ABSTRACT
Objective To analyze mechanical characteristics for stress accumulation of the maxillary complex during expansion until complete fracture of the mid-palatal suture by using the three-dimensional (3D) finite element method, and verify validity of the model. Methods The finite element maxillary complex model containing the microimplants was established. The yield strength of the mid-palatal suture was set, and the transverse displacement of 0.25 mm was loaded every 5 ms as the load until the suture was completely fractured. The CT images of one clinical patient before and after expansion were compared and verified. Results During 0-17 ms, the stress was mainly concentrated around the microimplants, the middle of the mid-palatal suture and the zygomatico-maxillary sutures. During 18-60 ms, cracks began to occur in the mid-palatal suture, and expanded forward and backward. During 61-71 ms, the rupture path was followed by posterior part of the mid, palatal suture-the front part and the back part. Conclusions The 3D finite element model of microimplant-assisted expansion based on fracture mechanics was effective and the calculated fracture process result were more consistent with clinical practice. The research findings provide the mechanical reference model for more effective research on microimplant-assisted palatal expansion in the future.
ABSTRACT
Angiosteosis is associated with increased vascular stiffness and leads to clinical manifestations such as high blood pressure and heart failure,which increases the risk of cardiovascular morbidity and mortality.Angiosteosis is considered to be ectopic deposits of calcium phosphate crystallization in the form of hydroxyapatite in cardiovascular tissue.However,the mechanism of angiosteosis is not yet clear.The pathophysiologic process of angiosteosis is similar to normal bone mineralization.Matrix vesicles (MV) play an important role in bone mineralization.Researches confirmed the existence of MV in the calcified arteries under the microscope.Angiosteosis is widely found in clinical diseases,so the studies of the mechanism of angiosteosis and the role of MV in angiosteosis are of great significance.
ABSTRACT
BACKGROUND:Mesenchymal stem cel s are multipotent progenitor cel s that can be isolated from the bone marrow, adipose tissue, umbilical cord blood and so on. Mesenchymal stem cel s possess strong immunosuppressive effects on both innate and adaptive immunity. OBJECTIVE:To summarize the immunomodulatory properties of mesenchymal stem cel s for T lymphocytes, B lymphocytes, natural kil er cel s and dentritic cel s and prospect its therapeutic implication. METHODS:PubMed and CNKI databases were searched for relevant literatures published from 2000 to 2015. The key words were“mesenchymal stem cel s, immunomodulator, T cel s, B cel s, NK cel s, dendriticc cel s”in Chinese and English, respectively. Then, 61 papers were included and further analyzed. RESULTS AND CONCLUSION:The immunomodulatory effects of MSCs on lymphocytes, B lymphocytes, natural kil er cel s and dentritic cel s were elicited by cel-cel contact and soluble cytokines. But mesenchymal stem cel s from different sources hold different immunomodulatory effect on immune cel s. When we use mesenchymal stem cel s in clinic, some important factors, such as isolation methods, cel sources, colonization sites, should be taken into account. In order to ensure the clinical safety and effectiveness, there are stil many problems to be further studied before mesenchymal stem cel s can be widely used in clinic.
ABSTRACT
Objective To explore the protective effects of quercetin on damage induced by oxidative stress and to clari?fy its molecular mechanism. Methods Chang liver cell cultures were randomly divided into control groups, H2O2 group and 3 doses of quercetin groups. Cell survival rate was detected with MTT. Cell apoptotic rate was measured by FACS(Fluores?cence-activated cell sorting). Intracellular reactive oxygen species (ROS) level in Chang liver cells were tested by flow cy?tometer. The DCF fluorescence intensity of DCFH-DA-stained intracellular ROS was observed by fluorescence microscope. The levels of malondialdehyde (MDA), superoxide dismutase(SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were determined in liver cells using commercial available kits. The expression of Nrf2 were detected by Western blot. Re?sults Compared with control, cell survival rate and levels of SOD, CAT and GSH-Px decreased significantly in H2O2 group (P < 0.05 ),while cell appotosis rate, content of MDA and mean fluorescence intensity(MFI) increased in H2O2 group (P <0.05). In comparison with H2O2, expression of Nrf2 protein was higher in all three quercetin treatment groups (P<0.05). Con?clusion Quercetin protected Chang liver cells from H2O2-induced oxidative stress, which may be caused by the increased ex?pressions of down stream antioxidant genes via activating the Nrf2-ARE signaling pathway.
