Publications by authors named "Hideaki Kudo"

Anadromous Pacific salmon (genus Oncorhynchus) are known for homing behavior to their natal rivers based on olfactory imprinted memories during seaward migration. The SNARE complex is a regulator of vesicle exocytosis from the presynaptic membrane. Our previous study suggested that its component genes (Snap25, Stx1, and Vamp2) are more highly expressed in the olfactory nervous system (ONS) during the migration stages associated with olfactory imprinting in the evolutionary species of Pacific salmon, such as chum (O.

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Fish use a variety of sensory systems when foraging. Salmonids are generally considered visual feeders. However, some species feed on zooplanktons under dark conditions, suggesting they also detect prey using nonvisual cues.

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Anadromous Pacific salmon (genus Oncorhynchus) are known for their homing behavior based on olfactory imprinting, which is formed during their seaward migration. Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE/Snare) complex is a minimum unit of vesicle exocytosis from the pre-synaptic membrane. Its component genes (synaptosome-associated protein 25, syntaxin 1, and vesicle-associated membrane protein 2) are more strongly expressed in the olfactory nervous system (olfactory epithelium, olfactory bulb, and telencephalon) at the migration stages related to olfactory imprinting and/or retrieval in salmon.

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The expression of synaptic vesicle exocytosis-regulator SNARE complex component genes (snap25, stx1 and vamp2) was examined in the olfactory nervous system during seaward and homeward migration by pink salmon (Oncorhynchus gorbuscha). The expression levels of snares in the olfactory organ were higher in seaward fry than in feeding and homeward adults, reflecting the development of the olfactory nervous system. The expression of snap25a, b and stx1a was upregulated or stable in the adult olfactory bulb and telencephalon.

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Anadromous Pacific salmon (Genus Oncorhynchus) imprint odorants from their natal streams during their seaward migration, and adult salmon use olfaction to identify their natal streams during their homeward migration. However, little is known about the molecular mechanisms of olfactory imprinting in the salmon nervous system. Our previous study suggested that the snap25s gene (encoding a soluble N-ethylmaleimide-sensitive factor attachment protein receptor [SNARE] protein) is involved in pre-synaptic functions for olfactory imprinting and/or olfactory memory retrieval in chum salmon (O.

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Thyroid hormone (TH) plays an important role in regulating multiple cellular and metabolic processes, including cell proliferation, cell death, and energy metabolism, in various organs and tissues of vertebrates. It is generally accepted that anadromous Pacific salmon ( spp.) imprint odorants from their natal stream during their seaward migration, and they then use olfaction to discriminate their natal stream during the spawning migration.

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Mature male Pacific salmon (Oncorhynchus spp.) develop a hooknose, as a secondary male sexual characteristic, during the spawning period. It is likely that androgens regulate hooknose formation.

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It is generally accepted that information about some of the odorants in the natal streams of anadromous Pacific salmon (Genus Oncorhynchus) is imprinted during their seaward migration, and that anadromous Pacific salmon use olfaction to identify their natal streams during the homeward migration. However, little is known about the molecular mechanisms of the various pre-synaptic functions that are important for olfactory imprinting and memory retrieval in the salmon brain. Synaptosome-associated protein-25 (SNAP-25) mediates pre-synaptic vesicle exocytosis and regulates synaptic transmission and neuronal plasticity.

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Mature male Pacific salmon (Genus Oncorhynchus) demonstrate prominent morphological changes, such as the development of a dorsal hump. The degree of dorsal hump formation depends on the species in Pacific salmon. It is generally accepted that mature males of sockeye (O.

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A novel mesophilic, strictly hydrogen-oxidizing, sulfur-, nitrate- and thiosulfate-reducing bacterium, designated strain Monchim33(T), was isolated from a deep-sea hydrothermal vent chimney at the Central Indian Ridge. The non-motile, rod-shaped cells were Gram-stain-negative and non-sporulating. Growth was observed between 15 and 37 °C (optimum 33 °C; 3.

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Mature male Pacific salmon (Genus Oncorhynchus) develop a dorsal hump, as a secondary male sexual characteristic, during the spawning period. Previous gross anatomical studies have indicated that the dorsal humps of salmon are mainly composed of cartilaginous tissue (Davidson [1935] J Morphol 57:169-183.) However, the histological and biochemical characteristics of such humps are poorly understood.

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To investigate the regulation of lipid uptake into the eel oocyte in more detail, effects of 11-ketotestosterone (11-KT) and lipid transporters (lipoproteins) were determined in vitro. Ovarian explants from previtellogenic Japanese eels (Anguilla japonica) were incubated for 28 days with 11-KT and/or with very low density lipoproteins (Vldl), low density lipoproteins (Ldl), or high density lipoproteins (Hdl) purified from eel plasma. The androgen 11-KT induced notable increases in oocyte diameter, which were accompanied by the appearance of vacuoles rather than lipid.

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The xenobiotic metabolizing system is considered to play important roles in the olfaction by the chemical homeostasis. Several phase I and phase II xenobiotic metabolizing enzymes are expressed in the olfactory epithelium in vertebrates. Multidrug resistance-related proteins (MRPs) are the phase III xenobiotic metabolizing pumps that eliminate some conjugated ligands from cells.

