29 results on '"Ohkawa, Y."'
Search Results
2. DEVELOPMENT OF SIMTRACS AND ITS APPLICATIONS
- Author
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Watanabe, T., primary, Ikeda, H., additional, Ohkawa, Y., additional, and Satou, A., additional
- Published
- 1987
- Full Text
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3. FLOATING TRAFFIC CONTROL FOR PUBLIC TRANSPORTATION SYSTEM
- Author
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Sasama, H., primary and Ohkawa, Y., additional
- Published
- 1984
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4. Hyperglycaemia induces diet-dependent defects of the left-right axis by lowering intracellular pH.
- Author
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Matsuoka R, Kitajima K, Nii T, Zou Z, Tanaka K, Joo K, Ohkawa Y, Ohga S, and Meno C
- Subjects
- Animals, Mice, Female, Pregnancy, Hyperglycemia metabolism, Hyperglycemia pathology, Hydrogen-Ion Concentration, Homeobox Protein PITX2, Wnt Signaling Pathway, Transcription Factors metabolism, Transcription Factors genetics, Body Patterning genetics, Gene Expression Regulation, Developmental, Diet, Diabetes Mellitus, Experimental metabolism, Diabetes Mellitus, Experimental pathology, Mice, Knockout, Nodal Protein metabolism, Nodal Protein genetics, Mice, Inbred C57BL, Wnt3A Protein metabolism, Wnt3A Protein genetics, Homeodomain Proteins metabolism, Homeodomain Proteins genetics
- Abstract
Pregestational diabetes is a risk factor for congenital anomalies, including heterotaxy syndrome, a rare birth defect characterized by the abnormal arrangement of organs relative to the left-right (L-R) body axis. To provide insight into the underlying mechanism by which diabetes induces heterotaxy, we here analyzed the L-R axis of mouse embryos of diabetic dams. Various Pitx2 expression patterns indicative of disruption of L-R axis formation were apparent in such embryos. Expression of Nodal at the node, which triggers a Nodal-Pitx2 expression cascade in lateral plate mesoderm, showed marked regression associated with L-R axis malformation. This regression was similar to that apparent in Wnt3a
-/- embryos, and canonical Wnt signalling was indeed found to be downregulated in embryos of diabetic dams. RNA sequencing revealed dysregulation of glycolysis in embryos of diabetic dams, and high glucose lowered intracellular pH in the primitive streak, leading to the suppression of Wnt signalling and the regression of Nodal expression. Of note, maternal vitamin A intake increased the incidence of L-R axis defects in embryos of diabetic dams, with dysregulation of retinoic acid metabolism being apparent in these embryos and in Wnt3a-/- embryos. Our results shed light on the mechanisms underlying embryopathies associated with maternal diabetes and suggest the importance of diet for prevention of heterotaxy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
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5. N-glycan branching enzymes involved in cancer, Alzheimer's disease and COPD and future perspectives.
- Author
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Taniguchi N, Ohkawa Y, Maeda K, Kanto N, Johnson EL, and Harada Y
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- Humans, N-Acetylglucosaminyltransferases genetics, Polysaccharides, Alzheimer Disease, 1,4-alpha-Glucan Branching Enzyme, Neoplasms, Pulmonary Disease, Chronic Obstructive
- Abstract
Over the past 3 decades, our group has been involved in studies related to the biosynthesis of N-glycan branching and related glycosyltransferases and have purified most of these Golgi-derived enzymes to homogeneity using classical purification methods and cloned the cDNA of GnT-III, IV, V, VI and Fut8 except GnT-IX(Vb) which was obtained by homology cloning. Based primarily on our data, we briefly summarize the significance of three major enzymes and discuss perspectives for future studies on the occasion of Ernesto's 90th birthday celebration., Competing Interests: Declaration of competing interest The authors declare that we have no financial interests/personal relationships which may be considered as potential competing interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
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6. Reduction of tethering distance by papillary muscle tugging approximation with mitral valve replacement for non-ischemic functional mitral regurgitation induces left ventricular reverse remodeling.
- Author
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Ishigaki T, Wakasa S, Shingu Y, Ohkawa Y, Yamada A, Anzai T, and Matsui Y
- Subjects
- Humans, Mitral Valve surgery, Papillary Muscles, Ventricular Function, Left physiology, Ventricular Remodeling, Mitral Valve Insufficiency
- Abstract
Background: Functional mitral regurgitation (FMR) is caused by left ventricular (LV) remodeling and subsequent tethering of the mitral valve (MV). If LV remodeling is irreversibly advanced, it could not be attenuated by the MV procedure alone, although the additional subvalvular procedure could induce LV reverse remodeling by forcibly reducing MV tethering. This study aimed to assess the anti-tethering effect of papillary muscle tugging approximation (PMTA) on LV reverse remodeling after mitral valve replacement (MVR) for non-ischemic FMR., Methods: The study subjects were 19 patients who underwent MVR with and without PMTA [MVR + PMTA (n = 11) and MVR alone (n = 8), respectively] for non-ischemic FMR. The tethering distance (TD) and LV end-systolic volume (ESV) at the preoperative, postoperative, and follow-up periods were assessed in terms of their correlation and time-dependent changes. The intra-LV energy efficiency was also evaluated through vector flow mapping analysis., Results: TD and ESV were comparable between both procedures preoperatively and did not change after MVR alone. In MVR + PMTA, however, a significant decrease was identified in TD and ESV at the early postoperative and follow-up periods, respectively [TD = 48, 30, and 31 mm (p < 0.001) and ESV = 159, 133, and 82 mL (p < 0.001) at the preoperative, postoperative, and follow-up periods, respectively]. Finally, at follow-up, the extent of change from the preoperative value in ESV significantly correlated with that in TD (ρ = 0.81, p < 0.001 for overall; ρ = 0.93, p < 0.001 for MVR + PMTA; ρ = 0.86, p = 0.011 for MVR alone). The ratio of TD to ESV was also significantly correlated with systolic energy loss to LV stroke work after MVR + PMTA (ρ = 0.81, p = 0.015)., Conclusions: PMTA for non-ischemic FMR could induce LV reverse remodeling depending on the extent of postoperative TD reduction. A smaller TD to ESV was associated with a higher intra-LV energy efficiency after PMTA + MVR., (Copyright © 2021. Published by Elsevier Ltd.)
