冻干辐照猪硬脑膜的抗原性

背景:抗原性是异种组织移植最主要的问题,是移植成功与否的关键。目的:观察经冻干辐照处理后的猪硬脑膜抗原性变化。方法:取新鲜猪硬脑膜,经冻干、辐照处理后分别制备成冻干猪硬脑膜、辐照猪硬脑膜和冻干辐照猪硬脑膜。分别移植于大白兔硬脑膜上,于术后3,8周行各组实验动物淋巴细胞毒实验。结果与结论:移植冻干组和辐照组淋巴细胞死亡率比较差异无显著性意义(P0.05),但均高于冻干辐照组(P0.05)。结果提示经冻干辐照处理后的猪硬脑膜抗原性低。     

脂多糖诱导对内皮细胞释放内皮细胞微粒的影响

目的探讨脂多糖刺激对内皮细胞释放内皮细胞微粒(EMP)的影响。方法取人脐静脉内皮细胞培养,分为正常对照组(无脂多糖诱导)和不同浓度脂多糖(浓度分别为0.1、1.0、10.0、20.0μg/m L)组,脂多糖诱导24 h后收集细胞培养液并消化内皮细胞制成细胞悬液。离心法提取细胞培养液内的EMP,加入特异性荧光抗体(anti-CD31-CFS、anti-CD51-PE、anti-CD54-FITC、antiCD144-PE、anti-CD62E-APC)。采用流式细胞仪检测脂多糖诱导内皮细胞释放荧光标记EMP的变化以及内皮细胞的凋亡率。对数据行方差分析、t检验、Dunnett-t检验。结果对照组和0.1、1.0、10.0、20.0μg/m L脂多糖组CD31~+EMP数量水平分别为(1.23±0.43)×10~6、(1.92±0.64)×10~6、(2.55±0.78)×10~6、(3.96±0.78)×10~6、(6.96±1.80)×10~6,组间比较差异有统计学意义(F=5.83,P0.05),CD31~+EMP占总体EMP的比值分别为(4.57±1.33)%、(5.92±1.24)%、(6.93±1.61)%、(7.44±1.09)%、(13.44±3.39)%,组间比较差异有统计学意义(F=3.43,P0.05)。与对照组比较,10.0、20.0μg/m L脂多糖组CD31~+EMP数量水平明显升高,差异均有统计学意义(t=-3.06、-3.61,P值均小于0.05);20.0μg/m L脂多糖组CD31~+EMP数量水平高于0.1、1.0μg/m L脂多糖组,差异均有统计学意义(P值均小于0.05)。CD31~+EMP占总体EMP的比值20.0μg/m L脂多糖组高于对照组和0.1μg/m L脂多糖组,差异均有统计学意义(P值均小于0.05)。对照组和0.1、1.0、10.0、20.0μg/m L脂多糖组CD54+EMP数量水平分别为(4.70±1.01)×10~6、(9.20±3.34)×10~6、(8.83±1.70)×10~6、(17.18±3.78)×10~6、(17.73±4.98)×10~6,组间比较差异有统计学意义(F=3.35,P0.05)。与对照组比较,10.0、20.0μg/m L脂多糖组CD54+EMP数量水平明显升高,差异均有统计学意义(t=-3.19、-3.00,P值均小于0.05)。对照组和0.1、1.0、10.0、20.0μg/m L脂多糖组CD144~+EMP数量水平分别为(3.93±1.22)×10~6、(6.80±1.36)×10~6、(8.03±2.53)×10~6、(17.22±4.52)×10~6、(11.05±5.80)×10~6,组间比较差异有统计学意义(F=3.17,P0.05)。10.0μg/m L脂多糖组CD144~+EMP数量水平高于对照组及0.1、1.0μg/m L脂多糖组,差异均有统计学意义(P值均小于0.05)。20.0μg/m L脂多糖组CD62E+EMP数量水平为(2.95±0.26)×10~6,明显高于对照组(1.26±0.26)×10~6,差异有统计学意义(t=-4.45,P0.05)。各组内皮细胞凋亡率比较差异无统计学意义(F=0.17,P0.05)。结论脂多糖损伤内皮细胞可表现为表达特异性标记的EMP的大量释放,可能是脓毒症内皮细胞损伤机制之一。     

