不同剂量蛇床子素对OPG基因敲除小鼠和去卵巢骨质疏松大鼠作用疗效的比较研究

目的 观察不同剂量蛇床子素对OPG基因敲除小鼠和去卵巢骨质疏松大鼠的影响。方法 选择3种不同剂量的蛇床子素作用于OPG基因敲除小鼠和去卵巢骨质疏松大鼠,以双能X骨密度仪检测动物全身骨密度的变化;将动物腰椎做硬组织切片,并进行骨形态计量学分析其骨小梁的变化。结果 对于OPG基因敲除小鼠,蛇床子素能提高其全身BMD,以中剂量（10mg/（kg?d））组提高最为明显,低剂量（5mg/（kg?d））次之,而高剂量（15mg/（kg?d））组效果最差。蛇床子素能提高OPG基因敲除小鼠腰椎骨小梁体积分数,增加骨小梁数目,增加骨小梁厚度,降低骨小梁分离度,其中以5mg/(kg?d)组作用最明显,其次为10mg/(kg?d)组,而15mg/(kg?d)组则效果最差;对于去卵巢骨质疏松大鼠,不同剂量的蛇床子素均能显著提高大鼠全身BMD,其中以中剂量（100mg/（kg?d））组为最佳。蛇床子素能显著提高大鼠腰椎骨小梁体积分数,以100mg/（kg?d）组最明显。显著增加大鼠腰椎骨小梁数目,以75mg/（kg?d）组最明显。蛇床子素100mg/（kg?d）组能增加大鼠腰椎骨小梁厚度。不同剂量的蛇床子素均能显著降低大鼠腰椎骨小梁分离度,其中以75mg/（kg?d）组和100mg/（kg?d）组最明显。结论 蛇床子素能促进骨形成,抑制骨吸收,从而起到抗骨质疏松的作用,其疗效与给药剂量密切相关。     

骨宝液在去卵巢大鼠骨质疏松症中抑制骨转换作用的实验研究

目的：探讨骨宝液对去卵巢大鼠骨质疏松症中抑制骨转换作用。方法：60只大鼠去卵巢诱导骨质疏松症，随机分为正常对照组、模型组、尼尔雌醇组、骨宝液低、中、高剂量组。正常对照组、模型组以0．9％生理盐水每天10ml／kg，尼尔雌醇组以尼尔雌醇每2周1mg／kg，其他三组每天分别以骨宝液5、10、15ml／kg的剂量灌胃给药3个月后，以比色法测定其血清钙（s-Ca）、骨碱性磷酸酶（b-AKP）和血清抗酒石酸酸性磷酸酶（s-TRAP）的活性，竞争放射免疫法测定血清中骨钙素（s-BGP）的含量；双能x线骨密度仪（DEXA）测定股骨及腰椎的骨密度；三点弯曲试验法测定骨生物力学；扫描电镜进行骨小梁形态计量学分析。结果：骨宝液组与其他组比较，s-TRAP水平降低，腰椎骨密度增加，股骨抗弯抗拉能力改善，骨小梁形态改善，骨小梁平均宽度（MTT）与骨小梁面积百分比（TS％）显著增加。结论：骨宝液对去卵巢大鼠骨质疏松症具有防治作用，其机制可能与抑制骨转换有关。     

联合补充大豆异黄酮和钙预防去势大鼠骨质疏松的实验研究

目的 研究联合补充大豆异黄酮和钙对去卵巢大鼠骨质疏松的预防作用。方法 将50只3月龄SD雌性大鼠摘除卵巢后按体重随机分成5组：假手术对照组、手术对照组、大豆异黄酮组（40mg／kgBW）、钙组（100mg／kgBW）、钙＋大豆异黄酮组（Ca100mg／kgBW＋SI40mg／kgBW）。连续灌胃饲养3个月后测定大鼠血清骨钙素，左侧股骨测定骨密度和骨钙含量、右侧股骨进行骨组织形态学计量分析。结果 Ca＋SI组血清BGP水平和股骨骨密度均高于其他去卵巢各组（P〈0．05），但低于Sham组（P〈0．05）；Ca＋SI组大鼠股骨的骨钙含量与Ca组、Sham组差异均无统计学意义；在去卵巢各组大鼠中手术对照组、大豆异黄酮组和钙组大鼠的骨小梁数目和骨小梁厚度显著减少，骨小梁间距明显增宽，与钙＋大豆异黄酮组相比有显著差异（P〈0．05）。结论 与单独补充大豆异黄酮或钙相比，大豆异黄酮与钙的联合应用能够更有效地预防去卵巢大鼠骨质疏松的发生。     

