Publications by authors named "Tsunekawa H"

Cell-to-cell transmission of α-synuclein (α-syn) pathology is considered to underlie the spread of neurodegeneration in Parkinson's disease (PD). Previous studies have demonstrated that α-syn is secreted under physiological conditions in neuronal cell lines and primary neurons. However, the molecular mechanisms that regulate extracellular α-syn secretion remain unclear.

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Selegiline, an irreversible inhibitor of monoamine oxidase (MAO)-type B, is widely prescribed for Parkinson's disease and, at higher doses, for major and atypical depression, whereby it is non-selectively inhibitory to both MAO-A and MAO-B activities. MAO inhibitors have been considered to function as antidepressants through MAO-A inhibition. We have previously reported that selegiline exerts antidepressant-like effects in the mouse forced swim test (FST) via dopamine D1 receptor activation.

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3,4-Dihydroxy-l-phenylalanine (l-Dopa) remains the most effective drug for treating the motor symptoms of Parkinson's disease (PD). However, its long-term use is limited due to motor complications such as wearing-off and dyskinesia. A clinical study in PD patients with motor complications has demonstrated that selegiline, a monoamine oxidase type B inhibitor, is effective in reducing off time without worsening dyskinesia, although another study has shown worsening dyskinesia.

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Working muscle conserves adenosine triphosphate (ATP) for muscle contraction by attenuating protein synthesis through several different pathways. Regulated in development and DNA damage response 1 (REDD1) is one candidate protein that can itself attenuate muscle protein synthesis during muscle contraction. In this study, we investigated whether endurance exercise induces REDD1 expression in association with decreased mammalian target of rapamycin (mTOR) complex I (mTORC1) signaling and global protein synthesis in rat skeletal muscle.

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Objectives: To investigate the long-term effect of infliximab on ocular and extraocular manifestations in patients with Behçet's disease.

Methods: Seven patients with active Behçet's disease and treated with infliximab at Aichi Medical University Hospital for more than 18 months were included in the study. We evaluated visual acuity, the average number of uveitis attacks involving the posterior segment, and general disease activity every 2 months.

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Purpose: To describe two patients with Behçet's disease who underwent cataract surgery one week after infliximab administration.

Methods: Patients received preoperative antibiotic therapy with 0.5% levofloxacin eye drops and 500 mg levofloxacin oral tablets, followed by cataract surgery one week after infliximab administration.

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To elucidate functional diversity of cytochrome P450 monooxygenases from the white-rot basidiomycete Phanerochaete chrysosporium (PcCYPs), we conducted a comprehensive functional screening using a wide variety of compounds. A functionomic survey resulted in characterization of novel PcCYP functions and discovery of versatile PcCYPs that exhibit broad substrate profiles. These results suggested that multifunctional properties of the versatile PcCYPs would play crucial roles in diversification of fungal metabolic systems involved in xenobiotic detoxification.

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Purpose: Tumor necrosis factor-alpha (TNF-α) may disrupt the extracellular matrix components comprising the blood-retinal barrier (BRB) in patients with posterior uveitis, such as Behçet's disease. We investigated changes in the mRNA expression levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human BRB cells in the presence of TNF-α in vitro and examined the effect of infliximab addition.

Methods: Cells were cultured in the presence or absence of TNF-α, and TNF-α-exposed cells were treated with or without infliximab.

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In Alzheimer's disease (AD), the expression of matrix metalloproteases (MMPs), which are capable of degrading extracellular matrix proteins, is increased in the brain. Previous studies with cultured glial cells have demonstrated that amyloid beta (Abeta) protein can induce the expression of MMPs, which could be involved in the degradation of Abeta. In the present study, we investigated the role of MMP-2 and MMP-9 in cognitive impairment induced by the injection of Abeta in mice.

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Selegiline, an irreversible inhibitor of monoamine oxidase B used in the treatment of Parkinson's disease, has been demonstrated to have a potential cognition-improving effect in patients with Alzheimer's disease (AD) undergoing treatment with an acetylcholinesterase inhibitor donepezil. To confirm such clinical events, we investigated whether co-administration of donepezil with selegiline had a synergistic cognition-improving effect in an animal model of AD. Intracerebroventricular injection of amyloid beta protein fragment 25-35 [Abeta(25-35)] induced impairment of learning and memory in a Y-maze, novel object recognition and contextual fear conditioning tests.

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(R)-(-)-1-(Benzofuran-2-yl)-2-propylaminopentane hydrochloride [(-)-BPAP] is a highly potent enhancer of impulse propagation-mediated monoamine release and an inhibitor of monoamine uptake. We evaluated the efficacy of (-)-BPAP as a drug for mood disorders by using two animal models. (1) Acute, but not chronic, administration of (-)-BPAP and imipramine significantly attenuated immobility in mice induced by forced swimming.

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Recently, we reported a profound depletion of cardiac sympathetic nerve fibers in Parkinson's disease (PD). This cardiac sympathetic denervation is a characteristic hallmark of PD. Cardiac sympathetic dysfunction was also observed in 1-methyl-4-phenyl-1,2,3,6-tetrahydroxypyridine (MPTP)-treated mice, a model of PD.

