睾丸酮对雄性大鼠类固醇性骨质疏松的影响

目的探讨睾丸酮对雄性大鼠类固醇性骨质疏松的影响。方法30只3月龄雄性SD大鼠,随机分成对照组(A组)、泼尼松组(B组)、睾丸酮(C组)。A组灌生理盐水(4mL·kg-1·d-1),B组予醋酸泼尼松灌胃(4mg·kg-1·d-1),C组灌胃给予甲睾酮(0.2mg·kg-1·d-1)+醋酸泼尼松(4mg·kg-1·d-1),共90d。实验结束后,处死全部大鼠取腰椎和胫骨上段进行不脱钙骨包埋切片,应用计算机自动图像分析系统进行骨组织形态计量学分析。结果与泼尼松组比较,胫骨上端松质骨的%Tb.Ar增加了108%(P<0.01),Tb.N增加了96%(P<0.05),Tb.Sp减少60%;BFR/TV增加了172%(P<0.05),Oc.N减少40.7%(P<0.05);腰椎松质骨的%Tb.Ar增加了52.4%(P<0.05),Tb.Th增加了42%(P<0.05),Tb.Sp减少20%(P<0.05),MAR增加26%(P<0.05)。结论睾丸酮可以有效阻止泼尼松所引起的骨骨质丢失,维持正常的骨质结构。     

骨形态计量学观察睾酮对雄性去势大鼠皮质骨的影响

目的通过骨形态计量方法观察雄激素替代疗法对去睾丸大鼠皮质骨代谢的影响。方法30只4月龄SD雄性大鼠,随机分成基础对照组(A组、实验开始时处死),年龄对照组(B组)、去睾丸组(C组)和去睾丸加睾丸酮组(D组),B组和C组生理盐水5ml·kg-1·d-1,D组甲基睾丸酮片1.8mg·kg-1·d-1,灌胃90d。实验结束,处死全部大鼠,取胫骨中段进行不脱钙骨制片,用计算机全自动图象分析系统进行骨组织形态计量学分析。结果去睾丸后皮质骨静态参数如截面总面积、髓腔面积等无明显变化,动态参数骨外膜骨形成降低(P<0.05),内膜骨形成和吸收均有增加趋势。睾酮则使去睾丸大鼠皮质骨的静态参数有增加趋势,促使骨外膜形成增加,减少内膜骨吸收(P<0.05),对内膜骨形成影响不大。结论睾酮补充治疗短期内能对抗去睾丸引起的大鼠皮质骨内外膜的代谢变化,维持正常的皮质骨结构。     

强骨康疏胶囊对去卵巢骨质疏松大鼠骨细微结构及骨代谢的影响

目的:观察强骨康疏胶囊对去卵巢骨质疏松大鼠的骨密度、OPG及RANKL蛋白表达、骨组织形态计量学参数及骨组织细微结构的影响。方法:制备去卵巢骨质疏松大鼠模型后,分组:正常对照组、模型空白组、中药低剂量预防组、中药高剂量预防组、雌激素预防组。给药1月后,检测各组股骨骨密度值,显微镜下观察股骨骨小梁的结构变化,并检测骨组织形态计量学参数。采用免疫组织化学染色法检测大鼠股骨OPG及RANKL蛋白表达。结果:模型空白组大鼠股骨骨密度减少,骨小梁厚度、面积、面积百分数均减少,骨小梁间距增大,股骨OPG蛋白平均光密度值显著降低,RANKL蛋白平均光密度值明显增高;雌激素预防组、中药低剂量组、中药高剂量组对上述指标均有明显改善。结论:强骨康疏胶囊能有效提高骨量,维持骨小梁立体空间结构,改善大鼠股骨远端松质骨的显微结构,能够提高骨OPG蛋白表达及抑制RANKL蛋白表达。     

低蛋白饲料对雄性大鼠胫骨上段和腰椎的骨计量学研究

目的比较低蛋白饲料对大鼠胫骨上段和腰椎松质骨的影响。方法12只3月龄SD雄性大鼠,随机分成正常对照组、低蛋白组LPD(Pr8%)。实验90d时取胫骨上段和第五腰椎行不脱钙骨制片,骨组织形态计量学测量。结果与对照组比,LPD组胫骨上段骨小梁面积百分率(%Tb.Ar)减少(P<0.01),骨结构变差,骨转换率下降;而腰椎松质骨各项指标的变化均无统计学意义。结论低蛋白饲料诱导大鼠胫骨上段骨丢失,而对腰椎骨丢失无明显影响。     

