天麻素对大鼠局灶性脑缺血损伤的保护作用研究

目的 探讨天麻素(Gastrodine,Gas)对大鼠局灶性脑缺血损伤的保护作用及机制.方法 线栓法制备大鼠大脑中动脉栓塞模型,缺血2h后再灌注.天麻素(5,10,20 mg/kg)再灌注同时腹腔给药,再灌注后24 h,测定大鼠神经功能缺失评分和脑梗死体积,伊文思蓝法观察血脑屏障破坏程度,Western blot检测梗死半暗带皮层组织炎症因子TNF-α、IL-1β和IL-6的蛋白表达.结果 天麻素(10,20 mg/kg)能改善大鼠脑缺血后神经功能缺失,减小脑梗死体积,降低血脑屏障的通透性.天麻素(20 mg/kg)对梗死半暗带皮层组织TNF-α表达的抑制率为24％,对IL-1β表达的抑制率为34％,对IL-6表达水平的抑制率为38％.结论 天麻素可降低血脑屏障的通透性,其通过减低炎症反应而对局灶性脑缺血损伤发挥保护作用.     

原花青素对脑缺血再灌注损伤羟自由基含量和肿瘤坏死因子-α表达影响

目的：观察葡萄籽原花青素（GSP）对大鼠脑缺血再灌注损伤中羟自由基含量和肿瘤坏死因子-α（TNF-α）表达的影响。方法 Wistar大鼠48只随机分为四组：假手术组、缺血再灌注模型组、GSP大剂量（40 mg/kg）组、GSP小剂量（10 mg/kg）组,每组12只,应用线栓法制作大鼠大脑中动脉栓塞模型（MCAO）,缺血2 h再灌注24 h。假手术组手术过程相同但不栓塞大脑中动脉。其中GSP大剂量组、小剂量组术前7 d分别腹腔注射2 ml/kg葡萄籽原花青素,模型组大鼠术前7 d腹腔注射2 ml/kg生理盐水,1次/d,再灌注前15 min加注1次。MCAO模型制作完成后首先进行神经功能评分,然后利用生物化学技术检测大鼠血清羟自由基含量和一氧化氮合酶活性,免疫组织化学染色检测半暗带区颞顶部脑皮质神经细胞TNF-α的表达。结果 GSP对大鼠脑缺血再灌注损伤有保护作用。其机制可能与降低NOS活性、脑组织羟自由基含量,降低脑组织TNF-α的表达,抑制神经细胞凋亡等有关。结论 GSP对脑缺血再灌注损伤具有一定的保护作用,具有临床研究价值。     

川芎嗪对大鼠局灶性脑缺血再灌注损伤的保护作用及机制研究

目的探讨川芎嗪对大鼠局灶性脑缺血再灌注损伤的保护作用及机制。方法将64只健康雄性SD大鼠随机分为四组：（1）假手术组;（2）缺血再灌注组;（3）川芎嗪20 mg/kg处理组;（4）川芎嗪40 mg/kg处理组。每组各16只,8只用于脑梗死体积测定,8只用于mRNA和蛋白的测定。采用线栓法制备大鼠局灶性大脑中动脉栓塞模型,缺血2 h再灌注24 h。术后对大鼠神经功能进行评分;2,3,5-氯化三苯四氮唑染色观察脑梗死体积;酶联免疫吸附法测定脑组织中肿瘤坏死因子-α（TNF-α）、白介素-1β（IL-1β）和核因子-κBp65（NF-κBp65）水平;实时定量聚合酶链反应和蛋白质印迹法分别检测Toll样受体4（TLR4）mRNA和蛋白的表达。结果与假手术组比较,缺血再灌注组大鼠的神经功能缺陷评分和脑梗死体积明显增加;脑组织中TNF-α、IL-1β和NF-κBp65水平以及TLR4的表达也显著升高,差异均有统计学意义（P〈0.05）。川芎嗪处理组上述指标,与缺血再灌注组比较,差异有统计学意义（P〈0.05）;不同剂量川芎嗪处理组间比较,差异无统计学意义（P〉0.05）。结论川芎嗪可抑制脑缺血再灌注诱导的损伤,其机制与抑制TLR4/NF-κB信号通路,进而减少炎症因子的产生有关。     

