267 research outputs found

    Leydig Cell Tumour and Mature Ovarian Teratoma: Rare Androgen-Secreting Ovarian Tumours in Postmenopausal Women

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    Androgen-secreting ovarian tumours are extremely rare accounting for <5% of all ovarian neoplasms. They are more frequent in postmenopausal women and should be suspected in the case of a rapid onset of androgenic symptoms. We report 4 cases of postmenopausal women who presented with signs of virilisation. All patients revealed increased serum levels of testosterone, normal dehydroepiandrosterone-sulfate and negative pelvic ultrasound for adnexal masses. An androgen-secreting ovarian tumour was suspected and all of them were submitted to bilateral oophorectomy. Histology confirmed the diagnosis of Leydig cell tumours in 3 patients and mature teratoma in 1. A successful response to surgery, which includes a decline in serum androgen levels and signs of hyperandrogenism, was observed in our patients. This case series demonstrates that androgen-secreting ovarian neoplasms may not be detectable by imaging studies, but should be considered in the differential diagnosis of all postmenopausal women with signs of hyperandrogenism.info:eu-repo/semantics/publishedVersio

    Modificação de betumes com aditivos líquidos para aplicação em países tropicais

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    A modificação de betumes é uma das soluções mais utilizadas na pavimentação, sobretudo em países com climas quentes, pois permite minimizar problemas tais como o fendilhamento, o envelhecimento do betume, e em especial as deformações permanentes. Este trabalho visa estudar uma solução para modificação do betume de modo a contornar os problemas acima indicados do betume puro existente nesses países. Para isso foram utilizados dois aditivos líquidos, SBR líquido e ácido polifosfórico (PPA), e foram estudadas diferentes percentagens de adição dos mesmos em betumes puros, de modo a selecionar o aditivo com mais potencial e a percentagem em que devia ser incorporado.Fundos QREN, através da ANI, no âmbito do projeto Tropical-Pav – “Soluções de Pavimentação Rodoviária para Climas Tropicais”, num consórcio constituído por duas empresas e quatro entidades do Sistema Científico e Tecnológico Nacional (SCTN), nomeadamente Elevo Grupo, Mota-Engil Engenharia e Construção, Instituto Superior Técnico, Laboratório Nacional de Engenharia Civil, Universidade de Coimbra e Universidade do Minho

    The path from the choroid plexus to the subventricular zone: go with the flow!

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    In adult mammals, under physiological conditions, neurogenesis, the process of generating new functional neurons from precursor cells, occurs mainly in two brain areas: the subgranular zone in the dentate gyrus of the hippocampus, and the subventricular zone (SVZ) lining the walls of the brain lateral ventricles. Taking into account the location of the SVZ and the cytoarchitecture of this periventricular neural progenitor cell niche, namely the fact that the slow dividing primary progenitor cells (type B cells) of the SVZ extend an apical primary cilium toward the brain ventricular space which is filled with cerebrospinal fluid (CSF), it becomes likely that the composition of the CSF can modulate both self-renewal, proliferation and differentiation of SVZ neural stem cells. The major site of CSF synthesis is the choroid plexus (CP); quite surprisingly, however, it is still largely unknown the contribution of molecules specifically secreted by the adult CP as modulators of the SVZ adult neurogenesis. This is even more relevant in light of recent evidence showing the ability of the CP to adapt its transcriptome and secretome to various physiologic and pathologic stimuli. By giving particular emphasizes to growth factors and axonal guidance molecules we will illustrate how CP-born molecules might play an important role in the SVZ niche cell population dynamics.Ana M. Falcão and Ashley Novais are recipients of Ph.D.Fellowships from the Fundação para a Ciência e Tecnologia (FCT,Portugal).Fernanda Marques is a recipiente of post docToral fellowship from the Fundação para a Ciência e Tecnologia (FCT,Portugal).This work is supported by a grant from FCT (PTDC/SAU-OSM/104475/2008

    Preoperative Location Of Parathyroid Adenomas In Primary Hyperparathyroidism: The Role of Cervical Doppler Ultrasound

