自身免疫甲状腺病循环和甲状腺内细胞毒性T细胞(T_8/S_6F_1)的实验研究

应用新型单克隆抗体T_8/S_6F_1和流体细胞测定仪双色荧光程序检测了15例Graves病和8例Hashimoto甲状腺炎患者循环和甲状腺内的细胞毒性T细胞(cytotoxic T ceils,Tc)的分布。传统的单克隆抗体CD_8(OKT_8或Leu_2)仅能检测含有两个次亚群——抑制性T细胞(Ts)和细胞毒性T细胞(Tc)的Ts/TcT细胞亚群,不能将它们区别开来。本文应用的单克隆抗体T_8/S-6F_1首次能够单独测定Tc亚群。Graves病和Hashimoto甲状腺炎患者的循环Tc亚群分别为27.6±11.2％和27.5％±12.2％,与正常对照组差异无显著性。两组患者甲状腺内的Tc亚群数目也未见增加。Graves病患者甲状腺内Te细胞为16.45±4.7％。本文结果提示:AITD患者循环内和甲状腺内的细胞毒性T细胞亚群的数目未见增加。     

Magnetic resonance imaging of prosthetic heart valves

To evaluate the safety of magnetic resonance (MR) imaging of prosthetic heart valves, nine different synthetic and tissue valves were studied ex vivo. Deflection was measured in 0.35-tesla (T) and 1.5-T superconducting magnets and at the edge of the bore of a 2.35-T electromagnet in field gradients of 5, 1.1, and 6.3 mT/cm, respectively. No valve deflected in the 0.35-T magnet; six synthetic valves deflected 0.25 degrees-3 degrees in the 1.5-T magnet; all valves deflected 1 degree-27 degrees at the edge of the 2.35-T magnet. Each valve was then submerged in a vial of water and the temperature was measured immediately before and after each of two spin-echo imaging sequences in the two superconducting magnets. No significant temperature rise followed exposure in either magnet. Image distortion varied from negligible to severe in both imagers; magnitude of distortion paralleled magnitude of deflection. These data suggest that patients with present-day prosthetic heart valves can be safely imaged in present-day MR imagers and that prosthesis-induced artifacts will not interfere with interpretation in most instances.     

A computerized method for rapid quantification of gallbladder volume from real-time sonograms

A computerized method that requires only 1-2 minutes to quantify gallbladder volume from real-time sonograms is described. This time is considerably shorter than that required using the hand-calculation method. There was a highly significant correlation between gallbladder volumes calculated by computer and hand (r = 0.97; P less than .001).     

ECG-synchronized cardiac MR imaging: method and evaluation

An electrocardiographic (ECG) sensing and gating device compatible with a 0.35-tesla (T) magnetic resonance (MR) imager has been developed and used to produce 802 MR images of the heart in 30 patients. The instrument consists of an isolated acquisition module, an electrically floating preamplifier, and a monitor gating module. Two spin-echo images were acquired for each of five, 0.7-cm thick, transaxial sections from the base to the apex of the heart during each ECG-synchronized imaging run. Image quality was assessed in a blind study by two investigators, on a scale from 0 to 3, as diagnostic [2-3] or nondiagnostic [0-1]. There was agreement in 91.4% of their assessments of diagnostic images (68.1% of the images studied). Resolution of heart anatomy on the MR images was adversely affected by prolonged spin-echo time delay, imaging in late diastole, image acquisition at the cardiac apex, irregular triggering, and artifacts. The synchronization of gradient pulses to the ECG at 0.35 T appears safe for patients, permits diagnostic resolution of images, allows image acquisition at distinct points during the cardiac cycle, and enables monitoring of patients during imaging.     

一氧化氮的脊髓作用对局麻药耐药反应的影响

目的 探讨一氧化氮（NO）在脊髓的作用与局麻药外围神经阻滞耐药的关系。方法 ①鼠随机分为3组，组1腹腔和蛛网膜下腔注射生理盐水（NS），组2接受NS腹腔和5个剂量之一的L－NAME蛛网膜下腔给药，组3接受5个测量之一的L－NAME腹腔和NS蛛网膜下腔注射。L－NAME剂量是1，10，100，1000，10000nmol(n=9)；②蛛网膜下腔注射NS，L－NAME或D－NMAE 1000nmol(n=9).③蛛网膜下腔注射NS，精氨酸25μmol跟 随L－NAME1000nmol或NS（n=9)。随后用3％氯普鲁卡因0．3ml依次3次阻滞鼠坐骨神经，用热板、触觉复位、单足跳和肌力测试记录阻滞时间。结果 L－NAME蛛网膜下腔和腹腔给药阻止局麻药耐药的作用与剂量有关，蛛网膜下腔ED50明显低于腹腔ED50比率超过20倍。D－NAME对局麻耐药无显著影响（P＞0．05），精氨酸显著增加局麻药耐药（P＜0．05）并抑制L－NAME抗耐药的作用。结论 该实验表明L－NAME通过NO脊髓受体作用抑制局麻药耐药反应的发生。     

Murine JAK3 is preferentially expressed in hematopoietic tissues and lymphocyte precursor cells

To elucidate the role of cytokine receptor signal transduction in T- cell development, we have investigated the expression pattern and biochemical characteristics of the murine Janus family tyrosine kinase, JAK3. Previous studies have shown that JAK3 is expressed in lymphoid and myeloid tumor cell lines and in a small number of lymphoid tissues. To further characterize JAK3 expression, we used a quantitative polymerase chain reaction approach to compare JAK3 mRNA levels at multiple stages of T-cell differentiation and in a broad range of mouse tissues. These studies, in conjunction with analyses of JAK3 protein expression, show that the highest levels of JAK3 are in adult, 2-week- old, and fetal thymus, followed by somewhat lower levels in bone marrow, spleen, fetal liver, and adult CD4-CD8- thymocytes. We also show that different forms of JAK3 mRNA arise by alternative splicing. Finally, our biochemical studies show that the JAK3 kinase domain, but not the pseudo-kinase domain, has tyrosine kinase activity and, furthermore, that JAK3 kinase activity is abolished by an amino acid substitution of the conserved lysine in the kinase domain (K851R). These studies show that JAK3 expression is profoundly skewed to hematopoietic and lymphoid precursor cells, strongly suggesting a role for JAK3 in hematopoiesis and T- and B-cell development.