连续周围神经阻滞用于术后镇痛的研究进展

连续周围神经阻滞术后镇痛效果好,副作用少,能够有效地缓解术后疼痛,促进手术后功能恢复,而得到越来越广泛的应用。近年来,神经刺激器、超声引导下定位技术的出现,使得连续周围神经阻滞定位更加准确,技术日趋完善,而对于局部麻醉药的选择、药物浓度等的相关研究使这一技术更加安全,有效。     

Fibrinogen predicts ischaemic stroke and advanced atherosclerosis but not echolucent, rupture-prone carotid plaques: the Copenhagen City Heart Study.

AIMS: Whether the association between fibrinogen and cardiovascular events reflects an association with advanced atherosclerosis in general, or rupture-prone plaques in particular, is unclear. We examined whether fibrinogen predicts incidence of ischaemic stroke, advanced atherosclerosis (measured as carotid artery stenosis) and/or echolucent, rupture-prone plaques. METHODS AND RESULTS: Study 1-8755 Copenhagen City Heart Study stroke-free participants; we observed 235 ischaemic strokes during 6 years of follow-up. Study 2-318 carotid stenosis patients and 1584 age- and gender-matched controls. Study 3-159 patients with echolucent vs 159 patients with echo-rich carotid artery plaques. Fibrinogen above vs below the median value of 3 g l(-1)predicted risk of ischaemic stroke (relative risk: 1.9; 95% CI: 1.4-2.5; 235 events). Significant risk was found in men (2.7; 1.7-4.2; 113 events) and with a similar trend in women (1.4; 0.9-2.0; 122 events), in young (5.2; 1.1-26; eight events) and middle aged (2.9; 1.6-5.4; 64 events) with a similar trend in the elderly (1.4; 1.0-2.0; 163 events). Fibrinogen levels in those with and without ischaemic stroke were 3.6 and 3.1 g l(-1)(ANCOVA: P<0.0001). Likewise, in those with and without carotid artery stenosis fibrinogen levels were 4.7 and 3.1 g l(-1)(P<0.0001); equivalent values for high-sensitive C-reactive protein were 3.6 and 1.4 mg l(-1)(P<0.0001). Finally, neither fibrinogen nor high-sensitive C-reactive protein levels differed between those with echolucent and echo-rich carotid artery plaques (P=0.61 and P=0.28); the power to exclude a 15% increase in fibrinogen or a 50% increase in high-sensitive C-reactive protein was 98 and 54%, respectively. CONCLUSIONS: Elevated fibrinogen predicts future ischaemic strokes, particularly in men and in the young and middle aged. This is most likely a reflection of advanced atherosclerosis, rather than an association with rupture-prone plaques.     

Anisotropy of Young's modulus of human tibial cortical bone

The anisotropy of Young's modulus in human cortical bone was determined for all spatial directions by performing coordinate rotations of a 6 by 6 elastic stiffness matrix. The elastic stiffness coefficients were determined experimentally from ultrasonic velocity measurements on 96 samples of normal cortical bone removed from the right tibia of eight human cadavers. The following measured values were used for our analysis: c ₁₁ =19.5 GPa, c ₂₂ =20.1 GPa, c ₃₃ =30.9 GPa, c ₄₄ =5.72 GPa, c ₅₅ =5.17 GPa, c ₆₆ =4.05 GPa, c ₂₃ =12.5 GPa. The remaining coefficients were determined by assuming that the specimens possessed at least an orthorhombic elastic symmetry, and further assuming that c ₁₃ =c ₂₃ , c ₁₂ =c ₁₁ –2c ₆₆ . Our analysis revealed a substantial anisotropy in Young's modulus in the plane containing the long axis of the tibia, with maxima of 20.9 GPa parallel to the long axis, and minima of 11.8 GPa perpendicular to this axis. A less pronounced anisotropy was observed in the plane perpendicular to the long axis of the tibia. To display our results for the full three-dimensional anisotropy of cortical bone, a closed surface was used to represent Young's modulus in all spatial directions.     

