孕酮在脑缺血大鼠TNF-α和IL-6引起脑损伤中的作用

目的 观察孕酮在炎症因子TNF-α和IL-6引起新生鼠缺氧缺血性脑损伤中的作用,进一步探讨孕酮神经保护作用的分子机制.方法 96只7日龄新生Wistar大鼠随机分成4组,正常对照组、假手术组、缺氧缺血组、药物预防组.缺氧缺血组和药物预防组动物先行左侧颈总动脉结扎术,然后将动物置于37℃恒温的密闭容器中,以1.5L/min的速度吸入80ml/L氧气和920ml/L氮气混合气体2.5h建立缺氧缺血脑病动物模型.药物预防组动物于建立模型前30min按8mg/kg腹腔注射0.5g/L孕酮溶液.采用ELISA法检测脑组织中TNF-α和IL-6含量的变化,RT-PCR检测TNF-α和IL-6 mRNA的表达.结果 缺氧缺血组脑组织中炎症因子TNF-α和IL-6含量在缺氧缺血后6h、24h、48h、72h明显高于对照组和假手术组大鼠(P＜0.05),且在缺氧后24h升到最高点,以后逐渐下降,至7d两者差异不显著,药物预防组在缺氧缺血后各时间点均低于缺氧缺血组(P＜0.05).且缺氧24h后缺氧缺血组脑组织TNF-α、IL-6 mRNA的表达明显高于正常对照组和假手术组,药物预防组mRNA的表达明显低于缺氧缺血组(P＜0.05).结论 孕酮可以保护新生鼠缺氧缺血后引起的脑损伤,其作用机制与抑制炎症因子TNF-α和IL-6 mRNA的表达以及抑制TNF-α和IL-6的生成有关.     

孕酮通过PI3K/Akt信号通路减轻新生大鼠缺血缺氧性脑损伤

目的探讨孕酮是否通过PI3K/Akt信号通路减轻新生大鼠缺血缺氧性脑损伤。方法取40只7 d龄新生Wistar大鼠随机分成4组:假手术组:仅做颈部切口,不做缺氧缺血处理;模型组:按动物模型的方法进行缺氧缺血处理;孕酮组:动物进行缺氧缺血处理且在缺氧前30 min按8 mg/kg腹腔注射孕酮溶液;抑制剂组:在建立缺血缺氧性脑损伤模型前30 min,按16μg/kg剂量在大鼠左侧海马区注射Wortmannin。电镜观察新生鼠缺氧缺血性脑损伤神经元的变化,采用免疫组织化学法检测海马pAkt及NF-κB的蛋白表达,应用Western blot检测海马pAkt及NF-κB的蛋白含量。结果 24 h后假手术组神经元结构基本正常,模型组神经元由于缺氧缺血损伤呈空化改变,给予孕酮后的缺氧缺血神经元受损情况改善,空化现象减少,应用抑制剂神经元空化改变明显。缺氧缺血后海马神经元pAkt蛋白表达减少,NF-κB表达增加;孕酮预处理可增加pAkt的表达,降低NF-κB表达;使用抑制剂组pAkt蛋白表达减少,NF-κB表达增加。结论孕酮可通过激活PI3K/Akt信号通路,增加pAkt的水平,抑制NF-κB表达,减轻缺血缺氧性脑损伤中的炎症反应,发挥脑保护作用。     

