缺血性脑损伤大鼠脑组织病理形态改变及丹酚酸B的干预作用

目的 探讨局灶性脑缺血再灌注损伤大鼠的脑组织病理改变及丹酚酸B的保护作用。方法 健康雄性Wistar大鼠32只,随机分为假手术组、模型组、丹酚酸B中剂量组和丹酚酸B高剂量组,每组8只。前两组蒸馏水灌胃,后两组丹酚酸B 96 mg/kg和192 mg/kg灌胃,1次/d,连续7 d。末次给药后1 h除假手术组外其他3组大鼠线栓法制备大脑中动脉局灶性缺血再灌注模型,缺血2 h,再灌注24 h。实验结束时HE染色观察大鼠脑组织病理形态,并检测缺血面积,TUNEL法检测凋亡细胞,计算细胞凋亡指数。结果 与假手术组比,模型组大鼠损伤侧脑组织出现灶状缺血区,组织结构紊乱,间质水肿,神经元变性、坏死,细胞凋亡指数增加。与模型组比较,丹酚酸B中、高剂量组脑组织缺血区结构紊乱及间质水肿减轻,坏死细胞明显减少,细胞变性程度减轻,缺血面积分别减小12%和14%（P<0.01）,细胞凋亡指数分别下降16.0%和17.3%（P<0.01）,但无剂量依赖关系。结论 丹酚酸B对局灶性脑缺血再灌注损伤大鼠脑组织形态具有保护作用。     

垂体腺苷酸环化酶激活肽对大鼠脑缺血-再灌注后IL-1β表达的影响

目的 探讨PACAP对大鼠局灶性脑缺血-再灌注损伤后脑保护作用及保护机制.方法 采用大脑中动脉线栓法建立局灶性脑缺血-再灌注模型,对36只大鼠随机分为假手术组、缺血-再灌注组和PACAP组,在大鼠脑缺血2h后进行12h、24h再灌注,比较光镜下细胞损伤变性程度,应用免疫组化法检测IL-1β的表达.结果 PACAP组大鼠脑标本光镜下细胞损伤变性程度与缺血-再灌注组相比明显减轻;IL-1β灰度值PACAP组分别为120±5、114±4,与缺血-再灌注组178±4、162±6比较,有显著性差异(P<0.01).结论 PACAP能抑制大鼠局灶性脑缺血-再灌注时IL-1β的表达,可能是其脑保护作用之一.     

大鼠局灶性脑缺血再灌注血管内皮生长因子的表达变化及意义

目的探讨Wistar大鼠局灶性脑缺血再灌注后脑组织血管内皮生长因子(VEGF)的表达变化及意义。方法选择体质量250～300g健康雄性Wistar大鼠60只,随机分为对照组、假手术组、局灶性脑缺血2h后再灌注0、1、3、6、9、12、24、72h及1、2周组共12组,每组5只,用线栓法制备大脑中动脉闭塞和再灌注(MCAO/R)模型。各组分别于相应时间点取鼠脑行冠状切片的HE及免疫组化染色。结果HE染色结果可见缺血后脑组织出现神经元变性、坏死,细胞周围水肿,软化灶形成。免疫组化染色结果显示:缺血2h后再灌注各组缺血灶周围小血管内皮细胞VEGF表达均较对照组、假手术组增高,内皮细胞在再灌注24、72h组表达量最高,再灌注1周组表达有所下降,再灌注2周组表达量仍较对照组、假手术组高;神经元及胶质细胞在再灌注9、12h组VEGF表达量最高,再灌注24、72h组较再灌注9、12h组有所下降,再灌注1、2周组无表达。结论脑缺血再灌注后VEGF在内皮细胞、神经元和胶质细胞表达增加但不同步,提示VEGF通过不同机制参与脑缺血的病理生理过程。     

预防性应用阿托伐他汀对SD大鼠局部脑缺血再灌注脑组织Caspase-3表达的影响

目的 探讨预防性应用阿托伐他汀对SD大鼠局灶性脑缺血再灌注损伤是否具有脑保护作用及其可能的机制.方法 72只雄性SD大鼠,按随机化原理分成3组:假手术组(n=24)、缺血再灌注组(简称对照组n=24)、阿托伐他汀组(n=24),各组按缺血2 h再灌注2 h、6 h、24 h、36 h分为4个亚组,每组各6只.结果 各相同再灌注时间点,阿托伐他汀组与对照组比较,缺血区变性、坏死的神经元数量减少,空泡样改变减轻,组织间水肿减轻.阿托伐他汀组较对照组Caspase-3阳性表达细胞数明显减少,再灌注2 h、6 h,2组间比较差别有统计学意义(P＜0.05),再灌注24 h及36 h 2组间比较差别有显著性统计学意义(P＜0.01).结论 预防性应用阿托伐他汀能减轻SD大鼠局灶性脑缺血再灌注损伤,减轻神经细胞变性、坏死及组织水肿,使缺血周边区及海马区Caspase-3表达减少.     

大鼠局灶性脑缺血与缺血再灌注损伤IL—8的研究

目的　探讨IL-8在脑缺血损伤及缺血再灌注损伤中的作用。方法　(1)采用改良ZeaLonga线栓法大鼠大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)模型。(2)应用双抗体夹心间接ELISA法检测脑缺血组与缺血再灌注组大鼠受损脑组织和血清中IL-8的浓度。结果　(1)脑缺血再灌注组受损脑组织中IL-8含量比脑缺血组高(P<0.05)，二者IL-8含量的变化均呈时间依赖性。前者于再灌注22h达高峰之后很快下降；后者于缺血6h达高峰，之后缓慢下降。(2)脑缺血再灌注组血清IL-8浓度于再灌注1h达峰值（7.08±1.36）pg/mL，之后很快降至较低水平；而在脑缺血组3h最高，为(3.61±0.81)pg/mL，随后缓慢下降。结论　脑缺血和脑缺血再灌注损伤均有IL-8参与，IL-8在脑缺血再灌注损伤中所起的作用较在脑缺血损伤中大。     

缺血再灌注蛋白激酶C同工酶表达与神经元凋亡关系的研究

目的 研究局灶脑缺血／再灌注大鼠蛋白激酶C（PKC）同工酶表达在缺血性脑损害中可能的作用机制。方法 采用线栓法制备大鼠局灶脑缺血／再灌注模型。于缺血1．5h再灌注4h、24h、72h观察PKCγ、δ表达及神经元坏死、凋亡的变化规律。结果 再灌注4h PKCγ、δ及神经元凋亡明显升高，PKCγ在24h达高峰，72h开始下降（P＜0．05）；PKCδ在再灌注24h、72h仍保持一高水平（P＞0．05），神经元凋亡的变化规律同PKCγ（P〈0.05)；神经元坏死在再灌注各时相点无显著性差异（P＞0．05）。结论 PKCγ、δ的异常表达与神经元坏死、凋亡有密切的联系。     

脑缺血再灌注后热休克蛋白70、c-fos的表达及柘树制剂的神经保护作用

目的 观察局灶脑缺血再灌注后热休克蛋白（HSP）70、c-fos的表达及其与细胞调亡的关系,探讨柘树制剂对脑缺血后神经细胞损伤的保护作用。方法 采用改良Longa法制作大鼠局灶脑缺血冉灌注模型。柘树制剂预处理组（柘树组）大鼠在实验前灌服柘树制剂2ml每日3次,连用5d。在缺血再灌注不同时点（1h、6h、12h、24h、3d、7d）将大鼠处死取腑,进行HSP70及c-fos免疫组化染色、c-fos mRNA原位杂交、原位末端标记（TUNEL）及HE染色,许对其阳性结果进行半定量分析。结果脑缺血再灌注能诱导HSP70及c-fos的表达。缺血冉灌注6h绀HSP70存缺血侧皮质及基底节开始表达,24h达高峰。缺血再灌注1h组c-fos即有表达,6h达高峰,后逐渐下降。细胞凋亡于缺血再灌注6h最显著。柘树组HSP70及c-fos表达的阳性细胞数均较缺血再灌注组明监增加,两组比较差异均有显著性（均P〈0．01）,而TUNEL阳性细胞数明显减少。结论 HSP70及c=-ros均参与了脑缺血的病理生理过程,柘树制剂对脑缺吡冉灌注损伤有保护作用。     

依达拉奉对脑缺血再灌注大鼠脑组织及血清超氧化物歧化酶、一氧化氮、丙二醛水平的影响

目的探讨依达拉奉对局灶性脑缺血再灌注损伤的影响。方法将SD大鼠分为假手术组,脑缺血再灌注组和依达拉奉干预组(干预组),采用线栓法制备大脑中动脉缺血再灌注模型;缺血1h后,设再灌注2h、6h、12h、24h组,采用化学比色法检测各组脑组织及血清超氧化物歧化酶(SOD)、一氧化氮(NO)、丙二醛(MDA)浓度。结果缺血再灌注组脑组织SOD下降,血清SOD先升后降;脑组织NO浓度先降后升,血清NO浓度持续升高;脑组织及血清MDA浓度均先升后降;与缺血再灌注组比,干预组SOD下降幅度小(均P<0·01),NO、MDA浓度明显降低;干预组6h、12h脑组织含水量明显低于缺血再灌注组(均P<0·01)。结论依达拉奉可降低羟自由基水平,对脑缺血再灌注损伤有保护作用。     

阿斯匹林干预对沙鼠脑缺血再灌注后NF-κB、MCP-1表达的影响

目的 通过研究阿斯匹林干预对沙鼠脑缺血再灌注后NF-κB、MCP-1表达的影响，旨在进一步探讨阿斯匹林在脑缺血再灌注损伤中的作用。方法 将50只健康蒙古沙鼠随机分为正常对照组、假手术组、脑缺血再灌注组（I／R组）、阿斯匹林干预组；夹闭双侧颈总动脉10min后松夹，建立沙鼠全脑缺血再灌注模型；用免疫组化法检测缺血脑组织NF-κBp65、MCP-1的表达。结果缺血再灌注后6h～7d NF-κBp65的表达量显著高于正常对照组及假手术组（P〈0．01），且出现MCP-1阳性表达；同I／R组比较，阿斯匹林干预组在缺血再灌注后6h、1d、3d、7d NF-κBp65与MCP-1表达量均下降（P〈0．05）。结论 阿斯匹林能够下调NF-κB、MCP-1的表达而减轻脑缺血再灌注损伤。     

高热对局灶性脑缺血再灌注大鼠缺血灶5-LO表达的影响

目的观察高热对局灶性脑缺血再灌注大鼠缺血灶5-脂氧酶（5-Lipoxygenase,5-LO）表达的影响,探讨高热对脑缺血再灌注后的影响及机制。方法通过线栓法制作大鼠大脑中动脉缺血再灌注模型,缺血时间为2 h。动物随机分为假手术组（Sham）、缺血再灌注（cerebral ischemic reperfusion,CIR）后正常体温组（normathermia,NT）、缺血再灌注后高热组（hyperthermia,HT）。对大鼠进行神经功能缺损评分和计算梗死体积;使用免疫组化法检测5-LO的表达。结果 （1）大鼠CIR HT组12 h2、4 h、48 h后神经功能缺损评分、梗死体积和缺血灶周边5-LO免疫阳性神经元细胞分别较NT组相应时间点明显增加（P〈0.05）;（2）大鼠CIR后梗死体积与缺血灶周边5-LO免疫阳性神经元细胞数明显相关（r=0.694,P〈0.05）。结论大鼠CIR后48h内高热可加重脑损伤,其机制可能与高热诱发5-LO在缺血灶周边过度表达有关。     

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.