Science.gov

Sample records for adult japanese medaka

  1. Histological and Transcriptomic Analysis of Adult Japanese Medaka Sampled Onboard the International Space Station

    PubMed Central

    Murata, Yasuhiko; Yasuda, Takako; Watanabe-Asaka, Tomomi; Oda, Shoji; Mantoku, Akiko; Takeyama, Kazuhiro; Chatani, Masahiro; Kudo, Akira; Uchida, Satoko; Suzuki, Hiromi; Tanigaki, Fumiaki; Shirakawa, Masaki; Fujisawa, Koichi; Hamamoto, Yoshihiko; Terai, Shuji; Mitani, Hiroshi

    2015-01-01

    To understand how humans adapt to the space environment, many experiments can be conducted on astronauts as they work aboard the Space Shuttle or the International Space Station (ISS). We also need animal experiments that can apply to human models and help prevent or solve the health issues we face in space travel. The Japanese medaka (Oryzias latipes) is a suitable model fish for studying space adaptation as evidenced by adults of the species having mated successfully in space during 15 days of flight during the second International Microgravity Laboratory mission in 1994. The eggs laid by the fish developed normally and hatched as juveniles in space. In 2012, another space experiment (“Medaka Osteoclast”) was conducted. Six-week-old male and female Japanese medaka (Cab strain osteoblast transgenic fish) were maintained in the Aquatic Habitat system for two months in the ISS. Fish of the same strain and age were used as the ground controls. Six fish were fixed with paraformaldehyde or kept in RNA stabilization reagent (n = 4) and dissected for tissue sampling after being returned to the ground, so that several principal investigators working on the project could share samples. Histology indicated no significant changes except in the ovary. However, the RNA-seq analysis of 5345 genes from six tissues revealed highly tissue-specific space responsiveness after a two-month stay in the ISS. Similar responsiveness was observed among the brain and eye, ovary and testis, and the liver and intestine. Among these six tissues, the intestine showed the highest space response with 10 genes categorized as oxidation–reduction processes (gene ontogeny term GO:0055114), and the expression levels of choriogenin precursor genes were suppressed in the ovary. Eleven genes including klf9, klf13, odc1, hsp70 and hif3a were upregulated in more than four of the tissues examined, thus suggesting common immunoregulatory and stress responses during space adaptation. PMID:26427061

  2. Histological and Transcriptomic Analysis of Adult Japanese Medaka Sampled Onboard the International Space Station.

    PubMed

    Murata, Yasuhiko; Yasuda, Takako; Watanabe-Asaka, Tomomi; Oda, Shoji; Mantoku, Akiko; Takeyama, Kazuhiro; Chatani, Masahiro; Kudo, Akira; Uchida, Satoko; Suzuki, Hiromi; Tanigaki, Fumiaki; Shirakawa, Masaki; Fujisawa, Koichi; Hamamoto, Yoshihiko; Terai, Shuji; Mitani, Hiroshi

    2015-01-01

    To understand how humans adapt to the space environment, many experiments can be conducted on astronauts as they work aboard the Space Shuttle or the International Space Station (ISS). We also need animal experiments that can apply to human models and help prevent or solve the health issues we face in space travel. The Japanese medaka (Oryzias latipes) is a suitable model fish for studying space adaptation as evidenced by adults of the species having mated successfully in space during 15 days of flight during the second International Microgravity Laboratory mission in 1994. The eggs laid by the fish developed normally and hatched as juveniles in space. In 2012, another space experiment ("Medaka Osteoclast") was conducted. Six-week-old male and female Japanese medaka (Cab strain osteoblast transgenic fish) were maintained in the Aquatic Habitat system for two months in the ISS. Fish of the same strain and age were used as the ground controls. Six fish were fixed with paraformaldehyde or kept in RNA stabilization reagent (n = 4) and dissected for tissue sampling after being returned to the ground, so that several principal investigators working on the project could share samples. Histology indicated no significant changes except in the ovary. However, the RNA-seq analysis of 5345 genes from six tissues revealed highly tissue-specific space responsiveness after a two-month stay in the ISS. Similar responsiveness was observed among the brain and eye, ovary and testis, and the liver and intestine. Among these six tissues, the intestine showed the highest space response with 10 genes categorized as oxidation-reduction processes (gene ontogeny term GO:0055114), and the expression levels of choriogenin precursor genes were suppressed in the ovary. Eleven genes including klf9, klf13, odc1, hsp70 and hif3a were upregulated in more than four of the tissues examined, thus suggesting common immunoregulatory and stress responses during space adaptation.

  3. Trenbolone acetate metabolites promote ovarian growth and development in adult Japanese medaka (Oryzias latipes).

    PubMed

    Forsgren, Kristy L; Qu, Shen; Lavado, Ramon; Cwiertny, David; Schlenk, Daniel

    2014-06-01

    Trenbolone acetate, a synthetic androgen, has been used as a growth promoter in beef cattle in the US since 1987. While several teleost studies have investigated the masculinization effects of the metabolite 17β-trenbolone, few have focused on the reproductive impacts of all three trenbolone acetate (TBA) metabolites including trendione. Adult female medaka (Oryzias latipes) were exposed to TBA metabolites (10, 100, and 1000ng/L) for 14days (n=3). Histological examination revealed that TBA metabolites (1000ng/L) significantly reduced the percentage of primary ovarian follicles and increased the percentage of vitellogenic follicles compared to control fish. 17α-Trenbolone significantly increased whereas trendione reduced whole body levels of estradiol-17β. Testosterone was significantly reduced by trendione treatment and only the highest dose of 17β-trenbolone and lowest dose of trendione altered 11-ketotestosterone. Additionally, TBA metabolites may be further broken down and/or metabolized or converted by the animal influencing both sex steroid levels and ovarian development.

  4. RELATIONSHIP BETWEEN ETHINYLESTRADIOL-MEDIATED CHANGES IN ENDOCRINE FUNCTION AND REPRODUCTION IMPAIRMENT IN JAPANESE MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    Many biochemical endpoints currently are used to describe endocrine function in fish; however, the sensitivity of these parameters as biomarkers of impaired reproduction or sexual development is not well understood. In the present study, adult Japanese medaka (Oryzias latipes) we...

  5. Transgenerational and developmental exposure of Japanese medaka (Oryzias latipes) to ethinylestradiol results in endocrine and reproductive differences in the response to ethinylestradiol as adults.

    PubMed

    Foran, Christy M; Peterson, Bethany N; Benson, William H

    2002-08-01

    17alpha-Ethinylestradiol (EE), a synthetic estrogen found in birth control pills, has been detected in the effluent of municipal wastewater treatment plants in several countries. Because EE was designed to be extremely potent at the estrogen receptor (ER), environmental exposure to low concentrations has the potential to disrupt the development of normal endocrine and reproductive function when exposure occurs during critical periods in development. Japanese medaka, Oryzias latipes, were used to evaluate the effect of exposure to EE during development on adult reproduction and endocrine function and the sensitivity of these animals to estrogen exposure as adults. To determine if the response to exogenous estrogen stimulation was diminished or sensitized, adults resulting from the developmental exposure groups were reexposed to EE at respectively higher concentrations. Hatchling exposure produced no changes in adult vitellogenin (VTG) content in the liver or circulating steroid concentrations, nor was reproduction affected. Reexposure of these adults inhibited reproduction, increased hepatic VTG and ER, and increased estrogen concentration measured in male plasma. Parental exposure produced permanent changes in hepatic content of ER and VTG in the adults resulting from exposure during gametogenesis and was related to a diminished response of males to subsequent estrogen exposure. The potential for this transgenerational exposure to decrease the responsiveness of males to EE is supported by comparing the concentration-response curves for hepatic VTG and ER in males exposed in ovo and as hatchlings. Our results indicate that the relationship between biomarkers and estrogen exposure will be altered by the timing and frequency of exposure.

  6. Molecular and cellular markers of toxicity in the Japanese Medaka @

    SciTech Connect

    Shugart, L.R.; McCarthy, J.F.; D'Surney, S.J.; Greeley, M.S. Jr.; Hull, C.G.

    1990-01-01

    The Japanese Medaka (Oryzias latipes) has been recommended for use as a model organism to detect carcinogenic, teratogenic, cytotoxic, and genotoxic compounds in aquatic systems. Because a long latent period often occurs between initial contact with deleterious chemicals and subsequent expression of the pathology, we are investigating early biologically-relevant responses that can be used as genotoxicity markers of exposure and effect. This project focuses on the development of genotoxic bioassays and experimental protocols for exposing Japanese Medaka to genotoxic compounds. 21 refs., 8 figs, 2 tabs.

  7. PROLIFERATIVE LESIONS IN SWIMBLADDER OF JAPANESE MEDAKA ORYZIAS LATIPES AND GUPPY POECILIA RETICULATA

    EPA Science Inventory

    Thirteen cases of proliferative lesions of the swimbladder were encountered in Japanese medaka Oryzias latipes and guppy Poecilia reticulata from about 10,000 medaka and 5,000 guppies used in carcinogenicity tests and histologically examined. Two of the four cases from medaka and...

  8. Immunotoxicological Assays Using the Japanese Medaka

    DTIC Science & Technology

    1990-05-14

    oyster ( Crassostrea virginica ). Although the ultimate goal is to quantify the generation of reactive oxygen metabolities by medaka blood cells, the... Crassostrea virginica ), NBT reduction in unstimulated blood cells ranged from about 0.04 to 0.15 OD5i5 /2X10 6 cells/hr; phagocytic stimulation produced an...year one support) 1 NBT reduction patterns in adherent hemocytes of Crassostrea virginica . 2. Quantitative assays of superoxide anion and hydrogen

  9. Immunotoxicological Assays Using the Japanese Medaka

    DTIC Science & Technology

    1992-07-31

    details of medaka husbandry were being worked out, some initial immunotoxicological studies were carried out on the Eastern oyster ( Crassostrea virginica ...stimulated hemocytes has been used to estimate ROI production in several bivalves such as Crassostrea virginica , (Larson et al., 1989) Crassostrea gigas, and...The CL response of oyster ( Crassostrea virginica ) blood cells either exposed in vitro or collected from oysters after various periods of in vivo

  10. Bioaccumulation, subcellular distribution, and acute effects of chromium in Japanese medaka (Oryzias latipes).

    PubMed

    Li, Lixia; Chen, Hongxing; Bi, Ran; Xie, Lingtian

    2015-11-01

    Chromium (Cr) is an essential element but is toxic to aquatic organisms at elevated concentrations. In the present study, adult Japanese medaka (Oryzias latipes) were exposed to a sublethal hexavalent chromium (Cr(VI)) concentration via dissolved and dietary exposures for 6 d. Various measurements of Cr were made: bioaccumulation in different tissues, subcellular distribution in the liver, effects on antioxidants and acetylcholinesterase (AChE), and Cr-induced lipid peroxidation. The results showed that bioaccumulation increased dramatically in all tested tissues from dissolved exposure but only significantly in the intestine from dietary treatment, implying that dissolved exposure may be predominant for Cr accumulation in medaka. Subcellular distribution revealed that Cr accumulated in the liver was mainly (46%) associated with the heat-stable protein fraction. Among the antioxidants examined, catalase (CAT) responded to dissolved Cr exposure in most tissues whereas superoxide dismutase (SOD) was less responsive. Malondialdehyde concentrations were significantly elevated in most tissues examined in the dissolved Cr-exposed fish, but were only elevated in the liver and intestine in the dietary Cr-exposed fish. The AChE activity in the brain was stimulated by 49% in the dissolved Cr-exposed fish. Reductions in condition factor and gonadosomatic index were also observed. These data help in an understanding of Cr tissue distribution and the acute effects of Cr in Japanese medaka.

  11. Atrazine reduces reproduction in Japanese medaka (Oryzias latipes).

    PubMed

    Papoulias, Diana M; Tillitt, Donald E; Talykina, Melaniya G; Whyte, Jeffrey J; Richter, Catherine A

    2014-09-01

    Atrazine is an effective broadleaf herbicide and the second most heavily used herbicide in the United States. Effects along the hypothalamus-pituitary-gonad axis in a number of vertebrate taxa have been demonstrated. Seasonally elevated concentrations of atrazine in surface waters may adversely affect fishes, but only a few studies have examined reproductive effects of this chemical. The present study was designed to evaluate a population endpoint (egg production) in conjunction with histological (reproductive stage, gonad pathology) and biochemical (aromatase activity, sex hormone production) phenotypes associated with atrazine exposure in Japanese medaka. Adult virgin breeding groups of one male and four females were exposed to nominal concentrations of 0, 0.5, 5.0, and 50 μg/L (0, 2.3, 23.2, 231 nM) of atrazine in a flow-through diluter for 14 or 38 days. Total egg production was lower (36-42%) in all atrazine-exposed groups as compared to the controls. The decreases in cumulative egg production of atrazine-treated fish were significant by exposure day 24. Reductions in total egg production in atrazine treatment groups were most attributable to a reduced number of eggs ovulated by females in atrazine-treated tanks. Additionally, males exposed to atrazine had a greater number of abnormal germ cells. There was no effect of atrazine on gonadosomatic index, aromatase protein, or whole body 17 β-estradiol or testosterone. Our results suggest that atrazine reduces egg production through alteration of final maturation of oocytes. The reduced egg production observed in this study was very similar to our previously reported results for fathead minnow. This study provides further information with which to evaluate atrazine's risk to fish populations.

  12. Atrazine reduces reproduction in Japanese medaka (Oryzias latipes)

    USGS Publications Warehouse

    Papoulias, Diana M.; Tillitt, Donald E.; Talyknia, Melaniya G.; Whyte, Jeffrey J.; Richter, Catherine A.

    2014-01-01

    Atrazine is an effective broadleaf herbicide and the second most heavily used herbicide in the United States. Effects along the hypothalamus–pituitary–gonad axis in a number of vertebrate taxa have been demonstrated. Seasonally elevated concentrations of atrazine in surface waters may adversely affect fishes, but only a few studies have examined reproductive effects of this chemical. The present study was designed to evaluate a population endpoint (egg production) in conjunction with histological (reproductive stage, gonad pathology) and biochemical (aromatase activity, sex hormone production) phenotypes associated with atrazine exposure in Japanese medaka. Adult virgin breeding groups of one male and four females were exposed to nominal concentrations of 0, 0.5, 5.0, and 50 μg/L (0, 2.3, 23.2, 231 nM) of atrazine in a flow-through diluter for 14 or 38 days. Total egg production was lower (36–42%) in all atrazine-exposed groups as compared to the controls. The decreases in cumulative egg production of atrazine-treated fish were significant by exposure day 24. Reductions in total egg production in atrazine treatment groups were most attributable to a reduced number of eggs ovulated by females in atrazine-treated tanks. Additionally, males exposed to atrazine had a greater number of abnormal germ cells. There was no effect of atrazine on gonadosomatic index, aromatase protein, or whole body 17 β-estradiol or testosterone. Our results suggest that atrazine reduces egg production through alteration of final maturation of oocytes. The reduced egg production observed in this study was very similar to our previously reported results for fathead minnow. This study provides further information with which to evaluate atrazine's risk to fish populations.

  13. Chronic toxicity of chloroform to Japanese medaka fish.

    PubMed Central

    Toussaint, M W; Rosencrance, A B; Brennan, L M; Beaman, J R; Wolfe, M J; Hoffmann, F J; Gardner, H S

    2001-01-01

    Japanese medaka (Oryzias latipes) were continually exposed in a flow-through diluter system for 9 months to measured chloroform concentrations of 0.017, 0.151, or 1.463 mg/L. Parameters evaluated were hepatocarcinogenicity, hepatocellular proliferation, hematology, and intrahepatic chloroform concentration. Histopathology was evaluated at 6 and 9 months. Chloroform was not hepatocarcinogenic to the medaka at the concentrations tested. Chronic toxicity was evidenced at these time points by statistically significant ([alpha] = 0.05) levels of gallbladder lesions and bile duct abnormalities in medaka treated with 1.463 mg/L chloroform. We assessed hepatocellular proliferation by exposing test fish to 5-bromo-2'-deoxyuridine in the aquarium water for 72 hr after 4 and 20 days of chloroform exposure; we then quantified area-labeling indices of the livers using computer-assisted image analysis. We observed no treatment-related increases in cellular proliferation. We analyzed cells in circulating blood in medaka after 6 months of chloroform exposure. Hematocrit, leukocrit, cell viability, and cell counts of treated fish were not significantly different from those of control fish. Using gas chromatography (GC), we evaluated intrahepatic concentrations of chloroform in fish after 9 months of exposure. Livers from the 0.151 and 1.463 mg/L chloroform-treated fish had detectable amounts of chloroform, but these levels were always lower than the aquaria concentrations of chloroform. Thus, it appeared that chloroform did not bioaccumulate in the liver. Unidentified presumptive metabolite peaks were found in the GC tracings of these fish livers. PMID:11171522

  14. Ethanol teratogenesis in Japanese medaka: effects at the cellular level.

    PubMed

    Wu, Minghui; Chaudhary, Amit; Khan, Ikhlas A; Dasmahapatra, Asok K

    2008-01-01

    The adverse effects of alcohol on the developing humans represent a spectrum of structural and neurobehavioral abnormalities, most appropriately termed as fetal alcohol spectrum disorder (FASD). The mechanism by which ethanol induces FASD is unknown. Human studies of FASD are very limited due to ethical constraints; however, several animal models from nematodes to mammals are utilized to understand the molecular mechanism of this disorder. We have used Japanese medaka (Oryzias latipes) embryo-larval development as a unique non-mammalian model to study the molecular mechanism of FASD. Fertilized medaka eggs were exposed to ethanol (0-400 mM) for 48 h post fertilization (hpf) and then maintained in regular embryo rearing medium without ethanol. Viable embryos were harvested on 0, 2, 4 and 6 day post fertilization (dpf) and analyzed for DNA, RNA and protein contents of the embryos. By applying semi-quantitative RT-PCR (rRT-PCR) and quantitative real-time RT-PCR (qRT-PCR), RNA samples were further analyzed for seven transcription factors, emx2, en2, iro3, otx2, shh, wnt1 and zic5 which are expressed in the neural tube of medaka embryo during early phase of development. RNA and protein contents of the embryos were significantly reduced by ethanol at 400 mM dose on 4 and 6 dpf compared to the control (no ethanol), and 100 mM ethanol treated embryos. However, significant reduction of DNA was observed only in 4 dpf embryos. Total protein contents of yolk remained unaltered after ethanol treatment. Expression pattern of emx2, en2, iro3, otx2, shh, wnt1, and zic5 mRNAs were found to be developmentally regulated, however, remained unaltered after ethanol treatment. It is therefore concluded that alteration of nucleic acid and protein contents of medaka embryo by ethanol could be used as an indicator of embryonic growth retardation which might be the result of disruption of specific gene function during development.

  15. Toxic equivalency factors for halogenated aromatic hydrocarbons determined from embryotoxicity data with Japanese medaka

    SciTech Connect

    Metcalfe, C.D.; Harris, G.; Metcalfe, T.; Bennett, E.; Marshall, T.

    1995-12-31

    Toxic Equivalency Factors (TEFs) for non-ortho substituted PCBs and chlorinated diphenyl ethers have been developed from embryotoxicity data with the Japanese medaka (Oryzias latipes). The medaka TEF for non-ortho PCB congener 126 (0.1) approximates the TEF determined from mammalian experimental models, but the medaka TEFs for other non-ortho PCBs differ from mammalian TEFS. The toxicity of an extract from Lake Ontario rainbow trout to medaka embryos could not be predicted from the Toxic Equivalent Quantities (TEQs) of non-ortho PCBs, 2,3,7,8-TCDD and 2,3,7,8-TCDF in the extract. Embryotoxicity data with subtractions of the trout extract indicated that the ``non-toxic`` PCBs in complex mixtures may modify the toxicity of the non-ortho congeners. Data on the embryotoxicity of chlorinated diphenyl ethers (CDPEs) to medaka indicate that mono-ortho substituted CDPEs are more toxic than non-ortho substituted CDPEs. A fraction of extract prepared from Lake Ontario lake trout which was enriched with CDPEs was embryotoxic to medaka, which indicates that CDPEs may contribute significantly to the toxic burden of halogenated aromatic hydrocarbons in the eggs of wild fish.

  16. EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATIONS OF DIFFERENT NONYLPHENOL FORMULATIONS IN JAPANESE MEDAKA

    EPA Science Inventory

    The time course of exposure to p-nonylphenol (NP) from two different sources was compared to equivalent exposures of 17-b-estradiol (E2) and a solvent control (ethanol: EtOH). Japanese medaka were exposed for 4 days to a nominal concentration of 20 ?g/l of either NP-I (Schenectad...

  17. EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATIONS OF DIFFERENT NONYLPHENOL FORMULATIONS IN JAPANESE MEDAKA. (R827098)

    EPA Science Inventory

    The time course of exposure to p-nonylphenol (NP) from two different sources was compared to equalivent exposures of 17--estradiol (E2) and a solvent control (ethanol; EtOH). Japanese medaka were exposed for 4 days to a nomina...

  18. LARGE SCALE CARCINOGEN DOSE RESPONSE STUDIES WITH JAPANESE MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    To investigate the responses to low carcinogen doses in animal models, large sample sizes are needed and it is an advantage if the model has a low spontaneous tumor rate. Three large scale dose response studies were conducted using Japanese medaka and the carcinogen diethylnitros...

  19. REPRODUCTION AND DEVELOPMENT OF JAPANESE MEDAKA FOLLOWING AN EARLY LIFE STAGE EXPOSURE TO XENOESTROGENS (R823450)

    EPA Science Inventory

    Japanese medaka were exposed to environmentally-relevant concentrations of environmental estrogens: nonylphenol (NP, 0.5, 0.8 and 1.9 g l-1), methoxychlor (MXC, 0.2, 0.6 and 2.3 g...

  20. NOVEL ASSAY TO ASSESS CYP-2E1-LIKE ACTIVITY IN THE JAPANESE MEDAKA (ORYZIAS LATIPES).

    EPA Science Inventory

    Liver microsomes and S-9 fraction of Japanese medaka (Oryzias latipes) metabolized the CYP2E1 specific substrate, p-nitrophenol (PNP), to a single hydroxylated product, 4-nitrocatechol. The use of liver S-9 fraction proved to be a viable alternative to liver microsomes and allowe...

  1. USE OF THE JAPANESE MEDAKA (ORYZIAS LATIPES) AND GUPPY (POECILIA RETICULATA) IN CARCINOGENESIS TESTING UNDER NATIONAL TOXICOLOGY PROGRAM PROTOCOLS

    EPA Science Inventory

    that are economical, sensitive, and scientifically acceptable. Among small fish models, the Japanese medaka (Oryzias latipes) is preeminent for investigating effects of carcinogenic and/or toxic waterborne hazards to humans. The guppy (Poecilia reticulata), although less widely u...

  2. Uptake and depuration of the anti-depressant fluoxetine by the Japanese medaka (Oryzias latipes).

    PubMed

    Paterson, Gordon; Metcalfe, Chris D

    2008-12-01

    The selective serotonin reuptake inhibitor (SSRI) class of anti-depressants is among the most widely prescribed groups of pharmaceuticals. Consequently, aquatic ecosystems impacted by municipal wastewater discharges are predicted to receive substantial annual loadings of these compounds. Although SSRIs have been detected in fish tissues, little is known of their uptake and depuration in freshwater fish species. In this study, Japanese medaka (Oryzias latipes) were exposed to fluoxetine at a nominal concentration of 0.64 microg L(-1) for 7d and subsequently allowed to depurate in clean water over a 21d period. Fluoxetine uptake by medaka was observed within the first 5h of exposure and the biologically active metabolite, norfluoxetine, was also detected in medaka tissues during this timeframe. A maximum fluoxetine concentration was measured in medaka by the third day of the uptake phase, yielding an uptake rate constant (k(1)) of 5.9+/-0.5 (d(-1)). During the depuration phase of the experiment, a half life of 9.4+/-1.1d was determined for fluoxetine. Using these data, bioconcentration factor (BCF) values of 74 and 80 were estimated for fluoxetine and a pseudo-BCF (the ratio of the concentration of norfluoxetine in medaka and the aqueous fluoxetine concentration) of 117 was calculated for norfluoxetine. These results indicate longer persistence and greater potential for the bioaccumulation of fluoxetine and norfluoxetine in fish tissues than would be predicted from prior half life estimates derived using mammalian species.

  3. Unexpected effects of zinc pyrithione and imidacloprid on Japanese medaka fish (Oryzias latipes).

    PubMed

    Sánchez-Bayo, Francisco; Goka, Kouichi

    2005-09-30

    Biological effects of the biocide zinc pyrithione (Zpt), used in anti-dandruff shampoos and antifouling paints and the agricultural insecticide imidacloprid on Japanese medaka fish (Oryzias latipes) were assessed in experimental rice fields. Both chemicals are toxic to medaka, in particular Zpt, which also causes teratogenic effects such as spinal cord deformities in embryos at very low, sublethal concentrations. Rates of malformation in medaka fry from paddies treated twice a week with anti-dandruff shampoo (0.18-0.37 microL/L each time) over a period of 4 months were within the natural background, perhaps due to the quick dissipation rate of this chemical in the environment. Both Zpt and imidacloprid caused stress syndrome in juvenile medaka, with fish from Zpt-shampoo fields having a significantly lower weight to body length ratio than those from control fields. As it often happens with stressed fish, a massive infestation by a Trichodina ectoparasite was observed in medaka from imidacloprid fields. However, despite their high stress levels, fish from the Zpt fields did not suffer such infestation, supposedly because the disinfectant action of this biocide.

  4. Simplex PCR assay for positive identification of genetic sex in the Japanese medaka, Oryzias latipes.

    PubMed

    Patil, Jawahar G; Hinze, Susan J

    2008-01-01

    The medaka, Oryzias latipes, is a very popular model in biomedical research, particularly for elucidating sex differentiation and determination mechanisms and effects of endocrine disruptors among others. These studies require a sensitive, accurate, rapid, and reliable technique for genetic sexing of eggs, larvae, and adults. In this study, we report a simplex polymerase chain reaction approach that uses a single pair of primers for simultaneous amplification of sex-specific amplicons. Males and females yield a single diagnostic band of 933 and 1,906 bp, respectively, in three different strains of medaka tested, permitting gender identification accurately of both immature and adult fish. This technique will be useful in both ecological and biomedical researches that employ medaka and rely on genetic sexing.

  5. Toxicity of 17 {beta}-estradiol and dibutyl-n-phthalate to Japanese medaka (Oryzias latipes)

    SciTech Connect

    Patvna, P.J.; Cooper, K.R. |

    1995-12-31

    Phthalate esters are ubiquitous environmental contaminants that are hypothesized to cause developmental toxicity in aquatic organisms via an estrogenic mechanism. Japanese medaka embryos and larvae provide an excellent model for the study of toxicant effects on embryonic development. The following groups were examined (N = 10--20): a non-treatment control, a vehicle control, 17 {beta}-estradiol and Dibutyl-n-phthalate, in individual glass vials. The medaka embryos were treated beginning at the blastula stage, for ten days. At day 10, embryos were changed into fresh rearing solution. The embryos were observed daily, until three days post-hatching, for toxic developmental effects. Exposure to 17 {beta}-estradiol caused urinary bladder lesions at the lowest doses tested. At concentrations {le} 3 {micro}M/0.82 ppm, 17 {beta}-estradiol caused inhibition of swim bladder inflation, pericardial edema, and marked cachexia. Dibutyl-n-phthalate caused pronounced enlargement of the urinary bladder. No other gross lesions were observed. Both 17 {beta}-estradiol and Dibutyl-n-phthalate caused effects on the urinary tract which will be characterized at the light microscopic level. The lesions observed in the embryo medaka following Dibutyl-n-phthalate exposure were at or below water solubility and are in agreement with previously reported toxic levels.

  6. Fish short-term reproduction assay (FSTRA) with atrazine and the Japanese medaka (Oryzias latipes).

    PubMed

    Hosmer, Alan J; Schneider, Suzanne Z; Anderson, Julie C; Knopper, Loren D; Brain, Richard A

    2017-02-15

    Breeding groups of Japanese medaka (Oryzias latipes) were exposed to atrazine at measured concentrations of 0.6, 5.5, and 53 µg/L for 35 d. Evaluated endpoints included survival, fecundity, fertility, growth (weight and length), behavior, secondary sex characteristics (anal fin papillae), gonad histopathology, and hepatic vitellogenin. No statistically significant effects of atrazine exposure on survival and growth of medaka were noted during the test, and mean survival was ≥97.5% in all treatment groups on Day 35. No significant effects of atrazine exposure on reproduction were observed. The number of mean cumulative eggs produced in the negative control, 0.6, 5.5, and 53 µg/L treatment groups was 7158, 6691, 6883, and 6856 eggs, respectively. The mean number of eggs per female reproductive day was 40.9, 38.2, 40.2, and 39.2 eggs per day, respectively. There were also no dose-dependent effects on mean anal fin papillae counts among male fish or expression of vtg-II in males or females. In addition, atrazine exposure was not related to the development stage of test fish, with testes stages ranging from 2 to 3 in all groups and ovaries ranging from stage 2 to 2.5. Overall, exposure to atrazine up to 53 µg/L for 35 d did not result in significant, treatment-related effects on measured endpoints related to survival, growth, or reproduction in Japanese medaka. This article is protected by copyright. All rights reserved.

  7. Protection against nonylphenol-induced cell death by DJ-1 in cultured Japanese medaka (Oryzias latipes) cells.

    PubMed

    Li, Hong Mei; Taira, Takahiro; Maita, Chinatsu; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M M

    2006-12-07

    The Japanese medaka (Oryzias latipes) has been used to investigate diverse aspects of toxicology, genetics and developmental biology and to monitor biological changes caused by endocrine disruptors. In this study, we analyzed a medaka homolog of human DJ-1 (meDJ-1) in cultured medaka cells into which nonylphenol (NP) was added. Like human DJ-1, meDJ-1 was found to be oxidized by treatment with H(2)O(2) and its pI was shifted to acidic points. NP was found to induce cell death with kinetics similar to that of H(2)O(2) in cultured medaka OLHE-13 cells. After OLHE-13 cells had been treated with sub-lethal concentrations of H(2)O(2) and NP, production of reactive oxygen species and oxidation of meDJ-1 were observed. meDJ-1 knockdown by short interfering RNA rendered OLHE-13 cells susceptible to H(2)O(2) and NP-induced cell death, suggesting a protective role of DJ-1 against oxidative stress-induced cell death in medaka cells. These results suggest that meDJ-1 is a suitable biomarker for oxidative stress reactions in medaka.

  8. Developmental neurotoxicity of organophosphate flame retardants in early life stages of Japanese medaka (Oryzias latipes).

    PubMed

    Sun, Liwei; Tan, Hana; Peng, Tao; Wang, Sisi; Xu, Wenbin; Qian, Haifeng; Jin, Yuanxiang; Fu, Zhengwei

    2016-12-01

    Because brominated flame retardants are being banned or phased out worldwide, organophosphate flame retardants have been used as alternatives on a large scale and have thus become ubiquitous environmental contaminants; this raises great concerns about their environmental health risk and toxicity. Considering that previous research has identified the nervous system as a sensitive target, Japanese medaka were used as an aquatic organism model to evaluate the developmental neurotoxicity of 4 organophosphate flame retardants: triphenyl phosphate, tri-n-butyl phosphate, tris(2-butoxyethyl) phosphate, and tris(2-chloroethyl) phosphate (TCEP). The embryo toxicity test showed that organophosphate flame retardant exposure could decrease hatchability, delay time to hatching, increase the occurrence of malformations, reduce body length, and slow heart rate. Regarding locomotor behavior, exposure to the tested organophosphate flame retardants (except TCEP) for 96 h resulted in hypoactivity for medaka larvae in both the free-swimming and the dark-to-light photoperiod stimulation test. Changes of acetylcholinesterase activity and transcriptional responses of genes related to the nervous system likely provide a reasonable explanation for the neurobehavioral disruption. Overall, the present study clearly demonstrates the developmental neurotoxicity of various organophosphate flame retardants with very different potency and contribute to the determination of which organophosphate flame retardants are appropriate substitutes, as well as the consideration of whether regulations are reasonable and required. Environ Toxicol Chem 2016;35:2931-2940. © 2016 SETAC.

  9. Embryotoxicity of extracts from Lake Ontario rainbow trout (Oncorhynchus mykiss) to Japanese medaka (Oryzias latipes)

    SciTech Connect

    Harris, G.E.; Metcalfe, T.L.; Metcalfe, C.D. . Environmental and Resources Studies Program); Huestis, S.Y. )

    1994-09-01

    Various preparative techniques were used to extract nonpolar organic compounds from the muscle tissue of Lake Ontario rainbow trout (Oncorhynchus mykiss). In this extract, PCBs and organochlorine compounds were detected in nanogram-per-milliliter quantities, and polychlorinated dibenzo-p-dioxins and dibenzofurans were detected in picogram-per-milliliter quantities. The extract and various subfractions of the extract were tested for embryotoxicity in a bioassay with embryos of Japanese medaka (Oryzias latipes). The whole extract was embryotoxic to medaka, as were an extract fraction containing PCBs (fraction A) and extract fractions containing nonpolar organochlorine compounds (fractions B and C). When subfractions prepared from fraction A were tested for embryotoxicity, a subfraction containing non-ortho-substituted PCB congeners was embryo-toxic, whereas subfractions containing mono-ortho- and di-ortho-substituted PCB congeners were relatively nontoxic. Pathological lesions characteristic of exposure to planar halogenated aromatic hydrocarbons were observed only in embryos exposed to the non-ortho-PCB subfraction. The non-ortho-PCB subfraction of fraction A was more toxic than the original fraction A, which indicates that nontoxic PCBs reduce the toxicity of the non-ortho-PCBs through some unknown mechanism. This study indicates that organochlorine compounds and non-ortho-substituted PCBs have the potential to be embryotoxic to early life stages of Great lakes fish, but nontoxic contaminants can modify this toxic response. These data are relevant to the interpretation of correlations between embryo mortalities and concentrations of persistent organic contaminants in Great Lakes salmonids.

  10. Early life-stage mortalities of Japanese medaka (Oryzias latipes) exposed to polychlorinated diphenyl ethers

    SciTech Connect

    Metcalfe, C.D.; Metcalfe, T.L.; Cormier, J.A.; Huestis, S.Y.; Niimi, A.J.

    1997-08-01

    Polychlorinated diphenyl ethers (PCDEs) are a group of compounds that resemble polychlorinated dibenzofurans in structure that have been detected at ppb concentrations in fish from the Great Lakes. The objective of this project was to determine the toxicological significance of PCDE residues in fish. PCDE congener 77 (3,3{prime},4,4{prime}-tetrachlorodiphenyl ether), congener 71 (2,3{prime},4{prime},6-tetrachlorodiphenyl ether), congener 118 (2,3{prime}4,4{prime},5-pentachlorodiphenyl ether), and congener 105 (2,3,3{prime},4,4{prime}-pentachlorodiphenyl) were tested for toxicity with early life stages (ELS) of Japanese medaka, Oryzias latipes. These embryotoxicity data showed that the mono-ortho congeners 105 and 118 and the non-ortho congener 77 were embryotoxic to medaka. However, the toxic equivalency factors (TEFs) estimated for congeners 105, 77, and 118 relative to 2,3,7,8-TCDD were relatively low at 0.00056, 0.00003, and 0.00001, respectively. PCDE compounds were isolated in a fraction prepared from a bulk extract of Lake Ontario lake trout. In this fraction, congeners 99 (2,2{prime},4,4{prime},5-pentaCDE), 153 (2,2{prime},4,m4{prime},5,5{prime}-hexaCDE), 154 (2,2{prime},4,4{prime},5,6{prime}-hexaCDE), and 163 (2,3,3{prime},4{prime},5,6-hexaCDE) comprised 81.3% of total PCDEs, while congeners 77, 71, 118, and 105 comprised only 1.1% of total PCDEs. The LC50 for embryotoxicity of this fraction was equivalent to 15.5 ng/ml of total PCDEs. Toxicopathic lesions noted in medaka embryos exposed to either individual PCDEs or the lake trout extract included vascular hemorrhage but no edematous lesions. Medaka fry did not exhibit symptoms of hyperexcitability prior to death, as has been noted for ELS of lake trout exhibiting swim-up syndrome. These data indicate that PCDEs in Lake Ontario lake trout have the potential to induce toxic effects in early life stages of fish.

  11. Developmental expression and regulation of flavin-containing monooxygenase by the unfolded protein response in Japanese medaka (Oryzias latipes).

    PubMed

    Kupsco, Allison; Schlenk, Daniel

    2017-01-01

    Flavin-containing monooxygenases (FMOs) play a key role in xenobiotic metabolism, are regulated by environmental conditions, and are differentially regulated during mammalian development. Japanese medaka (Oryzias latipes) are a common model organism for toxicological studies. The goal of the current research was to characterize developmental expression and regulation of FMOs in Japanese medaka embryos to better understand the role of FMOs in this model species. Five putative medaka fmos were characterized from the medaka genome through the National Center for Biotechnology Information (NCBI) database by protein motifs and alignments, then identified as fmo4, fmo5A, fmo5B, fmo5C and fmo5D for the current study. Fmo gene expression was analyzed at 1dpf, 3dpf, 6dpf and 9dpf and distinct developmental patterns of expression were observed. Fmo4 and fmo5D increased 3-fold during mid organogenesis (6dpf), while fmo5B and fmo5C decreased significantly in early organogenesis (3dpf) and fmo5A was unaltered. Promoter analysis was performed for transcription factor binding sites and indicated regulation by developmental factors and a role for the unfolded protein response in fmo modulation. Fmo regulation by the UPR was assessed with treatments of 1μg/ml, 2μg/ml, and 4μg/ml Tunicamycin (Tm), and 2mM and 4mM dithiothreitol (DTT), well-known inducers of endoplasmic reticulum stress, for 24h from 5-6dpf. High concentrations to Tm induced fmo4 and fmo5A up to two-fold, while DTT significantly decreased expression of fmo5A, fmo5B, and fmo5C. Results suggest that medaka fmos are variably regulated by the UPR during organogenesis with variable developmental expression, and suggesting potential stage-dependent activation or detoxification of xenobiotics.

  12. Acute Exposure to 17α-Ethinylestradiol Alters Aggressive Behavior of Mosquitofish (Gambusia affinis) Toward Japanese Medaka (Oryzias latipes).

    PubMed

    Dang, Hieu M; Inagaki, Yoshihiko; Yamauchi, Yuta; Kurihara, Takaaki; Vo, Cong H; Sakakibara, Yutaka

    2017-02-03

    Behavior of the mosquitofish (Gambusia affinis) toward the Japanese medaka (Oryzias latipes) was tested under exposure to environmental 17α-ethinylestradiol (EE2), a synthetic derivative of natural estrogen, estradiol. The mosquitofish were exposed to EE2 at different concentrations-0, 0.5, 5.0, and 50.0 ng/L-for 2 days, before their behavioral changes toward the medaka were observed. Results indicate that female mosquitofish became more aggressive at the high level of EE2 (50 ng/L), in terms of how persistently they attempted to approach the medaka. The males showed increased aggressive behavior toward the medaka, by significantly increasing the number and persistence of approach attempts at the low (0.5 and 5 ng/L) levels of EE2. At the highest EE2 concentration (50 ng/L), however, the number of attempts decreased, while the persistence increased in the males showing the same pattern as in the females. All behavioral changes were reversed once EE2 was removed from the environment.

  13. Evaluation of potential mechanisms of atrazine-induced reproductive impairment in fathead minnow (Pimephales promelas) and Japanese medaka (Oryzias latipes)

    USGS Publications Warehouse

    Richter, Cathy; Papoulias, Diana M.; Whyte, Jeffrey J.; Tillitt, Donald E.

    2016-01-01

    Atrazine has been implicated in reproductive dysfunction of exposed organisms, and previous studies documented decreased egg production in Japanese medaka (Oryzias latipes) and fathead minnows (Pimephales promelas) during 30-d to 38-d exposures to 0.5 µg/L, 5 µg/L, and 50 µg/L atrazine. The authors evaluated possible mechanisms underlying the reduction in egg production. Gene expression in steroidogenesis pathways and the hypothalamus–pituitary–gonad axis of male and female fish was measured. Atrazine did not significantly induce gonad aromatase (cyp19a1a) expression. An atrazine-induced shift in the number of females in an active reproductive state was observed. Expression of the egg maturation genes vitellogenin 1 (vtg1) and zona pellucida glycoprotein 3.1 (zp3.1) in medaka females was correlated and had a bimodal distribution. In both species, females with low vtg1 or zp3.1 expression also had low expression of steroidogenesis genes in the gonad, estrogen receptor in the liver, and gonadotropins in the brain. In the medaka, the number of females per tank that had high expression of zp3.1 was significantly correlated with egg production per tank. The number of medaka females with low expression of zp3.1 increased significantly with atrazine exposure. Thus, the decline in egg production observed in response to atrazine exposure may be the result of a coordinated downregulation of genes required for reproduction in a subset of females.

  14. Adduct formation of 7,12-dimethylbenz(a)anthracene in the embryo of the Japanese medaka (Oryzias latipes)

    SciTech Connect

    Liu, H.; Cooper, K.R.

    1995-12-31

    DNA adduct formation of 7,1 2-dimethylbenz(a)anthracene (DMBA) in vivo in the Japanese medaka embryo were investigated using {sup 32}P-postlabeling analysis. 1-compounds (endogenous adducts) were not observed in the Japanese medaka embryo on days 4 (prior to liver formation), 6 (liver/swim bladder) or 10 (prior to hatch) of development. The level of DMBA:DNA adducts were concentration-dependent over the range of 0.625 ppm (Total Adducts 0.05707 pmol/mg of DNA) to 2.50 ppm (0.43341 pmol/mg of DNA) and decreased at 5.00 ppm (0.25338 pmol/mg of DNA) after medaka embryos were exposed to DMBA for 6 days from the day of fertilization. The decrease in DMBA:DNA adducts at 5.00 ppm was probably due to embryo toxicity (78% death). The level of DMBA:DNA adducts formed from the embryos exposed to DMBA for 24 hr decreased as the stage of development increased: day 4 > day 6 > day 10; 0.0262, 0.0179, 0.0129 pmol/mg of DNA, respectively. The level of DMBA:DNA adducts increased as the length of exposure increased: 4 day < 6 day < 10 day; 0.0233, 0.0614, 0.1502, respectively. There was both a time and dose dependence to the number of adducts detected. The data presented demonstrated the development of DM BA-DNA adducts in the developing Japanese medaka (Oryzias latipes) and the lack of I-compounds.

  15. Developmental toxicity and DNA damage from exposure to parking lot runoff retention pond samples in the Japanese medaka (Oryzias latipes).

    PubMed

    Colton, Meryl D; Kwok, Kevin W H; Brandon, Jennifer A; Warren, Isaac H; Ryde, Ian T; Cooper, Ellen M; Hinton, David E; Rittschof, Daniel; Meyer, Joel N

    2014-08-01

    Parking lot runoff retention ponds (PLRRP) receive significant chemical input, but the biological effects of parking lot runoff are not well understood. We used the Japanese medaka (Oryzias latipes) as a model to study the toxicity of water and sediment samples from a PLRRP in Morehead City, NC. Medaka exposed in ovo to a dilution series of PLRRP water had increased odds of death before hatching, but not teratogenesis or delayed hatching. Next, we adapted a long-amplicon quantitative PCR (LA-QPCR) assay for DNA damage for use with the Japanese medaka. We employed LA-QPCR to test the hypotheses that PLRRP water and sediments would cause nuclear and mitochondrial DNA damage with and without full-spectrum, natural solar radiation. Fluoranthene with and without natural sunlight was a positive control for phototoxic polycyclic aromatic hydrocarbon-induced DNA damage. Fluoranthene exposure did not result in detectable DNA damage by itself, but in combination with sunlight caused significant DNA damage to both genomes. PLRRP samples caused DNA damage to both genomes, and this was not increased by sunlight exposure, suggesting the DNA damage was unlikely the result of PAH phototoxicity. We report for the first time that PLRRP-associated pollutants cause both nuclear and mitochondrial DNA damage, and that fluoranthene-mediated phototoxicity results in similar levels of damage to the nuclear and mitochondrial genomes. These effects may be especially significant in sensitive marine ecosystems.

  16. Developmental toxicity and DNA damage from exposure to parking lot runoff retention pond samples in the Japanese Medaka (Oryzias latipes)

    PubMed Central

    Colton, Meryl D.; Kwok, Kevin W.H.; Brandon, Jennifer A.; Warren, Isaac H.; Ryde, Ian T.; Cooper, Ellen M.; Hinton, David E.; Rittschof, Daniel; Meyer, Joel N.

    2015-01-01

    Parking lot runoff retention ponds (PLRRP) receive significant chemical input, but the biological effects of parking lot runoff are not well understood. We used the Japanese medaka (Oryzias latipes) as a model to study the toxicity of water and sediment samples from a PLRRP in Morehead City, NC. Medaka exposed in ovo to a dilution series of PLRRP water had increased odds of death before hatching, but not teratogenesis or delayed hatching. Next, we adapted a long-amplicon quantitative PCR (LA-QPCR) assay for DNA damage for use with the Japanese medaka. We employed LA-QPCR to test the hypotheses that PLRRP water and sediments would cause nuclear and mitochondrial DNA damage with and without full-spectrum, natural solar radiation. Fluoranthene with and without natural sunlight was a positive control for phototoxic polycyclic aromatic hydrocarbon-induced DNA damage. Fluoranthene exposure did not result in detectable DNA damage by itself, but in combination with sunlight caused significant DNA damage to both genomes. PLRRP samples caused DNA damage to both genomes, and this was not increased by sunlight exposure, suggesting the DNA damage was unlikely the result of PAH phototoxicity. We report for the first time that PLRRP-associated pollutants cause both nuclear and mitochondrial DNA damage, and that fluoranthene-mediated phototoxicity results in similar levels of damage to the nuclear and mitochondrial genomes. These effects may be especially significant in sensitive marine ecosystems. PMID:24816191

  17. Effects of ionization on the toxicity of silver nanoparticles to Japanese medaka (Oryzias latipes) embryos.

    PubMed

    Lee, Byoung-Cheun; Kim, Jungkon; Cho, Jae-Gu; Lee, Jae-Woo; Duong, Cuong N; Bae, Eunjoo; Yi, Jongheop; Eom, Ig-Chun; Choi, Kyunghee; Kim, Pilje; Yoon, Junheon

    2014-01-01

    Increase in the use of manufactured nanomaterials (NMs) has led to concerns about the environmental impacts. Especially, hazard of metal-based NMs is more severe due to ions released from surface by water quality parameters and physicochemical properties after entering into the water environment. However, little is known about the effects of ionization on the toxicity of metal-based NMs in the water environment. To address this question, we prepared the suspensions of silver nanoparticles (AgNP) at 25 μg L(-1) containing different concentrations of Ag(+) (5, 10, 20, 45, and 75% Ag(+) to total Ag), and evaluated their toxicity to Japanese medaka (Oryzias latipes) embryos. Higher Ag(+) ratios in the AgNP suspension, suggesting the lower number of particles, led to the higher adverse effects on embryos and sac-fries. In addition, histopathology analysis revealed that AgNPs penetrated through chorion of eggs and skin membrane, and were distributed into the tissues. The results imply that the ionization could decrease the toxicity of metal-based NMs in the water environment.

  18. Development of the pancreas in medaka, Oryzias latipes, from embryo to adult.

    PubMed

    Otsuka, Takayoshi; Tsukahara, Tatsuya; Takeda, Hiroyuki

    2015-10-01

    To address conserved and unique features of fish pancreas development, we performed extensive analyses of pancreatic development in medaka embryos and adults using pdx1- and ptf1a-transgenic medaka, in situ hybridization and immunohistochemistry. The markers used in these analyses included pdx1, nkx6.1, nkx6.2, nkx2.2, Islet1, insulin, Somatostatin, glucagon, ptf1a, ela3l, trypsin, and amylase. The double transgenic (Tg) fish produced in the present study visualizes the development of endocrine (pdx1+) and exocrine (ptf1a+) parts simultaneously in living fishes. Like other vertebrates, the medaka pancreas develops as two (dorsal and ventral) buds in the anterior gut tube, which soon fuse into a single anlagen. The double Tg fish demonstrates that the differential property between the two buds is already established at the initial phase of bud development as indicated by strong pdx1 expression in the dorsal one. This Tg fish also allowed us to examine the gross morphology and the structure of adult pancreas and revealed unique characters of medaka pancreas such as broad and multiple connections with the gut tube along the anterior-posterior axis.

  19. Dynamic selenium assimilation, distribution, efflux, and maternal transfer in japanese medaka fed a diet of se-enriched mayflies.

    PubMed

    Conley, Justin M; Watson, Atlee T D; Xie, Lingtian; Buchwalter, David B

    2014-01-01

    Selenium (Se) trafficking in oviparous species remains understudied and a major source of uncertainty in developing sound Se regulations. Here, we utilized (75)Se to follow Se through a simulated natural food chain (water, periphyton, mayflies (Centroptilum triangulifer), fish (Japanese medaka)). We specifically examined Se assimilation efficiency, tissue distribution, efflux rate, and maternal transfer in medaka. Selenium assimilation efficiency (AE) averaged 63.2 ± 8.8% from mayfly diets and was not affected by mayfly [Se] across a dietary range of 5.6-38.7 μg g(-1) (dry wt). However, AE decreased significantly as mayfly larva size increased. Efflux rate constants (ke) were consistent between reproductively inactive (0.066 d(-1)) and spawning females (0.069 d(-1)). Total Se loss rate constant (ke+egg; efflux and egg deposition) was 0.17 d(-1) in spawning females. Interestingly, medaka appeared to rapidly shuttle Se to their eggs directly from their diet via the ovary, as opposed to mobilization from surrounding tissues, resulting in dynamic egg [Se] that was more attributable to recent dietary Se ingestion than female whole body [Se] in this asynchronous spawning fish. Spawning strategy likely plays a large role in the process of fish egg Se deposition and requires further attention to understand risk and toxicity of Se to fish.

  20. Transcriptional responses in male Japanese medaka exposed to antiandrogens and antiandrogen/androgen mixtures.

    PubMed

    Sun, Liwei; Peng, Tao; Liu, Fang; Ren, Lin; Peng, Zuhua; Ji, Guorong; Zhou, Yinfang; Fu, Zhengwei

    2016-11-01

    The occurrence of androgenic endocrine disrupting chemicals (EDCs) in water is thought to be linked to deviation from normal male developmental and reproductive functions in exposed aquatic organisms. Because aquatic environments represent a chemically complex medium, the combined effects of androgenic EDCs require urgent attention. In the present study, the effects of two model androgen receptor (AR) antagonists, flutamide (FLU), and vinclozolin (VIN), were first determined individually in male Japanese medaka using the transcriptional response for genes associated with the hypothalamic-pituitary-gonadal axis. The fish were further exposed to binary mixtures of VIN and 17β-trenbolone (TRE, AR agonist) to confirm the theoretical opposing effects of the AR antagonist and agonist. The results showed that exposure to FLU or VIN alone induced very similar transcriptional responses, demonstrating that gene transcription analysis could be successfully employed in identifying the action of single chemicals. For example, both exposures increased the transcription of cyp17b but decreased that of cyp19b in the gonad, demonstrating the compensatory response for AR blockage. However, in the case of exposure to mixtures, although the joint antagonistic action of TRE and VIN affected the most genes, the transcription profiles after exposure to mixtures were not consistent with expectations based on the results for individual chemicals, such as hepatic vtg, and star or cyp19a in gonads. Therefore, the limitation of gene transcription analyses in exposures to mixtures, as well as the potential for the extrapolation of single chemicals, should be considered in future studies. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1591-1599, 2016.