- Published
- 2022
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7. Usefulness of Multislice Computed Tomography in Percutaneous Coronary Intervention Following Valve-in-Valve Transcatheter Aortic Valve Replacement.
- Author
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Miura S, Yamashita T, Iwakiri N, Yoshida N, and Ohkawa Y
- Subjects
- Aortic Valve surgery, Aortic Valve Stenosis surgery, Humans, Multidetector Computed Tomography, Treatment Outcome, Percutaneous Coronary Intervention, Transcatheter Aortic Valve Replacement
- Published
- 2020
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8. The novel heme-dependent inducible protein, SRRD regulates heme biosynthesis and circadian rhythms.
- Author
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Adachi Y, Umeda M, Kawazoe A, Sato T, Ohkawa Y, Kitajima S, Izawa S, Sagami I, and Taketani S
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- Aminolevulinic Acid pharmacology, Animals, CLOCK Proteins genetics, Cell Proliferation, Circadian Rhythm Signaling Peptides and Proteins metabolism, Gene Expression Regulation drug effects, Gene Knockout Techniques, Mice, NIH 3T3 Cells, RNA, Messenger genetics, Circadian Rhythm, Circadian Rhythm Signaling Peptides and Proteins genetics, Heme metabolism
- Abstract
Heme plays a role in the regulation of the expression of genes related to circadian rhythms and heme metabolism. In order to identify new heme-regulated proteins, an RNA sequence analysis using mouse NIH3T3 cells treated without or with 5-aminolevulinic acid (ALA) was performed. Among the changes observed in the levels of various mRNAs including heme oxygenase-1 (HO-1) and ALA synthase-1 (ALAS1), a mouse homologue of the plant circadian-regulating protein SRR1, SRR1 domain containing (SRRD) was induced by the ALA treatment. The expression of SRRD was dependent on heme biosynthesis, and increased the production of heme. SRRD was expressed under circadian rhythms, and influenced the expression of clock genes including PER2, BMAL1, and CLOCK. The knockout of SRRD arrested the growth of cells, indicating that SRRD plays roles in heme-regulated circadian rhythms and cell proliferation., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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9. Glycolipids: Essential regulator of neuro-inflammation, metabolism and gliomagenesis.
- Author
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Furukawa K, Ohmi Y, Ji S, Zhang P, Bhuiyan RH, Ohkawa Y, Tajima O, Hashimoto N, and Furukawa K
- Subjects
- Animals, Complement System Proteins genetics, Complement System Proteins metabolism, Glioma genetics, Glioma pathology, Humans, Inflammation, Leptin genetics, Leptin metabolism, Membrane Microdomains chemistry, Membrane Microdomains metabolism, Membrane Microdomains pathology, Mice, Mice, Knockout, N-Acetylgalactosaminyltransferases deficiency, N-Acetylgalactosaminyltransferases genetics, Neoplasms, Nerve Tissue genetics, Neoplasms, Nerve Tissue pathology, Nerve Tissue pathology, Neurons metabolism, Neurons pathology, Receptors, Leptin genetics, Receptors, Leptin metabolism, Sialyltransferases deficiency, Sialyltransferases genetics, Gangliosides metabolism, Gene Expression Regulation, Neoplastic, Glioma metabolism, Neoplasms, Nerve Tissue metabolism, Nerve Tissue metabolism
- Abstract
Gene knockout mice of glycosyltransferases have clearly showed roles of their products in the bodies, while there are examples where phenotype of knockout was much less severe than expected probably due to functional redundancy. The most striking novel finding obtained from ganglioside-deficient mice was that progressive inflammatory reaction took place, leading to neurodegeneration. In particular, dysfunction of complement-regulatory proteins due to deteriorated architecture of lipid rafts seemed to be essential mechanisms for the inflammation. Furthermore, roles of gangliosides in neurons were demonstrated by neuron-specific transgenic of B4galnt1 with genetic background of B4galnt1 deficiency. From study of gene knockout mice of St8sia1, new roles of b-series gangliosides in leptin secretion from adipocytes, and roles of a-series gangliosides in leptin receptor, ObR in hypothalamus were demonstrated, leading to apparent intact balance of energy. Essential roles of b-series gangliosides in malignant properties of gliomas were also shown, suggesting their roles in the regulation of inflammation and proliferation in nervous tissues. How to apply these findings for the control of newly discovered patients with ganglioside deficiency remains to be investigated. This article is part of a Special Issue entitled Neuro-glycoscience, edited by Kenji Kadomatsu and Hiroshi Kitagawa., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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10. DND protein functions as a translation repressor during zebrafish embryogenesis.
