促红细胞生成素对大鼠脑缺血再灌注损伤后缺血侧皮层神经元凋亡和Bcl-2表达的影响

目的探讨促红细胞生成素(Erythropoietin，EPO)对大鼠局灶性脑缺血再灌注损伤后的保护作用。方法采用线栓法阻断大鼠一侧大脑中动脉(MCA)血流2h，再灌注24h制成局灶性脑缺血再灌注损伤模型。将32只雄性SD大鼠随机分成EPO组、缺血再灌注组、假手术组和正常组。于缺血开始时EPO组给EPO 3000U／kg腹腔注射；缺血再灌注组和假手术组给予等剂量生理盐水。再灌注24h后断头取脑、切片，进行HE染色、Bcl-2免疫组化染色和细胞凋亡检测。结果缺血2h再灌注24h后，EPO组和缺血再灌注组大鼠缺血侧皮层可检测到凋亡细胞，且EPO组凋亡细胞数明显少于缺血再灌注组，假手术组和正常组未见凋亡细胞；EPO组和缺血再灌注组缺血侧皮层Bcl-2阳性细胞数均高于假手术组和正常组，与缺血再灌注组相比，EPO组Bcl-2蛋白表达显著增高。结论EPO可抑制缺血再灌注损伤后缺血侧皮层的细胞凋亡，其机制可能是通过上调bcl-2基因表达而实现。     

高血压大鼠局灶性脑缺血再灌注后Survivin及Bcl-2表达

目的:研究肾性高血压大鼠局灶性脑缺血再灌注后脑组织Survivin、Bcl- 2表达和细胞凋亡,探讨其意义。方法:体重2 90～3 10g肾性高血压Wistar大鼠5 0只随机分成2组:A组(缺血再灌注组)及B组(假手术组)。采用线栓法制作局灶性脑缺血2h再灌注模型,假手术组不造成缺血。用免疫组化法和TUNEL法分别观察再灌注6、12、2 4、48和72h脑组织Survivin、Bcl- 2表达和凋亡细胞。结果:在缺血再灌注组中:①再灌注6h时较多Survivin表达,到72h仍见强烈表达;②再灌注6h即可见Bcl -2表达较多,2 4h达高峰,此后逐渐下降;③再灌注6h后已出现较多凋亡细胞,在72h达高峰。假手术组及再灌注组的非缺血侧未见Survivin、Bcl- 2阳性细胞,但见0～2个凋亡细胞。结论:局灶性脑缺血再灌注后Survivin、Bcl- 2表达显著增高,细胞凋亡参与了脑缺血再灌注过程。     

大鼠脑缺血再灌注损伤后的细胞凋亡与Bcl-2、Bax的表达

目的:观察脑缺血再灌注损伤中的细胞凋亡与Bcl2家族的关系。方法:参照ZeaLonga线栓法制作急性大鼠大脑中动脉缺血再灌注模型,观察脑缺血再灌注后大鼠缺血脑组织中的凋亡细胞变化情况及Bcl2、Bax蛋白表达情况,同时通过透射电镜观察缺血侧脑组织神经元超微结构变化。结果:同对照组相比缺血再灌注组凋亡神经元细胞增多(TUNEL阳性细胞)(P<0.05);Bax、Bcl2阳性细胞均升高(P<0.01),同时Bcl2/Bax比值降低;电镜观察神经元超微结构出现凋亡早期改变。结论:Bcl2/Bax比值影响脑缺血再灌注损伤后细胞凋亡。     

局灶性脑缺血预适应后大鼠血浆皮质醇含量变化

目的探讨脑缺血预适应后糖皮质激素与皮层神经元损伤的关系。方法利用线栓法建立大鼠大脑中动脉脑缺血再灌注模型,通过放射免疫方法测定脑缺血再灌注后各组大鼠再灌注3h、12h、24h和48h各时点的血浆皮质醇含量变化。结果缺血组和预缺血组在再灌注4个时点糖皮质激素含量均有增高,同对照组、假手术组相比有显著差异（P〈0．01）。预缺血组与缺血组相比,预缺血组在再灌注4个时点糖皮质激素含量低于缺血组（P〈0．05）。HE染色皮层神经元损伤显著,预缺血组明显轻于缺血组。结论脑缺血预适应导致缺血再灌注后血浆糖皮质激素含量降低,这可能是其减轻皮层神经元损伤的原因之一。     

