ABSTRACT
Vigilin proteins, the absence of which is known to cause abnormalities in heterochromatin, have been found to bind edited RNAs. Molecular complexes including vigilin comprise proteins involved with RNA editing and with DNA repair, making connections between these processes and RNA-based silencing mechanisms.
Subject(s)
Carrier Proteins/metabolism , DNA Repair , Heterochromatin/genetics , Models, Biological , RNA Interference , RNA-Binding Proteins/metabolism , RNA/metabolism , Autoantigens/metabolism , Carrier Proteins/genetics , DEAD-box RNA Helicases , DNA-Activated Protein Kinase , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Neoplasm Proteins , Protein Serine-Threonine Kinases/metabolism , RNA Helicases/metabolism , RNA-Binding Proteins/geneticsABSTRACT
Se presenta el caso de una mujer joven con un lupus eritematoso sistemico y titulo alto de anticuerpos anti-ribonucleoproteina que desarrollo el cuadro de una hipertension pulmonar primitiva grave en el breve curso de dos anos, a pesar de la completa remision de su enfermedad basica No hemos podido comprobar hallazgos similares en la literatura disponible
Subject(s)
Adult , Humans , Female , Hypertension, Pulmonary , Lupus Erythematosus, SystemicABSTRACT
Se presenta el caso de una mujer joven con un lupus eritematoso sistemico y titulo alto de anticuerpos anti-ribonucleoproteina que desarrollo el cuadro de una hipertension pulmonar primitiva grave en el breve curso de dos anos, a pesar de la completa remision de su enfermedad basica No hemos podido comprobar hallazgos similares en la literatura disponible
Subject(s)
Adult , Humans , Female , Hypertension, Pulmonary , Lupus Erythematosus, SystemicABSTRACT
The ultrastructure of photoreceptor cells of the crayfish (P. clarkii) has been examined by means of thin sections and freeze-fracturing. The study reveals that in the photoreceptor membranes there are particles associated primarily with the A faces of freeze-fracture preparations which have a mean diameter of 80-84 A and a density of 6,600 per per micrometer2. Treatment of the retina with digitonin (a substance capable of extracting visual photopigments) in Ringer's causes marked disruption of the hexagonal arrangement of the microvilli, breakdown of the microvilli into smaller segments, and gradual removal of the particles. The estimated photopigment concentration in the microvillus is 4,000 per micrometer. It is suggested that the observed particles represent the photopigment in situ.
Subject(s)
Astacoidea/ultrastructure , Photoreceptor Cells/ultrastructure , Animals , Cell Membrane/ultrastructure , Digitonin/pharmacology , Photoreceptor Cells/analysis , Photoreceptor Cells/drug effects , Retinal Pigments/analysisABSTRACT
Microspectrophotometric measurements of isolated crayfish rhabdoms illuminated transversely show that their photosensitive absorption exhibits a dichroic ratio of 2 in situ. The major absorption axis matches the axial direction of the closely parallel microvilli comprising the receptor organelle. Since these microvilli are regularly oriented transversely in about 24 layers, with the axes of the microvilli at 90 degrees in alternate layers, transverse illumination of a properly oriented rhabdom displays alternate dichroic and isotropic bands. Because all the microvilli from any one cell share the same orientation, the layers of microvilli constitute two sets of orthogonal polarization analyzers when illuminated along the normal visual axis. Furthermore, since the dichroic ratio is 2 and transverse absorption in isotropic bands is the same as that in the minor absorbing axis of dichroic bands, the simplest explanation of the analyzer action is that the absorbing dipoles of the chromophores, as in rod and cone outer segments, lie parallel to the membrane surface but are otherwise randomly oriented. The rhabdom's functional dichroism thus arises from its specific fine structural geometry.
Subject(s)
Crustacea , Photoreceptor Cells , Retina/cytology , Retinal Pigments/analysis , Adaptation, Ocular , Animals , Dark Adaptation , Optics and Photonics , Spectrophotometry , Visual PerceptionSubject(s)
Houseflies/physiology , Ocular Physiological Phenomena , Retina/physiology , Sensory Receptor Cells , Ultraviolet Rays , Vision, Ocular , Absorption , Animals , Cornea , Genotype , In Vitro Techniques , Light , Mutation , Potentiometry , Retinal PigmentsABSTRACT
Microspectrophotometric measurements of individual dark-adapted rhabdoms of the prawn Palaemonetes vulgaris reveal the presence of two light-sensitive pigments. A pigment with maximum absorbancy at 555 nanometers is converted by light to a long-lived intermediate with wavelength of maximum absorbancy at 496 nanometers. A second pigment with wavelength of maximum absorbancy at 496 nanometers bleaches in the light, seemingly without forming detectable products at wavelengths longer than 375 nanometers. Both pigments occur in each layer of microvilli.
