Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
1.
Proc Natl Acad Sci U S A ; 113(47): 13444-13449, 2016 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-27821732

RESUMEN

Prospective clinical studies support a link between psychological stress and multiple sclerosis (MS) disease severity, and peripheral stress systems are frequently dysregulated in MS patients. However, the exact link between neurobiological stress systems and MS symptoms is unknown. To evaluate the link between neural stress responses and disease parameters, we used an arterial-spin-labeling functional MRI stress paradigm in 36 MS patients and 21 healthy controls. Specifically, we measured brain activity during a mental arithmetic paradigm with performance-adaptive task frequency and performance feedback and related this activity to disease parameters. Across all participants, stress increased heart rate, perceived stress, and neural activity in the visual, cerebellar and insular cortex areas compared with a resting condition. None of these responses was related to cognitive load (task frequency). Consistently, although performance and cognitive load were lower in patients than in controls, stress responses did not differ between groups. Insula activity elevated during stress compared with rest was negatively linked to impairment of pyramidal and cerebral functions in patients. Cerebellar activation was related negatively to gray matter (GM) atrophy (i.e., positively to GM volume) in patients. Interestingly, this link was also observed in overlapping areas in controls. Cognitive load did not contribute to these associations. The results show that our task induced psychological stress independent of cognitive load. Moreover, stress-induced brain activity reflects clinical disability in MS. Finally, the link between stress-induced activity and GM volume in patients and controls in overlapping areas suggests that this link cannot be caused by the disease alone.


Asunto(s)
Encéfalo/patología , Evaluación de la Discapacidad , Esclerosis Múltiple/patología , Esclerosis Múltiple/psicología , Estrés Psicológico/patología , Atrofia , Mapeo Encefálico , Cognición , Demografía , Femenino , Sustancia Gris/patología , Frecuencia Cardíaca/fisiología , Humanos , Hidrocortisona/metabolismo , Imagen por Resonancia Magnética , Masculino , Matemática , Persona de Mediana Edad , Tamaño de los Órganos , Saliva/metabolismo , Estrés Psicológico/complicaciones , Análisis y Desempeño de Tareas , Sustancia Blanca/patología
2.
J Magn Reson Imaging ; 44(1): 51-8, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26714969

RESUMEN

PURPOSE: To assess if higher-resolution magnetic resonance elastography (MRE) is a technique that can measure the in vivo mechanical properties of brain tissue and is sensitive to early signatures of brain tissue degradation in patients with clinically isolated syndrome (CIS). MATERIALS AND METHODS: Seventeen patients with CIS and 33 controls were investigated by MRE with a 3T MRI scanner. Full-wave field data were acquired at seven drive frequencies from 30 to 60 Hz. The spatially resolved higher-resolution maps of magnitude |G*| and phase angle φ of the complex-valued shear modulus were obtained in addition to springpot model parameters. These parameters were spatially averaged in white matter (WM) and whole-brain regions and correlated with clinical and radiological parameters. RESULTS: Spatially resolved MRE revealed that CIS reduced WM viscoelasticity, independent of imaging markers of multiple sclerosis and clinical scores. |G*| was reduced by 14% in CIS (1.4 ± 0.2 kPa vs. 1.7 ± 0.2 kPa, P < 0.001, 95% confidence interval [CI] [-0.4, -0.1] kPa), while φ (0.66 ± 0.04 vs. 0.67 ± 0.04, P = 0.65, 95% CI [-0.04, 0.02]) remained unaltered. Springpot-based shear elasticity showed only a trend of CIS-related reduction (3.4 ± 0.5 kPa vs. 3.7 ± 0.5 kPa, P = 0.06, 95% CI [-0.6, 0.02] kPa) in the whole brain. CONCLUSION: We demonstrate that CIS leads to significantly reduced elasticity of brain parenchyma, raising the prospect of using MRE as an imaging marker for subtle and diffuse tissue damage in neuroinflammatory diseases. J. Magn. Reson. Imaging 2016;44:51-58.


