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Visual Defects (visual + defect)
Selected AbstractsDramatic Response of Choroidal Metastases from Breast Cancer to a Combination of Trastuzumab and VinorelbineTHE BREAST JOURNAL, Issue 1 2004MRCP, Zee-Wan Wong MBBS Abstract: We report the case of a 57-year-old woman with unilateral choroidal metastases from HER-2-positive breast cancer. She was given trastuzumab and vinorelbine with complete resolution of her visual defect after one cycle of treatment. This article illustrates that treatment using trastuzumab-containing chemotherapy regimens in HER-2-overexpressing breast cancer patients with choroidal metastases may be an alternative therapeutic strategy to initial orbital irradiation., [source] Molecular pathology of NEU1 gene in sialidosis,HUMAN MUTATION, Issue 5 2003Volkan Seyrantepe Abstract Lysosomal sialidase (EC 3.2.1.18) has a dual physiological function; it participates in intralysosomal catabolism of sialylated glycoconjugates and is involved in cellular immune response. Mutations in the sialidase gene NEU1, located on chromosome 6p21.3, result in autosomal recessive disorder, sialidosis, which is characterized by the progressive lysosomal storage of sialylated glycopeptides and oligosaccharides. Sialidosis type I is a milder, late-onset, normosomatic form of the disorder. Type I patients develop visual defects, myoclonus syndrome, cherry-red macular spots, ataxia, hyperreflexia, and seizures. The severe early-onset form, sialidosis type II, is also associated with dysostosis multiplex, Hurler-like phenotype, mental retardation, and hepatosplenomegaly. We summarize information on the 34 unique mutations determined so far in the sialidase gene, including four novel missense and one novel nonsense mutations found in two Czech and two French sialidosis patients. The analysis of sialidase mutations in sialidosis revealed considerable molecular heterogeneity, reflecting the diversity of clinical phenotypes that make molecular diagnosis difficult. The majority of sialidosis patients have had missense mutations, many of which have been expressed; their effects on activity, stability, intracellular localization, and supramolecular organization of sialidase were studied. A structural model of sialidase allowed us to localize mutations in the sialidase molecule and to predict their impact on the tertiary structure and biochemical properties of the enzyme. Hum Mutat 22:343,352, 2003. © 2003 Wiley-Liss, Inc. [source] Pigmentation development in hatchery-reared flatfishesJOURNAL OF FISH BIOLOGY, Issue 5 2000J. A. Bolker Malpigmentation is common in hatchery-reared flatfishes, decreasing the market value of whole fish, and increasing the risk of predation for juveniles released to enhance wild stocks. Pigmentation development in flatfishes occurs in two phases. First, during embryonic and larval stages pigment cells differentiate on both sides of the body. Second, at metamorphosis larval melanophores disappear, and adult melanophores differentiate on the ocular but not on the blind side. Malpigmentation seems to result from disruptions of the second phase, and may take the form of albinism on the ocular side or darkening of the blind side. Both types of aberration may be related to aspects of the hatchery environment such as lighting, substratum, and diet. Larval nutrition appears to be a key factor and enrichment of larval diets with fatty acids and Vitamin A can greatly reduce malpigmentation rates; however, levels suffcient to prevent pigmentation defects frequently cause other abnormalities. Two developmental explanations for albinism have been proposed. The first is that differentiation of ocular-side skin follows the normal blind-side pathway and adult melanophores therefore fail to develop on the ocular side. The second hypothesis suggests that dietary deficiencies inhibit retinal development and the resulting visual defects lead to failure of a hormonal signal required for melanophore differentiation. These hypotheses may well be complementary; as yet neither has been thoroughly tested. Definitive tests will require a combination of manipulative techniques such as tissue transplantation and cell culture with nutritional, behavioural and hormonal assays. Such integrative studies will further the understanding both of normal pigmentation development and of the environmental factors that contribute to high rates of albinism in hatchery-reared flatfish. [source] 4141: Visual phenotyping at the "Institut Clinique de la Souris"ACTA OPHTHALMOLOGICA, Issue 2010MJ ROUX Purpose Visual diseases come in many flavors, with a large variety of affected tissues (eye anterior segment, retina, optic nerve, cortex ,), ages of onset, rate of progression and causal factors. In Western countries, if the majority of these diseases are now curable, millions of people are still affected by blindness or low vision, as many retinal diseases (age-related macular degeneration, retinitis pigmentosa, diabetic retinopathy, glaucoma,) still lack efficient treatments. In a facility devoted to mouse phenotyping as the Mouse Clinic Institute (MCI), it is thus of major importance to propose an efficient visual phenotyping platform, to pick up visual defects in screened mutants, to assess the beneficial effects of potential treatments or the eventual adverse effects of drugs targeting the CNS. Methods Methods: Mouse mutant lines from the Eumodic European project, as well as lines from specific academic projects, go through clinical observation (slit lamp, fundus imaging) in the context of a behavioral phenotyping pipeline, or are assessed in more details with angiography, optomotor response, electroretinography, retinal histology and/or immunohistochemistry. Results To illustrate the possibilities offered by the MCI visual phenotyping platform, we will present results obtained from various projects, as well as the validation of electroretinography protocols to follow dark adaptation and the effect of acute drug injections. Conclusion In an environment allowing for an in depth phenotyping, from behavior to biochemistry, metabolism and cardiology, the MCI visual phenotyping platform provides a comprehensive set of tests to get the most out of genetically modified mice. [source] Scaling the structure,function relationship for clinical perimetryACTA OPHTHALMOLOGICA, Issue 4 2005Ronald S. Harwerth Abstract. Purpose:,The full ranges of glaucomatous visual field defects and retinal ganglion cell losses extend over several orders of magnitude and therefore an interpretation of the structure,function relationship for clinical perimetry requires scaling of both variables. However, the most appropriate scale has not been determined. The present study was undertaken to compare linear and logarithmic transformations, which have been proposed for correlating the perimetric defects and neural losses of glaucoma. Methods:,Perimetry, by behavioural testing, and retinal histology data were obtained from rhesus monkeys with significant visual field defects caused by experimental glaucoma. Ganglion cell densities were measured in histologic sections of retina that corresponded to specific perimetry test locations for the treated and control eyes. The linear (percentage) and logarithmic (decibel) relationships for sensitivity loss as a function of ganglion cell loss were analysed. Results:,With decibel scaling, visual sensitivity losses and ganglion cell densities were linearly correlated with high coefficients of determination (r2), although the parameters of the functions varied with eccentricity. The structure,function relationships expressed as linear percentage-loss functions were less systematic in two respects. Firstly, the relationship exhibited considerable scatter in the data for small losses in visual sensitivity and, secondly, visual sensitivity losses became saturated with larger losses in ganglion cell density. The parameters of the percentage-loss functions also varied with eccentricity, but the variation was less than for the decibel-loss functions. Conclusions:,Linear scaling of perimetric defects and ganglion cell losses might potentially improve the structure,function relationship for visual defects associated with small amounts of cell loss, but the usefulness of the relationship is limited because of the high variability in that range. With log,log co-ordinates, the structure,function relationship for clinical perimetry is relatively more accurate and precise for cell losses greater than about 3 dB. The comparatively greater accuracy and precision of decibel loss functions are a likely consequence of the logarithmic scale of stimulus intensities for perimetry measurements and because the relationship between visual sensitivity and the number of neural detectors is a form of probability summation. [source] | ||||||||||