木犀草素对大鼠脑缺血再灌注损伤的保护作用

目的 观察木犀草素对大鼠急性脑缺血再灌注损伤的保护作用.方法 采用大鼠急性不完全性脑缺血再灌注损伤模型,测定大鼠协调性运动评分和脑缺血体积的变化.结果 木犀草素对恢复缺血再灌注大鼠的协调性运动功能,减少脑缺血体积有显著疗效.结论 木犀草素具有保护脑缺血再灌注性损伤的作用.     

肉苁蓉总苷对清醒小鼠脑缺血再灌注致海马CA1区脑组织损伤的保护作用

目的 探讨肉苁蓉总苷(GCs)对脑缺血再灌注所致清醒小鼠海马CA1区脑组织损伤的保护作用。方法 结扎小鼠右侧颈总动脉建立脑缺血及脑缺血再灌注模型，动态观察GCs对脑缺血3小时再灌注24及48小时两个时点脑梗死范围百分比、脑缺血3小时再灌注24小时海马CA1区脑组织病理变化及脑细胞凋亡情况的影响。结果 脑缺血及脑缺血再灌注后脑梗死范围百分比明显增加；海马CA1区脑细胞密度降低，细胞皱缩明显，胞浆染色较深，核染色质凝聚，凋亡神经细胞明显增多；与缺血组相比，缺血再灌注组损伤加重。GCs可促进上述各项指标的恢复，显著降低脑梗死范围百分比，减轻脑组织病理损伤，抑制脑细胞凋亡。结论 GCs对脑缺血再灌注小鼠脑组织具有保护作用，其机制可能与抗氧化及抗脑细胞凋亡作用有关。     

电针对沙鼠急性脑缺血再灌注后神经原损伤的保护作用

本实验利用沙鼠急性脑缺血再灌注模型，研究电针对脑缺血及再灌注各期脑电活动的影响及组织病理学的改变。结果表明：缺血１０ｍｌｎ，脑电幅度受到严重抑制，甚至变平坦，总功率大大下降，再灌注后总功率难以恢复，在１２０ｍｉｎ时仅恢复到缺血前的２７．３９±１１．３１％，以后即不再进一步恢复，电针组动物缺血１０ｍｉｎ再灌注后，脑电的恢复明显比对照组快，１２０ｍｉｎ时恢复至缺血前的７１．４５±１６．４６％（Ｐ＜０．０１），２４０ｍｉｎ时继续恢复至缺血前的７５．２７±１８．４３％。同时电针能明显减轻缺血１０ｍｉｎ后再灌注２４小时的神经原缺血性损伤。结果提示：电针对急性脑缺血引起的神经原损伤具有保护作用，并能促进脑功能的恢复。     

P-选择素在大鼠全脑缺血再灌注微血管内皮细胞损伤中的作用

目的 探讨P-选择素（P-selectin)在大鼠全脑缺血再灌注血管内皮细胞损伤过程中的作用。方法 将大鼠随机分为假手术组和脑缺血30min再灌注1h,3h,6h,12h,24h,48h,72h组，动物模型采用全脑缺血模型三血管阻塞法，用免疫组化法检测脑组织缺血再灌注不同时间点FⅧ相关抗原（vWF)的表达以标记内皮细胞损伤与修复过程，同时用原位杂交方法检测P-选择素mRNA的表达变化。结果 假手术对照组未见P-选择素mRNA表达，脑缺血再灌注后1h表达出现上调，12-24h达高峰，72h仍有表达，FⅧ相关抗原在假手术组呈强阳性表达，脑缺血再灌注后3h表达下降，24-48h表达最低，72h表达开始恢复，结论 脑缺血再灌注微血管内皮细胞损伤主要发生在早期，此过程中P-选择素mRNA表达上调，说明P-选择素参与了脑缺血后内皮细胞的损伤过程。     

急性脑缺血再灌注损伤钙离子与氧自由基作用实验研究

为探讨钙离子与氧自由基在急性脑缺血再灌注损伤中的作用，用复制大鼠急性脑缺血再灌注动物模观察脑缺血再灌注过程中脑组织H2O2、Ca^2 、MDA含量及病理学变化及尼莫地平对上述指标的影响，结果表明，急性脑缺血再灌注后有细胞内钙超载和自由基代谢紊乱，且在再灌注损伤中有协同作用，加重组织损伤，促进脑水肿，尼莫地平对其有保护作用。     

