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Mesenchymal stem cells (MSCs) are a kind of stem cells with self-renewal ability and multidirectional differentiation potential. At present, as the main cell source for bone tissue engineering, MSCs can be used to treat various skeletal disorders. DNA methylation is an important epigenetic mechanism involving the occurrence and development of osteoporosis, osteonecrosis and other trauma-related skeletal disorders by regulating expression of osteogenic-specific genes in osteogenic differentiation of MSCs. The authors review the research progress in regulation of skeletal disorders by DNA methylation regulating osteogenic differentiation of MSCs by overviewing DNA methylation, mechanisms of DNA methylation regulating osteogenic differentiation of MSCs involving trauma-related bone disease and related treatment measures so as to provide references for the research and treatment of trauma-related skeletal disorders.
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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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ObjectiveTo investigate the effects of different ways of fluid resuscitation on uncontrolled traumatic hemorrhagic shock. MethodsThe retrospective analysis of data from 220 casualties with uncontrolled hemorrhagic shock admitted from September 2006 to October 2010 was carried out.There were two ways of fluid resuscitation used to treat casualties with hemorrhagic shock,conventional fluid resuscitation (group A) and limited fluid resuscitation (group B).The systolic pressure was maintained at 90 ～ 135 mm Hg in the group A and at 70 ～ 90 mm Hg in the group B.The data of body temperature,central venous pressure,quantity of blood transfused,urine output,renal function,hemoglobin,blood osmotic pressure (Osm) ,MODS and DIC rates,treatment costs and mortality of two groups were statistically analyzed and compared. Results After analyses of above mentioned variables except renal function and comparison made between two groups,the method of limited fluid resuscitation was much superior over conventional fluid resuscitation (P ＜ 0.05 ).There was no noticeable difference in rate of compromised renal function between two groups ( P ＞ 0.05 ). Conclusions In the case of uncontrolled exsanguination,the method of limited fluid resuscitation can maintain blood perfusion of vital organs,reduce the blood loss and decrease the incidence of MODS and mortality.
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BACKGROUND:The existed femoral head necrosis(FHN)model can not reflex the clinical necrosis of femoral head correctly.Microwave heating provides a new approach for model preparation.but the concrete standard remains uncertain.OBJECTIVE:To study the optimal temperature and time jn preparing a FHN model induced by microwave heating.METHODS:Totally 48 rabbits were randomly divided into 4 groups on the basis of the microwave temperature(50,55,60℃)and heating time(10,20 minutes).The microwave antenne was inserted into the rabbit femoral head.The rabbits were sacrificed immediately and at 1,2,4,8 and 1 2 weeks after operation.A series of examinations were performed including gross observation,X-ray.histology and MRI to observe the femoral head necrosis and repair status.RESULTS AND CONCLUSION:Marrow partially solidified in the group(50℃,10 minutes)at 1 week,and the osteonecrosis returned to normaI at 8 weeks after operation.1n the group(55℃,10 minutes),marrow was completely coagulated at 1 week and low signal on T1 weighted images and increased signal on T2 images were identified at 2 weeks.Osteonecrosis and repair occurred at the same time at 4 weeks.At 12 weeks,the osteonecrosis continued and the repair stopped,and the femorel heads started to collapse.All femoral heads collapsed at 8 weeks in group(50℃,20 minutes)and group(60℃,10 minutes).Accordingly.microwave heating is a good method in developing FHN model.55℃ and 10 minutes are the optimal temperature and time for the development of FHN model of rabbits induced by microwave heating.
