RESUMO
BACKGROUND: Up to 30% of patients with Guillain-Barré syndrome require mechanical ventilation and 5% die due to acute complications of mechanical ventilation. There is a considerable group of patients that will need prolonged mechanical ventilation (considered as >14 days) and should be considered for early tracheostomy. The objective of this study is to identify risk factors for prolonged mechanical ventilation. METHODS: We prospectively analyzed patients with Guillain-Barré diagnosis with versus without prolonged mechanical ventilation. We considered clinical and electrophysiological characteristics and analyzed factors associated with prolonged mechanical ventilation. RESULTS: Three hundred and three patients were included; 29% required mechanical ventilation. When comparing the groups, patients with prolonged invasive mechanical ventilation (IMV) have a lower score on the Medical Research Council score (19.5 ± 16.2 vs 27.4 ± 17.5, p = 0.03) and a higher frequency of dysautonomia (42.3% vs 19.4%, p = 0.037), as well as lower amplitudes of the distal compound muscle action potential (CMAP) of the median nerve [0.37 (RIQ 0.07-2.25) vs. 3.9 (RIQ1.2-6.4), p = <0.001] and ulnar nerve [0.37 (RIQ0.0-3.72) vs 1.5 (RIQ0.3-6.6), p = <0.001], and higher frequency of severe axonal damage in these nerves (distal CMAP ≤ 1.0 mV). Through binary logistic regression, severe axonal degeneration of the median nerve is an independent risk factor for prolonged IMV OR 4.9 (95%CI 1.1-21.5) p = 0.03, AUC of 0.774, (95%CI 0.66-0.88), p = < 0.001. CONCLUSIONS: Severe median nerve damage is an independent risk factor for prolonged mechanical ventilation.
Assuntos
Doenças do Sistema Nervoso Autônomo , Síndrome de Guillain-Barré , Humanos , Síndrome de Guillain-Barré/complicações , Respiração Artificial/efeitos adversos , Modelos Logísticos , Fatores de TempoRESUMO
Multiple sclerosis (MS) is an inflammatory neurodegenerative disease characterized by demyelination, progressive axonal loss, and varying clinical presentations. Axonal damage associated with the inflammatory process causes neurofilaments, the major neuron structural proteins, to be released into the extracellular space, reaching the cerebrospinal fluid (CSF) and the peripheral blood. Methodological advances in neurofilaments' serological detection and imaging technology, along with many clinical and therapeutic studies in the last years, have deepened our understanding of MS immunopathogenesis. This review examines the use of light chain neurofilaments (NFLs) as peripheral MS biomarkers in light of the current clinical and therapeutic evidence, MS immunopathology, and technological advances in diagnostic tools. It aims to highlight NFL multidimensional value as a reliable MS biomarker with a diagnostic-prognostic profile while improving our comprehension of inflammatory neurodegenerative processes, mainly RRMS, the most frequent clinical presentation of MS.
Assuntos
Esclerose Múltipla , Doenças Neurodegenerativas , Biomarcadores , Humanos , Filamentos Intermediários , PrognósticoRESUMO
The dopaminergic system plays an essential role in maintaining homeostasis between the central nervous system (CNS) and the immune system. Previous studies have associated imbalances in the dopaminergic system to the pathogenesis of multiple sclerosis (MS). Here, we examined the protein levels of dopaminergic receptors (D1R and D2R) in different phases of the experimental autoimmune encephalomyelitis (EAE) model. We also investigated if the treatment with pramipexole (PPX)-a dopamine D2/D3 receptor-preferring agonist-would be able to prevent EAE-induced motor and mood dysfunction, as well as its underlying mechanisms of action. We report that D2R immunocontent is upregulated in the spinal cord of EAE mice 14 days post-induction. Moreover, D1R and D2R immunocontents in lymph nodes and the oxidative damage in the spinal cord and striatum of EAE animals were significantly increased during the chronic phase. Also, during the pre-symptomatic phase, axonal damage in the spinal cord of EAE mice could already be found. Surprisingly, therapeutic treatment with PPX failed to inhibit the progression of EAE. Of note, PPX treatment inhibited EAE-induced depressive-like while failed to inhibit anhedonic-like behaviors. We observed that PPX treatment downregulated IL-1ß levels and increased BNDF content in the spinal cord after EAE induction. Herein, we show that a D2/D3 receptor-preferred agonist mitigated EAE-induced depressive-like behavior, which could serve as a new possibility for further clinical trials on treating depressive symptoms in MS patients. Thus, we infer that D2R participates in the crosstalk between CNS and immune system during autoimmune and neuroinflammatory response induced by EAE, mainly in the acute and chronic phase of the disease.
