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1.
目的:观察活体染料羧基荧光素乙酰乙酸(CFSE)标记的人羊膜间充质干细胞对四氯化碳诱导小鼠肝损伤模型的定位修复情况。方法:采用胰蛋白酶-胶原酶消化法从羊膜组织中分离间充质干细胞,通过流式细胞术和免疫荧光等方法进行鉴定。模型组按浓度为20μl/g剂量的四氯化碳和橄榄油混合液诱导小鼠肝损伤,治疗组经小鼠尾静脉注射羧基荧光素乙酰乙酸标记的人羊膜间充质干细胞约1×106个/ml。分别取模型组和细胞移植的治疗组小鼠眼球血和肝组织进行相关检测。结果:分离得到纯度较高的羊膜间充质干细胞;冰冻切片免疫荧光显示移植1周后细胞向小鼠受损肝组织定植,CFSE标记的人羊膜间充质干细胞呈绿色荧光;细胞移植后4周,与模型组比较,细胞移植组小鼠血清中天冬氨酸转移酶、丙氨酸氨基转移酶显著降低,而白蛋白明显升高(P0.01);肝组织病理切片模型组小鼠细胞水肿,坏死灶多见,脂肪变性,可见不同程度的炎性细胞浸润;治疗组小鼠肝组织病理学改变和损伤程度有较明显改善;小鼠肝组织冰冻切片的免疫荧光显示移植4周后人羊膜间充质干细胞周围分泌血清白蛋白。结论:羧基荧光素乙酰乙酸标记的人羊膜间充质干细胞可有效改善肝组织的生理功能,为细胞定位移植治疗肝脏疾病的修复情况提供实验数据。  相似文献   

2.
目的评价人骨髓间充质干细胞脑内移植对食蟹猴脑出血模型的治疗作用。方法符合普通级标准的成年食蟹猴12只,用自体股动脉抗凝血脑内注射方法建模后1周,用脑立体定位法在血肿周围植入人骨髓间充质干细胞,细胞数分别为高剂量5×106、低剂量1×106、对照组等体积生理盐水。利用MRI、PET、神经功能缺损评分和组织病理学对干细胞移植效果进行评价。结果神经功能评分显示干细胞移植1周后动物神经功能明显改善。PET结果显示干细胞移植后2周高剂量组血肿周围皮层、基底节核团的SUV%值与对照组间存在显著性差异(P=0.02)。移植后3周高、低剂量组血肿周围皮层、基底节核团的SUV%值与对照组间差异存在显著性(P值分别为0.03和0.04)。MRI显示剂量组血肿吸收速度大于对照组。病理检查可见剂量组坏死灶面积小于对照组,出血灶周围有大量新生血管生成,剂量组与对照组间差异存在显著性(P<0.01)。结论在损伤脑组织周围移植hBMSC可促进食蟹猴损伤神经组织的恢复,为hBMSC治疗脑出血的临床应用提供了重要实验依据。  相似文献   

3.
目的观察人骨髓间充质干细胞(human mesenchymal stem cells,hMSCs)移植4周和8周后,对食蟹猴脑出血模型脑组织损伤的修复作用。方法在脑定位仪定位下,通过自体血注入法制成食蟹猴脑出血模型,并将其随机分为高剂量治疗组、低剂量治疗组和模型组,分别在脑出血部位附近注入高、低密度的hMSCs和生理盐水。应用整体病理切片扫描、HE染色及免疫组织化学的方法观察hMSCs移植治疗食蟹猴脑出血4周和8周后脑损伤部位的病理变化。结果脑出血模型组可见脑出血损伤部位脑组织大面积变性坏死,多量吞噬含铁血黄素的泡沫细胞增生,周围少许肉芽组织增生伴局部纤维组织形成。hMSCs治疗组,整体切片扫描结果提示,与模型组相比,hMSCs低剂量及高剂量治疗组均可见脑组织变性坏死范围减小,且低剂量治疗组略好于高剂量治疗组;HE染色可见大脑注射部位局部脑组织变性坏死、吞噬含铁血黄素的泡沫细胞增生,周围肉芽组织增生伴局部纤维组织形成。免疫组化发现治疗组出血区内可见神经巢蛋白(Nestin)阳性细胞内散在分布,而在模型组中呈阴性表达。结论hMSCs可促进食蟹猴脑出血脑组织损伤的修复,且治疗效果可能与治疗剂量有一定相关性。  相似文献   

