蝙蝠葛酚性碱对动物学习记忆能力的影响

目的:观察并比较蝙蝠葛酚性碱和吡拉西坦(脑复康)对大鼠和小鼠学习能力的影响。方法:以东莨菪碱和乙醇分别使动物发生学习记忆获得障碍和记忆再现障碍,采用迷津法和跳台法进行测试。结果:蝙蝠葛酚性碱和脑复康对东莨菪碱和乙醇所致的学习记忆障碍均有改善作用;与模型组比较,蝙蝠葛酚性碱组、脑复康组P均<0.05,蝙蝠葛酚性碱100mg/kg组比50mg/kg组效果好。结论:蝙蝠葛酚性碱对动物学习记忆障碍有改善作用。     

蝙蝠葛酚性碱对小鼠脑缺血再灌注后软脑膜微循环的影响

目的:观察蝙蝠葛酚性碱对小鼠脑缺血再灌注后软脑膜微循环障碍的改善作用。方法:将60只小鼠随机分为假手术组、缺血再灌注组、蝙蝠葛酚性碱低、中、高剂量组、阳性对照组。用动脉夹夹闭小鼠双侧颈总动脉10 min后去掉动脉夹,制作脑缺血再灌注损伤模型, 应用BI2000微循环图像处理系统,通过开放式颅窗观察各组小鼠软脑膜微静脉、微动脉血流速度和微小血管开放数目,以及蝙蝠葛酚性碱对小鼠脑缺血再灌注后软脑膜微循环障碍的改善作用。结果:缺血损伤组软脑膜微小动脉、静脉血管直径明显缩小,血流速度缓慢,与正常对照组比较,差异有显著意义(P <0.05);蝙蝠葛酚性碱可剂量依赖性增加缺血再灌注所致的软脑膜微小动、静脉血流速度和血管开放数目。结论:蝙蝠葛酚性碱可增加小鼠脑缺血再灌注脑软膜血流量,改善脑缺血后脑软膜微循环障碍,发挥对脑缺血的保护作用。     

蝙蝠葛酚性碱对实验性心肌缺血保护作用的研究

目的:研究蝙蝠葛酚性碱对实验性心肌缺血的保护作用。方法:结扎大鼠冠状动脉左前降支建立急性心肌缺血模型,监测标准Ⅱ导心电图;颈总动脉取血,测定血清超氧化物歧化酶(SOD)的活性,丙二醛(MDA)的含量,乳酸脱氢酶(LDH)及肌酸激酶(CK)的活性。结果:蝙蝠葛酚性碱可抑制ST段抬高幅度,增强超氧化物歧化酶(SOD)的活性,降低丙二醛(MDA)的含量和乳酸脱氢酶(LDH)、肌酸激酶(CK)的活性。结论 蝙蝠葛酚性碱对大鼠实验性心肌缺血具有保护作用,其机理可能与抗自由基生成,增强心肌耐缺血能力有关。     

蝙蝠葛酚性碱在大鼠小肠吸收特性研究

目的研究蝙蝠葛酚性碱在大鼠小肠的吸收特性。方法采用大鼠肠灌流实验,主要从药物吸收部位、浓度和介质pH等三方面对蝙蝠葛酚性碱的吸收特性进行研究。结果蝙蝠葛酚性碱在大鼠小肠吸收速率（Ka）顺序为：回肠＞空肠≈十二指肠;药物浓度对Ka无显著影响;蝙蝠葛酚性碱在pH 5.4,6.8,7.8介质的Ka差异有统计学意义（P＜0.05）。结论蝙蝠葛酚性碱在大鼠小肠各肠段均有一定吸收,但在回肠段吸收更好;蝙蝠葛酚性碱的吸收机制为被动扩散;随着肠循环液pH增大,蝙蝠葛酚性碱Ka增大。     

蝙蝠葛酚性碱对胃癌菏瘤鼠抗肿瘤作用

目的:初步观察蝙蝠葛酚性碱对胃癌小鼠原位移植瘤生长的抑制作用。方法:取50只小鼠建立肿瘤鼠动物模型,测定小鼠瘤重、检测蝙蝠葛酚性碱对肿瘤的抑制率。结果:蝙蝠葛酚性碱各组对荷瘤鼠肿瘤生长具有抑制作用,三个剂量组的抑瘤率分别是55.13%、48.67%、39.92%,与模型对照组比较具有统计学意义(P<0.05)。结论:蝙蝠葛酚性碱对胃癌荷瘤鼠具有抑制作用,本研究为其在临床应用提供了一定的实验和理论依据。     

