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蜂毒肽的结构、功能及分子生物学研究进展 总被引:3,自引:0,他引:3
蜂毒肽 (melittin)亦称蜂毒溶血肽 ,是一种昆虫抗菌肽 ,是意大利蜂蜂毒的主要成分之一 ,占蜂毒干重的 5 0 % ,是蜂毒中的主要多肽成分 ,不仅具有抗菌、消炎、抗关节炎等作用 ,对辐射还有预防和治疗作用 ,可使受辐射动物的生存率提高2 0 %~ 6 0 % [1] 。近年来发现其具有抗肿瘤、抗艾滋病毒的作用 ,引起了人们的极大关注。1 蜂毒肽的结构蜂毒肽由 2 6个氨基酸残基组成 ,是由蜜蜂毒腺中合成的蜂毒肽前体蛋白 (promelittin)经二肽蛋白酶水解而成的 ,其相对分子质量为 2 84 9,氨基酸的排列顺序为 :甘 -异亮 -甘 -丙 -缬 -… 相似文献
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抗菌肽是一类广泛存在于各种生物体内的防御性小肽,为免疫系统的重要组成成分,是目前替代抗生素较为理想的抗菌剂之一。抗菌肽具有抗细菌、抗真菌、抗病毒、抗肿瘤等生物活性功能,还可作为信号分子、避孕剂、有丝分裂剂等。但目前抗菌肽也存在一些需要解决或具有争议的问题,如怎么提高基因工程抗菌肽的表达量和抗菌肽在体内的稳定性,其具体的耐药性机制尚未明确,抗菌肽与抗生素的协同作用机理等。文章从抗菌肽的结构特点、生理功能与作用机制、基因工程表达及其应用前景方面进行了阐述,并分析存在的问题,为研究绿色、高效、低毒、广谱的抑菌剂提供重要信息。 相似文献
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我国天然蜂毒主要采自意大利蜜蜂Apis mellifera ligustica),天然蜂毒是具有苦香气味的透明液体,在室温下很快就干燥至原来重量的30-40%。蜂毒是一种成分十分复杂的混合物,经过各国学者几十年的研究,已知蜂毒含有多种生物活性物质,如蜂毒肽(melittin)、蜂毒明肽(apamin)、MCD肽(mast cell deganulating peptide)、磷酸脂酶A2、玻璃酸酶和其他非肽类有机物质。其中蜂毒肽是蜂毒的主要成分,其重量占蜂毒干物质45-50%。蜂毒肽具有很高的生物学作用和药理作用,其半数致死量(LD50)为4.0mg/kg,现代药理研究表明蜂毒肽具有抗炎、镇痛、抑制血小板凝聚和抗肿瘤等作用。本文重点综述了蜂毒肽的抗肿瘤作用,抗菌作用和抗HIV病毒作用的新进展。 相似文献
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毕晋明 《兽药与饲料添加剂》2005,10(6):20-22
生物抗菌肽是具有抗菌活性肽类的总称,广泛存在于昆虫、植物、动物及人体内,具有非特异性抗细菌、真菌、病毒和肿瘤细胞的作用,又称为肽抗生素。这种内源性抗菌肽经诱导合成,在机体抵抗病原的入侵方面起着重要的作用。介绍了抗菌肽的分类、结构特征,抗菌肽的作用及其作用机理,并对抗菌肽在畜牧生产中的应用前景及其未来的发展作一展望。 相似文献
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通过对大学生公费医疗现状的分析,找出了大学生公费医疗存在的弊端:计划经济的垄断性、公费医疗覆盖的有限性和高校医院医疗水平的局限性。提出了大学生公费医疗体制改革的思路:1、尽快建立大学生医疗保障体系,加强政府的投入力度;2、推行分层次的公费医疗报销办法;3、建立学生团体平安保险与公费医疗改革的保障模式。 相似文献
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Images generated during the course of patient evaluation and management are an integral part of the medical record and must be retained according to local regulations. Digital Imaging and Communications in Medicine (DICOM) makes it possible for images from many different imaging modalities to be distributed via a standard internet network to distant viewing workstations and a central archive in an almost seamless fashion. The DICOM standard is a truly universal standard for the dissemination of medical images. Picture Archive and Communication System (PACS) refers to the infrastructure that links modalities, workstations, the image archive, and the medical record information system into an integrated system, allowing for efficient electronic distribution and storage of medical images and access to medical record data. This paper discusses the important elements to a successful PACS implementation in a practice, including how it interacts with other practice computing systems. 相似文献
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Davis MH 《Journal of veterinary medical education》2003,30(3):258-263
The move to outcome-based education has been one of the most important trends in health-profession education in recent years. This paper defines outcomes and outcome-based education, describes the development of outcome-based education, identifies several different ways that outcomes have been presented, and discusses the advantages and disadvantages of the outcome-based educational approach. The implementation of outcome-based education at the University of Dundee medical school, Scotland, UK is described as a case study for curriculum planners in veterinary medical education. The lessons learned in Dundee from six years' experience with outcome-based education are identified to aid veterinary medical educators wishing to implement the approach. 相似文献
