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41.
An 87-year-old woman suffered from Alzheimer's disease diagnosed 6 years prior to her death. Autopsy showed in addition to far-advanced Alzheimer's disease, a large, partially necrotic glioblastoma occupying her right hippocampus. Occurrence of a glial neoplasm in Alzheimer's disease could well be coincidental, since both entities are fairly common in elderly individuals; it is however, uncommon for gliomas to centre on the hippocampus itself. For these reasons it is possible (although cannot be proven from a single case), that florid reactive gliosis commonly associated with Alzheimer's disease, may have played a role in eventually initiating neoplastic proliferation of astrocytes in this patient. 相似文献
42.
Effect of CNTF on low-affinity NGF receptor expression by cultured neurons from different rat brain regions. 总被引:4,自引:0,他引:4
Our previous work indicated that in E14 embryonic rat spinal cord cultures ciliary neuronotrophic factor (CNTF) exerted (1) a survival-promoting effect on motor neurons and on a large population of unidentified neurons, and (2) a regulatory role on the expression of ChAT and low affinity NGF receptor (LNGFR) in a population of small/medium-sized neurons. In the present study, we examined the effect of CNTF on the expression of LNGFR in cultures of different regions from the E18 embryonic rat brain, namely cortex, septum, striatum, mesencephalon, hippocampus, brainstem, and cerebellum. The number of LNGFR-positive neurons (stained with the 192-IgG monoclonal antibody) was determined in untreated cultures and in cultures treated for 6 days (0-6) with human recombinant CNTF. To distinguish between effects on survival and on LNGFR expression, experiments were performed in which CNTF was administered only for the last 48 h of the culture (from days 4-6). LNGFR positive neurons were found in the cultures of all the regions examined. In each one of them, CNTF increased the number of LNGFR-positive neurons by three- to fourfold after 6 days of treatment. In the striatum, septum, mesencephalon, and cerebellum, the effect of CNTF was shown to be on the regulation of LNGFR expression and not on survival. In cultures from the cortex, hippocampus and brainstem, a survival-promoting role of CNTF could be demonstrated. The effect of CNTF was dose dependent, with half-maximal effects (ED50) achieved at 2-4.5 TU/ml for all the brain regions. Maximal effects were reached at 100-250 TU/ml. From these results, we conclude that (1) there exists a wide spectrum of CNTF-responsive neurons in the central nervous system, and (2) CNTF plays an important and widespread role in regulating the expression of the LNGFR in neurons. 相似文献
43.
电针对大鼠海马兴奋性突触后电位长时程增强的作用 总被引:4,自引:0,他引:4
目的 观察电针对麻醉状态下正常和东莨菪碱引起的学习记忆减退模型大鼠海马突触EPSP长时程增强(LTP)的作用。方法 引导大鼠海马齿状回颗粒细胞层突触后兴奋性电位群(EPSPs),强直刺激(HFS)大脑皮层前穿质区引起海马突触LTP反应;用东莨菪碱制备学习记忆障碍模型;观察电针大椎和肾俞穴对正常和模型大鼠海马LTP的影响。结果 电针对HFS诱发的海马突触LTP效应,其作用强于未电针组,部分参数和时段有统计学意义(P<0.05),且维持时间长于后者;东莨菪碱i.p可显著抑制HFS诱发的海马突触LTP(P<0.01),电针能显著对抗这一抑制作用(P<0.01;P<0.05)。结论 电针对HFS引起的海马突触LTP有一定的易化作用,并对东莨菪碱引起的学习记忆障碍有显著的对抗作用。 相似文献
44.
