163 research outputs found

    The use of Maytenus ilicifolia to prevent cisplatin-induced ototoxicity

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    Maytenus ilicifolia é uma planta sul americana apresenta várias propriedades medicinais, entre elas, a ação antioxidante. OBJETIVO: Por meio de um modelo original de ototoxicidade induzida pela cisplatina, verificar uma possível ação otoprotetora do extrato aquoso desta planta. MATERIAL E MÉTODO: Estudo clínico e experimental com cobaias fêmeas, albinas divididas em 5 grupos: 9 animais recebendo somente 3 doses de 7,5mg/kg/d do protocolo de cisplatina, 4 animais somente com o extrato, 10 animais com cisplatina e 1g/kg/d de extrato por 8 dias, 5 animais com cisplatina e 3g/kg/d do extrato por 8 dias e 5 animais recebendo extrato por 3 semanas e cisplatina na última semana. Os exames foram emissões otoacústica por produtos de distorção, potencial de tronco encefálico pré e após administração de cisplatina e, microscopia eletrônica de varredura. RESULTADOS: Os animais que receberam a cisplatina com o extrato, independente da dose, obtiveram alterações em todos os testes, com lesões na região basal na microscopia eletrônica. CONCLUSÃO: Apesar do efeito antioxidante da Maytenus ilicifolia, ela não foi suficiente para bloquear o efeito ototóxico da cisplatina.Maytenus ilicifolia is a native plant from South America, with several medicinal properties including antioxidant effects. AIM: using an original cisplatin induced ototoxicity model, we evaluated a possible otoprotection caused by Maytenus ilicifolia extract. MATERIALS AND METHODS: clinical and experimental study design with female albino guinea pigs divided in groups as follows: 9 animals receiving cisplatin only (three doses of 7.5mg/kg/day), 4 animals receiving the plant extract only, 10 animals receiving the cisplatin protocol and 1g/kg/day of extract for 8 days, 5 animals with cisplatin and 3g/kg/day of extract for 8 days, and 5 animals receiving extract for 3 weeks and cisplatin in the last week. The tests were distortion product otoacoustic emissions, brainstem auditory response, before and after medication and scanning electron microscopy. RESULTS: the animals receiving cisplatin plus plant extract, had alterations in all the tests, showing lesions on the basal cochlear region under electron microscopy. CONCLUSIONS: Despite of the plant extract's antioxidant effect, it was not sufficient to protect the cochlea against cisplatin ototoxicity

    Uma análise de como o ambiente influência na aprendizagem e no comportamento de estudantes sua importância na formação inicial de professores

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    O trabalho apresentado trata-se de um relato de experiência a respeito de  atividade realizada no horto medicinal da Universidade Federal de Lavras, referente a disciplina de Psicologia da Educação em uma de suas aulas. Objetiva-se compreender e analisar como o ambiente pode proporcionar benefícios para os estudantes, e a sua importância na formação inicial de professores. Para analisar os resultados obtidos, utilizou-se a pesquisa qualitativa, para uma melhor organização, foi utilizado o método de categorização onde foram encontradas quatro categorias: “Atividade vista como metodologia diferente da tradicional”; “maior participação do estudante e a mesma sendo em um ambiente que difere da sala de aula”; “a fim de aumentar os laços na relação estudante-educadora” e “uma forma de conhecer melhor o estudante”. O trabalho buscou compreender como metodologias diferentes são eficazes e auxiliam na formação da pessoa, e como esses meios interdisciplinares auxiliam no conhecimento e compreensão mais eficaz de mundo

    Uma análise de como o ambiente influência na aprendizagem e no comportamento de estudantes sua importância na formação inicial de professores

