889 resultados para Secreting Gland
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Apoptosis is an active process of cell death, which is an integral part of growth and development in multicellular organisms. The defender against cell death 1 (DAD1), the regulatory protein to inhibit the apoptosis process, was first cloned from the bay scallop Argopecten irradians by randomly sequencing a whole tissue cDNA library and rapid amplification of cDNA end (RACE). The full-length cDNA of the A. irradians DAD1 was 607 bp, consist of a 5'-terminal untranslated region (UTR) of 63 bp, a 3'-terminal UTR of 205 bp with a canonical polyadenylation signal sequence AATAAA and a poly (A) tail, and an open reading frame of 339 bp. The deduced amino acid sequence of the A. irradians DAD1 showed 75.5% identity to Araneus ventricosus, 74.5% to Drosophila melanogaster, and 73.6% to Homo sapiens, Sus scrofa, Mesocricetus auratus, Rattus norvegicus and Mus musculus. Excluding the Saccharomyces cerevisiae DAD1 homologue, all animal DAD1 including A. irradians DAD1 homologue formed a subgroup and all plant DAD1 proteins formed another subgroup in the phylogenetic analysis. The A. irradians DAD1 was expressed in all examined tissues including adductor muscle, mantle, gills, digestive gland, gonad and hemolymph, suggesting that A. irradians DAD1 is expressed in most body tissues. Furthermore, the mRNA expression levels of A. irradians DAD1 gene of hemolymph were particularly high after injury, suggesting that the gene is responsive to injury stimuli.
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利用扫描电镜和组织学研究相结合的方法研究了中国对虾早期的性别分化。扫描电镜观察的结果表明,中国对虾外部性征的性别分化是在变为仔是后第35天开始的,而内部性征则是在变为仔虾后的第76天观察到生殖腺原基向精巢和卵巢的分化。促雄腺(Androgenic gland)是控制甲壳动物性别分化的一个重要器官。到目前为止,已在软甲类的多数目中报道了促雄腺的存在。不同种类促雄腺的分布位置不同,外部形态也有很大差别。中国对虾的促雄腺位于第五对步足基部的肌肉间,于片状覆盖在精荚囊与射精管连接处。当用苏木精染色时,由于其嗜碱性比较强,整个腺体被染成深蓝色。扫描电镜观察可见,中国对虾的促雄腺具有葡萄串状的外形,它是由许多葡萄形的亚单位组成的,这些亚单位的大小、形态各异组织学观察的结果表明,中国对虾的促雄腺由两种类型的细胞组成。第一类细胞,数量少,核的嗜碱性很强,被苏木精染成深蓝色,核仁不易分辨;第二类细胞,数量大,核比较膨大,嗜碱性较弱,核质疏松,具有明显可见的核仁。不同大小的虾中,腺细胞的排列方式不同。随着对虾的发育成熟,腺细胞逐渐由索状排列变为成团排列,说明促雄腺的形成存在一个逐渐发育的过程。利用手术破坏促雄腺或用促雄腺匀浆液浸泡仔虾的方法研究了中国对虾促雄腺的功能,中国对虾促雄腺的存在与否对于雄性外部性征的发育和维持起着重要作用。破坏促雄腺的雄虾的交接器的发育明显受到抑制。但是,未观察到促雄腺对对虾内部性征发育的影响,这可能与进行手术时对虾所处的发育期有关。利用促雄腺的匀浆液浸泡仔虾,对雄虾交接器的发育有一定促进作用。高温处理对中国对虾受精卵孵化率的影响随处理温度及处理时间的改变而发生变化。用热处理方法成功地诱导了中国对虾三倍体,最高诱导率达75%,并对三倍体群体的生物学特性进行了研究。在中国对虾三倍体的群体中,雌体的巢存在两种类型:一种类型卵巢,生殖细胞停留在卵原细胞阶段,没有进一步发育;另一种类型的卵巢,生殖细胞由卵原细胞发育为初级卵母细胞,发育情况与对虾的类似。对卵巢处于发育的第II或第III期的中国对虾以及卵巢发育处在第I、II、III期的几纳对虾的血液和卵巢中法呢烯酸甲酯(MF)含量进行了研究,结果表明,中国对虾和凡纳对虾中均存在MF。凡纳对虾血液和卵巢发育具有明显的刺激作用,这种刺激作用是通过血液中法呢烯酸甲酯含量的提高来实现的。这一研究结果进一步说明了法呢烯酸甲酯与甲壳动物繁殖之间的关系。
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海水经济鱼类的养殖在我国已经形成第四次海水养殖浪潮,经济效益显著,有力地推动了我国海水养殖的产业结构调整和可持续发展。然而在海水养殖发展过程中也存在着诸多问题,尤其是早期发育阶段的高死亡率,严重制约了我国海水养殖产业的稳定和健康发展。 海水鱼类养殖的关键为高质量,高存活率苗种的生产和培育,由于鱼类种类繁多,生物多样性丰富,对应实际的繁育技术,尤其是新品种的开发,必须要做出相应的调整。这就要求我们必须对每一种鱼类早期发育有所了解,并将形态和组织上的数据用于指导生产。 本文通过显微观察和组织学研究,主要描述和研究了我国北方三种重要的海水经济鱼类(条斑星鲽、杂交鲆、条石鲷)的早期发育生物学,并结合实际生产进一步阐明关键期的产生原因,机理以及采用相应的对策。具体结果如下: 1.条斑星鲽:作为冷温性鲆鲽鱼类,条斑星鲽早期发育过程的特征主要有: ① 条斑星鲽受精卵无油球,卵子呈半浮性;不同步卵裂现象提前,发生在第三次卵裂;卵裂期裂球大小差异大。孵化过程较长,在水温8 ± 0.3℃,盐度33的条件下,经9 d孵化。条斑星鲽胚胎发育的不同时期对温度的敏感性不同,其中原肠期对温度比较敏感。 ②在8-10℃,盐度33的条件下,8-9 dph开口摄食。且开口时,其吻前端出现有一点状黑褐色素,构成了条斑星鲽仔鱼“开口期”的重要标志。卵黄囊于消失。在后期仔鱼末期,背鳍和臀鳍上形成特有的黑褐色条斑带。 ③杯状细胞首先出现在咽腔后部和食道前段,胃腺和幽门盲囊出现于29 dph,变态期始于30dph。在条斑星鲽早期发育过程中,观察到其直肠粘膜层细胞质出现大量嗜伊红颗粒,为仔鱼肠道上皮吸收的蛋白质。 ④首先淋巴化的免疫器官是头肾,然后是胸腺和脾脏,这与大部分硬骨鱼类不同。条斑星鲽除头肾和脾脏外,胸腺实质也形成MMCs。其中以脾脏形成MMCs最为丰富,形态多样。 2. 杂交鲆:为同属的牙鲆和夏鲆间的远缘杂交种,其发育过程的特点为: ① 在温度为15.4~16.0℃,杂交鲆胚胎从受精到孵化所需的时间为76 h左右,胚孔关闭前期,胚胎先出现视囊及克氏囊,而后形成体节。孵出前胚体在卵膜内环绕不到1周。 ② 孵化后消失。杂交鲆群体变态间隔长(34-60 dph),且变态高峰期出现的冠状幼鳍不明显(与母本牙鲆相比),数量为7-8根。 ③组织学观察发现,其消化系统中胃腺出现较晚,且胃腺发育过程缓慢(与母本牙鲆相比)。甲状腺滤泡增生不明显,颜色较浅,数量较少。杂交鲆在早期发育过程中,并没有出现鳔原基。 3. 条石鲷作为岩礁性的暖水性鱼类,早期发育过程也较为特殊,包括外形以及内部的器官结构。主要特点有: ① 受精卵:受精卵卵黄上具有龟裂结构,为鱼卵的分类特征之一。 ② 初孵仔鱼:初孵仔鱼背鳍膜上的黑色素,从体背面向背鳍膜边缘移动,到3dph仔鱼基本消失,此为本种仔鱼发育所特有的特点。 ③ 后期仔鱼和稚鱼:肠道肌肉层加厚明显,仔稚鱼胃肠排空率急剧上升,死亡率增加,通过改善常规的投饵方式部分解决了这个死亡高峰的问题。在幼鱼初期,牙齿融合为骨喙,为石鲷科鱼类的特征。 ④胸腺上皮分泌细胞:类似的现象同样在虹鳟鱼中发现,但是虹鳟鱼胸腺上皮分泌细胞不如条石鲷的丰富,同样也不如条石鲷的排列整齐,而是零星分布在胸腺上皮与咽腔接触的表面。除了正常的造血器官—脾脏和头肾外,肝脏、胰腺和鳔等多种组织等也出现MMCs,此现象在硬骨鱼类不多见,一般发生在软骨鱼类。
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Bacteria isolated from a highly toxic sample of gastropod Nassarius semiplicatus in Lianyungang, Jiangsu Province in July 2007, were studied to probe into the relationship between bacteria and toxicity of nassariid gastropod. The toxicity of the gastropod sample was 2 x 10(2) mouse unit (MU) Per gram Of tissue (wet weight). High concentration of tetrodotoxin (TTX) and its analogues (TTXs) were found in the digestive gland and muscle of the gastropod, using high performance liquid chromatography coupled with mass chromatography (LC-MS). Bacterial strains isolated from the digestive gland were cultured and screened for TTX with a competitive ELISA method. Tetrodotoxin was detected in a proportion of bacterial strains, but the toxin content was low. Partial 16S ribosomal DNA (rDNA) of the TTX-producing strains was then sequenced and compared with those published in the GenBank to tentatively identify the toxic strains. It was found that most of the toxic strains were closely affiliated with genus Vibrio, and the others were related to genus Shewanella, Marinomonas, Tenacibaculum and Aeromonas. These findings suggest that tetrodotoxin-producing bacteria might play an important role in tetrodotoxin accumulation/production in N. semiplicatus. (C) 2008 Elsevier Ltd. All rights reserved.
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The locations and effects of quantitative trait loci (QTL) were estimated for nine characters for growth-related traits in the Pacific abalone (Haliotis discus hannai Ino) using a randomly amplified polymorphic DNA (RAPD), amplification fragment length polymorphism (AFLP) and SSR genetic linkage map. Twenty-eight putatively significant QTLs (LOD > 2.4) were detected for nine traits (shell length, shell width, total weight, shell weight, weight of soft part, muscle weight, gonad and digestive gland weight, mantle weight and gill weight). The percentage of phenotypic variation explained by a single QTL ranged from 8.0% to 35.9%. The significant correlations (P < 0.001) were found among all the growth-related traits, and Pearson's correlation coefficients were more than 0.81. For the female map, the QTL for growth were concentrated on groups 1 and 4 linkage maps. On the male map, the QTL that influenced growth-related traits gathered on the groups 1 and 9 linkage maps. Genetic linkage map construction and QTL analysis for growth-related traits are the basis for the marker-assisted selection and will eventually improve production and quality of the Pacific abalone.
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To better understand the floral diversity and the phylogeny of the Swertiinae (Gentianaceae), the internal transcribed spacer (ITS) region of nrDNA for 17 species and one outgroup was sequenced. Our data suggest that corolla type, gland shape, and corolla appendage are poorly correlated with the ITS phylogeny. The genus Swertia s.l. and the rotate group previously recognized based on the corolla types and gland shapes are polyphyletic. Four genera with simple protruding glands and three taxa with corolla appendages are not clustered as the monophyletic groups. Four separate clades, corresponding to the four sections, were identified in Swertia s.1. Lomatogoniopsis with the simple protruding gland type of the tubular group closely related to Lomatogonium of the rotate group. The deeply lobing corolla and concave foveae may be ancestral in the Swertiinae, while the tubular corolla and the protruding glands may have undergone convergent evolution.
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This project was carried out with the aims to investigate the mechanism of circadian immune regulation by one of the core Clock gene, mPer2. To achieve this, we selected mPer2 knock out (mPer2-/-) mice as the optimal animal model. Two different approaches were performed. In the first approach, we injected WT or mPer2-/- mice with an equal dosage of lipopolysaccharide (LPS), and systematically measured serum corticosterone induction, expression of core Clock genes, as well as a key enzyme for corticosterone metabolism (mStAR) in adrenal gland. We found that the acute induction of corticosterone and mStAR were closely associated with the circadian immune response to LPS. Besides, real time quantitative PCR (q-PCR) and luciferase assay consistently showed that mStAR is a Clock controlled gene in adrenal gland, where its expression is negatively influenced by mPer2. In the second approach, expression level and circadian manner of 11 cytotoxicity regulation genes in WT or mPer2-/- mice bone marrow were measured by q-PCR in order to explore the candidate genes which could mediate the circadian immune regulation by mPer2. We found that expression level of Ly49C, Ly49I, and Nkg2d was significant down-regulated in mPer2-/- mice. Further, we found that daily expression of Ly49C and Nkg2d fluctuated in a circadian manner in WT mice, where these rhythms were disrupted in mPer2-/- mice. Thus, it was suggested that these two cytotoxic genes were two clock controlled genes whose circadian expression were regulated by mPer2. Taken together, our results suggested that corticosterone, mStAR, Ly49C, and Nkg2d were four candidate molecules that may mediate the circadian immune response regulation by mPer2.
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
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Anthropogenic pollutant chemicals pose a major threat to aquatic organisms. There is a need for more research on emerging categories of environmental chemicals such as nanomaterials, endocrine disruptors and pharmaceuticals. Proteomics offers options and advantages for early warning of alterations in environmental quality by detecting sub-lethal changes in sentinel species such as the mussel, Mytilus edulis. This thesis aimed to compare the potential of traditional biomarkers (such as enzyme activity measurement) and newer redox proteomic approaches. Environmental proteomics, especially a redox proteomics toolbox, may be a novel way to study pollutant effects on organisms which can also yield information on risks to human health. In particular, it can probe subtle biochemical changes at sub-lethal concentrations and thus offer novel insights to toxicity mechanisms. In the first instance, the present research involved a field-study in three stations in Cork Harbour, Ireland (Haulbowline, Ringaskiddy and Douglas) compared to an outharbour control site in Bantry Bay, Ireland. Then, further research was carried out to detect effects of anthropogenic pollution on selected chemicals. Diclofenac is an example of veterinary and human pharmaceuticals, an emerging category of chemical pollutants, with potential to cause serious toxicity to non-target organisms. A second chemical used for this study was copper which is a key source of contamination in marine ecosystems. Thirdly, bisphenol A is a major anthropogenic chemical mainly used in polycarbonate plastics manufacturing that is widespread in the environment. It is also suspected to be an endocrine disruptor. Effects on the gill, the principal feeding organ of mussels, were investigated in particular. Effects on digestive gland were also investigated to compare different outcomes from each tissue. Across the three anthropogenic chemicals studied (diclofenac, copper and bisphenol A), only diclofenac exposure did not show any significant difference towards glutathione transferase (GST) responses. Meanwhile, copper and bisphenol A significantly increased GST in gill. Glutathione reductase (GR) enzyme analysis revealed that all three chemicals have significant responses in gill. Catalase activity showed significant differences in digestive gland exposed to diclofenac and gills exposed to bisphenol A. This study focused then on application of redox proteomics; the study of the oxidative modification of proteins, to M. edulis. Thiol proteins were labelled with 5-iodoacetamidofluorescein prior to one-dimensional and two-dimensional electrophoresis. This clearly revealed some similarities on a portion of the redox proteome across chemical exposures indicating where toxicity mechanism may be common and where effects are unique to a single treatment. This thesis documents that proteomics is a robust tool to provide valuable insights into possible mechanisms of toxicity of anthropogenic contaminants in M. edulis. It is concluded that future research should focus on gill tissue, on protein thiols and on key individual proteins discovered in this study such as calreticulin and arginine kinase which have not previously been considered as biomarkers in aquatic toxicology prior to this study.
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BACKGROUND: Interleukin-10 (IL-10) is currently being extensively studied in clinical trials for the treatment of Crohn's disease (CD). Only marginal effects have, however, been reported, and the dose-response curve was bell-shaped contrasting with the reported data from in vitro experiments. AIM: To use another in vitro model to analyze the effect of rhIL-10 and rhIL-4 on the spontaneous mucosal TNF-alpha secretion in patients with CD, and to characterize the phenotype of the cells targeted by rhIL-10. METHODS: Non-inflamed colon biopsies from CD patients were cultured for 16 hours in presence of different concentrations of rhIL-10 or rhIL-4. The numbers of TNF-alpha-secreting cells among isolated lamina propria mononuclear cells (LPMNC) were estimated by Elispot. RESULTS: Both rhIL-10 and rhIL-4 down-regulate TNF-alpha secretion by LPMNC from CD patients, with a more pronounced effect with rhIL-10. These effects were closely linked to the cytokine concentrations used, with a bell-shaped dose-response curve. Residual TNF-alpha secretion, in the presence of optimal rhIL-10 concentration was mainly attributable to CD3+ T cells. In contrast, at higher rhIL-10 concentrations, CD3- cells contributed significantly to the TNF-alpha secretion. CONCLUSIONS: The in vitro model we used, demonstrates that IL-4, but mostly IL-10, efficiently suppresses TNF-alpha secretion in LPMNC from CD patients, with a dose-response curve similar to results obtained in vivo. Resistance at high rhIL-10 concentrations was associated with a change in the phenotype of TNF-alpha-secreting cells.