谷康泰灵对骨质疏松模型大鼠骨质变化的影响

目的：观察动物长干骨中多肽类的物质对骨质疏松模型大鼠骨质变化的影响,为临床应用提代实验依据。方法：SD大鼠44只,随机分为正常组（13只）和骨质疏松模型组（31只）。以维甲酸80mg.kg^-1.d^-1灌胃15d,诱导骨质疏松模型。模型复制成功后,各组处死5只,下组（8只）继续观察,骨质疏松模型组又随机分为无措施对照组（8只）、动物长干骨中多肽类物质治疗组（10只,0.08mg.kg^-1.d^-1谷康泰灵腹腔注射）和雌二醇治疗组（8只,0.05mg.只^-1,2次.W^-1苯甲酸雌二醇腹腔注射）。所有大鼠给予常规饲料蒸馏水,治疗期30d。观察造模期和治疗后大鼠股骨形态学变化。结果：维甲酸诱导15d后,大鼠股骨松质骨和皮质骨骨量减少,呈现骨质疏松变化。谷康泰灵和雌激素治疗30d后,骨质疏松大鼠股骨平均骨小梁数、平均骨小梁宽度、骨小梁面积百分比、皮质骨面积百分比等显著增加,与正常组大鼠骨质无差异。结论：动物长干骨中多肽类物质谷康泰灵对骨质疏松有明显的治疗作用,和雌激素比,无副作用,适合于临床应用。     

淫羊藿总黄酮对摘除卵巢大鼠骨质疏松症的防治作用

用除卵巢法结合低钙饲料建立大鼠骨质疏松模型。淫羊藿总黄酮在75-300mg/kg剂量范围内连续给药3个月，与模型组大鼠比较，能明显提高大鼠股骨表现观面密度（W/LD）和骨密度（BMD）而不升高子宫系数及血清雌二醇（s-E2)水平，并有提高骨Ca、骨P的趋势。高剂量组大鼠血清碱性磷酸酶（s-ALP)降低，股骨骨密度升高。骨形态计量学结果表明，高剂量组大鼠骨小梁吸收表面百分率（TRS%）和形成表面百分率（TFS%）等参数明显降低，骨小梁体积百分率（TBV%）明显提高。     

环磷酰胺对大鼠骨密度和骨微结构的影响

目的：研究不同剂量环磷酰胺对雌性SD大鼠骨密度和骨微结构的影响。方法40只3月龄SD雌性大鼠随机数字表法分为环磷酰胺低剂量组、中剂量组、高剂量组和对照组,每组各10只,环磷酰胺各组分别腹腔注射不同剂量（5 mg／kg、8 mg／kg、10 mg／kg）的环磷酰胺,对照组腹腔注射等量生理盐水,每天一次,连续15天,观察大鼠骨密度及骨微结构等指标。结果不同剂量的环磷酰胺组与对照组比较,全身骨密度分别下降了9．8％、13．3％和15．6％;股骨骨小梁数目分别下降了49．8％、65．5％和72．8％;股骨骨小梁分离度则分别上升了225．2％、416．9％和577．4％。结论环磷酰胺可使大鼠骨密度降低,骨小梁数量减少,骨微结构受损,且环磷酰胺剂量越大,骨微结构受损越严重。     

柚皮苷促进成骨细胞分化并有效改善卵巢切除所致的骨质疏松

目的 评价柚皮苷对成骨细胞增殖与分化的作用,并采用大鼠骨质疏松模型评价柚皮苷的治疗效果.方法 采用不同浓度的柚皮苷处理大鼠骨髓基质细胞,观察其增殖、分化与功能的改变.采用低、中、高三种不同剂量的柚皮苷作为治疗组,磷酸缓冲液(PBS)作为对照组,对卵巢摘除诱发骨质疏松的大鼠灌胃2个月.应用骨质疏松大鼠右侧股骨的X线照片和显微CT扫描测量骨矿密度以及骨体积分数,使用骨质疏松大鼠左侧胫骨的病理切片检测组间骨小梁厚度和骨小梁间隙的变化.结果 体外研究表明柚皮苷可有效增加骨髓基质细胞的增殖和成骨分化,浓度为10 μg/ml时对骨钙素的表达具有最显著的作用.骨髓基质细胞对柚皮苷的治疗呈现一种延迟反应模式.柚皮苷并有效逆转了卵巢切除导致的骨质疏松,增加了骨密度、骨容量和骨小梁厚度.300 mg/kg(中剂量)是具有满意治疗效果的最优剂量.结论 柚皮苷促进骨髓基质细胞的分化与增殖,增加骨钙素的表达,它能有效逆转卵巢切除大鼠的骨质疏松过程.本研究表明柚皮苷是治疗骨质疏松的潜在有效药物.     