低功率激光对Beagle犬胫骨种植体周骨愈合的影响

背景：低功率激光照射对种植体周骨愈合及骨结合的影响尚无确切的结论。 目的：探讨低功率氦氖激光局部照射对骨内种植体周骨愈合的影响。 方法：取6只Beagle犬,每只犬两侧胫骨分别植入3枚种植体,植入后分别采用低功率氦氖激光局部照射1周,2周或不照射。分别于第4,8,12周随机处死2只Beagle犬取材。 结果与结论：亚甲基蓝-酸性品红染色显示,给予低功率氦氖激光局部照射的种植体周骨组织愈合优于未照射者。骨形态计量学分析结果显示,随着种植体植入时间的延长,种植体-骨结合率逐渐增高;在相同时间点,种植体-骨结合率以照射2周组最高,照射1周组次之。提示低功率氦氖激光局部照射能显著促进种植体周骨组织愈合及其改建成熟,同时增加种植体骨结合面积。     

去睾丸大鼠骨形态计量学的研究

目的：探讨4月龄雄性大鼠去睾丸后骨量的变化，重点比较松质骨和皮质骨骨代谢的变化。方法：20只4月龄SD雄性大鼠，随机分为假手术组（A组）和去睾丸组（B组），同等条件下饲养90d后，取腰椎和胫骨中段行不脱钙制片进行骨形态计量学观察。结果：去睾丸组与假手术组比较，前者腰椎松质骨吸收增加、骨形成下降（P〈0．05），出现明显骨质疏松；皮质骨外膜的骨形成动态参数如矿化沉积率、骨形成率下降（P〈0．05），内膜骨形成和吸收均有增加趋势。结论：去睾丸90d能使大鼠松质骨出现骨质疏松，皮质骨丢失不如松质骨显著。松质骨对去睾丸敏感性比皮质骨高。     

钙干预对生长性骨痛儿童骨代谢的影响

通过对确诊为生长性骨痛的儿童进行钙干预,探讨其对儿童生长性骨痛骨代谢的影响.将157例患儿随机分为补钙组、对照组,不同时点记录骨代谢生化指标血bALP、尿Ca、血Ca的变化.生长性骨痛的儿童钙干预后,其骨释放减少;血钙值无统计学差异;补钙组尿钙排出量不变,对照组尿钙排出量减少且低于实验组.生长性骨痛的儿童适当补充钙,对...     

仙珍骨宝胶囊对去卵巢大鼠股骨颈骨代谢的影响

背景：用骨组织形态计量学方法探讨中药对去卵巢大鼠股骨颈骨质疏松的影响,可为采用中药防治绝经后妇女骨质疏松性股骨颈骨折提供实验依据。 目的：观察仙珍骨宝胶囊对去卵巢大鼠股骨颈松质骨的影响。 方法：3月龄SD雌鼠随机分为4组：基础对照组于实验开始时处死取材,去卵巢组和仙珍骨宝组去卵巢造模,仙珍骨宝组在去卵巢后灌胃仙珍骨宝,去卵巢组和年龄对照组灌胃生理盐水,90 d后处死,取股骨颈经不脱钙骨制片进行骨组织形态计量学参数测量。 结果与结论：与年龄对照组比较,去卵巢大鼠静态参数的骨小梁面积百分数和骨小梁数量明显减少(P < 0.01),骨小梁间隙明显增大(P < 0.01);动态参数的每毫米破骨细胞数和破骨细胞贴壁表面长度明显增加(P < 0.01),骨矿化沉积率明显减少(P < 0.01)。说明去卵巢能导致大鼠股骨颈骨量显著减少。给予仙珍骨宝治疗后,大鼠的骨小梁厚度及骨小梁面积明显增加(P < 0.05),每毫米破骨细胞数和破骨细胞贴壁表面长度有所减少,标记周长百分数则有所增加。说明仙珍骨宝能阻止去卵巢所致的大鼠股骨颈骨量丢失。     

胫骨密质骨相对钙含量沿径向分布的研究

本文应用离子探针技术研究了成年牛和人胫骨骨干密质骨中相对钙含量沿径向的分布,发现径向内外侧的相对钙含量大于中间部位,得到相对钙含量的分布曲线,它的分布规律对于胫骨中不同的微观几何结构是相同的,并对这种分布规律形成的原因和对密质骨力学性质的影响进行了初步的分析。     