红景天苷联合阿司匹林对大鼠脑缺血再灌注损伤的保护作用研究

目的 研究红景天苷联合阿司匹林在大鼠脑缺血再灌注损伤的保护作用。方法 选取6周龄SPF级成年雄性SD大鼠50只,采用线栓法建立大鼠脑缺血再灌注脑损伤动物模型。随机分为A组（正常组）、B组(MCAO模型组)、C组[模型红景天苷给药组（5 mg/kg）]、D组[模型阿司匹林给药组（10 mg/kg）]、E组[模型联合给药组（5 mg/kg红景天苷和10 mg/kg阿司匹林）],每组10只。依据Longa评分各组神经功能损伤并测定脑梗死体积;采用ELISA法测定组织中i NOS和GSH-PX的活性以及血中TNF-α和IL-6的含量;Western blotting检测大鼠缺血组织中Bcl-2和Bax蛋白表达水平。结果 C组、D组和E组都对鼠脑损伤具有保护作用,且E组具有更好的保护作用;E组可显著降低大鼠脑组织中的i NOS活性、提高GSH-PX活性、增加Bcl-2蛋白表达、减少Bax蛋白表达,且能显著减少大鼠血中TNF-α和IL-6的含量。结论 红景天苷联合阿司匹林可通过增加自由基清除、抑制凋亡信号通路、减少炎症细胞因子含量来减轻脑缺血再灌注造成的大鼠脑组织损伤。     

黄芪甲苷调节IL-10/β-EP信号通路对腰椎间盘突出症模型大鼠神经根损伤的影响

目的 探究黄芪甲苷调节白介素-10(IL-10)/β-内啡肽(β-EP)信号通路对腰椎间盘突出症(LDH)大鼠神经根损伤的影响。方法 随机选择10只大鼠记为假手术组(Sham组),其余大鼠通过移植髓核构建LDH大鼠模型,将造模成功大鼠随机分为LDH组、黄芪甲苷组(20 mg/kg黄芪甲苷)、 AS10组(0.5 mg/kg IL-10/β-EP信号通路抑制剂AS10)、黄芪甲苷+AS10组(20 mg/kg黄芪甲苷+0.5 mg/kg AS10),每组10只,Sham组和LDH组给予等量0.9%氯化钠溶液。机械刺激敏感性实验以及热刺激敏感性实验检测大鼠机械缩足阈值(PWT)以及热痛阈(TWL);ELISA法检测血清白介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)水平;免疫荧光染色测定小胶质细胞和星形胶质细胞活性;TUNEL染色检测细胞凋亡;Western blot检测IL-10、β-EP蛋白表达。结果 与Sham组比较,LDH组PWT值、TWL值、IL-10、β-EP蛋白水平显著减小(P<0.05),细胞凋亡率、TNF-α、IL-1β水平、离子钙接头蛋白分子1(Iba1...     

灵仙新苷对大鼠心肌缺血再灌注损伤的保护作用及机制研究

目的 考察灵仙新苷对大鼠心肌缺血再灌注损伤（MIRI）的保护作用,并阐述可能的作用机制。方法 SD大鼠随机分为6组：假手术组、模型组、丹参酮Ⅱ_A（阳性药,16 mg/kg）组和灵仙新苷低、中、高（8、16、32 mg/kg）组,连续ig给药7 d;采用结扎冠状动脉左前降支法制备大鼠MIRI模型,缺血40 min再灌120 min;试剂盒法检测MIRI大鼠血清肿瘤坏死因子-α（TNF-α）、白介素-1β（IL-1β）、白介素-6（IL-6）水平;TTC染色法检测心肌梗死率,流式细胞术检测心肌细胞凋亡率;Western blotting法检测心肌组织中Bcl-2、Bax、TNF-α及Caspase-3的蛋白表达水平。结果 与模型组比较,灵仙新苷（8、16、32 mg/kg）显著降低MIRI模型大鼠血清中TNF-α、IL-1β、IL-6水平,心肌梗死率和心肌细胞凋亡率;明显上调Bcl-2蛋白表达水平,下调Bax、TNF-α、Caspase-3蛋白表达水平,且均具有显著性差异（P<0.05、0.01）。结论 灵仙新苷对MIRI大鼠心肌具有保护作用,其机制可能与抑制TNF-α,调节Bcl-2/Bax蛋白平衡,减少MIRI诱导的心肌细胞凋亡有关。     

芦丁对大鼠脑缺血性再灌注损伤的保护作用

目的 探讨芦丁对脑缺血再灌注损伤的作用及机制.方法 30只SD大鼠随机分为3组.模型组和芦丁组采用线栓法构建大脑中动脉局灶缺血(1.5 h)再灌注损伤模型,芦丁组在缺血前15 min腹腔注射芦丁(10 mg/kg),模型组腹腔注射等量生理盐水.术后24 h处死大鼠,收集脑组织和血清,HE染色观察脑组织病理形态学变化,ELISA检测和RT-PCR检测脑组织促炎症细胞因子TNF-α,IL-1β和IL-8的表达变化,Western Blot检测脑组织中Wnt,β-catenin,cyclin D 1和survivin的表达变化.结果 芦丁可减轻脑缺血再灌注损伤大鼠的脑组织病理形态学变化,Wnt和β-catenin的表达和促炎症细胞因子TNF-α,IL1β和IL-8表达(P＜0.05).结论 芦丁可通过抑制Wnt/β-catenin信号途径介导的炎性反应而减轻脑缺血再灌注损伤.     

