竹叶提取物对缺氧/复氧心肌细胞的保护作用

目的本研究旨在探讨竹叶提取物(BLE)对缺氧/复氧心肌细胞的保护作用及其分子机制.方法采用原代培养的新生大鼠心肌细胞建立缺氧/复氧损伤模型,实验分为正常细胞培养组、缺氧/复氧损伤模型组、缺氧/复氧损伤+ BLE(10-1, 10-2, 10-3, 10-4, 10-5 g·L-1)组、缺氧/复氧损伤+ Xiangdan(2.5×10-3g·L-1)组.检测培养基质乳酸脱氢酶(LDH)的活性,细胞线粒体脱氢酶活性,超氧化物歧化酶活性(SOD),NO的含量,心肌细胞Ca2+和丙二醛(MDA)浓度.结果 BLE可显著提高缺氧/复氧心肌细胞SOD的活性及细胞线粒体脱氢酶活性,并能显著抑制LDH的活性、MDA的生成,提高NO的含量,降低Ca2+的含量.结论 BLE对缺氧/复氧心肌细胞损伤具有一定的保护作用.     

荭草苷对缺氧-复氧心肌细胞的保护作用

目的探讨荭草苷 (orientin)对缺氧 复氧损伤心肌细胞的保护作用及其机制。方法采用原代培养的新生大鼠心肌细胞建立缺氧 复氧损伤模型 ,实验分为正常细胞培养组、缺氧 复氧损伤模型组、缺氧 复氧损伤 +荭草苷 (3、10、30 μmol·L-1)组、缺氧 复氧损伤 +verapamil(5 μmol·L-1)组。用黄嘌呤氧化酶法测定SOD的活力 ,硫代巴比妥酸显色法测定MDA含量 ,MTT染色法测定线粒体脱氢酶活性改变并测定LDH含量变化 ,荧光法测定细胞内钙浓度的变化。结果荭草苷可显著提高缺氧 复氧损伤心肌细胞内SOD的活性及细胞内线粒体脱氢酶活性 ,并能显著抑制LDH的活性、MDA的生成以及细胞内钙浓度。结论荭草苷具有明显的抗缺氧 复氧损伤 ,保护心肌细胞的作用     

环维黄杨星D对培养大鼠乳鼠心肌细胞缺氧/复氧损伤的保护作用

目的研究环维黄杨星D对纯化培养大鼠乳鼠心肌细胞缺氧/复氧损伤的保护作用及机制。方法采用纯化培养的心肌细胞建立缺氧/复氧损伤模型,测定细胞凋亡率、caspase-3、超氧化物歧化酶(SOD)、丙二醛(MDA)和乳酸脱氢酶(LDH)含量。结果与正常组比较,模型组LDH、MDA含量、caspase-3活性及细胞凋亡率明显增高(P<0.01),SOD活性明显降低(P<0.01);CVB-D(1×10-5mol.L-1)组降低LDH、MDA含量、caspase-3活性和细胞凋亡率,提高SOD活性,与缺氧/复氧组比较各实验指标均差异具有显著性(P<0.05)。结论CVB-D对缺氧/复氧造成的心肌细胞损伤具有保护作用,作用机制与清除氧自由基,抗脂质过氧化及降低细胞凋亡率有关。     

PGE_1对培养乳鼠心肌细胞缺氧/复氧损伤的保护作用

目的　研究PGE1对纯化培养心肌细胞缺血再灌注损伤的保护作用及机制。方法　采用纯化培养的心肌细胞建立缺氧 /复氧损伤模型 ,实验分 5组 :正常细胞培养组、缺氧 /复氧损伤模型组、缺氧 /复氧损伤 +PGE1(5、15、4 5 μg·L-1)组。分别用黄嘌呤氧化酶法测定SOD活力 ,硫代巴比妥酸显色法测定MDA含量 ,MTT染色法测定线粒体脱氢酶活性改变并测定LDH含量变化。结果　PGE1可明显提高SOD、LDH活性 ,降低MDA含量并可提高线粒体脱氢酶活性。结论　PGE1具有明显的抗缺氧复氧损伤、保护心肌作用     

重组鼠骨形态发生蛋白-7基因转染对心肌细胞缺氧复氧损伤的影响

为探讨转染骨形态发生蛋白-7(BMP-7)基因对心肌细胞缺氧复氧损伤的保护作用,将体外培养的乳大鼠心肌细胞分为3组:①阴性对照组;②缺氧复氧组:培养的心肌细胞缺氧120min,复氧240min;③转染组:转染基因后,再行缺氧120min/复氧240min。心肌细胞损伤程度以心肌细胞搏动次数和乳酸脱氢酶(LDH)、磷酸肌酸激酶(CPK)活性来表示。采用锥虫蓝排斥法检测心肌细胞存活率,同时检测心肌细胞超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。结果表明,心肌细胞缺氧复氧后可使细胞LDH活性显著增高,锥虫蓝摄取率明显升高,MDA含量较正常细胞显著增高,SOD含量较正常细胞显著降低;经BMP-7转染的心肌细胞可显著降低锥虫蓝摄取率,降低LDH、CPK活性,并提高细胞抗氧化能力,增高SOD活性,降低MDA含量。结论:BMP-7转染可对抗缺氧复氧对心肌细胞的损伤,其机制与提高心肌细胞抗氧化损伤能力有关。     

