姜黄素体外增敏抗肿瘤药物作用

目的 探讨姜黄素与抗癌药物长春新碱、阿霉素合用对KB及KBv200细胞的体外杀伤作用。方法 采用MIT法测定药物的体外杀伤作用，用荧光分光光度法进行细胞内阿霉素蓄积测定。结果 姜黄素与长春新碱、阿霉素合用，在KB及KBv200细胞中均有增敏作用。蓄积实验说明，在KBv200细胞，其增敏作用与增加细胞内阿霉素蓄积有关；而在KB细胞中的增敏作用与细胞内阿霉素蓄积量无关。结论 姜黄素通过不同机理增敏抗癌药对敏感细胞KB及其耐药细胞KBv200的毒性。     

番荔枝内酯单体89-2实验治疗KBv200及KB细胞移植瘤的作用

目的番荔枝内酯单体89-2是自阿蒂莫耶番荔枝植物分离获得。本研究旨在探讨89-2对MDR肿瘤的实验治疗作用。方法以MTT法测定细胞毒;KBv200及KB细胞裸鼠移植瘤模型研究89-2对MDR肿瘤的实验治疗作用;以Fura-2-AM法测定P-糖蛋白(P-gp)功能。结果89-2对KBv200及KB细胞的IC₅₀分别为48.7和64.6 nmol·L^-1(P>0.05)。89-2对KB及KBv200细胞裸鼠移植瘤具有相似的剂量依赖性抑制作用,而毒性可以耐受。89-2剂量依赖性地增加KBv200细胞的Fura-2积累。结论89-2体内外均抑制KB和KBv200细胞生长,具有开发前景。     

荧光分光光度法检测大鼠膀胱组织中表阿霉素浓度

目的建立大鼠膀胱组织中表阿霉素(Epirubicin,EPI)的荧光分光光度法检测方法。了解聚维酮(polyvidone,PVP)是否有促进EPI进入膀胱壁的作用。方法建立雌性Sprague-Dawley大鼠膀胱灌注模型,经大鼠尿道单独灌注1mg·mL-1表阿霉素或联合1%聚维酮溶液灌注后,保留药物2h后,处死大鼠,分离及匀浆膀胱组织,用含0.3mol·L-1HCl的50%乙醇抽提,离心取上清液,用荧光分光光度计在λex/em为470/554nm测定其荧光值,通过标准曲线方程计算表阿霉素浓度。结果样本扫描未见杂峰,日内精密度<2.75%,日间精密度<4.01%,表阿霉素于肿瘤组织匀浆中抽提回收率>86.0%,表阿霉素联合1%聚维酮灌注组的膀胱组织内表阿霉素浓度明显高于单灌表阿霉素组,P<0.01。结论本方法特异性高,快速、简便,结果准确可靠,适用于大鼠膀胱组织中EPI药代动力学研究。1%PVP联合膀胱灌注能促使表阿霉素进入膀胱壁。     

姜黄素与阿霉素合用对KB及KB_(v200)细胞的杀伤作用

目的　了解姜黄素与阿霉素联合应用对人口腔上皮癌KB细胞及其多药耐药KBv2 0 0 细胞的杀伤作用及其作用机制。方法　采用MTT法测定药物的体外杀伤作用 ,应用金氏公式进行联合用药分析 ;采用荧光分光光度法进行细胞内阿霉素蓄积测定 ,以荧光探针DPH标记 ,用荧光偏振法测定细胞膜流动性。结果　姜黄素 4 2 5～ 17 0 0 μmol·L-1与阿霉素合用 ,对KB及KBv2 0 0 细胞可产生单纯相加至增强的协同杀伤效果。姜黄素对阿霉素蓄积的影响 ,在KBv2 0 0 细胞显示增加 ,而在KB细胞则显示降低 ;膜流动性实验表明 ,姜黄素对KB及KBv2 0 0 细胞膜流动性均无影响。结论　姜黄素与阿霉素同时联合用药可产生协同作用。其机制在KBv2 0 0 细胞与增加细胞内阿霉素蓄积有关 ;在KB细胞可能与药效协同作用有关 ;但姜黄素对两种细胞的作用均与细胞膜流动性改变无关     

