University of Hamburg

About: University of Hamburg is a education organization based out in Hamburg, Germany. It is known for research contribution in the topics: Population & Laser. The organization has 45564 authors who have published 89286 publications receiving 2850161 citations. The organization is also known as: Hamburg University.

Mutations in RPE65 cause autosomal recessive childhood-onset severe retinal dystrophy.

Abstract: Autosomal recessive childhood-onset severe retinal dystrophy (arCSRD) designates a heterogeneous group of disorders affecting rod and cone photoreceptors simultaneously1. The most severe cases are termed Leber congenital amaurosis (LCA), while the less aggressive forms are usually considered juvenile retinitis pigmentosa. Recently, mutations in the retinal-specific guanylate cyclase gene were found in patients with LCA2. Disease genes implicated in other forms of arCSRD are expected to encode proteins present in the neuroretina or in the retinal pigment epithelium (RPE). The RPE, a monolayer of cells separating the vascular-rich choroid and the neuroretina, is in intimate contact with the outer segments of rods and cones via the microvilli surrounding the photoreceptors. The RPE expresses a tissue-specific and evolutionary highly conserved 61 kD protein (RPE65) present at high levels in vivo3–6. Although the function of RPE65 is not yet known, an important role in the RPE/photoreceptor vitamin-A cycle is suggested by the fact that RPE65 associates both with serum retinol-binding protein7,8 and with the RPE-specific 11-cis retinol dehydrogenase, an enzyme active in the synthesis of the visual pigment chromophore 11-cis retinal9. Here we report that the analysis of RPE65 in a collection of about 100 unselected retinal-dystrophy patients of different ethnic origin revealed five that are likely to be pathogenic mutations, including a missense mutation (Pro363Thr), two point mutations affecting splicing (912+1G→T and 65+5G→A) and two small re-arrangements (ins144T and 831del8) on a total of nine alleles of five patients with arCSRD. In contrast to other genes whose defects have been implicated in degenerative retinopathies, RPE65 is the first disease gene in this group of inherited disorders that is expressed exclusively in the RPE, and may play a role in vitamin-A metabolism of the retina.

All unitary ray representations of the conformal group SU(2,2) with positive energy

Abstract: We find all those unitary irreducible representations of the ∞-sheeted covering group\(\tilde G\) of the conformal group SU(2,2)/ℤ4 which have positive energyP0≧0. They are all finite component field representations and are labelled by dimensiond and a finite dimensional irreducible representation (j1,j2) of the Lorentz group SL(2ℂ). They all decompose into a finite number of unitary irreducible representations of the Poincare subgroup with dilations.