ObjectiveTo investigate the effects of propofol and etomidate on apoptosis in hippocampal neurons in rats.MethodsOne hundred and forty male 4 weeks old SD rats were randomly divided into 7 groups (n =20 each):control group (group C) ; groups P1,2,3 received intraperitoneal (IP) propofol 50,100 and 200mg/kg and groups E1,2,3 received IP etomidate 10,30 and 60 mg/kg respectively.Arterial blood samples were obtained at 2 h after the animals were fully awake for blood gas analysis.The animals were then sacrificed and their brains removed for microscopic examination of the ultrastructure of neurons in hippocampal CA1 area and detection of Survivin and Caspase-3 mRNA and protein expression in hippocampus by RT-PCR and Western blot analysis.ResultsThere was no significant difference in PaO2,PaCO2,SaO2,HCO3-,BE and pH value among the 7 groups.The neurons in CA1 area were basically normal in groups C,P1 and E1 while condensation of the chromatin of the nucleus and apoptotic bodies were observed in groups P3 and E3.Caspase-3 mRNA and protein expression was significantly up-regulated while Survivin mRNA and protein down-regulated in groups P3 and E3.Conclusion High dose of propofol and etomidate may induce apoptosis in hippocampal neurons in rats by up-regulation of Caspase-3 expression and down-regulation of Survivin expression.

Objective To investigate the effect of morphine on the expression of p53 mRNA and E2F-1 mRNA in human gastric carcinoma cell line MGC-803 .Methods The human gastric cancer cell line MGC-803 was purchased from Cell Biology Research Institute, Chinese Academy of Sciences, and cultured in DMEM liquid culture mediun. The cells were seeded in 6-well plates (1 × 103/ml or 2 × 105/ml, 1 ml/well) and divided into 2 groups (n = 18 wells each):group Ⅰ normal control (group C); group Ⅱ was exposed to 10 μmol/L morphine (group M). The proliferation of the cells was determined by colony formation assay at 7 day of incubation with morphine. The expression of p53 mRNA and E2F-1 mRNA was detected and the ulrastructure of the cells examined with transmission electron microscope after being incubated with morphine for 24 h. Results The proliferation of the cells and E2F-1 mRNA expression were significantly lower and p53 mRNA expression was significantly higher in group M than in group C (P ＜ 0.05). The nuclear evelope was intact and the nucleolus and chromosomes were clearly visible in group C, while in group M fragmentation of nuclear envelope and nucleolus and apoptotic bodies were observed. Conclusion Morphine can inhibit the proliferation of the cells and accelerate the cell apoptosis through up-regulating the expression of p53 gene and down-regulating the expression of E2F-1gene in human gastric carcinoma cell line MGC-803.

Objective To investigate the effects of different doses of propofol anesthesia on the long-term cognitive function in neonatal rats.Methods One hundred 7-day-old male Sprague-Dawley rats,weighing 9-18 g,were randomly divided into 5 groups (n =20 each) ∶ control group (C group) and propofol 25,50,100 and 200mg/kg groups (groups P1-4,respectively).Groups P1 and P2 received intraperitoneal propofol 25 and 50 mg/kg,respectively.Groups P3 and P4 received intraperitoneal propofol 100 and 200 mg/kg,respectively,and after righting reflex completely recovered,an increment of propofol 50 mg/kg was given until the total amount was finished.Five animals in each were chosen and arterial blood samples were obtained immediately after the animals were fully awake for blood gas analysis.The rats were then continuously fed.When the rats were 9 weeks old,the spatial learning and memory function was tested by Morris water maze.The animals were then sacrificed and their brains were removed for detection of the expression of nerve growth factor (NGF) and Caspase-9 protein and mRNA in hippocampal tissues (by Western blot analysis and RT-PCR) and for microscopic examination of the ultrastructure of hippocampal neurons.Results There was no significant difference in blood gas analysis index between the 5 groups (P ＞ 0.05).Compared with group C,no significant change was found in the escape latency and frequency of crossing the original platform in group P1,the escape latency was prolonged and the frequency of crossing the original platform was decreased in groups P2-4,the expression of NGF protein and mRNA was down-regulated and the expression of Caspase-9 protein and mRNA was up-regulated in groups P1-4 (P ＜ 0.05).The escape latency was gradually prolonged,the expression of NGF protein and mRNA was gradually down-regulated and the expression of Caspase-9 protein and mRNA was gradually up-regulated in groups P1-4.The frequency of crossing the original platform was decreased in groups P2-4 compared with group P1 (P ＜ 0.05).There was no significant difference in the frequency of crossing the original platform between groups P2-4 (P ＞ 0.05).Nucleus condensation,chromatin condensation,nuclear fragmentation and apoptotic bodies were observed in groups P2-4.Conclusion Propofol anesthesia can impair the long-term cognitive function in neonatal rats,the effect is related to the dose,and inhibition of NGF expression and increase in the activity of Caspase-9 may be involved in the mechanism.

