Objective To observe the effects of octreotide on fecal characteristics and humoral immunity in neonates with necrotizing enterocolitis(NEC).Methods A retrospective study was conducted on 60 newly born NEC patients at Hebei PetroChina Central Hospital from March 2022 to September 2023.The patients were separated into the observation group(30 cases)and the routine group(30 cases)based on treatment methods.The conventional group was treated with total parenteral nutrition and gastrointestinal decompression plus piperacillin sodium and tazobactam sodium for 7 days.The observation group was treated with octreotide in addition to the routine group for 5 days.The treatment efficacy,general clinical data,degree of intestinal microbiota disorder,expression levels of intestinal microbiota markers and immune indicators were compared between the two groups.Results The total effective rate of the observation group was higher than that of the routine group(P＜0.05).After treatment,body weight of the observation group was higher than that of the routine group.The hospitalization time,vomiting relief time,abdominal distension relief time,diarrhea relief time and complete recovery time of fecal characteristics were lower in the observation group than those in the routine group.Compared with before treatment,the degree of intestinal microbiota disorder and high mobility group box protein 1(HMGB1)were reduced in both groups after treatment,and expression levels of human β defensin 2(HBD2),autoinducer-2(AI-2)and serum immunoglobulin(Ig)A,IgG and IgM were increased(P＜0.05).After treatment,HMGB1 was lower in the observation group than that in the routine group,while HBD2,AI-2 and serum IgA,IgG and IgM were higher than those in the routine group(P＜0.05).Conclusion Octreotide can effectively treat children with NEC,improve stool characteristics,and enhance immunity.

Objective:This study comprehensively analyzed the genomic characterizations of human parainfluenza virus type 3 (HPIV3) strains circulating in six provinces and cities of China (Beijing, Henan, Jilin, Anhui, Gansu, and Shandong) during the period of 2019-2020. The aim was to elucidate the intricate genetic variations and molecular evolutionary trends within the HPIV3 genome.Methods:Based on genotypic differentiation, genetic divergence, and spatial and temporal distribution, 12 representative HPIV3 strains (including 7 of C3a subtype, 2 of C3b subtype and 3 of C3f subtype) were selected from the aforementioned provinces, and the complete genome sequence was successfully obtained by overlapping amplification of fragments using nested RT-PCR. Subsequently, a complete genome database of global representative HPIV3 strains was constructed and analyzed using bioinformatics tools.Results:The length of complete genome of the 12 HPIV3 strains in the present study varied between 15 227 bp and 15 370 bp, the G+ C content ranged from 35.1% to 35.3% and the nucleotide identity intermediated from 97.6% to 99.6%. Compared with the prototype strain (GenBank accession number: NC_001796.2), the nucleotide identity of 12 HPIV3 strains ranged from 94.2% to 94.5%. Analysis of the complete genome of HPIV3 available in China and globally showed that the genomic variation of HPIV3 was mainly shaped by substitution mutations, and no base deletions or gene recombination were observed.Only a six-base insertion (ATTAAA) was found in the F gene’s 3′UTR region of a representative strain originating from Jilin province (CHN/Jilin036/2019/C3b) in this study, and its potential pathogenic significance needs to be further investigated. Amino acid analysis of the encoded proteins revealed that the C3a lineage of HPIV3, widely prevalent both in China and worldwide, exhibits lineage-specific mutation sites in the N, P and L proteins. Furthermore, within the Chinese prevalent C3a strains, a distinctive mutation site (N216S) in L protein was also identified. Notably, specific variant sites have not been found in Chinese C3b and C3f branch strains. Based on the complete genome, the comprehensive evolutionary analysis showed that the time to the most recent common ancestor (tMRCA) of global HPIV3 strains was estimated to 1927 (95% HPD: 1901-1945), with an average molecular evolutionary rate of 5.29 × 10 -4 substitutions/site/year, while the average molecular evolutionary rate of HPIV3 strains in China is 5.24 × 10 -4 substitutions/site/year. In addition, each gene of HPIV3 was subjected to negative selection pressure, with the P, HN and F genes showing the most significant nucleotide variation and higher rates of molecular evolution than the other genes. Conclusions:This study reveals that the complete genome of HPIV3 strains circulating in six provinces and cities of China tend to evolve conservatively. Moreover, substitution emerge as the main driving force for molecular evolution of HPIV3.