909 resultados para mammalian cell culture
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O sucesso do tratamento endodôntico depende da cuidadosa realização de todas as suas fases, terminando com uma obturação tridimensional que alcance todo o sistema de canais radiculares. Desta forma, os materiais obturadores, ou as substâncias liberadas, entrarão em contato com os tecidos perirradiculares, o que poderá influenciar a resposta inflamatória e o processo de reparo. A terapia laser de baixa potência (TLBP) tem sido estudada quanto à sua ação anti-inflamatória, favorecendo o reparo. O objetivo deste estudo foi investigar a produção das citocinas IL-1β, IL-6 e IL-8 por fibroblastos de gengiva humana (linhagem FMM1) como resposta à presença dos extratos dos cimentos endodônticos AH Plus, MTA Fillapex e EndoSequence BC Sealer, bem como a eficácia da TLBP, neste modelo. Para isto, extratos destes cimentos, recém-manipulados e após 24 h do endurecimento, foram preparados em meio de cultura DMEM fresco, conforme as normas ISO 10993-12. Inicialmente, a citotoxicidade dos cimentos foi avaliada, após a interação das células com a diluição seriada destes extratos (1:1 a 1:16), por meio do ensaio MTT. Para a análise da produção de citocinas, 106 células por poço foram cultivadas em placas de cultura de 24 poços, para a interação com os extratos dos cimentos, na diluição 1:4. Estabeleceram-se os grupos não irradiado e irradiado. No grupo irradiado, as culturas celulares receberam duas irradiações do laser InGaAlP (660 nm, 30 mW, 5 J/cm2 e área do feixe de 0,028 cm2), com intervalo de 12 h. O grupo não irradiado foi submetido às mesmas condições ambientais que o irradiado. Os sobrenadantes das culturas foram coletados, centrifugados, aliquotados e armazenados congelados, para a posterior análise pelo ensaio de ELISA. Todos os dados obtidos (médias erro padrão) foram tratados estatisticamente por ANOVA one-way, complementado pelo teste de Tuckey e ANOVA two-way, com correção de Bonferroni (p< 0,05). A citotoxicidade dos cimentos AH Plus e EndoSequence BC Sealer revelou-se tempo/concentração-dependente, enquanto a do MTA Fillapex mostrou-se concentração-dependente. Os cimentos endodônticos induziram a produção das citocinas IL-1β, IL-6 e IL-8 pelos fibroblastos, sem diferença significativa com os controles (p> 0,05). Somente o LPS de E. coli induziu a secreção de IL-8, com diferença estatística (p< 0,05). A TLBP não foi capaz de modular a produção das citocinas em questão, significativamente.
