1.Identification of adenovirus epidemic strains and analysis of hexon gene characteristics in Anqing area from 2013 to 2015
Mengchan CAO ; Jun HE ; Xianxiang LI ; Siqing XU
Chinese Journal of Microbiology and Immunology 2018;38(11):855-861
Objective To investigate the characteristics of human adenovirus ( HAdv) epidemic strains and the variations of hexon protein and amino acid residues in acute respiratory infections in Anqing. Methods A total of 596 throat swab samples of children with acute respiratory infections were collected from influenza surveillance sites between 2013 and 2015 and detected with real-time fluorescent PCR adeno-virus nucleic acid test kit. Hep cells were used to separate viruses from positive samples. PCR amplification of hexon gene and sequencing analysis were conducted. Homologous alignment and phylogenetic tree analysis were performed between the obtained sequences and those published in GenBank. Results HAdv-positive samples accounted for 11. 4% (68). Thirty-four viruses were successfully isolated, including nine HAdv-3 (26. 5% ), 12 HAdv-7 (35. 3% ), 12 HAdv-14 (35. 3% ) and one HAdv-55 (2. 9% ). The 9 strains of HAdv-3 had a close genetic relationship with KX384958, sharing a homology of 99. 8%-100% . Three muta-tions in main amino acid residues were found in them as compared with reference strains. The 12 strains of HAdv-7 were genetically related to KX897164 and KU361344 with a homology ranging from 99. 8% to 100% and had seven major amino acid residue mutations in comparison to reference strains. The 12 strains of HAdv-14 were highly similar to JF420883 with a homology of 99. 6%-99. 9% , and possessed three major variations in amino acid residues in comparison to reference strains. The HAdv-55 strain was closely related to KP279748 and KX289874, showing a homology of 100% in both nucleotide and amino acid sequences. HAdv-7 strains had the greatest variations, followed by HAdv-14 strains. Conclusion From 2013 to 2015, the epidemic adenovirus strains causing acute respiratory infections in Anqing area were mainly HAdv-3, HAdv-7 and HAdv-14 with a small number of HAdv-55. The hexon genes of HAdv-55 strains were stable and no variation occurred. However, HAdv-3, HAdv-7 and HAdv-14 strains all had some variations in nu-cleotides and amino acids. Amino acid variations in the antigenic determinants of HVR1, HVR2 and HVR7 regions were detected.
2.Quality comparison of cold cryoprecipitates in two different volumes
Jing ZHOU ; Qianqian DA ; Shuming DAI ; Mengchan LI ; Bing YAN
Chinese Journal of Blood Transfusion 2021;34(12):1379-1381
【Objective】 To study the concentration, content and yield of coagulation factor Ⅷ(FⅧ) and fibrinogen(Fg) in 25 mL and 45 mL cryoprecipitate. 【Methods】 Forty aliquots(200 mL fresh whole blood) were divided into group A and group B, with 20 samples in each group. Fresh frozen plasma(FFP) was prepared within 6 hours(anticoagulant ACD) according to the standard operating procedure for component preparation. After one week, the prepared FFP was prepared into(25±5) mL and(45±5) mL cold precipitates by siphon method. After freezing for one week, the concentrations of FⅧ and Fg were detected after meltingin by water bath at 37℃, and the content and yield were calculated. 【Results】 The FⅧ concentration, content and yield in group A and group B were(2.990±0.988) vs(2.744±0.940) IU/mL, (74.75±24.71) vs(113.75±30.06)IU, and(70.1±16.6) vs(85.0±7.6)%, respectively.The Fg concentration, content and yield was(6.013±1.679) vs(5.844±0.683) g/L, (150.33±41.99) vs(252.23±26.90)mg, and(41.7±8.6) vs (49.1±9.6)%, respectively. Statistical analysis suggested that the content and yield of FⅧ and Fg were statistically different between the two groups(P<0.05), but the concentration of FⅧ and Fg was not statistically different(P>0.05). 【Conclusion】 FⅧ and Fg of low-volume cryoprecipitate presented lower content and yield, but slightly higher concentration. Both products can meet the quality requirements of whole blood and blood component. Therefore, reducing product capacity appropriately is suggested when preparing cryoprecipitate with 200mL whole blood