Modulation of Oligodendrocyte Differentiation by Mechanotransduction

Oligodendrocytes (OLs) are responsible for the myelination of axons in the central nervous system (CNS). The differentiation of OLs encompasses several stages, through which cells undergo dramatic biochemical and morphological changes. OL differentiation is modulated by soluble factors (SFs)—such as growth factors and hormones—, known to be essential for each maturation stage. Besides SFs, insoluble factors such as extracellular matrix (ECM) proteins and other microenvironmental elements also play a pivotal role during OL differentiation. Recently, a growing number of studies were published concerning the effect of biophysical properties of the extracellular milieu on OL differentiation and myelination, showing the importance of ECM stiffness and topography, strain forces and spatial constraints. For instance, it was shown in vitro that OL differentiation and maturation is enhanced by substrates within the reported range of stiffness of the brain and that this effect is potentiated by the presence of merosin, whereas the myelination process is influenced by the diameter of axonal-like fibers. In this mini review article, we will discuss the effect of mechanical cues during OL differentiation and the possible molecular mechanisms involved in such regulation

Estudo da função ventricular por strain obtido por speckle tracking em doentes com cardiomiopatia hipertrófica

Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Área de especialização: Ultrassonografia cardiovascularIntrodução: A Miocardiopatia Hipertrófica (MCH) é uma miocardiopatia caracterizada pela presença de hipertrofia ventricular esquerda (HVE) e disfunção diastólica. Disfunção sistólica subclínica também ocorre apesar da fracção de ejecção se manter frequentemente conservada até uma fase tardia da doença. A avaliação ecocardiográfica da deformação miocárdica permite detectar e compreender melhor a disfunção sistólica subclínica que ocorre na MCH. Objectivo: Avaliação da função ventricular de doentes com MCH através de strain obtido por speckle tracking, com maior ênfase no twist ventricular. Metodologia: Estudo prospectivo incluindo 20 doentes com MCH, 16 doentes com HVE secundária à hipertensão arterial e 17 controlos. Colhidos dados demográficos e clínicos. Efectuado ecocardiograma transtorácico com avaliação da deformação miocárdica por speckle tracking 2D, incluindo o twist ventricular. Resultados: Os valores globais de strain e strain rate longitudinais foram menores na MCH que nos outros grupos de indivíduos. O twist ventricular estava aumentado nos doentes com MCH comparativamente aos controlos. Mais especificamente, o twist estava aumentado nos doentes com MCH obstrutiva, em comparação com os doentes com MCH não obstrutiva e os controlos, nos quais o twist estava preservado (27.9±9.0º vs. 15.3±4.4º vs. 15.9±5.8º; p=0.001; p=0.001). O aumento do twist nos doentes com MCH obstrutiva deveu-se a um aumento da rotação quer basal quer apical do VE. O gradiente de pressão na câmara de saída do VE foi preditor independente do twist nos doentes com MCH. Conclusões: O twist ventricular está aumentado nos doentes com MCH obstrutiva por aumento da rotação quer basal quer apical do VE.ABSTRACT - Introduction: Hypertrophic cardiomyopathy (HCM) is a cardiomyopathy characterized by left ventricular hypertrophy (LVH) and diastolic dysfunction. Subclinical systolic dysfunction also develops in spite of preservation of left ventricular ejection fraction until a late stage of the disease. Echocardiographic evaluation of strain allows the detection and better understanding of the subclinical systolic dysfunction that occurs in HCM. Aim: Evaluation of left ventricular function in patients with HCM using strain obtained by speckle tracking, particularly ventricular twist. Methods: Prospective study including 20 patients with HCM, 16 patients with LVH secondary to arterial hypertension and 17 healthy controls. Demographic and clinical data were obtained. Transthoracic echocardiogram was performed with evaluation of strain by 2D speckle tracking, including ventricular twist. Results: Global longitudinal strain and strain rate were lower in HCM than in the other groups of individuals. LV twist was increased in patients with HCM, when compared to controls. More specifically, LV twist was increased in patients with obstructive HCM, when compared to patients with nonobstructive HCM and controls, in whom LV twist was preserved (27.9±9.0º vs. 15.3±4.4º vs. 15.9±5.8º; p=0.001; p=0.001). The increase of LV twist in patients with obstructive HCM was due to an increase of basal and apical LV rotation. The pressure gradient on the outflow tract was an independent predictor of LV twist in patients with HCM. Conclusion: LV twist is increased in patients with obstructive HCM due to an increase of basal and apical LV rotation.N/

