顺铂联合热疗对卵巢癌铂敏感细胞株COC1和铂耐药细胞株COC1/DDP的影响

目的 探讨热疗联合化疗对卵巢癌铂敏感细胞株COC1和铂耐药细胞株COC1/DDP增殖、凋亡的作用、逆转耐药细胞的耐药性及其可能机制.方法 采用MTT法检测热疗及联合不同浓度的顺铂(1.25、2.5、5、10、20μg·mL-1)对卵巢癌细胞株COC1,COC1/DDP生长的抑制作用;RT-PCR法检测两种细胞株中Sur...     

尼古丁对肺腺癌细胞生长及化疗敏感性的影响

目的:研究尼古丁体外对肺腺癌细胞生长及化疗敏感性的影响。方法:应用MTT探讨尼古丁对肺腺癌细胞SPC-A-1对5-FU,DDP和ADM化疗敏感性的影响;采用实时荧光定量PCR技术研究尼古丁对MDR1基因表达的影响。结果:1～100ng.mL-1尼古丁能显著促进SPC-A-1细胞的生长,各系列浓度的尼古丁(1,10,100,1000ng.mL-1)对SPC-A-1细胞的生长抑制率分别为-43.5%,-29.6%,-22.3%和28.0%。100ng.mL-1尼古丁分别与各系列浓度的5-FU(10～1000ng.mL-1)、DDP(50～50000ng.mL-1)和ADM(20～20000ng.mL-1)联合处理,均不提高SPC-A-1细胞的生长抑制率,且与对应各系列浓度的5-FU、DDP和ADM的单独处理相比,没有显著差异(P>0.05)。1～100ng.mL-1尼古丁处理后,在SPC-A-1细胞,未检测到MDR1基因表达;而在阳性对照细胞K562诱导MDR1基因表达。结论:尼古丁能显著促进SPC-A-1细胞生长,且能明显降低该细胞对1ng.mL-15-FU的化疗敏感性,但并不减低对DDP和ADM的化疗敏感性。尼古丁也不能显著诱导对SPC-A-1细胞的MDR1基因表达。     

人肝癌耐药细胞系的建立及生物学特性的研究

目的:培养建立耐药肝癌细胞模型QGY7703/DDP,分析人肝癌耐药细胞系生物学特性的改变.方法:应用人肝癌细胞株QGY7703,采用顺铂(DDP)逐步提高加间歇诱导历时6个月在体外建立QGY7703/DDP细胞系模型.观察该细胞的生长规律,利用四甲基偶氮唑蓝(MTT)法分析暴露前后细胞的增殖和药物对细胞毒性的差异.结果:经过将QGY7703持续暴露,细胞对化疗药物5-氟尿嘧啶(5-FU)、DDP、阿霉素(ADM)、丝裂霉素(MMC)的敏感性发生了改变.QGY7703/DDP对5-FU的耐药性是亲代细胞的1.533倍,对DDP的耐药性是亲代细胞的2.181倍,对ADM的耐药性是亲代细胞的7.080倍,对MMC的耐药性是亲代细胞的9.461倍.结论:化疗药物能够诱导培养的肿瘤细胞产生耐药性.     

mdr1反义寡核苷酸增强多药耐药肝癌细胞HepG2/ADM化疗敏感性的实验研究

目的：探讨在体外实验条件下mdr1反义寡核苷酸对多药耐药肝癌细胞株化疗敏感性的影响。方法以肝癌细胞HepG2/ADM为研究对象,设立mdr1反义寡核苷酸组和空白试剂组作对照,利用脂质体包载肿瘤耐药基因mdr1的反义寡核苷酸进行细胞转染,通过反转录聚合酶链反应（RT-PCR）、免疫印迹实验（Western blotting）分别检测mdr1基因mRNA和P-gp蛋白表达,通过MTT实验检测细胞转染前后对阿霉素（ADM）、顺铂（DDP）和5-氟尿嘧啶（5-FU）的化疗敏感性。结果 HepG2/AMD肝癌细胞经反义寡核苷酸处理后,mdr1 mRNA、P-gp蛋白表达水平均明显降低,对ADM、DDP 和5-FU的化疗敏感性明显增强。结论反义寡核苷酸能在体外有效增加肝癌细胞HepG2/ADM对化疗药物的敏感性。     

Cyclin L2在化疗诱导肝癌细胞凋亡中的作用

目的探讨cyclin L2基因在化疗药物顺铂（DDP）、5-氟尿嘧啶（5-FU）和多西紫杉醇（Doc）诱导的肝癌细胞凋亡中的作用。方法用肝癌SMMC7721细胞株进行培养传代,MTT试验检测DDP、5-FU和Doe不同药物浓度对肝癌细胞生长的抑制作用,以及cyclin L2转染及反义转染后对该细胞生长抑制作用的影响。用流式细胞术定量检测细胞凋亡。结果不同浓度DDP、5-FU和Doc对肝癌细胞生长均有明显的浓度依赖性抑制作用。细胞凋亡率和cyclinL2基因表达率成正相关。在5-FU和DDP作用下,cyclin L2转染组凋亡率均高于对照组（P〈0．01）,反义转染组细胞凋亡率低于对照组（P〉0．05）。结论Cyclin L2基因在化疗药物诱导肝癌细胞凋亡中起重要作用。     

