肝脏螺旋CT动态增强扫描时肝动脉期肝实质一过性异常强化的研究

目的　研究肝脏螺旋CT动态增强扫描时肝动脉期肝实质一过性异常强化 (transienthepaticabnormalenhancement,THAE)的表现特征 ,探讨其产生原因及临床意义。方法　 1999年 1月至2 0 0 1年 9月 92 6例患者因各种原因接受了肝脏或上腹部螺旋CT扫描。CT扫描常规先作全肝或上腹部螺旋CT平扫 ;注射对比剂开始后 2 5～ 3 0s行肝动脉期扫描 ,65～ 70s行门静脉期扫描 ;对部分病例还行病灶局部延迟扫描 ,延迟时间为 3、5及 10～ 15min。肝动脉期共检出 82例 (男 72例 ,女 10例 ;年龄 2 6～ 78岁 )具有THAE ,着重对其在平扫和增强各期图像上的表现、与肝内或肝外病灶的关系以及门静脉系统情况做详细观察和记录。结果　 82例 (8 9% )共有 12 2处肝动脉期THAE ,其中 110处(90 2 % )平扫未显示THAE区域密度异常 ,12处 (9 8% )呈稍低密度 ;所有 12 2处THAE在肝动脉期都为均匀的高密度影 ;在门静脉期 ,10 9处 (89 3 % )转为等密度而不能分辨 ,余 13处 (10 7% )为均匀稍高密度影 (其中 10处作了延迟扫描 ,均转为等密度 )。 83处 (68 0 % )THAE呈边缘光滑的楔形或扇形 ,2 9处呈不规则形 (2 3 8% ) ,余为其他形状。THAE紧贴肝内肿瘤或其他病灶的有 46处 (3 7 7% ) ,邻近肝外肿瘤或其他病灶 2 0处 (16 4% ) ,余 5 6处 (45     

明显强化孤立肺结节血流模式的临床价值

目的利用4层螺旋CT动态增强技术定量评价不同性质的明显强化孤立肺结节的血流模式并初步评价血管内皮生长因子(VEGF)表达阳性的孤立性肺腺癌血管生成与血流模式定量CT参数的相关性.方法 78例孤立明显强化肺结节(直径≤4 cm,68例恶性,10例活动性炎性),行多层螺旋CT(MSCT)动态增强(以4 ml/s的流率注入对比剂).记录孤立肺结节增强前后各时相的CT值并计算强化值、灌注值,结节-主动脉强化值比.灌注值等于时间-密度曲线最大斜率除以主动脉强化值.其中30例VEGF表达阳性的肺腺癌患者用免疫组织化学测定微血管密度(MVD)并标定VEGF,评价肺腺癌血流模式定量CT参数(强化值、灌注值、结节-主动脉强化值比及平均通过时间)与MVD的相关性.结果恶性结节强化值(35.79±10.76) HU与活动性炎性结节(39.76±4.59) HU差异无显著意义 (t=1.148 , P=0.255).恶性结节的结节-主动脉强化值比(14.27±4.37)%及灌注值(3.02±0.96)ml-1·min-1·kg-1均低于活动性炎性结节(18.51±2.71)%,(6.34±4.39)ml-1·min-1·kg-1 (t=2.978,P=0.004;t=5.590,P<0.0001).VEGF表达阳性的肺腺癌强化值(33.06±13.57)HU、结节-动脉强化值比(14.25±4.92)%及灌注值(2.97 ±0.56) ml-1·kg-1·min-1与MVD(70.15±20.03)条/视野,均呈正相关性(r=0.781, P<0.0001;r=0.688, P<0.0001;r=0.716, P<0.0001).平均通过时间(14.86±5.84)s与MVD无显著相关性(r=0.260, P=0.200).结论恶性与活动性炎性孤立肺结节血流模式不同,恶性结节通过结节-大动脉强化值比和灌注值可有效区别于活动性炎性结节,有助于两者鉴别诊断.肺腺癌强化值、结节-动脉强化值比及灌注值反映了VEGF表达阳性的肺腺癌的MVD.强化值、结节-动脉强化及灌注值可作为VEGF相关的肺腺癌血管生成的指标.     

异搏定区域动脉灌注在阻止急性胰腺炎重症化治疗中的作用

目的探讨钙拮抗剂异搏定区域动脉灌注在阻止急性胰腺炎重症化治疗中的作用。方法45例轻型急性胰腺炎患者被随机分为3组常规治疗组、静脉治疗组及动脉灌注组。入院后,常规治疗组采取常规保守治疗;静脉治疗组行合理液体治疗,静脉注射异搏定;动脉灌注组液体补充同时采用持续动脉灌注异搏定1~2周。测定治疗后1、4及7d血清肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、黏附分子-1(ICAM-1)及P-选择素(P-selectin)水平。结果治疗后4、7d,血清TNF-α和P-selectin水平动脉灌注组较静脉治疗组及常规治疗组明显降低(P<0.05);血清IL-1β水平动脉灌注组和静脉治疗组均较常规治疗组明显降低(P<0.05);血清ICAM-1水平动脉灌注组明显低于常规治疗组(P<0.05)。结论持续区域动脉灌注异搏定可能通过减少细胞因子的产生,抑制黏附分子P-selectin和ICAM-1的上调,阻止急性胰腺炎重症化发展。     

强迫症的局部脑血流动态显像研究

目的　探讨强迫症患者各脑叶的代谢状态及脑功能异常与其发病的关系。　　方法　采用单光子发射计算机扫描 (SPECT)技术 ,对未服药的 2 2例强迫症患者于静息及症状诱发状态下行局部脑血流 (rCBF)动态显像研究。　　结果　 1 8例有rCBF异常 ,表现为皮层内局限性放射性分布稀疏、缺损区 ,异常脑叶主要为顶叶、额叶、颞叶 ,并发现脑功能异常与强迫症状的严重程度及药物治疗反应有关。　　结论　大脑顶叶、额叶等脑叶的功能异常是部分强迫症发病的神经病理学基础     

Nuclear bridges in multinucleated giant cells associated with primary lymphoma of the brain in acquired immune deficiency syndrome (AIDS)

Summary In an autopsied case of a 37-year-old man with acquired immune deficiency syndrome (AIDS), multinucleated giant cell encephalopathy was noted in close proximity to multiple nodules of primary lymphoma of the brain. Some multinucleated giant cells and macrophages contained HTLV-III-like viral particles. Nuclear bridges, thin strands connecting individual nuclei with one another, were observed with both light and electron microscopes within some of the multinucleated giant cells. There were also thin tapering nuclear processes, which were probably part of nuclear bridges. The possibility that the nuclear bridges and processes represent amitotic nuclear division is discussed.     

Control of tectal cell number during larval development in Rana pipiens

Cell production and cell deaths were determined in larval Rana pipiens both in control tecta and in tecta following unilateral eyeball removal in embryos and larvae. Such enucleations produce significantly reduced rates of cell division in the contralateral tecta for virtually the entire larval period (confirming studies with enucleation almost exclusively performed in embryos--Kollros: J. Exp. Zool. 123:153-187, '53, and J. Comp. Neurol. 205:171-178, '82). Significant numbers of cell deaths in all nonependymal tectal cell layers were also observed. Control cell division rates peak at stage X, while cell death peaks are reached in stages XIII-XX. Overall, about 10(6) nonependymal cells are produced in control tecta, and about 350,000 of them die by the end of metamorphosis. Control of cell numbers following enucleation is shown to depend mainly on reductions in cell division rates when the operation occurs early in development and mainly on increases in cell death rates when the operation occurs late in larval life. Such increases in death rates are invariably present within 1 day of the operation whereas the reduced division rates ordinarily require several more days to be seen. The modified rates, both of cell divisions and cell death, are limited to tectal areas to which optic nerve fibers have already extended. Maps of the positions of tectal cell divisions in many larval stages provide the basis for modifying the current dogma that tectal formation occurs as a series of newly formed mediocaudal wedges pushing previously produced wedges rostrolaterad. All such "old" wedges receive substantial cell additions for many stages, with the rate of addition decreasing rostrad earlier than caudad.     

