首发精神分裂症患者神经认知功能的遗传学分析

目的 探索精神分裂症患者及其亲属共同存在的神经认知功能损害,并对22号染色体上儿茶酚氧位甲基转移酶(COMT)基因和脯氨酸脱氢酶(PRODH)基因的5个候选单核苷酸多态性(SNP)位点进行相关的遗传学分析。方法 采用14个神经心理测验(共29项)对235例首发精神分裂症患者(患者组)、322名未患病亲属(亲属组)和133名正常对照(正常对照组)进行有关智力、注意、记忆、言语功能和执行功能等评定,比较各组间的神经认知功能有无差异,并对上述神经认知功能测验与COMT和PRODH基因的5个候选SNP进行定量性状的传递不平衡测试。结果 (1)患者组所有测验的成绩均差于正常对照组,差异有显著性(P<0.01和P<0.05),而亲属组的记忆、注意、言语功能和执行功能界于患者与正常对照之间;(2)PRODH1 195G/A与即刻逻辑记忆测验(P=0.03)、言语流畅性测验的正确数(P=0.03)和连线测验B的犯规数(P=0.01)相关,PRODH1945G/A与数字符号测验(P:0.01)、连线测验A的错误数(P:0.02)、HANOI塔测验的总分(P=0.01)、威斯康星卡片分类测验(WCST)的总错误数(P=0.01)、WCST的非持续错误数(P:0.02)和WCST的总分类数(P=0.02)相关。结论 精神分裂症患者在记忆、注意、言语功能和执行功能等方面存在广泛的神经认知功能损害,这种损害可能是精神分裂症的遗传“内表     

精神分裂症与Xp11区HSU93305基因座的单体型及22 q11～13区相关基因的关联性研究

目的探讨Xp11区HSU93305基因座单体型、22 q11～13区α2肾上腺素能受体(A2αR)基因和儿茶酚-氧-甲基转移酶(COMT)基因多态性与精神分裂症的关联.方法分别提取59个中国汉族核心家系成员(母59名,父56名,精神分裂症患者59例)的DNA,采用基因扩增和限制性片段长度多态性技术,进行HSU93305基因座的单体型研究;选择其中56个父母均存活的家系进行A2αR基因和COMT基因多态性传递不平衡检验(TDT)的研究,并应用复等位基因TDT、基于单体型的单体型相对风险率(HHRR)检验等.结果 (1)Xp11区HSU93305基因座经Msp Ⅰ及Dra Ⅱ酶切后产生四种单体型D1M1,D1M2,D2M1,D2M2.父母组以单体型D2M1频率最高(57.7%);患者组也以D2M1传递率最高(59.0%),其次为D1M2(28.9%),D2M2传递率最低(1.2%).(2)经复等位基因TDT分析,精神分裂症与Xp11区HSU93305基因座相关联(χ2=9.28,v=3,P<0.05);与A2αR基因(χ2=1.09,v=1,P>0.05)和COMT基因(χ2=0.31,v=1,P>0.05)未见关联.(3)经HHRR检验,A2αR基因(χ2=1.21,v=1,P>0.05)和COMT基因(χ2=0.37,v=1,P>0.05)与精神分裂症亦未见关联.结论精神分裂症与HSU93305基因座相关联,其易感基因可能位于Xp11区;与A2αR基因和COMT基因多态性可能无关.     