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Background: The government recommends home care for self-care-dependent older people in order to suppress care expenditure. Family relationships between primary caregivers and self-care-dependent older people might be one of the factors influencing the institutionalized rate.

Method: We investigated family relationships between primary caregivers and self-care-dependent older people at home in the rural town of Oodate, Akita Prefecture, and the urban district of Katsushika, Tokyo, in 2003.

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Article Synopsis
  • Anadromous Pacific salmon imprint on odors from their birth streams during migration and use their sense of smell to navigate home.
  • The development and structure of the olfactory organ, crucial for this imprinting, were studied in chum salmon, specifically looking at changes in olfactory lamellae and olfactory receptor neurons (ORNs) from alevin to maturity.
  • The research found that the number of lamellae increased significantly during early development and that the number of ORNs grows dramatically from about 180,000 in fry to 14.2 million in mature salmon, demonstrating a relationship between body size and olfactory neuron quantity throughout their life cycle.
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The progression of rat liver fibrosis induced by intraperitoneal administration of thioacetamide (TAA) was evaluated by immunocytochemistry using anti-alpha-smooth muscle actin (alpha-SMA), antiendothelin-converting enzyme (ECE)-1, and anti-monocyte chemotactic protein (MCP)-1 antibodies. The fibrous septal spaces gradually increased after administration of TAA, and pseudolobules were established in the 7-week TAA-treated groups. Immunoreactivities against alpha-SMA were not detected in hepatic stellate cells (HSCs) of the control group without TAA treatment, although they were observed in the HSCs around the fibrous septal spaces in all TAA-treated groups, indicating that activation of HSCs occurs during the establishment of pseudolobules.

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Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive malformation syndrome characterized by microcephaly, syndactyly of toes, ambiguous genitalia, and mental retardation. The underlying DHCR7 gene has been identified and a wide variety of distinct mutations were reported in USA and European SLOS patients. A significant difference has been suggested in the frequency of SLOS among different ethnic populations.

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The infective third-stage larvae (L3s) of Strongyloides ratti, a parasitic nematode in rodents, showed two types of chemokinesis on a gradient of sodium chloride (NaCl) in an in vitro agarose tracking assay. The types were a consistent directional avoidance behavior under unfavorable environmental conditions and a reduced avoidance behavior under favorable conditions. We examined the effects of treatments with glycolytic enzymes and lectins by analyzing the avoidance behavior.

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Wistar rats were deeply anesthetized and perfused by Hanks' solution bubbled with either 95% air and 5% CO2 (normoxic group) or 95% N2 and 5% CO2 (hypoxic group) from the thoracic aorta for 30 minutes. The isolated abdominal aortas were used for electron microscopy, immunocytochemistry of endothelin-1 (ET-1) and endothelin-converting enzyme-1 (ECE-1), and in situ hybridization of preproendothelin-1 mRNA. A remarkable increase in the number of Weibel-Palade bodies, storage sites of ET-1 and ECE-1, occurred in the hypoxic group when compared with the normoxic group.

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The infective third-stage larvae (L3s) of a parasitic nematode of rodents, Strongyloides ratti, showed three types of thermokinesis on a temperature gradient using an in vitro agarose tracking assay method. These depended both on the pattern of gradient temperature and the prior culture temperature. Most L3s (> or = 80%) isolated from rat feces cultured at 25 degrees C and placed on a gradient at temperatures between 30 degrees C and 37 degrees C showed no directional response, at 22-29 degrees C more than 50% of the L3s showed positive thermokinesis, at 21 degrees C L3s showed positive, negative and no directional responses in the same ratio, while at 18-20 degrees C, L3s showed negative thermokinesis (approx.

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We previously reported that 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB) increased the 8-hydroxyguanine (8-OH-Gua) content in nuclear DNA and the base excision repair activity in mouse liver. However, to understand the mechanism of 3'-MeDAB carcinogenesis, a further investigation of the 8-OH-Gua repair systems was necessary. In this report, we examined the expression of the repair enzyme, 8-oxoguanine DNA glycosylase 1 (OGG1), in 3'-MeDAB-treated mouse liver.

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Vasculogenesis is defined as a neovascularization manner by which endothelial progenitor cells are successively incorporated into the growing capillaries, whereas angiogenesis is another neovascularization manner which includes mitotic proliferations of endothelial cells of the preexisting capillaries and their migration to the vascular tips forming so called "vascular sprouts" or "endothelial buds". Although angiogenesis had been considered to be more prevalent during organogenesis as well as during a wound healing process of adult mammals, recent findings that endothelial progenitor cells were isolated from human peripheral blood and incorporated into sites of active neovascularization have led many researchers to recognize the significance of vasculogenesis in a phenomenon of neovascularization. This paper mainly deals with the history of morphological approaches to clarify the crucial roles of vasculogenesis during organogenesis and a wound healing process.

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In this study, we investigated the expression of vascular endothelial growth factor (VEGF) mRNA along with its receptors in the healing process following rat femoral drill-hole injury. The cellular events involved in the differential expression of VEGF were studied by reverse transcription-polymerase chain reaction, immunocytochemistry, and in situ hybridization. Abundant alkaline phosphatase-positive osteoprogenitor cells were present in the bone marrow cavity surrounding the wound region at day 3.

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