Collaboration--a new IT-service in the next generation of regional health care networks

During the past 10–15 years, Regional Health Care Networks (RHCN) have been established in many regions throughout the world. RHCN build on well-known techniques, methodologies and appropriate standards. Most of the European Countries today have set up IT strategic plans that focus on the establishment of RHCN. The benefits of having access to all relevant information are tremendous and contribute to cost-effective and coherent health services. By the rapid spread and use of Internet, technology has made it possible to interconnect all kinds of applications. In 2000, the most experienced regions in Europe joined PICNIC, a European project to develop the Next Generation Regional Health Care Networks and to support their new ways of providing health and social care. The previous generation of Regional Health Care Networks supported the interconnection of applications by transfer of messages. Messaging is an effective means of integration for isolated high-specialised systems that only need to exchange data. This service will continue to be one of the most important services in the future health care networks. However, tighter coupling may be desirable in some instances to avoid replicating the same functionality in several applications. In other words, certain services can be common and used by a number of applications instead of building that service inside each application. These common services are called middleware services. In PICNIC (http://www.medcom.dk/picnic), a new middleware Collaboration IT service has been identified and developed. This service allows the end users to perform real-time clinical collaboration, with exchange of text, structured data, voice and images across the limits of a single region. A clinical collaboration is associated with the shared clinical context to provide a record of relevant clinical information and facilitates synchronous as well as asynchronous collaboration. This new IT service builds on the increasing popularity of instance messaging and presence systems that facilitate smooth transition between synchronous and asynchronous interaction. The new Collaboration IT service is expected to have a strong impact on the practice of health care in the next generation of Regional Health Care Networks.     

Quantitative Characterization of Epicardial Wave Fronts During Regional Ischemia and Elevated Extracellular Potassium Ion Concentration

This study applied zero-delay wave number spectral estimation as a means of quantifying the changes in activation and recovery sequences of propagating plane waves on the epicardial surface of in situ porcine hearts during regional hyperkalemia and ischemia. Unipolar electrograms (104) were recorded from the left ventricular surface of nine hearts using a plaque electrode array with 1 mm spatial sampling intervals. The objectives were (1) to define a set of parameters capable of quantifying the spatial and temporal changes in measured extracellular potentials associated with localized ischemia prior to the onset of conduction block; (2) to elevate regional levels of extracellular potassium ion concentration and quantify potential changes due to this known physiologic manipulation; and (3) to use quantitative parameters to make statistical comparisons in order to distinguish wave fronts during normal, ischemic and hyperkalemic conditions. Results showed that the parameters of wave number and average temporal frequency and the associated power, as determined from the wave number spectrum, provided statistically significant (p < 0.05) quantification of changes in wave front features during normal and ischemic or hyperkalemic conditions. The results were consistent with results obtained from conventional time–space domain methods like isochronal mapping and electrograms, with the advantage of a quantitative result enabling simple comparisons and trend analysis for large numbers of heart beats. © 1998 Biomedical Engineering Society. PAC98: 8759Wc, 8722Fy, 8780+s     

Regional differentiation of sympathetic activity during hypothalamic heating and cooling in anesthetized rabbits

Summary In anesthetized rabbits immobilized with succinyl choline, the discharges of sympathetic efferents supplying cutaneous and visceral regions were simultaneously recorded. The effects of thermal stimulation of the hypothalamic region were tested on the basis of the integrated discharges. During hypothalamic heating cutaneous sympathetic activity decreased, corresponding to increased ear blood flow, while visceral sympathetic activity increased. During hypothalamic cooling there was, on the average, no significant change of regional sympathetic activity. However, in single experimental periods an increase of cutaneous and a decrease of visceral sympathetic activity was found.The observed responses of regional sympathetic activity were compared with findings about regional cutaneous and intestinal blood flow under the same thermal stimulus and further with corresponding former investigations on regional blood flow and regional sympathetic activity during spinal thermal stimulation. It is suggested by this comparison that regional differentiation of sympathetic activity represents a specific thermoregulatory response of the vasomotor system mediated by the hypothalamic thermoregulatory center.