164 research outputs found

    The Zebrafish Kupffer’s Vesicle: A Special Organ in a Model Organism to Study Human Diseases

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    The Kupffer’s vesicle (KV) is a small, ciliated organ transiently present during embryogenesis of the zebrafish and other teleosts. The KV is required to the establishment of visceral laterality, such as the heart on the left side, being also known by the name left-right organizer (LRO). The LRO is found in other vertebrates, including mice, rabbits, frogs and human embryos. Among these, the KV became an excellent model organ to investigate the early left-right events during development and in disease. Many ciliary molecular players associated to the human disease primary ciliary dyskinesia have been tested in the zebrafish looking at KV cilia and its downstream effects on flow and left-right markers. Additionally, given its morphology and molecular features, we proposed the KV as a model organ to study the molecular mechanisms of the renal cyst inflation that occurs in the autosomal dominant polycystic kidney disease. Although having no connection to the kidney, the KV mimics a renal cyst because it is a fluid-filled vesicle, lined by monociliated epithelial cells that express polycystin-2, which knockdown leads to the organ luminal enlargement through changes in ion/water epithelial transport. Here, we explore the usefulness of the zebrafish KV to model these diseases

    Helicobacter pylori—Associated Dyspepsia in Paediatrics

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    Helicobacter pylori ubiquitously infects the human gastric mucosa since time immemorial,predictably before the man’s diaspora out of East Africa around 58,000 years ago [1].Colonization may have been somehow beneficial for human carriers, allowing the coevolutionof this gram-negative bacterium and its host over the centuries. Yet, at leastnowadays [2], this may not be a peaceful association, with infection almost invariablycausing an acute host immune response. However, in a fully adapted manner, H. pyloriavoids recognition and, thus, clearance, by the host immune system, with both infectionand the consequent gastritis persisting throughout the patients’ life. The clinical outcomeof this persistence is dependent on a sophisticated crosstalk between the host and thepathogen. If often asymptomatic, the H. pylori-associated non-ulcer dyspepsia is clearly thestrongest aetiological factor for severe gastric diseases that will develop late in adult life ina minority of infected patients, i.e., peptic ulcer disease, both gastric and duodenal ulcers,and gastric cancer, namely, adenocarcinoma and mucosa associated lymphoid tissue(MALT) lymphoma (reviewed in [3]). Peptic ulcer disease rarely occurs soon after H. pyloriinfection [4-8] that generally starts in childhood; this presumably reflects marked differencesin the virulence [9-16] and/or in the susceptibility of young patients [17-19].This chapter, focussing on the paediatric population, seeks to explore: the prevalence of H.pylori infection; the molecular mechanism used by H. pylori during colonization and infection;the role of this bacterium in the development of peptic ulcer-related organic dyspepsia; andthe genetic/proteome profile of the H. pylori-strains associated with peptic ulcer disease.BNP Paribas, Sociedade Portuguesa de Gastrenterologi

    Estereótipos de género nas relações de parentalidade: um estudo exploratório

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    O presente estudo tem como objetivo investigar a que níveis os estereótipos de género se perpetuam no contexto familiar. Participaram neste estudo 20 sujeitos, os quais incluem 8 jovens de ambos os sexos com idades compreendidas entre os 15 e 23 anos, com um irmão ou irmã que seja do outro sexo, e os seus respetivos pai e/ou mãe (N=12). Os dados foram recolhidos através de entrevistas semiestruturadas e analisados com recurso à análise de conteúdo. Os resultados revelaram que os estereótipos de género se encontram, sobretudo, nas expetativas que os progenitores têm para o comportamento de rapazes e raparigas, refletindo-se pelo modo como avaliam ou reagem às suas atitudes. Os pais e mães mostram ser mais exigentes e restritivos com as filhas, e por sua vez, assumem uma postura mais severa com os filhos perante escolhas que não aceitem. Também ao nível da comunicação, nota-se uma grande proximidade e confiança entre as raparigas e suas mães; Gender stereotypes in parenting: An exploratory study - Abstract: The present study aims to investigate the levels at which gender stereotypes are perpetuated in the family context. Participated in this study 20 subjects, which include 8 young people of both sexes, aged between 15 and 23 years old, with a brother or sister who is of the other and their respective father and/or mother. Data was collected through semi-structured interviews assessed through content analysis. The results revealed that gender stereotypes are mainly found in the expectations that parents have for the behavior of boys and girls, reflected in the way they evaluate or react to their attitudes. Fathers and mothers show that they are more demanding and restrictive with their daughters, and in turn, take a more severe stance with their children in the face of choices they do not accept. Also, in terms of communication, there is a great closeness and trust between the girls and their mothers

    Microtubule cytoskeleton perturbation induced by taxol and colchicine affects chaperonin containing TCP-1 (CCT) subunit gene expression in Tetrahymena cells

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    We report the existence of a CCTϵ subunit gene that encodes subunit ϵ of the chaperonin CCT (chaperonin containing TCP-1) in Tetrahymena pyriformis. This work focuses on the study of the effects of the microtubule polymerizing agent taxol and the depolymerizing agent colchicine on microtubule dynamics and their role in the regulation of tubulin and CCT subunit genes. Under taxol treatment some TpCCT and tubulin genes are distinctly expressed until 30 min of treatment. Cytoplasmic TpCCT mRNA levels slightly decrease while tubulin transcripts are increasing. In colchicine treated cells TpCCT and tubulin transcripts decrease in the initial 30 min of treatment and then start to increase. However, both antimitotic agents induce TpCCT and tubulin gene transcription. This induction does not correlate with increased steady-state levels of TpCCT proteins and seems to be necessary to replete cytoplasmic TpCCT mRNAs. Moreover, we found that TpCCTϵ and TpCCTα but not TpCCTη are present in the insoluble fraction after a postmitochondrial fractionation that contains components of the ciliate cortex structure, basal bodies and cilia. This suggests that some TpCCT subunits may be associated with these structures. The association of TpCCTϵ subunit is stimulated either by taxol or colchicine treatment. These observations support the idea that CCT subunits could have additional roles in vivo.info:eu-repo/semantics/publishedVersio

    Pkd2 Affects Cilia Length and Impacts LR Flow Dynamics and Dand5

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    Funding: This work was supported by the Fundação para a Ciência e a Tecnologia (FCT-ANR/BEX-BID/0153/2012 research grant). SL is funded by an FCT CEEC contract for Principal Investigator. The work was also supported by Sociedade Portuguesa de Nefrologia (research grant 2015), iNOVA4Health – UID/Multi/04462/2013 (a program financially supported by Fundação para a Ciência e Tecnologia/ Ministério da Educação e Ciência, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement) and Fundação para a Ciência e Tecnologia (research grant – PTDC/BEXBID/1411/2014). MR-R was supported by national funds through Fundação para a Ciência e Tecnologia, in the context of the celebration of the program contract foreseen in the numbers 4, 5, and 6 of article 23 of D.L. no. 57/2016 of 29 August, as amended by Law no. 57/2017 of 19 July. Zebrafish used as animal model were reared and maintained in the CEDOC Fish Facility, with the support from the research consortia Congento, co-financed by Lisboa Regional Operational Program (Lisboa2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and Fundação para a Ciência e TecnologiaThe left-right (LR) field recognizes the importance of the mechanism involving the calcium permeable channel Polycystin-2. However, whether the early LR symmetry breaking mechanism is exclusively via Polycystin-2 has not been tested. For that purpose, we need to be able to isolate the effects of decreasing the levels of Pkd2 protein from any eventual effects on flow dynamics. Here we demonstrate that curly-up (cup) homozygous mutants have abnormal flow dynamics. In addition, we performed one cell stage Pkd2 knockdowns and LR organizer specific Pkd2 knockdowns and observed that both techniques resulted in shorter cilia length and abnormal flow dynamics. We conclude that Pkd2 reduction leads to LR defects that cannot be assigned exclusively to its putative role in mediating mechanosensation because indirectly, by modifying cell shape or decreasing cilia length, Pkd2 deficit affects LR flow dynamics.publishersversionpublishe

    Screening of Prophage Sequences Among Helicobacter Pylori

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    Until recently, Helicobacter pylori was considered a bacterium without prophages. The presence of an incomplete prophage sequence in strain B38 and a complete prophage sequence in strain B45 showed otherwise. Using a PCR strategy, based on degenerated primers designed after aligning bacteriophage integrase genes from H. pylori strains B38 and B45, and H. acinonychis prophage II, we found that integrase sequence was present in 21.4% (73/341) of the H. pylori clinical strains tested. The phylogenetic analysis of the sequenced region revealed that strains cluster according to their geographic origin, but not to their pathology. We have applied the same methodology to additional 147 European strains and 77 African strains, determining the presence of integrase sequence in 25.2% (37/147) of the former and in 19.5% (15/77) of the latter. Currently, we have a total of 565 strains screened for the presence of integrase gene, with 125 positive for this sequence (22.1%). To understand if these integrase sequences belong to reminiscent or complete prophages we are also screening for the presence of other prophage coding sequences. Among integrase positive strains, we found 19.2% (5/26) positive strains for the primase sequence and 53.3% (8/15) for the presence of the end of the phage. Presently, we are running the sequencing of the PCR amplified products in order to conduct the phylogenetic analysis. The results reinforce the abundance of prophages sequences in H. pylori and suggest that the majority of them belong to reminiscent prophages integrated within the bacterium genome

    Zebrafish model as a screen to prevent cyst inflation in autosomal dominant polycystic kidney disease

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    Funding Information: Funding: This work was supported by Sociedade Portuguesa de Nefrologia, iNOVA4Health-UID/Multi/04462/2013 (a program financially supported by Fundação para a Ciência e Tecnolo-gia (FCT)/Ministério da Educação e Ciência, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement) and FCT-ANR/BEX-BID/0153/2012 and PTDC/BEX-BID/1411/2014 research grants. M.R.R. was supported by national funds through FCT, first with an iNOVA post-doctoral fellowship and, more recently, with a contract in the context of the celebration of the program contract foreseen in the numbers 4, 5, and 6 of article 23.◦ of D.L. no. 57/2016 of 29 August, as amended by Law no. 57/2017 of 19 July. S.S.L. had a FCT-Investigator contract, followed by NOVA NMS contracts and, at the moment, a FCT CEEC (Concurso Estímulo ao Emprego Científico) contract, as principal investigator. This article is supported by the LYSOCIL project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 811087. Zebrafish used as an animal model were reproduced and maintained in the CEDOC Fish Facility, with the support from the research infrastructure Congento, co-financed by Lisboa Regional Operational Programme (Lisboa2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and FCT under the project LISBOA-01-0145-FEDER-022170. Funding Information: This work was supported by Sociedade Portuguesa de Nefrologia, iNOVA4Health-UID/Multi/04462/2013 (a program financially supported by Funda??o para a Ci?ncia e Tecnolo-gia (FCT)/Minist?rio da Educa??o e Ci?ncia, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement) and FCT-ANR/BEX-BID/0153/2012 and PTDC/BEX-BID/1411/2014 research grants. M.R.R. was supported by national funds through FCT, first with an iNOVA post-doctoral fellowship and, more recently, with a contract in the context of the celebration of the program contract foreseen in the numbers 4, 5, and 6 of article 23.? of D.L. no. 57/2016 of 29 August, as amended by Law no. 57/2017 of 19 July. S.S.L. had a FCT-Investigator contract, followed by NOVA NMS contracts and, at the moment, a FCT CEEC (Concurso Est?mulo ao Emprego Cient?fico) contract, as principal investigator. This article is supported by the LYSOCIL project. This project has received funding from the European Union?s Horizon 2020 research and innovation programme under grant agreement No 811087. Zebrafish used as an animal model were reproduced and maintained in the CEDOC Fish Facility, with the support from the research infrastructure Congento, co-financed by Lisboa Regional Operational Programme (Lisboa2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and FCT under the project LISBOA-01-0145-FEDER-022170. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.In autosomal dominant polycystic kidney disease (ADPKD), kidney cyst growth requires the recruitment of CFTR (cystic fibrosis transmembrane conductance regulator), the chloride channel that is defective in cystic fibrosis. We have been studying cyst inflation using the zebrafish Kupffer’s vesicle (KV) as model system because we previously demonstrated that knocking down polycystin 2 (PC2) induced a CFTR-mediated enlargement of the organ. We have now quantified the PC2 knock-down by showing that it causes a 73% reduction in the number of KV cilia expressing PC2. According to the literature, this is an essential event in kidney cystogenesis in ADPKD mice. Additionally, we demonstrated that the PC2 knockdown leads to a significant accumulation of CFTR-GFP at the apical region of the KV cells. Furthermore, we determined that KV enlargement is rescued by the injection of Xenopus pkd2 mRNA and by 100 µM tolvaptan treatment, the unique and approved pharmacologic approach for ADPKD management. We expected vasopressin V2 receptor antagonist to lower the cAMP levels of KV-lining cells and, thus, to inactivate CFTR. These findings further support the use of the KV as an in vivo model for screening compounds that may prevent cyst enlargement in this ciliopathy, through CFTR inhibition.publishersversionpublishe

    New NCI-N87-derived human gastric epithelial line after human telomerase catalytic subunit over-expression

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    AIM: To establish a cellular model correctly mimicking the gastric epithelium to overcome the limitation in the study of Helicobacter pylori (H. pylori ) infection. METHODS: Aiming to overcome this limitation, clones of the heterogenic cancer-derived NCI-N87 cell line were isolated, by stably-transducing it with the human telomerase reverse-transcriptase (hTERT) catalytic subunit gene. The clones were first characterized regarding their cell growth pattern and phenotype. For that we measured the clones' adherence properties, expression of cell-cell junctions' markers (ZO-1 and E-cadherin) and ability to generate a sustained transepithelial electrical resistance. The gastric properties of the clones, concerning expression of mucins, zymogens and glycan contents, were then evaluated by haematoxylin and eosin staining, Periodic acid Schiff (PAS) and PAS/Alcian Blue-staining, immunocytochemistry and Western blot. In addition, we assessed the usefulness of the hTERT-expressing gastric cell line for H. pylori research, by performing co-culture assays and measuring the IL-8 secretion, by ELISA, upon infection with two H. pylori strains differing in virulence. RESULTS: Compared with the parental cell line, the most promising NCI-hTERT-derived clones (CL5 and CL6) were composed of cells with homogenous phenotype, presented higher relative telomerase activities, better adhesion properties, ability to be maintained in culture for longer periods after confluency, and were more efficient in PAS-reactive mucins secretion. Both clones were shown to produce high amounts of MUC1, MUC2 and MUC13. NCI-hTERT-CL5 mucins were shown to be decorated with blood group H type 2 (BG-H), Lewis-x (Lex), Ley and Lea and, in a less extent, with BG-A antigens, but the former two antigens were not detected in the NCI-hTERT-CL6. None of the clones exhibited detectable levels of MUC6 nor sialylated Lex and Lea glycans. Entailing good gastric properties, both NCIhTERT- clones were found to produce pepsinogen-5 and human gastric lipase. The progenitor-like phenotype of NCI-hTERT-CL6 cells was highlighted by large nuclei and by the apical vesicular-like distribution of mucin 5AC and Pg5, supporting the accumulation of mucus-secreting and zymogens-chief mature cells functions. CONCLUSION: These traits, in addition to resistance to microaerobic conditions and good responsiveness to H. pylori co-culture, in a strain virulence-dependent manner, make the NCI-hTERT-CL6 a promising model for future in vitro studies.info:eu-repo/semantics/publishedVersio

    The limbic system conception and its historical evolution

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    Throughout the centuries, scientific observers have endeavoured to extend their knowledge of the interrelationships between the brain and its regulatory control of human emotions and behaviour. Since the time of physicians such as Aristotle and Galen and the more recent observations of clinicians and neuropathologists such as Broca, Papez, and McLean, the field of affective neuroscience has matured to become the province of neuroscientists, neuropsychologists, neurologists, and psychiatrists. It is accepted that the prefrontal cortex, amygdala, anterior cingulate cortex, hippocampus, and insula participate in the majority of emotional processes. New imaging technologies and molecular biology discoveries are expanding further the frontiers of knowledge in this arena. The advancements of knowledge on the interplay between the human brain and emotions came about as the legacy of the pioneers mentioned in this field. The aim of this paper is to describe the historical evolution of the scientific understanding of interconnections between the human brain, behaviour, and emotions

    New NCI-N87-derived human gastric epithelial line after human telomerase catalytic subunit over-expression

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    Supported by Grants from the Fundacao para a Ciencia e a Tecnologia (FCT, Portugal), No. PPCDT/SAL-IMI/57297/2004 and No. PTDC/BIM-MEC/1051/2012; The Swedish Cancer foundation; The Swedish Research Council, No. K2010-79X-21372-01-3; Forska utan djurforsok, Animal Free Research; and by Research fellowship 2011 from the Sociedade Portuguesa de Gastrenterologia (Portugal).AIM: To establish a cellular model correctly mimicking the gastric epithelium to overcome the limitation in the study of Helicobacter pylori (H. pylori) infection. METHODS: Aiming to overcome this limitation, clones of the heterogenic cancer-derived NCI-N87 cell line were isolated, by stably-transducing it with the human telomerase reverse-transcriptase (hTERT) catalytic subunit gene. The clones were first characterized regarding their cell growth pattern and phenotype. For that we measured the clones' adherence properties, expression of cell-cell junctions' markers (ZO-1 and E-cadherin) and ability to generate a sustained transepithelial electrical resistance. The gastric properties of the clones, concerning expression of mucins, zymogens and glycan contents, were then evaluated by haematoxylin and eosin staining, Periodic acid Schiff (PAS) and PAS/Alcian Blue-staining, immunocytochemistry and Western blot. In addition, we assessed the usefulness of the hTERT-expressing gastric cell line for H. pylori research, by performing co-culture assays and measuring the IL-8 secretion, by ELISA, upon infection with two H. pylori strains differing in virulence. RESULTS: Compared with the parental cell line, the most promising NCI-hTERT-derived clones (CL5 and CL6) were composed of cells with homogenous phenotype, presented higher relative telomerase activities, better adhesion properties, ability to be maintained in culture for longer periods after confluency, and were more efficient in PAS-reactive mucins secretion. Both clones were shown to produce high amounts of MUC1, MUC2 and MUC13. NCI-hTERT-CL5 mucins were shown to be decorated with blood group H type 2 (BG-H), Lewis-x (Le(x)), Le(y) and Le(a) and, in a less extent, with BG-A antigens, but the former two antigens were not detected in the NCI-hTERT-CL6. None of the clones exhibited detectable levels of MUC6 nor sialylated Le(x) and Le(a) glycans. Entailing good gastric properties, both NCI-hTERT-clones were found to produce pepsinogen-5 and human gastric lipase. The progenitor-like phenotype of NCI-hTERT-CL6 cells was highlighted by large nuclei and by the apical vesicular-like distribution of mucin 5AC and Pg5, supporting the accumulation of mucus-secreting and zymogens-chief mature cells functions. CONCLUSION: These traits, in addition to resistance to microaerobic conditions and good responsiveness to H. pylori co-culture, in a strain virulence-dependent manner, make the NCI-hTERT-CL6 a promising model for future in vitro studies.publishersversionpublishe
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