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从七叶树(Aesculus Chinensis Bunge)的未成熟的果实的子叶中诱导出愈伤组织;愈伤组织在pH5.8,温度26 ± 1 ℃,加有NAA,TBA,K,CA的MS培养基上生长良好。光对愈伤组织的生长有促进作用,植醇对生长有抑制作用;进行了发酵罐培养。 利用TLC、质谱分离鉴定了γ-生育酚的存在,并利用HPLC、荧光法测定了生育酚的含量。结果表明,愈伤组织中生育酚的含量在3.2~6.6mg/100g干重;光对生育酚的合成有促进作用;植醇是生育酚合成的可能前体;悬浮培养不利于生育酚的合成,培养液中没有发现生育酚的存在。生育酚的合成与组织的生长速率成正相关。
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本文在本实验室提供的新疆紫草愈伤组织高产系A1的基础上,采用二步培养法,进行摇瓶悬浮培养,分别在生长及生产培养基中测定了细胞生长,次生产物合成,培养基的C源(蔗糖)消耗,溶氧,电导率和pH值的动态变化曲线,确定了各动态曲线之间的关系,为进一步的放大培养提供了参考依据。同时,还测定了与细胞生长密切相关的过氧化物酶及与产物合成密切相关的苯丙氨酸解氨酶(PAL)的活性的动态变化曲线,进一步将宏观参数的动态变化与微观参数的动态变化联系起来。 本文还对不同理化因子对生产培养基中悬浮培养的细胞的生长及紫草宁衍生物合成的影响进行了研究。结果表明:过高或过低的供氧水平均不利于细胞的生长及产物的合成;C源及N源有较好的协同作用,适当地提高C源及N源的水平能明显提高紫草宁衍生物的产量:接种前往培养基里加入一定量的前体苯丙氨酸( Phe),能明显提高紫草宁衍生物的产量,而在培养中期添加则有一定的负致应;一定量的拜土及琼脂(agar)的添加,对产物的合成均具有正效应,并且作用大小和细胞的生理状态有关。高密度培养的研究表明,在合适的接种量和培养基浓度下,适当提高溶氧,较大幅度地提高产量是有可能的,这还有待于进一步的研究验证。
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水母雪莲属菊科植物,为名贵中药材其主要活性成分为黄酮类化合物。为解决雪莲资源其中匮乏,本文开展了利用水母雪莲细胞培养生产黄酮类活性成分的可行性研究。 采用目视法从水母雪莲原始愈伤组织中筛选得到白色、黄色和红色3种细胞系,其中黄色系的黄酮含量最高。利用γ射线辐射处理从红色系得高产黄酮细胞系。 证明了多种理化因子对水母雪莲培养细胞中黄酮类合成的调控作用。研究发现,温度和光照对水母雪莲愈伤组织黄酮合成影响较大。25℃是最佳培养温度;红光促进愈伤组织生长,蓝光促进黄酮的合成;进一步研究表明:光调节黄酮代谢途径第一步所需酶苯丙氨酸裂解酶(PAL)活性,PAL活性被红光所抑制,被蓝光所促进。碳源、氮源、植物激素对愈伤组织生长和黄酮形成影响较为显著。对MS培养基成分进行调整得到M-13培养基,在M-13培养基上培养的愈伤组织生长量和黄酮产量比MS培养基分别提高33%和82%。 首次建立水母雪莲细胞悬浮培养体系。确定了水母雪莲细胞悬浮培养的最适培养条件和最适培养基成分组成。摇床转速 90~120 r/min、接种量 2.5~4.0gDW/L、接种物种龄 8~10 d 对黄酮合成有利。调整MS培养基成分得到适合于培养水母雪莲悬浮细胞的生长培养基G和黄酮合成培养基MP,从而使细胞生长量与黄酮产量分别长比MS培养基提高32%和70%。 应用2-L搅拌式生物反应器对水母雪莲细胞进行了悬浮培养。TLC和HPLC分析表明,水母雪莲细胞培养物能够形成2种黄酮活性成分金合欢素和高车前素。本论文对水母雪莲细胞培养生产药用活性成分作了基础性工作。
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水母雪莲(Saussurea medusa Maxim.)和新疆雪莲(Saussurea involucrata Karel. et Kir.)是我国珍稀的药用植物资源,具有清热解毒、止痉镇痛、敛伤、消肿及治疗热病、风湿等多种功效。雪莲的主要药用成份为紫丁香甙(Syringin)、芦丁(Rutin)、高车前素(Hispidulin)和Jaceosidin等苯基丙酸类(phenylpropanoid)和黄酮类(flavonoids)物质。最新的药理研究表明,上述物质还具有抗菌消炎、保肝降压、延缓衰老和抑制癌细胞增殖等重要的研发价值。 雪莲生境恶劣,生长缓慢,人工引种困难,加上长期掠夺性采挖,已使雪莲处于灭绝的边缘。为了保存国家珍稀植物品种,保护生态环境,满足临床上对雪莲药物的需求,本研究在雪莲组织培养的基础上,应用诱导子添加技术和毛状根培养技术对雪莲中具有重要药用价值的次生代谢物质进行调控,并对雪莲MYB类转录因子的功能进行了初步探索,为保护珍稀植物资源、维护生态环境、开发野生雪莲替代产品、缩短雪莲药用成份的生产周期奠定了基础。