300 and CREB-binding protein (CBP) with promoter and Va enhancer of IL-4 gene in peripheral blood CD4 + T cells.Flow cytometry was performed to analyze the proportion of CD4 + IL-4 + T cells (Th2) and protein le-vels of phosphorylated signal transducer and activator of transcription 6 (pSTAT6), GATA binding protein 3 (GATA3), nuclear factor 1 of activated T cells(NFAT1), transforming growth factor-β receptor Ⅱ (TGF-βRⅡ), and phosphorylated L-type amino acid transporter 1(pLAT1). Quantitative real-time PCR was used to evaluate the transcription levels of IL-4, IL-5, IL-13, IL-4 receptor α (IL-4Rα), transforming growth factor-β receptor Ⅰ (TGF-βRⅠ) and sex-determining region Y(SRY)-box 4 (SOX4) in CD4 + T cells.Plasma concentrations of IL-4 and transforming growth factor-β(TGF-β) were measured by enzyme-linked immunosorbent assay. Results:(1)Compared with control group, the proportion of Th2 cells, expression levels of Th2-associated cytokines (IL-4, IL-5 and IL-13) and histone H4 acetylation levels associating with IL-4 promoter and Va enhancer, increased remarkably during acute KD(all P<0.05), and restored after IVIG therapy(all P<0.05). Meanwhile, all the former items in KD patients with coronary artery lesions (CAL) were higher than those in patients with non-coronary artery lesions (NCAL) (all P<0.05). (2) Compared with control group, binding abilities of p300 and CBP with IL-4 promoter and Va enhancer in CD4 + T cells were up-regulated significantly during acute KD (all P<0.05), and decreased in varying degrees after IVIG treatment (all P<0.05). Positive correlations between binding abilities of p300 with IL-4 (promoter and Va enhancer) and the expression of IL-4 promoter and Va enhancer were detected in patients with acute KD ( r=0.72, 0.43, all P<0.05). Furthermore, binding abilities of p300 and CBP with IL-4 promoter and Va enhancer in CAL group were higher than those in NCAL group (all P<0.05). (3) Compared with control group, patients with acute KD had remarkably increased plasma concentration of IL-4, and expression levels of IL-4Rα/STAT6/GATA-3 and pLAT1/NFAT1 in CD4 + T cells (all P<0.05), and significantly down-regulated plasma concentration of TGF-β and expression level of TGF-βRⅡ/TGF-βRⅠ/SOX4 (all P<0.05). All the items mentioned above restored in varying degrees after IVIG treatment (all P<0.05). Simultaneously, the 6 items aforementioned in CAL group were found to be higher than those in NCAL group (all P<0.05), while the latter four items were lower than those in NCAL group (all P<0.05). Conclusion:Histone hyperacetylation of IL-4 gene may be related to immune dysfunction in patients with KD.

Objective To explore the situation and risk factors of peripherally inserted central catheter (PICC)-related infections among neonate so as to provide a nursing reference for preventing catheter-related infections. Methods From September 2015 to June 2017, a prospective study was carried out to 811 neonates with PICC from 7 hospitals in Shenzhen City to observe the incidence of catheter-related infections. Simple correlation and multiple factors unconditional Logistic regression was used to analyze the correlative factors of catheter-related infections. Results Among 811 neonates, there were 770 (94.9%) without and 41 (5.1%, 1.95/1 000 catheter days) with catheter-related infections along with 20 cases with exit-site infection and 21 cases with catheter related bloodstream infections (CRBSI). Top three pathogens of CRBSI included Staphylococcus epidermidis, fungus and klebsiella pneumonia. Simple correlation showed that there were statistical differences in gestational age, birth weight of the neonate, disinfection methods of infusion connector, sterile protective barrier during maintenance of catheter between infection group and non-infection group (χ2=4.026,4.964, 4.369,7.463;P＜ 0.05). Multiple factors unconditional Logistic regression revealed that the risk factor contained birth weight＜ 1 200 g (OR=2.099, 95%CI: 1.103-3.996, P＜ 0.05), and the protective factors consisted of sterile protective barrier during maintenance of catheter (OR=0.393, 95%CI: 0.206-0.749,P＜0.01). Conclusions Birth weight ＜1 200 g, sterile protection during maintenance of catheter are the influencing factors of neonatal PICC catheter-related infections. Sterile protective barrier during maintenance of PICC for neonate should include wearing sterile mask, round hat, using aseptic packets and wearing sterile gloving to maintain the catheter. Aseptic technique should be paid more attention to during indwelling catheter and maintaining catheter for premature with birth weight ＜1 200 g.

Objective To establish a non-invasive single nucleotide polymorphism genotyping technology based on direct TaqMan-PCR for high-throughput genotyping of site rs688 and rs964184 associated with lipid metabolism to meet the need for early screening of at-risk populations.Methods Extracted DNA was used to optimize the PCR annealing extension temperature and amplification procedure for the designed TaqMan probe;the oral swabs were placed into the sample treatment solution and then briefly centrifuged,and a small amount of the supernatant was taken for the direct qPCR amplification analysis;the freeze-thawing stability of probe and the effects of sample stor-age time on genotyping results were explored.Results The technology requires only simple treatment of oral swab for PCR analysis and can be stored at room temperature for 4 d.The optimized method was able to distinguish homo-zygous wild type,homozygous mutant type and heterozygote at rs688 and rs964184 loci.Conclusions A fast,con-venient,high-throughput,and low-cost SNP genotyping method has been established,providing an efficient and accurate new approach for large-scale screening of high-risk populations carrying susceptibility genes.