蝙蝠葛酚性碱对脑缺血再灌注大鼠脑水肿及血脑屏障通透性的影响

目的 研究蝙蝠葛酚性碱对脑缺血再灌注大鼠脑水肿及血脑屏障通透性的影响.方法 线栓法制备大鼠大脑中动脉阻断局灶性脑缺血模型,缺血2 h后实行再灌注,采用干湿重方法 测定脑含水量,用伊文思蓝法(Evans Blue,EB)观察再灌注不同时间点血脑屏障通透性变化,并观察蝙蝠葛酚性碱对不同再灌注时间大鼠脑水肿和血脑屏障通透性的影响.结果 蝙蝠葛酚性碱能明显降低脑缺血再灌注大鼠的脑含水量和EB含量.结论 蝙蝠葛酚性碱对脑缺血再灌注大鼠脑水肿及血脑屏障通透性具有保护作用.     

蝙蝠葛苏林碱在犬体内药动学-药效学结合模型研究

目的 :研究蝙蝠葛苏林碱在beagle犬体内的药动学与药效学之间的关系。 方法 :4只beagle犬给予蝙蝠葛苏林碱 6mg·kg-1静脉注射后 ,分时取血 ,同时通过生理记录仪观察犬心电、血压及血流动力学的变化。采用反相高效液相色谱法测定血浆中蝙蝠葛苏林碱的浓度。结果 :蝙蝠葛苏林碱在犬体内动力学行为符合二房室开放模型 ,对犬药效学影响峰值为 10～ 15min ,皆明显滞后于血药浓度峰值。结论 :通过在beagle犬体内建立的蝙蝠葛苏林碱药动学 药效学 (PK PD)结合模型 ,可以成功预测蝙蝠葛苏林碱的血药浓度及其药理效应。     

蝙蝠葛酚性碱对脑缺血再灌注大鼠脑水肿及血脑屏障通透性的影响

目的研究蝙蝠葛酚性碱对脑缺血再灌注大鼠脑水肿及血脑屏障通透性的影响。方法线栓法制备大鼠大脑中动脉阻断局灶性脑缺血模型,缺血2 h后实行再灌注,采用干湿重方法测定脑含水量,用伊文思蓝法(Evans Blue,EB)观察再灌注不同时间点血脑屏障通透性变化,并观察蝙蝠葛酚性碱对不同再灌注时间大鼠脑水肿和血脑屏障通透性的影响。结果蝙蝠葛酚性碱能明显降低脑缺血再灌注大鼠的脑含水量和EB含量。结论蝙蝠葛酚性碱对脑缺血再灌注大鼠脑水肿及血脑屏障通透性具有保护作用。     

蝙蝠葛酚性碱对大鼠局灶性脑缺血-再灌注继发炎性损伤的保护作用

目的研究蝙蝠葛酚性碱对大鼠局灶性脑缺血-再灌注继发炎性损伤的保护作用及其机制。方法用线栓法制作大鼠右侧大脑中动脉栓塞模型，缺血2 h后，将线抽出实行再灌注，观察蝙蝠葛酚性碱对粘附分子(ICAM-1)表达、白细胞的粘附与浸润、髓过氧化物酶(MPO)活性和一氧化氮(NO)含量的影响。结果蝙蝠葛酚性碱可明显抑制ICAM-1的表达，减轻白细胞的粘附与浸润，降低缺血侧大脑皮层和海马组织中的MPO活性和NO含量。结论蝙蝠葛酚性碱对大鼠局灶性脑缺血-再灌注后的炎性损伤有明显保护作用，其机制可能与抑制ICAM-1表达，减轻白细胞的粘附与浸润，减少NO产生有关。     

蝙蝠葛酚性碱对BXPC-3肿瘤抑制作甩及外周血IL-1含量的影响

目的观察蝙蝠葛酚性碱对BXPC-3荷瘤裸鼠的肿瘤抑制作用及外周血IL-1含量的影响。方法建立BXPC-3荷瘤裸鼠动物模型,检测蝙蝠葛酚性碱对转移瘤的抑制率;采用ELISA法检测荷瘤小鼠外周血IL-1含量变化。结果蝙蝠葛酚性碱高、中、低剂量对BXPC-3荷瘤裸鼠均有明显抑制肿瘤生长的作用,其抑瘤率分别为34．91％,52．83％和41．51％,可以降低BXPC-3荷瘤小鼠血清IL-1含量。结论蝙蝠葛酚性碱对BXPC-3荷瘤裸鼠具有明显的抑瘤作用,其抑瘤作用可能与降低BXPC-3荷瘤小鼠血清IL-1含量有关,该研究为其临床应用提供了一定的实验和理论依据。     

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.