- Author
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Kobayashi M, Tani-Matsuhana S, Ohkawa Y, Sakamoto H, and Inoue K
- Subjects
- Animals, Nanog Homeobox Protein genetics, RNA, Messenger genetics, RNA-Binding Proteins genetics, Zebrafish Proteins genetics, Protein Biosynthesis physiology, RNA-Binding Proteins physiology, Repressor Proteins physiology, Zebrafish embryology, Zebrafish Proteins physiology
- Abstract
Germline and somatic cell distinction is regulated through a combination of microRNA and germ cell-specific RNA-binding proteins in zebrafish. An RNA-binding protein, DND, has been reported to relieve the miR-430-mediated repression of some germ plasm mRNAs such as nanos3 and tdrd7 in primordial germ cells (PGCs). Here, we showed that miR-430-mediated repression is not counteracted by the overexpression of DND protein in somatic cells. Using a λN-box B tethering assay in the embryo, we found that tethering of DND to reporter mRNA results in translation repression without affecting mRNA stability. Translation repression by DND was not dependent on another germline-specific translation repressor, Nanos3, in zebrafish embryos. Moreover, our data suggested that DND represses translation of nanog and dnd mRNAs, whereas an RNA-binding protein DAZ-like (DAZL) promotes dnd mRNA translation. Thus, our study showed that DND protein functions as a translation repressor of specific mRNAs to control PGC development in zebrafish., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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11. Periostin Promotes Scar Formation through the Interaction between Pericytes and Infiltrating Monocytes/Macrophages after Spinal Cord Injury.
- Author
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Yokota K, Kobayakawa K, Saito T, Hara M, Kijima K, Ohkawa Y, Harada A, Okazaki K, Ishihara K, Yoshida S, Kudo A, Iwamoto Y, and Okada S
- Subjects
- Animals, Antibodies, Neutralizing pharmacology, Axons drug effects, Axons metabolism, Axons pathology, Cell Adhesion Molecules deficiency, Cell Adhesion Molecules genetics, Cell Proliferation drug effects, Female, Macrophages drug effects, Mice, Inbred C57BL, Mice, Knockout, Monocytes drug effects, Nerve Regeneration drug effects, Pericytes drug effects, RNA, Messenger genetics, RNA, Messenger metabolism, Recovery of Function drug effects, Spinal Cord Injuries genetics, Spinal Cord Injuries physiopathology, Tumor Necrosis Factor-alpha pharmacology, Cell Adhesion Molecules metabolism, Cicatrix pathology, Macrophages pathology, Monocytes pathology, Pericytes pathology, Spinal Cord Injuries pathology
- Abstract
Scar formation is a prominent pathological feature of traumatic central nervous system (CNS) injury, which has long been implicated as a major impediment to the CNS regeneration. However, the factors affecting such scar formation remain to be elucidated. We herein demonstrate that the extracellular matrix protein periostin (POSTN) is a key player in scar formation after traumatic spinal cord injury (SCI). Using high-throughput RNA sequencing data sets, we found that the genes involved in the extracellular region, such as POSTN, were significantly expressed in the injured spinal cord. The expression of POSTN peaked at 7 days after SCI, predominantly in the scar-forming pericytes. Notably, we found that genetic deletion of POSTN in mice reduced scar formation at the lesion site by suppressing the proliferation of the pericytes. Conversely, we found that recombinant POSTN promoted the migration capacity of the monocytes/macrophages and increased the expression of tumor necrosis factor-α from the monocytes/macrophages in vitro, which facilitated the proliferation of pericytes. Furthermore, we revealed that the pharmacological blockade of POSTN suppressed scar formation and improved the long-term functional outcome after SCI. Our findings suggest a potential mechanism whereby POSTN regulates the scar formation after SCI and provide significant evidence that POSTN is a promising therapeutic target for CNS injury., (Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
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12. Increased a-series gangliosides positively regulate leptin/Ob receptor-mediated signals in hypothalamus of GD3 synthase-deficient mice.
- Author
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Ji S, Tokizane K, Ohkawa Y, Ohmi Y, Banno R, Okajima T, Kiyama H, Furukawa K, and Furukawa K
- Subjects
- Adipocytes cytology, Adipose Tissue, Brown metabolism, Animals, Cell Nucleus metabolism, G(M1) Ganglioside metabolism, Immunohistochemistry, Leptin metabolism, Male, Mice, Mice, Knockout, Neurons metabolism, STAT3 Transcription Factor genetics, Signal Transduction, Gangliosides metabolism, Hypothalamus metabolism, Receptors, Leptin genetics, Sialyltransferases metabolism
- Abstract
Gangliosides are widely involved in the regulation of cells and organs. However, little is known about their roles in adipose tissues and hypothalamus. In GD3 synthase-knockout (GD3S KO) mice, deletion of b-series gangliosides resulted in the reduction of serum leptin due to disturbed secretion from adipocytes. To examine whether leptin signals altered, leptin/leptin receptor (ObR)-mediated signaling in hypothalamus was analyzed. Hypothalamus of GD3S KO mouse showed increased expression of GM1 and GD1a, and increased activation of ObR-mediated signals such as pSTAT3 and c-Fos. Leptin stimulation of hypothalamus-derived N-41 cells and their transfectants with GD3S cDNA showed that a-series gangliosides positively regulate leptin/ObR-mediated signals. Co-precipitation analysis revealed that ObR interacts with a-series gangliosides with increased association by leptin stimulation. In brown adipose tissues (BAT) of GD3S KO mice, their weights and adipocyte numbers were increased, and BAT markers such as PGC1α and UCP-1 were also up-regulated. These results suggested that leptin/ObRb-mediated signals were enhanced in hypothalamus of GD3S KO mice due to increased a-series gangliosides, leading to the apparently similar features of energy expenditure between the KO and wild type mice., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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13. Identification of low-abundance proteins in serum via the isolation of HSP72 complexes.