当归对宫内缺氧新生大鼠神经干细胞增殖、分化的影响

背景：实验小组前期研究发现孕鼠宫内缺氧可刺激胎鼠神经干细胞的增殖,缺氧6 h时增殖达高峰,在9 h也表现增殖,但能力开始下降。而缺氧达12 h时即表现为坏死或凋亡,但随缺氧天数的延长及时段的不同,对神经干细胞的影响又如何？ 目的：进一步探讨宫内缺氧对新生大鼠神经干细胞增殖、分化的影响及当归注射液的保护作用。 方法：孕 SD大鼠随机分为对照组、缺氧组和当归治疗组。孕14 d开始将当归组与缺氧组孕鼠置于三气培养箱中,制作缺氧性脑损伤新生鼠模型,此前1 h分别给于当归注射液和生理盐水尾静脉注射,对照组不缺氧,余同缺氧组。孕鼠分娩后立即取新生鼠大脑组织,经胶质纤维酸性蛋白、神经元特异性烯醇化酶免疫组织化学染色后行图像分析。 结果与结论：①缺氧组新生鼠海马胶质纤维酸性蛋白免疫组织化学阳性细胞的表达较相应对照组增加;而神经元特异性烯醇化酶免疫组织化学阳性细胞的表达较对照组减小。②当归治疗组新生鼠海马胶质纤维酸性蛋白免疫组织化学阳性细胞的表达较相应缺氧组减少;而神经元特异性烯醇化酶免疫组织化学阳性细胞的表达较对照组增大。结果表明,一定程度的缺氧可刺激神经干细胞增殖,并可刺激神经干细胞向神经胶质细胞分化,以及导致神经元的减少;当归注射液可减弱由于缺氧导致的神经干细胞的增殖和向胶质细胞分化的能力,并可缓解神经元的减少,提示当归可能对缺氧大鼠神经系统有一定的保护作用。     

神经节苷脂GM1阻抑急性脑梗塞溶栓治疗再灌注损害实验研究

目的 :观察神经节苷脂对脑缺血再灌注损伤的保护作用。方法 :采用自体血栓塞大脑中动脉造成的大脑中动脉梗塞 (MCAO)动物模型。测定缺血对照组、处理组 (2 0 mg/ kg,缺血 5分钟尾静脉给药 )缺血 2 h再灌 2 4 h、 4 8h血清和脑组织中 NSE、 MDA的含量 ,观察有无出血并发症的发生 ,并测定 HSP70和 TGF-β的表达。结果 :脑缺血对照组 MDA、 NSE较 GM1处理组显著性升高 ,而 GM1处理组 HSP70和 TGF-β的表达较缺血对照组显著性增加 ,且表达提前。结论 :GM1能阻抑急性脑梗塞溶栓治疗再灌注损害的氧自由基产生过多的损害 ,且减少了脑出血的发生 ,增强HSP70、 TGF-β的表达 ,而发挥脑保护作用     

在缺氧条件下培养的海马神经元形态结构及热休克蛋白(HSP)70表达变化及丹参的影响

在体研究曾发现在缺血再灌注模型中，丹参具神经保护作用。本文采用新生大鼠海马神经元培养技术，以细胞形态学及HSP70免疫性细胞表达为指标，首次观察了缺氧条件下培养的海马神经无形态结构及HSP70表达变化及丹参的影响。结果发现：（1）不论缺氧1h或2h，在培养的海马神经细胞中，有的细胞出现细胞体周围光晕消失，胞浆内颗粒变性，细胞膜肥厚、粗糙，轴突变粗、断裂，并且出现HSP70免疫阳性细胞；（2）缺氧1h组的海马神经细胞存活率及HSP70免疫阳性细胞率均显著高于缺氧2h组，（3）丹参组（在缺氧0．5h前给丹参100mg／ml（终浓度）的海马神经细胞存活率及HSP70免疫阳性细胞率均显著高于缺氧2h组。结果提示丹参具有直接的抗缺氧性神经细胞损伤的作用，减轻了缺氧所造成的神经细胞形态学上的改变。     

缺氧预处理对创伤性脑损伤大鼠 Claudin5 表达及血脑屏障通透性的影响

目的探讨缺氧预处理对创伤性脑损伤大鼠脑组织紧密连接蛋白Claudin-5的表达及血-脑屏障通透性的影响。方法204只大鼠随机分为创伤性脑损伤组（T组）96例,缺氧预处理后脑损伤组（H组）96例及对照组12例。T组行自由落体撞击法建立大鼠创伤性脑损伤模型,H组给予3d缺氧预处理后,同法致脑损伤,两组大鼠于伤后1h、4h、8h、12h、24h、3d、7d、14d断头处死。采用干湿重法测脑组织含水量：Real—timePCR和Westernblot检测各组大鼠挫伤区周围脑组织Claudin-5mRNA及蛋白表达变化;IgG法检测血一脑屏障通透性变化。结果T组和H组伤后1hClaudin-5mRNA及蛋白表达开始降低,8～12h降至最低点,1d开始上升,直至伤后14d渐趋于对照组水平;其中H组各时间点Claudin-5mRNA及蛋白表达均高于T组。T组各时间点血一脑屏障通透性及脑组织含水量均明显高于H组（P〈0．05）,且两组均高于对照组（P〈0．05）。结论缺氧预处理可在创伤性脑损伤早期上调紧密连接蛋白Claudin-5的表达,维持血-脑屏障完整性,减轻脑水肿。     

新生小鼠缺血缺氧性脑损伤中TLR4-TRIF信号通路的表达

目的 建立新生小鼠缺血缺氧模型,探讨TLR4-TRIF信号通路中TLR4、IRF3的表达.方法 将60只7日龄C57BL/6小鼠分为假手术组、缺血缺氧1 d、2 d、3 d、4 d、7 d、建立新生小鼠缺血缺氧性脑病模型,比较鼠脑左右半球的质量,确定模型是否建立成功.以逆转录-聚合酶链反应（RT -PCR）检测大脑皮质和海马中TLR4 mRNA、IRF3m RNA的表达.结果 缺血缺氧1 d组右侧的脑质量明显重于左侧,说明缺氧缺血1 d后,右脑水肿明显.缺氧缺血组的TLR4m RNA、IRF3m RNA的表达水平均明显高于假手术组.结论 脑缺氧缺血损伤可激活TLR4,引起IRF3表达量增加.     

脑缺氧缺血新生大鼠诱生型一氧化氮合酶基因的表达及其与脑细胞凋亡的关系

目的　探讨新生大鼠缺氧缺血后脑内诱生型一氧化氮合酶 (i NOS)基因表达的变化及其与脑缺氧缺血所致细胞凋亡的关系。方法　建立新生大鼠缺氧缺血性脑损伤动物模型 ,应用快速竞争性逆转录 PCR技术及原位末端标记法观察脑缺氧缺血后不同时间点缺氧缺血侧大脑组织中 i NOS m RNA的表达及神经细胞凋亡的情况。结果　新生大鼠缺氧缺血后 ,缺氧缺血侧大脑 i NOS m RNA表达自 6h开始明显增强 ,其相对表达量为(0 .41± 0 .1 3 ) ;2 4h达高峰 ,相对表达量为 (2 .0 2± 0 .2 4) ,7d时回至基线水平。缺氧缺血侧脑组织中凋亡细胞数目亦自缺氧缺血后 6h开始明显增多 ,平均为 (2 1 .3± 3 .5 ) /1 0个高倍视野 (1 0 hpf) ;2 4h达高峰 ,约 (63 .7±3 .2 ) /1 0 hpf,与对照组 [平均为 (7.3± 2 .3 ) /1 0 hpf]比较差异有显著性 (P <0 .0 1 )。i NOS m RNA的表达高峰与缺氧缺血后脑细胞凋亡的高峰时相相吻合。结论　缺氧缺血可使新生大鼠脑 i NOS m RNA的表达增强和凋亡细胞增加 ,i NOS过表达在缺氧缺血后脑细胞凋亡的调控过程中起一定作用。     

