脊髓前动脉损伤致脊髓缺血性损伤模型的MRI评价

目的：研究经脊髓前动脉损伤，致脊髓缺血性损伤模型的高场强MRI信号表现特征。方法：选用12只家犬经颈前手术入路，切断脊髓前动脉，经高场强MRI扫描，对照病理分析脊髓前动脉损伤后脊髓的MRI信号变化特征。结果：脊髓前动脉损伤后脊髓MRI表现出异常T2WI高信号，且出现在脊髓前动脉损伤节段的前2／3，多表现为一例受累及或偏向一例。结论：MRI能确定脊髓缺血性损伤的部位及信号特征。     

High-dose contrast-enhanced computed tomography (CECT) with iopamidol in the detection of cerebral metastases

Summary Intravenously admistered iodinated contrast media have been demostrated, since early experience with computed tomography of the brain, to improve clinical value of the procedure for detecting intracranial lesions. There is no universal agreement about the amount and the method of administration of the contrast medium. Many authors maintain that the use of large doses gives better results for the diagnosis of tumors and metastases. The purpose of this paper is to evaluate the tolerance of iopamidol administered by rapid intravenous infusion in a large number of patients undergoing contrast enhanced computed tomography to detect brain metastases. The authors examined 969 consecutive adult patients suffering from lung cancer, brain metastases have been detected in 17% of cases. Adverse reactions to contrast media occurred in 3 patients. Non ionic contrast media are recommended in this diagnostic procedure.     

High-frequency ventilation (HFV) in hyaline membrane disease —a preliminary report

Eight premature babies affected by hyaline membrane disease and needing mechanical respiratory support were ventilated by means of a VDR 1 (Bird Space Technology) respirator at 10 Hz during a mean time of 51 h. Before HFV 7 infants had been on conventional mechanical ventilation (CMV) and one on nasal CPAP. The values of mean airway pressure (MAP) and oxygenation index (PaO₂/FIO₂) on CMV and HFV were (mean and range): 1. CMV: MAP 15 (4–29) mm Hg, ox. index 15.47 (5.07–23.19) kPa; 2. HFV after 1 h: MAP 15 (10–19) mm Hg, ox. index 24.13 (9.07–46.12) kPa. Improved oxygenation allowed rapid reduction of FIO₂ in the following hours. Only 3 infants were weaned directly from VDR 1, 5 were switched back to CMV mainly because of technical failures of the respirator. The change from HFV to CMV was associated with a fall of PaO₂/FIO₂ from 35.99 (15.86–74.52) to 22.39 (7.33–31.46) kPa. The mean time of artificial ventilation (CMV+HFV) was 121 h (range 46–166). Except for 1 pneumothorax no medical complications were seen during HFV, and all patients survived. Despite impressive improvements in oxygenation it is cautioned against the use of the VDR 1 because of the high incidence of technical problems.     

Route of lymphocyte migration through the high endothelial venule (HEV) in human palatine tonsil

Eleven palatine tonsils were collected from subjects who underwent tonsillectomy in Christian Medical College Hospital and the route of migration of lymphocytes through the high endothelial vessel was studied under EM. In the interendothelial route, migration of a lymphocyte through HEV wall began with the adhesion of a lymphocyte to the surface of endothelial cells by means of a short cytoplasmic projection in the vicinity of intercellular space. The projection extended into the cleft between adjacent endothelial cells. The lymphocyte migrated through HEV by diapedesis. After the lymphocyte had traversed the interendothelial space, it occupied the subendothelial space. In the transendothelial route, migration of a lymphocyte through HEV was initiated by adherence of the lymphocyte to the endothelial cell. The adherent lymphocyte compressed or invaginated into the cytoplasm of the endothelial cell, entered the endothelial cell, was completely enclosed within the endothelial cell cytoplasm, and emerged from the endothelial cell to occupy the subendothelial space. Evidence is presented from static transmission electron microscopic pictures for the migration of lymphocytes by both interendothelial and transendothelial routes through the high endothelial venule.     

Loading anticancer drugs into HDL as well as LDL has little affect on properties of complexes and enhances cytotoxicity to human carcinoma cells

Low density lipoprotein (LDL) has been found to represent a suitable carrier for cytotoxic drugs that may target them to cancer. This study investigated whether very low density lipoprotein (VLDL), LDL and high density lipoprotein (HDL) can be used to effectively incorporate four cytotoxic drugs, 5-fluorouracil (5-FU), 5-iododeoxyuridine (IUdR), doxorubicin (Dox) and vindesine; characterized the complexes; and examined the effect of incorporation on drug cytotoxicity against HeLa cervical and MCF-7 breast carcinoma cells. Significant drug loading was achieved into all three classes of lipoproteins, consistent with the sizes and hydrophobicity of the drugs. The relative loading efficiency was found to be vindesine>IUdR>Dox>5-FU for all three classes of lipoproteins. As shown by electron microscopy (EM), drug incorporation did not affect the size or morphology of the lipoproteins. Differential scanning calorimetry (DSC) showed that drug loading did not significantly change the thermal transition temperature of core lipids in the lipoproteins. The transition enthalpy was changed only for LDL–Dox and LDL–vindesine. The drugs remained stable in the lipoproteins as determined by high performance liquid chromatography (HPLC). EM, DSC and HPLC data suggest that drugs were incorporated into lipoproteins without disrupting their integrity and drugs remained in their stable forms inside lipoproteins. Compared with free drugs in cytotoxicity assays, the IC₅₀ values of LDL– and HDL–drug complexes were significantly lower (2.4- to 8.6-fold for LDL complexes and 2.5- to 23-fold for HDL complexes). All free or lipoprotein-bound drug formulations were comparably more cytotoxic against MCF-7 than HeLa cells. Upregulating the lipoprotein receptors enhanced, and downregulating them inhibited, the cytotoxicity, indicating the mechanistic involvement of lipoprotein receptor pathways. Complexes of all four drugs with VLDL, in contrast to LDL and HDL, had the same cytotoxicity as the four corresponding free drugs. Our results suggest that further studies are required of the potential of HDL to be a cancer targeting drug carrier.     

