K+通道在Jurkat细胞调节性体积减小中的作用

目的：研究K^ 通道在Jurkat细胞调节性体积减小(RVD)中的作用。方法：调节细胞外不同离子浓度，用细胞成像系统测定Jurkat细胞(人T淋巴细胞肿瘤细胞株)在不同渗透压时细胞容积的变化。结果：细胞培养液中缺少Ca2^ ，或细胞培养液中的K^ 浓度升高，或使用Ca^2 敏感的K^ 通道(KCa)阻断剂均可抑制Jurkat细胞的RVD；应激免疫抑制蛋白(ISPS)具有抑制Jurkat细胞RVD的作用。结论：Jurkat细胞中KCa通道是RVD不可缺少的因素。ISPS对免疫功能抑制作用的机理之一，可能是抑制了T淋巴细胞上的K^ 通道。     

非神经性AChRs对脾淋巴细胞增殖的调节作用及药理学特征

目的:观察淋巴细胞非神经性AChRs对脾淋巴细胞增殖的调节作用。方法:利用MTT比色法检测AChRs激动剂氨甲酰胆碱对刀豆蛋白A诱导的离体小鼠脾淋巴细胞增殖反应的影响。结果:氨甲酰胆碱在不同的浓度呈现不同的作用,在10-11～10-9mol·L-1和10-5～10-4mol·L-1时显著促进淋巴细胞的增殖,阿托品(10-7mol·L-1)可以阻断该效应。而氨甲酰胆碱(10-7～10-6mol·L-1)可显著抑制淋巴细胞的增殖,美加明(10-7mol·L-1)可以阻断其作用。提示氨甲酰胆碱在10-11～10-9mol·L-1和10-5～10-4mol·L-1可通过激活mAChRs促进淋巴细胞的增殖,而在10-7～10-6mol·L-1通过激活nAChRs抑制淋巴细胞的增殖。结论:氨甲酰胆碱通过激活非神经性mAChRs和nAChRs对淋巴细胞增殖反应产生促进增殖和抑制增殖的双向调节作用。     

二烯丙三硫对人前列腺癌PC-3细胞生物学行为的影响及与uPA系统关系的初探

目的:研究二烯丙三硫(DATS)对人前列腺癌PC-3细胞生物学行为的影响及对尿激酶型纤溶酶激活物(uPA)系统的调节作用。方法:细胞增殖活性(MTS)比色法测定20、40、60μmol·L-1DATS处理前列腺癌PC-3细胞24、48、72h后PC-3细胞的增殖能力;细胞体外侵袭试验检测20、40、60μmol·L-1DATS对PC-3细胞侵袭能力的作用;划痕试验观察40μmol·L-1DATS处理PC-3细胞24h后PC-3细胞迁移能力;逆转录聚合酶链式反应(RT-PCR)和蛋白印迹(Western blot)法分别检测40μmol·L-1DATS作用PC-3细胞后的uPA、uPAR和PAI-1的mRNA及其蛋白表达水平。结果:20、40、60μmol·L-1DATS对PC-3细胞的生长均有较明显的抑制作用,且呈浓度和时间依赖性;DATS呈浓度依赖抑制细胞的浸润能力,其中40μmol·L-1与体内试验更接近;40μmol·L-1DATS明显抑制细胞的迁移能力,并在mRNA和蛋白水平上,显著上调PAI-1的表达,但对uPA和uPAR的表达无显著影响。结论:DATS抑制PC-3细胞的增殖、浸润和迁移,该效应可能与DATS显著上调PAI-1的表达有关系。     