另外,分析了野生雪莲和雪莲培养物中主要生物活性成份的种类及含量,为今后雪莲药理药效研究及品质评价奠定了基础。 为了提高雪莲黄酮的产量,满足工业化生产的需要,在细胞培养水平上,通过添加茉莉酸甲酯(MJ),对雪莲黄酮类物质的代谢进行调控。研究了诱导子的添加时间、添加浓度对水母雪莲红色系悬浮细胞的生物量和总黄酮产量的影响。发现在细胞培养的指数期(第9天)添加5.0 µmol/L的MJ,可以使总黄酮产量提高2.4倍(1134.5 ± 63.86 mg/L),而雪莲细胞干重(dw)仅比对照提高23.8 %(20.4 ±0.27 g/L)。另外,细胞中苯丙氨酸裂解酶(PAL)的活性分析表明,MJ添加后PAL活性的增加与雪莲总黄酮含量增长之间存在相关性。 在器官培养水平上,对雪莲毛状根的诱导频率及其培养条件进行了研究。结果表明,选择发根农杆菌R1601侵染预培养2天的新疆雪莲根段外植体,毛状根的诱导效率可达到83 %。毛状根的冠瘿碱检测、PCR和Southern分析表明,Ri质粒中的T-DNA已整合到植物基因组中并稳定表达。以新疆雪莲毛状根为外植体,能够容易地获得再生芽。在含有1.0 mg/L 6-BA的MS固体培养基上,其再生频率高达91 ± 5.9 %,是其正常根的2.4倍。而水母雪莲在该培养条件下,仅有少量的畸形芽出现。进而对毛状根的培养条件进行初步研究,结果表明在无激素附加的MS液体培养基中,新疆雪莲的HR1601根系在一个培养周期内(32 天),其生物量能够达到接种量的16倍,而紫丁香甙含量(43.5 ± 1.13 mg/g dw)能够达到野生雪莲的83倍。从而显示了雪莲毛状根培养体系的优良特性。 在基因水平上,对雪莲黄酮类物质代谢调控的研究已经展开。玉米P基因编码的Myb类转录因子能够调节黄酮类物质代谢途径关键酶基因的表达。根据P基因的保守序列设计引物,从雪莲细胞培养物中获得了SmP基因。核酸序列分析表明,SmP基因与烟草中涉及苯丙素类物质代谢途径的LBM 1、LBM 3和MybAS 1基因具有较高的一致性,分别为66 %、60 %和61 %。因此为了研究雪莲SmP基因的功能,构建了正义表达载体,并与先前构建好的反义表达载体分别导入烟草,分析了转基因植株的形态特征及黄酮类物质的含量变化。其中,约有30 %转反义SmP基因的株系表现叶片皱缩、叶脉紊乱、主侧脉角度缩小、叶片、花瓣失去对称性以及花粉败育等性状。 另外,通过正交试验设计优化了雪莲提取工艺的条件,并对雪莲细胞提取物进行了分离纯化。正交试验设计结果表明,温度对雪莲黄酮提取效率的影响极为显著,而分批多次提取比一次性浸提,能够收到较好的提取效果。考虑到工业生产中的实际问题,推荐在60 ℃水浴条件下,采用50 %乙醇对雪莲样品连续浸提2次的方案。对雪莲提取物的纯化研究表明,雪莲成份复杂,仅依靠单一的分离手段,往往难以奏效。另外,野生雪莲及雪莲培养物中生物活性成份的比色法、HPLC(High Performance Liquid Chromatography)、LC-ESI-MS(Liquid Chromotagraphy Electrospray Ionization Mass Spectrometry)分析表明,传统的NaNO2-AlCl3 法测定雪莲总黄酮的含量,结果偏高,不利于雪莲黄酮的实验室研究分析与今后工业化生产的质量监控。而AlCl3 法的显色反应较为特异,今后有望取代NaNO2-AlCl3 法,作为雪莲类药材品质评价的标准。而HPLC-DAD结合LC-ESI-MS可以对雪莲中的主要生物活性成份进行较为准确的定性分析,从而解决了由于缺乏相应的雪莲化合物标准品而难以对雪莲中的成份进行定性定量分析及比较的难题。最后综合利用上述分析方法,对雪莲细胞培养物中的花素类物质进行了分析。结果表明,雪莲细胞中至少含有7种花色素类物质,分别为矢车菊素-3-O-葡萄糖甙及其衍生物、天竺葵素糖甙衍生物和芍药色素糖甙衍生物。
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A TiNi/diamond-like-carbon (DLC) microcage for biological application has been designed, fabricated and characterized. A compressively stressed DLC film with TiNi pattern on top lifts the fingers upwards once they are released from the substrate, and the microcage can be closed through shape memory effect of top TiNi film with temperature below 80°C. Further heating above 100°C, the gradual opening of the microcage can be obtained due to thermal bimorph effect. The biocompatibility of both the TiNi and DLC films has been proved using a cell-culture method.