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    The present work is an experience report about an activity carried out in the medical horticulture of the Federal University of Lavras, referring to the discipline of Educational Psychology in one of its classes. The work in question aims to understand and analyze how the environment can provide benefits for students, and their importance in initial teacher training. In order to analyze the obtained results, we used the qualitative research, which approaches the direct proximity of the researcher, for a better organization, the categorization method was used where four categories were found: "Activity seen as a methodology different from the traditional one"; “student participation and the same being in an environment that differs from the classroom"; " increase the ties in the student-educator relationship" and”"way to get to know the student better". The work seeks to understand how different methodologies are effective and help in the formation of the person, and how these interdisciplinary means help in the most effective knowledge and understanding of the world.El trabajo presentado se trata de un relato de experiencia acerca de una actividad realizada en el huerto medicinal de la Universidad Federal de Lavras, referente a la disciplina de Psicología de la Educación en una de sus clases. Objetivos comprender y analizar cómo el ambiente puede proporcionar beneficios para los estudiantes, y su importancia en la formación inicial de profesores. Para analizar los resultados obtenidos, se utilizó la investigación cualitativa, para una mejor organización, se utilizó el método de categorización donde se encontraron cuatro categorías: "Actividad vista como una metodología diferente de la tradicional"; "mayor participación del estudiante y la misma siendo en un ambiente que difiere del aula"; "a fin de aumentar los vínculos en la relación estudiante-educador" y "una forma de conocer mejor al estudiante". El trabajo busco comprender cómo metodologías diferentes son eficaces y auxilian en la formación de la persona, y cómo esos medios interdisciplinarios auxilian en el conocimiento y la comprensión más eficaz del mundo.O trabalho apresentado trata-se de um relato de experiência a respeito de  atividade realizada no horto medicinal da Universidade Federal de Lavras, referente a disciplina de Psicologia da Educação em uma de suas aulas. Objetiva-se compreender e analisar como o ambiente pode proporcionar benefícios para os estudantes, e a sua importância na formação inicial de professores. Para analisar os resultados obtidos, utilizou-se a pesquisa qualitativa, para uma melhor organização, foi utilizado o método de categorização onde foram encontradas quatro categorias: “Atividade vista como metodologia diferente da tradicional”; “maior participação do estudante e a mesma sendo em um ambiente que difere da sala de aula”; “a fim de aumentar os laços na relação estudante-educadora” e “uma forma de conhecer melhor o estudante”. O trabalho buscou compreender como metodologias diferentes são eficazes e auxiliam na formação da pessoa, e como esses meios interdisciplinares auxiliam no conhecimento e compreensão mais eficaz de mundo

    Composição química e atividade inibidora de acetilcolinesterase de óleos voláteis de Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedeliana O. Berg, Myrtaceae

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    The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesquiterpenes were found in higher amounts, being valerianol the major compound, and this oil presented a strong acetylcholinesterase inhibition.A composição química dos óleos voláteis de duas espécies de Myrtaceae, Myrceugenia myrcioidese Eugenia riedeliana, ambas nativas da Mata Atlântica, foi analisada por CG-EM. A atividade inibidora de acetilcolinesterase foi determinada colorimetricamente para estes óleos. Em M. myrcioides, hidrocarbonetos monoterpênicos representaram a classe majoritária de compostos presentes no óleo volátil, sendo α-pineno o componente mais abundante e a atividade inibidora de acetilcolinesterase foi baixa, enquanto para E. riedelianaos sesquiterpenos foram observados em maiores concentrações, sendo o valerianol o componente majoritário, e este óleo apresentou uma forte atividade inibidora da enzima.BIOTA/FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    In vitro and in vivo assessment of the anti-malarial activity of Caesalpinia pluviosa

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    <p>Abstract</p> <p>Background</p> <p>To overcome the problem of increasing drug resistance, traditional medicines are an important source for potential new anti-malarials. <it>Caesalpinia pluviosa</it>, commonly named "sibipiruna", originates from Brazil and possess multiple therapeutic properties, including anti-malarial activity.</p> <p>Methods</p> <p>Crude extract (CE) was obtained from stem bark by purification using different solvents, resulting in seven fractions. An MTT assay was performed to evaluate cytotoxicity in MCF-7 cells. The CE and its fractions were tested <it>in vitro </it>against chloroquine-sensitive (3D7) and -resistant (S20) strains of <it>Plasmodium falciparum</it> and <it>in vivo </it>in <it>Plasmodium chabaudi</it>-infected mice. <it>In vitro </it>interaction with artesunate and the active <it>C. pluviosa </it>fractions was assessed, and mass spectrometry analyses were conducted.</p> <p>Results</p> <p>At non-toxic concentrations, the 100% ethanolic (F4) and 50% methanolic (F5) fractions possessed significant anti-malarial activity against both 3D7 and S20 strains. Drug interaction assays with artesunate showed a synergistic interaction with the F4. Four days of treatment with this fraction significantly inhibited parasitaemia in mice in a dose-dependent manner. Mass spectrometry analyses revealed the presence of an ion corresponding to <it>m/z </it>303.0450, suggesting the presence of quercetin. However, a second set of analyses, with a quercetin standard, showed distinct ions of <it>m/z </it>137 and 153.</p> <p>Conclusions</p> <p>The findings show that the F4 fraction of <it>C. pluviosa </it>exhibits anti-malarial activity <it>in vitro </it>at non-toxic concentrations, which was potentiated in the presence of artesunate. Moreover, this anti-malarial activity was also sustained <it>in vivo </it>after treatment of infected mice. Finally, mass spectrometry analyses suggest that a new compound, most likely an isomer of quercetin, is responsible for the anti-malarial activity of the F4.</p

