Identificação de padrões de resposta das células de Müller na retinopatia degenerativa em murganho

Dissertação de Mestrado Integrado em Medicina VeterináriaEste trabalho teve como objectivo caracterizar as alterações retinianas observadas num modelo murino de retinopatia com degenerescência dos fotorreceptores, de forma a poder estabelecer padrões de resposta nas diferentes fases de evolução do processo degenerativo-inflamatório. Material e Métodos: Neste estudo foram utilizadas retinas de murganhos ICR adultos. Foram constituídos grupos de 4 animais. Os murganhos foram injetados intraperitonealmente com uma dose de 100 mg/Kg de iodato de sódio e eutanasiados 24, 48 e 72 horas após a injeção. Um animal não injetado serviu como controlo em cada grupo. As retinas foram analisadas por meio de técnicas de histologia de rotina, imunohistoquímica, Western Blotting e q-RT-PCR. Resultados: A gliose reativa ocorre em resposta a estímulos agressivos. Nos processos de retinopatia, a ativação das células de Müller induz a sobre-expressão da proteína glial fibrilhar acídica (GFAP). As técnicas de imunohistoquímica, Western Blotting e q-RT-PCR utilizadas permitiram caracterizar, no modelo em estudo, níveis de expressão de GFAP específicos de cada uma das fases pré-definidas da resposta inflamatória. Conclusões: No modelo estudado de retinopatia induzida pela injeção de iodato de sódio, as diferenças de expressão de GFAP permitiram estabelecer padrões de resposta passíveis de ser utilizados na identificação da fase do processo inflamatório em curso.ABSTRACT - Identification of Müller cell response patterns during degenerative retinopathy in mice - Introduction The purpose of this study was to characterize the structural retinal alterations in a murine model of retinopathy with photoreceptor degeneration, in order to establish response patterns in the different stages of the degenerative-inflammatory process. Material and Methods: In this work, retinas from adult ICR mice were used. Groups of 4 animals were intraperitoneally injected with 100 mg/Kg of sodium iodate, and euthanized 24, 48 and 72 hours after injection. A non-injected animal was used as a control in each group. The retinas were analyzed by means of conventional histological techniques, immunohistochemistry, Western Blotting and q-RT-PCR. Results: Reactive gliosis occurs in response to aggressive stimuli. During retinopathy, Müller cell activation induces glial fibrillary acidic protein (GFAP) over-expression. Immunohistochemistry, Western Blotting and q-RT-PCR techniques allowed us to characterize the levels of GFAP expression of each predefined inflammatory stage. Conclusions: In the analyzed murine sodium iodate injection-induced model of retinopathy, differences in GFAP expression allowed us to establish expression patterns of this protein which may be used to identify the phase of the inflammatory response in progress

Vascular Interstitial Cells in Retinal Arteriolar Annuli Are Altered During Hypertension

Hypertension; Interstitial cells; Arteriolar annuliHipertensió; Cèl·lules intersticials; Arteriolar annuliHipertensión; Células intersticiales; Arteriolar annuliPurpose: It has been suggested that arteriolar annuli localized in retinal arterioles regulate retinal blood flow acting as sphincters. Here, the morphology and protein expression profile of arteriolar annuli have been analyzed under physiologic conditions in the retina of wild-type, β-actin-Egfp, and Nestin-gfp transgenic mice. Additionally, to study the effect of hypertension, the KAP transgenic mouse has been used. Methods: Cellular architecture has been studied using digested whole mount retinas and transmission electron microscopy. The profile of protein expression has been analyzed on paraffin sections and whole mount retinas by immunofluorescence and histochemistry. Results: The ultrastructural analysis of arteriolar annuli showed a different cell population found between endothelial and muscle cells that matched most of the morphologic criteria established to define interstitial Cajal cells. The profile of protein expression of these vascular interstitial cells (VICs) was similar to that of interstitial Cajal cells and different from the endothelial and smooth muscle cells, because they expressed β-actin, nestin, and CD44, but they did not express CD31 and α-SMA or scarcely express F-actin. Furthermore, VICs share with pericytes the expression of NG2 and platelet-derived growth factor receptor beta (PDGFR-β). The high expression of Ano1 and high activity of nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase observed in VICs was diminished during hypertensive retinopathy suggesting that these cells might play a role on the motility of arteriolar annuli and that this function is altered during hypertension. Conclusions: A novel type of VICs has been described in the arteriolar annuli of mouse retina. Remarkably, these cells undergo important molecular modifications during hypertensive retinopathy and might thus be a therapeutic target against this disease