Objective To evaluate the effects of propofol anesthesia on hippocampal protein kinase A (PKA)-cAMP response element binding protein (CREB) signaling pathway in neonatal rats.Methods One hundred and seventy-five male Sprague-Dawley rats,aged 7 days,weighing 8-15 g,were randomly divided into 5 groups (n =35 each) using a random number table:control group (C group) and propofol 25,50,100 and 200 mg/kg groups (P~ groups).Groups P1 and P2 received intraperitoneal propofol 25 and 50 mg/kg,respectively.Groups P3 and P4 received intraperitoneal propofol 100 and 200 mg/kg,respectively,and after righting reflex completely recovered,an increment of propofol 50 mg/kg was given until the total amount was finished.Five animals in each group were chosen and arterial blood samples were obtained immediately after the animals were fully awake for blood gas analysis.Five animals in each group were chosen at 2 h after fully awake and the age of 9 weeks,the rats were sacrificed and their brains were removed for microscopic examination of the ultrastructure of hippocampal neurons and for determination of PKA mRNA,CREB mRNA,PKA protein and pCREB protein in hippocampus (using RT-PCR and Western blot analysis).Results There was no significant difference in the indexes of blood gas analysis anong the five groups (P ＞ 0.05).Nuclear swelling and fragmentation,chromatin condensation,apoptotic bodies,decreased number of synapses and widened synaptic space were observed in P2,P3 and P4 groups.Compared with group C,the expression of PKA mRNA,CREB mRNA,PKA protein and pCREB protein was significantly down-regulated at 2 h after fully awake and the age of 9 weeks in P1,P2,P3 and P4 groups (P ＜ 0.05).Conclusion The mechanism by which propofol anesthesia induces neurotoxicity in neonatal rats may be related to inhibition of the activity of PKA-CREB signaling pathway.

Objective:To explore the function of the cya gene and the preliminary mechanism of attenuated strain.Methods:The biological characteristics of cya mutant in acid and alkali resistant,salt resistance,motility,biofilm components,poisonous to the cells of epithelial cell adhesion,invasion were analysis.Results:The mobility capabilities,acid and alkali resistance and salt tolerance of cya mutant were significantly lower than the parent strain;the composition testing revealed that the cya mutant did not produce cellulose,curli and biofilm;at the same time the adhesion and invasion to epithelial cells of cya mutant had a prominent depression,and the toxicity to HeLa cells was weaker than the parent strain.Conclusion:The function of cya gene is closely related to athletic ability, penetration of cell membrane, the formation biofilm and virulence.It will provide a theory reference to the functional research of Salmonella typhimurium cya gene and the mechanism of attenuated strain.This will contribute to the development of oral vaccine using attenuated Salmonella typhimurium as vector.

OBJECTIVETo assess the efficacy of Dexamethasone (DM) pericoronal injection for the control of swelling and trismus caused by impacted mandibular third molars extraction.

METHODSCochrane, PUBMED, EMBASE and CBM were searched for eligible studies. Hand-searching included references of the included studies and Chinese dental journals. Risk of bias of the included studies was assessed by two reviewers independently using Cochrane Collaboration's tool, and data extraction was done by them. Meta-analysis was delivered with Revman 5.1.