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    Introduction: Parathyroid adenoma is the most frequent cause of primary hyperparathyroidism. In recent years, the preoperative location of parathyroid adenomas allowed minimally invasive surgical techniques that have become preferred over the traditional bilateral neck exploration. The more recent guidelines on this subject highlight the role of nuclear medicine imaging tests. The aim of this study was to review the current role of Doppler ultrasound (US) in assessing the preoperative location of parathyroid adenomas in patients with primary hyperparathyroidism. Material and methods: Retrospective study based on data from patients with primary hyperparathyroidism that underwent parathyroidectomy between January 2013 and January 2022 at the Centro Hospitalar Universitário Lisboa Central. Statistical analysis was performed with IBM SPSS Statistics, version 26.0.0.0®. Results: Parathyroidectomy was performed in 171 patients (77.8% females) with primary hyperparathyroidism. Cervical Doppler ultrasound was the most performed test (64.3%, n = 110) for preoperative location and detected a suspicious lesion in 98 patients (89.1%). The preoperative location of the parathyroid adenomas was assessed through the Doppler ultrasound and was compared with the surgical reports and histological findings; a correct identification was made in 76 patients (77.6%). Doppler ultrasound slightly underestimated the mean adenoma size (18.1 ± 7.7 mm preoperative versus 22 ± 8.4 mm postoperative). Calcium, parathyroid hormone levels, adenoma size and concomitant presence of thyroid nodules did not affect the accuracy of Doppler ultrasound. Conclusion: Doppler ultrasound showed high diagnostic accuracy even in patients with nodular thyroid disease regardless of calcium and parathyroid hormone levels and adenoma size. Furthermore, its safety, affordability and availability should favor its use as first line test in primary hyperparathyroidism to assess the preoperative location of parathyroid adenomas.info:eu-repo/semantics/publishedVersio

    Avaliação do desempenho de misturas betuminosas recicladas com elevadas taxas de material fresado

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    Atualmente, e com o desenvolvimento constante da sociedade, o aumento excessivo da utilização dos recursos naturais têm-se tornado um tema de grande preocupação. Nesse sentido, a reutilização dos materiais existentes é uma solução viável que se tem tornado cada vez mais comum. No que respeita à indústria da construção, nomeadamente à indústria de pavimentação, a reciclagem de materiais é uma questão que assume uma importância ainda mais relevante, pois a reutilização do material fresado (MF) dos pavimentos permite a redução de custos e do impacto ambiental das atividades de pavimentação. Contudo, a incorporação de MF na produção de novas misturas pode causar alguns problemas devido às características do betume envelhecido presente no MF, sendo o uso de aditivos rejuvenescedores uma forma de contornar este problema. Neste estudo foram estudados três rejuvenescedores e dois ligantes diferentes, tendo-se concluído que os rejuvenescedores testados apresentam resultados semelhastes em termos de modificação das misturas

    Desenvolvimento de uma metodologia de avaliação da resistência ao rolamento de diferentes misturas betuminosas

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    Os pavimentos rodoviários são infraestruturas de grande importância para o desenvolvimento económico de qualquer país. Atualmente, o principal critério utilizado na conceção dessas infraestruturas deixou de ser apenas o seu menor custo, valorizando-se a perspetiva ambiental e procurando determinar todos os impactos de longo prazo (económicos, ambientais ou sociais) deste tipo de investimentos. Nesse sentido, o consumo de combustível dos veículos que circulam nos pavimentos tem um peso significativo em termos económicos e ambientais, justificando a procura de soluções que permitam reduzir esse consumo de forma a garantir um desenvolvimento mais sustentável. No que diz respeito às características dos pavimentos, um dos fatores que mais influencia o consumo dos veículos é a resistência ao rolamento. Tendo em conta que as características dos pavimentos, em especial as superficiais, têm uma influência significativa nessa propriedade, com o presente trabalho pretendeu desenvolver-se uma metodologia de avaliação da resistência ao rolamento de misturas betuminosas com diferentes características superficiais. Assim, é possível avaliar que misturas ou características superficiais permitem contribuir para uma redução do consumo de combustível e das emissões de gases resultantes da sua queima ao longo do ciclo de vida de um pavimento. A obtenção de resultados do consumo energético necessário para circular sobre diferentes misturas betuminosas foi conseguida através do desenvolvimento de um protótipo. O consumo energético do movimento circular das rodas, equipadas com pneus convencionais de veículos ligeiros, foi medido para diferentes superfícies e a sua utilização para a avaliação da sustentabilidade das misturas estudadas é analisada no presente artigoFEDER através do Programa Operacional de Competitividade - COMPETE e por fundos nacionais através da FCT - Fundação para a Ciência e a Tecnologia - no âmbito do Projeto PLASTIROADS - PTDC/ECM/119179/201

    Experimental analysis on the functional properties of rendering mortars with superficial addition of TiO2 nanoparticles

