血浆同型半胱氨酸及其酶基因多态性与老年脑梗死的关系

目的探讨血浆同型半胱氨酸(Hcy)及其代谢酶N~(5,10-)亚甲基四氢叶酸还原酶(MTHFR)和胱硫醚β合成酶(CBS)基因多态性与老年脑梗死的关系。方法应用高效液相色谱荧光法、聚合酶链限制性内切酶片段长度多态性分析和扩增阻滞突变体系法对61例首次发病的老年脑梗死患者和57例对照者血浆Hcy浓度、MTHFR及CBS基因型进行检测。结果脑梗死组血浆Hcy浓度[(13·07±3·96)μmol/L]显著高于对照组[(11·51±3·90)μmol/L](P<0·05);两组间基因型分布、纯合子频率和等位基因频率无差异;血浆Hcy浓度在MTHFR C677T、CBS G919A、CBS T833C各突变位点的纯合子、杂合子和野生型间差异无显著性;Logistic多元回归及相关分析表明血浆Hcy浓度升高是脑梗死的独立危险因素。结论老年患者MTHFR和CBS基因突变不产生高Hcy血症;血浆Hcy浓度升高是老年脑梗死的独立危险因素;单纯MTHFR和CBS突变不能被确定为老年脑梗死的独立遗传危险因素。     

血浆同型半胱氨酸水平及N5,N10-亚甲四氢叶酸还原酶基因多态性与老年期抑郁症的关联研究

目的探讨血浆同型半胱氨酸(Hcy)水平及N5,N10-亚甲四氢叶酸还原酶(MTHFR)基因多态性与老年期抑郁症发病的关系.方法采用毛细管电泳-紫外检测法、聚合酶链反应-限制性片段长度多态性技术测定60例老年期抑郁症患者(抑郁症组)和80名正常人(对照组)的血浆总Hcy水平和MTHFR基因多态性.患者入组时评定汉密尔顿抑郁量表(HAMD),治疗第6周末评定疗效(HAMD减分率≥50%为有效,<50%为无效).结果 (1)抑郁症组的血浆Hcy水平[(17±6)μmol/L]明显高于对照组[(12±4)μmol/L],差异有统计学意义(P<0.01).<60岁首次发病(以下简称首发)患者(n=30)的血浆Hcy水平[(16±5)μmol/L]与≥60岁首发患者[n=30,(19±6)μmol/L]的差异无统计学意义(P>0.05);单次发作患者(n=17)的血浆Hcy水平[(18±6)μmol/L]与反复发作患者[n=43,(17±5)μmol/L]的差异无统计学意义(P>0.05);伴心脑血管疾病患者(n=27)的血浆Hcy水平[(19±6)μmol/L]与不伴心脑血管疾病患者[n=33,(16±5)μmol/L]的差异无统计学意义(P>0.05);治疗有效患者(n=40)的血浆Hcy水平[(18±5)μmol/L]与治疗无效患者 [n=20,(17±6)μmol/L]的差异无统计学意义(P>0.05).(2)抑郁症组治疗前后HAMD评分的减分率与血浆Hcy水平无显著相关性(P>0.05).(3)MTHFR C677T基因型有3种,即纯合子突变型(T/T)、杂合子突变型(T/C)和野生型(C/C).抑郁症组的基因型及等位基因频率与对照组比较,差异均无统计学意义(P>0.05).抑郁症组患者的首发年龄、发病次数、是否伴发心脑血管疾病及抗抑郁药治疗第6周末的疗效与MTHFR C677T基因型分布均无关联(P>0.05).(4)不同基因型的受试者(不论是抑郁症组还是对照组)血浆Hcy水平的差异无统计学意义(P>0.05).结论血浆Hcy水平升高可能是老年期抑郁症发病的一个独立危险因素.     

