多层螺旋CT定量评估慢性阻塞性肺疾病病情的价值

目的探讨多层螺旋CT(MSCT)定量评估慢性阻塞性肺疾病病情的价值。方法选取2017年8月～2018年7月在湖州市第一人民医院就诊的73例慢性阻塞性肺疾病(COPD)患者作为研究对象,按照病情轻重分为Ⅰ组(轻度患者17例)、Ⅱ组(中度患者32例)、Ⅲ组(重度患者24例),并选取同期于该院体检的健康者20例为对照组。所有研究对象均行MSCT低剂量扫描,观察比较各组管腔面积(Ai)、支气管壁面积百分比(WA%)、管壁厚度与体表面积比值(T/BSA)、壁厚度与直径比值(TDR),同时予以肺功能检查,采用定量CT气道分析软件分别测量气道相关参数,并用Siemens Pulmo软件Pearson定量分析其相关性。结果对照组、Ⅰ组、Ⅱ组、Ⅲ组的FEV1均呈逐渐下降趋势,FEV1/FVC呈逐渐上升趋势,差异均有统计学意义(P0.05)。对照组、Ⅰ组、Ⅱ组、Ⅲ组的WA%、T/BSA、TDR比较,均呈逐渐上升趋势,Ai呈下降趋势,差异均有统计学意义(P0.05)。FEV1与WA%、TDR之间呈负相关(r=-0.291,P=0.000;r=-0.473,P=0.000),FEV1/FVC与WA%、TDR之间呈正相关(r=0.285,P=0.000;r=0.472,P=0.000)。结论 MSCT扫描及定量分析可为COPD患者气道病变情况提供可靠的评估信息。     

高血胆固醇症病人体内铁贮水平与心肌灌注 左心室功能的相关研究

目的评价血清铁参数与高血胆固醇症(HCL)病人心肌灌注、室壁运动异常及血管造影显示的冠状动脉疾病(CAD)程度的相互关系.方法选择38名具有高血胆固醇症(LDL-C＞3.38mmol/L)从未治疗过的男性病人(平均年龄59±6岁)作为HCL组和32名年龄匹配而胆固醇水平正常(NCL)的男性为NCL组,进行冠状动脉造影并在10d内行SPECT检查,应用99mTc-甲氧基异丙基异氰(MIBI)进行静息/负荷门控断层心肌灌注显像、室壁运动功能图像分析;同时测定血清铁参数、血脂及常规血液学参数.结果在HCL组发现血清铁蛋白(SF)与心肌灌注系数(r=0.70,P＜0.01),可逆系数(r=0.66,P＜0.01)和室壁运动系数(r=0.53,P＜0.05)之间呈显著性相关;而总铁结合力与灌注系数之间呈一弱(负)相关(r=-0.52,P＜0.05).在NCL组铁参数与灌注系数及室壁运动系数之间无显著性相关.多元回归分析证实血清铁蛋白水平是决定HCL病人中心肌灌注的独立因素(β=0.55,P＞0.05).铁参数与两组通过冠状动脉造影(CAG)进行评分所定义的CAD程度无关.结论体内铁贮水平升高与HCL病人心肌灌注和功能异常的严重性和程度有着密切的关系,但与CAD的造影显示的病变范围无关.血清铁蛋白水平增高,可增加铁介导的氧化应力和LDL过氧化作用,导致HCL相关的血管内皮功能紊乱并进一步损伤心肌灌注和室壁运动功能.     

