Oral squamous cell carcinoma is a common malignant tumor of the head and neck.Early surgery can achieve good results,but most patients have cervical lymph node metastasis at the time of initial diagnosis.Although surgery combined with radiotherapy or chemotherapy can delay the progression of the disease,the overall prognosis is still not ideal.Especially in patients at stage Ⅲ/Ⅳ,the long-term survival rate has not improved.As a key microbubble in intercellular communication,exosomes contain a large number of biological molecules such as nucleic acids,proteins and lipids.Tumor-derived exosomes play a key role in regulating the tumor micro-environment.This article reviews the effects of tumor-derived exosomes on tumor proliferation,metastasis,immune regulation,diagnosis and treatment in oral squamous cell carcinoma,in order to provide new ideas for early diagnosis and treatment of oral cancer.

Oral squamous cell carcinoma is a common malignant tumor of the head and neck.Early surgery can achieve good results,but most patients have cervical lymph node metastasis at the time of initial diagnosis.Although surgery combined with radiotherapy or chemotherapy can delay the progression of the disease,the overall prognosis is still not ideal.Especially in patients at stage Ⅲ/Ⅳ,the long-term survival rate has not improved.As a key microbubble in intercellular communication,exosomes contain a large number of biological molecules such as nucleic acids,proteins and lipids.Tumor-derived exosomes play a key role in regulating the tumor micro-environment.This article reviews the effects of tumor-derived exosomes on tumor proliferation,metastasis,immune regulation,diagnosis and treatment in oral squamous cell carcinoma,in order to provide new ideas for early diagnosis and treatment of oral cancer.

OBJECTIVE To investigate the metabolic changes in MEG-01 megakaryocytes after treatment with linezolid (LZD) from metabolomic perspective and its impact on the the proliferation of cells and generation of platelet precursors. METHODS MEG-01 cells were seeded in proliferation medium and divided into blank control group (untreated),solvent control group (4‰DMSO),and 100,200,400,800 μg/mL LZD groups. The proliferation status of cells in each group was observed under the microscope;cell proliferation and viability were assessed. Cells were also seeded in differentiation medium and divided into blank control group (untreated),solvent control group (4‰DMSO),and 400 μg/mL LZD group;after 14 days of culture,platelet precursor generation was observed under the microscope;immunofluorescence staining was performed to count the proportion of cells producing pseudopodia,the relative length of pseudopodia was measured,and the expression levels of CD41 and CD42b mRNA were assessed. Cells from the solvent control group and the 400 μg/mL LZD group,cultured in differentiation medium for 14 days,were extracted and subjected to non-targeted metabolomics and targeted energy metabolomics analysis using liquid chromatography-tandem mass spectrometry. The relative content of pyruvate in cells,after being cultured for 14 days with the addition of pyruvate (10 mmol/L) or LZD (400 μg/mL)+pyruvate (10 mmol/L),was measured and observed,as well as its effects on cell proliferation and platelet precursor generation. RESULTS 400 μg/mL LZD could significantly inhibit the proliferation of MEG-01 cells and the generation of platelet precursors (P<0.01). Non-targeted metabolomic analysis of MEG-01 cells after 400 μg/mL LZD treatment revealed significant changes in energy metabolism-related pathways such as mTOR signaling pathway,alanine,aspartate and glutamate metabolism,and central carbon metabolism in cancer. Targeted energy metabolomic analysis further showed that the relative contents of adenosine triphosphate,guanosine triphosphate,and pyruvate in MEG-01 cells were significantly reduced (P<0.01),while the relative contents of lactate were significantly increased (P<0.01). Compared with the LZD group,the relative content of pyruvate,cell count,the proportion of cells producing pseudopodia and the relative length of pseudopodia were significantly increased in the LZD+pyruvate group (P<0.01). CONCLUSIONS LZD may reduce pyruvate production by inhibiting mitochondrial energy metabolism,thereby suppressing megakaryocyte proliferation and platelet precursor production,ultimately leading to the occurrence of thrombocytopenia.

Objective By observing the effect of deeply needling Lianquan (CV23) plus acupuncture at the ten nape points on the deglutition function in post-stroke pseudobulbar palsy, to objectively evaluate the efficacy of deeply needling Lianquanplus acupuncture at the ten nape points in treating post-stroke pseudobulbar palsy.Method A total of 141 patients diagnosed with post-stroke pseudobulbar palsy were divided into a treatment group (71 cases) and a control group (70 cases) by following asimple-randomized design (random number table). The treatment group was intervened by deeply needling Lianquan plus acupuncture at the ten nape points, while the control group was intervened by conventional acupuncture. A month later, the general therapeutic efficacy, Kubota's water drinking test, Toshima Ichiro's swallowing assessment, and Standardized Swallowing Assessment (SSA) were evaluated, and the therapeutic efficacies of the two groups were compared.Result The general therapeutic efficacy, waterdrinking test result, Toshima Ichiro's swallowing assessment, and SSA score were significantly improved in both groups after the treatment (P<0.05). After the treatment, the general therapeutic efficacy, water drinking test result, Toshima Ichiro's swallowing assessment, and SSA score in the treatment group were significantly different from those in the control group (P<0.05), and the treatmentwas superior to the control group. The total effective rate was 91.5% in the treatment group, versus 70.0% in the control group, and the between-group difference was statistically significant (P<0.05).Conclusion Deeply needling Lianquan plus acupunctureat the ten nape points is effective in treating post-stroke pseudobulbar palsy, superior to the conventional needling method.

