7,901 research outputs found

    Identification of side population cells in mouse primordial germ cells and prenatal testis

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    In mammals, the stem cells of spermatogenesis are derived from an embryonic cell population called primordial germ cells (PGCs). Spermatogonial stem cells displaying the "side population" (SP) phenotype have been identified in the immature and adult mouse testis, but noting is known about the expression of the SP phenotype during prenatal development of germ cells. The SP phenotype, defined as the ability of cells to efflux fluorescent dyes such as Hoechst, is common to several stem/progenitor cell types. In the present study, we analyzed and characterized the Hoechst SP via cytofluorimetric analysis of disaggregated gonads at different time points during embryonic development in mice. To directly test the hypothesis that the SP phenotype is a feature of germ cell lineage, experiments were performed on transgenic animals expressing enhanced green fluorescent protein (EGFP) under the control of the Oct4 promoter, to identify early germ cells up to PGCs. We found that prenatal gonads contain a fraction of SP cells at each stage analyzed, and the percentage of cells in the SP fraction decreases as development proceeds. Surprisingly, more than 50% of the PGCs displayed the SP phenotype at 11.5 dpc (days post coitum). The percentage of germ cells with the SP phenotype decreased steadily with development, to less than 1% at 18.5 dpc. Cytofluorimetric analysis along with immunocytochemistry performed on sorted cells indicated that the SP fraction of prenatal gonads, as in the adult testis, was heterogeneous, being composed of both somatic and germ cells. Both cell types expressed the ABC transporters Abcg2, Abcb1a, Abcb1b and Abcc1. These findings provide evidence that the SP phenotype is a common feature of PGCs and identifies a subpopulation of fetal testis cells including prospermatogonia whose differentiation fate remains to be investigated. © 2011 UBC Press

    Diagnostic imaging and CEUS findings in a rare case of Desmoid-type fibromatosis. A case report

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    Desmoid-type fibromatosis (DF), also known as aggressive fibromatosis, is a locally aggressive benign fibroblastic neoplasm that can infiltrate or recur but cannot metastasize. It is rare, with an estimated annual incidence of two to four new cases per million people. Most DFs occur sporadically, but it may also be associated with the hereditary syndrome familial adenomatous polyposis. Treatment is necessary when the disease is symptomatic, especially in case of compression of critical structures. When possible, surgical resection is the treatment of choice; however, recurrence is common. Due to the high rate of recurrence, imaging plays an important role not only in diagnosis, but also in the management of DF. Although there are a number of studies describing CT and MRI findings of DF, there is no description of contrast-enhanced ultrasound findings

    Se apro gli occhi non sono più qui. Cinema e psichiatria

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    Esperienza di filmtherapy come arte-terapia nel trattamento integrato della riabilitazione psichiatrica presso il Day Hospital psichiatrico della Sapienza Università di Roma - Policlinico Umberto

    Otolaryngologic symptoms in multiple sclerosis: a review

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    Many symptoms of multiple sclerosis may affect the ear, nose and throat. The most common otolaryngologic symptoms of multiple sclerosis are speech disorders, followed by sleep disorders, vertigo and disequilibrium, dysphagia, smell alterations, and hearing loss. Less common symptoms include sialorrhea, facial palsy, taste alterations, trigeminal neuralgia and tinnitus. The origin of otolaryngologic symptoms in multiple sclerosis is mainly central, although increasing evidence also suggests a peripheral involvement. Otolaryngologic symptoms in multiple sclerosis may have different clinical presentations; they can appear in different stages of the pathology, in some cases they can be the presenting symptoms and their worsening may be correlated with reactivation of the disease. Many of these symptoms significantly affect the quality of life or patients and lead to increased morbidity and mortality. Otolaryngologic symptoms are common in multiple sclerosis; however, they are often overlooked. In many cases, they follow the relapsing-remitting phases of the disease, and may spontaneously disappear, leading to a delay in multiple sclerosis diagnosis. Clinicians should be aware of otolaryngologic symptoms of multiple sclerosis, especially when they are associated to neurologic symptoms, as they may be early signs of a still undiagnosed multiple sclerosis or could help monitor disease progression in already diagnosed patients

    Future of oil and gas development in the western Amazon

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    The western Amazon is one of the world's last high-biodiversity wilderness areas, characterized by extraordinary species richness and large tracts of roadless humid tropical forest. It is also home to an active hydrocarbon (oil and gas) sector, characterized by operations in extremely remote areas that require new access routes. Here, we present the first integrated analysis of the hydrocarbon sector and its associated road-building in the western Amazon. Specifically, we document the (a) current panorama, including location and development status of all oil and gas discoveries, of the sector, and (b) current and future scenario of access (i.e. access road versus roadless access) to discoveries. We present an updated 2014 western Amazon hydrocarbon map illustrating that oil and gas blocks now cover 733 414 km(2), an area much larger than the US state of Texas, and have been expanding since the last assessment in 2008. In terms of access, we documented 11 examples of the access road model and six examples of roadless access across the region. Finally, we documented 35 confirmed and/or suspected untapped hydrocarbon discoveries across the western Amazon. In the Discussion, we argue that if these reserves must be developed, use of the offshore inland model-a method that strategically avoids the construction of access roads-is crucial to minimizing ecological impacts in one of the most globally important conservation regions

    The ovarian reserve as target of insulin/IGF and ROS in metabolic disorder-dependent ovarian dysfunctions

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    It is known for a long time that metabolic disorders can cause ovarian dysfunctions and affect a woman's fertility either by direct targeting follicular cells and/or the oocytes or by indirect interference with the pituitary-hypothalamic axis, resulting in dysfunctional oogenesis. Such disorders may also influence the efficiency of the embryo implantation and the quality of the embryo with permanent effects on the fertility and health of the offspring. Thanks to the expanding knowledge on the molecular mechanisms governing oogenesis and folliculogenesis in mammals, we are beginning to understand how such disorders can negatively affect this process and consequently fertility in women. In the present review, we point out and discuss how the disturbance of insulin/IGF-dependent signalling and increased reactive oxygen species (ROS) level in the ovary typically associated to metabolic disorders such as type II diabetes and obesity can dysregulate the dynamics of the ovarian reserve and/or impair the survival and competence of the oocytes
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