Search PubMed⌕ Search

Biomedical subjects

T Numaga

Publications and source records attributed to T Numaga.

9 recordsLinked to original sources
PubMed2007

TRPC7.

Canonical transient receptor potential7 (TRPC7) is the seventh identified member of the mammalian TRPC channel family, comprising nonselective cation channels activated through the phospholipase C (PLC) signaling pathway. TRPC7 is directly activated by diacylglycerol (DAG), one of the PLC products, having high sequence homologywith TRPC3 and TRPC6, which are also activated by DAG. TRPC7 shows unique properties of activation, such as constitutive activity and susceptibility to negative regulation by extracellular Ca2+. Although the physiological importance of TRPC7 in the native environment remains elusive, TRPC7 would play important roles in Ca2+ signaling pathway through these characteristic features.

Animals↗
PubMed1991

[Morphology of live retinal pigment epithelial cells].

We attempted to observe, by means of fluorescein angiography, the retinal pigment epithelial cells in pigmented rabbits. Fluorescein angiography was performed in 31 pigmented rabbits, after intravenous injection of 14mg/kg fluorescein sodium. The angiograms were evaluated as prints and as negative film under a light microscope. Animals were sacrificed and submitted to studies by scanning electron microscopy and fluorescein light microscopy. On fluorescein angiograms, we observed mosaic pattern which consisted of numerous polygonal spots overlying choroidal vasculature. Each polygonal spot showed central hypofluorescent area surrounded by hyperfluorescent rim. They were seen in all the eyes except 4 lightly pigmented eyes. They seemed to correspond, in size, to each retinal pigment epithelial cell. This pattern appeared from the early choroidal phase on, to become more distinct 5 to 15 minutes after dye injection. A hexagonal pattern was regularly seen away from the medullary rays by 3 or more disc diameters. The pattern became larger in the periphery than in the posterior pole. These angiographic findings closely matched those of retinal pigment epithelial cells as seen by scanning electron microscopy and fluorescein light microscopy in sizes and shapes. The findings indicate that it is possible to identify retinal pigment epithelial cells in pigmented rabbits by conventional fluorescein angiography.

Animals↗
PubMed1986

Epivascular glia and paravascular holes in normal human retina.

We examined the retinal surface of 28 autopsy eyes by scanning electron microscopy (SEM). Glialike cells or their processes, arranged in rows, were observed along retinal vessels in 22 eyes. Additionally, there were clusters of glialike cells over retinal vessels in 8 eyes. These proliferations ranged from focal to extensive ones, the latter resulting in distinct preretinal membranes. Focal defects of the superficial retina along the vessel were noted in 6 of 28 eyes. Transmission electron microscopic study in 2 surgically enucleated eyes with normal retinae revealed epivascular retinal degeneration and thinning of Müller cells. Glial processes appeared to be covering the defect of the internal limiting membrane and some projections of these cells continued inwards. These findings were consistent with the SEM findings of epivascular glialike structure. Our conclusions are that epivascular glialike structures and paravascular surface defects appear as a common finding in normal senile eyes, and that occasionally membranous formations arise from the epivascular area.

Adult↗
PubMed1982

Structure of the inner retinal surface in simple diabetic retinopathy.

An eye with moderate simple diabetic retinopathy in a 47-year-old man was enucleated for rubeotic glaucoma of 2 months' duration and was subjected to histopathological and ultrastructural studies. Particular attention was paid to the structure of the retinal surface as examined by scanning electron microscopy. Six normal eyes and 2 eyes with long-standing central retinal vein occlusion served as the control. The inner retinal surface in normal eyes with posterior vitreous detachment appeared as a smooth, continuous sheet seen by scanning electron microscopy. No cell-like structure was detected on the retinal surface. In the eye with simple diabetic retinopathy, on the other hand, numerous spherical cells with pseudopodic protrusions were observed throughout the retinal surface which were identified as macrophages in light, scanning and transmission electron microscopic studies. The macrophages were particularly dense and were arranged in circinate pattern corresponding to circinate lesions within the retina. The macrophages were also densely populated in retinal areas with hard exudates. In areas adjacent to the macrophages, the inner retinal surface lost its smooth and continuous structure. The matrix in the inner limiting membrane disappeared in such areas so that a coarse network of filaments lay bare on the retinal surface. These findings indicate that the inner retinal surface would be pathologically altered in simple diabetic retinopathy, particularly where hard exudates are located.

Diabetic Retinopathy↗