ABSTRACT
Objective To establish the theoretical basis of the probiotic application among very low birth weight(VLBW) infants,the efficacy of probiotics on the gut microbiota of VLBW infants on the 14th postnatal day was studied.Method The VLBW infants admitted to BaoAn Maternal and Child Care Hospital from January 2015 to December 2015 were randomly assigned into probiotics group and placebo group.From the first feeding to corrected gestational age of 36 weeks,probiotics group was treated with a combination of Bifidobacterium and Lactobacillus while placebo group with placebo.Fecal samples were collected on the 1st and 14th postnatal day.Total bacterial DNA was extracted and sequenced using high-throughput 16S rRNA gene sequencing on MiSeq sequencing platform.Result A total of 21 VLBW infants were enrolled,9 in probiotics group and other 12 placebo group.No significant differences of clinical data existed between the two group (P ＞ 0.05),The abundance and diversity of microflora (P ＞ 0.05) on the first day between the two group were similar.Compared with placebo group,the relative abundance of Bifidobacterium and Lactobacillales in stool samples on the 14th day was significantly increased,while the Halomonas was significantly decreased.The relative abundance of the Shannon-index was increased,but without significant difference (P =0.16).Conclusion Enteral supplementation of probiotics in VLBW infants may increase probiotic bacterium and microflora diversity.
ABSTRACT
Objective To explore the effect and mechanism of Kruppel-associated box(KRAB) type zinc-finger protein Apak on the transcription of ribosomal RNA(rRNA) under hypoxic conditions.Methods Real-time quantitative PCR(qRT-PCR) was used to detect the level of rRNA and the effect of Apak on the transcription of rRNA.The expression and phosphorylation level of proteins were examined by Western blotting.Immunofluorescence assay was used to observe the location of Apak.Results Under hypoxia (0.3%O2),the transcription level of rRNA increased first and then decreased in Apak wild type cells.In Apak knock-out cells,the transcription level of rRNA kept decreasing under hypoxic conditions.The repression of Apak on rRNA synthesis and the nucleolus location of Apak disappeared,and the expression and phosphorylation level of Apak were down-regulated under hypoxic conditions for 3 h.Conclusion Under hypoxic conditions,the disapperance of Apak repression on rRNA transcription could lead to a temporary increase in rRNA.