Responsabilidade social nas indústrias culturais e criativas: estudo exploratório em organização de atividades culturais no subsetor das artes performativas

A escolha do tema da responsabilidade social nas indústrias culturais e criativas reflete o interesse de perceber como estas organizações operam e se a responsabilidade social é uma componente presente na estratégia e nas atividades das organizações. No que se refere ao objetivo geral, pretende-se identificar e analisar o nível de desenvolvimento das práticas de responsabilidade social nas organizações pertencentes ao domínio das atividades culturais nucleares, relativamente à sua dimensão interna e externa e nas vertentes económicas, sociais e ambientais. O estudo utilizou a abordagem mista (quantitativa e qualitativa) recolhendo dados através de entrevistas semiestruturadas e inquéritos por questionário, com o propósito de gerar conclusões para a questão de partida e objetivos. Foram identificas várias práticas de responsabilidade social nos teatros que participaram neste estudo. Estas organizações na sua dimensão interna expressaram vincadamente: a importância da gestão dos recursos humanos, o empenho dos seus colaboradores, a importância de uma comunicação eficaz, a conciliação da vida profissional com a vida pessoal através de horários flexíveis e a relevância da formação regular aos seus colaboradores. Na sua dimensão externa foi destacado principalmente: a realização de parcerias e cooperações com outras entidades, a importância da contemplação dos interesses do público e o privilégio dos fornecedores locais no que toca ao fornecimento de material administrativo, técnico e serviços de manutenção. Os resultados expuseram que estes teatros promovem nas suas comunidades desenvolvimentos mais a nível económico, social e cultural do que ambiental, pois nesta vertente apresentam práticas mais reduzidas; Social Responsibility in Cultural and Creative Industries: Exploratory Study in Organization of Cultural Activities in the Performing Arts Subsector Abstract: Social responsibility is the selected topic for this study, it aims to understand and perceive how theatres operate and whether social responsibility is a component present in the strategy and activities of these organizations. The overall objective is to identify and analyse the level of development of social responsibility practices in organizations that act in the field of nuclear cultural activities, taking into account their internal and external dimension and economic, social and environmental aspects. The study will use the mixed approach (quantitative and qualitative), collecting data through semi-structured interviews and questionnaires, with the purpose to generate conclusions for the starting question and objectives. Several social responsibility practices were identified in the theatres that participated in this study. In the internal dimension these organization have clearly expressed: the importance of human resource management, the commitment of their employees, the importance of effective communication, the reconciliation between work and personal life through flexible schedules and the relevance of regular training to its employees. In the external dimension, it was mainly highlighted: the establishment of partnerships and cooperation with other organizations, the importance of their public’s interest and the privilege of local suppliers for maintenance services and administrative/technical material. The results showed that theatres promote more economic, social and cultural developments in the community than environmental development, due to the fact that they only have a few practices directed to the environment

