OBJECTIVE: To observe the clinical character of antibiotic associated diarrhea(AAD)in order to provide reference for prevention measures. METHODS: Retrospective analysis was applied to analyze 488 inpatients treated with antibiotics in our hospital from 2006 to 2008,of which 42 AAD cases were analyzed in terms of clinical manifestation,utilization of antibiotics, therapy and prognosis, etc. RESULTS: The incidence of AAD arrived at 8.6%. The reason that incidence of AAD was higher than that of control group was above 7 days of antibiotics treatment, broad-spectrum antibiotic, more than two kinds of antibiotics and over 70 years old. CONCLUSION: The key point of preventing AAD is rational use of antibiotics.

Axenfeld-Rieger syndrome is a rare autosomal dominant hereditary disease characterized by anterior segment dysgenesis, which may be accompanied by various systemic defects, including craniofacial dysmorphism, hypodontia, microdontia, and redundant periumbilical skin.Its typical ocular manifestations include posterior embryotoxon, iris hypoplasia, peripheral anterior synechiae, corectopia and polycoria with a high prevalence of glaucoma.Patients can exhibit any combination of these features.However, family members with the same genotype may present different phenotypes due to phenotypic heterogeneity.Emerging evidence suggests that PITX2 and FOXC1 genes encoding transcription factors are primarily associated with genetic variants in ARS.Intragenic mutations and gene deletions are common types of genetic variations suspected to trigger changes in gene dosages and protein function.However, the underlying molecular mechanism remains unclear.Some patients with ARS carry mutations in the COL4A1, PRDM5, and CYP1B1 genes, but the pathogenicity of these variations has yet to be confirmed by further studies.This article provided an overview of the typical clinical features, potential correlations between phenotype and genotype, as well as gene function.

Objective:To identify disease-causing variation in a Chinese family with Axenfeld-Rieger syndrome (ARS) through the analysis of clinical symptoms and hereditary information.Methods:The method of pedigree investigation was adopted.A Chinese ARS family including 15 family members of 3 generations was recruited in the Second Affiliated Hospital of Harbin Medical University in 2018.There were 3 patients in the family.The family history and clinical data were collected.Ophthalmic and general examinations were carried out in all the members included.DNA and RNA were extracted from collected peripheral venous blood samples of 2-5 ml from each member.Whole exome sequencing was used to screen the variations in the proband.Suspected variations screened through searching population databases and bioinformatics analysis were verified by Sanger sequencing and real-time quantitative PCR.Conservation analysis and deleteriousness prediction of suspected variations were conducted.The pathogenecity of candidate rare variations were evaluated according to the American College of Medical Genetics and Genomics (ACMG) standards and guidelines.This study followed the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the Second Affiliated Hospital of Harbin Medical University (No.KY2019-231).Written informed consent was obtained from each subject or custodian prior to entering the study cohort.Results:The 3 patients all had typical ARS clinical features in eyes, teeth and umbilicus, and carried the same heterozygous variant, c.525delC (p.Asp175Glufs *) in the PITX2 gene, which were not found in other members, indicating co-segregation.The relative expression of PITX2 mRNA was 0.672±0.063 in the patients, which was significantly lower than 1.015±0.179 in the healthy controls ( t=8.847, P<0.001).This variant was not recorded in dbSNP, 1000G, gnomeAD, ExAC, Korea1K and EVS databases, and it was labelled as deleterious by MutationTaster.The affected conservative amino acid sequences were found in 9 species.The variant was determined as pathogenic according to the ACMG standards and guidelines. Conclusions:The c.525delC (p.Asp175Glufs *) mutation of PITX2 gene is pathogenic in the pedigree.This is the first time that this mutation has been reported in Chinese family with ARS.