Objective To detect the expression of DNA damage response genes induced by radiation in human peripheral blood lymphocyte,and to explore the new biomarkers of radiation.Methods The human peripheral blood cells were irradiated to X-rays at different doses of 0,1,2,3,4,and 5 Gy.The quantitative real.time qPCR wag used to detect the expressions of cyclin-dependent kinase inhibitor l a gene(Cdknl a)and growth arrest and DNA damage inducible gene(Gadd45a)in lymphoeytes at 4 and 24 h post-irradiation,respectively.The method of CB mieronucleus was used to determine the change of micronucleus ratio.Results The expression of Cdknl a in peripheral blood lymphocytes wag increased significantly at 4 and 24 h post-irradiation to 0-5 Gy.reached the peak at 4 Gy and began to decrease at 5 Gy,which showed a dose-dependent manner(r=0.946,0.975,P<0.05).Similarly,the expression of Gadd45α in human peripheral blood lymphocytes was also increased significantly at 4 and 24 h post-irradiation to 0-5 Gy in a dose-dependent manner,while the expression of Gadd45a at 4 h wag higher than that at 24 h(r=0.936,0.797,P<0.05).The ratio of micronuclei wag increased significantly at 4 and 24 h post-irradiation to 0-5 Gy(r=0.990,0.984,P<0.05).Conciusions Cdknl a and Gadd45α expression could be increaged significandy at 4 and 24 h post-irradiation to 0-5 Gy,showing a good linear relationship.which might be candidate for radiation biological dosimeter.

Objective To investigate the effects of ionizing radiation on the expression of P21 protein in Jurkat cell line and p21 gene in thymocytes and splenocytes of mice.Methods Flow cytometry (FCM)was used to analyze the expression of P21 protein in Jurkat cells at 12 and 24 h after irradiation to 0,0.5,1.0,2.0,4.0,and 6.0 Gy.Real-time PCR was used to detect the expression of p21 gene in thymocytes and splenocytes of mice at4 and 24 h after irradiation to 0,0.5,1.0,2.0,4.0,and 6.0 Gy.Multi-staining was used to analyze the micronucleus rates of Rct in bone marrow.Results The expressions of P21 protein were increased in a dose-dependent manner during 0.5-4.0 Gy(t=-24.23--3.96,P<0.05),but decreased at 6.0 Gy at 12 and 24 h post-irradiation(t=-11.19,-14.50,P<0.05).The expressions of p2 1 gene in both thymocytes and splenocytes of mice were increased in dose-dependent manner in the range of 0-6.0 Gy(including 6.0 Gy)(t=-29.96-8.80,P<0.05),and reached to the peak at 6.0 Gy at 4 and 24 h post-irradiation(t=-11.84--3.42,P<0.05),except thymocytes at 4 h and 1.0 Gy post-irradiation(t=-3.42,P>0.05).Conclusions The expressions of P21 protein and p21 gene could be increased by X-ray irradiation.which shows good dosedependent manners in certain range of dose.

Objective:To disclose the genome characteristics and mutations of 2019 novel coronavirus (2019-nCoV) strains from the imported cases of Coronavirus Disease 2019 (COVID-19) in Gansu province, thereby to provide scientific reference for the prevention and control of COVID-19 in Gansu province. Methods:The respiratory tract specimens of imported COVID-19 cases from seven countries in Gansu province in 2020 were collected. The virus genome was sequenced by the second-generation sequencing technology, the whole genome sequences were compared and analyzed, and the MEGA software was used to construct a phylogenetic tree based on the neighbor-joining method.Results:A total of 46 2019-nCoV genome sequences with a length of 29 605~29 903 bp were obtained. Compared with the Wuhan reference strain (GenBank ID: NC_045512.2), it was found that the median (minimum to maximum) number of the nucleotide mutations of the 2019-nCoV genome sequence of the imported cases was 10 (7-24). A total of 134 nucleotide mutation sites were found in all 2019-nCoV genome sequences from 7 entry countries in Gansu province, distributed in 11 open reading frames (ORFs). The top three nucleotide mutations in different proteins: ORF1ab (78), S(20), N(12). Among the 134 nucleotide mutations, 82 caused amino acid mutations, and all of them were missense mutations. No insertions or deletions were seen. Types of deletion mutations, the top three amino acid mutations in different proteins: ORF1ab (46), S(11), N(10); the key sites of the receptor binding domain (RBD) of the S protein have not been mutated.Conclusions:No imported cases in Gansu province have been found to carry the reported mutations that can clearly lead to changes in the spread and pathogenicity of 2019-nCoV.

Objective: To analyze the epidemiological and etiological characters of hand, foot and mouth disease ( HFMD ) in Gansu during 2013 to 2015 and provide evidence for the development of effective prevention and control measures. Methods: The descriptive epidemiological analysis was used to analyze the data of HFMD, and the specimens were collected from hospitals to detect the pathogens by RT- PCR or Real-time RT-PCR. The nucleotide sequences of VP1 encoding region of virus strains were amplified by RT-PCR method, and determined and analyzed. Results: Total of 29 934 HFMD cases were reported in Gansu from 2013 to 2015, including 81 severe cases and 2 deaths; the largest number occurred in Lanzhou was 7 053, accounting for 23.56% of the cases in the province. HFMD cases were mostly reported during May to July, accounted for 61.69% in total cases; the male to female ratio was 1.5: 1, and most cases were under the age of five and accounted for 83.02%. A total of 5 251 laboratory confirmed cases were reported, of which the number of cases caused by human enterovirus (HEV) were 2 972, the positive rate was 56.60%. Among the severe 81 cases, the positive rate of HEV was 67.90%, and both of the 2 death cases were infected by EV71. 341 strains of viruses were isolated, the genotyping of VP1 encoding region showed that all the 133 EV71 were C4a; among the 134 CVA16 isolates, 6 were B1a and 128 were B1b. Conclusions In Gansu province, there is a high infection rate of HFMD in children under the age of five, the proportion of other HEV is more and more, and the incidence is related to the difference of pathogens that showed alternant epidemic characteristics. CVA16 and EV71 viruses have the phenomenon of alternating.

Objective: To analyze the genotypes, amino acid vatiations and molecular epidemiological characteristics of respiratory syncytial virus (RSV) infection in pediatric patients in Gansu province for the future research. Methods: A total of 4 556 respiratory tract specimens were colleted from pediatric patients under 10 years of age in five cities in Gansu from 2012 to 2017. These specimens were tested for RSV and its subtypes.The coding region of the RSV G gene was amplified using reverse transcription-polymerase chain reaction (RT-PCR) and sequenced for RSV positive specimens. Sequences were edited using DNA Star software. Sequence alignment and phylogenetic trees were built by MEGA 6.0 software. Results: Out of 4 556 specimens, 1 135 (24.91%) were positive for RSV, totally 216 G protein sequences were obtained. RSV A isolates were clustered into three genotypes: NA1、NA3 and ON1. The nucleotides and amino-acid homology was 84.9%-100% and 77.3%-100%, respectively. The nucleotides and amino-acid homology between this study and prototype long strain was 81.2%-83.3% and 74.1%-88.0%. RSV B isolates were clustered into only BA9 one genotypes. The nucleotides and amino-acid homology was 97.7%-100% and 95.8%-100%, respectively. The nucleotides and amino-acid homology between this study and prototype CH18537 strain was 84.9%-85.7% and 77.9%-80.1%. Conclusions The genetic characteristics and the amino-acid changes were analyzed systematically using data of RSV G gene collected from 2012 to 2017 in Gansu province in this study. These data were used for analyses of the etiology, control and prevention of RSV infection.