4.
目的:评价骨诱导磷酸钙生物陶瓷(BAMOICPC)与可吸收胶原膜(BME-10X医用胶原膜)在牙种植体周围骨缺损中的修复能力。方法:在兔股骨上植入羟基磷灰石涂层BLB种植体,然后在其侧壁制造高4 mm、宽3 mm、深2 mm的骨缺损。对照组为单纯侧壁骨缺损,实验A组骨缺损区仅覆盖BME-10X膜,B组骨缺损区植入BAMOICPC,C组骨缺损区植入BAMOICPC并加盖BME-10X膜。于术后6个月取带种植体的骨段,通过HE染色和扫描电镜(SEM)分析。结果:对照组骨缺损区种植体表面见纤维包裹,实验A组骨缺损边界区少许骨质移行覆盖,实验B组下半部分缺损区新生骨覆盖。C组新生骨完全覆盖骨缺损区,且较B组硬度高,扫描电镜见与种植体结合更紧密。组织学观察B、C两实验组新生骨均可见比较成熟的哈弗氏管系统。结论:骨诱导磷酸钙生物陶瓷BAMOICPC是一种较理想的骨替代材料,联合运用胶原膜修复种植体周骨缺损效果佳。  相似文献   

5.
目的应用Micro-CT研究不同剂量CdCl2染毒后大鼠胫骨松质骨骨小梁密度和骨微结构的差异。方法 24只3月龄雄性SD大鼠随机分成4组,对照组、低剂量组、中剂量组和高剂量组,分别背部皮下注射生理盐水(0.5 mL)和0.1、0.5、1.5 mg/(kg.bw)CdCl2,每周称体重,并根据体重调整注射量。染毒后第8周对所有大鼠左侧胫骨近端进行活体Micro-CT扫描及三维重建。选取距生长板远端0.8、1.2 mm厚的骨组织为感兴趣区域,进行骨形态计量分析。结果镉染毒组大鼠体重和对照组相比有不同程度下降,高剂量组和其他组相比差异有显著性(P<0.05);镉染毒组大鼠骨密度、骨体积分数及骨小梁数量较对照组明显减少,高剂量组与对照组相比差异有显著性(P<0.01);镉染毒组大鼠胫骨骨小梁分离度及骨结构模型指数都较对照组有明显增高,并且随着染毒剂量的增加而升高。二维及三维图象显示,镉作用后大鼠胫骨骨髓腔增宽,骨量、骨小梁数量及骨小梁连接明显减少,板状骨数量减少,杆状骨数量增加。结论镉染毒对大鼠胫骨骨量及骨微观结构有明显损害。  相似文献   

6.
以胶原膜(含87.5 mg I型胶原蛋白)为载体, 复合3.5 mg rhBMP-2(人基因重组骨形成蛋白-2), 制备胶原蛋白/BMP复合材料。复合材料首先在兔背阔肌中埋置, 预构新生骨组织, 并采用ALP染色、Von Kossa染色和HE染色等观察复合材料的成骨过程和组织形态。然后将形成的新骨组织游离移植修复自体下颌骨体部洞穿性缺损; 并设以胶原为载体的rhBMP-2复合骨修复材料直接修复为对照组, 骨缺损不修复组为空白组。采用X线、抗压强度、硬组织切片、四环素荧光染色、骨形态计量检查, 观察复合材料修复骨缺损的质量和效果。结果表明, 胶原蛋白/BMP复合材料在兔背阔肌中4~6周成骨, 胶原材料于3~5周降解; 成骨过程为是以软骨成骨为主的方式, 新骨形态为编织骨, 可见明显的微血管分布; 游离移植修复自体下颌骨缺损, 6周缺损区为骨性愈合, 与对照组在抗压强度(P = 0.041)、新骨量(P = 0.034)均有显著性差异。胶原蛋白/BMP复合材料在骨骼肌中形成的新生骨组织可作为供骨修复一定范围的骨缺损。  相似文献   

