ABSTRACT
PURPOSE: The aim of this study was to present new a model that allows the study of the bone healing process, with an emphasis on the biological behavior of different graft-to-host interfaces. A standardized “over-inlay” surgical technique combined with a differential histomorphometric analysis is presented in order to optimize the use of critical-size calvarial defects in pre-clinical testing. METHODS: Critical-size defects were created into the parietal bone of 8 male Wistar rats. Deproteinized bovine bone (DBBM) blocks were inserted into the defects, so that part of the block was included within the calvarial thickness and part exceeded the calvarial height (an “over-inlay” graft). All animals were sacrificed at 1 or 3 months. Histomorphometric and immunohistochemical evaluation was carried out within distinct regions of interest (ROIs): the areas adjacent to the native bone (BA), the periosteal area (PA) and the central area (CA). RESULTS: The animals healed without complications. Differential morphometry allowed the examination of the tissue composition within distinct regions: the BA presented consistent amounts of new bone formation (NB), which increased over time (24.53%±1.26% at 1 month; 37.73%±0.39% at 3 months), thus suggesting that this area makes a substantial contribution toward NB. The PA was mainly composed of fibrous tissue (71.16%±8.06% and 78.30%±2.67%, respectively), while the CA showed high amounts of DBBM at both time points (78.30%±2.67% and 74.68%±1.07%, respectively), demonstrating a slow remodeling process. Blood vessels revealed a progressive migration from the interface with native bone toward the central area of the graft. Osterix-positive cells observed at 1 month within the PA suggested that the periosteum was a source of osteoprogenitor elements. Alkaline phosphatase data on matrix deposition confirmed this observation. CONCLUSIONS: The present model allowed for a standardized investigation of distinct graft-to-host interfaces both at vertically augmented and inlay-augmented sites, thus possibly limiting the number of animals required for pre-clinical investigations.
Subject(s)
Animals , Humans , Male , Rats , Alkaline Phosphatase , Blood Vessels , Bone Regeneration , Bone Transplantation , Osteogenesis , Parietal Bone , Periosteum , Rats, Wistar , Skull , TransplantsABSTRACT
At times in clinical neurology, the identification of a subtle clinical or radiological sign can lead to prompt diagnosis of a very rare or difficult case. We report on a patient who presented with untreatable headache and unilateral ptosis. Computed tomography (CT) scan of the head did not reveal any structural cause. Magnetic resonance angiogram showed absence of left internal carotid artery, which was eventually confirmed by a catheter angiography. Reviewing the case, it emerged that a feature on the initial CT scan "bone window" would have confirmed the diagnosis, had it been searched for: the underdeveloped carotid canal, which is a consequence and a marker of internal carotid artery agenesis.
Em algumas circunstâncias, o reconhecimento de um sinal clínico ou radiológico sutil pode tornar simples o diagnóstico de um caso raro ou muito difícil em neurologia clínica. Relatamos o caso de uma paciente que apresentava cefaleia intratável e ptose palpebral unilateral. A tomografia computadorizada (TC) de crânio não permitiu identificar nenhuma causa estrutural. A ressonância magnética evidenciou ausência da artéria carótida interna esquerda, posteriormente confirmada por arteriografia convencional. Retrospectivamente, descobriu-se que um dado da janela óssea da primeira TC de crânio teria confirmado o diagnóstico, tivesse ele sido pesquisado: o hipodesenvolvimento do canal carotídeo, que é uma consequência e um marcador de agenesia da artéria carótida interna.
Subject(s)
Adult , Female , Humans , Carotid Artery, Internal/abnormalities , Horner Syndrome/diagnosis , Cerebral Angiography , Diagnosis, Differential , Magnetic Resonance Imaging , Tomography, X-Ray ComputedABSTRACT
Neurointensive care arose from the specific growth of the various therapeutic methods in neuroscience, similar to the formation of specific units in other specialties. The progress of the neurological intensive treatment is more recent and because of the high frequency of pathologies in this area it became necessary to structure this specialty in terms of theoretical and physical aspects. In this text, a commentary on the chronology of this development is set out briefly and objectively.
O neurointensivismo surgiu a partir do crescimento específico das diversas formas terapêuticas em neurociências, à semelhança da formação de unidades específicas em outras especialidades. O progresso do tratamento neurológico intensivo é mais recente e, em virtude da alta frequência das patologias nessa área, tornou-se necessária a estruturação dessa especialidade do ponto de vista teórico e físico. Neste texto, um comentário à cronologia desse desenvolvimento é exposto de maneira breve e objetiva.