  1. Differential genetic responses to ionizing irradiation in individual families of Japanese medaka, Oryzias latipes.

    PubMed

    Tsyusko, O; Glenn, T; Yi, Y; Joice, G; Jones, K; Aizawa, K; Coughlin, D; Zimbrick, J; Hinton, T

    2011-01-10

    Although no statistically significant hereditary effects have yet been detected in the children of survivors from the atomic bombings in Hiroshima and Nagasaki, recent animal studies have found that exposure to ionizing radiation can cause genomic and epigenomic instability in the exposed individuals, as well as their offspring, and therefore, may have much larger genetic effects than predicted by earlier studies. When individuals are exposed to various environmental insults, including radiation, individual sensitivity to the insults often varies. Variance in germ-line response to radiation among individuals has been widely recognized, but it is difficult to address due to the use of inbred strains and the limited number of offspring that can be produced by a pair of mice, the common model used to study genetic effects of radiation. Herein is the first study to examine individual family responses to ionizing radiation using a parent-pedigree approach in an outbred strain of a vertebrate model, the Japanese medaka fish. Changes in frequencies of radiation-induced germline mutations at nine microsatellite loci were examined in the same families before and after exposure to one of four acute doses of ionizing radiation (0.1, 0.5, 2.5, 5Gy, plus sham-exposed controls). Families varied significantly in pre-exposure mutation frequencies and responses to irradiation, but germline mutations were elevated in at least one family after 0.1, 0.5, and 5Gy exposures. Variance among individuals in sensitivity to radiation is well documented for many endpoints, and our work now extends these endpoints to include germ-line mutations. Further studies are needed to elucidate dose response, effects at varying stages of spermatogenesis, and the mechanisms underlying the variance in these individual responses to radiation.

  2. Retinoic acid and meiosis induction in adult versus embryonic gonads of medaka

    PubMed Central

    Adolfi, Mateus C.; Herpin, Amaury; Regensburger, Martina; Sacquegno, Jacopo; Waxman, Joshua S.; Schartl, Manfred

    2016-01-01

    In vertebrates, one of the first recognizable sex differences in embryos is the onset of meiosis, known to be regulated by retinoic acid (RA) in mammals. We investigated in medaka a possible meiotic function of RA during the embryonic sex determination (SD) period and in mature gonads. We found RA mediated transcriptional activation in germ cells of both sexes much earlier than the SD stage, however, no such activity during the critical stages of SD. In adults, expression of the RA metabolizing enzymes indicates sexually dimorphic RA levels. In testis, RA acts directly in Sertoli, Leydig and pre-meiotic germ cells. In ovaries, RA transcriptional activity is highest in meiotic oocytes. Our results show that RA plays an important role in meiosis induction and gametogenesis in adult medaka but contrary to common expectations, not for initiating the first meiosis in female germ cells at the SD stage. PMID:27677591

  3. Mechanisms of Selenomethionine Developmental Toxicity and the Impacts of Combined Hypersaline Conditions on Japanese Medaka (Oryzias latipes)

    PubMed Central

    2015-01-01

    Selenium (Se) is an essential micronutrient that can cause embryotoxicty at levels 7–30 times above essential concentrations. Exposure to hypersaline conditions and 50 μM selenomethionine (SeMet) decreased embryo hatch and depleted glutathione in Japanese medaka embryos without affecting Se accumulation. To better understand the impacts of nonchemical stressors on developmental toxicity of Se in fish, several adverse outcome pathways were evaluated in the Japanese medaka (Oryzias latipes). We treated medaka embryos at 12 h post fertilization with 50 μM SeMet for 12 hours in freshwater or in 13 ppth hypersalinity and evaluated the contributions of oxidative stress, the unfolded protein response and apoptosis to reduced hatch. Exposure to SeMet and hypersalinity decreased embryo hatch to 3.7% ± 1.95, and induced teratogenesis in 100% ± 0 of hatched embryos. In contrast, treatments of freshwater, saltwater, and SeMet in freshwater resulted in 89.8% ± 3.91–86.7% ± 3.87 hatch, and no significant increase in deformities. We found no significant differences in lipid peroxidation, indicating that oxidative stress may not be responsible for the observed toxicity in embryos at this time point (24 h). Although significant changes in apoptosis were not observed, we witnessed up to 100 fold increases in transcripts of the endoplasmic reticulum (ER) chaperone, immunoglobulin binding protein (BiP) and trends toward increasing downstream signals, activating transcription factor 4 (ATF4) and ATF6 indicating potential contributions of the unfolded protein response to the effects of SeMet and hypersaline conditions. These data indicate that multiple adverse outcome pathways may be responsible for the developmental toxicity of Se and salinity, and these pathways may be time dependent. PMID:24856650

  4. Use of Medaka in Toxicity Testing

    PubMed Central

    Cowden, John; Hinton, David E.; Johnson, Rodney; Flynn, Kevin; Hardman, Ronald C.; Yuen, Bonny; Law, Sheran; Kullman, Seth W.; Au, Doris W.T.

    2015-01-01

    Small aquarium fishes are increasingly used as animal models, and one of these, Japanese Medaka (Oryzias latipes), is frequently utilized for toxicity testing. While these vertebrates have many similarities with their terrestrial counterparts, there are differences that must be considered if these organisms are to be used to their highest potential. Testing commonly may employ either the developing embryo or adults; both are easy to use and to work with. We present here three main protocols to illustrate the utility and breadth of toxicity testing possible using medaka fish. The first protocol assesses neurotoxicity in developing embryos. The second protocol describes the sexual genotyping of medaka to evaluate toxicant effects on sexual phenotype after treatment with endocrine disrupting chemicals. The third protocol assesses hepatotoxicity in adult fish after treatment with a model hepatotoxicant. The methods run the gamut from immunohistology through PCR to basic histological techniques. PMID:20922755

  5. GONADAL DEVELOPMENT AND ENDOCRINE RESPONSES IN JAPANESE MEDAKA (ORYZIAS LATIPES) EXPOSED TO O,P'-DDT IN WATER OR THROUGH MATERNAL TRANSFER

    EPA Science Inventory

    Various isomers and metabolites of DDT disrupt endocrine systems and gonadal development in fish andxwildlife and o,p'-DDT has been shown to be a relatively potent estrogen agonist. In this study, we exposed Japanese medaka (Oryzias latipes) to o,p'-DDT using two exposure protoco...

  6. Developmental toxicity of PAH mixtures in fish early life stages. Part II: adverse effects in Japanese medaka.

    PubMed

    Le Bihanic, Florane; Clérandeau, Christelle; Le Menach, Karyn; Morin, Bénédicte; Budzinski, Hélène; Cousin, Xavier; Cachot, Jérôme

    2014-12-01

    In aquatic environments, polycyclic aromatic hydrocarbons (PAHs) mostly occur as complex mixtures, for which risk assessment remains problematic. To better understand the effects of PAH mixture toxicity on fish early life stages, this study compared the developmental toxicity of three PAH complex mixtures. These mixtures were extracted from a PAH-contaminated sediment (Seine estuary, France) and two oils (Arabian Light and Erika). For each fraction, artificial sediment was spiked at three different environmental concentrations roughly equivalent to 0.5, 4, and 10 μg total PAH g(-1) dw. Japanese medaka embryos were incubated on these PAH-spiked sediments throughout their development, right up until hatching. Several endpoints were recorded at different developmental stages, including acute endpoints, morphological abnormalities, larvae locomotion, and genotoxicity (comet and micronucleus assays). The three PAH fractions delayed hatching, induced developmental abnormalities, disrupted larvae swimming activity, and damaged DNA at environmental concentrations. Differences in toxicity levels, likely related to differences in PAH proportions, were highlighted between fractions. The Arabian Light and Erika petrogenic fractions, containing a high proportion of alkylated PAHs and low molecular weight PAHs, were more toxic to Japanese medaka early life stages than the pyrolytic fraction. This was not supported by the toxic equivalency approach, which appeared unsuitable for assessing the toxicity of the three PAH fractions to fish early life stages. This study highlights the potential risks posed by environmental mixtures of alkylated and low molecular weight PAHs to early stages of fish development.

  7. Arginine vasotocin neuronal development and its projection in the adult brain of the medaka.

    PubMed

    Kagawa, Nao; Honda, Akira; Zenno, Akiko; Omoto, Ryosuke; Imanaka, Saya; Takehana, Yusuke; Naruse, Kiyoshi

    2016-02-02

    The neurohypophysial peptide arginine vasotocin (AVT) and its mammalian ortholog arginine vasopressin function in a wide range of physiological and behavioral events. Here, we generated a new line of transgenic medaka (Oryzias latipes), which allowed us to monitor AVT neurons by enhanced green fluorescent protein (EGFP) and demonstrate AVT neuronal development in the embryo and the projection of AVT neurons in the adult brain of avt-egfp transgenic medaka. The onset of AVT expression manifested at 2 days postfertilization (dpf) as a pair of signals in the telencephalon of the brain. The telencephalic AVT neurons migrated and converged on the preoptic area (POA) by 4dpf. At the same stage, another onset of AVT expression manifested in the central optic tectum (OT), and they migrated to the ventral part of the hypothalamus (VH) by 6dpf. In the adult brain, the AVT somata with EGFP signals existed in the gigantocellular POA (gPOA), magnocellular POA (mPOA), and parvocellular POA (pPOA) and in the VH. Whereas the major projection of AVT fibers was found from the pPOA and VH to the posterior pituitary, it was also found that AVT neurons in the three POAs send their fibers into wide regions of the brain such as the telencephalon, mesencephalon and diencephalon. This study suggests that the avt-egfp transgenic medaka is a useful model to explore AVT neuronal development and function.

  8. Effects of propranolol on heart rate and development in Japanese medaka (Oryzias latipes) and zebrafish (Danio rerio).

    PubMed

    Finn, Juliane; Hui, Michelle; Li, Vincent; Lorenzi, Varenka; de la Paz, Nayeli; Cheng, Shuk Han; Lai-Chan, Leo; Schlenk, Daniel

    2012-10-15

    Propranolol is a β-adrenergic receptor antagonist (β-blocker) that is frequently used to treat hypertension and other cardiovascular conditions in humans. Detected in surface waters due to discharge of domestic wastewater, propranolol has demonstrated significant species differences in toxicity between fish. The aim of this study was to investigate the effects of propranolol on heart rate and development in embryos of two species of fish; Japanese medaka (JM) Oryzias latipes and zebrafish (ZF) Danio rerio. Parents and fertilized embryos of each species were exposed to nominal (measured) concentrations of 0.1 (0.09), 1 (1.1) and 10 (8.3) μg/L of propranolol. Heart rate was monitored during subsequent exposure in embryos at incremental developmental periods (44, 54, 64 h post-fertilization (hpf) for ZF and 68, 116, 164 hpf for JM). Heart development and morphology was examined using whole mount immunostaining with distance measurements between the sinus venosus (SV) and bulbus arteriosis (BV). Morphological measurements were made at 44 hpf for ZF and 164 hpf for JM. In ZF, a significant reduction in heart rate was observed at 0.08 μg/L propranolol, along with an increase in the SV-BA distance at 44 hpf. Significant reductions in heart rate were also observed in ZF at 54 and 64 hpf at all concentrations of propranolol. For JM, heart rates generally decreased at all developmental timepoints (68, 116 and 164 hpf) after propranolol treatment, with concentration dependent decreases observed at 164 hpf and a lowest observed effect concentration (LOEC) of 0.09 μg/L propranolol at each timepoint. However, significant alterations in cardiac morphology were not observed in JM at 164 hpf. In contrast, heart rates and morphology in ZF were affected with a non-monotonic concentration response in morphology and a LOEC of 0.09 μg/L propranolol for morphological alterations at 44 hpf and for heart rate at each timepoint. These data indicated unique developmental stages of

  9. Comparative embryotoxicity of pulp mill extracts in rainbow trout (Oncorhynchus mykiss), American flagfish (Jordanella floridae) and Japanese medaka (Oryzias latipes).

    PubMed

    Orrego, Rodrigo; Guchardi, John; Beyger, Lindsay; Krause, Rachelle; Holdway, Douglas

    2011-08-01

    This study evaluated the effects of Chilean pulp mill effluent extracts (untreated, primary and secondary treated pulp mill effluents), along with steroid standards (testosterone and 17β-estradiol) and a wood extractive standard (beta-sitosterol) on developing post-fertilized fish embryos. Our study included a cold freshwater species, rainbow trout (Oncorhynchus mykiss), and two warm freshwater species American flagfish (Jordanella floridae) and Japanese medaka (Oryzias latipes). Embryotoxicity results included delay in time to hatch and decreased hatchability but no significant egg and larvae mortality was observed in the pulp mill extract exposed embryos. By contrast, significant early hatching and increased hatchability were observed in beta-sitosterol exposed embryos, along with high mortality of testosterone exposed embryos across species. Teratogenic responses were observed in medaka embryos in all treatments. Abnormalities were detected starting at development stages 19-20 (2-4 somite stages) and included optical deformities (micro-opthalmia, 1 or 2 eyes) and lack of development of brains and hearts. Additionally, phenotypic sex identification of surviving offspring found female-biased sex-ratios in all treatments except testosterone across species. Overall, our study indicated that Chilean pulp and paper mill extractives caused embryotoxicity (post-fertilized embryos) across species and irrespective of the effluent treatment. The effects were mainly associated with delayed time to hatch, decreased hatchability, and species-specific teratogenesis.

  10. Ovarian structure protein 1: A sensitive molecular biomarker of gonadal intersex in female Japanese medaka after androgen exposure.

    PubMed

    Abdel-Moneim, Ahmed; Mahapatra, Cecon T; Hatef, Azadeh; Sepúlveda, Maria S

    2015-09-01

    Intersex in gonochoristic fish can be induced after exposure to androgens and estrogens. The main objective of the present study was to identify biomarkers that would be predictive of intersex in Japanese medaka (Oryzias latipes) after exposure to synthetic hormones. First a gene was identified, ovarian structure protein 1 (osp1), with strong female-specific expression during gonadal differentiation. The authors hypothesized that osp1 expression would decrease to male levels in females after the exposure of larvae (15-25 d postfertilization [dpf]) to 17β-trenbolone (TRB; 5 ng/L) and would increase to female levels in males exposed to 17α-ethinylestradiol (EE2; 5 ng/L) and that gonadal intersex would be induced later in life (60 dpf). Tissue distribution and cellular localization of OSP1 was investigated using Western blot and immunohistochemistry. The results indicate that this exposure regime delays testicular maturation in males and development of ovarian intersex in females. Although decreased osp1 expression in females exposed to TRB correlated to changes in ovarian phenotype, up-regulation of osp1 was not observed in males exposed to EE2. In addition, OSP1 was only observed in ovaries and localized in the cytoplasm and follicular layer of immature and mature oocytes. The authors conclude that osp1 is a promising biomarker of androgen exposure and gonadal intersex in female medaka.

  11. Apoptosis and morphological alterations after UVA irradiation in red blood cells of p53 deficient Japanese medaka (Oryzias latipes).

    PubMed

    Sayed, Alla El-Din Hamid; Watanabe-Asaka, Tomomi; Oda, Shoji; Mitani, Hiroshi

    2016-08-01

    Morphological alterations in red blood cells were described as hematological bioindicators of UVA exposure to investigate the sensitivity to UVA in wild type Japanese medaka (Oryzias latipes) and a p53 deficient mutant. The fewer abnormal red blood cells were observed in the p53 mutant fish under the control conditions. After exposure to different doses of UVA radiation (15min, 30min and 60min/day for 3days), cellular and nuclear alterations in red blood cells were analyzed in the UVA exposed fish compared with non-exposed controls and those alterations included acanthocytes, cell membrane lysis, swollen cells, teardrop-like cell, hemolyzed cells and sickle cells. Those alterations were increased after the UVA exposure both in wild type and the p53 deficient fish. Moreover, apoptosis analyzed by acridine orange assay showed increased number of apoptosis in red blood cells at the higher UVA exposure dose. No micronuclei but nuclear abnormalities as eccentric nucleus, nuclear budding, deformed nucleus, and bilobed nucleus were observed in each group. These results suggested that UVA exposure induced both p53 dependent and independent apoptosis and morphological alterations in red blood cells but less sensitive to UVA than Wild type in medaka fish.

  12. The Effects of Rearing Density, Salt Concentration, and Incubation Temperature on Japanese Medaka (Oryzias latipes) Embryo Development

    PubMed Central

    Rosemore, Bethany J.

    2012-01-01

    Abstract Environmental stressors are often present when an aquatic species, such as the Japanese medaka (Oryzias latipes) fish, are developing. This study examined the effects of some of these environmental stressors (variation in rearing density, salinity, and incubation temperature) on medaka embryo development. The hypotheses are if rearing density is increased, then hatching success will also be improved, while having no effect on embryo development; if the salt concentration is increased to 20 parts per thousand (ppt), then the rate of development will also be increased; if temperature is increased to 32°C, then the rate of development will also be increased. To determine the effects of variations in rearing density (1, 2, 3, and 4 eggs per well), the time of hatch was observed and noted. When testing variations in temperature (24°, 28°, and 32°C) and salinity (0.3, 10, 15, and 20 ppt), the onset of heartbeat and onset of retina pigmentation were observed. The original hypotheses were not all supported: as rearing density increased, success of hatch decreased; as salinity increased, only the rate of development for heartbeat increased; as temperature increased, the rate of development for both onset of the heartbeat and retina pigmentation also increased. PMID:23244689

  13. p53 Mutation suppresses adult neurogenesis in medaka fish (Oryzias latipes)

    SciTech Connect

    Isoe, Yasuko; Okuyama, Teruhiro; Taniguchi, Yoshihito; Kubo, Takeo; Takeuchi, Hideaki

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer Progenitor migration is accompanied by an increase in their numbers in the adult brain. Black-Right-Pointing-Pointer p53 Mutation suppressed an increase in the number of the migrated progenitors. Black-Right-Pointing-Pointer The decreased progenitor number is not due to enhanced cell death. Black-Right-Pointing-Pointer p53 Mutation did not affect proliferation of stem cells. -- Abstract: Tumor suppressor p53 negatively regulates self-renewal of neural stem cells in the adult murine brain. Here, we report that the p53 null mutation in medaka fish (Oryzias latipes) suppressed neurogenesis in the telencephalon, independent of cell death. By using 5-bromo-29-deoxyuridine (BrdU) immunohistochemistry, we identified 18 proliferation zones in the brains of young medaka fish; in situ hybridization showed that p53 was expressed selectively in at least 12 proliferation zones. We also compared the number of BrdU-positive cells present in the whole telencephalon of wild-type (WT) and p53 mutant fish. Immediately after BrdU exposure, the number of BrdU-positive cells did not differ significantly between them. One week after BrdU-exposure, the BrdU-positive cells migrated from the proliferation zone, which was accompanied by an increased number in the WT brain. In contrast, no significant increase was observed in the p53 mutant brain. Terminal deoxynucleotidyl transferase (dUTP) nick end-labeling revealed that there was no significant difference in the number of apoptotic cells in the telencephalon of p53 mutant and WT medaka, suggesting that the decreased number of BrdU-positive cells in the mutant may be due to the suppression of proliferation rather than the enhancement of neural cell death. These results suggest that p53 positively regulates neurogenesis via cell proliferation.

  14. Toxicity of oil sands acid-extractable organic fractions to freshwater fish: Pimephales promelas (fathead minnow) and Oryzias latipes (Japanese medaka).

    PubMed

    Bauer, Anthony E; Frank, Richard A; Headley, John V; Peru, Kerry M; Farwell, Andrea J; Dixon, D George

    2017-03-01

    The Alberta oil sands are one of the largest global petroleum deposits and, due to non-release practices for oil sands process-affected waters, produced tailings are stored in large ponds. The acid extractable organic (AEO) compounds in oil sands process-affected water are of greatest concern due to their persistence and toxicity to a variety of aquatic biota. The present study evaluated the toxicity of the five AEO fractions to two fish species: Oryzias latipes (Japanese medaka) and Pimephales promelas (fathead minnow). The fractions (F1-F5) were comprised of AEO with increasing mean molecular weight and subsequent increases in cyclicity, aromaticity, degree of oxygenation, and heteroatom content. The lowest molecular weight fraction, F1, displayed the lowest acute toxicity to both fish species. For fathead minnow, F5 displayed the greatest toxic potency, while F2 to F4 displayed intermediate toxicities. For Japanese medaka, F2 and F3 displayed the greatest acute toxicities and F1, F4 and F5 were significantly less potent. Overall, fathead minnow were more acutely sensitive to AEO than Japanese medaka. The present study indicates that AEO toxicity may not be solely driven by a narcotic mode of action, but chemical composition such as aromaticity and heteroatom content and their relation to toxicity suggest other drivers indicative of additional modes of toxic action.

  15. Environmental concentrations of benz[a]anthracene induce developmental defects and DNA damage and impair photomotor response in Japanese medaka larvae.

    PubMed

    Le Bihanic, Florane; Sommard, Vivien; Perrine, de Lansalut; Pichon, Anaïk; Grasset, Julie; Berrada, Saadia; Budzinski, Hélène; Cousin, Xavier; Morin, Bénédicte; Cachot, Jérôme

    2015-03-01

    Benz[a]anthracene (BaA) is a ubiquitous polycyclic aromatic hydrocarbon found in numerous aquatic ecosystems. However, ecotoxicological data in aquatic organisms are scarce. To remedy this lack of data, Japanese medaka (Oryzias latipes) embryos were exposed to BaA and toxic effects were investigated at multiple toxicological endpoints. Japanese medaka embryos were incubated onto BaA-spiked artificial sediment for 9 days at low or moderate environmental concentrations ranging from 0.9 to 12 µgg(-1) dw. BaA-exposed embryos exhibited significant tachycardia. BaA exposure was also shown to increase CYP1A activity in the hepato-biliary tissue as well as craniofacial deformities and DNA damage in pro-larvae. The photomotor response of BaA-exposed larvae was reduced in comparison to the control group. According to this set of tests, the lowest tested and observed effect concentration (LOEC) for Japanese medaka early life stages was equivalent to 0.92 µgg(-1) dw of BaA. This concentration fall into the range of concentrations frequently encountered in sediments of polluted aquatic ecosystems. Taking into consideration these results, BaA represents a threat for fish early life stages in particular those developing onto or into contaminated sediments.

  16. Fish multigeneration test with preliminary short-term reproduction assay for estrone using Japanese medaka (Oryzias latipes).

    PubMed

    Nakamura, Ataru; Tamura, Ikumi; Takanobu, Hitomi; Yamamuro, Masumi; Iguchi, Taisen; Tatarazako, Norihisa

    2015-01-01

    The most potent chemicals potentially causing adverse effects on fish species are estrogens in human waste.Sewage is a source of these estrogens and it is difficult to reduce. In particular, although the bioactivity of estrone is estimated to be about half of that of estradiol, multiple studies report that more than 100 ng l(–1) of estrone can be detected in urban rivers, including discharges from sewage treatment works; approximately two times as high as estradiol. Few studies have been conducted to investigate the long-term effects of estrone on wildlife; therefore, we conducted fish multigeneration test using Japanese medaka (Oryzias latipes). Medaka were exposed to estrone for 27 weeks across three generations in environmentally relevant concentrations, being 5.74, 11.4, 24.0, 47.1 and 91.4 ng l(–1). No effects on reproduction were observed in the first generation; however, a decline in egg production and fertility was observed in the second generation exposed to 91.4 ng l(–1) estrone, which is lower than some known environmental concentrations in urban environments. Furthermore, histopathological abnormalities were observed in the third generation exposed to both 47.1 and 91.4 ng l(–1), suggesting that estrone possibly exerts severe effects on the third or later generations. However, appearances of testis–ova were observed in the second and third generation they were not consistent with actual effects on reproduction, notwithstanding the testis-ovais regarded as the key evidence for endocrine disruption. Accordingly, we consider that qualitative measurement of abnormalities using histopathological observations is required for appropriate evaluation of endocrine disruption.

  17. Effects of the brominated flame retardant TBCO on fecundity and profiles of transcripts of the HPGL-axis in Japanese medaka.

    PubMed

    Saunders, David M V; Podaima, Michelle; Wiseman, Steve; Giesy, John P

    2015-03-01

    The novel brominated flame retardant, 1,2,5,6-tetrabromocyclooctane (TBCO) is an additive flame retardant which is marketed under the trade name Saytex BCL-48. TBCO has recently been investigated as a potential alternative to the major use brominated flame retardant, hexabromocyclododecane (HBCD), which could have major implications for significant increases in amounts of TBCO used. Yet there is a lack of information regarding potential toxicities of TBCO. Recently, results of in vitro experiments have demonstrated the potential of TBCO to modulate endocrine function through interaction with estrogen and androgen receptors and via alterations to the synthesis of 17-β-estradiol and testosterone. Further research is required to determine potential endocrine disrupting effects of TBCO in vivo. In this experiment a 21-day fecundity assay with Japanese medaka (Oryzias latipes) was conducted to examine endocrine disrupting effects of TBCO in vivo. Medaka were fed a diet containing either 607 or 58μg TBCO/g food, wet mass (wm). Fecundity, measured as cumulative deposition of eggs and fertilization of eggs, as well as abundances of transcripts of 34 genes along the hypothalamus-pituitary-gonadal-liver (HPGL) axis were measured as indicators of holistic endocrine disruption and to determine mechanisms of effects, respectively. Cumulative fecundity was 18% lesser by medaka exposed to 58μg TBCO/g, wm food. However, fecundity of medaka exposed to 607μg TBCO/g, wm food was not significantly different from that of controls. Organ-specific and dose-dependent alterations to abundances of transcripts were observed in male and female medaka. A pattern of down-regulation of expression of genes involved in steroidogenesis, metabolism of cholesterol, and regulatory feedback mechanisms was observed in gonads from male and female medaka which had been exposed to the greater concentration of TBCO. However, these effects on expression of genes were not manifested in effects on

  18. Neoplastic and nonneoplastic liver lesions induced by dimethylnitrosamine in Japanese medaka fish.

    PubMed

    Hobbie, K R; DeAngelo, A B; George, M H; Law, J M

    2012-03-01

    Small fish models have been used for decades in carcinogenicity testing. Demonstration of common morphological changes associated with specific mechanisms is a clear avenue by which data can be compared across divergent phyletic levels. Dimethylnitrosamine, used in rats to model human alcoholic cirrhosis and hepatic neoplasia, is also a potent hepatotoxin and carcinogen in fish. We recently reported some striking differences in the mutagenicity of DMN in lambda cII transgenic medaka fish vs. Big Blue(®) rats, but the pre-neoplastic and neoplastic commonalities between the two models are largely unknown. Here, we focus on these commonalities, with special emphasis on the TGF-β pathway and its corresponding role in DMN-induced hepatic neoplasia. Similar to mammals, hepatocellular necrosis, regeneration, and dysplasia; hepatic stellate cell and "spindle cell" proliferation; hepatocellular and biliary carcinomas; and TGF-β1 expression by dysplastic hepatocytes all occurred in DMN-exposed medaka. Positive TGF-β1 staining increased with increasing DMN exposure in bile preductular epithelial cells, intermediate cells, immature hepatocytes and fewer mature hepatocytes. Muscle specific actin identified hepatic stellate cells in DMN-exposed fish. Additional mechanistic comparisons between animal models at different phyletic levels will continue to facilitate the interspecies extrapolations that are so critical to toxicological risk assessments.

  19. Early Life Exposure to Ractopamine Causes Endocrine-Disrupting Effects in Japanese Medaka (Oryzias latipes).

    PubMed

    Sun, Liwei; Wang, Sisi; Lin, Xia; Tan, Hana; Fu, Zhengwei

    2016-02-01

    β-Agonists, which are used as human pharmaceuticals or feed additives, have been detected in aquatic environments. β-Agonists have also been proposed for use in aquaculture. However, there are limited data available regarding the adverse effects of β-agonists in aquatic organisms. In this study, ractopamine was selected as the representative β-agonist, and medaka embryos were exposed at concentrations ranging from 5 to 625 μg/L for 44 days. In contrast to what has been found in mammals, ractopamine caused no growth response in medaka. However, the transcriptional changes of genes related to the hypothalamic-pituitary-gonadal (HPG) axis, especially in females, suggested that β-agonists may have the potential to disrupt the endocrine system. Moreover, genes involved in anti-oxidative activity or detoxification were affected in a gender-specific manner. These findings, particularly the effects on the endocrine system of fish, will advance our understanding of the ecotoxicity of β-agonists.

  20. Cold Lake Blend diluted bitumen toxicity to the early development of Japanese medaka.

    PubMed

    Madison, Barry N; Hodson, Peter V; Langlois, Valerie S

    2017-03-20

    Diluted bitumen (dilbit) from Alberta oil sands (Canada) is transported across major continental watersheds, yet little is known about its toxicity to fish if spilled into aquatic environments. The toxicity of Cold Lake (CLB) dilbit was assessed for medaka embryos (Oryzias latipes) exposed to water accommodated fractions (WAF) and chemically-enhanced WAF (CEWAF) using Corexit(®)EC9500A as dispersant. The effects of CLB toxicity were similar to conventional crude oils and Access Western Blend (AWB) dilbit. The prevalence of malformations and cyp1a mRNA synthesis in hatched fish increased monotonically with concentration during WAF and CEWAF treatments and provided a novel indicator of dilbit PAH toxicity. Apart from nfe2 (an antioxidant transcription factor), there were no statistically significant monotonic exposure-responses of ahr, arnt2, cat, sod, gpx, gst, gsr, g6pdh, p53, and hsp70 transcripts at total polycyclic aromatic hydrocarbons (TPAH) concentrations bracketing EC50s for embryotoxicity (WAF ≅ 3 μg/L; CEWAF ≅ 0.1 μg/L TPAH). Based on measured TPAH concentrations in exposure test solutions, CLB dilbit was 6-10 fold more toxic to medaka than AWB during chronic exposures. Lack of direct monotonic gene transcription responses to increasing oil concentrations during exposures that were embryotoxic suggests that the capacity of the oxidative stress response is limited in earlier lifestages or that differences exist among species in mechanisms of toxicity. This study provides a comparative framework for identifying suitable biomarkers and toxicity methods for those fish species in sensitive lifestages at highest risk of Canadian oil sands dilbit exposure following a spill in the freshwater environment.

  1. Inheritance patterns of lateral dimorphism examined through breeding experiments in Tanganyikan cichlid (Julidochromis transcriptus) and Japanese Medaka (Oryzias latipes).

    PubMed

    Hata, Hiroki; Takahashi, Rieko; Ashiwa, Hiroshi; Awata, Satoshi; Takeyama, Tomohiro; Kohda, Masanori; Hori, Michio

    2012-01-01

    The asymmetry of mouth morphology, in which the mouth opens either leftward or rightward, is a unique example of antisymmetry that is widely found in fishes, such as Tanganyikan scale-eating cichlids, herbivorous cichlids, and the Japanese freshwater goby. This dimorphism is thought to be heritable in a Mendelian manner similar to that of the dominance of the lefty allele over righty, with homozygotes of lefty alleles being absent. This study aims to reveal whether this trait is inherited in the same Mendelian manner in fishes other than those examined to date, and whether the absence of the dominant homozygote is due to a lethal effect. We conducted F(1) and F(2) breeding experiments using the Tanganyikan cichlid Julidochromis transcriptus and Japanese medaka Oryzias latipes. For both J. transcriptus and O. latipes, the F(1) generations produced by incrossing lefty parents showed a lefty:righty ratio of 2:1, whereas incrosses of righties produced only righty offspring. Test crosses between lefty and righty produced a 1:1 ratio of lefty and righty offspring. These results are consistent with the inheritance model in which righty is homozygous for a recessive righty allele and lefty is heterozygous for dominant lefty and recessive righty alleles, in agreement with previous observations. The F(2) test cross also confirmed this pattern. Furthermore, no lethal effects on hatchability of O. latipes were detected, refuting the suggestion that the dominant homozygote is embryonic lethal. We conclude that mouth laterality is inherited in the same Mendelian manner in these two species, similar to that other fish species studied previously. However, the reason for absence of the dominant homozygote remains unclear.

  2. Lysosomal localization of Japanese medaka (Oryzias latipes) Neu1 sialidase and its highly conserved enzymatic profiles with human.

    PubMed

    Ryuzono, Sena; Takase, Ryo; Oishi, Kazuki; Ikeda, Asami; Chigwechokha, Petros Kingstone; Funahashi, Aki; Komatsu, Masaharu; Miyagi, Taeko; Shiozaki, Kazuhiro

    2016-01-10

    Desialylation in the lysosome is a crucial step for glycoprotein degradation. The abnormality of lysosomal desialylation by NEU1 sialidase is involved in diseases of mammals such as sialidosis and galactosialidosis. Mammalian Neu1 sialidase is also localized at plasma membrane where it regulates several signaling pathways through glycoprotein desialylation. In fish, on the other hand, the mechanism of desialylation in the lysosome and functions of Neu1 sialidase are still unclear. Here, to understand the significance of fish Neu1 sialidase, neu1 gene was cloned from medaka brain and the profiles of its polypeptides were analyzed. Open reading frame of medaka neu1 consisted 1,182 bp and the similarity of its deduced amino acids with human NEU1 was 57%. As this recombinant polypeptide did not show significant sialidase activity, medaka cathepsin A, known in mammals as protective protein activating Neu1, was cloned and then co-expressed with medaka Neu1 to examine whether medaka cathepsin A activates Neu1 activity. As a result, Neu1/cathepsin A showed a drastic increase of sialidase activity toward MU-NANA. Major substrate of medaka Neu1 was 3-sialyllactose and its optimal pH was 4.0. With immunofluorescence analysis, signal of overexpressed medaka Neu1 was found to coincide with Lysotracker signals (organelle marker of lysosome) and co-localized with medaka cathepsin A in fish hepatic Hepa-T1 cells. Furthermore, part of medaka Neu1 was also detected at plasma membrane. Medaka Neu1 possessed signal peptide sequence at N-terminal and incomplete lysosomal targeting sequence at C-terminus. Medaka neu1 gene was ubiquitously expressed in various medaka tissues, and its expression level was significantly higher than other sialidase genes such as neu3a, neu3b and neu4. The present study revealed the profiles of fish Neu1 sialidase and indicated its high conservation with human NEU1 for the first time, suggesting the presence of similar desialylation system in the medaka

  3. Evaluation of 2,4-dichlorophenol exposure of Japanese medaka, Oryzias latipes, using a metabolomics approach.

    PubMed

    Kokushi, Emiko; Shintoyo, Aoi; Koyama, Jiro; Uno, Seiichi

    2016-04-07

    In this study, the metabolic effects of waterborne exposure of medaka (Oryzias latipes) to nominal concentrations of 20 (L group) and 2000 μg/L (H group) 2,4-dichlorophenol (DCP) were examined using a gas chromatography/mass spectroscopy (GC/MS) metabolomics approach. A principal component analysis (PCA) separated the L, H, and control groups along PC1 to explain the toxic effects of DCP at 24 h of exposure. Furthermore, the L and H groups were separated along PC1 at 96 h on the PCA score plots. These results suggest that the effects of DCP depended on exposure concentration and time. Changes in tricarboxylic cycle metabolites suggested that fish exposed to 2,4-DCP require more energy to metabolize and eliminate DCP, particularly at 96 h of exposure. A time-dependent response in the fish exposed to DCP was observed in the GC/MS data, suggesting that the higher DCP concentration had greater effects at 24 h than those observed in response to the lower concentration. In addition, several essential amino acids (arginine, histidine, lysine, isoleucine, leucine, methionine, phenylalanine, threonine, tryptophan, and valine) decreased after DCP exposure in the H group, and starvation condition and high concentration exposure of DCP could consume excess energy from amino acids.

  4. A mixture of the novel brominated flame retardants TBPH and TBB affects fecundity and transcript profiles of the HPGL-axis in Japanese medaka.

    PubMed

    Saunders, David M V; Podaima, Michelle; Codling, Garry; Giesy, John P; Wiseman, Steve

    2015-01-01

    The novel brominated flame retardants (NBFRs), bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) and 2-ethylhexyl-2,3,4,5 tetrabromobenzoate (TBB) are components of the flame retardant mixture Firemaster 550 and both TBPH and TBB have recently been listed as high production volume chemicals by the US EPA. These NBFRs have been detected in several environmental matrices but very little is known about their toxic effects or potencies. Results of in vitro assays demonstrated potentials of these NBFRs to modulate endocrine function through interactions with estrogen (ER) and androgen receptors (AR) and via alterations to synthesis of 17-β-estradiol (E2) and testosterone (T), but in vivo effects of these chemicals on organisms are not known. Therefore a 21-day short term fish fecundity assay with Japanese medaka (Oryzias latipes) was conducted to investigate if these NBFRs affect endocrine function in vivo. Medaka were fed a diet containing either 1422 TBPH:1474 TBB or 138:144 μg/g food, wet weight (w/w). Cumulative production of eggs was used as a measure of fecundity and abundances of transcripts of 34 genes along the hypothalamus-pituitary-gonadal-liver (HPGL) axis were quantified to determine mechanisms of observed effects. Cumulative fecundity was impaired by 32% in medaka exposed to the greatest dose of the mixture of TBPH/TBB. A pattern of global down-regulation of gene transcription at all levels of the HPGL axis was observed, but effects were sex-specific. In female medaka the abundance of transcripts of ERβ was lesser in livers, while abundances of transcripts of VTG II and CHG H were greater. In male medaka, abundances of transcripts of ERα, ERβ, and ARα were lesser in gonads and abundances of transcripts of ERβ and ARα were lesser in brain. Abundances of transcripts of genes encoding proteins for synthesis of cholesterol (HMGR), transport of cholesterol (HDLR), and sex hormone steroidogenesis (CYP 17 and 3β-HSD) were significantly lesser in male

  5. Alteration of development and gene expression induced by in ovo-nanoinjection of 3-hydroxybenzo[c]phenanthrene into Japanese medaka (Oryzias latipes) embryos.

    PubMed

    Chen, Kun; Tsutsumi, Yuki; Yoshitake, Shuhei; Qiu, Xuchun; Xu, Hai; Hashiguchi, Yasuyuki; Honda, Masato; Tashiro, Kosuke; Nakayama, Kei; Hano, Takeshi; Suzuki, Nobuo; Hayakawa, Kazuichi; Shimasaki, Yohei; Oshima, Yuji

    2017-01-01

    Benzo[c]phenanthrene (BcP) is a highly toxic polycyclic aromatic hydrocarbon (PAHs) found throughout the environment. In fish, it is metabolized to 3-hydroxybenzo[c]phenanthrene (3-OHBcP). In the present study, we observed the effects of 1nM 3-OHBcP on the development and gene expression of Japanese medaka (Oryzias latipes) embryos. Embryos were nanoinjected with the chemical after fertilization. Survival, developmental stage, and heart rate of the embryos were observed, and gene expression differences were quantified by messenger RNA sequencing (mRNA-Seq). The exposure to 1nM 3-OHBcP accelerated the development of medaka embryos on the 1st, 4th, and 6th days post fertilization (dpf), and increased heart rates significantly on the 5th dpf. Physical development differences of exposed medaka embryos were consistent with the gene expression profiles of the mRNA-Seq results for the 3rd dpf, which show that the expression of 780 genes differed significantly between the solvent control and 1nM 3-OHBcP exposure groups. The obvious expression changes in the exposure group were found for genes involved in organ formation (eye, muscle, heart), energy supply (ATPase and ATP synthase), and stress-response (heat shock protein genes). The acceleration of development and increased heart rate, which were consistent with the changes in mRNA expression, suggested that 3-OHBcP affects the development of medaka embryos. The observation on the developmental stages and heart beat, in ovo-nanoinjection and mRNA-Seq may be efficient tools to evaluate the effects of chemicals on embryos.

  6. A protocol for adult somatic cell nuclear transfer in medaka fish (Oryzias latipes) with a high rate of viable clone formation.

    PubMed

    Bubenshchikova, Ekaterina; Kaftanovskaya, Elena; Adachi, Tomoko; Hashimoto, Hisashi; Kinoshita, Masato; Wakamatsu, Yuko

    2013-12-01

    Previously, we successfully generated fully grown, cloned medaka (the Japanese rice fish, Oryzias latipes) using donor nuclei from primary culture cells of adult caudal fin tissue and nonenucleated recipient eggs that were heat shock-treated to induce diploidization of the nuclei. However, the mechanism of clone formation using this method is unknown, and the rate of adult clone formation is not high enough for studies in basic and applied sciences. To gain insight into the mechanism and increase the success rate of this method of clone formation, we tested two distinct nuclear transfer protocols. In one protocol, the timing of transfer of donor nuclei was changed, and in the other, the size of the donor cells was changed; each protocol was based on our original methodology. Ultimately, we obtained an unexpectedly high rate of adult clone formation using the protocol that differed with respect to the timing of donor nuclei transfer. Specifically, 17% of the transplants that developed to the blastula stage ultimately developed into adult clones. The success rate with this method was 13 times higher than that obtained using the original method. Analyses focusing on the reasons for this high success rate of clone formation will help to elucidate the mechanism of clone formation that occurs with this method.

  7. Aquaporin expression in the Japanese medaka (Oryzias latipes) in freshwater and seawater: challenging the paradigm of intestinal water transport?

    PubMed

    Madsen, Steffen S; Bujak, Joanna; Tipsmark, Christian K

    2014-09-01

    We investigated the salinity-dependent expression dynamics of seven aquaporin paralogs (aqp1a, aqp3a, aqp7, aqp8ab, aqp10a, aqp10b and aqp11a) in several tissues of euryhaline Japanese medaka (Oryzias latipes). All paralogs except aqp7 and aqp10a had a broad tissue distribution, and several were affected by salinity in both osmoregulatory and non-osmoregulatory tissues. In the intestine, aqp1a, aqp7, aqp8ab and aqp10a decreased upon seawater (SW) acclimation in both long-term acclimated fish and during 1-3 days of the transition period. In the gill, aqp3a was lower and aqp10a higher in SW than in freshwater (FW). In the kidney no aqps were affected by salinity. In the skin, aqp1a and aqp3a were lower in SW than in FW. In the liver, aqp8ab and aqp10a were lower in SW than in FW. Furthermore, six Na(+),K(+)-ATPase α-subunit isoform transcripts were analysed in the intestine but none showed a consistent response to salinity, suggesting that water transport is not regulated at this level. In contrast, mRNA of the Na(+),K(+),2Cl(-)-cotransporter type-2 strongly increased in the intestine in SW compared with FW fish. Using custom-made antibodies, Aqp1a, Aqp8ab and Aqp10a were localized in the apical region of enterocytes of FW fish. Apical staining intensity strongly decreased, vanished or moved to subapical regions, when fish were acclimated to SW, supporting the lower mRNA expression in SW. Western blots confirmed the decrease in Aqp1a and Aqp10a in SW. The strong decrease in aquaporin expression in the intestine of SW fish is surprising, and challenges the paradigm for transepithelial intestinal water absorption in SW fishes.

  8. Fluorescence in situ hybridization techniques (FISH) to detect changes in CYP19a gene expression of Japanese medaka (Oryzias latipes)

    SciTech Connect

    Park, June-Woo; Tompsett, Amber; Zhang, Xiaowei; Newsted, John L.; Jones, Paul D.; Au, Doris; Kong, Richard; Wu, Rudolf S.S.; Giesy, John P. Hecker, Markus

    2008-10-15

    The aim of this study was to develop a sensitive in situ hybridization methodology using fluorescence-labeled riboprobes (FISH) that allows for the evaluation of gene expression profiles simultaneously in multiple target tissues of whole fish sections of Japanese medaka (Oryzias latipes). To date FISH methods have been limited in their application due to autofluorescence of tissues, fixatives or other components of the hybridization procedure. An optimized FISH method, based on confocal fluorescence microscopy was developed to reduce the autofluorescence signal. Because of its tissue- and gender-specific expression and relevance in studies of endocrine disruption, gonadal aromatase (CYP19a) was used as a model gene. The in situ hybridization (ISH) system was validated in a test exposure with the aromatase inhibitor fadrozole. The optimized FISH method revealed tissue-specific expression of the CYP19a gene. Furthermore, the assay could differentiate the abundance of CYP19a mRNA among cell types. Expression of CYP19a was primarily associated with early stage oocytes, and expression gradually decreased with increasing maturation. No expression of CYP19a mRNA was observed in other tissues such as brain, liver, or testes. Fadrozole (100 {mu}g/L) caused up-regulation of CYP19a expression, a trend that was confirmed by RT-PCR analysis on excised tissues. In a combination approach with gonad histology, it could be shown that the increase in CYP19a expression as measured by RT-PCR on a whole tissue basis was due to a combination of both increases in numbers of CYP19a-containing cells and an increase in the amount of CYP19a mRNA present in the cells.

  9. Serum vitellogenin levels and reproductive impairment of male Japanese Medaka (Oryzias latipes) exposed to 4-tert-octylphenol.

    PubMed Central

    Gronen, S; Denslow, N; Manning, S; Barnes, S; Barnes, D; Brouwer, M

    1999-01-01

    The induction of synthesis of the "female" yolk precursor protein vitellogenin (VTG) in male fish by estrogenic chemicals in the environment has been demonstrated in many recent reports. However, little is known about the organismal and biological significance of this phenomenon. To examine the relationship between VTG production in male fish and reproductive impairment, adult male medaka were exposed to 4-tert-octylphenol (OP), a known environmental estrogen, in concentrations ranging from 20 to 230 ppb for 21 days, under flow-through conditions. Following exposure, male fish were mated, in the absence of OP, with unexposed females. Breeding groups composed of exposed males and control females produced about 50% fewer eggs than control groups. VTG levels in serum of male fish increased with increasing OP exposure concentration and decreased after OP exposure was discontinued. Nevertheless, significant correlations (p<0.01) were observed between VTG levels in exposed male fish and 1) OP exposure concentrations, 2) percent of fertilized eggs, and 3) survival of embryos. OP-induced VTG synthesis and reproductive impairment appear to be closely linked phenomena. Histological examination indicated spermatogenesis in OP-exposed fish was inhibited, and some exposed fish had oocytes in their testes. Finally, OP caused a significant increase in the number of abnormally developing embryos, suggesting that OP may be genotoxic as well as estrogenic. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10210694

  10. P-NITROPHENOL METABOLISM BY JAPANESE MEDAKA (ORYZIAS LATIPES) LIVER MICROSOMES AND S-9 FRACTION: ADDITIONAL EVIDENCE FOR THE EXISTENCE OF A CYP2E1-LIKE ISOFORM IN TELEOSTS

    EPA Science Inventory

    Liver microsomes and S-9 fraction of Japanese medaka (Oryzias latipes) metabolized the CYP2E1 specific substrate, p-nitrophenol (PNP), to a single hydroxylated product, 4-nitrocatechol. The use of liver S-9 fraction proved to be a viable alternative to liver microsomes and allowe...

  11. The effect of bisphenol A and chlorinated derivatives of bisphenol A on the level of serum vitellogenin in Japanese medaka (Oryzias latipes).

    PubMed

    Tabata, A; Watanabe, N; Yamamoto, I; Ohnishi, Y; Itoh, M; Kamei, T; Magara, Y; Terao, Y

    2004-01-01

    2,2-bis (4-hydroxyphenyl) propane or Bisphenol A (BPA), has been reported to behave as an endocrine disrupter below acute toxic levels, and is widely present in the water environment. Although BPA is easily chlorinated, very little is reported on the effect of chlorinated BPA to the aquatic organisms. In this study, the estrogenic activities of BPA and its chlorinated derivatives were evaluated by the induction of vitellogenin (VTG) in the serum of mature male Japanese medaka. In addition, the effect of sodium hypochlorite on the decomposition of BPA was tested. The relative potencies of estrogenic activities of chlorinated BPA descended in the order 3,3'-diCIBPA>BPA> or =3-CIBPA>3,3',5-triCIBPA, and no estrogenic activity was observed in 3,3',5,5'-tetraCIBPA. Lowest Observed Effect Concentration (LOEC) and No Observed Effect Concentration (NOEC) for both 3-CIBPA and 3,3'-diCIBPA were 500 microg/L and 200 microg/L, respectively. LOEC for 3,3',5-triCIBPA was >500 microg/L. When BPA was reacted with sodium hypochlorite (24 hours; residual chlorine at 1 ppm), however, complete decomposition of BPA and its chlorinated derivatives was observed. The decrease in BPA and its chlorinated derivatives paralleled the decrease in estrogenic potency evaluated by the induction of vitellogenin (VTG) in the serum of mature male Japanese medaka.

  12. Deep sexual dimorphism in adult medaka fish liver highlighted by multi-omic approach

    PubMed Central

    Qiao, Qin; Le Manach, Séverine; Sotton, Benoit; Huet, Hélène; Duvernois-Berthet, Evelyne; Paris, Alain; Duval, Charlotte; Ponger, Loïc; Marie, Arul; Blond, Alain; Mathéron, Lucrèce; Vinh, Joelle; Bolbach, Gérard; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-01-01

    Sexual dimorphism describes the features that discriminate between the two sexes at various biological levels. Especially, during the reproductive phase, the liver is one of the most sexually dimorphic organs, because of different metabolic demands between the two sexes. The liver is a key organ that plays fundamental roles in various physiological processes, including digestion, energetic metabolism, xenobiotic detoxification, biosynthesis of serum proteins, and also in endocrine or immune response. The sex-dimorphism of the liver is particularly obvious in oviparous animals, as the female liver is the main organ for the synthesis of oocyte constituents. In this work, we are interested in identifying molecular sexual dimorphism in the liver of adult medaka fish and their sex-variation in response to hepatotoxic exposures. By developing an integrative approach combining histology and different high-throughput omic investigations (metabolomics, proteomics and transcriptomics), we were able to globally depict the strong sexual dimorphism that concerns various cellular and molecular processes of hepatocytes comprising protein synthesis, amino acid, lipid and polysaccharide metabolism, along with steroidogenesis and detoxification. The results of this work imply noticeable repercussions on the biology of oviparous organisms environmentally exposed to chemical or toxin issues. PMID:27561897

  13. Deep sexual dimorphism in adult medaka fish liver highlighted by multi-omic approach.

    PubMed

    Qiao, Qin; Le Manach, Séverine; Sotton, Benoit; Huet, Hélène; Duvernois-Berthet, Evelyne; Paris, Alain; Duval, Charlotte; Ponger, Loïc; Marie, Arul; Blond, Alain; Mathéron, Lucrèce; Vinh, Joelle; Bolbach, Gérard; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-08-26

    Sexual dimorphism describes the features that discriminate between the two sexes at various biological levels. Especially, during the reproductive phase, the liver is one of the most sexually dimorphic organs, because of different metabolic demands between the two sexes. The liver is a key organ that plays fundamental roles in various physiological processes, including digestion, energetic metabolism, xenobiotic detoxification, biosynthesis of serum proteins, and also in endocrine or immune response. The sex-dimorphism of the liver is particularly obvious in oviparous animals, as the female liver is the main organ for the synthesis of oocyte constituents. In this work, we are interested in identifying molecular sexual dimorphism in the liver of adult medaka fish and their sex-variation in response to hepatotoxic exposures. By developing an integrative approach combining histology and different high-throughput omic investigations (metabolomics, proteomics and transcriptomics), we were able to globally depict the strong sexual dimorphism that concerns various cellular and molecular processes of hepatocytes comprising protein synthesis, amino acid, lipid and polysaccharide metabolism, along with steroidogenesis and detoxification. The results of this work imply noticeable repercussions on the biology of oviparous organisms environmentally exposed to chemical or toxin issues.

  14. The effect of chlorination of estrogenic chemicals on the level of serum vitellogenin of Japanese medaka (Oryzias latipes).

    PubMed

    Tabata, A; Miyamoto, N; Ohnishi, Y; Itoh, M; Yamada, T; Kamei, T; Magara, Y

    2003-01-01

    Mature male medaka were continually exposed to four chemicals, p-n-nonylphenol (p-n-NP), nonylphenol (p-NP), bisphenol-A (BPA) and 17beta-estradiol (E2) to evaluate their estrogenic activities in the laboratory. In order to understand the effect of the chlorination that is applied widely in water and wastewater treatment, the above chemicals were chlorinated and then exposed to mature male medaka. Furthermore, in the case of vitellogenin, a is a female specific protein induced by the exposure to test waters containing the above chemicals after 5 weeks, medaka was returned to uncontaminated tap water to determine whether male medaka have a self recovery function from the effect of estrogenic chemicals. Much greater vitellogenin compared to the background levels were induced in the male medaka by separate exposure to 100 microg/L of p-NP, 1,000 microg/L of BPA and 0.05 microg/L of E2. The levels of vitellogenin increased with increasing exposure periods. The relative potencies of these chemicals descended in the order of E2>p-NP>BPA. Vitellogenin levels inducible by these chemicals were drastically reduced as a result of the chlorination for 24 hours. However, a moderate increase in hepatocyte somatic index (HSI) meant the hepatic fatness was observed as a result of chlorination. It is not clear at this stage whether or not the formation of chlorination byproducts is responsible for this moderate increase in HSI. The vitellogenin concentration of male medaka exposed to chemicals for 5 weeks decreased gradually after return to the uncontaminated water. However, the vitellogenin concentration did not return to the initial normal levels even after 5 weeks. A clear relationship between the serum vitellogenin concentration and the hepatic vitellogenin concentration was also found. Since quantitative analytical procedures for hepatic vitellogenin are easier than those of the serum vitellogenin, measuring the estrogenic effect using the measurement of vitellogenin in liver

  15. Oral exposure of PBDE-47 in fish: toxicokinetics and reproductive effects in Japanese Medaka (Oryzias latipes) and fathead minnows (Pimephales promelas).