洛匹那韦逆转LLC/cMOAT细胞多药耐药的作用

目的研究洛匹那韦对LLC/cMOAT细胞株多药耐药的逆转作用及其可能机制。方法采用四甲基偶氮唑盐方法（MTT）检测洛匹那韦对细胞株LLC/CMV和LLC/cMOAT细胞生存的影响,并检测阿霉素（ADM）、长春新碱（VCR）、环磷酰胺（CTX）、顺铂（DDP）对上述细胞株的半数抑制浓度（IC50）。应用流式细胞术检测洛匹那韦处理后细胞内化疗药物阿霉素相关的荧光强度变化。结果 LLC/cMOAT细胞对ADM、VCR、DDP有不同程度的耐药,对CTX未产生耐药;洛匹那韦在浓度小于10.0μmol·L^-1,对LLC/cMOAT细胞无明显细胞毒性作用;用2.5μmol·L^-1洛匹那韦处理后,LLC/cMOAT细胞对VCR和DDP的敏感性增高,浓度提高至5.0μmol·L^-1,敏感性明显提高;用洛匹那韦处理后LLC/cMOAT细胞内ADM的蓄积增加,并表现为浓度依赖;细胞周期检测分析显示,使用洛匹那韦处理0、4、8、16 h后,G1期细胞百分比由（42.65±3.75）%分别增至（56.77±2.37）%、（68.13±4.30）%、（70.25±5.12）%,与0 h G1期细胞数比较差异显著（P〈0.05）;使用洛匹那韦处理细胞48 h后,凋亡率增高且呈时间和浓度依赖性。结论洛匹那韦可以部分逆转LLC-cMOAT的多药耐药,这种逆转可能与增加细胞内化疗药物蓄积,诱导细胞G1期阻滞,增强细胞凋亡有关。     

MTT法测定多柔比星和氟尿嘧啶及顺铂对肝癌耐药细胞Bel 7402/ADM的IC50值

目的研究多柔比星（ADM）、氟尿嘧啶（5 Fu）、顺铂（DDP）对人肝癌多药耐药细胞株Bel 7402/ADM 的细胞毒作用,为开展逆转肿瘤多药耐药研究提供实验依据。方法以MTT法测定ADM、5 Fu、DDP对Bel 7402/ADM的细胞毒作用,计算每种药物的半数抑制浓度（IC50）。结果ADM、5 Fu、DDP对Bel 7402/ADM的IC50分别为10.00,30.60,11.48 μmol&;#8226;L 1。结论MTT法检测药物细胞毒作用方便快捷,节省试剂;随着化疗药物浓度的增加,药物对细胞的抑制率增加。     

LncRNA GAS5对结直肠癌5-FU耐药的作用研究

目的 探讨长链非编码RNA生长停滞特异性转录本5(LncRNA GAS5)对结直肠癌5-氟尿嘧啶(5-FU)耐药的作用。方法 选取人结肠癌细胞系HCT-8和SW480,建立5-FU耐药细胞株,构建LncRNA GAS5过表达结直肠癌细胞模型。反转录-聚合酶链式反应(RT-PCR)检测LncRNA GAS5在结直肠癌5-FU耐药细胞系中表达;CCK-8检测细胞增殖;流式细胞术检测细胞凋亡。结果 RT-PCR检测显示, LncRNA GAS5在结直肠癌HCT-8细胞与SW480细胞中的表达水平低于正常结肠细胞,差异有统计学意义(P<0.05);LV5-GAS5组HCT-8细胞、SW480细胞中LncRNA GAS5表达高于Vector组,差异有统计学意义(P<0.05)。CCK-8实验检测显示, LncRNA GAS5能明显抑制HCT-8细胞和SW480细胞的增殖(P<0.05)。AnnexinV/PI双重染色及流式细胞术结果显示,在结直肠癌HCT-8细胞与SW480细胞中LV5-GAS5组的细胞凋亡比例高于Vector组,差异有统计学意义(P<0.05)。结论 L...     

穿琥宁对COC1/DDP顺铂耐药性的逆转作用

 目的：建立人卵巢癌顺铂耐药细胞株COC1/DDP,探讨穿琥宁对COC1/DDP顺铂耐药性的逆转作用及其机制。方法：采用逐步递增顺铂浓度、体外间歇诱导法建立COC1/DDP;CCK-8试剂盒（Cell Counting Kit-8）检测穿琥宁对COC1/DDP顺铂耐药性的逆转作用;GSH和GSSG试剂盒检测细胞内GSH的水平;高效液相色谱测定细胞内顺铂的含量。结果：历时5个月建立的COC1/DDP细胞株对顺铂耐药性稳定,耐药指数为9.44,对卡铂、长春新碱和阿霉素有不同程度的交叉耐药性。穿琥宁对COC1/DDP的顺铂耐药性有逆转作用,逆转倍数达到5.63倍。与COC1比较,COC1/DDP细胞内GSH水平增高,顺铂含量下降,但经穿琥宁干预后,COC1/DDP胞内的GSH水平降低,顺铂的含量增加（P<0.01）。结论：穿琥宁对COC1/DDP的顺铂耐药性有逆转作用,其机制可能与干预COC1/DDP细胞内GSH/GST-π 解毒系统,增加COC1/DDP细胞内顺铂的含量有关。     

异钩藤碱逆转人肺腺癌细胞A549/DDP对顺铂耐药性

目的 研究异钩藤碱(IR)在体外对耐药人肺腺癌细胞系A549/DDP对顺铂(DDP)的耐药性.方法 采用MTT法检测药物细胞毒性作用及耐药细胞逆转倍数,电感耦合等离子体质谱(ICP-MS)法测定细胞内顺铂浓度.结果 IR无细胞毒浓度组(3.0μg·mL-1)使A549/DDP细胞对DDP的IC50由16.81 mg·L-1降至3.36 mg·L-1;低细胞毒浓度(8.0μg·mL-1)组的IC50降至2.34 mg·L-1;2组均明显提高DDP在A549/DDP细胞内的浓度.结论 研究表明IR能部分逆转A549/DDP细胞的MDR,并可增加肿瘤细胞内DDP药物浓度.     

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.