冻干去抗原羊松质骨支架的生物相容性评价

背景:异种骨具有与人类骨类似的天然多孔结构,在治疗骨缺损时可引导骨组织再生,但植入过程中也会引起不同程度的免疫反应。目的:采用冻干法制备去抗原羊脊椎松质骨支架材料,并评价其生物相容性。方法:取羊脊椎松质骨,制备两组去抗原异种骨支架,化学组经H2O2、甲醇/氯仿混合液等化学试剂处理;冻干组将经化学处理的羊松质骨在-80℃冰箱中低温冷冻4周,真空干燥,60Co照射消毒。①细胞毒性实验:分别采用化学组材料浸提液、冻干组材料浸提液与DMEM/F12培养基培养羊骨髓间充质干细胞。②热源实验、急性毒性实验:从兔耳缘静脉分别注射化学组材料浸提液、冻干组材料浸提液与生理盐水。③皮内刺激实验:分别在兔脊柱背部皮下注射化学组材料浸提液、冻干组材料浸提液、生理盐水及乙醇。结果与结论:冻干组支架无细胞毒性、急性毒性及热源反应,皮内刺激实验阴性;化学组支架有细胞毒性及轻微急性毒性反应,有致热源作用及轻度皮肤刺激性。结果表明经过化学处理羊脊椎松质骨支架的生物相容性相对较差,而化学处理配合低温冷冻、真空干燥及60Co照射的羊脊椎松质骨生物相容性较好,基本能达到骨组织工程支架材料的要求。     

住院高龄老年男性的白蛋白尿临床特点分析

目的探讨住院高龄老年男性(年龄不小于80岁)白蛋白尿的特点,为高龄保健人群慢性肾脏病研究提供理论依据。方法回顾性分析2012年6月至2014年12月住院治疗的262例患者临床资料,将晨尿白蛋白/肌酐(ACR)为30~300 mg/g诊断为白蛋白尿的218例患者纳入研究。按照年龄将住院高龄老年人群分为80+组(年龄80~89岁)157例和90+组(年龄90岁以上)61例,根据ACR结果分为白蛋白尿阳性组(ACR 30~300 mg/g)和白蛋白尿阴性组(ACR30 mg/g),队列研究分析白蛋白尿的临床特点。结果 218例住院高龄老年男性中53.21%出现白蛋白尿,Log ACR(1.78±0.85)mg/g。80+组白蛋白尿阳性率为45.16%,90+组为69.84%(P0.05)。白蛋白尿阳性组Log ACR(2.03±0.62)mg/g,白蛋白尿阴性组Log ACR(1.03±0.44)mg/g。80+组和90+组中患有糖尿病、高血压或者e GFR60 m L·(min·1.73 m2)-1者白蛋白尿的发生率分别是50%vs.77.5%(P0.05),50.38%vs.58.82%(P0.05),66.21%vs.75%(P0.05)。全组无糖尿病、高血压或者e GFR60 m L·(min·1.73 m2)-1的高龄老年人中,白蛋白尿的发生率分别是35.39%(21/59例),16.00%(4/25例)和25.84%(23/89例),低于本组的平均水平。结论住院高龄老年男性白蛋白尿发生率为53.21%,90岁以上者白蛋白尿发生率与80岁以上者比较具有增高的趋势。     

