Objective To study the effect of hypoxia on EMT molecule E-cadherin, Vimentin and invasion of human breast cancer MCF-7 cells, reveal the mechanism of breast cancer invasion and metastasis and provide experimental and theoretical basis. Methods Western blot was used to observe the change of HIF-1α, E-cadherin and Vimeutin during hypoxia on MCF-7. MTT was used to study the effects of viability.Transwell chamber was used to detect the ability of invasion and metastasis. Results The expression of E-cadherin was significantly lower (0.09±0.02)(t=30.98,P=0.0007) and the expression of Vimentin was significantly higher (0.69±0.04) (t=915,P=0.0000) with the extension of hypoxia.The capability of adhesion (81.23±0.74) (t=82.05,P=0.000),invasion(120±6) (t=22.78,P=0.0009) and migration(190±6) (t=23.49,P=0.000)was significantly increased after 72 h hypoxia(P＜0.05).Conclusion Hypoxia can downregulate E-cadherin and upregulate Vimentin and enhance the adhesion,invasion and migration of MCF-7.

Background and purpose: It was reported that activins, members of transforming growth factor-β superfamily, could induce several tumor cells into apoptosis. This study was designed to observe the effects of recombination human activin A on proliferation and apoptosis ofA549 cells. Methods: A549 cells were cultivated by routine method, then treated with different concentrations of recombination human activin A. Inhibitory effect of activin A on A549 cell proliferation was detected by MTT assay, and apoptosis of A549 cells was determined by flow cytometry. The expression of type Ⅱ receptors of activin (ActR Ⅱ and ActR Ⅱ B) was detected by Western blot. Results: Recombination human activin A inhibited the proliferation ofA549 cells in time-dependent and dose-dependent manners. Increases of apoptosis in A549 cells and expression of ActR I] and ActR ⅡB occurred dose-dependently after treated with acfivin A. Conclusion: Recombination human activin A inhibited cell proliferation and induced apoptosis in A549 cells, at least in part, by inducing expression of type Ⅱ receptors of activin and activation of its downstream signaling.

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.

The relation between the expression and activity of MMP-9 in C-reactive protein (CRP)-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B (NF-kappaB) was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 (control group), 25, 50 and 100 mug/mL (CRP groups) for 24 h. In PDTC (a specific NF-kappaB inhibitor) group, the cells were pre-treated with PDTC at 10 mumol/L and then with 100 mug/mL CRP. The conditioned media (CM) and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-kappaB inhibitor alpha (IkappaB-alpha) and NF-kappaB P(65) was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IkappaB-alpha expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-kappaB P65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 mumol/L, the decrease in IkappaB-alpha expression and the increase in NF-kappaB P(65) expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-kappaB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-kappaB activation.

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 therapeutic value and possible mechanism of diammonium glycyrrhizinate (DG) in treatment of airway remodeling in a murine model of chronic asthma. Methods Thirty male BALB/C mice were randomly divided into control group, OVA+DG group and OVA group (n=10). HE staining was used to observe the pathological changes, and Masson's staining was used to detect and measure collagen deposition. Alpha-SMA and PPARγmRNA expressions were analyzed by RT-PCR, and the protein expressions ofα-SMA and PPARγwere measured by Western blotting. Results After 75 days of OVA sensitization and challenge, obvious pathological changes occurred in the lung tissues, which was more severe in OVA group than in OVA+DG group. Collagen deposition was significantly increased after OVA stimulation, but was obviously milder in OVA+DG group than in OVA group. OVA-induced up-regulation ofα-SMA was notably attenuated by DG injection. The expression of PPARγ was markedly down-regulated after OVA stimulation but was substantially enhanced after DG intervention. Conclusion DG can inhibit airway smooth muscle proliferation possibly through up-regulation of PPARγ in a murine model of chronic asthma.

Objective To investigate the therapeutic value and possible mechanism of diammonium glycyrrhizinate (DG) in treatment of airway remodeling in a murine model of chronic asthma. Methods Thirty male BALB/C mice were randomly divided into control group, OVA+DG group and OVA group (n=10). HE staining was used to observe the pathological changes, and Masson's staining was used to detect and measure collagen deposition. Alpha-SMA and PPARγmRNA expressions were analyzed by RT-PCR, and the protein expressions ofα-SMA and PPARγwere measured by Western blotting. Results After 75 days of OVA sensitization and challenge, obvious pathological changes occurred in the lung tissues, which was more severe in OVA group than in OVA+DG group. Collagen deposition was significantly increased after OVA stimulation, but was obviously milder in OVA+DG group than in OVA group. OVA-induced up-regulation ofα-SMA was notably attenuated by DG injection. The expression of PPARγ was markedly down-regulated after OVA stimulation but was substantially enhanced after DG intervention. Conclusion DG can inhibit airway smooth muscle proliferation possibly through up-regulation of PPARγ in a murine model of chronic asthma.

OBJECTIVETo investigate the therapeutic value and possible mechanism of diammonium glycyrrhizinate (DG) in treatment of airway remodeling in a murine model of chronic asthma.

METHODSThirty male BALB/C mice were randomly divided into control group, OVA+DG group and OVA group (n=10). HE staining was used to observe the pathological changes, and Masson's staining was used to detect and measure collagen deposition. Alpha-SMA and PPARγ mRNA expressions were analyzed by RT-PCR, and the protein expressions of α-SMA and PPARγ were measured by Western blotting.

RESULTSAfter 75 days of OVA sensitization and challenge, obvious pathological changes occurred in the lung tissues, which was more severe in OVA group than in OVA+DG group. Collagen deposition was significantly increased after OVA stimulation, but was obviously milder in OVA+DG group than in OVA group. OVA-induced up-regulation of α-SMA was notably attenuated by DG injection. The expression of PPARγ was markedly down-regulated after OVA stimulation but was substantially enhanced after DG intervention.

CONCLUSIONDG can inhibit airway smooth muscle proliferation possibly through up-regulation of PPARγ in a murine model of chronic asthma.

Actins ; genetics ; metabolism ; Airway Remodeling ; drug effects ; Animals ; Anti-Inflammatory Agents ; pharmacology ; Asthma ; metabolism ; pathology ; Cell Proliferation ; drug effects ; Collagen ; metabolism ; Glycyrrhizic Acid ; pharmacology ; Lung ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Muscle, Smooth ; pathology ; Ovalbumin ; pharmacology ; PPAR gamma ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Up-Regulation

Objective:To summarize the status and trends of papers published by Chinese scholars on the combination teaching model in the area of medical education in China.Methods:Literature retrieval was performed on CNKI, WanFang, and VIP database, and studies regarding to combination teaching model in medical education were selected and analyzed. BICOMS-2 analysis software was used to extract and sort out keywords, provinces, authors and their organizations and generate co-occurrence matrix and/or word matrix. NetDraw and gCLUTO software were used to draw the network relationship diagram and cluster analysis respectively.Results:Totally 99 articles were included this study, and the number of articles published each year showed an increasing trend. Authors from 15 provinces contributed to these articles, with uneven development and limited cooperation across regions. The authors were divided into 4 main groups, but the communication among these groups was not enough. And there were 3 main research topics.Conclusion:The number of articles on combination teaching model in medical education in China is increasing, covering many authors, teams, institutions and regions. However, the communication and cooperation among these authors and institutions needs to be strengthened; and the research topics should be expanded.