高能聚焦超声刀联合氟脲嘧啶、四氢叶酸治疗晚期胰腺癌临床疗效观察

目的探讨高能聚焦超声刀加氟脲嘧啶、四氢叶酸治疗晚期胰腺癌临床疗效及毒副作用。方法30例经病理学或细胞学确诊的晚期胰腺癌病人先用高能聚焦超声刀(HIFU)治疗，再予氟脲嘧啶、四氢叶酸联合化疗。氟脲嘧啶500mg／m^2加入5％GNS500ml静滴持续6小时以每天1次连用5天，CF(四氢叶酸)100mg／m^2加入生理盐水250ml静滴每天1次连用5天，28天为1周期，至少治疗2个周期。结果CR1例；PR9例；MR9例；NC5例；PD6例。总有效率63％。毒副作用主要消化道反应，其他副作用轻微。结论应用HIFU局部治疗胰腺癌同时合用四氢叶酸加氟脲嘧啶全身化疗近期疗效提高明显，止痛明显达75％，副反应小，值得应用。     

眼球孤立性脉络膜血管瘤的HR-MRI表现

目的　探讨眼球孤立性脉络膜血管瘤的高分辨率磁共振 (HR MRI)影像学特征 ,进一步提高诊断水平。资料与方法　回顾性分析诊断明确的孤立性脉络膜血管瘤 16例共计 17个病灶的位置、数目、形态、大小、MRI信号、强化情况、有无合并视网膜脱离及有无视神经和眼外侵犯等。所有病例均行HR MRI及增强扫描 ,部分病例行脂肪抑制。结果　 17个病灶中的 16个呈扁丘状位于眼球内壁的后极。 15个病灶厚度 <5mm ,平均厚度为2 .9mm。病灶边缘清晰 ,T1WI上呈轻度高信号者 16个 ,T2 WI上呈等信号者 15个 ,增强扫描显著强化者有 12个。 3例合并视网膜脱离 ,在T2 WI上多呈等信号 ,T1WI上呈轻度高信号者 ,均无强化。无视神经及眼外侵犯病例。结论　 94 %孤立性脉络膜血管瘤的HR MRI表现具有特征性 ,表现为位于眼球内壁后极的较小、基底较宽、边缘清晰的扁丘状病灶。其T1WI信号高于玻璃体 ,T2 WI信号等于玻璃体 ,增强扫描瘤体显著强化。明确其HR MRI影像学特征有助于临床与恶性葡萄膜黑色素瘤相鉴别 ,避免不必要的眼球摘除     

噪声中EP信号的提取算法及研究进展

诱发电位的提取是脑电信号处理领域的前沿课题近年来 ,通过少次甚至单次试验提取诱发电位已经成为研究的主流。本文对近年来提取诱发电位的信号处理方法进行了简要的回顾 ,并分别从小波变换、神经网络、高阶累积量、独立分量分析等四个方面对算法进行了介绍     

急性脑出血患者血清谷氨酸动态变化分析

目的通过观察脑出血（intracerebral hemorrhage，ICH）患者血清中谷氨酸的动态变化来进一步评价谷氨酸对脑出血的作用。方法选择符合条件的30例急性高血压脑实质出血患者，给予神经内科脑出血常规治疗，采用高效液相色谱法检测起病后2d内、5．6d、8-9d和15．16d的血清谷氨酸浓度，同步进行神经功能评定，同时于发病后1．3d、d5-6d及d15．16行头部CT检查了解血肿体积大小。结果脑出血患者血中谷氨酸浓度与血肿体积及神经功能缺损评分之间呈正的直线相关。经治疗后，所有病例谷氨酸水平迅速下降，在5-6d和8—9d下降速度更加明显。结论谷氨酸可能参与了自发性脑出血患者的急性期脑损伤作用。     

高压液相色谱纯化肾综合征出血热病毒血凝素及其性状分析

用吐温８０－乙醚（ＴＥ）法、蔗糖－丙酮（ＳＡ）法、丙酮－乙醚（ＡＥ）法分别从肾综合征出血热病毒（ＨＦＲＳＶ）感染的Ｖｅｒｏ－Ｅ６细胞培养和乳小白鼠脑组织中制备病毒血凝素（ＨＡＮ），定量对比证明其制备效果，结果无明显差异。粗制ＨＡＮ经高压液相色谱（ＥＰＬＣ）纯化，有４个洗脱峰，血凝活性物质存在于峰１。纯化ＨＡＮ在ＳＤＳ－ＰＡＧＥ中呈单一区带，分子量５６．６ＫＤ，ＨＡＮ相对含量７９．６％。纯化ＨＡＮ在蔗糖密度梯度液中有一条１．１５～１．１６ｇ／ｃｍ３的沉淀，粗制ＨＡＮ有３条沉淀。电镜观察纯化ＨＡＮ中为大小相等的球状颗粒。粗制ＨＡＮ的高密度沉淀中可见到病样颗粒。对几种常用消毒剂、氧化剂、去垢剂对ＨＡＮ的灭活作用做了实验对比观察。