Objective To explore the different methods of decoloration for immunohistochemical HE slides,and their influence on tissue antigen expression.Methods Antigen retrieval solution (EDTA or citric acid solution) was used in immunohistochemistry to decolor HE slides,and was compared with the method of hydrochloric acid solution decoloration in normal temperature.Results Antigen heat retrieval decolors completely.Compared with other methods,it has shorter decoloration time (1 ～ 2min),more than 90％ of completely decoloration rate,the difference was significant(x2 =27.6,23.9,all P ＜ 0.01).Meanwhile,the method dose not damage slides,and the immunohistoehemical results are exact,without background coloring and unusual coloring,antigen expression rate and intensity are high.Conclusion Antigen heat retrieval decoloration not only simplifies the coloration process,but also protects tissue antigen activity better.It is the preferable method of decoloration and protecting antigen resource,which possesses some practical value in the pathology diagnosis.

Objective:To understand the genetic variation and the prevalence of H9N2 subtype avian influenza virus in Guizhou province, and to provide the scientific evidence for the prevention and control of avian influenza virus.Methods:The results of AIV detection in live poultry market(LPM) environment in Guizhou province from October 2018 to March 2019 were statistically analyzed, RNAs were extracted and sequenced from the HA genes of 13 samples of H9N2 positive screened by real-time PCR. Then the homology, the genetic evolution and the mutations of important amino acid were analyzed by bioinformation softwares. Results:The positive rate of AIV was 52.2% and the positive rate of H9N2 was 83.7% in LPM environment. The homology between nucleotides of the HA gene of 21 strains ranged from 91.6% to 100.0%, and the homology between amino acids of the HA gene ranged from 91.0% to 100.0%. All strains belonged to Y280 sublineage and G57 genotype. Key sites analysis showed that they had a common motif PSRSSRGLF and LSRSSRGLF at the cleavage site, which indicated that they were lentogenic and low pathogenic strains. Mutations H191N, E198T/A and Q234L at the receptor binding sites in the HA was found in 21 strains, while indicated the viruses had the potential to bind human-like receptor. The analysis results of glycosylation motifs showed that all 21 strains had 7 glycosylation sites, but had a site deletion at amino acid site 218 and an addition at 313.There was no significant mutation in the key site compared with the human infected strains. Conclusions:The detection rate of AIV in LPM environment in Guizhou province was high, and the pollution was very serious, and H9N2 subtype is the main subtype, All H9N2 subtype AIVs belonged to Y280 sublineage and G57 genotype, and they were low pathogenic avian influenza viruses in Guizhou province, but the genetic gap were widening and mutations of key amino acid site might enhance susceptibility and pathogenicity to human beings. Hence, It is necessary to strengthen the surveillance of molecular characteristic variation of H9N2 subtype AIV.

Objective To understand the genetic variations of influenza B virus outbreaks in Guizhou province in 2016,and to compare the matching situation of outbreak epidemic strains with the vaccine strains recommended by WHO and representative strains in China.Methods The haemagglutinin HA1 gene of 8 strains isolated from two episodes of influenza B virus outbreaks in Tongren area was amplified and sequenced.The sequencing products were analyzed by bioinformatics software DNAStar. Results The two episodes of influenza outbreaks were both caused by influenza B Victoria lineage virus (BV).The homologies of the isolated strains were 99.8%—100.0% in nucleotide and 99.5 %—100.0%in amino acid.Mutation was only detected at 274 site in some strains.Compared with reference strain B/Victoria/2/87,the homologies were 91 .8%—92.0% and 91 .5 %—92.0%,respectively.Mutations developed at 17 amino acid sites,among which,I143V,V163I and V201I site were associated with the main antigenic determinant area B,C and D.Compared with previous vaccine strain B/Brisbane/60/2008, the homologies were 98.2%—98.3% and 98.5 %—99.0%,respectively,and mutations were detected at 3 sites.Mutations at I143V and N155D were detected in all 8 strains and at T247I in some strains.The mutation of I143V was associated with antigenic determinant area B.Compared with the representative strain B/Chongqing-Yuzhong/1384/2010,the homologies were 96.7%—96.8% and 97.0%—97.5 %, respectively.A total of 6 sites developed mutations,among which,5 sites were P84L,I143V,N155D, V172I and T223N mutations.The mutation of T247I was detected in some strains,and I143V was associated with area B.Compared with the epidemic strain in Guizhou in 2016,the homologies were 99.8%—100.0% and 99.5 %—100.0%,respectively.Mutation was only detected at site 247 in some strains and was not associated with the main antigenic determinant area.Conclusions The two episodes of influenza outbreaks in Guizhou are caused by the same BV lineage epidemic virus strain.Haemagglutinin gene of BV lineage virus is constantly changing.However,there is no new mutation emerged at important site.Compared with previous influenza vaccine strain B/Brisbane/60/2008 recommended by WHO,BV lineage virus is well matched and could provide a positive protection effect.