Toxicology of potassium channel-directed compounds in mosquitoes

Potential targets for new vector control insecticides are nerve and muscle potassium channels. In this study, the activities of known potassium channel blockers (4-aminopyridine, quinidine, and tetraethylammonium) and the insecticide propoxur were compared to three experimental catechols and several other compounds against Anopheles gambiae and Aedes aegypti mosquitoes. Experimental catechol 1 was the most toxic experimental compound in all of the mortality assays conducted, but was at least 100-fold and 39-fold less toxic than propoxur against Ae. aegypti and An. gambiae, respectively. Injection treatment and synergist (piperonyl butoxide) bioassays found that catechol toxicity was not unduly impacted by cuticular transport or oxidative metabolism. Electrophysiological studies showed a decrease in amplitude of evoked muscle contractions, along with an increase in twitch duration at concentrations that increased basal muscle tension (mM). High concentration effects on basal muscle tension were matched by complete depolarization of the muscle membrane potential. Effects on muscle physiology and blockage of Kv2.1 potassium channels in patch clamp experiments were generally consistent with in vivo toxicity, except for 4-aminopyridine, which suggest the involvement of other potassium channel subtypes. Extensive melanization of Anopheles larvae, but not Aedes larvae, occurred from exposure to catechol compounds. Interaction with the phenol oxidase system within insects may be the cause of this melanization, but any contribution to toxicity requires further investigation.     

Enzymatic synthesis of catechol and hydroxyl-carboxic acid functionalized chitosan microspheres for iron overload therapy

Excess “free” iron which occurs under certain physiological conditions participates in the formation of toxic reactive oxygen species via the “fenton” chemistry. The reactive oxygen species oxidize biomolecules and have been implicated in many oxidative stress-related diseases. However, the ideal therapy for treating iron overload problems in humans has not yet been developed. In this study, the phenolic molecules catechol, caffeic acid, and 2,5-dihydroxybenzoic acid were successfully coupled to glucosamine as model substrate in a 1:1 ratio using laccase. Furthermore, coupling of these molecules onto chitosans of different sizes was demonstrated, resulting in decrease in –NH₂ groups as quantified via derivatization. A concomitant increase in iron-chelating capacity from below 3% to up to 70% upon phenolic functionalization was measured for the chitosans based on reduced ferrozine/Fe²⁺ complex formation. Interesting these phenolic compounds seems to also participate as cross-linkers in producing characteristic microspheres. This work therefore opens-up new strategies aimed at developing a new generation of iron-chelating biomedical polymers.     

精神分裂症与四个候选功能基因多态性的关系

目的 探讨多巴胺D2受体基因启动子(DRD2P)、5-羟色胺2A受体基因(5-m2A)、儿茶酚氧位甲基转移酶基因(C0MT)和单胺氧化酶A(MAO-A)基因相应多态性与汉族精神分裂症的关系及遗传学特征.方法 纳入至少有2名同胞符合国际疾病分类第10版的精神分裂症诊断标准、父母存活的核心家系43个,完成由哈佛大学提供的遗传学研究用诊断性检查和遗传学研究用家属会谈表,同时采集静脉血10ml,提取DNA.用聚合酶链反应(PCR)对候选基因片段进行扩增,酶切后用琼脂糖凝胶电泳检测基因型.统计分析方法 采用x2检验、相关分析及传递不平衡检验(TDT)等.结果 (1)DRD2P、5-HTzA、COMT的基因型和等位基因频率在患病同胞组、非患病同胞组和父母组之间的分布差异无显著性(P>0.05).MAO-A多态性在父母组(86名)的941T/941G和941G/941G基因型频率与患病同胞组(29例)及非患病同胞组(48名)之间的差异有显著性,但非患病同胞组与患病同胞组之间的差异无显著性(P<0.05).(2)在患病同胞中,MAO-A的941G等位基因传递较多[(x2=5.33,P<0.05,比数比(OR)=3.32,95%可信区间(95%CI)=1.58～6.99)];在非患病同胞中,DRD2P的-241A等位基因(x2=6.76,P<0.01,OR=3.17,95% CI=0.57～1.21)和MAO-A的941T等位基因(x2=4.84,P<0.05,OR=6.04,95% CI=2.01～18.69)传递较多.5-HT2A和COMT的等位基因在患病同胞和非患病同胞中均未见有明显的传递不平衡(P>0.05).(3)DRD2P、COMT、MAO-A基因型与精神分裂症的部分临床症状有显著性或非常显著性相关(P<0.05或P<0.01);5-HT2A受体基因型则否.结论 支持精神分裂症的多巴胺假说;上述4个候选功能基因与精神分裂症相关的密切程度有所不同,即MAO-A>DRD2P>COMT>5-HT2A.     