- Author
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Tanaka M, Shiota M, Nakao T, Uemura R, Nishi S, Ohkawa Y, Matsumoto M, Yamaguchi M, Osada-Oka M, Inagaki A, Takahashi K, Nakayama KI, Gi M, Izumi Y, Miura K, and Iwao H
- Subjects
- Animals, Humans, Rats, Recombinant Proteins chemistry, Antibodies, Monoclonal chemistry, Biomarkers, Tumor blood, Biomarkers, Tumor chemistry, Biomarkers, Tumor isolation & purification, Blood Proteins chemistry, Blood Proteins isolation & purification, Blood Proteins metabolism, HSP72 Heat-Shock Proteins chemistry, Multiple Myeloma blood, Neoplasm Proteins blood, Neoplasm Proteins chemistry, Neoplasm Proteins isolation & purification
- Abstract
Heat shock protein 72 (HSP72) is an intracellular molecular chaperone that is overexpressed in tumor cells, and has also been detected in extracellular regions such as the blood. HSP72 forms complexes with peptides and proteins that are released from tumors. Accordingly, certain HSP72-binding proteins/peptides present in the blood of cancer patients may be derived from tumor cells. In this study, to effectively identify low-abundance proteins/peptides in the blood as tumor markers, we established a method for isolating HSP72-binding proteins/peptides from serum. Nine HSP72-specific monoclonal antibodies were conjugated to N-hydroxysulfosuccinimide-activated Sepharose beads (NHq) and used to isolate HSP72 complexes from serum samples. Precipitated proteins were then identified by LC-MS/MS analysis. Notably, this approach enabled the isolation of low-abundance proteins from serum without albumin removal. Moreover, by subjecting the serum samples of ten patients with multiple myeloma (MM) to NHq analysis, we identified 299 proteins present in MM HSP72 complexes, including 65 intracellular proteins. Among the intracellular proteins detected, 21 were present in all serum samples tested, while 11 were detected in both the conditioned media from cultured multiple myeloma cells and serum from MM patients. These results suggest that the NHq method can be applied to discover candidate tumor markers., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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14. b-Series gangliosides crucially regulate leptin secretion in adipose tissues.
- Author
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Ji S, Ohkawa Y, Tokizane K, Ohmi Y, Banno R, Furukawa K, Kiyama H, and Furukawa K
- Subjects
- 3T3-L1 Cells, Adipose Tissue cytology, Animals, Caveolin 1 metabolism, Cell Differentiation, Leptin blood, Membrane Microdomains metabolism, Mice, Mice, Knockout, Sialyltransferases deficiency, Sialyltransferases genetics, Stromal Cells cytology, Stromal Cells drug effects, Stromal Cells metabolism, beta-Cyclodextrins pharmacology, Adipose Tissue metabolism, Gangliosides metabolism, Leptin metabolism
- Abstract
Gangliosides are widely involved in the regulation of cells and organs. However, little is known about their roles in leptin secretion from adipose tissues. Genetic deletion of b-series gangliosides resulted in the marked reduction of serum leptin. Expression analysis of leptin revealed that leptin accumulated in the adipose tissues of GD3 synthase-knockout (GD3S KO) mice. Analysis of primary cultured stromal vascular fractions (SVF) derived from GD3S KO mice revealed that leptin secretion was reduced, although leptin amounts in cells were increased compared with those of wild type. Interestingly, addition of b-series gangliosides to the culture medium of differentiated SVF resulted in the restoration of leptin secretion. Results of methyl-β-cyclodextrin treatment of differentiated 3T3-L1 cells as well as immunocytostaining of leptin and caveolin-1 suggested that b-series gangliosides regulate the leptin secretion from adipose tissues in lipid rafts., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
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15. Regulatory function of glycosphingolipids in the inflammation and degeneration.
- Author
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Furukawa K, Ohmi Y, Kondo Y, Ohkawa Y, Tajima O, and Furukawa K
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- Animals, Brain metabolism, Brain pathology, Complement Activation, Gangliosides genetics, Gangliosides metabolism, Globosides metabolism, Glycosphingolipids genetics, Humans, Inflammation pathology, Mice, Mice, Knockout, Mutation, Neurodegenerative Diseases pathology, Neuroglia physiology, Spinal Cord metabolism, Spinal Cord pathology, Glycosphingolipids physiology, Inflammation metabolism, Neurodegenerative Diseases metabolism
- Abstract
Recent progress in the biological sciences has revealed that a number of extrinsic and intrinsic environmental factors may cause chronic inflammation. When these insults are persistent or intermittently repeated, regardless of extrinsic or intrinsic origins, homeostasis of our bodies would be disturbed and undergo long-term impact. These situations might give rise to chronic inflammation, leading to various diseases as results of accumulative effects of various inflammatory reactions. Complex carbohydrates expressed mainly on the cell surface have been demonstrated to play roles in fine-tuning of various biological processes to maintain homeostasis of cells, organs and our bodies. When abnormal physicochemical insults and harmful pathogens invade, the fine-tuning including modification of the glycosylation patterns is continuously exerted. Therefore, defects in the proper response with proper glycosylation lead to chronic inflammation and subsequent deterioration of individual tissues and organs. Genetic depletion of sialic acid-containing glycolipids, gangliosides resulted in the inflammation of CNS and neurodegeneration. Lactosylceramide was also reported to mediate neuroinflammation, leading to chronic inflammatory diseases. Defects of globoseries glycolipids resulted in the increased sensitivity to LPS toxicity. Thus, possibilities that manipulation of synthesis and expression of glycosphingolipids may be applicable for the disease control are now proposed., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
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16. Wnt signaling regulates left-right axis formation in the node of mouse embryos.