    PubMed

    Muirhead, Elisabeth K; Skillman, Ann D; Hook, Sharon E; Schultz, Irvin R

    2006-01-15

    The toxicokinetics of 2,2,4,4-tetrabromodiphenyl ether (PBDE-47) was studied in the Japanese Medaka (Oryzias latipes) after a single oral exposure followed by termination at specific time points. The effects of repeated oral exposure to PBDE-47 on reproductive performance was assessed using a pair breeding experimental design with fathead minnows (Pimephales promelas) given daily PBDE-47 exposures for 25 days, during which fecundity was measured as an indicator of reproductive performance. Medaka and fathead minnows were orally exposed to PBDE-47 by bioencapsulation in brine shrimp, Artemia sp. In the medaka studies, measurable levels of PBDE-47 were detected in the carcass within 0.25 h with peak levels occurring at 8 h. The body levels of PBDE-47 slowly declined and were still 25% of peak levels at 624 h after dosing. Assimilation of the bioencapsulated dose was at least 80% and may well approach 100%. The PBDE-47 concentration-time profile was fitted to a one-compartment clearance-volume toxicokinetic model and the model-predicted value for elimination half-life was determined to be 281 h and the first-order absorption rate constant was Ka = 0.26 hr(-1). In the fathead minnow study, egg laying in the PBDE-treated breeding pairs stopped after 10 days. The condition factor of PBDE-treated males was significantly reduced (P <0.011) compared with control males, whereas no significant difference was observed in females. Histological examination revealed a greater than 50% reduction in mature sperm in PBDE-47 exposed minnows compared to controls. Collectively, these results suggest PBDE-47 is selectively toxic to sexually mature male fathead minnows.

  16. Oral Exposure of PBDE-47 in Fish: Toxicokinetics and Reproductive Effects in Japanese Medaka (Oryzias latipes) and Fathead Minnows (Pimephales promelas)

    SciTech Connect

    Muirhead, Elisabeth K.; Skillman, Ann D.; Hook, Sharon E.; Schultz, Irv R.

    2006-01-15

    The toxicokinetics of 2,2,4,4-tetrabromodipohenyl ether (PBDE-47) was studied in the Japanese Medaka (Oryzias latipes) after a single oral exposure followed by termination at specific time points. The effects of repeated oral exposure to PBDE-47 on reproductive performance was assessed using a pair breeding experimental design with fathead minnows (Pimephales promelas) given daily PBDE-47 exposures for 25 days, during which fecundity was measured as an indicator of reproductive performance. Medaka and fathead minnows were orally exposed to PBDE-47 by bioencapsulation in brine shrimp, Artemia sp. In the medaka studies, measurable levels of PBDE-47 were detected in the carcass within 0.25 hr with peak levels occurring at 8 hrs. The body levels of PBDE-47 slowly declined and were still 25% of peak levels at 624 hrs after dosing. Assimilation of the bioencapsulated dose was at least 80% and may well approach 100 %. The PBDE-47 concentration-time profile was fitted to a one-compartment clearance-volume toxicokinetic model and the model-predicted values for elimination half-life was determined to be 281 hrs and the first order absorption rate constant was (Ka) = 0.26 hr 1. In the fathead minnow study, egg laying in the PBDE-treated breeding pairs stopped after 10 days. The condition factor of PBDE-treated males was significantly reduced (P < 0.011) compared with control males, whereas no significant difference was observed in females. Histological examination revealed a greater than 50% reduction in mature sperm in PBDE-47 exposed minnows compared to controls. Collectively, these results suggest PBDE-47 is selectively toxic to sexually mature male fathead minnows.

  17. Full life-cycle assessment of gene flow consistent with fitness differences in transgenic and wild-type Japanese medaka fish (Oryzias latipes).

    PubMed

    Pennington, Kelly M; Kapuscinski, Anne R; Morton, Michael S; Cooper, Anne M; Miller, Loren M

    2010-01-01

    Transgenic fish in development for aquaculture could escape from farms and interbreed with wild relatives in the nearby environment. Predicting whether escapes would result in transgene introgression is a major challenge in assessing environmental risks of transgenic fish. Previous studies have simulated gene flow from transgenic fish using mathematical modeling of fitness traits to predict the relative selective value of transgenic genotypes. Here, we present the first study of gene flow over the full life cycle in openly-breeding populations of transgenic animals, along with measurement of fitness traits. We conducted two invasion experiments in which we released two lines of growth-enhanced transgenic fish (T67 and T400), Japanese medaka (Oryzias latipes), into populations of wild-type (W) medaka in structured mesocosms. After several generations, the frequency of transgenic fish varied across replicates in the first invasion experiment (6 months), but the frequency of transgenic fish decreased in the second experiment (19 months). We also measured selected fitness traits in transgenic and wild-type medaka because these traits could be used to predict the relative selective value of a genotype. We found that: T400 males were more fertile than W males; offspring of W females lived longer than those with transgenic mothers; and W and T67 females reached sexual maturity sooner than T400 females. In contrast with other research that reported larger transgenic males had a mating advantage, we found that W males obtained more matings with females than T males; genetic background effects may account for our differing results as we compared W and T fish derived from different strains. The decreasing frequency of transgenic fish in the second invasion experiment suggests that transgenic fish had a selective disadvantage in the experimental environment. Our finding of transgenic advantage of some fitness traits and wild-type advantage in others is consistent with our

  18. Adult perceptions of phonotactic violations in Japanese

    NASA Astrophysics Data System (ADS)

    Fais, Laurel; Kajikawa, Sachiyo; Werker, Janet; Amano, Shigeaki

    2001-05-01

    Adult Japanese speakers ``hear'' epenthetic vowels in productions of Japanese-like words that violate the canonical CVCVCV form by containing internal consonant clusters (CVCCV) [Dupoux et al., J. Exp. Psychol. 25, 1568-1578 (1999)]. Given this finding, this research examined how Japanese adults rated the goodness of Japanese-like words produced without a vowel in the final syllable (CVC), and words produced without vowels in the penultimate and final syllables (CVCC). Furthermore, in some of these contexts, voiceless vowels may appear in fluent, casual Japanese productions, especially in the Kanto dialect, and in some, such voiceless vowels may not appear. Results indicate that both Kanto and Kinki speakers rated CVC productions for contexts in which voiceless vowels are not allowed as the worst; they rated CVC and CVCC contexts in which voiceless vowel productions are allowed as better. In these latter contexts, the CVC words, which result from the loss of one, final, vowel, are judged to be better than the CVCC words, which result from the loss of two (final and penultimate) vowels. These results mirror the relative seriousness of the phonotactic violations and indicate listeners have tacit knowledge of these regularities in their language.

  19. The effects of methyltestosterone on the sexual development and reproduction of adult medaka (Oryzias latipes).

    PubMed

    Kang, Ik Joon; Yokota, Hirofumi; Oshima, Yuji; Tsuruda, Yukinari; Shimasaki, Yohei; Honjo, Tsuneo

    2008-04-08

    We examined the effects of methyltestosterone (MT) on the reproduction of medaka (Oryzias latipes). Six mating pairs of medaka were exposed for 3 weeks to MT at the measured concentrations of 22.5, 46.8, 88.1, 188, and 380 ng/L. The fecundity and fertility of paired medaka were significantly decreased in the 46.8, 88.1, 188, and 380 ng/L MT groups compared with those of controls. The gonadosomatic indices of female fish exposed to >or=46.8 ng/L were increased significantly. Gonadal histology showed degeneration of oocytes in the ovaries of fish in all MT treatment groups. Hepatic vitellogenin concentrations were significantly decreased in female fish treated with MT at 188 and 380 ng/L, and the hatchability and survival rate of the offspring were decreased in all MT treatment groups. These results clearly demonstrate that MT at >or=46.8 ng/L inhibited gonadal development and adversely affected the reproduction of medaka.

  20. p,p'-DDE Induces Gonadal Intersex in Japanese Medaka (Oryzias latipes) at Environmentally Relevant Concentrations: Comparison with o,p'-DDT.

    PubMed

    Sun, Jianxian; Wang, Chen; Peng, Hui; Zheng, Guomao; Zhang, Shiyi; Hu, Jianying

    2016-01-05

    Previous studies have reported high body burdens of dichlorodiphenyltrichloroethane (DDT) and its metabolites in wild fishes worldwide. This study evaluated the adverse effects of 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) and o,p'-DDT on gonadal development and reproduction by exposing transgenic Japanese medaka (Oryzias latipes) from hatch for 100 days. While both p,p'-DDE and o,p'-DDT induced intersex in male medaka, the lowest observable effective concentration (LOEC) of o,p'-DDT was 57.7 ng/g ww, about 5-fold lower than that (272 ng/g ww) of p,p'-DDE. Since LOECs of both chemicals were comparable to the body concentrations in wild fish, DDT contamination would likely contribute to the occurrence of intersex observed in wild fish. Exposure to o,p'-DDT resulted in much higher expression of vitellogenin in liver of males than p,p'-DDE, accordant with the higher potency of o,p'-DDT than p,p'-DDE to induce intersex. This phenomenon could be partly explained by the significantly elevated levels of 17β-estradiol in plasma of males exposed to o,p'-DDT, in addition to its estrogenic activity via the estrogen receptor. Significantly lower fertilization (p = 0.006) and hatchability (p = 0.019) were observed in the 13 intersex males. This study for the first time demonstrated the induction of intersex and reproductive effects of p,p'-DDE and o,p'-DDT at environmentally relevant concentrations.

  1. Salinity-dependent toxicity of water-dispersible, single-walled carbon nanotubes to Japanese medaka embryos.

    PubMed

    Kataoka, Chisato; Nakahara, Kousuke; Shimizu, Kaori; Kowase, Shinsuke; Nagasaka, Seiji; Ifuku, Shinsuke; Kashiwada, Shosaku

    2017-04-01

    To investigate the effects of salinity on the behavior and toxicity of functionalized single-walled carbon nanotubes (SWCNTs), which are chemical modified nanotube to increase dispersibility, medaka embryos were exposed to non-functionalized single-walled carbon nanotubes (N-SWCNTs), water-dispersible, cationic, plastic-polymer-coated, single-walled carbon nanotubes (W-SWCNTs), or hydrophobic polyethylene glycol-functionalized, single-walled carbon nanotubes (PEG-SWCNTs) at different salinities, from freshwater to seawater. As reference nanomaterials, we tested dispersible chitin nanofiber (CNF), chitosan-chitin nanofiber (CCNF) and chitin nanocrystal (CNC, i.e. shortened CNF). Under freshwater conditions, with exposure to 10 mg l(-1)  W-SWCNTs, the yolk sacks of 57.8% of embryos shrank, and the remaining embryos had a reduced heart rate, eye diameter and hatching rate. Larvae had severe defects of the spinal cord, membranous fin and tail formation. These toxic effects increased with increasing salinity. Survival rates declined with increasing salinity and reached 0.0% in seawater. In scanning electron microscope images, W-SWCNTs, CNF, CCNF and CNC were adsorbed densely over the egg chorion surface; however, because of chitin's biologically harmless properties, only W-SWCNTs had toxic effects on the medaka eggs. No toxicity was observed from N-SWCNT and PEG-SWCNT exposure. We demonstrated that water dispersibility, surface chemistry, biomedical properties and salinity were important factors in assessing the aquatic toxicity of nanomaterials. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Diploidized eggs reprogram adult somatic cell nuclei to pluripotency in nuclear transfer in medaka fish (Oryzias latipes).

    PubMed

    Bubenshchikova, Ekaterina; Kaftanovskaya, Elena; Motosugi, Nami; Fujimoto, Takafumi; Arai, Katsutoshi; Kinoshita, Masato; Hashimoto, Hisashi; Ozato, Kenjiro; Wakamatsu, Yuko

    2007-12-01

    Reprogramming of adult somatic cell nuclei to pluripotency has been unsuccessful in non-mammalian animals, primarily because of chromosomal aberrations in nuclear transplants, which are considered to be caused by asynchrony between the cell cycles of the recipient egg and donor nucleus. In order to normalize the chromosomal status, we used diploidized eggs by retention of second polar body release, instead of enucleated eggs, as recipients in nuclear transfer of primary culture cells from the caudal fin of adult green fluorescent protein gene (GFP) transgenic medaka fish (Oryzias latipes). We found that 2.7% of the reconstructed embryos grew into adults that expressed GFP in various tissues in the same pattern as in the donor fish. Moreover, these fish were diploid, fertile and capable of passing the marker gene to the next generation in Mendelian fashion. We hesitate to call these fish 'clones' because we used non-enucleated eggs as recipients; in effect, they may be chimeras consisting of cells derived from diploid recipient nuclei and donor nuclei. In either case, fish adult somatic cell nuclei were reprogrammed to pluripotency and differentiated into a variety of cell types including germ cells via the use of diploidized recipient eggs.

  3. Risks of single-walled carbon nanotubes acting as contaminants-carriers: potential release of phenanthrene in Japanese medaka (Oryzias latipes).

    PubMed

    Su, Yu; Yan, Xiaomin; Pu, Yubing; Xiao, Feng; Wang, Dongsheng; Yang, Min

    2013-05-07

    The performance of carbon nanotubes (CNTs) acting as contaminants-carriers in vivo is critical for understanding the environmental risks of CNTs. In this study, the whole-body accumulation and tissue distribution of phenanthrene in Japanese medaka was examined in the presence of single-walled carbon nanotubes (SWCNTs) and the potential release of phenanthrene was investigated from two types of SWCNTs suspensions that differed in surface charge and stability. The results showed that the coexistence of SWCNTs facilitated the accumulation of phenanthrene in the digestive track of fish and therefore enhanced the whole-body phenanthrene concentration by 2.1 fold after exposure for 72 h. Meanwhile, 6.4-48 and 20-34 times higher phenanthrene concentrations were measured in the liver and brain of fish exposure to the two mixtures, respectively, when comparing with the phenanthrene alone treatment with equal concentration of soluble phenanthrene. The extra phenanthrene was from the SWCNTs-associated phenanthrene that accumulated in the digestive track indicating the release of phenanthrene from SWCNTs did occur in fish. Moreover, the neutrally charged SWCNTs showed different agglomeration behaviors from the negatively charged SWCNTs, which could affect the accumulation of SWCNTs in the digestive track of fish and subsequently influence the retention of phenanthrene associated with the carbon nanotubes.

  4. In ovo exposure to o,p -DDE affects sexual development but not sexual differentiation in Japanese medaka (Oryzias latipes).

    USGS Publications Warehouse

    Papoulias, D.M.; Villalobos, Sergio A.; Meadows, J.; Noltie, Douglas B.; Giesy, J.P.; Tillitt, D.E.

    2003-01-01

    Despite being banned in many countries, dichlorodiphenyltrichloroethane (DDT) and its metabolites dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) continue to be found in fish tissues at concentrations of concern. Like o,p -DDT, o,p -DDE is estrogenic and is believed to exert its effects through binding to the estrogen receptor. The limited toxicologic data for o,p -DDE suggest that it decreases fecundity and fertility of fishes. We conducted an egg injection study using the d-rR strain of medaka and environmentally relevant concentrations of o,p -DDE to examine its effects on sexual differentiation and development. The gonads of exposed fish showed no evidence of sex reversal or intersex. However, other gonad abnormalities occurred in exposed individuals. Females exhibited few vitellogenic oocytes and increased atresia. Male testes appeared morphologically normal but were very small. Gonadosomatic index values for both sexes were lower for exposed fish. Our observations of abnormal female and very small male gonads after in ovo o,p -DDE exposure may be indicative of effects on early endocrine processes important for normal ovarian and testicular development.

  5. Uptake of silver nanoparticles and toxicity to early life stages of Japanese medaka (Oryzias latipes): effect of coating materials.

    PubMed

    Kwok, Kevin W H; Auffan, Melanie; Badireddy, Appala R; Nelson, Clay M; Wiesner, Mark R; Chilkoti, Ashutosh; Liu, Jie; Marinakos, Stella M; Hinton, David E

    2012-09-15

    Silver nanoparticles (AgNPs) with antimicrobial properties are perhaps the most deployed engineered nanomaterials in consumer products. Almost all AgNPs are coated with organic materials to enhance their dispersion in water. Contributions of coatings to the toxicity of NPs have received little attention. Studies using AgNPs with one of three different coating materials (citrate (Cit), gum arabic (GA), and polyvinylpyrrolidone (PVP)) showed significantly different toxicity. GA AgNP proved to be the most toxic, while PVP and Cit AgNP exhibited similar and lower toxicity. However, all AgNPs were about three to ten times less toxic than AgNO(3) when their toxicities were compared on a mass-concentration basis. Evidence for NP-specific toxicity was observed with longer time for initiation of toxicity and increased incidence of resultant spinal flexure of medaka exposed to AgNPs, compared to AgNO(3). Hyperspectral imaging of 6 μm paraffin sections of fish exposed to AgNPs revealed AgNPs and their aggregates in tissues of fish. Gill distribution was ubiquitous, while small amounts were found in other organs, including the liver and brain. AgNPs were observed regularly in the gut lumen, but rarely in mural elements and mesentery. These results suggest that while ingestion was common, gills were the principal sites of AgNP uptake. In conclusion, AgNPs is a source of toxic Ag ions, while itself contribute partially to its toxicity to fish, and which interact with skin surface and were taken up via the gills.

  6. Toxicokinetics and toxicodynamics of chlorpyrifos is altered in embryos of Japanese medaka exposed to oil sands process-affected water: evidence for inhibition of P-glycoprotein.

    PubMed

    Alharbi, Hattan A; Alcorn, Jane; Al-Mousa, Ahmed; Giesy, John P; Wiseman, Steve B

    2016-10-24

    Oil sands process-affected water (OSPW) is generated during extraction of bitumen in the surface mining oil sands industry in Alberta, Canada. Studies were performed in vitro by use of Caco-2 cells, and in vivo with larvae of Japanese medaka (Oryzias latipes) to determine if organic compounds from the aqueous phase of OSPW inhibit ATP binding cassette protein ABCB1 (permeability-glycoprotein, P-gp). Neutral and basic fractions of OSPW inhibited activity of P-gp in Caco-2 cells by 1.9- and 2.0-fold, respectively, while the acidic fraction had the least effect. The organophosphate pesticides chlorpyrifos (a substrate of P-gp) and malathion (not a substrate of P-gp), were used as model chemicals to investigate inhibition of P-gp in larvae. Co-exposure to chlorpyrifos and an extract of OSPW containing basic and neutral compounds reduced survival of larvae to 26.5% compared to survival of larvae exposed only to chlorpyrifos, which was 93.7%. However, co-exposure to malathion and the extract of OSPW did not cause acute lethality compared to exposure only to malathion. Accumulation and bioconcentration of chlorpyrifos, but not malathion, was greater in larvae co-exposed with the extract of OSPW. The terminal elimination half-life of chlorpyrifos in larvae exposed to chlorpyrifos in freshwater was 5 days compared with 11.3 days in larvae exposed to chlorpyrifos in OSPW. Results suggest that in non-acute exposures, basic and neutral organic compounds in the water-soluble fraction of OSPW inhibit activity of P-gp, which suggests that OSPW has the potential to cause adverse effects by chemosensitization. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Expression of c-fos gene in central nervous system of adult medaka (Oryzias latipes) after hypergravity stimulation

    NASA Astrophysics Data System (ADS)

    Shimomura, S.; Ijiri, K.

    The immediate-early genes serve as useful neurobiological tools for mapping brain activity induced by a sensory stimulation. In this study, we have examined brain activity related to gravity perception of medaka (Oryzias latipes) by use of c-fos. The gene, which is homologous to the c-fos genes of other vertebrates, was identified in medaka. Functionally important domains are highly conserved among all the vertebrate species analyzed. Intraperitoneal administration of kainic acid transiently induced the c-fos mRNAs in medaka brain. The results indicate that the expression of c-fos can be utilized as a suitable anatomical marker for the increased neural activities in the central nervous system of medaka. Fish were continuously exposed to 3G hypergravity by centrifugation. Investigation of c-fos mRNA expression showed that c-fos mRNA significantly increased 30 minutes after a start of 3G exposure. The distribution of its transcripts within brains was analyzed by an in situ hybridization method. The 3G-treated medakas displayed c-fos positive cells in their brainstem regions, which are related to vestibular function, such as torus semicircularis, posterior octavu nucleus, nucleus tangentialis and inferior olive. Our results established the method to trace the activated area in the fish brain following gravity stimulation. The method will be a useful tool for understanding gravity perception in the brain.

  8. Sensivity of Adult Reproduction and Reproductive Development in Japanese Medaka Exposed to 4-Tert-octylphenol

    EPA Science Inventory

    In response to legislation, the USEPA is developing assessment tools for identifying chemicals likely to cause sublethal effects on reproduction and reproductive development with ultimate adverse impacts on fish populations. While fecundity and fertility data from short-term adul...

  9. Older Japanese Adults and Mobile Phones: An Applied Ethnographic Study

    ERIC Educational Resources Information Center

    Hachiya, Kumiko

    2010-01-01

    This qualitative research investigates the meaning of "keitai" (mobile phones) for older Japanese adults between the ages of 59 and 79. Participants' emails from keitai, handwritten daily logs, and audio and video recordings from meetings and interviews were collected during my stay of nearly seven months in one of the largest cities in…

  10. Development of a possible nonmammalian test system for radiation-induced germ-cell mutagenesis using a fish, the Japanese medaka (Oryzias latipes)

    SciTech Connect

    Shima, A.; Shimada, A. )

    1991-03-15

    To develop a specific-locus test (SLT) system for environmental mutagenesis using vertebrate species other than the mouse, we first established a tester stock of the fish medaka (Oryzias latipes) that is homozygous recessive at three loci. The phenotypic expression of these loci can be easily recognized early in embryonic development by observation through the transparent egg membrane. We irradiated wild-type males with 137Cs gamma-rays to determine the dose-response relationships for dominant lethal and specific-locus mutations induced in sperm, spermatids, and spermatogonia. Through observation of 322,666 loci in control offspring and 374,026 loci in offspring obtained from 0.64-, 4.75-, or 9.50-Gy-irradiated gametes, specific-locus mutations were phenotypically detected during early development. These putative mutations, designated total mutation, can be recognized only in embryos of oviparous animals. The developmental fate of these mutant embryos was precisely followed. During subsequent embryonic development, a large fraction died and thus was unavailable for test-crossing, which was used to identify viable mutations. Our medaka SLT system demonstrates that the vast majority of total mutations is associated with dominant lethal mutations. Thus far only one spontaneous viable mutation has been observed, so that all doubling calculations involving this endpoint carry a large error. With these reservations, however, we conclude that the quantitative data so far obtained from the medaka SLT are quite comparable to those from the mouse SLT and, hence, indicate the validity of the medaka SLT as a possible nonmammalian test system.

  11. XENOBIOTIC INDUCED ORGAN-SPECIFIC GENE EXPRESSION AND MACRO/MICROARRAY DEVELOPMENT IN MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    As part of an ongoing effort to understand and address the short and long-term consequences of increasing levels of environmental contaminants, we used suppressive subtractive hydridization (SSH) to develop gene expression profiles from Japanese medaka (Oryzias latipes) exposed ...

  12. Immunogenicity of single-dose Vero cell-derived Japanese encephalitis vaccine in Japanese adults.

    PubMed

    Takeshita, Nozomi; Lim, Chang-Kweng; Mizuno, Yasutaka; Shimbo, Takuro; Kotaki, Akira; Ujiie, Mugen; Hayakawa, Kayoko; Kato, Yasuyuki; Kanagawa, Shuzo; Kaku, Mitsuo; Takasaki, Tomohiko

    2014-04-01

    In Japan, intensive immunization against Japanese encephalitis (JE) was performed from 1967 to 1976, and regular JE immunization was performed thereafter. However, for Japanese adults facing JE risk, dates of vaccination with new inactivated Vero cell-derived JE vaccine are unavailable. This study investigated how a single dose of Vero cell-derived JE vaccine affects Japanese adults. Neutralizing antibodies were measured pre- and post-JE vaccination in 79 participants (age 40.7 ± 9.4 years), enrolled between October 2009 and March 2011, whose JE-vaccination data were gathered from vaccination records and history taking. Before vaccination, the participants' seroprotection rate (SPR) was 51.9%, whereas SPR after vaccination was 93.7%. The seroconversion rate (SCR), which measures seronegative cases that turn seropositive after vaccination, was 86.8%. The geometric mean titer (GMT) was 14.7 before vaccination and 70.1 after vaccination. Age was a significant difference between seroprotected (42.8 years) and non-seroprotected (38.7 years) groups before vaccination. Then the difference of age, SCR, pre-vaccination GMT, post-vaccination GMT and sex ratio were also significant in participants aged 25-39 years and ≥40 years, who represent generations born when Japan's JE-vaccination policy changed. SCR was 100% in participants aged 25-39 years with a vaccination recorded 55.6% in participants aged 25-39 without a vaccination record, and 96.0% in participants aged ≥40 years. Thus, more participants aged 25-39 years were seroprotected before vaccination, but SCR was higher in those aged ≥40 years. Most Japanese adults can be protected after one-dose vaccination, but this may be insufficient for people aged 25-39 years without recorded JE vaccination.

  13. Conspecific injury raises an alarm in medaka

    PubMed Central

    Mathuru, Ajay S.

    2016-01-01

    In the late 1930s, Karl von Frisch reported that semiochemicals released upon injury, act as alarm substances (Schreckstoff) in fish. In Ostariophysi species, club cells in the epidermis are believed to contain cues related to alarm substance; however, the function of club cells, primarily as reservoirs of alarm substance has been debated. Here, I describe an alarm response in the Japanese rice fish Oryzias latipes (medaka), a member of the order Beloniformes. The response to alarm substance (Schreckreaction) in medaka is characterized by bouts of immobility and an increase in cortisol levels within minutes of exposure to conspecific skin extract. Histological analysis, however, suggests that club cells are either rare or absent in the medaka epidermis. In addition to describing an uncharacterized behavior in a vertebrate popular for genetic and developmental studies, these results support the hypothesis that the primary function of epidermal club cells may be unrelated to a role as alarm substance cells. The existence of similar behavioral responses in two evolutionarily distant but well established laboratory models, the zebrafish and the medaka, offers the possibility of comparative analyses of neural circuits encoding innate fear. PMID:27824153

  14. Novel method for the nuclear transfer of adult somatic cells in medaka fish (Oryzias latipes): use of diploidized eggs as recipients.

    PubMed

    Wakamatsu, Yuko

    2008-08-01

    Until recently, the nuclear transfer of adult somatic cell nuclei in fish has been unsuccessful. This is primarily because of chromosomal aberrations in nuclear transplants, which are thought to arise due to asynchrony between the cell cycles of the recipient egg and donor nucleus. We recently succeeded in circumventing this difficulty by using a new nuclear transfer method in medaka fish (Oryzias latipes). Instead of enucleated eggs, the method uses non-enucleated and diploidized eggs, obtained by retention of the second polar body release, as recipients in the nuclear transfer of primary culture cells from the caudal fin of an adult green fluorescent protein gene (GFP)-transgenic strain. We found that 2.7% of the reconstructed embryos grew into diploid and fertile adults exhibiting donor expression characteristics and transmission of the GFP marker gene to progeny. The mechanism underlying the generation of nuclear transplants using this method is unknown at present; however, analyses of donor and recipient nuclei behavior and the cytoskeletal mechanisms involved in the early developmental stages, as well as the special ability of diploidized eggs to facilitate reprogramming of the donor nuclei will result in elucidation of the mechanism.

  15. Ontogenetic improvement of visual function in the medaka Oryzias latipes based on an optomotor testing system for larval and adult fish

    USGS Publications Warehouse

    Carvalho, Paulo S. M.; Noltie, Douglas B.; Tillitt, D.E.

    2002-01-01

    We developed a system for evaluation of visual function in larval and adult fish. Both optomotor (swimming) and optokinetic (eye movement) responses were monitored and recorded using a system of rotating stripes. The system allowed manipulation of factors such as width of the stripes used, rotation speed of the striped drum, and light illuminance levels within both the scotopic and photopic ranges. Precise control of these factors allowed quantitative measurements of visual acuity and motion detection. Using this apparatus, we tested the hypothesis that significant posthatch ontogenetic improvements in visual function occur in the medaka Oryzias latipes, and also that this species shows significant in ovo neuronal development. Significant improvements in the acuity angle alpha (ability to discriminate detail) were observed from approximately 5 degrees at hatch to 1 degree in the oldest adult stages. In addition, we measured a significant improvement in flicker fusion thresholds (motion detection skills) between larval and adult life stages within both the scotopic and photopic ranges of light illuminance. Ranges of flicker fusion thresholds (X?? ?? SD) at log I=1.96 (photopic) varied from 37.2 ?? 1.6 cycles/s in young adults to 18.6 ?? 1.6 cycles/s in young larvae 10 days posthatch. At log I= - 2.54 (scotopic), flicker fusion thresholds varied from 5.8 ?? 0.7 cycles/s in young adults to 1.7 ?? 0.4 cycles/s in young larvae 10 days posthatch. Light sensitivity increased approximately 2.9 log units from early hatched larval stages to adults. The demonstrated ontogenetic improvements in visual function probably enable the fish to explore new resources, thereby enlarging their fundamental niche. ?? 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.

  16. Japanese guidelines for adult asthma 2017.

    PubMed

    Ichinose, Masakazu; Sugiura, Hisatoshi; Nagase, Hiroyuki; Yamaguchi, Masao; Inoue, Hiromasa; Sagara, Hironori; Tamaoki, Jun; Tohda, Yuji; Munakata, Mitsuru; Yamauchi, Kohei; Ohta, Ken

    2017-04-01

    Adult bronchial asthma is characterized by chronic airway inflammation, and presents clinically with variable airway narrowing (wheezes and dyspnea) and cough. Long-standing asthma induces airway remodeling, leading to intractable asthma. The number of patients with asthma has increased; however, the number of patients who die of asthma has decreased (1.2 per 100,000 patients in 2015). The goal of asthma treatment is to enable patients with asthma to attain normal pulmonary function and lead a normal life, without any symptoms. A good relationship between physicians and patients is indispensable for appropriate treatment. Long-term management by therapeutic agents and elimination of the causes and risk factors of asthma are fundamental to its treatment. Four steps in pharmacotherapy differentiate between mild and intensive treatments; each step includes an appropriate daily dose of an inhaled corticosteroid, varying from low to high levels. Long-acting β2-agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonist are recommended as add-on drugs, while anti-immunoglobulin E antibody and oral steroids are considered for the most severe and persistent asthma related to allergic reactions. Bronchial thermoplasty has recently been developed for severe, persistent asthma, but its long-term efficacy is not known. Inhaled β2-agonists, aminophylline, corticosteroids, adrenaline, oxygen therapy, and other approaches are used as needed during acute exacerbations, by choosing treatment steps for asthma in accordance with the severity of exacerbations. Allergic rhinitis, eosinophilic chronic rhinosinusitis, eosinophilic otitis, chronic obstructive pulmonary disease, aspirin-induced asthma, and pregnancy are also important issues that need to be considered in asthma therapy.

  17. The Genomic and Genetic Toolbox of the Teleost Medaka (Oryzias latipes)

    PubMed Central

    Kirchmaier, Stephan; Naruse, Kiyoshi; Wittbrodt, Joachim; Loosli, Felix

    2015-01-01

    The Japanese medaka, Oryzias latipes, is a vertebrate teleost model with a long history of genetic research. A number of unique features and established resources distinguish medaka from other vertebrate model systems. A large number of laboratory strains from different locations are available. Due to a high tolerance to inbreeding, many highly inbred strains have been established, thus providing a rich resource for genetic studies. Furthermore, closely related species native to different habitats in Southeast Asia permit comparative evolutionary studies. The transparency of embryos, larvae, and juveniles allows a detailed in vivo analysis of development. New tools to study diverse aspects of medaka biology are constantly being generated. Thus, medaka has become an important vertebrate model organism to study development, behavior, and physiology. In this review, we provide a comprehensive overview of established genetic and molecular-genetic tools that render medaka fish a full-fledged vertebrate system. PMID:25855651

  18. Low dose exposure to Bisphenol A alters development of gonadotropin-releasing hormone 3 neurons and larval locomotor behavior in Japanese Medaka.

    PubMed

    Inagaki, T; Smith, N; Lee, E K; Ramakrishnan, S

    2016-01-01

    Accumulating evidence indicates that chronic low dose exposure to Bisphenol A (BPA), an endocrine disruptor, may disrupt normal brain development and behavior mediated by the gonadotropin-releasing hormone (GnRH) pathways. While it is known that GnRH neurons in the hypothalamus regulate reproductive physiology and behavior, functional roles of extra-hypothalamic GnRH neurons remain unclear. Furthermore, little is known whether BPA interacts with extra-hypothalamic GnRH3 neural systems in vulnerable developing brains. Here we examined the impact of low dose BPA exposure on the developing GnRH3 neural system, eye and brain growth, and locomotor activity in transgenic medaka embryos and larvae with GnRH3 neurons tagged with GFP. Fertilized eggs were collected daily and embryos/larvae were chronically exposed to 200ng/ml of BPA, starting at 1 day post fertilization (dpf). BPA significantly increased fluorescence intensity of the GnRH3-GFP neural population in the terminal nerve (TN) of the forebrain at 3dpf, but decreased the intensity at 5dpf, compared with controls. BPA advanced eye pigmentation without affecting eye and brain size development, and accelerated times to hatch. Following chronic BPA exposure, 20dpf larvae showed suppression of locomotion, both in distance covered and speed of movement (47% and 43% reduction, respectively). BPA-induced hypoactivity was accompanied by decreased cell body sizes of individual TN-GnRH3 neurons (14% smaller than those of controls), but not of non-GnRH3 neurons. These novel data demonstrate complex neurobehavioral effects of BPA on the development of extra-hypothalamic GnRH3 neurons in teleost fish.

  19. Histopathology of a wavy medaka

    PubMed Central

    Irie, Kota; Kuroda, Yusuke; Mimori, Norihiko; Hayashi, Seigo; Abe, Masayoshi; Tsuji, Naho; Sugiyama, Akihiko; Furukawa, Satoshi

    2016-01-01

    Wavy medakas are medakas that exhibit spinal curvature characterized by dorsoventrally curved vertebrae. We found a spontaneous wavy medaka in our experimental stock and subjected it to a histopathological examination. Macroscopically, the wavy medaka’s spine formed an M shape, and its vertebrae displayed a dorsoventral curvature that started at the third vertebral bone. Microscopically, the vertebral cavities were filled with fibrous tissue, which was similar to that seen in the central parts of the intervertebral discs of a normal medaka. The vertebral joints were composed of vacuolated notochord cells without intervertebral disc formation. These changes were also observed in the caudal region, which exhibited less curvature. In the normal medaka, the intervertebral discs form via the regression of the notochord that plays a key role in the development of vertebrae and disc formation. We concluded that notochordal subinvolution had induced intervertebral disc dysplasia, leading to lordokyphosis, in the wavy medaka. PMID:27182116

  20. Development of the Fish Medaka in Microgravity

    NASA Technical Reports Server (NTRS)

    Wolgemuth, Debra J.

    1995-01-01

    The goal of these experiments was to determine the effect of microgravity on the early development of the fish medaka. There were two objectives for this flight series. The primary objective was to assess the effects of microgravity on different stages of development and to ascertain whether the relevant developmental questions can be addressed at the gross morphological level or if the issues involve more subtle questions about regulation at the molecular and cellular levels. The secondary objective was the assessment of the utility of flight hardware with the capabilities to perform embryological studies. We have been able to take advantage of the flight testing phase of the STL-B hardware to also study the effects of microgravity on the early development of the fish, Medaka. Our initial studies involved monitoring the early Medaka development and raising flight embryos for breeding. Images of the developing embryos were collected either via video which was either taken by the astronauts or broadcast to Earth. Sample video images were digitized and stored on a hard drive resident within the on-board STL-B unit. Embryos were fixed at specific intervals, returned to Earth and are being analyzed for the timing and location of molecular events associated with controlling the morphological pattern for the onset of adult structures.

  1. Masticatory ability and functional tooth units in Japanese adults.

    PubMed

    Ueno, M; Yanagisawa, T; Shinada, K; Ohara, S; Kawaguchi, Y

    2008-05-01

    The purposes of this study were (i) to examine the relationship between the number of natural teeth and the number of functional tooth units in Japanese adults, (ii) to evaluate how functional tooth units relate to subjective masticatory ability and (iii) to determine the minimum number of natural teeth and functional tooth units needed to maintain adequate self-assessed chewing function. A self-administered questionnaire was given and dental examination was conducted for 2164 residents aged 40 to 75 years. Counts were made on the number of functional tooth units of natural teeth (n-functional tooth units), the sum of natural teeth and artificial teeth on implant-supported and fixed prostheses (nif-functional tooth units) and the sum of natural teeth and artificial teeth on implant-supported, fixed and removable prostheses (total-functional tooth units). The average number of natural teeth, n-functional tooth units and nif-functional tooth units decreased with age, but these were often replaced by functional tooth units from artificial teeth on removable prostheses. Total-functional tooth units in 50-59 year old people were slightly lower compared with those in other age groups. Subjects who reported that they could chew every food item on an average had 23.4 total natural teeth, 12.6 posterior natural teeth, 7.6 n-functional tooth units, 8.6 nif-functional tooth units and 10.4 total-functional tooth units, and subjects without chewing difficulties had fewer functional tooth units from removable prostheses. Maintaining 20 and more natural teeth and at least eight nif-functional tooth units is important in reducing the likelihood of self-assessed chewing difficulties.

  2. Intonation Facilitates Contrast Resolution: Evidence from Japanese Adults and 6-Year Olds

    ERIC Educational Resources Information Center

    Ito, Kiwako; Jincho, Nobuyuki; Minai, Utako; Yamane, Naoto; Mazuka, Reiko

    2012-01-01

    Two eye-tracking experiments tested how pitch prominence on a prenominal adjective affects contrast resolution in Japanese adult and 6-year old listeners. Participants located two animals in succession on displays with multiple colored animals. In Experiment 1, adults' fixations to the contrastive target (pink cat [right arrow] GREEN cat) were…

  3. Contemporary Portraits of Japanese Adult Women: Life Course Plans and Junior Colleges.

    ERIC Educational Resources Information Center

    Inoue, Yukiko

    It has been documented that at the age of 20, Japanese women have not yet discovered the realities of the adult world. With the end of high growth in the Japanese economy, women of Japan have to face a new challenge. They frequently have to be not only a homemaker but also a breadwinner. Life course is a pathway along which people live, and life…

  4. Validation of the Japanese version of the power of food scale in a young adult population.

    PubMed

    Yoshikawa, Takahiro; Orita, Keisuke; Watanabe, Yasuyoshi; Tanaka, Masaaki

    2012-08-01

    To validate a Japanese version of Power of Food Scale (PFS-J), and to describe characteristics in appetitive motives among current Japanese young adults, the original English PFS was translated into Japanese and translated back into English, to confirm conceptual and linguistic equivalence, and administered to university students. Test-retest reliability of the PFS-J was evaluated in additional experiments. The PFS-J demonstrated good internal consistency and stability over time. Confirmatory factor analyses demonstrated that the PFS-J has acceptable factor structure. Criterion validity was suggested, in that the relationship between the original PFS and Three-Factor Eating Questionnaire Revised-21 was similar to that between the Japanese versions of the scales. While no association was observed between the scores of PFS-J and Body Mass Index, the scores were higher in women than in men. Characteristics of the appetitive motives in Japan might be different from those in western countries.

  5. Japanese Children's and Adults' Reasoning about the Consequences of Psychogenic Bodily Reactions

    ERIC Educational Resources Information Center

    Toyama, Noriko

    2011-01-01

    Four experiments were conducted with Japanese children and adult participants to assess their awareness of the effectiveness of biological and psychological treatments for psychogenic bodily reactions. Study 1 had 116 participants, composed of 4-year-olds (17), 5-year-olds (20), 7-year-olds (24), 10-year-olds (20), and college students (35). The…

  6. Syntax in a Native Language Still Continues to Develop in Adults: Honorification Judgment in Japanese

    ERIC Educational Resources Information Center

    Momo, Kanako; Sakai, Hiromu; Sakai, Kuniyoshi L.

    2008-01-01

    Native languages (L1s) are tacitly assumed to be complete and stable in adults. Here we report an unexpected individual variation in judgment of L1 regarding Japanese sentences including honorification, and further clarify its neural basis with functional magnetic resonance imaging (fMRI). By contrasting an honorification judgment task with a…

  7. Prejudice and Pride: Japanese Americans in the Young Adult Novels of Yoshiko Uchida.

    ERIC Educational Resources Information Center

    McDiffett, Danton

    2001-01-01

    Discusses five books for young adults by author Yoshiko Uchida. Notes that these books, accessible to children in grades 5 and above, describe the prejudice against Japanese Americans, internment camps, and upheaval, sorrow, and anger spawned by the American government's racist actions. Shows how the books can prompt discussions about cultural…

  8. A New Functional Health Literacy Scale for Japanese Young Adults Based on Item Response Theory.

    PubMed

    Tsubakita, Takashi; Kawazoe, Nobuo; Kasano, Eri

    2017-03-01

    Health literacy predicts health outcomes. Despite concerns surrounding the health of Japanese young adults, to date there has been no objective assessment of health literacy in this population. This study aimed to develop a Functional Health Literacy Scale for Young Adults (funHLS-YA) based on item response theory. Each item in the scale requires participants to choose the most relevant term from 3 choices in relation to a target item, thus assessing objective rather than perceived health literacy. The 20-item scale was administered to 1816 university students and 1751 responded. Cronbach's α coefficient was .73. Difficulty and discrimination parameters of each item were estimated, resulting in the exclusion of 1 item. Some items showed different difficulty parameters for male and female participants, reflecting that some aspects of health literacy may differ by gender. The current 19-item version of funHLS-YA can reliably assess the objective health literacy of Japanese young adults.

  9. A large outbreak of Japanese encephalitis predominantly among adults in northern region of West Bengal, India.

    PubMed

    Gurav, Yogesh K; Bondre, Vijay P; Tandale, Babasaheb V; Damle, Rekha G; Mallick, Sanjay; Ghosh, Uday S; Nag, Shankha S

    2016-11-01

    Unusual rise of acute encephalitis syndrome cases (AES) were reported in July 2014 in the northern region of West Bengal, India. Investigations were carried out to characterize the outbreak and to identify the associated virus etiology. This observational study is based on 398 line listed AES cases, mostly (70.8%, 282/398) adults, with case fatality ratio of 28.9% (115/398). Japanese encephalitis virus infection was detected in 134 (49.4%) among 271 AES cases tested and most of them (79.1%, 106/134) were adults. The study reports a large outbreak of genotype III Japanese encephalitis among adults in northern region of West Bengal, India. J. Med. Virol. 88:2004-2011, 2016. © 2016 Wiley Periodicals, Inc.

  10. Allergic Sensitization to Perennial Allergens in Adults and Children Sensitized to Japanese Cedar or Japanese Cypress Pollen in Japan

    PubMed Central

    2014-01-01

    In Japan, seasonal allergic rhinitis in the spring due to exposure to Japanese cedar or Japanese cypress pollen is common. However, the allergic profile for perennial allergens in spring pollinosis remains unclear. Therefore, in this study, we investigated the allergic profiles of 652 patients with rhinitis. Total serum IgE, serum-specific IgE, and blood eosinophil counts were measured. Allergic sensitization, determined by the serum allergen-specific IgE level, did not always correspond with the patient's symptoms. Only 27% of patients with allergic symptoms in response to spring pollens were sensitized to these allergens alone; 31% of patients were also sensitized to perennial allergens, even without symptoms due to perennial allergens. Total serum IgE and eosinophil cell counts were significantly elevated in patients sensitized to perennial allergens and spring pollens, as compared to patients sensitized only to spring pollens. Most children sensitized to spring pollen (84%) were sensitized to perennial allergens, at a higher rate than adults (49%). Patients sensitized to spring pollens are likely to be latently sensitized to perennial allergens. This is especially true for children and should be monitored closely. Improvement in seasonal allergic conditions, including latent perennial allergy, is important to prevent symptoms that could advance to asthma. PMID:24757445

  11. A method for real-time measurement of respiratory rhythms in medaka (Oryzias latipes) using computer vision for water quality monitoring.

    PubMed

    Zheng, Hongyuan; Liu, Rong; Zhang, Rong; Hu, Yanqing

    2014-02-01

    The respiratory rhythms of Japanese medaka is considered to be an efficient indicator for monitoring water quality since they are sensitive to chemicals and can be measured directly from the movement of fish gill tissue generated by their breathe. However, few methods have been established to measure the feature of small free-swimming fish intuitively. In this article, a method is proposed to measure the influence of the pollution to the Japanese medaka's respiratory rhythms with computer vision technology in real time. In order to get the images which contains the complete gill tissue remotely and steadily, a special object container and an experiment platform are designed. With the aim of capturing Japanese medaka's respiratory rhythms in real time, a set of image processing algorithms such as the color distribution table, Support Vector Machine (SVM), adaptive boosting (Adaboost) and mathematical morphology are applied. Then, in order to verify the effectiveness and accuracy of the whole method, fourteen groups of Japanese medakas are respectively exposed to copper ions solutions with different concentrations of 0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 mg/L for 48 h. The comparison between the human eyes observation and the above method indicates that the data obtained through the method is generally accurate. We found that the respiratory rate of Japanese medaka showed a downward trend initially when exposed in the copper ions solution, afterwards fluctuated repeatly arounding the lower rate, before death, the respiratory rate rised slowly for a while. With the increase of concentration, this trend will be more obvious. But the above phenomenon is absolutely different from that in the standard dilution water. Moreover, the two kinds of special respiratory rhythm of medakas poisoning were discovered. This method can be widely applied to study some toxic substances' effects on Japanese medaka's respiratory rhythms and to assess the degree of risk of the water

  12. Japanese macaque (Macaca fuscata) mothers huddle with their young offspring instead of adult females for thermoregulation.

    PubMed

    Ueno, Masataka; Nakamichi, Masayuki

    2016-08-01

    It is unclear whom animals select to huddle with for thermoregulation. In this study, we investigated whom Japanese macaque (Macaca fuscata) mothers huddled with-their young offspring or other adult group members-when there is need for thermoregulation. We used a focal-animal sampling method, targeting 17 females at Katsuyama, Okayama Prefecture, Japan. A majority of huddling among adult females was recorded during winter season (December, January, and February). Females who had young (0- or 1-year-old) offspring huddled less frequently with other adult females compared to females who did not have young offspring in winter. However, including young offspring, the frequency of huddling with any other individuals did not differ by whether females had young offspring. Moreover, the females who did not have young offspring huddled with other adult females more often in cloudy than in sunny weather during winter season. In contrast, females who had young offspring increased huddling with their young offspring in cloudy than in sunny weather, but did not do so with other adult females. This study indicates that Japanese macaque mothers huddle with their young offspring instead of other adult females when there is need for thermoregulation.

  13. Gender-Specific Toxicological Effects of Chronic Exposure to Pure Microcystin-LR or Complex Microcystis aeruginosa Extracts on Adult Medaka Fish.

    PubMed

    Le Manach, Séverine; Khenfech, Nour; Huet, Hélène; Qiao, Qin; Duval, Charlotte; Marie, Arul; Bolbach, Gérard; Clodic, Gilles; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-08-02

    Cyanobacterial blooms often occur in freshwater lakes and constitute a potential health risk to human populations, as well as to other organisms. However, their overall and specific implications for the health of aquatic organisms that are chronically and environmentally exposed to cyanobacteria producing hepatotoxins, such as microcystins (MCs), together with other bioactive compounds have still not been clearly established and remain difficult to assess. The medaka fish was chosen as the experimental aquatic model for studying the cellular and molecular toxicological effects on the liver after chronic exposures (28 days) to environmentally relevant concentrations of pure MC-LR, complex extracts of MC producing or nonproducing cyanobacterial biomasses, and of a Microcystis aeruginosa natural bloom. Our results showed a higher susceptibility of females to the different treatments compared to males at both the cellular and the molecular levels. Although hepatocyte lysis increased with MC-containing treatments, lysis always appeared more severe in the liver of females compare to males, and the glycogen cellular reserves also appeared to decrease more in the liver of females compared to those in the males. Proteomic investigations reveal divergent responses between males and females exposed to all treatments, especially for proteins involved in metabolic and homeostasis processes. Our observations also highlighted the dysregulation of proteins involved in oogenesis in female livers. These results suggest that fish populations exposed to cyanobacteria blooms may potentially face several ecotoxicological issues.

  14. Development of space-fertilized eggs and formation of primordial germ cells in the embryos of medaka fish

    NASA Astrophysics Data System (ADS)

    Ijiri, K.

    In the second International Microgravity Laboratory (IML-2) mission in 1994, four small Japanese killifish (Medaka, Oryzias latipes) made a space travel of 15 days aboard a space shuttle. These four adult Medaka fish successfully mated in space for the first time among vertebrate animals. Moreover, the eggs they laid developed normally, at least in their external appearance, hatching as fry (baby fish) in space. Fish mated and laid eggs every day during the first week. Near the end of the mission most of the eggs had a well-developed body with two pigmented eyes. In total, 43 eggs were laid (detected), out of which 8 fry hatched in space, as truly `space-originated' babies. A further 30 fry hatched within 3 days after landing. This is the normal hatching rate, compared with the ground-based data. Among the 8 space-originated fry, four were killed for histological sections, and germ cells at the gonadal region were counted for each fry. Their numbers were in the range of the germ cells of the normal control fry (ground-kept samples). Thus, as embryos developed normally in their external appearance, inside the embryos the formation of primordial germ cells took place normally in space, and their migration to the genital ridges was not hindered by microgravity. The two of the remaining space-originated fry have grown up and been creating their offspring in the laboratory. This proved that the primordial germ cells formed in space were also normal from a functional point of view. The four space-travelled adult fish re-started mating and laying eggs on the 7th day after landing and continued to do so every day afterward. Fertilization rate and hatchability of these eggs were as high as the eggs laid by the laboratory-kept fish. This fact implies that in gametogenesis of adult fish, there are no specific stages of germ cells extremely susceptible to microgravity.

  15. Expression Profiles of Branchial FXYD Proteins in the Brackish Medaka Oryzias dancena: A Potential Saltwater Fish Model for Studies of Osmoregulation

    PubMed Central

    Yang, Wen-Kai; Kang, Chao-Kai; Chang, Chia-Hao; Hsu, An-Di; Lee, Tsung-Han; Hwang, Pung-Pung

    2013-01-01

    FXYD proteins are novel regulators of Na+-K+-ATPase (NKA). In fish subjected to salinity challenges, NKA activity in osmoregulatory organs (e.g., gills) is a primary driving force for the many ion transport systems that act in concert to maintain a stable internal environment. Although teleostean FXYD proteins have been identified and investigated, previous studies focused on only a limited group of species. The purposes of the present study were to establish the brackish medaka (Oryzias dancena) as a potential saltwater fish model for osmoregulatory studies and to investigate the diversity of teleostean FXYD expression profiles by comparing two closely related euryhaline model teleosts, brackish medaka and Japanese medaka (O. latipes), upon exposure to salinity changes. Seven members of the FXYD protein family were identified in each medaka species, and the expression of most branchial fxyd genes was salinity-dependent. Among the cloned genes, fxyd11 was expressed specifically in the gills and at a significantly higher level than the other fxyd genes. In the brackish medaka, branchial fxyd11 expression was localized to the NKA-immunoreactive cells in gill epithelia. Furthermore, the FXYD11 protein interacted with the NKA α-subunit and was expressed at a higher level in freshwater-acclimated individuals relative to fish in other salinity groups. The protein sequences and tissue distributions of the FXYD proteins were very similar between the two medaka species, but different expression profiles were observed upon salinity challenge for most branchial fxyd genes. Salinity changes produced different effects on the FXYD11 and NKA α-subunit expression patterns in the gills of the brackish medaka. To our knowledge, this report is the first to focus on FXYD expression in the gills of closely related euryhaline teleosts. Given the advantages conferred by the well-developed Japanese medaka system, we propose the brackish medaka as a saltwater fish model for

  16. Temperature-dependent growth rates and gene expression patterns of various medaka Oryzias latipes cell lines derived from different populations.