BACKGROUND:Due to limitations of the physicochemical properties of soft denture liner material itself, whisker has been added in the soft lining material in recent years, so as to enhance its mechanical properties. OBJECTIVE:To investigate the effect of different additive amount of anhydrous calcium sulfate whisker on the mechanical function of self-curing soft denture liner. METHODS: There were six groups in this experiment. Anhydrous calcium sulfate whisker at the mass fraction of 0 (control), 1%, 2%, 3%, 4%, 5% was respectively added into self-curing soft liner materials, 10 test specimens in each group, a total of 60 test specimens. The shear bond strength, Shore hardness and tensile strength were detected. RESULTS AND CONCLUSION: With the increasing amount of the anhydrous calcium sulfate whisker, the Shore hardness of the soft lining material was increased continuously, and the tensile strength was increased firstly and then reduced. When 3% anhydrous calcium sulfate whisker was added, the bond strength and tensile strength of soft lining material reached the peak. Taken together, the mechanical properties of the soft lining materials became perfect when 3% anhydrous calcium sulfate whisker was added. These results demonstrate that anhydrous calcium sulfate whisker may affect the mechanical properties of self-curing soft liner.

Objective To understand the epidemic characteristics and regularity of influenza B virus in Guizhou Province, and provide scientific evidence for the control and prevention of influenza.Methods Results of reverse transcription polymerase chain reaction(PT-PCR) of influenza B virus in Guizhou Province from April 1, 2013 to March 31, 2016 were statistically analyzed.Results A total of 1 904 samples were detected influenza B virus by RT-PCR, B/Yamagata (By) lineage and B/Victoria (Bv) lineage were 1 215 and 642 respectively.In April 2013-March 2014 and April 2014-March 2015, the predominant strains of influenza B were both By lineage, in April 2015-March 2016, the predominant strains of influenza B were Bv and By lineages, the epidemic peaks were in winter and spring;there's a higher positive percentage of influenza B in male, accounting for 56.83%;the highest detection rate of influenza B virus was found in population aged <15 years(70.80%),Bv and By lineages were the highest in the 0~ (42.37%) and 5~ age groups (35.56%) respectively;the main pathogen causing mixed infection was By+Bv (67.65%),mixed infection with influenza B virus accounted for 95.59%.Conclusion There are two lineages By and Bv epidemic in Guizhou Province, the epidemic peaks of influenza B are in winter and spring, male cases are higher than female, people under 15 years old are the high-risk group for influenza B, it is of great significance to strengthen the vaccination and surveillance of influenza in low age population.

Objective To investigate the imaging features of the cerebral complications of infective endocarditis (IE)and the evolution process of infective cerebral infarction.Methods The clinical and imaging data from 5 patients diagnosed as IE with neurological complications were retrospectively and comprehensively reviewed,so that the imaging features of cerebral complications and infective cerebral infarctions were summarized.Results Among the 5 cases,3 showed multiple acute infarctions,including 2 massive ones.All the 5 cases showed multiple hemorrhagic lesions at different stages.The infarction and hemorrhage were mostly located at the corticalGmedullary junction.1 case of subarachnoid hemorrhage and 1 case of meningitis were also observed.Two massive infarctions mentioned above showed irregular patchy shape,which evolved into cerebral abscesses after 1 2 and 1 5 days of neurological symptoms showing up,then abscesses started shrinking after 33 and 3 1 days,respectively.Conclusion MRI can accurately reflect the features of cerebral complications of IE and the evolution process of infective cerebral infarctions,which provides evidences for physicians to make correct diagnoses and the treatment plans.

