OBJECTIVETo construct a 3D finite-element model of the craniofacial complex with the original DICOM data of CT and to investigate the preliminary biomechanical characteristics with different directions and magnitudes of retractive forces to the maxilla of rhesus monkeys.

METHODSA male rhesus monkey with mixed dentition was used. Spiral CT was performed to establish a 3D finite-element model of the craniofacial complex. The ANSYS 12.1 software was used to analyze craniofacial complex displacement.

RESULTSEach landmark showed larger displacement with increasing force value. The displacement values and force size exhibited a linear relationship. In the x-axis direction, all displacements were small. In the y-axis direction, all displacements showed significantly higher changes with increasing force value displacement. In the z-axis direction, the A-point and ANS point moved downward, but PNS moved upward.

CONCLUSIONLoading retractive force resultes in an apparent backward and clockwise rotation on the maxilla with no obvious effects on the width of the upper jaw.

Objective To detect biofilm formation and biofilm-associated genes of methicillin-resistant Staphylococcus aureus (MRSA) in clinical isolates. Methods The biofilm were determined by microtiter plate assay (MPA) and congo red agar (CRA) and the biofilm-associated genes icaA,sarA,fnbA,fnbB were detected by PCR in 33 strains of MRSA in clinical isolates. Results Of the 33 MRSA isolates, 29(87.9%) were MPA positive, 16(48.5%) were CRA positive; The icaA gene was present in 39.4% of isolated strains. Furthermore, 69.7% of strains harboured the sarA gene, 39.4% were fnbA positive and 75.8% were fnbB positive. As many as 87.9% strains had the ability to form biofilm in vitro. 44.8% of MRSA formed biofilm in ica-dependent mechanism and 55.2% of MRSA isolates formed biofilm in ica-independent mechanism. Of the biofilm positive MRSA, 75.9% were sarA positive, 37.9% were fnbA positive and 79.3% were fnbB positive. Conclusion Most of the MRSA strains formed biofilm in ica-independent mechanism. fnbB and sarA gene shows higher frequency among the biofilm-associated genes of MRSA, it may infer that most of the MRSA strains biofilm formation are fnbB-mediated. Meanwhile, sarA may be a positive regulator of fnbB, and thus drives the biofilm formation.

ObjectiveTo explore the relationship between the mRNA and protein expressions of NIX and the pulmonary alveolus apoptosis following severe acute lung injury (ALI).Methods Rat models of severe collision injury on the chest were built.The mRNA and protein expressions of NIX in the alveolar cells at 6,12,24,48,72 and 96 hours after injury were detected using immunohistochemistry,immunoblotting and RT-PCR.Meanwhile,apoptosis of the alveolar cells was checked at different time points with Tunel assay.ResultsThe protein expression of NIX in the alveolar cells was observed both in experimental and control groups,which increased at 6 h post injury,peaked at 48 h and then declined till approaching the pre-injury level at 96 h.In the meantime,NIX showed a high expression both in the vascular endothelial cells (VECs) and the renal interstitial fibroblasts.The apoptosis of alveolar cells mainly presented in bronchi,blood vessel endothelium (BVE) and alveolar epithelium at 24 h post injury.The post-injury apoptosis rate of the alveolar cells was significantly higher than the pre-injury rate ( P ＜ 0.01 ),which reached the peak at 72 h and then decreased gradually.The changes of NIX protein in lung tissue showed a positive correlation with the apoptosis rate of alveolar cells after injury (r =0.303,P ＜ 0.01 ).ConclusionsThe up-regulated expression of NIX takes part in the pathophysiological process of apoptosis of the alveolar cells and shows consistency with the apoptosis rate change of the alveolar cells,as may be the molecular basis for apoptosis of the alveolar cells after ALI.

