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41.
Objective. Employing [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) to assess the correlation between the effect of deep brain stimulation (DBS) on the subthalamic nucleus (STN) and the regional cerebral metabolic rate of glucose (rCMRGlc) in advanced Parkinson's disease patients (N = 8). Materials and Methods. On the basis of patients’ diary records, we performed FDG‐PET during the off‐period of motor activity with on‐ or off‐stimulation by STN‐DBS on separate days and analyzed the correlation between changes in motor symptoms and alterations in the rCMRGlc. Result. When FDG‐PET was performed, the motor score on the unified Parkinson's disease rating scale (UPDRS) was 64% lower with on‐stimulation than with off‐stimulation (p < 0.001, Wilcoxon single‐rank test). STN‐DBS increased the rCMRGlc in the posterior part of the right middle frontal gyrus, which corresponded to the premotor area, and the right anterior lobe of the cerebellum (p < 0.005, paired t‐test). No region exhibited a decrease in rCMRGlc. Among the items of the UPDRS motor score, the changes in resting tremor and rigidity of the left extremities showed a significant correlation with the changes in rCMRGlc observed in the right premotor area (p < 0.02 and p < 0.05, respectively, Spearman's rank correlation). Conclusions. STN‐DBS either activates the premotor area or normalizes the deactivation of the premotor area. These FDG‐PET findings obtained are consistent with the idea that STN‐DBS modifies the activities of neural circuits involved in motor control.  相似文献   
42.
毛慧生  宁连胜 《中国肿瘤临床》1992,19(3):174-179,240
应用激光多普勒血流仪测量比较津白Ⅱ号小鼠三个部位皮肤的血流,观察HDZ对血流的影响,评价了HDZ的体内热增敏作用。结果发现,同一小鼠不同部位的血流是不同的,同一部位的连续6天结果无何区别。但同部位小鼠间的血流差别可达1倍以上。提示了预测放、化、热疗的疗效时,监测个体血流的前后变化有重要意义。2.5mg/kg以上的HDZ可以明显降低血流75%左右。HDZ与高温联合应用时对肿瘤显示了热增敏效应。  相似文献   
43.
High frequency electrical stimulation by means of electrodes implanted into the brain has become an accepted technique for treatment of Parkinson's disease. The electrical field distribution normally inserted into the sub thalamic nucleus minimise abnormal brain activity. Square wave pulses of 1–3.6 V with duration of 60–90 μs at a frequency range of 130–185 pps are generally used. Every electrode unit consists of four cylindrical electrodes positioned in a row and can be switched on independently. This paper determines the contact impedance of the electrodes for different frequencies and proposes improvement to reduce the contact impedance between the electrodes and the brain. Measurements were performed by placing the electrodes in a tank filled with saline. Different frequencies were applied on two electrodes via a resistor. The current was measured through the resistor and the voltage was registered between one of the electrodes and a third non current carrying electrode. The obtained values were used to calculate the contact impedance. The result shows large contact impedance for the used frequency compared to the impedance of the treated tissue, which means that variation in contact impedance can result in variation in the electrical field applied to the tissue.  相似文献   
44.
史晓林  李春雯 《中国骨伤》2005,18(8):462-463
目的:通过对髂外动静脉及股动静脉与髋臼解剖学与临床的研究,探讨在全髋臼置换术中拉钩在髋放置位置对下肢深静脉血栓的影响。方法:通过解剖学研究56具成年骨盆标本中髂外动静脉及股动静脉来源及走行、与髋臼的关系进行测量分析;并通过临床观察22例(股骨颈骨折12例、股骨头缺血性坏死6例、类风湿性关节炎4例)在人工全髋置换术(THR)中拉钩放置安全区,经下肢静脉超声多普勒检查观察下肢深静脉血栓发病率。结果:在左侧3-5点间、右侧7-9点、左侧9点、右侧3点使用拉钩用力要适度,牵拉时间过长,会造成臀下血管、股动脉的牵拉过度或时间过长,易引起下肢深静脉血栓;通过临床22例THR拉钩放置安全区的观察,无一例下肢深静脉血栓,仅有2例轻度深静脉血流缓慢、但无明显的症状体征,经过口服活血通络中药后消失。结论:通过解剖学与临床观察研究,确定在THR中拉钩放置位置、深度是避免下肢深静脉血栓的重要因素。  相似文献   
45.