香芹酚抑制人胃癌细胞增殖的体外实验研究

目的:研究香芹酚对胃癌BGC-823细胞的生长、凋亡及侵袭的影响。方法:采用MTT法检测香芹酚对胃癌BGC-823细胞的增殖抑制作用;流式细胞技术检测香芹酚对胃癌BGC-823细胞凋亡的影响;Transwell法检测香芹酚对胃癌BGC-823细胞侵袭能力的影响;实时荧光定量PCR检测MMP-9、TIMP-1的表达;Western blot检测caspase-9、PARP的表达以及ERK、P38信号通路的激活情况。结果:香芹酚能够明显抑制胃癌细胞生长(P<0.05),与对照组相比,香芹酚处理组胃癌BGC-823细胞凋亡明显增加(0μmol·L-1vs 10μmol·L-1,0μmol·L-1vs 20μmol·L-1,0μmol·L-1vs 40μmol·L-1,0μmol·L-1vs80μmol·L-1),侵袭能力显著降低(0μmol·L-1vs 80μmol·L-1),差异均有统计学意义(P<0.000 1)。香芹酚处理组细胞caspase-9、TIMP-1表达升高(P<0.000 1)、PARP发生裂解(P<0.000 1),P38信号被激活,同时MMP-9表达降低(P<0.000 1),ERK信号通路受到抑制。结论:香芹酚能够抑制胃癌细胞的增殖和侵袭,诱导其凋亡,其作用与MAPK信号通路激活密切相关。     

羟基红花黄色素A促犬胸主动脉内皮细胞增殖及其机制初探

目的研究羟基红花黄色素A(HSYA)对常氧低氧两种条件下体外培养的犬胸主动脉内皮细胞增殖的影响,且探讨其增殖作用是否与血管内皮生长因子(VEGF)有关。方法采用内膜消化刮取法获取犬胸主动脉内皮细胞;分别在常氧(21%)低氧(10%)两种条件下,以噻唑蓝(MTT)法观察HSYA对血管内皮细胞(VEC)增殖的影响,VEGF作为阳性对照;并且观察VEGF抗体及其两种酪氨酸受体(Flt1和KDR)的抗体对HSYA促VEC增殖及分泌VEGF的影响,采用ELISA法检测VEGF水平。结果HSYA1×10-3mol·L-1、1×10-4mol·L-1在常氧条件下孵育72h、96h和120h或在低氧条件下孵育24h、48h、72h对VEC都有明显促增殖作用,并具有浓度和时间依赖性,HSYA1×10-3mol·L-1与VEGF2.6×10-7mol·L-1在同样条件下对VEC的促增殖作用强度相当;10μg·mL-1的VEGF、Flt1和KDR的抗体均能明显抑制1×10-3mol·L-1HSYA的促VEC增殖作用,尤其10μg·mL-1的VEGF抗体和Flt1抗体能明显抑制1×10-3mol·L-1HSYA的促VEC分泌VEGF作用。结论在常氧低氧两种条件下,HSYA均具有明显促VEC增殖作用,尤其在低氧条件下更为明显;而且HSYA的促VEC增殖作用可能与VEGF或VEGF受体有关。     

螺内酯诱导人急性白血病细胞Jurkat凋亡的作用研究

目的研究螺内酯对人急性白血病细胞Jurkat体外增殖的抑制及诱导凋亡的作用。方法将终浓度分别是10、50及100μmol/L的螺内酯加入Jurkat细胞的培养体系中,24 h内每隔4 h通过MTT法分析Jurkat细胞的增殖抑制率,Annexin V/PI流式细胞术法分析Jurkat细胞的早期凋亡率。结果螺内酯与Jurkat细胞共同培养12 h后,螺内酯能显著增加对细胞的增殖抑制作用,并且与药物浓度成正相关,各浓度组的抑制率随着培养时间的延长而升高,与药物干预时间成正相关;螺内酯处理Jurkat细胞24 h,各浓度组诱导细胞凋亡率分别为:10μmol/L组(11.2±0.35)%、50μmol/L组(29.8±1.27)%及100μmol/L(56.5±1.41)%,各个浓度组诱导细胞凋亡率与药物浓度成正相关。结论螺内酯对人T淋巴细胞白血病Jurkat细胞具有抑制增殖和诱导凋亡的作用,提示该药可能具有潜在抑瘤作用。     

