30,188 research outputs found
The lymphatic vascular system: Secondary or primary?
No full textIt has generally been accepted that the blood vascular system is primary and the lymphatic vascular system secondary. Diseases of the blood vascular system are the leading cause for mortality and morbidity in developed nations. In contrast, lymphedema is seldom life-threatening and can generally be well-managed by combined physiotherapy. During ontogeny, the blood vessels and the heart develop much earlier than the lymphatic vessels. However, there is growing evidence that the first vascular system occurring during ontogeny and phylogeny has lymphatic functions. Defense mechanisms are crucial for all organisms irrespective of their size. Macrophages precede the emergence of erythrocytes during ontogeny, and their circulation in the hemolymphatic (more accurately, lymphohematic) system of insects, which do not possess erythrocytes, shows that the lymphatic function is primary whereas the nutritive function is secondary, needed only in larger organisms. In molluscs and arthropods, which have an open vascular system, hemocyanin has both oxygen transporting and defense functions. In vertebrates, the early blood vessels have structural characteristics of lymphatics and express the lymphendothelial receptor flt-4 (Vascular Endothelial Growth Factor Receptor-3). Later, flt-4 becomes restricted to the definitive lymphatics, which are either formed from the primary vessels or from mesodermal lymphangioblasts. The primary lymphatic function has become overruled by the nutritive function in blood vessels of larger animals. The circular movement of cells is driven by a blood heart, which, however, is not an unique organ. Lymph hearts are present in lower vertebrates, still develop transiently in birds, and are vestigial in the contractile lymphangion which "circulates" immune cells. We conclude that the definitive lymphatics are perhaps secondary in mammals, but the blood vascular system seems to develop on the basis of an ancestral lymphatic system with lymph hearts
Maria Bersani
No full textLa voce illustra la biografia e l'apporto letterario dato da Maria Bersani alla letteratura per l'infanziaThe headword explains the biography and the contribution of the author Maria Bersani to the children's literatur
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
O curso de licenciatura em educação física da Universidade Federal de Santa Catarina: suas concepções de ensino e de educação física
No full textDissertação (mestrado) - Universidade Federal de Santa Maria. Centro de Educação Fisica e Desporto
Erratum: Lack of immunity against rubella among Italian young adults. [BMC Infect Dis., 17, (2017) (199)] Doi: 10.1186/s12879-017-2295-y
No full textAfter publication of this article [1], the authors noted that the given names and family names of all authors had been inverted, and are therefore incorrect in the original article. In the original article, the author names appear as the following: Gallone Maria Serena, Gallone Maria Filomena, Larocca Angela Maria Vittoria, Germinario Cinzia and Tafuri Silvio. However, this is incorrect, and the author names should appear as per the below: Maria Serena Gallone, Maria Filomena Gallone, Angela Maria Vittoria Larocca, Cinzia Germinario, Silvio Tafuri. The author names have been corrected in the author list and the citation for this Erratum
Hepatocyte growth factor/c-Met signaling promotes the progression of experimental human neuroblastomas
No full textNeuroblastoma is the most frequent solid childhood malignancy. Despite aggressive therapy, mortality is high due to rapid tumor progression to advanced stages. The molecules and mechanisms underlying poor prognosis are not well understood. Here, we report that cultured human neuroblastoma cells express the hepatocyte growth factor (HGF) and its receptor c-Met. Binding of HGF to c-Met triggers receptor autophosphorylation, indicating functional relevance of this interaction. HGF activates several downstream effectors of c-Met such as the mitogen-activated protein kinases extracellular signal-regulated kinase 1/extracellular signal-regulated kinase 2 and phospholipase C-gamma, whereas signal transducer and activator of transcription 3 is constitutively activated in neuroblastoma cells expressing c-Met. In addition, HGF is able to stimulate expression and proteolytic activity of matrix metalloproteinase-2 and tissue-type plasminogen activator in neuroblastoma cells, thereby promoting degradation of extracellular matrix components. We show that HGF stimulates invasion of neuroblastoma cells in vitro and in vivo, and it promotes the formation of angiogenic neuroblastomas in vivo. These processes can be blocked by specific inhibitors of the mitogen-activated protein kinase cascade, by inhibitors of phospholipase C-gamma, and also by the expression of a dominant negative signal transducer and activator of transcription 3 mutant. Our data provide the first evidence that the HGF/c-Met pathway is essential for invasiveness and malignant progression of human neuroblastomas. They further suggest that specific inhibitors of this pathway may be suitable as therapeutic agents to improve clinical outcome of neuroblastomas
Imagens de Otto Maria Carpeaux: esboço de biografia