Objective: To investigate the molecular characteristics and tracing of the hemagglutinin (HA) gene, and to analyze the risk of human infection with influenza virus A (H7N9) in Guizhou Province, so that to provide evidence for the prevention and control of highly pathogenic avian influenza A (H7N9). Methods: Nucleic acids of 5 strains of H7N9 including 1 sample of the patient′s nasopharyngeal swab and 4 samples of the live poultry market (LPM) environment were extracted and HA genes were amplified and sequenced. Then the homology, genetic evolution and the pivotal sites related to receptor binding regions, pathogenicity and potential glycosylation of the avian influenza A (H7N9) viruses were analyzed by a series of bioinformatics softwares. Results: Homology analysis revealed that the homologies of nucleotide and amino-acid of the HA gene of H7N9 strains from the patient and LPM in Weining County, Guizhou Province were 99.8% and 99.6%, respectively, while those of 4 strains from LPM were both 100%. The homologies of nucleotide and amino-acid of the HA gene of H7N9 strains were the highest with the strain of A/Guangxi/5/2017 isolated from a Guangxi infected patient (99.7%-99.9% and 99.4%-99.8%, respectively), while those with the strain isolated from LPMs environment at the end of 2016 (A/Environment/Guangdong/C16283222/2016) were 99.0%-99.2% and 98.9%-99.2%, respectively. However, the homologies of nucleotide and amino-acid of the HA gene of H7N9 strains with A/Shanghai/2/2013 recommended by world health organization and the candidate vaccine strain A/Anhui/1/2013 were 96.8%-97.0% and 95.8%-96.2%, respectively. Phylogenetic analysis showed that the 5 strains had the nearest genetic distance to the strain A/Guangxi/5/2017. All the 5 strains cleavage site sequences of HA protein showed mutation of PEVPKRKRTAR↓GLF, and they were highly pathogenic avian influenza viruses mutant strains, which all had mutation of G186V at the receptor binding sites of HA gene, while no Q226L mutation was found. All 5 strains had new mutation of A363S, and new mutations of R56K and I297V were only found in the strain isolated from the patient. Among the five potential glycosylation motifs in the HA, only 421NWT and 493NNT had variation of the position post shift. Conclusions All the 5 H7N9 strains isolated in Weining County, Guizhou Province are highly pathogenic avian influenza mutative viruses. The current candidate vaccine may not provide a very good protection. The mutations of cleavage site of HA protein, G186V as well as other new mutation sites of HA may enhance the susceptibility and pathogenicity to human beings.

Objective:To analyze the molecular evolution characteristics of HA and NA genes of influenza B/Yamagata (BY) and influenza B/Victoria (BV) lineage viruses in Guizhou Province, aiming to provide reference for scientific prevention and control of influenza. Methods:The prevalence of various types of influenza viruses in Guizhou Province from 2017 to 2021 was analyzed. The nucleic acid of influenza B viruses was extracted, and then the HA and NA genes were amplified by RT-PCR. Fourteen strains were sequenced and the sequences of 83 strains were obtained from GISAID. Homologies between the 97 influenza B viruses as well as the phylogenetic characteristics and amino acid site variations were analyzed. Results:Influenza A, BY and BV lineage viruses co-circulated in Guizhou Province and BV lineage was the predominant type. The homologies of HA and NA genes were 98.7%-99.4% and 98.4%-99.6% between BY lineage viruses and the reference vaccine strain B/PHUKET/3073/2013. BV lineage viruses shared 98.3%-99.3% and 98.9%-99.6% homologies with the reference vaccine strain B/Colorado/06/2017. The BY lineage strains in Guizhou Province mainly belonged to Y3 genetic group with HA gene in two branches of Y3-H1-2 and NA gene in three branches of Y3-N1-3. Three reassortant strains were found in Y3 clade. The isolated BV lineage strains mainly belonged to V1A-2 genetic group with HA gene in four branches of V1A-2 H1-4 and NA gene in five branches of V1A-2 N1-5. Twenty reassortant strains were found in V1A-2 clade and no inter-lineage reassortants were found. Analysis of variations at key amino acid sites showed that there was no mutation at epitopes in Y3 genetic group. However, there were point mutations at four main epitopes and a shift mutation in 190 helix in V1A-2 genetic group. There was no mutation in drug resistance sites. Conclusions:Various types of influenza viruses circulated in Guizhou Province. The homology between influenza B viruses and vaccine strains was decreasing. Different branches of HA and NA genes had been evolved and various forms of mutations were detected in the sequences. Intra-lineage reassortant strains and new varieties emerged. Surveillance of influenza B viruses should be strengthened.

The number of H7N9 bird flu cases was high and the situation was grim in guizhou province in 2017. To understand the molecular characteristics of the hemagglutinin gene (HA) and the risk of human infection with avian influenza virus A(H7N9) in Guizhou Province, 2017. Homology, genetic evolution and pivotal sites related to receptor binding regions, pathogenicity and potential glycosylation of 14 avian influenza viruses A(H7N9) were analyzed by a series of bioinformation softwares. It was cleared that there was 95.9%-100% similarity among 14 strains in nucleotide of the HA gene, and there were 96.8%-97.8% and 96.8%-97.9% similarities with vaccine strains A/Shanghai/2/2013 and A/Anhui/1/2013 recommended by WHO, respectively. Phylogenetic analysis showed that 14 HA genes were directly evolved in the Yangtze River Delta evolution branch, but they could be derived from five diffenrent strains. Then 13 of 14 strains cleavage site sequences of HA protein revealed they were low pathogenic avian influenza viruses, while A/Guizhou-Weining/CSY01/2017 was high pathogenic avian influenza virus. Mutation G186V at the receptor binding sites in the HA was found in all 14 strains, and mutation Q226L in 13 strains besides A/Guizhou-Weining/CSY01/2017. All five potential glycosylation motifs in the HA were conservative.