143 research outputs found

    Embryo Size Regulates the Timing and Mechanism of Pluripotent Tissue Morphogenesis

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    Mammalian embryogenesis is a paradigm of regulative development as mouse embryos show plasticity in the regulation of cell fate, cell number, and tissue morphogenesis. However, the mechanisms behind embryo plasticity remain largely unknown. Here, we determine how mouse embryos respond to an increase in cell numbers to regulate the timing and mechanism of embryonic morphogenesis, leading to the formation of the pro-amniotic cavity. Using embryos and embryonic stem cell aggregates of different size, we show that while pro-amniotic cavity formation in normal-sized embryos is achieved through basement membrane-induced polarization and exocytosis, cavity formation of increased-size embryos is delayed and achieved through apoptosis of cells that lack contact with the basement membrane. Importantly, blocking apoptosis, both genetically and pharmacologically, alters pro-amniotic cavity formation but does not affect size regulation in enlarged embryos. We conclude that the regulation of embryonic size and morphogenesis, albeit concomitant, have distinct molecular underpinnings

    Embryo size regulates the timing and mechanism of pluripotent tissue morphogenesis.

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    Mammalian embryogenesis is a paradigm of regulative development as mouse embryos show plasticity in the regulation of cell fate, cell number, and tissue morphogenesis. However, the mechanisms behind embryo plasticity remain largely unknown. Here, we determine how mouse embryos respond to an increase in cell numbers to regulate the timing and mechanism of embryonic morphogenesis, leading to the formation of the pro-amniotic cavity. Using embryos and embryonic stem cell aggregates of different size, we show that while pro-amniotic cavity formation in normal-sized embryos is achieved through basement membrane-induced polarization and exocytosis, cavity formation of increased-size embryos is delayed and achieved through apoptosis of cells that lack contact with the basement membrane. Importantly, blocking apoptosis, both genetically and pharmacologically, alters pro-amniotic cavity formation but does not affect size regulation in enlarged embryos. We conclude that the regulation of embryonic size and morphogenesis, albeit concomitant, have distinct molecular underpinnings

    Bread preservation with use of edible packaging

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    We live in a world that usually use plastic bags either to go shopping or to pack the snack for a short trip. However, packaging makes life easier and serves as protection for products such as food. Bread is a common food product that needs packaging in order to be protected at storage and transportation. Therefore, with aim of reducing petroleum derived packagin g consumption it was developed an edible film from potato starch to packeg bread and some quality characteristics like water content, firmness and weight loss were evaluated, showing that edible film can be used as a packagingPostprint (published version

    Taxonomic and non-taxonomic responses of benthic macroinvertebrates to metal toxicity in tropical reservoirs: The case of cantareira complex, São Paulo, Brazil

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    Benthic macroinvertebrates are organisms that are recognized as water quality bio-indicators. A wide variety of indices and metrics have been shown to respond to a variety of anthropogenic impacts, usually under a general condition of environmental impairment. The absence of a clear distinction in the relations between specific pollutants and biotic variables is very common and can lead to biased interpretation of biomonitoring. The aims of this research were to test taxonomic and non-taxonomic responses to specific environmental conditions instead to general conditions. For this purpose, we estimated the theoretical toxicity by comparing toxicity values published by EPA with metal concentrations in water and sediments. Then we tested the responses of biological variables to toxicity and other environmental conditions using the linear mixed effects models approach. We generated 32 models considering 24 different biological metrics and indices that were grouped in five levels. Taxonomic and abundance metrics were best predictor than functional or tolerance-based indexes. The strongest model was that which considered subfamily taxonomic resolution responding to Al_w and Cr_s.Fil: de Souza, Frederico Guilherme. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Cetra, Maurício. Universidade Federal do São Carlos; BrasilFil: Marchese Garello, Mercedes Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: López Dovál, Júlio César. Universidade de Sao Paulo; BrasilFil: Rosa, André H.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Pompêo, Marcelo L. M.. Universidade de Sao Paulo; BrasilFil: Moschini Carlos, Viviane. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi

    Secondary syphilis presenting as a corymbiform syphilide: case report and review

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    It is essential that healthcare providers are familiar with the full spectrum of clinical presentations of syphilis. A rare manifestation of secondary syphilis is the corymbiform (or corymbose) arrangement, in which a central greater papule is surrounded by smaller satellite lesions. Very few reports of corymbiform syphilis are available in current biomedical databases. We present the case of a 28 year-old HIV-infected male patient on regular, successful antiretroviral therapy who developed an asymptomatic corymbiform maculopapular lesion in the medial aspect of the right thigh. There were also a few brownish macular lesions on the left sole. New serological tests for syphilis (which had been negative in the past) were reactive. The coymbiform lesion slowly regressed and the non-treponemal test reverted to negative after benzathine penicillin G treatment. A review of the literature is provided. This is the first report of corymbiform syphilis in an HIV-infected patient