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em História, Florianópolis, 2015.Este esboço de biografia procura citar algumas imagens de Otto Maria Carpeaux: construções biográficas de naturezas múltiplas, elaboradas em contextos, por atores e sob condições igualmente díspares. Está constituído a partir de uma visão crítica da História, o que permite que ?outras imagens?, fragmentárias e não monumentais, também tenham espaço. Em diálogo com o princípio da montagem, este esboço apresenta-se em duas partes. Na primeira, Imagens possíveis, estão citadas as imagens elaboradas em vida e post mortem acerca do austríaco-brasileiro que nasceu em Viena em 1900, se exilou no Brasil em 1939 e morreu no Rio de Janeiro, em 1978. Na segunda, Montagens possíveis, apresentam-se duas possibilidades de exercício biográfico: pela leitura alegórica do documentário O velho e o Novo (Otto Maria Carpeaux), entendido como instrumento de intervenção no contexto ditatorial brasileiro e de uma reelaboração biográfica concernentes às suas experiências europeias; e pelo Caderno de imagens críticas, registro dos encontros em Carpeaux pelo meio de imagens críticas produzidas a partir da cesura do presente.Abstract : This biographical sketch attempts to quote some images of Otto Maria Carpeaux: various types of biographical constructions, carried out in different contexts by disparate authors under conditions just as distinct. It stems from a critical view of history, allowing for ?other images? fragmented and non-monumental ? to share the space.In dialogue with the montage principle, this sketch has two parts. The first, Possible Images, quotes the images produced during and after the life of the Austrian-Brazilian, who was born in Vienna in 1900, went to Brazil in exile in 1939 and died in Rio de Janeiro in 1978. The second part, Possible Montages, presents two possibilities of a biographical exercise: through the allegorical reading of documentary O Velho e o Novo (Otto Maria Carpeaux), understood as an instrument of intervention in the Brazilian dictatorship context and as a biographical retelling of the author?s European experiences; and through my Scrapbook of Critical Images, a record of the encounters in Carpeaux through critical images produced from the caesura of the present
The proepicardium delivers hemangioblasts but not lymphangioblasts to the developing heart
No full textThe mass of the myocardium and endocardium of the vertebrate heart derive from the heart-forming fields of the lateral plate mesoderm. Further components of the mature heart such as the epicardium, cardiac interstitium and coronary blood vessels originate from a primarily extracardiac progenitor cell population: the proepicardium (PE). The coronary blood vessels are accompanied by lymph vessels, suggesting a common origin of the two vessel types. However, the origin of cardiac lymphatics has not been studied yet. We have grafted PE of HH-stage 17 (day 3) quail embryos hetero- and hornotopically into chick embryos, which were re-incubated until day 15. Double staining with the quail endothelial cell (EC) marker QH1 and the lymphendothelial marker Prox1 shows that the PE of avian embryos delivers hernangioblasts but not lymphangioblasts. We have never observed quail ECs in lymphatics of the chick host. However, one exception was a large lymphatic trunk at the base of the chick heart, indicating a lympho-venous anastomosis and a 'homing' mechanism of venous ECs into the lymphatic trunk. Cardiac lymphatics grow from the base toward the apex of the heart. In murine embryos, we observed a basal to apical gradient of scattered Lyve-(+)/ CD31(+)/CD45(+) cells in the subepicardium at ernbryonic day 12.5, indicating a contribution of immigrating lymphangioblasts to the cardiac lymphatic system. Our studies show that coronary blood and lymph vessels are derived from different sources, but grow in close association with each other. (c) 2007 Elsevier Inc. All rights reserved.NICHD NIH HHS [N01-HD-6-2915
Development of an arterial tree in C6 gliomas but not in A375 melanomas
No full textThe microcirculation of tumors is severely disturbed. Tumors are usually supplied by fragile capillaries and do not possess the natural hierarchy of blood vessels. The detection of specific markers for arterial and venous endothelial cells (ECs) now enables us to study the vascular tree in tumors. We have injected rat C6 glioma and human A375 melanoma cells into 3.5- to 4-day-old avian embryos. After 10-12 days of reincubation the tumor cells formed solid tumors vascularized by host ECs. In contrast to the melanomas, the gliomas induced an almost normal vascular tree with arterial and venous vessels. The arterial vessels express the arterial EC marker ephrin-B2, and possess a media of smooth muscle alpha-actin (alphaSMA)-positive cells. Venular vessels in the gliomas are ephrin-B2-negative/alphaSMA-positive. Although the gliomas may represent a rare case of vascular tree induction in tumors, the results underline the heterogeneity of tumor-induced angiogenesis. This has an impact on tumor blood flow and thereby also on the efficacy of chemotherapy and radiotherapy
Development of lymphatic vessels: Tumour lymphangiogenesis and lymphatic invasion
No full textIn human solid cancer, the lymph node status is the most important prognostic indicator for the clinical outcome of patients. Follow-up data has shown that about 80% of metastasis follows an orderly pattern of progression via the lymphatic network while about 20% systemic metastasis occurs, bypassing the lymphatic system. Over the past few years, advances have been made in understanding the cellular and molecular aspects of physiological lymphangiogenesis and tumour-induced lymphangiogenesis, and the majority of studies point out to a positive correlation between tumour-induced lymphangiogenesis and lymphatic metastasis. However, the impact of intra- and peritumoural lymphatics on the tumour biology and the first steps of lymphatic metastasis, i.e. the invasion of tumour cells into the lymphatic vessels, are not well understood. We will give an outline of i. the physiological process of lymphangiogenesis, ii. tumour-induced lymphangiogenesis and lymphatic metastasis, iii. lymphatic invasion and the common pathways of tumour-lymphangiogenesis and lymphatic invasion. The growing interest in this topic has brought up a number of new molecular players in the field, which may provide the basis for a rational therapy against the process of lymphatic dissemination of tumour cells
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