    PubMed

    Hirayama, Makoto; Mitani, Hiroshi; Watabe, Shugo

    2006-05-01

    Medaka Oryzias latipes has several geographically and genetically distinct populations. We examined temperature acclimation response in various medaka cell lines derived from different populations. Measurement of cell growth at various temperatures suggested that 15 degrees Celsius was the permissive growth temperature in all cell lines from the Northern Japanese and East Korean populations, but not in those from the Southern Japanese population and medaka-related species Oryzias celebensis, which inhabits a tropical zone. RT-PCR for 102 temperature-responsive genes, previously reported in other species, revealed that the accumulated mRNA level of a gene encoding HSP47 was lower at 25 degrees Celsius than at 33 degrees Celsius, and vice versa for 12 genes including IkappaBalpha and Rab-1c, in OLHNI-1 cell line from the Northern Japanese population. Further analysis by real-time PCR demonstrated that the accumulated mRNA levels of IkappaBalpha and Rab-1c in OLHNI-1 and OLSOK-e7 cell lines from the East Korean population were increased when the culture temperature was shifted from 33 to 15 degrees Celsius, but not in OLHdrR-e3 cell line from the Southern Japanese population. Since IkappaBalpha and Rab-1c are related to the NFkappaB cascade and endoplasmic reticulum-to-Golgi transport, respectively, it is inferred that immune responses and intracellular transport are possibly critical to temperature adaptation for medaka.

  17. Factor structure of the 12-item General Health Questionnaire in the Japanese general adult population.

    PubMed

    Doi, Yuriko; Minowa, Masumi

    2003-08-01

    The 12-item General Health Questionnaire (GHQ-12) has been extensively used in a variety of settings across countries. The main aim of the present study was to assess the factor structure of the GHQ-12 for the Japanese general adult population. Data came from a sample of 1808 Japanese aged 20 years or older who were randomly selected based on the 1995 census (897 men and 911 women). Cronbach's alpha coefficients were 0.83 for men and 0.85 for women. Overall, the corrected item-total correlation coefficients were >0.20 for both genders. The GHQ-12 yielded a two-factor solution of psychological distress (items 2, 5, 6, 9, 10 and 11) and social dysfunction (items 1, 3, 4, 7 and 8), which jointly accounted for 49.1% of the total variance, for women. Item 12 on happiness was not discernable. For men, item 12 was separated from a social dysfunction factor and yielded the third factor with item 3 on social role, and the three factors jointly accounted for 57.6%. The results of the present study suggest that the GHQ-12 can be used as an internally reliable and homogeneous scale that produces mainly the factors of psychological distress and social dysfunction. Item 12 may be structurally different in the case of Japanese adults.

  18. Longitudinal association of dentition status with dietary intake in Japanese adults aged 75 to 80 years.

    PubMed

    Iwasaki, M; Yoshihara, A; Ogawa, H; Sato, M; Muramatsu, K; Watanabe, R; Ansai, T; Miyazaki, H

    2016-10-01

    Limited information is available on the temporal association between dentition status and dietary intake. The aim of this 5-year prospective cohort study was to investigate whether impaired dentition was associated with subsequent decline in dietary intake in older Japanese adults. Two hundred and eighty-six community-dwelling Japanese individuals, all aged 75 years at baseline, were included in the study. Functional tooth units (FTUs), defined as a pair of opposing natural or prosthetic teeth excluding third molars (range: 0-14), were counted on the basis of baseline dental examinations. Individuals with ≤5 FTUs were defined as having impaired dentition. Dietary intake was assessed at baseline and 5 years later, using a validated dietary questionnaire. Robust regression analyses were used to evaluate the differences in change in dietary intake between participants with and without impaired functional dentition, after adjustment for potential confounders. Sixty-one study participants (21·3 %) were defined as having impaired dentition. Overall, mean values for all estimated dietary variables (energy, nutrients and food groups) declined over time. Notably, individuals with impaired dentition demonstrated a significantly (P < 0·05) greater degree of decline in the intake of multiple nutrients (protein, sodium, potassium, calcium, vitamin A, vitamin E and dietary fibre) and food groups (vegetable and meat) than those without impaired dentition, after adjusting for potential confounders. The results of this study describe the temporal association of impaired dentition with the decline in selected nutrient and food group intake among older Japanese adults.

  19. Susceptibility of the Adult Japanese Beetle, Popillia japonica to Entomopathogenic Nematodes.

    PubMed

    Morris, E Erin; Grewal, Parwinder S

    2011-09-01

    To build upon prior research demonstrating the potential of entomopathogenic nematode dissemination by infected adult Japanese beetle, Popillia japonica, we evaluated susceptibility of the adult beetles to 20 strains of Steinernema and Heterorhabditis under laboratory conditions. The nematodes were applied at a rate of 10,000 infective juveniles per 10 adult beetles in 148 mL plastic cups containing autoclaved sand and sassafras leaves as a source of food for the beetles. All strains infected the beetles and caused 55% to 95% mortality. The most virulent strains that caused 50% beetle mortality in less than 5 days included a strain of H. georgiana (D61), three strains of Steinernema sp. (R54, R45, and FC48), and two strains of S. carpocapsae (All and D60). The ability of two strains of Steinernema sp. (R45 and R54) and two strains of Heterorhabditis bacteriophora (D98 and GPS11) to infect and reproduce in the beetle was further examined to assess the potential of infected beetles to disseminate nematodes upon their death. All four strains infected and killed the beetles, but only Steinernema strains reproduced in the cadavers. We conclude that both Heterorhabditis and Steinernema strains are able to cause mortality to adult Japanese beetle, but Steinernema strains may be effectively disseminated due to their reproduction in the beetle.

  20. Susceptibility of the Adult Japanese Beetle, Popillia japonica to Entomopathogenic Nematodes

    PubMed Central

    Morris, E. Erin; Grewal, Parwinder S.

    2011-01-01

    To build upon prior research demonstrating the potential of entomopathogenic nematode dissemination by infected adult Japanese beetle, Popillia japonica, we evaluated susceptibility of the adult beetles to 20 strains of Steinernema and Heterorhabditis under laboratory conditions. The nematodes were applied at a rate of 10,000 infective juveniles per 10 adult beetles in 148 mL plastic cups containing autoclaved sand and sassafras leaves as a source of food for the beetles. All strains infected the beetles and caused 55% to 95% mortality. The most virulent strains that caused 50% beetle mortality in less than 5 days included a strain of H. georgiana (D61), three strains of Steinernema sp. (R54, R45, and FC48), and two strains of S. carpocapsae (All and D60). The ability of two strains of Steinernema sp. (R45 and R54) and two strains of Heterorhabditis bacteriophora (D98 and GPS11) to infect and reproduce in the beetle was further examined to assess the potential of infected beetles to disseminate nematodes upon their death. All four strains infected and killed the beetles, but only Steinernema strains reproduced in the cadavers. We conclude that both Heterorhabditis and Steinernema strains are able to cause mortality to adult Japanese beetle, but Steinernema strains may be effectively disseminated due to their reproduction in the beetle. PMID:23431080

  1. Iodine Excretion in 24-hour Urine Collection and Its Dietary Determinants in Healthy Japanese Adults

    PubMed Central

    Katagiri, Ryoko; Asakura, Keiko; Uechi, Ken; Masayasu, Shizuko; Sasaki, Satoshi

    2016-01-01

    Background Since seaweed is a common component of the Japanese diet, iodine intake in Japanese is expected to be high. However, urinary iodine excretion, measured using 24-hour urine samples, and its dietary determinants are not known. Methods Apparently healthy adults aged 20 to 69 years living in 20 areas throughout Japan were recruited in February and March, 2013. Urinary iodine excretion was evaluated using 24-hour urine collected from 713 subjects (362 men and 351 women), and the difference among age groups was assessed. The association between dietary intake of food groups and urinary iodine excretion was assessed among 358 subjects who completed a semi-weighed 4-day diet record (DR) and urine collection. The correlations between iodine intake and iodine excretion were also evaluated, and correlation coefficients were calculated for iodine intake in the DR of the overlapping day or the DR 1 day before and after urine collection. Results Median iodine excretion in 24-hour urine was 365 µg, and excretion was significantly higher in older subjects. Iodine intake estimated by the DRs was significantly correlated with urinary iodine excretion when DRs and urine collection were obtained on the same day (r = 0.37). After adjustment for confounding factors, iodine excretion was significantly associated with intakes of kelp and soup stock from kelp and fish. Conclusions Although multiple measurements for urinary iodine are required to confirm our results, this study showed the current iodine status of healthy Japanese adults. The results suggest that kelp and fish are the main contributors to Japanese iodine status measured by 24-hour urine. PMID:27374137

  2. Sources of strength-training information and strength-training behavior among Japanese older adults.

    PubMed

    Harada, Kazuhiro; Shibata, Ai; Lee, Euna; Oka, Koichiro; Nakamura, Yoshio

    2016-03-01

    The promotion of strength training is now recognized as an important component of public health initiatives for older adults. To develop successful communication strategies to increase strength-training behavior among older adults, the identification of effective communication channels to reach older adults is necessary. This study aimed to identify the information sources about strength training that were associated with strength-training behaviors among Japanese older adults. The participants were 1144 adults (60-74 years old) randomly sampled from the registry of residential addresses. A cross-sectional questionnaire survey was conducted. The independent variables were sources of strength-training information (healthcare providers, friends, families, radio, television, newspapers, newsletters, posters, books, magazines, booklets, the Internet, lectures, other sources), and the dependent variable was regular strength-training behavior. Logistic regression analysis was used to identify potential relationships. After adjusting for demographic factors and all other information sources, strength-training information from healthcare providers, friends, books and the Internet were positively related to regular strength-training behavior. The findings of the present study contribute to a better understanding of strength-training behavior and the means of successful communication directed at increasing strength training among older adults. The results suggest that healthcare providers, friends, books and the Internet are effective methods of communication for increasing strength-training behaviors among older adults.

  3. Relationship between bicultural identity and psychological well-being among American and Japanese older adults

    PubMed Central

    Yamaguchi, Ayano; Kim, Min-Sun; Oshio, Atsushi; Akutsu, Satoshi

    2016-01-01

    In a large national sample of American and Japanese older adults, this study investigated how bicultural identity affects perception of health and well-being in 11 individual psychological variables (i.e. positive well-being: self-esteem, optimism, subjective well-being Japanese equivalent, gratitude, Positive and Negative Affect Schedule–positive adjectives, and satisfaction with life; negative well-being: depression, pessimism, social anxiety, Positive and Negative Affect Schedule–negative adjectives, and perceived stress). This sample consisted of 1248 Americans from the Midlife in the United States survey, 2004–2006, and 380 Japanese from the Midlife in Japan survey in Tokyo, Japan, 2008–2010. Results showed that bicultural individuals (having both highly independent and interdependent self-construals) in both countries tend to exhibit higher scores across most perceived health and well-being measures when compared to other groups (i.e. marginal, interdependent, and independent). Cultural-specific aspects of self-construal, health, and well-being are explained to support the findings. Discussion of these findings and their implications is also provided. PMID:28070404

  4. Sex determination. foxl3 is a germ cell-intrinsic factor involved in sperm-egg fate decision in medaka.

    PubMed

    Nishimura, Toshiya; Sato, Tetsuya; Yamamoto, Yasuhiro; Watakabe, Ikuko; Ohkawa, Yasuyuki; Suyama, Mikita; Kobayashi, Satoru; Tanaka, Minoru

    2015-07-17

    Sex determination is an essential step in the commitment of a germ cell to a sperm or egg. However, the intrinsic factors that determine the sexual fate of vertebrate germ cells are unknown. Here, we show that foxl3, which is expressed in germ cells but not somatic cells in the gonad, is involved in sperm-egg fate decision in medaka fish. Adult XX medaka with disrupted foxl3 developed functional sperm in the expanded germinal epithelium of a histologically functional ovary. In chimeric medaka, mutant germ cells initiated spermatogenesis in female wild-type gonad. These results indicate that a germ cell-intrinsic cue for the sperm-egg fate decision is present in medaka and that spermatogenesis can proceed in a female gonadal environment.

  5. Japanese adult's and children's production and perception of English fricatives: A longitudinal study

    NASA Astrophysics Data System (ADS)

    Aoyama, Katsura; Guion, Susan; Yamada, Tsuneo; Akahane-Yamada, Reiko

    2002-05-01

    This study examined the production and perception of English fricatives by native Japanese (NJ) adults and children (16 per group, mean age=40 and 10 years), and age-matched native English (NE) adults and children (16 per group). The subjects were tested two times (T1, T2) 1 year apart. (At T1, the NJ subjects' mean length of residence in the U.S. was 0.5 year.) A picture-naming task was used to elicit the production of English words beginning with /s/ and /θ/, and intelligibility scores were obtained for both. The intelligibility scores of the NJ children but not adults improved significantly from T1 to T2. The NJ children obtained significantly lower scores than the NJ adults did at T1, but at T2 the adult-child difference was nonsignificant. The perception of /s/ and /θ/ was tested by a categorial discrimination task. Although the NJ adult's and children's scores improved from T1 to T2, the T1-T2 differences were nonsignificant. Thus, the results showed that the NJ children's production scores improved significantly from T1 to T2, while there was no significant change for the perception scores on the discrimination of /s/-/θ/. The relationship between production and perception in L2 speech learning will be discussed. [Work supported by NIH.

  6. Relationship between impacts attributed to malocclusion and psychological stress in young Japanese adults.

    PubMed

    Ekuni, Daisuke; Furuta, Michiko; Irie, Koichiro; Azuma, Tetsuji; Tomofuji, Takaaki; Murakami, Takashi; Yamashiro, Takashi; Ogura, Toshio; Morita, Manabu

    2011-10-01

    Identifying risk factors is important to prevent a wide range of health-damaging behaviours and to improve the quality of life of young people. The aim of this study was to investigate the relationship between impacts on daily performance attributed to malocclusion and psychological stress in healthy young Japanese adults. Medical and oral health data were collected during a cross-sectional examination conducted by the Health Service Center of Okayama University. Systemically healthy non-smoking students aged 18 and 19 years (n = 641; 329 males and 312 females) were included. Malocclusion was defined using a modified version of the Index of Orthodontic Treatment Need (IOTN). The impacts on daily performance attributed to malocclusion and psychological stress were assessed using self-reported questionnaires, the condition-specific oral impacts on daily performances (CS-OIDP), and the Hopkins Symptoms Checklist. Mann-Whitney U- and chi-square tests and structural equation modelling (SEM) were used for statistical analysis. Forty per cent of subjects had a malocclusion (n = 255). Subjects with impacts on daily performance had a significantly higher prevalence of malocclusion than those without impacts (P < 0.001). SEM showed that psychological stress, especially interpersonal sensitivity and depression, was significantly correlated with CS-OIDP and malocclusion. Negative impacts on daily performance attributed to malocclusion may contribute to psychological stress in young Japanese adults.

  7. Neurological effects on startle response and escape from predation by medaka exposed to organic chemicals

    SciTech Connect

    Carlson, R.; Drummond, R.; Hammermeister, D.; Bradbury, S.

    1995-12-31

    Simultaneous electrophysiological and behavioral studies were performed on juvenile Japanese medaka (Oryzias latipes) exposed to representative neurotoxic organic chemicals at sublethal concentrations. Non-invasive recordings were made of the electrical impulses generated within giant neuronal Mauthner cells, associated interneurons or motoneurons, and musculature, all of which initiate the startle or escape response in fish. Timing in milliseconds between these electrical sequelae was measured for each fish before and at 24 and 48 hours exposure to a chemical. Also noted was the number of startle responses to number of stimuli ratio (R/S). Other groups of medaka were fed to bluegills and consumption times recorded to assess their ability to escape predation. These results were compared to neurophysiological effect levels. Phenol, 2,4-dinitrophenol, chlorpyrifos, fenvalerate, and 1-octanol impaired the ability of medaka to escape predation at all concentrations. Medaka were more susceptible to predation in high concentrations of carbaryl and strychnine, but less susceptible at low concentrations, whereas the reverse was true for endosulfan. The variety of neurological effects detected at these concentrations suggest that different mechanisms may be responsible. Phenol and strychnine affected Mauthner cell to motoneuron transmission, chlorpyrifos and carbaryl showed neuromuscular effects, and R/S was affected by most chemicals. Although a variety of neurotoxic mechanisms were examined, the exposure threshold for significant effects for each specific compound was found to be consistent for both the neurophysiological and behavioral endpoints.

  8. Japanese and Canadian Children’s Beliefs about Child and Adult Knowledge: A Case for Developmental Equifinality?

    PubMed Central

    Fitneva, Stanka A.; Pile Ho, Elizabeth; Hatayama, Misako

    2016-01-01

    Children do not know everything that adults know, nor do adults know everything that children know. The present research examined the universality of beliefs about child and adult knowledge and their development with 4- and 7-year-old Canadian and Japanese children (N = 96). In both countries, all children were able to identify adult-specific knowledge and only older children displayed beliefs about child-specific knowledge. However, Japanese and Canadian children differed in whether they used their own knowledge in deciding whether a person who knew an item was a child or an adult. In addition, parental and child beliefs were related in Japan but not in Canada. These findings indicate that children growing up in different cultures may take different paths in developing beliefs about age-related knowledge. Implications for theories of socio-cognitive development and learning are discussed. PMID:27632387

  9. Post-hatch heat warms adult beaks: irreversible physiological plasticity in Japanese quail

    PubMed Central

    Burness, Gary; Huard, Jacqueline R.; Malcolm, Emily; Tattersall, Glenn J.

    2013-01-01

    Across taxa, the early rearing environment contributes to adult morphological and physiological variation. For example, in birds, environmental temperature plays a key role in shaping bill size and clinal trends across latitudinal/thermal gradients. Such patterns support the role of the bill as a thermal window and in thermal balance. It remains unknown whether bill size and thermal function are reversibly plastic. We raised Japanese quail in warm (30°C) or cold (15°C) environments and then at a common intermediate temperature. We predicted that birds raised in cold temperatures would develop smaller bills than warm-reared individuals, and that regulation of blood flow to the bill in response to changing temperatures would parallel the bill's role in thermal balance. Cold-reared birds developed shorter bills, although bill size exhibited ‘catch-up’ growth once adults were placed at a common temperature. Despite having lived in a common thermal environment as adults, individuals that were initially reared in the warmth had higher bill surface temperatures than cold-reared individuals, particularly under cold conditions. This suggests that blood vessel density and/or the control over blood flow in the bill retained a memory of early thermal ontogeny. We conclude that post-hatch temperature reversibly affects adult bill morphology but irreversibly influences the thermal physiological role of bills and may play an underappreciated role in avian energetics. PMID:23884093

  10. Swimming behavior of larval Medaka fish under microgravity

    NASA Astrophysics Data System (ADS)

    Furukawa, R.; Ijiri, K.

    Fish exhibit looping and rolling behaviors when subjected to short periods of microgravity during parabolic flight. Strain-differences in the behavioral response of adult Medaka fish ( Oryzias latipes) were reported previously, however, there have been few studies of larval fish behavior under microgravity. In the present study, we investigated whether microgravity affects the swimming behavior of larvae at various ages (0 to 20 days after hatching), using different strains: HNI-II, HO5, ha strain, and variety of different strains (variety). The preliminary experiments were done in the ground laboratory: the development of eyesight was examined using optokinetic response for the different strains. The visual acuity of larvae improved drastically during 20 days after hatching. Strain differences of response were noted for the development of their visual acuity. In microgravity, the results were significantly different from those of adult Medaka. The larval fish appeared to maintain their orientation, except that a few of them exhibited looping and rolling behavior. Further, most larvae swam normally with their backs turning toward the light source (dorsal light response, DLR), and the rest of them stayed with their abdomen touching the surface of the container (ventral substrate response, VSR). For larval stages, strain-differences and age-differences in behavior were observed, but less pronounced than with adult fish under microgravity. Our observations suggest that adaptability of larval fish to the gravitational change and the mechanism of their postural control in microgravity are more variable than in adult fish.

  11. TRANSGENERATIONAL AND DEVELOPMENTAL EXPOSURE OF JAPANESE MEDAKA (ORYZIAS LATIPES) TO ETHINYLESTRADIOL RESULTS IN ENDOCRINE AND REPRODUCTIVE DIFFERENCES IN THE RESPONSE TO ETHINYLESTRADIOL AS ADULTS. (R827098)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  12. TRANSGENERATIONAL AND DEVELOPMENTAL EXPOSURE OF JAPANESE MEDAKA (ORYZIAS LATIPES) TO ETHINYLESTRADIOL RESULTS IN ENDOCRINE AND REPRODUCTIVE DIFFERENCES IN THE RESPONSE TO ETHINYLESTRADIOL AS ADULTS

    EPA Science Inventory

    17a-Ethinylestradiol (EE), a synthetic estrogen found in birth control pills, has been detected in the effluent of municipal wastewater treatment plants in several countries. Because EE was designed to be extremely potent at the estrogen receptor (ER), environmental exposure to l...

  13. High quality nutrient intake is associated with higher household expenditures by Japanese adults.

    PubMed

    Fukuda, Yoshiharu; Hiyoshi, Ayako

    2012-08-01

    There is little evidence of socioeconomic differences in dietary intake in the Japanese population. This study examined the association between household expenditures and dietary intake using nationally representative surveys of Japan. We analyzed data from the Comprehensive Survey of Living Conditions and National Health and Nutrition Survey, 2003-2007. For subjects ages 18 to 74 years (11,240 men and 11,472 women), the sex-specific association between household expenditure quartiles and selected nutrient intake was examined using comparison of means and prevalence of a healthy intake. Higher household expenditures were associated with an increase in the mean levels of total energy, fat, protein, carbohydrates, calcium, vitamins A and C, niacin, and fiber for both men and women and salt for men. Prevalence comparison indicated that most of the recommendations for dietary intake were met for people with higher household expenditures than for those with lower household expenditures. There was no clear association between fat intake and expenditures. Higher household expenditures were associated with a healthy and balanced nutrient intake in Japanese adults. The findings suggest that socioeconomic differences in dietary patterns contribute to socioeconomic inequalities in mortality and morbidity in Japan.

  14. Serum chemistry reference values in adult Japanese quail (Coturnix coturnix japonica) including sex-related differences.

    PubMed

    Scholtz, N; Halle, I; Flachowsky, G; Sauerwein, H

    2009-06-01

    Serum chemistry reference values may provide useful information about the physical condition of individuals, making them a useful tool in differentiating normal and healthy animals from abnormal or diseased states. For Japanese quail that are used for producing eggs and meat for human consumption and also as laboratory animals, we aimed to extend the available array of reference values and to compare 16-wk-old adult male versus female birds. In the present study, clinical chemistry data (albumin, total protein, glucose, uric acid, cholesterol, bilirubin, cholinesterase, creatinine, triglycerides, alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase) in blood serum from up to 125 male and 151 female Japanese quail were established. Statistical comparisons were made between male and female birds. Aspartate aminotransferase, alanine aminotransferase, glucose, cholinesterase, and bilirubin values were higher (P < 0.01) in males, whereas females had higher (P < 0.05) concentrations of albumin, total protein, gamma-glutamyltransferase, total cholesterol, and triglycerides. No significant sex-based differences were observed for creatinine and uric acid. The reference values provided are relevant in particular for the use of quail as laboratory animals when responses to specific treatments have to be monitored and appraised.

  15. Medaka haploid embryonic stem cells.

    PubMed

    Hong, Yunhan

    2010-01-01

    The appearance of diploidy, the presence of two genomes or chromosome sets, is a fundamental hallmark of eukaryotic evolution and bisexual reproduction, because diploidy offers the basis for the bisexual life cycle, allowing for oscillation between diploid and haploid phases. Meiosis produces haploid gametes. At fertilization, male and female gametes fuse to restore diploidy in a zygote, which develops into a new life. At sex maturation, diploid cells enter into meiosis, culminating in the production of haploid gametes. Therefore, diploidy ensures pluripotency, cell proliferation, and functions, whereas haploidy is restricted only to the post-meiotic gamete phase of germline development and represents the end point of cell growth. Diploidy is advantageous for evolution. Haploidy is ideal for genetic analyses, because any recessive mutations of essential genes will show a clear phenotype in the absence of a second gene copy. Recently, my laboratory succeeded in the generation of medaka haploid embryonic stem (ES) cells capable of whole animal production. Therefore, haploidy in a vertebrate is able to support stable cell culture and pluripotency. This finding anticipates the possibility to generate haploid ES cells in other vertebrate species such as zebrafish. These medaka haploid ES cells elegantly combine haploidy and pluripotency, offering a unique yeast-like system for in vitro genetic analyses of molecular, cellular, and developmental events in various cell lineages. This chapter is aimed to describe the strategy of haploid ES cell derivation and their characteristics, and illustrate the perspectives of haploid ES cells for infertility treatment, genetic screens, and analyses.

  16. Syntax in a native language still continues to develop in adults: honorification judgment in Japanese.

    PubMed

    Momo, Kanako; Sakai, Hiromu; Sakai, Kuniyoshi L

    2008-10-01

    Native languages (L1s) are tacitly assumed to be complete and stable in adults. Here we report an unexpected individual variation in judgment of L1 regarding Japanese sentences including honorification, and further clarify its neural basis with functional magnetic resonance imaging (fMRI). By contrasting an honorification judgment task with a spelling judgment task, the lower performance group showed more extensive activation in the left inferior frontal gyrus than did the higher performance group. Moreover, activation in the left dorsal and ventral triangular parts negatively correlated with the performance of the honorification judgment task. This modulation pattern demonstrates that cortical activations recruited for sentence processing depend on individual performances even in L1.

  17. Association of Filial Responsibility, Ethnicity, and Acculturation Among Japanese American Family Caregivers of Older Adults

    PubMed Central

    Miyawaki, Christina E.

    2015-01-01

    Challenges of filial caregiving practices by 1st-generation immigrants due to differences in caregiving values between their home and host countries are well documented. This study explored the filial responsibility of later generation Japanese American caregivers of older adults. Acculturation and filial responsibility were measured using the Suinn-Lew Asian Self Identity Acculturation scale and Filial Values Index, respectively. A qualitative interview guide was developed using Gordon’s assimilation theory, and 21 caregivers (M age = 68 years, 86% female, seven in each generation) were interviewed. Despite the 3rd-generation caregivers’ high acculturation level, their filial responsibility scores remained high. Qualitative interviews also revealed later generation caregivers’ strong filial responsibility and continued caregiving involvement. Unexpectedly, caregivers’ own future expectancy of care included placement in mainstream residential facilities rather than ethnicspecific settings. Findings point to the need to develop caregiver services that consider later generation caregivers’ culture and level of assimilation. PMID:25883044

  18. The Association between Sarcopenic Obesity and Depressive Symptoms in Older Japanese Adults

    PubMed Central

    Chang, Chang; Tanaka, Tomoki; Kuroda, Aki; Tsuji, Tetsuo; Akishita, Masahiro; Iijima, Katsuya

    2016-01-01

    The effects of sarcopenic obesity, the co-existence of sarcopenia and obesity, on mood disorders have not been studies extensively. Our objective was to examine the association of depressive symptoms with sarcopenia and obesity status in older Japanese adults. We analyzed data from 1731 functionally-independent, community-dwelling Japanese adults aged 65 years or older (875 men, 856 women) randomly selected from the resident register of Kashiwa city, Chiba, Japan in 2012. Sarcopenia was defined based on appendicular skeletal muscle mass, grip strength and usual gait speed. Obesity was defined as the highest sex-specific quintile of the percentage body fat. Depressive symptoms were defined as a Geriatric Depression Scale 15-item score ≥ 6. Multiple logistic regression was employed to examine the association of depressive symptoms with four groups defined by the presence/absence of sarcopenia and obesity. The prevalence of depressive symptoms was 10.1% and the proportions of sarcopenia/obesity, sarcopenia/non-obesity, non-sarcopenia/obesity, non-sarcopenia/non-obesity were 3.7%, 13.6%, 16.9% and 65.8%, respectively. After adjustment for potential confounders, sarcopenia/obesity was positively associated with depressive symptoms compared with non-sarcopenia/non-obesity, whereas either sarcopenia or obesity alone was not associated with depressive symptoms. The association was particularly pronounced in those aged 65 to 74 years in age-stratified analysis. We conclude that our findings suggest a synergistic impact exerted by sarcopenic obesity on the risk of depressive symptoms, particularly in those aged 65 to 74 years. PMID:27627756

  19. Exposure to the synthetic FXR agonist GW4064 causes alterations in gene expression and sublethal hepatotoxicity in eleutheroembryo medaka (Oryzias latipes)

    SciTech Connect

    Howarth, Deanna L.; Law, Sheran H.W.; Law, J. McHugh; Mondon, J.A.; Kullman, Seth W.; Hinton, David E.

    2010-02-15

    The small freshwater teleost, medaka (Oryzias latipes), has a history of usage in studies of chronic toxicity of liver and biliary system. Recent progress with this model has focused on defining the medaka hepatobiliary system. Here we investigate critical liver function and toxicity by examining the in vivo role and function of the farnesoid X receptor alpha (FXRalpha, NR1H4), a member of the nuclear receptor superfamily that plays an essential role in the regulation of bile acid homeostasis. Quantitative mRNA analysis of medaka FXRalpha demonstrates differential expression of two FXRalpha isoforms designated Fxralpha1 and Fxralpha2, in both free swimming medaka embryos with remaining yolk (eleutheroembryos, EEs) and adults. Activation of medaka Fxralpha in vivo with GW4064 (a strong FXRalpha agonist) resulted in modification of gene expression for defined FXRalpha gene targets including the bile salt export protein, small heterodimer partner, and cytochrome P450 7A1. Histological examination of medaka liver subsequent to GW4064 exposure demonstrated significant lipid accumulation, cellular and organelle alterations in both hepatocytes and biliary epithelial cells of the liver. This report of hepatobiliary injury following GW4064 exposure extends previous investigations of the intrahepatic biliary system in medaka, reveals sensitivity to toxicant exposure, and illustrates the need for added resolution in detection and interpretation of toxic responses in this vertebrate.

  20. Principal function of mineralocorticoid signaling suggested by constitutive knockout of the mineralocorticoid receptor in medaka fish

    PubMed Central

    Sakamoto, Tatsuya; Yoshiki, Madoka; Takahashi, Hideya; Yoshida, Masayuki; Ogino, Yukiko; Ikeuchi, Toshitaka; Nakamachi, Tomoya; Konno, Norifumi; Matsuda, Kouhei; Sakamoto, Hirotaka

    2016-01-01

    As in osmoregulation, mineralocorticoid signaling is implicated in the control of brain-behavior actions. Nevertheless, the understanding of this role is limited, partly due to the mortality of mineralocorticoid receptor (MR)-knockout (KO) mice due to impaired Na+ reabsorption. In teleost fish, a distinct mineralocorticoid system has only been identified recently. Here, we generated a constitutive MR-KO medaka as the first adult-viable MR-KO animal, since MR expression is modest in osmoregulatory organs but high in the brain of adult medaka as for most teleosts. Hyper- and hypo-osmoregulation were normal in MR-KO medaka. When we studied the behavioral phenotypes based on the central MR localization, however, MR-KO medaka failed to track moving dots despite having an increase in acceleration of swimming. These findings reinforce previous results showing a minor role for mineralocorticoid signaling in fish osmoregulation, and provide the first convincing evidence that MR is required for normal locomotor activity in response to visual motion stimuli, but not for the recognition of these stimuli per se. We suggest that MR potentially integrates brain-behavioral and visual responses, which might be a conserved function of mineralocorticoid signaling through vertebrates. Importantly, this fish model allows for the possible identification of novel aspects of mineralocorticoid signaling. PMID:27897263

  1. Chronic fluoxetine treatment induces anxiolytic responses and altered social behaviors in medaka, Oryzias latipes.

    PubMed

    Ansai, Satoshi; Hosokawa, Hiroshi; Maegawa, Shingo; Kinoshita, Masato

    2016-04-15

    Medaka (Oryzias latipes) is a small freshwater teleost that is an emerging model system for neurobehavioral research and toxicological testing. The selective serotonin reuptake inhibitor class of antidepressants such as fluoxetine is one of the widely prescribed drugs, but little is known about the effects of these drugs on medaka behaviors. To assess the behavioral effects of fluoxetine, we chronically administrated fluoxetine to medaka adult fish and analyzed the anxiety-related and social behaviors using five behavioral paradigms (diving, open-field, light-dark transition, mirror-biting, and social interaction) with an automated behavioral testing system. Fish chronically treated with fluoxetine exhibited anxiolytic responses such as an overall increased time spent in the top area in the diving test and an increased time spent in center area in the open-field test. Analysis of socially evoked behavior showed that chronic fluoxetine administration decreased the number of mirror biting times in the mirror-biting test and increased latency to first contact in the social interaction test. Additionally, chronic fluoxetine administration reduced the horizontal locomotor activity in the open-field test but not the vertical activity in the diving test. These investigations are mostly consistent with previous reports in the other teleost species and rodent models. These results indicate that behavioral assessment in medaka adult fish will become useful for screening of effects of pharmaceutical and toxicological compounds in animal behaviors.

  2. Host suitability and diet mixing influence activities of detoxification enzymes in adult Japanese beetles.

    PubMed

    Adesanya, Adekunle; Liu, Nannan; Held, David W

    2016-05-01

    Induction of cytochrome P450, glutathione S transferase (GST), and carboxylesterase (CoE) activity was measured in guts of the scarab Popillia japonica Newman, after consumption of single or mixed plant diets of previously ranked preferred (rose, Virginia creeper, crape myrtle and sassafras) or non-preferred hosts (boxelder, riverbirch and red oak). The goal of this study was to quantify activities of P450, GST and CoE enzymes in the midgut of adult P. japonica using multiple substrates in response to host plant suitability (preferred host vs non-preferred hosts), and single and mixed diets. Non-preferred hosts were only sparingly fed upon, and as a group induced higher activities of P450, GST and CoE than did preferred hosts. However, enzyme activities for some individual plant species were similar across categories of host suitability. Similarly, beetles tended to have greater enzyme activities after feeding on a mixture of plants compared to a single plant type, but mixing per se does not seem as important as the species represented in the mix. Induction of detoxification enzymes on non-preferred hosts, or when switching between hosts, may explain, in part, the perceived feeding preferences of this polyphagous insect. The potential consequences of induced enzyme activities on the ecology of adult Japanese beetles are discussed.

  3. Strength-training behavior and perceived environment among Japanese older adults.

    PubMed

    Harada, Kazuhiro; Oka, Koichiro; Shibata, Ai; Ishii, Kaori; Nakamura, Yoshio; Inoue, Shigeru; Shimomitsu, Teruichi

    2011-07-01

    The authors examined the relationship between strength-training behavior and perceived environment in older Japanese adults. An Internet-based survey was conducted of 293 adults age 68.2 ± 2.8 yr. The dependent variable was regular strength-training behavior. The IPAQ environment module, access to facilities for strength training, and home equipment for strength training were environmental factors. Logistic-regression analysis was employed. After demographic variables (gender, age, educational background, household income, body-mass index, self-rated health status, smoking habit, and residential area) were adjusted for, home equipment for strength training (OR = 2.14, 95% CI = 1.50-3.06), access to facilities for strength training (OR = 2.53, 95% CI = 1.32-4.85), and observing active people (OR = 2.20, 95% CI = 1.06-4.58) were positively correlated with regular strength-training behavior. In conclusion, environmental factors associated with strength-training behavior were access to facilities for strength training, having home equipment for strength training, and observing active people.

  4. Qualitative Analysis of the Resilience of Adult Japanese Patients with Type 1 Diabetes

    PubMed Central

    Nishio, Ikuko; Chujo, Masami

    2016-01-01

    Background Resilience strategies are what we use to avoid and recover from error. In this study, we used the grounded theory approach to evaluate the resilience of Japanese patients with Type 1 diabetes. Methods Semi-structured interviews were conducted with 15 adults with Type 1 diabetes. Then, using grounded theory, we created a new model of resilience in this population. Results The results suggested a core category, “to make progress along the resilience path,” comprising seven concepts classified into three stages. These seven concepts were as follows: “suffering from treatment,” “damaged trust as a person,” “persistence of afflictions,” “awareness of supporters,” “joy to be kept alive by insulin,” “actively seeking a future,” “being able to manage by oneself.” Individuals with Type 1 diabetes used difficult experiences to motivate their resilience and to improve their situation. Additionally, resilience was an important contributor to these individuals’ beliefs in their ability to face difficulties, to accept their illness and insulin therapy, and to control their illness. Resilience was also important to these individuals’ faith in the future and in medical care. Our results are applicable to clinical care and research, such as the development of preventive interventions aimed at building or strengthening protective skills related to diabetes and its management. Conclusion Ultimately, our goal is to equip adults with Type 1 diabetes with the tools to obtain sufficient behavioral and health-related resilience. Furthermore, these results highlight that maintaining resilience-related coping skills is important for adults and indicate that different psychological processes underlie resilience across the lifespan. PMID:27708534

  5. Dosage response mortality of Japanese beetle, masked chafer, and June beetle (Coleoptera: Scarabaeidae) adults when exposed to experimental and commercially available granules containing Metarhizium brunneum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adult beetles of three different white grub species, Japanese beetle, Popillia japonica, June beetle, Phyllophaga spp., and masked chafer, Cyclocephala spp. were exposed to experimental and commercially available granules containing Metarhizium brunneum (Petch) strain F52, to determine susceptibilit...

  6. Effects of Biopesticides on Foliar Diseases and Japanese Beetle (Popillia japonica) Adults in Roses (Rosa spp.), Oakleaf Hydrangea (Hydrangea quercifolia), and Crapemyrtle (Lagerstroemia indica)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated efficacy of biopesticides for reducing foliar diseases and feeding damage from Japanese beetle adults on hybrid T rose (Rosa spp.), oakleaf hydrangea (Hydrangea quercifolia), and crapemyrtle (Lagerstroemia indica). The materials tested included household soaps with Triclosan act...

  7. In vivo Magnetic Resonance Microscopy and Hypothermic Anaesthesia of a Disease Model in Medaka

    PubMed Central

    Ueno, Tomohiro; Suzuki, Hirokazu; Hiraishi, Masahiro; Amano, Hideaki; Fukuyama, Hidenao; Sugimoto, Naozo

    2016-01-01

    In medical and pharmacological research, various human disease models in small fish, such as medaka (Oryzias latipes), have been created. To investigate these disease models noninvasively, magnetic resonance imaging (MRI) is suitable because these small fish are no longer transparent as adults. However, their small body size requires a high spatial resolution, and a water pool should be avoided to maximize the strength of MRI. We developed in vivo magnetic resonance microscopy (MR microscopy) without a water pool by combining hypothermic anaesthesia and a 14.1 T MR microscope. Using in vivo MR microscopy, we noninvasively evaluated the hepatic steatosis level of a non-alcoholic fatty liver disease model in medaka and followed the individual disease progression. The steatosis level was quantified by the MRI-estimated proton density fat-fraction (MRI-PDFF), which estimates the triglyceride fat concentration in liver tissue and is recognized as an imaging biomarker. The MRI-PDFF results agreed with a histological analysis. Moreover, we optimized the hypothermic anaesthesia procedure to obtain a recovery proportion of 1 in the experiment involving MR microscopy. Recovered medaka could not be distinguished from naïve medaka after the experiment. Therefore, the in vivo MR microscopy will expand the possibilities of a human disease model in fish. PMID:27251889

  8. Differential maturation of rhythmic clock gene expression during early development in medaka (Oryzias latipes).

    PubMed

    Cuesta, Ines H; Lahiri, Kajori; Lopez-Olmeda, Jose Fernando; Loosli, Felix; Foulkes, Nicholas S; Vallone, Daniela

    2014-05-01

    One key challenge for the field of chronobiology is to identify how circadian clock function emerges during early embryonic development. Teleosts such as the zebrafish are ideal models for studying circadian clock ontogeny since the entire process of development occurs ex utero in an optically transparent chorion. Medaka (Oryzias latipes) represents another powerful fish model for exploring early clock function with, like the zebrafish, many tools available for detailed genetic analysis. However, to date there have been no reports documenting circadian clock gene expression during medaka development. Here we have characterized the expression of key clock genes in various developmental stages and in adult tissues of medaka. As previously reported for other fish, light dark cycles are required for the emergence of clock gene expression rhythms in this species. While rhythmic expression of per and cry genes is detected very early during development and seems to be light driven, rhythmic clock and bmal expression appears much later around hatching time. Furthermore, the maturation of clock function seems to correlate with the appearance of rhythmic expression of these positive elements of the clock feedback loop. By accelerating development through elevated temperatures or by artificially removing the chorion, we show an earlier onset of rhythmicity in clock and bmal expression. Thus, differential maturation of key elements of the medaka clock mechanism depends on the developmental stage and the presence of the chorion.

  9. Technology with High-Speed Movies to Analyze the Movement of Internal Organs in Medaka

    NASA Astrophysics Data System (ADS)

    Watanabe-Asaka, Tomomi; Niihori, Maki; Terada, Masahiro; Oda, Shoji; Iwasaki, Ken-Ichi; Sudoh, Masamichi; Yamada, Shin; Ohshima, Hiroshi; Mukai, Chiaki

    Living organisms are always exposed and respond to various stresses from the external world - the environment, such as temperature, gravity, radiation or circadian. Understanding and addressing the effects of the environment on human health is a major issue. To clarify this issue, we are studying both human and medaka. Medaka is a good model organism to verify the effects of the space environment for their features including their short life cycle, productivity, mapped whole genome sequences, and transparency even in adults. We are trying to evaluate the heartbeat using transparent medaka with live imaging. Despite the importance of functions of internal organs, its observation has been difficult. Imaging technologies has developed remarkably in a decade. With the retirement of the space shuttle, experimental procedures without sample collection will be required. We established an approach to acquire the images and the methodology of the analysis from high-speed movies. We are subsequently going to introduce a method of verifying the movement of internal organs in medaka experiments using high-speed movies.

  10. Prevalence and Correlates of Insufficient Sleep Syndrome in Japanese Young Adults: A Web-Based Cross-Sectional Study

    PubMed Central

    Morita, Yuko; Sasai-Sakuma, Taeko; Asaoka, Shoichi; Inoue, Yuichi

    2015-01-01

    Study Objectives: This study investigated the prevalence and risk factors of insufficient sleep syndrome (ISS), and factors associated with daytime dysfunction in the disorder in Japanese young adults. Methods: In this cross-sectional study, a web-based questionnaire survey was used to assess demographic variables, sleep habits and quality, depressive symptoms, and health-related quality of life (HRQOL) in 2,276 participants aged 20–25. Results: Eleven percent of participants were classified as having ISS. Multiple logistic regression analysis revealed that the presence of ISS was significantly associated with social status (student or full-time employee). The participants with ISS had significantly higher depression scores and lower mental component summary scores than healthy sleepers. In the participants with ISS, a delayed sleep-wake schedule was extracted as a factor associated with worse mental component summary. Conclusions: Results indicate a relatively high proportion of Japanese young adults suffer from ISS, and that the condition is associated with a social status of student or full-time employee. Moreover, a delayed sleep-wake schedule may lead to further deterioration of mental HRQOL in ISS-affected persons. Citation: Morita Y, Sasai-Sakuma T, Asaoka S, Inoue Y. Prevalence and correlates of insufficient sleep syndrome in Japanese young adults: a web-based cross-sectional study. J Clin Sleep Med 2015;11(10):1163–1169. PMID:26094926

  11. Effect of Bombyx mori chitinase against Japanese pine sawyer (Monochamus alternatus) adults as a biopesticide.

    PubMed

    Kabir, Khondkar Ehteshamul; Sugimoto, Hiroyuki; Tado, Hiroyuki; Endo, Katsuhiko; Yamanaka, Akira; Tanaka, Shuhei; Koga, Daizo

    2006-01-01

    Bombyx mori chitinase (Bm-CHI), with a molecular mass of 75 kDa, was investigated on the possibility that it can serve as a biocontrol agent against the adult Japanese pine sawyer (JPS), Monochamus alternatus (Coleoptera: Cerambycidae). Oral ingestion of purified chitinase at concentrations of 3 microM (11.25 microg/50 microl) and 0.3 micoM (1.125 microg/50 microl) caused high mortality in JPS, a significant decrease in bark consumption, and, only in high concentration, a slight reduction of body weight. Fluorescence assays indicated that peritrophic membrane (PM) chitin is degraded by the action of orally ingested Bm-CHI at 3 microM concentration only. Scanning electron micrographs clearly indicated that the beetles that ingested Bm-CHI of the same high concentration had their PM perforated and disrupted, but ultrastructural studies showed that the ingested chitinase did not affect the midgut epithelium. These findings open up the possibility of using insect chitinase as a biopesticidal enzyme. It should have agronomic potential for insect control.

  12. Prevalence and risk factors for peri-implant diseases in Japanese adult dental patients.

    PubMed

    Ogata, Yorimasa; Nakayama, Yohei; Tatsumi, Junichi; Kubota, Takehiko; Sato, Shuichi; Nishida, Tetsuya; Takeuchi, Yasuo; Onitsuka, Tokuya; Sakagami, Ryuji; Nozaki, Takenori; Murakami, Shinya; Matsubara, Naritoshi; Tanaka, Maki; Yoshino, Toshiaki; Ota, Junya; Nakagawa, Taneaki; Ishihara, Yuichi; Ito, Taichi; Saito, Atsushi; Yamaki, Keiko; Matsuzaki, Etsuko; Hidaka, Toshirou; Sasaki, Daisuke; Yaegashi, Takashi; Yasuda, Tadashi; Shibutani, Toshiaki; Noguchi, Kazuyuki; Araki, Hisao; Ikumi, Noriharu; Aoyama, Yukihiko; Kogai, Hideki; Nemoto, Kenji; Deguchi, Shinji; Takiguchi, Takashi; Yamamoto, Matsuo; Inokuchi, Keita; Ito, Takatoshi; Kado, Takashi; Furuichi, Yasushi; Kanazashi, Mikimoto; Gomi, Kazuhiro; Takagi, Yukie; Kubokawa, Keita; Yoshinari, Nobuo; Hasegawa, Yoshiaki; Hirose, Tetsushi; Sase, Toshinaga; Arita, Hirokazu; Kodama, Toshiro; Shin, Kitetsu; Izumi, Yuichi; Yoshie, Hiromasa

    2017-03-31

    We investigated the prevalences and risk factors for peri-implant diseases in Japanese adult dental patients attending a follow-up visit at dental hospitals or clinics as part of their maintenance program. This cross-sectional multicenter study enrolled patients with dental implants who attended regular check-ups as part of a periodontal maintenance program during the period from October 2012 through September 2013. Patients with implants with at least 3 years of loading time were included in the study. The condition of peri-implant tissue was examined and classified into the following categories: healthy, peri-implant mucositis, and peri-implantitis. Patients were also evaluated for implant risk factors. A total of 267 patients (110 men, 157 women; mean age: 62.5 ± 10.7 years) were analyzed. The prevalence of patient-based peri-implant mucositis was 33.3% (n = 89), and the prevalence of peri-implantitis was 9.7% (n = 26). Poor oral hygiene and a history of periodontitis were strong risk factors for peri-implant disease. The present prevalences were lower than those previously reported. The quality of periodontal therapy before and after implant installation and patient compliance and motivation, as indicated by plaque control level, appear to be important in maintaining peri-implant tissue health.

  13. Phonetic training with acoustic cue manipulations: A comparison of methods for teaching English /r/-/l/ to Japanese adults

    NASA Astrophysics Data System (ADS)

    Iverson, Paul; Hazan, Valerie; Bannister, Kerry

    2005-11-01

    Recent work [Iverson et al. (2003) Cognition, 87, B47-57] has suggested that Japanese adults have difficulty learning English /r/ and /l/ because they are overly sensitive to acoustic cues that are not reliable for /r/-/l/ categorization (e.g., F2 frequency). This study investigated whether cue weightings are altered by auditory training, and compared the effectiveness of different training techniques. Separate groups of subjects received High Variability Phonetic Training (natural words from multiple talkers), and 3 techniques in which the natural recordings were altered via signal processing (All Enhancement, with F3 contrast maximized and closure duration lengthened; Perceptual Fading, with F3 enhancement reduced during training; and Secondary Cue Variability, with variation in F2 and durations increased during training). The results demonstrated that all of the training techniques improved /r/-/l/ identification by Japanese listeners, but there were no differences between the techniques. Training also altered the use of secondary acoustic cues; listeners became biased to identify stimuli as English /l/ when the cues made them similar to the Japanese /r/ category, and reduced their use of secondary acoustic cues for stimuli that were dissimilar to Japanese /r/. The results suggest that both category assimilation and perceptual interference affect English /r/ and /l/ acquisition.

  14. Changes in the dielectric properties of medaka fish embryos during development, studied by electrorotation

    SciTech Connect

    Shirakashi, Ryo; Mischke, Miriam; Fischer, Peter; Memmel, Simon; Krohne, Georg; Fuhr, Guenter R.; Zimmermann, Heiko; Sukhorukov, Vladimir L.

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Electrorotation offers a non-invasive tool for dielectric analysis of fish embryos. Black-Right-Pointing-Pointer The three-shell dielectric model matches the rotation spectra of medaka eggs. Black-Right-Pointing-Pointer The capacitance value suggests a double-membrane structure of yolk envelope. -- Abstract: The Japanese medaka fish, Oryzias latipes, has become a powerful vertebrate model organism in developmental biology and genetics. The present study explores the dielectric properties of medaka embryos during pre-hatching development by means of the electrorotation (ROT) technique. Due to their layered structure, medaka eggs exhibited up to three ROT peaks in the kHz-MHz frequency range. During development from blastula to early somite stage, ROT spectra varied only slightly. But as the embryo progressed to the late-somite stage, the ROT peaks underwent significant changes in frequency and amplitude. Using morphological data obtained by light and electron microscopy, we analyzed the ROT spectra with a three-shell dielectric model that accounted for the major embryonic compartments. The analysis yielded a very high value for the ionic conductivity of the egg shell (chorion), which was confirmed by independent osmotic experiments. A relatively low capacitance of the yolk envelope was consistent with its double-membrane structure revealed by transmission electron microscopy. Yolk-free dead eggs exhibited only one co-field ROT peak, shifted markedly to lower frequencies with respect to the corresponding peak of live embryos. The dielectric data may be useful for monitoring the development and changes in fish embryos' viability/conditions in basic research and industrial aquaculture.

  15. Breath hydrogen test for detecting lactose malabsorption in infants and children. Prevalence of lactose malabsorption in Japanese children and adults.

    PubMed

    Nose, O; Iida, Y; Kai, H; Harada, T; Ogawa, M; Yabuuchi, H

    1979-06-01

    The breath hydrogen test (BHT) was adapted for use in young infants and children. The diagnostic criterion of sugar malabsorption in the BHT was determined by oral administration of 0.5 g/kg of unabsorbable sugar (lactulose) to 21 healthy infants and children. A maximum increase in breath hydrogen less than 0.05 ml/min per m2 was observed in all subjects. A good correlation between results by the BHT and by the ordinary lactose tolerance test was obtained after oral administration of 2 g/kg lactose to 21 healthy infants and children, 2 congenital lactase-deficient infants, and 7 adults. Using this test, 80 healthy Japanese infants and children (aged between one month and 15 years) and 18 adults were examined for lactose malabsorption after a dose of 1 g/kg lactose. All infants and children under 2-years old absorbed lactose completely. The incidence of lactose malabsorption was 30% in 3-year, 36% in 4-year, 58% in 5-year, and 86% in 6-year-old children, 85% in schoolchildren, and 89% in adults. Thus the incidence of lactase deficiency gradually increases with age from 3 years, and about 90% of all normal Japanese adults are lactase-deficient.