木犀草素抑制JAK2/STAT3信号通路减轻大鼠脑缺血 再灌注损伤作用的研究

目的 观察木犀草素减轻大鼠脑缺血再灌注损伤的作用并探讨其潜在机制。方法 SD大鼠按随机数字 表法分为假手术组、大脑中动脉栓塞（MCAO）组、木犀草素低剂量组（50 mg/kg）、木犀草素高剂量组（100 mg/kg）及尼 莫地平组（15 mg/kg）,灌胃给药,共7 d。采用线栓法建立MCAO大鼠模型,比较神经功能损伤评分、脑组织含水量、 脑梗死体积,测定各组肿瘤坏死因子α（TNF-α）、白细胞介素（IL）-6、IL-1β、B细胞淋巴瘤因子2（Bcl-2）、Bcl-2相关 X蛋白（Bax）、半胱氨酸蛋白酶3（Caspase-3）含量及磷酸化Janus蛋白酪氨酸激酶2（p-JAK2）、磷酸化信号转导及转 录激活蛋白3（p-STAT3）蛋白表达等变化情况。结果 与假手术组比较,MCAO组大鼠神经功能损伤评分、脑组织含 水量、脑梗死体积、脑组织TNF-α、IL-6、IL-1β、Bax、Caspase-3含量及JAK2、STAT3蛋白磷酸化水平均明显增加（P＜ 0.05）,而脑组织Bcl-2含量明显降低（P＜0.05）;与MCAO组比较,木犀草素低、高剂量组及尼莫地平组大鼠神经功能 损伤评分、脑组织含水量、脑梗死体积、脑组织TNF-α、IL-6、IL-1β、Bax、Caspase-3含量及JAK2、STAT3蛋白磷酸化 水平均明显降低（P＜0.05）,而脑组织Bcl-2含量明显增加（P＜0.05）。结论 木犀草素具有减轻大鼠脑缺血再灌注 损伤的作用,该作用与抑制JAK2/STAT3信号通路活化,进而减弱炎症反应及减少细胞凋亡有关。     

依达拉奉对脑缺血再灌注损伤大鼠脑组织Fas及细胞凋亡的影响

目的观察依达拉奉对脑缺血再灌注损伤大鼠脑组织Fas及细胞凋亡的影响。方法24只雄性SD大鼠随机分为三组：假手术组（SH组）、缺血再灌注组（IR组）、依达拉奉治疗组（EDA组）,每组8只。IR组和EDA组线栓法制备脑缺血再灌注模型;SH组栓线只进入颈外动脉。EDA组于再灌注前30min和再灌注12h经腹腔注射依达拉奉3mg/kg,SH组和IR组在相同时间点注射等容量生理盐水。再灌注24h取血清测超氧化物歧化酶（SOD）活力、丙二醛（MDA）含量;取脑组织检测缺血半暗带Fas的表达及细胞凋亡情况;于再灌注3h和24h,参照Zealonga五级神经功能缺损评分标准评价神经功能损伤情况。结果与SH组比较,IR组和EDA组再灌注24h血清SOD活力降低（P〈0.01）,IR组SOD活力低于EDA组（P〈0.01）。与SH组比较,IR组和EDA组再灌注24h时血清MDA含量升高（P〈0.01）;IR组MDA含量高于EDA组（P〈0.05）。SH组脑组织无或仅有少量细胞Fas表达呈阳性,IR组与EDA组缺血半暗带均有大量Fas表达;EDA组平均灰度值较IR组大（P〈0.01）。SH组脑组织仅有少量凋亡细胞,IR组与EDA组缺血半暗带可见大量凋亡神经细胞;EDA组凋亡细胞数较IR组少（P〈0.01）。SH组各时点无神经损伤症状,再灌注3h,IR组与EDA组大鼠神经功能损伤差异无显著性（P〉0.05）;再灌注24h,与IR组比较EDA组大鼠神经功能损伤减轻（P〈0.05）。结论脑缺血再灌注后,大鼠血清SOD活力降低、MDA含量升高、大脑皮层半暗带Fas表达及凋亡细胞数明显增多。依达拉奉可保护SOD活力,降低MDA含量,减少缺血再灌注大脑皮层半暗带Fas的表达及细胞凋亡,从而减轻神经功能损伤,对脑缺血再灌注损伤具有一定的保护作用。     

