115 research outputs found

    Capsaicin partially mimics heat in mouse fibroblast cells in vitro

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    Capsaicin activates transient receptor potential vanilloid 1 (TRPV1), a cation channel in the transient receptor potential family, resulting in the transient entry of Ca2+ and Mg2+ and a warm sensation. However, the effects of capsaicin on cells have not fully elucidated in fibroblasts. In this study, we investigated whether capsaicin could induce signal transduction in mouse fibroblast cells and compared the effect with that of heat-induced signal transduction. The activation of the mitogen-activated protein kinases (MAPKs) ERK and p38 MAPK, expression levels of heat shock protein 70 (HSP70) and HSP90, actin assembly, and cell proliferation were analyzed in NIH3T3 mouse fibroblast cells. A 15-min stimulation with capsaicin (∼100 μM) phosphorylated ERK and p38 MAPK and induced actin assembly. A 2-day stimulation with capsaicin increased the level of HSP70, but not HSP90, and the 2-day stimulation with capsaicin (∼100 μM) did not affect cell proliferation. A 15-min exposure to moderate heat (39.5 °C) phosphorylated both ERK and p38 MAPK and induced actin assembly to similar degrees as stimulation with capsaicin. A 2-day exposure to moderate heat increased the levels of both HSP70 and HSP90 and prevented cell proliferation. However, the 2-day stimulation with capsaicin (100 μM) failed to prevent heat shock-induced cell death. Thus, our results suggest that the effects of capsaicin on fibroblast cells partially differ from those of heat. Notably, the 2-day stimulation with capsaicin was not sufficient to develop heat tolerance in fibroblast cells. © 2016 Springer-Verlag Berlin HeidelbergEmbargo Period 12 month

    The Incidence of Desaturation during Anesthesia in Adult and Pediatric Patients: A Retrospective Study

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    We investigated the incidence of desaturation during general anesthesia in preoperatively hypoxic (< 92%), and nonhypoxic (≥ 92%) pediatric (n=1,090) and adult (n=5,138) patients. We plotted the patients’ SpO2 value time-courses and assessed desaturation in 6,228 patients. The crude overall incidence (95%CI) for desaturation was 11.1% (9.4-13.1) in the pediatric patients and 0.9% (0.6-1.2) in the adults. The crude incidence of desaturation in the hypoxic pediatric patients was 2.5 times the risk in the nonhypoxic patients: risk ratio (RR) 2.5 (1.8-3.5), p<0.001. The risk of desaturation in the hypoxic adult patients was 20.1 times the risk in the nonhypoxic adult patients: RR 20.1 (10.3-39.2), p<0.001. When the patients were separately stratified by American Society of Anesthesiologists Physical Status (ASA-PS) and by age, the directly adjusted risk-ratio (RRS) showed that the hypoxic pediatric patients had 1.8 and 1.6 times the risk in the nonhypoxic pediatric patients: ASA-PS adjusted RRS 1.6 (1.8-2.2), p<0.001; age-adjusted RRS 1.8 (1.3-2.5), p<0.001, and the hypoxic adult patients had 13.8 times the risk in the nonhypoxic adult patients: RRS 13.8 (6.9-27.6), p<0.001. A pulse-oximeter check before the start of general anesthesia could ensure timely preparation to avoid intraoperative desaturation

    Prox1 Inhibits Proliferation and Is Required for Differentiation of the Oligodendrocyte Cell Lineage in the Mouse

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    Central nervous system injury induces a regenerative response in ensheathing glial cells comprising cell proliferation, spontaneous axonal remyelination, and limited functional recovery, but the molecular mechanisms are not fully understood. In Drosophila, this involves the genes prospero and Notch controlling the balance between glial proliferation and differentiation, and manipulating their levels in glia can switch the response to injury from prevention to promotion of repair. In the mouse, Notch1 maintains NG2 oligodendrocyte progenitor cells (OPCs) in a progenitor state, but what factor may enable oligodendrocyte (OL) differentiation and functional remyelination is not understood. Here, we asked whether the mammalian homologue of prospero, Prox1, is involved. Our data show that Prox1 is distributed in NG2+ OPCs and in OLs in primary cultured cells, and in the mouse spinal cord in vivo. siRNA prox1 knockdown in primary OPCs increased cell proliferation, increased NG2+ OPC cell number and decreased CC1+ OL number. Prox1 conditional knockout in the OL cell lineage in mice increased NG2+ OPC cell number, and decreased CC1+ OL number. Lysolecithin-induced demyelination injury caused a reduction in CC1+ OLs in homozygous Prox1-/- conditional knockout mice compared to controls. Remarkably, Prox1-/- conditional knockout mice had smaller lesions than controls. Altogether, these data show that Prox1 is required to inhibit OPC proliferation and for OL differentiation, and could be a relevant component of the regenerative glial response. Therapeutic uses of glia and stem cells to promote regeneration and repair after central nervous system injury would benefit from manipulating Prox1

