Small GTPase RhoA and its effector rho kinase mediate oxygen glucose deprivation-evoked in vitro cerebral barrier dysfunction

BACKGROUND AND PURPOSE: Enhanced vascular permeability attributable to disruption of blood-brain barrier results in the development of cerebral edema after stroke. Using an in vitro model of the brain barrier composed of human brain microvascular endothelial cells and human astrocytes, this study explored whether small GTPase RhoA and its effector protein Rho kinase were involved in permeability changes mediated by oxygen-glucose deprivation (OGD), key pathological phenomena during ischemic stroke.

METHODS: OGD increased RhoA and Rho kinase protein expressions in human brain microvascular endothelial cells and human astrocytes while increasing or unaffecting that of endothelial nitric oxide synthase in respective cells. Reperfusion attenuated the expression and activity of RhoA and Rho kinase in both cell types compared to their counterparts exposed to equal periods of OGD alone while selectively increasing human brain microvascular endothelial cells endothelial nitric oxide synthase protein levels. OGD compromised the barrier integrity as confirmed by decreases in transendothelial electric resistance and concomitant increases in flux of permeability markers sodium fluorescein and Evan's blue albumin across cocultures. Transfection of cells with constitutively active RhoA also increased flux and reduced transendothelial electric resistance, whereas inactivation of RhoA by anti-RhoA Ig electroporation exerted opposite effects. In vitro cerebral barrier dysfunction was accompanied by myosin light chain overphosphorylation and stress fiber formation. Reperfusion and treatments with a Rho kinase inhibitor Y-27632 significantly attenuated barrier breakdown without profoundly altering actin structure.

CONCLUSIONS: Increased RhoA/Rho kinase/myosin light chain pathway activity coupled with changes in actin cytoskeleton account for OGD-induced endothelial barrier breakdown.

Multifocal remitting-relapsing cerebral demyelination twenty years following allogeneic bone marrow transplantation

We report a case study of a female who received an allogeneic bone marrow transplantation (BMT) from a sex-mismatched related donor and who, after a twenty-year interval, developed an acute fulminant biopsy-proven demyelinating disorder of cerebral white matter which followed a remitting-relapsing chronic course. In situ hybridization studies using Y-chromosome-specific markers revealed Y-chromosome-positive mononuclear cells in biopsy samples of white matter. Magnetic resonance imaging (MRI) studies of the asymptomatic healthy male donor showed multiple white matter lesions. These observations suggest that donor lymphocytes were sensitized to central nervous system (CNS) antigens prior to or at the time of transplantation but remained dormant for 20 years before becoming activated to cause widespread demyelination.

The role of the cerebral cortex in postural responses to externally induced perturbations

The ease with which we avoid falling down belies a highly sophisticated and distributed neural network for controlling reactions to maintain upright balance. Although historically these reactions were considered within the sub cortical domain, mounting evidence reveals a distributed network for postural control including a potentially important role for the cerebral cortex. Support for this cortical role comes from direct measurement associated with moments of induced instability as well as indirect links between cognitive task performance and balance recovery. The cerebral cortex appears to be directly involved in the control of rapid balance reactions but also setting the central nervous system in advance to optimize balance recovery reactions even when a future threat to stability is unexpected. In this review the growing body of evidence that now firmly supports a cortical role in the postural responses to externally induced perturbations is presented. Moreover, an updated framework is advanced to help understand how cortical contributions may influence our resistance to falls and on what timescale. The implications for future studies into the neural control of balance are discussed.

A systematic review of evidence-based assessment practices by allied health practitioners for children with cerebral palsy

AIM: The routine use of psychometrically robust assessment tools is integral to best practice. This systematic review aims to determine the extent to which evidence-based assessment tools were used by allied health practitioners for children with cerebral palsy (CP).

METHOD: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis protocols 2015 was employed. A search strategy applied the free text terms: 'allied health practitioner', 'assessment', and 'cerebral palsy', and related subject headings to seven databases. Included articles reported assessment practices of occupational therapists, physiotherapists, or speech pathologists working with children with CP aged 0 to 18 years, published from the year 2000.

RESULTS: Fourteen articles met the inclusion criteria. Eighty-eight assessment tools were reported, of which 23 were in high use. Of these, three tools focused on gross motor function and had acceptable validity for use with children with CP: Gross Motor Function Measure, Gross Motor Function Classification System, and goniometry. Validated tools to assess other activity components, participation, quality of life, and pain were used infrequently or not at all.

INTERPRETATION: Allied health practitioners used only a few of the available evidence-based assessment tools. Assessment findings in many areas considered important by children and families were rarely documented using validated assessment tools.