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The chromosome scaffolds in higher eukaryotic nuclei have been described elsewhere. But it is unknown when they evolved. The dinoflagellates are the primitive organisms that may be the intermediate between prokaryotes and eukaryotes. Combining chromosome scaffold preparation methods with embedment-free section microscopy, we demonstrate that the dinoflagellate Crypthecodinium cohnii chromosome retains a protein scaffold after the depletion of DNA and soluble proteins. This scaffold preserves the morphology characteristic of the chromosome. Two-dimensional electrophoreses show that the chromosome scaffolds are mainly composed of acidic proteins. Our results suggest that a framework similar to the chromosome scaffold in the mammalian cell appeared in the primitive eukaryote. We propose that the chromosome scaffold possibly originated from the early stages of eukaryote evolution.
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To investigate whether aberrant hypermethylation in plasma DNA could be used as diagnosis makers for hepatocellular carcinoma (HCC), we performed methylation-specific PCR (MSP) to check the methylation status of five tumor associated genes in 36 cases of
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Changes of plasminogen activators (PA) during different stages of development of the corpus luteum, and their possible physiological role in luteolysis were studied in rhesus monkeys. It was demonstrated for the first time that monkey corpus luteal cells not only produce PA, but that the function of the corpus luteum is also closely related to the activity of this enzyme system. Generally, the life span for a corpus luteum in monkey is approximately 14-16 days, its demise beginning thereafter. In the present study, we found that urokinase in the corpus luteum is higher on day 5 and day 10 after human chorionic gonadotrophin injection, while the tissue type (t) PA is mainly produced on day 13 when luteolysis may take place. Progesterone production remained high on day 5 and day 10 and decreased dramatically from day 13, indicating the important role of tPA but not urokinase (u) PA in suppressing luteal function. When purified tPA (but not uPA) monoclonal antibody was added to luteal cell culture to neutralize endogenously produced tPA activity, progesterone production in the cells was increased significantly. Interestingly, prolactin alone was capable of increasing PA production by luteal cells; prolactin together with luteinizing hormone, however, had a synergistic luteotrophic effect.