The aim of this study was to investigate a potential technique for image-guided minimally invasive neurosurgical interventions. Focused ultrasound (FUS) delivers thermal energy without an invasive probe, penetrating the dura mater, entering through the cerebrospinal fluid (CSF) space, or harming intervening brain tissue. We applied continuous on-line monitoring by MRI to demonstrate the effect of the thermal intervention on the brain tissue. For this, seven rabbits had a part of their skull removed to create access for the FUS beam into the brain through an acoustic window of 11 mm in diameter. Dura was left intact and skin was sutured. One week later, the rabbits were sonicated for 3 seconds with 21 W acoustic power, and the FUS focus was visualized with a temperature-sensitive T1-weighted MRI pulse sequence. The tissue reaction was documented over 7 days with T2-weighted images of the brain. The initial area of the central low signal intensity in the axial plane was .4 ± .3 mm2, and for the bright hyperintensity surrounding the lesion, it was 2.3 ± .6 mm2 (n = 7). In the coronal plane, the corresponding values were .4 ± .1 mm2 and 3.4 ± .9 mm2 (n = 5). The developing brain edema culminated 48 hours later and thereafter diminished during the next 5 days. Histology revealed a central necrosis in the white matter surrounded by edematous tissue with inflammatory cells. In summary, the image-guided thermal ablation technique described here produced a relatively small lesion in the white matter at the targeted location. This was accomplished without opening the dura or the need for a stereotactical device. MRI allowed on-line monitoring of the lesion setting and the deposition of thermal energy and demonstrated the tissue damage after the thermal injury.  相似文献   
46.
Deep inspiration preceding Valsalva maneuver and rapid expiration immediately following it (DIVE) enhance venous blood flow on color Doppler flow imaging (CDI). The effect of DIVE was assessed in 115 consecutive lower extremity examinations. Of these, 95 or 115 (83%) had negative CDI sonograms, and 20 of 115 (17%) had partially (six of 115) or completely (14 of 115) occluding deep vein thrombosis. DIVE enhanced venous blood flow in 68% of the negative cases, resulting in transient venous distention, and/or more complete color filling, and/or greater spectral flow velocities. The 14 cases with completely occluding thrombi showed no response to DIVE. Six cases with partially occluding thrombi showed moderate to mild response to DIVE, with improved color delineation of the residual patent lumen around the thrombus. The authors conclude that DIVE facilitates deep venous CDI, especially when compression cannot be used to augment venous flow.  相似文献   
47.
目的 探讨基于雨课堂的混合式教学在护理教育学课程教学中的应用效果。方法 将2019年开课的护理本科教学班设为观察组(n=20),采用课堂教学与雨课堂平台线上学习相结合的混合式教学;将2018年同期开课、学生数量相同、实施传统课堂教学模式的教学班设为对照组(n=20)。应用SPSS 22.0进行统计学处理,采用独立样本t检验对两个班次学生的研讨课、模拟授课和课终理论考核成绩及对课程教学效果的评价进行分析。结果 两组学生的模拟授课成绩比较差异无统计学意义(t=0.21,P=0.834),观察组学生的研讨课成绩[91.18±1.20](t=3.09,P<0.05)和课终理论考试成绩[78.63±6.28](t=3.33,P<0.05)高于对照组,且信息检索和处理能力(t=-3.33,P<0.05)、发现问题能力(t=-2.17,P<0.05)、独立思考能力(t=-2.53,P<0.05)、知识整合能力(t=-3.86,P<0.001)、自主学习能力(t=-3.12,P<0.05)及对护理教师角色功能的认同感(t=-2.53,P<0.05)、主动学习的意识(t=-3.13,P<0.05)和终身学习的态度(t=-4.46,P<0.001)得分高于对照组。结论 基于雨课堂的混合式教学有利于学生探究学习能力的培养和对理论知识的深度学习,促进课程教学目标的有效达成。  相似文献   
48.
