红景天苷对吊尾应激小鼠睾酮水平的影响

<正>应激尤其是长期慢性应激严重影响人类的身心健康,并促进机体衰老。工作环境和光照条件以及紧张的生活节奏,均会导致与应激有关的疾病[1-4]。随着应激对人类的危害日益受重视,抗应激药物的研究显得尤为重要和紧迫。     

PM2.5对去势后雌性SD大鼠骨微结构micro-CT的影响

目的探讨不同浓度的PM_(2.5)暴露对去势SD雌性大鼠骨微结构的影响。方法用不同浓度(35、70、150μg/m3)的PM_(2.5)对SD大鼠进行气道滴注,随机分为低剂量组、中剂量组和高剂量组,滴注后5个月末行去势手术;滴注后9个月末取股骨、胫骨、腰椎,运用显微计算机断层扫描术(micro-CT)分别检测三者骨微结构。结果与对照组相比,PM_(2.5)暴露组胫骨、股骨、腰椎的骨小梁骨密度(Tb.BMD)减小、骨体积分数(BV/TV)减小、结构模型指数(SMI)增大、骨小梁厚度(Tb.Th)减小、骨小梁数量(Tb.N)减少、骨小梁分离度(Tb.Sp)增加; PM_(2.5)暴露组中,胫骨骨小梁的BV/TV、Tb.Th、Tb.N、Tb.Sp指标改变与对照组比较差异有统计学意义(P0.05),股骨骨小梁的Tb.BMD、BV/TV、SMI、Tb.N、Tb.Sp指标改变与对照组比较差异有统计学意义(P0.05),腰椎骨小梁的SMI、Tb.Th、Tb.N、Tb.Sp指标改变与对照组比较差异有统计学意义(P0.05)。从micro-CT三维重建图结果看,与对照组比较,PM_(2.5)暴露组胫骨骨髓腔内明显空虚,骨小梁缺如;股骨Ward三角区骨小梁数量稀疏、间隙变大;腰椎骨小梁结构的完整性被破坏,杆状结构增多。结论表明PM_(2.5)暴露可使去势后雌性SD大鼠胫骨、股骨、腰椎骨小梁结构遭到破坏,数量减少,由片状结构转为杆状结构,由此可见PM_(2.5)暴露可加重绝经后骨量丢失。     

变频振动对尾吊大鼠失重性骨质疏松防治作用的研究

目的探讨变频振动对尾吊大鼠失重性骨质疏松模型的防治作用。方法采用目前世界上广泛应用且技术已经成熟的鼠尾悬吊动物模型模拟失重环境,应用电磁振动台将振动强度为0.5 g(g为加速度)在不同频率45 Hz、90 Hz、变频(5~90Hz)振动应力作用于3月龄SD雄性大鼠40只,随机分成5组,每组8只:对照组(非鼠尾悬吊组);45 Hz组、90 Hz组、变频(5~90 Hz)组,鼠尾悬吊非振动组,每次振动10 min,每天1次,每周5次,休息间隔为2天,共4周。所有对照组不进行振动治疗,但置于与振动治疗组相同噪音环境下。实验后用Micro-CT测量股骨远端骨量、自动化分析仪测定血生化指标以及Elisa试剂盒测定骨钙素。结果振动刺激对失重性骨质疏松骨微结构的恢复及骨密度有明显的改善作用,变频振动对骨微结构的恢复及增加骨密度一定程度上要好于固定频率振动。结论对尾吊大鼠28天的不同频率振动刺激使松质骨骨矿物质以及空间上的结构进行了重构,导致尾吊大鼠骨质疏松模型中骨量的增加,骨密度的提高,对失重性骨质疏松有一定的防治作用,为临床上防治微重力环境下骨丢失提供了实验依据。     