Tissue remodeling of rat pulmonary artery in hypoxic breathing. I. Changes of morphology, zero-stress state, and gene expression

The remodeling of the pulmonary arterial tissue in response to a step change of the oxygen concentration in the gas in which a rat lives was recorded as function of time and function of O₂ concentration. Three steps of changing from 20.9% to 17.2%, 13.6%, and 10% O₂ were imposed. Earlier work in our laboratory has shown that pulmonary arterial tissue remodeling is significant in the first 24 h after a step change of oxygen tension. Hence we made measurements in this period. Furthermore, data were obtained for tissue remodeling of circumferential and axial lengths of the pulmonary arteries. We recorded the activities of gene expressions in the lung tissues by microarray, determined the dose response curves of gene expression in the homogenized whole lungs with respect to four levels of O₂ concentration, and obtained the time courses of gene expression in the lung parenchyma in 30 days after a step decrease of O₂ concentration from 20.9% to 10%. We would like to suggest that the correlation of gene expression with physiological function parameters, i.e., time, O₂ tension, blood pressure, opening angle, wall thicknesses, etc., is the way to narrow down the search for specific genes for specific physiological functions. © 2001 Biomedical Engineering Society. PAC01: 8719Uv     

Application of Scanning Acoustic Microscopy for Assessing Stress Distribution in Atherosclerotic Plaque

Scanning acoustic microscopy (SAM) was equipped to assess the acoustic properties of normal and atherosclerotic coronary arteries. The SAM image in the atherosclerotic lesion clearly demonstrated that the sound speed was higher than that in the normal intima, and that the variation of elasticity was found within the fibrous cap of the plaque. Young's elastic modulus of each region was calculated and the finite element analysis was applied to derive the stress distribution in these arterial walls. In a case of normal coronary artery, the stress was dominant in the intima and the distribution was rather homogeneous and in a case of atherosclerosis, high stress was concentrated to the relatively soft lesion in the fibrous cap overlying lipid pool. SAM provides information on the physical properties, which cannot be obtained by the optical microscope. The results would help in understanding the pathological features of atherosclerosis. © 2001 Biomedical Engineering Society. PAC01: 8764-t, 8763Df, 8719Xx, 8719Rr     

Elevation of plasma viscosity induces sustained NO-mediated dilation in the hamster cremaster microcirculation in vivo

 We studied whether a flow-independent increase of luminal wall shear stress (WSS) could dilate hamster arterioles in vivo and which endothelial mediators are potentially involved. To this end the plasma viscosity was elevated by exchanging blood for dextran-erythrocyte solution thereby augmenting WSS. Diameters of small and large arterioles as well as red blood cell velocities were measured before and after exchange of blood for solutions of identical haematocrit containing either high- (HMWD) or low-molecular weight dextran (LMWD). The potential role of endothelial autacoids was investigated by local application of the NO-synthase inhibitor N ^G-nitro-L-arginine (L-NNA), the inhibitor of cyclooxygenase, indomethacin (3 μM), or the K⁺-channel blocker, tetrabutylammonium (TBA, 0.1 mM) to assess the potential effects of EDHF. HMWD (n = 11 animals) increased plasma viscosity by 64 ± 3% and dilated arterioles of all branching orders (A1–A4) significantly [by 24 ± 3% (A1–A2) and 32 ± 3% (A3–A4)]. This dilation compensated fully for the calculated initial increase of WSS. LMWD (n = 6) did not affect plasma viscosity or arteriolar diameters. Tissue treatment with L-NNA (30–300 μM, n = 12) substantially diminished the HMWD-induced dilation in small arterioles (A3–A4; to 13 ± 3%; P<0.05) and virtually abolished it in large ones (A1–A2). Consequently, the calculated WSS increased significantly in these arterioles (by 31 ± 5%). TBA combined with L-NNA (n = 4) did not reduce further the remaining dilation. Indomethacin (n = 6) had no effect on HMWD-induced dilation. We conclude that an increase of WSS induces a mainly NO-mediated arteriolar dilation. This dilation occurs in all arteriolar branching orders and is of sufficient magnitude to compensate for the initial WSS-increase. Thus, any elevations of WSS fulfil the requirement for a signal to change diameter along the arteriolar tree in a coordinated manner. The fully compensating dilation which we observed indicates that WSS is a controlled variable. It does, however, raise questions as to its role as a continuous endothelial stimulus. Received: 2 August 1996 / Received after revision: 24 February 1997 / Accepted: 14 April 1997     

