巴曲酶对大鼠缺血再灌注损伤的保护作用——降低NO神经毒性作用

本文用Ｗｉｓｔａｒ大鼠四条血管关闭的全脑缺血再灌注模型，观察脑缺血再灌注脑组织ＮＯ含量的变化及巴曲酶对它的影响。提示巴曲酶通过降低ＮＯ的神经毒性作用起到保护脑组织、减轻缺血再灌注损伤作用。     

红景天保护缺血再灌注损伤鼠脑细胞的作用及机理研究

目的研究红景天对大鼠脑缺血再灌注损伤的作用。方法４ＶＯ法复制缺血再灌注动物模型;放免法及化学发光法测定乙酰胆碱（Ａｃｈ）、一氧化氮（ＮＯ）及内皮素（ＥＴ）含量;细胞培养观察红景天对神经细胞的作用。结果（１）缺血再灌注组（ＩＲ）Ａｃｈ含量显著低于假手术组（ＳＡＭ）,药物预防后缺血再灌注组（Ｒ＋ＩＲ）及缺血再灌注后药物治疗组（ＩＲ＋Ｒ）较ＩＲ组显著升高。（２）ＩＲ组ＮＯ含量显著高于ＳＡＭ组,Ｒ＋ＩＲ组及ＩＲ＋Ｒ组ＮＯ含量显著降低。（３）ＩＲ组ＥＴ含量显著高于ＳＡＭ组而Ｒ＋ＩＲ组显著降低。（４）红景天甙培养组细胞存活率及ＬＤＨ含量明显高于对照组,ＮＭＤＡ损伤＋红景天甙组细胞存活率明显高于ＮＭＤＡ损伤组,ＬＤＨ含量却明显降低。结论红景天对大鼠脑缺血再灌注损伤时脑神经细胞具有保护作用。     

巴曲酶对大鼠大脑缺血及缺血再灌注ET1基因表达的影响

本实验采用大鼠急性脑缺血及缺血再灌注模型，研究巴曲酶对脑缺血及脑缺血再灌注时内皮素（ET1）基因表达的影响。用中大脑动脉（MCA）线检法大鼠模型，共12只，分为缺血组及缺血再灌注组（每组各6只），每组又分为巴曲酶组及盐水组（对照组）。缺血组在缺血后24h，再灌注组则在缺血1．5h及再灌注24h后用原位杂交，并采用IBHS图像分析系统研究ET1基因表达。发现巴曲酶组或对照组手术侧大脑皮质及尾壳核ET1mRNA表达均显著高于对侧（非手术侧）。但是巴曲酶组手术侧的ET1mRNA表达显著低于对照组。结果提示，巴曲酸可使缺血及缺血再灌注ET1基因表达下调。这可能是巴曲酶对缺血再灌注的脑保护作用机理之一。     

大鼠急性局灶性脑缺血再灌注脑组织NO含量和NOS活性的变化

目的探讨一氧化氮（ＮＯ）和神经元型ＮＯ合酶（ｎＮＯＳ）是否参与急性局灶性脑缺血再灌注的发病机理。方法采用栓红法建立大鼠大脑中动脉阻塞（ＭＣＡＯ）模型,观察脑组织ＮＯ含量和一氧化氮合酶（ＮＯＳ）活性的变化及ｎＮＯＳ抑制剂７－硝基吲唑（７－ＮＩ）对再灌注期两者的影响。结果缺血３０分种ＮＯ含量和ＮＯＳ活性显著升高,缺血３小进两者下降;再灌注３０分种ＮＯＴ和ＮＯＳ再次升高,而再灌注３小时两者又下降。７－Ｎ     

大鼠脑缺血再灌注海马区血小板活化因子和过氧化脂质的改变及药物影响

目的观察缺血性大鼠脑海马区血小板活化因子（ＰＡＦ）和过氧化脂质（ＬＰＯ）含量的改变及兆科蝮蛇抗栓酶的影响。方法用４ＶＯ大鼠脑缺血模型，用放免分析法和ＴＢＡ法测定ＰＡＦ及ＬＰＯ含量。结果缺血２０ｍｉｎ再灌注６０ｍｉｎ脑海马中ＰＡＦ及ＬＰＯ含量明显高于正常对照组（Ｐ＜０．０１），但造模前用兆科蝮蛇抗栓酶预处理动物，能够显著抑制缺血再灌注脑海马区ＰＡＦ及ＬＰＯ含量的升高。结论ＰＡＦ参与了脑缺血再灌注损伤，与ＬＰＯ生成密切相关，兆科蝮蛇抗栓酶对脑缺血再灌注损伤有保护作用。     