KBv200裸鼠移植瘤模型的建立及其耐药特性的探讨

目的　建立一种人多药抗药性 (MDR)细胞株的裸鼠移植瘤模型并探讨其MDR特性 ,为筛选MDR逆转剂进行体内逆转MDR的研究提供模型。方法　按SPF级动物常规饲养裸鼠 ,鼠腋窝皮下接种 1× 10 7个细胞 ,观察成瘤率及生长特性 ,并比较裸鼠体内细胞与原代细胞耐药特性。细胞毒测定采用MTT法。P糖蛋白 (Pgp)的测定采用流式细胞仪法。结果　KBv2 0 0裸鼠移植瘤的成瘤率为 10 0 % ;在本研究的饲养条件下 ,19d瘤重可达 1 0～ 2 5 g ,平均 (2 1±0 4) g。原代及裸鼠体内KBv2 0 0对长春新碱 (VCR)的IC50分别为 1 479和 1 472 μmol·L-1,两者比较差异无显著性(P >0 0 5 )。原代及裸鼠体内KBv2 0 0的Pgp的表达率分别为 92 1%、91 9% ,二者差异无显著性 ;二者荧光强度亦未见明显改变 ,即Pgp表达量未见改变。 结论　以KBv2 0 0细胞所建立的裸鼠移植瘤模型 ,成瘤率高 ,在实验期间 15～ 2 0d内仍保持其MDR的特性 ,可提供做为MDR研究的体内模型。     

三种荧光分光光度法测定肿瘤组织中阿霉素含量的研究

目的 :通过比较测定肿瘤组织中阿霉素(ADR)含量的 3种荧光分光光度法 ,建立简便、快捷的测定肿瘤组织中阿霉素含量的荧光分光光法。方法 :分别采用正丁醇法、硝酸银法、酸性异丙醇法测定水溶液及肿瘤组织匀浆中ADR的含量 ,比较荧光光谱曲线、回收率和灵敏度。结果 :硝酸银法测定瘤组织匀浆中的ADR含量 ,背景荧光值低 ,线性范围0 .2～ 0 .8mg·L-1,最低检出量 0 .15mg·L-1,回收率超过 97%以上。酸性异丙醇法与正丁醇法测定瘤组织中的ADR含量 ,背景荧光值高 ,回收率分别 <4 0 %和 5 0 %。结论 :硝酸银法适合肿瘤组织中的ADR的含量测定 ,该方法准确、灵敏、可靠。     

脂质体阿霉素逆转肿瘤多药耐药的活性和机制研究

目的 探讨脂质体阿霉素( PLD)逆转肿瘤多药耐药(MDR)的活性及其逆转机制.方法 以噻唑蓝(MTT)方法检测PLD对多药耐药肿瘤细胞MCF-7/ADR及KBv200的耐药逆转活性.结果 PLD在体内具有较强的逆转活性,逆转活性大于公认的强逆转剂维拉帕米的活性;在5.0μmol/L浓度下使多药耐药细胞KBv200对长春新碱的敏感性增加了45倍.PLD浓度依赖性增加(0、2.5、5.0、10 μmol/L)KBv200细胞内的罗丹明蓄积.PLD的心脏毒性、骨髓抑制以及脱发等不良反应显著降低.结论 脂质体阿霉素具有较强的逆转MDR的活性,主要通过持续向肿瘤组织聚集,肿瘤局部药物浓度升高,抗肿瘤的活性增强.     

本芴醇衍生物LY980503逆转人乳腺癌多药耐药细胞株MCF/DOX对多柔比星的耐药性

目的　探讨本芴醇衍生物LY980 5 0 3对肿瘤多药耐药的逆转作用及其作用机理。方法　采用噻唑蓝 (MTT)法检测细胞毒作用 ;采用流式细胞术测定细胞内多柔比星 (Dox)浓度 ;应用人乳腺癌裸鼠移植瘤模型研究LY980 5 0 3对肿瘤多药耐药的体内逆转作用。结果　LY980 5 0 3在 4 .0 μmol·L- 1(非细胞毒剂量 )能大部逆转人乳腺癌耐Dox细胞株MCF/Dox对Dox的耐药性 ;药物蓄积实验表明 ,LY980 5 0 3能显著增加MCF/Dox细胞内Dox蓄积 ;10 μmol·L- 1LY980 5 0 3作用 96h能明显抑制MCF/Dox细胞mdr 1基因表达水平。将MCF/Dox细胞接种于裸鼠皮下 ,接种后d 4 2 ,合用LY980 5 0 3(2 0 0mg·kg- 1·d- 1×3,ig)的移植瘤体积 (0 .34± 0 .19)cm3较单用Dox的移植瘤体积 (0 .90± 0 .32 )cm3显著缩小。结论LY980 5 0 3在体外及体内均能有效逆转MCF/Dox细胞对Dox的耐药性。     

灵芝破壁孢子粉的抗肿瘤活性研究

目的 研究灵芝破壁孢子粉对乳腺癌和口腔癌生长的抑制作用。方法 采用灵芝破壁孢子粉乙醇提取物处理乳腺癌MCF-7细胞、口腔癌KB细胞和宫颈癌HeLa细胞,检测三种细胞的增殖情况。构建裸鼠乳腺癌MCF-7移植瘤和口腔癌KB移植瘤模型,评价灵芝破壁孢子粉进行灌胃治疗后的肿瘤生长抑制情况。结果 灵芝破壁孢子粉乙醇提取物显著抑制MCF-7、KB和HeLa细胞的增殖,且该抑制效应呈剂量依赖性。在MCF-7移植瘤模型中,低、中、高3组灵芝破壁孢子粉给药剂量均有显著的肿瘤生长抑制作用,肿瘤抑制率分别为50.35%、65.72%和80.55%;但在KB移植瘤模型中,低剂量组没有显示显著的肿瘤生长抑制作用,而中剂量组和高剂量组表现出明显的抗肿瘤作用,3组肿瘤抑制率分别为4.03%、37.63%和40.59%。结论 灵芝破壁孢子粉能够抑制MCF-7乳腺癌和KB口腔癌荷瘤裸鼠肿瘤的生长。     

白术内酯Ⅰ对人胃癌细胞SGC-7901裸鼠移植瘤生长及凋亡的影响

目的：研究白术内酯Ⅰ（atractylenolide Ⅰ）对人胃癌细胞SGC-7901裸鼠移植瘤生长及凋亡相关蛋白Bax、cleaved caspase-3、p53、Bcl-2表达的影响。方法：建立SGC-7901裸鼠移植瘤模型,观察白术内酯Ⅰ对肿瘤生长的影响;TUNEL法检测移植瘤组织中的细胞凋亡;Western blotting检测瘤组织中Bax、Bcl-2、cleaved caspase-3及p53蛋白表达。结果：白术内酯Ⅰ不同程度抑制裸鼠SGC-7901移植瘤的生长,与对照组比较,给药后肿瘤体积（TV,tumor volume）、相对肿瘤体积（RTV,relative tumor volume）和相对肿瘤增殖率[T/C（%）,T_RTV/C_RTV]明显下降;移植瘤组织中凋亡细胞明显增多;白术内酯Ⅰ上调移植瘤组织中Bax、cleaved caspase-3及p53的蛋白表达,下调Bcl-2 的蛋白表达。结论：白术内酯Ⅰ能明显抑制人胃癌细胞SGC-7901裸鼠移植瘤的生长,分子机制主要包括增加Bax、cleaved caspase-3、p53蛋白表达,减少Bcl-2蛋白表达,最终导致肿瘤细胞凋亡。     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.