NATIONAL SURVEY OF CAT TUMORS IN 2019: A RETROSPECTIVE STUDY

Cancer is one of the most common causes of death in cats. Besides its clinical importance, small animals with spontaneous tumours are attractive comparative models for Oncologic studies. Cancer registries are important to provide increased information, which can be used in epidemiological studies and prophylactic and treatment strategies. The aim of this study was to characterize the current distribution of feline tumors in Portugal. A total of 752 feline histopathology records obtained in 2019 were included and data regarding breed, sex, age, type of tumor and malignancy were recorded. Statistical analysis was conducted to detect associations between variables using an alpha value of 0.05. One or more tumours were present in 417 animals, and a total of 475 tumors were reported (63.2%, n=475/752), of which 74.7% were malignant (n=355/475). Mammary tumors were the most common (43.7%, n= 207/475), including carcinoma (n=158) and adenoma (n=36). Mammary tumors were followed in frequency by tumors of the soft/mesenchymal tissue (19.6%, n=93/475) and epithelial skin (18.4%, n=87/475), which differs from published data in other countries. Similarly, to mammary tumors, soft/mesenchymal (64,5%, n=60/93) and epithelial skin tumors (18.4%, n=87/475) were also highly malignant. In the soft/mesenchymal tumors, lipoma (18.3%, n=17/93) and fibrosarcoma (17.2%, n=16/93) were the most common types; nevertheless, other tumors were also frequent, such as mastocitoma, lymphoma and hemangiosarcoma. Finally, in the epithelial skin tumours, the most prevalent was the squamous cell carcinoma (48.3%, n=42/87). Tumor malignancy was associated with older ages (mean 10.6 ± 3.4 years, p<0,001), whereas no association was obtained between breed and tumor type or tumor malignancy. Sex was associated with tumor type, as females presented a higher risk of developing mammary tumors. To our best knowledge this is the first retrospective study of this type conducted in Portugal. Given the high frequency of malignant tumors, early diagnosis and screening for nodules is of paramount importance, both at home and at veterinary consultations

Vascular Interstitial Cells in Retinal Arteriolar Annuli Are Altered During Hypertension.

Purpose: It has been suggested that arteriolar annuli localized in retinal arterioles regulate retinal blood flow acting as sphincters. Here, the morphology and protein expression profile of arteriolar annuli have been analyzed under physiologic conditions in the retina of wild-type, β-actin-Egfp, and Nestin-gfp transgenic mice. Additionally, to study the effect of hypertension, the KAP transgenic mouse has been used. Methods: Cellular architecture has been studied using digested whole mount retinas and transmission electron microscopy. The profile of protein expression has been analyzed on paraffin sections and whole mount retinas by immunofluorescence and histochemistry. Results: The ultrastructural analysis of arteriolar annuli showed a different cell population found between endothelial and muscle cells that matched most of the morphologic criteria established to define interstitial Cajal cells. The profile of protein expression of these vascular interstitial cells (VICs) was similar to that of interstitial Cajal cells and different from the endothelial and smooth muscle cells, because they expressed β-actin, nestin, and CD44, but they did not express CD31 and α-SMA or scarcely express F-actin. Furthermore, VICs share with pericytes the expression of NG2 and platelet-derived growth factor receptor beta (PDGFR-β). The high expression of Ano1 and high activity of nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase observed in VICs was diminished during hypertensive retinopathy suggesting that these cells might play a role on the motility of arteriolar annuli and that this function is altered during hypertension. Conclusions: A novel type of VICs has been described in the arteriolar annuli of mouse retina. Remarkably, these cells undergo important molecular modifications during hypertensive retinopathy and might thus be a therapeutic target against this disease

