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BACKGROUND:Local administration of anti-tuberculosis drugs is a commonly used therapy. Due to the rapid absorption, the drugs cannot have the durable therapy effect; therefore, it is necessary to seek an optimal carrier material for the agents. OBJECTIVE:To review the new development for the carrier materials of anti-tuberculosis drugs. METHODS:A computer-based search of PubMed and VIP databases was performed by the first author to search articles related to sustained-released anti-tuberculosis drugs published from January 1990 to December 2014. The key words were osteoarticular tuberculosis; anti-tuberculosis; sustained-released drugs in English and Chinese, respectively. RESULTS AND CONCLUSION:Inorganic materials (calcium phosphate, calcium sulfate), polymer materials (polylactic acid, polyglycolic acid, polylactic-co-glycolic acid) and biomaterials (protein, glutin, alginates, chitin, demineralized bone matrix) are the main three kinds of carrier materials for anti-tuberculosis drugs. These carrier materials have their own advantages and disadvantages, which cannot be the optimal carrier materials. However, the complex of these materials is a promising technology for the optimal carrier materials in the future.
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@#Objective To observe the efficacy of a kind of complex composed of biphasic ceramic biologic bone (BCBB), bone morphogenetic protein (BMP) and basic fibroblast growth factor (bFGF) on the repair of necrotic areas of the femoral head. Methods The femoral head necrosis model of 64 femoral heads in 32 rabbits induced with microwave heating were randomly divided into four groups, which implanted with nothing (group A), BCBB/BMP (group B), BCBB/BMP/bFGF (group C) and with cancellous bone autograft (group D). The specimens were harvested separately at the end of 2, 4, 8 and 12 weeks after operation. 4 femoral heads were taken off at each interval in every group. A series of examinations were carried out including of naked eyes and gross anatomic observation, X-ray, histology, and blood vessel immunohistochemical staining. Results In group A, 1 femoral head collapsed by the end of 12 weeks, and there was only a little osteoid tissue formed. At the same time, a lot of new bone formed in group B and group C, and the boundary between the bone grafting area and the post bone still existed, but the boundary was unclear in group D, with the density consistent to the post bone. Under X-ray, the defect could be found and one femoral head collapsed in group A by the end of 12 weeks. The density of bone grafting area was high and the boundary to the post bone was unclear in group B and in group C. The density of bone grafting area was the same as the post bone and the boundary between them was unclear in group D. There was only a little osteoid tissue formed in group A by the end of 4 weeks. At the same time, there was a little new bone formed in group B, and BCBB was partly degraded. There was a lot of new bone formed in group C and group D, and BCBB was partly degraded in group C, but cancellous bone autograft was almost absorbed in group D. The new bone area by the end of 4, 8 and 12 weeks from more to less were: group C and group D (P>0.05), group B, and group A (P<0.05). At the end of 2, 4 and 8 weeks, the blood vessel area of group C was more than that of group A, group B, and group D (P<0.05). Conclusion The BCBB/BMP/bFGF complex can induced osteoinduction and revascularization, to repair rabbit femoral head necrosis as effective as cancellous bone autograft.