脑血栓形成与亚甲基四氢叶酸还原酶基因多态性的关系

目的　探讨中国汉族人群脑血栓形成与亚甲基四氢叶酸还原酶 (MTHFR)基因多态性及血浆同型半胱氨酸 (Hcy)水平的关系。 方法　利用聚合酶链反应 限制性内切酶长度多态性 (PCR RFLP)方法分析脑血栓形成患者 (75例 )与健康人群 (62名 )的MTHFR基因突变的情况。采用高效液相色谱法测定血浆Hcy水平 ,并加以对照分析。 结果　脑血栓形成组与对照组MTHFR基因型频率CC、CT、TT型分别为 0 41、0 35、0 2 4及 0 58、0 2 3、0 1 9,两组相比差异无显著意义 (P =0 1 37)。患者组与对照组MTHFR的T等位基因频率分别为 0 41和 0 31 ,两组相比差异无显著意义 (P =0 0 67)。脑血栓形成组与对照组血浆Hcy水平分别为 (1 8 3± 7 2 ) μmol/L与 (1 3 6± 5 8)μmol/L ,二者比较差异有显著意义 (P <0 0 0 1 )。两组中MTHFR基因TT型者Hcy水平与CC型比较差异有显著意义 (P <0 0 5) ,Hcy水平与叶酸呈负相关 (患者组 :r =- 0 31 ,P <0 0 1 ;对照组 :r =- 0 2 8,P <0 0 5)。结论　血浆Hcy水平升高是脑血栓形成的危险因素之一 ,MTHFR基因突变可能是血浆Hcy升高的主要影响因素     

亚甲基四氢叶酸还原酶(MTHFR)C677T基因多态性与血管性认知功能障碍相关性的研究

目的 探讨亚甲基四氢叶酸还原酶(MTHFR) C677T突变基因与血管性认知功能障碍(VCI)的关系.方法 采用酶联免疫法测定血浆同型半胱氨酸(Hcy)浓度,应用聚合酶链反应-限制性内切酶片段长度多态性技术检测143例VCI患者、122例无认知损害脑梗死患者及140例正常对照的MTHFR C677T基因型.结果 (1)VCI组、脑梗死组和对照组的血浆同型半胱氨酸(Hcy)平均水平分别为(12.257±3.595) μmol/L、(11.028 ±3.198)μmol/L、(9.784±3.074) μmol/L,两病例组Hcy水平明显高于正常对照组(P＜0.05);(2)3组研究对象的TT基因型分布有明显差异(x2=19.464,P＜0.01),CT型及CC型分布无差异(P＞0.05);VCI组及脑梗死组的T等位基因发生频率明显高于正常对照组(P＜0.05),相对危险度分别为1.79和1.47;(3)VCI组、脑梗死组及正常对照组中,MTHFR基因有C677T突变者(尤其TT型者)血浆Hcy水平均显著高于无基因突变者.结论 血浆Hcy水平升高是VCI和脑梗死共同的致病基础;MTHFR C677T基因突变致血浆Hcy水平升高可能是VCI发病的重要遗传因素.     

血浆同型半胱氨酸水平及MTHFR基因多态性与中青年脑卒中的相关研究

目的探讨中青年脑卒中与血浆同型半胱氨酸(homocysteine Hcy)水平及亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase MTHFR)基因多态性的关系.方法利用多聚酶链反应-限制性内切酶片段长度多态性技术(PCR-PFLP)分析73例中青年脑卒中患者及134例老年脑卒中患者与27例中青年及38例老年正常对照人群MTHFR基因突变情况,并应用高效液相色谱(HPLC)法检测其血浆Hcy水平、放射免疫法测定叶酸、VitB2水平加以对照分析.结果中青年脑卒中组血浆Hcy水平(22.36±10.99μmol/L)及老年脑卒中组血浆Hcy水平(19.41±10.32μmol/L)均高于各自对照组(11.49±5.05μmol/L)及(12.26±5.24μmol/L),差异有显著性(P＜0.01),且中青年脑卒中组中血浆Hcy升高的比例(58%)显著高于老年脑卒中组(43%)(x2=4.69,P＜0.05).MTHFR有三种基因型,中青年脑卒中组及对照组C/C型C/T型T/T型分别为(0.25、0.44、0.31)及(0.52、0.32、0.16),两组相比差异有显著性(x2=8.51,P＜0.05);而老年脑卒中组及对照组分别为(0.35、0.46、0.19)及(0.52、0.32、0.16),两组相比无显著差异(x2=3.96,P＞0.05).各组MTHFR的T/T基因型血浆Hcy水平与C/C型比较有显著差异(P＜0.01),两脑卒中组MTHFR的C/T基因型血浆Hcy水平与C/C型比较也有显著差异(P＜0.05),且叶酸VitB12水平较各自对照组显著下降(P＜0.01),老年脑卒中组较中青年组叶酸水平降低更显著(P＜0.05).结论血浆Hcy水平升高是脑血管病的重要危险因索,MTHFR基因突变及叶酸VitB12变化均是血浆Hcy升高的重要影响因素,对于中青年患者意义更大.     

