Classificação de hidrópsia endolinfática em pacientes com suspeita de doença de Menière utilizando ressonância magnética

Mestrado em Radiações Aplicadas às Tecnologias da Saúde - Ramo de especialização: Imagem por Ressonância Magnética.A doença de Ménière (DM) é uma patologia idiopática do ouvido interno, caracterizada por episódios de vertigem recorrentes, hipoacusia flutuante e acufenos. Esta tríade de sintomas foi descrita pela primeira vez em 1861 por Prosper Ménière, apontando a disfunção do ouvido interno como a origem do complexo de sintomas auditivo e vestibular. Quando a etiologia de Hidrópsia Endolinfática (HE) é conhecida, designa-se por Síndrome de Ménière (SM). A classificação morfológica da HE no vestíbulo e na cóclea é feita com recurso à utilização de imagem por Ressonância Magnética (RM) através da escala de Nagoya, 2008. Esta dissertação tem como objetivos compreender os benefícios da utilização da RM na Doença de Ménière, avaliar a sensibilidade da RM para a diferenciação entre ouvido sintomático e ouvido assintomático e comparar a sintomatologia associada a estes pacientes com o grau atribuído pelo observador através da análise das imagens de RM. Para a elaboração deste estudo foi utilizada uma amostra de 51 pacientes que foram submetidos a exame de RM dos ouvidos. Para a aquisição das imagens de RM foi utilizado um protocolo específico com administração de contraste endovenoso (Gadolíneo) e 4h após a sua injeção foram incluídas as sequências específicas, sendo estas T1 3D IR e 3D Fluid Atennuation Inversion Recovery (3D-FLAIR). As regiões de interesse para a análise deste estudo foram o vestíbulo e a cóclea. A RM evidenciou uma sensibilidade de 74,5% para a deteção da DM em pacientes com sintomas característicos da patologia, bem como que um maior numero de sintomas associados à mesma é fator preponderante para um diagnóstico de DM confirmado pelas imagens de RM. A RM permite a realização de um diagnóstico diferencial para a caracterização de um paciente com ouvido sintomático.ABSTRACT - Ménière's disease (MD) is an idiopathic pathology of the inner ear, characterized by episodes of recurrent vertigo, fluctuating hearing loss, and tinnitus. This triad of symptoms was first described in 1861 by Prosper Ménière, pointing to dysfunction of the inner ear as the origin of the complex of auditory and vestibular symptoms. When the etiology of Endolymphatic Hydropsy (HE) is known, it is called Ménière's Syndrome (SM). The morphological classification of HE in the vestibule and cochlea is made using the Magnetic Resonance Imaging (MR) image using the Nagoya scale, 2008. This dissertation aims to understand the benefits of using Ménière's Disease, to evaluate MRI sensitivity for the differentiation between the symptomatic ear and asymptomatic ear, and to compare the symptomatology associated with these patients with the degree assigned by the observer through the analysis of MRI. For the preparation of this study, a sample of 51 patients who underwent MRI of the ears was used. For the acquisition of MR imaging, a specific protocol with intravenous contrast administration (Gadolíneo) and 4h after its injection were included in the specific sequences, being these T1 3D IR and 3D Fluid Attenuation Inversion Recovery (3D-FLAIR). The regions of interest for the analysis of this study were the vestibule and the cochlea. MRI showed a sensitivity of 74.5% for the detection of DM in patients with symptoms characteristic of the pathology, as well as a greater number of symptoms associated with it, which is a preponderant factor for a diagnosis of DM confirmed by MR images. MRI allows the performance of a differential diagnosis for the characterization of a patient with the symptomatic ear.N/

Ethanol affects the absorption and tissue distribution of orally administered antigens in mice

The aim of this work was to evaluate the effects of ethanol on the adsorption and tissue distribution of orally administered antigens in mice. Results showed that ethanol reduced the level of anti-ovalbumin IgA antibodies in intestinal fluid for the mice treated orally with a palmitoyl-ovalbumin conjugate. Ethanol was administered intragastrically to mice at 5 g/kg body weight for 14 days (chronic treatment), or 10 g/kg body weight every 7th day up to 14 days (acute treatment). Thereafter, 99m technetium-labeled antigens were administered and lymphoid tissues were collected. Ethanol interfered with the transport of ovalbumin to the liver. Moreover, the transport of palmitoyl-ovalbumin to mesenteric lymph nodes was reduced 6 h after the antigen administration. In conclusion, there was a relationship between the suppression of ethanol-mediated specific local IgA responses and the decreased transport of palmitoyl-ovalbumin to mesenteric lymph nodes

Probiotic Propionibacterium freudenreichii requires SlpB protein to mitigate mucositis induced by chemotherapy

Propionibacterium freudenreichii CIRM-BIA 129 (P. freudenreichii wild type, WT) is a probiotic bacterium, which exerts immunomodulatory effects. This strain possesses extractable surface proteins, including SlpB, which are involved in antiinflammatory effect and in adhesion to epithelial cells. We decided to investigate the impact of slpB gene mutation on immunomodulation in vitro and in vivo. In an in vitro assay, P. freudenreichii WT reduced expression of IL-8 (p<0.0001) and TNF-α (p<0.0001) cytokines in LPS-stimulated HT-29 cells. P. freudenreichii ΔslpB, lacking the SlpB protein, failed to do so. Subsequently, both strains were investigated in vivo in a 5-FU-induced mucositis mice model. Mucositis is a common side effect of cytotoxic chemotherapy with 5-FU, characterized by mucosal injury, inflammation, diarrhea, and weight loss. The WT strain prevented weight loss, reduced inflammation and consequently histopathological scores. Furthermore, it regulated key markers, including Claudin-1 (cld1, p<0.0005) and IL-17a (Il17a, p<0.0001) genes, as well as IL-12 (p<0.0001) and IL-1β (p<0.0429) cytokines levels. Mutant strain displayed opposite regulatory effect on cld1 expression and on IL-12 levels. This work emphasizes the importance of SlpB in P. freudenreichii ability to reduce mucositis inflammation. It opens perspectives for the development of probiotic products to decrease side effects of chemotherapy using GRAS bacteria with immunomodulatory surface protein properties