钾通道开放剂比那地尔对卵巢癌细胞增殖及凋亡的影响

目的 研究钾通道开放剂比那地尔对卵巢癌细胞(SKOV3)增殖和凋亡的作用.方法 将比那地尔(浓度分别为10、50、200、500 mmol·L-1)作用于卵巢癌细胞,用MTT法检测细胞活性,采用Hoechest33258荧光染色检测细胞凋亡,同时通过碘化丙啶(PI)染色,采用流式细胞仪检测细胞凋亡比率.结果 比那地尔对SKOV3细胞的增殖抑制效应具有剂量依赖性特点,并能诱导SKOV3细胞凋亡.结论 钾通道对SKOV3细胞增殖具有重要调控作用,钾通道开放剂可促进细胞凋亡.     

盐酸小檗碱诱导Jurkat细胞凋亡的研究

目的本研究旨在观察盐酸小檗碱能否抑制Jurkat细胞的增殖、并对其作用机制进行初步探讨。从而为临床上应用治疗急性T淋细胞白血病提供实验依据。方法MTT比色法检测盐酸小檗碱对Jurkat细胞增殖的影响;AO／EB染色法观察细胞凋亡的形态学改变;TUNEL方法检测细胞凋亡的生化功能变化。结果盐酸小檗碱对Jurkat细胞的生长有抑制作用,呈现明显的剂量和时间依赖性,24h、48h、72h、96h、120h的IC50分别为107．5567μg·mL^-1、23．5600μg·mL^-1、10．8069μg·mL^-1、9．2660μg·mL^-1和2．7121μg·mL^-1盐酸小檗碱处理Jurkat细胞可见典型的细胞凋亡形态学改变;TUNEL可见深棕色凋亡细胞。结论盐酸小檗碱能有效地抑制体外Jurkat细胞的增殖,其作用可能是通过诱导Jurkat细胞凋亡有关。     

山奈酚对急性短暂缺氧时大鼠海马CA1神经元电压依赖性钾通道的作用

目的研究山奈酚对正常和急性短暂缺氧时大鼠海马CA1锥体神经元电压依赖性钾通道的作用.方法急性分离大鼠海马CA1区锥体神经元,采用全细胞记录,用含有氰化钾(KCN)60μmol·L-1的标准外液灌流模拟细胞缺氧,观察山奈酚对正常和缺氧时海马CA1区神经元电压依赖性钾通道的作用.结果山奈酚对正常和缺氧时海马CA1神经元电压依赖性K 电流有明显的抑制作用,可同时抑制瞬时外向型钾电流(IA)和延迟整流性钾电流(Ik),具有浓度依赖和电压依赖性;山奈酚对IA的半数抑制浓度(IC50)约为50μmol·L-1,对IK的IC50约为80μmol·L-1.结论山奈酚对正常和缺氧时大鼠海马CA1神经元电压依赖性钾通道有抑制作用,其对钾通道的抑制作用可能参与脑缺血保护.     

番茄红素干预食管癌细胞系(Eca9706)及表皮生长因子表达的研究

目的研究番茄红体外对食管癌细胞素(Eca9706)的作用及可能机制.方法番茄红素10-3、10-4、10-5、10-6、10-7 mol·L-15个浓度组干预食管细胞24 h,观察细胞存活量及蛋白含量,并用免疫组织化学的方法观察干预前后表皮生长因子(EG-FR)的表达情况.结果番茄红素10-3mol·L-1时,促进肿瘤细胞生长,10-4、10-5、10-6mol·L-1有抑制肿瘤细胞生长作用,而且10-4mol·L-1效果最好,10-7mol·L-1对抑制瘤生长效果不明显,仅有轻度抑制作用(P＞0.05).而蛋白含量仅有10-6和10-7mol·L-1有轻度抑制作用但无统计学意义(P＞0.05).免疫组织化学结果显示,干预前有PGFR表达,干预后未见表达.结论番茄红素对食管癌细胞系(ECA9706)有抑制生长作用,呈剂量反应关系,此作用与抑制EGFR蛋白表达有关.     

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.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

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.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.