bFGF对大鼠局灶性缺血再灌注脑组织的保护作用

目的探讨bFGF对大鼠脑缺血再灌注损伤后神经细胞凋亡和脑组织中SOD、MDA含量变化的影响。方法应用线栓法制作大鼠局灶性脑缺血再灌注模型,大脑中动脉阻塞1h再灌注损伤24h,检测假手术组、缺血再灌注组和bFGF组的凋亡细胞数和脑组织中SOD、MDA的含量。结果假手术组偶见凋亡细胞,缺血再灌注组和bFGF组凋亡细胞数分别是26.35±5.67和18.65±5.91,与缺血再灌注组相比,bFGF组缺血区皮质凋亡神经元明显减少(P<0.05)。SOD,MDA测定结果显示三组间比较,具有显著性差异(P<0.01和P<0.05)。结论抗氧化作用可能是bFGF减少大鼠脑缺血再灌注损伤后细胞凋亡的分子机制之一。     

17-β雌二醇对大鼠脑缺血再灌注损伤细胞凋亡影响的实验研究

目的观察雌二醇对大鼠脑缺血再灌注损伤脑细胞凋亡的影响。方法72只大鼠随机分为假手术组（n=8）、实验对照组及雌二醇治疗组,后两组又进一步分为3h、6h、12h、24h4个时间点,每时间点8只。线栓法建立大鼠局灶性脑缺血再灌注损伤模型,石蜡切片HE染色及免疫组化染色检测脑组织的细胞凋亡情况及凋亡调控基因Bcl-2、Caspase-3的表达。结果雌二醇治疗组的脑组织缺血半暗带区细胞凋亡较实验对照组明显减少;随着再灌注时间的延长,治疗组半暗带区Bcl一2的表达上调而Caspase-3的表达上调减弱。结论17-β雌二醇具有减少脑缺血再灌注损伤细胞凋亡的作用,而凋亡抑制基因Bcl-2的表达升高及凋亡执行蛋白Caspase-3的表达减弱可能其是重要机制之一。     

垂体腺苷酸环化酶激活肽对大鼠脑缺血再灌注损伤后缺血皮层p-JNK表达及神经细胞凋亡的影响

目的研究活化的c-Jun氨基末端激酶（p-JNK）在大鼠局灶性脑缺血再灌注损伤后的表达和垂体腺苷酸环化酶激活肽（PACAP）的影响、抑制细胞凋亡的机制。方法制成局灶性脑缺血再灌注损伤模型。72只大鼠随机分成假手术组、缺血再灌注对照组、PACAP治疗组。缺血开始时治疗组静脉注射PACAP 2．5μg。再灌注后各时间点处死取脑,进行HE染色、p-JNK免疫组化染色和TUNEL法检测神经元凋亡。结果不同时间点PACAP组神经细胞缺血性损伤较缺血再灌注对照组减轻。缺血再灌注对照组p-JNK分别在2、48h成2次表达高峰,凋亡细胞较多;PACAP组再灌注后pJNK表达下降,凋亡细胞减少。结论PACAP对局灶性脑缺血再灌注损伤有保护作用,可抑制细胞凋亡．部分依赖于其可下调p—JNK表达。     

脑缺血再灌注损伤时 c-fos、c-jun 的表达和细胞凋亡

目的　研究脑缺血再灌注大鼠神经细胞凋亡和原癌基因c fos、c jun表达。 方法　 8周龄健康雄性Wistar大鼠 2 4只 ,随机分为缺血再灌注组、假手术组和对照组 ,每组各 8只。制作大鼠大脑中动脉栓塞 (MCAO)再灌注模型 ,缺血 4h再灌注 2h后断头处死 ,TUNEL法检测神经细胞凋亡 ,免疫组织化学法检测神经细胞c fos、c jun蛋白的表达。结果　缺血再灌注组细胞凋亡率、平均吸光度及c fos、c jun阳性细胞率、平均吸光度均高于假手术组和对照组 (P <0 .0 5 )。结论　脑缺血再灌注损伤可诱导c fos、c jun蛋白的表达和细胞凋亡 ;脑缺血再灌注大鼠神经功能评分与c fos、c jun蛋白的表达和细胞凋亡呈正相关。     