  16. Comparison of cephalometric norms between Japanese and Caucasian adults in antero-posterior and vertical dimension.

    PubMed

    Ioi, Hideki; Nakata, Shunsuke; Nakasima, Akihiko; Counts, Amy L

    2007-10-01

    The aims of this study were to determine Japanese cephalometric norms in the antero-posterior and vertical dimension, and to test the hypothesis that there are racial differences in cephalometric measurements between Japanese and Caucasian norms. Radiographs were obtained from 25 healthy Japanese males (aged 25.1 +/- 2.7 years) and 24 healthy Japanese females (aged 23.6 +/- 1.3 years). Inclusion criteria were an ANB angle between 2 and 5 degrees, a normal occlusion with minor or no crowding, all teeth present except third molars, no previous orthodontic treatment, and no prosthetic replacement of teeth. Two angular and five linear measurements were constructed for the skeletal hard tissue analysis, one angular and six linear measurements for the dental hard tissue analysis, and two angular and seven linear measurements for the soft tissue analysis. The mean and standard deviations for the hard and soft tissue measurements were determined for each gender. Unpaired t-tests were used to determine the mean differences for each cephalometric measurement between the Japanese and the Caucasians. In the antero-posterior dimension, the Japanese subjects had a significantly more retruded chin position (P < 0.001), typically protruding mandibular incisors, and protruded lip positions compared with the Caucasian norms. In the vertical dimension, the Japanese had a significantly steeper mandibular plane (P < 0.01). The Japanese females had a significantly larger lower face height and increased dental height (P < 0.001). The results of this study suggest that these cephalometric measurements might be helpful to formulate treatment plans for Japanese patients.

  17. A Qualitative Study of Confusing Experiences among Japanese Adult Patients with Type 1 Diabetes

    PubMed Central

    Nishio, Ikuko; Chujo, Masami; Kataoka, Hideyuki

    2016-01-01

    Background In this study, we investigated the powerlessness of patients with type 1 diabetes (T1D), and described the structure of powerlessness that these individuals experienced. In order for patients to recover from this state, we recommend that they take steps to regain their power. Methods Fifteen Japanese adults with T1D participated in this study. Data were collected from all subjects between July 2013 and March 2014 via in-depth semi-structured interviews. Qualitative data analysis was conducted according to a grounded theory approach. Finally, the core category was identified, which allowed us to build a new powerlessness structure for T1D. Results The results suggested a core category, ‘Wandering a tangled path,’ comprising four categories, eight subcategories, and twenty-six concepts. These four categories were as follows: ‘being burdened by T1D,’ ‘suffering from insulin-related troubles,’ ‘being unable to cope with difficulties in self-management,’ and ‘facing social prejudice.’ In the state of powerlessness, negative emotional experiences snowballed, with patients feeling more and more depressed until they ultimately reached ‘rock bottom.’ Conclusion We found that as negative emotional experiences related to powerlessness increased, negative feelings intensified until the patients reached rock bottom. Powerlessness is like ‘wandering a tangled path,’ a state in which T1D patients struggle to cope with reality on their own when faced with both internal and external events. ‘Wandering a tangled path’ is at the core of powerlessness. A primary characteristic of the structure of powerlessness is suffering from confusing experiences. To help patients cope with T1D without being crushed by powerlessness, nurses must pay attention to signs of powerlessness. Powerlessness is not just an emotional state, but a combination of feelings, perceptions, and thoughts; therefore, it is important to comprehensively understand patients

  18. Professional and consumer insecticides for management of adult Japanese beetle on hybrid tea rose.

    PubMed

    Gupta, Garima; Krischik, Vera A

    2007-06-01

    In many states, Japanese beetle, Popilliajaponica Newman (Coleoptera: Scarabeidae), is no longer quarantined, and management is left to professional applicators and consumers. Adult management in hybrid tea rose, Rosa L., was compared among biorational insecticides, novel imidacloprid applications (tablet, gel, and root dip), and conventional insecticides. Efficacy of biorational insecticides used by consumers varied widely and may not offer predictable management: mortality was 3.0% with Garlic Barrier, 5.0% with Monterey Neem Oil, 15.1% with Pygenic (1.4% pyrethrins), and 27.3% with Orange Guard (D-limonene). Only JB Killer (0.02% pyrethrins plus 0.2% piperonyl butoxide) had mortality of 90.9%, probably due to piperonyl butoxide. Professional biorationals did not show significant mortality: 7.7% with Azatin XL (azadirachtin) and 3.7% Conserve (spinosad). In contrast, conventional insecticides demonstrated significant mortality; 88.4% with Decathlon 20 WP (cyfluthrin) and 83.3% with Discus SC (imidacloprid plus cyfluthrin). New imidacloprid applications (tablet, gel, and root dip) worked as well as standard drench and granular methods, but they showed 9.1-42.7% mortality. However, beetles were incapacitated as demonstrated by inability to walk (82-106-s flip time) compared with controls (30-s flip time). No phytotoxicity was observed in any treatments. However, some imidacloprid treatments produced growth enhancement: higher leaf chlorophyll (1X, 3X granular, and one tablet), and larger leaf area and higher nitrogen (3X granular, drench). The highest (active ingredient) imidacloprid was in 3X granular treatment, which in an unplanned infestation, showed highest numbers of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). Effects of imidacloprid on leaf quality and mite outbreaks deserves research.

  19. Less indoor cleaning is associated with poor health and unhappiness in adults: Japanese General Social Survey, 2010.

    PubMed

    Shiue, Ivy

    2015-12-01

    Indoor environment is important to human health and well-being. The aim of the present study was to investigate the relationships among indoor cleaning, rubbish disposal and human health and well-being in a national and population-based setting. Data was retrieved from the Japanese General Social Survey, 2010. Information on demographics, lifestyle factors, frequency of indoor cleaning and rubbish disposal and self-reported health and well-being in Japanese adults was obtained by household interview. Analysis included chi-square test, logistic and multi-nominal regression modelling. Of 5003 Japanese adults (aged 20-89) included in the study cohort, 11.4 % (n = 566) never cleaned their living place, 39.1 % had occasional cleaning and 49.6 % had frequent cleaning. Moreover, 17.5 % (n = 869) never disposed rubbish, 24.9 % had occasional rubbish disposal and 57.6 % had frequent rubbish disposal. 15.0 % of Japanese adults claimed poor self-rated health, and 5.9 % reported unhappiness. Compared to people who frequently cleaned the living place, others tended to report poor self-rated health condition (relative risk ratios (RRR) 1.52, 95 % confidence intervals (CI) 1.24-1.85, P < 0.001) and unhappiness (RRR 1.47, 95 % CI 1.10-1.95, P < 0.001). The combined effects of never cleaning and never rubbish disposal significantly impacted on poor self-rated health (RRR 2.61, 95 % CI 1.40-4.88, P = 0.003) and unhappiness (RRR 2.72, 95 % CI 1.72-4.30, P < 0.001). Only half of the Japanese population frequently cleaned their living place and disposed rubbish. Less or never cleaning and rubbish disposal were associated with poor self-rated health, subjective happiness and potentially other health conditions. Public education on maintaining clean indoor environments to optimise psychological well-being in addition to the known physical health would be suggested.

  20. Origin of adult-type pigment cells forming the asymmetric pigment pattern, in Japanese flounder (Paralichthys olivaceus).

    PubMed

    Yamada, Toshiyuki; Okauchi, Masanori; Araki, Kazuo

    2010-12-01

    The flatfish-specific asymmetric pigment pattern depends on the asymmetric appearance of adult-type pigment cells after the late metamorphic stages. To understand the mechanism enabling the formation of this asymmetric pattern, we investigated the behavior of pigment cell latent precursors in postembryonic Japanese flounder, Paralichthys olivaceus, by analysis of the expression patterns of pigment lineage markers (colony stimulating factor 1 receptor, dopachrome tautomerase, kit) and the DiI (DiO) labeling test for latent precursors. We found that, throughout the larval stages, pigment cell latent precursors were predominantly localized along the dorsal and ventral margins of the flank symmetrically and migrated continuously from these regions to the lateral sides symmetrically, and after late metamorphic stages these precursors differentiated into adult-type pigment cells on the lateral side asymmetrically. We conclude that adult-type pigment cells that form the asymmetric pigment pattern are continuously derived from the dorsal and ventral margins of the flank during larval development.

  1. Far from Oblivion: the Nanking Massacre in Japanese historical writing for children and young adults.

    PubMed

    Penney, Matthew

    2008-01-01

    The Nanking Massacre of 1937 frequently has been described as a forgotten genocidal act or "Holocaust." Concentrating on atrocity as reflected in Japanese popular historical writing for children and adolescents since the 1960s, this essay argues that such war crimes are far from ignored. Representations of the Nanking Massacre in particular, and of Japanese World War II atrocities in general, have been widely mobilized in Japan to inculcate an anti-war philosophy.

  2. Relationship between Self-Reported Dietary Nutrient Intake and Self-Reported Sleep Duration among Japanese Adults

    PubMed Central

    Komada, Yoko; Narisawa, Hajime; Ueda, Fumitaka; Saito, Hitomi; Sakaguchi, Hiroyuki; Mitarai, Makoto; Suzuki, Rina; Tamura, Norihisa; Inoue, Shigeru; Inoue, Yuichi

    2017-01-01

    Several studies have reported that short sleep duration is a risk factor for obesity and metabolic disease. Moreover, both sleep duration and sleep timing might independently be associated with dietary nutrient intake. In this study, we investigated the associations between self-reported sleep duration and dietary nutrient intake, with and without adjustments for variations in sleep timing (i.e., the midpoint of sleep). We conducted a questionnaire survey, comprising a validated brief self-administered diet history questionnaire (BDHQ) and the Japanese version of the Pittsburgh Sleep Quality Index (PSQI) among 1902 healthy Japanese adults and found that the dietary intakes of several nutrients correlated with sleep duration among men regardless of adjustment for the midpoint of sleep. Particularly, (1) small but significant correlations were observed between sleep duration and the percentage of energy from protein, regardless of adjustment for the midpoint of sleep; (2) energy-adjusted intakes of sodium, vitamin D, and vitamin B12 also significantly correlated with sleep duration; and (3) intakes of bread, pulses, and fish and shellfish correlated with sleep duration. In contrast, no significant correlations were observed between sleep duration and dietary intakes among women. This study revealed that after controlling for the midpoint of sleep, sleep duration correlated significantly with the dietary intake of specific nutrients and foods in a population of Japanese men. PMID:28208812

  3. Estimation of sodium and potassium intakes assessed by two 24 h urine collections in healthy Japanese adults: a nationwide study.

    PubMed

    Asakura, Keiko; Uechi, Ken; Sasaki, Yuki; Masayasu, Shizuko; Sasaki, Satoshi

    2014-10-14

    Excess Na intake and insufficient K intake are well-known risk factors for CVD. International comparative studies have reported that Japan has the highest intake of Na and the lowest intake of K in the world. However, no recent study has precisely assessed Na and K intakes in Japanese adults. In the present study, Na and K intakes were estimated from two 24 h urine collections implemented in twenty-three out of forty-seven prefectures in Japan. Apparently healthy men (n 384) and women (n 376), aged 20 to 69 years, who had been working in welfare facilities were recruited, with data collection conducted in February and March 2013. The mean Na excretion was 206·0 mmol/d in men and 173·9 mmol/d in women. The respective values of K excretion were 51·6 and 47·2 mmol/d. The excretion of both Na and K varied considerably among the prefectures, and was higher in subjects with a higher BMI. In contrast, only K excretion was associated with age. After estimating the usual intakes of Na and K, it was found that none of the male subjects met the recommended Na intake values of the WHO, and that only 3·2 % met those of the Japanese government. The respective values for females were 0·1 and 5·0 %. For K intake, 7·5 % of the total subjects met the recommended values of the WHO and 21·7 % met those of the Japanese government. These findings suggest that there is an urgent need for the development of an effective intervention programme to reduce Na intake and promote K intake in the Japanese population.

  4. Development and validation of a new instrument for testing functional health literacy in Japanese adults.

    PubMed

    Nakagami, Katsuyuki; Yamauchi, Toyoaki; Noguchi, Hiroyuki; Maeda, Tohru; Nakagami, Tomoko

    2014-06-01

    This study aimed to develop a reliable and valid measure of functional health literacy in a Japanese clinical setting. Test development consisted of three phases: generation of an item pool, consultation with experts to assess content validity, and comparison with external criteria (the Japanese Health Knowledge Test) to assess criterion validity. A trial version of the test was administered to 535 Japanese outpatients. Internal consistency reliability, calculated by Cronbach's alpha, was 0.81, and concurrent validity was moderate. Receiver Operating Characteristics and Item Response Theory were used to classify patients as having adequate, marginal, or inadequate functional health literacy. Both inadequate and marginal functional health literacy were associated with older age, lower income, lower educational attainment, and poor health knowledge. The time required to complete the test was 10-15 min. This test should enable health workers to better identify patients with inadequate health literacy.

  5. EFFECTS OF CADMIUM ON THE REPRODUCTIVE AXIS OF JAPANESE MEDAKA

    EPA Science Inventory

    Cadmium (Cd) is a ubquitous element and a significant inorganic pollutant that has previously been found to bioaccumulate in reproductive organs of fish and disrupt important endocrine processes, especially those involved in synthesis, release and metabolism of hormones. Clearly,...

  6. Frequency of soup intake and amount of dietary fiber intake are inversely associated with plasma leptin concentrations in Japanese adults.

    PubMed

    Kuroda, Motonaka; Ohta, Masanori; Okufuji, Tatsuya; Takigami, Chieko; Eguchi, Masafumi; Hayabuchi, Hitomi; Ikeda, Masaharu

    2010-06-01

    Previous studies have shown that the intake of soup negatively correlates with the body mass index (BMI), suggesting that soup intake reduces the risk of obesity. In this study, to clarify the association of the intake of soup and various nutrients with plasma leptin concentration, a cross-sectional study on 504 Japanese adults aged 20-76 years (103 men and 401 women) was performed. The intake of soup and various nutrients was investigated by food frequency questionnaires. Plasma leptin concentration was measured in fasting blood by radioimmunoassay. The correlation was analyzed by multiple regression analysis. The average frequency of soup intake was 7.6 times/week. The average plasma leptin concentration was 7.76 ng/ml. After adjusting the confounding factors, the frequency of soup intake has a significant inverse association with plasma leptin concentration. Among the macronutrients, only dietary fiber intake negatively correlated with plasma leptin concentration after the adjustment for potential confounding factors. These results suggest that the intakes of soup and dietary fiber were negatively correlated with plasma leptin concentration in Japanese adults.

  7. The labial-coronal effect revisited: Japanese adults say pata, but hear tapa.

    PubMed

    Tsuji, Sho; Gomez, Nayeli Gonzalez; Medina, Victoria; Nazzi, Thierry; Mazuka, Reiko

    2012-12-01

    The labial-coronal effect has originally been described as a bias to initiate a word with a labial consonant-vowel-coronal consonant (LC) sequence. This bias has been explained with constraints on the human speech production system, and its perceptual correlates have motivated the suggestion of a perception-production link. However, previous studies exclusively considered languages in which LC sequences are globally more frequent than their counterpart. The current study examined the LC bias in speakers of Japanese, a language that has been claimed to possess more CL than LC sequences. We first conducted an analysis of Japanese corpora that qualified this claim, and identified a subgroup of consonants (plosives) exhibiting a CL bias. Second, focusing on this subgroup of consonants, we found diverging results for production and perception such that Japanese speakers exhibited an articulatory LC bias, but a perceptual CL bias. The CL perceptual bias, however, was modulated by language of presentation, and was only present for stimuli recorded by a Japanese, but not a French, speaker. A further experiment with native speakers of French showed the opposite effect, with an LC bias for French stimuli only. Overall, we find support for a universal, articulatory motivated LC bias in production, supporting a motor explanation of the LC effect, while perceptual biases are influenced by distributional frequencies of the native language.

  8. Validity of predictive equations for basal metabolic rate in Japanese adults.

    PubMed

    Miyake, Rieko; Tanaka, Shigeho; Ohkawara, Kazunori; Ishikawa-Takata, Kazuko; Hikihara, Yuki; Taguri, Emiko; Kayashita, Jun; Tabata, Izumi

    2011-01-01

    Many predictive equations for basal metabolic rate (BMR) based on anthropometric measurements, age, and sex have been developed, mainly for healthy Caucasians. However, it has been reported that many of these equations, used widely, overestimate BMR not only for Asians, but also for Caucasians. The present study examined the accuracy of several predictive equations for BMR in Japanese subjects. In 365 healthy Japanese male and female subjects, aged 18 to 79 y, BMR was measured in the post-absorptive state using a mask and Douglas bag. Six predictive equations were examined. Total error was used as an index of the accuracy of each equation's prediction. Predicted BMR values by Dietary Reference Intakes for Japanese (Japan-DRI), Adjusted Dietary Reference Intakes for Japanese (Adjusted-DRI), and Ganpule equations were not significantly different from the measured BMR in either sex. On the other hand, Harris-Benedict, Schofield, and Food and Agriculture Organization of the United Nations/World Health Organization/United Nations University equations were significantly higher than the measured BMR in both sexes. The prediction error by Japan-DRI, Adjusted-DRI, and Harris-Benedict equations was significantly correlated with body weight in both sexes. Total error using the Ganpule equation was low in both males and females (125 and 99 kcal/d, respectively). In addition, total error using the Adjusted-DRI equation was low in females (95 kcal/d). Thus, the Ganpule equation was the most accurate in predicting BMR in our healthy Japanese subjects, because the difference between the predicted and measured BMR was relatively small, and body weight had no effect on the prediction error.

  9. Effects of methyl testosterone exposure on sexual differentiation in medaka, Oryzias latipes

    USGS Publications Warehouse

    Papoulias, D.M.; Noltie, Douglas B.; Tillitt, D.E.

    2000-01-01

    Studies were conducted to characterize effects of a known androgen on sexual differentiation and development of medaka, Oryzias latipes (d-rR strain), at two life stages. Embryos were injected with graded doses of methyl testosterone (MT) prior to epiboly. The occurrence of sex-reversal, and the gonadosomatic index (GSI) were evaluated in adults. Primary germ cells were counted and gonad volumes calculated for larvae to determine if sex-reversal could be detected at an early life stage. Sex-reversal of genetic females to phenotypic males was observed at both life stages. The GSI for phenotypic females was greater than for phenotypic males, while the GSI in XX males was similar to XY males. MT appeared to reduce the GSI of XX females exposed to MT but not sex-reversed. Our results indicate that embryonic exposure to androgens influences sexual development in medaka. Utilizing the d-rR strain of medaka allows detection of an effect as early as 2 weeks after chemical exposure making this a useful tool to screen chemicals for effects on sexual differentiation. Copyright (C) 2000.

  10. pnp4a Is the Causal Gene of the Medaka Iridophore Mutant guanineless

    PubMed Central

    Kimura, Tetsuaki; Takehana, Yusuke; Naruse, Kiyoshi

    2017-01-01

    See-through medaka lines are suitable for observing internal organs throughout life. They were bred by crossing multiple color mutants. However, some of the causal genes for these mutants have not been identified. The medaka has four pigment cell types: black melanophores, yellow xanthophores, white leucophores, and silvery iridophores. The causal genes of melanophore, xanthophore, and leucophore mutants have been elucidated, but the causal gene for the iridophore mutant remains unknown. Here, we describe the iridophore mutant, guanineless (gu), which exhibits a strong reduction in visible iridophores throughout its larval to adult stages. The gu locus was previously mapped to chromosome 5, but was located near the telomeric region, making it difficult to integrate into the chromosome. We sought the causal gene of gu using synteny analysis with the zebrafish genome and found a strong candidate, purine nucleoside phosphorylase 4a (pnp4a). Gene targeting and complementation testing showed that pnp4a is the causal gene of gu. This result will allow the establishment of inbred medaka strains or other useful strains with see-through phenotypes without major disruption in the genetic background of each strain. PMID:28258112

  11. Life-cycle experiments of medaka fish aboard the international space station.

    PubMed

    Ijiri, Kenichi

    2003-01-01

    Fish are the most likely candidates to be the first vertebrate to live their life cycle aboard the International Space Station (ISS). In the space-shuttle experiment using medaka, the fry born in space had the same number of germ cells as the ground control fish, and these germ cells later developed to produce the offspring on the ground. Fry hatched in space did not exhibit any looping behavior regardless of their strain, visual acuity, etc. The aquatic habitat (AQH) is a space habitat designed for long-term breeding of medaka, zebrafish and Xenopus, and recent advancements in this hardware also support fish life-cycle experiments. From the crosses between two strains, fish having good eyesight and less sensitivity to gravity were obtained, and their tolerance to microgravity was tested by parabolic flight using an airplane. The fish exhibited less looping and no differences in degree of looping between light and dark conditions. These are possible candidates for the first adult medaka (parent fish) to start a life cycle aboard ISS. Embryos were treated with a three-dimensional clinostat. Such simulated microgravity caused no differences in tissue architecture or in gene expression within the retina, nor in formation of cartilage (head skeleton). Otolith formation in embryos and fry was investigated for wild-type and mutant (ha) medaka. The ha embryos could not form utricular otoliths. They formed saccular otoliths but with a delay. Fry of the mutant fish lacking the utricular otoliths are highly light-dependent at the time of hatching, showing a perfect dorsal-light response (DLR). As they grow, they eventually shift from being light dependent to gravity dependent. Continuous treatment of the fry with altered light direction suppressed this shift to gravity dependence. Being less dependent on gravity, these fish can serve as model fish in studying the differences expected for the fish that have experienced a life cycle in microgravity.

  12. Effect of Bifidobacterium animalis ssp. lactis GCL2505 on visceral fat accumulation in healthy Japanese adults: a randomized controlled trial

    PubMed Central

    TAKAHASHI, Shota; ANZAWA, Daisuke; TAKAMI, Kazuyo; ISHIZUKA, Akihiro; MAWATARI, Takashi; KAMIKADO, Kohei; SUGIMURA, Haruhi; NISHIJIMA, Tomohiko

    2016-01-01

    Bifidobacterium animalis ssp. lactis GCL2505 (B. lactis GCL2505) is able to survive passage through the intestine and then proliferate, leading to an increase in the amount of gut bifidobacteria. In the present study, we evaluated the impact of B. lactis GCL2505 on abdominal visceral fat storage in overweight and mildly obese Japanese adults. This clinical study was a double-blind, randomized, placebo-controlled, parallel-group comparative trial performed for 12 weeks. Healthy Japanese subjects (N=137) with body mass indices ranging from 23 to 30 kg/m2 consumed either fermented milk containing B. lactis GCL2505 or a placebo every day, and then visceral and subcutaneous abdominal fat areas were measured by computed tomography as the primary endpoints. The number of fecal bifidobacteria was also measured. Visceral fat area, but not subcutaneous fat area, was significantly reduced from baseline at 8 and 12 weeks in the GCL2505 group, compared with the placebo group. The total number of fecal bifidobacteria was significantly increased in the GCL2505 group. These results indicate that B. lactis GCL2505 reduces abdominal visceral fat, a key factor associated with metabolic disorders. This finding suggests that this probiotic strain can potentially serve as a specific functional food to achieve visceral fat reduction in overweight or mildly obese individuals. PMID:27867803

  13. Serum γ-glutamyltransferase level is associated with periodontal disease independent of drinking habits in Japanese adults.

    PubMed

    Morita, Toyoko; Yamazaki, Yoji; Fujiharu, Chika; Ishii, Takanori; Seto, Misae; Nishinoue, Norihide; Sasaki, Yoshiyuki; Kawato, Takayuki; Motohashi, Masafumi; Maeno, Masao

    2014-10-31

    Background Non-alcoholic fatty liver disease is considered a hepatic manifestation of metabolic syndrome. Periodontal disease is a mild chronic inflammatory disease with systemic effects, and many studies have indicated an association between metabolic syndrome and periodontitis. In the present study, we investigated the relationship between periodontitis and liver biochemical parameters according to alcohol drinking habits through a cross-sectional study based on data from Japanese people in occupational settings. Material and Methods The subjects were 1510 employees (1218 males, 292 females, mean age 50.4 years) who underwent dental and medical checkups in 2012. Associations between the presence of periodontal pockets and serum levels of liver biochemical parameters were assessed. Results Alanine aminotransferase (ALT) and γ-glutamyltransferase (GGT) levels were higher in subjects with than without periodontal pockets. Multiple logistic regression analysis (adjusting for age, gender, cigarette smoking, and alcohol drinking habits, and components of metabolic syndrome) with GGT or ALT as the dependent variable revealed that there was a significant association between periodontal pockets and GGT (odds ratio, OR=1.48), but not ALT. Similar associations were observed when an analysis was performed according to the presence or absence of alcohol drinking habits; the OR was higher in subjects without (OR=1.84) than with drinking habits (OR=1.41). Conclusions The presence of periodontal pockets was associated with serum levels of GGT, a liver biochemical parameter, in Japanese adults with no drinking habit, suggesting that periodontal disease is associated with liver function, independent of alcohol ingestion.

  14. a Cross-Sectional Study on Insomnia among Japanese Adult Women in Relation to Night-Time Road Traffic Noise

    NASA Astrophysics Data System (ADS)

    Kageyama, T.; Kabuto, M.; Nitta, N.; Kurokawa, Y.; Taira, K.; Suzuki, S.; Takemoto, T.

    1997-08-01

    In an effort to determine the contribution of night-time road traffic noise to insomnia in the general population, 3600 adult Japanese women living in urban residential areas were surveyed. Living near a road with a heavy traffic volume is one of the risk factors for insomnia. The risk for insomnia in the zones 0-20 m from the main roads increased linearly with the night-time traffic volume. This suggests that road traffic noise raises the sound level in bedrooms in such zones, and consequently the prevalence rate of insomnia among the residents, and that noise-induced insomnia is an important public health problem, at least in highly urbanized areas.

  15. Early life exposure to a rodent carcinogen propiconazole fungicide induces oxidative stress and hepatocarcinogenesis in medaka fish.

    PubMed

    Tu, Tzu-Yi; Hong, Chwan-Yang; Sasado, Takao; Kashiwada, Shosaku; Chen, Pei-Jen

    2016-01-01

    Conazole pollution is an emerging concern to human health and environmental safety because of the broad use of conazole fungicides in agriculture and medicine and their frequent occurrence in aquifers. The agricultural pesticide propiconazole has received much regulatory interest because it is a known rodent carcinogen with evidence of multiple adverse effects in mammals and non-targeted organisms. However, the carcinogenic effect and associated mechanism of propiconazole in fish under microgram-per-liter levels of environmental-relevant exposure remains unclear. To explore whether early life of propiconzaole exposure would induce oxidative stress and latent carcinogenic effects in fish, we continuously exposed larvae of wild type or p53(-/-) mutant of medaka fish (Oryzias latipes) to propiconazole (2.5-250μg/L) for 3, 7, 14 or 28 days and assessed liver histopathology and/or the oxidative stress response and gene expression during exposure and throughout adulthood. Propiconazole dose-dependently induced reactive oxygen species (ROS) level, altered homeostasis of antioxidant superoxide dismutase, catalase and glutathione S-transferase and caused lipid and protein peroxidation during early life exposure in wild type medaka. Such exposure also significantly upregulated gene expression of the cytochrome P450 CYP1A, but marginally suppressed that of tumor suppressor p53 in adults. Furthermore, histopathology revealed that p53(-/-) mutant medaka with early life exposure to propiconazole showed increased incidence of hepatocarcionogensis, as compared to the p53(-/-) control group and wild type strain. We demonstrated that propiconazole can initiate ROS-mediated oxidative stress and induce hepatic tumorigenesis associated with CYP1A- and/or p53 -mediated pathways with the use of wild type and p53(-/-) mutant of medaka fish. The toxic response of medaka to propiconazole is compatible with that observed in rodents.

  16. Annual changes in serum leptin concentration in the adult female Japanese black bear (Ursus thibetanus japonicus).

    PubMed

    Tsubota, Toshio; Sato, Miho; Okano, Tsukasa; Nakamura, Sachiko; Asano, Makoto; Komatsu, Takeshi; Shibata, Haruki; Saito, Masayuki

    2008-12-01

    In the present study, assay of the serum leptin concentration of the Japanese black bear (Ursus thibetanus japonicus) was attempted using a canine-leptin-specific sandwich enzyme-linked immunosorbent assay (ELISA). The dose-response curve of the bear serum was linear and parallel to the canine leptin standard curve. In mated and unmated bears, the serum leptin concentration was stable at low levels from May to August or September, gradually increased from September or October, and then remarkably increased in late November. We conclude that this method may be useful for measuring bear serum leptin concentration and that the serum leptin concentration changes annually with a peak in late November.

  17. Differential expression of anti-Müllerian hormone (amh) and anti-Müllerian hormone receptor type II (amhrII) in the teleost medaka.

    PubMed

    Klüver, Nils; Pfennig, Frank; Pala, Irene; Storch, Katja; Schlieder, Marlen; Froschauer, Alexander; Gutzeit, Herwig O; Schartl, Manfred

    2007-01-01

    In mammals, the anti-Müllerian hormone (Amh) is responsible for the regression of the Müllerian ducts; therefore, Amh is an important factor of male sex differentiation. The amh gene has been cloned in various vertebrates, as well as in several teleost species. To date, all described species show a sexually dimorphic expression of amh during sex differentiation or at least in differentiated juvenile gonads. We have identified the medaka amh ortholog and examined its expression pattern. Medaka amh shows no sexually dimorphic expression pattern. It is expressed in both developing XY male and XX female gonads. In adult testes, amh is expressed in the Sertoli cells and in adult ovaries in granulosa cells surrounding the oocytes, like in mammals. To better understand the function of amh, we cloned the anti-Müllerian hormone receptor type II (amhrII) ortholog and compared its expression pattern with amh, aromatase (cyp19a1), and scp3. During gonad development, amhrII is coexpressed with medaka amh in somatic cells of the gonads and shows no sexually dimorphic expression. Only the expression level of the Amh type II receptor gene was decreased noticeably in adult female gonads. These results suggest that medaka Amh and AmhrII are involved in gonad formation and maintenance in both sexes.

  18. Impact of population aging on trends in diabetes prevalence: A meta-regression analysis of 160,000 Japanese adults

    PubMed Central

    Charvat, Hadrien; Goto, Atsushi; Goto, Maki; Inoue, Machiko; Heianza, Yoriko; Arase, Yasuji; Sone, Hirohito; Nakagami, Tomoko; Song, Xin; Qiao, Qing; Tuomilehto, Jaakko; Tsugane, Shoichiro; Noda, Mitsuhiko; Inoue, Manami

    2015-01-01

    Aims/Introduction To provide age- and sex-specific trends, age-standardized trends, and projections of diabetes prevalence through the year 2030 in the Japanese adult population. Materials and Methods In the present meta-regression analysis, we included 161,087 adults from six studies and nine national health surveys carried out between 1988 and 2011 in Japan. We assessed the prevalence of diabetes using a recorded history of diabetes or, for the population of individuals without known diabetes, either a glycated hemoglobin level of ≥6.5% (48 mmol/mol) or the 1999 World Health Organization criteria (i.e., a fasting plasma glucose level of ≥126 mg/dL and/or 2-h glucose level of ≥200 mg/dL in the 75-g oral glucose tolerance test). Results For both sexes, prevalence appeared to remain unchanged over the years in all age categories except for men aged 70 years or older, in whom a significant increase in prevalence with time was observed. Age-standardized diabetes prevalence estimates based on the Japanese population of the corresponding year showed marked increasing trends: diabetes prevalence was 6.1% among women (95% confidence interval [CI] 5.5–6.7), 9.9% (95% CI 9.2–10.6) among men, and 7.9% (95% CI 7.5–8.4) among the total population in 2010, and was expected to rise by 2030 to 6.7% (95% CI 5.2–9.2), 13.1% (95% CI 10.9–16.7) and 9.8% (95% CI 8.5–12.0), respectively. In contrast, the age-standardized diabetes prevalence using a fixed population appeared to remain unchanged. Conclusions This large-scale meta-regression analysis shows that a substantial increase in diabetes prevalence is expected in Japan during the next few decades, mainly as a result of the aging of the adult population. PMID:26417410

  19. Impact of rituximab desensitization on blood-type-incompatible adult living donor liver transplantation: a Japanese multicenter study.

    PubMed

    Egawa, H; Teramukai, S; Haga, H; Tanabe, M; Mori, A; Ikegami, T; Kawagishi, N; Ohdan, H; Kasahara, M; Umeshita, K

    2014-01-01

    We evaluated the effects of rituximab prophylaxis on outcomes of ABO-blood-type-incompatible living donor liver transplantation (ABO-I LDLT) in 381 adult patients in the Japanese registry of ABO-I LDLT. Patients underwent dual or triple immunosuppression with or without B cell desensitization therapies such as plasmapheresis, splenectomy, local infusion, intravenous immunoglobulin and rituximab. Era before 2005, intensive care unit-bound status, high Model for End-Stage Liver Disease score and absence of rituximab prophylaxis were significant risk factors for overall survival and antibody-mediated rejection (AMR) in the univariate analysis. After adjustment for era effects in the multivariate analysis, only absence of rituximab prophylaxis was a significant risk factor for AMR, and there were no significant risk factors for survival. Rituximab prophylaxis significantly decreased the incidence of AMR, especially hepatic necrosis (p < 0.001). In the rituximab group, other B cell desensitization therapies had no add-on effects. Multiple or large rituximab doses significantly increased the incidence of infection, and early administration had no advantage. In conclusion, outcomes in adult ABO-I LDLT have significantly improved in the latest era coincident with the introduction of rituximab.

  20. Numerical Analysis of Organ Doses Delivered During Computed Tomography Examinations Using Japanese Adult Phantoms with the WAZA-ARI Dosimetry System.

    PubMed

    Takahashi, Fumiaki; Sato, Kaoru; Endo, Akira; Ono, Koji; Ban, Nobuhiko; Hasegawa, Takayuki; Katsunuma, Yasushi; Yoshitake, Takayasu; Kai, Michiaki

    2015-08-01

    A dosimetry system for computed tomography (CT) examinations, named WAZA-ARI, is being developed to accurately assess radiation doses to patients in Japan. For dose calculations in WAZA-ARI, organ doses were numerically analyzed using average adult Japanese male (JM) and female (JF) phantoms with the Particle and Heavy Ion Transport code System (PHITS). Experimental studies clarified the photon energy distribution of emitted photons and dose profiles on the table for some multi-detector row CT (MDCT) devices. Numerical analyses using a source model in PHITS could specifically take into account emissions of x rays from the tube to the table with attenuation of photons through a beam-shaping filter for each MDCT device based on the experiment results. The source model was validated by measuring the CT dose index (CTDI). Numerical analyses with PHITS revealed a concordance of organ doses with body sizes of the JM and JF phantoms. The organ doses in the JM phantoms were compared with data obtained using previously developed systems. In addition, the dose calculations in WAZA-ARI were verified with previously reported results by realistic NUBAS phantoms and radiation dose measurement using a physical Japanese model (THRA1 phantom). The results imply that numerical analyses using the Japanese phantoms and specified source models can give reasonable estimates of dose for MDCT devices for typical Japanese adults.

  1. Effect of glyphosate-based herbicide on early life stages of Java medaka (Oryzias javanicus): a potential tropical test fish.

    PubMed

    Yusof, Shahrizad; Ismail, Ahmad; Alias, Mohamad Shafiq

    2014-08-30

    Glyphosate is globally a widely used herbicide, yet there is little information on their toxicity to marine fishes. Java medaka, a small tropical fish native to coastal areas in several Southeast Asian countries, is viewed as a suitable candidate for toxicity test and thus was used for this study. Java medaka adults were cultured in the laboratory and the fertilized eggs of the F2 generation were exposed to different concentrations of glyphosate-based herbicide (100, 200, 300, 400 and 500 ppm) until they hatched. The survival and hatching rates of the embryos, changes in the heart rate and morphological impairments were recorded. Generally, survival and hatching percentage decreased as glyphosate concentration increased. Absence of pectoral fin(s) and cornea, permanently bent tail, irregular shaped abdomen, and cell disruption in the fin, head and abdomen are among the common teratogenic effects observed. Furthermore, risk factor also increased with the increased in glyphosate concentrations.

  2. Ipsilateral patterns of the rotational range of motion of the hip in healthy Japanese adults

    PubMed Central

    Han, Heonsoo; Kubo, Akira; Kurosawa, Kazuo; Maruichi, Shizuka; Ishizaka, Masahiro; Sadakiyo, Kaori; Nomura, Takahiro; Honzawa, Kaoru

    2016-01-01

    [Purpose] This study aimed to categorize the internal and external rotation range of motion (ROM) of ipsilateral hip joints into specific patterns based on the differences between them, and clarify the distribution of these patterns. [Subjects and Methods] A total of 222 healthy Japanese medical students (162 males, 60 females) with a mean age of 21.2 ± 4.0 years were enrolled. The ROM of internal and external rotation at the hip were randomly measured with the subjects in the prone position. Thereafter, the difference between internal and external rotations was assessed. Hip ROM patterns were classified into 3 types based on the differences in the rotation ROM on each side. A total of 9 overall patterns were then determined based on the combination of patterns on both sides. [Results] Although all the subjects were healthy, an asymmetrical ROM between internal and external rotation in ipsilateral hip joints could be detected via pattern classification. Moreover, the distribution of each hip ROM pattern was clarified. [Conclusion] Pattern classification based on differences in internal and external rotation ROM could serve as a useful evaluation method for clinical manipulative therapy. PMID:27799692

  3. Home modification and prevention of frailty progression in older adults: a Japanese prospective cohort study.

    PubMed

    Mitoku, Kazuko; Shimanouchi, Setsu

    2014-08-01

    The aim of this study was to determine whether home modification was associated with subsequent progression of frailty and mortality in older adults. We conducted a prospective cohort study in 574 adults 65 and older who required a low or moderate level of care. Of these, 34% modified their homes-most frequently a corridor-and the most common type of modification was the installation of handrails. The mortality was significantly lower among older adults with home modifications than in those without home modifications at 2 years (adjusted hazard ratio [HR] = 0.52; 95% confidence interval [CI] [0.32, 0.87]), 3 years (HR = 0.57, 95% CI [0.54, 0.81]), and 4.7 years (HR = 0.65, 95% CI [0.65, 0.91]). These findings suggest that home modification may prevent the progression of frailty (i.e., need for low/moderate level of care increasing to the need for high level of care) in older adults.

  4. Immunoglobulin heavy chains in medaka (Oryzias latipes)

    PubMed Central

    2011-01-01

    Background Bony fish present an immunological system, which evolved independently from those of animals that migrated to land 400 million years ago. The publication of whole genome sequences and the availability of several cDNA libraries for medaka (Oryzias latipes) permitted us to perform a thorough analysis of immunoglobulin heavy chains present in this teleost. Results We identified IgM and IgD coding ESTs, mainly in spleen, kidney and gills using published cDNA libraries but we did not find any sequence that coded for IgT or other heavy chain isotypes described in fish. The IgM - ESTs corresponded with the secreted and membrane forms and surprisingly, the latter form only presented two constant heavy chain domains. This is the first time that this short form of membrane IgM is described in a teleost. It is different from that identified in Notothenioid teleost because it does not present the typical splicing pattern of membrane IgM. The identified IgD-ESTs only present membrane transcripts, with Cμ1 and five Cδ exons. Furthermore, there are ESTs with sequences that do not have any VH which disrupt open reading frames. A scan of the medaka genome using transcripts and genomic short reads resulted in five zones within a region on chromosome 8 with Cμ and Cδ exons. Some of these exons do not form part of antibodies and were at times interspersed, suggesting a recombination process between zones. An analysis of the ESTs confirmed that no antibodies are expressed from zone 3. Conclusions Our results suggest that the IGH locus duplication is very common among teleosts, wherein the existence of a recombination process explains the sequence homology between them. PMID:21676244

  5. Of the family tree: congruence on filial obligation between older parents and adult children in Japanese Canadian families.

    PubMed

    Kobayashi, Karen M; Funk, Laura

    2010-03-01

    Drawing on the intergenerational stake hypothesis (Bengtson and Kuypers, 1971), this article explores intergenerational congruence and incongruence on filial obligation, and implications for social support, between older nisei (second generation) parents and adult sansei (third generation) children in Japanese Canadian families. Using data from semi-structured interviews with 100 parent-child dyads in British Columbia, congruence on close-ended responses to value statements (degree congruence) and the content congruence of open-ended responses are examined. The findings show the majority of parent-child dyads indicate overall (both degree and content) congruence in filial obligation, especially when a parent is female, widowed, and/or has poor/fair health status. We conclude that despite markedly different historical life course experiences and acculturation processes, both generations continue to regard filial obligation as important. These findings are discussed with respect to implications for social support exchanges given a continued valuation of filial obligation in Asian post-immigrant (North American-born) and immigrant families.

  6. Male predominance among Japanese adult patients with late-onset hemorrhagic cystitis after hematopoietic stem cell transplantation.

    PubMed

    Asano, Y; Kanda, Y; Ogawa, N; Sakata-Yanagimoto, M; Nakagawa, M; Kawazu, M; Goyama, S; Kandabashi, K; Izutsu, K; Imai, Y; Hangaishi, A; Kurokawa, M; Tsujino, S; Ogawa, S; Aoki, K; Chiba, S; Motokura, T; Hirai, H

    2003-12-01

    Late-onset hemorrhagic cystitis (LHC) after hematopoietic stem cell transplantation (HSCT) is mainly caused by viral infections. We retrospectively analyzed the records of 141 Japanese adult patients who underwent a first allogeneic HSCT from 1995 to 2002. In all, 19 patients developed LHC a median of 51 days after HSCT. Adenovirus (AdV) was detected in the urine of 10 LHC patients, of whom eight had AdV type 11. Five of the six available serum samples from these patients were also positive for AdV type 11, but the detection of AdV in serum was not associated with a worse outcome. Male sex and the development of grade II-IV acute graft-versus-host disease were identified as independent significant risk factors for LHC. Male predominance was detected in LHC after HSCT, as has been previously shown in children with AdV-induced acute HC. The detection of AdV DNA in serum did not predict a poor outcome.

  7. Perceptual narrowing towards adult faces is a cross-cultural phenomenon in infancy: a behavioral and near-infrared spectroscopy study with Japanese infants.

    PubMed

    Kobayashi, Megumi; Macchi Cassia, Viola; Kanazawa, So; Yamaguchi, Masami K; Kakigi, Ryusuke

    2016-12-05

    Recent data showed that, in Caucasian infants, perceptual narrowing occurs for own-race adult faces between 3 and 9 months of age, possibly as a consequence of the extensive amount of social and perceptual experience accumulated with caregivers and/or other adult individuals of the same race of the caregiver. The neural correlates of this developmental process remain unexplored, and it is currently unknown whether perceptual tuning towards adult faces can be extended to other cultures. To this end, in the current study we tested the ability of 3- and 9-month-old Japanese infants to discriminate among adult and infant Asian faces in a visual familiarization task (Experiment 1), and compared 9-month-olds' cerebral hemodynamic responses to adult and infant faces as measured by near-infrared spectroscopy (NIRS) (Experiment 2). Results showed that 3-month-olds exhibit above-chance discrimination of adult and infant faces, whereas 9-month-olds discriminate adult faces but not infant faces (Experiment 1). Moreover, adult faces, but not infant faces, induced significant increases in hemodynamic responses in the right temporal areas of 9-month-old infants. Overall, our data suggest that perceptual narrowing towards adult faces is a cross-cultural phenomenon occurring between 3 and 9 months of age, and translates by 9 months of age into a right-hemispheric specialization in the processing of adult faces.

  8. Descriptive epidemiological study of food intake among Japanese adults: analyses by age, time and birth cohort model

    PubMed Central

    2014-01-01

    Background Although food and nutrient consumption among the Japanese population, known to have one of the longest life expectancies in the world, has changed markedly after World War II, little is known about the influences age, time and birth cohort have had. The present study examined the effects age, time and birth cohort have had on intake of 14 food groups from 1989 to 2009, using published data from the National Health and Nutrition Survey in Japan. Methods The survey included 575 adults (271 men and 304 women) in 1989, 8431 (3952 men and 4479 women) in 1999 and 5632 (2629 men and 3003 women) in 2009. The effects of age on energy-adjusted food intakes defined by gender and birth cohort (birth in 1930–1939, 1940–1949, 1950–1959, 1960–1969, 1970–1979) were estimated using the mean polish process. Results Intakes of meat and confectionary increased whereas those of milk and dairy products, sugar, and fats and oils decreased from 1989 to 2009. Both men and women in the 1940’s birth cohort consumed more fruit, although differences in food intake by birth cohort were less discernible. Furthermore, meat, fats and oils, and wheat intake decreased while fruits, fish, beans and vegetables consumption increased with aging in both men and women. Conclusions The present analysis suggests intakes of meat and confectionary have increased in Japan over the past 20 years regardless of age and generation. Also, younger individuals are less likely to consume fruits, fish, beans and vegetables regardless of the birth cohort and time period. Differences in food group consumption by birth cohorts born between 1930 and 1979 were not obvious. The first indication of these findings would be that in order to avoid ongoing increases in meat and confectionery intake, the public health strategy should target the whole Japanese population. Secondly, intervening with the diet of younger individuals, especially today, would be reasonable as it is unknown whether today

  9. Disability, compensatory behavior, and innovation in free-ranging adult female Japanese macaques (Macaca fuscata).

    PubMed

    Turner, Sarah E; Fedigan, Linda M; Matthews, H Damon; Nakamichi, Masayuki

    2012-09-01

    Little is known about consequences of disability in nonhuman primates, yet individuals with disabilities can reveal much about behavioral flexibility, innovation, and the capabilities of a species. The Macaca fuscata population surrounding the Awajishima Monkey Center has experienced high rates of congenital limb malformation for at least 40 years, creating a unique opportunity to examine consequences of physical impairment in situ, in a relatively large sample of free-ranging adult monkeys. Here we present behavioral data on 11 disabled adult females and 12 nondisabled controls from 279 hours of randomly ordered 30-minute focal animal follows collected during May-August in 2005, 2006, and 2007. We quantified numerous statistically significant disability-related behavioral differences among females. Disabled females spent less time begging for peanuts from tourists, and employed a behavioral variant of such peanut begging; they had a lower frequency of hand use in grooming and compensated with increased direct use of the mouth or a two-arm pinch technique; and they had a higher frequency of self-scratching, and more use of feet in self-scratching. Self-scratching against substrates was almost exclusively a disability associated behavior. Two females used habitual bipedalism. These differences not withstanding, disabled females behaved similarly to controls in many respects: overall reliance on provisioned and wild foods, time spent feeding, and feeding efficiency did not differ among females, and there was no time difference in behavior performed arboreally or terrestrially. Disabled adult females were able to compensate behaviorally to perform social and life-sustaining activities, modifying existing behaviors to suit their individual physical situations and, occasionally, inventing new ways of doing things.

  10. Glycemic index and postprandial blood glucose response to Japanese strawberry jam in normal adults.

    PubMed

    Kurotobi, Tomoka; Fukuhara, Kimiaki; Inage, Hiroko; Kimura, Shuichi

    2010-01-01

    We investigated in 30 healthy adults the glycemic index (GI) of five strawberry jams made from various sugar compositions. The jam containing the highest ratio of glucose showed a high GI, while that containing a high ratio of fructose, a jam made from polydextrose, showed a low GI. There was a high correlation (r=0.969, p=0.006) between the GI and the predicted GI calculated from the sugar composition of the jams. Moreover, the influence on postprandial blood glucose response after an intake of only 20 g of jam and one slice of bread with 20 g jam was measured in 8 healthy adults. The blood glucose level after an intake of 20 g of the high GI jam containing the high glucose ratio was higher than that of other jams at 15 min, but there was no significant difference after 30 min. Regardless of whether the GI was low or high, differences in the jams were not observed in the postprandial blood glucose level or the area under the curve after eating either one slice of bread (60 g) or one slice of bread with less than 20 g of jam.

  11. Characterization and expression of trypsinogen and trypsin in medaka testis.

    PubMed

    Rajapakse, Sanath; Ogiwara, Katsueki; Takahashi, Takayki

    2014-12-01

    Previously, we reported that the medaka testis abundantly expresses the mRNA for trypsinogen, which is a well-known pancreatic proenzyme that is secreted into and activated in the intestine. Currently, we report our characterization of the medaka trypsin using a recombinant enzyme and show that this protein is a serine protease that shares properties with trypsins from other species. Two polypeptides (28- and 26-kDa) were detected in the testis extracts by Western blot analysis using antibodies that are specific for medaka trypsinogen. The 28-kDa polypeptide was shown to be trypsinogen (inactive precursor), and the 26-kDa polypeptide was shown to be trypsin (active protease). We did not detect enteropeptidase, which is the specific activator of trypsinogen, in the testis extract. Immunohistochemical analyses using the same trypsinogen-specific antibody produced a strong signal in the spermatogonia and spermatozoa of the mature medaka testis. Substantial staining was found with spermatocytes, whereas extremely weak signals were observed with spermatids. In vitro incubation of testis fragments with the trypsinogen antibody strongly inhibited the release of sperm from the testis into the medium. Trypsin activity was detected in sperm extracts using gelatin zymographic analysis. Immunocytochemistry showed that trypsinogen and trypsin were localized to the cell membranes surrounding the sperm head. Collectively, these results suggest that trypsin plays an important role in the testis function of the medaka.

  12. Defective fin regeneration in medaka fish (Oryzias latipes) with hypothyroidism.

    PubMed

    Sekimizu, Koshin; Tagawa, Masatomo; Takeda, Hiroyuki

    2007-07-01

    Wild-type medaka are known to have remarkable capabilities of fin, or epimorphic, regeneration. However, a hypothyroid mutant, kamaitachi (kmi), frequently suffers from injury in fins, suggesting an important role of thyroid hormone in fin regeneration. This led us to examine the relationship between thyroid hormone and fin regeneration using medaka as a model. For this, we first set up a medaka experimental system in which the rate of regeneration was statistically analyzed after caudal fin amputation under normal and hypothyroid conditions. As expected, the regeneration of amputated caudal fins was delayed in hypothyroid kmi -/- mutants. We then examined wild-type medaka with thiourea-induced hypothyroidism to evaluate the requirement of thyroid hormone during epimorphic fin regeneration. The results demonstrate that the growth rate of regenerates was much reduced in severely hypothyroid medaka throughout the regeneration period. This reduction in regenerative rate was recovered by exogenous administration of L-thyroxine. The present study is thus the first to report the direct involvement of thyroid hormone in teleost fin regeneration, and provides a basic framework for future molecular and genetic analyses.

  13. Oral toxicity of extracts of the microcystin-containing cyanobacterium Planktothrix agardhii to the medaka fish (Oryzias latipes).

    PubMed

    Djediat, Chakib; Moyenga, David; Malécot, Mélodie; Comte, Katia; Yéprémian, Claude; Bernard, Cécile; Puiseux-Dao, Simone; Edery, Marc

    2011-07-01

    As previously demonstrated the medaka fish appears to offer a good model for studies of microcystins (MCs) effects. Since cyanobacterial toxins are released with other molecules in the aquatic environment when the producers are dying, in this study, we performed additional experiments in order to compare the described effects obtained with the pure toxin microcystin-LR (MC-LR), among the most toxic MCs, to those induced by complex extracts of an MCs-producer Planktothrix agardhii, strain PMC 75.02 and a natural bloom containing the MCs-producer P. agardhii. The toxicity of these extracts containing several variants of MC was determined in adult medaka treated by gavage. Extracts of an MCs-free strain of P. agardhii (PMC 87.02) were assayed for comparison. Extracts effects were analysed on two tissues, liver and intestine by means of photon and transmission electron microscopy. MC was localized in these tissues by immunocytochemistry. No effect was detectable with extracts of the MCs-free P. agardhii strain. The two MCs-P. agardhii extracts (strain and natural bloom) were able to induce harmful effects in the liver and intestine of the medaka fish in acute intoxication by gavage. In these target organs as shown by toxin immunolocalization, reactions leading to cell disjunction and lysis were observed apparently associated with an immune reaction implying MC containing macrophages. These effects are similar to those previously described with photonic microscopy in medaka treated with pure MC-LR with additional results obtained under the electron microscope. Since no significant effect was detected with the MCs-free (PMC 87.02) extract, we then conclude that MCs, even in complex association with other cyanobacterial components, should be responsible for the toxic effects observed in treated fish.

  14. The teleost fish medaka ( Oryzias latipes) as genetic model to study gravity dependent bone homeostasis in vivo

    NASA Astrophysics Data System (ADS)

    Wagner, T. U.; Renn, J.; Riemensperger, T.; Volff, J.-N.; Köster, R. W.; Goerlich, R.; Schartl, M.; Winkler, C.