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Sertoli cells play a central role in the control and maintenance of spermatogenesis. Isolated Sertoli cells of mouse and rat testes have been shown to secrete plasminogen activator (PA) and a plasminogen activator inhibitor type-1 (PAI-1) in culture. In this study, we have investigated the hormonal regulation of PA and PAI-1 activities in cultured monkey Sertoli cells. Sertoli cells (5x10(5) cells/well) isolated from infant rhesus monkey testes were preincubated at 35 degrees C for 16 h in 24-well plates precoated with poly(D-lysine) (5 mu g/cm(2)) in 0.5 mi McCoy's 5a medium containing 5% of fetal calf serum and further incubated for 48 h in 0.5 mi serum-free medium with or without various hormones or other compounds, PA as well as PAI-1 activities in the conditioned media were assayed by fibrin overlay and reverse fibrin autography techniques respectively. The Sertoli cells in vitro secreted only tissue-type PA (tPA), no detectable amount of urokinase-type PA (uPA) could be observed, Monkey Sertoli cells were also capable of secreting PAI-1, Immunocytochemical studies indicated that both tPA and PAI-1 positive staining localized in the Sertoli cells, spermatids and residual bodies of the seminiferous epithelium; Northern blot analysis further confirmed the presence of both tPA and PAI-1 mRNA in monkey Sertoli cells. Addition of follicle-stimulating hormone (FSH) or cyclic adenosine monophosphate (cAMP) derivatives or cAMP-generating agents and gonadotrophin-releasing hormone (GnRH) agonist or phorbol ester (PMA) to the cell culture significantly increased tPA activity. PAI-1 activity in the culture was also enhanced by these reagents except 8-bromo-dibutyryl-cAMP, forskolin and 3-isobutyl-1-methylxanthin (MIX) which greatly stimulated tPA activity, whereas decreased PAI-1 activity, implying that neutralization of PAI-1 activity by tile high level of tPA in the conditioned media may occur. These data suggest that increased intracellular signals which activate protein kinase A (PKA), or protein kinase C (PKC) can modulate Sertoli cell tPA and PAI-1 activities, The concomitant induction of PA and PAI-1 by the same reagents in the Sertoli cells may reflect a finely tuned regulatory mechanism in which PAI-1 could limit the excession of the proteolysis.
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Background: The anti-HIV-1 neutralizing antibody assay is widely used in AIDS vaccine research and other experimental and clinical studies. The vital dye staining method applied in the detection of anti-HIV-1 neutralizing antibody has been used in many laboratories. However, the unknown factor(s) in sera or plasma affected cell growth and caused protection when the tested sera or plasma was continuously maintained in cell culture. In addition, the poor solubility of neutral red in medium (such as RPMI-1640) also limited the use of this assay. Methods: In this study, human T cell line C8166 was used as host cells, and 3-(4,5-Dimethyl-2-thiazolyl)- 2,5-diphenyl-2H-tetrazolium bromide (MTT) instead of neutral red was used as vital dye. In order to avoid the effect of the unknown factor( s), the tested sera or plasma was removed by a washout procedure after initial 3 - 6 h culture in the assay. Result: This new assay eliminated the effect of the tested sera or plasma on cell growth, improved the reliability of detection of anti-HIV-1 neutralizing antibody, and showed excellent agreement with the p24 antigen method. Conclusion: The results suggest that the improved assay is relatively simple, highly duplicable, cost-effective, and well reliable for evaluating anti-HIV-1 neutralizing antibodies from sera or plasma.
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Beneficial effects on bone-implant bonding may accrue from ferromagnetic fiber networks on implants which can deform in vivo inducing controlled levels of mechanical strain directly in growing bone. This approach requires ferromagnetic fibers that can be implanted in vivo without stimulating undue inflammatory cell responses or cytotoxicity. This study examines the short-term in vitro responses, including attachment, viability, and inflammatory stimulation, of human peripheral blood monocytes to 444 ferritic stainless steel fiber networks. Two types of 444 networks, differing in fiber cross section and thus surface area, were considered alongside austenitic stainless steel fiber networks, made of 316L, a widely established implant material. Similar high percent seeding efficiencies were measured by CyQuant® on all fiber networks after 48 h of cell culture. Extensive cell attachment was confirmed by fluorescence and scanning electron microscopy, which showed round monocytes attached at various depths into the fiber networks. Medium concentrations of lactate dehydrogenase (LDH) and tumor necrosis factor alpha (TNF-α) were determined as indicators of viability and inflammatory responses, respectively. Percent LDH concentrations were similar for both 444 fiber networks at all time points, whereas significantly lower than those of 316L control networks at 24 h. All networks elicited low-level secretions of TNF-α, which were significantly lower than that of the positive control wells containing zymosan. Collectively, the results indicate that 444 networks produce comparable responses to medical implant grade 316L networks and are able to support human peripheral blood monocytes in short-term in vitro cultures without inducing significant inflammatory or cytotoxic effects.