Assuntos
Encefalomielite Autoimune Experimental/metabolismo , Receptores de Dopamina D1/fisiologia , Receptores de Dopamina D2/fisiologia , Anedonia/efeitos dos fármacos , Anedonia/fisiologia , Animais , Axônios/patologia , Fator Neurotrófico Derivado do Encéfalo/biossíntese , Fator Neurotrófico Derivado do Encéfalo/genética , Corpo Estriado/metabolismo , Depressão/etiologia , Depressão/prevenção & controle , Progressão da Doença , Avaliação Pré-Clínica de Medicamentos , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/psicologia , Feminino , Interleucina-1beta/biossíntese , Interleucina-1beta/genética , Linfonodos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Doenças Neuroinflamatórias/tratamento farmacológico , Doenças Neuroinflamatórias/metabolismo , Estresse Oxidativo , Fragmentos de Peptídeos/biossíntese , Fragmentos de Peptídeos/genética , Pramipexol/farmacologia , Pramipexol/uso terapêutico , Receptores de Dopamina D2/agonistas , Receptores de Dopamina D3/agonistas , Método Simples-Cego , Medula Espinal/metabolismo , Medula Espinal/patologiaRESUMO
Inorganic arsenic is among the major contaminants of groundwater in the world. Worldwide population-based studies demonstrate that chronic arsenic exposure is associated with poor cognitive performance among children and adults, while research in animal models confirms learning and memory deficits after arsenic exposure. The aim of this study was to investigate the long-term effects of environmentally relevant arsenic exposure in the myelination process of the prefrontal cortex (PFC) and corpus callosum (CC). A longitudinal study with repeated follow-up assessments was performed in male Wistar rats exposed to 3â¯ppm sodium arsenite in drinking water. Animals received the treatment from gestation until 2, 4, 6, or 12â¯months of postnatal age. The levels of myelin basic protein (MBP) were evaluated by immunohistochemistry/histology and immunoblotting from the PFC and CC. As plausible alterations associated with demyelination, we considered mitochondrial mass (VDAC) and two axonal damage markers: amyloid precursor protein (APP) level and phosphorylated neurofilaments. To analyze the microstructure of the CC in vivo, we acquired diffusion-weighted images at the same ages, from which we derived metrics using the tensor model. Significantly decreased levels of MBP were found in both regions together with significant increases of mitochondrial mass and slight axonal damage at 12â¯months in the PFC. Ultrastructural imaging demonstrated arsenic-associated decreases of white matter volume, water diffusion anisotropy, and increases in radial diffusivity. This study indicates that arsenic exposure is associated with a significant and persistent negative impact on microstructural features of white matter tracts.
Assuntos
Intoxicação por Arsênico/patologia , Doenças Desmielinizantes/patologia , Envelhecimento , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Intoxicação por Arsênico/diagnóstico por imagem , Arsenitos/toxicidade , Axônios/patologia , Corpo Caloso/patologia , Doenças Desmielinizantes/diagnóstico por imagem , Imagem de Tensor de Difusão , Água Potável , Imuno-Histoquímica , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteína Básica da Mielina/metabolismo , Proteínas de Neurofilamentos/metabolismo , Córtex Pré-Frontal/patologia , Ratos , Ratos Wistar , Compostos de Sódio/toxicidade , Substância Branca/diagnóstico por imagem , Substância Branca/patologiaRESUMO
Long-term exposure to fine particulate matter (PM2.5) and ozone (O3) above USEPA standards is associated with Alzheimer's disease (AD) risk. Metropolitan Mexico City (MMC) children exhibit subcortical pretangles in infancy and cortical tau pre-tangles, NFTs, and amyloid phases 1-2 by the 2nd decade. Given their AD continuum, we measured in 507 normal cerebrospinal fluid (CSF) samples (MMC 354, controls 153, 12.82±6.73 y), a high affinity monoclonal non-phosphorylated tau antibody (non-P-Tau), as a potential biomarker of AD and axonal damage. In 81 samples, we also measured total tau (T-Tau), tau phosphorylated at threonine 181 (P-Tau), amyloid-ß1-42, BDNF, and vitamin D. We documented by electron microscopy myelinated axonal size and the pathology associated with combustion-derived nanoparticles (CDNPs) in anterior cingulate cortex white matter in 6 young residents (16.25±3.34 y). Non-P-Tau showed a strong increase with age significantly faster among MMC versus controls (pâ=â0.0055). Aß1 - 42 and BDNF concentrations were lower in MMC children (pâ=â0.002 and 0.03, respectively). Anterior cingulate cortex showed a significant decrease (pâ=â<0.0001) in the average axonal size and CDNPs were associated with organelle pathology. Significant age increases in non-P-Tau support tau changes early in a population with axonal pathology and evolving AD hallmarks in the first two decades of life. Non-P-Tau is an early biomarker of axonal damage and potentially valuable to monitor progressive longitudinal changes along with AD multianalyte classical CSF markers. Neuroprotection of young urbanites with PM2.5 and CDNPs exposures ought to be a public health priority to halt the development of AD in the first two decades of life.