玻璃化法处理同种异体动脉的移植

背景:体外血管预处理及保存方法有多种,经过学者们长期大量的研究观察,各种方法均得到了改进,但是仍然存在弊端。因此找到一种更有效的或者几种体外血管预处理保存方法的结合,还需要大量的研究实践。目的:拟通过比较玻璃化法和传统冷冻法保存处理的同种异体血管移植后效果,找出一种更为实用且制作简便的血管处理方法。方法:选用健康青紫兰兔96只,手术切除双侧股动脉,根据不同体外血管预处理方法将实验分为3组,即新鲜血管自体移植组、冷冻+辐照预处理血管同种异体移植组及玻璃化+辐照预处理血管同种异体移植组。血管移植后1,2,8,12周,每组取6只动物进行腹主动脉数字减影血管造影、扫描电子显微镜、组织病理学观察,观察移植血管通畅率、动脉瘤形成情况及组织形态学变化。结果与结论:移植后12周,新鲜血管自体移植组血管的累计通畅率显著高于冷冻+辐照预处理组(P0.05),玻璃化+辐照预处理组与其他两组比较,差异无显著性意义(P0.05)。组织病理学检查显示,玻璃化+辐照处理的同种异体血管内膜及中层平滑肌增生较冷冻+辐照预处理组轻,管腔狭窄不明显,炎症反应较轻。经玻璃化法+辐照保存的同种异体血管制作程序简单,移植血管通畅率高,组织反应轻,是一种比较理想的同种异体血管体外处理方法。     

膝关节单髁置换胫骨优化截骨设计的生物力学研究

目的 比较膝关节单髁置换术(unicompartmental knee arthroplasty, UKA)常规截骨、保留圆角截骨及全新扩大圆角截骨方法对术后胫骨近端生物力学特性的影响。方法 基于Sawbones胫骨的CT数据,构建完整胫骨模型及不同截骨方式下UKA术后胫骨模型,采用轴向压缩工况对模型进行有限元分析,比较不同模型间胫骨近端应变情况及骨水泥应力差异。结果 在轴向压缩工况下,扩大圆角组其截骨区皮质骨von Mises应变峰值较常规截骨组与保留圆角组有所增加,而松质骨von Mises应变峰值则分别减少24.3%～42.9%、26.0%～48.7%。对比截骨区松质骨与皮质骨von Mises应变峰值差Δε_peak,发现扩大圆角组其Δε_peak远远小于其余两组。UKA后不同模型间胫骨前内侧皮质骨最小主应变无明显差异,但较完整胫骨模型增加23.3%～34.5%。扩大圆角组骨水泥单元平均von Mises应力随着圆角半径增大呈现下降趋势,且整体均小于常规截骨组与保留圆角组。结论 全新扩大圆角截骨方法可使健康骨质条件下胫骨近端应力传递更均匀...     

环氧乙烷处理同种异体皮质骨板移植组织学研究

目的研究环氧乙烷处理同种异体皮质骨板移植组织学表现.方法分别移植经过零下70℃深低温冷冻4周、零下70℃深低温冷冻4周+48℃环氧乙烷灭菌处理的山羊同种异体皮质骨板,对移植骨板以及周围软组织进行组织学检查.结果术后3～6周深低温冷冻组移植骨板周围软组织少量炎性细胞浸润,环氧乙烷+深低温冷冻组移植骨板周围软组织较多炎性细胞浸润,但炎细胞浸润评分差别无统计学意义(P＞0.05);术后6～24周两组移植骨板周围软组织炎性细胞浸润进一步减轻.深低温冷冻组和环氧乙烷+深低温冷冻组术后3周部分移植骨板原哈佛式管扩大,其内有少量间充质组织和新生血管;6周间充质细胞分化为破骨细胞和成骨细胞,破骨细胞使移植骨板哈佛式管进一步扩大以及出现骨吸收隙窝,在哈佛式管和骨吸收隙窝边缘出现成骨细胞贴附和新骨形成;12周移植骨板骨吸收隙窝缩小,成骨细胞和新骨形成增多,部分新骨改建形成板层骨;24周移植骨板基本完成吸收替代和改建塑形.两组移植骨板内无炎细胞浸润,组织学表现相似.结论环氧乙烷灭菌同种异体皮质骨板移植周围软组织出现炎细胞浸润,不影响移植骨板爬行替代和内部改建塑形.     