促红细胞生成素干预缺氧缺血性脑损伤新生鼠神经干细胞巢蛋白的表达☆

背景: 巢蛋白是一种存在于神经干细胞的特异性抗原,在神经系统发生病变或损伤引起再生时广泛表达,因此巢蛋白表达常用作判定神经系统发生病变或损伤后能否促进神经再生的一种手段。 目的：从神经再生和神经干细胞激活的角度,探讨外源性促红细胞生成素对新生鼠缺氧缺血性脑损伤后神经干细胞巢蛋白表达的影响。 方法：结扎大鼠右侧颈总动脉和8%低氧暴露2 h制备新生大鼠缺氧缺血性脑损伤模型。对照组仅游离右侧颈总动脉,不予结扎和缺氧处理。干预组大鼠缺氧缺血后立即腹腔注射重组人促红细胞生成素5 000 IU/kg,1次/d,连用3 d。缺氧缺血性脑损伤组大鼠缺氧缺血后连续腹腔注射等量生理盐水溶液3 d。每组随机取8只分别于术后4,7,14 d处死。应用免疫组化方法和计算机图像分析技术检测不同时点海马齿状回巢蛋白标记阳性细胞的变化。 结果与结论：各时点缺氧缺血性脑损伤组巢蛋白阳性细胞数较对照组增加(P < 0.05);各时点干预组巢蛋白阳性细胞较对照组和缺氧缺血性脑损伤组均增加(P < 0.05)。3组大鼠海马齿状回区巢蛋白阳性细胞数均于术后 7 d 达高峰。结果提示早期给予重组人促红细胞生成素可促使新生鼠缺氧缺血性脑损伤后海马齿状回区巢蛋白表达增加,促进神经干细胞的增殖再生,在缺氧缺血性脑损伤后神经再生、修复中发挥一定的保护作用。     

蛋白酶体抑制剂诱导帕金森病大鼠模型海马区HSP70表达

目的观察蛋白酶体抑制剂Lactacystin诱导帕金森病大鼠模型海马区HSP70表达。方法将Lactacystin 10μg（2μl）经立体定向仪注射到大鼠（Lactacystin组,n=36）左侧黑质致密部,对照组（n=36）以等体积生理盐水代替;分别在药物注射后24h、3d、5d、7d、9d、11d、14d、18d和21d提取海马标本,通过免疫组化和RT-PCR观察HSP70的表达。结果Lactacystin组大鼠海马区HSP70表达较对照组高,表现为注药24h后表达开始增高,5d达高峰,11d开始减少;且海马区表达分布呈CA3〉CA2〉CA1。结论Lactacystin诱导帕金森病大鼠海马区HSP70表达增高,且呈明显区域性和时间依从性;增加的热休克蛋白可能参与拮抗蛋白酶体抑制毒性而起到神经细胞保护作用。     

Mechanisms of the suppression of the nociceptive reflex of the opening of the mouth during stimulation of the structures of the limbic brain

The comparative effectiveness of the inhibitory influence of tetanic stimulation of hypothalamus, amygdala and limbic cortex on EMG-response of m. digastricus evoked by electrical stimulation of tooth pulp nociceptive afferents was studied in cats anesthetized with a mixture of chloralose and nembutal. It was found that inhibition of the EMG-component of the jaw-opening reflex is most pronounced in case of stimulation of medial and lateral region of the hypothalamus, the inhibitory effect of central and medial nuclei of the amygdala is less pronounced and the effect of the limbic cortex is the weakest. It was shown that the mechanism of the antinociceptive effect of tetanic stimulation of the hypothalamus is not related to the concomitant increase of the blood pressure. After stabilization of the blood pressure the suppressive effect of the hypothalamus remains without changes, that points out to a direct, primary, not baro-afferent mechanism of the inhibition of the activity of nociceptive neurons of the trigeminal sensory nuclei. Noradrenaline, injected intravenously, induced a large increase of the blood pressure accompanied by a pronounced inhibition of the pain reflex. Angiotensin causes the same degree of blood pressure elevation without changes in the amplitude of the EMG-response of the pain reflex. Hypothalamic and noradrenergic mechanisms for control of pain sensitivity are discussed.     

