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基因药物的传递面临着体内外稳定性差、缺乏靶向性、难入胞、在细胞内难以释放等一系列障碍和挑战。因此,要实现基因药物在 体内有效传递需构建能克服这些障碍的药物传递系统。随着材料科学和纳米科技的发展,大量新型的纳米载体已被用于基因药物的传递。 综述目前基因药物传递所面临的障碍和挑战,基因药物纳米给药系统的设计思路及研究进展。 相似文献
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从人肝癌细胞(BEL-7402)高度免疫过的绵羊的淋巴器官中抽提的肝癌“免疫”RNA,和正常人外周血淋巴细胞温育后,在体外能介导肝癌细胞的免疫细胞溶解。用5-~(125)碘-2′-脱氧尿嘧啶核苷标记人肝癌靶细胞的微量细胞毒性试验进行测定时观察到,正常人淋巴细胞经肝癌“免疫”RNA处理后,其细胞毒性指数在16次实验中有10次有显著增高,但是,在与对照RNA温育后其细胞毒性指数(除一次实验外)均未出现有显著意义的变化。肝癌“免疫”RNA在用RNA酶降解后,传递细胞毒性免疫反应的活性即消失,而用DNA酶或灰链霉菌蛋白酶处理,却仍保持这种传递能力。由此证明,异种“免疫”RNA能够把针对人肝癌细胞表面抗原的细胞免疫性传递给正常人淋巴细胞。 相似文献
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一.引言有机体在繁殖过程中,通过生殖细胞(有性繁殖)或营养体(无性繁殖),把亲代的遗传特性传递给子代,使每种生物表现了一定的遗传性。但是任何性状不能直接由生殖细胞或营养体传递给子代,它是在一定物貭基础上通过个体发育而表现出来的。那么生物的性状究竟借什么而遗传呢?到底有没有遗传物貭?它的性貭怎样?这个问题一直是生物科学上争论的焦点之一。 相似文献
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共刺激分子免疫球蛋白家族—B7家族成员与CD28家族成员之间相互作用向T细胞传递共刺激信号,在T细胞充分活化和功能发挥中发挥了重要的功能。近几年研究表明,部分B7家族成员向T细胞传递免疫信号的同时,也向表达B7分子的抗原提呈细胞传递反向信号,增强或抑制了抗原提呈细胞的功能,并进一步在维持T细胞免疫和T细胞耐受中发挥重要的功能。 相似文献
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共刺激分子免疫球蛋白家族-B7家族成员与CD28家族成员之间相互作用向T细胞传递共刺激信号,在T细胞充分活化和功能发挥中发挥了重要的功能.近几年研究表明,部分B7家族成员向T细胞传递免疫信号的同时,也向表达B7分子的抗原提呈细胞传递反向信号,增强或抑制了抗原提呈细胞的功能,并进一步在维持T细胞免疫和T细胞耐受中发挥重要的功能. 相似文献
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机会性致病微生物在机体免疫功能正常时不能导致具有明显临床症状的感染性疾病, 但当机体微生态失调或免疫功能受损时, 可导致明显的临床感染性疾病, 甚至危及患者的生命。现代医疗技术的进步使先天性免疫功能缺陷者、肿瘤患者等免疫功能降低者生存期延长, 滥用抗生素致使正常微生态失调, 以及大量耐药变异菌株出现等诸多因素使得临床机会性感染逐渐增多。机会性感染多发生于免疫功能降低者, 可为耐药菌或多重耐药菌感染, 或为正常菌群致病; 临床表现复杂且不典型, 给治疗带来极大困难。了解常见机会性感染病原体及其特点对及时诊断和治疗机会性感染具有重要的临床意义。 相似文献
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【目的】普遍存在于鳞翅目昆虫中的ENF肽具有非常相似的结构和生理功能, 对昆虫的发育、 免疫、 应激反应等方面都起着重要的调控作用。有研究报道, 作为ENF肽家族成员之一的家蚕Bombyx mori麻痹肽(paralytic peptide, PP)通过激活MAPK来调控家蚕的免疫应答, 但其完整的分子作用机制尚不明确。本研究旨在解析传递家蚕PP免疫诱导信号的分子通路。【方法】首先通过荧光定量PCR检测了多种昆虫细胞系在PP诱导下抗菌肽基因的转录水平, 并利用Western blot检测p38 MAPK的磷酸化水平, 然后利用不同信号传递分子的抑制剂处理BmE细胞筛选参与传递PP免疫诱导信号的分子。【结果】PI3K抑制剂LY294002和受体型酪酸激酶抑制剂Genistein抑制了PP对BmE细胞抗菌肽基因表达的诱导作用; 且BmE细胞和家蚕血细胞在PP的诱导下, Akt和大小约为70 kDa的细胞膜蛋白均出现磷酸化水平的动态变化。【结论】PI3K/Akt信号通路和Genistein敏感性的受体型酪氨酸激酶介导了PP免疫诱导信号的传递。 相似文献
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Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献
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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献