ASSOCIATION OF PLASMA HOMOCYSTEINE LEVEL AND N^5,N^10—METHYLENETETRAHYDROFOLATE REDUCTASE GENE POLYMORPHISM WITH CEREBRAL INFARCTION

OBJECTIVE: To investigate the relationship of plasma homocysteine (Hcy) level to stroke and genetic factor to elevated plasma Hcy level. METHODS: The plasma Hcy level was measured by capillary electrophoresis-ultraviolet detection and the gene polymorphism of N5,N10-methylenetetrahydrofolate reductase (MTHFR) was studied with PCR-RFLP assay in 43 patients with cortical cerebral infarction and 42 healthy control. RESULTS: The plasma Hcy level of the patients (19.3 +/- 6.0 micromol/L) was markedly higher than that of the controls (13.7 +/- 5.4 micromol/L) (t = 4.16, P < 0.001). There are 3 genotypes, C/C, C/T and T/T, about base-variation of MTHFR gene at locus 677. The plasma Hcy level of the subjects with T/T genotype was higher than that of subjects with other genotypes. However, the frequencies of each genotype and allele were not significantly different between the patients and the controls. CONCLUSIONS: The elevated plasma Hcy level is a risk factor for atherothrombotic cerebral infarction, and is related to the C-->T mutation at locus 677 of MTHFR gene.     

Cortical circumferential profile of SPECT cerebral perfusion in Alzheimer''s disease

We developed a semiautomatic method termed “cortical circumferential profiling” for objective analysis of cerebral cortex function in emission tomographic neuroimaging studies. This method treats cortex as a continuous ring near the outer brain edge. A computer algorithm samples the cortex at 60 contiguous, equiangular locations, using 1-cm² samples. These values are plotted as a function of cortical angle to produce the cortical circumferential profile. This method was used in a study of regional cerebral perfusion in 15 patients with Alzheimer's disease and 8 elderly control subjects using N-isopropyl [I-123]-iodoamphetamine. Cortical circumferential profiling decreases variability, examines the entire cortex within slices at preselected levels above the orbital-meatal line, and facilitates intrasubject and intersubject comparisons.     

醒脑静注射液对脑缺血再灌注小鼠记忆功能的保护作用

目的：观察醒脑静（XNJI）对脑缺血再灌注后小鼠记忆功能的保护作用。方法：采用暂时性阻断两侧颈总动脉的方法制备小鼠脑缺血再灌注损伤的模型。测试其被动回避能力，脑内抗氧化酶活性及小鼠断头喘气时间，结果：XNJI可延长脑缺血再灌注小鼠的避暗潜伏期，减少错误次数，并提高谷胱甘肽过氧化物酶（GSH-Px)的活性。延长小鼠断头喘气时间。结论：XNJI可明显减轻脑缺血再灌注导致的小鼠学习记忆功能障碍状态。其主要机制可能与抗氧化作用有关。     

住院脑血管病人主要照顾者负荷

目的 探讨影响住院脑血管病人主要照顾负荷的相关因素。方法采用问卷方式对1997年～2000年60名符合研究对象进行调查。结果脑血管病人的主要照顾中60％为配偶，且年龄较大，知识水平偏低，使其身体、心理、社交方面的负荷增大。同时发现雇用身体及心理压力明显低于家属，但两社交负荷无差异。结论临床护理人员应给予住院病人主要照顾一定的协助及指导，减轻家属的压力，使主要照顾能有效地承担起照顾责任。     

高温、亚低温对大鼠脑缺血再灌注损伤的作用及其机制研究

目的：研究轻度高温、亚低温对大鼠脑缺血再灌注损伤组织兴奋性氨基酸（EAA）与氧自由基的相互关系及病理损伤程度的影响。方法：60只Wistar大鼠按不同脑温条件随机分为生化组（n=28）和病理组（n=32)，采用改良Nagasawa局灶脑缺血再灌注模型，观察脑缺血再灌注损伤组织谷氨酸（Glu），超氧化物歧化酶（SOD）、丙二醛（MDA）的变化及光镜，电镜下的病理变化。结果：轻度高温明显加重常温脑缺血再灌注损伤组织Glu、MDA的升高（P＜0．01）及SOD的下降（P＜0．05），加重常温脑缺血再灌注组织病理损伤程度，亚低温的作用则相反，结论：轻度高温可能通过同时促进EAA合成，释放和氧自由基生成系统活化，造成大鼠脑缺血再灌注损组织损伤加重；亚低温可能通过同时抑制EAA合成，释放和氧自由基生成系统活化，减轻大鼠脑缺血再灌注组织损伤程度，对大鼠脑缺血再灌注损伤组织起保护作用。     

^1H-magnetic resonance spectroscopy screening for animals with acute cerebral infraction suitable forthrombolytic therapy