- Author
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Kitajima K, Oki S, Ohkawa Y, Sumi T, and Meno C
- Subjects
- Animals, Female, Hepatocyte Nuclear Factor 3-beta physiology, Immunoglobulin J Recombination Signal Sequence-Binding Protein physiology, Intercellular Signaling Peptides and Proteins physiology, Mice, Mice, Inbred ICR, Wnt3 Protein physiology, Body Patterning, Wnt Signaling Pathway physiology
- Abstract
The node triggers formation of the left-right axis in mouse embryos by establishing local asymmetry of Nodal and Cerl2 expression. We found that Wnt3 is expressed in perinodal crown cells preferentially on the left side. The enhancer responsible for Wnt3 expression was identified and found to be regulated by Foxa2 and Rbpj under the control of Notch signaling. Rbpj binding sites suppress enhancer activity in pit cells of the node, thereby ensuring crown cell-specific expression. In addition, we found that the expression of Gdf1 and Cerl2 is also regulated by Notch signaling, suggesting that such signaling may induce the expression of genes related to left-right asymmetry as a set. Furthermore, Cerl2 expression became symmetric in response to inhibition of Wnt-β-catenin signaling. Our results suggest that Wnt signaling regulates the asymmetry of Cerl2 expression, which likely generates a left-right difference in Nodal activity at the node for further amplification in lateral plate mesoderm., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
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17. Surf4 modulates STIM1-dependent calcium entry.
- Author
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Fujii Y, Shiota M, Ohkawa Y, Baba A, Wanibuchi H, Kinashi T, Kurosaki T, and Baba Y
- Subjects
- Animals, Calcium Channels, Cell Line, Endoplasmic Reticulum metabolism, HEK293 Cells, HeLa Cells, Humans, Membrane Proteins genetics, Mice, Sequence Deletion, Stromal Interaction Molecule 1, Calcium metabolism, Membrane Glycoproteins metabolism, Membrane Proteins metabolism
- Abstract
Store-operated Ca(2+) entry (SOCE) is crucial for various physiological responses in immune cells. Although it is known that STIM1 relocates into discrete puncta juxtaposed to the plasma membrane to initiate SOCE, the machinery modulating the function of STIM1 remains unclear. We explored to find its modulators using affinity purification for STIM1-binding proteins and identified surfeit locus protein 4 (Surf4). Surf4 associated with STIM1 in the endoplasmic reticulum. Deletion of Surf4 in DT40 B cells resulted in marked increase of SOCE and facilitation of STIM1 clustering upon store-depletion. These findings suggest the modulatory function of Surf4 for STIM1-mediated SOCE., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2012
- Full Text
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18. Electroded avalanche amorphous selenium (a-Se) photosensor.
- Author
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Bubon O, Decrescenzo G, Zhao W, Ohkawa Y, Miyakawa K, Matsubara T, Kikuchi K, Tanioka K, Kubota M, Rowlands JA, and Reznik A
- Abstract
Although avalanche amorphous selenium (a-Se) is a very promising photoconductor for a variety of imaging applications, it is currently restricted to applications with electron beam readout in vacuum pick-up tube called a High-gain Avalanche Rushing Photoconductor (HARP). The electron beam readout is compatible with high definition television (HDTV) applications, but for use in solid-state medical imaging devices it should be replaced by an electronic readout with a two-dimensional array of metal pixel electrodes. However, due to the high electric field required for avalanche multiplication, it is a technological challenge to avoid possible dielectric breakdown at the edges, where electric field experiences local enhancement. It has been shown recently that this problem can be overcome by the use of a Resistive Interface Layer (RIL) deposited between a-Se and the metal electrode, however, at that time, at a sacrifice in transport properties.Here we show that optimization of RIL deposition technique allows for electroded avalanche a-Se with transport properties and time performance previously not achievable with any other a-Se structures. We have demonstrated this by detailed analysis of transport properties performed by Time-of-Flight (TOF) technique. Our results showed that a stable gain of 200 is reached at 104 V/μm for a 15-μm thick a-Se layer, which is the maximum theoretical gain for this thickness. We conclude that RIL is an enabling technology for practical implementation of solid-state avalanche a-Se image sensors.
- Published
- 2012
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19. Wisp2/CCN5 up-regulated in the central nervous system of GM3-only mice facilitates neurite formation in Neuro2a cells via integrin-Akt signaling.
- Author
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Ohkawa Y, Ohmi Y, Tajima O, Yamauchi Y, Furukawa K, and Furukawa K
- Subjects
- Animals, Cell Line, Tumor, Central Nervous System metabolism, Extracellular Signal-Regulated MAP Kinases metabolism, Mice, N-Acetylgalactosaminyltransferases genetics, Neurites metabolism, Phosphorylation, Recombinant Proteins genetics, Recombinant Proteins metabolism, Sialyltransferases genetics, Signal Transduction, Up-Regulation, Central Nervous System growth & development, Integrins metabolism, Intracellular Signaling Peptides and Proteins metabolism, Neurites physiology, Proto-Oncogene Proteins c-akt metabolism, Sialyltransferases metabolism
- Abstract
Wisp2/CCN5 belongs to CCN family proteins which are involved in cell proliferation, angiogenesis, tumorigenesis and wound healing. Although a number of studies on the roles of Wisp2/CCN5 in cancers have been reported, no study on the expression and function of Wisp2/CCN5 in the central nervous system has been reported. In this study, we focused on Wisp2/CCN5 that was up-regulated in nervous tissues in GM3-only mice. Over-expression of Wisp2/CCN5 enhanced neurite outgrowth potently after serum withdrawal with increased phosphorylation levels of Akt and ERKs. When cells were cultured with recombinant Wisp2/CCN5 proteins, more and longer neurites were formed than in the controls. Thus, we demonstrated for the first time that Wisp2/CCN5 facilitates neurite formation in a mouse neuroblastoma cell line, Neuro2a. Akt phosphorylation induced by recombinant Wisp2/CCN5 was suppressed after knockdown of integrin β1. Moreover, Wisp2/CCN5-over-expressing cells were resistant to apoptosis induced by H(2)O(2). These results suggested that secreted Wisp2/CCN5 induces Akt and ERK phosphorylation via integrins, and consequently facilitates neurite formation and conferred resistance to apoptosis. Up-regulation of Wisp2/CCN5 in GM3-only mice should be, therefore, a reaction to protect nervous tissues from neurodegeneration caused by ganglioside deficiency., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
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20. The LTB4-BLT1 axis mediates neutrophil infiltration and secondary injury in experimental spinal cord injury.
