BACKGROUND:With the development of science and technology and modern aerospace, the effects of mechanobiology in extreme mechanical environment—high acceleration are becoming an issue of concern. Studies have shown that high acceleration has certain effects on the cels. OBJECTIVE:Based on a centrifuge, to design a cel loading centrifuge used for exploration of cel mechanobiology under high acceleration. METHODS:For the cel loading centrifuge, a culture plate or/and culture bottle ful of culture fluid was/were loaded with constant acceleration or variable velocity to explore the experimental feasibility. Besides, a finite element model was built by ANSYS software according to structure and properties of the rotor. The rotor system was calculated under equilibrium and dangerous working conditions, respectively, to analyze the stress and deformation distribution. Moreover, the strength of the main shaft was checked under the dangerous working conditions. Then the analysis results of ANSYS were compared with the results of strength check. RESULTS AND CONCLUSION:Experimental findings showed that the culture plate or/and the culture bottle could be used for (0-40)×g highly constant acceleration or variable acceleration loading. Through the simulation and comparison analysis, we confirmed the reliability of the cel loading centrifuge. This cel loading centrifuge can be used to implement the study of cel mechanobiology under high acceleration in the general biology laboratory. It also provides a basis for wide application of cel loading centrifuge in the future.

Objective To analyze the clinical features and prognosis in adult Chinese patients with anti-γ-aminobutyric acid B receptor (GABA-BR) encephalitis.Methods We reviewed the clinical manifestations,cerebrospinal fluid (CSF) examinations,brain magnetic resonance imaging and prognosis of 12 patients who were diagnosed as anti-GABA-BR encephalitis in Capital Medical University Xuanwu Hospital from March 2013 to December 2015.Results The major clinical features of anti-GABA-BR encephalitis patients included seizures (12/12),cognitive disorder (10/12),psychiatric symptoms (10/12),sleep disorders (3/12),visual hallucination (2/12),involuntary movements (2/12),decreased consciousness (3/12),cerebellar signs (2/12),fever (2/12).GABA-BR-antibody was positive in CSF and serum of all the patients.Electroencephalogram revealed epileptic discharges in 4/12 patients.Brain MRI showed abnormal signal in up to 9/12 patients,located in the hippocampus,temporal lobes,thalamus and periventricular area.PET or SPECT indicated hypometabolism in 5/6 patients.After the average of fourteen months follow-up,9/12 patients had good prognosis,3 patients did not.Of 3 patients with poor outcome,2 had small cell lung cancer.Conclusions The predominant clinical features of the anti-GABA-BR encephalitis are seizures,cognitive disorder and psychiatric symptoms.The lesions are not only located in limbic system.Early diagnosis and immune modulation may provide a good outcome.

BACKGROUND: In tissue engineering, three-dimensional biodegradable scaffolds are generally used as a basic structure for cell anchorage, proliferation. Currently, no perfect scaffold is available. OBJECTIVE: To observe the growth of rabbit bone marrow stromal cells (BMSCs) cultured in different-intensity three-dimensional fibrin glue in vitro, and to discuss the feasibility of fibrin glue used as a scaffold material of bone tissue engineering. DESIGN, TIME AND SETTING: The single sample observational study was performed at the China-Japan Union Hospital of Jilin University and School of Mechanical Engineering of Tianjin University of Technology from September 2007 to January 2008. MATERIALS: Fibrinogen and thrombin were mixed at various proportions, and prepared into different intensity fibrin glue. A month-old male New Zealand white rabbits, weighing 0.25 kg was used in this study. METHODS: Rabbit BMSCs were cultured and serial subcultivation in a CO2 incubator. And then the amplified BMSCs were collected and continue to be cultured in different intensity fibrin glue for 4 weeks. MAIN OUTCOME MEASURES：Observation of growing BMSCs is performed using the phase contrast microscope. The activity of BMSCs in fibrin glue at different stages was observed using hematoxylin-eosin staining. The ultrastructural changes of BMSCs were observed which had been cultivated in fibrin glue for 4 weeks. RESULTS: After growing in fibrin glue for 4 weeks, BMSCs showed strongly active status in low intensity fibrin glue and growing slowly or dying in high intensity fibrin glue. Under the electron microscope, BMSCs following 4 weeks culture in fibrin glue (proportation of fibrinogen and thrombin was 4:1) were found, with visible cellular organs, and BMSCs had good activities. CONCLUSION: BMSCs can spread and proliferate quickly in low intensity fibrin glue. The optimal proportion of fibrinogen and thrombin is 4: 1.