OBJECTIVE:To investigate synergistic effect of carbapenems combined with fosfomycin(FOS)on carbapenems-re-sistant Pseudomonas aeruginosa isolates from urinary tract infections in vitro. METHODS:The minimum inhibitory concentration was detected using agar double dilution method. The fractional inhibitory concentration index was determined by checkerboard meth-od. The effect of carbapenems combined with FOS on biofilm of P. aeruginosa isolates was determined using 96 crystal violet stain-ing. RESULTS:12 strains of carbapenem-resistant P. aeruginosa isolates were highly sensitive to FOS and amikacin,and were com-pletely resistant to imipenem and meropenem. The combination of imipenem with FOS could induce a synergistic effect on 4 strains (33.3%);meropenem combined with FOS could induce a synergistic effect on 5 strains(41.7%);no antagonistic effect of carbap-enems combined with FOS appeared. FOS combined with carbapenems could inhibit the biofilm of carbapenems-resistant P. aerugi-nosa(P<0.05 or P<0.01). CONCLUSIONS:The combination of carbapenems with FOS possesses in vitro synergistic antibacteri-al effect on part of carbapenems-resistant P. aeruginosa isolates,the mechanism of which may be associated with inhibiting the bio-film.

Objective To study the biofilm formation ability and related gene distribution of Staphylococcus (S .) aureus iso‐lated from urinary tract infections to provide the theoretical basis for the prevention and treatment of clinical infection .Methods The minimal inhibitory concentration was detected using the agar double dilution method .The bacterial adhesion ability was deter‐mined by flat colony counting method .The biofilm formation ability was analyzed by the 96‐well crystal violet staining method .The biofilm‐associated genes were detected by PCR amplification .Results Eleven clinical strains of S .aureus were high resistant to pen‐icillin and erythromycin ,whereas were all sensitive to vancomycin and nitrofurantoin .All the isolates had a strong ability of adhe‐sion ,but the biofilm formation ability was weak .Among them ,the icaAD and icaBC genes were amplified in 10 S .aureus isolates . Conclusion The adhesion ability and biofilm formation ability of S .aureus isolated from urinary tract infections have the strain differences ,and ica is an important gene of S .aureus biofilm formation .

OBJECTIVE:To investigate the effect of subinhibitory concentration of erythromycin on adhesion of clinical isolated Staphylococcus(S.) epidermidis.METHODS:The subinhibitory concentration of erythromycin was determined based on the susceptibility test,and the representative strain Se.015 was treated with subinhibitory concentration of erythromycin.The optical density value determined by microtiter-plate assay was used to evaluate the effect of erythromycin on the adhesion of the representative strain Se.015,and electron microcopy was employed to observe the adhesion of Se.015 in samples with blank solvent served as control.RESULTS:Compared with control group,erythromycin(4 mg?L-1) group showed significantly higher optical density value(P

Objective To investigate the correlation of biofilm forming ability with biofilm associated gene of the clinically isolated Staphylococcus aureus for providing basis for the further studies of the mechanisms of biofilm formation.Methods Safranine staining was conducted for the detection of the forming ability of biofilm in 96-well plates.icaAD,icaBC,sar,agr and sigB was amplified by PCR.Results Formation of biofilm could be found macroscopically in 17 out of 27 strains,especially to X387 and X409.icaAD and icaBC were amplified in 22 isolates and sar,agr and sigB in all 27 S.aureus strains.Conclusion ica operon is the key gene for biofilm formation but cooperative action of other genes is needed during the process of biofilm formation.

Objective To study the macrolide-resistance,ability of biofilm formation and icaA-genetypes of 68 stains of clinically isolated Staphylococcus epidermidis(S.epidermidis) so as to explore the efficacy of macrolide to prevent biofilm-associated infections caused by S.epidermidis.Methods Minimum inhibitory concentration(MIC) were detected by agar-plate dilution method,and microtiter-plate assay was used to investigate the ability of biofilm formation,and icaA genetype was identified by PCR.Results High macrolide-resistant rate(88.2%) was showed for clinical isolated S.epidermidis,and biofilms for macrolide-resistant strains were significantly stronger than that of macrolide-sensitive strains,but there was no dependability found between these two for icaA positive rate.Conclusion Frequently-used macrolide such as erythromycin,azithromycin,and clarithromycin may incompetence to prevent biofilm-associated infections caused by S.epidermidis.

OBJECTIVE:To study the?-lactamase production in multi-drug resistant acinetobacter baumannii isolated in clinic.METHODS:Susceptivity to antibiotics of the bacteria was measured by K-B and agar diffusion methods.The?-lac-tamase production of acinetobacter baumannii was examined by nitrocefin disc test,then their plasmid and chromosome ex-tracted as templete,the genes coded the?-lactamase were amplified by PCR with commercial kits.Furthermore,the sequence and homology of PCR products were analyzed.RESULTS:Total12acinetobacter baumannii in this study were?-lacta-mases-producing strains with a high resistance to cephalosporin.However,it is sensitive to carbapenem-antibiotics and cephalosporin with?-lactamase inhibitors,and6strains of them were confirmed that there were?-lactamases AmpC gene on plasmid by PCR amplification and sequence analysis.CONCLUSIONS:The?-lactamases AmpC mediated by plasmid would be main factor in the high resistance to cephalosporin of acinetobacter baumannii isolated clinically.