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BACKGROUND: Alginic acid has a relatively mild gel condition and good biocompatibility, and it has been widely used in bio-tissue engineering.OBJECTIVE: To construct bone tissue engineering scaffolds using alginate gel composite bone xenograft approach, and to observe the cell biological properties and in vivo osteogenic potential in scaffolds.METHODS: The bone marrow was harvested from two 2-week-old New Zealand rabbits, 1 ×10~(-8)mol/L recombinant human bone morphogenetic protein-2 was used to induce bone marrow mesenchymal stem cells. The induced bone marrow mesenchymal stem cells at the second generation were incubated into 1% sodium alginate gel, after cultured for 4 days, the cell morphology in gel was observed by hematoxylin-eosin staining. Bone marrow mesenchymal stem cells at the second generation were divided into simple DMEM gel group and DMEM containing 1% sodium alginate gel group, followed by a culture of 7 days. Then bone morphogenic protein-2 immunohistochemical staining was performed. A total of 24 nude mice were randomly divided into two groups, both sides of the thigh muscle pockets were implanted with bone marrow-derived mesenchymal stem cells/alginate gel/bovine cancellous bone complex as an experimental group, with bone marrow-derived mesenchymal stem cells/bovine cancellous bone as a control group. At 2 and 4 weeks post-operation, the osteogenesis in the composite was observed by histological examination, the percentage area of new bone or cartilage was determined using image analysis system.RESULTS AND CONCLUSION: The bone marrow-derived mesenchymal stern cells in the sodium alginate gel exhibited a well-stacked morphology, they suspended in a gel, showing cell division and mitosis phase. In the simple DMEM gel group and DMEM gel containing 1% sodium alginate group, the immunohistochemical results showed that, cell division and proliferation were normal, with prominence at a variety of forms, large nucleus, and clear nucleolus. The bone morphogenetic protein-2 expression had no significant difference between the simple DMEM gel group and DMEM gel containing 1% sodium alginate group (P>0.05).Scanning electron microscopy revealed that, the alginate gel evenly composited in bovine cancellous bone micropores, cell grew at different planes. Animal experiments showed that there were significant differences regarding the percentage of new bone or cartilage area between the experimental group and control group at 2 and 4 weeks postoperation (P< 0.05). It is indicated that constructing bone tissue engineering scaffolds by using alginate gel/bovine cancellous bone, complies with the ultra-structural principle of tissue engineering scaffolds, can maximize the cell loads, achieve good bio-performance, without adverse affects on the proliferation, osteogenic phenotype and related biological properties of bone marrow-derived mesenchymal stem calls, the in vivo osteogenic efficiency was high.
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BACKGROUND: Matrix material for cartilage tissue engineering exhibits too fast or too slow chondrocytes degradation in vivo, affecting tissue regeneration and shaping reconstruction, which has troubled scholars.OBJECTIVE: To amply bone marrow stromal cells (BMSCs) and induce them to chondrocytes in vitro, so as to study the feasibility of repairing articular cartilage defects in rabbits using poly(lactic-co-glycolic acid) (PLGA) loaded with BMSC-derived chondrocytes.DESIGN, TIME AND SETTING: Comparative experiment was performed at the Institute of Orthopaedics in the Fourth Military Medical University of Chinese PLA and the Center Laboratory of the Airforce General Hospital of Chinese PLA between June 2002 and June 2008.MATERIALS: A total of 36 two-month-old New Zealand white rabbits were used, and 4-6 mL bone marrow was aspirated from bilateral femoral trochanters in each animal. Primary culture and subcultures were done. In subcultures, the medium contained bone morphogenetic protein-2 (100 μg/L.), and high polymer hyaluronic acid was spread on bottom of the culture flasks in advance.In this way, the BMSCs were induced into chondrocytes and the third passage of cells at the adjusted density of 2.0×10~(10)/L wereco-cultured with PLGA for 24 hours, then PLGA-cell composites were prepared.METHODS: A defect of 4-mm in diameter and reaching medullary cavity were created in femoral condyles of 36 rabbits, and 36 right knees were treated with PLGA-cell composites, serving as experimental group, while 18 left knees with PLGA only as material group, and the other 18 knees remained untreated, as blank control group.MAIN OUTCOME MEASURES: At 4,8,12, 24 weeks after operation, the animals were euthanized and the newly formed tissues were observed macroscopically and microscopically, graded histologically, and analyzed statistically.RESULTS: Material group and blank control group shared identical outcomes of gross and histological observation, thus assigning into a control group. In the experimental group at 24 weeks, the defects were filled with white translucent cartilage tissue which appeared smooth and tenacious. The color and the luster were similar to that of normal cartilage, and was ill-demarcated from the surrounding normal cartilage. The cells on the surface paralleled to joint surface. Though the cells in the deep layer arranged disorderly, they tended to align vertically. The matrix was extensively stained. The subchondral bone formed.The tide mark basically recovered, and the new cartilage integrated with normal cartilage finely. In the control group, chondrocytes proliferated in the border, but in the bottom, there were mainly fibrous tissues. The histological grade of 12 and 24 weeks was different significantly from that of 4 and 8 weeks (P < 0.01). There were also significant differences between experimental group and control group at each time intervals after operation (P < 0.01).CONCLUSION: BMSCs were successfully induced into chondroncytes by use of bone morphogenetic protein-2 and high polymer hyaluronic acid. PLGA can be degraded and absorbed gradually while new cartilage tissues form. It can be used as a suitable scaffold material for repairing articular cartilage defects in tissue engineering.