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。     

胎肾细胞移植对维甲酸所致大鼠骨质疏松症的实验研究

目的：探讨胎肾细胞悬液对维甲酸所致大鼠骨质疏松症的作用,为防治骨质疏松症寻找理想的药物。方法：通过静脉输液胎肾细胞悬液,观察胎肾对维甲酸所致骨质疏松大鼠血钙,磷,尿钙,磷,尿羟脯氨酸等生化指标和骨形态结构的影响。并与防治骨质疏松药物尼尔雌醇及生理盐水进行对照,观察其对上述生化指标及骨质疏松模型大鼠骨质的改善。结果：与尼尔雌醇组及生理盐水组相比,胎肾组大鼠血钙明显升高,尿羟脯氨酸水平降低（P＜0．05）,而尿钙、尿磷无显性差异（P＞0．05）。在骨显微结构的病理变化中,胎肾组大鼠的骨小梁厚度,面积及密度均高于尼尔雌醇组及生理盐水组,而骨小梁间隙和骨髓腔明显缩小（P＜0．05）,结论：胎肾细胞移植能有效治疗维甲酸所致大鼠骨质疏松。     

咪达普利对实验性骨质疏松大鼠的骨代谢和生物力学的影响

目的探讨ACEI药物咪达普利对维甲酸所致的实验性骨质疏松的大鼠骨代谢和生物力学的影响。方法将60只SD雌性大鼠随机分为5组,为对照组(Ⅰ组)和维甲酸诱导骨质疏松模型组(Ⅱ组),模型+不同剂量的咪达普利干预3组(Ⅲ,Ⅳ,Ⅴ组),每组12只。对Ⅱ,Ⅲ,Ⅳ和Ⅴ组的大鼠用维甲酸80 mg/(kg·d)连续灌胃21 d建立实验性骨质疏松模型,Ⅰ组用等体积的生理盐水对照。造模后,Ⅲ,Ⅳ和Ⅴ组分别给予低,中和高剂量咪达普利(5 mg, 10 mg,20 mg)灌胃,Ⅰ和Ⅱ组采用安慰剂对照,持续7d后处死大鼠,分别检测各组大鼠的体重,脏器指数,股骨骨密度,股骨长度和干湿重,骨代谢指标和骨生物学力学指标。结果与正常组对比,模型组在大鼠的体重、各脏器指数、股骨骨密度、骨干湿重、骨代谢指标方面均存在统计学差异(P0.05)。ACEI类药物咪达普利干预后,与模型组相比,大鼠的体重、股骨长度、干湿重增加(P0.05),股骨中钙和磷的含量明显增加(P0.05),血清中ALP和BGP的含量增加(P0.05),TRAP和PTH的含量下降(P0.05),肱骨生物力学最大载荷、最大扰度、最大弯度、、骨应力和骨应变增加(P0.05)。结论咪达普利能增加维甲酸所致的实验性骨质疏松大鼠体重,提高骨密度,增加肱骨长度和干湿重,减少骨质流失,促进骨形成和矿物质的沉积,增加骨的生物力学强度,减少骨折的发生,对骨质疏松具有保护作用。     