Assuntos
Poluição do Ar/efeitos adversos , Doença de Alzheimer/etiologia , Exposição Ambiental/efeitos adversos , Proteínas tau/líquido cefalorraquidiano , Adolescente , Doença de Alzheimer/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Criança , Pré-Escolar , Feminino , Humanos , Masculino , México , Fosforilação , Projetos Piloto , Estudos Prospectivos , População UrbanaRESUMO
Traumatic brain injury (TBI) is a leading cause of death and disability and is a risk factor for the later development of neuropsychiatric disorders and neurodegenerative diseases. Many models of TBI have been developed, but their further refinement and a more detailed long-term follow-up is needed. We have used the Thy1-YFP-H transgenic mouse line and the parallel rod floor test to produce an unbiased and robust method for the evaluation of the multiple effects of a validated model of controlled cortical injury. This approach reveals short- and long-term progressive changes, including compromised biphasic motor function up to 85 days post-lesion, which correlates with neuronal atrophy, dendrite and spine loss, and long-term axonal pathology evidenced by axon spheroids and fragmentation. Here we present methods for inducing a controlled cortical injury in the Thy1-YFP-H transgenic mouse line and for evaluating the resulting deficits in the parallel rod floor test. This technique constitutes a new, unbiased, and robust method for the evaluation of motor and behavioral alterations after TBI. © 2018 by John Wiley & Sons, Inc.
Assuntos
Lesões Encefálicas Traumáticas , Modelos Animais de Doenças , Animais , Astrócitos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Comportamento Animal , Encéfalo/metabolismo , Encéfalo/patologia , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/fisiopatologia , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Exame Neurológico , Neurônios/metabolismo , Neurônios/patologia , Ratos Sprague-DawleyRESUMO
INTRODUCTION: Multiple Sclerosis (MS) is a chronic, inflammatory, neurodegenerative demyelinating disease of the central nervous system (CNS). Unfortunately, MS causes important disability in young adults and its prevalence is increasing. While the etiology of MS etiology is not completely understood, it seems to be a multifactorial entity that is influenced by both genetic and epigenetic modifications. Epigenetic mechanisms add or remove different chemical groups for the activation or inhibition of gene expression to block the production of proinflammatory proteins. It is truly important to identify the factors that can trigger epigenetic changes in MS to complement the therapeutic approach, prevent disability and improve patients quality of life. Here, we have conducted a review of external factors that influence in MS and their epigenetic mechanisms. For example, hypomethylation can promote changes in the myelin and subsequent autoimmune reactions. Therapeutic tools can be used, including the histone deacetylase inhibitor Trichostatin A, which ameliorates demyelinating diseases in rodents. However, drugs are not only the therapeutic option: recent studies have also evaluated the therapeutic potential of several bioactive dietary components in neurodegeneration and axonal dysfunction. Numerous food-derived molecules exert important metabolic actions. These molecules include plant polyphenols such as catechins and isoflavones, Ω-3 and Ω-6 polyunsaturated fatty acids, short-chain fatty acids, sulfur-containing compounds such as dally sulfide and other compounds. Antioxidant and anti-inflammatory components in the diet involve transcription factors as well. However, many external factors have shown to influence MS, although no specific epigenetic mechanisms are known. CONCLUSION: In this review, we gather both established and new evidences about the genetic, epigenetic and environmental factors influencing MS and the dietary components that could modulate MS relapse and progression.
Assuntos
Antioxidantes/administração & dosagem , Epigênese Genética/fisiologia , Esclerose Múltipla/dietoterapia , Esclerose Múltipla/metabolismo , Polifenóis/administração & dosagem , Animais , Antioxidantes/metabolismo , Metilação de DNA/fisiologia , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Ômega-6/administração & dosagem , Ácidos Graxos Ômega-6/metabolismo , Humanos , Esclerose Múltipla/genética , Polifenóis/metabolismoRESUMO
Resumen:El Trauma Cráneo Encefálico (TCE) tiene hoy en día una incidencia muy alta de morbilidad y mortalidad en nuestra población, por lo que es de suma importancia esclarecer los conceptos básicos de las lesiones producidas por el TCE, su cronología y el pronóstico de dichos traumas. Este artículo se basa en identificar las lesiones primarias y secundarias más frecuentes y las características más importantes de cada una de ellas, así como describir los mecanismos de trauma frecuentemente implicados.