血浆同型半胱氨酸水平与Binswanger病的分析

目的探讨血浆同型半胱氨酸(Hcy)水平与Binswanger病(BD)的关系。方法应用荧光极化免疫法测定50例BD患者和53例健康体检者(健康对照组)的血浆Hcy水平,采用相关统计学方法进行分析。结果 BD组患者血浆Hcy水平(19.84±7.26)μmol/L,显著高于健康对照组的(15.00±5.76)μmol/L(P<0.01)。结论高Hcy血症可能参与了BD的发病过程。     

MTHFR基因多态性及同型半胱氨酸与青年脑血管病的关系

目的:研究Ns,N10-亚甲基四氢叶酸还原酶(MTHFR)基因多态性及血浆同型半胱氨酸(Hcy)水平与青年脑血管病的关系。方法:研究对比40例青年脑血管病患者(首次发病年龄≤50岁)及32例健康青年人的MTHFR基因多态性及血浆Hcy水平。结果:(1)对照组及病例组T/T纯合子率分别为37.5％和22.5％;T等位基因频率分别为60.9％和51.3％,差异均无显著统计意义(均P>0.05)。(2)病例组血浆Hcy几何均值(11.0±2.3μmol/L)显著高于对照组(8.0±1.4μmol/L,P<0.05)。(3)所有受试者中T/T组Hcy值高于C/C组(10.4μmol/L和7.6μmol/L),但差异无显著性(P>0.05)。结合叶酸考虑,进一步将所有受试者按叶酸中位数水平分组。叶酸中位数以下组中,T/T组Hcy值显著高于C/C组(P<0.05);而叶酸中位数以上组中,T/T组Hcy值与C/C组无显著差异。(4)血浆Hcy与叶酸、维生素B12呈显著负相关,与肌酐呈显著正相关。吸烟者血浆Hcy水平显著高于不吸烟者(P<0.05)。结论:(1)本组人群MTHFR基因C677T突变的纯合子在低叶酸状态下可引起血浆Hcy水平显著增高,但与青年脑血管病无显著关系。MTHFR基因677TT纯合突变可能为健康青年人脑血管的保护因素。(2)血浆Hcy水平与青年脑血管病的发生密切相关。(3)叶酸、维生素B12肌酐、吸烟是Hcy的非遗传影响因素。     

血浆同型半胱氨酸水平及其代谢酶基因多态性与脑梗死的关系

目的　探讨血浆同型半胱氨酸 (Hcy)水平、5 ,10 亚甲基四氢叶酸还原酶 (MTHFR)和胱硫醚 β合成酶 (CBS)基因多态性与脑梗死的关系。 方法　用高效液相色谱仪HPLC FD法和PCR 限制性内切酶片段长度多态性分析及扩增阻滞突变体系法检测 87例动脉粥样硬化性血栓性脑梗死患者和 80例对照者血浆Hcy浓度和MTHFR及CBS基因型。 结果　病例组和对照组平均空腹血浆Hcy浓度分别为 (15 3± 4 3) μmol/L和 (11 3± 3 9) μmol/L ,差异有显著意义 (P <0 0 0 1) ;两组基因型分布、纯合子突变率及等位基因频率差异无显著意义 ;血浆Hcy浓度与MTHFR基因型、CBSG919A基因型、CBST833C基因型、性别和血浆肌酐浓度相关。结论　血浆Hcy浓度升高是脑梗死的独立危险因素 ,单纯的MTHFR和CBS突变并非脑梗死的危险因素。     