人体脊柱胸腰段椎骨显微骨硬度分布特征研究

目的 探讨人体胸腰椎段椎骨显微骨硬度的分布特征及临床应用前景。方法 选取3具新鲜成人尸体标本,取出其T₁₁~L₂椎骨后剔除软组织。将每一个椎骨分为椎体区和附件区,经高精慢速锯切割成若干厚约3 mm的骨组织切片,12块椎骨标本共计产生72个骨组织切片。应用维氏显微硬度测量仪测量骨组织切片不同区域皮质骨和松质骨的显微硬度值,每一个区域选取5个有效显微硬度值,全体有效值的平均值作为该区域的硬度值。结果 12块椎骨共进行660次有效压痕实验并取得显微硬度值。(1)胸腰段椎休总体硬度为11.6 ~48.3 HV,其中皮质骨硬度为13.8~48.3(31.62±5.66) HV,松质骨硬度11.6~44.9 (29.62±5.38) HV;(2) 胸腰段椎体区和附件区皮质骨硬度分别为(29.99 ±5.27)HV和(32.92 ±5.63) HV,松质骨硬度分别为(28.44 ±4.79) HV和(30.81±5.71)HV,附件区均高于椎体区,差异均有统计学意义(t=5.098、2.011, P值均＜0.05);(3)椎体区皮质骨硬度由高到低依次为下终板(33.94±4.31)HV、上终板(29.76±4.35)HV、外周终板(28.13±5.07)HV,下终板皮质的骨硬度高于上终板、外周终板,差异均有统计学意义(P值均＜0.05);(4)附件区皮质骨中,硬度由高到低依次为椎弓根皮质(34.78 ±5.30)HV、上关节突(33.73±5.68)HV、椎板(33.15±5.28)HV、横突(31.69±5.37)HV和下关节突(31.26 ±5.91)HV,其中椎弓根皮质骨硬度与横突和下关节突相比,差异均有统计学意义(P值均＜0.05)。结论 本实验首次应用维氏显微硬度方法对人体胸腰椎段椎骨显微硬度的分布规律进行研究,发现胸腰椎段椎骨附件区皮质骨、松质骨骨硬度分别高于椎体区皮质骨、松质骨骨硬度,胸腰椎段T₁₁~L₂之间、不同标本的胸腰椎段的骨显微硬度存在差异,但分布规律相对一致,是微观结构、力学承载共同作用的结果,符合人体正常生理及负重功能。本研究结果可为3D打印制备具有梯度硬度的人工椎骨提供数据支持。     

小分子干扰RNA沉默CTGF对肾小管上皮细胞的作用及对氧化应激的影响

目的研究小分子干扰RNA沉默结缔组织生长因子(CTGF)基因对高糖诱导肾小管上皮细胞的作用及对氧化应激的影响。方法肾小管上皮细胞(HK-2)分组:①正常对照组(A组),培养基含D-葡萄糖1 g/L;②高糖组(B组),培养基含D-葡萄糖4.5 g/L;③高糖+阴性对照组(C组):细胞转染含无关序列的重组质粒后于D-葡萄糖4.5 g/L的高糖培养基中培养;④高糖+干扰组(D组):细胞转染针对CTG F的siRNA表达质粒后于D-葡萄糖4.5 g/L的高糖培养基中培养。Q-PCR和western blot检测CTGF的表达。ELISA检测氧化应激指标F2-aisoprostanes、8-OHdG、NT、MDA水平。结果与A组相比,B和C组CTGF mRNA和蛋白表达水平上调(P0.05);B组和C组CTGF mRNA和蛋白表达水平无明显变化(P0.05);与C组相比,D组CTGF mRNA和蛋白表达水平下调(P0.05)。与A组相比,B和C组F2-aisoprostanes、8-OHdG、NT、MDA水平上调(P0.05);B组和C组F2-aisoprostanes、8-OHdG、NT、MDA水平无明显变化(P0.05);与C组相比,D组F2-aisoprostanes、8-OHdG、NT、MDA水平下调(P0.05)。结论沉默CTGF基因可抑制高糖诱导的肾小管上皮细胞氧化应激。     

