Distribution and risk factor analysis for-associated diarrhea among hospitalized children over one year of age

Importance: Clostridium difficile-associated diarrhea (CDAD) is a severe type of antibiotic-associated diarrhea (AAD). However, the risk factors for CDAD in children with AAD have not yet been clarified.Objective: To investigate the distribution and risk factors for CDAD among hospitalized children in Beijing Children’s Hospital.Methods: Stool samples from 197 children with AAD were tested for theC. difficile pathogenic genes (tcdA, tcdB, tcdC, tcdD, tcdE, cdtA, andcdtB) using polymerase chain reaction between January 2011 and January 2014. Children who tested positive fortcdA ortcdB were included in the CDAD group, and those remaining comprised the non-CDAD group.Results: The rate of CDAD among the 197 children with AAD was 42.6% (84/197). The age distribution was 1-15.6 years, among which the majority of children (54.8%, 46/84) were aged 1-4 years. Differences in the CDAD-positive rates among AAD children belonging to different age groups were not statistically significant. Univariate analysis revealed that the duration of antibiotic therapy, the length of hospitalization prior to diarrhea, and gastrointestinal tract operations were significant risk factors (P < 0.05). Children with CDAD underwent more antibiotic therapy and had longer periods of hospitalization prior to diarrhea onset than children in the non-CDAD group. Using multivariate regression analysis, hospitalization for ≥ 10 days prior to diarrhea was found to be an independent risk factor for CDAD.Interpretation: This study revealed that the length of hospitalization (≥ 10 days) prior to diarrhea was an independent risk factor for CDAD in children with AAD.

Rare variants in novel and known genes associated with primary angle closure glaucoma based on whole exome sequencing of 549 probands

Primary angle closure glaucoma(PACG)is one of the most common causes of irreversible blindness in Asia and about 80%of PACG are present in Asia(Song et al.,2017).Genetics plays an important role in the development of PACG(Gramer et al.,2014).Recently,eight common SNPs were found to be strongly associated with PACG(Vithana et al.,2012;Khor et al.,2016)and mutations in MYRF cause high hyperopia accompanied with PACG(Xiao et al.,2019).

MicroRNA-mediated DNA methylation in plants

DNA methylation,a major event in epigenetics,plays an essential role in the control of gene expression.Increasing evidence suggests that long and short non-coding RNAs are involved extensively in plants to direct the establishment,spread,and removal of DNA cytosine methylation throughout their genomes.Yet,little has been known about the role of microRNAs(miRNAs)in DNA methylation although the role of small interfering RNAs(siRNAs)in DNA methylation has been well established.Several recent studies,however,provided the evidence for miRNA-directed DNA methylation in plants,and the working mechanisms still need to be fully explored.In this review,we highlight the key features of miRNA-directed DNA methylation in plants and provide insight into the complexities of such an event in plants.The interaction between miRNAs and the epigenetic machinery and the future potential research questions are briefly discussed.