    Maternal Toxoplasma gondii infection affects proliferation, differentiation and cell cycle regulation of retinal neural progenitor cells in mouse embryo

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    BackgroundToxoplasmosis affects one third of the world population and has the protozoan Toxoplasma gondii as etiological agent. Congenital toxoplasmosis (CT) can cause severe damage to the fetus, including miscarriages, intracranial calcification, hydrocephalus and retinochoroiditis. Severity of CT depends on the gestational period in which infection occurs, and alterations at the cellular level during retinal development have been reported. In this study, we proposed a mouse CT model to investigate the impact of infection on retinal development.MethodsPregnant females of pigmented C57BL/6 strain mice were infected intragastrically with two T. gondii cysts (ME49 strain) at embryonic day 10 (E10), and the offspring were analyzed at E18.ResultsInfected embryos had significantly smaller body sizes and weights than the PBS-treated controls, indicating that embryonic development was affected. In the retina, a significant increase in the number of Ki-67-positive cells (marker of proliferating cells) was found in the apical region of the NBL of infected mice compared to the control. Supporting this, cell cycle proteins Cyclin D3, Cdk6 and pChK2 were significantly altered in infected retinas. Interestingly, the immunohistochemical analysis showed a significant increase in the population of β-III-tubulin-positive cells, one of the earliest markers of neuronal differentiation.ConclusionsOur data suggests that CT affects cell cycle progression in retinal progenitor cells, possibly inducing the arrest of these cells at G2/M phase. Such alterations could influence the differentiation, anticipating/increasing neuronal maturation, and therefore leading to abnormal retinal formation. Our model mimics important events observed in ocular CT

    MORTALITY FROM BREAST CANCER AMONG WOMEN BELOW 40 YEARS OLD

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    Trata-se de uma pesquisa documental descritiva cujo objetivo foi reconhecer o perfil epidemiológico dos óbitos ocorridos entre mulheres com menos de 40 anos, diagnosticadas com câncer de mama. A coleta dos dados foi realizada no Serviço de Registro Hospitalar de Câncer do Hospital de Clínicas da Universidade Federal do Paraná-Brasil, compreendendo informações registradas entre janeiro de 2003 e dezembro de 2011. Foram identificadas 638 notificações de câncer de mama, dos quais 68 foram de mulheres com menos de 40 anos e dessas 21 foram a óbito. Verificou-se que a sobrevida foi, em média, de 40 meses e 76,2% apresentaram estádio clínico avançado (III ou IV). Ressalta-se que o rastreamento do câncer de mama em mulheres de alto risco, permite detectar o tumor mais precocemente, reduzir a incidência no número de óbitos e melhorar os indicadores de saúde.This is a descriptive documental study aiming to investigate the epidemiological profile of the deaths which occurred among women aged below 40 years old, diagnosed with breast cancer. Data collection was undertaken in the Hospital Records (Cancer) Service of the Teaching Hospital of the Federal University of Paraná, Brazil, including information recorded between January 2003 and December 2011. A total of 638 notifications of breast cancer were identified, of which 68 were of women aged below 40 years old, of whom 21 died. It was ascertained that the survival was, on average, of 40 months; and that 76.2% were at advanced stages (III or IV). It is emphasized that screening for breast cancer in women at high risk allows the detection of tumors at earlier stages, reducing the incidence in the number of deaths and improving the health indicators.Es una investigación documental descriptiva cuyo objetivo fue reconocer el perfil epidemiológico de los óbitos ocurridos entre mujeres con menos de 40 años, diagnosticadas con cáncer de mama. Los datos fueron obtenidos en el Servicio de Registro Hospitalar de Cáncer del Hospital de Clínicas de la Universidad Federal de Paraná-Brasil, comprendiendo informaciones registradas entre enero de 2003 y diciembre de 2011. Fueron identificadas 638 notificaciones de cáncer de mama, de las cuales 68 fueron de mujeres con menos de 40 años y de esas 21 fueron a óbito. Se verificó que la sobrevida fue, en media, de 40 meses y 76,2% presentaron estadio clínico avanzado (III o IV). Se resalta que rastrear el cáncer de mama en mujeres de alto riesgo posibilita detectar el tumor más precozmente, reducir la incidencia en el número de óbitos y mejorar los indicadores de salud

    An in vitro stem cell model of human epiblast and yolk sac interaction.

