1,720,960 research outputs found
Analysis of SARS-CoV-2 and ACE2, TMPRSS2 receptors in salivary glands and periodontal tissues: a biomolecular, immunohistochemical, and ultrastructural evaluation from COVID-19 fatal cases
No full textO início de uma nova doença, cujo epicentro se deu em Wuhan - China - com sintomas similares a de uma pneumonia com alto potencial de disseminação, fez com que a Organização Mundial de Saúde decretasse o status de pandemia a está nova doença, chamando a, então, de COVID-19. O agente causador dessa doença foi identificado como um vírus da família coronoviridae denominado SARS-CoV-2. Tal patógeno apresenta como seu órgão alvo o pulmão, instalando um dano alveolar difuso e consequentemente a falência respiratória aguda levando milhares de pessoas a óbito através do mundo. Assim como outros vírus da família coronoviridae, o SARS-CoV-2 utiliza-se de receptores ACE2 e TMPRSS para ligar-se as células do hospedeiro, apresentando assim intenso tropismo por tecidos epiteliais. Neste racional o objetivo deste trabalho foi aprofundar o conhecimento sobre as interações do SARS-CoV-2 e os nichos epiteliais da cavidade oral a partir de autópsias de pacientes que foram a óbito por complicações da COVID-19, desenvolvendo novas metodologias de coletas e reflexões sobre o papel desta técnica na odontologia com diferentes ensaios. Foram realizadas 40 autopsias minimamente invasivas, coletando múltiplos sítios da cavidade oral com o intuito de identificar e caracterizar a presença do SARS-CoV-2 em tecidos de glândulas salivares e periodonto, assim como, avaliar clinicamente potenciais lesões orais. Por fim, avaliar a interação de agentes descontaminantes do vírus nos tecidos da cavidade oral e demonstrar a importância da utilização das autopsias para a odontologia em diversas abordagens metodológicas. Foram realizadas análises biomoleculares dos tecidos glandulares e periodontais sendo as amostras positivas em 5/7 periodontos e 22/35 das glândulas salivares maiores e 80% das menores. A avaliação IHC anti-SARS-CoV-2 foi positiva 55% dos casos. As reações de imunopostividade para os receptores ACE2 e TMPRSS2 foram francamente positivas em todos os casos de tecido periodontal e glândulas salivares. As avaliações das lesões orais se mostraram majoritariamente como coinfecções decorrentes da deterioração da saúde geral dos pacientes. Visto a cinética viral nos nichos orais, os relatos de casos corresponderam com o racional viral, não tendo capacidade sustentada de erradicar o vírus das amostras avaliadas. A utilização das autópsias para avaliação dos tecidos orais se mostrou uma técnica segura e que permite uma avaliação ampla das amostras, assim como, das interações do mesmo com outros órgãosResume: The beginning of a new disease, in Wuhan China that presents pneumonia symptoms and high transmissibility, made the World Health Organization decree a pandemic status, calling this disease COVID-19. The pathogen of this disease was a new virus, named SARS-CoV-2. The viruss main targets are the lung epithelial cells causing diffuse alveolar damage and consequently respiratory distress, leading thousands of people to death. Like other coronaviridae viruses, the SARS-CoV-2 uses ACE2 and TMPRSS2 receptors to bond into membrane host cells, showing intense epithelial tropism. The aim of this research is to understand and create knowledge about the relation between the SARS-CoV-2 and oral epithelial niches based on autopsies from COVID-19 deceased patients, developing new sample methodologies and insights about the autopsy role in dentistry in several methodological approaches. We performed 40 minimally invasive autopsies, sampling multiple oral cavity sites aiming to identify and characterize the SARS-CoV-2 presence in salivary glands and periodontal tissues, as well as, evaluate some clinically evident oral lesions. Finally, evaluate the decontaminate potential from chemical agents and show the value of autopsies in dentistry science. We did analyze tissues from salivary glands and gingiva using biomolecular assays that resulted positive for SARSCoV-2 in 5/7 periodontal tissues and 22/35 major salivary glands and 80% of minor ones. The immunohistochemistry analysis showed positivity in 55% of the cases. Immunopositivity for ACE2 and TMPRSS2 was frankly positive in all cases involving periodontal and glandular tissue. The evaluation of oral lesions showed in the vast majority as coinfections that appear in recurrence of the poor health status of the patients. The case reports using different methods of decontamination showed transient results, with recontamination during time in the analyzed sample. The use of autopsies to evaluate oral samples seems to be a secure method and allows us an overview of oral and systemic health, the use of new biomolecular techniques must be employed for further validation of new diseases using samples coming from deceased patient
e-caderin and b-catenin expression in carcinoma ex-pleomorphic adenoma carcinomatous area