血栓内微泡联合尿激酶介导的超声溶栓体外实验

目的探讨血栓内微泡联合尿激酶介导的超声溶栓对体外血栓的溶解效果。方法取牛全血制作血栓样本50个,随机平均分为5组后于带有侧支循环的体外循环装置中进行处理。实验1组为超声微泡尿激酶组,实验2组为超声微泡组,实验3组为超声尿激酶组,实验4组为单纯尿激酶组,实验5组为无处理组。计算并比较各组的溶栓率。并进行HE染色及免疫荧光组织学观察。结果实验1组溶栓率为(73.64±14.16)%,实验2组为(47.97±11.66)%,实验3组为(57.33±8.65)%,实验4组为(50.85±9.63)%,实验5组为(29.76±18.06)%。其中实验1组溶栓率高于其余各组,差异均有统计学意义(P均0.05);该组HE染色组织学检查可见明显多灶状血栓溶解,边缘可见血栓崩裂,免疫荧光可见纤维蛋白网断裂。结论血栓内微泡联合尿激酶介导的超声溶栓在体外实验中可提高血栓的溶解率。     

腹腔镜超声在经腹腔镜输尿管上段切开取石术中的应用

目的 探讨腹腔镜超声(LUS)在腹腔镜输尿管上段切开取石术中的应用价值。方法 对7例输尿管上段结石患者在腹腔镜输尿管上段切开取石术中应用LUS对输尿管和结石定位。结果 7例LUS检查输尿管均显像，超声引导下顺利游离出输尿管；7例结石均获得准确定位，5例用无损伤钳顺利取出结石，2例按LUS定位切开输尿管后取出结石。LUS检查时间9-20min，平均14min。结论 LUS在腹腔镜输尿管上段切开取石术中有实际应用价值。     

Determination of acoustic power outputs in the microwatt-milliwatt range

A system using an electrobalance for radiation pressure measurements has been developed capable of determining acoustic powers in the microwatt-milliwatt range. Low background “noise” levels are achieved by effective isolation of the balance from building vibrations and shielding the target from convection currents. The standard deviation for a power output of 1 mW is typically less than 1 percent.     

Choice of standard target for medical pulse-echo equipment evaluation

Comparisons have been made between plane, spherical and cylindrical targets in relation to their suitability for quantitative evaluation of the performance of pulse-echo equipment for visualizing tissues. Using fifteen different transducers, with various frequencies and beam-shapes, spherical targets were found to relate much more closely (scatter of 12 dB) than did plane targets (40 dB) with the target strength measured in post mortem human liver.     

磁共振胆胰管成像与B超对胆胰疾病诊断的价值

目的利用ROC曲线评估磁共振胆胰管成像（MRCP）与B超对胆胰系统疾病的诊断效能，探讨MRCP的临床应用价值。方法以2002年至2004年拟诊胆胰系统疾病的62例病例为研究对象，所有病例均有完整的MRCP、B超及最终诊断资料，应用ROCKIT软件进行ROC分析。结果MRCP与B超均是诊断胆胰系统疾病的有效方法，但MRCP的诊断准确率高于B超（MRCP的ROC曲线下面积a=0．930，B超的ROC曲线下面积a=0．739）。特别是在胆总管下段疾病的诊断上，MRCP明显优于B超。结论MRCP作为一种无创性检查，对胆胰疾病有很好的定位诊断效能，与原始图像相结合分析有助于判断病因。     

An unusual flat interface in orbital ultrasonic examinations

Systems of classifying orbital echograms have been developed to aid in increasing the diagnostic accuracy of the technique. An unusual flat interface was recorded in the retrobulbar region of three patients and in each case shown to be a horizontal plane separating two fluid regions. The dynamic behaviour of these regions was studied in one patient over a 30 min period and possible interpretations of the phenomenon discussed. In the other two patients the interface was restricted to one tumour lobule. The characteristic appearance described has been added to our diagnostic criteria and we expect it to add to the value of the technique in diagnosis of orbital pathology.