BACKGROUND: A superior composite scaffold hopes be constructed to resolve adhesion between seed cell and scaffoldmaterial.OBJECTIVE: To construct composite scaffolds with fibrin glue and xenogeneic inorganic bone and to explore the three-dimensional culture of rabbit marrow stromal cells (MSCs).DESIGN, TIME AND SETTING: Observational experiment was performed at the Department of Orthopedics of China-Japan Union Hospital and the Department of Mechanical Engineering, College of Mechanical Engineering of Jilin University from November 2007 to March 2008.MATERIALS: Fibrin glue was made by a certain ratio of fibrinogen and thrombin; bovine cancellous bone following defatting and deproteinization was mixed with fibrin glue to establish composite scaffold.METHODS: Rabbit MSCs were cultured in v#ro and transferred, and the MSCs were collected for three-dimensional culture withcombined scaffolds made of xenogeneic inorganic bone and fibrin glue.MAIN OUTCOME MEASURES: The growth and proliferation of MSCs were examined by phase-contrast microscope andtransmission electron microscopy.RESULTS: Phase contrast microscope showed that the MSCs could spread evenly in the combined scaffolds. After cultured 4 weeks, the MSCs formed into densely three-dimensional net. It could be observed under the transmission electron microscopethat there were micro-protrusions in local stromal cells at 4 weeks after culture, and the mitochondrion as well as ribosomes wasobserved in the cytoplasm with rough endoplasmic reticulum.CONCLUSION: The MSCs cultured in the combination of fibrin glue and xenogeneic inorganic bone scaffolds show a betteractivity, and they can proliferate rapidly.

ObjectiveTo explore the effect of osteoarthritis (OA) chondrocytes and normal chondrocytes on the chondrogenesis of bone marrow mesenchymal stem cells(BMSCs) in self designed co-culture system. MethodsRabbit BMSCs and chondrocytes were isolated and expanded in vitro. OA chondrocytes were harvested from the rabbit of established osteoarthritis model. We made a BMSCs-low melting agarose constructs, then put it onto the self-made 6 well plates lattice assembly for co-culture with chondrocytes. The groups were divided into Normal P0-BMSCs, Normal P3-BMSCs, OA PO-BMSCs, OA P3-BMSCs and BMSCs (control) group. At 3, 7, 14 day culture, cultured cells in all groups were collected for real-time PCR, glycosaminoglycan (GAG) content, cytoactive detection, and histological observation. ResultsType Ⅱ collagen gene expression was up-regulated in group Normal PO-BMSCs, which showed 5.1-, 7.2-, 11.2-fold increase over that of control group at 3, 7, 14 days, respectively. Type Ⅰ, Ⅱ collagen and aggrecan gene expressions were not obviously up-regulated. In group OA P3-BMSCs, type Ⅰ collagen gene expression level lower than the control group in 3, 7, 14 day. In normal PO-BMSCs, GAG content showed 2.59-fold increase over that of the control group. GAG content of group OA PO-BMSCs and control group showed no significant differences.Others groups showed significant differences in comparison with the control group(P＜0.05). Alcian stain showed positive in all groups. The normal PO-BMSCs group showed the darkest blue-stained. Conclusion Rabbit normal PO chondrocytes and rabbit OA P0 chondrocytes significantly enhanced chondrogenic differentiation of rabbit BMSCs. The secreted morphogens of the rabbit normal P3 chondrocytes and rabbit OA P3 chondrocytes do not have a significant effect on chondrogenic differentiation of rabbit BMSCs.

Objective To set up the 3D-finite element(FE)model of normal acetabulum-cartilage-femoral head,so that to provide an effective model for biomechanical analysis of femoral head.Methods(1)The hip joint in one healthy adult male volunteer was scanned by MRI at coronal section.The 3D reconstruction model of acetabulum-cartilage-femoral head was constructed with MATLAB and ANSYS software.(2)The 3D orthotropy finite element model of the acetabulum-cartilage-femoral head was constructed by givig the corresponding material parameters to the different structures of the model of acetabulum-cartilage-femoral head and divided into networks through ANSYS software.(3)The standing status was imitated on the model to set boundary condition and loading and then calculated.The effect of the model was evaluated in comparison with that of literature.Results A 3D orthotropy FE model of acetabulum-cartilage-femoral head was established successfully,including 89 961 points of 448 159 units.The maximal displacement was on the femoral head,and the maximal Von Mises stress was on the femur neck.The stress analysis was the same as the results of literature and the actuality.Conclusion A 3D orthotropy FE model of acetabulum-cartilage-femoral head can be setup based on MRI images,which can provide a reasonable and effective model for biomechamical analysis of femoral head.