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Objective To observe pathological features of peripheral vessel injury caused by ex-plosion shock wave so as to provide theoretical basis for emergency treatment, prevention and complication reduction of war extremity injuries. Methods A total of 18 rabbits were randomly divided into three groups (six rabbits in each group) and placed respectively at 1, 2 and 3 m away from the explosion cen-ter. The animal model with blast injury was made by using fluid dynamite that electrically exploded at 60 cm above the ground. The physical parameters of blast wave were recorded using pressure transducers (PCB, UAS). After explosion, the femoral arteries were examined grossly, histologically and immunohis-tochemically. Results The results showed that vascular endothelial cells were denudated, the spaces of contractile fiber cells increased and appeared puff, the vassular elastic fibers ruptured, flexed and de-formed visibly. Some parts of the vessel wall ruptured completely or partly, leading to bleeding. TUNEL staining and fluorescence microscope found large number of apoptotic cells in endothelium layer, smooth muscle layer and membrana adventitia layer of the blood vessels. Conclusion Explosion shock wave can result in severe large blood vessel injury, which should be paid much attention during treatment of ex-plosion shock injury.
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Objective To validate the effect of anti-infective reconstituted bone xenograft (ARBX) in treating posttraumatic osteomyelitis by one-stage grafting in the adults.Methods With clinical application approval of Medical Command,Logistics Ministry of PLA,ARBX was used to treat 27 adult patients (29 lesions) with posttraumatic osteomyelitis by one-stage grafting after debridement since September 2001.The study analyzed 27 patients (29 grafts) who were followed up for average 26 months (12-63 months).Results The follow-up for average 26 months (12-63 months) in 27 patients showed that infection of 22 patients (24 lesions) was controlled and cured,except for three with failure to control the infection or with recurrence of infection,two with controlled infection but with postoperative nonunion.The infection control rate was 89.7% (26/29) and the cure rate was 82.8% (24/29) ,which were better than the results of traditional therapy.Conclusions ARBX has high osteoinductive activity and enhanced anti-infective capability,which enables it to be used as one-stage grafting to treat posttraumatic osteomyelitis in the adults.
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Under laboratory condition, the compound materials of Poly (DL-lactic-co-glycolic acid)/Tricalcium phosphate [PLGA/TCP(L), with component ratio of 7:3] were fabricated by combining the thermally induced phase separation (TIPS) with solvent-casting particulate-leaching (SCPL) approach. On the other hand, rapid prototyping (RP) technique manufactured PLGA/TCP scaffolds [PLGA/TCP(RP)] were obtained. These two kinds of carriers were coated with collagen type I (Col I). The extracted bovine bone morphogenetic protein (bBMP) was loaded into carriers to establish biomimetic synthetic bones. PLGA/TCP(L) scaffolds, demineralized bone matrices (DBM) of bovine cancellous bone, PLGA/TCP(L) scaffolds, biomimetic synthetic bones and OsteoSet bone graft substitutes were investigated. Scanning electron microscopy revealed that the microarchitecture of PLGA/TCP(RP) scaffolds was much better than that of PLGA/TCP(L) scaffolds. The diameter of macropore of PLGA/TCP(RP) scaffold was 350 microm. The porosities of PLGA/ TCP(L) scaffolds, DBM, PLGA/TCP(RP) scaffolds and OsteoSet bone graft substitutes were 21.5%, 70.4%, 58.6% and 0%, respectively (P<0.01). Modification of PLGA/TCP scaffolds with collagen type I [PLGA/TCP(L)-Col I and PLGA/TCP(RP)-Col I] essentially increased the affinity of the carriers to bBMP. Among these synthetic materials, PLGA/TCP(RP)-Col I-bBMP composite is promising as a novel bone graft substitute due to its advanced fabrication technique, good tri-dimensional microarchitecture and ideal components.