    2003-10-01

    Long-term space flight and microgravity result in bone loss that can be explained by reduced activity of bone-forming cells (osteoblasts) and/or an increase in activity of bone resorbing cells (osteoclasts). Osteoprotegerin (OPG) has been shown to regulate the balance between osteoblast and osteoclast cell numbers and is involved in maintaining constant bone mass under normal gravitational conditions. The small bony fish medaka ( Oryzias latipes) has attracted increasing attention as a genetic model system to study normal embryonic developmental and pathological processes. To analyze the molecular mechanisms of bone formation in this small vertebrate, we have isolated two opg genes, opgl and opg2, from medaka. Our phylogenetic analysis reveals that both genes originated from a common ancestor by fish-specific gene duplication and represent the orthologs of the mammalian opg gene. Both opg genes are differentially expressed during embryonic and larval development, in adult tissues and in cultured primary osteoblast-like cells. Furthermore, we have characterized the opg2 promoter region and identified consensus binding sites for the transcription factor core-binding-factor-1A (CBFA1). In mammals, CBFA1 has been shown to be a regulator of opg expression and to be essential for several steps during osteoblast differentiation. Here we show that sequence and expression domains of opg, cbfal and a member of the dlx gene family are highly conserved between medaka and higher vertebrates. This suggests that not only single genes but entire genetic networks for bone formation are conserved between teleosts and mammals. These findings will open medaka fish as a genetic model to monitor bone formation under different gravity conditions in a living whole animal allowing the identification of novel factors involved in bone homeostasis.

  15. The teleost fish medaka (Oryzias latipes) as genetic model to study gravity dependent bone homeostasis in vivo.

    PubMed

    Wagner, T U; Renn, J; Riemensperger, T; Volff, J-N; Köster, R W; Goerlich, R; Schartl, M; Winkler, C

    2003-01-01

    Long-term space flight and microgravity result in bone loss that can be explained by reduced activity of bone-forming cells (osteoblasts) and/or an increase in activity of bone resorbing cells (osteoclasts). Osteoprotegerin (OPG) has been shown to regulate the balance between osteoblast and osteoclast cell numbers and is involved in maintaining constant bone mass under normal gravitational conditions. The small bony fish medaka (Oryzias latipes) has attracted increasing attention as a genetic model system to study normal embryonic developmental and pathological processes. To analyze the molecular mechanisms of bone formation in this small vertebrate, we have isolated two opg genes, opgl and opg2, from medaka. Our phylogenetic analysis reveals that both genes originated from a common ancestor by fish-specific gene duplication and represent the orthologs of the mammalian opg gene. Both opg genes are differentially expressed during embryonic and larval development, in adult tissues and in cultured primary osteoblast-like cells. Furthermore, we have characterized the opg2 promoter region and identified consensus binding sites for the transcription factor core-binding-factor-1A (CBFA1). In mammals, CBFA1 has been shown to be a regulator of opg expression and to be essential for several steps during osteoblast differentiation. Here we show that sequence and expression domains of opg, cbfal and a member of the dlx gene family are highly conserved between medaka and higher vertebrates. This suggests that not only single genes but entire genetic networks for bone formation are conserved between teleosts and mammals. These findings will open medaka fish as a genetic model to monitor bone formation under different gravity conditions in a living whole animal allowing the identification of novel factors involved in bone homeostasis.

  16. Self-reported taste preference can be a proxy for daily sodium intake in middle-aged Japanese adults.

    PubMed

    Takachi, Ribeka; Ishihara, Junko; Iwasaki, Motoki; Ishii, Yuri; Tsugane, Shoichiro

    2014-05-01

    Reducing dietary salt intake remains a challenging issue in the management of chronic disease. Taste preference is suspected to be an important proxy index of daily sodium consumption. This study examined the difference in daily sodium intake according to self-reported taste preference for miso soup as representative of homemade cooking in middle-aged urban Japanese adults. Among 896 candidates randomly selected from examinees of cancer screening provided by the National Cancer Center, Japan, 143 men and women participated in this cross-sectional study. During the period from May 2007 through April 2008, participants provided a food frequency questionnaire, which included information on taste preference and dietary behaviors, a weighed food record over 4 consecutive days, a simultaneous 24-hour urine collection, and a sample of miso soup as it is usually prepared in the home. Mean 24-hour urinary sodium excretion and daily sodium intake were compared according to the self-reported taste preference for miso soup. Taste preference was significantly associated with both 24-hour urinary sodium excretion (trend P<0.01) and daily sodium intake (trend P=0.01), with a corresponding regression coefficient per 1 rank preference increment of 403 mg and 315 mg/day, respectively. The observed association between preference and urinary excretion was attenuated by further adjustment for discretionary salt-related behaviors. These findings suggest that self-reported taste preference for homemade cooking is a defining feature of daily sodium intake through discretionary salt-related dietary behaviors. A reduction in daily sodium consumption per 1 rank light preference was estimated to equate to approximately 1 g salt/day.

  17. The relationship between traffic noise and insomnia among adult Japanese women

    NASA Astrophysics Data System (ADS)

    Sasazawa, Y.; Kawada, T.; Kiryu, Y.; Suzuki, S.

    2004-10-01

    To clarify the relationship between traffic noise and insomnia, the authors conducted a survey and measured the actual sound level of noise in an urban area. Questionnaires were distributed to adult women who lived within 150 m from two major roads and were completed by 648 of the 1286 subjects (50.4%). The area was divided into three zones according to distance from the road (more than 50, 20-50 and 0-19.9 m). Fifty-seven subjects (8.8%) were classified as having insomnia. Average values of sound level at distances of 20, 50, and 100 m from the major road were Leq 64.7, 57.1, and 51.8 dBA, respectively. Overall, there were no significant differences among the three zones in the prevalence of insomnia and no association between distance from the road and insomnia. However, the result from a sub-data set of the subjects who lived in the areas that showed decreasing noise level as the distance from the main road increased showed that distance from the road was associated with insomnia. This study suggests that researchers should consider the actual traffic situation and its sound level in epidemiological studies about the effects of traffic noise on insomnia.

  18. Toward a molecular equivalent dose: use of the medaka model in comparative risk assessment.

    PubMed

    Hobbie, Kristen R; Deangelo, Anthony B; King, Leon C; Winn, Richard N; Law, J McHugh

    2009-03-01

    Recent changes in the risk assessment landscape underscore the need to be able to compare the results of toxicity and dose-response testing between a growing list of animal models and, quite possibly, an array of in vitro screening assays. How do we compare test results for a given compound between vastly different species? For example, what dose level in the ambient water of a small fish model would be equivalent to 10 ppm of a given compound in the rat's drinking water? Where do we begin? To initially address these questions, and in order to compare dose-response tests in a standard rodent model with a fish model, we used the concept of molecular dose. Assays that quantify types of DNA damage that are directly relevant to carcinogenesis integrate the factors such as chemical exposure, uptake, distribution, metabolism, etc. that tend to vary so widely between different phyletic levels. We performed parallel exposures in F344 rats and Japanese medaka (Oryzias latipes) to the alkylating hepatocarcinogen, dimethylnitrosamine (DMN). In both models, we measured the DNA adducts 8-hydroxyguanine, N(7)-methylguanine and O(6)-methylguanine in the liver; mutation frequency using lambda cII transgenic medaka and lambda cII transgenic (Big Blue(R)) rats; and early morphological changes in the livers of both models using histopathology and immunohistochemistry. Pulse dose levels in fish were 0, 10, 25, 50, or 100 ppm DMN in the ambient water for 14 days. Since rats are reported to be especially sensitive to DMN, they received 0, 0.1, 1, 5, 10, or 25 ppm DMN in the drinking water for the same time period. While liver DNA adduct concentrations were similar in magnitude, mutant frequencies in the DMN-exposed medaka were up to 20 times higher than in the Big Blue rats. Future work with other compounds will generate a more complete picture of comparative dose response between different phyletic levels and will help guide risk assessors using "alternative" models.

  19. Mutation of Gonadal soma-derived factor induces medaka XY gonads to undergo ovarian development.

    PubMed

    Imai, Takuto; Saino, Kentaro; Matsuda, Masaru

    2015-11-06

    Gonochoristic species have a bipotential gonad that develops into a testis or an ovary. In species whose sex is determined by a genetic factor, the expression of a sex-determining gene is the first cue that directs the development of a bipotential gonad. Subsequent expression of downstream genes induces the gonad to develop into a testis or an ovary. The TGF-ß family member Gonadal soma-derived factor (Gsdf) is thought to be an important gene for gonadal development in teleost fish, and it is expressed at higher levels in the testis than in the ovary from early to mature stages. However, there is little functional information about the gene. In this study, we targeted the Gsdf coding region in the medaka fish Oryzias latipes using transcription activator-like effector nucleases (TALENs) and studied the phenotypes of the Gsdf mutant medaka. Although normal and heterozygous XY gonads developed into a testis, all XY gonads with a homozygous mutation in Gsdf developed into an ovary at early developmental stages. However, two-thirds of Gsdf mutant XY gonads developed into testes in the adult stages. These results demonstrate that although a gonad can develop into a complete testis in the absence of Gsdf, Gsdf function is critical for directing the bipotential gonad at early developmental stages. Therefore, Gsdf is an endogenous inducer of testicular development similar to a master sex-determining gene.

  20. Early-life-stage toxicity in offspring from exposed parent medaka, Oryzias latipes, to mixtures of tributyltin and polychlorinated biphenyls.

    PubMed

    Nakayama, Kei; Oshima, Yuji; Nagafuchi, Ken; Hano, Takeshi; Shimasaki, Yohei; Honjo, Tsuneo

    2005-03-01

    The present study examined the effects of tributyltin (TBT), polychlorinated biphenyls (PCBs), and mixtures of both chemicals on reproduction in Japanese medaka, Oryzias latipes. For 21 d we gave groups of medaka freeze-dried brine shrimp flakes contaminated with a mixture of either 0, 1, 5, or 25 microg TBT g(-1) plus 0 or 25 .micro PCBs g(-1). We measured the fecundity and fertility of the parent fish and assessed the deformity, hatchability, time-to-hatching, and swim-up failure rate of the next generation. Fertilization success in the third week of the administration period was significantly decreased by administration of 25 microg TBT g(-1) (77%) compared with the control group (87%). Both TBT and PCBs were transferred maternally into the eggs of the next generation, causing early life-stage toxicity. Administration of 1 microg TBT g (-1) was not toxic to embryological development, but abnormal eye development (i.e., small eyes or no eyes) occurred when TBT at the same concentration was mixed with PCBs (6.4%). Administration of TBT alone significantly decreased hatchability and increased swim-up failure, and administration of PCBs alone significantly increased time-to-hatching. Statistical analysis by two-way analysis of variance detected an interaction between TBT and PCBs in these three parameters. TBT induces abnormal development of the eyes, reduced hatchability, and increased swim-up failure, whereas PCBs delay time-to-hatching. Administration of mixtures of TBT and PCBs has more adverse effects on the developmental stage of medaka than does that of each chemical alone.

  1. In vitro and in vivo estrogenic effects of 17alpha-estradiol in medaka (Oryzias latipes).

    PubMed

    Huang, Chong; Zhang, Zhaobin; Wu, Shimin; Zhao, Yanbin; Hu, Jianying

    2010-07-01

    17alpha-Estradiol (17alpha-E2), the stereoisomer of 17beta-estradiol (17beta-E2), is considered a weak estrogen in mammals. However, little is known about its estrogenic potency in teleost fish, even though 17alpha-E2 has been frequently detected in aquatic environment. To investigate the estrogenic activity of 17alpha-E2, an in vitro assay based on the ligand-dependent interaction between medaka estrogen receptor alpha (med-ERalpha) and coactivator was conducted. Japanese medaka (Oryziaslatipes) were exposed to 1, 10, 100, 1000 and 10000ng L(-1) 17alpha-E2 (actual concentrations of 1.91, 12.81, 96.24, 1045.15, and 9320.81ng L(-1), respectively) for 3 weeks, and expression for vitellogenins (VTG-I), Choriogenin H (CHG-H) and estrogen receptor alpha (ERalpha) mRNA in the livers was analyzed by quantitative real-time RT-PCR (Q-RT-PCR). The in vitro study showed that the EC(50) of 17alpha-E2 was 114.10nM, which was 30 times less potent than that of 17beta-E2 (3.80nM). Dose-dependent induction of gene expression of VTG-I, CHG-H and ERalpha were observed. The benchmark dose (BMD) values for VTG-I, CHG-H and ERalpha were 44.16ng L(-1), 15.25ng L(-1) and 66.03ng L(-1), which were about 11-, 17- and 14-times less potent than that of 17beta-E2, respectively. Comparing this study with those reported previously in mammals, it is suggested that fish species may be more susceptive to 17alpha-E2 than mammals.

  2. Disruption of circulation by ethanol promotes fetal alcohol spectrum disorder (FASD) in medaka (Oryzias latipes) embryogenesis.

    PubMed

    Hu, Yuhui; Khan, Ikhlas A; Dasmahapatra, Asok K

    2008-09-01

    Japanese medaka (Oryzias latipes) embryos exposed to ethanol have developed craniofacial, cardiovascular and skeletal defects which can be compared with the phenotypic features of fetal alcohol spectrum disorder (FASD) observed in human. The present experiment was designed to show that the disruption in circulation by ethanol during embryogenesis is a potential cause of FASD. Fertilized eggs were exposed to ethanol (0, 100 and/or 400 mM) for 24 or 48 h at various developmental stages (Iwamatsu stages 4-30) and were analyzed at 6 day post fertilization (dpf). It was observed that controls and the embryos exposed to 100 mM ethanol were in circulating state; however, a significant number of embryos of stages 4-24 exposed to 400 mM ethanol had disrupted circulation. Compared to controls, protein and RNA contents were significantly reduced in non-circulating embryos. Lipid peroxidation (LPO) analysis was made at 3, 6, 24, 48, 96 and 144 hour post fertilization (hpf). LPO was increased with the advancement of morphogenesis; however, ethanol or the circulation status had no effect. We further analyzed alcohol dehydrogenase (Adh 5 and adh8) and aldehyde dehydrogenase (Aldh9A and Aldh1A2) enzyme mRNAs in the embryos exposed to 400 mM ethanol for 24 h. A developmental stage-specific reduction in these enzyme mRNAs by ethanol was observed. We conclude that ethanol-induced disruption in circulation during embryogenesis is a potential cause of the development of FASD features in medaka.

  3. Self-reported aural symptoms, headache and temporomandibular disorders in Japanese young adults

    PubMed Central

    2013-01-01

    Background To investigate the associations of aural symptoms, headache and depression with the presence of temporomandibular disorder (TMD) symptoms in a young adult population in Japan. Methods A personal interview survey was conducted on first-year university students (n = 1,930) regarding symptoms of TMD, aural problems, headache, shoulder pain and depression. Logistic regression was applied to assess the associations of these problems with the presence of TMD symptoms after controlling for age and gender. Results Among the 1,930 students, 543 students exhibited TMD symptoms and were classified into 7 groups: clicking only (Group I, n = 319), pain in the TMJ only (Group II, n = 21), difficulty in mouth opening only (Group III, n = 18), clicking and pain (Group IV, n = 29), clicking and difficulty in mouth opening (Group V, n = 48), difficulty in mouth opening and pain (Group VI, n = 11), and combination of three symptoms (Group VII, n = 97). The control group (n = 1,387) were subjects without any TMD symptoms. After adjusting for age and gender, a strong association was observed between TMD symptoms (Group II and IV) and tinnitus (OR = 12.1 and 13.2, respectively). TMD symptoms (Group I, II and III) were also associated with vertigo and headache. Otalgia and depression were significantly associated with the presence of clicking only. Conclusions TMD symptoms were significantly correlated to aural symptoms and headache. A functional evaluation of the stomatognathic system should be considered in subjects with unexplained aural symptoms and headache. PMID:23384362

  4. Myostatin-deficient medaka exhibit a double-muscling phenotype with hyperplasia and hypertrophy, which occur sequentially during post-hatch development.

    PubMed

    Chisada, Shin-Ichi; Okamoto, Hiroyuki; Taniguchi, Yoshihito; Kimori, Yoshitaka; Toyoda, Atsushi; Sakaki, Yoshiyuki; Takeda, Shunichi; Yoshiura, Yasutoshi

    2011-11-01

    Myostatin (MSTN) functions as a negative regulator of skeletal muscle mass. In mammals, MSTN-deficient animals result in an increase of skeletal muscle mass with both hyperplasia and hypertrophy. A MSTN gene is highly conserved within the fish species, allowing speculation that MSTN-deficient fish could exhibit a double-muscled phenotype. Some strategies for blocking or knocking down MSTN in adult fish have been already performed; however, these fish show either only hyperplastic or hypertrophic growth in muscle fiber. Therefore, the role of MSTN in fish myogenesis during post-hatch growth remains unclear. To address this question, we have made MSTN-deficient medaka (mstnC315Y) by using the targeting induced local lesions in a genome method. mstnC315Y can reproduce and have the same survival period as WT medaka. Growth rates of WT and mstnC315Y were measured at juvenile (1-2wk post-hatching), post-juvenile (3-7wk post-hatching) and adult (8-16wk post-hatching) stages. In addition, effects of MSTN on skeletal muscle differentiation were investigated at histological and molecular levels at each developmental stage. As a result, mstnC315Y show a significant increase in body weight from the post-juvenile to adult stage. Hyper-morphogenesis of skeletal muscle in mstnC315Y was accomplished due to hyperplastic growth from post-juvenile to early adult stage, followed by hypertrophic growth in the adult stage. Myf-5 and MyoD were up-regulated in mstnC315Y at the hyperplastic growth phase, while myogenin was highly expressed in mstnC315Y at the hypertrophic growth phase. These indicated that MSTN in medaka plays a dual role for muscle fiber development. In conclusion, MSTN in medaka regulates the number and size of muscle fiber in a temporally-controlled manner during posthatch growth.

  5. Medaka fish exhibits longevity gender gap, a natural drop in estrogen and telomere shortening during aging: a unique model for studying sex-dependent longevity

    PubMed Central

    2013-01-01

    Introduction Females having a longer telomere and lifespan than males have been documented in many animals. Such linkage however has never been reported in fish. Progressive shortening of telomere length is an important aging mechanism. Mounting in vitro evidence has shown that telomere shortening beyond a critical length triggered replicative senescence or cell death. Estrogen has been postulated as a key factor contributing to maintenance of telomere and sex-dependent longevity in animals. This postulation remains unproven due to the lack of a suitable animal system for testing. Here, we introduce a teleost model, the Japanese medaka Oryzias latipes, which shows promise for research into the molecular mechanism(s) controlling sex difference in aging. Results Using the medaka, we demonstrate for the first time in teleost that (i) sex differences (female > male) in telomere length and longevity also exist in fish, and (ii) a natural, ‘menopause’-like decline of plasma estrogen was evident in females during aging. Estrogen levels significantly correlated with telomerase activity as well as telomere length in female organs (not in males), suggesting estrogen could modulate telomere length via telomerase activation in a sex -specific manner. A hypothetical in vivo ‘critical’ terminal restriction fragment (TRF, representing telomere) length of approximately 4 kb was deduced in medaka liver for prediction of organismal mortality, which is highly comparable with that for human cells. An age conversion model was also established to enable age translation between medaka (in months) and human (in years). These novel tools are useful for future research on comparative biology of aging using medaka. Conclusion The striking similarity in estrogen profile between aging female O. latipes and women enables studying the influence of “postmenopausal” decline of estrogen on telomere and longevity without the need of invasive ovariectomy. Medaka fish is advantageous

  6. Development of a molecular biomarker for detecting intersex after exposure of male medaka fish to synthetic estrogen.

    PubMed

    Zhao, Yanbin; Hu, Jianying

    2012-08-01

    Although intersex of fish species has been widely reported in aquatic environments, there is no appropriate biomarker of the effects to assess the occurrence of intersex. In the present study, mRNA expression profiles of 14 genes, which are either involved in ovary development and maintenance or have relatively high mRNA transcription levels in ovarian gene expression profiles in fish species, were comprehensively evaluated in male Japanese medaka (Oryzias latipes) exposed to 17α-ethynylestradiol (EE2) to investigate their utility as indicators of the severity index of intersex. Of these 14 genes, mRNA expression of a novel gene, termed ovary structure protein 1 (OSP1) in the present study, showed female-like expression pattern with the highest transcription levels, and displayed the most significantly positive correlation with the severity index of intersex (r(2) =0.8215, p<0.0001). The full-length mRNA sequence of OSP1 is 802 bp, with an open reading frame (ORF) of 642 bp that encodes a 214-amino acid peptide. Reverse transcription polymerase chain reaction and in situ hybridization revealed that OSP1 was expressed exclusively in the ovaries, specifically in the oogonia and primary oocytes in ovaries and in testis with intersex. These results suggest that the analysis of mRNA expression of OSP1 can be used to indicate intersex in male medaka.

  7. Genetic similarity of the Hainan medaka populations collected from hyper- and hypo-osmotic environments in northern Vietnam

    NASA Astrophysics Data System (ADS)

    Hayakawa, Hideki; Le, Quang Dung; Kinoshita, Masato; Takehana, Yusuke; Sakuma, Kei; Takeshima, Hirohiko; Kojima, Shigeaki; Naruse, Kiyoshi; Inoue, Koji

    2015-06-01

    Ricefishes of the genus Oryzias, including Japanese medaka ( O. latipes), are known as excellent model organisms for studies in various fields of science. Some species of the genus inhabit brackish water, and such species are recognized to be useful to investigate physiological phenomena in seawater. However, only a limited number of species have been recorded from brackish waters. In addition, there is no information about the genetic relationship among populations inhabiting sites with different salinities. Here we report the discovery of Oryzias fish in two locations near Haiphong, northern Vietnam, a brackish mangrove planting area and a freshwater pond. A phylogenetic analysis using mitochondrial 12S and 16S ribosomal RNA (rRNA) gene sequences indicated that the fish from the two localities are the same species, Hainan medaka, O. curvinotus. Population genetic analysis using the mitochondrial 12S and 16S rRNA gene sequences revealed a close genetic relationship between the two populations. These results suggest that O. curvinotus is adaptable to both hyperosmotic and hypoosmotic environments. Due to its osmotic adaptability and ease of rearing in the laboratory, this species is expected to become a model for marine environmental and toxicological studies, as well as for studies of osmotic adaptation mechanisms.

  8. Measuring the toxicity of alkyl-phenanthrenes to early life stages of medaka (Oryzias latipes) using partition-controlled delivery.

    PubMed

    Turcotte, Dominique; Akhtar, Parveen; Bowerman, Michelle; Kiparissis, Yiannis; Brown, R Stephen; Hodson, Peter V

    2011-02-01

    Alkyl-phenanthrenes are a class of compounds present in crude oil and toxic to developing fish. Most research on alkyl-phenanthrenes has focused on retene (7-isopropyl-1-methyl-phenanthrene), but little is known about the chronic toxicity of related congeners to the early life stages of fish. This project is the first to describe the chronic toxicity of a series of alkyl-phenanthrenes to the embryos of Japanese medaka (Oryzias latipes) using the partition-controlled delivery (PCD) method of exposure and is the first to establish a relationship between toxicity of alkyl-phenanthrenes and log P. With PCD, test concentrations were maintained by equilibrium partitioning of test chemicals from polydimethylsiloxane (PDMS) films containing various concentrations of C1 to C4 phenanthrenes. Log film:solution partition constants (log K(fs)) and aqueous solubility limits were determined for each alkyl-phenanthrene. The prevalence of abnormalities in fish embryos increased in an exposure-dependent manner, with median effective concentration (EC50) values lower than experimental solubility limits of the compounds, and typical of environmental concentrations. Alkyl-phenanthrenes were more toxic to medaka embryos than unsubstituted phenanthrene, with effects resembling those of dioxin and indicating a specific receptor-based mechanism of toxicity. These results extend conclusions for the Exxon Valdez oil spill, suggest a specific mechanism of toxicity for alkyl-phenanthrenes, and provide a model for assessing the risks of mixture toxicity.

  9. MEPD: medaka expression pattern database, genes and more

    PubMed Central

    Alonso-Barba, Juan I.; Rahman, Raza-Ur; Wittbrodt, Joachim; Mateo, Juan L.

    2016-01-01

    The Medaka Expression Pattern Database (MEPD; http://mepd.cos.uni-heidelberg.de/) is designed as a repository of medaka expression data for the scientific community. In this update we present two main improvements. First, we have changed the previous clone-centric view for in situ data to a gene-centric view. This is possible because now we have linked all the data present in MEPD to the medaka gene annotation in ENSEMBL. In addition, we have also connected the medaka genes in MEPD to their corresponding orthologous gene in zebrafish, again using the ENSEMBL database. Based on this, we provide a link to the Zebrafish Model Organism Database (ZFIN) to allow researches to compare expression data between these two fish model organisms. As a second major improvement, we have modified the design of the database to enable it to host regulatory elements, promoters or enhancers, expression patterns in addition to gene expression. The combination of gene expression, by traditional in situ, and regulatory element expression, typically by fluorescence reporter gene, within the same platform assures consistency in terms of annotation. In our opinion, this will allow researchers to uncover new insights between the expression domain of genes and their regulatory landscape. PMID:26450962

  10. Diffusion of small molecules into medaka embryos improved by electroporation

    PubMed Central

    2013-01-01

    Background Diffusion of small molecules into fish embryos is essential for many experimental procedures in developmental biology and toxicology. Since we observed a weak uptake of lithium into medaka eggs we started a detailed analysis of its diffusion properties using small fluorescent molecules. Results Contrary to our expectations, not the rigid outer chorion but instead membrane systems surrounding the embryo/yolk turned out to be the limiting factor for diffusion into medaka eggs. The consequence is a bi-phasic uptake of small molecules first reaching the pervitelline space with a diffusion half-time in the range of a few minutes. This is followed by a slow second phase (half-time in the range of several hours) during which accumulation in the embryo/yolk takes place. Treatment with detergents improved the uptake, but strongly affected the internal distribution of the molecules. Testing electroporation we could establish conditions to overcome the diffusion barrier. Applying this method to lithium chloride we observed anterior truncations in medaka embryos in agreement with its proposed activation of Wnt signalling. Conclusions The diffusion of small molecules into medaka embryos is slow, caused by membrane systems underneath the chorion. These results have important implications for pharmacologic/toxicologic techniques like the fish embryo test, which therefore require extended incubation times in order to reach sufficient concentrations in the embryos. PMID:23815821

  11. Estimation of habitual iodine intake in Japanese adults using 16 d diet records over four seasons with a newly developed food composition database for iodine.

    PubMed

    Katagiri, Ryoko; Asakura, Keiko; Sasaki, Satoshi; Hirota, Naoko; Notsu, Akiko; Miura, Ayako; Todoriki, Hidemi; Fukui, Mitsuru; Date, Chigusa

    2015-08-28

    Although habitual seaweed consumption in Japan would suggest that iodine intake in Japanese is exceptionally high, intake data from diet records are limited. In the present study, we developed a composition database of iodine and estimated the habitual intake of iodine among Japanese adults. Missing values for iodine content in the existing composition table were imputed based on established criteria. 16 d diet records (4 d over four seasons) from adults (120 women aged 30-69 years and 120 men aged 30-76 years) living in Japan were collected, and iodine intake was estimated. Habitual intake was estimated with the Best-power method. Totally, 995 food items were imputed. The distribution of iodine intake in 24 h was highly skewed, and approximately 55 % of 24 h values were < 300 μg/d. The median iodine intake in 24 h was 229 μg/d for women and 273 μg/d for men. All subjects consumed iodine-rich foods (kelp or soup stock) on one or more days of the sixteen survey days. The mean (median) habitual iodine intake was 1414 (857) μg/d for women and 1572 (1031) μg/d for men. Older participants had higher intake than younger participants. The major contributors to iodine intake were kelp (60 %) and soup stock (30 %). Habitual iodine intake among Japanese was sufficient or higher than the tolerable upper intake level, particularly in older generations. The association between high iodine intake as that observed in the present study and thyroid disease requires further study.

  12. Influence of single nucleotide polymorphisms of cytokine genes on anti-HBs antibody production after hepatitis B vaccination in a Japanese young adult population.

    PubMed

    Yukimasa, Nobuyasu; Sato, Shoichi; Oboshi, Wataru; Watanabe, Toru; Uzawa, Ryuichi

    2016-01-01

    Hepatitis B (HB) vaccination is one of the most efficient tools to prevent the transmission of the virus. Considerable variability exists in HB vaccine responses, with 5-10% of healthy Japanese adults demonstrating no response following a standard vaccination. Recently, polymorphisms of immune-regulatory genes, such as cytokine genes, have been reported to influence the immune response to HB vaccine. The aim of this study was to investigate the underlying mechanisms of the genetic association between several cytokine gene polymorphisms and the immune response to HB vaccination in a Japanese population. One hundred and twenty three vaccinated young adults were classified according to the level of antibody-titer (anti-HBs). Single nucleotide polymorphism typing for IFN-γ (+874, 3'-UTR), IL-10 (-591, -819, -1082), and TNF-α (-308, -857), was accomplished using the PCR-RFLP or SSP-PCR method. The TNF-α (-857) CC type and the IL-10 (-1082) AG type were present more frequently in the low titer group than in the high titer group. The TNF-α (-857) CC type was found to be significantly associated with low response of serum anti-HBs. The anti-HBs antibody was not readily produced in the IL-10 (-1082) AG and TNF-α (-857) CC haplotype. Conversely, the antibody was readily produced in the IL-10 (-1082) AA and TNF-α (-857) CC haplotype, and the IL-10 (-1082) AA and TNF-α (-857) CT haplotype, suggesting a high likelihood of the IL-10 (-1082) AG type to be included in the low anti-HBs group, and high anti-HBs antibody production in those with the TNF-α (-857) CT type. These SNPs may produce ethnically-specific differences in the immune response to HB vaccine in the Japanese population. J. Med. Invest. 63: 256-261, August, 2016.

  13. Morphogenesis of the medaka cerebellum, with special reference to the mesencephalic sheet, a structure homologous to the rostrolateral part of mammalian anterior medullary velum.

    PubMed

    Ishikawa, Yuji; Yamamoto, Naoyuki; Yasuda, Takako; Yoshimoto, Masami; Ito, Hironobu

    2010-01-01

    We have examined cerebellar morphogenesis after neural tube stage in medaka (Oryzias latipes), a ray-finned fish, by conventional histology and immunohistochemistry using anti-proliferating cell nuclear antigen (PCNA) and anti-acetylated tubulin antibodies. Our results indicate that the medaka cerebellum is formed in 4 successive stages: (1) formation and enlargement of the cerebellar primordia; (2) rostral midline fusion of the left/right halves of the cerebellar primordia; (3) formation of the cerebellar matrix zones in the midline and caudalmost regions of the primitive cerebellum, and (4) growth and differentiation of the cerebellum. Our results also show that cerebellar morphogenesis is different from that in mammals in 3 important points: the developmental origins of the primordia, directions along which cerebellar fusion proceeds, and number, locations and duration of the cerebellar matrix zones. During the course of this study, an alar-derived membranous structure between the cerebellum and the midbrain in the adult medaka brain was identified as the structure homologous to the rostrolateral part of the mammalian anterior medullary velum. We have named this structure in the adult teleostean brains as the 'mesencephalic sheet'. The present study indicates that there exists both conserved and divergent patterns in cerebellar morphogenesis in vertebrates.

  14. Pravastatin reduces the risk for cardiovascular disease in Japanese hypercholesterolemic patients with impaired fasting glucose or diabetes: diabetes subanalysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study.

    PubMed

    Tajima, Naoko; Kurata, Hideaki; Nakaya, Noriaki; Mizuno, Kyoichi; Ohashi, Yasuo; Kushiro, Toshio; Teramoto, Tamio; Uchiyama, Shinichiro; Nakamura, Haruo

    2008-08-01

    Diabetes mellitus (DM) is a major risk factor for cardiovascular disease (CVD) in patients with no history of CVD. Evidence for the effect of statins on CVD in the diabetic population in low-risk populations (e.g., Japanese) is limited. We evaluated the effect of pravastatin on risk reduction of CVD related to baseline glucose status in a primary prevention setting. The Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study, in patients with mild-to-moderate hypercholesterolemia (220-270 mg/dL), showed that low-dose pravastatin significantly reduced the risk for CVD by 26%. This exploratory subanalyses examined the efficacy of diet plus pravastatin on CVD in 2210 patients with abnormal fasting glucose (AFG, including 1746 patients with DM and 464 patients with impaired fasting glucose (IFG) at 5 years in the MEGA Study. CVD was threefold higher in AFG patients (threefold higher in DM, and twofold higher in IFG) compared with normal fasting glucose (NFG) patients in the diet group. Diet plus pravastatin treatment significantly reduced the risk of CVD by 32% (hazard ratio 0.68, 95% CI 0.48-0.96, number needed to treat, 42) in the AFG group compared with the diet alone group, and no significant interaction between AFG and NFG (interaction P=0.85) was found. Safety problems were not observed during long-term treatment with pravastatin. In conclusion, pravastatin reduces the risk of CVD in subjects with hypercholesterolemia and abnormal fasting glucose in the primary prevention setting in Japan.

  15. Effects of 4-tert-pentylphenol on the gene expression of P450 11beta-hydroxylase in the gonad of medaka (Oryzias latipes).

    PubMed

    Yokota, Hirofumi; Abe, Tatsuo; Nakai, Makoto; Murakami, Hidekazu; Eto, Chizumi; Yakabe, Yoshikuni

    2005-01-26

    Alkylphenols including 4-tert-pentylphenol (4-PP) have been shown to alter sexual differentiation in fish due to their estrogenic properties. Medaka (Oryzias latipes) is so sensitive to these substances because morphological sex reversal and testis-ova induction are well developed in the exposed males. However, little work has been done to characterize the molecular effects of estrogenic substances on the morphological and gonadal feminization in male fish. Cytochrome P450 11beta-hydroxylase (P450(11beta)) is a key steroidogenic enzyme in production of 11-ketotestosterone which is the predominant androgen in male fish. In this study, we cloned a cDNA encoding medaka testicular P450(11beta), and then investigated the gene expression of P450(11beta) in the testes of genetically male medaka exposed to 4-PP. The cDNA contains 1740 nucleotides that encode a protein of 543 amino acids, which shares 68.9% and 73.4% homology with testicular P450(11beta)s from Japanese eel (Anguilla japonica) and rainbow trout (Oncorhynchus mykiss), respectively. HeLa cells transfected with an expression vector containing the open reading frame of medaka P450(11beta) cDNA showed 11beta-hydroxylating activity in the presence of exogenous testosterone. Analysis of tissue distribution by RT-PCR showed great abundance of P450(11beta) mRNA in testis. In the partial life-cycle exposure with 4-PP, morphologically sex-reversal was observed in XY medaka exposed to 4-PP concentrations of > or =238 microg/L. Furthermore, exposure to 4-PP completely inhibited P450(11beta) mRNA expression in the gonads of sex-reversed XY fish at 60-day posthatch. These results suggest that xeno-estrogen 4-PP may have inhibitory effects on the synthesis of testicular 11-oxygenated androgens through downregulation of P450(11beta) expression in the genetically male fish.

  16. Japanese language and Japanese science

    NASA Astrophysics Data System (ADS)

    Tanikawa, Kiyotaka

    2003-08-01

    Japanese mathematical scientists including astronomers, physicists, and mathematicians obtain ideas in Japanese, discuss their problems in Japanese, and arrive at conclusions in Japanese, and yet they write their results in foreign languages such as English. This uncomfortable situation has continued for nearly one hundred years and has had serious effects on Japanese science. In this short report, the author discusses and analyses these effects. In order to put Japanese science on a sound basis, the author proposes to increase the number of articles, reviews and textbooks in Japanese, first by translation and second by the voluntary efforts of scientists themselves. As centers devoted to this activity, the author proposes to construct "Airborne Libraries" which are maintained and accumulate in an electronic form the scientific documents written in Japanese.

  17. Safety and immunogenicity of an AS01-adjuvanted varicella zoster virus subunit candidate vaccine (HZ/su): a phase-I, open-label study in Japanese adults.

    PubMed

    Lal, Himal; Zahaf, Toufik; Heineman, Thomas C

    2013-07-01

    An adjuvanted recombinant subunit candidate vaccine (HZ/su) containing varicella zoster virus envelope glycoprotein E was developed for the prevention of herpes zoster and its complications. This study evaluated safety and reactogenicity of HZ/su in an ethnic Japanese population. This was a phase I, open-label and single-center study conducted between March and November of 2010 in Australia. Twenty healthy ethnic Japanese subjects, aged 18-30 y and 50-69 y (1:1) were enrolled. Subjects were administered two doses of HZ/su vaccine according to a 0, 2-mo schedule. Local and general solicited symptoms were recorded for 7 d post-vaccination. Unsolicited symptoms were recorded for 30 d post-vaccination. Serious adverse events (SAEs), new onset of autoimmune disease (NOAD), other potential immune mediated disorders and HZ cases were recorded throughout the study period. All 20 subjects were included in the according-to-protocol cohort for safety. A total of 18 subjects were included in the according-to-protocol cohort for immunogenicity: 10 in the 18-30 y age group and 8 in the 50-69 y age group. The most commonly reported local and general solicited symptoms were pain and fatigue in both groups. Back pain (in the 18-30 y age group) and chills (in the 50-69 y age group) were the most frequently reported unsolicited symptoms. There were no reports of death, SAEs, NOADs, other autoimmune mediated inflammatory disorder or suspected HZ cases. This study indicated that the two-dose regimen of HZ/su exhibited a clinically acceptable safety profile in healthy young and older ethnic Japanese adults.

  18. Comparative safety of the antifouling compound butenolide and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) to the marine medaka (Oryzias melastigma).

    PubMed

    Chen, Lianguo; Ye, Rui; Xu, Ying; Gao, Zhaoming; Au, Doris W T; Qian, Pei-Yuan

    2014-04-01

    This study evaluated the potential adverse effects of butenolide, a promising antifouling compound, using the marine medaka (Oryzias melastigma), a model fish for marine ecotoxicology. The active ingredient used in the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) was employed as the positive control. Adult marine medaka (4-month-old) were exposed to various concentrations of butenolide or DCOIT for 28 days and then depurated in clean seawater for 14 days (recovery). A suite of sensitive biomarkers, including hepatic oxidative stress, neuronal signal transmission, endocrine disruption, and reproductive function, was used to measure significant biological effects induced by the chemicals. Compared to DCOIT, chronic exposure to butenolide induced a lower extent of oxidative stress in the liver of male and female medaka. Furthermore, butenolide-exposed fish could recover faster from oxidative stress than fish exposed to DCOIT. Regarding neurotransmission, DCOIT significantly inhibited acetylcholinesterase (AChE) activity in the brain of both male and female medaka, whereas this was not significant for butenolide. In addition, plasma estradiol (E2) level was elevated and testosterone (T) level was decreased in male medaka exposed to DCOIT. This greatly imbalanced sex hormones ratio (E2/T) in exposed males, indicating that DCOIT is a potent endocrine disruptive chemical. In contrast, butenolide induced only moderate effects on sex hormone levels in exposed males, which could be gradually recovered during depuration. Moreover, the endocrine disruptive effect induced by butenolide did not affect normal development of offspring. In contrast, DCOIT-exposed fish exhibited a decrease of egg production and impaired reproductive success. Overall, the above findings demonstrated that chronic exposure to butenolide induced transient, reversible biological effect on marine medaka, while DCOIT could impair reproductive success of fish, as

  19. Relationship Between Urinary Concentrations of Nine Water-soluble Vitamins and their Vitamin Intakes in Japanese Adult Males

    PubMed Central

    Shibata, Katsumi; Hirose, Junko; Fukuwatari, Tsutomu

    2014-01-01

    Excess water-soluble vitamins are thought to be eliminated in the urine. We have reported a strong relationship between water-soluble vitamin intake and urinary excretion in females. The relationship, however, is not well understood in males. In the present experiment, 10 Japanese male subjects were given a standard Japanese diet for the first week. The subjects remained on the same diet, and a synthesized water-soluble vitamin mixture containing one time the Dietary Reference Intakes (DRIs) for Japanese was given for the second week, three times the DRIs for the third week, and six times the DRIs for the fourth week. Twenty-four-hour urine samples were collected each week. Urinary excretion levels for seven of the nine water-soluble vitamin levels, excluding vitamin B12 and folate, increased linearly and sharply in a dose-dependent manner. These results suggest that measuring urinary water-soluble vitamins can be good nutritional markers for assessing vitamin intakes in humans. PMID:25210461

  20. Identification of Robust Hypoxia Biomarker Candidates from Fin of Medaka (Oryzias latipes)✰

    PubMed Central

    Zhang, Ziping; Wells, Melissa C.; Boswell, Mikki G.; Beldorth, Ion; Kirk, Lyndsey M.; Wang, Yilei; Wang, Shulong; Savage, Markita; Walter, Ronald B.; Booth, Rachell E.

    2011-01-01

    Aquatic hypoxia caused by organic pollution and eutrophication is a pressing worldwide water pollution problem. Better methods for monitoring oxygen levels are needed to assist efforts to maintain and protect the health of natural aquatic environments. In this project, we used a Japanese ricefish (medaka, Oryzias latipes) 8K oligonucleotide array as a platform to identify potential hypoxic biomarkers in different organs (fin, gill, liver and brain) upon exposure to hypoxia. The microarray results were validated by qRT-PCR employing a subset of candidate biomarkers. Interestingly, the largest number and most significant of hypoxia responding array features were detected in hypoxia exposed fin tissues. We identified 173 array features that exhibited a significant response (over 2 fold change in expression) upon exposure to hypoxic conditions and validated a subset of these by quantitative RT-PCR. These gene targets were subjected to annotation and gene ontology mining. Positively identifiable gene targets that may be useful for development of a rapid and accurate biomarker test using fin clips are discussed in relation to previous reports on hypoxia responsive genes. PMID:21664487

  1. Japanese Competitiveness and Japanese Management.

    ERIC Educational Resources Information Center

    Minabe, Shigeo

    1986-01-01

    Analyzes and compares Japanese and American industrial policy and labor practices. Proposes that certain aspects of the Japanese system be adapted by American businesses for purpose of increasing international competitiveness. Proposes specific actions and plans for both the Japanese and American systems. (ML)

  2. Confirmation of the factorial structure of the Japanese short version of the TEMPS-A in psychiatric patients and general adults

    PubMed Central

    Nakato, Yasuya; Inoue, Takeshi; Nakagawa, Shin; Kitaichi, Yuji; Kameyama, Rie; Wakatsuki, Yumi; Kitagawa, Kan; Omiya, Yuki; Kusumi, Ichiro

    2016-01-01

    Background The Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Auto-questionnaire (TEMPS-A) is a 110-item questionnaire that assesses five affective temperaments. However, a valid shortened version is desired for large-scale investigations to enhance the compliance of respondents. Methods A confirmatory factor analysis was conducted among 320 psychiatric patients and 61 general adults. The participants completed the Japanese 39-item short version of the TEMPS-A, and a portion of the participants completed the 110-item version. An exploratory factor analysis with the principal factor method and varimax rotation was conducted to identify a more suitable model of the short version of the TEMPS-A. Results The confirmatory factor analysis revealed that the 39-item version exhibited a poor model fit. However, we found that the 18-item version exhibited a firm five-factor structure based on the exploratory factor analysis, and this model exhibited an acceptable model fit. It had good or acceptable internal consistency (Cronbach’s αs: 0.672–0.819). Limitations The majority of the subjects in the present study were patients, and the temperament data may have been affected by psychiatric symptoms. Conclusion A firm five-factor structure was not found in the 39-item short version of the Japanese TEMPS-A. Therefore, an 18-item version was proposed. This new 18-item version of the TEMPS-A might be useful for clinical applications and large-scale investigations. PMID:27601911

  3. Transgenic medaka fish as models to analyze bone homeostasis under micro-gravity conditions in vivo

    NASA Astrophysics Data System (ADS)

    Winkler, C.; Wagner, T.; Renn, J.; Goerlich, R.; Schartl, M.

    Long-term space flight and microgravity results in bone loss that can be explained by reduced activity of bone-forming osteoblast cells and/or an increase in activity of bone resorbing osteoclast cells. Osteoprotegerin (OPG), a secreted protein of 401 amino acids, has been shown to regulate the balance between osteoblast and osteoclast formation and thereby warrants constant bone mass under normal gravitational conditions. Consistent with this, earlier reports using transgenic mice have shown that increased activation of OPG leads to exc essive bone formation (osteopetrosis), while inactivation of OPG leads to bone loss (osteoporosis). Importantly, it has recently been reported that expression of murine OPG is regulated by vector averaged gravity (Kanematsu et al., 2002, Bone 30, p553). The small bony fish medaka (Oryzias latipes ) has attracted increasing attention as genetic model system to study developmental and pathological processes. To analyze the molecular mechanisms of bone formation in this small vertebrate, we have isolated two related genes, opr-1 and opr -2, from medaka. Our phylogenetic analysis revealed that both genes originated from a common ancestor by fish-specific gene duplication and represent the orthologs of the mammalian OPG gene. Both opr genes are differentially expressed during embryonic and larval development, in adult tissues and in cultured primary osteoblast cells. We have characterized their promoter regions and identified consensus binding sites for transcription factors of the bone-morphogenetic-protein (BMP) p thway and for core-binding-factor-1Aa (cbfa1). Cbfa1 has been shown to be the key regulator of OPG expression during several steps of osteoblast differentiation in mammals. This opens the possibility that the mechanisms controlling bone formation in teleost fish and higher vertebrates are regulated by related mechanisms. We are currently generating transgenic medakafish expressing a GFP reporter gene under control of the

  4. Psychometric properties of the Japanese version of the Adult Attention-deficit hyperactivity disorder (ADHD) Self-Report Scale (ASRS-J) and its short scale in accordance with DSM-5 diagnostic criteria.

    PubMed

    Takeda, Toshinobu; Tsuji, Yui; Kurita, Hiroshi

    2017-04-01

    We developed the Japanese version of the Adult ADHD Self-Report Scale (ASRS-J) and report its psychometric properties. The ASRS-J and other questionnaires were administered to 48 adults with ADHD, 46 adults with non-ADHD psychiatric disorders, 96 non-clinical adults, and 894 university students. ADHD diagnoses were made using the Japanese semi-structured diagnostic interview for adult ADHD, which is compatible with the DSM-5. The ASRS-J, its subscales, and the short form, all had Cronbach's α values of around 0.80. Total scores on the ASRS-J and the ASRS-J-6 were highly correlated with readministration after a two-week interval. The total and 18 individual item scores in the ASRS-J were significantly higher in the ADHD group than the other three groups. ASRS-J scores were correlated with scores on the Japanese version of Conners' Adult ADHD Rating Scales-Self Report subscales (0.59≤r≤0.77), with one exception. ASRS-J scores were also correlated (albeit more weakly; r=0.38) with Beck Depression Inventory-II total scores. Employing optimal cut-offs, sensitivity, specificity, and positive and negative predictive values of the ASRS-J and ASRS-J-6 are all above 0.69. The ASRS-J and ASRS-J-6 showed acceptable psychometric properties, although further study is necessary.

  5. Direct gene disruption by TALENs in medaka embryos.

    PubMed

    Wang, Tiansu; Hong, Yunhan

    2014-06-10

    Targeted gene disruption (GD) is powerful for generating genetic alterations in animal genomes. Engineered endonucleases such as zinc finger nucleases and transcription activator-like effector nucleases (TALENs) allow for GD directly in animal embryos to achieve germline transmission. Here we report procedures and parameters of TALEN-mediated GD in the fish medaka by using a germ cell-specific gene dnd as a model. Embryos at the 1-cell stage were microinjected with synthetic TALEN mRNAs and examined for the survival rate and GD efficiency. Medaka embryos can tolerate a high dosage of TALEN-mRNA injection and exhibit a steadily increasing GD efficiency with increasing mRNA dosages before peaking at 100 ng/μl. This dosage produced ~24% efficiency for somatic GD. Some of the animals from manipulated embryos developed into fertile female and male. Most importantly, four fish (3 males and 1 female) examined by progeny-test were able to produce GD-bearing male and female gametes for germline transmission to F1 generation at ~10% efficiency. Therefore, TALEN is proficient for somatic and germline GD in medaka embryos, and disruption of one dnd copy does not compromise somatic development and gamete production.

  6. Formation and cultivation of medaka primordial germ cells.

    PubMed

    Li, Zhendong; Li, Mingyou; Hong, Ni; Yi, Meisheng; Hong, Yunhan

    2014-07-01

    Primordial germ cell (PGC) formation is pivotal for fertility. Mammalian PGCs are epigenetically induced without the need for maternal factors and can also be derived in culture from pluripotent stem cells. In egg-laying animals such as Drosophila and zebrafish, PGCs are specified by maternal germ plasm factors without the need for inducing factors. In these organisms, PGC formation and cultivation in vitro from indeterminate embryonic cells have not been possible. Here, we report PGC formation and cultivation in vitro from blastomeres dissociated from midblastula embryos (MBEs) of the fish medaka (Oryzias latipes). PGCs were identified by using germ-cell-specific green fluorescent protein (GFP) expression from a transgene under the control of the vasa promoter. Embryo perturbation was exploited to study PGC formation in vivo, and dissociated MBE cells were cultivated under various conditions to study PGC formation in vitro. Perturbation of somatic development did not prevent PGC formation in live embryos. Dissociated MBE blastomeres formed PGCs in the absence of normal somatic structures and of known inducing factors. Most importantly, under culture conditions conducive to stem cell derivation, some dissociated MBE blastomeres produced GFP-positive PGC-like cells. These GFP-positive cells contained genuine PGCs, as they expressed PGC markers and migrated into the embryonic gonad to generate germline chimeras. Our data thus provide evidence for PGC preformation in medaka and demonstrate, for the first time, that PGC formation and derivation can be obtained in culture from early embryos of medaka as a lower vertebrate model.

  7. Germline replacement by blastula cell transplantation in the fish medaka

    PubMed Central

    Li, Mingyou; Hong, Ni; Xu, Hongyan; Song, Jianxing; Hong, Yunhan

    2016-01-01

    Primordial germ cell (PGC) specification early in development establishes the germline for reproduction and reproductive technologies. Germline replacement (GR) is a powerful tool for conservation of valuable or endangered animals. GR is achievable by germ cell transplantation into the PGC migration pathway or gonads. Blastula cell transplantation (BCT) can also lead to the chimeric germline containing PGCs of both donor and host origins. It has remained largely unknown whether BCT is able to achieve GR at a high efficiency. Here we report efficient GR by BCT into blastula embryos in the fish medaka (Oryzias latipes). Specifically, dnd depletion completely ablated host PGCs and fertility, and dnd overexpression remarkably boosted PGCs in donor blastulae. BCT between normal donor and host produced a germline transmission rate of ~4%. This rate was enhanced up to ~30% upon PGC boosting in donors. Most importantly, BCT between PGC-boosted donors and PGC-ablated hosts led to more than 90% fertility restoration and 100% GR. Therefore, BCT features an extremely high efficiency of fertility recovery and GR in medaka. This finding makes medaka an ideal model to analyze genetic and physiological donor-host compatibilities for BCT-mediated surrogate production and propagation of endangered lower vertebrates and biodiversity. PMID:27406328

  8. INFLUENCE OF EXPOSURE HISTORY ON VITELLOGENIN INDUCTION IN MEDAKA: A CASE OF "ESTROGEN MEMORY"?

    EPA Science Inventory

    Influence of Exposure History on Vitellogenin Induction in Medaka: a Case of "Estrogen Memory"? (Abstract). Mar. Environ. Res. 50(1-5):196.

    In this study, we exposed female medaka to aqueous solutions of o,p'-DDT until tissues residues reached approximately 100 g/g. Male...

  9. GENDER-SPECIFIC GROWTH AND HEPATIC NEOPLASIA IN MEDAKA (ORYZIAS LATIPES). (R825433)

    EPA Science Inventory

    Brief exposure of hatchling medaka (Oryzias latipes), to diethylnitrosamine (DEN), resulted in hepatic tumor formation in female medaka at an incidence of 2–3-fold higher than that of their male cohorts. Spontaneous liver tumor incidence was reported in unexposed...

  10. Super-Protective Child-Rearing by Japanese Bess Beetles, Cylindrocaulus patalis: Adults Provide Their Larvae with Chewed and Predigested Wood.