大鼠急性脑缺血再灌注损伤精氨酸加压素变化和脑水肿实验研究

应用大鼠急性脑缺血再灌注动物模型，观察精氨酸加压素（ＡＶＰ）在急性脑缺血再灌注损伤中的变化及与脑水肿关系，结果表明丘脑下部ＡＶＰ含量在脑缺血３０ｍｉｎ明显增加，再灌注６０ｍｉｎ后进一步增加，且与大脑皮层水含量是显著相关性。提示，ＡＶＰ参与急性脑缺血再灌注损伤，丘脑下部ＡＶＰ含量增高，可加重或促进脑缺血再灌注后脑水肿形成。     

大鼠脑缺血-再灌注损伤中P-选择素的表达对脑血流的影响

目的　探讨脑缺血-再灌注损伤中P-选择素(PS)的表达及其与脑缺血后脑血流恢复的关系。方法　建立脑缺血-再灌注损伤大鼠模型,实验动物随机分为假手术组、非治疗组和藻酸双酯钠治疗组。观察大鼠治疗前后脑组织中PS表达、髓性过氧化物酶(MPO)活性和大鼠脑血流。结果　大鼠脑缺血再灌注损伤组织PS表达及MPO活性增高,缺血侧脑血流量明显减低。藻酸双酯钠治疗组脑组织中PS表达和MPO活性增高受抑,相应的再灌后脑血流量较非治疗组的明显增高。结论　抑制脑缺血-再灌注损伤脑组织中PS表达可改善脑缺血后无复流现象。     

丁咯地尔对大鼠急性脑缺血再灌注损伤IL-1β、TNF-α表达的影响

脑梗死是严重危害人类健康的疾病之一,具有高发病率、高致残率的特点.脑缺血后尽早恢复血供是治疗脑梗死的关键措施.近年来研究发现脑缺血后再灌注损伤是影响原缺血病变脑组织功能恢复的重要原因,而炎症因子引起的炎症反应在脑缺血再灌注损伤中起重要作用.丁咯地尔作为一种血管活性药物,在临床上用来治疗缺血性脑血管病,其疗效已得到肯定,但其对炎性因子作用的报道不多.本文通过对大鼠脑缺血再灌注损伤后即刻应用丁咯地尔,检测脑缺血再灌注后不同时限脑组织匀浆内TNF-α、L-1β的表达,来探讨丁咯地尔的脑保护作用.     

常压氧疗法对脑缺血再灌注损伤的研究进展

脑缺血再灌注损伤(cerebral ischemia reperfusion injury,GIRI)是指脑缺血致脑细胞损伤,恢复血液再灌注后组织损伤反而加重,甚至发生不可逆性损伤的的现象.CIRI是创伤性颅脑损伤、脑梗死等脑缺血性疾病共同出现的病理生理现象.近年来大量研究表明,常压氧疗法能通过多种机制,抢救急性缺血脑组织,延长急性脑卒中治疗的时间窗,是一种有效的神经保护方法.本文就常压氧疗法对脑缺血再灌注损伤的疗效、机制、治疗方式和不良反应的研究进展综述如下.     

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。     

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.     

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.     

Sense of coherence as a predictor of subjective state of health: results of 4 years of follow-up of adults

A number of cross-sectional population studies have shown that a strong sense of coherence (SOC) is associated with various aspects of good perceived health. The association does not seem to be entirely attributable to underlying associations of SOC with other variables, such as age or level of education. OBJECTIVE: The aim of the study reported here was to determine whether SOC predicted subjective state of health. METHODS: The study was carried out as a two-way panel mail survey of 1976 individuals with 4 years interval for two collections of data. The statistical method used was multivariate cumulative logistic modeling. Age, initial subjective state of health, initial occupational training level, and initial degree of social integration were included as potential explanatory variables. RESULTS: A strong SOC predicted good health in women and men. CONCLUSIONS: SOC can be interpreted as an autonomous internal resource contributing to a favorable development of subjective state of health. SOC data should, however, be regarded as complementary to and not a substitute for information already known to be associated with increased risk of future ill health.