体质指数对女性胫骨超声传导速度的影响

目的研究体质指数(BMI)对骨峰值期和绝经后女性的胫骨超声传导速度(SOS)的影响。方法采用骨定量超声仪测量399例骨峰值期和589例绝经后女性的胫骨SOS值,并按BMI不同各分为低体重组、正常体重组和肥胖组进行分析。结果骨峰值期,女性BMI与胫骨SOS无相关性(r=0.054,P=0.287),低体重组、正常体重组和肥胖组的胫骨SOS差异无显著性(F=0.2,P=0.801);绝经后,女性BMI与胫骨SOS呈正相关(r=0.115,P=0.006),肥胖组的胫骨SOS高于低体重组和正常体重组(F=4.2,P=0.016),且肥胖组和正常体重组骨质疏松症的患病率均低于低体重组(P<0.001)。结论女性骨峰值期,BMI对胫骨的强度影响小;绝经后,BMI大者能延缓胫骨的强度下降。     

医用硬组织黏接胶黏接胫骨中段蝶形骨折的生物力学研究

在粉碎性骨折的治疗中 ,数目较多的骨折碎块的固定仍是一个临床常见的难题。医用硬组织黏接胶是治疗粉碎性骨折的又一新方法 .采用完整新鲜人胫骨、骨块缺失的新鲜人胫骨、黏接后的新鲜人胫骨在扭转、三点弯曲、压缩等状态下的应力 -应变指标变化 ,研究医用硬组织黏接胶黏接人胫骨蝶形骨块后的力学指标的改变。在弯曲、扭转、压缩等实验中 ,胫骨中段的蝶形骨缺损 ,显著减弱了胫骨的抗弯曲、抗扭转、抗压缩的强度。在扭转实验中 ,完整胫骨的扭距大于黏接后的胫骨 ,黏接后胫骨的扭距大于缺损的胫骨。在压缩实验中 ,胶体断裂前 ,完整胫骨的压缩曲线斜率大于黏接后的胫骨的压缩曲线斜率 (P<0 .0 1) ,黏接后胫骨压缩曲线斜率大于缺损胫骨的压缩曲线斜率 ,并有统计学显著性差异 (P<0 .0 5 )。三点弯曲实验中 ,在胶体断裂前 ,完整胫骨的曲线斜率与黏接后的胫骨无显著差异 (P>0 .0 5 ) ,黏接后胫骨与缺损的胫骨曲线斜率有显著差异 (P<0 .0 5 )。黏接后的胫骨 ,其弹性模量、刚度系数与完整的胫骨无显著差异 (P>0 .0 5 )。医用硬组织黏接胶黏接蝶形骨块后 ,能显著提高其抗弯曲、抗扭转、抗压缩应力。在临床操作中 ,可以最大程度上减少骨折碎块固定时周围的软组织剥离 ,有利于骨折的愈合     

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。     

ClC-3基因过表达对小鼠骨量和骨结构的影响

 目的: 研究过表达电压门控氯通道家族蛋白成员3(voltage-gated chloride channel family protein 3,ClC-3)基因对小鼠骨骼的影响。方法: 3月龄雄性FVB小鼠用鼠尾基因检测法确定基因型后分为2组:野生型(WT)组和ClC-3过表达(ClC-3 transgene)组,每组各8只。分别测量2组小鼠体重,右侧胫骨长度和重量。取胫骨上段和中段进行脱钙,石蜡包埋,切片,HE染色后,采用骨形态计量学分析胫骨上段松质骨的骨小梁面积百分数(percent trabecular area,%Tb.Ar)、骨小梁数量(trabecular number,Tb.N)、骨小梁宽度(trabecular width,Tb.Wi)、骨小梁分离度(trabecular separation,Tb.Sp)和胫骨中段皮质骨的骨组织总面积(total tissue area,T.Ar)、皮质骨面积(cortical area,Ct.Ar)、皮质骨面积百分数(percent cortical area,%Ct.Ar)、骨髓腔面积(marrow area,Ma.Ar)、骨髓腔面积百分数(percent marrow area,%Ma.Ar)。结果: 小鼠经鼠尾基因检测后确认为野生型或ClC-3过表达型。与WT组相比,ClC-3 transgene组小鼠体重及胫骨长度重量均减小(P<0.05);松质骨的%Tb.Ar和Tb.Wi均减小(P<0.05),Tb.Sp增大(P<0.05),Tb.N的变化无统计学意义;皮质骨的T.Ar、Ct.Ar和%Ct.Ar均减小(P<0.05),%Ma.Ar增大(P<0.05),Ma.Ar的变化无统计学意义。结论: ClC-3过表达导致小鼠的皮质骨和松质骨骨量减少,骨结构变差,提示ClC-3可能参与了骨形成和/或骨吸收。     

No deleterious effect of low dose methotrexate on titanium implant osseointegration in a rabbit model

OBJECTIVE:

To evaluate the effect of low dose methotrexate alone or in combination with glucocorticoid treatment on titanium implant osseointegration.

