21 research outputs found

    Molecular characterization of a mariner-like element in the Atta sexdens rubropilosa genome

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    Mobile elements are widely present in eukaryotic genomes. They are repeated DNA segments that are able to move from one locus to another within the genome. They are divided into two main categories, depending on their mechanism of transposition, involving RNA (class I) or DNA (class II) molecules. The mariner-like elements are class II transposons. They encode their own transposase, which is necessary and sufficient for transposition in the absence of host factors. They are flanked by a short inverted terminal repeat and a TA dinucleotide target site, which is duplicated upon insertion. The transposase consists of two domains, an N-terminal inverted terminal repeat binding domain and a C-terminal catalytic domain. We identified a transposable element with molecular characteristics of a mariner-like element in Atta sexdens rubropilosa genome. Identification started from a PCR with degenerate primers and queen genomic DNA templates, with which it was possible to amplify a fragment with mariner transposable-element homology. Phylogenetic analysis demonstrated that this element belongs to the mauritiana subfamily of mariner-like elements and it was named Asmar1. We found that Asmar1 is homologous to a transposon described from another ant, Messor bouvieri. The predicted transposase sequence demonstrated that Asmar1 has a truncated transposase ORF. This study is part of a molecular characterization of mobile elements in the Atta spp genome. Our finding of mariner-like elements in all castes of this ant could be useful to help understand the dynamics of mariner-like element distribution in the Hymenoptera.FAPESPFAPESPCNPqCNP

    Molecular characterization of a mariner-like element in the Atta sexdens rubropilosa genome

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    Mobile elements are widely present in eukaryotic genomes. They are repeated DNA segments that are able to move from one locus to another within the genome. They are divided into two main categories, depending on their mechanism of transposition, involving RNA (class I) or DNA (class II) molecules. The mariner-like elements are class II transposons. They encode their own transposase, which is necessary and sufficient for transposition in the absence of host factors. They are flanked by a short inverted terminal repeat and a TA dinucleotide target site, which is duplicated upon insertion. The transposase consists of two domains, an N-terminal inverted terminal repeat binding domain and a C-terminal catalytic domain. We identified a transposable element with molecular characteristics of a mariner-like element in Atta sexdens rubropilosa genome. Identification started from a PCR with degenerate primers and queen genomic DNA templates, with which it was possible to amplify a fragment with mariner transposable-element homology. Phylogenetic analysis demonstrated that this element belongs to the mauritiana subfamily of mariner-like elements and it was named Asmar1. We found that Asmar1 is homologous to a transposon described from another ant, Messor bouvieri. The predicted transposase sequence demonstrated that Asmar1 has a truncated transposase ORF. This study is part of a molecular characterization of mobile elements in the Atta spp genome. Our finding of mariner-like elements in all castes of this ant could be useful to help understand the dynamics of mariner-like element distribution in the Hymenoptera.FAPESPFAPESPCNPqCNP

    Decreased expression of ADAMTS-1 in human breast tumors stimulates migration and invasion

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    Abstract\ud \ud \ud \ud Background\ud \ud ADAMTS-1 (a disintegrin and metalloprotease with thrombospondin motifs) is a member of the ADAMTS family of metalloproteases. Here, we investigated mRNA and protein levels of ADAMTS-1 in normal and neoplastic tissues using qPCR, immunohistochemistry and immunoblot analyses, and we addressed the role of ADAMTS-1 in regulating migration, invasion and invadopodia formation in breast tumor cell lines.\ud \ud \ud \ud Results\ud \ud In a series of primary breast tumors, we observed variable levels of ADAMTS-1 mRNA expression but lower levels of ADAMTS-1 protein expression in human breast cancers as compared to normal tissue, with a striking decrease observed in high-malignancy cases (triple-negative for estrogen, progesterone and Her-2). This result prompted us to analyze the effect of ADAMTS-1 knockdown in breast cancer cells in vitro. MDA-MB-231 cells with depleted ADAMTS-1 expression demonstrated increased migration, invasion and invadopodia formation. The regulatory mechanisms underlying the effects of ADAMTS-1 may be related to VEGF, a growth factor involved in migration and invasion. MDA-MB-231 cells with depleted ADAMTS-1 showed increased VEGF concentrations in conditioned medium capable of inducing human endothelial cells (HUVEC) tubulogenesis. Furthermore, expression of the VEGF receptor (VEGFR2) was increased in MDA-MB-231 cells as compared to MCF7 cells. To further determine the relationship between ADAMTS-1 and VEGF regulating breast cancer cells, MDA-MB-231 cells with reduced expression of ADAMTS-1 were pretreated with a function-blocking antibody against VEGF and then tested in migration and invasion assays; both were partially rescued to control levels.\ud \ud \ud \ud Conclusions\ud \ud ADAMTS-1 expression was decreased in human breast tumors, and ADAMTS-1 knockdown stimulated migration, invasion and invadopodia formation in breast cancer cells in vitro. Therefore, this series of experiments suggests that VEGF is involved in the effects mediated by ADAMTS-1 in breast cancer cells.This investigation was supported by The State of São Paulo Research Foundation (FAPESP grants 2006/54963-0, 2006/01026-0, 2008/57103-8, 2010/07699-1), and Brazilian National Council for Scientific and Technological Development (CNPq grant 470779/2007-1). The authors also want to thank Dr. Stanley Zucker (Stony Brook University; Stony Brook, NY, USA) and Dr. Rama Khokha (University of Western Ontario, Toronto, Canada) for suggestions made on data analysis