- Author
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Saiwai H, Ohkawa Y, Yamada H, Kumamaru H, Harada A, Okano H, Yokomizo T, Iwamoto Y, and Okada S
- Subjects
- Animals, Apoptosis, Fas Ligand Protein biosynthesis, Female, Flow Cytometry methods, Interleukin-1beta biosynthesis, Interleukin-6 biosynthesis, Leukotriene B4 metabolism, Mice, Mice, Inbred C57BL, Receptors, Leukotriene B4 metabolism, Tumor Necrosis Factor-alpha biosynthesis, Gene Expression Regulation, Leukotriene B4 physiology, Neutrophils metabolism, Receptors, Leukotriene B4 physiology, Spinal Cord pathology, Spinal Cord Injuries pathology
- Abstract
Traumatic injury in the central nervous system induces inflammation; however, the role of this inflammation is controversial. Precise analysis of the inflammatory cells is important to gain a better understanding of the inflammatory machinery in response to neural injury. Here, we demonstrated that leukotriene B4 plays a significant role in mediating leukocyte infiltration after spinal cord injury. Using flow cytometry, we revealed that neutrophil and monocyte/macrophage infiltration peaked 12 hours after injury and was significantly suppressed in leukotriene B4 receptor 1 knockout mice. Similar findings were observed in mice treated with a leukotriene B4 receptor antagonist. Further, by isolating each inflammatory cell subset with a cell sorter, and performing quantitative reverse transcription-PCR, we demonstrated the individual contributions of more highly expressed subsets, ie, interleukins 6 and 1beta, tumor necrosis factor-alpha, and FasL, to the inflammatory reaction and neural apoptosis. Inhibition of leukotriene B4 suppressed leukocyte infiltration after injury, thereby attenuating the inflammatory reaction, sparing the white matter, and reducing neural apoptosis, as well as inducing better functional recovery. These findings are the first to demonstrate that leukotriene B4 is involved in the pathogenesis of spinal cord injury through the amplification of leukocyte infiltration, and provide a potential therapeutic strategy for traumatic spinal cord injury.
- Published
- 2010
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21. Intermittent administration of human parathyroid hormone (1-34) increases new bone formation on the interface of hydroxyapatitecoated titanium rods implanted into ovariectomized rat femora.
- Author
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Ohkawa Y, Tokunaga K, and Endo N
- Subjects
- Animals, Biomechanical Phenomena, Coated Materials, Biocompatible, Disease Models, Animal, Durapatite therapeutic use, Female, Femur ultrastructure, Humans, Ovariectomy, Rats, Rats, Sprague-Dawley, Arthroplasty, Replacement, Hip instrumentation, Bone Density Conservation Agents therapeutic use, Bone Regeneration drug effects, Osteoporosis, Postmenopausal physiopathology, Parathyroid Hormone therapeutic use
- Abstract
Background: As hydroxyapatite (HA) has good osteoconductive properties, HA is used as coating material for the implants in cementless arthroplasty. However, its effect is not sufficient for osteoporotic bone. Parathyroid hormone (PTH) is known to have anabolic effects on bone formation. Intermittent administration of PTH increases both cancellous and cortical bone mass. The aim of this study was to confirm the effect of the fixation strength of HA-coated implants in the osteoporotic condition with a mechanical test and a bone histomorphometric method., Methods: Female Sprague-Dawley rats were used for this study. Four weeks after ovariectomy (OVX) or sham surgery, HA-coated titanium rods were inserted into the distal femoral canal (Sham+HA group and OVX+HA group). PTH was administered immediately after the implantation of the HAcoated rods (OVX+HA+P group). We measured the shear strength at the bone-implant interface by a push-out test and the newly formed bone volume on the implant (BV.Im) by bone histomorphometry at 2 and 4 weeks after implantation., Results: The bone-implant shear strength in the OVX+HA group was significantly lower than that in the Sham+HA group at 2 weeks after implantation of the rods. In the OVX+HA+P group, the strength was significantly higher than that in the other groups. Similarly, at 4 weeks, statistically significant differences were confirmed in the bone-implant shear strength among the Sham+HA group, the OVX+HA group, and the OVX+HA+P group. BV.Im in the OVX+HA group was significantly lower than that in the Sham+HA group at 2 weeks after implantation. BV.Im was significantly higher in the OVX+HA+P group than that in the OVX+HA group. However, there was no difference in BV.Im between the Sham+HA group and the OVX+HA+P group. At 4 weeks after implantation, BV.Im was significantly lower in the OVX+HA group than that in the other groups, but no difference was found between the Sham+HA group and the OVX+HA+P group., Conclusions: Intermittent administration of PTH has an effect to increase new bone formation on the surface of HA-coated implants in the osteoporotic condition. This finding suggests that PTH administration is useful to improve the initial fixation of HA-coated implants even in osteoporotic patients.
- Published
- 2008
- Full Text
- View/download PDF
22. Essential roles of integrin-mediated signaling for the enhancement of malignant properties of melanomas based on the expression of GD3.