    Lying in Wait: The Resurgence of Dengue Virus After the Zika Epidemic in Brazil

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    After the Zika virus (ZIKV) epidemic in the Americas in 2016, both Zika and dengue incidence declined to record lows in many countries in 2017-2018, but in 2019 dengue resurged in Brazil, causing ~2.1 million cases. In this study we use epidemiological, climatological and genomic data to investigate dengue dynamics in recent years in Brazil. First, we estimate dengue virus force of infection (FOI) and model mosquito-borne transmission suitability since the early 2000s. Our estimates reveal that DENV transmission was low in 2017-2018, despite conditions being suitable for viral spread. Our study also shows a marked decline in dengue susceptibility between 2002 and 2019, which could explain the synchronous decline of dengue in the country, partially as a result of protective immunity from prior ZIKV and/or DENV infections. Furthermore, we performed phylogeographic analyses using 69 newly sequenced genomes of dengue virus serotype 1 and 2 from Brazil, and found that the outbreaks in 2018-2019 were caused by local DENV lineages that persisted for 5-10 years, circulating cryptically before and after the Zika epidemic. We hypothesize that DENV lineages may circulate at low transmission levels for many years, until local conditions are suitable for higher transmission, when they cause major outbreaks

    Domestication of Campylobacter jejuni NCTC 11168

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    Reference and type strains of well-known bacteria have been a cornerstone of microbiology research for decades. The sharing of well-characterized isolates among laboratories has run in parallel with research efforts and enhanced the reproducibility of experiments, leading to a wealth of knowledge about trait variation in different species and the underlying genetics. Campylobacter jejuni strain NCTC 11168, deposited at the National Collection of Type Cultures in 1977, has been adopted widely as a reference strain by researchers worldwide and was the first Campylobacter for which the complete genome was published (in 2000). In this study, we collected 23 C . jejuni NCTC 11168 reference isolates from laboratories across the UK and compared variation in simple laboratory phenotypes with genetic variation in sequenced genomes. Putatively identical isolates, identified previously to have aberrant phenotypes, varied by up to 281 SNPs (in 15 genes) compared to the most recent reference strain. Isolates also display considerable phenotype variation in motility, morphology, growth at 37 °C, invasion of chicken and human cell lines, and susceptibility to ampicillin. This study provides evidence of ongoing evolutionary change among C. jejuni isolates as they are cultured in different laboratories and highlights the need for careful consideration of genetic variation within laboratory reference strains. This article contains data hosted by Microreact

    A cyclopalladated complex interacts with mitochondrial membrane thiol-groups and induces the apoptotic intrinsic pathway in murine and cisplatin-resistant human tumor cells

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    <p>Abstract</p> <p>Background</p> <p>Systemic therapy for cancer metastatic lesions is difficult and generally renders a poor clinical response. Structural analogs of cisplatin, the most widely used synthetic metal complexes, show toxic side-effects and tumor cell resistance. Recently, palladium complexes with increased stability are being investigated to circumvent these limitations, and a biphosphinic cyclopalladated complex {Pd<sub>2 </sub>[<it>S<sub>(-)</sub></it>C<sup>2</sup>, N-dmpa]<sub>2 </sub>(μ-dppe)Cl<sub>2</sub>} named C7a efficiently controls the subcutaneous development of B16F10-Nex2 murine melanoma in syngeneic mice. Presently, we investigated the melanoma cell killing mechanism induced by C7a, and extended preclinical studies.</p> <p>Methods</p> <p>B16F10-Nex2 cells were treated <it>in vitro </it>with C7a in the presence/absence of DTT, and several parameters related to apoptosis induction were evaluated. Preclinical studies were performed, and mice were endovenously inoculated with B16F10-Nex2 cells, intraperitoneally treated with C7a, and lung metastatic nodules were counted. The cytotoxic effects and the respiratory metabolism were also determined in human tumor cell lines treated <it>in vitro </it>with C7a.</p> <p>Results</p> <p>Cyclopalladated complex interacts with thiol groups on the mitochondrial membrane proteins, causes dissipation of the mitochondrial membrane potential, and induces Bax translocation from the cytosol to mitochondria, colocalizing with a mitochondrial tracker. C7a also induced an increase in cytosolic calcium concentration, mainly from intracellular compartments, and a significant decrease in the ATP levels. Activation of effector caspases, chromatin condensation and DNA degradation, suggested that C7a activates the apoptotic intrinsic pathway in murine melanoma cells. In the preclinical studies, the C7a complex protected against murine metastatic melanoma and induced death in several human tumor cell lineages <it>in vitro</it>, including cisplatin-resistant ones. The mitochondria-dependent cell death was also induced by C7a in human tumor cells.</p> <p>Conclusions</p> <p>The cyclopalladated C7a complex is an effective chemotherapeutic anticancer compound against primary and metastatic murine and human tumors, including cisplatin-resistant cells, inducing apoptotic cell death via the intrinsic pathway.</p
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