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Humanos , Materiales Biocompatibles , Química , Proteínas Morfogenéticas Óseas , Química , Sustitutos de Huesos , Química , Fosfatos de Calcio , Química , Ácido Láctico , Química , Microscopía Electrónica de Rastreo , Ácido Poliglicólico , Química , Porosidad , Propiedades de Superficie , Ingeniería de Tejidos , MétodosRESUMEN
Normal cells have limited proliferation ability.After certain cycles of proliferation,they will lose the response ability to growth factors and finally cease division and start the course of aging. In current opinion,lacking of the terminal end of a chromosome(telomere)is the cause for cells to loss the proliferation ability and leads cells to aging and death.The human telomerase catalytic subunit 1(hTERT)can activate telomemse which prolong DNAs of the terminal end of chmmosome and help cells gain genomic stabilization.The discoveries of telomere,telomerase and hTERT provide new idea for studying of cell aging and the findings are also applied in the establishment of immortal cell line. Also they may play an important role in the studv of biological feature of seed cell in tissue engineering and the establishment of cell bank.
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BACKGROUND: Due to the difference of species, the data of vessel in human are particularly useful for the clinical practice.OBJECTIVE: To analyze the longitudinal residue strain and the relationship between stress and strain of human limb arteries and veins, and explore the influence of different biomechanical properties on the repairs of limb injury.DESIGN: Observational trials.SETTING: Institute of Orthopaedics, Xijing Hospital of the Fourth Military Medical University of Chinese PLA.PARTICIPANTS: The experiment was carried out in the Xijing Hospital Affiliated to the Fourth Military Medical University of Chinese PLA from September 2005 to September 2006. The specimens were taken from 13 male amputee donors(who treated for accident injury), aged 18 to 30 years. Those tissue samples were used with the approval from the donors and offered by Xijing Hospital Affiliated to the Fourth Military Medical University of Chinese PLA.METHODS: ①Harvest and preservation of samples: The samples were obtained within 2 hours after death. The vessels were calibrated and harvested without any large branch to avoid the influence on the mechanical property of vessel wall,and then token on major vessels of limbs with Methylene Blue. The distance between the points token on vessel was measured by vernier caliper. The token vessels were cut and taken into Kreb's liquid in ice casement, then were kept into freezer (0-5 ℃). ②Longitudinal stretch ratio measurement: The vessels were taken into Kreb's liquid and the distance between the points token on vessel was measured by vernier caliper. The longitudinal residue strain was expressed by longitudinal stretch ratio. Lab temperature was 20-25 ℃, experiment was finished in 2 hours after sampling.③Stretch test: The vessel cut 1.0 cm was set into the instrument with Kreb's liquid for uniaxial tension test. The change length of each vascular specimen with or without the load and each load was measured three times and was averaged, lab temperature was 20-25 ℃, and experiments were finished in 5 hours after sampling. The curve of stress-strain was fitted by the measured data.MAIN OUTCOME MEASURES: Longitudinal stretching ratio, residue strain and stress-strain relationship of normal limb arteries and veins.RESULTS: The longitudinal stretch ratio of each artery decreased along vascular branch from proximal heart part to distal heart part, and that of each vein was contrast; There were significant difference in the longitudinal stretch ratios of major artery compared with those of saphena megna vein and branchiocephalicae vein (P ＜ 0.001). The curve of artery shifting right showed the stiffness of vessels decreased along vascular branch from proximal heart part to distal heart part. That of vein shifting left showed the stiffness of vessels increased along vascular branch.CONCLUSION: With the major artery of human limbs from proximal end to distal end, both the longitudinal residue strain and the vascular stiffness gradually decreases, as for the vein, the condition is contrast. It suggests that the longitudinal biomechanical property should be involved into the consideration of repairing the artery and vein injuries of different sites.
