姜黄素抗肿瘤作用机制的研究进展

多种恶性肿瘤细胞中表达细胞凋亡抑制蛋白（IAPs）,如：Survivin、NAIP、XIAP、Livin等,同样表达抗细胞凋亡Bcl-2家族蛋白。IAPS介导的凋亡抑制可能是肿瘤细胞耐药而存活的原因之一;Bcl-2家族蛋白在抗肿瘤凋亡及促其凋亡中发挥作用。姜黄素具有抗炎、抗氧化、抑制血管新生等,可以通过调控蛋白表达及相关信号通路促进细胞凋亡、抗肿瘤作用。     

治疗慢性粒细胞白血病新药imatinib

慢性粒细胞白血病（CML）患者体内有异常染色体形成并产生BCR－ABL融合蛋白,该融合蛋白能激活酪氨酸激酶,刺激细胞过度增生导致慢性粒细胞白血病的发生。imatinib(格列卫）能特异性抑制BCR－ABL,抑制信号传导,减少细胞增生并使细胞凋亡,从而有效治疗慢性粒细胞白血病。     

伊马替尼相关基因多态性与伊马替尼耐药

伊马替尼属靶向小分子酪氨酸激酶抑制剂,为治疗慢性粒细胞白血病的一线药物,临床用其甲磺酸盐。随着其广泛应用,耐药也迅速产生。伊马替尼的耐药机制十分复杂,涉及多个基因、蛋白及信号传导通路的异常表达或改变。本文主要分析接受伊马替尼治疗的慢性粒细胞白血病患者相关基因的多态性与其耐药机制的关系,为实现慢性粒细胞白血病的合理有效治疗提供依据。     

慢性粒细胞白血病患者发生伊马替尼耐药病例1例并文献复习

研究证实,BCR-ABL融合蛋白是导致慢性粒细胞白血病(chronic myelogenous leukemia,CML)发病的根本原因。因此,它是目前治疗CML最理想的药物靶标。伊马替尼是第一个上市的BCR-ABL蛋白激酶抑制剂,在靶向治疗慢性粒细胞白血病上取得了很大成功。但是部分患者在多种机制的作用下,发生了BCR-ABL激酶区的基因突变,尤其以T315I突变耐药     

苦参碱类生物碱抗粒细胞和单核细胞性白血病的药理作用研究进展

苦参碱类生物碱对人红白血病K562细胞、TF-1细胞、急性早幼粒细胞白血病HL-60细胞、NB4细胞、急性单核细胞白血病THP-1细胞、白血病KG1a干细胞、慢性粒细胞白血病细胞和辐射引起的骨髓造血畸变细胞等均有抑制增殖并诱导分化和凋亡的作用。其诱导分化和凋亡及抑制增殖的作用机制是多方面的,与下调原癌基因c-myc、β-链蛋白、生存素表达和端粒酶活性以及上调半胱天冬酶活性和白血病细胞表面分化抗原CD11b、CD15表达有关。苦参碱类生物碱上调白血病细胞表面自然杀伤细胞活化受体NKG2D的配体表达,能提高白血病细胞对自然杀伤细胞的敏感性。综述苦参碱类生物碱抗粒细胞和单核细胞性白血病的药理作用文献,并对其研究进展做了分析。     

抑制PI3K/PKB信号通路提高胃癌细胞化疗敏感性的研究

目的探讨磷脂酰肌醇3激酶(phosphatidylinositol 3-kinase,PI3K)抑制剂LY294002提高胃癌耐药细胞SGC7901/VCR和亲代细胞SGC7901对化疗药物敏感性的作用及其机制。方法MTT法分别检测胃癌细胞SGC7901和SGC7901/VCR对化疗药长春新碱(VCR)的敏感性;RT-PCR法和免疫细胞化学法检测LY294002处理前后多药耐药蛋白1(multidrug resistance protein-1,MDR1)和X染色体连锁的凋亡抑制蛋白(X-linked inhibitor of apoptosis,XIAP)基因和蛋白水平;Westernblot法检测LY294002处理前后细胞PKB总蛋白水平和磷酸化水平;并用流式细胞仪检测细胞的凋亡率。结果2×10-5mol·L-1 LY294002能明显增加SGC7901和SGC7901/VCR细胞对VCR的敏感性(P<0.01),其IC50分别由(0.20±0.03)和(8.09±0.60)mg·L-1降至(0.05±0.006)和(1.70±0.20)mg·L-1;降低细胞MDR1和XIAP的基因和蛋白水平;降低磷酸化PKB水平,而对其总蛋白水平无影响;LY294002联合VCR用药后细胞凋亡率明显高于单独VCR处理(P<0.01)。结论LY294002通过降低耐药基因MDR1和抗凋亡基因XIAP的表达,提高耐药和非耐药胃癌细胞对化疗药物的敏感性,此过程与抑制PI3K/PKB通路密切相关。     