Objective:To study possibility of traditional Chinese drug preparation of controlled drug delivered to the colonic region. Methods: After the herbs was extracted and refined, micropills was produced with pectin selected as coating material and thallium monochloride was as internal standard substance. Results: The preparation was testified to attain schedule colon target. Conclusions: This research provided a way for traditional Chinese drug preparation of colon targeting.

Objective To investigate the chondrocyte proliferation and extracellular matrix biosynthesis of electrospun PCL scaffolds seeded with rabbit chondrocytes under flow perfusion culture in vitro.Methods Nonwoven PCL microfiber mats were fabricated,and contra-aperture cylindrical glass equipment as a perfusion bioreactor was designed and manufactured on our own.The experiment included peffusion culture group and static culture group.Primary chondrocytes were isolated from the knee joints of two-month-old New Zealand white rabbits and seeded into scaffolds.The scaffold-cell complexes were harvested at 3,7,and 14 days of culture for scanning electron micrograph (SEM) analysis,biochemical assay,real-time PCR and histology analysis.Results Electrospun PCL scaffolds were composed of microfibers with a diameter of 1.67±0.76 μm and pores with a diameter of 17.65±7.11 μm.SEM showed a better cell proliferation with typical morphology of chondrocytes under perfusion culture.At 7 days of culture,DNA content in perfusion culture group was higher than in static culture group.At 3,7 and 14 days of culture,compared with the static culture group,glycosaminoglycan (GAG) content and GAG/DNA ratio in perfusion culture group were higher,and the differences were statistically significant.At 14 days of culture,real-time PCR showed aggrecan and collagen type Ⅱ gene expression and collagen type Ⅱ to collagen type Ⅰ ratio were higher in perfusion culture group than in static culture group; HE and safranin O staining showed a significant cell proliferation,infiltration,as well as extracellular matrix biosynthesis in perfusion culture group.Conclusion Under flow perfusion culture,the electrospun PCL scaffolds seeded with rabbit chondrocytes can enhance chondrocyte proliferation and extracellular matrix biosynthesis,which is a promising method for cartilage tissue engineering.

There are many physical factors affecting the development of cartilage tissue,the mechanical con-dition is the main important one that particularly act.The mechanical conditions used in engineering cartilage tissue,such as compressive and shear force,fluid flow,hydrostatic pressure and tissue deformation or with some of them combined,were reviewed.From the standpoint of bionics,the mechanical environments ap-plied on tissue engineering should work in three aspects:providing adequately mechanical stimuli to the cells seeded in 3-D scaffold;ensuring the efficient mass-transport of the nutrients and waste products in the cells:promoting the development of functionally extracellular matrix in 3-D scaffold.The mechanical environments currently used only represented the part of mechanical conditions of in vive articular cartilage will be reviewed.In our view that rolling depression load may achieve the fit mechanical environment for cultivation of functional cartilage constructs in vitro.

BACKGROUND: It is of great significance to study the resilience of articular cartilage for human daily routine and their match quality. OBJECTIVE: To analyze the micromechanical properties of articular cartilage resilience under different loads and at time points. METHODS: The swine cartilage samples coated with tracers were compressed using the MTF-100 tensile machine, and the cartilage compression and resilience were recorded by CCD. Images were processed using digital image correlation technology.RESULTS AND CONCLUSION: During resilience, the strain value on the superficial surface of the cartilage was decreased most, successively followed by the middle layer and the deep layer, while the time of a decrease from 20%, 10% and 6% to 3% was similar. The longer the resilience time was, the more slowly the strain changed in different layers of the cartilage, but the ultimate strain was less than 1%. On the same layer under different compressive stress, the larger load caused faster strain change firstly, and then the smaller load brought about faster strain change. The effect of different continuous compressive time on the same layer of cartilage was similar with the load. These results showed that 90% resilience of the articular cartilage occurred within the first 15 minutes. The mechanical resilience of different layers of the articular cartilage has a close relationship with the loading and the loading time, and both compressive time and loading do harm to the resilience of articular cartilage. Besides, the cartilage will rebound to the state before compression.