In order to study genetic variation diversity of porcine circovirus type 2 (PCV2) strains in Shanxi,the genomic sequences of nine PCV2 strains including SXQX,SXCZ,SXTY2,SXJC,SXJX,SXLL,SXPY,SXPG and SXXY recently isolated from some areas of Shanxi from 2013 to 2016,was cloned,sequenced and received by GenBank.The amplified PCV2 genomic sequences,ORF2 sequences and Cap protein amino acid of these nine strains were analysed and compared with those of published 28 PCV2 strains by DNAStar,drawing phylogenetic tree.The results showed that the genomic sequences of SXJX,SXJC and SXXY PCV2 strains were 1 768 bp,and the others were 1 767 bp,which accounted for 33％ and 67％,respectively.The homologies of nucleotide sequences of the nine strains were 94.7％-99.8％,the homologies of nucleotide sequences of the nine strains with the 28 isolates from different regions of the world PCV strain were 93.9％-99.9％,and the homologies of nucleotide sequences of the nine strains with the domestic vaccine strains were 95.1％-99.8％.The phylogenetic analysed that SXJX,SXJC and SXXY belonged to genotype PCV-2D,SXLL,SXPY and SXCZ belonged to genotype PCV-1C,and SXTY14,SXPG and SXQX belonged to genotype PCV-1A/1B.Thus it proved that the epidemic strain of PCV2 was mainly PCV-2b in Shanxi.The homologies of ORF2 nucleotide sequences and Cap amino acid of the nine strains were 90.0％-100.0％ and 87.1 ％-100.0％ respectively,the homologies of ORF2 nucleotide sequences and Cap amino acid of the nine strains with the 28 isolates from different regions of the world PCV strain were 87.6％-100.0％ and 84.1％-100.0％ respectively,and the homologies of ORF2 nucleotide sequences and Cap amino acid of the nine strains with the domestic vaccine strains were 91.0％-100.0％ and 89.3％-100.0％ respectively.The Cap amino acids of SXQX,SXJX,SXTY14,SXPG,SXJC and SXXY PCV2 were 233,ORF2 of SXQX,SXTY14 and SXPG located at 1 033-1 734 bp,ORF2 of SXXY,SXJX and SXJC located at 1 033-1 734 bp,and the Cap amino acids of SXCZ,SXLL and SXPY PCV2 were 234,ORF2 of them located at 1 030-1 734 bp,in addition,the positions of 1 030-1 734 bp were more three bases TCA than other ORF2 genome sequence of 1 767 bp,resulting in increasing a K (Lys) of amino acid sequencein at the 234 position.Also Cap protein of 9 PCV2 strains showed more amino acid variation in addition to the only high-ly conserved glycosylation sites (NYS) (pp.143-145 amino acid).It provided theoretical basis for the PCV2 immune prevention of research in Shanxi,and the data of basic theory of molecular pathogenesis of PCV2.

Objective:To observe the effects of preemptive analgesia with parecoxib sodium on differentiation of peripheral T helper cells(Th) in patients with radical mastectomy .Methods :A toal of 50 patients with radical mastectomy were randomly di-vided into parecoxib group(Group P) and the control group(Group C) .Parecoxib sodium(40 mg ,diluted with normal saline into 5 mL ,the same below ) was intravenously injected 1 h before operation in Group P ,and 12 h after the first injection .The same dose of normal saline was intravenously injected in Group C at the same time-point .Patient-controlled intravenous analgesia (PCIA) with fentanyl had implemented in two groups after operation .The levels of interferon-γ(IFN-γ) ,interleukin-4(IL-4) in Th1 and Th2 were measured by flow cytometry before anesthesia(T0) ,2 h(T1) ,12 h(T2) ,24 h(T3) ,48 h(T4)after operation in the two groups .Th1 cell was marked by CD3+ CD8- IFN-γ+ .Th2 cell was marked by CD3+ CD8- IL-4+ .Th1/Th2 was calculated by the level of IFN-γ+ /IL-4+ .The visual analogue scale (VAS) ,Bruggemann comfort scale(BCS) ,dosage of fenta-nyl at each time-point in two groups were compared .Results:VAS scores in group P were significantly lower than those in Group C at T2 ,T3 ,T4 .BCS scores at T1 ,T2 ,T3 in group P were significantly higher than those in Group C .The dosages of fentany at T2 ,T3 in Group P were significantly lower than those in Group C .Compared with T0 ,Th1/Th2 ratios in the two groups at T2 ,T3 ,T4 were lower(P<0 .05) .Th1/Th2 in Group P was higher than those in Group C at T2 ,T3 ,T4(P<0 .05) . Conclusions :Th1/Th2 in patients decreases after radical mastectomy .Preemptive analgesia with parecoxib sodium assisted with fentanyl PCIA can inhibit the shift of the balance of Th1/Th2 towards Th2 type .