Surgical operation is the main treatment of oral and maxillofacial tumors.Dysphagia is a common postoperative complication.Swal-lowing disorder can not only lead to mis-aspiration,malnutrition,aspiration pneumonia and other serious consequences,but also may cause psychological problems and social communication barriers,affecting the quality of life of the patients.At present,there is no systematic evalua-tion and rehabilitation management plan for the problem of swallowing disorder after oral and maxillofacial tumor surgery in China.Combining the characteristics of postoperative swallowing disorder in patients with oral and maxillofacial tumors,summarizing the clinical experience of ex-perts in the field of tumor and rehabilitation,reviewing and summarizing relevant literature at home and abroad,and through joint discussion and modification,a group of national experts reached this consensus including the core contents of the screening of swallowing disorders,the phased assessment of prognosis and complications,and the implementation plan of comprehensive management such as nutrition management,respiratory management,swallowing function recovery,psychology and nursing during rehabilitation treatment,in order to improve the evalua-tion and rehabilitation of swallowing disorder after oral and maxillofacial tumor surgery in clinic.

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.

Although there are 125 predicted DNase Ⅱ-like family genes in the Trichinella spiralis genome, plancitoxin-1-like (Ts-Pt) contains the HKD motif, a typical conserved region of DNase Ⅱ, in N- and C-terminal. It is generally believed that histidine is the active site in DNase Ⅱ. To study the nuclease activity of recombinant Ts-Pt with mutations in the active site from T. spiralis, different fragments of the mutated Ts-Pt genes were cloned using overlap PCR technique and inserted into the expressing vector pET-28a(+), and transformed into Escherichia coli Rosseta (DE3). The fusion proteins were purified by Ni-NTA affinity chromatography and SDS-PAGE. Nuclease activity of the recombinant proteins was detected by agarose gel electrophoresis and nuclease-zymography. The recombinant plasmids harboring the mutated Ts-Pt genes were constructed and expressed as inclusive body in a prokaryotic expression system. After renaturation in vitro, the recombinant proteins had no nuclease activity according to agarose gel electrophoresis. However, the expressed proteins as inclusive body displayed the ability to degrade DNA after renaturation in gel. And the nuclease activity was not affected after subjected to mutation of active site in N- and C-termini of Ts-Pt. These results provide the basis to study the relationship between DNase Ⅱ-like protein family and infection of T. spiralis.

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.

OBJECTIVE: To observe the effect of flurbiprofen( FPA) combined with dexamethasone on preemptive analgesia for whole lung lavage in pneumoconiosis patients. METHODS: Ninety pneumoconiosis patients who underwent whole lung lavage under general analgesia were divided into three groups by random number table method: combine treatment group,FPA group and control group,30 cases in each group. Patients in combine treatment group were given 2 mg/kg body weight( bw) of flurbiprofen axetil injection and 10 mg of dexamethasone through intravenous injection before 2 hours of surgery. Patients in FPA group were given 2 mg/kg bw of FPA axetil injection intravenously. The control group was injected with 2 m L 0. 9% sodium chloride solution. Visual Analogue Scale( VAS) score,Bruggramann Comfort Scale( BCS) score,and adverse reaction of the three groups were recorded in 2,6,8,12 and 24 hours after operation. RESULTS: The postoperative VAS and BCS scores of combine treatment group at the 5 time points after operation were lower than that of control group and FPA group respectively( P < 0. 01). The VAS score between the 5 time points presented an decreasing tendency with the increase of time in the combine treatment group( P < 0. 05),and the BCS score presented an increasing tendency with the increase of time( P < 0. 05). The adverse reaction,such as nausea,vomiting dizziness and drowsiness,sore throat and skin itching in combine treatment group was lower than that of control group and FPA group 24 hours postoperatively( P < 0. 017). CONCLUSION: The therapy of FPA combined with dexamethasone on preemptive analgesia is a safe and effective method for reducing postoperative pain of whole lung lavage in pneumoconiosis patients.

In order to develop a recombinant attenuated Salmonella typhimurium as oral live vaccine vector, we constructed recombinant plasmid pYA-sopENt100 by replacing the trc promoter with the sopE promoter and secretion signal sequence sopENt100 of Salmonella typhimurium on the basis of plasmid pYA3493. Then, the complementary plasmid pYA-sopENt100 was transformed into ΔcrpΔasdSL1344 by electroporation to generate attenuated Salmonella typhimurium type III secretion system ΔcrpΔasdSL1344 (pYA-sopENt100). We further characterized ΔcrpΔasdSL1344 (pYA-sopENt100). We also constructed a recombinant strain ΔcrpΔasdSL1344 (pYA-sopENt100-egfp) that harbored the reporter gene-enhanced green fluorescent protein (egfp) gene. Vero cells were infected with ΔcrpΔasdSL1344 (pYA-sopENt100-egfp) and the ability of delivery foreign antigens was tested via Western blotting analysis. The results of PCR, enzyme digestion and sequencing showed that the ΔcrpΔasdSL1344 (pYA-sopENt100) type III secretion system was constructed successfully. The serotype of ΔcrpΔasdSL1344 (pYA-sopENt100) was identical to ΔcrpΔasdSL1344 and SL1344. Compared with wild strain SL1344, the biochemical characteristics of ΔcrpΔasdSL1344 (pYA-sopENt100) had obvious change, but it was basically the same with ΔcrpΔasdSL1344. The growth speed was much slower than that of the wild strain SL1344. The chicken virulence test (LD₅₀) showed that the virulence of ΔcrpΔasdSL1344 (pYA-sopENt100) was 7×10⁴ times lower than SL1344. In addition, we observed the 37 kDa SopENt100-egfp protein in the cultured supernatant of ΔcrpΔasdSL1344 (pYA-sopENt100-egfp) strain by Western blotting analysis. However, both the 37 kDa SopENt100-egfp protein and 27 kDa EGFP protein were detected in ΔcrpΔasdSL1344 (pYA-sopENt100-egfp)-infected Vero cells. These results demonstrated that the recombinant Salmonella typhimurium type III secretion system ΔcrpΔasdSL1344 (pYA-sopENt100) was successfully constructed, and it should be used as a live vaccine vector for expressing foreign genes.
Animals ; Bacterial Proteins ; genetics ; Cercopithecus aethiops ; Mice ; Plasmids ; Promoter Regions, Genetic ; Salmonella typhimurium ; genetics ; Type III Secretion Systems ; genetics ; Vaccines, Attenuated ; genetics ; Vero Cells ; Virulence

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 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.