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In the present study, we aimed to investigate the role of N-methyl-D-aspartate (NMDA) receptors in the antidepressant-like effects of a sigma(1) receptor agonist, 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA-4503), in the olfactory bulbectomized (OB) rat model of depression. A symptomatology-based behavioral investigation was made by reconstructing in OB rats the symptoms of depression, such as psychomotor agitation, loss of interest, and cognitive dysfunction, using a typical antidepressant, desipramine, as a positive control. Repeated treatment with SA-4503 ameliorated the behavioral deficits in OB rats resembling depression symptoms in the open-field test, sexual behavior test, and cued and contextual fear-conditioning test.

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In order to probe the nature and validity of olfactory bulbectomized (OB) rats as a model of depression, we reevaluated their behavioural and neurochemical deficits in relation to the symptoms and neurochemical abnormalities of depression using our protocols, which distinguish anhedonia-resembling behaviour in sexual behavioural test, the hippocampus (Hip)-dependent long-term memory and anxiety-resembling behaviour specially. Besides exploratory hyperactivity in response to a novel environmental stress resembling the psychomotor agitation, OB rats showed a decrease of libido, and a deficit of long-term explicit memory, resembling loss of interest and cognitive deficits in depressive patients, respectively. OB rats also exhibited the anxiety symptom-resembling behaviour in social interaction and plus-maze tests.

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Neurotrophin-3 (NT3) and neurotrophin-4 (NT4) affect the survival and maintenance of central and peripheral neurons. Using an immunohistochemical method, we examined whether the taste bud cells in the circumvallate papillae of normal mice expressed NT3, NT4, and their respective receptors TrkC and TrkB, and if so, what type of cells in the taste buds expressed them. Double immunostaining for either of them and PGP 9.

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Study Design: An electrophysiologic analysis was performed on a chronic lumbar spinal stenosis model of rats. The effects of venous stasis on ectopic firing originating in the nerve root were investigated.

Objectives: To elucidate the mechanisms of neurogenic intermittent claudication in lumbar spinal canal stenosis.

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An optimal feed rate profile of a substrate (tylosin) for a novel antibiotic, acetyl-isovaleryl tylosin (AIV) production process was investigated. In the first step of optimization, a kinetic model for production of AIV from tylosin by Streptomyces thermotolerans was established properly using the least square method, followed by the confirmation that the proposed model could be used to predict the production process of AIV from tylosin. An objective function, state equations and an inequality constraint with respect to the tylosin feeding rate profile were applied to maximize the amount of AIV produced from tylosin in a fed-batch culture.

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Pseudomonas putida T-57 was isolated from an activated sludge sample after enrichment on mineral salts basal medium with toluene as a sole source of carbon. P. putida T-57 utilizes n-butanol, toluene, styrene, m-xylene, ethylbenzene, n-hexane, and propylbenzene as growth substrates.

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R-(-)-1-(Benzofuran-2-yl)-2-propylaminopentane [(-)-BPAP] is a catecholaminergic and serotonergic activity enhancer that increases impulse-evoked catecholamine and serotonin release from nerve terminals, and is a candidate for symptomatic treatment of early Parkinson's disease. We now report the catecholamine and serotonin transporter-mediated actions of (-)-BPAP. The effects of (-)-BPAP on inhibition of neurotransmitter uptake and radioligand binding were assessed using human embryonic kidney 293 cells (HEK 293 cells) expressing cDNA for the human dopamine transporter (hDAT), norepinephrine transporter (hNET), and serotonin transporter (hSERT).

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Nitric oxide is thought to be involved in the pathophysiology of radiculopathy attributable to herniated intervertebral disc, but its effect on ectopic firing, which is the main source of sciatica, has not been investigated. The authors investigated whether ectopic firing is elicited when the lumbar nerve root is exposed to nitric oxide using rats with and without cauda equina compression. A group of animals had partial L3 laminectomy, and a silicone tube was inserted in the epidural space to compress the cauda equina.

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Prostaglandin (PG) E(2) is synthesized from arachidonic acid by cyclooxygenase (COX) and acts as a regulator in ovulation and fertilization reactions. We present the temporal and regional expression patterns of mRNAs for the two Gs-coupled PGE receptors, EP2 and EP4, and for COX-1 and COX-2 in mouse periovulatory follicles and oviducts during superovulation. Analysis using reverse transcription polymerase chain reaction revealed that the mouse ovaries express a significant amount of EP4 mRNA in addition to EP2 mRNA during superovulation.

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Biotransformation of L-lysine (L-Lys) to L-pipecolic acid (L-PA) using lat-expressing Escherichia coli has been reported (Fujii et al., Biosci. Biotechnol.

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The enzyme involved in the reduction of delta1-piperideine-6-carboxylate (P6C) to L-pipecolic acid (L-PA) has never been identified. We found that Escherichia coli JM109 transformed with the lat gene encoding L-lysine 6-aminotransferase (LAT) converted L-lysine (L-Lys) to L-PA. This suggested that there is a gene encoding "P6C reductase" that catalyzes the reduction of P6C to L-PA in the genome of E.

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