- Author
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Ohkawa Y, Miyazaki S, Miyata M, Hamamura K, Furukawa K, and Furukawa K
- Subjects
- Cell Adhesion, Cell Line, Tumor, Cell Proliferation, Crk-Associated Substrate Protein metabolism, Extracellular Matrix metabolism, Humans, Integrin beta1 genetics, Melanoma metabolism, Neoplasm Invasiveness, Paxillin metabolism, Phosphorylation, Signal Transduction, Skin Neoplasms metabolism, Focal Adhesions metabolism, Gangliosides metabolism, Integrin beta1 metabolism, Melanoma pathology, Skin Neoplasms pathology
- Abstract
We reported that ganglioside GD3 enhances cell proliferation and invasion of melanomas causing stronger tyrosine-phosphorylation of p130Cas and paxillin after stimulation with fetal calf serum. Besides signals via growth factor/receptor, adhesion signals via integrin might be also enhanced by GD3. Here, roles of integrin-mediated signaling in the cell proliferation and invasion, and in the activation of adaptor molecules were examined, showing that integrin was also important for the cell growth and invasion. p130Cas and paxillin underwent stronger tyrosine-phosphorylation in GD3+ cells than in GD3- cells during the adhesion in the absence of serum. On the other hand, no proteins underwent tyrosine phosphorylation in GD3+ and GD3- cells in a suspension state when stimulated with fetal calf serum. These results suggested that integrin-mediated signaling is essential in the effects of GD3 on the malignant properties of melanomas. Co-localization of GD3 and integrin at the focal adhesion supported these results.
- Published
- 2008
- Full Text
- View/download PDF
23. Calcineurin-mediated pathway involved in the differentiated phenotype of smooth muscle cells.
- Author
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Ohkawa Y, Hayashi K, and Sobue K
- Subjects
- Animals, Calcineurin Inhibitors, Calmodulin-Binding Proteins genetics, Calmodulin-Binding Proteins metabolism, Carrier Proteins metabolism, Cells, Cultured, Chick Embryo, Cyclosporine pharmacology, Enzyme Inhibitors pharmacology, Genes, Reporter, Insulin-Like Growth Factor I metabolism, Integrin alpha1 genetics, Integrin alpha1 metabolism, Myocytes, Smooth Muscle cytology, Myocytes, Smooth Muscle drug effects, Phenotype, Phosphatidylinositol 3-Kinases metabolism, Promoter Regions, Genetic, Proto-Oncogene Proteins metabolism, Proto-Oncogene Proteins c-akt, Tacrolimus pharmacology, Calcineurin metabolism, Cell Differentiation physiology, Myocytes, Smooth Muscle physiology, Protein Serine-Threonine Kinases, Signal Transduction physiology
- Abstract
The calcineurin-mediated pathway is involved in skeletal and cardiac hypertrophy and vascular development in vivo, but the relationship between this pathway and the phenotype of smooth muscle cells (SMCs) remains unknown. Using visceral SMCs in culture as a model system of differentiated SMCs, we investigated the role of the calcineurin-mediated pathway in maintaining the differentiated phenotype of SMCs, which depends on the insulin-like growth factor (IGF-I)-triggered activation of the phosphatidylinositol 3-kinase (PI3-K)/protein kinase B (PKB(Akt)) pathway. Treatment with calcineurin inhibitors, cyclosporin A or FK506, or the forced expression of the natural calcineurin inhibitor, CAIN, induced SMC dedifferentiation. Notably, suppression of the promoter activities of the SMC molecular markers caldesmon and alpha1 integrin by blocking the PI3-K/PKB(Akt) pathway was rescued by the forced expression of constitutively active calcineurin Aalpha, suggesting that the calcineurin-mediated pathway is critical for maintaining the differentiated phenotype of SMCs and works downstream of the PI3-K/PKB(Akt) pathway.
- Published
- 2003
- Full Text
- View/download PDF
24. Cerebral atrophy in multiple system atrophy by MRI.
- Author
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Horimoto Y, Aiba I, Yasuda T, Ohkawa Y, Katayama T, Yokokawa Y, Goto A, and Ito Y
- Subjects
- Aged, Atrophy, Cognition Disorders etiology, Disease Progression, Female, Follow-Up Studies, Humans, Male, Middle Aged, Multiple System Atrophy diagnosis, Multiple System Atrophy psychology, Brain pathology, Magnetic Resonance Imaging, Multiple System Atrophy pathology
- Abstract
Cranial magnetic resonance images (MRI) of the cerebral areas of 40 patients with multiple system atrophy (MSA) and of 61 age-matched controls were analyzed. The cerebral area of MSA patients was 131. 95+/-15.89 cm(2) (mean+/-S.D.), which was significantly smaller than that of normal controls at 149.01+/-10.93 cm(2) (P<0.0001). All 23 MSA cases subjected to the MRI study over a 1-year period showed progressive cerebral atrophy, and the atrophy rate was 2.46+/-1. 66%/year. There were no significant differences within the MSA subtypes or between gender. The progression of cerebral atrophy in MSA correlated more with duration (r=-0.634) than age (r=-0.421). We conclude that MRI findings throughout the course of MSA suggest progressive cerebral atrophy, which is common in all subtypes and reflects duration of the disease rather than age.