散发性乳腺癌COMT、p21和NuMA基因多态性研究

目的探讨山东省内女性人群中,儿茶酚-O-甲基转移酶(COMT)、细胞周期循环激酶抑制基因p21WAF1、核有丝分裂器蛋白(NuMA)单核苷酸多态性与散发性乳腺癌发生的关系。方法采用等位基因特异性扩增法(ASA)对山东省122例正常对照者和140例乳腺癌患者的COMT基因Val158Met、p21WAF1基因Ser31Arg、NuMA基因Ala794Gly单核苷酸多态性进行检测,比较两组中各种基因型分布频率的差异,并进行统计学分析。结果 27.1%(38/140)散发性乳腺癌患者和8.2%(10/122)正常对照者的COMT基因发生纯合变异,两组间Met/Met纯合基因型分布频率的差异有统计学意义(χ2=15.638,P<0.001);随着乳腺癌临床分期(OR=5.00,P<0.001)、组织学分级(OR=5.40,P<0.001)的升高及淋巴结转移增多(OR=3.00,P=0.002),COMT突变基因型所占比例明显增大。而p21WAF1基因与NuMA基因各基因型分布频率在病例组和对照组间的差异无统计学意义(χ2=0.373,P=0.541;χ2=0.020,P=0.886)。结论 COMT基因Val158M...     

Effect of catechol oestrogens on extraneuronal metabolism of noradrenaline by rabbit uterine endometrium and myometrium

Summary The effects of 2-hydroxy and 2-methoxy oestrogens on the extraneuronal O-methylation of ³H-(–)noradrenaline were examined in progesterone-dominated, monoamine oxidase (MAO)-inhibited, rabbit uterine tissues in vitro. Both the corticosteroid- sensitive system in myometrium and the cocaine-sensitive system in endometrium were examined.In myometrial slices preincubated with nialamide to inhibit MAO and incubated with cocaine to inhibit neuronal uptake, ³H-normetanephrine (³H-NMN) formation was inhibited in the order of potency 2-hydroxy oestrone 2-hydroxy oestradiol = 2-methoxy oestradiol 2-methoxy oestrone. In myometrial slices not exposed to cocaine and nialamide, inhibition of ³H-NMN formation by both 2-hydroxy and 2-methoxy oestradiol did not affect the formation of deaminated metabolites of ³H-(–)-noradrenaline by the alternative metabolising pathway. In endometrial slices preincubated with nialamide to inhibit MAO, only 2-hydroxy oestrogens inhibited ³H-NMN formation, but they were one to two orders of magnitude less potent in this regard than in the myometrium. The uptake of ³H-(–)-noradrenaline by MAO- and COMT-inhibited myometrial slices was inhibited by 2-hydroxy and 2-methoxy oestrogens in the order of potency 2-methoxy oestradiol 2-methoxy oestrone 2-hydroxy oestrone > 2-hydroxy oestradiol. Uptake of ³H-(–)-noradrenaline by endometrial slices was not affected by either 2-hydroxy or 2-methoxy oestrogens.It is concluded that the O-methylatiog system for noradrenaline in myometrial tissue is more sensitive than that in endometrial tissue to the inhibitory actions of 2-hydroxy and 2-methoxy oestrogens. 2-Hydroxy oestrogens inhibit ³H-NMN formation by competing for COMT rather than noradrenaline uptake sites, since (1) they inhibited O-methylation but not uptake of ³H-noradrenaline in endometrium and (2) 2-hydroxy oestrogens were two orders of magnitude more potent against ³H-NMN formation than ³H-(–)-noradrenaline uptake in myometrium. In contrast, the ability of 2-methoxy oestrogens to inhibit myometrial but not endometrial ³H-NMN formation reflects the selective inhibitory effect of 2-methoxy oestrogens on the corticosteroid-sensitive uptake system for noradrenaline which predominates in myometrium but is minimal in endometrium. These interactions may be important in pregnancy when the local concentrations of catechol and methoxy oestrogens rise.     

Putative cortical dopamine levels affect cortical recruitment during planning

Planning, the decomposition of an ultimate goal into a number of sub-goals is critically dependent upon fronto-striatal dopamine (DA) levels. Here, we examined the extent to which the val158met polymorphism in the catechol O-methyltransferase (COMT) gene, which is thought to primarily alter cortical DA levels, affects performance and fronto-parietal activity during a planning task (Tower of London). COMT genotype was found to modulate activity in the left superior posterior parietal cortex (SPC) during planning, relative to subtracting, trials. Specifically, left SPC blood oxygenation level-dependent (BOLD) response was reduced in groups with putatively low or high cortical DA levels (COMT homozygotes) relative to those with intermediate cortical DA levels (COMT heterozygotes). These set of results are argued to occur either due to differences in neuronal processing in planning (and perhaps subtracting) caused by the COMT genotype and/or the cognitively heterogeneous nature of the TOL, which allows different cognitive strategies to be used whilst producing indistinguishable behavioural performance in healthy adults. The implications of this result for our understanding of COMT′s effect on cognition in health and disease are discussed.     

咖啡因拮抗噪声引起机体损害作用的研究

噪声和咖啡因联合作用于大鼠后,观察大鼠血清及心肌中Ca~(++)、Mg~(++)含量的变化、心肌儿茶酚胺(CA)和血浆cAMP的变化,并用JEM-1200EX电镜观察了心肌超微结构的改变。结果表明,噪声可导致血清Mg~(++)含量升高,心肌Mg~(++)含量降低,心肌Ca~(++)明显升高。心肌CA和血浆cAMP含量上升。应用咖啡因后心肌Ca~(++)、Mg~(++)及血清Mg~(++)含量接近正常水平,心肌CA降低,血浆cAMP升高。提示咖啡因对可噪声所致的Ca~(++)、Mg~(++)含量异常有一定的拮抗作用,对CA和cAMP有调节作用,对噪声引起的大鼠心肌超微结构的损伤有明显减轻作用。     

Stereoselectivity of the arene epoxide pathway of mephenytoin hydroxylation in man

Stereoselective metabolism of mephenytoin has been investigated in four normal subjects by comparing urinary recoveries of hydroxylated metabolites after administration of racemic RS-mephenytoin (1.4 mmol/day) and R-mephenytoin (0.7 mmol/day) on separate occasions. Gas chromatography-mass spectrometry was employed to measure the urinary recovery of 3-methyl-5-(4-hydroxyphenyl)-5-ethylhydantoin (4-OH-M) and mephenytoin catechol, methylcatechol, and dihydrodiol metabolites. Following a single oral dose of racemic mephenytoin, 4-OH-M, mephenytoin catechol, and methylcatechol metabolites were identified in urine mainly as conjugates, whereas the dihydrodiol metabolite was recovered mainly in its unconjugated form. Urinary elimination of each metabolite was similar on days 1 and 10 of chronic racemic mephenytoin administration. Following R-mephenytoin administration, urinary recoveries of hydroxylated metabolites were five to 10 times smaller than after administration of the racemic drug. This implies substrate-stereoselective hydroxylation of the S-enantiomer of mephenytoin. In one subject with a genetic deficiency of aromatic mephenytoin hydroxylation deficiency, the excretion of each hydroxylated mephenytoin metabolite after RS-mephenytoin administration was decreased to 5-15% of the values found in the four extensively hydroxylating study volunteers. The impaired formation of hydroxylated mephenytoin metabolites in genetic hydroxylation deficiency, in conjunction with stereoselective hydroxylation of S-mephenytoin via an extensive NIH shift in normal man, is consistent with the hypothesis that the formation of the S-mephenytoin arene oxide is under genetic control and represents the initial enzymatic reaction of stereoselective aromatic mephenytoin hydroxylation. The formation of this potentially reactive metabolite of S-mephenytoin may have implications in mephenytoin-induced toxicity.