Objective:To explore the role and molecular mechanisms of S100A6 protein in neonatal meningitis caused by Streptococcus agalactiae. Methods:Human brain microvascular endothelial cells (HBMECs) were used as an in vitro experimental model, and siRNA was employed to construct S100A6 gene knockdown HBMECs strain. The S100A6 gene overexpression cell line was established by lentiviral transfection method. Western blot was used to detect the expression level of S100A6 protein in HBMECs after Streptococcus agalactiae infection, and the change in intracellular inflammatory cytokine protein levels after S100A6 gene knockdown or overexpression. A neonatal bacterial meningitis model was established by injecting Streptococcus agalactiae suspension into the cisterna magna of neonatal Sprague-Dawley (SD) rats. HE staining was used to observe pathological changes in brain tissue; immunohistochemistry was used to detect the expression and distribution of S100A6 protein in brain tissue; Western blot and ELISA were used to measure S100A6 protein levels in cerebrospinal fluid (CSF). Results:Compared with the control group, the intracellular S100A6 protein level in HBMECs increased significantly following Streptococcus cgalactiae infection. After S100A6 gene knockdown, the invasion rate of Streptococcus agalactiae into the HBMECs was significantly reduced ( P<0.01), while intracellular TNF-α and IL-6 protein levels were elevated markedly ( P<0.01). In contrast, overexpression of S100A6 gene increased the invasion rate ( P<0.01) and notably decreased TNF-α and IL-6 protein levels ( P<0.001). In the neonatal SD rat bacterial meningitis model, HE staining revealed substantial neutrophil infiltration in brain tissue after Streptococcus agalactiae infection. Immunohistochemistry showed extensive deposition of S100A6 protein around the meninges, and significant expression of S100A6 protein was also detected in CSF. Conclusions:S100A6 protein is crucial in mediating neonatal meningitis caused by Streptococcus agalactiae infection. S100A6 gene knockdown promotes the production of intracellular inflammatory cytokines and reduces Streptococcus agalactiae invasion into cells, thereby alleviating bacteria-induced cellular damage. Additionally, the increased expression of S100A6 protein in brain tissue and CSF after Streptococcus agalactiae infection suggests its potential as a diagnostic biomarker for bacterial meningitis.

Objective:To explore the role and molecular mechanisms of S100A6 protein in neonatal meningitis caused by Streptococcus agalactiae. Methods:Human brain microvascular endothelial cells (HBMECs) were used as an in vitro experimental model, and siRNA was employed to construct S100A6 gene knockdown HBMECs strain. The S100A6 gene overexpression cell line was established by lentiviral transfection method. Western blot was used to detect the expression level of S100A6 protein in HBMECs after Streptococcus agalactiae infection, and the change in intracellular inflammatory cytokine protein levels after S100A6 gene knockdown or overexpression. A neonatal bacterial meningitis model was established by injecting Streptococcus agalactiae suspension into the cisterna magna of neonatal Sprague-Dawley (SD) rats. HE staining was used to observe pathological changes in brain tissue; immunohistochemistry was used to detect the expression and distribution of S100A6 protein in brain tissue; Western blot and ELISA were used to measure S100A6 protein levels in cerebrospinal fluid (CSF). Results:Compared with the control group, the intracellular S100A6 protein level in HBMECs increased significantly following Streptococcus cgalactiae infection. After S100A6 gene knockdown, the invasion rate of Streptococcus agalactiae into the HBMECs was significantly reduced ( P<0.01), while intracellular TNF-α and IL-6 protein levels were elevated markedly ( P<0.01). In contrast, overexpression of S100A6 gene increased the invasion rate ( P<0.01) and notably decreased TNF-α and IL-6 protein levels ( P<0.001). In the neonatal SD rat bacterial meningitis model, HE staining revealed substantial neutrophil infiltration in brain tissue after Streptococcus agalactiae infection. Immunohistochemistry showed extensive deposition of S100A6 protein around the meninges, and significant expression of S100A6 protein was also detected in CSF. Conclusions:S100A6 protein is crucial in mediating neonatal meningitis caused by Streptococcus agalactiae infection. S100A6 gene knockdown promotes the production of intracellular inflammatory cytokines and reduces Streptococcus agalactiae invasion into cells, thereby alleviating bacteria-induced cellular damage. Additionally, the increased expression of S100A6 protein in brain tissue and CSF after Streptococcus agalactiae infection suggests its potential as a diagnostic biomarker for bacterial meningitis.

