P-gp、TS在肝细胞肝癌中的表达及意义

目的研究多药耐药基因P-糖蛋白(P-gp)、胸苷酸合成酶(TS)在肝细胞肝癌(HCC)中表达,探讨其表达的临床意义。方法采用免疫组织化学SP法对48例HCC组织及43例癌旁组织行P-gp、TS检测。结果 P-gp、TS在HCC组织中的阳性表达率均高于相应的癌旁组织(P<0.05);P-gp阳性表达率明显高于TS的阳性表达率(P<0.05)。结论肝细胞肝癌多药耐药与P-gp、TS表达相关;联合检测这两种耐药基因对HCC患者化疗药物的选择、优化组合具有指导意义。     

三苯氧胺对晚期大肠癌多药耐药逆转作用研究

目的 探讨三苯氧胺对多药耐药大肠癌患者外周血淋巴细胞膜P-糖蛋白含量的影响及对FOLFOX4方案化疗效果的影响.方法 选择淋巴细胞膜 P-gp表达阳性大肠癌患者62 例,随机分为三苯氧胺组 (33 例) 和单纯化疗组 (29 例).应用流式细胞免疫学方法对两组患者治疗前后淋巴细胞膜 P-gp含量进行定量研究,观察化疗效果.结果 三苯氧胺能显著降低外周血淋巴细胞膜P-gp 含量(P< 0.01),提高P -g p 转阴率(P< 0.01),显著提高化疗总有效率(P< 0.01)、中位生存期(P< 0.05)和1年生存率(P< 0.01).结论 三苯氧胺能有效逆转晚期大肠癌多药耐药,提高化疗效果.     

系统性红斑狼疮患者P-糖蛋白与淋巴细胞亚群的相关性研究

目的探讨多药耐药蛋白P-糖蛋白(P-gp)的表达水平与淋巴细胞亚群计数在系统性红斑狼疮(SLE)患者中的关系及在预测疾病耐药性方面可能的机制。方法选择初发SLE患者20例和健康对照组15名。通过流式细胞术测定外周血淋巴细胞P-gp的表达水平和淋巴细胞亚群的计数。分析SLE患者外周血淋巴细胞P-gp的表达水平与淋巴细胞亚群中CD4+T细胞,CD8+T细胞、自然杀伤细胞、总T细胞和总B细胞等的相关性。采用t检验和χ2检验、Pearson相关性分析进行统计学分析。结果①健康对照组与SLE患者外周血淋巴细胞的相对荧光强度(RFI)平均值分别为2.2±0.7、3.3±2.0,差异有统计学意义(t=18.8,P<0.01)。②SLE患者外周血淋巴细胞P-gp的表达与淋巴细胞亚群中总T细胞,总B细胞,NK细胞的计数均无相关性,但P-gp的表达水平与CD4+T细胞、CD4+/CD8+比值有相关性(r=0.602,P=0.002;r=0.561,P=0.005)。③根据SLE患者外周血淋巴细胞亚群计数分为增高组和降低组,分别与相应的RFI值比较,发现CD4+T细胞及CD4+/CD8+比值的增高组与相应P-gp的表达呈正相关(r=0.713,P=0.025;r=0.628,P=0.014)。结论外周血淋巴细胞的P-gp表达是SLE患者多药耐药性的指标,SLE患者药物跨膜转运蛋白P-gp表达水平尚与其存在免疫功能异常亢进淋巴细胞亚群中CD4+T细胞及CD4+/CD8+比值密切联系,提示P-gp可能是药物治疗疗效的指标,对改善预后和联合治疗减少耐药有重要的意义。     

环磷酰胺对肾病综合征患儿淋巴细胞P-gp170表达的影响

目的 探讨环磷酰胺(CTX)对肾病综合征(NS)患儿P-糖蛋白170(P-gp170)表达的影响.方法 以流式细胞术检测频繁复发NS患儿(33例,研究组)CTX治疗前后外周血CD3淋巴细胞P-gp170表达,反相高效液相色谱法检测血清CTX浓度.对照组为14例糖皮质激素(GC)敏感非依赖NS患儿.结果 研究组治疗前CD3/P-gp170表达为(8.25±2.03)％,明显高于治疗后3个月的(2.92±1.94)％(P＜0.01);治疗后CD3/P-gp170表达与血清CTX浓度呈负相关(P＜0.05).结论 下调外周血淋巴细胞P-gp170的表达可能为CTX逆转NS患儿GC耐药的机制之一.CTX可通过抑制P-gp170表达而节约GC用量.     

鼻腔、鼻咽部恶性淋巴瘤多药耐药基因表达的临床研究

目的:探讨多药耐药基因-1(MDR-1)表达产物P-糖蛋白(P-gp)在鼻腔、鼻咽部恶性淋巴瘤组织中表达的临床意义。方法:用S-P免疫组化染色方法,检测37例鼻腔、鼻咽部恶性淋巴瘤组织中P-gp表达情况,并与患者的初诊与复诊、原发部位、病理类型、免疫组化分型等不同组织中P-gp的表达及预后相关性进行分析。结果:P-gp表达阳性的是复诊患者87.5%(7/ 8)、鼻咽部患者70.0%(7/10),与初诊患者34.5%(10/29)、鼻腔部患者37.0%(10/27)相比,均有明显差异;P-gp阳性表达患者耐药率88.2%(15/17),与P-gp阴性表达患者耐药率10.0%(2/20)相比,有明显差异。结论:P-gp阳性表达对预测耐药及临床医师选药、制定方案提供科学依据。     