Vascular interstitial cells in retinal arteriolar annuli are altered during hypertension

Research Areas: OphthalmologyABSTRACT - Purpose: It has been suggested that arteriolar annuli localized in retinal arterioles regulate retinal blood flow acting as sphincters. Here, the morphology and protein expression profile of arteriolar annuli have been analyzed under physiologic conditions in the retina of wild-type, β-actin–Egfp, and Nestin–gfp transgenic mice. Additionally, to study the effect of hypertension, the KAP transgenic mouse has been used.info:eu-repo/semantics/publishedVersio

L-Ferritin Binding to Scara5 : A New Iron Traffic Pathway Potentially Implicated in Retinopathy

Iron is essential in the retina because the heme-containing enzyme guanylate cyclase modulates phototransduction in rods and cones. Transferrin endocytosis is the classical pathway for obtaining iron from the blood circulation in the retina. However, the iron storage protein ferritin has been also recently proposed as an iron carrier. In this study, the presence of Scara5 and its binding to L-ferritin was investigated in the retina. Our results showed that Scara5, the specific receptor for L-ferritin, was expressed in mouse and human retinas in many cell types, including endothelial cells. Furthermore, we showed that intravenously injected ferritin crossed the blood retinal barrier through L-ferritin binding to Scara5 in endothelial cells. Thus, suggesting the existence of a new pathway for iron delivery and trafficking in the retina. In a murine model of photoreceptor degeneration, Scara5 was downregulated, pointing out this receptor as a potential player implicated in retinopathy and also as a possible therapeutic target

The GO-DACT protocol : a multicentre, randomized, double-blind, parallel-group study to compare the efficacy of golimumab in combination with methotrexate (MTX) versus MTX monotherapy

© 2001-2020 Sociedade Portuguesa de ReumatologiaThe GO-DACT is an investigator-initiated, national, multicentric randomized placebo-controlled double-blinded trial, that assesses dactylitis as primary endpoint. Psoriatic arthritis patients naïve to methotrexate and biologic disease modifying anti-rheumatic drugs, with at least one active dactylitis, were assigned to golimumab in combination with methotrexate or placebo in combination with methotrexate, for 24 weeks. Both clinical (dactylitis severity score and the Leeds dactylitis index) and imaging (high resolution magnetic resonance imaging), among others, were assessed as outcomes. The main objective of GO-DACT is to provide evidence to improve the treatment algorithm and care of psoriatic arthritis patients with active dactylitis. In this manuscript we describe the GO-DACT protocol and general concepts of the methodology of this trial.info:eu-repo/semantics/publishedVersio

GO-DACT : a phase 3b randomised, double-blind, placebo-controlled trial of GOlimumab plus methotrexate (MTX) versus placebo plus MTX in improving DACTylitis in MTX-naive patients with psoriatic arthritis