RESULTSSeven randomized controlled trials, involving 684 participants, were included. Six of them had moderate risk of bias and one had high risk of bias. Meta-analysis showed that DM pericoronal injection could relieve trismus by 6.77 mm (P=0.02) within 1-2 days after the surgery. It could also reduce 51% of the risk of moderate-severe trismus(P<0.000 01) and could significantly control facial swelling (P<0.05). There was no differences between 4 mg and 8 mg DM (P>0.05).

CONCLUSIONPeriodontal injection of 4-5 mg DM could control facial swelling and trismus following impacted mandibular third molar extraction. But more randomized controlled trials are needed.

Objective: To develop an oral live vaccine vector which stably carries exogenous genes.Methods:SL1344ΔsipBΔasd host-vector balanced lethal system was constructed by the method of recombinant suicide plasmid-mediated allelic exchange on the basis of attenuated Salmonella typhinurium SL1344ΔsipB.Then,the biological characteristics of SL1344ΔsipBΔasd was analyzed.Results:The results showed that the mutant was stabile with the Δasd gene in vitro;the serotype and growth rate of SL1344ΔsipBΔasd strain was almost same as the parent SL1344ΔsipB and SL1344 strain.And the mutant strains remain swim ming zones.Virulence test in mice showed that the virulence of SL1344ΔsipBΔasd which carried complementary plasmid pYA3493 by electro-transformation decreased by 1.4%compared with SL1344.Conclusion: These results showed that the SL1344ΔsipBΔasd mutant was successfully constructed.It is likely that this mutant should be used as a live vector to express foreign genes.

Objective:To explore the different patterns of brain structural abnormalities in patients with delayed neuromyelitis optica pedigree disease (LO-NMOSD) and its relationship with clinical neuropsychological scale score based on the quantitative analysis of three-dimensional (3D) brain structure MRI.Methods:Patients with neuromyelitis optica pedigree disease in remission (NMOSD group) who received treatment at Jilin University First Hospital from January 2016 to December 2018 were prospectively included and divided into LO-NMOSD subgroup and early-onset NMOSD (EO-NMOSD) subgroup according to whether the age of first onset was>50 years. Another age-and sex-matched healthy volunteers with NMOSD patients were recruited as the control group. 3D brain T 1WI and T 2 fluid-attenuated inversion recovery sequence imaging were acquired, and clinical data, neuropsychological scores of all subjects were analyzed. Total gray matter volume (GMV), cerebral gray matter fraction (GMF), cerebral white matter fraction (WMF), and cerebral white matter high signal fraction (WMHF) were obtained by quantitative analysis of MRI data using voxel-based morphology and lesion segmentation tool techniques. Analysis of covariance was used to compare the differences in brain structure between LO-NMOSD subgroup and EO-NMOSD subgroup, NMOSD group and control group. Partial correlation analysis was used to analyze the correlation between GMF, WMHF and patient clinical data, neuropsychological scale scores, and the correlation between WMHF and GMF, WMF. Results:There were 47 cases in the NMOSD group, including 7 males and 40 females aged 18-66 years. Among them, there were 20 cases in the LO-NMOSD subgroup and 27 cases in the EO-NMODS subgroup. The control group consisted of 50 individuals (13 males and 37 females, aged 18 to 77 years). Compared with the control group, the GMV of the right caudate nucleus in the LO-NMOSD group was reduced ( t=3.33, P<0.05), and the GMV of multiple brain regions in the bilateral frontal and temporal lobes in the EO-NMOSD group was reduced considerably (FDR corrected, P<0.05), which was consistent with the NMOSD group. After adjusting for age, there was no statistically significant difference in WMHF between the LO-NMOSD and EO-NMOSD groups ( F=0.22, P=0.644). The LO-NMOSD subgroup showed a negative correlation between global GMF and the extended disability status scale (EDSS) score ( r=-0.53, P=0.025). WMHF in the NMOSD group was positively correlated with annual recurrence rate and EDSS ( r=0.35 and 0.35, respectively, and P=0.017 and 0.018, respectively), while other indicators were not correlated ( P>0.05). The EO-NMOSD subgroup WMHF showed a negative correlation with GMF and WMF ( r=-0.76, -0.70, respectively, P<0.001). The NMOSD group showed a negative correlation between WMHF and GMF, WMF ( r=-0.38, -0.55, respectively, P<0.05). There was no correlation between WMHF and GMF, WMF in the LO-NMOSD subgroup ( P>0.05). Conclusions:The extent and location of gray matter atrophy in patients with LO-NMOSD are different from those of EO-NMOSD. The correlation between WMHF and brain structural changes and clinical data is different between the two groups of patients. These suggest that LO-NMOSD patients may have different patterns of brain structural damage.