    PubMed

    Mishima, Tatsuya; Wada, Noriko; Iwata, Ryûtarô; Anzai, Hirosi; Hosoya, Tadatsugu; Araya, Kunio

    2016-04-26

    Beetles of the family Passalidae (Coleoptera: Scarabaeoidea) are termed subsocial. The insects inhabit rotten wood as family groups consisting of the parents and their offspring. The Japanese species Cylindrocaulus patalis has the lowest fecundity among passalids because siblicide occurs among the first-instar larvae; accordingly, parental care toward the survived larva is the highest among Passalidae. To clarify the nutritional relationships between the parents and their offspring, we investigated their ability to digest three types of polysaccharides that are components of wood (cellulose and β-1,4-xylan) and fungal cell walls (β-1,3-glucan). Although carboxymethyl-cellulase activity was barely detectable, β-xylosidase, β-glucosidase, β-1,4-xylanase and β-1,3-glucanase activities were clearly detected in both adults and larvae. Because the activities of enzymes that digest β-1,3-glucan were much higher than those for degrading β-1,4-xylan, in both adults and larvae, it is concluded that they are mainly fungivorous. Furthermore, these digestive enzymatic activities in second- and third-instar larvae were much lower than they were in adults. Although all larval instars grew rapidly when fed chewed wood by their parents, larvae ceased growing and died when fed only artificially ground wood meals. We conclude that the larvae are assumed to be provided with chewed predigested wood in which β-1,3-glucan is degraded by parental enzymes.

  11. Super-Protective Child-Rearing by Japanese Bess Beetles, Cylindrocaulus patalis: Adults Provide Their Larvae with Chewed and Predigested Wood

    PubMed Central

    Mishima, Tatsuya; Wada, Noriko; Iwata, Ryûtarô; Anzai, Hirosi; Hosoya, Tadatsugu; Araya, Kunio

    2016-01-01

    Beetles of the family Passalidae (Coleoptera: Scarabaeoidea) are termed subsocial. The insects inhabit rotten wood as family groups consisting of the parents and their offspring. The Japanese species Cylindrocaulus patalis has the lowest fecundity among passalids because siblicide occurs among the first-instar larvae; accordingly, parental care toward the survived larva is the highest among Passalidae. To clarify the nutritional relationships between the parents and their offspring, we investigated their ability to digest three types of polysaccharides that are components of wood (cellulose and β-1,4-xylan) and fungal cell walls (β-1,3-glucan). Although carboxymethyl-cellulase activity was barely detectable, β-xylosidase, β-glucosidase, β-1,4-xylanase and β-1,3-glucanase activities were clearly detected in both adults and larvae. Because the activities of enzymes that digest β-1,3-glucan were much higher than those for degrading β-1,4-xylan, in both adults and larvae, it is concluded that they are mainly fungivorous. Furthermore, these digestive enzymatic activities in second- and third-instar larvae were much lower than they were in adults. Although all larval instars grew rapidly when fed chewed wood by their parents, larvae ceased growing and died when fed only artificially ground wood meals. We conclude that the larvae are assumed to be provided with chewed predigested wood in which β-1,3-glucan is degraded by parental enzymes. PMID:27128944

  12. Efficacy and safety of growth hormone replacement therapy in Japanese adults with growth hormone deficiency: a post-marketing observational study.

    PubMed

    Shimatsu, Akira; Tai, Shigeru; Imori, Makoto; Ihara, Katsuichiro; Taketsuna, Masanori; Funai, Jumpei; Tanaka, Toshiaki; Teramoto, Akira; Irie, Minoru; Chihara, Kazuo

    2013-01-01

    This large-scale observational study examined the long-term effectiveness and safety of growth hormone (GH) replacement therapy for adult GH deficiency (GHD) in Japanese clinical practice using the Hypopituitary Control and Complications Study database. The study included 402 GHD patients for safety analyses and a subset of 209 patients (149 adult-onset and 60 childhood-onset GHD patients) who had not previously received GH replacement therapy for the efficacy analyses. Data on clinical, metabolic, quality of life (QoL) characteristics, and all adverse events (AEs) were collected at baseline (start of GH treatment), 6 months, 1 year and 2 years. Over the observation period, there were improvements from baseline in insulin-like growth factor-I standard deviation scores (P<0.001), although the changes in metabolic parameters were minimal. QoL (Short Form-36) Z-scores significantly increased from baseline in both onset-type groups for several subscale domains (P<0.05). A total of 145 (36.1%) patients experienced ≥1 AE. Common AEs were hyperlipidaemia (2.7%) and hyperinsulinaemia (2.2%). Some patients experienced recurrent hypothalamic/pituitary tumour (events per 1000 patient-years: 2.78), new benign (0.93), malignant tumour (10.28) or other new tumour (0.93), new diabetes mellitus (7.45), and new stroke (3.71). Seven patients died during the observation period. Our safety findings are inconclusive about the associations between GH replacement and AEs, although the incidence of diabetes mellitus and cardiovascular events are similar to those reported in the Japanese general population. In conclusion, the key beneficial effects of GH replacement therapy for GHD are observed in routine clinical practice in Japan.

  13. Spatio-temporal Features of Neurogenesis in the Retina of Medaka, Oryzias latipes

    PubMed Central

    Kitambi, Satish S.; Malicki, Jarema J.

    2010-01-01

    The vertebrate retina is very well conserved in evolution. Its structure and functional features are very similar in phyla as different as primates and teleost fish. Here we describe the spatio-temporal characteristics of neurogenesis in the retina of a teleost, medaka, and compare them to other species, primarily the zebrafish. Several intriguing differences are observed between medaka and zebrafish. For example, photoreceptor differentiation in the medaka retina starts independently in two different areas, and at more advanced stages of differentiation, medaka and zebrafish retinae display obviously different patterns of the photoreceptor cell mosaic. Medaka and zebrafish evolutionary lineages are thought to have separated from each other 110 million years ago, and so the differences between these species are not unexpected, and may be exploited to gain insight into the architecture of developmental pathways. Importantly, this work highlights the benefits of using multiple teleost models in parallel to understand a developmental process. PMID:19035349

  14. Physical Fitness Measures as Potential Markers of Low Cognitive Function in Japanese Community-Dwelling Older Adults without Apparent Cognitive Problems.

    PubMed

    Narazaki, Kenji; Matsuo, Eri; Honda, Takanori; Nofuji, Yu; Yonemoto, Koji; Kumagai, Shuzo

    2014-09-01

    Detecting signs of cognitive impairment as early as possible is one of the most urgent challenges in preventive care of dementia. It has still been unclear whether physical fitness measures can serve as markers of low cognitive function, a sign of cognitive impairment, in older people free from dementia. The aim of the present study was to examine an association between each of five physical fitness measures and global cognition in Japanese community-dwelling older adults without apparent cognitive problems. The baseline research of the Sasaguri Genkimon Study was conducted from May to August 2011 in Sasaguri town, Fukuoka, Japan. Of the 2,629 baseline subjects who were aged 65 years or older and not certified as individuals requiring nursing care by the town, 1,552 participants without apparent cognitive problems (Mini-Mental State Examination score ≥24) were involved in the present study (59.0% of the baseline subjects, median age: 72 years, men: 40.1%). Global cognitive function was measured by the Japanese version of the Montreal Cognitive Assessment. Handgrip strength, leg strength, sit-to-stand rate, gait speed, and one-leg stand time were examined as physical fitness measures. In multiple linear regression analyses, each of the five physical fitness measures was positively associated with the Montreal Cognitive Assessment score after adjusting for age and sex (p < 0.001). These associations were preserved after additional adjustment for years of formal education, body mass index, and other confounding factors (p < 0.001). The present study first demonstrated the associations between multiple aspects of physical fitness and global cognitive function in Japanese community-dwelling older people without apparent cognitive problems. These results suggest that each of the physical fitness measures has a potential as a single marker of low cognitive function in older populations free from dementia and thereby can be useful in community-based preventive care of

  15. A Report of an Adult Case of Tubulointerstitial Nephritis and Uveitis (TINU) Syndrome, with a Review of 102 Japanese Cases

    PubMed Central

    Matsumoto, Keiichiro; Fukunari, Kenichi; Ikeda, Yuji; Miyazono, Motoaki; Kishi, Tomoya; Matsumoto, Ryoko; Fukuda, Makoto; Ichiumi, Saori; Yoshizaki, Mai; Nonaka, Yasunori; Kanaya, Akiko

    2015-01-01

    Patient: Female, 44 Final Diagnosis: Tubulointerstitial nephritis • uveitis syndrome Symptoms: — Medication: Loxoprofen sodium hydrate Clinical Procedure: Renal biopsy Specialty: Nephrology Objective: Rare disease Background: Although TINU syndrome is characterized by idiopathic TIN with bilateral anterior uveitis, few reports have provided a comprehensive summary of the features of this disorder. Previous reports have suggested that many Japanese patients had HLA-A2 and -A24 (7), but there is no evidence. Case Report: A 44-year-old female was referred to our hospital due to renal dysfunction in March 2012. After admission, her symptoms improved spontaneously without medication within 2 weeks. In the outpatient clinic, she was diagnosed with idiopathic bilateral anterior uveitis in May, and her renal dysfunction relapsed in November. A renal biopsy showed diffuse TIN. We made a diagnosis of TINU syndrome because we could not explain the origin, and treated her with a systemic corticosteroid. Her renal function and ocular symptoms have been improving. The patient had HLA-A24, -B7, -DR1, -C*07: 02 and -DQB1*05: 01: 01. We collected 102 Japanese cases in PubMed, Ovid MEDLINE, and the Japanese Medical Abstracts Society and compared our case with the previous cases. Conclusions: This disorder affects primarily young females (median age, 14 years), and the most common symptom is fever (44/102 cases). We conducted a statistical analysis using contingency table and Pearson’s chi-square test, for HLA-A2 and A24, and calculated the odds ratio (OR). There are no significant differences (A2 was present in 7/22 cases and in 19/50 controls, p value (P) 0.61, OR 0.76 (95% confidence interval (CI)) 0.27–2.2; A24 was present in 10/22 cases and in 33/50 controls, P 0.10, OR 0.43, CI 0.16–1.2). PMID:25725230

  16. Pharmacokinetic Profiles of Active Components After Oral Administration of a Kampo Medicine, Shakuyakukanzoto, to Healthy Adult Japanese Volunteers.

    PubMed

    Sadakane, Chiharu; Watanabe, Junko; Fukutake, Miwako; Nisimura, Hiroaki; Maemura, Kazuya; Kase, Yoshio; Kono, Toru

    2015-11-01

    Shakuyakukanzoto (SKT), a traditional Japanese (Kampo) medicine, has been used by patients with muscle cramps and abdominal pains. In this trial, we analyzed plasma concentrations of active components after SKT was administered as a single oral dose of 2.5 or 5.0 g/day per person. The study was a randomized, open-label, two-arm, two-period, crossover trial conducted in healthy Japanese volunteers. Albiflorin (ALB), paeoniflorin (PAE), glycycoumarin (GCM), isoliquiritigenin (ILG), glycyrrhetic acid (GA), and glycyrrhetic acid-3-O-monoglucuronide were targeted, and the plasma concentration of each component was measured using a liquid chromatography-tandem mass spectrometry method. The pharmacokinetic parameters were calculated, and the linearity was assessed. All targeted components were detected in the plasma after oral administration of SKT. ALB, PAE, GCM, and ILG were detected at an early stage. The linearity was observed for the maximum plasma concentration of GCM, ILG, and GA and for the area under the plasma concentration-time curve of GA. In this trial, we demonstrated for the first time in humans that these components were absorbed into the blood after oral administration of SKT. The results of this pharmacokinetic trial in humans are also important and useful for understanding the mechanism of action of SKT, verifying the active components predicted in basic research, and conducting pharmacokinetics and safety studies in the future.

  17. Exposure evaluation of adult male Japanese smokers switched to a heated cigarette in a controlled clinical setting.

    PubMed

    Sakaguchi, Chikako; Kakehi, Aoi; Minami, Naoki; Kikuchi, Akira; Futamura, Yasuyuki

    2014-08-01

    The objective of this clinical study was to investigate changes in levels of biomarkers of exposure (BOEs) in healthy Japanese male smokers who switched to a prototype heated cigarette (HC). This was a controlled, semi-randomized, open-label, residential study conducted in Japan. A total of 70 healthy Japanese male smokers were enrolled. Following enrollment, subjects smoked their usual brand of cigarette for 2days and were subsequently randomized either to an HC group or a 10mg tar conventional cigarette (CC10) group for four consecutive weeks. Levels of BOEs for ten selected cigarette smoke constituents (nicotine, carbon monoxide (CO), benzene, 1,3-butadiene, acrolein, hydrogen cyanide, crotonaldehyde, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone [NNK], pyrene, 4-aminobiphenyl), and urine mutagenicity were measured at several time points during the study period. At the end of the study period, except for blood carboxyhemoglobin, levels of BOEs for the other nine constituents and urine mutagenicity were significantly lower in the HC group compared to the CC10 group. These results suggest that exposure to most cigarette smoke constituents, except CO, can be reduced by switching from CC10 to HC.

  18. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish.

    PubMed

    Lin, Chun-Hung; Chou, Pei-Hsin; Chen, Pei-Jen

    2014-07-30

    Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish populations in the aquatic environment.

  19. Preliminary ecological risk assessment of butylparaben and benzylparaben -1. Removal efficiency in wastewater treatment, acute/chronic toxicity for aquatic organisms, and effects on medaka gene expression.

    PubMed

    Yamamoto, Hiroshi; Watanabe, Mikako; Hirata, Yoshiko; Nakamura, Yuki; Nakamura, Yudai; Kitani, Chise; Sekizawa, Jun; Uchida, Masaya; Nakamura, Hiroshi; Kagami, Yoshihiro; Koshio, Masaaki; Hirai, Narisato; Tatarazako, Norihisa

    2007-01-01

    Butylparaben and benzylparaben, used as preservatives mainly in cosmetic products, have recently been found to be weakly estrogenic. Batch activated-sludge treatment and batch chlorination were carried out to roughly determine the removal efficiency of a wastewater treatment plant. Combining the removal efficiency with the estimated annual consumption and the unaltered excretion ratio, the maximum predicted environmental concentration (PEC) was estimated. Conventional acute/chronic toxicity tests were conducted using Japanese medaka (Oryzias latipes), daphnia (Daphnia magna), and green algae (Pseudokirchneriella subcapitata) for n-butylparaben, i-butylparaben, and benzylparaben. Medaka vitellogenin assays were also conducted for the three compounds and DNA microarray analysis was carried out to examine the effects of benzylparaben on gene expression. The plasma vitellogenin concentration of male medaka increased for concentrations of 200, 100, and 100 microg L(-1) n-butylparaben, i-butylparaben, and benzylparaben for 14 days, respectively, while the expression levels of genes encoding proteins such as p53, cytochrome P450 3A40, and choriogenin-L increased for concentrations higher than 4 microg L(-1) of benzylparaben. Furthermore, the predicted no-effect concentration (PNEC) was calculated using the lethal or effect concentration 50 (LC50 or EC50) values and no-effect concentrations (NOECs) obtained in the toxicity tests for these compounds. The maximum concentrations found in the aquatic environment or sewage effluent (MEC eff) were used to carry out preliminary environmental risk assessment. The calculated MEC/PNEC ratio suggests the necessity of further study such as a more detailed large-scale monitoring and chronic toxicity tests including reproduction inhibition and endocrine disruption.

  20. Statistical analysis of biomechanical properties of the adult skull and age-related structural changes by sex in a Japanese forensic sample.

    PubMed

    Torimitsu, Suguru; Nishida, Yoshifumi; Takano, Tachio; Koizumi, Yoshinori; Makino, Yohsuke; Yajima, Daisuke; Hayakawa, Mutsumi; Inokuchi, Go; Motomura, Ayumi; Chiba, Fumiko; Otsuka, Katsura; Kobayashi, Kazuhiro; Odo, Yuriko; Iwase, Hirotaro

    2014-01-01

    The purpose of this research was to investigate the biomechanical properties of the adult human skull and the structural changes that occur with age in both sexes. The heads of 94 Japanese cadavers (54 male cadavers, 40 female cadavers) autopsied in our department were used in this research. A total of 376 cranial samples, four from each skull, were collected. Sample fracture load was measured by a bending test. A statistically significant negative correlation between the sample fracture load and cadaver age was found. This indicates that the stiffness of cranial bones in Japanese individuals decreases with age, and the risk of skull fracture thus probably increases with age. Prior to the bending test, the sample mass, the sample thickness, the ratio of the sample thickness to cadaver stature (ST/CS), and the sample density were measured and calculated. Significant negative correlations between cadaver age and sample thickness, ST/CS, and the sample density were observed only among the female samples. Computerized tomographic (CT) images of 358 cranial samples were available. The computed tomography value (CT value) of cancellous bone which refers to a quantitative scale for describing radiodensity, cancellous bone thickness and cortical bone thickness were measured and calculated. Significant negative correlation between cadaver age and the CT value or cortical bone thickness was observed only among the female samples. These findings suggest that the skull is substantially affected by decreased bone metabolism resulting from osteoporosis. Therefore, osteoporosis prevention and treatment may increase cranial stiffness and reinforce the skull structure, leading to a decrease in the risk of skull fractures.

  1. Dosage Response Mortality of Japanese Beetle, Masked Chafer, and June Beetle (Coleoptera: Scarabaeidae) Adults When Exposed to Experimental and Commercially Available Granules Containing Metarhizium brunneum.

    PubMed

    Behle, Robert W; Goett, Erica J

    2016-05-01

    Field-collected adults of three genera of turf-infesting scarabs, Japanese beetle (Popillia japonica Newman), June beetles (Phyllophaga spp.), and masked chafers (Cyclocephala spp.), were exposed to experimental and commercial granule formulations of the entomopathogenic fungus Metarhizium brunneum (Petch) strain F52 to determine their relative susceptibility. Experimental granules contained microsclerotia produced by liquid fermentation with the ability to produce fresh conidia when rehydrated and commercial granules were Met 52 granular bioinsecticide. All three groups of scarab adults showed a positive dosage response to the fungus when exposed in cups of potting mix treated with the granules. LC50 values for microsclerotia granules were 1.9 × 10(7), 7.1 × 10(6), and 3.2 × 10(6) conidia cup(-1) for P. japonica, Phyllophaga spp., and Cyclocephala spp., respectively. LC50 values for Met 52 granules were 5.9 × 10(7), 5.1 × 10(7), and 7.6 × 10(6) conidia cup(-1), respectively. The experimental granules containing microsclerotia show promise as a viable commercial control agent. They can be produced using lower cost fermentation methods and applied at lower dosages (97 g for 100 m(2) as opposed to 489 g per 100 m(2) for Met 52). If M. brunneum is applied to control the aforementioned white grubs, our data indicate the potential for the adult beetles to also be infected as they enter the soil to lay eggs.

  2. When Ontogeny Matters: A New Japanese Species of Brittle Star Illustrates the Importance of Considering both Adult and Juvenile Characters in Taxonomic Practice

    PubMed Central

    Martynov, Alexander; Ishida, Yoshiaki; Irimura, Seiichi; Tajiri, Rie; O’Hara, Timothy; Fujita, Toshihiko

    2015-01-01

    Current taxonomy offers numerous approaches and methods for species delimitation and description. However, most of them are based on the adult characters and rarely suggest a dynamic representation of developmental transformations of taxonomically important features. Here we show how the underestimation of ontogenetic changes may result in long term lack of recognition of a new species of one of the most common ophiacanthid brittle stars (Echinodermata: Ophiuroidea) from the North Pacific. Based on vast material collected predominantly by various Japanese expeditions in the course of more than 50 years, and thorough study of appropriate type material, we revise the complex of three common species of the ophiuroid genus Ophiacantha which have been persistently confused with each other. The present study thus reveals the previously unrecognized new species Ophiacantha kokusai sp.nov. which is commonly distributed off the Pacific coast of Japan. The new species shows developmental differentiation from the closely related species Ophiacantha rhachophora H. L. Clark, 1911 and retains clearly expressed early juvenile features in the adult morphology. Another species, Ophiacantha clypeata Kyte, 1977, which had been separated from O. rhachophora, is in turn shown to be just a juvenile stage of another North Pacific species, Ophiacantha trachybactra H.L. Clark, 1911. For every species, detailed morphological data from both adult and juvenile specimens based on scanning electron microscopy are presented. A special grinding method showing complex internal features has been utilized for the first time. For all three species in this complex, a clear bathymetric differentiation is revealed: O. rhachophora predominantly inhabits shallow waters, 0–250 m, the new species O. kokusai lives deeper, at 250–600 m, and the third species, O. trachybactra, is found at 500–2,000 m. The present case clearly highlights the importance of considering developmental transformations, not

  3. Permanent and functional male-to-female sex reversal in d-rR strain medaka (Oryzias latipes) following egg microinjection of o,p'-DDT.

    PubMed Central

    Edmunds, J S; McCarthy, R A; Ramsdell, J S

    2000-01-01

    Complete sex reversal of fish is accomplished routinely in aquaculture practices by exposing fish to exogenous sex steroids during gonadal differentiation. A variety of environmental chemicals are also active at sex steroid receptors and theoretically possess the potential to alter normal sexual differentiation in fish. However, in controlled environmental chemical exposures to date, only partial alterations of fish sexual phenotype have been observed. Here we report complete, permanent, and functional male-to-female sex reversal in the Japanese medaka (Oryzias latipes, d-rR strain) after a onetime embryonic exposure to the xenoestrogen o, p'-DDT. d-rR strain medaka are strict gonochorists that possesses both sex-linked pigmentation, which distinguishes genotypic sex, and sexually dimorphic external secondary sexual characteristics, which distinguish phenotypic sex. We directly microinjected the xenoestrogen o, p'-DDT into the egg yolks of medaka at fertilization to parallel the maternal transfer of lipophilic contaminants to the embryo. At 10 weeks of age, microinjected medaka were examined for mortality and sex reversal. A calculated embryonic dose of 511 +/- 22 ng/egg o, p'-DDT (mean +/- standard error) resulted in 50% mortality. An embryonic exposure of 227 +/- 22 ng/egg o, p'-DDT resulted in 86% (6 of 7) sex reversal of genetic males to a female phenotype (XY females). XY females were distinguished by sex-linked male pigmentation accompanying female secondary sexual characteristics. Histologic examination of the gonads confirmed active ovaries in 100% of the XY females. In 10-day breeding trials in which XY females were paired with normal XY males, 50% of the XY females produced fertilized embryos; this represents a comparable breeding success rate to normal XX females. Fertilized eggs produced from XY females hatched to viable larvae. These results clearly indicate that a weakly estrogenic pesticide, o, p'-DDT, when presented during the critical period of

  4. Effect of estrogenic activity, and phytoestrogen and organochlorine pesticide contents in an experimental fish diet on reproduction and hepatic vitellogenin production in medaka (Oryzias latipes).

    PubMed

    Inudo, Makiko; Ishibashi, Hiroshi; Matsumura, Naomi; Matsuoka, Munekazu; Mori, Taiki; Taniyama, Shigeto; Kadokami, Kiwao; Koga, Minoru; Shinohara, Ryota; Hutchinson, T H; Iguchi, Taisen; Arizono, Koji

    2004-12-01

    Endocrine-disrupting chemicals (EDCs) are giving rise to serious concerns for humans and wildlife. Phytoestrogens, such as daidzein and genistein in plants, and organochlorine pesticides are suspected EDCs, because their chemical structure is similar to that of natural or synthetic estrogens and they have estrogenic activity in vitro and in vivo. We assessed estrogenic activity and dietary phytoestrogen and organochlorine pesticide contents of various fish diets made in the United Kingdom, and compared them with those features of diets made in Japan that were tested in a previous study. Genistein and daidzein were detected in all of the diets. Using an in vitro bioassay, many of these diets had higher activation of estrogen beta-receptors than estrogen alpha-receptors. Organochlorine pesticides such as hexachlorobenzene, beta-benzene hexachloride (BHC), and gamma-BHC were detected in all fish diets. On the basis of these data, we investigated the effect of differing dietary phytoestrogen content in Japanese fish diets on hepatic vitellogenin production and reproduction (fecundity and fertility) in medaka (Oryzias latipes). Assessment of the effects of a 28-day feeding period on reproduction of paired medaka did not indicate significant differences in the number of eggs produced and fertility among all feeding groups. However, hepatic vitellogenin values were significantly higher for male medaka fed diet C (genistein, 58.5 +/- 0.6 microg/g; daidzein, 37.3 +/- 0.2 microg/g) for 28 days compared with those fed diet A (genistein, < 0.8 microg/g; daidzein, < 0.8 microg/g) or diet B (genistein, 1.4 +/- 0.1 microg/g; daidzein, 2.0 +/- 0.1 microg/g). Our findings indicate that fish diets containing high amounts of phytoestrogens, such as diet C, have the potential to induce hepatic vitellogenin production in male medaka, even if reproductive parameters are unaffected. Therefore, some diets, by affecting vitellogenin production in males, may alter estrogenic activity of in

  5. Neighborhood food environment and body mass index among Japanese older adults: results from the Aichi Gerontological Evaluation Study (AGES)

    PubMed Central

    2011-01-01

    Background The majority of studies of the local food environment in relation to obesity risk have been conducted in the US, UK, and Australia. The evidence remains limited to western societies. The aim of this paper is to examine the association of local food environment to body mass index (BMI) in a study of older Japanese individuals. Methods The analysis was based on 12,595 respondents from cross-sectional data of the Aichi Gerontological Evaluation Study (AGES), conducted in 2006 and 2007. Using Geographic Information Systems (GIS), we mapped respondents' access to supermarkets, convenience stores, and fast food outlets, based on a street network (both the distance to the nearest stores and the number of stores within 500 m of the respondents' home). Multiple linear regression and logistic regression analyses were performed to examine the association between food environment and BMI. Results In contrast to previous reports, we found that better access to supermarkets was related to higher BMI. Better access to fast food outlets or convenience stores was also associated with higher BMI, but only among those living alone. The logistic regression analysis, using categorized BMI, showed that the access to supermarkets was only related to being overweight or obese, but not related to being underweight. Conclusions Our findings provide mixed support for the types of food environment measures previously used in western settings. Importantly, our results suggest the need to develop culture-specific approaches to characterizing neighborhood contexts when hypotheses are extrapolated across national borders. PMID:21777439

  6. The overnight effect of dietary energy balance on postprandial plasma free amino acid (PFAA) profiles in Japanese adult men.

    PubMed

    Nishioka, Manabu; Imaizumi, Akira; Ando, Toshihiko; Tochikubo, Osamu

    2013-01-01

    The plasma free amino acid (PFAA) profile is affected by various nutritional conditions, such as the dietary energy balance. Regarding the clinical use of PFAA profiling, it is of concern that differences in food ingestion patterns may generate systematic errors in a plasma amino acid profile and constitute a confounding factor in assessment. In this study, the overnight impact of the dietary energy balance on the postprandial plasma amino acid profile was investigated to elucidate in particular the effects of high protein meals typical in Japanese cuisine. We conducted diet-controlled, crossover trials in eleven healthy male volunteers aged 40-61 y. They consumed either a normal meal (meal N) or high protein meal (meal H) at dinner. Forearm venous blood was collected, and plasma amino acid concentrations were measured before dinner and the next morning. We found that a high protein meal in the evening that contained 40% energy would significantly increase the PFAA concentration the next morning, even more than 12 hours after the meal. Among amino acids, the most significant difference was observed in the branched-chain amino acids (BCAAs) and in some urea-cycle related compounds. If the subject consumed the high protein diet at dinner, the PFAA profile after overnight fasting might be still affected by the meal even 12 hours after the meal, suggesting that the PFAA profile does not reflect the subject's health condition, but rather the acute effect of high protein ingestion.

  7. Laughter is the Best Medicine? A Cross-Sectional Study of Cardiovascular Disease Among Older Japanese Adults

    PubMed Central

    Hayashi, Kei; Kawachi, Ichiro; Ohira, Tetsuya; Kondo, Katsunori; Shirai, Kokoro; Kondo, Naoki

    2016-01-01

    Background We sought to evaluate the associations between frequency of daily laughter with heart disease and stroke among community-dwelling older Japanese women and men. Methods We analyzed cross-sectional data in 20 934 individuals (10 206 men and 10 728 women) aged 65 years or older, who participated in the Japan Gerontological Evaluation Study in 2013. In the mail-in survey, participants provided information on daily frequency of laughter, as well as body mass index, demographic and lifestyle factors, and diagnoses of cardiovascular disease, hyperlipidemia, hypertension, and depression. Results Even after adjustment for hyperlipidemia, hypertension, depression, body mass index, and other risk factors, the prevalence of heart diseases among those who never or almost never laughed was 1.21 (95% CI, −1.03–1.41) times higher than those who reported laughing every day. The adjusted prevalence ratio for stroke was 1.60 (95% CI, 1.24–2.06). Conclusions Daily frequency of laughter is associated with lower prevalence of cardiovascular diseases. The association could not be explained by confounding factors, such as depressive symptoms. PMID:26972732

  8. Effects of tritiated water on germ cells in medaka embryos.

    PubMed

    Etoh, H; Hyodo-Taguchi, Y

    1983-02-01

    Embryos of medaka, Oryzias latipes, were exposed to tritiated water and 137Cs gamma rays continuously from the one-cell stage until hatching (10 days at 26 degrees C). Germ cells in the gonads of newly hatched fry were counted in histological sections and compared with controls. The accumulated dose for 50% survival of germ cells was 195 rad for tritium beta rays and 350 rad for 137Cs gamma rays. Female progeny were produced using Yamamoto's method. The 50% survival doses for female germ cells treated in a manner similar to that described above were 140 rad for beta rays and 305 rad for gamma rays. When embryos of medaka were irradiated with gamma rays below an accumulated dose of 475 rad or treated with tritiated water at a concentration of 0.2 mCi/ml or lower, the dose response of the germ cells showed an exponential relationship. It appeared that there was no threshold or significant dose-rate effect for either beta or gamma rays on germ cell survival, and that tritium beta rays were more effective than 137Cs gamma rays in germ cell killing.

  9. A detailed linkage map of medaka, Oryzias latipes: comparative genomics and genome evolution.

    PubMed Central

    Naruse, K; Fukamachi, S; Mitani, H; Kondo, M; Matsuoka, T; Kondo, S; Hanamura, N; Morita, Y; Hasegawa, K; Nishigaki, R; Shimada, A; Wada, H; Kusakabe, T; Suzuki, N; Kinoshita, M; Kanamori, A; Terado, T; Kimura, H; Nonaka, M; Shima, A

    2000-01-01

    We mapped 633 markers (488 AFLPs, 28 RAPDs, 34 IRSs, 75 ESTs, 4 STSs, and 4 phenotypic markers) for the Medaka Oryzias latipes, a teleost fish of the order Beloniformes. Linkage was determined using a reference typing DNA panel from 39 cell lines derived from backcross progeny. This panel provided unlimited DNA for the accumulation of mapping data. The total map length of Medaka was 1354.5 cM and 24 linkage groups were detected, corresponding to the haploid chromosome number of the organism. Thirteen to 49 markers for each linkage group were obtained. Conserved synteny between Medaka and zebrafish was observed for 2 independent linkage groups. Unlike zebrafish, however, the Medaka linkage map showed obvious restriction of recombination on the linkage group containing the male-determining region (Y) locus compared to the autosomal chromosomes. PMID:10747068

  10. Interordinal chimera formation between medaka and zebrafish for analyzing stem cell differentiation.

    PubMed

    Hong, Ni; Chen, Songlin; Ge, Ruowen; Song, Jianxing; Yi, Meisheng; Hong, Yunhan

    2012-08-10

    Chimera formation is a standard test for pluripotency of stem cells in vivo. Interspecific chimera formation between distantly related organisms offers also an attractive approach for propagating endangered species. Parameters influencing interspecies chimera formation have remained poorly elucidated. Here, we report interordinal chimera formation between medaka and zebrafish, which separated ∼320 million years ago and exhibit a more than 2-fold difference in developmental speed. We show that, on transplantation into zebrafish blastulae, both noncultivated blastomeres and long-term cultivated embryonic stem (ES) cells of medaka adopted the zebrafish developmental program and differentiated into physiologically functional cell types including pigment cells, blood cells, and cardiomyocytes. We also show that medaka ES cells express differentiation gene markers during chimeric embryogenesis. Therefore, the evolutionary distance and different embryogenesis speeds do not produce donor-host incompatibility to compromise chimera formation between medaka and zebrafish, and molecular markers are valuable for analyzing lineage commitment and cell differentiation in interspecific chimeric embryos.

  11. Changes in expression of hepatic genes involved in energy metabolism during hibernation in captive, adult, female Japanese black bears (Ursus thibetanus japonicus).

    PubMed

    Shimozuru, Michito; Kamine, Akari; Tsubota, Toshio

    2012-10-01

    Hibernating bears survive up to 6 months without feeding by utilizing stored body fat as fuel. To investigate how bears maintain energy homeostasis during hibernation, we analyzed changes in mRNA expression of hepatic genes involved in energy metabolism throughout the hibernation period in captive, adult, female Japanese black bears (Ursus thibetanus japonicus). Real-time PCR analysis revealed down-regulation of glycolysis- (e.g., glucokinase), amino acid catabolism- (e.g., alanine aminotransferase) and de novo lipogenesis-related genes (e.g., acetyl-CoA carboxylase 1), and up-regulation of gluconeogensis- (e.g., pyruvate carboxylase), β-oxidation- (i.e., uncoupling protein 2) and ketogenesis-related genes (i.e., 3-hydroxy-3-methylglutary-CoA synthase 2), during hibernation, compared to the active period (June). In addition, we found that glycolysis-related genes (i.e., glucokinase and pyruvate kinase) were more suppressed in the early phase of hibernation (January) compared to the late phase (March). One week after the commencement of feeding in April, expression levels of most genes returned to levels comparable to those seen in June, but β-oxidation-related genes were still up-regulated during this period. These results suggest that the modulation of gene expression is not static, but changes throughout the hibernation period. The transcriptional modulation during hibernation represents a unique physiological adaptation to prolonged fasting in bears.

  12. Sex differences in whole body skeletal muscle mass measured by magnetic resonance imaging and its distribution in young Japanese adults

    PubMed Central

    Abe, T; Kearns, C; Fukunaga, T

    2003-01-01

    Objectives: To determine sex differences in the distribution of regional and total skeletal muscle (SM) using contiguous whole body magnetic resonance imaging (MRI) data, and to examine the relations between fat free mass (FFM) and total and regional SM masses. Methods: A total of 20 Japanese college students (10 women and 10 men) volunteered for the study. FFM was measured by two compartment densitometry. Whole body MRI images were prepared using a 1.5 T scanner. Contiguous transverse images with 1.0 cm slice thickness were obtained from the first cervical vertebra to the ankle joints. All MRI scans were segmented into four components (SM, subcutaneous adipose tissue, bone, and residual tissues). In each slice, the SM tissue cross sectional areas (CSAs) were digitised, and the muscle tissue volume per slice was calculated by multiplying muscle CSA by slice thickness. SM volume units (litres) were converted into mass units (kg) by multiplying the volumes by the assumed constant density (1.041 mg/ml) for SM. Results: The SM distribution pattern (shape of curve) from the contiguous whole body slices was essentially similar for the two sexes, with two large peaks and three smaller peaks (arms excluded). However, the largest peak was observed at the upper portion of the thigh for women and at the level of the shoulder for men. Men had larger (p<0.01) total and regional SM mass than women. All regional SM masses correlated highly (r = 0.90–0.99, p<0.01) with total SM mass. A strong positive correlation was observed between FFM and total and regional SM masses in both sexes (women, r = 0.95; men, r = 0.90; all p<0.01). As FFM increased, there was a corresponding increase in SM/FFM ratio for all subjects (r = 0.86, p<0.01). Conclusions: Sex differences in total SM/FFM ratio and regional SM distributions are associated with the degree of absolute FFM accumulation in men and women. PMID:14514537

  13. Omics of the marine medaka (Oryzias melastigma) and its relevance to marine environmental research.

    PubMed

    Kim, Bo-Mi; Kim, Jaebum; Choi, Ik-Young; Raisuddin, Sheikh; Au, Doris W T; Leung, Kenneth M Y; Wu, Rudolf S S; Rhee, Jae-Sung; Lee, Jae-Seong

    2016-02-01

    In recent years, the marine medaka (Oryzias melastigma), also known as the Indian medaka or brackish medaka, has been recognized as a model fish species for ecotoxicology and environmental research in the Asian region. O. melastigma has several promising features for research, which include a short generation period (3-4 months), daily spawning, small size (3-4 cm), transparent embryos, sexual dimorphism, and ease of mass culture in the laboratory. There have been extensive transcriptome and genome studies on the marine medaka in the past decade. Such omics data can be useful in understanding the signal transduction pathways of small teleosts in response to environmental stressors. An omics-integrated approach in the study of the marine medaka is important for strengthening its role as a small fish model for marine environmental studies. In this review, we present current omics information about the marine medaka and discuss its potential applications in the study of various molecular pathways that can be targets of marine environmental stressors, such as chemical pollutants. We believe that this review will encourage the use of this small fish as a model species in marine environmental research.

  14. Association of oxytocin level and less severe forms of childhood maltreatment history among healthy Japanese adults involved with child care

    PubMed Central

    Mizuki, Rie; Fujiwara, Takeo

    2015-01-01

    Background: Oxytocin (OT) is known to play a role in stress regulation. The association between childhood maltreatment history and neuropeptide OT concentration is inconsistent due to the varying degrees of severity of childhood maltreatment, among other contributing factors. Less severe forms of childhood maltreatment history might enhance OT concentrations as a response to coping with social stress within the family. The purpose of this study is to investigate the association between less severe forms of childhood maltreatment history and OT concentrations among healthy adults. Method: Eighty adults (49 women and 31 men) with 18- to 48-month-old children were recruited using a snowball sample in Tokyo, Japan. Urine samples were collected for OT measurement. Less severe (low and moderate) childhood maltreatment history, including physical abuse, physical neglect, emotional abuse, emotional neglect, and sexual abuse, was assessed using the self-report questionnaire, the Childhood Trauma Questionnaire. Results: Less severe physical abuse was significantly associated with higher OT concentration after adjusting for age (p = 0.014). Also, less severe forms of physical abuse were independently significantly associated with higher OT concentration after controlling for other types of childhood maltreatment (p = 0.027). A positive dose-response association between the number of less severe childhood maltreatment types and OT concentration was observed (p = 0.031). Conclusion: A history of less severe forms of childhood physical abuse was associated with higher OT concentration in healthy adults. Poly-victimization of several types of less severe childhood maltreatment was also associated with higher OT concentrations. Less severe forms of childhood maltreatment might enhance OT concentrations in order to cope with social stress. PMID:26157369

  15. Leptin receptor-deficient (knockout) medaka, Oryzias latipes, show chronical up-regulated levels of orexigenic neuropeptides, elevated food intake and stage specific effects on growth and fat allocation.

    PubMed

    Chisada, Shin-ichi; Kurokawa, Tadahide; Murashita, Koji; Rønnestad, Ivar; Taniguchi, Yoshihito; Toyoda, Atsushi; Sakaki, Yoshiyuki; Takeda, Shunichi; Yoshiura, Yasutoshi

    2014-01-01

    The first studies that identified leptin and its receptor (LepR) in mammals were based on mutant animals that displayed dramatic changes in body-weight and regulation of energy homeostasis. Subsequent studies have shown that a deficiency of leptin or LepR in homoeothermic mammals results in hyperphagia, obesity, infertility and a number of other abnormalities. The physiological roles of leptin-mediated signaling in ectothermic teleosts are still being explored. Here, we produced medaka with homozygous LepR gene mutation using the targeting induced local lesions in a genome method. This knockout mutant had a point mutation of cysteine for stop codon at the 357th amino acid just before the leptin-binding domain. The evidence for loss of function of leptin-mediated signaling in the mutant is based on a lack of response to feeding in the expression of key appetite-related neuropeptides in the diencephalon. The mutant lepr−/− medaka expressed constant up-regulated levels of mRNA for the orexigenic neuropeptide Ya and agouti-related protein and a suppressed level of anorexigenic proopiomelanocortin 1 in the diencephalon independent of feeding, which suggests that the mutant did not possess functional LepR. Phenotypes of the LepR-mutant medaka were analyzed in order to understand the effects on food intake, growth, and fat accumulation in the tissues. The food intake of the mutant medaka was higher in post-juveniles and adult stages than that of wild-type (WT) fish. The hyperphagia led to a high growth rate at the post-juvenile stage, but did not to significant alterations in final adult body size. There was no additional deposition of fat in the liver and muscle in the post-juvenile and adult mutants, or in the blood plasma in the adult mutant. However, adult LepR mutants possessed large deposits of visceral fat, unlike in the WT fish, in which there were none. Our analysis confirms that LepR in medaka exert a powerful influence on the control on food intake. Further

  16. Estimated tooth loss based on number of present teeth in Japanese adults using national surveys of dental disease.

    PubMed

    Yoshino, Koichi; Ishizuka, Yoichi; Fukai, Kakuhiro; Takiguchi, Toru; Sugihara, Naoki

    2015-01-01

    Oral health instruction for adults should take into account the potential effect of tooth loss, as this has been suggested to predict further tooth loss. Therefore, the purpose of this study was to determine whether further tooth loss could be predicted from the number of present teeth (PT). We employed the same method as in our previous study, this time using two national surveys of dental disease, which were deemed to represent a generational cohort. Percentiles were estimated using the cumulative frequency distribution of PT from the two surveys. The first was a survey of 704 participants aged 50-59 years conducted in 2005, and the second was a survey of 747 participants aged 56-65 years conducted in 2011. The 1st to 100th percentiles of the number of PT were calculated for both age groups. Using these percentiles and a generational cohort analysis based on the two surveys, the number of teeth lost per year could be calculated. The distribution of number of teeth lost generated a convex curve. Peak tooth loss occurred at around 12-14 PT, with 0.54 teeth being lost per year. The percentage of teeth lost (per number of PT) increased as number of PT decreased. The results confirmed that tooth loss promotes further tooth loss. These data should be made available for use in adult oral health education.

  17. Cellular Immune Responses to Live Attenuated Japanese Encephalitis (JE) Vaccine SA14-14-2 in Adults in a JE/Dengue Co-Endemic Area

    PubMed Central

    Tatullo, Filippo; Bali, Tanushka; Ravi, Vasanthapuram; Soni, Mohammed; Chan, Sajesh; Chib, Savita; Venkataswamy, Manjunatha M.; Fadnis, Prachi; Yaïch, Mansour; Fernandez, Stefan; Klenerman, Paul; Satchidanandam, Vijaya; Solomon, Tom

    2017-01-01

    Background Japanese encephalitis (JE) virus (JEV) causes severe epidemic encephalitis across Asia, for which the live attenuated vaccine SA14-14-2 is being used increasingly. JEV is a flavivirus, and is closely related to dengue virus (DENV), which is co-endemic in many parts of Asia, with clinically relevant interactions. There is no information on the human T cell response to SA14-14-2, or whether responses to SA14-14-2 cross-react with DENV. We used live attenuated JE vaccine SA14-14-2 as a model for studying T cell responses to JEV infection in adults, and to determine whether these T cell responses are cross-reactive with DENV, and other flaviviruses. Methods We conducted a single arm, open label clinical trial (registration: clinicaltrials.gov NCT01656200) to study T cell responses to SA14-14-2 in adults in South India, an area endemic for JE and dengue. Results Ten out of 16 (62.5%) participants seroconverted to JEV SA14-14-2, and geometric mean neutralising antibody (NAb) titre was 18.5. Proliferation responses were commonly present before vaccination in the absence of NAb, indicating a likely high degree of previous flavivirus exposure. Thirteen of 15 (87%) participants made T cell interferon-gamma (IFNγ) responses against JEV proteins. In four subjects tested, at least some T cell epitopes mapped cross-reacted with DENV and other flaviviruses. Conclusions JEV SA14-14-2 was more immunogenic for T cell IFNγ than for NAb in adults in this JE/DENV co-endemic area. The proliferation positive, NAb negative combination may represent a new marker of long term immunity/exposure to JE. T cell responses can cross-react between JE vaccine and DENV in a co-endemic area, illustrating a need for greater knowledge on such responses to inform the development of next-generation vaccines effective against both diseases. Trial Registration clinicaltrials.gov (NCT01656200) PMID:28135273

  18. Oral conditions and dysphagia in Japanese, community-dwelling middle- and older- aged adults, independent in daily living

    PubMed Central

    Inui, Akinari; Takahashi, Ippei; Kurauchi, Sizuka; Soma, Yuki; Oyama, Toshiaki; Tamura, Yoshihiro; Noguchi, Takao; Murashita, Kouichi; Nakaji, Shigeyuki; Kobayashi, Wataru

    2017-01-01

    Purpose Prevention, early detection and effective rehabilitation of dysphagia are important issues to be considered in an aging society. Previous studies have shown conflicting findings regarding the association between dysphagia and its potential risk factors, including age, malnutrition, oral conditions, lifestyle and medical history. Herein, we assessed the prevalence and association of dysphagia with potential risk factors in 50- to 79-year-old adults dwelling in a community in Japan. Patients and methods In this study, there were 532 participants (185 males and 347 females). Participants who responded positively to the question “Do you sometimes choke on drinks/food such as tea and soup?” or those who presented with abnormal repetitive saliva swallowing test findings were diagnosed with dysphagia. The data collected from these participants included the following: number of teeth, occurrence of oral dryness, age, body mass index, serum albumin concentration, smoking, drinking and exercise habits, presence of diseases, such as diabetes mellitus and hypertension, and questions from the Mini–Mental State Examination. Results Dysphagia was observed in 33 males (17.8%) and 76 females (21.9%). To explore the effect of the potential risk factors on the prevalence of dysphagia, a model was built by multivariate logistic regression analysis. Using the forced entry method, oral dryness (odds ratio [OR] =3.683 and P=0.003 in males; OR =1.797 and P=0.032 in females) and the number of teeth (OR =0.946 and P=0.038 in males) were found to be significantly related to dysphagia. Conclusion This cross-sectional study demonstrated associations between oral conditions and dysphagia. Factors such as oral dryness and number of teeth may contribute to dysphagia more so than aging, lifestyle and comorbidity in community-dwelling adults over the age of 50. PMID:28352164

  19. Conserved Expression Signatures between Medaka and Human Pigment Cell Tumors

    PubMed Central

    Schartl, Manfred; Kneitz, Susanne; Wilde, Brigitta; Wagner, Toni; Henkel, Christiaan V.; Spaink, Herman P.; Meierjohann, Svenja

    2012-01-01

    Aberrations in gene expression are a hallmark of cancer cells. Differential tumor-specific transcript levels of single genes or whole sets of genes may be critical for the neoplastic phenotype and important for therapeutic considerations or useful as biomarkers. As an approach to filter out such relevant expression differences from the plethora of changes noted in global expression profiling studies, we searched for changes of gene expression levels that are conserved. Transcriptomes from massive parallel sequencing of different types of melanoma from medaka were generated and compared to microarray datasets from zebrafish and human melanoma. This revealed molecular conservation at various levels between fish models and human tumors providing a useful strategy for identifying expression signatures strongly associated with disease phenotypes and uncovering new melanoma molecules. PMID:22693581

  20. Sequential organogenesis sets two parallel sensory lines in medaka

    PubMed Central

    Seleit, Ali; Krämer, Isabel; Ambrosio, Elizabeth; Dross, Nicolas; Engel, Ulrike

    2017-01-01

    Animal organs are typically formed during embryogenesis by following one specific developmental programme. Here, we report that neuromast organs are generated by two distinct and sequential programmes that result in parallel sensory lines in medaka embryos. A ventral posterior lateral line (pLL) is composed of neuromasts deposited by collectively migrating cells whereas a midline pLL is formed by individually migrating cells. Despite the variable number of neuromasts among embryos, the sequential programmes that we describe here fix an invariable ratio between ventral and midline neuromasts. Mechanistically, we show that the formation of both types of neuromasts depends on the chemokine receptor genes cxcr4b and cxcr7b, illustrating how common molecules can mediate different morphogenetic processes. Altogether, we reveal a self-organising feature of the lateral line system that ensures a proper distribution of sensory organs along the body axis. PMID:28087632

  1. Skipping breakfast and less exercise are risk factors for bone loss in young Japanese adults: a 3-year follow-up study.

    PubMed

    Nagata, Keiji; Yoshida, Munehito; Ishimoto, Yuyu; Hashizume, Hiroshi; Yamada, Hiroshi; Yoshimura, Noriko

    2014-07-01

    Although bone loss contributes to osteoporosis (OP) in the elderly, little is known about changes in bone mineral density (BMD) in young adults that lead to bone loss. Here, we evaluated the rate of bone change and risk factors for bone loss in young men and women using data from a 3-year prospective study of Japanese medical students. The study included a self-administrated questionnaire survey, anthropometric measurements, and BMD measurements of the spine (L2-L4) and femoral neck (FN). After 3 years, the BMD of the participants was again measured at the same sites. In all, 458 students (95.4 %; 298 men and 160 women; age range, 18-29 years; mean age, 20.2 years) completed both the baseline and follow-up surveys. The mean L2-L4 BMD value at baseline increased significantly within 3 years. This tendency was also observed for the FN in men but not in women. The annual changes at L2-L4 were 1.78 % in men and 0.97 % in women per year; those for FN were 1.08 % in men and 0.08 % in women per year. However, 20.3 % and 38.5 % of the total freshmen lost BMD in the lumbar spine and FN, respectively. After adjustment for age and body mass index, logistic regression analysis revealed that bone loss in men at L2-L4 at the baseline was affected by skipping breakfast. In contrast, exercise (>2 h/week) increased lumbar spine BMD in both genders. These findings indicate that breakfast and exercise are important for maintaining BMD in young men and women.

  2. Expression of GFP in nuclear transplants generated by transplantation of embryonic cell nuclei from GFP-transgenic fish into nonenucleated eggs of medaka, Oryzias latipes.

    PubMed

    Niwa, K; Kani, S; Kinoshita, M; Ozato, K; Wakamatsu, Y

    2000-01-01

    In order to investigate whether foreign genes can be used as genetic markers of donor nuclei in fish nuclear transplantation, expression of the GFP gene derived from donor nuclei was examined in nuclear transplants in medaka (Oryzias latipes). Embryonic nuclei were obtained from blastula embryos produced by crossing of transgenic fish of the wild-type strain heterozygous for the GFP gene with nontransgenic ones or by mutual crossing between transgenic fish. The GFP gene was driven by the promoter of the medaka elongation factor gene, EF-1alpha-A, which is known to induce GFP expression in many tissues except for the muscle in the transgenic fish. The nuclei were transplanted into nonenucleated unfertilized eggs of the orange-red strain. Adult nuclear transplants were successfully obtained at the rate of about 2% of the operated eggs. They were triploid and had no reproductive potential. The GFP gene was expressed in embryos, fry, and adults of nuclear transplants in a pattern similar to that in the transgenic fish. These results indicate that GFP is useful as a foreign genetic marker of donor nuclei in fish nuclear transplantation.

  3. Purification and molecular cloning of aspartic proteinases from the stomach of adult Japanese fire belly newts, Cynops pyrrhogaster.

    PubMed

    Nagasawa, Tatsuki; Sano, Kaori; Kawaguchi, Mari; Kobayashi, Ken-Ichiro; Yasumasu, Shigeki; Inokuchi, Tomofumi

    2016-04-01

    Six aspartic proteinase precursors, a pro-cathepsin E (ProCatE) and five pepsinogens (Pgs), were purified from the stomach of adult newts (Cynops pyrrhogaster). On sodium dodecylsulfate-polyacrylamide gel electrophoresis, the molecular weights of the Pgs and active enzymes were 37-38 kDa and 31-34 kDa, respectively. The purified ProCatE was a dimer whose subunits were connected by a disulphide bond. cDNA cloning by polymerase chain reaction and subsequent phylogenetic analysis revealed that three of the purified Pgs were classified as PgA and the remaining two were classified as PgBC belonging to C-type Pg. Our results suggest that PgBC is one of the major constituents of acid protease in the urodele stomach. We hypothesize that PgBC is an amphibian-specific Pg that diverged during its evolutional lineage. PgBC was purified and characterized for the first time. The purified urodele pepsin A was completely inhibited by equal molar units of pepstatin A. Conversely, the urodele pepsin BC had low sensitivity to pepstatin A. In acidic condition, the activation rates of newt pepsin A and BC were similar to those of mammalian pepsin A and C1, respectively. Our results suggest that the enzymological characters that distinguish A- and C-type pepsins appear to be conserved in mammals and amphibians.

  4. The interaction effects of binary mixtures of benzene and toluene on the developing heart of medaka (Oryzias latipes).