墨旱莲对维甲酸所致大鼠骨质疏松症的药效学研究

目的探讨中药墨旱莲对维甲酸所致大鼠骨质疏松症的药效作用。方法 3月龄SPF级雌性SD大鼠60只,随机分为正常对照组、模型组(RA,75 mg/(kg·d))、墨旱莲组(1.46、0.73、0.37 g/(kg·d))、仙灵骨葆组(1.5 g/(kg·d))。除正常组外,其余各组给予维甲酸造模2 w,造模同时给予墨旱莲、仙灵骨葆。实验过程每日称量体重,连续给药6w后测定血钙(S-Ca)、血磷(S-P)、血清中碱性磷酸酶(ALP)和骨钙素(OCN)的水平,尿液中钙(U-Ca)、磷(U-P)、脱氧吡啶啉(DPD)的水平。采用DXA型骨密度仪检测大鼠的股骨、第4椎骨、胫骨的骨密度(bone mineral density,BMD)。三点弯曲试验检测左侧股骨生物力学性能:最大载荷、结构硬度、能量吸收、最大应力、弹性模量。Micro CT法分析右侧股骨骨微结构。结果墨旱莲1.46 g/(kg·d)能显著升高模型组大鼠的血钙水平,同时降低尿钙、ALP、OCN和DPD(P0.05)水平。与模型组相比,墨旱莲1.46 g/(kg·d)对维甲酸所致骨质疏松大鼠的股骨、第四椎骨及胫骨骨密度分别提高8.17%、11.79%、14.59%(P0.05),对最大载荷、结构硬度、能量吸收、最大应力、弹性模量等生物力学参数分别提高13.98%、16.33%、40.18%、12.45%、34.96%(P0.05),同时能有效抑制维甲酸所致大鼠股骨干骺端骨小梁微结构的退化(P0.05)。结论墨旱莲1.46 g/(kg·d)对维甲酸所致大鼠的骨质疏松症有防治作用,其作用机制可能与增强钙吸收、促进成骨细胞活性、降低骨转换率有关。     

Effects of endurance exercise on three-dimensional trabecular bone microarchitecture in young growing rats

Appropriate endurance exercise is capable of increasing bone mass and strength in both animals and humans. We examined the skeletal changes induced by treadmill running exercise in young growing rats with a particular emphasis on three-dimensional trabecular bone microarchitecture. Fourteen male Wistar rats were divided into sedentary (CON; n = 7) and exercised (RUN; n = 7) groups at the age of 4 weeks. The rats in the RUN group performed the treadmill running exercise of 30 m/min for 60 min, 5 times a week. After 10 weeks of exercise, bone mineral density (BMD), cortical geometry, diaphyseal breaking force, and trabecular bone microarchitecture in the femur were measured. Three-dimensional trabecular bone microarchitecture was evaluated at the distal femoral metaphysis using microcomputed tomography. The running exercise significantly increased BMD, bone volume, bone volume fraction, trabecular thickness, and trabecular number, whereas trabecular bone pattern factor, the parameter associated with decreased trabecular connectivity, was significantly lower in the RUN group than the CON group. On the other hand, no significant difference in the degree of anisotropy and structure model index was observed between the two groups. At the femoral diaphysis, running exercise significantly increased cortical bone area, width, and maximum load without affecting bending stress, implying that the material properties of bone had not changed in the exercised rats. These results suggest that the increase in bone strength induced by endurance exercise is mediated by changes in trabecular bone microarchitecture as well as density and cortical geometry.     

胎肾细胞悬液对维甲酸所致骨质疏松大鼠部分钙调节激素的影响

目的探讨胎肾细胞悬液改善维甲酸所致大鼠骨质疏松的机理,为临床用药提供客观依据.方法通过静脉输注胎肾细胞悬液,采用放免分析法测定维甲酸所致骨质疏松大鼠血清雌二醇、降钙素、甲状旁腺素、骨钙素等钙调节激素含量,观察胎肾对上述指标和骨形态的影响.结果与维甲酸造模组比较,胎肾细胞悬液组大鼠血清雌二醇、降钙素、骨钙素水平升高,甲状旁腺素降低（P＜0.05）,胫骨骨重、灰重和骨基质均增加（P＜0.01）,胫骨骨长变化不大（P＞0.05）.骨病理形态计量中,胎肾细胞组大鼠骨小梁厚度、面积及密度均高于模型组,而骨小梁间隙明显缩小（P＜0.05）.结论胎肾细胞改善维甲酸所致大鼠骨质疏松机制与部分钙调节激素的变化有关.     

双骨胶囊对维甲酸致骨质疏松大鼠下颌骨结构影响的初步研究

目的观察中药双骨胶囊对维甲酸所致骨质疏松大鼠下颌骨结构的影响。方法选择3月龄SD雌性大鼠,采用85mg·kg-1·d-1维甲酸灌胃15d复制模型,模型复制成功后,采用“双骨胶囊”进行治疗。治疗30d、60d后,取大鼠磨牙段下颌骨进行组织切片观察,并作形态计量学测量。结果光镜观察显示,双骨胶囊组和雌激素组下颌骨骨小梁增宽,骨小梁间隙减小,骨髓腔缩小。组织形态计量学测量结果表明,两治疗组骨小梁平均宽度明显增加,骨小梁平均间隔宽度明显减小。结论中药“双骨胶囊”可通过全身用药,改善颌骨结构,抑制破骨细胞活性增强引起的骨吸收,从而减缓下颌骨骨量丢失     

