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Biomedical subjects

Kiyomitsu Oyanagi

Publications and source records attributed to Kiyomitsu Oyanagi.

21 records · Page 2Linked to original sources
PubMed2002

Enhanced SUMOylation in polyglutamine diseases.

Small ubiquitin-like modifiers (SUMOs) are proteins homologous to ubiquitin that possibly regulate intranuclear protein localization, nuclear transport, and ubiquitination. We examined patients of DRPLA, SCA1, MJD, and Huntington's disease and found that neurons in affected regions of the brain react strongly to SUMO-1, a family member of SUMOs. Western blot with a transgenic mouse expressing mutant ataxin-1 showed the increase of SUMOylated proteins in the cerebellar cortex, which we named ESCA1 and ESCA2. These results indicated activation of SUMO-1 system in polyglutamine diseases and predicted its involvement in the pathology.

Animals↗
PubMed2002

Degeneration of retinal neuronal processes and pigment epithelium in the early stage of the streptozotocin-diabetic rats.

Early pathological and electro-physiological changes of the retina in the streptozotocin (STZ)-diabetic rats were investigated through optical and electron microscopy in two strains and electro-retinography in one strain. In Sprague-Dawley (SD) rats I month after the onset of diabetes, the thickness of the inner plexiform layer (IPL) and photoreceptor segment layer (PSL) was significantly reduced by 9.9% and 18.9%, respectively (P < 0.01, P < 0.05). In Brown-Norway (BN) rats STZ-diabetic for 1 month, the thickness of the IPL was also significantly reduced by 15.7% (P < 0.05). Cytochemical study using peanut agglutinin (PNA), a lectin binding selectively to the cone photoreceptor-associated domains of the inter-photoreceptor matrix, revealed a marked reduction in intensity, number and length of the PNA-binding cone photoreceptors. Electron microscopy showed deepened hollows in the basal infoldings of the retinal pigment epithelium (RPE) of STZ-rats diabetic for 1 month and large concavities into the cytoplasm in STZ-rats diabetic for 6 months. Blood vessels in the retina and choroid were unremarkable. Single-flash electro-retinogram revealed a reduction in the amplitudes of alpha- and beta-waves of electro-retinogram (ERG) of 1 month STZ BN rats (P < 0.05). These findings indicate that the degeneration of rods/cones in the PSL and RPE are the most prominent pathological alteration sites in the early stage of diabetic rats.

Animals↗