- Published
- 2000
- Full Text
- View/download PDF
25. Electron microscopic study on nerve terminals during dentin bridge formation after pulpotomy in dog teeth.
- Author
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Inoue H, Muneyuki H, Izumi T, Taguchi K, Nishigawa Y, Watanabe K, Ohkawa Y, and Tamura N
- Subjects
- Animals, Cell Differentiation, Dental Pulp innervation, Dental Pulp ultrastructure, Dental Pulp Capping, Dogs, Microscopy, Electron methods, Postoperative Period, Time Factors, Dentin, Secondary ultrastructure, Nerve Endings ultrastructure, Pulpotomy, Wound Healing
- Abstract
This study was designed to examine the relation between pulpal nerves and the differentiation of pulpal cells into preodontoblasts and odontoblasts during the healing process after pulpotomy. A total of 36 upper and lower teeth obtained from six adult dogs were used. The pulp chamber was opened with a sterile diamond bur, the coronal pulp was exposed, and the whole surface of the amputated pulp was capped with calcium hydroxide. The interval between pulpotomy and extraction was 5, 7, 10, 15, 20, 30, 40, 50, and 60 days, and then specimens were examined ultrastructurally. Close contact between fibroblast-like cells/osteoblast-like cells and nerve terminals at the calcification front was observed in the early healing process after pulpotomy, suggesting a close relation between nerve fibers and pulpal cell differentiation.
- Published
- 1997
- Full Text
- View/download PDF
26. Chromosomal aberrations in V79 cells induced by superoxide radical generated by the hypoxanthine-xanthine oxidase system.
- Author
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Iwata K, Shibuya H, Ohkawa Y, and Inui N
- Subjects
- Animals, Catalase toxicity, Cell Survival, Cells, Cultured, Cricetinae, Cricetulus, Drug Interactions, Hypoxanthine, Male, Superoxide Dismutase toxicity, Chromosome Aberrations, Hypoxanthines toxicity, Xanthine Oxidase toxicity
- Abstract
The effect of the superoxide radical, generated by the hypoxanthine-xanthine oxidase system, on chromosomal mutation was examined in Chinese hamster V79 cells. When cells were treated with this system for 1 h in Hanks' solution, the incidence of metaphases with chromosomal aberrations was increased with hypoxanthine at concentrations of 2.5 to 10 micrograms/ml. On the other hand, in Eagle's minimum essential medium (MEM) or MEM supplemented with 10% fetal bovine serum, only hypoxanthine at 5 micrograms/ml plus xanthine oxidase induced chromosomal aberrations and higher concentrations of hypoxanthine were cytotoxic to V79 cells. The increased frequency of chromosomal aberrations and the cytotoxicity of hypoxanthine plus xanthine oxidase were not affected by superoxide dismutase, but were strongly inhibited by catalase.
- Published
- 1984
- Full Text
- View/download PDF
27. Surgical treatment of anomalous origin of the left coronary artery from the pulmonary artery associated with tetralogy of Fallot.
- Author
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Akasaka T, Itoh K, Ohkawa Y, Nakayama S, Miyamoto H, Nishi T, Satoh H, and Takarada M
- Subjects
- Aortography, Child, Cineangiography, Coronary Angiography, Coronary Circulation, Coronary Vessel Anomalies complications, Humans, Male, Tetralogy of Fallot complications, Coronary Vessel Anomalies surgery, Pulmonary Artery, Tetralogy of Fallot surgery
- Abstract
An 8-year-old boy with anomalous origin of the left coronary artery from the pulmonary artery associated with tetralogy of Fallot, which was definitely diagnosed preoperatively, was operated on with success. Direct implantation of the left coronary artery into the aorta following division of the left coronary artery from the pulmonary artery and, concomitantly, total repair for tetralogy of Fallot using an external valved conduit were performed. Postoperative cineangiogram revealed a hemodynamically well-repaired intracardiac condition and anterograde filling of the left coronary artery, compared with retrograde left coronary flow from intercoronary collateral vessels preoperatively. To the best of our knowledge, there is not a previously published report of anomalous origin of the left coronary artery from the pulmonary artery associated with tetralogy of Fallot that was treated surgically with success.
- Published
- 1981
- Full Text
- View/download PDF
28. Surgical treatment of congenital distal tracheal stenosis involving the carina.
- Author
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Minato N, Itoh K, Ohkawa Y, Matsunaga H, Nagata N, and Fukatsu O
- Subjects
- Child, Preschool, Female, Humans, Male, Pneumonia etiology, Trachea surgery, Tracheal Stenosis complications, Tracheal Stenosis congenital, Tracheal Stenosis surgery
- Abstract
Untreated congenital stenosis of the distal trachea frequently results in lethal airway obstruction. A 3-year-old boy with segmental stenosis of the distal trachea and a 2-year-old girl with segmental stenosis involving the carina and the right main bronchus were treated successfully with resection and reanastomosis. Operative techniques, anesthetic management, postoperative care, and tracheal growth after anastomosis are discussed.
- Published
- 1986
- Full Text
- View/download PDF
29. Histidine increases the frequency of chromosomal aberrations induced by the xanthine oxidase-hypoxanthine system in V79 cells.
- Author
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Shibuya H, Iwata K, Ohkawa Y, and Inui N
- Subjects
- Animals, Cell Survival drug effects, Cells, Cultured, Cricetinae, Cricetulus, Dose-Response Relationship, Drug, Free Radicals, Hypoxanthine, Oxygen toxicity, Superoxide Dismutase pharmacology, Chromosome Aberrations, Histidine toxicity, Hypoxanthines toxicity, Xanthine Oxidase toxicity
- Abstract
The combined effects of the xanthine oxidase (XO)-hypoxanthine (HX) system and the various kinds of amino acids in Eagle's minimum essential medium on chromosomal aberrations were studied in Chinese hamster V79 cells. Among 13 amino acids tested, only histidine significantly increased the number of aberrant chromosomes and cytotoxicity in combination with the XO-HX system. This enhancing effect of histidine on chromosomal aberrations was dose-dependent at 0.063% - 0.25%; it was not affected by superoxide dismutase, but was strongly inhibited by catalase.
- Published
- 1985
- Full Text
- View/download PDF
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