Developments in cardiovascular ultrasound. Part 2: Arterial applications

Many of the changes resulting from arterial disease can be measured, using Doppler ultrasound for measurement of blood velocity and B-scan imaging for measurement of tissue structure and composition. Wall thickness, the degree of arterial narrowing and plaque volume can be measured using B-scan imaging, and 3D ultrasound can be used to improve the accuracy of measurements of plaque volume and for improved visualisation of complex arterial geometries. Measurement of the dynamic properties of the arterial wall permits estimation of wall elasticity and plaque motion. From the Doppler signal, measurements of blood velocity are used to estimate the degree of arterial narrowing and volumetric flow, although measurement errors can be large. Wall shear stress can be estimated by measuring the velocity gradient at the vessel wall. The problems of inadequate spatial resolution and interference from overlying tissue are largely removed when intravascular systems are used, and these have superior capability in the assessment of arterial structure and tissue composition. However, measurement of quantities relating to blood flow is more difficult using the intravascular approach, as the indwelling cather disturbs the blood flow pattern, and currently, assessment of flow and vessel cross-section are not performed at the same site.     

用组织多普勒技术评价扩张型心肌病室壁运动

目的　用组织多普勒技术分析扩张型心肌病 (DCM)室壁运动。方法　选择 DCM患者和正常对照各 30例 ,用组织多普勒技术于胸骨旁长轴检测室间隔及左室后壁中间段短轴方向心肌运动速度 (MV) ,并计算心肌运动速度阶差 (MVG) ;经心尖窗检测左室前、后、下、侧壁和前、后室间隔中间段长轴方向 MV。结果　 DCM组患者有 4种 MV频谱异常表现 ,且 MV明显低于对照组 (P<0 .0 5 ) ,并以长轴为甚 ;MVG明显减低 (P<0 .0 5 ) ;室壁各种速度差异消失。结论　组织多普勒技术可定量反映 DCM患者室壁运动异常     

GK型机械瓣空化可视化研究

对国产GK27型机械二尖瓣进行了单次关闭方式的离体空化实验，采用数码相机拍摄了空泡照片。机械瓣阻塞体关闭后，云状空泡出现在挡座周围，呈放射状向外运动，空化原因是机械瓣关闭时阻塞体与挡座的撞击形成的局部挤压射流，挤压缝隙出口射流速度高达9m/s，局部低压造成空化，在机理上，这是附壁射流引起的旋涡空化。关闭速度是衡量机械瓣空化趋势的重要指标之一。空化历时随心室载荷率的增加而增加，在载荷率为2750mmHg/s时，最大空化历时达440μs。机械瓣空化临界载荷率为420mmHg/s，这比动物实验所得的正常生理条件750mmHg/s低，因此在人体正常生理条件下，机械二尖瓣存在空化的可能。     

珍稀中草药金线莲的RAPD研究

为了鉴别金线莲的品种,探索同属植物之间的亲缘关系及同种植物不同产地的遗传变异,并制定正品金线莲的DNA指纹图谱,采用随机扩增多态DNA(RAPD)技术对兰科开唇兰属植物花叶开唇兰Anoectochilus roxburghii(Wall．)．Lindl．、台湾开唇兰A.formosanus Hay．进行了鉴定,结果选择的7个引物对3个品种共扩增出98个位点,其中3个引物为高特异性引物。结论 RAPD技术不仅能鉴别种间差异,而且能揭示同种不同产地植物的遗传变异。     

Management of submacular hemorrhage with intravitreous tissue plasminogen activator injection and pneumatic displacement

Objective

To investigate the efficacy and safety of treating thick submacular hemorrhages with intravitreous tissue plasminogen activator (tPA) and pneumatic displacement.