胱硫醚β合酶基因T833C多态及血浆同型半胱氨酸水平与缺血性脑血管病的相关性

目的 探讨血浆同型半胱氨酸(Hcy)水平、胱硫醚β合酶(CBS)基因T833C多态与缺血性脑血管病(ICVD)的相关性.方法 应用高效液相色谱仪-FD法和扩增阻滞突变体系法(ARMS)检测360例ICVD患者和210名健康体检者的血浆Hcy水平和CBS T833C基因型,并进行相关分析.结果 ICVD组和对照组空腹血浆Hcy浓度分别为(17.6±4.8)μmol/L和(13.3±4.3)μmol/L,差异有统计学意义(t=10.716,P<0.05).ICVD组CBS基因第833位点T/T、T/C、C/C和基因型频率与对照组比较差异无统计学意义(χ2=o.785,P>0.05),C等位基因频率与对照组差异也无统计学意义(χ2=0.941,P>0.05).ICVD组各亚组CBS基因第833位点T/T和T/C+C/C基因型频率比较差异无统计学意义(χ2=1.691,P>0.05),C等位基因频率比较差异也无统计学意义(χ2=1.617,P>0.05).CBS T833C不同基因型之间血浆Hcy水平不同(F=6.56,P<0.05),TC、CC基因型组血浆Hcy水平明显高于TT基因型组,TC、CC基因型组间血浆Hcy水平差异无统计学意义.结论 血浆Hcy水平升高可能为ICVD的危险因素,CBS T833C基因多态可能不是ICVD的独立危险因子.     

缺血性青年脑卒中脑动脉狭窄与血浆HCY水平及MTHFR C677T基因多态性的相关性研究

目的研究缺血性青年脑卒中脑动脉狭窄与同型半胱氨酸(HCY)的水平及亚甲基四氢叶酸还原酶(MTHFR) C677T基因多态性的关系。方法在吉林大学中日联谊医院神经内科二病区随机选取缺血性青年脑卒中的住院患者50例,其中符合纳入标准的41例,根据有无脑血管狭窄分为狭窄组(20例)及非狭窄组(21例),分别对其血浆HCY的水平及MTHFR C677T基因多态性进行测定并进行统计学分析。结果在41例患者中HCY的水平CC基因型(10. 61±2. 66)μmol/L低于TT基因型(19. 65±14. 43)μmol/L(P=0. 033)及CT+TT基因型(16. 65±12. 48)μmol/L(P=0. 015)。脑动脉狭窄组与非狭窄组HCY的水平分别为(20. 44±14. 70)μmol/L、(11. 03±4. 40)μmol/L(P=0. 012);其中狭窄组HCY的水平CC基因型(12. 23±2. 18)μmol/L低于TT基因型为(28. 55±16. 82)μmol/L(P=0. 043)及CT+TT基因型(22. 48±15. 82)μmol/L(P=0. 023);非狭窄组的HCY水平CC基因型(8. 46±1. 40)μmol/L低于TT基因型为(11. 86±5. 0)μmol/L(P=0. 161)及CC+TT基因型(11. 46±4. 60)μmol/L(P=0. 048);两组同一基因型HCY的水平TT基因型分别为(28. 55±16. 82)μmol/L、(11. 86±5. 02)μmol/L(P=0. 040),CC基因型分别为(12. 23±2. 18)μmol/L,(8. 46±1. 40)μmol/L(P=0. 049),CT基因型分别为(17. 77±14. 12)μmol/L、(11. 14±4. 48)μmol/L(P=0. 178)。两组MTHFR C677T的TT、CT、CT+TT基因型分别与CC基因型比较P 0. 05,T与C等位基因比较P 0. 05; Logistic回归分析可知HCY(OR=1. 168、95%CI1. 015～1. 344、P=0. 030)是脑血管狭窄的危险因素。结论 HCY的水平是缺血性青年脑卒中患者脑动脉狭窄的高危因素。MTHFR C677T的TT基因型是影响血浆HCY水平的关键因素,但C677T基因型及等位基因频率与脑动脉狭窄无直接的相关性。     

N,N dimethylglycine and epilepsy

Nineteen institutionalized patients with frequent seizures (group average two to three per day; seizure types--generalized, akinetic/myoclonic), were treated randomly with either placebo or N,N dimethylglycine (DMG) for 28 days. Dosage was 300 mg/day for the first 14 days and then 600 mg/day. Plasma levels were measured at baseline, days 2, 5, 8, 15, 22, 30, and 1 and 2 weeks after the study ended. No differences in seizure frequency were noted between placebo and DMG or between baseline and test conditions. No toxicity was noted.     