Objective To assess antifungal activity of aspirin and fluconazole administered alone or in combination against Candida albicans biofilms in vitro,and to evaluate the combined effect of these two drugs.Methods The MIC50 of aspirin and fluconzole against biofilm-associated adherent cells were determined respectively,then the efficacy of combinations of aspirin and fluconazole were evaluated by calculating the fractional inhibitory concentration (FIC) index.The influence of aspirin on the mRNA expression of gene ALS3,HWP1 in biofilm cells were analyzed by fluorescent quantitative PCR assay.Results The MIC50 of aspirin for ATCC64550,clinical strains 14215,15346,15538,16335 were ＞ 1440 mg/L,＞ 1440 mg/L,1440 mg/L,720 mg/L and 1440 mg/L respectively,the MIC50 of fluconazole for biofilms cells of all the strains were ＞ 64 mg/L.Aspirin did not enhance the antifungal effect of fluconazole against biofilm formed by ATCC64550,but synergistic and additive effects were found for the combination of aspirin and fluconazole to block the biofilm formation by clinical isolates (FIC index =0.75,0.5,0.75,0.75).Quantitative real-time PCR analysis showed aspirin could reduce the transcript level of ALS3 and HWP1.Conclusion Aspirin could inhibit C.albicans biofilm formation; it may increase the sensitivity of biofilm cells of C.albicans to fluconazole.

The study of protein-surface interactions represents one of the most important topics in the field of biomaterials.It is believed that blood cells do not actually contact the biomaterial surface directly,but rather interact with the molecular structure of the adsorbed protein layer.Therefore,protein plays a key role in regulation and induction of cells.It provides ideas for biomaterials designing that exploring the molecular mechanism of controlling protein adsorption and regulating cell response.This paper reviews the research progress of the interactions of protein and surfaces,and prospects the future research direction.

Total RNA was isolated from Trichomonas vaginalis and Tv-Sir2-like cDNA was amplified by RT-PCR and cloned into pGEM-T Easy plasmid. A fragment of Tv-Sir2-like cDNA was subcloned into the expression vector pET-41b and expressed in E.coli BL21 with induction of IPTG. The full-length of Tv-Sir2-like cDNA was cloned and sequenced. The prokaryotic expression system of pET-41b/Tv-Sir2-like was constructed. The fusion protein of Tv-Sir2-like was expressed in E.coli BL21, occupying 30% of the total bacterial protein after being induced by IPTG for 5 h. SDS-PAGE analysis showed that the fusion protein was about Mr 59 000. The recombinant protein of Tv-Sir2-like is efficiently expressed in E.coli BL21.

Objective To investigate the acute myocardial infarction (AMI) patient's electrocardiogram appearing fragment QRS wave (fQRS) and brain natriuretic peptide (BNP) level and scope of coronary lesions,severe cardiac complications,and the cor relation of cardiac death.Methods For selected patients with AMI,whether based on electrocardiogram (ECG) appeared in fQRS group and non fQRS groups; immunofluorescence technique was used to detect the plasma BNP level in patients with AMI.Two groups of patients with serious cardiac events and coronary artery lesions scope were observed; Coronary artery lesion count and BNP level were recorded.Results The incidence of fragment QRS wave in patients with AMI was 34.0％,fQRS wave group height/three degree atri oventricular block,ventricular tachycardia/ventricular fibrillation,cardiac shock,cardiac death rate was higher than non fQRS wave group (P ＜0.05).fQRS wave group of plasma BNP and left ventricular end-diastolic diameter,the double branch lesion,multivessel lesions were significantly higher than that of non fQRS group (P ＜ 0.01) ; left ventricular ejection fraction,the single lesion was sig nificantly lower than non fQRS wave group (P ＜0.01).The BNP levels in single,double,and multivessel lesions in the group with the increase of the lesion count were increased.Conclusions The AMI patients with fQRS easily complicated with severe arrhythmia,and case fatality rate was high,the prognosis was poor.fQRS on electrocardiogram (ECG) and BNP level had a certain relationship with range and degree of coronary artery lesions,degree of indexes might be used as a prediction of coronary lesions,and multivessel lesions had certain prediction value.

Objective To elucidate the molecular basis for induced resistance of N. gonorrhoeae to ceftriaxone in vitro. Methods The reference strain ATCC49226 and clinical isolate ZSSY00205 of N. gon-orrhoeae were exposed to subinhibitory concentration of ceftriaxone for the induction of resistance. Then,suppression subtractive hybridization was performed with the pre-induction parent strains as drivers and post-induction mutant strains as testers to create a subtractive cDNA library. Following that, a total of 192 clones were randomly selected from the library, and arrayed by spotting onto nylon membranes. Finally, dif-ferentially expressed genes were screened by hybridization with labeled-RsaI restriction fragments from the sensitive and resistant N.gonorrhoeae strains respectively, and analyzed by sequencing and homology research using Blast program. Results A subtractive library for these resistant N.gonorrhoeae strains was generated by SSH technique. Microarray analysis and homology research confirmed 5 genes related to ceftriaxone resistance, i.e. mtrR, mtrC, gyrB, rpsJ and PJD1. Conclusions The induced resistance of N. gonorrhoeae to ceftriaxone may be associated with mtrR, mtrC, gyrB, rpsJ and PJD1 genes which probably mediate the resistance by enhancing the activity of efflux pump system.

