901 resultados para innate immune system
Resumo:
血管生成是肿瘤生长、发展的必经之路,并且与实体瘤的发生、转移有着密切的关系,抑制肿瘤新生血管生成具有特异性高、疗效好、不易产生耐药性以及毒副作用低等特点,因此抑制肿瘤血管形成可望成为治疗癌症的一个突破点,以抗血管生成为主的肿瘤生物治疗研究已成为近十年的研究热点。玻璃海鞘(Coina intestinalis)属于内性目、玻璃海鞘科,因其进化上的独特地位常作为研究神经发育、免疫系统进化的材料。在其它种属的海鞘中分离发现了多种具有抗肿瘤活性的多肽,但关于玻璃海鞘抗血管生成活性多肽的分离纯化和活性研究未见报道。本文利用多种分离纯化手段,采用活性追踪的方法首次从玻璃海鞘中分离得到具有抗新生血管生成作用的多肽,并对其抗血管生成活性做了初步研究。 本研究利用冷丙酮分级沉淀,超滤截留分子量小于5kDa的蛋白,再经SephadexG25、Superdex75柱层析,µRPC C2/C18反相柱层析等分离手段,采用活性追踪的方法,由玻璃海鞘(Coina intestinalis)中分离纯化出抗血管生成多肽PCI,据保留时间计算其分子量为1.8 kDa。MTT检测表明其对人脐静脉血管内皮细胞(HUVEC)具有强烈的抑制作用,IC50为7.5 μg/ml,并对多种肿瘤细胞有直接的抑制作用。斑马鱼胚胎体内实验进一步表明PCI在40 μg/ml的浓度下作用12h,斑马鱼胚胎新生血管生成受到显著抑制,肠下静脉血管长度为正常组的30%,斑马鱼胚胎血管生成率为正常组的45%。
Resumo:
The coelomocytes suspended in the coelomic fluid and occurring in the coelomic epithelial layer of the sea cucumber Apostichopus japonicus (Selenka) (Holothuroidea: Aspidochirota: Stichopodidae) function as mediators of the immune system, trephocytic cells and nutrient transport cells. Types of coelomocytes are characterized based on their morphological and ultrastructural features. Flow cytometry plus light and electron microscopic analyses were conducted in order to characterize the coelomocytes of A. japonicus. Six types of coelomocytes were identified: lymphocytes, morula cells, amoebocytes, crystal cells, fusiform cells and vibratile cells. Within these major categories, several distinctive cell types occurred that might represent developmental stages. The mean +/- SD coelomocyte concentration in the individuals (body length: 10 to 15 cm; weight: 100 to 150 g) was (3.79 +/- 0.65) X 10(6) cells ml(-1). The coelomic fluid contained mainly hyalinocytes (76.69%) and granulocytes (23.31 %).
Resumo:
HSP22 is a member of a small HSP subfamily contributing to the growth, transformation and apoptosis of the cell as well as acting as a molecular chaperone. In the present study, CfHSP22 cDNA was cloned from Chlamys farreri by the rapid amplification of cDNA ends technique. The full-length cDNA of CfHSP22 was of 1279 bp, consisting of a 5'-terminal untranslated region (5'UTR) of 122 bp, a 3'UTR of 581 bp with a canonical polyadenylation signal sequence AATAAA and a poly( A) tail, and an open reading frame of 576 bp encoding a polypeptide with a molecular mass of 22.21 kDa and a predicted isoelectric point of 9.69. There was an alpha-crystallin domain, a hallmark of the sHSP subfamily, in the C-terminus, and the deduced amino acid sequence of CfHSP22 showed high similarity to previously identified HSP22s. CfHSP22 was constitutively expressed in the haemocyte, muscle, kidney, gonad, gill, heart and hepatopancreas, and the expression level in the hepatopancreas was higher than that in the other tissues. CfHSP22 transcription was up-regulated and reached a maximal level at 12 h after the bacterial challenge, and then declined progressively to the original level at 48 h. These results suggested that CfHSP22 perhaps play a critical role in response to the bacterial challenge in haemocytes of scallop C. farreri.