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BACKGROUND: In contrast to adults, ulcers are un-common in Helicobacter pylori-infected children. Since immunological determinants influence the outcome of H. pylori infection, we have investigated mucosal T cell responses in H. pylori-infected children and compared them with those of adults and negative controls. MATERIAL AND METHODS: Mucosal biopsies were obtained from 43 patients undergoing an upper GI endoscopy for dyspeptic symptoms. The concentrations of released cytokines and the density of CD3+, CD25+ and CD69+cells were evaluated by flow cytometry, and the numbers of cytokine-secreting cells were measured by ELISPOT. RESULTS: The numbers of isolated antral CD3+ lymphocytes were only significantly raised in infected adults compared with noninfected controls (p < 0.05), whereas the proportion of CD3+ cells expressing activation markers (CD25 or CD69) remained low. In the stomach, IFN-gamma concentrations increased in infected children and infected adults compared with controls (p < 0.05), but IFN-gamma concentrations were tenfold lower in children than in adults (p < 0.01). IL-2, IL-4, IL-10 and TNF-alpha concentrations were similar in infected and in uninfected children and adults. In contrast, in the duodenum, IFN-gamma, as well as IL-4 and IL-10 concentrations were only increased in infected children compared with controls (p < 0.05). The concentrations of these cytokines were similar in both groups of adults who, however, like children, displayed a higher number of duodenal IL-4-secreting cells compared to controls (p < 0.05). CONCLUSION: These results suggest that IFN-gamma secretion in the stomach of H. pylori-infected patients is lower in children than in adults. This could protect children from development of severe gastro-duodenal diseases such as ulcer disease. In addition, infected patients are characterised by a dysregulation of the mucosal cytokine secretion at distance from the infection site.
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Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease characterized by polyclonal B cell activation and by the production of anti-double-stranded (ds) DNA antibodies. Given the inhibitory effects of IL-12 on humoral immune responses, we investigated whether IL-12 displayed such an activity on in vitro immunoglobulin production by SLE PBMC. Spontaneous IgG, IgG1, IgG2, IgG3 and IgM antibody production was dramatically reduced by addition of IL-12. These results were confirmed by Elispot assays detecting IgG- and anti-dsDNA-secreting cells. While IL-6 and TNF titres measured in PBMC supernatants were not modified by addition of IL-12, interferon-gamma (IFN-gamma) titres were up-regulated and IL-10 production down-regulated. Since addition of IFN-gamma did not down-regulate immunoglobulin production and since the inhibitory activity of IL-12 on immunoglobulin synthesis was not suppressed by anti-IFN-gamma antibody, we concluded that the effect of IL-12 on immunoglobulin production was not mediated through IFN-gamma. Our data also argue against the possibility that down-regulation of endogenous IL-10 production was responsible for the effect of IL-12. Thus, inhibition of IL-10 production by IFN-gamma was not accompanied by inhibition of immunoglobulin production, and conversely, restoration of IL-10 production by anti-IFN-gamma antibody did not suppress the inhibitory activity exerted by IL-12 on immunoglobulin production. Taken together, our data indicate that reduction of excessive immunoglobulin and anti-dsDNA antibody production by lupus PBMC can be achieved in vitro by IL-12, independently of IFN-gamma and IL-10 modulation.
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BACKGROUND: Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses. AIMS: To quantify interferon gamma (IFN-gamma) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation. PATIENTS: Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa. METHODS: Intraepithelial and lamina propria cell suspensions were assayed for numbers of cells spontaneously secreting IFN-gamma and IL-4 by a two site reverse enzyme linked immunospot technique (ELISPOT). RESULTS: The relatively high proportion of duodenal lymphocytes spontaneously secreting IFN-gamma (IEL 3.6%; LPL 1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very low numbers of spontaneously IFN-gamma SC and the absence of spontaneously IL-4 SC among peripheral blood mononuclear cells. In the basal state, both IFN-gamma and IL-4 were mainly produced by CD4+ cells. Within the colon, only 0.2% of IEL and LPL secreted IFN-gamma in the basal state, and 0.1% secreted IL-4. CONCLUSIONS: Compared with peripheral lymphocytes substantial proportions of intestinal epithelial and lamina propria lymphocytes spontaneously secrete IFN-gamma and/or IL-4. These cytokines are probably involved in the normal homoeostasis of the human intestinal mucosa. Disturbances in their secretion could play a role in the pathogenesis of gastrointestinal diseases.