BACKGROUND: As a non-invasive technique which can provide comprehensive biological information, 1H-magnetic resonance spectroscopy (1H-MRS) may provide valuable reference data for irreversible recovery or reversible changes in ischemic tissue after stroke. OBJECTIVE: To monitor and evaluate the effect of the urokinase thrombolytic therapy after experimental acute cerebral ischemia by 1H-MRS technology and investigate its adaptability. DESIGN: Randomly controlled animal study. SETTINGS: Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom & Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science. MATERIALS: Eleven healthy adult Sprague-Dawley (SD) rats, weighing 260–300 g and of both genders, were supplied by Experimental Animal Center of Tongji Medical Collage, Huazhong University of Science and Technology [SCXK (e) 2004-007]. 4.7T superconducting nuclear magnetic resonance meter was provided by Brucker Company. METHODS: The experiment was carried out in Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom & Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science from August 2003 to December 2005. ① The rats were randomly divided into 30-minute self-thrombo-embolism group (n =6) and 60-minute self-thrombo-embolism group (n =5). Six rats in 30-minute self-thrombo-embolism group were occluded with clot embolus for 30 minutes and 5 rats in 60-minute self-thrombo-embolism group were occluded for 60 minutes. 10 000 U/kg urokinase was dissolved in 2 mL saline and the operation lasted for 5 minutes. ② 1H-MRS was performed before thrombolysis and at 3 hours and 24 hours after successful embolization. The metabolic changes of N-acetyl-L-aspartic acid (NAA)/phosphocreatine (PCr) + creatine (Cr), choline phosphate (Cho)/PCr+Cr and lactic acid (Lac)/PCr+Cr in the region of interests were analyzed. ③ The T2W image was conducted 24 hours after the thrombolytic therapy with TR=500 ms and TE=25 ms. ④ The subjects were sacrificed immediately after 1H-MRS and the brain tissues were cut into pieces and stained with HE method; in addition, pathological changes were observed under optic microscope. MAIN OUTCOME MEASURES: ① Metabolic changes of NAA/PCr+Cr, Cho/PCr+Cr and Lac/PCr+Cr in the region of interests; ② T2W image at 24 hours after the thrombolysis; ③ pathological observation of brain tissue. RESULTS: Eleven rats were all involved in the final analysis. ① Metabolic changes in the region of interests : In 30-minute self-thrombo-embolism group, the Lac peak emerged immediately after the embolism, but the ischemic zone decreased 3 hours after the thrombolytic therapy (0.252±0.01, 0.603±0.01, P < 0.01). Lac/(PCr+Cr) ratio was 0.290±0.01 at 24 hours after thrombolysis, which was higher than that at 3 hours after thrombolysis (P < 0.01). The NAA/ (PCr+Cr) ratio decreased significantly at 3 hours after the thrombolysis as compared with that before thrombolysis (0.922±0.16, 1.196±0.01, P < 0.05). In 60-minute self-thrombo-embolism group, the Lac/(PCr+Cr) ratio was higher at 3 hours after thrombolysis than that before thrombolysis (0.846±0.12, 0.601±0.11, P < 0.05) and the NAA/(PCr+Cr) decreased at 3 hours after the embolism. Fluctuation of NAA/ (PCr+Cr) ranged from 0.68 to 0.75 before thrombolysis and from 0.71 to 0.75 at 3 hours after thrombolysis. ② T2W image: T2W image showed that 2 subjects in 30-minute self-thrombo-embolism group whose Lac/NAA was higher than 0.7 suffered from intracranial hemorrhage. This meant that the subjects with Lac/NAA > 0.7 were more likely to suffer from intracranial hemorrhage. ③ Histological and morphological examinations: Optic microscope demonstrated that interspace surrounding nerve cells was widened at ischemic center; neurons were swelling; nucleus was stained lightly; pyknosis and mesenchymal edema were mainly observed in lateral cortex of brow and vertex and in lateral part of corpus striatum. CONCLUSION: ①Compound parameters in ischemic area before thrombolysis should be regarded as an important predicting marker for thrombolytic therapy, effect evaluation and termination. ② 1H-MRS combining with other imaging technique is a detecting way for screening cases who are suitable for thrombolytic therapy.     

缺氧诱导因子-lα与脑缺氧缺血性损伤

缺氧诱导因子-lα（hypoxia-inducible factor-1alpha，HIF-lα）是近来发现的广泛存在于哺乳动物和人体内的一种缺氧应答调控因子，在调节缺氧诱导的基因表达中起关键性作用。它可调节表达多种靶基因如血管内皮生长因子、促红细胞生成素等，对改善脑缺氧缺血后能量代谢障碍、促进脑血流动力学恢复、抑制兴奋性氨基酸毒性、减少细胞凋亡等起重要作用。通过进一步对HIF-lα及其靶基因的研究，可能为临床治疗脑缺氧缺血性损伤提供了一种新的治疗策略。