50 Hz 1.8 mT正弦交变电磁场通过促进骨形成抑制尾吊大鼠的骨量丢失

目的探究50 Hz 1.8 m T正弦交变电磁(sinusoidal electromagnetic fields,SEMFs)是否能抑制尾吊(hind-limb suspension,HLS)所致大鼠的骨量丢失。方法 30只雌性SD大鼠(180±10)g,分为3组,每组10只,分别为对照组、HLS组和HLS+SEMFs组。除对照组外,HLS组和HLS+SEMFs组大鼠进行尾吊,之后,HLS+SEMFs组大鼠每天进行1.5 h 50 Hz1.8 m T正弦交变电磁场干涉。4 w后处死全部大鼠,对各组大鼠进行重要脏器的器官指数计算和病理学观察、离体骨密度检测、骨生物力学分析和骨形态计量学分析以及Micro-CT扫描。结果实验期间各组大鼠的体重及重要脏器的器官指数差异无统计学意义(P0.05),脏器病理学观察未见异常变化;骨密度结果显示,SEMFs有效提高股骨和椎骨的离体骨密度;生物力学实验表明,SEMFs减轻了HLS引起的股骨和椎骨力学性能的降低。此外,SEMFs能增加骨钙素(osteocalcin,OC)含量,并且对抗酒石酸酸性磷酸酶5b(tartrate-resistant acid phosphatase 5b,TRACP-5b)具有一定的抑制作用;Micro-CT结果显示,SEMFs部分抑制HLS造成的松质骨骨微结构的减少,相比HLS组,骨小梁数、骨小梁厚度、骨小梁面积显著升高,且分离度下降;骨组织形态学分析同样表明SEMFs改善了松质骨骨微结构的恶化。结论 50 Hz 1.8 m T SEMFs能抑制HLS所致大鼠的骨量丢失,其可能机制是具有抑制骨吸收和提高骨形成的双重活性,这将为电磁场治疗骨质疏松症的临床应用提供依据。     

下肢旋转对站立位下肢全长髋-膝-踝角的影响

目的 探讨下肢旋转对站立位下肢全长X线片测量髋-膝-踝角(hip-knee-ankle angle,HKA)的影响.方法 测量2017年10月至2019年2月我院106例患者站立位下肢全长X线片上的HKA,其中男29例,女77例;年龄22.9～87.7岁,平均(59.2±12.4)岁.每例均包括中立位、外旋30°位和内...     

黄芪散对肥胖模型大鼠胫骨骨结构的研究

目的观察黄芪散对肥胖模型大鼠胫骨上段松质骨和中段皮质骨的影响。方法 180～200 g雄性SD大鼠,实验分为正常组、高脂模型组、立普妥组(2 mg/kg)、黄芪散低剂量组(1.2 g/kg,10 mL/kg)、黄芪散高剂量组(2.4 g/kg,10 mL/kg);通过高脂饲料喂养诱导肥胖模型7周,造模成功后开始给药,持续给药15周,处死大鼠,对胫骨松质骨和皮质骨进行骨组织形态计量学考察。结果与正常对照组相比,模型组胫骨松质骨骨小梁面积百分数(Tb.Ar%)、骨小梁宽度(Tb.Th)显著减少;胫骨中段皮质骨面积百分数(Ct.Ar%)明显增加,骨髓腔面积百分数(Ma.Ar%)明显减小,骨外膜面骨形成率(P-BFR/BS)降低。与模型组相比,黄芪散使胫骨上段的Tb.Ar%、Tb.Th、Tb.N均增加;新骨年形成率(BFR/BV)和中段骨Ma.Ar%明显减少,P-BFR/BS显著增加。结论肥胖可致模型大鼠胫骨松质骨结构发生明显变化,呈现骨质疏松状态;皮质骨骨量增加。黄芪散可抑制肥胖引起大鼠胫骨松质骨的骨丢失,可维持肥胖引起大鼠胫骨皮质骨的促生长作用。其机制可能与抑制骨吸收有关。黄芪散对皮质骨无明显作用。     

尾悬吊状态对性成熟期雄性大鼠生殖功能的影响

目的:探讨尾悬吊造成的模拟失重状态对性成熟期雄性大鼠生殖功能的影响及其机制,为研究太空环境对人类生殖功能的影响打基础。方法:性成熟期健康SD雄性大鼠40只,随机分为4组,每组10只,分为实验1组(尾悬吊14 d)、实验2组(尾悬吊28 d)和对照1组(自由活动14 d)、对照2组(自由活动28 d),观察睾丸的重量和形态学改变、精子数量和质量改变、血液中激素含量的改变,并利用原位缺口末端标记法(TUNEL)检测睾丸细胞的凋亡。结果:各悬吊组大鼠睾丸重量与相应对照组相比明显下降(P<0.05),附睾精子数量和活动率明显减少(P<0.05),精子畸形率和凋亡率明显增加(P<0.05),卵泡刺激素和黄体生成素轻度增高,而睾酮含量明显下降(P<0.05)。但上述变化在悬吊14 d组和28 d组之间无明显差异(P>0.05)。另外,悬吊组睾丸组织生精小管萎缩,生精上皮细胞层数逐渐减少,管腔内的精子数明显减少,悬吊28 d组比悬吊14 d组改变更明显。结论:模拟失重对性成熟期雄性大鼠生殖功能有较明显的损害,这种损伤可能与引起睾丸生精细胞凋亡有关。抑制睾丸生精细胞凋亡也许可以防护失重状态下的生殖损害。     

PTH对大鼠胫骨远心端松质骨的影响及其组织形态计量学检测

目的用骨组织形态计量学方法定量检测大鼠胫骨远心端不活跃的骨小梁，并观察甲状旁腺激素（ＰＴＨ）对此骨骺已关闭部位低转化骨的影响。方法：３月龄ＳＤ大鼠２１只随机分３组：（１）对照组，（２）ＰＴＨ３０ｍｇ组，（３）ＰＴＨ８０ｍｇ组，（均按ｋｇ－１ｄ－１计，皮下注射２１ｄ）。各组动物于实验２１天处死，取胫骨远心段不脱钙骨制片测量。结果：（１）静态参数：用药两组和对照组比较骨小梁面积和骨结构无变化。（２）动态参数：荧光周长百分率（％Ｌ．Ｐｍ），矿化沉积率（ＭＡＲ），类骨质周长百分率（％Ｏ．Ｐｍ）和骨形成率（ＢＦＲ）用药两组比对照组明显增加，且呈量效关系。但骨吸收的参数比较未见差异。结论：胫骨远心段骨转化率虽然很低，但对ＰＴＨ合成代谢药物短期内仍有明显反应。     

神经生长因子对胫骨骨折大鼠骨力学、骨强度及骨桥蛋白及下游相关因子水平的影响

目的 探讨神经生长因子（NGF）对胫骨骨折大鼠骨力学、骨强度及骨桥蛋白（OPN）及下游相关因子水平的影响。方法 将42只大鼠按照随机数字表法分为A组（腓肠肌两侧注射生理盐水）、B组（腓肠肌两侧注射NGF）,每组21只。建立胫骨骨折模型后,观察两组骨痂的大小、骨折愈合情况,测定生物力学检测指标（最大载荷、弹性载荷、最大挠度）、胫骨骨强度指标（骨密度和骨矿含量）,HE染色观察胫骨骨折形态,Western blot法检测OPN和局部黏着斑激酶（FAK）蛋白表达。结果 (1) B组骨折愈合更快,更早地完成了骨痂重塑,且愈合过程中,形成的骨痂更大。(2)术后1、3、5周,B组最大载荷、弹性载荷、最大挠度及OPN、FAK蛋白表达、骨密度明显大于A组（P<0.05）,骨矿含量明显少于A组（P<0.05）;A组术后各时间点各项指标比较差异均无统计学意义（P> 0.05）;B组骨矿含量随时间推移逐步降低,其余指标随时间推移逐步升高（P<0.05）。(3) B组骨痂组织中软骨组织形成更早,面积更大,软骨组织向骨组织转化的过程更快。结论 NGF可以改善大鼠胫骨骨折最大载荷、弹性载荷、...     

神经病理性痛对大鼠脊髓水平GABAB受体亚型蛋白表达的影响

大量的研究表明,神经病理性痛等慢性疼痛状态可导致脊髓背角一系列神经递质和神经递质受体系统发生改变。GABAB受体的改变能影响机体GABA能系统的功能,从而影响痛觉信息在脊髓背角的整合、传递和调控。GABAB受体以其两个亚型(GABAB1、GABAB2)的异二聚体形式存在并发挥功能[1,2]     

Management of osteonecrosis of proximal tibia using trabecular osteonecrotic rods

Osteonecrosis of the knee is a well-described cause of acute knee pain. It can lead to significant functional impairment, rapid arthritic joint changes and subsequent collapse. Several hypotheses exist different treatment options are used ranging from conservative management to joint arthroplasty. The majority of cases involve the distal femoral condyle and to a much lesser extent the medial tibial plateau.We are presenting a rare case of osteonecrosis of the proximal tibia affecting the lateral tibial condyle in 44 years old Caucasian male which was treated successfully using osteonecrotic tantalum rods with 26 month follow-up.     

去卵巢大鼠胫骨和椎骨松质骨微结构的显微CT分析

目的观察大鼠去卵巢后,椎骨和胫骨松质骨微结构变化。方法 50只7月龄SD大鼠随机分为基线组,去卵巢组和假手术组。基线组在试验开始时处死,去卵巢组和假手术组分别在去卵巢后3周、15周各处死。分离大鼠第五腰椎和左侧胫骨,用显微CT(microCT)对椎骨及胫骨骨骺端松质骨进行扫描,对其微结构定量分析。结果去卵巢第3周和第15周,OVX组胫骨骨体积分数(BV/TV)、骨小梁数量(Tb.N)和连接密度(Conn.D)均显著性小于SHAM组,骨小梁间隔(Tb.Sp)和结构模型指数(SMI)均明显大于SHAM组。去卵巢第3周,OVX组椎骨BV/TV显著性小于SHAM组,SMI明显大于SHAM组,至第15周,OVX、SHAM两组间椎骨的微结构差异与胫骨相同。纵向观察,OVX组胫骨随着时间变化出现BV/TV和Conn.D进行性减少,Tb.Sp进行性增加,面积骨密度(tBMD)和骨小梁厚度(Tb.Th)在第3到15周分别出现下降和增加。OVX组椎骨BV/TV在去卵巢3周内下降,Conn.D和Tb.Sp在3到15周内分别出现减少和增加。胫骨和椎骨的Tb.N随时间均进行性减少,SMI均在3周内增加。结论雌激素缺乏时大鼠松质骨微结构改变呈现出区域性,胫骨松质骨微结构丢失的发生比椎骨早,更为显著。     

强骨饮对去卵巢大鼠骨折愈合骨小梁Micro-CT改变研究

目的研究强骨饮对去卵巢大鼠骨折愈合骨小梁Micro-CT的影响。方法将32只雌性SD大鼠随机分为4组:A组(假手术组)、B组(模型组)、C组(强骨饮组)、D组(基础用药组)。骨松造模组(B、C、D组)术前随机取8只大鼠进行骨密度测量,后骨松造模组摘除双侧卵巢,A组切除少许脂肪后缝合,3月后随机取骨松造模组8只大鼠进行骨密度测量以证明造模成功;将所有大鼠进行骨折造模,后将C组强骨饮灌胃、D组进行碳酸钙和维生素D3灌胃,A、B两组用等量生理盐水灌胃;在6周后时各取8只大鼠股骨骨折处骨痂进行Micro-CT分析,参数包括BV/TV、Tb.Th、Tb.N、Tb.Sp。结果 B组骨小梁数量、骨小梁厚度与骨体积分数低于C、D组(P0.05),骨小梁分离度指数高于C、D组(P0.05);C组与D组骨小梁数量、骨小梁厚度比较差异有统计学意义(P0.05),而与D组的骨小梁分离度及骨体积分数比较差异无统计学意义(P0.05)。结论强骨饮能增加骨量、改善骨质疏松骨三维结构特别是增加骨小梁数量与厚度,其可能机制是强骨饮通过抑制破骨细胞活性,从而增强骨强度、促进骨折愈合。     

The effect of intermittent local heating on fracture healing in the distal tibia of the rabbit

Summary Two series of controlled experiments were carried out to investigate the effect of intermittent local heating on fracture healing in the distal tibia of the rabbit. In the first series, the distal tibia was fractured in a reproducible manner and then treated by compression plate fixation. Nine animals received intermittent local heating around the fracture site for 6 weeks postoperatively in comparison with 5 control animals. The mechanical strength of the healed tibia was then measured in a standardized 3-point bend test. Intermittent local heating produced stronger bones than the untreated controls in 6 of the 9 cases, a result which was marginally significant (P=0.055). In the second series of experiments, a reproducible bone defect was created by drilling a 2 mm diameter hole through the distal tibia; compression plate stabilization was not required. Fourteen animals received intermittent local heating around the fracture site for 3 weeks postoperatively in comparison with 7 control animals. Intermittent local heating produced stronger bones than the untreated controls in 8 of the 14 cases, a result which was not significant (P>0.1). It is concluded that intermittent local heating of the type studied has too small an effect on accelerating the rate of fracture repair to be clinically useful.

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Résumé Deux séries d'expérimentations contrôlées ont été effectuées dans le but d'évaluer les effets de l'échauffement local intermittent sur la consolidation des fractures au niveau de l'extrémité distale du tibia du lapin. Dans la première série, le tibia était fracturé de façon reproductible et traité par mise en place d'une plaque à compression. Neuf animaux furent soumis à un échauffement intermittent a niveau du foyer de fracture pendant six semaines post-opératoires et comparés à cinq animaux de contrôle. La résistance mécanique du tibia consolidé fut alors mesurée grâce à un test de flexion standardisé. L'échauffement local intermittent détermina des os plus solides que ceux des animaux non traités dans six cas sur neuf. Ce résultat était légèrement significatif (P=0,055). Dans la deuxième série, on créa une perte de substance osseuse reproductible en forant un trou de 2 mm de diamètre au travers du tibia, à sa partie distale. On n'utilisa pas de plaque de fixation. Quatorze animaux bénéficièrent d'un échauffement intermittent du foyer de fracture pendant trois semaines postopératoires et furent comparés à sept animaux de contrôle. L'échauffement local intermittent produisit des os plus solides que ceux des témoins dans huit des quatorze cas, ce qui n'était pas significatif (P>0,1). On peut en conclure que l'échauffement local intermittent, selon les modalités étudiées, n'a qu'un trop faible effet sur l'accélération du temps de consolidation des fractures pour pouvoir être utilisé en clinique.

     

Predicting regional variations in trabecular bone mechanical properties within the human proximal tibia using MR imaging

Trabecular bone density changes throughout the proximal tibia are indicative of several musculoskeletal disorders of the knee joint. Many of these disorders involve not only changes in the amount of bone, but also in the surrounding soft tissue. Osteoarthritis, for instance, involves bone density changes below the subchondral bone and throughout the proximal tibia, along with degradation evident in the articular cartilage. Osteoporosis, characterized by low bone density may also involve changes in bone size, structure or microarchitecture, each of which may contribute to fracture risk. Recent studies have shown that magnetic resonance (MR) imaging, most frequently applied for soft tissue imaging, also allows non-invasive 3-dimensional characterization of bone microstructure. The purpose of the current study is to use whole joint MR images to acquire regional apparent bone volume fraction (appBVF) throughout the proximal tibia and correlate with mechanical properties measured on the corresponding ex vivo specimens. To compare our method to a high-resolution imaging modality, micro-CT analysis was performed in a subset of specimens. Using linear mixed-effects models, significant correlations (p<0.05) were determined between MR appBVF and Young's modulus (r(2)=0.58, MPSE=3633 MPa(2)), yield stress (r(2)=0.73, MPSE=1.53 MPa(2)) and ultimate stress (r(2)=0.72, MPSE=2.29 MPa(2)). Comparable significant correlations (p<0.05) were also determined between micro-CT BVF and Young's modulus (r(2)=0.47, MPSE=5179 MPa(2)), yield stress (r(2)=0.80, MPSE=1.23 MPa(2)) and ultimate stress (r(2)=0.83, MPSE=1.76 MPa(2)). The current study demonstrates that MR imaging may be used as an in vivo imaging tool to determine differences in bone strength between subjects and regional variations within a single tibia.     

Computational biomechanics of the distal tibia from high-resolution MR and micro-CT images