计算机辅助骨形态计量学分析系统的构建与应用

本研究旨在构建计算机辅助的骨形态计量学分析系统。基本方法为利用显微镜、数码相机、计算机及相关软件构建不脱钙切片的显微图像数码整合系统,利用Freeplus和自编软件对每一幅图像进行基本测量,再根据骨形态计量学的定义,计算出反映骨量、骨结构与骨代谢变化的计量参数。此方法已应用于骨质疏松症的动物实验和临床研究,在骨质疏松性骨折风险预测和药物疗效评定中都发挥了重要作用。     

Skeletal alterations in hypophysectomized rats: II. A histomorphometric study on tibial cortical bone

Background: Pituitary hormones play an important role in bone growth, modeling, and remodeling. The purpose of this study is to examine the effect of hypophysectomy (HX) on tibial cortical bone with histomorphometry. Methods: Forty-Five female Sprague-Dawiey rats, at 3 months of age, were hypophysectomized or served as intact controls. They were sacrificed at 0, 2, and 5 weeks after the surgery. Cortical bone histomorphometry was performed on double-fluorescent-labeled 30-mcm-thick sections of the tibial shaft. Results: The dry weight and density of tibial diaphysis and the cortical bone area of the tibial shaft in the HX rats were significantly lower (P<0.05) than that of the age-matched intact rats, but did not differ between the HX and basal control rats. The dynamic data show that the bone formation parameters (labeled surface, mineral apposition rate, and bone formation rate) were profoundly decreased (P<0.01) on both the periosteal and endocortical surfaces in the HX rats as compared with the age-matched intact rats at the 2 and 5 weeks. However, the decrease in the labeled surface was much less on the endocortical envelope than on the periosteal envelope in the HX rats. Although no significant change was detected in the medullar size between the HX and age-matched intact rats, the eroded surface on the endocortical surface was greater (P<0.05) in the HX rats than in the intact rats at either time point. Conclusions: Hypophysectomy-suppressed, radial growth-dependent bone gain without a bone loss in the tibial shaft of the young rat. This is associated with decreased modeling-dependent bone formation. A greater eroded surface on the endosteum did not affect the marrow size at 5 weeks after hypophysectomy. © 1995 Wiley-Liss, Inc.     

Establishing a rapid animal model of osteoporosis with ovariectomy plus low calcium diet in rats

The objective of this study was to rapidly develop osteoporotic model animals by combining ovariectomy with a low calcium diet in rats. Thirty, eight-week-old, female, Sprague-Dawley rats were either sham-operated (Sham) or ovariectomized (Ovx) and divided into three groups: Sham, Ovx, and Ovx + low calcium diet. Rats in the Sham and Ovx groups were fed a standard diet containing 1.1% w/w calcium while rats in the Ovx + low calcium diet group were fed a diet containing 0.1% w/w calcium. Serum osteocalcin and bone mineral density (BMD) of the lumbar vertebrae were measured 4 and 8 weeks after surgery. The rats were euthanized 12 weeks after surgery, and the BMD of the right femur and histomorphometry of the femoral neck were assessed at that time. The Ovx + low-calcium diet group had a significantly lower mean BMD of the lumbar vertebra and higher mean serum osteocalcin concentration than the Sham and Ovx groups. Twelve weeks after surgery, rats in the Ovx + low calcium diet group had a significantly lower BMD, smaller Tb.Th and Tb.N, and larger Tb.Sp of the right femoral neck than did rats in the Sham and Ovx groups. These data indicate that a low calcium diet can significantly accelerate bone loss in ovariectomized rats. Combining ovariectomy and a low calcium diet can save considerable time in the creation of osteoporotic model animals.     

Short-term healing kinetics of cortical and cancellous bone osteopenia induced by unloading during the reloading period in young rats

 We investigated the short-term recuperation of bone mass during skeletal reloading after a period of unloading in young rats. One hind limb of 4-week-old rats was either unloaded irreversibly by sciatic neurectomy, or unloaded reversibly by external fixation. Other animals were sham-operated. After 9 days, the fixation-unloaded limbs were reloaded for 1–3 weeks and were compared with the hind limbs of age-matched unloaded (neurectomized) and sham-operated controls. Cortical and cancellous bone mass was measured using ashing and histomorphometry. Cortical bone mass (expressed as femoral dry and ash weight and tibial cortical bone area) was reduced in both unloaded groups and was accompanied by production of hypomineralized bone, as shown by a reduction in the percent ash of the dry weight. Cancellous bone mass (expressed as bone area and surface at the tibial metaphysis) was also reduced in both unloaded groups. Cortical bone mass deficit was greater in the fixation group than in the neurectomy group. Thereafter it increased in the neurectomy group despite a normal longitudinal growth rate, but returned to age-matched values in the reloaded group by 3 weeks. The changes in tibial cancellous bone mass were more pronounced but followed a similar pattern and normalized by 2 weeks. These data demonstrate that total unloading produced by external fixation causes a greater degree of bone mass deficit than partial unloading (produced by neurectomy); the rate of bone loss during unloading in the rat hind limb is more rapid than its recovery during reloading; and cancellous bone recuperates during the reloading phase faster than does cortical bone. Received: 11 February 1997 / Accepted: 28 May 1997     