No full textO carcinoma ex-adenoma pleomórifoco (CXAP) é a contraparte maligna do Adenoma pleomórfico (AP), sendo sua malignização descrita em 10% dos AP. Histológicamente o CXAP apresenta grande variação morfológica vista a capacidade do componente maligno se originar de diferentes estruturas do componente misto do AP. Nota-se que grande parte dos CXAP apresentam caráter infiltrativo, metástase linfonodal e metástase tardia. Para que as células neoplásicas adquiram um fenótipo com maior capacidade infiltrava é necessário que passem por um processo de transição de um fenótipo epitelial para mesenquimal. Este processo é conhecido como Transição epitélio-mesênquima (TEM). Tal processo é visto em situações fisiológicas, tais quais, migração de células ectodérmicas durante o período embriológico, reparação e cicatrização e também em processos neoplásicos. O objetivo deste trabalho é avaliar a presença de proteínas inerentes ao processo de transição epitélio mesênquima e comparar a expressão destas proteínas com achados histopatológicos sugestivos de invasão e mestástase. A análise das proteínas E-caderina e Beta-catenina em células neoplásicas de CXAP foi realizada de forma semi-quantitativa conforme sugerido pela literatura. Os casos foram subdividos de acordo com a positividade da reação de imunohistoquímica. Onde houve ausência de células positivas o caso recebeu escore 0, casos onde houve 75% das células eram positivas. Tais achados foram relacionados com presença de invasão angiolinfática, perineural, metástase tardia, recorrência e metástase linfonodal. De um total de 16 casos de CXAP, o sitio mais acometido foi a parótida e 53% da nossa amostra era composta por homens, a idade média foi de 52,9 anos e a parótida foi o sitio mais acometido. A análise histopatológica demonstrou que quando havia marcação para E-caderina a mesma se dava em membrana celular. 12,5% ausência de marcação, 50% dos casos com marcação fraca 31,25% dos casos com expressão moderada e 6,25% dos casos com marcação intensa. Já para Beta-catenina um caso apresentou marcação citoplasmática e os restantes em membrana celular.18,75% ausente de marcação, 25 % com marcação fraca, 50% dos casos com marcação moderada e 6,25 dos casos com marcação intensa. A imuno-marcação estava distribuída de forma difusa tanto no front de invasão quanto no parênquima do carcinoma. Casos com maior presença de E-caderina apresentaram mais metástases linfonodais, p=0,035. Para outros critérios de invasão nenhuma relação estatística significante foi observada. Sugere-se que E-caderina e Beta-catenina não fazem parte do processo de invasão e metástase de CXAP nem são fatores relacionados a invasão dos tecidos adjacentes.Carcinoma ex-pleomorphic adenoma (CXAP) is the malignant counterpart of pleomorphic adenoma(PA), although malignant transformation of PA is unusual occurring in 10% of the PA cases. The CXAP histologically presents an intense morphologic variation due to the ability of the malignant tissue to originate from any structure of de mixed component. A significant number of CXAPs show an infiltrative behavior, lymph node metastasis and late metastasis. The cell component must undergo a morphologic alteration changing the epithelial phenotype to a mesenchymal one. That development process is known as epithelial-mesenchymal transiction (MET). This process is seen in physiologic situations, like cell migration on embryologic ectodermal evolution, tissue repair and int neoplastic processes. The main objective of this study was to evaluate immunohistochemical expression of epithelial-mesenchymal transiction proteins, e-caderin and beta-catenin in malignant areas of CXAP and correlate with pathologic parameters that indicates migration, like perineural and angiolymphatic invasion and metastasis as suggested by the literature. Immunohistochemical analysis was performed semiquantitatively according to the scores 0 (no positive cell), 1 (75% positive cells). These results were also correlated with pathological parameters of neoplastic aggressiveness using the Fisher\'s exact test. Of the16 cases, the parotid gland was the most involved site and men were affected in 53.8 % of our sample. The mean age was 52.9 year. The histopathological analysis showed that in all cases in which e-caderin was positive, the immunoreaction was of the cell membrane 12,5% of the cases showed absent of e-caderin expression, 50% showed weak expression, 31,25% showed moderate expression and 6,25 show strong one. In the other hand, b-catenin showed cytoplasmic expression in one case, all other cases showed protein in cell membrane. 18,75 showed absent expression, 25% showed weak expression, 50% showed moderate and 6,25% showed intense one. The immunohistochemical reaction was diffuse and presented itself in invasion front as well as in the carcinoma parenchyma. Cases presenting high expression of e-caderin developed more lymph node metastasis, p=0,035. For the others invasion parameters there was no statistic summary observed. This work suggest that e-caderin and b-catenin have no relation to CXAP carcinogenesis or invasion proces
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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