E. SCHÜTZ M. LUY-KALTEFLEITER M. KALTEFLEITER M. BURDELSKI† B. RINGE V. W. ARMSTRONG M. OELLERICH 《European journal of clinical investigation》1996,26(10):907-916
Abstract. Post-transplant assessment of early graft function has become an essential part of monitoring, especially when deciding on retransplantation. If primary non-function is indicated, retransplantation is inevitable; early graft dysfunction may be related to subsequent complications. In a prospective study in 84 patients after orthotopic liver transplantation (OLT) we measured aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), bilirubin (BIL), prothrombin time, MEGX formation, hyaluronic acid (HA) and soluble interleukin-2 receptor (sIL-2R) concentrations during the first 2 postoperative weeks; graft outcome was followed over 4 months. The aim of this study was to determine whether graft survival could be predicted by such variables early after OLT. Compared with patients with stable graft function (n= 25), patients with post-transplant icteric cholestasis (n= 30) exhibited no difference in graft survival, despite a decrease in MEGX formation to a nadir median of 12 μgL-1 on day 10. Patients with rejection (n= 8) and septicaemia (n= 6) showed a marked decrease in MEGX values and an increase in HA and sIL-2R concentrations between postoperative days 3 and 7. Patients with primary non-function (PNF; n= 5) were characterized by strongly reduced MEGX formation (median 4 μgL) and increased HA values (median 2300 μgL-1) on day 3 after OLT. A total of 24/84 grafts were lost within 120 days. In a survival analysis using the Cox proportional hazards regression, HA and MEGX values on day 1 were the only independent variables entering the model that showed an adequate prognostic sensitivity. At cut-off points of 22 μgL-1 (MEGX) and 730 μgL-1 (HA) the combined use of these parameters in a parallel approach yielded a sensitivity of 58% with a corresponding specificity of 95% for 120-day graft survival. These findings suggest that the inclusion of MEGX and HA in postoperative monitoring of OLT patients may be helpful in the early prediction of graft survival. 相似文献
45.
吗啡导致猕猴海马神经元自发放电节律转变 总被引:5,自引:0,他引:5
目的 分析吗啡对猕猴海马神经元自发放电节律的影响。方法 分析注射吗啡后猕猴海马神经元自发放电节律变化情况,并用数学方法加以验证。结果 在吗啡作用下海马神经元自发放电节律会发生转变,纳络酮可以逆转这种转变,共观察到种转变形式。为了研究这种转变的动力学机制,用数学模型模拟吗啡对神经元自发放电节律的影响,得到了与在体实验一致的结果。结论 在吗啡作用下海马神经自发放电节律发生转变。利用数学模型研究发现节律转变的原因是吗啡改变了膜上钠,钾,超极化电流等离子通道的功能所致,节律转变的过程存在着混沌规律。 相似文献
46.
目的:探讨不同培养阶段骨髓基质干细胞成骨能力的变化及BMP-2对其成骨能力的影响。方法:培养兔骨髓基质干细胞,测定第3代和第18代细胞碱性磷酸酶及骨钙素活性;测定BMP-2对不同培养时间骨髓基质干细胞成骨能力的影响;测定rhBMP-2对细胞增殖的影响。结果:细胞传至第18代后,分泌的骨钙素(OC)水平及ALP活力明显降低,与第3代细胞相比,差异显著(P〈0.05)。第3代细胞在rhBMP-2的诱导下,分泌的OC水平及ALP活力在原基础上进一步升高,与对照组相比,差异显著(P〈0.05)。结第18代细胞在rhBMP-2的诱导下,分泌的OC水平及ALP活力在原基础上升高,与对照组相比,差异不显著(P〉0.05);随培养时间的延长,各组细胞数量均有所增加,rhBMP-2诱导组与对照组细胞无显著性差异(P〉0.05)。细胞的传代次数对细胞增殖无明显影响(P〉0.05)。结论:rhBMP-2对细胞增殖无影响。随着传代次数的增加,骨髓基质干细胞的成骨能力下降,rhBMP-2促进其成骨的能力亦下降。 相似文献
47.
