Guangzhou, China
Guangzhou, China

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Song G.,China Institute of Technology | Song G.,Sun Yat Sen University | Zhang Y.,458 Hospital of Chinese PLA | Liu B.-Q.,Sun Yat Sen University | And 2 more authors.
Journal of Clinical Rehabilitative Tissue Engineering Research | Year: 2010

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) differentiating into neural cells is an effective way of cell therapy of nervous system disease. However, the methods used nowadays still need to be improved. OBJECTIVE: To induce the differentiation of rhesus monkey BMSCs into neuron-like cells by using sonic hedgehog factor. METHODS: Rhesus monkey BMSCs differentiating into neuron-like cells was induced by typical retinoic acid and sonic hedgehog factor. Rhesus monkey BMSCs were isolated and cultured by density gradient centrifugation method. Cell growth was observed under an inverted phase contrast microscope and cell growth curve was determined using MTT assay. Flow cytometry was performed to characterize the phenotype of BMSCs, and immunohistochemistry was utilized to assess differentiated cells.Ultra-structure of the differentiated cells was observed by transmission and scanning electron microscopes. RESULTS AND CONCLUSION: Rhesus monkey BMSCs cultured in vitro were identified by flow cytometry, with high homogenicity. Following sonic hedgehog factor disposal for 7 days, differentiated cells were mainly positive for neurone specific enolase, neurofilament protein, Tau and glial fibrillary acidic protein (GFAP). Image statistical analysis found that in sonic hedgehog factor scheme, neural stem cells marker Nestin positive rate was significantly higher compared with the retinoic acid scheme (P < 0.01). GFAP-positive rate was greater in the retinoic acid scheme than in the sonic hedgehog factor scheme (P < 0.05). Results indicated that sonic hedgehog factor scheme is an effective pathway of rhesus monkey BMSC differentiation into neuron-like cells.


Song G.,China Institute of Technology | Song G.,Sun Yat Sen University | Zhang Y.,458 Hospital of Chinese PLA | Liu B.-Q.,Sun Yat Sen University | And 2 more authors.
Journal of Clinical Rehabilitative Tissue Engineering Research | Year: 2010

BACKGROUND: Present studies have demonstrated that during neural development, differentiation of neural stem cells (NSCs) was affected by various regulatory factors from surrounding microenvironment. Sonic hedgehog (Shh) is a key induction signal during neural fetal development, and can be an effective inductor to regulate differentiation of neural cells. OBJECTIVE: To investigate the signal transduction pathway of SHH for differentiation of rhesus monkey bone marrow mesenchymal stem cells (BMSCs) into of neuron-like cells by sonic hedgehog factor. METHODS: Rhesus monkey BMSCs were isolated and cultured by conventional density gradient centrifugation. BMSCs in the induction group were treated with L-DMEM containing FGF2, B27 and fetal bovine serum for preinduction of 24 hours, and then with DMEM supplemented with 0.5 μmol/L retinoic acid or 400 μmol/L SHH for 8 days. Non-induced cells served as control group. Following labeling with neuron enolase, positive cells were screened by flow cytometry. RT-PCR and Western-blot were used to detect SHH- and retinoic acid-induced cell membrane receptor and intracellular signal protein changes. RESULTS AND CONCLUSION: SHH specific membrane receptor Ptc, retinoic acid specific receptor RARa, signal protein molecule ptch1 and Smad expressed in normal cells. Ptc expression upregulated in SHH-induced cells. High expression lasted for a long time with induction time, which was significantly stronger compared with the retinoic acid and control groups (P < 0.01). Intracellular ptch1 protein molecule expression showed similar tendency as this, but could not induce upregulation of RARa expression. During induction, retinoic acid-stimulated cells did not activate Ptc pathway. Four days following induction, RARa expression upregulated and lasted till 6 days, but there were no significant differences. No significant change in ptch1 expression was determined. SHH- and retinoic acid-induced cell Smad molecule expression upregulated, but no significant difference was determined. Results verified that SHH-induced scheme participated in cell induction and differentiation by persistently activating its specific receptors. However, there was no significant receptor pathway crossing between retinoic acid-induced and SHH-induced schemes.