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BACKGROUND:The structure of tissue engineering carrier affects the bio-action of cells greatly.OBJECTIVE: To investigate the biological characteristics of bone marrow stem cells (MSCs) in different concentrations of alginate combined with de-antigen bone xenograft (DBX).DESIGN: Observational trial.SETTING: PLA Institute of Trauma and Orthopedics, the Fourth Military Medical University of Chinese PLA.MATERIALS: Alginate, calcium chloride, MSCs, bone xenograft.METHODS: Bovine cancellous bone was out into cubes, which were degreased, deproteinized and then lyophilized.Cubes in pore size within 300-500 μm were selected for use after ethylene oxide sterilization. The purified sodium alginate was dissolved in DMEM cell culture medium of concentrations as different as 0.5%, 2%, 8% and 16%; 1×1012 L-1 induced MSCs were blended with isopyknic alginate-DMEM and compounded with DBX at a status of 0.5 Mpa negative pressure for 5 minutes in order to make a cell suspension fully fill into the pores of the cancellous bone. Then alginate was crosslinked with 50 g/L calcium gluconic acid for 30 seconds. The complex was put into a CO2 incubator and cultured for 4 days. The gel compound and cell growth in the pores of the complex were grossly observed with an inverted microscope. Status of cell growth in the complex with different concentrations of alginate was observed with scanning electron microscopeMAIN OUTCOME MEASURES: Compound status of alginate and bone xenograft, cell growth status and matrix secretion in compound carries.RESULTS: When the concentration of alginate was 0.25% or 1%, alginate was equally combined in DBX, while that of 4% and 8% only combined on the surface of cancellous bone. After in vitro cultured for 4 days, alginate of 0.25% were broken off from DBX surface. But alginate of 1% was equally combined with DBX pores with cells secreting well in alginate. Development of cells in alginate of 4% was restricted and no cells were seen in alginate of 8%.CONCLUSION: Alginate of 1% is suitable for constructing the carrier of bone tissue engineering with bone xenograft.
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Objective To clone NT-3 gene from normal rat brain and to purify its fusion protein and to prepare specific high titer antibody so that to provide a foundation for further study for peripheral nerve injury.MethodsWe amplified target gene by RT-PCR and cloned it into the vector of pMD-18T,then analyzed its sequence and compared it with the sequence from GenBank.We subcloned it into pRSET-A vector and introduced it into Escherichia coli BL21.The expression was induced by IPTG,and identified by SDS-PAGE.The fusion protein was purified by niccolum purify kit.We immuned rabbits with immunological adjuvant for specificity antibody preparation.Results We got a 777 bp gene segment by RT-PCR.The DNA sequence was identical to rat NT-3 gene sequence in GenBank.It proved that the target gene was correctly inserted into the vector.A new protein band of about 34 ku appeared on SDS-PAGE after induction of IPTG.A specific high titer antibody of 1∶64000 was gained by immunizing rabbits with adjuvant.