药物治疗与合并认知行为治疗对强迫症疗效的比较

目的探讨认知行为心理治疗(CBT)在强迫症(OCD)患者各亚型治疗中的有效性和规律性。方法本研究为临床对照研究。符合入组标准的强迫症患者按患者自愿原则分为两组,治疗观察3、6、12个月。疗效评定分别运用Yale-Brown强迫量表,自拟的自评好转程度量表和临床疗效评定。结果认知行为心理治疗合并药物治疗组31例,临床有效率70.9%,其中治愈率1.8%。单纯药物治疗组24例,临床有效率33.3%。Yale-Brown强迫量表和自评量表得分在6个月和12个月两组有显著差异(P<0.05)。其中强迫症亚型(怕脏型、反复检查型和反复担心型)的疗效比较,怕脏型在治疗3个月末两组间自评量表评分有显著性差异(P<0.05);反复担心型在治疗6个月末两组间Yale-Brown强迫量表总分有显著性差异(P<0.05);反复检查型两组间无统计学差异。结论认知行为心理治疗合并药物治疗强迫症的疗效明显优于单纯药物治疗。强迫症的亚型在治疗中的有效性次序为:反复担心型>怕脏型>反复检查型。     

Characteristics of the sympathetic innervation of the nictitating membrane and of the vasculature of the nose and tongue of the cat

Summary Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves.Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue, whose activity was revealed after-receptor blockade, had a similar threshold to the vasoconstrictor fibres.Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa.The preganglionic compound nerve action potential had four major components, S₁–S₄. S₁, S₂ and usually S₃ fibres were associated with membrane contraction; S₂, S₃ and sometimes S₁ fibres were associated with nasal vasoconstriction; and S₃, usually S₂ and occasionally S₁ fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S₄ fibres, may include fibres associated functionally with the three effectors.There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions.     

Development of the projection from the nucleus of the brachium of the inferior colliculus to the superior colliculus in the ferret

Neurons in the deeper layers of the superior colliculus (SC) have spatially tuned receptive fields that are arranged to form a map of auditory space. The spatial tuning of these neurons emerges gradually in an experience-dependent manner after the onset of hearing, but the relative contributions of peripheral and central factors in this process of maturation are unknown. We have studied the postnatal development of the projection to the ferret SC from the nucleus of the brachium of the inferior colliculus (nBIC), its main source of auditory input, to determine whether the emergence of auditory map topography can be attributed to anatomical rewiring of this projection. The pattern of retrograde labeling produced by injections of fluorescent microspheres in the SC on postnatal day (P) 0 and just after the age of hearing onset (P29), showed that the nBIC-SC projection is topographically organized in the rostrocaudal axis, along which sound azimuth is represented, from birth. Injections of biotinylated dextran amine-fluorescein into the nBIC at different ages (P30, 60, and 90) labeled axons with numerous terminals and en passant boutons throughout the deeper layers of the SC. This labeling covered the entire mediolateral extent of the SC, but, in keeping with the pattern of retrograde labeling following microsphere injections in the SC, was more restricted rostrocaudally. No systematic changes were observed with age. The stability of the nBIC-SC projection over this period suggests that developmental changes in auditory spatial tuning involve other processes, rather than a gross refinement of the projection from the nBIC.     

A contribution to the study of the architecture of the autonomic nervous system of the digestive tract of the rat

Summary The distribution of aminergic and non-aminergic nerve fibres to the different constituents of the wall of the digestive tract in various regions is described. Aminergic fibres synapse with all nervous perikarya. Densely interlacing networks of nerve fibres are found in both layers of the tunica muscularis and in the lamina muscularis mucosae. A finely meshed plexus is observed in relation to the wall of the blood vessels in the wall of the gut. There are many fibres connecting the muscular and the vascular plexus. No nerve fibres have been observed in direct relation to the epithelium.The functional implications of these findings are discussed.