Topographic MN-SSEPs (N18, N20 and N30) might characterize underlying CNS involvements in representative types of cerebral palsy

This study is aimed at constructing the neurophysiological basis for determining the characteristic features of cerebral motor disturbance in representative cerebral palsy (CP) types using topographical S-SEPs technology. Median-nerve stimulated S-SEPs (MN-SSEPs) were examined for 23 patients with four representative types of cerebral palsy: 6 athetotic (including 3 patients due to hypoxic-ischemic encephalopathy (HIE) and 3 to kernicterus), 7 hemiplegic, 5 diplegic and 5 tetraplegic types, and 13 normal controls. In HIE group of athetotic CP, frontal N30 specifically showed severe amplitude reduction or abolishment. In hemiplegic CP, both N20 and N30 on the affected cerebral side tended either to disappear or to be normally evoked at the same time, and their mean amplitudes declined severely. In diplegic CP, the amplitudes of subcortical N18 and parietal N20 were not small but significantly enlarged. N30 amplitude stayed within normal. The reason for this unexpected enlargement of N18 and N20 is unclear, but may be partly due to premature birth which caused abnormally abundant dendritic spine due to absence from perinatal normal spine elimination in the brainstem. In several quadriplegic patients, both N20 and N30 disappeared. The mean amplitude of N30 severely decreased. In conclusion, topographical results of N18, N20 and N30 may basically suggest the underlying involvement of nervous structures in CP according to their representative type.     

Abnormalities in Event-Related Potentials: N100, N200 and P300 Topography in Alcoholics

Abstract: Event-related potentials were recorded in 30 abstinent alcoholics, and 30 gender- and age-matched controls during a two-tone discrimination (odd ball) task. All the subjects were free from medication and dextral. The amplitudes of N100, N200 and P300 in the alcoholics were reduced and the P300 latency prolonged as compared with those of the controls. A P300 amplitude reduction occurred in the left and midline frontal, and the left and midline central regions. This is the first report of the amplitude of P300 being markedly decreased in the left hemispheres of the brains of the alcoholics. The results are discussed in terms of the cognitive dysfunctions of alcoholics.     

事件相关脑电位N400在精神科的应用

目的取得本实验室的事件相关脑电位(ERP)-N400实验方法。方法应用中国广州润杰WJ-1型ERP仪,对46名20～54岁右利手正常成人受试者和38名精神分裂症患者,进行汉语成语正常结尾(匹配)与成语结尾歧义词(不匹配)的N400基本波型研究。结果(1)正常成人N400波形较稳定。(2)波形分析所见,结尾词不匹配组的N400较匹配组潜伏期较长,波幅高。(3)精神分裂症组N400潜伏期延长和波幅下降。结论正常成人N400是可靠的,可作为一个有临床价值的ERP而用于精神分裂症及伴有语言障碍疾病的评估。     

Attention selection, distractor suppression and N2pc

N2pc is generally interpreted as the electrocortical correlate of the distractor-suppression mechanisms through which attention selection takes place in humans. Here, we present data that challenge this common N2pc interpretation. In Experiment 1, multiple distractors induced greater N2pc amplitudes even when they facilitated target identification, despite the suppression account of the N2pc predicted the contrary; in Experiment 2, spatial proximity between target and distractors did not affect the N2pc amplitude, despite resulting in more interference in response times; in Experiment 3, heterogeneous distractors delayed response times but did not elicit a greater N2pc relative to homogeneous distractors again in contrast with what would have predicted the suppression hypothesis. These results do not support the notion that the N2pc unequivocally mirrors distractor-suppression processes. We propose that the N2pc indexes mechanisms involved in identifying and localizing relevant stimuli in the scene through enhancement of their features and not suppression of distractors.     

