Optic Nerve Drusen: Find the Differences

Introdução: Os drusens do disco ótico são anomalias congénitas do desenvolvimento da cabeça do nervo ótico, correspondendo a depósitos hialinos calcificados, localizados anteriormente à lâmina crivosa. O seu diagnóstico é maioritariamente acidental, em doentes normalmente assintomáticos. Material e Métodos: Os autores apresentam 5 casos clínicos de doentes com idades de apresentação compreendidas entre 6 e 12 anos, observados na Consulta de Oftalmologia Pediátrica e Estrabismo, à qual foram referenciados por diferentes motivos. Resultados: Nos casos clínicos apresentados os motivos de consulta foram diminuição da acuidade visual, estrabismo divergente, cefaleias com suspeita de papiledema e rotina. O exame oftalmológico e os meios complementares de diagnóstico realizados, nomeadamente retinografia, ecografia ocular, tomografia de coerência ótica e campos visuais, contribuíram para o diagnóstico de drusens do nervo ótico. Foram ainda encontrados erros refractivos em 4 dos casos descritos. Conclusão: Salienta-se a importância de uma história clínica e observação detalhadas para o diagnóstico diferencial e despiste de patologias oftalmológicas concomitantes, em doentes com drusens do disco ótico e seus familiares.

Transimpedance amplifier for integrated SpO2 optic sensor

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

Experimental procedures for the identification of material properties of intervertebal disc - a contribution for the development of biomimetic substitutes for the nucleus pulposus

Tese de Doutoramento em Engenharia Mecânica.

Leber's hereditary optic neuropathy (LHON) : involvement of mitochondrial permeability transition in the pathogenesis and protective actions of minocycline

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2008

CD95-induced apoptosis in health and disease dimers at the DISC and the effect of c-FLIP R on L. Monocytogenes infection

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2013

apoptosis-regulator c-FLIP : functional role in urothelial carcinoma and autoimmunity and identification of novel CD95 DISC-interacting proteins

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2013

Weighted Hardy spaces for the unit disc: approximation properties

In this paper we study basic properties of the weighted Hardy space for the unit disc with the weight function satisfying Muckenhoupt's (Aq) condition, and study related approximation problems (expansion, moment and interpolation) with respect to two incomplete systems of holomorphic functions in this space.

Cells with neuronal characteristics differentiate and persist for one year in rat optic nerve explants cultures.

Evidence concerning the presence or absence of common neuronglia lineages in the postnatal mammalian central nervous system is still a matter of speculation. We address this problem using optic nerve explants, which show an extremely long survival in culture. Morphological, immunocytochemical and immunochemical methods were applied. The results obtained from in vitro tissue were compared with optic nerves (ONs) and whole-brain samples from animals of different ages. Newborn rat ONs represented the starting material of our tissue culture; they are composed of unmyelinated axons, astrocytes and progenitor cells but devoid of neuronal cell bodies. At this age, Western blots of ONs were positively stained by neurofilament and synapsin I specific antibodies. These bands increased in intensity during postnatal in situ development. In explant cultures, the glia cells reach a stage of functional differentiation and they maintain, together with undifferentiated cells, a complex histotypic organization. After 6 days in vitro, neurofilaments and synapsin I could not be detected on immunoblots, indicating that 1) axonal degeneration was completed, and 2) neuronal somata were absent at the time. Surprisingly, after about 4-5 weeks in culture, a new cell type appeared, which showed characteristics typical of neurons. After 406 days in vitro, neurofilaments and synapsin I were unequivocally detectable on Western blots. Furthermore, both immunocytochemical staining and light and electron microscopic examinations corroborated the presence of this earlier-observed cell type. These in vitro results clearly show the high developmental plasticity of ON progenitor cells, even late in development. The existence of a common neuron-glia precursor, which never gives rise to neurons in situ, is suggested.

Optic perineuritis secondary to Wegener's granulomatosis.

BACKGROUND: Optic perineuritis (OPN) is an inflammatory condition involving the optic nerve sheath because of a variety of causes. We describe three patients in whom OPN was secondary to Wegener's granulomatosis (WG) and compare the clinical findings in these cases with those of idiopathic OPN. METHODS: This is a retrospective small case series derived from patients with OPN seen in an outpatient neuro-ophthalmology clinic. Medical records and imaging studies of these patients were reviewed. RESULTS: These patients shared clinical similarities with idiopathic OPN including age, sex, symptoms, radiographic findings and steroid responsiveness. However, recurrence of symptoms on lowering the prednisone dose below 40 mg distinguished these patients from those with idiopathic OPN. CONCLUSIONS: Steroid dependency in idiopathic OPN should raise suspicion of WG. Patients with OPN should be specifically questioned regarding pre-existing upper respiratory tract disorders and rheumatic symptoms and laboratory testing should include acute phase reactants, anti-neutrophil cytoplasmic antibodies and tests of renal function.

Bucket-handle tear of the triangular fibrocartilage complex : case report of a complex peripheral injury with separation of the distal radioulnar ligaments from the articular disc.

Palmer previously proposed a classification system of triangular fibrocartilage complex (TFCC) injuries that proved to be useful in directing clinical management. However, dorsal peripheral tears (variants of class 1C) were not described and have rarely been reported in the literature since. We herewith present a rare case of bucket-handle tear of the TFCC. To our knowledge, this is the first case demonstrating partial separation of both the palmar and dorsal distal radioulnar ligaments (DRULs) from the articular disc. The particular wrist magnetic resonance (MR) arthrographic findings of this unusual complex peripheral TFCC tear (a variant of both class 1B and 1C) were nicely appreciated upon sagittal reformatted images.

Early functional differentiation in the chick embryonic disc: interaction between mechanical activity and extracellular matrix

The mechanical behaviour of ectodermal cells in the area opaca and the supracellular organization of fibronectin in the adjacent extracellular matrix were studied in whole chick blastoderms developing in vitro. The pattern of spontaneous mechanical activity and its modification by immunoglobulins against fibronectin were determined using a real-time image-analysis system. The pattern of fibronectin was studied using immunocytochemical techniques. It was found that the ectodermal cells in the area opaca actively develop a radially oriented contraction, which leads to a distension of the area pellucida from which the embryo develops. Abnormally increased tension resulted in perturbations of gastrulation and neurulation. An optimized mechanical equilibrium within the blastoderm seems to be necessary for normal development. Anti-fibronectin antibodies applied to the basal side of the blastoderm led rapidly and reversibly to an increase of tension in the contracted cells. This observation indicates that modifications of the extracellular matrix can be transmitted to cytoskeletal elements within adjacent cells. The extracellular matrix of the area opaca contains fibronectin arranged in radially oriented fibrils. This orientation corresponds to the direction of migration of the mesodermal cells. Interestingly, the radial pattern of fibronectin is found in the regions where the ectodermal cells are contracted and develop radially oriented forces. This observation suggests that the supracellular assembly of the extracellular materials could be influenced by the mechanical activity of adjacent cells. Possible modulations of the supracellular organization of extracellular matrix by other factors, e.g. diffusible metabolites, is also discussed. The presence of characteristically organized extracellular matrix components, of spatially differentiated cell activities and of reciprocal interactions between them makes the young chick blastoderm an excellent system for physiological studies of the coordinated cellular activities that lead to changes in form, complexity and function.

Anterior segment granuloma and optic nerve involvement as the presenting signs of systemic sarcoidosis.

PURPOSE: To report a case with anterior and posterior nodules associated with systemic sarcoidosis. METHODS: A patient with decreased vision underwent complete ophthalmologic examination, ultrasound biomicroscopy, fluorescein and indocyanine green (ICG) angiography. RESULTS: The patient presented a nodule of the iris of the OS and of the optic nerves of both eyes. Chest computed tomography and tissue biopsy established the diagnosis. CONCLUSIONS: Fluorescein and ICG angiography are the only objective exams to demonstrate the extent of ocular involvement in a patient with sarcoidosis.

Autophagy promotes survival of retinal ganglion cells after optic nerve axotomy in mice.

Autophagy is an essential recycling pathway implicated in neurodegeneration either as a pro-survival or a pro-death mechanism. Its role after axonal injury is still uncertain. Axotomy of the optic nerve is a classical model of neurodegeneration. It induces retinal ganglion cell death, a process also occurring in glaucoma and other optic neuropathies. We analyzed autophagy induction and cell survival following optic nerve transection (ONT) in mice. Our results demonstrate activation of autophagy shortly after axotomy with autophagosome formation, upregulation of the autophagy regulator Atg5 and apoptotic death of 50% of the retinal ganglion cells (RGCs) after 5 days. Genetic downregulation of autophagy using knockout mice for Atg4B (another regulator of autophagy) or with specific deletion of Atg5 in retinal ganglion cells, using the Atg5(flox/flox) mice reduces cell survival after ONT, whereas pharmacological induction of autophagy in vivo increases the number of surviving cells. In conclusion, our data support that autophagy has a cytoprotective role in RGCs after traumatic injury and may provide a new therapeutic strategy to ameliorate retinal diseases.