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101.
Measurement of ultrasonographic parameters provides information concerning not only bone density but also bone architecture. We investigated the usefulness of ultrasonographic parameters and bone mineral density (BMD) to evaluate the probability of Colles' fracture. Two-hundred eighty-nine postmenopausal women (62.3 +/- 8.7 yr) with (n = 76) and without (n = 213) Colles' fracture were studied. BMD of lumbar spine and proximal femur was evaluated in all women by dual-energy X-ray absorptiometry (DXA) and speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness in the calcaneus were measured by a Sahara ultrasonometer (Hologic). Patients suffering from Colles' fracture had lower values of BMD adjusted by height at the lumbar spine, L2-L4 (0.797 g/cm2 vs 0.860 g/cm2), femoral neck (0.685 g/cm2 vs 0.712 g/cm2 ), SOS (1518 m/sg vs 1525 m/sg), and stiffness (74.6 vs 77.7) (p < 0.05). Nevertheless, BUA values were similar in both groups. After stepwise logistic regression analysis, the area found under receiver operating characteristic (ROC) curves was 0.60 for L2L4 and 0.63 for a formula combining L2L4 and height. Our data suggest that patients suffering from Colles' fracture have lower values of BMD by DXA, SOS, and stiffness. However, the ability of these techniques to discriminate is low because the values for the area under ROC curve are 0.60 for L2-L4 and 0.63 for a formula derived of the combination of L2-L4 and height.  相似文献   
102.
We tested the hypothesis that bone mineral density (BMD) and bone mineral content (BMC) in proximal human femur specimens in the upper neck region of interest (ROI) and femoral neck axis length (FNAL) provide a significantly better prediction of femoral bone strength than standard ROIs in vitro. BMD and BMC were measured in 110 proximal femur specimens using a standard dual-energy X-ray absorptiometry (DXA) scanner. The analysis included a new ROI in the upper neck as well as the standard ROIs. FNAL was obtained from the scan images. The specimens' failure-load was measured in a mechanical loading device, simulating a fall on the greater trochanter. For the standard ROIs, correlations between failure-load and BMD ranged from R2 = 0.64 (shaft ROI) to R2 = 0.70, p < 0.001 (femoral neck). Prediction of strength by BMD did not significantly differ from those of BMC (R2 ranging from 0.65 to 0.75, p < 0.001). In the upper neck ROI, for both BMD and BMC correlations with failure-load were higher (R2 = 0.76 and 0.81, respectively; p < 0.001). A lower, yet still significant, correlation was found between FNAL and bone strength (R2 = 0.23, p < 0.001). Normalization of failure-load with respect to FNAL did not significantly increase the correlations with densitometric measures. This study provides in vitro evidence indicating that among the ROIs of the proximal femur the newly defined upper neck ROI provides the best prediction of bone strength. Only a weak association was observed between failure load and FNAL.  相似文献   
103.
目的观察按压骨穴对围绝经期妇女心脏植物神经功能的影响。方法设按压骨穴组30例、空白对照组30例。用美国BraemarDL700型动态心电检测仪,检测试验前后的心率变异性(HRV):TF代表总频,LF代表交感神经活性,HF代表迷走神经活性,LF/HF代表交感神经与迷走神经均衡性。结果按压骨穴后4项指标均有显著下降(P<0.01,P<0.05)。空白对照组变化不显著(P>0.05)。骨穴组4项指标的变化率与对照组比较均有显著性差异(P<0.01)。结论按压骨穴有抑制心脏交感神经活性的良性调整作用,此效应具有相对的特异性。  相似文献   
104.
An investigation was made into the directional sensitivity of cells in the macaque anterior superior temporal polysensory region (STPa) to the motion of objects. The cells studied were sensitive to the presence of motion but showed little or no selectivity for the form of the stimulus. Directional tuning was not continuously distributed about all possible directions. The majority of cells were most responsive to motion in a direction within 15° of one of the three cartesian axes (up/down, left/right, towards/away). Tuning to direction varied in sharpness. For most (34/37) cells the angular change in direction required to reduce response to half maximal was between 45 and 70° (for 3/37 cells it was > 90°). The estimates of the directionality (median I d = 0.97) of STPa cells was similar to that reported for posterior motion processing areas (the middle temporal area, MT, and the medial superior temporal area, MST). The tuning for direction (sharpness, distribution and discrimination) of the motion-sensitive STPa cells were found to be similar to the tuning for perspective view of STPa cells selective for static form of the head and body. On average the STPa responses showed a 100- to 300-ms transient burst of activity followed by a tonic discharge maintained at approximately 20% of the peak firing rate for the duration of stimulation. The responses of motion-sensitive STPa cells occurred at an earlier latency (mean 91 ms) than responses of cells selective for static form (mean 119 ms), but the time course of responses of the two classes of cell were similar in many other respects. The early response latency and directional selectivity indicate that motion sensitivity in STPa cells derives from the dorsal visual pathway via MT/MST. The similarity of tuning for direction and perspective view within STPa may facilitate the integration of motion and form processing within this high-level brain area.  相似文献   
105.