Objective To investigate the mechanisms of the alleviation of islet graft earlier injury in the gastric submucosa.Methods The recipients were divided into gastric submucosa group (n =8) and hepatic portal vein group (n =8).1200IEQ SD rat islets were transplanted into diabetic SD rats induced by the administration of streptozocin (STZ).Glucose tolerance test and pathological examination were performed 14 days post transplantation.30 min after the transplantation,the C-peptide of the two groups were detected.12 h after the transplantation,IL-1β and TNF-α of the two groups were examined.Results The mean survival time (MST) of grafts in gastric submucosa group was (25.9 ± 4.1) d and (16.0 ± 0.8) d (P ＜0.01) in portal vein group.The results of glucose tolerance test and immunofluorescent staining demonstrated that grafts in gastric submucosa group survived well and got excellent function 14 days post transplantation.Compared with the gastric submucosa group,after 30 min of the transplantation,C-peptide in portal vein group was significantly higher [(1.46 ± 0.28) ng/ml.vs.(3.84 ± 0.22) ng/ml,P ＜ 0.01].Additionally,the level of IL-1β [(29 ± 1.41) pg/ml.vs.(262.26 ± 53.37) pg/ml,P ＜ 0.01] and TNF-α [(23 ± 1.41) pg/ml.vs.(138.51 ± 39.5) pg/ml,P ＜ 0.01] in portal vein group,were also significantly higher than the gastric submucosa group,after 12 h of the transplantation.Conclusion Islet transplantation in gastric submucosa prolongs islet grafts survival by avoiding or alleviating IBMIR and the injuries induced by early inflammatory mediators.

AIM:Panton-Valentine leukocidin(PVL)is a pore-forming toxin secreted by Staphylococcus aureus epidemiologieally associated with the often-lethal necrotizing pneumonia.Until now,the mechanisms of pathogene-sis of PVL leading to the fatal pulmonia remains undefined and also acquired plenty of the toxins is difficult.In the present study，we obtain recombinant staphylococcal F and S components of the Panton-Valentine leukocidin by gene engineering and evaluate its biological activity in vitro,which provides an experimental basis for the further studies of its biological func-tion and its toxicity in pneumonia.METHODS:The full-length of F and S components of PVL gene amplified from the strain of Staphylococcus aureus DNA by hiSh-fidelity PCR was cloned into prokaryotic expression vector pET22b(+),and the vector was transformed into BL21(DE3)plysS to construct a prokaryotie expression system.The integrity of the opening-reading frame of each construct was verified by DNA sequencing.The recombinant PVL(rPVL)was induced by1.0 mmol/L IPTG.The expressed products were identified by SDS-PAGE and the fusion proteins(6His-LukS-PV and 6His-LukF-PV)were purified from lysates of transfeeted E.coli cells by affinity chromatography on nitrilotriacetic acid columns.The eytolytie activity was tested by incubation of rPVL with human polymorphonuclear neutrophils(PMNs)in vitro.RESULTS:The nueleotide sequence of the cloned PVL gene was the same as that of reported in GenBank.E coli BL21(DE3)plysS containing recombinant vectors grow at 37℃causes some proteins to accumulate as inclusion bodies.while incubation at 30℃led to a significant amount of soluble active proteins which accounted for about 31.7％ of the total bacterial protein.The relative molecular weight showed on SDS-PAGE profile was consistent with the expected value which the LukS-PV protein was about 34 kD.and the LukF-PV protein was about 35 kD.The purified rPVL was obtained and its cytolytic activity to PMNs was demonstrated.CONCLUSION:The genes of 1ukS-PV and lukF-PV are successfully cloned into plasmid pET22b(+)and expressed in E coli respectively.which provide a basis for analyzing the toxicity related to the diseases and further studies about the pathogenesis of PVL.