7.
胶原蛋白/BMP复合材料的制备和成骨性能研究   总被引:6,自引:0,他引:6  
以胶原膜(含87.5 mg I型胶原蛋白)为载体, 复合3.5 mg rhBMP-2(人基因重组骨形成蛋白-2), 制备胶原蛋白/BMP复合材料。复合材料首先在兔背阔肌中埋置, 预构新生骨组织, 并采用ALP染色、Von Kossa染色和HE染色等观察复合材料的成骨过程和组织形态。然后将形成的新骨组织游离移植修复自体下颌骨体部洞穿性缺损; 并设以胶原为载体的rhBMP-2复合骨修复材料直接修复为对照组, 骨缺损不修复组为空白组。采用X线、抗压强度、硬组织切片、四环素荧光染色、骨形态计量检查, 观察复合材料修复骨缺损的质量和效果。结果表明, 胶原蛋白/BMP复合材料在兔背阔肌中4~6周成骨, 胶原材料于3~5周降解; 成骨过程为是以软骨成骨为主的方式, 新骨形态为编织骨, 可见明显的微血管分布; 游离移植修复自体下颌骨缺损, 6周缺损区为骨性愈合, 与对照组在抗压强度(P = 0.041)、新骨量(P = 0.034)均有显著性差异。胶原蛋白/BMP复合材料在骨骼肌中形成的新生骨组织可作为供骨修复一定范围的骨缺损。  相似文献   

8.
目的:评价壳聚糖/碳酸钙三维复合材料(CS/CaCO3)和壳聚糖/羟基磷灰石复合材料(CS/HA)用于骨缺损修复的可行性.方法:家兔24只,随机分为对照、CS/CaCO3、CS/HA三组.左前肢去毛后,2%巴比妥钠(30mg/kg,iv)麻醉,距桡骨远端3cm处截骨1cm,形成骨缺损,分别植入相应材料.术后4w、8w、12w分别处死动物,X线摄片后,取骨缺损标本,进行大体与组织学观察.结果:术后4周植入块颜色变红,周围有较多量的新生骨样组织包裹,骨痂增多,向植入块内移行;术后8周,植入块周围有明显新骨生成,将材料分隔包围,新骨中央区可见材料呈蜂窝状残留.术后12周缺损区大部分编织骨被成熟的板层骨组织替代,并形成髓腔.结论:CS/CaCO3和CS/HA两种仿生复合材料能明显促进兔桡骨骨缺损修复,诱导骨痂生成.  相似文献   

9.
目的探讨低强度脉冲超声波辐照对节段性骨缺损修复效果的影响。方法将直径12 mm长20mm泡沫TiC/Ti植入6只Beagle犬的左侧胫骨节段性骨缺损区。随机分为超声组和对照组,超声组采用低强度脉冲超声波辐照(频率1.5 MHz、强度30 mW/cm2、脉冲宽度200μs、脉冲周期1 kHz、20 min/次、1次/d),对照组为不开功率源的假辐照,术后4、8周后分别行X线检查及骨密度测定,观察及分析材料周围骨愈合情况。结果 6只beagle犬均进入结果分析。术后4周超声组骨早期成熟度优于对照组,表现在材料周围骨痂影密度增高,骨痂影由两端向中央生长;对照组仅见骨痂区密度低,还可见部分骨痂缺如。术后8周超声组新生骨痂面积优于对照组,骨干结构相对稳定;对照组骨缺损区未闭合,在骨干两侧看到少量骨痂,愈合较差。骨密度测定结果显示,4周时超声组高于对照组,两组间存在统计学差异;8周时超声组略高于对照组,但两组间没有统计学差异。结论通过联合应用低强度脉冲超声波辐照与人工骨材料修复可提高新骨形成速度及骨组织密度,缩短节段性骨缺损的骨愈合时间。  相似文献   

10.
灵芝多糖对小鼠细胞免疫功能调节作用的实验研究   总被引:27,自引:0,他引:27  
研究灵芝多糖 (GLB7)对小鼠细胞免疫功能调节作用的影响。实验小鼠分成 4组 ,分别经胃灌注不同剂量 (高、中、低 )灵芝多糖 ,每天 1次 ,连续 14d ,对照组小鼠用以等量蒸馏水代替。分别于实验第 15 ,2 8d进行小鼠细胞免疫功能调节作用的测试。灵芝多糖喂药后 2周 ,3个剂量组小鼠脾淋巴细胞转化试验、小鼠腹腔巨噬细胞对鸡血红细胞的吞噬百分率和吞噬指数 ;低剂量组小鼠迟发型变态反应 (DTH)、小鼠碳廓清 ;高剂量组小鼠NK细胞活性和对照组比较均有显著性差异 (P <0 .0 5 )。喂药后 4周 :上述实验结果和对照组比较均无显著性差异 (P >0 .0 5 )。结果提示灵芝多糖能提高小鼠的非特异性和特异性细胞免疫功能。  相似文献   

