Myocardial perfusion and function in dogs with moderate coronary stenosis

MRI studies of first-pass contrast enhancement with polylysine-Gd-DTPA and myocardial tagging using spatial modulation of magnetization (SPAMM) were performed to assess the feasibility of a combined regional myocardial blood flow and 2D deformation exam. Instrumented closed-chest dogs were imaged at a baseline control state (Cntl) followed by two interventions: moderate coronary stenosis (St) achieved by partial occlusion of the left anterior descending (LAD) and moderate coronary stenosis with dobutamine loading (StD). Hypoperfusion of the anterior region (ANT) of the myocardium (LAD distribution) relative to the posterior wall (POS) based on the upslope of the signal intensity time curve from the contrast-enhanced MR images was demonstrated only with dobutamine loading (ANT:POS Cntl=1.077 ± 0.15 versus ANT:POS StD=0.477 ± 0.11, P<0.03) and was confirmed with radio-labeled microspheres measurements (ANT:POS Cntl=1.18 ± 0.2 ml/min/g versus ANT:POS StD=0.44 ± 0.1 ml/min/g; P<0.002). Significant changes in regional myocardial shortening were only seen in the StD state (P<0.02); the anterior region showed impaired myocardial shortening with dobutamine loading (P=NS), whereas the nonaffected POS region showed a marked increase in shortening when compared with Cntl (Cntl=0.964 ± 0.02 versus StD=0.884 ± 0.03; P<0.001). These results demonstrate that an integrated quantitative assessment of regional myocardial function and semiquantitative assessment of myocardial blood flow can be performed noninvasively with ultrafast MRI.     

The hepatic immune system

The liver regulates T-cell homeostasis, induces T-cell tolerance, and supports intrahepatic T-cell responses against hepatotropic pathogens. Many data from clinical and preclinical systems provide supportive evidence for these diverse roles of the liver in modulating peripheral (systemic, mucosal, and intrahepatic) T-cell immunity. Little information is available on the cellular and molecular mechanisms that mediate the dual role of the liver in tolerizing T-cell responses and in supporting intrahepatic priming of T-cell responses. Understanding these immunoregulatory effects in the liver may offer insight into clinically relevant immunopathologies of this organ.     

Policies of academic medical centers for disclosing financial conflicts of interest to potential research participants.

PURPOSE: To document the current state of institutional review board (IRB) and conflict of interest committee policies regarding disclosures of financial conflicts of interest to potential research participants, and to use this information to identify and share models for effectively achieving disclosure. METHOD: The authors identified the 123 U.S. academic medical centers that have IRBs and sought their IRB and institutional policies regarding financial conflicts of interest. In February and March 2004, using manual and key word searches, each institution's Web site was searched to identify documents containing information regarding the disclosure of financial conflicts of interest. Letters were sent to 24 institutions that had either no information or incomplete information posted on their Web sites. To assess institutions' guidelines for disclosure, the authors extracted and content coded each institution's information on disclosure. RESULTS: Relevant information was obtained from 120 (98%) academic medical centers (AMCs), of which 57 (48%) mentioned disclosing financial conflicts to potential research participants. Of these 57, 33 (58%) included verbatim language that could be used in informed consent documents. AMCs' recommendations and requirements for disclosure included details of the financial arrangement, administrative management of conflicts of interest, and encouragement of dialogue between the investigator and the potential research participant. CONCLUSIONS: Considerable variability exists concerning the specific information that should be disclosed. Most of the AMCs' policies were consistent with the goal of protection from legal liability. Significant questions remain, however, concerning the goals of disclosure and the most effective methods for achieving those goals.     

Electrophysiological and pharmacological evidence in favor of amino acid neurotransmission in fimbria-fornix fibers innervating the lateral septal complex of rats

Summary Electrical stimulation of fimbria-fornix (fifx) fibers monosynaptically activated many of the neurons tested in the lateral septal complex (LSC) of the rat. The orthodromically activated LSC neurons were classified as strongly orthodromically activated (SOA) or weakly orthodromically activated (WOA) cells according to their threshold for eliciting a response, stability of the response latency, frequency following and the stimulus-response ratio.Microiontophoretically applied glutamate (GLU) could excite both SOA and WOA neurons. However, the expelling currents needed to activate the SOA cells were often considerably lower than those necessary to excite the WOA cells suggesting higher sensitivity to GLU of those cells which receive a strong fi-fx innervation. Iontophoretically administered glutamic acid diethylester (GDEE) in general reversibly attenuated excitatory responses of LSC cells to GLU but not to acetylcholine. GDEE was also effective in blocking the synaptic responses of SOA septal cells to fi-fx stimuli. In addition, GDEE administered topically reversibly suppressed the field potential induced in the LSC by fi-fx stimulation.These electrophysiological and pharmacological results support recent biochemical observations suggesting that the excitatory innervation of LSC neurons by fi-fx fibers is mediated by GLU or a closely related excitatory amino acid.The investigations were supported by the Foundation for Medical Research FUNGO which is subsidized by the Netherlands Organization for Advancement of Pure Research (Z.W.O.), grant 13-31-045 awarded to I.J. A. Urban     

磁刺激用平面线圈结构的优化研究

文中建立了采用任意形状平面线圈磁刺激仪的RLC模型，给出了模型参数的计算方法。为了优化线圈，将磁刺激仪线圈的性能指标分为反映线圈输出性能的峰值磁能和反映线圈结构的几何变量。在磁刺激激活函数达到阈值条件下，调整平面螺旋线圈的结构并计算出依赖于线圈结构参数的输出性能值，从而，寻找最优的线圈几何参数。优化结果表明：线圈外半径是关键因素，给定阈值条件，选择合适的线圈外半径，可以大大降低线圈峰值磁能；另外，现在使用的圆环线圈并非最优，D形线圈优于圆环线圈。     

Integrating complementary and alternative medicine instruction into health professions education: organizational and instructional strategies.