Abstract:The Brain Trauma (TCE) has a very high incidence of morbidity and mortality in its population today, so it is very important to clarify the basic concepts of the injuries produced by the TCE, its timing and the prognosis of these traumas. This article is based on identifying the most frequent primary and secondary lesions and the most important characteristics of each, as well as describing the mechanisms of trauma frequently involved
Assuntos
Humanos , Masculino , Feminino , Traumatismos Cranianos Fechados , Médicos Legistas , Lesão Axonal Difusa , Lesões Encefálicas Traumáticas , Medicina Legal , Traumatismos Craniocerebrais , Hematoma Epidural Craniano , Hematoma SubduralRESUMO
Although previous studies have shown that forced exercise modulates inflammation and is therapeutic acutely for experimental autoimmune encephalomyelitis (EAE), the long-term benefits have not been evaluated. In this study, we investigated the effects of preconditioning exercise on the clinical and pathological progression of EAE. Female C57BL/6 mice were randomly assigned to either an exercised (Ex) or unexercised (UEx) group and all of them were induced for EAE. Mice in the Ex group had an attenuated clinical score relative to UEx mice throughout the study. At 42 dpi, flow cytometry analysis showed a significant reduction in B cells, CD4(+) T cells, and CD8(+) T cells infiltrating into the spinal cord in the Ex group compared to UEx. Ex mice also had a significant reduction in myelin damage with a corresponding increase in proteolipid protein expression. Finally, Ex mice had a significant reduction in axonal damage. Collectively, our study demonstrates for the first time that a prolonged and forced preconditioning protocol of exercise improves clinical outcome and attenuates pathological hallmarks of EAE at chronic disease. In this study, we show that a program of 6 weeks of preconditioning exercise promoted a significant reduction of cells infiltrating into the spinal cord, a significant reduction in myelin damage and a significant reduction in axonal damage in experimental autoimmune encephalomyelitis (EAE) mice at 42 dpi. Collectively, our study demonstrates for the first time that a preconditioning protocol of exercise improves clinical outcome and attenuates pathological hallmarks of EAE at chronic disease.
Assuntos
Axônios/patologia , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/prevenção & controle , Condicionamento Físico Animal/fisiologia , Natação/fisiologia , Animais , Doenças Autoimunes Desmielinizantes do Sistema Nervoso Central/patologia , Doenças Autoimunes Desmielinizantes do Sistema Nervoso Central/prevenção & controle , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Condicionamento Físico Animal/métodos , Resultado do TratamentoRESUMO
The physiopathology of symptoms and signs in multiple sclerosis (MS) is a less divulged topic albeit its importance in the patients' management. OBJECTIVE: It was to summarize the main biophysical and biochemical mechanisms which produce the clinical manifestations in MS. RESULTS: The mechanisms underpinning neurological deficits are described in the relapsing and in the progressive phases, stressing inflammatory and neurodegenerative components, especially demyelination, axonal damage and conduction impairment. Transient worsening based in Uhthoff's phenomenon, mechanisms producing positive symptoms, as paraesthesias and Lhermitte sign due to axonal hiperexcitability and ephaptic interactions, and development of cortical symptoms will also be addressed. The variety of processes leading to neural repair and functional recovery in the remitting phase is focused, as remyelination and adaptive changes due to neural plasticity. CONCLUSION: The awareness of mechanisms producing symptoms in MS emphasises the role of symptomatic and rehabilitation therapies in the improvement of patients' well-being.
A fisiopatologia dos sintomas e sinais na esclerose múltipla (EM) é um tópico pouco divulgado apesar da sua importância na abordagem dos doentes. OBJETIVO: Foi apresentar os principais mecanismos biofísicos e bioquímicos que produzem manifestações clínicas da EM. RESULTADOS: Descrevem-se os mecanismos subjacentes aos défices neurológicos nas fases de surto e progressivas, realçando as componentes inflamatória e neurodegenerativa, especialmente desmielinização, lesão axonal e alterações da condução. Serão igualmente referidos os sintomas transitórios explicados pelo fenômeno de Uhthoff, a produção de sintomas positivos, como as parestesias e o sinal de Lhermitte por hiperexcitabilidade axonal e interações efáticas, e o desenvolvimento de sintomas corticais. Apresentam-se os diversos processos de reparação neural e de recuperação funcional nas fases de remissão, como a remielinização e as alterações adaptativas por neuroplasticidade. CONCLUSÃO: O conhecimento dos mecanismos que produzem os sintomas da EM realça o papel das terapêuticas sintomáticas e de reabilitação na melhoria do bem-estar dos doentes.