11.
探讨生物活性接骨板研制的动物实验模型   总被引:1,自引:0,他引:1  
目的探索生物活性接骨板修复骨折和骨缺损的动物实验模型,为研制不同强度的生物活性接骨板、观察骨折和骨缺损修复的机制提供实验对象。方法通过观察2.0cm兔股骨骨折和去骨膜缺损动物模型、2.0cm兔胫骨骨折和去骨膜缺损动物模型以及2.0cm兔桡骨骨折和去骨膜缺损动物模型,比较三种不同动物实验模型在兔节段性骨折和缺损实验修复中的大体标本及其术后4周的X线图片,了解三种动物实验模型在生物活性接骨板研制中的优缺点。结果2.0cm兔股骨骨折和去骨膜缺损组及2.0cm兔胫骨骨折和去骨膜缺损组术后均出现固定石膏脱落,生物活性接骨板断裂,骨折和缺损部位移位等现象;而2.0cm兔桡骨骨折和去骨膜缺损组术后4周X片发现生物活性接骨板的固定和复位良好,并且有骨痂形成。结论2.0cm兔桡骨骨折和去骨膜缺损动物模型,较好地模拟人体骨折和骨缺损的愈合过程,可能是研制生物活性接骨板的最佳动物实验模型之一。  相似文献   

12.
目的:应用自体骨髓基质干细胞(Bone Marrow Stromal Cells,BMSCs)复合经低晶态羟基磷灰石(Low Crystalline Hydroxyap- atite,LcHA)涂层的双相陶瓷(Biphasic Calcium Phosphate,BCP)构建的组织工程化骨(LcBCP)修复兔桡骨节段性缺损。方法:体外分离培养、诱导扩增兔BMSCs,取第三代细胞复合LcBCP(实验组)后修复15只兔左侧桡骨15mm缺损;右侧桡骨缺损处植入复合BMSCs的BCP(对照组),于植入后4、8和12周处死动物,通过大体形态、组织学、影像学和扫描电镜检测骨缺损修复效果。结果:BMSCs-LcBCP复合物生长良好,随时间延长,X线显示实验组连接处骨痂形成,对照组连接处始终愈合稍差,12周大体观察实验组骨修复良好,髓腔再通;组织学显示板层骨形成,连接处骨性愈合,实验对照组连接处虽然也为骨性愈合,但尚有较多编织骨形成。结论:自体BMSCs复合LcBCP形成的组织工程化骨可修复兔桡骨节段性缺损,低晶态羟基磷灰石涂层能够增强双相陶瓷的早期成骨。  相似文献   

13.
To further improve our understanding of trabecular bone mechanical behavior in torsion, our objective was to determine the effects of strain rate, apparent density, and presence of bone marrow on trabecular bone shear material properties. Torsion tests of cylindrical trabecular bone specimens from sheep lumbar vertebrae with and without bone marrow were conducted. The bones with marrow were divided into two groups and tested at shear strain rates of 0.002 and 0.05s(-1) measured at the specimen perimeter. The bones without marrow were divided into three groups and tested at shear strain rates of 0.002, 0.015, and 0.05s(-1). Comparing the results of bones with and without marrow tested at low (0.002s(-1)) and high (0.05s(-1)) strain rates, presence of bone marrow did not have any significant effect on trabecular bone shear modulus and strength. In specimens without marrow, power relationships were used to define shear strength and modulus as dependent variables in terms of strain rate and apparent density as independent variables. The shear strength was proportional to the apparent density raised to the 1.02 power and to the strain rate raised to the 0.13 power. The shear modulus was proportional to the apparent density raised to the 1.08 power and to the strain rate raised to the 0.07 power. This study provides further insight into the mechanism of bone failure in trauma as well as failure at the interface between bone and implants as it relates to prediction of trabecular bone shear properties.  相似文献   

14.
目的:研究去势手术建立骨质疏松兔模型中松质骨微观结构和微观成分的时间序贯性变化。方法:40只新西兰白兔随机分为假手术组(sham组,n=20)和骨质疏松组(OP组,n=20)。OP组兔子给予去势手术处理,sham组给予假手术处理。分别于术后的0周、4周、6周、8周,利用DXA测量腰椎骨密度(每组每个时间点选择5只动物)。之后处死动物,采集腰椎标本。利用Micro-CT、FTIR、腰椎轴向压缩试验得到松质骨的微观结构、微观成分(骨矿盐晶体和胶原)和宏观力学参数。利用t检验比较同一时间点两组之间的相关参数。结果:OP组BMD逐渐下降,松质骨微观结构逐渐疏松,微观组成属性逐渐改变,宏观力学强度均逐渐下降。FTIR在4周时即检测到OP组腰椎骨矿盐和胶原基质比(P=0.046)、骨矿盐结晶度(P=0.018)、胶原交联比(P=0.006)发生显著性改变,早于BMD和微观结构的变化。OP组腰椎宏观生物力学强度在第8周时达到最低点(P=0.001)。结论:去势手术后,腰椎松质骨骨矿盐晶体和胶原属性最早发生变化,松质骨微观成分和微观结构的改变是导致椎体强度明显改变的原因。FTIR技术可以较早的检测到骨质疏松发生过程中骨组织微观成分的改变。  相似文献   