A few years ago, the National Institutes of Health National Center for Complementary and Alternative Medicine funded a program called the Complementary and Alternative Medicine (CAM) Education Project. Grantees were 14 medical and nursing schools and the American Medical Student Association, which funded six additional medical schools. Grants were awarded in cohorts of five per year in 2000, 2001, and 2002-2003.The R25 grant recipients identified several major themes as crucial to the success of integrating CAM into health professions curricula. The rationale for integrating CAM curricula was in part to enable future health professionals to provide informed advice as patients dramatically increase the use of CAM. Success of new CAM education programs relied on leadership, including top-down support from institutions' highest administrators. Formal and informal engagement of key faculty and opinion leaders raised awareness, interest, and participation in programs. A range of faculty development efforts increased CAM-teaching capacity. The most effective strategies for integration addressed a key curriculum need and used some form of evidence-based practice framework. Most programs used a combination of instructional delivery strategies, including experiential components and online resources, to address the needs of learners while promoting a high level of ongoing interest in CAM topics. Institutions noted several benefits, including increased faculty development activities, the creation of new programs, and increased cross- and inter-university collaborations. Common challenges included the need for qualified faculty, crowded and changing curricula, a lack of defined best practices in CAM, and post-grant sustainability of programs.     

乙醇对人绒毛孕酮分泌的影响

本工作利用灌流技术观察了四种不同浓度的乙醇(0.5％、1％、2.5％、5％)对妊娠早期人工流产新鲜胎盘绒毛分泌孕酮的影响。结果表明,乙醇具有促进孕酮分泌的作用,并存在剂量依赖的关系。提示乙醇可能破坏胎盘激素内分泌的平衡,从而影响胎儿的正常生长与发育。     

MCP-1-dependent signaling in CCR2(-/-) aortic smooth muscle cells

Monocyte chemoattractant protein-1 (MCP-1, CCL2) is a mediator of inflammation that has been implicated in the pathogenesis of a wide variety of human diseases. CCR2, a heterotrimeric G-coupled receptor, is the only known receptor that functions at physiologic concentrations of MCP-1. Despite the importance of CCR2 in mediating MCP-1 responses, several recent studies have suggested that there may be another functional MCP-1 receptor. Using arterial smooth muscle cells (SMC) from CCR2(-/-) mice, we demonstrate that MCP-1 induces tissue-factor activity at physiologic concentrations. The induction of tissue factor by MCP-1 is blocked by pertussis toxin and 1,2-bis(O-aminophenyl-ethane-ethan)-N,N,N',N'-tetraacetic acid-acetoxymethyl ester, suggesting that signal transduction through the alternative receptor is G(alphai)-coupled and dependent on mobilization of intracellular Ca(2+). MCP-1 induces a time- and concentration-dependent phosphorylation of the mitogen-activated protein kinases p42/44. The induction of tissue factor activity by MCP-1 is blocked by PD98059, an inhibitor of p42/44 activation, but not by SB203580, a selective p38 inhibitor. These data establish that SMC possess an alternative MCP-1 receptor that signals at concentrations of MCP-1 that are similar to those that activate CCR2. This alternative receptor may be important in mediating some of the effects of MCP-1 in atherosclerotic arteries and in other inflammatory processes.     

动脉导管溶栓治疗急性肢体动脉栓塞14例分析

目的 探讨动脉导管溶栓治疗急性肢体动脉栓塞的方法和疗效。方法回顾性分析14例肢体动脉栓塞的诊断方法和介入手术治疗方案。结果治愈11例，治愈率78．6％(11／14)；2例好转。无患肢缺血坏死或截肢，无术后因肾功能衰竭死亡。结论动脉导管溶栓是治疗急性肢体动脉栓塞有效的方法，值得进一步开展和探索。     

乙型肝炎病毒前S1抗原检测及其临床意义

为探讨检测乙型肝炎病毒前S1抗原(Pre-S1Ag)的临床意义,本文对338例各型乙型肝炎患者进行Pre-S1Ag检测,同时检测HBV标志物和HBV-DNA,对其阳性率及相互关系进行分析比较.结果表明:338例患者,Pre-S1Ag阳性检测率为63.02%,HBeAg阳性检测率为48.52%,HBV-DNA阳性检测率为68.05%.Pre-S1Ag阳性与HBV-DNA阳性的符合率为78.56%;Pre-S1Ag与HBeAg阳性的符合率为81.17%;Pre-S1Ag与HBeAg、HBV-DNA具有显著相关性(P＜0.01),提示Pre-S1Ag能够较好地反映病毒复制状况,有可能作为体内病毒复制存在的实验室指标.