Publications by authors named "Kotaka T"

The ovarian steroid hormones, estrogen and progesterone, the levels of which fluctuate dynamically with the estrous cycle, alter circadian behavioral rhythms in mammals. However, it remains unclear whether the sleep-wake rhythm fluctuates with the menstrual cycle in humans. To ascertain the relationship between the menstrual cycle and sleep-wake rhythms, we evaluated the objective and long-term sleep-wake rhythms of ten healthy women using a recently developed wearable device.

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This study analyzed a recently developed bone substitute biomaterial made of chitosan-xanthanhydroxyapatite-graphene oxide (CXHAG). The CXHAG particles underwent in vitro structural and morphological characterization, and in vivo testing with or without osteogenic conditioned medium from mesenchymal stem cells. Aim: The aim of this study was to determine whether the CXHAG novel biomaterial, supplemented with conditioned medium from mesenchymal stem cells, could be useful for bone regeneration.

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The aim of this study was to test whether lyophilized conditioned media from human dental pulp mesenchymal stem cell cultures promote the healing of critical-size defects created in the calvaria of rats. Prior to the surgical procedure, the medium in which dental pulp stem cells were cultured was frozen and lyophilized. After general anesthesia, an 8 mm diameter bone defect was created in the calvaria of twenty-four rats.

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Synchrotron X-ray radiography, due to its high temporal and spatial resolutions, provides a valuable means for understanding the in operando water transport behaviour in polymer electrolyte membrane fuel cells. The purpose of this study is to address the specific artefact of imaging sample movement, which poses a significant challenge to synchrotron-based imaging for fuel cell diagnostics. Specifically, the impact of the micrometer-scale movement of the sample was determined, and a correction methodology was developed.

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Application of camphor to the skin has been empirically thought to improve blood circulation. However, camphor's effects on blood circulation to the skin and on thermal sensation have not been well elucidated. In this study, we examined its effects on the quality of sensation as well as on skin and muscle blood flow in human.

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We report a 34-year-old Japanese female with the vascular type of Ehlers-Danlos syndrome. She had thin translucent skin, extensive bruising, toe joint hypermobility, left lower extremity varicose veins, and chronic wrist, knee and ankle joint pain. She also had dizziness caused by autonomic dysfunction.

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Experimental studies have demonstrated that not only dopaminergic signaling but also glutamatergic/NMDA receptor signaling play indispensable roles in the development of methamphetamine psychosis. Our recent genetic studies provided evidence that genetic variants of glutamate-related genes such as DTNBP1, GLYT1, and G72, which are involved in glutamate release and regulation of co-agonists for NMDA receptors, conferred susceptibility to methamphetamine psychosis. Serine racemase converts l-serine to d-serine, which is an endogenous co-agonist for NMDA receptors.

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Leukemia inhibitory factor (LIF), a member of the interleukin-6 cytokine family, regulates the neuronal phenotype and coordinates astrocyte, oligodendrocyte, microglia, and inflammatory cell responses. The LIF gene is located on 22q12.1-q12.

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Aims: Neuropeptide Y (NPY) is a 36-amino acid peptide that is widely distributed in the brain, adrenal medulla, and sympathetic nervous system. Several lines of evidence suggest a possible involvement of the NPY system in the physiological effects of several classes of abused substances including alcohol, phencyclidine, cocaine, and marijuana and in endogenous psychosis. Accordingly, it was hypothesized that the NPY system may also be involved in methamphetamine dependence or psychosis.

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Methamphetamine psychosis is considered as one of the pharmacological models of schizophrenia, and a hyperdopaminergic one. However, many lines of experimental evidence indicate that glutamatergic signaling is also involved in development of methamphetamine psychosis. Several genes related to glutamate function, e.

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Objective: One of the clinically significant adverse effects of olanzapine treatment is weight gain, which shows substantial inter-individual differences and may be influenced by genetic variation. The aim of this investigation was identification of genetic risk factors associated with olanzapine-induced weight gain.

Method: Inpatients with DSM-IV-TR schizophrenia (N = 164) were administered olanzapine for 8 to 24 (mean +/- SD = 17.

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Casein kinase 1 epsilon (CKIepsilon) is a component of the DARPP-32 in second-messenger pathway. CKIepsilon phosphorylates and activates DARPP-32, a key molecule in various complex signaling pathways, including dopamine and glutamine signaling, which have both been demonstrated to be main pathways in substance dependence. A recent clinical study showed that rs135745, a noncoding single nucleotide polymorphism of the 3'-untranslated region of the CSNK1E gene, was associated with the intensity of the subjective response to an oral amphetamine dose in normal volunteers.

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Background: Frizzled 3 (Fzd3) is a receptor required for the Wnt-signaling pathway, which has been implicated in the development of the central nervous system, including synaptogenesis and structural plasticity. We previously found a significant association between the FZD3 gene and susceptibility to schizophrenia, but subsequent studies showed inconsistent findings. To understand the roles of the FZD3 gene in psychotic disorders further, it should be useful to examine FZD3 in patients with methamphetamine psychosis because the clinical features of methamphetamine psychosis are similar to those of schizophrenia.

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Because methamphetamine (METH) is metabolized by CYP2D6 at the first step of hydroxylation and demethylation, it is possible that functional variants of CYP2D6 alter susceptibility to methamphetamine-induced dependence. We genotyped CYP2D6*1, *4, *5, *10, and *14 for 202 patients with METH dependence and 337 controls in a Japanese population and found a significant association of the CYP2D6 gene with METH dependence (p=0.0299).

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Glycine transporter (GlyT)-1 plays a pivotal role in maintaining the glycine level at the glutamatergic synapse. Glycine is an allosteric agonist of N-methyl-D-aspartate (NMDA) receptors. Because activation of NMDA receptors is an essential step for induction of methamphetamine dependence and psychosis, differences in the functioning of GlyT-1 due to genetic variants of the GlyT-1 gene (GLYT1) may influence susceptibility.

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Background: The dysbindin (DTNBP1 [dystrobrevin-binding protein 1]) gene has repeatedly been shown to be associated with schizophrenia across diverse populations. One study also showed that risk haplotypes were shared with a bipolar disorder subgroup with psychotic episodes, but not with all cases. DTNBP1 may confer susceptibility to psychotic symptoms in various psychiatric disorders besides schizophrenia.

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Background: Serine racemase (SRR) is a brain-enriched enzyme that converts L-serine to D-serine, which acts as an endogenous ligand of N-methyl D-aspartate (NMDA) receptors. Dysfunction of SRR may reduce the function of NMDA receptors and susceptibility to schizophrenia.

Methods: We genotyped three single-nucleotide polymorphisms (SNPs) of the 5' region of the SRR gene in 525 patients with schizophrenia and 524 healthy controls.

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In agarose gel electrophoresis, in a steady, continuous field, it is well known that the mobility mu, versus size M relation for linear DNAs (L-DNAs) can be divided into three regimes: Ogston regime I for small DNAs, where M dependence of mu, is weak; entangled but unstretched regime II for intermediate-size L-DNAs (of M < 20 kbp), where mu, sigma M-1 so that efficient fractionation is possible; and entangled and stretched regime III for large L-DNAs, where M dependence of mu s is again weak. Although mu s and the regimen boundaries can be altered by adjusting the gel concentration Cgel and/or the field strength E, the features of the M dependence of mu s are essentially unchanged. As to the effect of DNA topology on mu s, we found that in dilute gels (Cgel < 1.

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The attachment of cells onto the surfaces of various block copolymers fabricated either as well-defined, ordered Langmuir-Blodgett (LB) films, or solvent cast microphase-separated structures was studied. In general, more platelets adhered onto the multilayered LB surface than onto microphase-separated cast surfaces. Scanning electron micrographs of adhered platelets showed extensive morphological changes associated with the LB surface as compared to cast film surfaces.

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The molecular weight of Streptomyces subtilisin inhibitor (SSI), a protein proteinase inhibitor, and that of the complex of SSI and subtilisin BPN' [EC 3.4.21.

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