Asunto(s)
Enfermedades Desmielinizantes/diagnóstico por imagen , Enfermedades Desmielinizantes/fisiopatología , Diagnóstico por Imagen de Elasticidad/métodos , Epilepsia/patología , Epilepsia/fisiopatología , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Adulto , Diagnóstico Precoz , Módulo de Elasticidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Resistencia al Corte , Estrés Mecánico
3.
J Neuroimmunol ; 297: 56-62, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27397076

RESUMEN

We analyzed the fine specificity of antibodies to Epstein-Barr nuclear antigen-2 (EBNA-2) and other Epstein-Barr virus (EBV) proteins in 29 patients with clinically isolated syndrome (CIS, the first clinical manifestation of multiple sclerosis [MS]) and 29 controls with a peptide microarray containing 117 overlapping peptides representing the full-length EBNA-2 protein and 71 peptides from 8 further EBV proteins. While EBV peptide antibodies were elevated in CIS, suggesting that EBV contributes to MS early during disease development, they discriminated groups only slightly better than EBNA-1 antibodies. Thus, the additional value of EBV peptide antibodies as diagnostic biomarkers for CIS appears moderate.


Asunto(s)
Anticuerpos Antivirales/metabolismo , Formación de Anticuerpos/fisiología , Infecciones por Virus de Epstein-Barr/complicaciones , Antígenos Nucleares del Virus de Epstein-Barr/inmunología , Esclerosis Múltiple/etiología , Proteínas Virales/inmunología , Adulto , Animales , Evaluación de la Discapacidad , Ensayo de Inmunoadsorción Enzimática , Infecciones por Virus de Epstein-Barr/inmunología , Femenino , Herpesvirus Humano 4/inmunología , Herpesvirus Humano 4/patogenicidad , Humanos , Inmunoglobulina G/sangre , Imagen por Resonancia Magnética , Masculino , Ratones Endogámicos BALB C , Persona de Mediana Edad , Esclerosis Múltiple/sangre , Esclerosis Múltiple/diagnóstico por imagen , Esclerosis Múltiple/inmunología , Análisis por Matrices de Proteínas , Estadísticas no Paramétricas , Adulto Joven
4.
PLoS One ; 11(1): e0147968, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26820970

RESUMEN

BACKGROUND: In response to DNA double-strand breaks, the histone protein H2AX becomes phosphorylated at its C-terminal serine 139 residue, referred to as γ-H2AX. Formation of γ-H2AX foci is associated with recruitment of p53-binding protein 1 (53BP1), a regulator of the cellular response to DNA double-strand breaks. γ-H2AX expression in peripheral blood mononuclear cells (PBMCs) was recently proposed as a diagnostic and disease activity marker for multiple sclerosis (MS). OBJECTIVE: To evaluate the significance of γ-H2AX and 53BP1 foci in PBMCs as diagnostic and disease activity markers in patients with clinically isolated syndrome (CIS) and early relapsing-remitting MS (RRMS) using automated γ-H2AX and 53BP1 foci detection. METHODS: Immunocytochemistry was performed on freshly isolated PBMCs of patients with CIS/early RRMS (n = 25) and healthy controls (n = 27) with γ-H2AX and 53BP1 specific antibodies. Nuclear γ-H2AX and 53BP1 foci were determined using a fully automated reading system, assessing the numbers of γ-H2AX and 53BP1 foci per total number of cells and the percentage of cells with foci. Patients underwent contrast enhanced 3 Tesla magnetic resonance imaging (MRI) and clinical examination including expanded disability status scale (EDSS) score. γ-H2AX and 53BP1 were also compared in previously frozen PBMCs of each 10 CIS/early RRMS patients with and without contrast enhancing lesions (CEL) and 10 healthy controls. RESULTS: The median (range) number of γ-H2AX (0.04 [0-0.5]) and 53BP1 (0.005 [0-0.2]) foci per cell in freshly isolated PBMCs across all study participants was low and similar to previously reported values of healthy individuals. For both, γ-H2AX and 53BP1, the cellular focus number as well as the percentage of positive cells did not differ between patients with CIS/RRMS and healthy controls. γ-H2AX and 53BP1 levels neither correlated with number nor volume of T2-weighted lesions on MRI, nor with the EDSS. Although γ-H2AX, but not 53BP1, levels were higher in previously frozen PBMCs of patients with than without CEL, γ-H2AX values of both groups overlapped and γ-H2AX did not correlate with the number or volume of CEL. CONCLUSION: γ-H2AX and 53BP1 foci do not seem to be promising diagnostic or disease activity biomarkers in patients with early MS. Lymphocytic DNA double-strand breaks are unlikely to play a major role in the pathophysiology of MS.


Asunto(s)
Daño del ADN , Histonas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Linfocitos/metabolismo , Esclerosis Múltiple/genética , Adulto , Biomarcadores/metabolismo , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/metabolismo , Esclerosis Múltiple/patología , Proteína 1 de Unión al Supresor Tumoral P53 , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA