Search results for "Retina"

Diagnostic morphology of human eye-related storage disorders

1989

While retina and other ocular tissues are involved clinically and morphologically in a variety of lysosomal disorders, it is only the conjunctiva that is accessible by biopsy to morphological, i.e., electron microscopic recognition of the patient's individual lysosomal disease. However, this procedure is not utilized by many. Instead, skin and circulating lymphocytes are the most frequently obtained tissues for diagnostic investigation, as skin contains an abundance of diversified cell types for morphological examination and simultaneously fibroblasts to be cultured for biochemical investigation. It is the tissue most suitable for identifying lysosomal disorders and parallels in diagnostic …

Neurosteroidogenesis in Rat Retinas

2002

Neurosteroids (steroids synthesized in the CNS) function by modulating neurotransmission. To establish an experimental model for investigation of neurosteroid synthesis and regulation, independent of blood-borne steroids, we examined the steroidogenic activity of isolated rat retinas. We identified progesterone, pregnenolone, dehydroepiandrosterone, desoxycorticosterone, 3 alpha,5 alpha-tetrahydrodesoxycorticosterone, 3 alpha-hydroxy-5 alpha-dihydroprogesterone, 17-hydroxyprogesterone, and 17-hydroxypregnenolone together with their esterified forms. As pregnenolone is the precursor of all steroids, its formation was studied in detail as an index of a steroid-synthesizing tissue. Pregnenolon…

Ophthalmologic Imaging Methods

2005

Color Doppler ultrasonography of the eye and orbit

1993

Color Doppler imaging is the recent development in ultrasonography that allows simultaneous two-dimensional structural imaging in Doppler evaluation of blood flow. With this technique, it is possible for the first time to indirectly display the fine orbital vessels such as the ophthalmic artery and its branches, the central retinal artery, the posterior ciliary artery, and the lacrimal artery. Also, the display of venous structures such as the superior ophthalmic vein, the vortex vein, and the central retinal vein is possible. In addition to the qualitative display of those vessels, the hemodynamics in those vessels can be quantitatively assessed by looking at the Doppler spectrum and deter…

Ozone Therapy as treatment for severe cases without good evolution in ophthalmology [abstract]

2019

PURPOSE: In ophthalmology many diseases lead to irreversible blindness, something that implies millions of dollars in care because people with these difficulties loose their autonomy, becoming dependent in all their everyday activities.
 This presentation will focus on clinical cases of the following pathologies treated with Ozone Therapy because all these were already being treated in a conventional way without signs of improvement. They are primary open-angle glaucoma, age-related macular degeneration, diabetic retinopathy, occlusion of the central retinal artery, facial paralysis and herpetic polyneuropathy associated with orbital apex syndrome.
 
 CASE PRESENTATION: As an…

The retinitis pigmentosa 28 protein FAM161A is a novel ciliary protein involved in intermolecular protein interaction and microtubule association

2012

Loss-of-function mutations in the gene encoding FAM161A were recently discovered as the cause for RP28, an autosomal recessive form of retinitis pigmentosa. To initiate the characterization of the cellular role of FAM161A in the retina, we focused on its subcellular localization and conducted in vitro studies to identify FAM161A-interacting proteins and associated cellular structures. Immunohistochemistry revealed the presence of mouse FAM161A in the photoreceptor inner segments, the synaptic regions of the outer and inner plexiform layers and the ganglion cells. In mouse and human retinal sections from unfixed eyes, FAM161A localized to the ciliary region linking photoreceptor outer and in…

Apprehending ganglioside diversity: a comprehensive methodological approach

2015

Gangliosides make a wide family of glycosphingolipids ubiquitously expressed in mammalian tissues and particularly abundant in the brain and nervous system. They exhibit a huge diversity due to structural variations in both their oligosaccharidic chain and ceramide moiety, which represent a real analytical challenge. Since their discovery in the 1940s, methods have persistently improved until the emergence of Liquid Chromatography/Mass Spectrometry (LC/MS) which offers a high level of specificity and sensitivity and is suitable with high-throughput profiling studies. We describe here a comprehensive approach relying on various techniques and aiming at fully characterizing gangliosides in bi…

Inflammatory cytokines decrease viability and alter ganglioside profile in retinal pigment epithelium cells

2013

Purpose Early stages of Age related Macular Degeneration (AMD) are characterized by dysfunction and degeneration of the retinal pigment epithelium (RPE) cells, which participate in the death of the overlying photoreceptors ultimately leading to loss of vision. Gangliosides (GG) make a wide and heterogeneous family of sialic-acid-containing glycosphingolipids, composed of a sugar chain branched on a ceramide. They are major components of cellular membranes, particularly abundant in the brain and nervous tissue, including retina. While their developmental and neuroprotective actions have been demonstrated, their precise role in retina’s function and its pathologies is still poorly understood.…

Electrophysiological Investigations of Retinogeniculate and Corticogeniculate Synapse Function

2019

The lateral geniculate nucleus is the first relay station for the visual information. Relay neurons of this thalamic nucleus integrate input from retinal ganglion cells and project it to the visual cortex. In addition, relay neurons receive top-down excitation from the cortex. The two main excitatory inputs to the relay neurons differ in several aspects. Each relay neuron receives input from only a few retinogeniculate synapses, which are large terminals with many release sites. This is reflected by the comparably strong excitation, the relay neurons receive, from retinal ganglion cells. Corticogeniculate synapses, in contrast, are simpler with few release sites and weaker synaptic strength…

Assessment of the Potential Energy Hypersurfaces in Thymine within Multiconfigurational Theory: CASSCF vs. CASPT2

2016

The present study provides new insights into the topography of the potential energy hypersurfaces (PEHs) of the thymine nucleobase in order to rationalize its main ultrafast photochemical decay paths by employing two methodologies based on the complete active space self-consistent field (CASSCF) and the complete active space second-order perturbation theory (CASPT2) methods: (i) CASSCF optimized structures and energies corrected with the CASPT2 method at the CASSCF geometries and (ii) CASPT2 optimized geometries and energies. A direct comparison between these strategies is drawn, yielding qualitatively similar results within a static framework. A number of analyses are performed to assess t…