ABSTRACT
We screened differential expression bone-related microRNAs (miRNAs) in serum of patients with osteogenesis imperfect (OI). First, we selected the reference gene (s) fit for quantitative detection of serum miRNAs by using geNorm and several other programmes. Then real-time fluorescent quntitative PCR was used to detect the expression level of bone-related miRNAs gained by means of miRanda, Targetscan and Pictar softwares caculation and reading literature. Then, the results were analyzed with the matched t test. All 6 candidate reference genes had a stable expression level in serum of healthy controls and patients with different characters, and the optimal number of reference genes is 4 (miR-16, let-7a, snRNAU6, miR-92a) after Pairwise Variations analysis (V4/5 = 0.133 < 0.15). For validating the universality of expression stability, we detected the relative expression value of miR-16, let-7a, snRNAU6 and miR-92a in another 8 healthy controls and 16 patients with OI and the result revealed that the expression of 4 genes remained stable (M < 1.5). After measuring serum levels of more than 100 bone-related miRNAs in patients with real-time qPCR, 11 miRNAs showed differential expression, and bioinformatic analysis suggested these altered expressional mioRNAs had possibilities to participate in the process of OI. So the experiment indicated that there existed many differential expression bone-related miRNAs in serum of patients with OI, and these miRNAs had potentials to be promising biomarkers for serologic tests and diagnosis of OI.
Subject(s)
Child , Female , Humans , Male , Biomarkers , Blood , Case-Control Studies , Gene Expression Profiling , Gene Expression Regulation , MicroRNAs , Blood , Genetics , Osteogenesis Imperfecta , Blood , GeneticsABSTRACT
Objective To investigate the G2 cell cycle arrest and apoptosis induced by HIV-1 Vpr gene on Hela,Lovo and HepG2 cancer cells.Methods Recombinant vector pcDNA4-Vpr was constructed by DNA recombination technology and was then transfected into Hela,Lovo and HepG2 cells.Meanwhile,pcDNA4-EGFP plasmid group,FUGENE group and blank group were also set up as control.Ratio of cytostasis was evaluated by MTS assay 24 h,48 h and 72 h later,cell cycle arrest examined by flow cytometry and apoptosis detected by staining with ANNEXIN V and PI double dyes.Results Compared to the control group,the value of inhibition ratio,G2 arrest and apoptosis of Hela,Lovo and HepG2 cells increased obviously 24 h,48 h and 72 h after the transfection ( P ＜ 0.05 ).72 h after the transfection,the inhibition ratio of Hela,Lovo and HepG2 was 29.67％,27.35％ and 31.67％ respectively.Percentage of G2 phase cells was 24.9％,18.8％and 32.1％ respectively.Apoptosis percentage of Hela,Lovo and HepG2 ceils was 15.46％,7.7％ and 41.5％ correspondingly.Conclusion HIV-1 Vpr gene can induce cell cycle G2 arrest and apoptosis of Hela,Lovo and HepG2 cell lines in vitro.
ABSTRACT
Objective To evaluate the clinical value of color ultrasound guided coarse needle bioptic histo-pathology in the diagnosis of retroperitoneal solid mass. Methods 32 cases with retroperitoneal solid mass accepted coarse needle biopsy (CNB) guided by color ultrasound, and followed to surgical mass resection. The histopathologi-cal result of CNB was compared to the post-operative pathological diagnosis. Results CNB were successful in all ca-ses and no complications occurred. Compared with the pest-operative pathology,the accuracy of CNB was 93.75% (30/32). There was no false-negative and very low rate of false-positive (3.13% ,1/32) of CNB in diagnosing ma-lignant tumor. Conclusions CNB guided by color ultrasound is a safe and an effective method in diagnosis of retro-peritoneal solid mass.