Objective To evaluate the role of vimentin(Vim)in neonatal meningitis induced by group B streptococcus(GBS)and explore its molecular mechanism,so as to provide experimental basis for the prevention and treatment of GBS neonatal meningitis. Methods Human brain microvascular endothelial cells(HBMECs)were used as the cell model,the Vim knockdown strain was constructed by transfection of Vim small interfering RNA(siRNA)sequence into HBMECs,and NC siRNA group transfected with negative control sequence was set at the same time. The inhibitory effect of Vim was detected by Western blot and immunofluorescence assay. After 48 h of transfection,the cells were infected with GBS at a MOI of 100,and adhesion and invasion tests were performed 2 h and 3 h after infection,respectively. After 3 h of infection,the effect of Vim inhibition on NF-κB p65 nuclear translocation in HBMECs was measured by Western blot and immunofluorescence assay,and the effect of Vim inhibition on ERK pathway activation related proteins and inflammatory factors in HBMECs was detected by Western blot. Results Compared with the control group,the Vim protein level and fluorescence intensity in HBMECs of Vim siRNA group significantly decreased(t = 3. 242 and 71. 51,P < 0. 05 and < 0. 001,respectively). Compared with NC siRNA + GBS group,the adhesion rate and invasion rate of Vim siRNA + GBS group decreased significantly(t = 9. 949 and 30. 050,respectively,each P < 0. 001);the phosphorylated p65 level decreased significantly(t = 2. 824,P < 0. 05),the nuclear translocation of p65 protein was inhibited,and the intensity of green fluorescence in nucleus decreased significantly;the levels of TNF-α,IL-6 and phosphorylated ERK1/2 proteins were significantly inhibited(t = 4. 000,6. 367 and 3. 872,respectively,each P < 0. 05). Conclusion Inhibition of Vim can reduce the adhesion and invasion of GBS to HBMECs,inhibit the activation of NF-κB and ERK signaling pathway and the production of downstream inflammatory factors,thus reducing the damage of GBS to HBMECs.

Objective:To investigate whether memantine hydrochloride (MEM) could promote the bactericidal effect of neutrophils against methicillin-resistant Staphylococcus aureus (MRSA) and the possible mechanism. Methods:Neutrophils were co-incubated with different concentrations of MEM and MRSA for 4 h. Then the cell lysates were collected and cultured on plate for survival bacteria counting. After co-incubation, the neutrophils were collected to detect the production of reactive oxygen species (ROS) and the release of neutrophil extracellular traps (NETs). A mouse model of MRSA infection was established, and then the mice were treated with or without MEM. Blood, spleen and kidney samples were collected from the mice for bacterial colony counting and blood procalcitonin (PCT) detection. In the 48 h survival experiment, the mice were first infected with MRSA, and then treated with MEM or PBS. The survival rates of the mice were calculated and the survival curves were drawn.Results:The number of MRSA co-cultured with neutrophils decreased significantly in the presence of MEM, and within a certain concentration range, the survival number of MRSA decreased with the increase of MEM concentration. Moreover, MEM could significantly promote the production of ROS by neutrophils and the formation of NETs. In vivo experiment showed that the concentration of PCT in mouse blood samples was lower in the MRSA+ MEM group than in the MRSA+ PBS group. The animal experiment also revealed that MEM significantly decreased the bacteria loads in mouse blood and organs and increased the 48 h survival rate after MRSA infection.Conclusions:MEM could significantly promote the bactericidal effect of neutrophils against MRSA, which might be related to the enhanced generation of ROS by neutrophils and the formation of NETs.

Objective:To investigate the correlation between hematological parameters and testicular viability, and to identify potential indicators of intraoperative testicular viability or postoperative testicular atrophy.Methods:Clinical data of 173 children with testicular torsion treated by emergency operation in the Department of Urology, Beijing Children′s Hospital, Capital Medical University from January 2006 to January 2020 were retrospectively analyzed.According to the surgical methods, 90 and 83 cases were included in the orchiectomy group and orchiopexy group, respectively.The duration of onset, spermatic cord torsion degree and hematological parameters of the 2 groups were compared by the independent-samples t test, χ2 test and Mann- Whitney U test.Risk factors for testicular resection were analyzed by multivariate Logistic regression.In addition, 30 children in the orchiopexy group were followed up for bilateral scrotal ultrasound at 6 months postoperatively.They were sub-grouped into testicular atrophy group (13 cases, 43.3%) and non-atrophy group (17 cases). Differences between 2 subgroups were compared by the independent-samples t test and Mann- Whitney U test.Receiver operating characteristic (ROC) curves were plotted to analyze the prognostic potentials of indexes with significant differences in children with the duration of onset of >6-<51 h. Results:Duration of onset (9.3 h vs.51.0 h)( Z=-8.293, P<0.001), spermatic cord torsion degree (360.0° vs. 540.0°)( Z=-5.267, P<0.001), mean platelet volume (MPV) (9.8 fL vs.10.1 fL)( Z=-2.018, P=0.044) and age (147.5 months vs. 143.0 months)( Z=-2.165, P=0.030) were significantly different between the orchiopexy group and the orchiectomy group.The multivariate Logistic regression analysis suggested that the duration of onset ( OR=1.033, P<0.001), spermatic cord torsion degree ( OR=1.004, P<0.001) and MPV ( OR=1.662, P=0.044) were positively correlated with testicular resection.For patients with the duration of onset of >6-<51 h, the area under the curve (AUC) of duration of onset, spermatic cord torsion degree and MPV was 0.753, 0.755 and 0.629, respectively.MPV was significantly different in the postoperative testicular atrophy group and the non-atrophy group [(10.2±0.5) fL vs.(9.8±0.5) fL]( t=2.426, P=0.022). The ROC curve analysis showed that the cut-off value of MPV for predicting testicular atrophy was 9.9 fL, and its sensitivity and specificity were 83.3% and 70.6%, respectively, the AUC was 0.752. Conclusions:The duration of onset, spermatic cord torsion degree and MPV can be used as predictors of intraoperative testicular viability, which are helpful for clinicians to predict and judge the testicular necrosis caused by testicular torsion before operation.In addition, 43.3% of children with testicular torsion eventually developed testicular atrophy after orchiopexy, and only MPV may be used as a predictor of postoperative testicular atrophy.

Objective: To investigate the effects of different concentrations of MgSiF₆ as electrolyte on the bond strength between titanium and porcelain after micro-arc oxidation (MAO) treatment and screen the suitable concentration of MgSiF₆ that can improve the bond strength between titanium and porcelain. Methods: Four different concentrations of MgSiF₆ (10, 20, 30, 40 g/L) were chosen as MAO reaction solutions. Sandblasting treatment was selected as a control group. After porcelain was fused to each specimen, titanium-porcelain bond strengths were evaluated by the three-point bending test according to ISO 9693. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were adopted to evaluate the morphologies and elemental compositions of both the MAO coatings and the interfaces of the titanium-porcelain restoration. Results: The surface of titanium specimen in the control group was sharp and rough, while specimens in both 10 g/L group and 20 g/L group were porous and homogeneous. However, the pores found on the specimens in the latter group were larger in diameter (approximately 1.0-2.0 μm) than those on the former one (0.2-0.5 μm). The bond strengths of the control group and the experimental groups (10, 20, 30, 40 g/L MgSiF₆) were (27.08±3.16), (38.18±2.65), (44.75±2.21), (36.44±2.04), (31.04±2.59) MPa, respectively. All the experimental groups showed higher bond strengths than the control group did (P<0.05), and the bond strength of 20 g/L MgSiF₆ group was significantly higher than those of the other groups (P<0.05). Besides, the interfaces between titanium and porcelain were tight and compact in the 20 g/L group, while different amounts of pores and cracks were visible in the other groups. Additionally, after the three-point bending test, few residual porcelains could be observed on the surfaces of specimens in the control group. Conclusions MAO treatment with 20 g/L MgSiF₆ on titanium can improve bonding strength between titanium and porcelain.