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BACKGROUND: An ideal model of osteonecrosis of the femoral head is beneficial to the study on the cause of disease, pathogenesy and treatment. So far there has not been a coherent method to prepare this model. OBJECTIVE: To establish a rabbit model of osteonecrosis of femoral head induced by microwave heating, and to decide optimum microwave temperature and heating time.DESIGN: Randomized controlled animal trial.SETTING: Animal Experimental Center of Kunming Medical College.MATERIALS: The experiment was performed at the Animal Experimental Center of Kunming Medical College between September 2004 and November 2005. Forty-eight healthy adult New Zealand rabbits, either male or female, were provided by the Animal Experimental Center of Kunming Medical College. The animal procedure was accorded with the ethical standards. GW-92C multi-functional microwave therapy apparatus was the product of Grand World Medical Apparatus (Tianjin) Co., Ltd. METHODS: The microwave antenna was inserted into the rabbit femoral head. Ninety-six femoral heads in forty-eight rabbits were randomly divided into four groups (n =24) according to the microwave temperature and heating time: microwave heating at 50 ℃ for 10 minutes group; 55 ℃ for 10 minutes group; 50 ℃ for 20 minutes group and 60 ℃ for 10 minutes group. The models of osteonecrosis of femoral head were induced by microwave heating using multi-functional microwave therapy apparatus according to the temperature and heating time of grouping. MAIN OUTCOME MEASURES: In each group, two rabbits (four femoral heads) were killed immediately, one, two, four, eight and twelve weeks after operation, respectively. A series of examinations were carried out, including gross observation, X-ray to observe bone trabecular arrangement, cystis degeneration, head collapse or hip joint destruction, MRI to observe the necrotic area, and HE staining to observe the osteonecrosis and bone repair. RESULTS: Marrow tissues partially coagulated in the microwave heating at 50 ℃ for 10 minutes group at the end of the 1st week, and the osteonecrosis returned to normality at the end of the 8th week. In 55 ℃ for 10 minutes group, marrow tissues were completely coagulated at the end of the 1st week, and decreased signal on T1 weighted images and increased signal on T2 images were identified at the end of the 2nd week. In the 4th week, bone repair was found simultaneously when osteonecrosis occurred. At the end of the 12th week, the osteonecrosis continued and the repair stopped, and the femoral head collapse occurred. All femoral heads collapsed at the end of the 8th week in 50 ℃ for 20 minutes group and 60 ℃ for 10 minutes group. CONCLUSION: Microwave heating at 55 ℃ for 10 minutes is the optimal choice to develop a rabbit model of osteonecrosis of the femoral head.
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[Objective]To prepare a kind of biphasic ceramic biologic active bone and study its biocompatibility.[Method]Biphasic ceramic biologic bone(BCBB) was mixed with collage type I,bone morphogenetic protein(BMP) and basic fibroblast growth factor(bFGF),and then the third generation cultured rabbit bone mesenchymal stem cells(MSCs) were seeded on BCBB/BMP/bFGF in vitro.The tissue engineering bone(BCBB/BMP/bFGF/MSCs) was observed by upside down microscope,scanning electron microscope(SEM) and examined using methylthiazol tetrazolium(MTT).[Result]Biphasic ceramic biologic active bone BCBB/BMP/bFGF was successfully prepared by reconstituting collage type I,BMP,bFGF and BCBB together.The rabbit cells grew in and on the BCBB/BMP/bFGF to form an ideal tissue engineering bone,and the cells quantity was the most on the 6th day.[Conclusion]BCBB/BMP/bFGF possesses a good biocompatibility with rabbit bone mesenchymal stem cells.
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[Objective]To observe the effect of composite(AACB/BMP/bFGF)of allogeneic antigen-extracted cancellous bone(AACB),bone morphogenetic protein(BMP)and basic fibroblast growth factor(bFGF)on the repair of defective and necrotic areas of the femoral head,and evaluate the revaseularization the femoral head defect and necrosis model using liquid nitrogen,and randomly divided into 3 groups with 12 femoral heads in each group,which were implanted with nothing(group A),AACB/BMP(group B)and AACB/BMP/bFGF(group C)respectively.Every femoral head was implanted with about AACB 0.33 g,BMP 12.5 mg and bFGF 2000 U.Two canines were sacrificed respectively at 3th,6th,and 12th weeks after operation in every group.Histologically,immunohitochemical vessel staining,vessel count and vessel surface area image analysis,calcium content and the correlation between revascularization effect and calcium content were investigated in the femoral heads after the operation.[Result]Histology,the detects were still infilled by fibrillar tissue in group,A;there were a great deal of new bone formed in group B;and the detects were repaired completely in group C 12 weeks after operation.Measurement of vessel count and vessel surface area showed a large quantity of new vessel proliferated around the infilling material in group C on the 3rd week.The vessel count and vessel surface area continuously increased on the 6th week and 12th week.They were more than those of group B and group A at every definite time point(P
