三角帆蚌多糖抑瘤作用的实验研究

目的　研究三角帆蚌多糖的抗肿瘤活性。方法　给荷HepA腹水瘤小鼠胃饲三角帆蚌多糖 (每日剂量 5 0 ,2 5 0和5 0 0mg/kg) 8d ,检测抑瘤率、胸腺指数和脾指数 ;采用3H TdR掺入法 ,检测三角帆蚌多糖对HepA腹水瘤细胞DNA合成的影响。结果　在上述三种试验剂量 ,三角帆蚌多糖对小鼠HepA腹水瘤的抑制率分别为 3 4.9%、48.6%和 5 1.0 % ;与对照组比较 ,试验组的胸腺指数分别提高 5 5 .6% ,61.1%和 77.8% ,脾指数分别提高 8.2 % ,12 .3 %和 16.3 % ;在离体细胞培养试验中仅高浓度组 (10 0 0 μg/mL)三角帆蚌多糖对HepA瘤细胞DNA合成和细胞增殖有显著的抑制作用 (P <0 .0 5 )。 结论　三角帆蚌多糖有一定的抗肿瘤活性 ,其作用机制可能与增强胸腺免疫功能有关。     

普伐他汀对非对称性二甲基精氨酸促血管平滑肌细胞增殖的影响

目的　探讨非对称性二甲基精氨酸 (ADMA)对血管平滑肌细胞增殖的作用和普伐他汀对ADMA促平滑肌细胞增殖的影响及其机制。方法　用[3H]TdR掺入法和MTT比色法检测ADMA对培养的牛胸主动脉平滑肌细胞增殖作用的量效关系和时效关系 ,以及普伐他汀等药物对ADMA刺激平滑肌细胞增殖的影响。结果　用 30～ 30 0 μmol·L- 1ADMA分别孵育平滑肌细胞后 ,都明显增加血管平滑肌细胞DNA的合成 ,表现在 [3H]TdR掺入量由对照组的(6 38± 134)cpm增加到大剂量ADMA组的 (12 79±111)cpm。用 30 0 μmol·L- 1ADMA孵育细胞 2 4～ 96h呈时间依赖性地促进血管平滑肌细胞增殖 ,表现为 [3H]TdR掺入量随着时间的延长分别增加为对照组的 1.5 ,2 .7,4 .3和 5 .6倍。普伐他汀 (10 0 μmol·L- 1)可逆转ADMA所致的细胞DNA合成的增加 ,[3H]TdR掺入量由ADMA单独孵育组的 (6 10± 2 0 2 )cpm降低至普伐他汀处理组的 (35 6± 12 6 )cpm。此外 ,一氧化氮供体硝普钠和抗氧化剂吡咯烷二硫代氨基甲酸盐处理后也可逆转这种增加。MTT法测定细胞数也证明 ,30～ 30 0 μmol·L- 1普伐他汀呈剂量依赖性地对抗ADMA所致的平滑肌细胞增殖。结论ADMA可促进血管平滑肌细胞的增殖 ;普伐他汀对ADMA所诱导的平滑肌细胞增殖具有抑制作用 ;这两者均可能与细?     

聚酯型儿茶素对人肝癌细胞生长的抑制作用及其机制

目的　探讨聚酯型儿茶素对人肝癌SMMC 772 1细胞的生长抑制作用及其机制。方法　应用MTT法、集落形成试验、同位素掺入试验、细胞内cAMP/cGMP浓度测定、原位杂交等方法进行检测。结果　 5 0mg·L-1聚酯型儿茶素对SMMC 772 1细胞的生长、集落形成有明显的抑制作用 ;[3H] TdR、[3H] Leu掺入试验证明其可明显抑制细胞DNA和蛋白质合成 ;聚酯型儿茶素作用后 ,SMMC 772 1细胞内cAMP及cGMP浓度明显增加 ,细胞的c myc基因mR NA水平表达明显降低 ,而 p5 3基因mRNA水平表达明显升高。结论　聚酯型儿茶素对肝癌SMMC 772 1细胞的生长有明显的抑制作用 ,此作用与其抑制细胞DNA和蛋白质合成、升高细胞内cAMP浓度和抑制c myc基因表达、增强p5 3基因表达有关     