硫酸镁对大鼠脑缺血再灌流损伤保护作用的研究

目的:探讨ＭｇＳＯ４对大鼠脑缺血再灌流损伤的保护作用。方法:线栓法将ＳＤ大鼠制成脑缺血再灌流模型,分组测定脑组织Ｎａ＋－Ｋ＋－ＡＴＰａｓｅ活性、ＭＤＡ、ＮＯ含量。结果:治疗１组(３００ｍｇ·ｋｇ－１)和治疗２组(６００ｍｇ·ｋｇ－１)与对照组比较,Ｎａ＋－Ｋ＋－ＡＴＰａｓｅ活性增加,ＭＤＡ、ＮＯ含量降低,且治疗２组比治疗１组作用更明显。结论:ＭｇＳＯ４对脑缺血再灌流损伤有保护作用,６００ｍｇ·ｋｇ－１较３００ｍｇ·ｋｇ－１更显著。     

巴曲酶对脑缺血再灌注细胞外液单胺类及其代谢产物的影响——微透析研究

目的巴曲酶对脑缺血再灌流损伤的保护机理。方法采用脑内微透析技术结合高灵敏度的高压液相色谱－电化学检测手段（ＨＰＬＣ－ＥＤ），测定前脑缺血３０ｍｉｎ再灌注１２０ｍｉｎ时的纹状体细胞外液（ＥＣＦ）的ＤＡ、５－ＨＴ和ＮＥ及其代谢产物（５－ＨＩＡＡ）和ＨＶＡ的变化和巴曲酶的影响。结果显示脑缺血时，ＥＣＦＤＡ、ＮＥ及５－ＨＴ明显升高，巴曲酶能显著地降低脑缺血时ＥＣＦＤＡ及再灌注时ＥＣＦＨＶＡ和５－ＨＩＡＡ的水平。结论巴曲酶影响单胺神经递质是对脑缺血再灌注损伤起保护作用的机理之一     

SHR在MCAO后脑组织NOS活性的变化

一氧化氮（ＮＯ）在脑缺血中起重要作用，一氧化氮合成酶（ＮＯＳ）作为ＮＯ合成的关键酶，其活性变化直接调节ＮＯ的生成量及生物学效应。本文在建立ＳＨＲＭＣＡＯ局灶脑缺血模型基础上，测定脑缺血后不同时间和正常脑组织的ＮＯＳ活性，结果显示脑缺血早期（１、４ｈ），晚期（２４、４８ｈ）ＮＯＳ活性明显升高，提示脑缺血后缺血组织ＮＯ含量增加。     

NO代谢变化对缺血性脑组织内皮素产生的影响

在兔大脑中动脉阻断（ＭＣＡｏ）型局灶脑缺血前后分别应用外源性一氧化氮合成酶（ＮＯＳ）抑制剂Ｌ－ＮＮＡ和ＮＯ合成底物Ｌ－ａｒｇｉｎｉｎｅ，观察缺血４小时后脑组织内皮素（ＥＴ）含量的变化。结果发现Ｌ－ＮＮＡ组较缺血对照组脑组织ＥＴ含量明显增多（１２６２．９±３８７．６ｖｓ７８９．３±１８８．４ｐｇ／ｍｇ·ｐｒｏ，Ｐ值＜０．０１），脑水肿显著；而Ｌ－ａｒｇｉｎｉｎｅ用药组脑组织ＥＴ含量较缺血对照组明显减少（Ｐ值＜０．０５），且脑水肿减轻。本研究提示ＮＯ能抑制缺血脑组织ＥＴ的产生。ＮＯ对脑缺血影响可能与此途径有关。     

一氧化氮在脑缺血再灌流神经损伤中作用的实验研究

采用改良的Ｇｒｉｅｓｓ法，测定了脑缺血再灌流大鼠血清和脑组织中一氧化氮（ＮＯ）代谢产物ＮＯｘ（ＮＯ２＋ＮＯ３）的含量。结果表明，在脑缺血再灌流过程中实验大鼠血清和脑组织中ＮＯｘ含量的变化表现出独特的双峰现象，其第二高峰的出现时间与迟发性神经元损伤的发生相吻合。这提示，ＮＯ在脑缺血再灌流神经损伤中可能具有重要作用。     

Denervation study of synapses of organ of corti of old world monkeys

Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.     

Mechanism of action of tubocurarine on nicotinic cholinoreceptors of neurons of the sympathetic ganglia of rats

Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.     

The effect of age of onset of PD on risk of dementia

Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005     

Limits of deinstitutionalization--perspectives of relatives of psychiatric patients

After a hopeful beginning, the social process of the reintegration of those with severe mental illness has come to a standstill. I am led to wonder whether "the community" really wants to live together with people suffering from severe mental illness, and if so, how closely? As long as the medical treatment of mental illness provided by the general practitioners is fundamentally deficient, as they are not able to prescribe the necessary interventions--such as out-patient psychiatric nursing, and service providers in the out-patient sector are content with offering increasingly intensive forms of care for the less seriously ill at the cost of the Social Welfare System--the reintegration of those with serious mental illness remains an illusion--which is mainly to the benefit of providers of residential care in homes and hostels.     

Summary of Legislation of 1933 of interest to the Department of Mental Hygiene

Psychiatric Quarterly -