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BACKGROUND:The treatment of avascular necrosis of femoral head remains a clinical challenge. However, recent study shows that basic fibroblast growth factor (Bfgf) is an effective angiogenic growth factor. We suppose that Bfgf has the potential in treating avascular necrosis of femoral head through revascularizing effect and steogenesis.OBJECTIVE: To develop a rabbit model that simulates the clinical situation with trapdoor bone rafting and evaluate the revascularizing effect in the repair of femoral head defect with Bfgf/partially deproteinised bone (PDPB).DESIGN: A completely randomized controlled trial.SETTING: Animal Experimental Center of Kunming Medical College.MATERIALS: The experiment was conducted in the Animal Experimental Center of Kunming Medical College between July 2002 and July 2003.Totally 27 adult male healthy New Zealand rabbits, weighing 2.2 to 2.8 kg,were recruited and randomly divided into Bfgf/composite PDPB group,single PDPB group, and blank control group with 9 rabbits in each group.INTERVENTIONS: ① Preparation of Bfgf/PDPB: containing Bfgf 10 ng/mm3. ② Establishment and repair of femoral head defect model:Totally 27 rabbits were chosen. Bone defect model was stablished by opening a trapdoor between femoral head and femoral neck. Bfgf/PDPB was implanted in composite group; single PDPB was implanted in PDPB group; no implants were given in blank control group. The rabbits were killed after injection through blood vessels with prepared Chinese ink 2, 4and 8 weeks after operation, and then the femoral head of each rabbit was taken out as specimen.MAIN OUTCOME MEASURES: ① Histological examination and blood vessel counting. ② Image analysis of microvessel area.RESULTS: Twenty-seven rabbits all entered the result analysis. ① Histological examination and vessel count of femoral head specimens in rabbits:8 weeks after operation, composite bone group: implants were replaced with bone tissues and medullary cavity of bone formed. A lot of medullary vessels were present. DPB group: implants were enwrapped by bonelike tissues and most of them were absorbed. Blank control group: the area of femoral head defect was filled with fibrous tissues. New bonelike tissues and scattered chondrocyte island appeared in the adjacent connective tissues of defect area, with a small number of blood vessels. Microvessel count at week 2 in composite group was significantly higher than that in PDPB group and blank control group [(31.833±7.914) vs (22.917±2.079)and (11.250±4.220) (number of blood vessel/field), P ＜ 0.01, P ＜ 0.05].The number of microvessels at weeks 4 and 8 in composite bone group and DPB group was significantly greater than that in blank control group. ②Image analysis of microvessel area: The transparent samples of 20 μm thick were observed under the optical microscope: 2, 4 and 8 weeks after operation, there were many vessels woven into nets. Many vessels woven into nets were also found in PDPB group; there were scattered vessels in blank control group.CONCLUSION: Bfgf has the revascularizing effect on the repair of femoral head defect, and has the potential and advantages in treating avascular necrosis of femoral head.
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Objective To evaluate a new type of bone graft material made by combining bFGF,BMP with AACB in the clinic repair of ANFH(avascular necrosis of the femoral head)in animal experiments.Methods The combined material of bFGF/BMP/AACB was made and then this composite was transplanted to the models of canine femoral head defects and necrosis established by liquid nitrogen freezing,The specimens were harvested respectively at the end of three,six and 12 weeks after operation.A series of examinations were carried out to evaluate the repair results,including gross observation,radiography,histology,image pattern analy sis,blood vessel immuhistochemical staining,EDAX(energy dispersion analysis X-ray),and mechanical measurement.Results All the animals had no toxic or inflammatory reactions.Little new bone formed in group A(control group)by the end of 12 weeks.Group B(AACB group)was better than group A,and group C(BMP/AACB group)better than group B in osteogenesis.All the results showed that group D(bFGF/BMP/AACB group)was much superior to groups A,B and C in angiogenesis and osteogenesis at all intervals,and even better than group E(bone autograft group)by the end of three weeks and six weeks.By the end of 12 weeks,bone repairing and remodeling effects in group D were as good as in group E.Conclusions Since the bFGF/BMP/AACB compsite has great potential for enhacing revascularization and osteogenesis in repairing the defect and necrosis model of canine femoral head,it can be used as a substitute bone graft material for clinical patients with ANFH.