Dynamic imaging with lanthanide chelates in normal brain: contrast due to magnetic susceptibility effects

Using a one-dimensional rapid imaging technique, we have found that injection of lanthanide chelates such as Gd(DTPA)2- leads to a significant decrease (50%) in rat brain signal intensity at 1.45 T using T2-weighted pulse sequences; however, no effect of comparable size is observed with T1-weighted pulse sequences. The transient effect and its kinetics were followed with a temporal resolution of between 1 and 8 s. Experiments with different lanthanide chelates show that the observed decrease in signal intensity correlates with the magnetic moment of each agent but not with their longitudinal relaxivity. Three-dimensional chemical-shift resolved experiments demonstrate significant line broadening in brain during infusion with Dy(DTPA)2-. Our results show that the cause of this effect is the difference in susceptibility between the capillaries, containing the contrast agent, and the surrounding tissue. As a result of these susceptibility differences, field gradients are produced in the tissue and diffusion of water through these gradients leads to a loss of spin phase coherence and thus a decrease in signal intensity. We propose this as a new type of contrast agent mechanism in NMR. The effect and its kinetics are likely to be related to important physiological parameters such as cerebral blood volume and cerebral blood flow, and do not depend on a breakdown of the blood-brain barrier as do conventional contrast agent techniques.     

顺丁烯二酸水溶液的热反应动力学

研究了不同温度、浓度条件下，顺丁烯二酸（顺酸）非催化反应网络，即顺酸可生成反丁烯二酸（反酸）和苹果酸，反酸与苹果酸存在可逆反应。建立了该反应网络的动力学模型。测定了不同反应条件下顺酸、反酸和苹果酸浓度随时间变化的规律，据此，动力学参数进行了估值。     

水痘发病与季节关系初探

目的　探讨水痘发病与季节的关系。　方法　随机采集我院近 5年住院的 312例水痘患者 ,用圆形分布法统计分析其发病与季节的关系。　结果　 312例水痘患者好发于 4月 2 8日～ 9月 2 4日 ,集中于 7月 11日 ,各月之间比较差异显著 (r=0 .4 4 79,P<0 .0 1)。　结论　水痘好发于春末夏初     

贲门失弛缓症的超声诊断价值

目的:探讨超声在贲门失弛缓症诊断中的应用价值。方法:对临床拟诊为贲门失弛缓症病人首先采用超声检查,诊断贲门失弛缓症38例,同时进行了X线钡剂食管及胃肠造影,并与40例正常人进行了对照。结果:超声对贲门失弛缓症的诊断符合率为100%,失弛缓症的食管管径明显大于正常对照组(P<0.01),管壁厚度亦大于正常对照组(P<0.01)食管蠕动明显减弱,甚者消失,扩张的食管腔内见有潴留的内容物。结论:超声对贲门失弛缓症诊断具有重要的临床应用价值,可取代传统的X线钡剂造影检查。     

浅谈血液层流病房净化工程招标技术管理

1招标内容:血液层流病房净化工程,包括: 1.1血液层流病房净化工程范围: 1.2血液层流病房净化工程方案设计; 1.3血液层流病房净化工程设备、材料的供应与安装; 1.4血液层流病房净化工程施工组织; 1.5病房及辅助功能区内的配套设施的施工与安装.     

Appropriateness of hysterectomy in Taiwan.

BACKGROUND AND PURPOSE: Hysterectomy is among the most frequently performed surgical procedures in developed countries, but few studies from the Asia-Pacific region have assessed the appropriateness of hysterectomy. The purpose of this study was to examine the rate of inappropriate hysterectomy in Taiwan and its association with patient characteristics and indications for the procedure. METHODS: A random sample of hysterectomies for which claims were submitted to the Taiwan Bureau of National Health Insurance from July 1, 1997 to June 30, 1998 was selected. A total of 658 charts were reviewed by an expert panel composed of 5 senior gynecologists. RESULTS: Overall, 74.2% of patients underwent hysterectomy for appropriate reasons, 5.6% for uncertain reasons, and 20.2% for inappropriate reasons. Inappropriate procedures were positively associated with younger age and premenopausal status. Primary indications that accounted for over 25% of inappropriate procedures were chronic pelvic pain (42.9%), abnormal uterine bleeding (37.5%), and endometriosis (27.7%). CONCLUSIONS: This study found a high rate of inappropriate hysterectomy in Taiwan. Gynecologists and physician organizations should take action to improve physician agreement on the use of hysterectomy, especially for indications associated with high rates of inappropriate procedures.     

全喉切除改良气管-咽吻合Ⅰ期发声重建术

目的：探讨全喉切除Ⅰ期发声重建术的改进术式。方法：采用低位气管切开，全喉切除，食管前壁黏膜重建声门，气管切口处造瘘．颈段气管上提并缩窄吻合于舌根的方法行全喉切除及Ⅰ期发声重建木35例。结果：33例(94．29％）术后获得了不同程度的发声功能．不能发声者仅2例(5．71％)。全部患者术后均可经口进食，未出现严重的影响生存质量的误咽。结论：与以往的发声重建术相比，本术式具有发声成功率高、发声质量良好、误咽率低等优点，且无须置人人工发声装置．值得推广。     

先天性齿槽突裂整复术(附10例报告)

应用自体髂松质骨髓颗粒植入整复10例单侧上颌齿槽突裂,并关闭口鼻瘘。10例伤口一期愈合,术后观察3~6个月,外观改善明显,X线检查有明显骨形成,骨密度近似正常骨组织,两者间无明显界限。     

硝酸甘油、米力农和尼卡地平缓解桡动脉痉挛作用的比较

目的：比较硝酸甘油、米力农和尼卡地平3种药物对桡动脉的解痉作用。方法：收集手术后多余的人体桡动脉标本，采用器官浴槽方法，比较上述3种药物对预收缩的离体桡动脉的解痉作用。结果：米力农和硝酸甘油对预收缩的桡动脉的舒张作用明显强于尼卡地平；米力农和硝酸甘油的疗效相似。结论：米力农和硝酸甘油更适用于缓解冠状动脉旁路移植术中桡动脉的痉挛。