XIAP抑制剂的研究进展

凋亡抑制蛋白（XIAP）被认为是凋亡抑制蛋白家族中对细胞凋亡抑制作用最强的蛋白，研究发现。它在许多肿瘤细胞中有过量表达，其作用机制是XIAP对执行凋亡的caspase家族蛋白产生抑制作用。近年来，XIAP小分子抑制剂研究越来越受到人们的重视。该文对XIAP抑制剂的研究进行综述。     

消瘤1号通过影响XIAP表达诱导MCF-7人乳腺癌细胞凋亡

目的探讨中成药消瘤1号诱导MCF-7人乳腺癌细胞的凋亡作用,并通过分析其作用后的MCF-7细胞XIAP蛋白表达的变化,探讨其诱导MCF-7细胞凋亡的分子机制。方法采用细胞培养技术,用不同浓度药物处理MCF-7细胞24、48、72 h,用CCK-8法检测药物对细胞增殖的影响;用HE染色细胞,观察细胞形态变化;采用Western blot法检测XIAP和caspase-3表达。结果消瘤1号处理MCF-7细胞24 h,随着药物浓度增加,作用时间延长,细胞增殖速度减慢;细胞经染色后,与对照组相比,经药物处理后的细胞核出现皱缩,细胞膜褶皱、卷曲和破碎,提示凋亡细胞的增多。Western blot检测结果表明,消瘤1号通过下调XIAP,上调caspase-3蛋白表达诱导乳腺癌细胞的凋亡,并且呈浓度依赖性。结论消瘤1号能够通过XIAP直接抑制凋亡效应分子caspase-3的活性,促进MCF-7细胞凋亡,抑制细胞增殖。     

X连锁凋亡抑制蛋白与肿瘤关系的研究进展

XIAP(连锁凋亡抑制蛋白)是凋亡抑制蛋白家族中最强的内源性的抑制因子,其可以通过不同的信号转导通路及调控相关凋亡蛋白酶的表达产生抗凋亡作用。研究发现其与肿瘤的发生、发展有着密切的关系,已经成为许多肿瘤的治疗靶点。凋亡抑制蛋白家族的组成成分是细胞内源性的凋亡抑制蛋白,目前,共发现有16种此类蛋白,其中的8个是人类的IAPs家族成员:它们是XIAP、c-IAP1、c-IAP2、神经凋亡抑制蛋白、存活素、BRUCE、ML-IAP、ILP-2等。XIAP是IAPs家族中最具有效力的半胱氨酸天冬氨酸蛋白酶的抑制物,具有极强的抗凋亡作用。     

BCL—2蛋白：抗癌药物作用的新靶点

BCL-2蛋白抑制细胞凋亡是肿瘤发生和产生耐药的重要原因之一,本文通过综述BCL-2蛋白的抗凋亡机制,结构与功能,基于bcl-2基因的肿瘤反义治疗研究成果,阐明BCL-2蛋白作为抗肿瘤药物作用的新靶点和发展其小分子抑制剂的可行性.     

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.

     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.     

Glycofection: The Ubiquitous Roles of Sugar Bound on Glycoplexes

Glycofection (transfection by using sugar-substituted polylysine) was assessed in order to provide an alternative to viral vectors for the transfer of genes into vascular smooth muscle cells. A rabbit vascular smooth muscle cell line (Rb-1 cells) was selectively transfected by using glycoplexes (glycosylated polylysine/pSV2LUC complexes) in the presence of 10 mu M of the fusogenic peptide GALA. A sugar-specific transfection was obtained when the glycofection was conducted for 1 h with glycoplexes containing either alpha Gal, alpha -Glc, alpha -GalNAc, beta -GlcNAc, or beta -GalNAc residues. The gene expression was high after transfection, with glycoplexes bearing alpha Gal, alpha -GalNAc, or beta -GalNAc residues that were weakly internalized, and low with glycoplexes carrying Lact or Rha residues that were well taken up by cells. These results suggest that 1) glycofection can be a good approach for a selective transfer of genes intovascular smooth muscle cells, 2) an efficient uptake of the glycoplexes is not the unique limiting step for an efficient transfection, and 3) the sugar-dependent trafficking of the glycoplexes inside the cells may account for the transfection efficiency.     

直肠癌下切缘病理组织学分析

目的探讨直肠癌逆向浸润与下切缘的安全距离的关系。方法对36例直肠癌Miles手术和Dixon手术后标本的肿瘤下缘1.0cm、2.0cm、3.0cm的肠壁及对应的系膜病理组织学检查,观察直肠癌逆向浸润或转移的距离。结果36例直肠癌标本距癌肿下缘1.0 cm、2.0cm、3.0cm的肠壁及对应的系膜病理组织学检查均为阴性,结论直肠癌远恻逆向浸润或转移未见超过1.0cm,因此认为保肛手术时切除肿瘤远侧肠管(包括系膜)2.0cm是安全的。