Improving allied health professionals' research implementation behaviours for children with cerebral palsy: protocol for a before-after study

BACKGROUND: Cerebral palsy is a permanent disorder of posture and movement caused by disturbances in the developing brain. It affects approximately 1 in every 500 children in developed countries and is the most common form of childhood physical disability. People with cerebral palsy may also have problems with speech, vision and hearing, intellectual difficulties and epilepsy. Health and therapy services are frequently required throughout life, and this care should be effective and evidence informed; however, accessing and adopting new research findings into day-to-day clinical practice is often delayed.

METHODS/DESIGN: This 3-year study employs a before and after design to evaluate if a multi-strategy intervention can improve research implementation among allied health professionals (AHPs) who work with children and young people with cerebral palsy and to establish if children's health outcomes can be improved by routine clinical assessment. The intervention comprises (1) knowledge brokering with AHPs, (2) access to an online research evidence library, (3) provision of negotiated evidence-based training and education, and (4) routine use of evidence-based measures with children and young people aged 3-18 years with cerebral palsy. The study is being implemented in four organisations, with a fifth organisation acting as a comparison site, across four Australian states. Effectiveness will be assessed using questionnaires completed by AHPs at baseline, 6, 12 and 24 months, and by monitoring the extent of use of evidence-based measures. Children's health outcomes will be evaluated by longitudinal analyses.

DISCUSSION: Government, policy makers and service providers all seek evidence-based information to support decision-making about how to distribute scarce resources, and families are seeking information to support intervention choices. This study will provide knowledge about what constitutes an efficient, evidence-informed service and which allied health interventions are implemented for children with cerebral palsy.

TRIAL REGISTRATION: Trial is not a controlled healthcare intervention and is not registered.

Classifying cerebral palsy: are we nearly there?

BACKGROUND: Cerebral palsy (CP) is the most common cause of physical disability in childhood in developed countries and encompasses a wide range of clinical phenotypes. Classification of CP according to movement disorder or topographical distribution is widely used. However, these classifications are not reliable nor do they accurately predict musculoskeletal pathology. More recently, the Gross Motor Function Classification System (GMFCS) has been introduced and its validity, reliability, and clinical utility have been confirmed. In 2005 it was suggested that children should be described and classified according to the GMFCS in all outcome studies involving children with CP, in the Journal of Pediatric Orthopaedics (JPO). This study aimed to describe utilization of the GMFCS in 3 journals: Journal of Bone and Joint Surgery (JBJS Am), JPO, and Developmental Medicine and Child Neurology (DMCN), over a 7-year period (2005 to 2011), and any relationship to the journal's impact factor. A secondary aim was to establish if differences in methodological quality existed between those studies utilizing GMFCS and those that did not.

METHODS: A targeted literature search of the 3 selected journals using the term "cerebral palsy" was conducted using the Medline database. Utilization of the GMFCS was assessed using report of these data in the methods or results section of the retrieved papers. The Methodological Index for Non-Randomized Studies (MINORS) was employed to evaluate the quality of papers published in JPO.

RESULTS: One hundred and fifty-four studies met the inclusion criteria and in 85 (68%) the GMFCS was used. Of these, 112 were published in JPO, of which 51 (46%) utilized the GMFCS, compared with 72% for JBJS Am, and 88% for DMCN. In the JPO, utilization of the GMFCS improved from 13% to 80%, over the 7-year study period.

CONCLUSIONS: Utilization of the GMFCS has increased rapidly over the past 7 years in the JPO but there is room for further improvement.

LEVEL OF EVIDENCE: Not applicable.

Efficacy and Acceptability of Reduced Intensity Constraint-Induced Movement Therapy for Children Aged 9–11 years with Hemiplegic Cerebral Palsy: A Pilot Study

OBJECTIVE: Assess efficacy and acceptability of reduced intensity constraint-induced movement therapy (CIMT) in children with cerebral palsy (CP).

METHODS: Single-subject research design and semi-structured interviews. Children (9-11y) with hemiplegia underwent five baseline assessments followed by two weeks CIMT. Six further assessments were performed during treatment and follow-up phases. The primary outcome was the Melbourne Assessment of Unilateral Upper Limb Function (MUUL). Quantitative data were analysed using standard single-subject methods and qualitative data by thematic analysis.

RESULTS: Four of the seven participants demonstrated statistically significant improvements in MUUL (3-11%, p < .05). Two participants achieved significant improvements in active range of motion but strength and tone remained largely unchanged. Qualitative interviews highlighted limitations of the restraint, importance of family involvement, and coordination of treatment with education.

CONCLUSIONS: Reduced intensity CIMT may be effective for some children in this population; however it is not suitable for all children with hemiplegia.

Quebra de barreiras de comunicação para portadores de paralisia cerebral

Tese dout., Engenharia Electrónica e Computação, Universidade do Algarve, 2009

Atitudes dos enfermeiros perante morte cerebral e transplantação de órgãos

Dissertação de mest., Psicologia (Psicologia da Saúde), Faculdade de Ciências Humanas e Sociais, Univ. do Algarve, 2010

Neural network classification of cerebral embolic signals

The presence of circulating cerebral emboli represents an increased risk of stroke. The detection of such emboli is possible with the use of a transcranial Doppler ultrasound (TCD) system.

Contribuição da ecografia cerebral transfontanelar para a avaliação do crescimento cerebral do recém-nascido pré-termo

Tese de doutoramento, Medicina (Pediatria), Universidade de Lisboa, Faculdade de Medicina, 2013

Papel do peptídeo natriurético cerebral de tipo B na classificação do tipo de AVC isquémico

Tese de doutoramento, Medicina Clinica (Neurologia), Universidade de Lisboa, Faculdade de Medicina, 2014

Avaliação da participação em crianças e jovens com paralisia cerebral, na ilha de S. Miguel, Açores

Introdução: Nas crianças/jovens com Paralisia Cerebral (PC), as limitações motoras repercutem-se em limitações funcionais e, consequentemente, na diminuição da participação em ocupações. Sendo as manifestações da PC diferentes de indivíduo para indivíduo, estas vão refletir, dependendo da gravidade, quadro motor, ambiente físico e social, diferentes níveis de participação. Objetivo: O objetivo deste estudo foi avaliar a relação entre a idade, sexo e grau de comprometimento motor e a participação em crianças/jovens com diagnóstico de paralisia cerebral com idades compreendidas entre os 5 e os 18 anos na ilha de São Miguel. Amostra e Métodos: 25 crianças de ambos os sexos (5- 18 anos), sinalizadas em instituições especializadas de reabilitação e em Centros de Atividades Ocupações (CAO’s) na Ilha de São Miguel – Açores. Foram aplicados dois instrumentos de avaliação às crianças/jovens, Gross Motor Function Measure e Quality of Upper Extremity Skills Test, e foram entregues aos pais os outros dois instrumentos para autopreenchimento, Assessment of Life Habits e Child Health Questionnaire – Parent- Form 50. Na análise estatística, recorreu-se a testes como o Kolmogorov-Smirnov, Tstudent ou Mann-Whitney, teste de Fisher, teste de Spearman e ANOVA. Resultados: Não foram encontradas relações significativas entre a idade e o sexo e o nível de participação das crianças/jovens com PC. Contrariamente, ao avaliarmos a relação entre o grau de participação e o grau de afetação verificamos que esta é significativa (p=0,004). Conclusão: Na nossa amostra não se encontrou uma influência da idade e do sexo com a frequência da participação (relações não foram significativas). Contudo, pode-se concluir que as crianças/jovens que apresentam menos limitações motoras, como as que se enquadram no nível I/II da Gross Motor Function Classification System, apresentam níveis de participação maiores do que as que apresentam níveis de afetação motora maiores (Nível V)

Influência do alinhamento do pé nos Ajustes Posturais Antecipatórios em crianças com Paralisia Cerebral

Introdução: A dificuldade na organização dos ajustes posturais antecipatórios (APAs) é frequentemente associada ao défice de controlo postural (CP) em crianças/jovens com um quadro motor de hemiplegia espástica, resultante de paralisia cerebral. As alterações biomecânicas da tibiotársica e do pé são características comummente observadas nestas crianças/jovens e influenciam o CP na sua globalidade. Objectivo(s): descrever o comportamento dos APAs associados ao início da marcha, face à modificação do alinhamento do pé em crianças/jovens com hemiplegia espástica, após 12 semanas de intervenção, segundo o Conceito Bobath-TND e aplicação de uma Ligadura Funcional (LF). Métodos: Foram avaliadas quatro crianças/jovens num momento inicial (M0) e após 12 semanas de intervenção e de aplicação de uma LF (M1). Recorrendo à eletromiografia de superfície, registaram-se os timings de activação dos músculos tibial anterior, solear, recto abdominal e erector da espinha (bilateralmente). O início do movimento foi calculado a partir da alteração do sinal obtido através da plataforma de pressões. Recorreu-se à aplicação da TMFM-88 para avaliar a função motora global e à aplicação da CIF-CJ para classificar a funcionalidade mediante as actividades e a participação. Procedeu-se ao registo de imagem para facilitar a observação/avaliação das componentes de movimento das crianças/jovens em estudo. Resultados: Após o período de intervenção, verificou-se uma modificação nos valores dos timings de ativação dos músculos em análise, que se aproximaram da janela temporal definida como APAs, bem como na distribuição de carga na base de suporte, nos scores da TMFM-88 e nos qualificadores das “Actividades e Participação”, sugestivos de uma melhor organização dos mecanismos de controlo postural. Conclusão: As crianças/jovens em estudo evidenciaram, após uma intervenção de fisioterapia baseada no Conceito Bobath- TND e aplicação de uma LF, uma evolução favorável tanto ao nível do CP da tibiotársica e do pé, apresentando timings de ativação muscular temporalmente mais ajustados à tarefa, com repercussões positivas nas actividades e participação.