IgG4: related disease presenting with headache and papilloedema

A previously healthy man aged 57years presented with a 4-week duration of predominant decubitus daily holocranial headache after minor head injury. Apart from unintentional weight loss of 8 pounds, there were no associated constitutional or systemic manifestations.The generalandneurologicalexamination was unremarkable. The funduscopy showed bilateral grade 2 papilloedema. Brain magnetic resonance (MRI) findings are shown in figure 1A–E. The brain MRI showed the presence of diffuse dural thickening (figure 1B–E) hypointense on unenhanced T1 imaging (figure 1B–F), with dural enhancement on T1-weighed imaging (figure 1B–F). The opening cerebrospinal fluid (CSF) pressure was 380mm Hg. With the exception of serum-elevated IgG4 immunoglobulin (IgG4=302 mg/dL) and elevated CSF protein level (68 mg/dL), the wide and extensive complementary study including body positron emission tomography scan, laboratory blood/CSF work-up was negative, excluding neoplastic, infectious, autoimmune and collagen vascular disorders. Meningeal biopsy showed fibrous thickening with moderate and predominant B and T cells inflammatory infiltrate. The patient improved with spinal taps evacuation and methylprednisolone treatment. Intracranial hypertrophic pachymeningitis is a severe and rare manifestation in the spectrum of IgG4-related diseases.12Biopsy of meninges is the gold standard for the diagnosis.3 Exclusion of systemic inflammatory disorders and demonstration elevated serum IgG4 can support the diagnosis in patients with typical diffuse dural thickening.13The disease respondsto immunosuppressive drugs such as corticosteroids, methotrexate, azathioprine, mycophenolate or cyclophosphamide.12Mass effect due to dural thickening can cause progressive neurological debilitation,blindness and cerebellarataxia.In the case of symptomatic hydrocephalus, surgical exploration for decompression maybe require

Lung caught in Nilutamide treatment

An 86-year-old male patient was attended with dyspnoea for 2 weeks, with progressive worsening, dry cough and decreased appetite. He had a personal history of prostate cancer diagnosed 2 years before and dyslipidaemia. He denied smoking history, exposure to inhaled toxic substances or family history of chronic lung disease. The patient was receiving treatment with rosuvastatin 10 mg and nilutamide 150 mg which was started 1 month earlier. On physical examination we found the patient with globally decreased breath sounds and crackles at the base of the right hemithorax. Laboratory tests showed no other abnormalities besides C-reactive protein 69 g/L and slight hypoxaemia. The chest X-ray showed bilateral interstitium infiltrates with slight effacement of the costophrenic angles and elevation of the right hemicupula (figure 1A). The thorax CT scan was consistent with interstitial pneumonitis (figure 1B, C). Serological tests for viral atypical organisms, antinuclear antibodies, ACE inhibitors and antineutrophil cytoplasmic antibodies were carried out but with negative results. Pulmonary function tests, alveolar lavage and lung biopsy were not performed. The treatment with nilutamide was discontinued and the patient was started on bronchodilator therapy and prednisolone 40 mg/day with clinical improvement after 3 days of hospitalisation and discharge from hospital at day 14 with normal clinical observation, gasimetric normalisation, negative RCP and improved chest X-ray imaging. Nilutamide is a non-steroidal antiandrogen, which competitively inhibits the binding of androgens to the androgen receptor.1 Interstitial pneumonitis is an extremely rare, although reversible, adverse reaction to non-steroidal antiandrogen treatment, being described in 1–2% of the patients taking the drug.2 The mechanisms by which non-steroidal antiandrogens cause pulmonary disease remain unclear.3 The onset of symptoms was reported 2–8 months after the beginning of the treatment.2 The prognosis of drug-induced pneumonitis is relatively good and can be treated with the withdrawal of the drug with or without the association of steroids

Avaliação de propriedades mecânicas da resina composta Z250 fotoativada com diferentes métodos

This study evaluated some mechanical parameters of Z250 composite resin using different light-curing methods. Ten specimens were prepared for each mechanical test group with different dimensions according to the test. Light-curing was performed by: a). continuous light (800mW/cm²-40s); b). exponential light (0-800mW/cm²-40s); c). intermittent light (2s-600mW/cm²; 2s without light-80s); d). stepped light (10s-150mW/cm²; 30s-650mW/cm²); e). PAC (1320mW/cm²-3s); f). LED (350mW/cm²-40s). After 24 ± 1 h, the specimens were loaded at a crosshead speed of 0.5 mm/min until fracture. The mechanical properties were calculated and analyzed by ANOVA and Tukey test (5%). The results showed that the highest compressive strength values were found for the continuous, exponential, intermittent and stepped light methods, whereas PAC and LED obtained the lowest values. LED, stepped light, PAC, exponential and continuous light presented the highest values for diametral tensile strength. The intermittent light showed the lowest value, which was significantly lower than the value obtained for LED only. Flexural strength results were not significantly different between all light-curing methods. Finally, the highest modulus of elasticity values were obtained for LED, exponential, continuous and intermittent light, whereas PAC and stepped light showed the lowest values. The mechanical properties were affected by light-curing methods employed.Este estudo avaliou algumas propriedades mecânicas da resina composta Z250 usando diferentes métodos de fotoativação. Dez amostras foram preparadas para cada grupo, com diferentes dimensões de acordo com o ensaio. Os métodos de fotoativação foram: a) luz contínua (800mW/cm²-40s); b) luz exponencial (0-800mW/cm²-40s); c) luz intermitente (2s-600mW/cm²; 2s sem luz-80s); d) dupla intensidade (10s-150mW/cm²; 30s-650mW/cm²); e) PAC (1320mW/cm²-3s); f) LED (350mW/cm²-40s). Após 24 ± 1 h, as amostras foram carregadas até fraturar (v=0,5 mm/min.). As propriedades mecânicas foram calculadas e os dados analisados estatisticamente (ANOVA e teste de Tukey 5%). Os resultados mostraram que, para resistência à compressão, os maiores valores foram encontrados com os métodos luz contínua, intermitente, exponencial e dupla intensidade, enquanto que PAC e LED obtiveram os menores valores. Os métodos LED, PAC, luz contínua, exponencial e dupla intensidade, mostraram os maiores valores para resistência à tração diametral, enquanto luz intermitente mostrou os menores valores, que diferiram apenas do LED. Para a resistência flexural, não houve diferença entre os métodos. Já, para o módulo de elasticidade, os maiores valores foram obtidos com LED, luz exponencial, contínua e intermitente, enquanto que PAC e dupla intensidade mostraram os menores valores. As propriedades mecânicas podem ser afetadas pelo método de fotativação utilizado

Pilocytic astrocytoma

Pilocytic astrocytoma (PA) is a benign tumour of childhood, often located in deep midline structures such as the brainstem and the cerebellum.1 Gross surgical resection is curative in the majority of patients.2 We report a case of recurrent PA diagnosed after an acute confusional state and rightsided spastic hemiparesis in a previously healthy 38-year-old woman. Her initial brain CT showed a left temporal mass causing obstructive hydrocephalus (figure 1A–C). Acute surgical extraction was performed (figure 1D) and the biopsy confirmed the diagnosis of PA grade I (WHO). The patient remained clinically asymptomatic for 1 year, when a progressive headache emerged. At this time, the neurological examination disclosed the presence of dysarthria and right-sided hemiparesis with facial involvement. Brain MRI showed the presence of recurrent PA (figure 1E, F). The patient again underwent surgery due to the mass effect and brainstem compression caused by the tumour, and the diagnosis of PA was reconfirmed histologically. The patient fully recovered after the intervention. PA occurs commonly in the first 2 decades of life.1 Information on the characteristics of PA in adulthood is scarce due to its rarity. Some studies indicate the adult prognosis to be similar to that in children, while others indicate that PA may show aggressive behaviour with tumour recurrence and death.2 Anaplastic features are associated with worse prognosis, but little is known about the value of genetic characterisation in adulthood PA.3 In conclusion, this case offers a unique description of adult onset PA in an atypical location outside the midline structures, and also provides an example of early recurrence

Aprender juntos: projeto de apoio curricular entre pares

Several schools recognize the advantages of cooperative learning and use it as a strategy to promote school success. Our study focuses on a learning project among students belonging to the same class, presenting its main characteristics, identifying students’ perceptions regarding their participation in the project and its functioning and impact on academic results and on the learning environment. The analysis of the obtained data highlights the sociability, the relational horizontality and the trust between the pairs, and it notes the predominance of the content-based learning and of methodologies that favor memorization and training oriented towards the final evaluation.Várias escolas reconhecem as vantagens da aprendizagem cooperativa e usam-na como estratégia de promoção do sucesso escolar. O nosso estudo incide num projeto de aprendizagem entre alunos da mesma turma, apresenta as suas principais caraterísticas, identifica as perceções dos alunos relativamente à sua participação no projeto e ao funcionamento e impacto deste nos resultados académicos e no ambiente de aprendizagem. A análise dos dados obtidos destaca a sociabilidade, a horizontalidade relacional e a confiança entre os pares e constata a predominância do carácter conteudista da aprendizagem e de metodologias que favorecem a memorização e a exercitação com vista à prestação de contas nas provas de avaliação sumativa

Preliminary results with the use of ossifying collagen membranes in the horizontal alveolar defects treatment after dental implant placement

Introdução: A reabilitação com implantes dentários é um tratamento que está associado a uma alta taxa de sucesso na reabilitação de pacientes parcial ou totalmente edêntulos. Doenças sistémicas, periodontais, trauma, tumores e extração dentária podem levar a uma perda de volume ósseo, que limitam o correto posicionamento dos implantes dentários. Objetivo: O objetivo deste estudo é avaliar os resultados clínicos e radiográficos na colocação de implantes dentários em cristas edêntulas tratadas com uma membrana de colagénio com propriedades ossificantes para o aumento horizontal do volume alveolar perdido. Materiais e Métodos: Este estudo avaliou as alterações volumétricas a nível vestibular através da sobreposição de impressões digitais, estudando as variáveis Buccal Volume variation (BVv) e Mean Buccal Variation (MBV). Em termos de alterações ósseas marginais foram realizadas radiografias periapicais em dois tempos: baseline (T0) e 6 meses (T1) após colocação dos implantes em simultâneo com colocação da membrana de colagénio OSSIX Volumax. Estas alterações foram caracterizadas em duas variáveis mesial Marginal Bone Changes (mMBC) e distal Marginal Bone Changes (dMBC). Resultados: O uso da membrana OSSIX Volumax em termos de variações volumétricas apresentou um aumento médio de 32,06% (BVv) e de 0,97mm (MBV). Em termos de alterações ósseas marginais os resultados foram uma perda óssea marginal média de 0,75mm entre T0 e T1 para o (mMBC) e de 0,80mm para o (dMBC). Conclusão: O uso da membrana OSSIX Volumax está associada a um ganho de volume vestibular nas zonas alveolares reabilitadas, contudo os resultados a nível de alterações ósseas marginais não mostraram uma vantagem concreta na utilização deste tipo de membrana comparativamente aos valores apresentados pela literatura.Introduction: Rehabilitation with dental implants is a treatment that has high success rate in the rehabilitation of partially or totally edentulous patients. Systemic diseases, periodontal diseases, trauma, tumors, and tooth extraction can lead to loss of bone volume and these bone defects limit the bone volume required for correct implant positioning. Objective: The aim of this study is to evaluate the clinical and radiographic results of dental implant placement in edentulous ridges treated with a collagen membrane with ossifying properties for horizontal augmentation of the lost ridge volume. Materials and Methods: This study evaluated the volumetric changes at the buccal level by superimposing digital files. The variables obtained were Buccal Volume variation (BVv) and Mean Buccal Variation (MBV). In terms of marginal bone changes, periapical radiographs were taken at two times: baseline (T0) and 6 months (T1) after implant insertion simultaneously with the placement of a OSSIX Volumax collagen membrane. These changes were characterized in two variables, mesial Marginal Bone Changes (mMBC) and distal Marginal Bone Changes (dMBC). Statistical significance was set at P 0,05. Results: The use of these cross-linked membrane showed an average increase of 32.06% in terms of volumetric changes (BVv) and 0.97mm at the linear measurements of the alveolar surface (MBV). In terms of marginal bone changes the results showed a mean bone reduction of 0.75mm between T0 and T1 for the mesial sites (mMBC) and 0.80mm for the distal sites (dMBC). Conclusion: The use of OSSIX Volumax membrane is associated with a buccal volume gain, however in terms of marginal bone maintenance the results were not statistically significant and no improvement was noticed comparing with the literature outcomes