    Nasal polyposis : more than a chronic inflammatory disorder : a disease of mechanical dysfunction : the São Paulo position

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    Introduction The importance of our study lies in the fact that we have demonstrated the occurrence of mechanical dysfunction within polypoid tissues, which promotes the development of polyps in the nasal cavity. Objective To change the paradigm of nasal polyposis (NP). In this new conception, the chronic nasal inflammatory process that occurs in response to allergies, to pollution, to changes in the epithelial barrier, or to other factors is merely the trigger of the development of the disease in individuals with a genetic predisposition to an abnormal tissue remodeling process, which leads to a derangement of the mechanical properties of the nasal mucosa and, consequently, allows it to grow unchecked. Data Synthesis We propose a fundamentally new approach to intervening in the pathological process of NP, addressing biomechanical properties, fluid dynamics, and the concept of surface tension. Conclusion The incorporation of biomechanical knowledge into our understanding of NP provides a new perspective to help elucidate the physiology and the pathology of nasal polyps, and new avenues for the treatment and cure of NP

    Vivência do familiar na qualidade de cuidador responsável pela diálise peritoneal domiciliar: baseado na teoria do autocuidado / Experience of the family member as the caregiver responsible for peritoneal dialysis at home: based on the theory of self-care

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    A Doença Renal Crônica (DRC) é uma das patologias que mais compromete o estilo de vida tanto físico, social, econômico, emocional de seus portadores, devido ao esgotamento gradual dos rins que, se não tratado, levará o paciente á óbito, as principais causas de perda da função renal no nosso meio são as doenças crônicas como hipertensão arterial (35% das causas), diabetes mellitus (28,5%) seguidas das glomerulonefrites (11,5%), objetivando conhecer o impacto da doença renal crônica na vida do familiar/ cuidador, do paciente em diálise peritoneal, a metodologia utilizada tratou-se de um estudo de abordagem exploratória, descritiva de cunho qualitativo, a pesquisa foi realizada após a aprovação do comitê de ética em pesquisa, no setor de hemodiálise do hospital de clínicas Gaspar Viana, durante o intervalo das consultas de seus entes cuidados, concluiu-se que o diagnóstico da doença renal crônica no âmbito familiar exigi um cuidador que faça a terapia dialítica e se responsabilize pelos cuidados no domicílio, de forma rigorosa. A maioria dos pacientes nessa atividade é realizada por apenas um familiar que geralmente é selecionado por afinidade ou por ser a única opção, sendo chamado de cuidador principal

    A importância da equidade no pré-natal em uma estratégia saúde da família (ESF) / The importance of prenatal equity in a family health strategy (ESF)

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    Objtivo. Relatar experiência durante a prática de enfermagem na assistência ao pré-natal e sua relação com a equidade no atendimento, vivenciada por discentes do 6º semestre de enfermagem da Universidade da Amazônia. Métodos. Trata-se de um estudo descritivo com abordagem qualitativa, do tipo relato de experiência, realizado a partir da vivência de acadêmicos de enfermagem. Resultados. Durante as consultas de enfermagem realizadas com gestantes, identificou-se a importância de o enfermeiro realizar uma boa classificação, afim de reconhecer qual grávida deveria ser atendida de forma mais prioritária. Nessa circunstância, percebia-se princípios do SUS como a equidade, quando as gestantes eram classificadas segundo o risco de sua gravidez e assim a assistência tornava-se diferenciada ao existir uma gestante de alto risco. Conclusão. O trabalho da enfermagem prestado às gestantes é de suma importância para que a mesma possa ser assistida da melhor forma possível, além disso, ao se realizar uma boa consulta de enfermagem, proporciona-se uma assistência humanizada e equânime

    MCF-7 cells as a 3d model in the study of human breast cancer.