Objective To analyze the biological characteristics of a mutant strain of Salmonella ty-phimurium SL1344 with sseK2-deletion (SL1344△sseK2) in order to provide reference for further study of safe and effective live vaccines. Methods The mutant strain SL1344△sseK2 with a deletion of 1047 bp in sseK2 gene was constructed through a two-step allelic exchange using recombinant suicide plasmid. Its com-plemented strain, SL1344C△sseK2, was also constructed. Biological and immunological characteristics of the mutant strain were detected. Results PCR, double-enzyme digestion and sequencing analysis showed that the mutant strain SL1344△sseK2 and the complemented strain SL1344C△sseK2 were successfully con-structed. The serotype of the mutant strain was 1,4,[5],12:i:1,2, identical to the parent strain SL1344. In addition, the mutant strain showed no significant change in biochemical characteristics or growth rate and was genetically stable in vitro. Compared with the parent strain SL1344, the virulence of SL1344△sseK2 was attenuated in BALB/ c mice. The median lethal dose of SL1344△sseK2 for 6-week-old BALB/ c mice was 3. 44×108 colony-forming units (CFU), which was 1620 times lower than that of SL1344. Oral immuniza-tion with SL1344△sseK2 protected 62. 5％ of the mice against challenge with wild Salmonella typhimurium strains on 17 d after vaccination. The levels of serum IgG antibody peaked on 14 d after immunization. No significant difference in biological characteristics was observed between the complemented and the parent strains, indicating that the mutant strain was basically complemented to the wild-type strain.Conclusions The mutant strain SL1344△sseK2 was constructed successfully and genetically stable with sig-nificantly attenuated virulence and good immunogenicity. This study suggested that sseK2 gene played an im-portant role in regulating the virulence of SL1344, which might provide reference for further study of its func-tion and for assessing its potential as a candidate live attenuated vaccine.

Objective To study the sequence structure of Salmonella typhimurium Ssek3 gene and to express it at protein level in a prokaryotic expression system .Methods Sequence of Ssek3 gene was ob-tained from Salmonella typhimurium SL1344 strain.Bioinformatics methods were used for systematic analy-sis .A prokaryotic expression system for expressing Sse3k gene was constructed and the expressed protein was purified by Ni-NTA affinity chromatography .Results Sequence analysis showed that the Ssek3 gene of Sal-monella typhimurium was 1008 bp in length, encoding a protein of 335 amino acids and 72 amino acid resi-dues.The molecular weight, molecular formula and isoelectric point of Ssek3 protein was 37.89×103, C1700 H2629 N463 O497 S12 and 6.7, which indicated that it was a stable and hydrophilic protein .Ssek3 protein was a membrane protein without signal peptide or transmembrane region , containing five N-glycosylation sites , three O-glycosylation sites , 33 phosphorylation sites , 22 linear B-cell epitopes , 11 T-cell epitopes and 21 di-sulfide bonds.The secondary structure of Ssek3 protein contained 114 α-helices (Hh) (34.03％), 72 ex-tended chain (Ee) (21.49％), 30β-sheets (Tt) (8.96％) and 119 random coils (Cc) (35.52％).Re-sults of SDS-PAGE showed that the fusion protein Ssek 3 expressed in the prokaryotic expression system was a secretory protein with a molecular weight of about 40×103 .Conclusion The Ssek3 gene of Salmonella typh-imurium is successfully cloned , sequenced and expressed in this study , which will lay a foundation for fur-ther studying the role of Ssek3 protein in host cells during Salmonella typhimurium infection.