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BACKGROUND:At present, there are several limb-preserving methods,such as xenogenic bone joint replacement, artificial metal prothesis replacement and inactivation and replantation of tumor bone segment, etc.Each method has its advantages and disadvantages. In addition, mismatch of xenogenic and autogeneic joints and articular cartilage necrosis in the late stage, which affects joint function, are two important problems for large frozen bone-joint allograft at ultra-low temperature in repair of bone defect following bone tumor resections in extremities.OBJECTIVE:To evaluate a method to obtain outline information on the cartilage surface through spiral CT scanning data, so as to lay foundation for study on individualized artifical semi-knee joint based on rapid prototyping (RP) technique.DESIGN: Open experiment.SETTING: First Department of Trauma, Urumqi General Hospital of Lanzhou Military Area Command of Chinese PLA.MATERIALS: This experiment was carried out at Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University of Chinese PLA, and Institute of Advanced Manufacturing, Xi'an Jiaotong University from September 2001 to May 2003. CT scanning subject was a 25-year-old healthy male volunteer.METHODS:Distal femur was performed 1 mm in thickness scanning with Picker 6 000 spiral CT. Three-dimensional volume reconstruction was conducted at the Voxel Q Image workstation on Picker 6000 CT, then, two-dimensional tomography image of reconstruction data were downloaded with spacing of 0.1 mm. Data format converter software was self-developed. The downloaded image was treated through smoothing, de-noise and so on.Vector data of two-dimensional borderline outline of tomography image was calculated and input into Surfacer 9.0 software (American Imageware company) for vectorial three-dimensional reconstruction. According to recognition of articular cartilage outline and request of prothesis design, the threedimensional images of interested articular cartilage surface outline were extracted and used in the computer-aided design for individualized artificial semi-knee joint.MAIN OUTCOME MEASURES:Vector converting of CT image and vector image of three-dimensional reconstruction of femoral condyle.RESULTS:Vector converting of CT image dafa had been come true using self-developed medical image vector converter software. Three-dimensional solid model of individualized femoral condyle was constructed with Surfacer9.0 three-dimensional processing software and edited according to design request. Three-dimensional model of articular cartilage requested by artifical semi-knee joint prothesis was extracted for computer-aided design. The constructed articular surface outline could be treated further to complete computer-aided design of artificial semi-knee joint prothesis; The file format was .stl, which could be recognized by RP software and used in engineering.CONCLUSION:Vector reconstruction of articular cartilage outline is performed based on spiral CT data that can obtain precise three-dimensional solid model of articular cartilage outline. The three-dimensional model can be edited, which lays foundation for computer-aided design and RP manufacturing of artificial semi-knee joint prothesis compounded with large segment xenogenic bone; It is easy and practicable in vector converting of medical image information with this method, and it also has good application prospect in biomanufacturing field in orthopaedic and oral maxillofacial surgery.
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The objective of this program is to investigate the biological effect of dynamic strain on human periosteal cells in vitro. Using a well-established model, the Flexercell unit, we placed mechanical stress (50,000 microstrain, 1 Hz and sine wave) on human periosteal cells grown in collagen coated flexible membrane. The time points of proliferative and differentiative properties were assessed by means of cell counting, thymidine incorporation, synthesis of alkaline phosphatase and osteocalcin, and long term of mechanical load induced calcium nodules formation was also demonstrated. The results showed that the application of highly controlled strains exerted a significant effect on human periosteal cells by up regulation of osteogenic properties rather than exercised an influence on proliferation. The results suggested that the promoting effects of dynamic strain on human periosteal cells probably contribute to the biological function of mechanical loading bearing.