15.
Animal models of multiple myeloma vary in terms of consistency of onset, degree of tumour burden and degree of myeloma bone disease. Here we describe five pre-clinical models of myeloma in NOD/SCID-GAMMA mice to specifically study the effects of therapeutic agents on myeloma bone disease. Groups of 7–8 week old female irradiated NOD/SCID-GAMMA mice were injected intravenously via the tail vein with either 1x106 JJN3, U266, XG-1 or OPM-2 human myeloma cell lines or patient-derived myeloma cells. At the first signs of morbidity in each tumour group all animals were sacrificed. Tumour load was measured by histological analysis, and bone disease was assessed by micro-CT and standard histomorphometric methods. Mice injected with JJN3, U266 or OPM-2 cells showed high tumour bone marrow infiltration of the long bones with low variability, resulting in osteolytic lesions. In contrast, mice injected with XG-1 or patient-derived myeloma cells showed lower tumour bone marrow infiltration and less bone disease with high variability. Injection of JJN3 cells into NOD/SCID-GAMMA mice resulted in an aggressive, short-term model of myeloma with mice exhibiting signs of morbidity 3 weeks later. Treating these mice with zoledronic acid at the time of tumour cell injection or once tumour was established prevented JJN3-induced bone disease but did not reduce tumour burden, whereas, carfilzomib treatment given once tumour was established significantly reduced tumour burden. Injection of U266, XG-1, OPM-2 and patient-derived myeloma cells resulted in less aggressive longer-term models of myeloma with mice exhibiting signs of morbidity 8 weeks later. Treating U266-induced disease with zoledronic acid prevented the formation of osteolytic lesions and trabecular bone loss as well as reducing tumour burden whereas, carfilzomib treatment only reduced tumour burden. In summary, JJN3, U266 or OPM-2 cells injected into NOD/SCID-GAMMA mice provide robust models to study anti-myeloma therapies, particularly those targeting myeloma bone disease.  相似文献   

16.
目的探讨翻白草对高血脂大鼠和家兔的降血脂作用。方法采用Wistar大鼠60只(其中50只为高脂饲料诱导成高血脂动物模型,10只为空白对照组),家兔36只(其中30只为高脂饲料诱导成高血脂动物模型,6只为空白对照组)。随机分为6组(翻白草大、中、小3个剂量组,模型组,脂必妥对照组,空白对照组)。连续给药6周,分别于给药后第4周、第6周采血,检测血清中胆固醇(TC)、甘油三脂(TG)及低密度脂蛋白(LDL)浓度。结果翻白草各给药组与模型组比较,给药后第4周,翻白草可降低高血脂大鼠和家兔血清中TC、TG、LDL的含量(P〈0.05);给药后第6周,可显著降低高血脂大鼠和家兔血清中TC、TG、LDL的含量(P〈0.01)。结论翻白草具有很好的降血脂作用。  相似文献   

17.
Experimental osteoarthritis induced by Candida albicans in rats was studied using micro-computed tomography (micro-CT). When C. albicans cells at a nonlethal dose were intravenously injected into 40 rats, joint swelling was induced in 24 rats. Two or more joints were affected in 10 of the 24 rats. Tarsal regions of the hind paw were affected most frequently, followed by elbows of the fore paw. Micro-CT analysis in vivo showed that erosions of the affected tarsal joint bones were apparent several days after the onset of swelling. Thereafter, severe surface roughness and disintegration in the joint bones progressed during the development of arthritis. Three-dimensional (3D) trabecular microstructures and changes in 3D bone parameters were characterized ex vivo with calcanei from affected hind paws. Three-dimensional morphology showed coarsening of the trabecular distribution and weakening of the trabecular connectivity in arthritic bones. These morphological changes were quantitatively confirmed by changes in 3D bone parameters measured from consecutively scanned bone slices. Micro-CT has been shown to be useful for quantifying morphological changes occurring in Candida arthritic bones.  相似文献   

18.
Finite element (FE) models of long bones constructed from computed-tomography (CT) data are emerging as an invaluable tool in the field of bone biomechanics. However, the performance of such FE models is highly dependent on the accurate capture of geometry and appropriate assignment of material properties. In this study, a combined numerical-experimental study is performed comparing FE-predicted surface strains with strain-gauge measurements. Thirty-six major, cadaveric, long bones (humerus, radius, femur and tibia), which cover a wide range of bone sizes, were tested under three-point bending and torsion. The FE models were constructed from trans-axial volumetric CT scans, and the segmented bone images were corrected for partial-volume effects. The material properties (Young's modulus for cortex, density-modulus relationship for trabecular bone and Poisson's ratio) were calibrated by minimizing the error between experiments and simulations among all bones. The R(2) values of the measured strains versus load under three-point bending and torsion were 0.96-0.99 and 0.61-0.99, respectively, for all bones in our dataset. The errors of the calculated FE strains in comparison to those measured using strain gauges in the mechanical tests ranged from -6% to 7% under bending and from -37% to 19% under torsion. The observation of comparatively low errors and high correlations between the FE-predicted strains and the experimental strains, across the various types of bones and loading conditions (bending and torsion), validates our approach to bone segmentation and our choice of material properties.  相似文献   

19.
Breast cancer cells frequently metastasize to the ends of long bones, ribs and vertebrae, structures which contain a rich microvasculature that is closely juxtaposed to metabolically active trabecular bone surfaces. This study focuses on the effects of osteoblast secretions on the surface presentation of adhesive proteins on skeletal vascular endothelial cells. Vascular endothelial cells were isolated from trabecular bone regions of the long bones of 7-week-old Swiss Webster mice and also from the central marrow cavity where trabecular bone is absent. Both types of endothelial cells were placed in culture for 7 days, then exposed 24 h to conditioned media from MC3T3-E1 osteoblasts. Conditioned medium (CM) from two different stages of osteoblast development were tested: (1) from immature MC3T3-E1 cells cultured for 5-7 days and (2) from mature MC3T3-E1 cells cultured for 28-30 days. The immature osteoblasts were in a stage of rapid proliferation; the mature osteoblasts formed a matrix that mineralized. Following exposure to the conditioned media, the vascular cells were exposed to anti-P-selectin, anti-E-selectin, anti-ICAM-1, and anti-VCAM-1 to detect the corresponding adhesive proteins on their surfaces. Breast cancer cells are known to bind to these adhesive proteins. Of the four proteins evaluated, E-selectin was consistently found on more cell surfaces (approximately 30%) of bone-derived vascular endothelial cells (BVECs) when exposed to the immature CM whereas vascular endothelial cells from marrow (MVECs) did not show this response to either immature CM or mature CM. These studies suggest that the BVEC blood vessels near immature bone cells express more surface adhesive protein that could enhance entrapment and extravasation of breast cancer cells. Once cancer cells have undergone extravasation into marrow adjacent to bone, they could be readily attracted to nearby bone surfaces.  相似文献   

20.
Mechanical loading is one of the determining factors for bone modulation, and is therefore frequently used to treat or prevent bone loss; however, there appears to be no data on the effects of baseline bone quantity on this response. This study aimed to verify whether baseline bone quantity affects osteoporotic trabecular bone adaptive response to mechanical stimulation. Twenty-four female Sprague-Dawley (SD) rats were ovariectomized (OVX). After 3 weeks of OVX, rats were divided into a high bone quantity and a low bone quantity group, and rats in each group were then subdivided into 4 groups that were exposed to different loading strategies. In the loading groups, tibiae were stimulated through axial loading at 2000με of strain, for 1500 cycles each of 75s, 150s, or 250s. The sham treatment groups received no loading. Changes in BV/TV for trabecular bone in the tibia were measured at the baseline (before loading), and at 3 weeks and 6 weeks after loading. BV/TVs in loading groups of the low baseline bone quantity group were significantly increased at 6 weeks, compared with those in the no-loading groups (p<0.05), while those in the high quantity groups were not increased (p>0.05). A significant negative correlation was observed between baseline BV/TV and its relative variations at 3 weeks or 6 weeks (p<0.05). These results indicate that adaptive responses of osteoporotic trabecular bone to mechanical loading depend on baseline bone quantity.  相似文献   

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