Cellular and molecular aspects of drugs of the future: oxaliplatin

Oxaliplatin (Eloxatine) is a third-generation platinum compound which has shown a wide antitumour effect both in vitro and in vivo, a better safety profile than cisplatin and a lack of cross-resistance with cisplatin and carboplatin. In this scenario, oxaliplatin may represent an innovative and challenging drug extending the antitumour activity in diseases such as gastrointestinal cancer that are not usually sensitive to these coordination complexes. Oxaliplatin has a non-hydrolysable diaminocyclohexane (DACH) carrier ligand which is maintained in the final cytotoxic metabolites of the drug. Like cisplatin, oxaliplatin targets DNA producing mainly 1,2-GG intrastrand cross-links. The cellular and molecular aspects of the mechanism of action of oxaliplatin have not yet been fully elucidated. However, the intrinsic chemical and steric characteristics of the DACH-platinum adducts appear to contribute to the lack of cross-resistance with cisplatin. To date, mismatch repair and replicative bypass appear to be the processes most likely involved in differentiating the molecular responses to these agents. Received 15 March 2002; received after revision 13 May 2002; accepted 21 May 2002 RID="*" ID="*"Corresponding author.     

AMPA receptors: potential implications in development and disease

α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) receptors are one type of ionotropic glutamate receptor involved in rapid excitatory synaptic transmission. AMPA receptors have been increasingly implicated in long-term potentiation, and recent evidence suggests that they may play a role in disorders affecting the nervous system. The finding that early in postnatal development AMPA receptors are not expressed has lately been the focus of much attention. Resolving the factors involved in AMPA receptor expression suggests that their induction is a developmentally regulated process with the possibility that alterations in receptor expression may be correlated with pathology in neurological disorders. This paper provides an overview of factors involved in AMPA receptor induction as well as of their role in plasticity and neuronal pathologies. Received 5 December 2000; received after revision 12 January 2001; accepted 2 February 2001     

SD大鼠心气虚证动物模型的建立与评价

目的　探讨心气虚证动物模型的建立方法。方法　SD大鼠 4 0只采用基础进食量 2 4d ,每日按自身体重的5 %强迫负重游泳至力竭 ,大剂量灌服心得安 2 4mg 10 0g等综合方法建立心气虚证动物模型 ,其中 2 0只作为人参药物反证组。并设立正常对照组 4 0只 ,以进一步证明所建立模型是心气虚证动物模型。结果　与正常对照组比较 ,模型组大鼠心脏收缩功能和舒张功能均有所下降 ,反映虚证的SOD含量减少 ,MDA含量增加。而所有定量指标均发生了符合心气虚证的变化。结论　采用基础进食量、强迫负重游泳及大剂量灌服心得安的综合方法建立心气虚证动物模型是可行的     

镁的生物功能和草食动物镁缺症综述

镁是草食动物机体组织必须营养元素,在草食动物体内发挥着重要的作用.为改善镁的生物学可利用性及其在草食动物食物中的合理利用,对镁的生物学功能,草食动物镁的来源、吸收和代谢,草食动物镁营养缺乏,镁补充的营养效率进行了综述.     

老年虚秘不同舌象的血液流变学比较

为了探讨老年虚秘病理舌象的形成与血液流变学的关系,我们对虚秘中的阳虚湿盛证与阴液不足证的患者进行了舌诊检查与血液流变学检测,结果表明两组病理舌象与血液流变学均有明显差异,并呈正相关.提示了血液流变学可作为研究舌诊的客观指征之一.     

Identification of quantitative trait loci affecting tolerance to low phosphorus in rice (Oryza Sativa L.)

Phosphorus (P)-deficiency in rice (Oryza. Sativa. L) may cause yield reductions. This research has been conducted to map quantitative trait loci (QTLs) for tolerance to low phosphorus stress in a doubled haploid (DH) population. By using the linkage map of this population, the QTLs for relative dry weight, relative P content and relative P utilization efficiency have been located. The results indicate that one RFLP marker located on chromosome 6 is closely associated with relative root dry weight, relative shoot dry weight and relative total dry weight, which explain 24.9%, 20.5% and 25.2% of the total phenotypic variations, respectively. Two QTLs affect relative P uptake content, which account for 20.7% of the total phenotypic variations. One micro-effect QTL has been found to be associated with relative P utilization efficiency. It is suggested that the P uptake efficiency is more associated with P efficiency. Among the secondary physiological indices of P uptake efficiency, the root dry weight is more important than others.     

Identification of quantitative trait loci affecting tolerance to low phosphorus in rice (Oryza Sativa L.)

Phosphorus (P)-deficiency in rice (Oryza.Sativa.L) may cause yield reductions.This research has been conducted to map quantitative trait loci (QTLs) for tolerance to low phosphorus stress in a doubled haploid (DH) population.By using the linkage map of this population,the QTLs for relative dry weight,relative P content and relative P utilization efficiency have been located.The results indicate that one RFLP marker located on chromosome 6 is closely associated with relative root dry weight,relative shoot dry weight and relative total dry weight,which explain 24.9%,20.5% and 25.2% of the total phenotypic variations,respectively.Two QTLs affect relative P uptake content,which account for 20.7% of the total phenotypic variations.One micro-effect QTL has been found to be associated with relative P utilization efficiency.It is suggested that the P uptake efficiency is more associated with P efficiency.Among the secondary physiological indices of P uptake efficiency,the root dry weight is more important than others.     

试探我国现行房地产税费制度的缺憾

我国现行房地产税费制度对我国房地产业的发展具有不可估量的作用。但是 ,目前许多人对房地产税费不分 ,税费制度也存在许多缺憾。本文就房地产税费的区别及我国现行房地产税费制度的缺憾进行了探讨 ,并提出了建议和设想。     

基于时间方向划分的三类遗忘症特征分析

记忆障碍多为脑创伤导致,其影响范围越来越广.根据遗忘的时间方向将遗忘症分为顺行性遗忘、逆行性遗忘和进行性遗忘.海马和颞叶内侧损伤导致的遗忘综合征主要表现为顺行性遗忘,而某些苯二氮卓类药物亦可诱发.间脑损伤导致的科萨科夫综合征主要表现为逆行性遗忘,另外,颞叶癫痫、ECT治疗等也会伴随该症状.随病程日益加重的进行性遗忘,主要形式为阿尔茨海默病.目前,记忆障碍只能以记忆康复为主,主要包括通过联想法、图像法等记忆技巧达到的内部代偿,以及利用外显方式、编制程序等方法达到的外部代偿.以脑神经科学为核心的记忆康复,是未来临床神经心理学发展的方向和领域.     

锌缺乏对海马锌离子及锌转运蛋白ZnT4表达的影响

目的探讨锌缺乏对小鼠大脑海马锌离子和锌转运蛋白4（Zinc Transporter 4,ZnT4）表达的影响.方法建立锌缺乏动物模型,给断乳后的CD-1小鼠分别喂养缺锌饲料和正常饲料,5周后取大脑海马组织,应用锌金属自显影技术、免疫组织化学技术和Western blotting技术分别进行两组海马锌离子含量和ZnT4表...