Resumo:
The modulation of carrageenan oligosaccharides from Kappaphycus striatum on the immune system in S 180-bearing mice was investigated. The mice inoculated with S180 cell suspension were treated p.o. with carrageenan oligosaccharides (50, 100 and 200 mu g/g) for 14 days. The effects of carrageenan oligosaccharides on transplantable tumors and macrophage phagocytosis, quantitative hemolysis of sheep red blood cells (QHS),. lymphocyte proliferation, the activity of natural killer cells (NK), production of interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) were studied. Carrageenan oligosaccharides could significantly inhibit the growth of transplantable sarcoma S180 and increase macrophage phagocytosis, the form of antibody secreted by spleen cells, spleen lymphocyte proliferation, NK cells activity, serumal IL-2 and TNF-alpha level in S 180-bearing mice. Considering all these results, it is suggested that carrageenan oligosaccharides exert their antitumor effect by promoting the immune system. (c) 2005 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Substantial nutritional and energetic demands m-e associated with immune activation and the maintenance of an efficient immune system. One-year-old Chlamys farreri (Jones and Preston) scallops were maintained ill lantern nets ill different nutritional conditions (satiation and starvation) for 40 days. After the 40-day treatments, the condition index and the total hemocyte count (THC) decreased significantly in the starved group compared with the satiated and initial control groups. The percentage of phagocytic hemocytes also was significantly reduced with starvation. In contrast. no significant effect of starvation was observed oil reactive oxygen species (ROS) production. The acid phosphatase (ACP) activities in cell-free hemolymph increased significantly in scallops in starved and satiated treatments compared with the initial control. whereas ACP activity in hemocyte lysate was significantly lower ill the starved group. These results indicate that starvation stress compromises immunological activities of scallops.
Resumo:
Sponges (phylum Porifera) had been considered as an enigmatic phylum, prior to the analysis of their genetic repertoire/tool kit. Already with the isolation of the first adhesion molecule, galectin, it became clear that the sequences of sponge cell surface receptors and of molecules forming the intracellular signal transduction pathways triggered by them, share high similarity with those identified in other metazoan phyla. These studies demonstrated that all metazoan phyla, including Porifera, originate from one common ancestor, the Urmetazoa. The sponges evolved prior to the Ediacaran-Cambrian boundary (542 million years ago [myr]) during two major "snowball earth events", the Sturtian glaciation (710 to 680 myr) and the Varanger-Marinoan ice ages (605 to 585 myr). During this period the ocean was richer in silica due to the silicate weathering. The oldest sponge fossils (Hexactinellida) have been described from Australia, China and Mongolia and are thought to have existed coeval with the diverse Ediacara fauna. Only little younger are the fossils discovered in the Sansha section in Hunan (Early Cambrian; China). It has been proposed that only the sponges possessed the genetic repertoire to cope with the adverse conditions, e.g. temperature-protection molecules or proteins protecting them against ultraviolet radiation. The skeletal elements of the Hexactinellida (model organisms Monorhaphis chuni and Monorhaphis intermedia or Hyalonema sieboldi) and Demospongiae (models Suberites domuncula and Geodia cydonium), the spicules, are formed enzymatically by the anabolic enzyme silicatein and the catabolic enzyme silicase. Both, the spicules of Hexactinellida and of Demospongiae, comprise a central axial canal and an axial filament which harbors the silicatein. After intracellular formation of the first lamella around the channel and the subsequent extracellular apposition of further lamellae the spicules are completed in a net formed of collagen fibers. The data summarized here substantiate that with the finding of silicatein a new aera in the field of bio/inorganic chemistry started. For the first time strategies could be formulated and experimentally proven that allow the formation/synthesis of inorganic structures by organic molecules. These findings are not only of importance for the further understanding of basic pathways in the body plan formation of sponges but also of eminent importance for applied/commercial processes in a sustainable use of biomolecules for novel bio/inorganic materials.