Objective To explore the relationship between self efficacy and fall efficacy in patients with stroke.Methods The falls efficacy scale-international (FES-I) and the stroke self-efficacy questionnaire(SSEQ) were applied to 300 patients with stroke.Results The FES-I score of the participants was 39.13± 16.40,the scores of the indoor activity dimension and outdoor activity dimension were (26.01 ± 11.13) and (18.33 ± 7.76),respectively.The total mean score of SSEQ was (40.11 ± 22.37),the scores of the activity function dimension and self-management dimension were (24.97± 14.40)and (15.14±8.35),respectively.FES-I scores were positively correlated with SSEQ scores (r=0.550-0.802,P＜0.05).Falls efficacy could explain 34.3％ and 36.8％ variation amount for each dimension of self-efficacy in patients with stroke.Conclusion Falls efficacy is closely related to self-efficacy in patients with stroke.In order to improve the quality of medical care,medical staff should pay attention to the occurrences of reduction of self-efficacy and selfesteem in patients with stroke when they avoid falling during some activities.

Objective To translate the English version of the stroke self-efficacy questionnaire (SSEQ) into Chinese,and to evaluate the reliability and validity of the Chinese version of SSEQ.Methods The reliability and validity of the Chinese version of SSEQ were tested among 300 stroke patients in Jinzhou city.Data were analyzed by SPSS 17.0 software and AMOS 17.0 software.Results The Cronbach's α was 0.972,the test-retest reliability coefficient was 0.806,the correlations between items and total scale ranged from 0.729 to 0.831 (P＜0.01).A two-factor model was got by exploratory factor analysis,the communalities of the items was 0.672 to 0.929,and the cunulative explained variance was 82.687 percent.The confirmatory factor analysis revealed a good model fit,and the fit indices were x2/df =1.740,GFI =0.918,AGFI =0.853,RMSEA =0.070,NFI =0.965,CFI =0.985,standardized regression weights was 0.701 to 0.984.Conclusion The Chinese version of the SSEQ is proved to be reliable and valid.It can be used to assess the self-efficacy of stroke patients in china.

Objective To test the reliability and validity of the Chinese version of Osteoporosis Knowledge Assessment Tool (OKAT).Methods The English version of OKAT was introduced and the Chinese version was confirmed by translation,revision,retroversion and expert discussion.A sample of 400 community-living aged people were recruited to complete the OKAT (Chinese version).Internal consistency test,split-half reliability,correlation analysis,items analysis,content validity,exploratory factor analysis,confirmatory factor analysis and ROC curve were used for examination.Results The Cronbach's α of the total scale was 0.821.The split half reliability coefficient was 0.934,test-retest reliability was 0.866,inter rater reliability coefficient was 0.786,the correlations between items and total scale ranged from 0.163 to 0.542.A two-factor model containing 20 items was got by exploratory factor analysis,the cumulative contribution rate of the items was 75.528 percent.The confirmatory factor analysis revealed a good model fit.Conclusions The Chinese version of the OKAT in the elderly is proved to be reliable and valid.It can be used to assess osteoporosis for the aged people in China.

Objective To evaluate the effect of abdominal fat ratio (AFR,abdominal fat volume to total abdominal volume)at the umbilical level on hepatic CT enhancement in humans.Methods We analyzed data in 87 patients (40 women and 47 men)by Pearson correlation and linear regression analysis to assess the association of patient age and AFR with adjusted maximal hepatic enhancement (aMHE,maximal hepatic enhancement divided by the dose of iodine divided by body weight)by sex.Results aMHE was positively correlated with AFR for both men and women (r=0.48 and 0.46,respectively,both P <0.01)but not patient age.Conclusion Pa-tients with more abdominal fat seem to require relatively less amount of contrast media to get the CT enhanced degree of liver similar to those with less fat.