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    Human embryogenesis entails complex signalling interactions between embryonic and extra-embryonic cells. However, how extra-embryonic cells direct morphogenesis within the human embryo remains largely unknown due to a lack of relevant stem cell models. Here, we have established conditions to differentiate human pluripotent stem cells (hPSCs) into yolk sac-like cells (YSLCs) that resemble the post-implantation human hypoblast molecularly and functionally. YSLCs induce the expression of pluripotency and anterior ectoderm markers in human embryonic stem cells (hESCs) at the expense of mesoderm and endoderm markers. This activity is mediated by the release of BMP and WNT signalling pathway inhibitors, and, therefore, resembles the functioning of the anterior visceral endoderm signalling centre of the mouse embryo, which establishes the anterior-posterior axis. Our results implicate the yolk sac in epiblast cell fate specification in the human embryo and propose YSLCs as a tool for studying post-implantation human embryo development in vitro.</i

    Eritema elevatum diutinum como diagnóstico diferencial das doenças reumatológicas: relato de caso

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    Erythema elevatum diutinum is a chronic and rare cutaneous leukocytoclastic vasculitis, characterized by red, purple and yellow papules, plaques and nodules, distributed symmetrically on the extensor surfaces of the limbs. It is associated with several autoimmune, neoplastic and infectious processes, mainly hematological malignancies in about 30% of the cases. Joint pain and arthritis are frequent symptoms, affecting approximately 40% of the patients, indicating the need for its inclusion in the differential diagnosis of rheumatic diseases, chiefl y the other presentations of leukocytoclastic vasculitis, which are characterized by the combination of rheumatic manifestations and peculiar cutaneous lesions. We report the case of an 18-year-old female patient who developed erythema elevatum diutinum and whose diagnosis was based on the morphologic characteristics, the distribution pattern of the cutaneous lesions and the histopathological fi ndings of leuko- cytoclastic vasculitis. The major systemic symptom was severe arthritis.O eritema elevatum diutinum é uma vasculite leucocitoclástica cutânea crônica e rara, caracterizada por pápulas, placas e nódulos vermelhos, purpúreos e amarelados, distribuídos simetricamente sobre as superfícies extensoras das extremidades. Está associado a vários processos autoimunes, neoplásicos e infecciosos, principalmente malignidades hematológicas (cerca de 30% dos casos). Artralgia e artrite são sintomas frequentes, que afetam por volta de 40% dos pacientes, o que indica a necessidade de sua inclusão no diagnóstico diferencial das doenças reumatológicas, principalmente se em conjunto com outras apresentações da vasculite leucocitoclástica, caracterizadas pela combinação de manifestações reumáticas com alterações cutâneas características. Descrevemos o caso de uma paciente de 18 anos que desenvolveu eritema elevatum diutinum, cujo diagnóstico baseou-se nas características morfológicas, no padrão de distribuição das lesões cutâneas e nos achados histopatológicos de vasculite leucocitoclástica. O principal sintoma sistêmico era uma artrite severa

    One-Step reverse transcriptase PCR for detection of arboviruses in serum samples of patients assisted in Basic health Units in the State of Maranhão, Brazil / PCR de transcriptase reversa em uma etapa para detecção de arbovírus em amostras de soro de pacientes atendidos em Unidades Básicas de Saúde no estado do Maranhão, Brasil

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    polymerase chain reaction to detect acute infections caused by dengue, zika, chikungunya, and mayaro virus in clinical samples. Methods: We evaluated 620 sera samples collected from March 2016 to March 2018 and provided by the Central Health Laboratory of Maranhão (LACEN-MA). Total RNA was isolated from clinical specimens and used as the template for one-step RT-PCR assays with specific-primers designed for this study. Results: Of the 620 sera evaluated, 386 (62.2%) were positive, among them 330 (85.5%) amplified a specific fragment for chikungunya, 55 (14.2%) showed a fragment compatible with dengue serotype 4, and 1 (0.3%) exhibited profile for mayaro virus. Conclusions: The results obtained here were more sensitive than IgM-ELISA because the viral RNA was detected in serum samples from patients, not only from 1 to 6 days but also from 7 to 10 days after the beginning of clinical signs (convalescent period). Besides, the mayaro virus was detected in one serum sample that was IgM-ELISA negative for dengue, zika, and chikungunya. 
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