粒细胞集落刺激因子对大鼠脑缺血再灌注损伤脑Caspase-3与细胞色素C表达的影响

目的探讨粒细胞集落刺激因子(G-CSF)在大鼠脑缺血再灌注损伤中的神经保护作用机制。方法将36只健康成年雄性SD大鼠随机分为假手术组、缺血再灌注组、G-CSF治疗组,每组12只。采用线栓法制作大鼠大脑中动脉缺血再灌注模型,于脑缺血2 h再灌注0 h及24 h给予G-CSF治疗组G-CSF(按体质量50μg/kg)腹部皮下注射,给予假手术组和缺血再灌注组等量生理盐水。采用Longa评分法进行神经功能评分,采用免疫组化法检测各组大鼠脑组织细胞色素C、半胱氨酸蛋白酶-3(Caspase-3)表达水平,应用原位末端转移酶标记(TUNEL)检测神经细胞凋亡情况,TTC染色检测脑梗死体积。结果假手术组大鼠未发现脑梗死病灶,细胞色素C和Caspase-3阳性细胞数及凋亡细胞亦少见。G-CSF治疗组细胞色素C、Caspase-3阳性细胞数及凋亡细胞数均较缺血再灌注组明显减少(P<0.01);缺血再灌注组和G-CSF治疗组均可见大脑中动脉供血区梗死灶,但G-CSF治疗组梗死灶较缺血再灌注组明显缩小(P<0.01),神经功能明显改善。结论 G-CSF对脑缺血再灌注损伤有神经保护作用,其作用机制可能通过阻断线粒体/细胞色素C途径抑制细胞凋亡。     

脑缺血再灌注后白质损伤研究

目的 观察大鼠脑缺血再灌注后不同时间髓鞘和轴突损伤的病理变化,明确脑缺血后白质损伤情况.方法 利用线栓法制备雄性SD大鼠大脑中动脉闭塞(MCAO)模型.将大鼠随机分为假手术组和缺血2 h再灌注6 h、12 h、1 d、3 d、7 d、14 d和21 d组,每组4只.于规定时间点处死大鼠取脑,行常规HE染色观察皮层区神经元病理变化,行Luxol fast blue-periodic acid Schiff(LFB-PAS)染色法标记大脑神经髓鞘,Bielschowsky银染法标记轴突,计算缺血侧与健侧髓鞘染色的积分吸光度(integrated optical densities,IODs)比值代表白质受损程度.结果 MCAO再灌注6 h皮层区即已出现细胞间质水肿,核深染、固缩,细胞变性坏死.随再灌注时间延长损伤加重,神经元进一步减少.再灌注14 d及21 d有大量胶质细胞增生.与假手术组比较,再灌注6 h时髓鞘染色IODs比值亦开始下降(P<0.01);12 h时有空洞形成,再灌注14 d髓鞘损伤达高峰,IODs比值降到最低,髓鞘脱失明显;21 d时髓鞘IODs比值与14 d比较差异无统计学意义(P>0.05).轴突变化规律与髓鞘基本相同.结论 脑白质对缺血同样敏感,在急性脑缺血早期即已存在白质损伤,并随再灌注时间延长逐渐加重,提示脑缺血后应及早对白质损伤进行干预.     

Neuroimaging in epilepsy in tropics

Epilepsy is a major public health problem in many tropical countries. Also, some of the tropical diseases are major contributors to the higher prevalence of epilepsy in these countries. The etiologic factors responsible for epilepsy in these countries are quite different from those in the developed world. This article discusses the etiologic factors and neuroimaging of epilepsy in light of the conditions in these tropical countries.     

癫痫与抑郁关系的研究进展

抑郁是癫痫患者中常见的精神障碍,严重地影响了患者的生活质量。传统的观点认为癫痫患者因为存在着诸多社会学问题易出现抑郁倾向,癫痫和抑郁是单向的联系,但大量的研究已经证明癫痫和抑郁之间存在双向的联系,一种异常状态的存在可能易转化为另一种异常状态的发展。癫痫和抑郁存在着共同的发病机制。本文主要就癫痫和抑郁的双向联系以及抗抑郁药物在癫痫患者中的应用进行阐述。     

Sudanophilic lipid accumulation in astrocytes in periventricular leukomalacia in monkeys

Summary Sudanophilic lipid accumulation is a characteristic feature of periventricular leukomalacia (PVL) of infants. At least two types of lipid-containing cells have been identified, one being the macrophage, the other the pre-myelin glial cell. A third type of lipid-containing cell has been seen in two monkeys with spontaneous PVL. Electron microscopically this cell appears to be an astrocyte. This probably represents a reaction of the astrocyte to hypoxia and may be the equivalent of the hypertrophic astrocytes found in human infants.Supported in part by NIH grant HDO 8633 and the Regional Primate Research Center Grant RR-00166     

Increase in cathepsin D activity in rat brain in aging

Cathepsin D-like activity in homogenates of five brain areas of 3-month-old and 24-month-old Fischer 344 rats was measured. With hemoglobin as substrate at pH 3.2, more than 90% of the activity was inhibited by pepstatin. In each area studied, activity was more than twice as high in the old rat brain: 140-160% higher in the cortex, cerebellum, pons-medulla, and striatum and 90-100% higher in the hippocampus and spinal cord. The greatly increased metabolic capacity in the absence of an increase in protein turnover may have a role in age-related pathological degeneration in the brain.     

Characteristics of nociceptors in the periodontium--an in vitro study in rats

Recent studies have indicated that nociceptors can be classified into various types according to their physiological properties. These studies have clarified that the frequency distribution of various nociceptor types is different among body sites and animal species. In the present study, we investigated the physiological properties of rat's periodontal nociceptors in an in vitro jaw-nerve preparation. Responses were recorded from functional single filaments in the inferior alveolar nerve. To determine the nociceptor type, calibrated von Frey filaments, heat, and bradykinin (BK) stimuli were used. We found five subtypes of nociceptors in the periodontal ligaments of the lower incisor: Adelta-high threshold mechanonociceptors (Adelta-HTM, n=28), Adelta-mechanoheat nociceptors (Adelta-MH, n=6), Adelta-polymodal nociceptors (Adelta-POLY, n=26), C-high threshold mechanonociceptors (C-HTM, n=3) and C-polymodal nociceptors (C-POLY, n=4). Most nociceptors were Adelta-innervated, while only a small number of C-innervated nociceptors were found. The present results suggest that periodontal nociceptors transmit mainly fast pain, and may thus play a role in rapid detection of injure-related stimuli during mastication.     

Gender in Voice Perception in Autism

Deficits in the perception of social stimuli may contribute to the characteristic impairments in social interaction in high functioning autism (HFA). Although the cortical processing of voice is abnormal in HFA, it is unclear whether this gives rise to impairments in the perception of voice gender. About 20 children with HFA and 20 matched controls were presented with voice fragments that were parametrically morphed in gender. No differences were found in the perception of gender between the two groups of participants, but response times differed significantly. The results suggest that the perception of voice gender is not impaired in HFA, which is consistent with behavioral findings of an unimpaired voice-based identification of age and identity by individuals with autism. The differences in response times suggest that individuals with HFA use different perceptual approaches from those used by typically developing individuals.     

Defects in Bioenergetic Coupling in Schizophrenia

Synaptic neurotransmission relies on maintenance of the synapse and meeting the energy demands of neurons. Defects in excitatory and inhibitory synapses have been implicated in schizophrenia, likely contributing to positive and negative symptoms as well as impaired cognition. Recently, accumulating evidence has suggested that bioenergetic systems, important in both synaptic function and cognition, are abnormal in psychiatric illnesses such as schizophrenia. Animal models of synaptic dysfunction demonstrated endophenotypes of schizophrenia as well as bioenergetic abnormalities. We report findings on the bioenergetic interplay of astrocytes and neurons and discuss how dysregulation of these pathways may contribute to the pathogenesis of schizophrenia, highlighting metabolic systems as important therapeutic targets.     

