The PCR product of PvpA gene was cloned into prokaryotic expression vector pET41a(+) and the recombinant expression vector was then transformed into E.coli DH5a after identified by restriction enzyme digestion and PCR.The positive recombinant plasmid was transformed into E.coli BL21 (D3) and induced to express PvpA protein.The obtained protein was analyzed by SDS-PAGE and Western blotting,purified by Ni-NTA affinity chromatography.The results showed that the purified PvpA fusion protein was obtained successfully.The expressed protein reacted to the high anti-PvpA immune serum from rabbit specially by western blotting.This study would be helpful to established a new diagnostic method for the detection of M.gallisepticum.

Objective To evaluate preventive effect of polysaccharides from Lycium ruthenicum Murray against photodamage in HaCaT cells,and to explore its possible mechanism.Methods Ultrasoundassisted extraction was used to extract polysaccharides from Lycium ruthenicum Murray in Qaidam Basin.In vitro cultured HaCaT cells were randomly divided into 3 groups:control group receiving no treatment,ultraviolet B (UVB) group irradiated with 30 nJ/cm2 UVB alone for 1 hour,experimental group pretreated with 2 g/L Lyeium ruthenicum polysaccharide solution followed 6 hours later by 30 mJ/cm2 UVB radiation for 1 hour.At twelve hours after UVB radiation,an inverted microscope was used to observe cell morphology.Then,MTS assay was performed to estimate cell proliferation,flow cytometry to detect cell apoptosis,an enzyme-labeled antigen method to detect levels of malondialdehyde (MDA) and glutathione peroxidase (GSH-Px),as well as to evaluate the activity of superoxide dismutase (SOD) and catalase (CAT),and enzyme-linked immunosorbent assay (ELISA) to measure levels of intedeukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-α) in HaCaT cells and their culture supernatant.Results Compared with the control group,the UVB group showed obscure cell morphology,cell death and floating phenomenon,while cells became swollen but renained morphologically distinct in the experimental group.MTS assay revealed that the cell proliferative activity significantly differed among the above 3 groups (F =48.88,P ＜ 0.01),and the cell proliferative activity was significantly lower in the UVB group (1.72 ± 0.12) than in the control group (2.34 ± 0.11,P ＜ 0.05) and experimental group (2.11 ± 0.10,P ＜ 0.05).Moreover,the apoptosis rate was significantly higher in the UVB group (82.41％ ± 2.49％) than in the control group (3.98％ ± 0.19％,P ＜ 0.05) and experimental group (22.79％ ± 0.97％,P ＜ 0.05),as well as higher in the experimental group than in the control group (P ＜ 0.05).Compared with the control group,the UVB group showed significantly higher levels of MDA,supernatant levels of IL-1 and TNF-α,and intracellular levels of TNF-α,but significantly lower GSH-Px levels and activity of SOl and CAT (all P ＜ 0.05).However,there was no signifi-cant difference in the intracellular level of TNF-α between the UVB group and control group (P ＞ 0.05).Conclusion Lycium ruthenicum polysaccharide has protective effects against photodamage in HaCaT cells,likely by reducing the synthesis and secretion of inflammatory substances as well as free radicals.

Objective: To investigate the changes and clinical significance of vascular endothelial (VE)-cadherin and procalcitonin (PCT) in serum and cerebrospinal fluid (CSF) of children with viral encephalitis or bacterial meningitis(BM). Methods: A total of 42 cases of children with viral encephalitis(viral encephalitis group), 36 cases of children with BM(BM group), and 20 cases of children with non-nervous system injury(control group) were selected from September 2016 to June 2018 at the Third Hospital of Zhengzhou University.The serum and CSF levels of VE-cadherin and PCT levels of the 3 groups were detected by using enzyme-linked immunosorbent assay. Results: The levels of VE-cadherin in the serum of viral encephalitis group, BM group and control group at the acute phase were (5.60±1.17) mg/L, (7.08±1.01) mg/L and (2.52±0.68) mg/L respectively, and the levels of VE-cadherin in CSF of viral encephalitis group, BM group and control group were (6.00±1.09) mg/L, (6.97±1.11) mg/L and(1.93±0.88) mg/L, respectively.The levels of PCT in the serum of viral encephalitis group, BM group and control group at the acute phase were (0.26±0.11) μg/L, (0.82±0.17) μg/L and (0.27±0.13) μg/L, respectively, and the levels of PCT in the CSF of viral encephalitis group, BM group and control group were (0.25±0.11) μg/L, (0.72±0.14) μg/L, (0.28±0.17) μg/L, respectively.As a result, the levels of VE-cadherin and PCT in the serum and CSF of BM group showed significant increase, compared with viral encephalitis group and control group in the acute phase(F=124.94, 163.21, 151.62, 127.37, all P<0.01). The levels of VE-cadherin in the serum and CSF of viral encephalitis group were also significantly higher than that of control group (all P<0.01), but there was no difference between viral encephalitis group and control group about the levels of PCT in the serum and CSF (all P>0.05). The levels of VE-cadherin in the serum of viral encephalitis group and BM group after treatment were (2.34±0.81) mg/L and (2.67±1.29) mg/L, and were(2.55±0.92) mg/L and(2.39±0.74) mg/L in the CSF.The levels of PCT in the serum of viral encephalitis group and BM group after treatment were (0.25±0.11) μg/L, (0.30±0.17) μg/L, and the levels of PCT in the CSF of viral encephalitis group and BM group were(0.22±0.10) μg/L and (0.27±0.12) μg/L.After effective treatment, the levels of VE-cadherin, PCT in serum and CSF of BM group and viral encephalitis group were almost equal, and the difference was not statistically significant(F=1.83, 0.76, 2.72, 3.89, all P>0.05). In the receiver operating characteristic (ROC) curve, the area under the ROC curve of VE-cadherin in serum and CSF was 0.896 and 0.912, and was 0.670 and 0.668 of PCT respectively. Conclusions VE-cadherin may be involved in the early stage of intracranial infection, and it may be helpful in differentiation of virus or bacterial infection with PCT.VE-cadherin has a good diagnostic value for intracranial infection.

Objective: To investigate the changes and clinical significance of Caveolin-1, matrix metalloproteinase-9(MMP-9) and interleukin-1β(IL-1β)in cerebrospinal fluid of children with bacterial meningitis or viral encephalitis. Methods: Thirty-six cases of children with bacterial meningitis, 42 cases of children with viral encephalitis, and 20 cases of children with non-nervous system infection were selected from September 2016 to June 2018 at the Third Affiliated Hospital of Zhengzhou University.The levels of Caveolin-1, MMP-9 and IL-1β in cerebrospinal fluid were detected by using enzyme linked immunosorbent assay(ELISA). Results: Cerebrospinal fluid Caveolin-1, MMP-9 , IL-1β levels in the acute phase of bacterial meningitis were(49.06±8.96) ng/L, (134.79±18.88) μg/L, (100.02±14.67) μg/L, respectively, and (29.13±7.25) ng/L, (18.69±7.23) μg/L, (47.57±8.95) μg/L in recovery phase, which were higher than those of the controls[(11.18±2.24) ng/L, (11.53±3.54) μg/L, (39.75±7.08) μg/L)], and the differences were significant (all P<0.05). Cerebrospinal fluid Caveolin-1, MMP-9, IL-1β levels in the acute phase of viral encephalitis were (42.71±10.48) ng/L, (62.78±17.39) μg/L, (57.97±11.28) μg/L, respectively, and (29.13±7.25) ng/L, (18.69±7.23) μg/L, (47.57±8.95) μg/L in recovery phase, which were higher than those of controls, and the differences were significant (all P<0.05). The levels of Caveolin-1, MMP-9 and IL-1β in cerebrospinal fluid of bacterial meningitis group and viral encephalitis group were significantly higher than those of convalescent group (all P<0.05). The levels of Caveolin-1, MMP-9, IL-1β in cerebrospinal fluid of bacterial meningitis group were significantly higher than those in viral encephalitis group (all P<0.05) in the acute phase, and no significant difference was found in the recovery phase(all P>0.05). Cerebrospinal fluid Caveolin-1, MMP-9, IL-1β showed no significant difference among children with different severity of intracranial infection.Correlation analysis showed that there was a positive correlation between Caveolin-1, MMP-9 and IL-1 β levels in cerebrospinal fluid of acute in bacterial meningitis group and viral encephalitis group(Caveolin-1 and MMP-9: R²=0.239, P<0.05; MMP-9 and IL-1β: R²=0.766, P<0.01; Caveolin-1 and IL-1β: R²=0.245, P<0.05). Conclusions Caveolin-1, MMP-9 and IL-1 β involved in the pathogenesis of intracranial infection in children, and the effects of different pathogens on intracranial infection were different.