Publications by authors named "Yasuhisa Tamura"

Malignant hypertension with renal thrombotic microangiopathy is a rare yet serious cause of acute kidney injury (AKI). Patients are often treated with antihypertensive therapy; however, managing their blood pressure is complex, with targets for initial treatment unclear. We report on a 55-year-old male with severe hypertension (blood pressure 210/140 mmHg), AKI (serum creatinine 9.

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Microscopic polyangiitis (MPA) is predominantly characterized by rapidly progressive glomerulonephritis (RPGN) associated with myeloperoxidase anti-neutrophil cytoplasmic antibodies (MPO-ANCA). Nonetheless, up to 30% of cases of ANCA-associated vasculitis (AAV) may exhibit a more indolent progression toward renal failure, an aspect less frequently discussed and understood in medical literature. This study seeks to clarify the clinical and pathological distinctions between the slowly and rapidly progressive forms of MPA, thereby enhancing understanding of their distinct pathogeneses and treatment responses.

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The incidence rate of malignancy in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is higher than that in the general population. Malignancy has been indicated to be a risk factor or inducer of AAV. Herein, we report the case of a healthy 84-year-old man with seronegative microscopic polyangiitis (MPA) after the diagnosis of renal pelvic carcinoma.

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Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease of unknown etiology and without effective treatment options. The onset of ME/CFS is often associated with neuroinflammation following bacterial or viral infection. A positron emission tomography imaging study revealed that the degree of neuroinflammation was correlated with the severity of several symptoms in patients with ME/CFS.

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Alpha-glycerylphosphorylcholine (αGPC) is a precursor of acetylcholine and can increase acetylcholine concentration in the brain. In addition, αGPC has a role in cholinergic function as well as monoaminergic transmission, including dopaminergic and serotonergic systems. These monoaminergic systems are related to feelings and emotions, including motivation, reward processing, anxiety, and depression.

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NG2 immunoreactive cells (NG2 cells) are found in the brain and peripheral tissues including the skin, intestinal tracts, and bladder. In a previous study, we observed the presence of NG2 cells in the stomach using bioluminescence imaging techniques in NG2-firefly luciferase (fLuc) transgenic (Tg) rats. Here, we aimed to identify and characterize NG2 cells in the adult rat stomach.

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The hair cycle consists of three different phases: anagen (growth), catagen (regression), and telogen (resting). During the anagen phase, hair follicle stem cells (HFSCs) in the bulge and the secondary hair germ proliferate and generate the outer and inner root sheath cells and the hair shafts. We previously identified NG2-immunoreactive (NG2+) cells as HFSCs in both regions of the hair follicles.

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Lamins are type V intermediate filament proteins that are located beneath the inner nuclear membrane. In mammalian somatic cells, LMNB1 and LMNB2 encode somatic lamins B1 and B2, respectively, and the LMNA gene is alternatively spliced to generate somatic lamins A and C. Mutations in lamin genes have been linked to many human hereditary diseases, including neurodegenerative disorders.

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Hair growth occurs periodically in a cycle that consists of three different phases: growth, regression, and resting. The length of each phase is regulated by both intrinsic and extrinsic factors throughout life, and influenced by physiological and pathological conditions. Elongation of the resting phase and shortening of the growth phase occur during physiological ageing and in baldness, respectively.

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With the objective of improving the poor water solubility of the potent antitumor compound SN-38, 10-O-substituted SN-38 derivatives were developed by the introduction of fluoroalkyl, fluorobenzoyl, or bromobenzoyl groups. The 10-O-fluoropropyl-substituted compound 2 {(S)-4,11-diethyl-9-(3-fluoropropoxy)-4-hydroxy-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)-dione} was found to be 17-fold more soluble than SN-38 in phosphate-buffered saline, and it exhibited a level of biological activity ≈50 % that of SN-38 in a cytotoxicity assay using the prostate cancer cell line PC-3. Five other derivatives did not show solubility improvements to the same extent, but their activities in cytotoxicity assays were nearly the same as that of SN-38.

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Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical technique and has been widely used in metabolomics. However, the intrinsic low sensitivity of NMR prevents its applications to systems with limited sample availabilities. In this study, a new experimental approach is presented to analyze mass-scarce samples in limited volumes of less than 300 nL with simple handling.

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It is widely accepted that listening to music improves subjective feelings and reduces fatigue sensations, and different kinds of music lead to different activations of these feelings. Recently, cardiac autonomic nervous modulation has been proposed as a useful objective indicator of fatigue. However, scientific considerations of the relation between feelings of fatigue and cardiac autonomic nervous modulation while listening to music are still lacking.

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Neural stem cells are present in 2 neurogenic regions, the subventricular zone (SVZ) and the subgranular zone (SGZ) of the hippocampal dentate gyrus (DG), and continue to generate new neurons throughout life. Adult hippocampal neurogenesis is linked to a variety of psychiatric disorders such as depression and anxiety, and to the therapeutic effects of antidepressants, as well as learning and memory. In vivo imaging for hippocampal neurogenic activity may be used to diagnose psychiatric disorders and evaluate the therapeutic efficacy of antidepressants.

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NG2-expressing neural progenitor cells (i.e., NG2 glial cells) maintain their proliferative and migratory activities even in the adult mammalian central nervous system (CNS) and produce myelinating oligodendrocytes and astrocytes.

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We describe two hemodialysis patients with high-risk myelodysplastic syndrome (MDS) treated with azacitidine. A 65-year-old woman (case 1) received azacitidine at 75 mg/m(2) for 7 days, and a 52-year-old man (case 2) with liver cirrhosis received a 70% dose of azacitidine. Both cases developed grade 4 cytopenia, but they achieved transfusion independence after 3 and 2 courses, and the durations of remission were 10 and 11 months, respectively.

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Unlabelled: Neural stem cells in two neurogenic regions, the subventricular zone and the subgranular zone (SGZ) of the hippocampal dentate gyrus, can divide and produce new neurons throughout life. Hippocampal neurogenesis is related to emotions, including depression/anxiety, and the therapeutic effects of antidepressants, as well as learning and memory. The establishment of in vivo imaging for proliferative activity of neural stem cells in the SGZ might be used to diagnose depression and to monitor the therapeutic efficacy of antidepressants.

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In the present study, prior to the establishment of a method for the clinical diagnosis of chronic fatigue in humans, we validated the utility of plasma metabolomic analysis in a rat model of fatigue using capillary electrophoresis-mass spectrometry (CE-MS). In order to obtain a fatigued animal group, rats were placed in a cage filled with water to a height of 2.2 cm for 5 days.

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During acute viral infections such as influenza, humans often experience not only transient fever, but also prolonged fatigue or depressive feelings with a decrease in social activity for days or weeks. These feelings are thought to be due to neuroinflammation in the brain. Recent studies have suggested that chronic neuroinflammation is a precipitating event of various neurological disorders, but the mechanism determining the duration of neuroinflammation has not been elucidated.

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Toward a therapeutic intervention of lissencephaly, we applied a novel calpain inhibitor, SNJ1945. Peri-natal or post-natal treatment with SNJ1945 rescued defective neuronal migration in Lis1⁺/⁻ mice, impaired behavioral performance and improvement of ¹⁸F-FDG uptake. Furthermore, SNJ1945 improved the neural circuit formation and retrograde transport of NFG in Lis1⁺/⁻ mice.

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Cortical spreading depression (SD) is propagating neuronal and glial depolarization and is thought to underly the pathophysiology of migraine. We have reported that cortical SD facilitates the proliferative activity of NG2-containing progenitor cells (NG2 cells) that give rise to oligodendrocytes and immature neurons under the physiological conditions in the adult mammalian cortex. Astrocytes have an important role in the maintenance of neuronal functions and alleviate neuronal damage after intense neuronal excitation, including SD and seizures.

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In this study we developed a new automatic quantification method to count the number of targeted fluorescently labeled molecules of in-vitro rat brain tissue images. NG2+ glial cells were monitored in order to detect their proliferation to their same kind of cells or to another astrocyte cells using different fluorescently labeled molecules. The method is based on morphological segmentation followed by depth-dependent detection operation applied to a stack of confocal microscopic images.

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In an earlier study in rodents, we showed that the aromatase that converts androgens to estrogens in the preoptic area and bed nucleus of stria terminalis was significantly increased in concentration after exposure to anabolic-androgenic steroids. To confirm whether this occurs in primates, we conducted a positron emission tomographic study using macaque monkeys. Male rhesus monkeys were treated with nandrolone decanoate for 3 weeks.

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Unlabelled: Neurogenic inflammation triggered by extravasation of plasma protein has been hypothesized as a key factor in the generation of the pain sensation associated with migraine. The principal immune cell that responds to this inflammation is the parenchymal microglia of the central nervous system.

Methods: Using a PET technique with (11)C-(R)-[1-(2-chlorophenyl)-N-methyl-N-(1-methyl-propyl)-3-isoquinolinecarboxamide] ((11)C-PK11195), a PET ligand for peripheral type-benzodiazepine receptor, we evaluated the microglial activation in the rat brain after generation of unilateral cortical spreading depression, a stimulation used to bring up an experimental animal model of migraine.

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In a previous study, we demonstrated that androgenic-anabolic steroids increased aromatase expression in the bed nucleus of stria terminalis and preoptic area in rat brain, as evaluated using autoradiography with [11C]vorozole, a potential positron emission tomography tracer for aromatase. In this study, we explored whether the increase in aromatase binding is mediated via androgen receptors and whether this increase occurs in neurons or glial cells. Rats were given nandrolone decanoate (15 mg/kg body weight once every 3 days) and flutamide (20 mg/kg/day) alone or in combination for 20 days.

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In the adult mammalian brain, multipotent stem or progenitor cells involved in reproduction of neurons and glial cells have been well investigated only in very restricted regions; the subventricular zone of the lateral ventricle and the dentate gyrus in the hippocampal formation. In the neocortex, a series of in vitro studies has suggested the possible existence of neural progenitor cells possessing neurogenic and/or gliogenic potential in adult mammals. However, the cellular properties of the cortical progenitor cells in vivo have not been fully elucidated.

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