前列地尔对培养乳鼠心肌细胞缺氧复氧损伤的保护作用

目的 :观察前列地尔对培养乳鼠心肌细胞缺氧复氧损伤的保护作用。方法 :采用纯化培养的心肌细胞建立缺氧复氧损伤模型 ,观察不同浓度前列地尔 (5 ,15 ,4 5 μg·L- 1)剂量组细胞的形态学变化 ,黄嘌呤氧化酶法测定细胞内超氧化物歧化酶(SOD)活力 ,硫代巴比妥酸显色法测定细胞内丙二醛 (MDA)含量 ,并测定缺氧复氧后细胞培养液中乳酸脱氢酶 (LDH)活性 ,透射电镜观察细胞超微结构改变。结果 :与正常组比较 ,模型组细胞SOD下降 ,MDA和LDH升高 (均P <0 .0 1)。前列地尔各剂量组与模型组比较 ,心肌细胞SOD(除小剂量组 )活性提高 ,MDA和LDH含量降低 (P <0 .0 1)。且心肌细胞形态及超微结构改善。结论 :前列地尔具有明显的抗缺氧复氧损伤、保护心肌细胞的作用。     

冠心苏合丸系列组方药物血清对心肌细胞缺氧复氧损伤的影响*

目的:观察冠心苏合丸系列组方药物血清对大鼠心肌细胞缺氧复氧损伤的影响,阐明系列组方抗缺氧复氧损伤作用机制上的异同。方法:用体外细胞培养方法,培养乳鼠心肌细胞,复制心肌细胞缺氧复氧模型;运用血清药理学方法,将心肌细胞与含药血清共培养,测定细胞活性、上清液中肌酸激酶(CK)活性、乳酸脱氢酶(LDH)活性、丙二醛(MDA)含量以及细胞超氧化物歧化酶(SOD)活性、Na ,K -ATP酶和Ca2 ,Mg2 -ATP酶活性。结果:含青木香的冠心苏合丸、含土木香的冠心苏合丸以及不含木香的冠心苏合丸给药后30~90 m in的药物血清均能不同程度地增强缺氧复氧损伤的心肌细胞活性;显著抑制缺氧复氧损伤所致心肌细胞LDH和CK的外漏;显著增强缺氧复氧损伤的心肌细胞SOD活性,降低MDA含量;显著增强缺氧复氧损伤的心肌细胞Na ,K -ATP酶和Ca2 ,Mg2 -ATP酶活性;含土木香及不含木香的冠心苏合丸方在个别指标上的作用优于含青木香的冠心苏合丸。结论:冠心苏合丸方系列组方对缺氧复氧心肌细胞损伤均有明显保护作用,作用机制相似;原方中青木香被土木香替换或者去掉青木香,不影响其抗缺氧复氧损伤的作用。     

氯离子对心肌细胞缺氧/复氧损伤的影响

目的　研究氯离子对心肌细胞缺氧/复氧损伤的影响。方法　利用原代培养的心肌细胞缺氧/复氧损伤模型,去除细胞外的氯离子或采用氯通道阻断剂DIDS、SITS进行干预,检测细胞存活率及LDH、MDA、SOD、GXH Px活性变化。结果　缺氧/复氧损伤组与对照组比,LDH、MDA活性升高,细胞存活率、SOD、GXH Px降低; Cl- free+A R组、SITS+A R组处理后较缺氧/复氧组LDH、MDA活性低,细胞存活率、SOD、GXH Px升高;DIDS+A R组的上述指标与缺氧/复氧组比无差异。结论　①氯离子在心肌细胞缺氧/复氧损伤中起了重要作用。②氯通道阻断剂SITS对抗心肌细胞缺氧/复氧损伤有明显的保护作用,而DIDS无保护作用。     

新型褪黑素受体激动剂Neu-P11激活AMPK减轻心肌细胞缺氧/复氧损伤

目的研究新型褪黑素受体激动剂Neu-P11对心肌细胞缺氧/复氧损伤的作用及分子机制。方法实验分为对照组、缺氧/复氧模型组(H/R组)、H/R+Neu-P11组、H/R+Compound C组、H/R+Neu-P11+Compound C组。构建H9c2心肌细胞缺氧/复氧模型,检测各组心肌细胞凋亡情况,细胞培养液中乳酸脱氢酶(LDH)、肌酸激酶(CK)、SOD活性及MDA含量及心肌细胞AMPK的活性。结果与缺氧/复氧组细胞相比,Neu-P11预处理组细胞凋亡率明显减少,CK、LDH、MDA含量明显下降,SOD活性增加,心肌细胞AMPK活性明显增高,而AMPK特异性抑制剂Compound C可以阻断Neu-P11的保护作用。结论 Neu-P11能够减轻心肌细胞缺氧/复氧损伤,这一保护作用与激活AMPK有关。     

二氢石蒜碱对大鼠乳鼠培养心肌细胞缺氧/复氧损伤的保护作用

目的观察二氢石蒜碱(dihydrolycorine,DL)对Wistar大鼠的乳鼠培养心肌细胞缺氧/复氧损伤(H/R)的保护作用。方法采用培养的Wistar乳鼠的心肌细胞,建立H/R损伤模型,检测指标包括:①心肌细胞存活率;②超氧化物歧化酶(SOD)活性;③丙二醛(MDA)含量;④乳酸脱氢酶(LDH)活性。结果模型组缺氧后心肌细胞存活率降低,复氧后进一步下降,各个时间点细胞内SOD活性下降,MDA含量升高,乳酸脱氢酶(LDH)活性升高,与正常组比较差异具有显著性(P<0.01);在DL1、10、100μmol·L-1组,随着给药浓度的增加,细胞存活率升高,LDH活性变低,MDA含量逐渐趋于恢复正常,SOD活性逐渐回升,表明经DL干预之后,心肌细胞抗损伤能力加强,发生损伤的程度减轻。结论DL对培养的乳鼠心肌细胞H/R损伤具有保护作用,其作用在一定范围内呈剂量依赖关系,机制可能与其阻断α、β受体、抑制心肌细胞脂质过氧化反应有关。     

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.