Event-related potential N270, a negative component to identification of conflicting information following memory retrieval

OBJECTIVE: N270, an endogenous ERP component of conflict effect, was evoked in previous studies with S1-S2 paradigm. The present experiment is designed to confirm the speculation that this conflict-related negativity could also be elicited by stimulus probes having conflict with a memorized item in a visual post-retrieval comparison task. METHODS: A Sternberg probe-matching paradigm was modified in the present study. The stimuli consisted of a memory set of 3 different items (simple figures) and a retrieval set of 3 probe figures. Subjects matched each probe to its corresponding item in the memory set. The tasks were designed with different conflict loads of no-conflict, low-conflict and high-conflict in the probe retrieval test. RESULTS: Probes of no-conflict elicited a major positive going component, P300, with bilateral parietal distribution. Probes of low- and high-conflict evoked N270, while N430 was elicited only in high-conflict condition. N270 was more negative in high-conflict condition than in low-conflict condition. The N270 was right hemispheric prominent in the low-conflict task and remarkably distributed over the right prefrontal areas. On the other hand, both N270 and N430 were distributed bilaterally on the scalp in the high-conflict task. CONCLUSIONS: The present results demonstrate that the N270 is an index to the conflict identification, while the N430 of the high-conflict task reflects the processing for complex conflicts following probe retrieval. These negativities are related to the processing of conflicts.     

46例正常成人事件相关脑电位N400实验研究

目的 取得本实验室正常成人事件相关脑电位(ERP)N 400实验方法及正常值.方法 应用中国广州润杰WJ-1型ERP仪,对46名20～54岁右利手正常成人受试者,进行汉语成语正常结尾(匹配)与成语结尾歧义词(不匹配)的研究.结果 (1)分析了N 400基本波型,正常成人N 400波形较稳定.(2)建立了Cz、Fz和Pz区域N 400指标平均值.(3)波形分析所见,不匹配结尾词的N 400较匹配的N 400潜伏期较长,波幅高.N 400分布于Fz、Cz和Pz各区.结论 正常成人N 400是可靠的,可作为有临床价值的ERP用于精神科伴有语言障碍疾病的评估.     

Wait,what? Assessing stereotype incongruities using the N400 ERP component

Numerous discoveries regarding stereotypes have been uncovered by utilizing techniques and methods developed by cognitive psychologists. The present study continues this tradition by borrowing psychophysiological techniques used for the study of memory and language, and applying them to the study of stereotypes. In this study, participants were primed with either the gender category ‘Women’ or ‘Men’, followed by a word which was either consistent with gender stereotypes (e.g. Women: Nurturing) or inconsistent (e.g. Women: Aggressive). Their task was to indicate whether the words matched or did not match, according to gender stereotypes. Both response times and event-related brain potentials (ERPs) were recorded during performance of the task. As predicted, stereotype incongruent word pairs were associated with larger N400 ERP amplitudes and slower response times, relative to congruent word pairs. The potential utility of this approach as an independent measure of stereotypes is discussed.     

Isolierte,unilaterale Parese des N. phrenicus nach Pneumonie und Pleuritis

Unilateral diaphragmatic paralysis has many causes. Tumor and trauma are the two most frequent identifiable causes. Infectious processes involving the lung and/or mediastinum may result in temporary or permanent diaphragmatic paralysis. We report the case of an 81-year old man who suffered from right-sided pneumonia followed by a period of several months with exertion dyspnea. Radiological examinations showed an elevated right diaphragm, abnormal restrictive lung function, and impaired diaphragmatic muscle strength. The neurophysiological studies provided evidence of a partial phrenic nerve lesion. We discuss the differential diagnosis of isolated phrenic nerve lesions with particular regard to infections.     

正常成人汉语句子识别的事件相关脑电位N400实验研究

目的探讨正常成人汉语句子结尾词匹配和非匹配事件相关脑电位（ERP）N400的特点。方法应用ERP仪,对58名19～63岁正常成人右利手受试者,进行汉语正常句子结尾词（匹配）与句子结尾歧义词（非匹配）N400的实验研究。结果正常成人中央区（Cz）、前额区（Fz）及顶区（Pz）脑区汉语句子结尾词匹配的N400平均潜伏期为364ms,平均波幅为8.9μV;非匹配的N400的平均潜伏期为409ms,平均波幅为12.9μV。正常成人各脑区匹配与非匹配的汉语句子结尾词的N400潜伏期、波幅比较有统计学差异。结论正常成人汉语句子识别的N400稳定、可靠;非匹配的汉语句子结尾词的N400潜伏期长,波幅高。