蒙药蓝刺头抗绝经后骨质疏松症骨微观形态学计量研究

目的通过研究证实蒙药蓝刺头防治绝经后骨质疏松症(postmenopausal osteoporosis,PMOP)的作用。基于蒙医药"补暖补精-清镇赫依-固骨质壮骨"经典理论,通过防治PMOP提供实验依据,揭示此理论、治法效应,为蒙医药现代化提供思路。方法分组:6月龄SD系SPF级健康雌性未孕大鼠84只,体重(250±20) g,随机分为假手术组(Sham)、去卵巢骨质疏松模型组(OVX)、蒙药蓝刺头高剂量组(Echinops-H)、中剂量组(Echinops-M)、低剂量组(Echinops-L)、中药对照组淫羊藿组(HEP)、西药对照组辅酶Q10组(Co-Q10) 7组。造模:采用双侧卵巢切除法(去势)制备绝经后骨质疏松模型,阴道上皮角化实验、骨密度检测、子宫病理学检查验证造模成功。给药:术后90 d,模型组、假手术组给予生理盐水灌胃,其余各组予相应药物灌胃。标本采集:末次灌胃后行标本采集。处死大鼠剔除右侧完整股骨并标记,4%多聚甲醛溶液固定保存。指标检测:右侧股骨采用骨密度仪测定离体骨骨密度(bone mineral density,BMD)(股骨近端BMD、股骨总BMD)检测,行Micro-CT骨微结构形态计量学测定。结果去卵巢术后各组大鼠BMD下降明显,表现为松质骨、皮质骨骨量相继减少,皮质骨变薄,BMD下降;去卵巢术后各组大鼠骨组织体积、骨小梁体积分数、骨小梁厚度、骨小梁宽度、骨小梁数目、骨小梁模块因素下降明显,骨小梁分离度升高明显;适当剂量蒙药蓝刺头可以明显提高大鼠骨组织体积、骨小梁体积分数、骨小梁厚度、骨小梁宽度、骨小梁数目、骨小梁模块因素,明显降低骨小梁分离度;其具明显抗PMOP作用。结论蒙药蓝刺头对PMOP模型大鼠具显著抗骨质疏松作用;蒙药蓝刺头能显著促进模型大鼠骨组织成骨分化、骨形成;降低PMOP模型大鼠骨代谢高转换指标,抑制骨吸收。     

Characterization of a rabbit osteoporosis model induced by ovariectomy and glucocorticoid

Background and purpose

Experimental models of osteoporosis in rabbits are useful to investigate anabolic agents because rabbits have an active Haversian remodeling and achieve skeletal maturiaty quickly. In this study, an experimental model of osteoporosis in rabbits induced by a combination of ovariectomy and glucocorticoid was characterized to provide a useful model for prevention and therapy of osteoporosis.

Methods

32 skeletally mature female rabbits were divided randomly into 4 groups: sham control, bilateral ovariectomy (OVX), 1mg/kg/day methylprednisolone (MP) for 8 weeks, and OVX in combination with MP. All rabbits were killed 10 weeks after surgery. Bone mineral density (BMD) of lumbar spine was measured by dual-energy X-ray absorptiometry at baseline, and at 6 and 10 weeks postoperatively. Bone microarchitecture and mechanical properties of lumbar vertebrae were investigated by high-resolution micro-computed tomography and compression test, respectively, after killing.

Results

Mean BMD of the OVX+MP group at 10 weeks was reduced by about 36% from baseline (p < 0.001). Bone microarchitecture of lumbar vertebrae in the OVX+MP group indicated osteoporosis-associated deterioration. There was a statistically significant reduction in maximum load, stiffness, and energy absorption capacity of lumbar vertebrae in the OVX+MP group, but not in the OVX group, compared to the sham control. In the MP group, BMD and some microarchitecture parameters such as trabecular thickness and bone volume fraction were reduced. The mechanical properties were not statistically significantly different from those in the sham control group, however, although a negative trend was observed.

Interpretation

Osteopenia can be induced experimentally in rabbits through a combination of OVX and MP, and can be evaluated by BMD, bone microstructure, and mechanical parameters.     

