AIM:To construct a prokaryotic expression system of staphylococcal enterotoxin A(SEA)gene and determine the effects of the recombinant expression product rSEA in promoting lymphocyte proliferation and inhibiting tumor cell growth.METHODS:PCR was used to amplify entire SEA gene of S.aureus strain ATCC13565.The cloned SEA gene was sequenced after T-A cloning.SDS-PAGE was applied to measure the output of rSEA expressed by pET32a-SEA-E.coli BL21DE3.Ni-NTA affinity chromatography was performed to extract rSEA.Cytotoxicity of rSEA to Vero cells was detected using TCID_ 50 titration method and then the value of TCIC_ 50 was determined.MTT colorimetry was established to examine the effects of rSEA at different dosages on proliferation of mouse splenocytes and human peripheral blood mononuclear cells(PBMC)as well as on growth of HepG2 cells and HeLa cells in vitro.RESULTS:In comparison with the published corresponding sequences,similarities of the nucleotide and putative amino acid sequences of the cloned SEA gene were 100%.The output of rSEA was approximate 25% of the total bacterial proteins.rSEA had a cytotoxicity with TCIC_ 50 of 3.14 ?g to Vero cells.1.0-20.0 mg/L rSEA showed the significant effects of promoting proliferation of mouse splenocytes and human PBMC(P

Objective To investigate possible role of 14 -3 -3 in the pathogenesis of asthma inflammation, the expression of 14 -3 -3 protein was observed in lung tissues of asthmatic rats.Methods Expressions of 14 -3 -3 protein was determined by immunohistochemisty method in lung tissues,and the relationship between 14 -3 -3 and asthma inflammation was analyzed.Results The location of positive expression of 14 -3 -3 protein was mainly at cytoplasm,while little at plasmalemma.The positive expression cell mostly was bronchial epithelial cell,others were lymphocytes,alveolar macrophages and vascular endothelial cells.On the other hand,the bronchial smooth muscle and vascular smooth muscle were negative expressed.Moreover,the expression level of 14 -3 -3 protein in asthma group [(0.353 ±0.023)absorbance]was significantly higher than that in the control group[(0.211 ±0.028 )absorbance] (t =10.969,P <0.01).Conclusion The results showed that the 14 -3 -3 protein was overexpressed in asthmatic lung tissue,it may play an important role in asthma inflammation through bronchial epithelial cells,lymphocytes, alveolar macrophages and vascular endothelial cell.

All-ceramic crowns and bridges have been widely used for dental restorations owing to their excellent functionality, aesthetics and biocompatibility. However, the premature clinical failure of all-ceramic crowns and bridges may easily occur when they are subjected to the complex environment of oral cavity. In the oral environment, all-ceramic materials are prone to aging. Aging can lead all-ceramic materials to change color, to lower bending strength, and to reduce anti-fracture toughness. There are many factors affecting the aging of the all-ceramic materials, for example, the grain size, the type of stabilizer, the residual stress and the water environment. In order to analyze the aging behavior, to optimize the design of all-ceramic crowns and bridges, and to evaluate the reliability and durability, we review in this paper recent research progress of aging behavior for all-ceramics restoration materials.
Ceramics ; chemistry ; Crowns ; Dental Materials ; chemistry ; Dental Porcelain ; chemistry ; Dental Restoration Failure ; Dental Restoration, Permanent ; Dental Stress Analysis ; Denture, Partial, Fixed ; Humans ; Surface Properties

The purpose of this study was to investigate the three-dimensional displacement of the cantilever fixed partial denture (CFPD) under an oblique loading. One Beagle dog was used in this experiment. The CFPD, which used the second premolar and the first molar as abutments and the second molar as pontic, was made in vitro fresh mandible of the Beagle dog, and the digital laser speckle (DLS) technique was employed to measure the three-dimensional displacement of the CFPD under the oblique loading for the first time. We found that when an oblique loading was exerted on the pontic, the displacement of CFPD was the greatest, and the displacement of the abutment near the pontic was smaller than that of the pontic but greater than that of the abutment far from the pontic. We also found that when an oblique loading was exerted on the abutment, the displacement of the directly loaded abutment was greater than that of the other abutment and the pontic. Under the oblique loading, the displacement increased with increasing of load. The experiment demonstrated that it would be advisable for the clinicians to avoid oblique loading, especially the oblique loading of the pontic when using the CPDF. The DLS technique may be one kind of methods for measuring the three-dimensional displacements of the small and irregular objects.
Animals ; Bite Force ; Dental Abutments ; Dental Stress Analysis ; methods ; Denture Design ; Denture, Partial, Fixed ; Dogs ; Imaging, Three-Dimensional ; Lasers ; Male ; Mandible ; Occlusal Adjustment ; Tooth Mobility