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    Recent developments in the area of nanomaterials science and nanotechnology are changing the field of construction and building industry. The construction industry has been increasingly identified as an important market for the use of nanomaterial´s since this can make buildings cleaner (minimizing the pollution effects and also reducing the building facades maintenance costs), resistant and energy efficient (thermal energy storage). In order to contribute for the development of this area, this work aims the production of rendering plastering mortars with multifunctional properties such as photocatalytic capacity and improving thermal capabilities. Standard plastering mortars were modified by spraying titanium dioxide (TiO2) from a water-based TiO2 nanoparticles solution. Two mortar compositions, which are representative of rendering mortars, namely composition, 1:1:6 and 1:2:9 (cement:lime:sand) in volume, were considered. Additionally, two distinct water/binder ratios were considered to induce distinct porosities and thus to evaluate the differences on the mechanical and physical properties of the mortars after the addition of the TiO2 nanoparticles

    Lipocalin 2 is present in the EAE brain and is modulated by natalizumab

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    The authors acknowledge the BiogenIdec, for providing Natalizumab (BiogenIdec, Boston, MA, USA). We are thankful to theCOST(European Cooperation in Science and Technology) Action NEURINFNETBM0603. We also thank Dr. Nadine Santos for critically reviewing this manuscript.Multiple sclerosis (MS) is a demyelinating disease that causes major neurological disability in young adults. A definitive diagnosis at the time of the first episode is still lacking, but since early treatment leads to better prognosis, the search for early biomarkers is needed. Here we characterized the transcriptome of the choroid plexus (CP), which is part of the blood-brain barriers (BBBs) and the major site of cerebrospinal fluid production, in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. In addition, cerebrospinal fluid samples from two cohorts of patients with MS and with optic neuritis (ON) were analyzed to confirm the clinical relevance of the findings. Genes encoding for adhesion molecules, chemokines and cytokines displayed the most altered expression, supporting the role of CP as a site of immune-brain interaction in MS. The gene encoding for lipocalin 2 was the most up-regulated; notably, the cerebrospinal fluid lipocalin 2 levels coincided with the active phases of the disease. Immunostaining revealed that neutrophils infiltrating the CP were the source of the increased lipocalin 2 expression in this structure. However, within the brain, lipocalin 2 was also detected in astrocytes, particularly in regions typically affected in patients with MS. The increase of lipocalin 2 in the cerebrospinal fluid and in astrocytes was reverted by natalizumab treatment. Most importantly, the results obtained in the murine model were translatable into humans since patients from two different cohorts presented increased cerebrospinal fluid lipocalin 2 levels. The findings support lipocalin 2 as a valuable molecule for the diagnostic/monitoring panel of MS.This work was supported by a grant from The Dana Foundation (USA) and by a grant from Fundação para a Ciência e Tecnologia(FCT, Portugal) (PIC/IC/83231/2007). Fernanda Marques and Sandro D. Mesquita are recipients of postdoctoral and doctoral fellow- ships from FCT, Portugal, respectively

    Plasticity of resting state brain networks in recovery from stress

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    Chronic stress has been widely reported to have deleterious impact in multiple biological systems. Specifically, structural and functional remodeling of several brain regions following prolonged stress exposure have been described; importantly, some of these changes are eventually reversible. Recently, we showed the impact of stress on resting state networks (RSNs), but nothing is known about the plasticity of RSNs after recovery from stress. Herein, we examined the "plasticity" of RSNs, both at functional and structural levels, by comparing the same individuals before and after recovery from the exposure to chronic stress; results were also contrasted with a control group. Here we show that the stressed individuals after recovery displayed a decreased resting functional connectivity in the default mode network (DMN), ventral attention network (VAN), and sensorimotor network (SMN) when compared to themselves immediately after stress; however, this functional plastic recovery was only partial as when compared with the control group, as there were still areas of increased connectivity in dorsal attention network (DAN), SMN and primary visual network (VN) in participants recovered from stress. Data also shows that participants after recovery from stress displayed increased deactivations in DMN, SMN, and auditory network (AN), to levels similar to those of controls, showing a normalization of the deactivation pattern in RSNs after recovery from stress. In contrast, structural changes (volumetry) of the brain areas involving these networks are absent after the recovery period. These results reveal plastic phenomena in specific RSNs and a functional remodeling of the activation-deactivation pattern following recovery from chronic-stress, which is not accompanied by significant structural plasticity.We are thankful to all study participants. Jose M. Soares, Paulo Marques, and Nadine C. Santos are supported by fellowships of the project SwitchBox-FP7-HEALTH-2010-grant 259772-2; Fernanda Marques is supported by the fellowship SFRH/BPD/33379/2008 funded by the Fundacao para a Ciencia e Tecnologia (FCT, Portugal). The work was supported by SwitchBox-FP7-HEALTH-2010-grant 259772-2
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