18 research outputs found

    Se-methylselenocysteine inhibits phosphatidylinositol 3-kinase activity of mouse mammary epithelial tumor cells in vitro

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    INTRODUCTION: Se-methylselenocysteine (MSC), a naturally occurring selenium compound, is a promising chemopreventive agent against in vivo and in vitro models of carcinogen-induced mouse and rat mammary tumorigenesis. We have demonstrated previously that MSC induces apoptosis after a cell growth arrest in S phase in a mouse mammary epithelial tumor cell model (TM6 cells) in vitro. The present study was designed to examine the involvement of the phosphatidylinositol 3-kinase (PI3-K) pathway in TM6 tumor model in vitro after treatment with MSC. METHODS: Synchronized TM6 cells treated with MSC and collected at different time points were examined for PI3-K activity and Akt phosphorylation along with phosphorylations of Raf, MAP kinase/ERK kinase (MEK), extracellular signal-related kinase (ERK) and p38 mitogen-activated protein kinase (MAPK). The growth inhibition was determined with a [(3)H]thymidine incorporation assay. Immunoblotting and a kinase assay were used to examine the molecules of the survival pathway. RESULTS: PI3-K activity was inhibited by MSC followed by dephosphorylation of Akt. The phosphorylation of p38 MAPK was also downregulated after these cells were treated with MSC. In parallel experiments MSC inhibited the Raf–MEK–ERK signaling pathway. CONCLUSION: These studies suggest that MSC blocks multiple signaling pathways in mouse mammary tumor cells. MSC inhibits cell growth by inhibiting the activity of PI3-K and its downstream effector molecules in mouse mammary tumor cells in vitro

    Manifestações otológicas em criança com síndrome da imunodeficiência adquirida Otologic manifestations in child with acquired immunodeficiency syndrome

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    As manifestações otológicas são particularmente comuns em crianças portadoras do Vírus da Imunodeficiência Humana (HIV). A disacusia nestes pacientes pode ser condutiva, principalmente decorrente de otite média ou sensorioneural, pela ação direta do vírus ou pela ação de drogas anti-retrovirais. Neste trabalho, relatamos o caso de uma criança de 10 anos de idade, portadora de HIV, com disacusia e revisamos a literatura.<br>Patients infected with Human immunodeficiency virus (HIV) often present with otologic manifestations. The hearing loss may be condutive type, resulting from middle ear disease or sensorineural type due virus action or drug therapy. In this paper we describe and discuss a case of a ten years old child with HIV and otologic manifestations including hearing loss
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