R P Vertes 《The Journal of comparative neurology》1992,326(4):595-622
The projections of the supramammillary nucleus (SUM) were examined in the rat by the anterograde anatomical tracer Phaseolus vulgaris leucoagglutinin (PHA-L). The majority of labeled fibers from SUM ascended through the forebrain within the medial forebrain bundle. SUM fibers were found to terminate heavily in the hippocampal formation, specifically within the granule cell layer and immediately adjoining molecular layer of the dentate gyrus. In addition, SUM fibers were shown to distribute densely to several structures with strong connections with the hippocampus, namely, the nucleus reunions of the thalamus, the medial and lateral septum, the entorhinal cortex, and the endopiriform nucleus. SUM fibers were also shown to project significantly to several additional subcortical and cortical sites. The subcortical sites were the dorsal raphe nucleus, the midbrain central gray, the fields of Forel/zona incerta, the dorsomedial hypothalamic area, midline/intralaminar nuclei of the thalamus (posterior paraventricular, rhomboid, central medial, intermediodorsal, and mediodorsal), the medial and lateral preoptic areas, the bed nucleus of the stria terminalis, the substantia innominata, the vertical limb of the diagonal band nucleus, and the claustrum. The cortical sites were the occipital, temporal, parietal, and frontal cortices. Some notable differences were observed in projections from the lateral as compared to the medial SUM. For example, fibers originating from the lateral SUM distributed heavily to the hippocampal formation and parts of the cortex, whereas those from the medial SUM projected sparsely to these two regions. The SUM projections to the hippocampal formation and associated structures may serve as the substrate for a SUM involvement in the generation of the theta rhythm of the hippocampus and the gating of information flow through the hippocampal formation. 相似文献
48.
实验性蛛网膜下腔出血后脑血管痉挛兔海马组织中Bcl-2和Bax mRNA的表达 总被引:6,自引:2,他引:4
目的:探讨蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)造成脑损伤的机制.方法:用反转录聚合酶链式反应(RT—PCB)技术检测兔SAH后CVS时海马组织Bcl—2和BaxmRNA的表达变化.结果:Bcl—2mBNA的表达水平在SAH组1d时即开始下降,3d时降至最低,持续至7d.SAH组海马组织中BaxmRNA的表达呈上升趋势,3d时达最高,7d时仍显著高于正常组.在假手术组海马组织内的Bcl—2和BaxmRNA的表达水平保持相对恒定.结论:Bcl—2和Bax可能参与了SAH后CVS所造成的海马神经元损伤过程。 相似文献
49.
三种淫羊藿的总黄酮分极提取物对小鼠免疫功能的影响 总被引:2,自引:0,他引:2
观察了巫山淫羊藿、柔毛淫羊藿和粗毛淫羊获的总黄酮正丁醇提取物(代号A1、A2、A3)和巫山淫羊藿总黄酮乙酸乙酯提取物(B1)对正常小鼠免疫功能的影响。结果;A1可以明显促进脾脏抗体形成细胞的功能(P<0.05),A2、A3虽也有一定的促进作用,但无统计学意义;4种提取物在体外实验中均没有协同ConA诱导牌细胞增殖作用,只有提取物浓度在100μg/ml时,有一定抑制作用。4种提取物对24小时培养脾细胞存活率无明显影响。 相似文献
50.
Research has demonstrated environmentally induced plasticity of hippocampal dentate gyrus-evoked potentials. Other research has shown a role of the NMDA receptor in dentate gyrus long-term potentiation (LTP). The authors tested the role of the NMDA receptor in one form of environmentally induced plasticity, in which transferring animals from their home cages to another environment results in significant excitatory postsynaptic potential (EPSP) enhancement and concomitant depression of the population spike. Rats were chronically implanted with stimulating electrodes in the perforant path and recording electrodes in the dentate gyrus bilaterally. Evoked potentials were recorded from freely behaving rats for four 20-minute sessions (1/wk), which took place immediately following an environmental transfer. Rats received 0.00, 0.05, 0.08, or 0.10 mg/kg MK-801 s.c. 30 minutes prior to recording sessions in either an ascending- or descending-dose series. Results showed that MK-801 produced a reduction of the EPSP enhancement, which takes place over the 20-minute session. The effects of MK-801 on spike depression varied as a function of dose series and time within a session, suggesting a long-term effect of MK-801 on spike depression. There was no detected effect of MK-801 on behavior. Results suggest a role of the NMDA receptor in this form of environmentally induced plasticity with different effects of NMDA receptor antagonism on EPSP enhancement and spike depression. 相似文献