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The use of a porous coating on prosthetic components to encourage bone ingrowth is an important way of improving uncemented implant fixation. Enhanced fixation may be achieved by the use of porous magneto-active layers on the surface of prosthetic implants, which would deform elastically on application of a magnetic field, generating internal stresses within the in-growing bone. This approach requires a ferromagnetic material able to support osteoblast attachment, proliferation, differentiation, and mineralization. In this study, the human osteoblast responses to ferromagnetic 444 stainless steel networks were considered alongside those to nonmagnetic 316L (medical grade) stainless steel networks. While both networks had similar porosities, 444 networks were made from coarser fibers, resulting in larger inter-fiber spaces. The networks were analyzed for cell morphology, distribution, proliferation, and differentiation, extracellular matrix production and the formation of mineralized nodules. Cell culture was performed in both the presence of osteogenic supplements, to encourage cell differentiation, and in their absence. It was found that fiber size affected osteoblast morphology, cytoskeleton organization and proliferation at the early stages of culture. The larger inter-fiber spaces in the 444 networks resulted in better spatial distribution of the extracellular matrix. The addition of osteogenic supplements enhanced cell differentiation and reduced cell proliferation thereby preventing the differences in proliferation observed in the absence of osteogenic supplements. The results demonstrated that 444 networks elicited favorable responses from human osteoblasts, and thus show potential for use as magnetically active porous coatings for advanced bone implant applications. © 2012 Wiley Periodicals, Inc.
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Vasa is essential for germline development. However, the precise processes in which vasa involves vary considerably in diverse animal phyla. Here we show that vasa is required for primordial germ cell (PGC) migration in the medakafish. vasa knockdown by two morpholinos led to the PGC migration defect that was rescued by coinjection of Vasa RNA. Interestingly, Vasa knockdown did not alter the PGC number, identity, proliferation and motility even at ectopic locations. We established a cell culture system for tracing PGCs at the single cell level in vitro. In this culture system, control and morpholino-injected gastrulae produced the same PGC number and the same time course of PGC survival. importantly, vasa-depleted PGCs in culture had similar motility and locomotion to normal PGCs. Expression patterns of wt1a, sdf1b and cxcT4b in migratory tissues remained unchanged by Vasa knockdown. By chimera formation we show that PGCs from vasa-depleted blastulae failed to migrate properly in the normal environment, whereas control PGCs migrated normally in vasa-disrupted embryos. Furthermore, ectopic PGCs in vasa-depleted embryos also retained all the PGC properties examined. Taken together, medaka vasa is cell-autonomously required for PGC migration, but dispensable to PGC proliferation, motility, identity and survival. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
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m Background: Cross-species nuclear transfer has been shown to be a potent approach to retain the genetic viability of a certain species near extinction. However, most embryos produced by cross-species nuclear transfer were compromised because that they were unable to develop to later stages. Gene expression analysis of cross-species cloned embryos will yield new insights into the regulatory mechanisms involved in cross-species nuclear transfer and embryonic development. Results: A novel gene, K31, was identified as an up-regulated gene in fish cross-subfamily cloned embryos using SSH approach and RACE method. K31 complete cDNA sequence is 1106 base pairs (bp) in length, with a 342 bp open reading frame (ORF) encoding a putative protein of 113 amino acids (aa). Comparative analysis revealed no homologous known gene in zebrafish and other species database. K31 protein contains a putative transmembrane helix and five putative phosphorylation sites but without a signal peptide. Expression pattern analysis by real time RT-PCR and whole-mount in situ hybridization (WISH) shows that it has the characteristics of constitutively expressed gene. Sub-cellular localization assay shows that K31 protein can not penetrate the nuclei. Interestingly, over-expression of K31 gene can cause lethality in the epithelioma papulosum cyprinid (EPC) cells in cell culture, which gave hint to the inefficient reprogramming events occurred in cloned embryos. Conclusion: Taken together, our findings indicated that K31 gene is a novel gene differentially expressed in fish cross-subfamily cloned embryos and over-expression of K31 gene can cause lethality of cultured fish cells. To our knowledge, this is the first report on the determination of novel genes involved in nucleo-cytoplasmic interaction of fish cross-subfamily cloned embryos.