© author(s) (or their employer(s)) 2020. Re-use permitted under CC BY- nC. no commercial re-use. see rights and permissions. Published by BMJ. This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-­NC 4.0) license.Objectives: To assess the efficacy of golimumab in combination with methotrexate (MTX) versus MTX monotherapy in psoriatic arthritis (PsA) dactylitis. Methods: Multicentre, investigator-initiated, randomised, double-blind, placebo-controlled, parallel-design phase 3b trial in 11 Portuguese rheumatology centres. Patients with PsA along with active dactylitis and naive to MTX and biologic disease-modifying antirheumatic drugs (bDMARDs) were randomly assigned to golimumab or placebo, both in combination with MTX. The primary endpoint was Dactylitis Severity Score (DSS) change from baseline to week 24. Key secondary endpoints included DSS and Leeds Dactylitis Index (LDI) response, and changes from baseline in the LDI and MRI dactylitis score. Analysis was by intention-to-treat for the primary endpoint. Results: Twenty-one patients received golimumab plus MTX and 23 MTX monotherapy for 24 weeks. One patient from each arm discontinued. Patient inclusion was halted at 50% planned recruitment due to a favourable interim analysis. Median baseline DSS was 6 in both arms. By week 24, patients treated with golimumab plus MTX exhibited significantly greater improvements in DSS relative to MTX monotherapy (median change of 5 vs 2 points, respectively; p=0.026). In the golimumab plus MTX arm, significantly higher proportions of patients achieved at least 50% or 70% improvement in DSS and 20%, 50% or 70% improvement in LDI in comparison to MTX monotherapy. Conclusions: The combination of golimumab and MTX as first-line bDMARD therapy is superior to MTX monotherapy for the treatment of PsA dactylitis.info:eu-repo/semantics/publishedVersio

Como comunicam as células? Em busca de Notch e dos seus parceiros

No crescimento, desenvolvimento e homeostasia dos seres multicelulares as suas células devem comunicar entre si eficientemente. Entre as várias estratégias possíveis, a via de comunicação intercelular Notch é uma das mais bem conservadas entre os metazoários. Notch está frequentemente implicada na regulação da diferenciação/proliferação celulares, sendo as suas ações específicas da célula em causa, do tecido onde se encontra e da fase de desenvolvimento do animal. Assim, a sua presença e atividade pode variar de acordo com os vários processos fisiológicos e patológicos de uma dada espécie. A regulação do desenvolvimento embrionário não é totalmente conhecida. A primeira autora desenvolveu estudos sobre a implicação da Notch na primeira diferenciação celular (de mórula para blastocisto), caracterizando a presença das proteínas que compõem Notch e a transcrição dos mRNA que lhes dão origem foi avaliada em embriões individuais –conjuntos de 70 células (no máximo) com forma esférica. Verificou-se que Notch é importante nesta fase, controlando o ritmo do desenvolvimento através do controlo de vários marcadores de pluripotência/diferenciação. Uma das características de processos neoplásicos é a incapacidade das células regularem o seu crescimento/diferenciação e Notch tem sido implicada nesta desregulação em humanos, incluindo em carcinomas das células escamosas. Num estudo da FMV-ULHT, constatou-se que esta é uma neoplasia comum em gatos em Portugal, sabendo-se também que diminui a sua qualidade de vida, implicando amiúde a eutanásia. Neste sentido iniciou-se um projeto de investigação exploratório para averiguar a presença da Notch nestes tumores e a sua relação com critérios de malignidade. Esta será a base para futuramente desenhar terapêuticas inovadoras dirigidas e eficazes, potencialmente transversais a Medicina Veterinária e Humana.   Palavras-chave: Comunicação intercelular, Desenvolvimento, Neoplasia, Expressão génica, Notch.   Financiamento: Projeto exploratório FMV-ULHT 2021- SkinNotch

Oral Health in Nursing Home Residents—Preliminary Results of an Exploratory Cross-Sectional Pilot Study

This study was conducted to assess the oral status of nursing home residents diagnosed with dementia in the Lisbon region, Portugal. In this cross-sectional observational pilot study, the oral and dental status were evaluated by determining the Decayed-Missing-Filled-Tooth (DMFT) index, frequency of oral hygiene, presence of erosion lesions or mucosal lesions, presence of dentures, and Shorted Xerostomia Inventory (SXI-5). This study aims to be a starting point for a broad analysis of this population and a further determination of potential associations between oral status and anamnestic factors as well as dementia data