Ethnic disparities in problem behaviour in adolescence contribute to ethnic disparities in social class in adulthood

BACKGROUND: It is important for prevention of social class disparities to know how ethnic disparities in social class arise among migrant children. We contribute to this understanding by examining the role of problem behaviour in adolescence. METHODS: Prospective observational study with 753 Dutch native and 217 Turkish migrant adolescents (11-18 year) followed for 10 years. Internalising and externalising problems were assessed in adolescence and employment status and occupational level were assessed in adulthood. The difference in odds ratios (OR) before and after adjustment for internalising and externalising problems was an indication of the predictive value of disparities in internalising and externalising problems for the development of social class disparities. RESULTS: A total of 135 (62%) of the Turkish and 602 (80%) of the Dutch adults were employed. Internalising and externalising problems were not associated with employment status. Of the employed, 65 (48%) Turkish and 179 (30%) Dutch adults worked in low-level occupations (p < 0.0001). Internalising and externalising problems were associated with both ethnicity and occupation. The OR for low-level occupation for Turkish adults was 1.78 (1.19-2.65), indicating ethnic disparities. Adjustment for internalising problems lowered the OR with 36% to 1.50 (0.97-2.31), and adjustment for externalising problems lowered it with 8% to 1.72 (1.15-2.57). Findings were similar for men and women and did not vary by age. CONCLUSIONS: Ethnic disparities in occupational level in adulthood could partly be attributed to disparities in mental health between Turkish migrants and Dutch natives in adolescence. Prevention of ethnic disparities in mental health at young age may therefore also contribute to the prevention of occupational differences in adulthood.     

Progress in neuroprotection in Parkinson's disease

Slowing or aborting the progress of neurodegeneration in Parkinson's disease (PD) remains the most important unmet need of this disorder. There are several recent developments in trial design and also in drugs under investigation for possible neuroprotective effect. Emphasis has been placed on clinical as opposed to imaging end-points and these include change in a clinical rating scale, e.g. United Parkinson's disease Rating Scale (UPDRS), or time to additional therapy. The introduction of the delayed-start, or wash-in, trial design adds an additional dimension to drug evaluation for neuroprotection. Compounds that have been recently tested in clinical trial include the monoamine oxidase-B inhibitor rasagiline, the anti-apoptotic agents TCH346 and CEP1347, and the promitochondrial agent creatine. The dopamine agonists have been evaluated for a neuroprotective effect using imaging end-points. Perhaps the most important and simplest concept for neuroprotection has been the theory that early dopaminergic support for the degenerating dopaminergic system per se provides significant long-term clinical benefit for PD patients.     

Changes in parasympathetic system in medulla oblongata in male pigs in the course of tachycardia-induced cardiomyopathy

Background

Autonomic imbalance constituting a fundamental feature of heart failure (HF) has been assessed mainly at the periphery. Changes in the functioning of autonomic centers in the brain remain unclear. We investigated the molecular elements of parasympathetic system, i.e. α7 nicotinic acetylcholine receptor (α7nAChR) and enzymes metabolizing acetylcholine (acetylcholinesterase, AChE, choline acetyltransferase, ChAT) in medulla oblongata (MO) of male pigs with chronic tachycardia-induced cardiomyopathy.

Methods

The mRNA levels of AChE, ChAT, α7nAChR and X-box binding protein 1 (spliced form, XBP1s) in MO were analyzed using qPCR, AChE and ChAT activities using spectrophotometry, proteasome activity using fluorometry, and the protein level of α7nAChR using Western blotting.

Results

The development of systolic HF was accompanied by an increase in circulating catecholamines, a decrease in the AChE and α7nAChR mRNA in MO, an increase in AChE activity (all p < 0.05), and no change in either the mRNA or activity of ChAT. Both circulating catecholamine levels and AChE activity were inversely related to systolic function of left myocardial ventricle (p < 0.05). The level of α7nAChR protein in MO and its cytoplasmatic fraction were higher in pigs with moderate and severe HF as compared to the other animals (p < 0.01). There was no difference in proteasome activity in MO between diseased and healthy animals, whereas the XBP1s mRNA decreased during HF progression (p < 0.05).

Conclusions

Molecular elements of parasympathetic system are changed within the medulla oblongata during the progression of systolic non-ischemic heart failure in male pigs, indicating a functional link between MO and heart in HF.