应用双光子及单光子吸收测定技术,检测了92名出生3d内的新生儿骨矿质含量,其中巨大儿30名,正常体重儿32名,低出生体重儿30名,其孕龄分别是40.1±0.7、39.1±1.5和37.4±1.2孕周。结果表明,巨大儿、正常体重儿、低出生体重儿的全身骨矿质含量分别是101.6±28.8、85.2±19.8、59.9±27.2g/cm2,巨大儿骨矿质含量最高,正常体重儿次之,低出生体重儿最低,差异有显著性(P<0.01)。颅骨、肱骨、股骨的骨矿质含量与全身的骨矿质含量有高度的相关性,相关系数分别是0.943、0.879和0.745(P<0.01)。全身的骨矿质含量与出生体重、孕龄及头围有高度相关性,相关系数分别是0.755、0.596和0.556(P<0.01)。提示颅骨、肱骨及股骨的任一部位均可代表全身的骨矿质含量,肱骨是确定全身骨矿质含量较好的部位,新生儿骨矿质含量受出生体重、孕龄及头围的影响较大。  相似文献   
106.
An advanced analysis of the mechanical properties of bone should include information about the microarchitecture of cancellous bone in addition to its density. It has recently been shown that high-resolution quantitative computed tomography and magnetic resonance imaging have the potential to assess such information in a noninvasive way in patients. Both techniques, however, lack sufficient spatial resolution to image the individual trabeculae with true precision. In this work, a new parameter, Ridge number density (RND), is introduced. RND is a measure for the trabecular number, which can be extracted directly from high-resolution three-dimensional (3D) images of patients. We applied the RND technique to a test group of nine healthy, postmenopausal women measured repetitively with a high-resolution 3D peripheral quantitative computed tomography (3D-pQCT) system with 165 × 165 × 165 μm3 voxel size. Simultaneously with the RND determination, the trabecular bone density (TBD) was also assessed in the same volume of interest. The examination site was the distal radius. The intersubject variability of the measured test group was 10.5% for RND and 26.3% for TBD. The root mean square error between first and second examinations (midterm reproducibility) was 1.6% and 1.1%, respectively. RND is determined independently from TBD and pertains to the structure of the cancellous bone. As such, it might add crucial information in cases where bone mass or bone density measurements alone give ambigous results.  相似文献   
107.
颞耳岩锥长轴方向的确定和应用   总被引:3,自引:1,他引:2  
用头颅表面两个标志点确定岩锥长轴方向,指导梅氏(Mayer)位和斯氏(Stenvers)位摄影操作。对120例正常头颅CT图像进行测量,进行统计学处理,确定正常人岩锥长轴前延长线与头颅表面交点的大概位置。结果为:岩锥长轴前延长线交于对侧听眦线外眦后0.82~2.90cm区间,平均值左为1.66cm,右为1.82cm。结论,以平均值的邻值2cm为常数,即对侧听眦线外眦后2cm为岩锥长轴前延长线的前端体表定位标志,与其后端的乳突最突点共同确定岩锥长轴方向。  相似文献   
108.
近3年来,用制备的胎骨充填良性骨肿瘤及病样病变术后骨缺损,经观察10例效果良好。胎骨因其自身组织学和生理学特点,具有抗原性小、诱导成骨活性高,利于“爬行各代”等优点。而且来源丰富、采制简单、储存容易、费用低度,是一种良好的植骨材料,特别适于儿童及年老体弱患者自身取骨困难的骨缺损植骨需要。但其为异体骨,有一定免疫原性,抗支撑强度略差,应注意严格无菌操作、消除免疫原性、配合使用内、外固定等措施。  相似文献   
109.
Volumes of medial and lateral temporal lobe structures were assessed using magnetic resonance imaging (MRI) in 11 patients with late-life onset schizophrenia (LOS), 18 normal elderly controls and 12 patients with moderate cognitive impairment due to Alzheimer's disease (AD) who had no non-cognitive symptoms. While both patient groups has smaller volumes of several medial temporal regions (e.g. entorhinal cortex, left hippocampus), schizophrenics had significantly smaller anterior superior temporal gyri (STG) than normal controls, but AD patients did not. We have previously demonstrated anterior STG volume to be reduced in early life onset schizophrenia.  相似文献   
110.
应用综合评估法术前评估骨巨细胞瘤的侵袭性   总被引:1,自引:0,他引:1  
应用穿刺活检进行病理诊断和分级,同时作DNA含量图象法分析,结合X线平片表现对骨巨细胞瘤的侵袭性进行综合评价,结果显示,在综合分级中,Ⅰ与Ⅱ级的复发率有显著性差异,而病理和X线分级则无显著性差异。提示综合分级对评估骨巨细胞瘤的侵袭性具有合理性和全面性,有助于指导治疗。  相似文献   
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