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Humanos , Fenómenos Biomecánicos , Proliferación Celular , Células Cultivadas , Periostio , Biología Celular , Estrés Mecánico , Cúbito , Biología Celular , Soporte de PesoRESUMEN
Tri-dimensional poly (DL-lactic-co-glycolic acid) (PLGA) scaffolds were fabricated using a rapid prototyping (RP) technique and the gene of human bone morphogenetic protein 2 (hBMP-2) was transferred into rabbit bone marrow stromal cells (MSCs) via recombinant adeno-associated virus vectors (rAAV-hBMP-2). Thirty-two PLGA scaffolds, size (4 mm X 4 mm X 4 mm), were coated with collagen type I and equally divided into 2 groups. In group A, each scaffold was loaded with 2 X 10(4) hBMP-2 (+) MSCs to establish a hBMP-2 (+) MSCs/PLGA composite. In group B, each scaffold was loaded with 2 X 10(4) hBMP-2 (-) MSCs to establish a hBMP-2 (-) MSCs/PLGA composite. The composites in both groups were cultured for subcutaneous implantation in nude mice. All animals were killed 30 days after implantation and the differentiation of composites was evaluated. As a result, MSCs infected with rAAV-hBMP-2 efficiently expressed hBMP-2 protein. RP-based PLGA scaffolds had ideal microarchitecture. The diameters of macropore and micropore of the scaffolds were 300 microm and 3-5 microm, respectively. At 3-5 days after culture, a number of seeding cells well grew on the scaffolds of both groups. The composites in group A had chondrogenesis ability in vivo and the expression of collagen type II was positive. In group B, however, only polymers and fiber tissues were predominantly found. The percentage of polymer remnant area was significantly lower in group A than in group B (P<0.01). Our results therefore indicate that RP-based PLGA scaffolds efficiently coated with collagen type I have good biocompatibility with hBMP-2 (+) MSCs and the techniques developed in this study may favor cartilage tissue engineering.
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Animales , Humanos , Masculino , Ratones , Conejos , Materiales Biocompatibles , Células de la Médula Ósea , Biología Celular , Proteína Morfogenética Ósea 2 , Proteínas Morfogenéticas Óseas , Genética , Diferenciación Celular , Células Cultivadas , Condrogénesis , Regeneración Tisular Dirigida , Métodos , Implantes Experimentales , Ácido Láctico , Ratones Desnudos , Ácido Poliglicólico , Polímeros , Células del Estroma , Biología Celular , Ingeniería de Tejidos , Métodos , Transfección , Factor de Crecimiento Transformador beta , GenéticaRESUMEN
[Objective]To investigate the effect of simvastatin on the osteoclast and the focal resorptin of calvaria bone.[Method]Animal model of calvaria bone resorption was induced by parathyroid hormone-related peptide in mice.[Result]Simvastatin on the dose of 10,20 mg/kg/d could inhibit the resorption of calvaria bone and the formation of osteoclast,while,no significant inhibition was observed on the low dose(0,5 mg/kd/d).[Conclusion]Simvastation can effectively inhibit the resorption of focal bone in mice.It may provide an important strategy in treatment of diseases involved focal bone resorption.
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[Objective]To study the effect of simvastatin in the osteoclastic resorption stimulated by PTHrP and murine bone anabolism in vitro.[Method]The bone resorption activities of the osteoclast stimulated by PTHrP were evaluated after treatment with simvastatin for 8 days in vitro;the concentration of Ca~(2+) in the supernatant was also detected by atomic absorption spectrometer.The concentration of ALP and Ca~(2+) of the supematant in murine calvarial organ culture were detected.The histology of calvaria was observed.[Result]Simvastatin greatly inhibited the osteoclastic bone resorption stimulated by PTHrP in vitro and reduced the release of Ca~(2+).Simvastatin increased the ALP activities and bone mineralization of murines calvarial organ culture in vitro.[Conclusion]Simvastatin may inhibit the osteoclasric resorption stimulated by PTHrP and promote osteoblast differentiation and bone mineralization in vitro,thus play an important role in the prevention and treatment of osteoporosis.
