Objective To evaluate the capability of three tests used alone or in combination for identification of Staphylococcus aureus.Methods Identification of Staphylococcus aureus by the detection of spa gene with PCR and the Vitek-2 system were selected as the reference methods.Comparison of three phenotypic tests including DNase,mannitol fermentation and tube coagulase test was carried out to analyze the sensitivity,specificity,positive/negative predictive value,positive/negative likelihood ratio and Youden index.The consistency,cost and related indexes of the assays were analyzed between the combined phenotypic tests and the reference methods.Results In the present study,324 isolates of Staphylococci,including 293 Staphylococcus aureus and 31 non-Staphylococcus aureus,were collected.Single biochemical test could not identify Staphylococcus aureus efficiently.Comparison between the reference methods and the combined three biochemical tests by Kappa statistic analysis indicated that an overall Kappa value was 0.9441,and the algorithm of combined test was less costly.The sensitivity and specificity of this algorithm were 100％ and 90.3％,respectively.Conclusion The cost-effective algorithm of combined DNase,mannitol fermentation and tube coagulase test could efficiently distinguish Staphylococcus aureus from other Staphylococcus species.

Objective To evaluate the practicability of CHROMagar orientation medium combined with simple biochemical tests for identification of common oxidase-negtive gram-negative bacilli.Methods The CHROMagar orientation medium was used together with biochemical tests including indole test , ornithine decarboxylase test and lysine decarboxylase test for identification of common oxidase -negtive gram-negative bacilli.The sensitivity, specificity, likelihood ratio, Youden index and Kappa value of the diagnostic assays were evaluated .McNemar test was performed to evaluate facticity, accuracy and cost of the method in com-parison with the Vitek-2 system as reference method .Results The identification of oxidase-negtive gram-negative bacilli from 318 bacterial strains showed that the sensitivities and specificities of CHROMagar orien-tation mediumm in combination with simple biochemical tests to Serratia marcescens, Stenotrophomonas mal-tophilia and Acinetobacter baumannii reached 100%, and for Escherichia coli, Enterobacter aerogenes and Klebsiella pneumoiae were above 90%.The specificities for identification of Enterobacter cloacae, Klebsiella oxytoca, Citrobacter freundii and Proteus mirabilis were all above 90%, but the sensitivities were around 75%-90%.Kappa values of the assays were above 0.85, howerer, which was only 0.5947 for Citrobacter freundii.McNemar test showed that all P values were above 0.05, and cost of the assays was reduced by 90%.Conclusion CHROMagar orientation medium in combination with simple biochemical tests is a cost-effective assay for identification of common oxidase-negtive gram-negative bacilli .

Objective To observe the expression dynamics of lens-related transcription factors in human embryonic stem cell (hESC) differentiated into lentoid body(LB).Methods A "three-stage" protocol was used for LB directional differentiation from hESC in vitro.The hESC (D0) and three differentiation stages cells were collected to analyze the expression dynamics of lens development-associated transcription factors by high throughput RNA sequencing technology in hESC-induced LB.Western blot and cell immunofluorescence were used to observe the involved genes at protein level.Results During D0-D6,cells became more round and compact.And during D7-D18,cells morphology gradually changed to spindle.At the end of D35,three-dimensional and transparent structurelentoid body (LB) was obtained.RT-PCR results showed that the stem cell related genes reduced and the lens specific genes increased significantly,and the LB was characterized by the expression of crystallins.According to clustering analysis of high throughput sequencing,a distinct difference in transcription factors gene expression was observed between D0 and D32.Meanwhile,the difference between D6 and D18 was minimum.The expressions of preplacodal genes,including DLX3,DLX5,DLX6,HES1,HES4,OTX2 and EYA1 increased remarkably at the first induction stage and then decreased.Lens-specification gene SOX2 declined gradually and then increased.In addition,the expression of PAX6 increased during all three induction stages.Furthermore,lens-differentiation genes including MAB21L1,CMAF,PROXI and PITX3 had no significant change in the early induction stage,but increased significantly at the third induction stage.Conclusions The expression dynamics of lens development-associated transcription factors in the hESC induced LB corresponded to those in vivo,which indicate that this induction system can recapitulate early lens development well and lay the foundation of studying lens embryonic development andtranscription factor associated congenital lens diseases.

ObjectiveTo investigate the expression levels of serum high-mobility group box 1 （HMGB1）， soluble CD163 （sCD163）， and prostaglandin E2 （PGE2） in patients with hepatitis B virus-related chronic-on-acute liver failure （HBV-ACLF）， and to evaluate the value of the three indicators used alone or in combination in predicting prognosis. MethodsA total of 76 patients with HBV-ACLF who were hospitalized in Department of Infectious Diseases， The First Affiliated Hospital of Xinxiang Medical University， from July 1， 2022 to September 30， 2023 were enrolled， and according to the 28-day prognosis， they were divided into survival group with 48 patients and death group with 28 patients. General data were collected， Model for End-Stage Liver Disease （MELD） score was calculated， and ELISA was used to measure the serum levels of HMGB1， sCD163， and PGE2. The independent-samples t test was used for comparison of normally distributed continuous data between two groups， and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups； the chi-square test was used for comparison of categorical data between two groups. The Spearman rank correlation test was used to analyze the correlation of HMGB1， sCD163， and PGE2 with MELD score； the receiver operating characteristic （ROC） curve was used to analyze the value of HMGB1， sCD163， and PGE2 used alone or in combination in predicting the prognosis of HBV-ACLF patients. ResultsThere were significant differences between the two groups in total bilirubin， white blood cell count， the percentage of neutrophils， procalcitonin， serum amyloid A， interleukin-6， serum sodium， and serum creatinine （all P<0.05）. Compared with the survival group， the death group had significantly higher serum levels of HMGB1 （Z=-2.997， P=0.003） and sCD163 （Z=-2.972， P=0.003）， a significantly higher MELD score （t=-6.997， P<0.001）， and a significantly lower serum level of PGE2 （Z=-4.909， P<0.001）. The Spearman rank correlation test showed that HMGB1 and sCD163 were positively correlated with MELD score （r=0.431 and 0.319， both P<0.05）， while PGE2 was negatively correlated with MELD score （r=-0.412， P<0.05）. The ROC curve analysis showed that HMGB1， sCD163， and PGE2 used alone had an area under the ROC curve （AUC） of 0.717， 0.716， and 0.856， respectively， while the combination of the three indicators had the highest predictive value， with an AUC of 0.930， a sensitivity of 0.778， and a specificity of 0.920. ConclusionSerum HMGB1， sCD163， and PGE2 used alone or in combination have a good reference value in predicting the prognosis of HBV-ACLF patients， and the combination of the three indicators has the highest predictive value， which holds promise for further observation and research.