康脑液1号对大鼠脑缺血再灌注细胞凋亡及GFAP表达的影响

目的观察康脑液1号对SD大鼠脑缺血再灌注细胞凋亡及胶质纤维酸性蛋白（GFAP）表达的影响,探讨其对脑缺血再灌注保护作用的可能机制。方法采用栓线法复制SD大鼠大脑中动脉梗死模型（MCAO）,分别于缺血2h后再灌注1d、3d、7d。将180只大鼠随机分为5组（每组36只）：假手术组,模型（缺血再灌注）组,盐酸法舒地尔注射液组,康脑液1号A组,康脑液1号B组。观察康脑液1号对大鼠脑缺血再灌注神经功能、脑梗死面积和病理形态学的影响。采用TUNEL法检测缺血半暗带和灶中心区凋亡细胞,采用免疫组化法检测缺血半暗带和灶中心区GFAP表达的变化。结果模型组与假手术组相比,缺血半暗带凋亡细胞及GFAP阳性细胞数目增多（P〈0.05）。康脑液1号可不同程度地降低实验性脑缺血大鼠的神经功能评分、减小梗死灶面积并减轻脑组织病理形态改变（P〈0.05）;康脑液1号2组大鼠脑组织缺血半暗带凋亡细胞和GFAP表达减少,而梗死灶中心凋亡细胞和GFAP表达却增多。结论康脑液1号可能通过调节脑缺血再灌注细胞凋亡和GFAP表达而促进脑损伤修复及重塑,从而发挥脑保护作用。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

2-(Acetoxyphenyl)-(Z)-styryl sulfides as cyclooxygenase inhibitors

2-(Acetoxyphenyl)-(Z)-styryl sulfides are described as selective cyclooxygenase-2 (COX-2) inhibitors, useful for treating inflammation and COX-2-mediated disorders including neoplasia. 2-(Acetoxyphenyl)-(Z)-styryl sulfide is claimed to be the most potent COX inhibitor in the series with a COX-2 selectivity ratio of 33. This compound is also claimed to be superior to celecoxib (Celebrex^®, Pfizer) in inhibiting cell growth of colorectal carcinoma cells. In this evaluation, the COX inhibitory activity of this compound is compared to that previously disclosed for diarylheterocycles and 2-(acetoxyphenyl)alkyl sulfides. The validity of the DLD-1 cell line in the growth inhibition studies is questioned based on recent literature reports indicating the lack of COX-2 expression in this cell line.     

Sleep-disordered breathing with chronic opioid use

Chronic opioid use for pain relief or as substitution therapy for illicit drug abuse is prevalent in our societies. In the US, retail distribution of methadone and oxycodone has increased by 824 and 660%, respectively, between 1997 and 2003. μ-Opioids depress respiration and deaths related to illicit and non illicit chronic opioid use are not uncommon. Since 2001 there has been an emerging literature that suggests that chronic opioid use is related to central sleep apnoea of both periodic and non-periodic breathing types, and occurs in ～ 30% of these subjects. The clinical significance of these sleep-related abnormalities are unknown. This review addresses the present knowledge of control of ventilation mechanisms during wakefulness and sleep, the effects of opioids on ventilatory control mechanisms, the sleep-disordered breathing found with chronic opioid use and a discussion regarding the future research directions in this area.     

Drug targets for cognitive enhancement in neuropsychiatric disorders

The investigation of novel drug targets for treating cognitive impairments associated with neurological and psychiatric disorders remains a primary focus of study in central nervous system (CNS) research. Many promising new therapies are progressing through preclinical and clinical development, and offer the potential of improved treatment options for neurodegenerative diseases such as Alzheimer's disease (AD) as well as other disorders that have not been particularly well treated to date like the cognitive impairments associated with schizophrenia (CIAS). Among targets under investigation, cholinergic receptors have received much attention with several nicotinic agonists (α7 and α4β2) actively in clinical trials for the treatment of AD, CIAS and attention deficit hyperactivity disorder (ADHD). Both glutamatergic and serotonergic (5-HT) agonists and antagonists have profound effects on neurotransmission and improve cognitive function in preclinical experiments with animals; some of these compounds are now in proof-of-concept studies in humans. Several histamine H3 receptor antagonists are in clinical development not only for cognitive enhancement, but also for the treatment of narcolepsy and cognitive deficits due to sleep deprivation because of their expression in brain sleep centers. Compounds that dampen inhibitory tone (e.g., GABA_A α5 inverse agonists) or elevate excitatory tone (e.g., glycine transporter inhibitors) offer novel approaches for treating diseases such as schizophrenia, AD and Down syndrome. In addition to cell surface receptors, intracellular drug targets such as the phosphodiesterases (PDEs) are known to impact signaling pathways that affect long-term memory formation and working memory. Overall, there is a genuine need to treat cognitive deficits associated with many neuropsychiatric conditions as well as an increasingly aging population.