METHODS:

Groups of 6–8 adult New Zealand White rabbits were treated for 18 weeks with saline (control), methotrexate, glucocorticoid, or methotrexate plus glucocorticoid. The animals received a titanium implant in the tibia at week 6. Lumbar spine and tibia bone mineral densities were analyzed before and after treatment. Histomorphometric analysis of bone cortical thickness, total bone area around the implant, and % of bone to implant contact was performed.

RESULTS:

After 18 weeks, the change in the bone mineral density in the lumbar spines and tibias in the methotrexate group was comparable to the control group (0.035 vs. 0.055 g/cm² and 0.021 vs. 0.041 g/cm², respectively). In contrast, both the glucocorticoid group and glucocorticoid plus methotrexate group had significant reductions at both sites. Histomorphometric analysis of the tibia in the control and methotrexate groups revealed no significant changes in cortical thickness (133 vs. 126 µm), total bone area around the implant (33 vs. 30%), or bone to implant contact (40 vs. 38%). In contrast, glucocorticoid group had significant reductions compared to controls in tibia cortical thickness (99 vs. 133 µm), total bone area around the implant (24 vs. 33%), and bone to implant contact (27 vs. 40%). Similar reductions were observed in the glucocorticoid plus methotrexate group.

CONCLUSIONS:

Our results demonstrate that low dose methotrexate treatment does not affect titanium implant osseointegration, suggesting that this therapy is safe for surgical procedures requiring a titanium implant.     

Relationships between material properties and CT scan data of cortical bone with and without metastatic lesions

Breast, prostate, lung, and other cancers can metastasize to bone and lead to pathological fracture. To lay the groundwork for new clinical techniques for assessing the risk of pathological fracture, we identified relationships between density measured using quantitative computed tomography (rhoQCT), longitudinal mechanical properties, and ash density (rhoAsh) of cortical bone from femoral diaphyses with and without metastatic lesions from breast, prostate, and lung cancer (bone with metastases from six donors; bone without metastases from one donor with cancer and two donors without cancer). Moderately strong linear relationships between rhoQCT and elastic modulus, strength, and rhoAsh were found for bone with metastases (0.73相似文献   

Effective Dosage and Administration Schedule of Oral Alendronate for Non-nociceptive Symptoms in Rats with Chronic Constriction Injury

We evaluated the efficacy of oral alendronate with different dosing regimens for non-nociceptive symptoms and osteoporosis in a sciatic nerve chronic constriction injury (CCI) model. Male Sprague-Dawley rats (n=60) were subdivided into sham control (SC) group and CCI groups, which were divided according to dosage and time of oral alendronate administration: no treatment (NT), low dosage early (LE), high dosage early (HE), low dosage late (LL) and high dosage late (HL). We measured the thickness and temperature of the hind paw, bone mineral density (BMD) of the tibia, along with tibia bone strength. On the 14th day post-CCI, the HE group showed significant reduction in thickness and temperature (P<0.001). On the 42nd day post-CCI, the HE group showed significant reduction in temperature compared to the NT group (P<0.001). Also, both HE and HL groups showed statistically significant increased tibia BMD (P<0.001), along with increase of tibia bone strength compared to the NT group. Based on these findings, early alendronate in high dosages is effective in the non-nociceptive symptoms; early and late alendronate in high dosages, are effective in preventing bone dystrophic changes in a CCI model.     

Effect of Low-Level Laser Therapy on Incorporation of Block Allografts

Objective To assess the effect of low-level laser therapy (LLLT) on the incorporation of deep-frozen block allografts in a rabbit model.Background Data Studies have shown that LLLT has beneficial effects on tissue repair and new bone formation.Methods Bone tissue was harvested from two rabbits, processed by deep-freezing and grafted into the calvaria of 12 animals, which were then randomly allocated into two groups: experimental (L) and control (C). Rabbits in group L were irradiated with an aluminum gallium arsenide diode laser (AlGaAs; wavelength 830 nm, 4 J/cm²), applied to four sites on the calvaria, for a total dose of 16 J/cm² per session. The total treatment dose after eight sessions was 128 J/cm². Animals were euthanized at 35 (n = 6) or 70 days (n = 6) postoperatively.Results Deep-freeze-processed block allografts followed by LLLT showed incorporation at the graft-host interface, moderate bone remodeling, partial filling of osteocyte lacunae, less inflammatory infiltrate in the early postoperative period, and higher collagen deposition than the control group.Conclusion Optical microscopy and scanning electron microscopy showed that allograft bone processed by deep-freezing plus LLLT is suitable as an alternative for the treatment of bone defects. Use of the deep-freezing method for processing of bone grafts preserves the structural and osteoconductive characteristics of bone tissue.     

Neuromuscular performance and bone structural characteristics in young healthy men and women

Muscle mass and strength have been shown to be important factors in bone strength. Low muscular force predisposes to falling especially among elderly. Regular exercise helps to prevent falls and resulting bone fractures. Better understanding of muscle function and its importance on bone properties may thus add information to fracture prevention. Therefore the purpose of this study was to examine the relationship between bone strength and muscular force production. Twenty-young men [24 (2) years] and 20 [24 (3) years] women served as subjects. Bone compressive (BSI_d) and bending strength indices (50 Imax) were measured with peripheral quantitative computed tomography (pQCT) at tibial mid-shaft and at distal tibia. Ankle plantarflexor muscle volume (MV) was estimated from muscle thickness measured with ultrasonography. Neuromuscular performance was evaluated from the measurements of maximal ground reaction force (GRF) in bilateral jumping and of eccentric maximal voluntary ankle plantarflexor torque (MVC). Specific tension (ST) of the plantarflexors was calculated by dividing the MVC with the muscle volume. Activation level (AL) was measured with superimposed twitch method. Distal tibia BSI_d and tibial mid-shaft 50 Imax correlated positively with GRF, MVC and MV in men (r = 0.45–0.67, P < 0.05). Tibial mid-shaft 50 Imax and neuromuscular performance variables were correlated in women (r = 0.46–0.59, P < 0.05), whereas no correlation was seen in distal tibia. In the regression analysis, MV and ST could explain 64% of the variance in tibial mid-shaft bone strength and 41% of the variation in distal tibia bone strength. The study emphasizes that tibial strength is related to maximal neuromuscular performance. In addition, tibial mid-shaft seems to be more dependent on the neuromuscular performance, than distal tibia. In young adults, the association between bone adaptation and neuromuscular performance seems to be moderate and also site and loading specific.     

小鼠同种异基因骨髓腔内骨髓移植促进早期造血功能重建

目的探讨同种异基因骨髓腔内骨髓移植(IBM-BMT)对小鼠早期造血功能重建的影响。方法将BALB/c小鼠骨髓单个核细胞(BMNCs)分别用胫骨骨髓腔内注射(IBMI)和尾静脉注射(IV)两种方法移植入经致死量60Coγ射线辐照后的60只C57BL/6小鼠。受鼠随机分为3组:骨髓腔内注射高和低剂量组(IBM1和IBM2组)、尾静脉注射组(IV组),每组20只。在骨髓移植后1、3、6和9d分别计数各组受鼠胫骨骨髓腔内有核细胞总数,并用流式细胞术检测供体植入水平(供体来源有核细胞总数、供体来源髓系细胞数)。结果于移植后6d,IBM1组和IBM2组注射侧胫骨骨髓腔内有核细胞总数、供体来源有核细胞总数、供体来源髓系细胞总数均明显高于IV组(P<0.05或P<0.01?。结论IBM-BMT较IV-BMT更能促进同种异基因骨髓移植后的早期造血功能重建。     

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。