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F. L. Pollari B. N. Bonnett D. G. Allen S. C. Bamsey S. W. Martin 《Preventive veterinary medicine》1996,27(3-4):141-154
This study was designed to evaluate the quality of data from computerized medical record abstracts at the Veterinary Teaching Hospital, Ontario Veterinary College. Information in the paper medical record (registration, physical exam, daily progress, laboratory, radiology, anaesthesia and surgery forms), the summary sheet, and the computerized record were compared. A random sample of 100 patient visits from a subset of visits that were identified as all possible dog or cat elective-surgery visits in the computerized records from 1983 through 1991 were used. Clinicians were responsible for summarizing the medical record on the summary sheet and health record technicians entered the information from the summary sheet into the computer record. Most of the discrepancies (n = 33) noted for diagnoses, procedures or complications were due to the lack of transfer of information from the paper forms to the summary sheet. Although the medical record technicians detected and entered some of these (n = 10), most were not entered into the computerized records. The next most-common discrepancies (n = 5) were due to the clinician writing a different entry on the summary sheet than was present on the other paper record forms. Only one record had a miscoded diagnosis and three had miscoded procedures. Misfiled forms in the medical record folders of two patients resulted in one incorrect diagnosis and one incorrect procedure recorded in the computer record. When any discrepancy between the paper and computer record for diagnoses, procedures or complications was considered, 41% of the visits had discrepancies (46% dogs; 36% cats). The percentage varied by surgery status: non-elective surgeries 82%, elective surgeries 37% and non-surgical visits 29%. There was no obvious time trend. The completeness and accuracy of information in the database was inadequate for the intended research on post-operative complications following elective surgeries. 相似文献
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医学史作为历史学和医学的交叉学科,不仅涉及到医学的各学科,而且与社会人文学科有着广泛的联系。文中论述了医学史课程在医科大学生的人文素质教育中的重要作用,并从教师、教学、研究生培养等几个方面讨论如何加强医学史的教学工作,使之真正成为医学与人文素质教育的桥梁。 相似文献
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101-澄清剂及其助剂在兽用中药提取中的应用 总被引:1,自引:1,他引:0
本文介绍了一类用于中药提取的新产品一101—澄清剂及其矿物助剂,简述了其功能与作用机理。简要介绍了其在中药提取中的应用和操作要点;并与传统的醇沉法作了对比,展望了其应用前景。 相似文献
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苯丙酮尿症(PKU)是一种代谢异常的常染色体隐性遗传病,可引起患儿神经认知及神经运动障碍、自闭症行为、湿疹和癫痫等并发症。在治疗过程中,通过低苯丙氨酸(Phe)限制饮食的同时,还需关注患儿其他营养素缺乏的营养问题,因此开发适用于1~10岁PKU儿童的特殊医学用途氨基酸代谢障碍配方粉,对保障患儿正常生长发育具有重要意义。本文在PKU分型、饮食疗法、PKU患儿营养素缺乏等方面进行了综述,重点分析低蛋白饮食、基于游离氨基酸的特殊医学用途氨基酸代谢障碍配方粉以及详述了PKU患儿体内某些营养素的缺乏与补充,以期为PKU饮食治疗中的营养问题以及特殊医学用途氨基酸代谢障碍配方粉的开发提供理论指导与参考。 相似文献