Leukoaraiosis (LA) is not only found in patients with vascular dementia,Alzheimer's disease,brain trauma,carbon monoxide poisoning Binswanger's disease,mild cognitive impairment,diabetes,but also have a certain proportion in the normal elderly.This article reviews the advances in research on the risk factors,pathogenesis,pathological changes,clinical manifestations,imaging characteristics and treatment of LA.

BACKGROUND: Resin adhesives include total-etching, self-etching and one-step adhesive. The studies concerning their adhesive properties remain different.OBJECTIVE: To compare the bonding strengths of fiber posts cemented to root canals with etch-and-rinse adhesives and self-etch adhesives, and to observe the physical interface bonding conformation using laser scanning confocal microscope so as to understand the retention of macro-and micro-morphology relationship.DESIGN, TIME AND SETTING: In vitro comparative observation was performed at the laboratories of Prosthodontics and Oral Surgery, Ninth People's Hospital, Shanghai Jiao Tong University from March 2008 to March 2009.MATERIALS: MATCHPOST fiber posts (Bisco, USA); etch-and-rinse adhesives (One-step, Bisco, USA) and self-etch adhesives (Panavia F adhesive system, Japan), fluorescein (Sigma, USA).METHODS: A total of 10 upper central incisor teeth, which had been freshly extracted for periodontal reasons, were selected,and the crown, 1 mm from the enamel-cementum junction, was cut. They were randomly divided into 2 groups with 5 specimens in each group. The fiber posts were bonded to root canals with One-Step or Panavia F which was tagged with rhodamine B.MAIN OUTCOME MEASURES: Each specimen was sectioned into two 2 mm-thick slices. A push-out test was made in a universal testing machine (EZ20), and confocal laser scanning microscopic (CLSM) analysis was performed to evaluate the primer penetration into dentin. The thickness of adhesive layer was measured by random software.RESULTS: The bonding strength of the group cemented with One-step was significantly greater than Panavia F (P < 0.05). The bonding strength of root crown was significantly greater than root apex (P < 0.05). One-step represented in CLSM image showed numerous and longer resin tags than Panavia F (P < 0.05).CONCLUSION: Etch-and-rinse adhesives (One-step) gained higher bonding strengths than self-etch adhesives (Panavia F).Resin binder to bond strength of fiber post and neck was greater than in the root apex.

Recent studies have shown that Notch signaling pathway can improve neural stem cell selfrepair ability and promote angiogenesis,but at the same time,it will also aggravate the inflammatory response after cerebral ischemia.This article reviews the relationship between Notch signaling pathway and cerebral

Objective To analyse the stress distribution of distal-extension removable partial dentures supported by mini implants. Methods The finite element analysis models of conventional removable partial dentures ( CRPD) and mini implants supported removable partial dentures (ISRPD) were established by modular denture model. The stress distribution of abutments and supporting tissues was compared by finite element analysis software Abaqus 6.5.Results Under vertical loading, the stress of abutment teeth, mucosa of edentulous region and alveolar bone of ISRPD model was lower than that of CRPD model. Under oblique loading, the stress of each part of CRPD model and alveolar bone of ISRPD model significantly increased, while that of abutment teeth and parodontium of ISPRD model decreased. Conclusion The distal-extension removable partial dentures supported by mini implants work well in protecting the abutments and supporting tissues.

Objective To analyse the stress distribution of precision attachment dentures used in distal-extension edentulous cases. Methods The finite element models of conventional removable partial dentures and precision attachment dentures were established by modular denture model, and the models of precision attachment dentures were established with 4┬4 as one abutment or 43┬34 as two abutments. The stress distribution of abutments and supporting tissues was compared by finite element analysis software Abaqus 6.5.Results Under vertical loading or oblique loading, the stress of abutments and supporting tissues from attachment dentures with two abutments was significantly lower than that from attachment dentures with one abutment. The stress of conventional removable partial dentures significantly increased under oblique loading. Conclusion It is reasonable for the design of attachment dentures with two abutments for mandibular distal-extension edentulous cases.

Objective To establish three dimensional finite element model libraries of telescopic dentures and removable partial dentures by means of model libraries, and compare the characteristics of stress distribution among three prostheses. Methods Normal model libraries were imported and edited, and models of bilateral free-ended cases were established. Based on the model libraries of fixed partial dentures and removable partial dentures, the finite element models of telescopic dentures and removable partial dentures with medial or distal occlusal rest were established using softwares such as DELL Precision Graphics Workstation, UG 5.0, HyperMesh 7.0 and Abaqus 6.5, then finite element stress analysis was performed. Results The stress distribution on abutment root, parodontium, alveolar mucosa and alveolar bone was uniform. The maximum value of stress on the abutment root (6.205 Mpa) was much less than those of two removable partial dentures (18.41 Mpa and 34.49 Mpa). Conclusion For bilateral free-ended cases, the telescopic denture design is uniform in stress distribution with less stress on abutment root, which is healthy to the abutment root and surrounding tissues.

Objective To redevelop the finite element model libraries and to analyse the stress distribution of telescopic crown dentures. Methods The finite element model libraries were redeveloped based on the model libraries of normal dentition, fixed partial denture and removable partial denture. With the help of softwares such as DELL Precision Graphics Workstation, UG 5.0, HyperMesh 7.0 and Abaqus 6.5, the telescopic denture models on the bilateral free-ended case were imported and edited, then the finite element stress analysis was performed. Results The models were easily established. The maximum value of stress and its distribution on abutment root, periodontal membrane, alveolar mucosa, alveolar bone and dental prostheses were observed and studied by the finite element stress analysis. Conclusion The way to establish models of telescopic crown dentures by model libraries is feasible and reliable.

Objective To investigate the stress distribution in the abutment and supporting tissues of distal-extension removable partial dentures with mesial and distal occlusal rest under loading. Methods A modular denture model was used to build a model of mandibular dentition defect ( 765┬567 loss) with HyperMesh 7.0 software. Prosthetics with mesial (M model) and distal occlusal rest (D model) were designed with UG 5.0 software, and the finite element models were completed with HyperMesh 7.0 software. The stress distribution was analyzed in the abutment and supporting tissues of distal-extension removable partial dentures with mesial and distal occlusal rest when bilateral vertical forces were applied. Results Compared with M model, D model provided much larger maximum stress in abutments and periodontal membrane. Stress of D model mainly concentrated on roots of 4┬4 , while that of M model uniformly distributed on roots of 43┬34 . The maximum stress of M model was significantly larger than that of D model on the mucosa of edentulous region. The maximum stress on alveolar bone of two models' edentulous region was equal, while the stress of M model distributed more widely. Conclusion It is prior to select mesial occlusal rest in distal-extension removable partial dentures.

Objective To investigate the experimental methods of transferring the synoviocytes with the reconstructed pcDNA3.1-TGF-β1 gene by the liposomes and study the feasibility of self-induction of synoviocytes to the chondrocytes in vitro so as to provide a scientific and experimental basis for the further gene enhanced tissue engineering research in articular cartilage repair.Methods Synoviocytes were cultivate in vitro and purified to construct the eucaryotic expression plasmid carrying the recombinant rabbit TGF-β1 gene.By means of Lipofectamine 2000,the synoviocytes were transfected with pcDNA3.1-TGF-β1 (experimental group) and with pcDNA3.1 ( + ) blank plasmid (control group).The synoviocytes free from transfection was set as blank group.After 48 hours of transfection,the cells were screened by G418.Representative sections from among the positive clones were used for RT-PCR assay of instant expression of TGF-β1.The other sections were used for immunohistochemical analysis with antibodies to TGF β1.Screening of cells by G418 was continued for 12 days of cell counting and drawing the growth curve.The antigens of TGF-β1 and collagen Ⅱ were examined every week three weeks after transfection.All images were processed by using analysis instrument (Image-Pro Plus V6.0).Statistical analysis was conducted with SPSS 13.0 software package.The difference between groups was tested by using variance ( ANOVA) analysis.Results The transfection efficiency in experimental group was 18% ,with temporary decreased living activity of the transfected cells shown by growth curve.The cell population decreased to 3.6 × 104/ml four days after transfection.After 72 hours of transfection,the positive fragment of TGF-β1 was detected by RT-PCR assay,and immunohistochemical staining of antibiotics to TGF-β1 showed positive particles only in the experimental group.After three weeks of tranfection,the immunohistochemical analysis with antibodies to TGF-β1 and type Ⅱ collagen showed that there were positive particles in the transfected cells in the experimental group,with no positive particle in the control and blank groups.According to the results of Image-Pro Plus V6.0,PU value of anti-TGF-β1 was (19.04±1.26) seven days after transfection,while that of control and blank groups were (4.07 ± 0.65)and (3.23 ±0.56) respectively,with statistical difference (P<0.05).PU value of anti-type Ⅱ collagen in experimental group,control group and blank group was (13.74 ± 1.27),(4.62 ±0.56) and (3.93 ± 0.38) 14 days after transfection,with statistical difference ( P < 0.05).Conclusions Transfection of the rabbit articular synoviocytes with the reconstructed pcDNA3.1-TGF-β1 gene can be successfully accomplished by using Lipofectamine 2000 method.The transfected synoviocytes can express TGF-β1 and excrete type Ⅱ collagen,have chondrogenic potential when transfected by pcDNA3.1-TGF-β1 gene and can be used as candidate cells for repair of articular cartilage.

We investigated the molecular characteristics of the full-length genome of 14 dengue serotype 1 virus (DENV-1)strains isolated in Sino-Myanmar border region in Yunnan Province,China during 2013-2015.Isolation of dengue virus was using C6/36 cell culture method.Viral RNA was extracted from virus isolates,and then the full-length genome was amplified by RT-PCR.The homology and phylogenetic analysis was made on the nucleotide and deduced amino acid sequences by bioinformatics software including ClastalX1.83 and MEGA6 etc.Results showed that fourteen strains of DENV-1 isolated from dengue fever cases,of these,9 strains from Ruili City of Dehong Prefecture,3 from Lincang Prefecture,2 from Kunming City.RT-PCR and sequencing indicated that the full-length genes (10 735 nt) of 14 DENV-1 strains were obtained,and their open reading frame (95-10 271) were coded 3 392 amino acid residues.The genotypes of DENV-1 were revealed by homology and phylogenetic analysis based on structural and non-structural proteins.Thirteen were genotype Ⅰ (G-Ⅰ) (7 from indigenous cases in Ruili and Lincang and 6 from imported case from Myanmar to Ruili,Lincang and Kunming),and 1 G-Ⅲ from imported case from India to Kunming.The phylogenic analysis indicated that the 13 isolates from Yunnan divided into 2 phylogenic subgroups,and they had a closer genetic relationship with the strains isolated from Southeast Asia.The gene sequences of the 13 G-Ⅰ strains have been acquired,the rate of their nucleotide homology and amino acid homology were 97.02 ％-100 ％ and 98.78 ％100 ％ respectively.Compared with 6 strains from Southeast Asia,nucleotide homology and amino acid homology were 96.53％-99.53％ and 97.33％-100％ respectively.Compared with prototype strain (US_Hawaii) of DENV-1,nucleotide homology and amino acid homology were 93.76％-94.45 ％ and 95.86 ％-96.91％ respectively.Compared with US_Hawaii strain,there were 44 and 150 different sites in amino acid of structural and non-structural proteins,respectively.The G-1 of DENV-1 have been popular in Sino-Myanmar border region in Yunnan,2013-2015.They have genetic diversity but multiple transmission sources were from Myanmar,and should strengthen control cross-border spread of dengue fever in this region.It is necessary to further study that change of the amino acid sites of Yunnan strains of DENV-1 is related to its antigenicity and pathogenicity.