The mechanical properties of bone estimated by micro-finite element (μFE) analysis on the basis of in vivo micro-MR images (μMRIs) of the distal extremities provide a new tool for direct assessment of the mechanical consequences of intervention. However, the accuracy of the method has not previously been investigated. Here, we compared μFE-derived mechanical parameters obtained from μMRIs at 160 μm isotropic voxel size now achievable in vivo with those derived from 25 μm isotropic (reference) μCT images of 30 cadaveric tibiae from 15 donors (4 females and 11 males, aged 55–84 years). Elastic and shear moduli estimated from 5 mm³ subvolumes of trabecular bone (TB) derived from μMRIs were significantly correlated with those derived from volume-matched reference μCT images (R² = 0.60–0.67). Axial stiffness of whole-bone sections (including both cortical and trabecular compartments) derived from μMR-based models were highly correlated (R² = 0.85) with those from high-resolution reference images. Further, μFE models generated from μCT images after downsampling to lower resolutions relevant to in vivo μMRI (100–160 μm) showed mechanical parameters to be strongly correlated (R² > 0.93) with those derived at reference resolution (25 μm). Incorporation of grayscale image information into the μMR-based μFE model yielded slopes closer to unity than binarized models (1.07 ± 0.15 vs. 0.71 ± 0.11) when correlated with reference subregional elastic and shear moduli. This work suggests that elastic properties of distal tibia can be reliably estimated by μFE analysis from μMRIs obtainable at in vivo resolution.     

Morphology-mechanical property relations in trabecular bone of the osteoarthritic proximal tibia

Alteration of morphologic and mechanical properties of trabecular bone in the osteoarthritic proximal tibia may be a contributing factor in tibial component loosening. To explore this issue, the authors performed tissue property measurements, morphologic analysis, and mechanical testing of subchondral, epiphyseal, and metaphyseal trabecular bone specimens retrieved from six human proximal tibias exhibiting a range of medial unicondylar osteoarthritic degeneration. Apparent density in the proximal tibia was altered according to varus misalignment and medial subluxation associated with medial osteoarthritis of the knee. In subchondral bone, a decrease in tissue mineralization contributed to a significant reduction in axial mechanical properties with degenerative disease (P < .0005). In epiphyseal and metaphyseal bone, trabecular thickness and the number of trabeculae increased linearly with volume fraction, providing a power law relationship between axial elastic modulus and apparent density (R² = .84). Average elastic properties of the tibial epiphysis and metaphysis were not reduced by degenerative disease (P < .05). The results suggest that absolute minimization of tibial resection might not be an optimal strategy for tibial component fixation and that mechanical properties of the tibial resection surface are more homogeneous in planes parallel to the joint surface than in a plane normal to the longitudinal axis of the tibia.     

大鼠卵巢去势后颌骨及胫骨结构的动态变化及意义

目的通过观察大鼠卵巢去势后颌骨和胫骨结构的动态变化,探讨颌骨、胫骨与骨质疏松的关系。方法切除SD雌性大鼠双侧卵巢建立骨质疏松动物模型,术后3、6个月处死大鼠,取颌骨和胫骨标本,对组织切片进行骨组织形态计量学分析。结果大鼠卵巢去势后3个月时胫骨骨小梁呈疏松化改变,骨量减少明显多于颌骨;6个月时颌骨骨小梁呈疏松化改变,骨量减少,与同期胫骨比较无显著差异。结论骨质疏松早期颌骨结构无明显改变,这为牙槽外科及种植外科的发展提供理论依据,为骨质疏松的防治开辟新的思路。     

Effect of etidronate on three-dimensional trabecular structure in ovariectomized or sciatic neurectomized rats

The purpose of this study was to evaluate the effect of etidronate (EHDP) on three-dimensional (3D) trabecular structure in ovariectomized (OVX) and sciatic neurectomized (NX) rats. Eight-week-old female Lewis rats received ovariectomy (n = 19) or sham operation (OVX-sham; n = 10). OVX rats received either vehicle (OVX-control; n = 9) or EHDP (OVX-EHDP; n = 10). Eight-week-old female Lewis rats received NX (n = 20) or sham operation (NX-sham; n = 10). NX rats received either vehicle (NX-control; n = 10) or EHDP (NX-EHDP; n = 10). EHDP at 5mg/kg or vehicle was subcutaneously injected 5 days a week. The treatment was initiated 2 weeks after surgery and was continued for 2 weeks. At 12 weeks of age, the rats were killed, and we scanned the proximal metaphysis of the tibia; this was done using micro-CT; ( CT20; SCANCO Medical). The recovery of structural parameters was not complete in NX rats compared to OVX rats. The 3D micro-CT images showed that the subcortical spongiosa, which was preserved in OVX rats, had marked loss in NX rats. Furthermore, these trabeculae were not restored after the EHDP treatment. In conclusion, the mechanical driving of the control of trabecular structure is inactive in NX, and EHDP treatment for 2 weeks does not restore this condition.