SB_(224289)对5-HT诱导的肺动脉平滑肌细胞增殖的影响

目的研究 5 HT1B受体拮抗剂SB2 2 42 89对 5 HT诱导的肺动脉平滑肌细胞增殖的影响 ,探讨肺血管构型重建的 5 HT1B受体机制。方法分离培养大鼠肺动脉平滑肌细胞 ,用MTT法和3 H TdR掺入法检测细胞增殖和DNA合成。结果SB2 2 42 89能剂量依赖地抑制 5 HT诱导的肺动脉平滑肌细胞增殖。SB2 2 42 89能剂量依赖地抑制 5 HT诱导的肺动脉平滑肌细胞的DNA合成 ,SB2 2 42 89能阻断 5 HT对肺动脉平滑肌细胞的促有丝分裂作用。结论SB2 2 42 89能抑制 5 HT引起的肺动脉平滑肌细胞的增殖。5 HT1B受体在 5 HT诱导的肺动脉平滑肌细胞增殖中有重要作用。     

神经酰胺诱导鼻咽癌细胞凋亡

目的　了解第二信使神经酰胺信号转导对鼻咽癌细胞生长的影响。方法　采用MTT法检测神经酰胺对鼻咽癌细胞株 (CNE 2 )增殖的抑制作用。光镜观察、荧光染色、流式细胞术检测细胞凋亡改变。Westernblot法检测p2 1WAF1的表达。结果　神经酰胺在 6 2 5、12 5、2 5、5 0 μm浓度下 ,对CNE 2细胞生长有明显的抑制作用 ,流式细胞仪检测发现亚G1峰出现 ,荧光染色可见核荧光强度增加、核片段化和凋亡小体。p2 1WAF1蛋白表达明显上调。结论　神经酰胺能诱导鼻咽癌细胞株CNE 2凋亡 ,且上调 p2 1WAF1蛋白表达。p2 1WAF1可能是神经酰胺诱导鼻咽癌细胞凋亡中起作用的因素之一。     

喹诺酮类化合物H25抗肿瘤侵袭活性体外研究

目的 研究喹诺酮类化合物H25抗肿瘤细胞侵袭转移的活性,初步探讨其作用机制.方法 明胶酶谱法验证H25对Ⅳ型胶原酶的竞争性抑制作用.MTT法检测H25对HT1080细胞的生长抑制作用.TranswellTM侵袭小室试验检测H25对HT1080细胞侵袭转移的抑制作用.明胶酶谱法和RT-PCR法检测H25对MMP-2、MMP-9表达水平的影响.细胞粘附试验观察H25对HT1080细胞粘附作用的影响.结果 H25能竞争性抑制Ⅳ型胶原酶的水解酶活性.5h和48h药物处理条件下,H25对HT1080细胞生长抑制作用的IC50分别为13.51和1.311μmol/L.TranswellTM侵袭小室试验中,H25对HT1080细胞侵袭Matrigel的抑制率分别为49.1%(1μmol/L,5h)、25.9%(0.1μmol/L,5h)、69.4%(0.1μmol/L,48h)、39.6%(0.01μmol/L,48h),其有效抑制浓度低于细胞生长抑制浓度.明胶酶谱分析证明,H25处理过的HT1080细胞培养上清中Ⅳ型胶原酶活性明显降低.但RT-PCR分析未检测到MMP-2、MMP-9 mRNA表达水平的变化.另外,1μmol/L的H25能抑制HT1080细胞的异质粘附作用.结论 H25能有效抑制HT1080细胞的侵袭,不仅因为H25是Ⅳ型胶原酶的竞争性抑制剂,而且可能与其对MMP-2、MMP-9表达的转录后抑制和异质粘附抑制相关.     

维生素E琥珀酸酯抑制人胃癌细胞DNA合成

目的　研究维生素E琥珀酸酯 (VES)对人胃癌细胞(SGC 790 1)生长以及DNA合成的影响。方法　以体外培养的人胃癌细胞 (SGC 790 1)作为研究对象 ,用活细胞计数方法绘制生长曲线。Giemsa染色方法计数细胞形成集落数。用流式细胞仪检测VES对SGC 790 1细胞周期的影响。并用3H TdR参入方法研究VES对SGC 790 1细胞DNA合成的影响。结果　VES可抑制SGC 790 1细胞的生长和集落形成 :5mg·L-1、10mg·L-1和 2 0mg·L-1VES处理SGC 790 1细胞 7d后 ,细胞生长抑制率分别为 41 2 %、98 3%和 10 0 % ;同样剂量的VES处理SGC 790 1细胞 2 4和48h后 ,集落形成抑制率分别为 6 7%、5 0 4%、87 2 %和2 4 7%、73 4%、10 0 %。细胞周期分析显示VES作用细胞48h后 ,G2 M期细胞比例降低 ,并呈一定的剂量效应关系 ;同时S期细胞比例升高。在培养 2 4和 48h后VES对SGC 790 1细胞3H TdR参入均有明显抑制作用 ,且呈剂量效应关系。结论　VES在体外可通过抑制细胞DNA合成来抑制人胃癌细胞生长     

姜黄素与5-氟尿嘧啶联用对人结肠癌HT-29细胞增殖的影响

目的　体外观察 5 氟尿嘧啶与姜黄素联用对人结肠癌HT 2 9细胞增殖的相互作用。方法　采用MTT法观察不同浓度姜黄素、5 氟尿嘧啶单独或联合应用对HT 2 9细胞生长的抑制作用 ,并利用中效原理判定两药合用的效果。结果　两种药物单独应用时 ,对HT 2 9细胞的抑制作用呈明显的剂量效应关系 ;对于HT 2 9细胞 ,姜黄素的中位抑制浓度为(32± 11) μmol·L- 1,5 氟尿嘧啶的中位抑制浓度为(10 4 0± 4 5 6 ) μmol·L- 1。应用中效原理分析显示 ,两药在联合应用时为协同效应 ,并且在不同的药物浓度配比下呈相同的趋势。增大姜黄素的用量可在更宽的效应范围内获得两种药物的协同效应。结论姜黄素与 5 氟尿嘧啶在联合应用时的相互作用为协同效应 ,本结果对于结肠癌的治疗具有一定的临床意义。     

舒马曲坦对大鼠肺动脉平滑肌细胞的促有丝分裂作用

目的　观察 5 HT1B/1D受体激动剂舒马曲坦对肺动脉平滑肌细胞 (PASMC)的促有丝分裂作用 ,探讨其作用机制和诱发肺血管构型重建的可能性。方法　分离培养大鼠PASMC ,用噻唑蓝 (MTT)法检测细胞增殖 ,用流式细胞术法分析细胞周期和DNA合成。结果　MTT法检测 5 羟色胺 (5 HT) 0 .0 1,0 .1,1.0 μmol·L- 1可促进PASMC增殖 ,增殖率分别增加2 0 1% ,2 2 8%和 2 5 6 %。舒马曲坦 0 .0 1,0 .1,1.0μmol·L- 1可促进PASMC增殖 ,增殖率分别增加199% ,2 2 0 %和 2 4 5 %。流式细胞术分析 5 HT 0 .1和1.0 μmol·L- 1组的细胞增殖指数分别为 2 2 .2 %和2 5 .9% ,S期细胞分数分别为 7.2 %和 9.8%。舒马曲坦 0 .1和 1.0 μmol·L- 1组的增殖指数分别为2 1.2 %和 2 3.9% ,S期细胞分数分别为 6 .6 %和8.8% ,均较对照组明显增高 (P <0 .0 5 )。 5 HT和舒马曲坦能够促进PASMC从G0 /G1期进入S期 ,5 HT的促有丝分裂作用可能有 5 HT1B/1D受体的参与。结论　舒马曲坦能促进PASMC的增殖。 5 HT1B/1D 受体在PASMC增殖和肺血管构型重建中有重要作用。舒马曲坦有致肺动脉高压的风险     

地塞米松抑制肿瘤坏死因子α介导的肾小球系膜细胞

目的 探讨肿瘤坏死因子α(TNFα)对人肾小球系膜细胞(MC)促增殖效应及地塞米松(DXM)对其的抑制作用。方法 培养人肾MC，采用^3H—胸腺嘧啶掺入法(^3H—TdR掺入法)测定MC增殖：ELISA法测定细胞因子(IL1)及细胞外基质ECM(FN、LN)。结果 TNFa明显刺激MC^3H—TdR掺入，与对照组比较P＜0.01，同时，TNFa促进MC分泌IL1、和LN、FN，与对照组比较P＜0.01。DXM抑制TNFa刺激MC^3H—TdR掺入及分泌ILl、LN、FN，呈剂量依赖关系(P＜0.01)。结论 细胞因子TNFa能明显促进MC增殖及细胞外基质合成，而DXM具有抑制TNFa的作用，为临床上使用DXM治疗肾小球疾病提供了新的理论依据。     

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.

---

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.