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    O diferencial da cultura de células em 3-dimensões é permitir que as células explorem as 3-dimensões do espaço, aumentando assim as interações com o ambiente e entre as células. Em estudos relacionados à biologia do câncer de mama, vem ganhando espaço a utilização de esferóides para estudos que visam à compreensão da morfogênese do espaço luminal. Neste trabalho foi mostrado que as células MCF-7 reorganizam-se em estruturas tubulares e acinares. Em ambas as situações, a formação do lúmen veio acompanhada pelo estabelecimento de uma camada de células polarizadas, arranjo este muito semelhante ao encontrado em glândulas mamárias. Os resultados apresentados apontam para a existência de uma população de células na linhagem MCF-7 que não estão totalmente comprometidas ao fenótipo tumoral. Mantidos diferenciados, os esferóides de células MCF-7 apontam como um novo modelo para estudos relacionados à formação do lúmen, permitindo assim explorar o papel de diferentes vias como as relacionadas a apoptose, autofagia, diferenciação e sobrevivência celular.As a particularity, a 3D cell culture permits cells to explore the three dimensions of the space thereby increasing cell-cell interactions, as well as interaction with the environment. In studies related to breast cancer biology, spheroids are becoming widely used in the aim to comprehend luminal space morphogenesis. We showed that MCF-7 cells reorganize themselves in tubular and acinar structures. In both situations, lumen formation was accompanied by the establishment of a layer of polarized cells, an arrangement that is very similar to that of breast glands. The presented results suggest the existence of an MCF cell line population not completely committed to the tumor phenotype. When maintained as differentiated, MCF-7 cell spheroids can be a new model for studies regarding lumen formation, thereby exploring the role of diiferent pathways, such as those related to cell apoptosis, autophagy, differentiation and survival

    Three-dimensional Reconstruction of Ovaries of Leaf-cutting Ant (Atta sexdens rubropilosa) Queens (Hymenoptera: Formicidae)

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    In this study, the ovary morphology of newly emerged ant queens of Atta sexdens rubropilosa was studied in whole mount preparations by confocal microscopy. The ovaries are composed of approximately 40 ovarioles, showing non-synchronic oocyte maturation. The terminal filament with clusters of undifferentiated cells was found at the distal end of the ovarioles. Next to this region is the germarium, composed of several elongated cystocytes interconnected by cytoplasmic bridges. The nurse cells (23-28 cells) result from asymmetric mitosis. Cytoskeleton analysis showed F-actin concentrated at the muscle cells of the external tunica and in fusomes inside the ovarioles. Microtubules were concentrated around the nuclei of the nurse and follicular cells. In contrast, the oocytes and the external tunica showed faint staining for tubulin.CNPqConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESPSecretaria da Educacao do Estado de Sao PauloSecretaria da Educacao do Estado de Sao Paul

    Cell death and lumen formation in spheroids of MCF-7 cells

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    3D (three-dimensional) cell culture permits a more integrated analysis of the relationship between cells, inserting them into a structure more closely resembling the cellular microenvironment in vivo. The development of in vitro parameters to approximate in vivo 3D cellular environments makes a less reductionist interpretation of cell biology possible. For breast cells, in vitro 3D culture has proven to be an important tool for the analysis of luminal morphogenesis. A greater understanding of this process is necessary because alterations in the lumen arrangement are associated with carcinogenesis. Following lumen formation in 3D cell culture using laser scanning confocal microscopy, we observed alterations in the arrangement of cytoskeletal components (F-actin and microtubules) and increasing levels of cell death associated with lumen formation. The formation of a polarized monolayer facing the lumen was characterized through 3D reconstructions and the use of TEM (transmission electron microscopy), and this process was found to occur through the gradual clearing of cells from the medullary region of the spheroids. This process was associated with different types of cell death, such as apoptosis, autophagy and entosis. The present study showed that changes in the extracellular matrix associated with long periods of time in 3D cell culture lead to the formation of a lumen in MCF-7 cell spheroids and that features of differentiation such as lumen and budding formation occur after long periods in 3D culture, even in the absence of exogenous extracellular compounds.FAPESP (Fundacao de Amparoa Pesquisa do Estado de Sao Paulo)[06/01026-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico)Capes (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Secretaria da Educacao do Estado de Sao PauloSecretaria da Educacao do Estado de Sao Paul
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