雷公藤多甙片对狼疮性肾炎外周血单个核细胞多药耐药蛋白表达的影响

目的研究雷公藤多甙片(TG)对狼疮性肾炎外周血单个核细胞(PBMCs)多药耐药蛋白表达的影响。方法选择2015年11月~2017年5月我院收治的58例LN患者为研究对象,分为接受TG治疗的TG组(29例)和接受常规激素治疗的对照组(29例),分别提取两组治疗前后PBMCs,采用反转录-聚合酶链反应(RT-PCR)法检测TG对PBMCs多药耐药相关蛋白蛋白(MRP)和多药耐药相关基因(MDR1)和P-糖蛋白170(P-gp 170)表达的影响。结果治疗3个月后,两组PBMCs MRP、MDR1 m RNA相对表达量均明显提高(P0.05),且TG组PBMCs MRP、MDR1 m RNA相对表达量显著高于对照组(P0.05);两组PBMCs P-gp 170阳性表达率均明显提高(P0.05),且TG组PBMCs P-gp 170阳性表达率显著高于对照组(P0.05)。结论 TG可有效提高LN患者PBMCs MRP、MDR1及P-gp 170表达,提高患者免疫力,改善预后,LN患者治疗中应检测多药耐药蛋白表达水平以确定其耐药性。     

低剂量甲基强的松龙诱导淋巴细胞糖皮质激素耐药与P-糖蛋白关系的研究

目的 研究低剂量甲基强的松龙(糖皮质激素)诱导淋巴细胞糖皮质激素耐药与P-糖蛋白的关系.方法 取健康人外周血,分离纯化淋巴细胞,予小剂量(2μg·mL-1)甲基强的松龙刺激72 h为耐药组,对照组常规培养;用流式细胞术检测P-gp表达;MTT法检测激素耐药倍数;甲基强的松龙(200μg·mL-1)刺激2组细胞24 h,用流式细胞术检测Annexin V(%)并分析P-gp与其相关性;耐药组,用5 μg·mL-1维拉帕米联合甲基强的松龙(200 μg·mL-1)刺激,检测Annexin V(%).结果 小剂量甲基强的松龙诱导后的淋巴细胞P-gp表达,耐药组较对照组显著升高,为对照组的(2.89±0.21)倍;甲基强的松龙刺激后,耐药组细胞凋亡率显著低于正常组,与Annexin V呈显著负相关;维拉帕米干预可显著增加甲基强的松龙诱导细胞凋亡的敏感性.结论 P-gp介导耐药可能是导致临床治疗后期的耐药或药物依赖的重要机制之一.     

多药耐药基因在大肠癌组织中的表达和临床研究

目的探讨大肠癌组织中7种多药耐药因子的表达、共表达及与患者临床病理特征的相关性。方法采用微波EnVision免疫组织化学法联合检测63例大肠癌患者癌组织中P-糖蛋白(P-gp)、谷胱甘肽-S转移酶-π(GST-π)、DNA拓扑异构酶(TopoⅡ)、胸苷酸合成酶(TS)、甲基鸟嘌呤甲基转移酶(MGMT)、肺耐药蛋白(LRP)及多药耐药相关蛋白(MRP)的表达水平。结果P-gp、GST-π、TopoⅡ、TS、MGMT、LRP和MRP在大肠癌组织中的阳性表达率分别为54%(34例)、71%(34例)、62%(39例)、67%(42例)、57%(36例)、79%(50例)和30%(19例)。所有的多药耐药因子表达均与患者的年龄、性别无相关。MGMT、LRP的表达与淋巴结转移相关;P-gp、GST-π、TopoⅡ、MRP的表达与组织学分级相关;TS、MGMT、LRP的表达与临床分期相关;P-gp、MGMT的表达与生存期明显相关。结论大肠癌组织表达多种耐药因子,各耐药因子间共表达具有明显相关性。大肠癌耐药由多种耐药基因共同参与,联合检测多项耐药因子有重要的临床意义。     

化疗后乳腺癌P糖蛋白表达与预后关系

目的 探讨化疗后乳腺癌中P糖蛋白(P-gp)的表达及其与预后的关系. 方法 应用SP法检测P-gp在50例化疗后乳腺癌中的表达, 并用χ2检验评价其对化疗后乳腺癌预后的影响. 结果 50例化疗后乳腺癌中P-gp的表达率70.0%, 与化疗后乳腺癌的预后相关(P＜0.001). 结论 P-gp是化疗后乳腺癌产生多药耐药(multi-drug resistance, MDR)的主要作用机制, P-gp可成为评估化疗后乳腺癌预后的有价值的指标.     

异博定逆转肝癌细胞多药耐药的研究

肿瘤细胞对化疗药物产生多药耐药(MDR)是肿瘤化疗失败的主要原因,为了寻找克服肿瘤细胞多药耐药的方法,将异博定加入体外培养诱导的人肝癌细胞多药耐药株SMMC-7721/ADM中,MTT法检测显示异博定增加了化疗药对SMMC-7721/ADM细胞的毒性,并随异博定浓度的增加其逆转活性也增强,(VPL25μg/ml时,SMMC-7721/ADM的活细胞为65％,而VPL20μg/ml时,SMMC-7721/ADM的活细胞率为39％,两者有显著差异)。流式细胞技术显示异博定使耐药细胞表面P-糖蛋白的浓度降低和耐药细胞内柔红霉素的浓度增加(P-gp由70.13下降到22.68,DNR浓度由133上升到163),因此研究表明异博定逆转肿瘤细胞的多药耐药机理是通过使肿瘤细胞表面的P-糖蛋白表达减少,增加肿瘤细胞内的化疗药物浓度而起作用。     

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.     

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.     

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.