Zhang S.-X.,Guangzhou University | Yu H.,Guangzhou University | Yang J.,458 Hospital of Chinese PLA | Zhou L.-H.,Southern Medical University | And 2 more authors.
Journal of Clinical Rehabilitative Tissue Engineering Research | Year: 2010

BACKGROUND: There is no domestic four-dimensional computerized tomography (4D-CT). The import 4D-CT system requires respiratory signals during image collection, limiting the reconstruction in only several CT machine. In addition, respiration monitor device and 4D-CT reconstruction software cost high, limiting the wide application in China. OBJECTIVE: To overcome the shortcoming of present commercial 4D-CT reconstruction system and implement 4D-CT reconstruction based on multi-slices CT scanner. METHODS: A 4D-CT reconstruction software program (GTH4DIM V2.0) was developed by using VC++ and VTK software tools. The CT data of patient undergoing free breathing were acquired in Cine mode by a GE LightSpeed 16 CT scanner, with the Cine during time equal to the breathing period of the patient plus one second (about 4-6 seconds), and 8 to 15 slices CT images were acquired by a row CT detector in every Cine scan. The phase of each CT slice was determined according to the volume change rule of scanned thoracic cavity and lung tissue during respiration. RESULTS AND CONCLUSION: All of the CT data with the same phase, which were acquired in Cine mode, were resorted by GTH4DIM V2.0 into a same CT series, and several 3D-CT series with the different phases could be obtained. 3D reconstruction of the CT data was completed by using GTH4DIM V2.0 software. Compared with the unsorted CT data, the motion artifacts in the 3D reconstruction of sorted CT data were significantly reduced, and all of the resorted multi-phase CT series result in a 4D-CT, which reflected the characteristics of the periodical motion viscera contained within the abdominal and thoracic cavities. The results suggest that time-resolved 4D-CT reconstruction of periodical motion viscera could be implemented with any general multi-slice CT scanners based on the volume change rule of scanned thoracic cavity and lung tissue during respiration, and the process of the 4D-CT data acquisition and reconstruction were independent on the respiration monitoring system and not restricted to the hardware or software of the CT scanner. Therefore, it is a universal 4D-CT reconstruction method.


Wang X.-J.,458 Hospital of Chinese PLA | Guo T.-W.,PLA Fourth Military Medical University | Zhang Y.-M.,PLA Fourth Military Medical University
Journal of Clinical Rehabilitative Tissue Engineering Research | Year: 2010

BACKGROUND: Due to the high cost of precious metals and biological safety of nickel-chromium alloy, titanium porcelain crown attracts attention. However, high production costs and weak bonding strength of titanium limit the use of titanium porcelain. This study aims to produce domestic titanium porcelain powder, reduce the cost of titanium porcelain, replace nickel-chromium alloy porcelain repair, and improve security of fixed dental prosthetics. OBJECTIVE: To develop a kind of new titanium-bonding-porcelain powder and to test its thermal property. METHODS: According to the basic requirement of titanium bonding porcelain, based on the expansion coefficient, viscosity, mechanical property and chemical stability of bonding porcelain, as well as influence of bonding porcelain on the wet ability of titanium, the major components of the titanium-bonding-porcelain were selected. The GGW experimental titanium-bonding-porcelain was made after repeated tests. The GGW titanium-bonding-porcelain was analyzed using differential scanning calorimetry and thermal expansion coefficients were determined, the glass transition temperature of GGW bonding-porcelain was also defined, as well as the matching correlation with casting titanium thermodynamics. RESULTS AND CONCLUSION: Differential scanning calorimetry showed that when GGW bonding-porcelain was about 650 °, crystal began to educe from the amorphous matrix, indicating the tentative sintering temperature of GGW titanium-bonding-porcelain was lower than 800 °. Under 537 ° glass transition temperature, the coefficients of thermal expansion of pure Ti and GWW experimental titanium-bonding-porcelain were 8.42×10-6/°, 8.29×10-6/° respectively. A difference of 0.13×10-6/° suggested GWW experimental titanium-bonding-porcelain has an ideal thermal compatibility with casted pure Ti. GGW bonding-porcelain has a promising future for titanium.

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