    Omega-3 Polyunsaturated Fatty Acids Enhance Neuronal Differentiation in Cultured Rat Neural Stem Cells

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    Polyunsaturated fatty acids (PUFAs) can induce neurogenesis and recovery from brain diseases. However, the exact mechanisms of the bene�cial effects of PUFAs have not been conclusively described. We recently reported that docosahexaenoic acid (DHA) induced neuronal differentiation by decreasing Hes1 expression and increasing p27 kip1 expression, which causes cell cycle arrest in neural stem cells (NSCs). In the present study, we examined the effect of eicosapentaenoic acid (EPA) and arachidonic acid (AA) on differentiation, expression of basic helix-loop-helix transcription factors (Hes1, Hes6, and NeuroD), and the cell cycle of cultured NSCs. EPA also increased mRNA levels of Hes1, an inhibitor of neuronal differentiation, Hes6, an inhibitor of Hes1, NeuroD, and Map2 mRNA and Tuj-1-positive cells (a neuronal marker), indicating that EPA induced neuronal differentiation. EPA increased the mRNA levels of p21 cip1 and p27 kip1 , a cyclin-dependent kinase inhibitor, which indicated that EPA induced cell cycle arrest. Treatment with AA decreased Hes1 mRNA but did not affect NeuroD and Map2 mRNA levels. Furthermore, AA did not affect the number of Tuj-1-positive cells or cell cycle progression. ese results indicated that EPA could be involved in neuronal differentiation by mechanisms alternative to those of DHA, whereas AA did not affect neuronal differentiation in NSCs

    Theobromine up-regulates cerebral brain-derived neurotrophic factor and facilitates motor learning in mice

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    Theobromine, which is a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. Theobromine works as a phosphodiesterase (PDE) inhibitor to increase intracellular cyclic adenosine monophosphate (cAMP). cAMP activates the cAMP-response element-binding protein (CREB), which is involved in a large variety of brain processes, including the induction of the brain-derived neurotrophic factor (BDNF). BDNF supports cell survival and neuronal functions, including learning and memory. Thus, cAMP/CREB/BDNF pathways play an important role in learning and memory. Here, we investigated whether orally administered theobromine could act as a PDE inhibitor centrally and affect cAMP/CREB/BDNF pathways and learning behavior in mice. The mice were divided into two groups. The control group (CN) was fed a normal diet, whereas the theobromine group (TB) was fed a diet supplemented with 0.05% theobromine for 30 days. We measured the levels of theobromine, phosphorylated vasodilator-stimulated phosphoprotein (p-VASP), phosphorylated CREB (p-CREB), and BDNF in the brain. p-VASP was used as an index of cAMP increases. Moreover, we analyzed the performance of the mice on a three-lever motor learning task. Theobromine was detectable in the brains of TB mice. The brain levels of p-VASP, p-CREB, and BDNF were higher in the TB mice compared with those in the CN mice. In addition, the TB mice performed better on the three-lever task than the CN mice did. These results strongly suggested that orally administered theobromine acted as a PDE inhibitor in the brain, and it augmented the cAMP/CREB/BDNF pathways and motor learning in mice. © 2016 Elsevier Inc.Embargo Period 12 month

    Antarctic micrometeorites collected at the Dome Fuji Station

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    Antarctic micrometeorites (AMMs) were found among the precipitated fine particles recovered from a water tank in the Dome Fuji Station. These AMMs had been contained in the recent fallen snow around the station. Initial processing of the precipitated particles revealed that they were dominated by natural and artificial terrestrial materials, thus a series of processes were developed to separate AMMs from terrestrial particles. The recovery rate of AMMs by the processes was approximately 45% in weight, which was determined from a weight ratio of recovered/accreted AMMs. The micro-morphology and major-element concentration of the recovered AMMs were characterized. They appear to have been heated upon atmospheric entry to varying temperatures and can be classified into two major types based on the degree of heating : (1) fine-grained, irregular-shaped, partial-melted micrometeorites with chondritic composition, and (2) total-melted spherical micrometeorites with chondritic composition except for volatile elements. A digital catalog for the AMMs identified in this study was established on the web site [URL : http : //dust. cc. gakushuin. ac. jp/], in which optical characteristics, high-resolution images, and chemical compositions of individual AMMs are presented. The AMMs listed in the catalog are the first Japanese collection of extraterrestrial dust. The criterion and techniques developed for the selection and initial analysis of AMMs are applicable for the dust samples that are being collected by the 39th Japanese Antarctic Research Expedition team

