ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) quickly became a major epidemic threat in the whole China. We analysed SARS-Cov-2 infected cases from Tibetan Autonomous Prefecture, and noted divergent characteristics of these Tibetans infected cases compared to Han Chinese, characterizing by a considerable proportion of asymptomatic carriers (21.7%), and few symptomatic patients with initial symptom of fever (7.7%). Here, we did a descriptive study on clinical characteristics of 18 asymptomatic individuals with SARS-CoV-2 infection. The median age of these asymptomatic carriers was 31 years and one third of them were students, aged under 20 years. Notably, some of asymptomatic carriers had recognizable changes in radiological and laboratory indexes. Our finding indicates a potentially big number of SARS-CoV-2 asymptomatic carriers in prevalent area, highlighting a necessity of screening individuals with close contact of infected patients, for a better control on the spread of SARS-CoV-2 infection.
ABSTRACT
Objective To explore the protective effect of long non-coding RNA(lncRNA) metasta-sis associated in lung denocarcinoma transcript 1 (MALAT1) involved in hyperoxia-induced lung injury in preterm infants.Methods This study had downloaded chip data set GSE25286 (Mouse GEO Genome 430 2.0 Array) from gene expression database gene expression omnibus (GEO),according to the state of hyperoxia exposure,the MALAT1 mRNA expression in rats normal lung tissues and hyperoxic lung tissues was compared at day 14th and 29th.In chip data set GSE43830(Human Exon 1.0 ST Arrays) from GEO,the expression of multi-ple genes[cell division cycle 6(CDC6),death effector domain containing 2(DEDD2),and Cyclin B1 (CCNB1)] in WI38 cells(lung fibroblasts) was compared before and after MALAT1 was knockout.At the same time,the peripheral blood samples of premature infants were collected to verify.Totally 40 premature infants were hospitalized in the department of neonatology in our hospital from Jan 2015 to Dec 2016,the pe-ripheral blood samples of 40 premature infants were collected.RNA was extracted and Real time-PCR was performed after reverse transcription,clinical data of these 40 cases were retrospectively analyzed. Results (1) By using Affymetrix Expression console and Affymetrix Transcriptome analysis console software source files of the chip of pretreatment and difference expression gene screening,the expression of lncRNA MALAT1 gene in lung tissues of hyperoxia lung injury mice significantly upregulated[fold change(FC) =2.33,P=0.001].(2) After MALAT1 in WI38 cell was knockout,MALAT1 expression was significantly reduced(FC= -15.6,P=0.000),the expression of CDC6(FC= -2.37,P=0.001) and CCNB1(FC=-2.16,P=0.002) were down regulated,DEDD2 expression was up regulated(FC =2.46,P =0.000). (3) The results of peripheral blood samples from preterm infants showed that the expression of MALAT1 was significantly increased in preterm infants with hyperoxia-induced lung injury(0.375 5 ± 0.081 9,t =4.634, P=0.015),compared with normal preterm infants(0.273 4 ± 0.067 3).Conclusion Through inhibiting cell apoptosis,lncRNA MALAT1 can protect preterm infants with hyperoxia-induced lung injury,it may provide a new strategy for prevention and treatment of hyperoxia-induced lung injury in premature infants.