Prolonged Treatments With Antiresorptive Agents and PTH Have Different Effects on Bone Strength and the Degree of Mineralization in Old Estrogen‐Deficient Osteoporotic Rats

Current approved medical treatments for osteoporosis reduce fracture risk to a greater degree than predicted from change in BMD in women with postmenopausal osteoporosis. We hypothesize that bone active agents improve bone strength in osteoporotic bone by altering different material properties of the bone. Eighteen‐month‐old female Fischer rats were ovariectomized (OVX) or sham‐operated and left untreated for 60 days to induce osteopenia before they were treated with single doses of either risedronate (500 μg/kg, IV), zoledronic acid (100 μg/kg, IV), raloxifene (2 mg/kg, PO, three times per week), hPTH(1–34) (25 μg/kg, SC, three times per week), or vehicle (NS; 1 ml/kg, three times per week). Groups of animals were killed after days 60 and 180 of treatment, and either the proximal tibial metaphysis or lumbar vertebral body were studied. Bone volume and architecture were assessed by μCT and histomorphometry. Measurements of bone quality included the degree of bone mineralization (DBM), localized elastic modulus, bone turnover by histomorphometry, compression testing of the LVB, and three‐point bending testing of the femur. The trabecular bone volume, DBM, elastic modulus, and compressive bone strength were all significantly lower at day 60 post‐OVX (pretreatment, day 0 study) than at baseline. After 60 days of all of the bone active treatments, bone mass and material measurements agent were restored. However, after 180 days of treatment, the OVX + PTH group further increased BV/TV (+30% from day 60, p < 0.05 within group and between groups). In addition, after 180 days of treatment, there was more highly mineralized cortical and trabecular bone and increased cortical bone size and whole bone strength in OVX + PTH compared with other OVX + antiresorptives. Treatment of estrogen‐deficient aged rats with either antiresorptive agents or PTH rapidly improved many aspects of bone quality including microarchitecture, bone mineralization, turnover, and bone strength. However, prolonged treatment for 180 days with PTH resulted in additional gains in bone quality and bone strength, suggesting that the maximal gains in bone strength in cortical and trabecular bone sites may require a longer treatment period with PTH.     

TBS在监测及诊断骨质疏松方面的应用价值

利用DXA（dual energy X-ray absorptiometry,双能X线吸收法）测得的单位面积骨密度值（areal bone mineral density,BMD）是诊断骨质疏松的金标准。骨质疏松患者骨量减少的同时通常存在骨微结构的退化,表现为骨小梁数量减少、间距增加以及骨小梁间连接性下降,而BMD仅能显示骨量的变化,不能提供关于骨结构的信息。因此,仅靠BMD来诊断或排除骨质疏松是不全面的。骨小梁分数（trabecular bone score,TBS）是一种可由DXA图像获得的反映图像上灰阶变化的结构参数,能有效评估骨的微结构、描述骨的质量。本文将从TBS的检测方法、与其他检测骨折风险指标之间的关系以及TBS的有效性和不足等方面来介绍TBS在监测及诊断骨质疏松方面的应用价值。     

Cortical bone is more sensitive to alcohol dose effects than trabecular bone in the rat

ObjectiveWhile chronic alcohol consumption is known to decrease bone mineral content (BMC), bone mineral density (BMD), and negatively modify trabecular bone microarchitecture, the impact of alcohol on cortical microarchitecture is still unclear. The aim of this study was to investigate the effects of various doses of alcohol on bone density, trabecular and cortical parameters and bone strength in rats.MethodsForty-eight male Wistar rats were divided into four groups: control (C), alcohol 25% v/v (A25), alcohol 30% v/v (A30) and alcohol 35% v/v (A35). Rats in the alcohol groups were fed a solution composed of ethanol and water for 17 weeks while the control group drank only water. Bone quality and quantity were evaluated through the analysis of density, trabecular and cortical bone microarchitectural parameters, osteocalcin and N-Telopeptide concentrations and a 3-point bending test.ResultsBone density along with trabecular and cortical thickness were lower in alcohol groups compared to C. BMD was lower in A35 vs. A30 and cortical thickness was lower in A35 vs. A25 and A30. Pore number was increased by alcohol and the porosity was greater in A35 compared to C. N-Telopeptide concentration was decreased in alcohol groups compared to control whereas no differences were observed in osteocalcin concentrations. Maximal energy to failure was lower in A25 and A35 compared to C.ConclusionChronic ethanol consumption increases cortical bone damage in rats and may have detrimental effects on bone strength. These effects were dose-dependent, with greater negative effects proportionate to greater alcohol doses.