Publications by authors named "Tatsuo Oikawa"

Sphingomyelin synthase 2 (SMS2) has attracted attention as a drug target for the treatment of various cardiovascular and metabolic diseases. The modification of a high throughput screening hit, 2-quinolone 10, enhanced SMS2 inhibition at nanomolar concentrations with good selectivity against SMS1. To improve the pharmaceutical properties such as passive membrane permeability and aqueous solubility, adjustment of lipophilicity was attempted and 1,8-naphthyridin-2-one 37 was identified as a potent and selective SMS2 inhibitor.

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Dysferlinopathies, which are muscular diseases caused by mutations in the dysferlin gene, remain serious medical problems due to the lack of therapeutic agents. Herein, we report the design, synthesis, and structure-activity relationships of a 2,6-disubstituted 3-imidazo[4,5-]pyridine series, which was identified from the phenotypic screening of chemicals that increase the level of dysferlin in myocytes differentiated from patient-derived induced pluripotent stem cells (iPSCs). Optimization studies with cell-based phenotypic assay led to the identification of a highly potent compound, , with dysferlin elevation effects at double-digit nanomolar concentrations.

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Dysferlinopathy is a progressive muscle disorder that includes limb-girdle muscular dystrophy type 2B and Miyoshi myopathy (MM). It is caused by mutations in the dysferlin (DYSF) gene, whose function is to reseal the muscular membrane. Treatment with proteasome inhibitor MG-132 has been shown to increase misfolded dysferlin in fibroblasts, allowing them to recover their membrane resealing function.

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Purinergic P2Y receptors, G-protein coupled receptors that primarily couple with Gα-proteins, are activated equipotently by adenosine-5'-triphosphate (ATP) and uridine-5'-triphosphate. Evidence suggests that P2Y agonists make potential drug candidates for the treatment of cardiovascular diseases. However, selective non-nucleotide, small-molecule P2Y agonists have yet to be developed.

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Despite considerable efforts to develop efficient carriers, the major target organ of short-interfering RNAs (siRNAs) remains limited to the liver. Expanding the application outside the liver is required to increase the value of siRNAs. Here we report on a novel platform targeted to muscular organs by conjugation of siRNAs with anti-CD71 Fab' fragment.

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Purpose: Intravascular ultrasonography (IVUS) and (18)F-FDG PET have been used to evaluate the efficacy of antiatherosclerosis drugs. These two modalities image different characteristics of atherosclerotic plaques, and a comparison of IVUS and PET images with histology has not been performed. The aim of this study was to align IVUS and PET images using anatomic landmarks in Watanabe heritable hyperlipidaemic (WHHL) rabbits, enabling comparison of their depiction of aortic atherosclerosis.

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Article Synopsis
  • The study focuses on understanding how hematopoietic stem cells mature into erythroid cells by identifying specific genes and markers involved in this process.
  • Researchers screened for genes that support the growth and development of erythroid cells, leading to the discovery of 17 candidate genes that play a role in erythroid colony formation.
  • The findings highlight Apoa-1 as a novel marker that increases as stem cells differentiate into mature erythroid cells, indicating its significance in both mice and humans.
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The gene transduction method is a very powerful tool, not only in basic science but also in clinical medicine. Regenerative medicine is one field that has close connection with both basic and clinical. Recently, it has been reported that induced pluripotent stem (iPS) cells can be produced from somatic cells by a three or four gene transduction.

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Growth arrest and DNA damage-inducible protein 45 (GADD45) plays an important role in suppressing multistep carcinogenesis. In this report, we describe the isolation of the complete wild-type feline GADD45 cDNA from feline tissues. Expression of feline GADD45 mRNA was detected in the liver, spleen, kidney, lung, and testis.

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Three beagle dogs were inoculated with mice spleen/liver homogenate infected with Ehrlichia species detected from Ixodes ovatus (EIO) and one dog was used as a control. All three infected dogs did not show clinical signs of disease except for mild pyrexia throughout the 41-day study period. Splenomegaly was observed from Day 7 post-inoculation (p.

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Elimination of the regulatory mechanism underlying numeral homeostasis of centrosomes, as seen in cells lacking p53, results in abnormal amplification of centrosomes, which increases the frequency of chromosome segregation errors, and thus contributes to the chromosome instability frequently observed in cancer cells. We have previously reported that p53(-/-) mouse cells in prolonged culture undergo genomic convergence similar to that observed during tumor progression; early-passage p53(-/-) cells are karyotypically heterogeneous due to extensive chromosome instability associated with centrosome amplification, while late-passage p53(-/-) cells are aneuploid yet karyotypically homogeneous and chromosomally stable. Moreover, they contain numerically normal centrosomes.

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OmpL1 is a 31-kDa outer membrane protein characterized in 1993 and known to be expressed only in pathogenic Leptospira spp. Recombinant OmpL1 (GST-rOmpL1) was expressed for use as an ELISA antigen for the detection of anti-Leptospira antibodies. In immunoblot analysis, the protein reacted with sera of dogs infected with three different serotypes of Leptospira interrogans, while did not react with sera of dogs both uninfected negative controls and infected with Borrelia burgdorferi, which is closely related to Leptospira spp.

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Article Synopsis
  • * Centrosome amplification and chromosomal instability were found in three of the five cell lines; one showed mutations in the p53 gene while the others did not have such abnormalities.
  • * The level of mdm2 mRNA was similar between normal cat blood cells and the lymphoma cell lines, suggesting that there might be another unknown mechanism causing centrosome amplification in feline lymphomas.
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  • Researchers created a GST-recombinant canine P53 fusion protein to identify anti-P53 antibodies in dogs with tumors.
  • Out of 16 tumor serum samples, four tested positive for reactions with the fusion protein, while the other samples and controls did not show any reaction.
  • Investigation of tumor tissues revealed a specific case with a p53 gene mutation that produced anti-P53 antibodies, indicating that these antibodies are linked to p53 mutations in tumor-affected dogs.
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