Progression of osteoporosis in cancellous bone depending on trabecular structure

Progression of osteoporosis is caused by a decline in bone formation activity relative to the resorption activity. In this paper, the authors carried out a theoretical analysis of the progression of osteoporosis to estimate the osteoporotic change in the upper end of the femur. According to this analysis, the progression rate of osteoporosis in cancellous bone depends on the product of remodeling activity,R _act, and the trabecular structure parameter,K _tr. To confirm that the theoretical results were reasonably comparable to actual osteoporotic change, these two factors were measured in rabbits. From the results, it was concluded that the highest progression rate was shown in bar/barlike trabecular structure (type 3); the next highest rate, was shown in plate/bar-like structure (type 2); and the plate/plate-like structure (type 1) was the most insensible. Furthermore, the bone volume fractions of cancellous bone were measured at the upper end of human femurs with and without osteoporosis. Then the measured value was compared with the theoretical value for each type of trabecular structure. Results showed that the decrease in bone volume fraction predicted by Eq. 7 was well in accord with the actual decrease.     

Synergistic effects of bisphosphonate and calcium phosphate nanoparticles on peri-implant bone responses in osteoporotic rats

The prevalence of osteoporosis will increase within the next decades due to the aging world population, which can affect the bone healing response to dental and orthopedic implants. Consequently, local drug targeting of peri-implant bone has been proposed as a strategy for the enhancement of bone-implant integration in osteoporotic conditions. In the present study, an established in-vivo femoral condyle implantation model in osteoporotic and healthy bone is used to analyze the osteogenic capacity of titanium implants coated with bisphosphonate (BP)-loaded calcium phosphate nanoparticles (nCaP) under compromised medical conditions. After 4 weeks of implantation, peri-implant bone volume (%BV; by μCT) and bone area (%BA; by histomorphometry) were significantly increased within a distance of 500 μm from implant surfaces functionalized with BP compared to control implants in osteoporotic and healthy conditions. Interestingly, the deposition of nCaP/BP coatings onto implant surfaces increased both peri-implant bone contact (%BIC) and volume (%BV) compared to the deposition of nCaP or BP coatings individually, in osteoporotic and healthy conditions. The results of real-time PCR revealed similar osteogenic gene expression levels to all implant surfaces at 4-weeks post-implantation. In conclusion, simultaneous targeting of bone formation (by nCaP) and bone resorption (by BP) using nCaP/BP surface coatings represents an effective strategy for synergistically improvement of bone-implant integration, especially in osteoporotic conditions.     

Mechanisms governing the inelastic deformation of cortical bone and application to trabecular bone

To understand the inelastic response of bone, a three-part investigation has been conducted. In the first, unload/reload tests have been used to characterize the hysteresis and provide insight into the mechanisms causing the strain. The second part devises a model for the stress/strain response, based on understanding developed from the measurements. The model rationalizes the inelastic deformation in tension, as well as the permanent strain and hysteresis. In the third part, a constitutive law representative of the deformation is selected and used to illustrate the coupled buckling and bending of ligaments that arise when trabecular bone is loaded in compression.     

Star volume in bone research. A histomorphometric analysis of trabecular bone structure using vertical sections

Conventional bone histomorphometry performed on iliac crest biopsies does not generally provide unbiased stereological estimates of parameters related to bone structure due to the anisotropy of trabecular bone; this, however, can be obtained with vertical sections, which are anisotropic sections, in combination with an anisotropic test system. A practical procedure for obtaining vertical sections from bone is described. The new stereological parameter, the star volume, can provide an unbiased estimation of the absolute mean size of the marrow space and thus give an indirect estimate of the connectivity of trabecular bone structure. The marrow space star volume of vertebral bodies and iliac crest increases with age in both sexes demonstrating that the structural bone changes which occur with age is a topological one with changes in trabecular connectivity. The practical procedure including sampling efficiency for marrow space star volume is described. © 1993 Wiley-Liss, Inc.