Resumo:
To investigate the antitumor effect of bromophenol derivatives in vitro and Leathesia nana extract in vivo, six bromophenol derivatives 6-(2,3-dibromo-4,5-dihydroxybenzyl)-2,3-dibromo-4,5-dihydroxy benzyl methyl ether (1), (+)-3-(2,3-dibromo-4,5-dihydroxyphenyl)-4-bromo-5,6-dihydroxy-1,3-dihydroisobenzofuran (2), 3-bromo-4-(2,3-dibromo-4,5-dihydroxybenzyl)-5-methoxymethyl-pyrocatechol (3), 2,2',3,3'-tetrabromo-4,4',5,5'-tetrahydroxy-diphenylmethane (4), bis(2,3-dibromo-4,5-dihydroxybenzyl) ether (5), 2,2',3-tribromo-3',4,4',5-tetrahydroxy-6'-ethyloxymethyldiphenylmethane (6) were isolated from brown alga Leathesia nana, and their cytotoxicity were tested by MTT assays in human cancer cell lines A549, BGC-823, MCF-7, B16-BL6, HT-1080, A2780, Bel7402 and HCT-8. Their inhibitory activity against protein tyrosine kinase (PTK) with over-expression of c-kit was analyzed also by ELISA. The antitumor activity of ethanolic extraction of Leathesia nana (EELN) was evaluated on S-180-bearing mice. All compounds showed very potent cytotoxicity against all of the eight cancer cell lines with IC50 below 10 mu g/mL. In PTK inhibition study, all bromophenol derivatives showed moderate inhibitory activity and compounds 2, 5 and 6 showed significant bioactivity with the inhibition ratio of 77.5%, 80.1% and 71.4%, respectively. Pharmacological studies reveal that EELN could inhibit the growth of Sarcoma 180 tumor and increase the indices of thymus and spleen to improve the immune system remarkably in vivo. Results indicated that the bromophenol derivatives and EELN can be used as potent antitumor agents for PTK over-expression of c-kit and considered in a new therapeutic strategy for treatment of cancer.
Resumo:
在深入分析生物免疫系统中T细胞对B细胞辅助调节作用的基础上,提出了免疫反馈原理。针对非最小相位极点系统控制的难点,借鉴免疫反馈原理,结合积分控制的规律,提出了一种模糊免疫非线性PID控制方法。由于该方法中的参数确定比较复杂,利用免疫进化算法进行参数优化设计,实现了控制参数的合理设计。仿真结果表明,该方法在非最小相位极点系统控制中可行且有效,优于PID控制方法,具有更好的响应特性和抗干扰性能。
Resumo:
Although the influence of emotional states on immune function has been generally recognized, researches on the effects of negative emotion on individual SIgA levels have reported mixed findings. Our study aimed to elucidate the relationship between changes in EEG activity and cognitive and psychological mechanisms to the immune changes induced by negative emotion. In experiment one, we investigated how the negative emotional arousal that was induced by watching a number of unpleasant pictures altered the concentration of secretory immunoglobulin A (SIgA). Although our results found discrepancies in the changing tendency of SIgA concentration among participants (some participants’ SIgA decreased after watching unpleasant pictures, whereas others increased), further analysis revealed a coherency among the changing of SIgA concentration, participants’ general coping styles and their actual emotion regulation strategies in perceiving unpleasant pictures, and the event-related potentials (ERPs) associated with the watching of unpleasant pictures. The participants whose SIgA increased after watching unpleasant pictures (the increasers) had higher positive coping scores in the Trait Coping Styles Questionnaire (TCSQ) than those whose SIgA decreased (the decreasers). Also, relative to the decreasers, the increasers tended to use more emotion regulation strategies especially when the presented pictures were extremely negative and exhibited a reverse dissociation pattern between the extremely negative pictures and the moderately negative ones in the amplitude of late positive potential (LPP) that was related to the cognitive evaluation of stimuli’s meaning. On this basis, Event-related potentials were recorded first while participants passively viewed unpleasant pictures, and then during an emotion regulation block in which participants were instructed to reappraise unpleasant pictures in the experiment two. We also collected the immune index before and after the passive viewing block and the emotion regulation block. Our study proved that participants felt a less intense emotional response to unpleasant pictures that followed a reappraisal instruction. The decreasing emotional responding to unpleasant pictures decreased the amplitude of the LPP. But larger N2 was induced in the emotion regulation block, because the participants needed to obtained more attentional resources to detect and integrate more stimulus features to use the cognitive reappraisal strategy effectively. The present study has important theoretic and practical significance. For the theoretic significance, our study elucidated the relationship between changes in EEG activity and cognitive and psychological mechanisms to the immune changes induced by negative emotion by using the technologies of ERP, experimental interview and psychological measurement. Meanwhile, our study also provided an explanation for the different changing tendencies of SIgA induced by negative emotions, and it plays an important role in further studying the cognitive neural mechanisms of immune level in response to emotion. As to the practical significance, our study suggests that individuals who use active emotion regulation in the face of negative emotion stimuli may experience significantly increases in immune system function, subsequently lowering the possibility of infection.
Resumo:
Sauze, C and Neal, M. 'Endocrine Inspired Modulation of Artificial Neural Networks for Mobile Robotics', Dynamics of Learning Behavior and Neuromodulation Workshop, European Conference on Artifical Life 2007, Lisbon, Portugal, September 10th-14th 2007.
Resumo:
Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas
Resumo:
Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas
Resumo:
Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas
Resumo:
Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
Resumo:
Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas