股骨近端髓内钉三维导航器的研制与测试

目的研发一种专用于防旋型股骨近端髓内钉置入时的三维导航器。方法选取颈干角为(135±5)°,并且股骨大转子顶点基本与股骨头中心等高的人体股骨骨骼的干标本32例,其中左侧16例,右侧16例。通过股骨头中心、平行于股骨干、垂直于股骨干与股骨颈所在的平面用钢锯将股骨标本的股骨头进行截骨;在股骨大粗隆顶端开口向股骨近端髓腔内插入PFNA主钉,主钉钉尾与股骨头中心点在同一高度上。在本课题所研发的股骨近端髓内钉三维导航器的导引下向股骨头颈部打入动力钉导引针,测量动力钉导引针在股骨头截骨面上的出针点与经股骨头中心点直线的垂直距离作为偏离值。结果利用本课题所研制的三维立体导航器在32例股骨骨骼的干标本上置入导引针,其中14例偏离值为0(占43.75%),最大偏离值为2mm,仅3例(占9.375%),平均误差只有0.69mm。结论本课题所研制的导航器结构简单,操作简便,定位精确,值得进一步在临床上研究应用。     

多参数MRI纹理分析预测直肠癌患者放射治疗后早期股骨头坏死

目的 探讨多参数MRI(mpMRI)纹理分析预测直肠癌患者放射治疗(放疗)后早期股骨头坏死(FHN)的价值。方法 回顾性分析52例接受盆腔放疗直肠癌患者放疗前2周及放疗后3个月内的盆腔MRI,其中31例未见FHN,21例出现早期FHN(Ⅰ期16例,Ⅱ期5例)。采用3D-slicer软件基于T1WI、T2WI和弥散加权成像(DWI)分割右侧股骨头,并提取其纹理参数;对比放疗前后纹理参数,将差异有统计学意义的放疗前参数纳入多因素logistic回归分析,建立模型_T1WI、模型_T2WI、模型_DWI及模型_{T1WI+T2WI+DWI}。根据放疗后影像学所见行股骨头坏死骨循环研究协会(ARCO)分期,以受试者工作特征(ROC)曲线分析单一纹理参数及联合模型预测直肠癌患者放疗后早期FHN的效能。结果 T1WI及T2WI纹理参数中,放疗前股骨头能量及均匀性高于放疗后;DWI纹理参数中,放疗前股骨头能量高于、而长行程高灰度强调及短行程高灰度强调低于放疗后。上述放疗前纹理参数单一预测直肠癌患者放疗后早期FHN的曲线下面积(AUC)为0.581~0.712,模型_T1WI、模型_T2WI、模型_DWI和模型_{T1WI+T2WI+DWI}的AUC分别为0.660、0.713、0.770和0.853。结论 mpMRI纹理分析可有效预测直肠癌患者放疗后早期FHN。     

人胚胎长骨的组织学观察

目的探讨人胚胎长骨的发生及发育过程。方法取第9～38周人胚胎股骨,用HE、硫堇-苦味酸及Mauory氏法染色,光镜观察。结果第9周胚胎股骨为软骨雏形。第10-38周胚胎股骨可分出骺软骨、干骺端及骨干三部分,干骺端原始骨髓腔内富含血管、成骨细胞及造血细胞,成骨细胞与造血细胞的比例随胎龄而异,第20周以前,以成骨细胞为主,造血细胞极少,随胎龄增加,成骨细胞的比例逐渐下降,造血细胞增加;骨干表面不光滑,有许多纵嵴、纵沟,骨外膜内层覆于嵴上并衬于沟内,纵嵴纵沟以第13—26周胚胎为多,第27周以后逐渐减少,骨干表面逐渐变得光滑,足月时出现外环骨板;骨干皮质由骨小梁网构成,胚胎早期网眼大、不规则,随胎龄增加,网眼变小,周围出现分层不清的同心圆状排列的骨板。结论人胚胎长骨的纵向生长速率随胎龄的增加而相对减慢,其横向生长是由于骨外膜内层的成骨细胞以形成纵嵴的方式,不断地在骨干表面添加新的骨质,并进而形成新的哈佛氏系统的结果。     

股骨上端解剖学观测与人工股骨头置换

目的：为选择人工股骨头提供可靠的解剖学数据。方法：对２５０例正常成人股骨上端进行了观测,并对大小转子间距与股骨头最大径作直线相关分析。结果：大小转子间距与股骨头最大径呈正相关（左侧ｒ＝０．４３１,右侧ｒ＝０．４４６,Ｐ〈０．０１）,大小转子间距与头颈长基本等长。结论：用大小转子间距估计股骨头最大径准确、实用、方便。     

股骨头缺血坏死的CT诊断

本文总结分析股骨间缺血坏死(ANFH)CT表现及CT诊断价值。在35例47个ANFH中,CT发现4例X线平片阴性的ANFH。CT较好的显示ANFH“星状征”异常。以及骨质增生硬化、囊变、碎裂和股骨头变形。CT在发现ANFH和表现其病变程度优于X线平片。     

动力加压髁螺钉治疗股骨髁部骨折临床与实验研究

本研究结合１４例股骨髁间、髁上骨折以动力加压髁螺钉（Ｄynamic Ｃondylar Ｓcrew ＤＣＳ）固定。目的：为临床提供应用ＤＣＳ的实验数据。方法：采用成人新鲜尸体股骨髁部标本,按照ＡＯ/ＡＳＩＦ分类,模拟Ｙ形骨折模型,以ＤＣＳ固定,置于ＷＤ－１０Ｅ万能电子力学实验机上其抗拉伸、抗扭转、抗村缩、抗剪切强度。结果：ＤＣＳ有较好的固定强度。临床应用１４例,随访６个月至１年,优良率为８５．７１％。结论：ＤＣＳ适合于     

人工股骨头置换术的应用解剖

目的:为临床人工股骨头置换术人工假体的选择、安装及定位提供可靠的解剖学参数。方法:对250例(左右各125例)正常成人股骨头、股骨颈、大转子与外上髁间距进行观测,并得出转子髁间距与股骨头最大径、股骨头颈前长和股骨头颈后长的相关系数和回归方程。结果:股骨头最大径为4.39±0.31cm,股骨头颈后长为6.89±0.49cm,股骨头颈前长为6.18±0.43cm,大转子与外上髁间距为34.40±1.79cm。结论:采用本文作者提供的方法选择、安装人工假体准确、实用、方便     

Effects of sciatic neurectomy on the femur in growing rats: Application of peripheral quantitative computed tomography and Fourier transform infrared spectroscopy

The effects of unilateral sciatic neurectomy (USN) on the development of the femur were studied in 15 growing Wistar-derived rats (age, 5 weeks). The rats were divided into four groups: USN-operated group (right femur), USN-nonoperated group (left femur), sham-operated group (right femur), and sham-nonoperated group (left femur). Bone mineral density (BMD), bone mineral content (BMC), bone area, periosteal circumference, and endosteal circumference were measured by peripheral quantitative computed tomography (pQCT) and the mineral/matrix ratio was evaluated by Fourier transform infrared spectroscopy (FTIR). The USN-operated group showed a significant decrease in cortical BMC, bone area, and periosteal circumference compared with the other groups (P < 0.05). The cortical BMD did not vary significantly between the groups. In the cancellous bone, the USN-operated group showed a significant decrease in BMD and BMC at the metaphysis compared with the other groups (P < 0.05). The mineral/matrix ratio of the cortical bone did not differ significantly between the USN-operated and USN-nonoperated groups. These results suggest that in cortical bone, USN inhibits periosteal bone formation but has no significant effect on the mineral/matrix ratio of cortical bone in femurs. In cancellous bone, USN induces bone loss at the metaphysis. Received: Nov. 19, 1998 / Accepted: Feb. 12, 1999     

Toxin pharmacology of the large-conductance Ca2+-activated K+ channel in the apical membrane of rabbit proximal convoluted tubule in primary culture

The patch-clamp technique was used to study the toxin pharmacology of the large-conductance Ca²⁺-activated K⁺ channel (BKCa) present in the apical membrane of rabbit proximal convoluted tubules (PCT) in primary culture. Experiments were performed with the inside-out configuration. This channel was very selective for K⁺ against Na⁺ and had a conductance of 180 pS with 140 mmol/l in the pipette and the bath. The action of toxins was studied on the extracellular side of the channel by using the pipette perfusion technique. Experimental conditions were 140 mmol/l KCl in the pipette and 140 mmol/l Nad in the bath. Pipette potential was maintained at 0 mV. Perfusion of crude venom from Leiurus quinquestriatus hebraeus inhibited reversibly the open probability (P _o) in a concentration-dependent fashion (IC₅₀=0.8 mg/l; n=3). The following synthetic or purified toxins were tested: synthetic charybdotoxin (ChTX) IC₅₀=7.3×10^–9 M (n=5); iberiotoxin (IbTX) IC₅₀=5.5×10^–7 mol/l (n=3); and kaliotoxin (KTX) IC₅₀=4.8×10^–7 mol/l (n=3). The suppression of the six first N-terminal amino-acids slightly reduced the affinity of ChTX (IC₅₀=1.2×10^–8 mol/l, n=4). Neither Dendroaspis polylepis venom nor purified dendrotoxin modified P _o even at high concentrations (20 mg/l and 10^–6 mol/l respectively). Apamin, which blocked the small-conductance K⁺ channel in cultured PCT, did not act on BKCa. These results indicate that ChTX is the most efficient known toxin against the epithelial BKCa in primary cultures of PCT. In spite of there being considerable homology of sequence between ChTX, IbTX and KTX, ChTX was about 100 times more effective than the others. Truncated ChTX kept a high affinity for this channel and could be used to obtain a labelled probe.     

Potassium-selective channels in the basolateral membrane of single proximal tubule cells of frog kidney

The membrane potential of proximal tubule cells is dominated by the potassium conductance of the basolateral membrane. In the present paper the nature of this conductance is investigated by the patch-clamp technique. Only one type of K channel was found in the basolateral membranes of freshly isolated proximal cells. In cell-attached patches, the current/voltage relationship is markedly non-linear with much larger inward (30 pS) than outward ( 6 pS) conductances, even in the presence of roughly symmetrical K concentrations. Thus the channels show inward rectification. The determination of the conductance for outward current flow is complicated since the current/voltage curves show an area of negative conductance. Nevertheless, taking the conductance for outward current flow and the density of the channels it is possible to account for all of the previously reported potassium conductance of amphibian proximal tubule cells. The open probability of the channels was found not to depend upon the membrane potential. However, the non-linearity of the current/voltage relationships will confer upon the channel the same voltage dependence as that seen in intact proximal tubules, i.e. the conductance decreases with depolarisation. Incubation of cells in Ringer with no substrates or in the presence of alanine and/or glucose showed no change in the activity of the channels. These findings suggest that, although these channels may represent the basolateral conductance of frog proximal tubule cells, they are not involved in the well-established coupling between transport rate and potassium conductance.This work was supported by the Wellcome Trust