RESUMO
BACKGROUND: Repetitive traumatic brain injury (TBI) is associated with chronic traumatic encephalopathy (CTE), a progressive neurodegenerative disorder characterized by Alzheimer-like changes in the brain. CTE has been defined through neuropathological findings among deceased athletes and others exposed to repetitive TBI, but to date there are no definitive clinical criteria for CTE. OBJECTIVE: To evaluate the utility of currently proposed clinical criteria for CTE and suggest improvements. METHODS: We describe two well-characterized patients referred for evaluation of CTE and apply the four major proposed criteria for CTE. These criteria were further assessed in a cohort of patients referred to a neurobehavior clinic with or without a history of TBI. RESULTS: Without a CTE biomarker, the current criteria were of limited utility when applied to the two patient and the Neurobehavior cohort. Six items were extracted as potentially improving the clinical diagnosis of CTE: length of exposure to head impacts, a progressive course, specific psychiatric symptoms, frontal-executive dysfunction, parkinsonism and tremors, and targeted findings on neuroimaging. CONCLUSIONS: The prevention and neurorehabilitation of CTE depends on clinical diagnosis, but, without a biomarker, the clinical diagnosis of CTE remains difficult. This report suggests that clinical criteria for CTE may be greatly improved with emphasis on several critical historical and clinical correlates of CTE.
Assuntos
Encefalopatia Traumática Crônica/diagnóstico , Escala de Gravidade do Ferimento , Encefalopatia Traumática Crônica/classificação , Encefalopatia Traumática Crônica/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Electrospinning using synthetic and natural polymers is a promising technique for the fabrication of scaffolds for tissue engineering. Numerous synthetic polymers are available to maximize durability and mechanical properties (polyurethane) versus degradability and cell adhesion (polycaprolactone). In this study, we explored the feasibility of creating scaffolds made of bicomponent nanofibers from both polymers using a coaxial electrospinning system. We used a core of poly(urethane) and a sheath of a mixture of poly(ε-caprolactone) and gelatin, all dissolved in 1,1,1,3,3,3-hexafluror-2-propanol. These nanofibrous scaffolds were then evaluated to confirm their core-sheath nature and characterize their morphology and mechanical properties under static and dynamic conditions. Furthermore, the antigenicity of the scaffolds was studied to confirm that there is no significant foreign body response to the scaffold itself that would preclude its use in vivo. The results show the advantages of combining both natural and synethic polymers to create a coaxial scaffold capable of withstanding dynamic culture conditions and encourage cellular migration to the interior of the scaffold for tissue-engineering applications. Also, the results show that there is no significant immunoreactivity in vivo to the components of the scaffolds.
Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Reação a Corpo Estranho/imunologia , Nanofibras/química , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Animais , Técnicas Eletroquímicas/métodos , Gelatina/química , Implantes Experimentais , Teste de Materiais , Camundongos , Células NIH 3T3 , Nanofibras/ultraestrutura , Poliésteres/química , Polímeros/síntese química , Polímeros/química , Polímeros/metabolismo , Poliuretanos/química , Porosidade , Estresse MecânicoRESUMO
PURPOSE: The purpose of this study was to compare the metabolic and cardiovascular responses of young (Y) and older (O) women ages 19-24 yr (N = 11) and 63-72 yr (N = 11), respectively, while performing shallow water exercise (SWE). METHODS: Resting metabolic rate was determined as was the metabolic (indirect calorimetry) and heart rate (Polar monitor) responses to five submaximal and one maximal SWE bout, and to a 40-min SWE class. RESULTS: 1) One metabolic equivalent (MET) equaled (mean +/- SE) 3.3 +/- 0.2 mL O(2).min-1.kg-1 (Y) and 2.8 +/- 0.1 mL O(2).min-1.kg-1 (O) (P < 0.05); 2) submaximal (bouts 1-5) MET and HR responses ranged from 3.5 to 8.6 and 95 to 144 bpm (Y), and 3.2 to 6.3 and 92 to 124 bpm (O); 3) estimated MET, % HR(peak), and kcal O(2) per minute at given relative efforts (% [OV0312]O(2peak)) were greater for the older group (P < 0.05), whereas no difference in RPE was found; 4) peak MET and HR equaled 11.7 +/- 0.8 and 182 +/- 3 bpm (Y) and 7.6 +/- 0.4 and 156 +/- 5 bpm (O), respectively (P < 0.05); 5) SWE class: overall, estimated average MET level was 4.9 +/- 0.3 (O) and 5.8 +/- 0.4 (Y) (P > 0.05); the overall relative intensity (% MET(peak)) was greater for the O group (61.5 +/- 2.5 vs 48.8 +/- 2.2) (P < 0.05). CONCLUSIONS: SWE elicited metabolic and cardiovascular responses that met ACSM's guidelines for establishing health benefits. Furthermore, older females may self-select a greater relative exercise intensity during SWE compared with younger counterparts when provided with the same verbal instructions and encouragement.