    Discovery of New Hydrothermal Activity and Chemosynthetic Fauna on the Central Indian Ridge at 18°–20°S

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    Indian Ocean hydrothermal vents are believed to represent a novel biogeographic province, and are host to many novel genera and families of animals, potentially indigenous to Indian Ocean hydrothermal systems. In particular, since its discovery in 2001, much attention has been paid to a so-called ‘scaly-foot’ gastropod because of its unique iron-sulfide-coated dermal sclerites and the chemosynthetic symbioses in its various tissues. Despite increasing interest in the faunal assemblages at Indian Ocean hydrothermal vents, only two hydrothermal vent fields have been investigated in the Indian Ocean. Here we report two newly discovered hydrothermal vent fields, the Dodo and Solitaire fields, which are located in the Central Indian Ridge (CIR) segments 16 and 15, respectively. Chemosynthetic faunal communities at the Dodo field are emaciated in size and composition. In contrast, at the Solitaire field, we observed faunal communities that potentially contained almost all genera found at CIR hydrothermal environments to date, and even identified previously unreported taxa. Moreover, a new morphotype of ‘scaly-foot’ gastropod has been found at the Solitaire field. The newly discovered ‘scaly-foot’ gastropod has similar morphological and anatomical features to the previously reported type that inhabits the Kairei field, and both types of ‘scaly-foot’ gastropods genetically belong to the same species according to analyses of their COI gene and nuclear SSU rRNA gene sequences. However, the new morphotype completely lacks an iron-sulfide coating on the sclerites, which had been believed to be a novel feature restricted to ‘scaly-foot’ gastropods. Our new findings at the two newly discovered hydrothermal vent sites provide important insights into the biodiversity and biogeography of vent-endemic ecosystems in the Indian Ocean

    Efficacy of prosultiamine treatment in patients with human T lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis: results from an open-label clinical trial

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    Background: Human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic myelopathy characterized by motor dysfunction of the lower extremities and urinary disturbance. Immunomodulatory treatments are the main strategy for HAM/TSP, but several issues are associated with long-term treatment. We conducted a clinical trial with prosultiamine (which has apoptotic activity against HTLV-I-infected cells) as a novel therapy in HAM/TSP patients. Methods: We enrolled 24 HAM/TSP patients in this open-label clinical trial. Prosultiamine (300 mg, orally) was administered once daily for 12 weeks. We monitored changes in the motor function of the lower extremities and urinary function as well as copy numbers of the HTLV-I provirus in peripheral blood mononuclear cells (PBMCs). Results: Improvement in the motor function of the lower extremities based on a reduction in spasticity (for example, decrease in time required for walking and descending a flight of stairs) was observed. In an urodynamic study (UDS), bladder capacity and detrusor pressure and then maximum flow rate increased significantly. Detrusor overactivity and detrusor-sphincter dyssynergia improved in 68.8% and 45.5% of patients observed at pretreatment, respectively. Improvement in UDS corresponded with improvements in the score of nocturia-quality of life questionnaire. HTLV-I proviral copy numbers in PBMCs decreased significantly (approximately 15.4%) compared with pretreatment levels.Conclusions: These data suggest that prosultiamine can safely improve motor dysfunction of the lower extremities and urinary disturbance as well as reduce HTLV-I provirus levels in peripheral blood. It therefore has potential as a new therapeutic tool for HAM/TSP patients.Trial registration: University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) number, UMIN000005969. Please see related commentary: http://www.biomedcentral.com/1741-7015/11/183

    Beneficial Effects of Citrus-Derived Polymethoxylated Flavones for Central Nervous System Disorders

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    The number of patients with central nervous system disorders is increasing. Despite diligent laboratory and clinical research over the past 30 years, most pharmacologic options for the prevention and long-term treatment of central nervous system disorders and neurodegenerative disorders have been unsuccessful. Therefore, the development of drugs and/or functional foods to prevent the onset of neurodegenerative disorders is highly expected. Several reports have shown that polymethoxylated flavones (PMFs) derived from citrus fruit, such as nobiletin, tangeretin, and 3,3&prime;,4&prime;,5,6,7,8-heptamethoxyflavone, are promising molecules for the prevention of neurodegenerative and neurological disorders. In various animal models, PMFs have been shown to have a neuroprotective effect and improve cognitive dysfunction with regard to neurological disorders by exerting favorable effects against their pathological features, including oxidative stress, neuroinflammation, neurodegeneration, and synaptic dysfunction as well as its related mechanisms. In this review, we describe the profitable and ameliorating effects of citrus-derived PMFs on cognitive impairment and neural dysfunction in various rat and murine models or in several models of central nervous system disorders and identify their mechanisms of action
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