The vascularization of the posterolateral area of the arm is supplied by the terminal branches of the deep brachial artery [middle collateral artery (MCA) and posterior radial collateral artery]. Their anatomy has been a field of confusion for a long time. An extended lateral arm flap, named the extreme lateral arm flap, supplied by these branches and dissected as a retrograde island flap has been proposed as an alternative for large compound defects of the distal forearm. We carried out an extensive anatomic study of the extreme lateral arm flap on 69 upper limbs: 54 fresh injected with colored latex, 10 embalmed and 5 radiographed after Micropaque injection. Two origin levels of the MCA were found: a proximal one (37%) above the radial groove, and a distal one (63%) at the level of the groove. The deep brachial artery always bifurcated after the origin of the MCA into a posterior radial collateral artery (PRCA) and anterior radial collateral artery (ARCA). Indeed in our dissections, after the origin of the MCA from the deep brachial artery, there was always a common trunk named the radial collateral artery (RCA) which bifurcated into the ARCA and PRCA. In all dissected arms we always found the MCA anastomosed in a transverse pattern with the inferior ulnar collateral artery (IUCA), contributing to the anastomotic circle of the elbow. This circle represents the unique vascularization source of the reverse extreme lateral arm flap.  相似文献   
49.
The purpose of this study was to elucidate the effect of raised body temperature per se during acute heat stress on the spontaneous arterial baroreflex control of heart rate (f c) in humans. To investigate whether unloading of cardiopulmonary baroreceptors during whole-body heating would alter the arterial baroreflex control of f c, we controlled loading of the cardiopulmonary baroreceptors by head-down tilt (HDT) at angles of 5°, 10°, 15°, and 30° during heat stress produced by hot-water-perfused suits. The sensitivity of the arterial baroreceptor-cardiac reflex was calculated from the spontaneous changes in beat-to-beat arterial pressure and f c. As an index of cardiopulmonary baroreceptor loading, the left atrial diameter (LAD) was measured by echocardiography. During whole-body heating, the LAD decreased with the rising body core temperature and increased with the HDT. The decreased LAD during heating almost recovered to the normothermic control level by 10° HDT. In the supine position, cardiac baroreflex sensitivity remained unchanged during heating. Arterial pressure, f c and cardiac baroreflex sensitivity were not changed by HDT ranging from 5° to 30° during heating. These results suggest that cardiac baroreflex sensitivity remain unchanged during graded loading of the cardiopulmonary baroreceptors in heat-stressed humans. Also, we conclude that the sensitivity of the spontaneous arterial baroreflex controlling the f c is not influenced by raised body temperature per se during acute heat stress. Electronic Publication  相似文献   
50.
实验高压电烧伤深筋膜微循环动态变化及意义   总被引:4,自引:7,他引:4  
梁彦  张庆富 《中国微循环》2005,9(1):12-14,17,i003
目的研究肢体高压电烧伤后深筋膜微循环变化规律。方法将28只家兔随机分成实验组与对照组。实验组家兔的右下肢采用1万伏额定电压 ,77mA电流及通电5s的方法制作单侧后肢电烧伤模型 ,对照组采用假电的方法制作单侧后肢假电烧伤模型 ,两组均采用“滴水开窗法”制作左侧下肢远端深筋膜微循环观测窗 ,并采用WX -9B型多部位微循环显微仪及其图像处理系统在通电前、通电后即刻、通电后30min、2、4、6h观测微动脉、毛细血管、后微静脉、微静脉的形态、流态、管周状态。结果肢体高压电烧伤后 ,微血管形态在30min内可观测到显著性变化 (P<0.05) ,表现为血管密度减小 ,微动脉、毛细血管、微静脉收缩 ,后微静脉扩张 ,微动脉、毛细血管均在6min以后变得不清以致模糊(P<0.05)、后微静脉、微静脉分别在2h、30min以后变得不清(P<0.05)。微血管内的流态以白微栓的变化可见规律性 ,即白微栓在电后2h开始出现 ,4h迅速达高峰 ,6h又有快速下降的趋势。微静脉和后微静脉在通电30min后有渗出(P<0.05) ,只有后微静脉在通电后2h有出血(P<0.05)。结论电烧伤后存在全身性反应 ,其在肢端深筋膜微循环的表现是一个阶段性加重的过程 :第一阶段电烧伤后30min内为缺血型微循环障碍 ,第二阶段微循环障碍包含两个方面 :其一是微血管的出血  相似文献   
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