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[Objective]To investigate the morphological changes that take place in the subchondral cocortical bone in steroid-induced osteonecrosis and analyze the reasons leading to humeral head collapse in juvenile rabbits.[Method]Five-six month-old female rabbits were separated by two groups.A modified version of the methods was used to replicate steroid enhanced osteonecrosis anminal humeral head models with Shwartzman reaction in group A,and group B served as the single control.Each humeral head was obtained 10 weeks after the drugs injection.Subchondral cortical bone was observed,and the number of haversian canals was counted.The microcirculatory changes were also detected with scanning electron microscope.[Result]In group A,the Haversian canals in' subchondral area almost disappeared;the subchondral cortical bone disappeared with its arch,dome and bridge structures.Microcirculatory stasis happened in the subchondral vessels.Some humeral heads collapse were observed.While in group B,subchondral cortical bone is integrity and continuity,forming arch,dome and brige structures with subtrabecular bone.[Conclusion]The disappearance of the subchondral cortical bone is a major reason leading humeral head collapse,and ischemia is the critical reason of it.
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[Objective]To evaluate the effect of massive bioactive bone substitute in repairing large animals bone defect and to know its degrading rate.[Method]The massive Polylevolactic acid?collage calcium phosphate(PLLA?cTCP) carrieres by rapid forming technology was making,and then compounding rhBMP-2 and carrieres in a ratio of 3mg rhBMP-2 to one carrier was compounded to prepare the massive bioactive bone substitutes for dogs bone defect.Then the massive bone substitutes were implanted into 2.0cm dogss radius defects in the experiment group,and the massive carriers were implanted into in the control group.The repairing effect was evaluated by radiography,histology and biomechanics,and the degrading rate of the substitues was calculated in an image analysis apparatus.[Result]Radiographically,in the experiment group,the defects were connected by callus in all dogs in 12 weeks postoperatively;in 24 weeks,the callus rebuilt well.But in the control group,there was no callus formed in 24 weeks postoperatively,and the defects were not repaired.Histologically,in 12 weeks postoperatively,the outer layer of the callus in the experiment groups was lamellar bone and the center were trabecular bone,myeloid tissue and partial degrading carrier;in 24 weeks,the lamellar bone was more compact,trabecular bone decreased,myeloid tissue increased,and the carrier degraded more.In the control group,in 12 weeks postoperatively,the fibrous tissue wrapped and infiltrated into carrier,at the same time,part of the carrier degraded;in 24 weeks,the carrier was divided up by fibrous tissue and degraded more.The degrading rate of the carder in 12 weeks in the experiment group was 43.2%,in the control group was 35.7%,in 24 weeks 58.4% and 45.4%.Biomechanics,in 24 weeks after postoperation,the radius strength in the experiment group was superior to that in the normal bone.[Conclusion]The massive bioactive bone substitutes have satisfactory repairing effect on the radius bone defects of the large animal,but its degrading rate needs improving.
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[Objective]To establish osteoarthritis model in rabbit knees by two kinds of surgery methods,and to explore their applicable conditions.[Method]Seventeen rabbits were divided into three groups(Hulth group,ligament-excised group and control group),they were anesthetized and operated differently according to their group.The rabbits were sacrificed at 1,3 and 6 weeks after surgery.The femoral condylars were harvested and studied in both gross morphological and pathohistological aspect.[Result]The degeneration of articular cartilage of the two surgery groups got worse by time,and their Mankin's scores were significantly higher than those in the control group(P
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[Objective]To observe the differentiation of adipose derived stem cells(ADSCs)into osteogenic cells in rabbit in vitro.[Method]ADSCs were prepared by collagenase Ⅰ digestion of subcutaneous fat from the nape of Japanese white rabbit after being excised and finely minced.Cells were identified by stro-1 immunocy to chemistry,and collagen Ⅰ immunocytochemistry,alkaline phosphatase assay and Von Kossa stain after osteogenic differentiation was performed.[Result](1)ADSCs were stro-1 positive.(2)The expression of collagen Ⅰ,alkaline phosphatase and calcium deposit of ADSCs were all positive under the influence of osteogenic differentiation medium.[Conclusion]ADSCs have similar characteristics to bone marrow stromal cells,but are much more easier to have high number upon harvest and bring less pain will occur during taking ADSCs than taking BMDCs.