    PubMed

    Teuschler, Linda K; Gennings, Chris; Hartley, William R; Carter, Hans; Thiyagarajah, Arunthavarani; Schoeny, Rita; Cubbison, Chris

    2005-03-01

    The United States Environmental Protection Agency (USEPA) has pursued the estimation of risk of adverse health effects from exposure to chemical mixtures since the early 1980s. Methods used to calculate risk estimates of mixtures were often based on single chemical information that required assumptions of dose-addition or response-addition and did not consider possible changes in response due to interaction effects among chemicals. Full factorial designs for laboratory studies can produce interactions information, but these are expensive to perform and may not provide the information needed to evaluate specific environmentally relevant mixtures. In this research, groups of Japanese medaka (Oryzias latipes) embryos were exposed to binary mixtures of benzene and toluene as well as to each of these chemicals alone. Endpoint specific dose-response models were built for the hydrocarbon mixture under an assumption of dose-additivity, using the single chemical dose-response information on benzene and toluene. The endpoints included heart rate, heart rate progression, and lethality. Results included a synergistic response for heart rate at 72 h of development, and either additivity or antagonism for all other endpoints at 96 h of development. This work uses an established statistical method to evaluate the toxicity of an environmentally relevant mixture to ascertain whether interaction effects are occurring, thus providing additional information on toxicity.

  5. Neoplastic and nonneoplastic liver lesions induced by dimethylinitrosamine in Japanese Medaka fish

    EPA Science Inventory

    Small fish models are becoming commonplace in the laboratory, and have been used for decades in chemical toxicity and carcinogenicity testing. However, extrapolation of findings from aquatic models to humans is still a concern in risk assessment. Demonstration of common morpholog...

  6. Effects of Silver Nanoparticles on Japanese Medaka (Oryzias latipes) and Daphnia magna

    EPA Science Inventory

    The introduction of nanoparticles into a variety of consumer products has raised questions about the potential effects of environmental release, and particularly whether the presence of materials at the nano-scale creates potential risks not associated with the bulk materials. C...

  7. Quantitative oral dosing of water soluble and lipophilic contaminants in the Japanese medaka (Oryzias latipes).

    PubMed

    Schultz, I R; Reed, S; Pratt, A; Skillman, A D

    2007-02-01

    Quantitative oral dosing in fish can be challenging, particularly with water soluble contaminants, which can leach into the aquarium water prior to ingestion. We applied a method of bioencapsulation using newly hatched brine shrimp (Artemia franciscana) nauplii to study the toxicokinetics of five chlorinated and brominated halogenated acetic acids (HAAs), which are drinking water disinfection by-products. These results are compared to those obtained in a previous study using a polybrominated diphenyl ether (PBDE-47), a highly lipophilic chemical. The HAAs and PBDE-47 were bioencapsulated using freshly hatched A. franciscana nauplii after incubation in concentrated solutions of the study chemicals for 18 h. Aliquots of the brine shrimp were quantitatively removed for chemical analysis and fed to individual fish that were able to consume 400-500 nauplii in less than 5 min. At select times after feeding, fish were euthanized and the HAA or PBDE-47 content determined. The absorption of HAAs was quantitatively similar to previous studies in rodents: rapid absorption with peak body levels occurring within 1-2 h, then rapidly declining with elimination half-life of 0.3-3 h depending on HAA. PBDE-47 was more slowly absorbed with peak levels occurring by 18 h and very slowly eliminated with an elimination half-life of 281 h.

  8. Chronic exposure to diclofenac on two freshwater cladocerans and Japanese medaka.

    PubMed

    Lee, Jinyoung; Ji, Kyunghee; Lim Kho, Young; Kim, Pilje; Choi, Kyungho

    2011-07-01

    Consequences of long-term exposure to diclofenac up to 3 months were evaluated using freshwater crustaceans (Daphnia magna and Moina macrocopa) and a fish (Oryzias latipes). Marked decrease of reproduction was observed at 25 mg/L for D. magna, and at 50 mg/L for M. macrocopa. Three-month exposure of fish to 0.001-10 mg/L of diclofenac resulted in significant decreasing trend in hatching success and delay in hatch. The hatching of the eggs produced from the fish exposed to 10 mg/L was completely interfered, while fertility of the parent generation was not affected. Gonadosomatic index (GSI) of female fish was also affected at 10 mg/L. Predicted no effect concentration of diclofenac was estimated at 0.1 mg/L, which is a few orders of magnitude greater than those observed in ambient water. Therefore direct impact of diclofenac exposure is not expected. However its bioaccumulation potential through food web should warrant further evaluation.

  9. Quantitative oral dosing of water soluble and lipophilic contaminants in the Japanese medaka (Oryzias latipes)

    SciTech Connect

    Schultz, Irv; Reed, Stacey M.; Pratt, Amanda V.; Skillman, Ann D.

    2007-02-01

    Quantitative oral dosing in fish can be challenging, particularly with water soluble contaminants, which can leach into the aquarium water prior to ingestion. We applied a method of bioencapsulation using newly hatched brine shrimp (Artemia franciscana) nauplii to study the toxicokinetics of five chlorinated and brominated halogenated acetic acids (HAAs), which are drinking water disinfection by-products. These results are compared to those obtained in a previous study using a polybrominated diphenyl ether (PBDE-47), a highly lipophilic chemical. The HAAs and PBDE-47 were bioencapsulated using freshly hatched A. franciscana nauplii after incubation in concentrated solutions of the study chemicals for 18 h. Aliquots of the brine shrimp were quantitatively removed for chemical analysis and fed to individual fish that were able to consume 400–500 nauplii in less than 5min. At select times after feeding, fish were euthanized and the HAA or PBDE-47 content determined. The absorption of HAAs was quantitatively similar to previous studies in rodents: rapid absorptionwith peak body levels occurringwithin 1–2 h, then rapidly declining with elimination half-life of 0.3–3 h depending on HAA. PBDE-47 was more slowly absorbed with peak levels occurring by 18 h and very slowly eliminated with an elimination half-life of 281 h.

  10. Chronic Mycobacterium marinum Infection Acts as a Tumor Promoter in Japanese Medaka (Oryzias latipes)

    EPA Science Inventory

    An accumulating body of research indicates there is an increased cancer risk associated with chronic infections. The genus Mycobacterium contains a number of species, including M tuberculosis, which mount chronic infections and have been implicated in higher cancer risk. Several ...

  11. Toxic responses of medaka, d-rR strain, to polychlorinated naphthalene mixtures after embryonic exposure by in ovo nanoinjection: A partial life-cycle assessment

    SciTech Connect

    Villalobos, S.A.; Papoulias, D.M.; Meadows, J.; Blankenship, A.L.; Pastva, S.D.; Kannan, K.; Hinton, D.E.; Tillitt, D.E.; Giesy, J.P.

    2000-02-01

    Polychlorinated naphthalenes (PCNs) are organic compounds with some chemical properties and uses similar to polychlorinated biphenyls. Polychlorinated naphthalenes have been detected in biota from certain aquatic environments. The toxicities of several PCN technical mixtures (Halowax) to medaka (Oryzias latipes) were determined by use of an embryo nanoinjection method. Medaka eggs (early gastrula) were injected with 0.5 nl of triolein (vehicle control) or 0.5 nl of four to five graded doses (0.3--30 ng/egg) of Halowax 1014, Halowax 1013, or Halowax 1051 in triolein. Following exposure, embryos developed, and fry were reared to sexual maturity (4 months), at which time they were euthanized. Responses were evaluated as early life stage (ELS) and early adult life stage (EALS) assessments. For ELS, lethality and sublethal alterations in embryos and larvae (<16 d old), such as craniofacial, cardiovascular, and myoskeletal deformities and abnormal or delayed hatch, were monitored for the first 9 d, and a dose severity index was computed. The EALS assessment examined the survival of 16-d-old larvae until early adulthood (123 {+-} 3 d old), including gonadosomatic index (GSI) and morphometry. Halowax 1014 was found to be the most toxic mixture (LD50 4.2 ng/egg), whereas Halowax 1013 and 1051 were significantly less toxic (LD50s could not be determined). The gonadosomatic index of females was significantly less in fish dosed with Halowax 1014 or 1051. The LD50 for medaka embryos nanoinjected with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is about 0.75 pg/egg. Thus, Halowax 1014 was 5,585-fold less potent than TCDD. For Halowax 1014, ELS assessments accurately predicted the results of EALS assessments.

  12. Toxic responses of medaka, D-rR strain, to polychlorinatednaphthalene mixtures after embryonic exposure by in ovo nanoinjection: A partial life-cycle assessment

    USGS Publications Warehouse

    Villalobos, Sergio A.; Papoulias, Diana M.; Meadows, John C.; Blankenship, Alan L.; Pastva, Stephanie D.; Kannan, Kurunthachalam; Hinton, D.E.; Tillitt, Donald E.; Giesy, John P.

    2000-01-01

    Polychlorinated naphthalenes (PCNs) are organic compounds with some chemical properties and uses similar to polychlorinated biphenyls. Polychlorinated naphthalenes have been detected in biota from certain aquatic environments. The toxicities of several PCN technical mixtures (Halowax) to medaka (Oryzias latipes) were determined by use of an embryo nanoinjection method. Medaka eggs (early gastrula) were injected with 0.5 nl of triolein (vehicle control) or 0.5 nl of four to five graded doses (0.3-30 ng/egg) of Halowax 1014, Halowax 1013, or Halowax 1051 in triolein. Following exposure, embryos developed, and fry were reared to sexual maturity (4 months), at which time they were euthanized. Responses were evaluated as early life stage (ELS) and early adult life stage (EALS) assessments. For ELS, lethality and sublethal alterations in embryos and larvae ( < 16 d old), such as craniofacial, cardiovascular, and myoskeletal deformities and abnormal or delayed hatch, were monitored for the first 9 d, and a dose severity index was computed. The EALS assessment examined the survival of 16-d-old larvae until early adulthood (123 ?? 3 d old), including gonadosomatic index (GSI) and morphometry. Halowax 1014 was found to be the most toxic mixture (LD50 4.2 ng/egg), whereas Halowax 1013 and 1051 were significantly less toxic (LD50s could not be determined). The gonadosomatic index of females was significantly less in fish dosed with Halowax 1014 or 1051. The LD50 for medaka embryos nanoinjected with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is about 0.75 pg/egg. Thus, Halowax 1014 was 5,585-fold less potent than TCDD. For Halowax 1014, ELS assessments accurately predicted the results of EALS assessments.

  13. Identification, Prokaryote Expression of Medaka gdnfa/b and Their Biological Activity in a Spermatogonial Cell Line.

    PubMed

    Wei, Jing; Liu, Linyan; Fan, Zhenhua; Hong, Yunhan; Zhao, Yang; Zhou, Linyan; Wang, Deshou

    2017-02-01

    The origin and evolution of molecular mechanisms underlying the self-renewal and differentiation of spermatogonial stem cells (SSCs) are fundamental questions in stem cell biology as well as reproduction medicine. In mammals, glial cell line-derived neurotrophic factor (GDNF) is crucial for SSC self-renewal and maintenance. However, in nonmammals, the role of Gdnf in SSCs still remains unknown. In this study, we report that the two GDNF homologs from medaka fish (Oryzias latipes), namely OlGdnfa and OlGdnfb, can promote proliferation activity and retain the spermatogonial property of SG3, a spermatogonial cell line derived from adult medaka showing the intrinsic property of SSCs by self-renewal and differentiation potential during 2 years of culture. Cloning and sequencing led to the identification of two cDNA sequences as Olgdnfa and Olgdnfb, which are 780-nt and 744-nt in length for 253 and 245 amino acid residues, respectively. Both are homologs of mammalian GDNF and share over 45% identity with the other known vertebrate homologs. Importantly, in a well-defined condition, the recombinant proteins, OlGdnfa and OlGdnfb, can significantly promote the proliferative activity of SG3 cells and retain the spermatogonial gene expression pattern and alkaline phosphatase activity. Meanwhile, both of the two recombinant proteins can upregulate the mRNA expression level of bcl6b, one of the prominent GDNF-regulated genes involved in SSC self-renewal and maintenance in mammals. Taken together, our findings suggest that just like the mammalian counterpart, the nonmammalian Gdnfs might mediate the self-renewal and maintenance of SSCs; moreover, Bcl6b might be a conserved regulator in SSC self-renewal across vertebrate taxa. This study extends our knowledge of GDNF functions in SSC biology during evolution.

  14. Novel insights into iron regulation and requirement in marine medaka Oryzias melastigma.

    PubMed

    Wang, Jian; Wang, Wen-Xiong

    2016-05-24

    Iron (Fe) is an essential trace element for marine fish. However, our knowledge of Fe requirements at different development stages of marine fish is still limited. Here, we reported the efficient Fe absorption strategies adopted by larval fish under different dietary Fe supplementary levels (i.e., 0-640 mg/kg). Biokinetically, the larval fish controlled their dietary Fe assimilation efficiency (AE, 1.6-18.5%), and enhanced their waterborne Fe uptake (ca. 2.5 fold change of uptake rate constant) once the dietary Fe was deficient (i.e., 27.4 mg Fe/kg feed). Transcriptionally, the expression of hepcidin1 (hep1; Fe regulator; i.e., 2.3-15.7 fold change) in larval fish was positively correlated with the Fe supplementary levels. Comparatively, the female adult fish were poor in assimilating the added Fe source (i.e., ferric form) with similar life-sustainable levels of Fe (i.e., 0.046-0.12 μg/g/d assimilated for Fe supplementary levels of 27.4, 162 and 657 mg Fe/kg feed). The overall feeding experiments suggested that dietary net Fe flux sufficient for the normal growth of larval medaka was 0.71-1.75 μg/g/d (i.e., 83.9 mg Fe/kg feed), consistent with the modeled value (i.e., 1.09-2.16 μg/g/d). In female adults, the estimated essential net Fe flux was 0.88-0.90 μg/g/d.

  15. Novel insights into iron regulation and requirement in marine medaka Oryzias melastigma

    PubMed Central

    Wang, Jian; Wang, Wen-Xiong

    2016-01-01

    Iron (Fe) is an essential trace element for marine fish. However, our knowledge of Fe requirements at different development stages of marine fish is still limited. Here, we reported the efficient Fe absorption strategies adopted by larval fish under different dietary Fe supplementary levels (i.e., 0–640 mg/kg). Biokinetically, the larval fish controlled their dietary Fe assimilation efficiency (AE, 1.6–18.5%), and enhanced their waterborne Fe uptake (ca. 2.5 fold change of uptake rate constant) once the dietary Fe was deficient (i.e., 27.4 mg Fe/kg feed). Transcriptionally, the expression of hepcidin1 (hep1; Fe regulator; i.e., 2.3–15.7 fold change) in larval fish was positively correlated with the Fe supplementary levels. Comparatively, the female adult fish were poor in assimilating the added Fe source (i.e., ferric form) with similar life-sustainable levels of Fe (i.e., 0.046–0.12 μg/g/d assimilated for Fe supplementary levels of 27.4, 162 and 657 mg Fe/kg feed). The overall feeding experiments suggested that dietary net Fe flux sufficient for the normal growth of larval medaka was 0.71–1.75 μg/g/d (i.e., 83.9 mg Fe/kg feed), consistent with the modeled value (i.e., 1.09–2.16 μg/g/d). In female adults, the estimated essential net Fe flux was 0.88–0.90 μg/g/d. PMID:27216705

  16. The medaka FoxP2, a homologue of human language gene FOXP2, has a diverged structure and function.

    PubMed

    Itakura, Tatsuo; Chandra, Abhishek; Yang, Zhi; Xue, Xiaodong; Wang, Bo; Kimura, Wataru; Hikosaka, Keisuke; Inohaya, Keiji; Kudo, Akira; Uezato, Tadayoshi; Miura, Naoyuki

    2008-03-01

    Forkhead box (Fox) genes are involved in organogenesis and cell differentiation. A mutation of FOXP2 was discovered in patients with severe defects in speech and language. The medaka FoxP2 was cloned in order to clarify the molecular evolution and difference in the protein structure and function by comparing human/mouse and medaka genes. The result showed that medaka FoxP2 had a 73.7% homology to the human and mouse counterparts, and its zinc finger, leucine zipper and forkhead domain structures were conserved. However, medaka FoxP2 lacked a long polyglutamine repeat and had two insertions of unique amino acid sequences. FoxP2 expression was found in the epiphysis and retina, in addition to the midbrain and cerebellum. The transcriptional assay revealed that medaka FoxP2 showed a very weak repressive activity to the CC10 promoter while mouse Foxp2 exhibited a strong repressive activity. Mutational analyses of medaka FoxP2 showed that the three amino acids of forkhead domain were responsible for the weak repressive activity. These results suggest that medaka FoxP2 may play a different function in the development of the medaka fish.

  17. Direct production of XYDMY− sex reversal female medaka (Oryzias latipes) by embryo microinjection of TALENs

    PubMed Central

    Luo, Daji; Liu, Yun; Chen, Ji; Xia, Xiaoqin; Cao, Mengxi; Cheng, Bin; Wang, Xuejuan; Gong, Wuming; Qiu, Chao; Zhang, Yunsheng; Ki Cheng, Christopher Hon; Zhu, Zuoyan; Hu, Wei

    2015-01-01

    Medaka is an ideal model for sex determination and sex reversal, such as XY phenotypically female patients in humans. Here, we assembled improved TALENs targeting the DMY gene and generated XYDMY− mutants to investigate gonadal dysgenesis in medaka. DMY-TALENs resulted in indel mutations at the targeted loci (46.8%). DMY-nanos3UTR-TALENs induced mutations were passed through the germline to F1 generation with efficiencies of up to 91.7%. XYDMY− mutants developed into females, laid eggs, and stably passed the YDMY− chromosome to next generation. RNA-seq generated 157 million raw reads from WT male (WT_M_TE), WT female (WT_F_OV) and XYDMY− female medaka (TA_F_OV) gonad libraries. Differential expression analysis identified 144 up- and 293 down-regulated genes in TA_F_OV compared with WT_F_OV, 387 up- and 338 down-regulated genes in TA_F_OV compared with WT_M_TE. According to genes annotation and functional prediction, such as Wnt1 and PRCK, it revealed that incomplete ovarian function and reduced fertility of XYDMY− mutant is closely related to the wnt signaling pathway. Our results provided the transcriptional profiles of XYDMY− mutants, revealed the mechanism between sex reversal and DMY in medaka, and suggested that XYDMY− medaka was a novel mutant that is useful for investigating gonadal dysgenesis in phenotypic female patients with the 46, XY karyotype. PMID:26365677

  18. High temperature causes masculinization of genetically female medaka by elevation of cortisol.

    PubMed

    Hayashi, Yuki; Kobira, Hiroshi; Yamaguchi, Toshiya; Shiraishi, Eri; Yazawa, Takashi; Hirai, Toshiaki; Kamei, Yasuhiro; Kitano, Takeshi

    2010-08-01

    In poikilothermic vertebrates, sex determination is sometimes influenced by environmental factors such as temperature. However, little is known about the molecular mechanisms underlying environmental sex determination. The medaka (Oryzias latipes) is a teleost fish with an XX/XY sex determination system. Recently, it was reported that XX medaka can be sex-reversed into phenotypic males by high water temperature (HT; 32-34 degrees C) treatment during the sex differentiation period. Here we report that cortisol caused female-to-male sex reversal and that metyrapone (an inhibitor of cortisol synthesis) inhibited HT-induced masculinization of XX medaka. HT treatment caused elevation of whole-body levels of cortisol, while metyrapone suppressed the elevation by HT treatment during sexual differentiation. Moreover, cortisol and 33 degrees C treatments inhibited female-type proliferation of germ cells as well as expression of follicle-stimulating hormone receptor (fshr) mRNA in XX medaka during sexual differentiation. These results strongly suggest that HT induces masculinization of XX medaka by elevation of cortisol level, which, in turn, causes suppression of germ cell proliferation and of fshr mRNA expression.

  19. Viable Neuronopathic Gaucher Disease Model in Medaka (Oryzias latipes) Displays Axonal Accumulation of Alpha-Synuclein

    PubMed Central

    Uemura, Norihito; Koike, Masato; Ansai, Satoshi; Kinoshita, Masato; Ishikawa-Fujiwara, Tomoko; Matsui, Hideaki; Naruse, Kiyoshi; Sakamoto, Naoaki; Uchiyama, Yasuo; Todo, Takeshi; Takeda, Shunichi; Yamakado, Hodaka; Takahashi, Ryosuke

    2015-01-01

    Homozygous mutations in the glucocerebrosidase (GBA) gene result in Gaucher disease (GD), the most common lysosomal storage disease. Recent genetic studies have revealed that GBA mutations confer a strong risk for sporadic Parkinson’s disease (PD). To investigate how GBA mutations cause PD, we generated GBA nonsense mutant (GBA-/-) medaka that are completely deficient in glucocerebrosidase (GCase) activity. In contrast to the perinatal death in humans and mice lacking GCase activity, GBA-/- medaka survived for months, enabling analysis of the pathological progression. GBA-/- medaka displayed the pathological phenotypes resembling human neuronopathic GD including infiltration of Gaucher cell-like cells into the brains, progressive neuronal loss, and microgliosis. Detailed pathological findings represented lysosomal abnormalities in neurons and alpha-synuclein (α-syn) accumulation in axonal swellings containing autophagosomes. Unexpectedly, disruption of α-syn did not improve the life span, formation of axonal swellings, neuronal loss, or neuroinflammation in GBA-/- medaka. Taken together, the present study revealed GBA-/- medaka as a novel neuronopathic GD model, the pahological mechanisms of α-syn accumulation caused by GCase deficiency, and the minimal contribution of α-syn to the pathogenesis of neuronopathic GD. PMID:25835295

  20. Japanese Characters in Written Japanese.

    ERIC Educational Resources Information Center

    Buck, James H.

    From the sixth to the eighth century A.D., Japan was the recipient of massive cultural infusions from China. This acceptance of the Chinese pattern included, and to a great extent was based on, the acceptance of the Chinese language. The Chinese writing system was applied to Japanese because there was no other model to follow and in spite of the…

  1. Development of Text Reading in Japanese: An Eye Movement Study

    ERIC Educational Resources Information Center

    Jincho, Nobuyuki; Feng, Gary; Mazuka, Reiko

    2014-01-01

    This study examined age-group differences in eye movements among third-grade, fifth-grade, and adult Japanese readers. In Experiment 1, Japanese children, but not adults, showed a longer fixation time on logographic kanji words than on phonologically transparent hiragana words. Further, an age-group difference was found in the first fixation…

  2. Independent analysis of the radiation risk for leukaemia in children and adults with mortality data (1950-2003) of Japanese A-bomb survivors.

    PubMed

    Kaiser, Jan Christian; Walsh, Linda

    2013-03-01

    A recent analysis of leukaemia mortality in Japanese A-bomb survivors has applied descriptive models, collected together from previous studies, to derive a joint excess relative risk estimate (ERR) by multi-model inference (MMI) (Walsh and Kaiser in Radiat Environ Biophys 50:21-35, 2011). The models use a linear-quadratic dose response with differing dose effect modifiers. In the present study, a set of more than 40 models has been submitted to a rigorous statistical selection procedure which fosters the parsimonious deployment of model parameters based on pairwise likelihood ratio tests. Nested models were consequently excluded from risk assessment. The set comprises models of the excess absolute risk (EAR) and two types of non-standard ERR models with sigmoidal responses or two line spline functions with a changing slope at a break point. Due to clearly higher values of the Akaike Information Criterion, none of the EAR models has been selected, but two non-standard ERR models qualified for MMI. The preferred ERR model applies a purely quadratic dose response which is slightly damped by an exponential factor at high doses and modified by a power function for attained age. Compared to the previous analysis, the present study reports similar point estimates and confidence intervals (CI) of the ERR from MMI for doses between 0.5 and 2.5 Sv. However, at lower doses, the point estimates are markedly reduced by factors between two and five, although the reduction was not statistically significant. The 2.5 % percentiles of the ERR from the preferred quadratic-exponential model did not fall below zero risk in exposure scenarios for children, adolescents and adults at very low doses down to 10 mSv. Yet, MMI produced risk estimates with a positive 2.5 % percentile only above doses of some 300 mSv. Compared to CI from a single model of choice, CI from MMI are broadened in cohort strata with low statistical power by a combination of risk extrapolations from several

  3. Biochemical characterization of the medaka (Oryzias latipes) orthologue for mammalian tissue-type transglutaminase (TG2).

    PubMed

    Takada, Yuki; Watanabe, Yuko; Okuya, Kazuho; Tatsukawa, Hideki; Hashimoto, Hisashi; Hitomi, Kiyotaka

    2017-03-01

    Transglutaminase is an enzyme family responsible for post-translational modification such as protein cross-linking and the attachment of primary amine and/or deamidation of glutamine-residue in proteins. Medaka (Oryzias latipes), a recently established model fish, has similar functional proteins to those characterized in mammals. Previously, we found the apparent orthologues that correspond to human transglutaminases in medaka. In this study, regarding the medaka orthologue of human tissue-type transglutaminase (OlTGT), recombinant protein was expressed in an active form in bacteria cultured at low temperature. Using the recombinant protein, we biochemically characterized the enzymatic activity and also obtained a monoclonal antibody that specifically recognized OlTGT. Immunochemical analysis revealed that OlTGT was not expressed ubiquitously, unlike its mammalian orthologue, but in primarily limited tissues such as the eye, brain, spinal cord, and gas gland.

  4. Comparative embryotoxicity of phenanthrene and alkyl-phenanthrene to marine medaka (Oryzias melastigma).

    PubMed

    Mu, Jingli; Wang, Juying; Jin, Fei; Wang, Xinhong; Hong, Huasheng

    2014-08-30

    Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are the predominant form of PAHs in oil, comprising 85-95% of total PAHs. However, little attention has been paid to these chemicals in ecological risk assessment of marine oil spill. A comparative study of the toxic effects of phenanthrene and retene (7-isopropyl-1-methylphenanthrene, an alkyl-phenanthrene) on the early life stage of marine medaka (Oryzias melastigma) was conducted. Results showed that retene was significantly more toxic than phenanthrene, and marine medaka could be more sensitive to retene than some freshwater fishes. Retene had a higher excretion rate than phenanthrene during the larvae stage. Both of compounds resulted in developmental malformation of marine medaka embryos, with phenanthrene affecting on peripheral vascular system and yolk sac, while retene affecting on cardiac tissues. The toxicity of phenanthrene might be mainly related to its anesthetic effects, and that of retene might be related to the CYP1A-mediated toxicity of its metabolites.

  5. Genetic Control of Startle Behavior in Medaka Fish

    PubMed Central

    Tsuboko, Satomi; Kimura, Tetsuaki; Shinya, Minori; Suehiro, Yuji; Okuyama, Teruhiro; Shimada, Atsuko; Takeda, Hiroyuki; Naruse, Kiyoshi; Kubo, Takeo; Takeuchi, Hideaki

    2014-01-01

    Genetic polymorphisms are thought to generate intraspecific behavioral diversities, both within and among populations. The mechanisms underlying genetic control of behavioral properties, however, remain unclear in wild-type vertebrates, including humans. To explore this issue, we used diverse inbred strains of medaka fish (Oryzias latipes) established from the same and different local populations. Medaka exhibit a startle response to a visual stimulus (extinction of illumination) by rapidly bending their bodies (C-start) 20-ms after the stimulus presentation. We measured the rates of the response to repeated stimuli (1-s interval, 40 times) among four inbred strains, HNI-I, HNI-II, HO5, and Hd-rR-II1, and quantified two properties of the startle response: sensitivity (response rate to the first stimulus) and attenuation of the response probability with repeated stimulus presentation. Among the four strains, the greatest differences in these properties were detected between HNI-II and Hd-rR-II1. HNI-II exhibited high sensitivity (approximately 80%) and no attenuation, while Hd-rR-II1 exhibited low sensitivity (approximately 50%) and almost complete attenuation after only five stimulus presentations. Our findings suggested behavioral diversity of the startle response within a local population as well as among different populations. Linkage analysis with F2 progeny between HNI-II and Hd-rR-II1 detected quantitative trait loci (QTL) highly related to attenuation, but not to sensitivity, with a maximum logarithm of odds score of 11.82 on linkage group 16. The three genotypes (homozygous for HNI-II and Hd-rR-II1 alleles, and heterozygous) at the marker nearest the QTL correlated with attenuation. Our findings are the first to suggest that a single genomic region might be sufficient to generate individual differences in startle behavior between wild-type strains. Further identification of genetic polymorphisms that define the behavioral trait will contribute to our

  6. Persistent endocrine disruption effects in medaka fish with early life-stage exposure to a triazole-containing aromatase inhibitor (letrozole).

    PubMed

    Liao, Pei-Han; Chu, Szu-Hung; Tu, Tzu-Yi; Wang, Xiao-Huan; Lin, Angela Yu-Chen; Chen, Pei-Jen

    2014-07-30

    Letrozole (LET) is a triazole-containing drug that can inhibit the activity of cytochrome P450 aromatase. It is an environmentally emerging pollutant because of its broad use in medicine and frequent occurrence in aquifers receiving the effluent of municipal or hospital wastewater. However, the toxic impact of LET on fish populations remains unclear. We exposed medaka fish (Oryzias latipes) at an early stage of sexual development to a continuous chronic LET at environmentally relevant concentrations and assessed the endocrine disruption effects in adulthood and the next generation. LET exposure at an early life stage persistently altered phenotypic sex development and reproduction in adults and skewed the sex ratio in progeny. As well, LET exposure led to a gender-different endocrine disruption as seen by the interruption in gene expression responsible for estrogen synthesis and metabolism and fish reproduction. LET interfering with the aromatase system in early life stages of medaka can disrupt hormone homeostasis and reproduction. This potent aromatase inhibitor has potential ecotoxicological impact on fish populations in aquatic environments.

  7. Anesthetic effects of clove oil and lidocaine-HCl on marine medaka (Oryzias dancena).

    PubMed

    Park, In-Seok; Park, Sung Jun; Gil, Hyun Woo; Nam, Yoon Kwon; Kim, Dong Soo

    2011-02-01

    Fish may be anesthetized for various experimental and practical purposes, primarily to immobilize them in order to facilitate handling. Marine medaka (Oryzias dancena) is a teleost fish used in marine ecotoxicology studies. Despite the importance of anesthesia in handling experimental fish, the effects of anesthesia in marine medaka have not yet been investigated. In this study, the authors evaluated the anesthetic effects (time required for anesthesia to take effect and recovery time) of two anesthetic agents, clove oil and lidocaine-HCl, on marine medaka. They anesthetized fish at different water temperatures (23 °C, 26 °C and 29 °C) and using different concentrations of clove oil (50 ppm, 75 ppm, 100 ppm, 125 ppm, 150 ppm and 175 ppm) or lidocaine-HCl (300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm and 800 ppm). The time required for anesthesia to take effect decreased significantly as both anesthetic concentration and water temperature increased for both clove oil and lidocaine-HCl. To anesthetize marine medaka within approximately 1 min, the optimal concentrations for clove oil were 125 ppm at 23 °C, 100 ppm at 26 °C and 75 ppm at 29 °C and for lidocaine-HCl were 800 ppm at 23 °C and 700 ppm at both 26 °C and 29 °C. The authors also compared anesthetic effects in marine medaka of different sizes. Both anesthetic exposure time and recovery time were significantly shorter for smaller fish than for larger fish. These results provide a useful foundation for the laboratory handling of marine medaka.

  8. Sexual dimorphism of brain aromatase activity in medaka: induction of a female phenotype by estradiol.

    PubMed

    Melo, A C; Ramsdell, J S

    2001-03-01

    In this study we identified sex-dependent dimorphism of brain aromatase in the teleost medaka and examined its regulation by sex steriods. We first investigated differential distribution of brain aromatase activity in sexually mature male and female medaka in serial coronal sections of the brain and identified the hypothalamic nuclei contained in each section using the brain atlas of medaka. In the brain of male medaka, high levels of activity are localized in sections containing the preoptic (POA) and suprachiasmatic nuclei (SC) (63-75 fmol/hr) and low levels in the nuclei periventricular dorsalis (HD), ventralis (HV), and caudalis (Hc), nuclei diffusus of lobulus inferiores (NDIL), and nuclei tuberi anteriores (TA) and posteriores (TP) (< 25 fmol/hr). In the brain of female medaka high aromatase activity is localized in sections containing the HD, HV, Hc, NDIL, TA, and TP (85-80 fmol/hr) and highly variable levels in the POA and SC (23-70 fmol/hr). The concentration and time dependency of the exposure of male medaka to estradiol on the total brain aromatase activity and morphologic sex characteristics were determined next. Estradiol increased the activity of brain aromatase in a concentration-dependent manner at 2.5 and 25 microg/L, but the increase was lower at higher concentrations of the hormone. The effect was time dependent, gradually increasing up to the fifth day of exposure, after which it reached a plateau. Estradiol induction of brain aromatase analyzed using Lineweaver-Burke plots of saturation assays revealed a non-first-order reaction. The results indicate that a positive feedback mechanism regulates brain aromatase and imply that the sexual dimorphic distribution of aromatase may be highly sensitive to physiologic cues and environmental perturbations in fish.

  9. A comparative view on sex determination in medaka.

    PubMed

    Schartl, Manfred

    2004-07-01

    In fish, an amazing variety of sex determination mechanisms are known, ranging from hermaphroditism to gonochorism and from environmental to genetic sex determination. This makes fish especially suited for studying sex determination from the evolutionary point of view. In several fish groups, different sex determination mechanisms are found in closely related species, and evolution of this process is still ongoing in recent organisms. The medaka (Oryzias latipes) has an XY-XX genetic sex determination system. The Y-chromosome in this species is at an early stage of evolution. The molecular differences between X and Y are only very subtle and the Y-specific segment is very small. The sex-determining region has accumulated duplicated sequences from elsewhere in the genome, leading to recombinational isolation. The region contains a candidate for the male sex-determining gene named dmrt1bY. This gene arose through duplication of an autosomal chromosome fragment of linkage group 9. While all other genes degenerated, dmrt1bY is the only functional gene in the Y-specific region. The duplication leading to dmrt1bY occurred recently during evolution of the genus Oryzias. This suggests that different genes might be the master sex-determining gene in other fish.

  10. Transcriptomic responses of marine medaka's ovary to hypoxia.

    PubMed

    Lai, Keng Po; Li, Jing Woei; Tse, Anna Chung Kwan; Cheung, Angela; Wang, Simon; Chan, Ting Fung; Kong, Richard Yuen Chong; Wu, Rudolf Shiu Sun

    2016-08-01

    Hypoxia, an endocrine disruptor, is pressing global problem affecting marine organisms in over 400 "Dead Zones" worldwide. There is growing evident demonstrated the disruptive effect of hypoxia on reproductive systems of marine fish through the impairments of steroidogenic gene expression, leading to the alteration of sex hormone production in gonads. But the detailed molecular mechanism underlying the responses of female reproductive systems to hypoxic stress remains largely unknown. In the present report, we used marine medaka Oryzias melastigma as a model, together with high-throughput transcriptome sequencing and bioinformatics analysis, aiming to determine the changes in transcriptional signature in the ovary of marine fish under hypoxic stress. Our result discovered over two hundred differential expressed genes in ovary in response to hypoxia. The bioinformatics analysis together with quantitative RT-PCR validation on the deregulated genes highlighted the dysregulations of a number of female reproductive functions including interruptions of ovarian follicle development, gonad development and steroid metabolic process. Additionally, we revealed that these deregulations are through the modulation of leukemia inhibitory factor (LIF), insulin-like growth factor 1 receptor (IGF1R) and follicle stimulating hormone (FSH). The result of this work complements previous studies and provides additional insights into the underlying molecular mechanism of hypoxia-induced impairment of female reproductive system.

  11. Turnover of Sex Chromosomes in Celebensis Group Medaka Fishes.

    PubMed

    Myosho, Taijun; Takehana, Yusuke; Hamaguchi, Satoshi; Sakaizumi, Mitsuru

    2015-10-23

    Sex chromosomes and the sex-determining (SD) gene are variable in vertebrates. In particular, medaka fishes in the genus Oryzias show an extremely large diversity in sex chromosomes and the SD gene, providing a good model to study the evolutionary process by which they turnover. Here, we investigated the sex determination system and sex chromosomes in six celebensis group species. Our sex-linkage analysis demonstrated that all species had an XX-XY sex determination system, and that the Oryzias marmoratus and O. profundicola sex chromosomes were homologous to O. latipes linkage group (LG) 10, while those of the other four species, O. celebensis, O. matanensis, O. wolasi, and O. woworae, were homologous to O. latipes LG 24. The phylogenetic relationship suggested a turnover of the sex chromosomes from O. latipes LG 24 to LG 10 within this group. Six sex-linkage maps showed that the former two and the latter four species shared a common SD locus, respectively, suggesting that the LG 24 acquired the SD function in a common ancestor of the celebensis group, and that the LG 10 SD function appeared in a common ancestor of O. marmoratus and O. profundicola after the divergence of O. matanensis. Additionally, fine mapping and association analysis in the former two species revealed that Sox3 on the Y chromosome is a prime candidate for the SD gene, and that the Y-specific 430-bp insertion might be involved in its SD function.

  12. The Acquisitional Value of Recasts in Instructed Second Language Speech Learning: Teaching the Perception and Production of English /?/ to Adult Japanese Learners

    ERIC Educational Resources Information Center

    Saito, Kazuya

    2013-01-01

    The current study investigated the impact of recasts together with form-focused instruction (FFI) on the development of second language speech perception and production of English /?/ by Japanese learners. Forty-five learners were randomly assigned to three groups--FFI recasts, FFI only, and Control--and exposed to four hours of communicatively…

  13. Effects of Di-butyl Phthalate (DBP) on Developing Medaka Embryos

    ERIC Educational Resources Information Center

    Tang, Sherry

    2012-01-01

    Plasticizers are chemical additives that enhance plastic flexibility. They are ubiquitous environmental contaminants and are commonly found in river and lake waters (Fromme et al 2002). The present study aimed to investigate the effects of a water-soluble plasticizer, dibutyl phthalate (DBP) on developing Medaka ("Oryzias latipes") embryos. Three…

  14. A purified diet for medaka (Oryzias latipes): refining a fish model for toxicological research

    SciTech Connect

    DeKoven, D.L.; Nunez, J.M.; Lester, S.M.; Conklin, D.E.; Marty, G.D.; Parker, L.M.; Hinton, D.E. )

    1992-04-01

    The overall nutritional adequacy of a purified casein-based diet (PC-diet) for the medaka (Oryzias latipes) was evaluated and compared with three diets: commercially available flaked fish food (FL-diet), live newly hatched Artemia (A-diet), and a combination of FL-diet plus A-diet (F/A-diet). Survival, growth, reproductive success, general and liver histopathology, and selected hepatic enzyme activities were compared in medaka from first feeding through reproductive maturity. The PC-diet proved adequate in all of the above criteria. When compared with fish fed F/A-diet, an initial lag in early growth rates (i.e., 0 to 30 days) occurred with the fish fed PC-diet. The FL-diet alone was not nutritionally adequate for medaka, resulting in poor growth, reduced reproductive success, lower survival, and emaciation. A significant number of spinal deformities (5.4%) were noted in medaka fed the F/A diet. Ethoxycoumarin 0-deethylase and glutathione S-transferase activities were monitored and a trend toward increasing activity with age was noted. This suggests that PC- and F/A-diets provide adequate nutrition for development of the xenobiotic metabolizing enzymes necessary for detoxification and activation of endogenous and foreign compounds. The PC-diet supported good survival, growth, reproduction, and normal histology. This diet provides a standardized, nutritionally adequate, and consistent alternative to undefined conventional diets and is less likely to contain the range of xenobiotics possible in whole, live food.

  15. Generation and Characterization of Neurogeninl-GFP Transgenic Medaka for High Throughput Developmental Neurotoxicity Screening

    EPA Science Inventory

    Fish models such as zebrafish and medaka are increasingly used as alternatives to rodents in developmental and toxicological studies. These developmental and toxicological studies can be facilitated by the use of transgenic reporters that permit the real-time, noninvasive observa...

  16. Discovery and functional characterization of novel miRNAs in the marine medaka Oryzias melastigma.

    PubMed

    Li, Jing-Woei; Lin, Xiao; Tse, Anna; Cheung, Angela; Chan, Ting Fung; Kong, Richard Yuen Chong; Lai, Keng Po; Wu, Rudolf Shiu Sun

    2016-06-01

    The marine medaka Oryzias melastigma has often been used as a marine fish model to investigate the biological responses to environmental stresses and pollutants in marine environments. miRNAs are post-transcriptional regulators of many biological processes in a variety of organisms, and have been shown to be affected by environmental stresses, but the novel miRNA profile of marine medaka has not been reported. Using both genome and small RNA sequencings coupled with different bioinformatics analyses, we have discovered 58, 82, 234, and 201 unannotated miRNAs in the brain, liver, ovary and testis tissues of marine medaka, respectively. Furthermore, these novel miRNAs were found to target genes with tissue-specific roles such as neuron development and synaptic transmission in the brain, glucose and fat metabolism in the liver and steroidogenesis in the gonads. We here report, for the first time, novel miRNA profile of marine medaka, which will provide a foundation for future biomarkers and transgenerational studies for the assessment of environmental stresses and pollutions in the marine environments. In a boarder context, our data will provide novel insight into our knowledge of miRNome and miR research.

  17. Proteasome inhibition in medaka brain induces the features of Parkinson's disease.

    PubMed

    Matsui, Hideaki; Ito, Hidefumi; Taniguchi, Yoshihito; Inoue, Haruhisa; Takeda, Shunichi; Takahashi, Ryosuke

    2010-10-01

    Recent findings suggest that a defect in the ubiquitin-proteasome system plays an important role in the pathogenesis of Parkinson's disease (PD). A previous report (McNaught et al. 2004) demonstrated that rats systemically injected with proteasome inhibitors exhibited PD-like clinical symptoms and pathology. However, because these findings have not been consistently replicated, this model is not commonly used to study PD. We used medaka fish to test the effect of systemic administration of proteasome inhibitors because of the high level of accessibility of the cerebrospinal fluid in fish. We injected lactacystin or epoxomicin into the CSF of medaka. With proteasome inhibition in the medaka brain, selective dopaminergic and noradrenergic cell loss was observed. Furthermore, treated fish exhibited reduced spontaneous movement. Treatment with proteasome inhibitors also induced the formation of inclusion bodies resembling Lewy bodies, which are characteristic of PD. Treatment with 6-OHDA also induced dopaminergic cell loss but did not produce inclusion bodies. These findings in medaka are consistent with previous results reporting that non-selective proteasome inhibition replicates the cardinal features of PD: locomotor dysfunction, selective dopaminergic cell loss, and inclusion body formation.

  18. MX, A DRINKING WATER CARCINOGEN, DOES NOT INDUCE MUTATIONS IN THE LIVER OF CII TRANSGENIC MEDAKA

    EPA Science Inventory

    MX, a drinking water carcinogen, does not induce mutations in the liver of cII transgenic medaka
    Geter, DR; Winn, RN; Fournie, JW; Norris, MB; DeAngelo, AB; and Hawkins, WE

    Abstract

    Geter et al., page 2
    Abstract
    "Salmonella" mutagenicity assays have shown t...

  19. Gonadotrophic cells and gonadal sex differentiation in medaka: Characterization of several northern and southern strains.

    PubMed

    Horie, Yoshifumi; Kobayashi, Tohru

    2015-07-01

    Gonadotropins play an important role in gametogenesis and reproduction in vertebrates. Their localization in the pituitary during gonadal sex differentiation has been studied mainly in southern (Oryzias latipes) strains of medaka fish, with that in northern medaka (O. sakaizumii) remaining poorly understood. Hence, in this study, we characterized gonadal differentiation and gonadotrophic cells during sex differentiation in two northern strains (HNI and Kaga) and two southern strains (Hd-rR and d-rR/Tokyo). All strains exhibited similar sex differentiation at hatching, such as (1) sex difference in germ cell number (XX > XY), and (2) the transition of XX germ cells into meiosis, and (3) presence of glycoprotein-α (Gpa)-positive cells. However, follicle-stimulating hormone-β (Fshb)-positive cells were first detected in the pituitary 1 day post-hatching in HNI. Exposure to high-temperature conditions and to cortisol in a dose dependent manner resulted in the localization of Fshb cells in the pituitary at hatching. This study demonstrates differences in gonadotropin subunit expression between northern and southern strains of medaka, and suggests that Fsh is not involved in early gonadal sex differentiation, such as the sex difference in germ cell number, and that high-temperature induce Fshb expression via cortisol production in medaka.

  20. Relationship between Hb and HbA1c in Japanese adults: an analysis of the 2009 Japan Society of Ningen Dock database.

    PubMed

    Takahashi, Eiko; Moriyama, Kengo; Yamakado, Minoru

    2014-06-01

    We investigated the effect of Hb on HbA1c levels in 265,427 Japanese individuals. The divergence between fasting plasma glucose (FPG) and HbA1c levels increased with lower Hb, resulting in HbA1c levels that were higher in relation to than the FPG levels. Similarly, the correlation between FPG and HbA1c levels, stratified by Hb, weakened as Hb decreased.

  1. Efficient targeted mutagenesis in medaka using custom-designed transcription activator-like effector nucleases.

    PubMed

    Ansai, Satoshi; Sakuma, Tetsushi; Yamamoto, Takashi; Ariga, Hiroyoshi; Uemura, Norihito; Takahashi, Ryosuke; Kinoshita, Masato

    2013-03-01

    Transcription activator-like effector nucleases (TALENs) have become powerful tools for targeted genome editing. Here we demonstrate efficient targeted mutagenesis in medaka (Oryzias latipes), which serves as an excellent vertebrate model for genetics and genomics. We designed and constructed a pair of TALENs targeting the medaka DJ-1 gene, a homolog of human DJ-1 (PARK7). These TALENs induced a number of insertions and deletions in the injected embryos with extremely high efficiency. This induction of mutations occurred in a dose-dependent manner. All screened G0 fish injected with the TALENs transmitted the TALEN-induced mutations to the next generation with high efficiency (44-100%). We also confirmed that these TALENs induced site-specific mutations because none of the mutations were found at potential off-target sites. In addition, the DJ-1 protein was lost in DJ-1(Δ7/Δ7) fish that carried a TALEN-induced frameshift mutation in both alleles. We also investigated the effect of the N- and C-terminal regions of the transcription activator-like (TAL) effector domain on the gene-disrupting activity of DJ1-TALENs and found that 287 amino acids at the N terminus and 63 amino acids at the C terminus of the TAL domain exhibited the highest disrupting activity in the injected embryos. Our results suggest that TALENs enable us to rapidly and efficiently establish knockout medaka strains. This is the first report of targeted mutagenesis in medaka using TALENs. The TALEN technology will expand the potential of medaka as a model system for genetics and genomics.

  2. Dual control by a single gene of secondary sexual characters and mating preferences in medaka

    PubMed Central

    Fukamachi, Shoji; Kinoshita, Masato; Aizawa, Kouichi; Oda, Shoji; Meyer, Axel; Mitani, Hiroshi

    2009-01-01

    Background Animals utilize a wide variety of tactics to attract reproductive partners. Behavioral experiments often indicate an important role for visual cues in fish, but their molecular basis remains almost entirely unknown. Studies on model species (such as zebrafish and medaka) allow investigations into this fundamental question in behavioral and evolutionary biology. Results Through mate-choice experiences using several laboratory strains of various body colors, we successfully identified one medaka mutant (color interfere; ci) that is distinctly unattractive to reproductive partners. This unattractiveness seems to be due to reduced orange pigment cells (xanthophores) in the skin. The ci strain carries a mutation on the somatolactin alpha (SLa) gene, therefore we expected over-expression of SLa to make medaka hyper-attractive. Indeed, extremely strong mating preferences were detected in a choice between the ci and SLa-transgenic (Actb-SLa:GFP) medaka. Intriguingly, however, the strains showed opposite biases; that is, the mutant and transgenic medaka liked to mate with partners from their own strain, similar to becoming sexually isolated. Conclusion This study spotlighted SLa as a novel mate-choice gene in fish. In addition, these results are the first demonstration of a single gene that can pleiotropically and harmoniously change both secondary sexual characters and mating preferences. Although theoretical models have long suggested joint evolution of linked genes on a chromosome, a mutation on a gene-regulatory region (that is, switching on/off of a single gene) might be sufficient to trigger two 'runaway' processes in different directions to promote (sympatric) speciation. PMID:19788724

  3. Estradiol-induced promotion of hepatocarcinogenesis in medaka: Relationship of foci of cellular alteration to neoplasia

    SciTech Connect

    Cooke, J.B.; Hinton, D.E.

    1995-12-31

    In some laboratory and field studies, female fish have higher prevalences of liver tumors than do males. The authors hypothesize gender and site-specific differences in prevalence are due to variable exposures of previously initiated fish to tumor modulating compounds. Estradiol, a growth promoter, increases incidences of hepatic tumors in carcinogen-treated rainbow trout and medaka (Oryzias latipes). Estradiol also increases incidences of hepatic foci of cellular alteration (FCA) in medaka. FCA are found in subadults of tumor-bearing feral populations. Lack of knowledge about the relationship of various phenotypes of FCA to eventual tumors, however, has prevented use of FCA as a biomarker. The authors examined fate and growth of liver FCA using a 2-step, initiation-promotion protocol. Three week old medaka were exposed to 200 ppm diethylnitrosamine (DEN) for 24 hr. and then fed 0.1 ppm 17-{beta}-estradiol (E2) continuously through sampling at weeks 4--26. Percent volume of FCA and morphometric characteristics of normal and focal hepatocytes, including numerical density and average hepatocyte volume were quantified using computer-assisted stereology. E2 increased percentage of liver occupied by DEN-initiated amphophilic, basophilic and eosinophilic FCA in both sexes. Focal parameters of young, DEN-initiated and estradiol-treated medaka were not reached until much later in fish given only DEN. Non-focal hepatocytes in estradiol-treated medaka were smaller and more numerous than in DEN-only counterparts. Morphometric analysis is quantitatively tracking the fate of specific phenotypes of FCA to determine their role in progression to cancer.

  4. Efficient Targeted Mutagenesis in Medaka Using Custom-Designed Transcription Activator-Like Effector Nucleases

    PubMed Central

    Ansai, Satoshi; Sakuma, Tetsushi; Yamamoto, Takashi; Ariga, Hiroyoshi; Uemura, Norihito; Takahashi, Ryosuke; Kinoshita, Masato

    2013-01-01

    Transcription activator-like effector nucleases (TALENs) have become powerful tools for targeted genome editing. Here we demonstrate efficient targeted mutagenesis in medaka (Oryzias latipes), which serves as an excellent vertebrate model for genetics and genomics. We designed and constructed a pair of TALENs targeting the medaka DJ-1 gene, a homolog of human DJ-1 (PARK7). These TALENs induced a number of insertions and deletions in the injected embryos with extremely high efficiency. This induction of mutations occurred in a dose-dependent manner. All screened G0 fish injected with the TALENs transmitted the TALEN-induced mutations to the next generation with high efficiency (44–100%). We also confirmed that these TALENs induced site-specific mutations because none of the mutations were found at potential off-target sites. In addition, the DJ-1 protein was lost in DJ-1Δ7/Δ7 fish that carried a TALEN-induced frameshift mutation in both alleles. We also investigated the effect of the N- and C-terminal regions of the transcription activator-like (TAL) effector domain on the gene-disrupting activity of DJ1-TALENs and found that 287 amino acids at the N terminus and 63 amino acids at the C terminus of the TAL domain exhibited the highest disrupting activity in the injected embryos. Our results suggest that TALENs enable us to rapidly and efficiently establish knockout medaka strains. This is the first report of targeted mutagenesis in medaka using TALENs. The TALEN technology will expand the potential of medaka as a model system for genetics and genomics. PMID:23288935

  5. Conservation of Skeletal Regulators in the Fish Model Medaka (Oryzias latipes)

    NASA Astrophysics Data System (ADS)

    Wagner, T.; Renn, J.; Koester, R.; Goerlich, R.; Schartl, M.; Winkler, C.

    Small aquarium fish species, like the well known zebrafish (Danio rerio) and the related Medaka (Oryzias latipes) represent vertebrate models that offer many advantages to study biomineralization in vivo. These fish produce large numbers of completely transparent embryos, thus allowing real-time analysis of skeletal development in living specimens. Using the calcium-binding fluorochrome Calcein and confocal laser scanning microscopy in Medaka, we followed the formation of calcified bone from day 6 of embryonic development until day 20 post hatching. To establish fish as models for human bone disease, we furthermore isolated 11 genes in medaka, the orthologs of which are known to be important regulators of osteoblast, osteoclast and chondrocyte formation in human. We show that these genes are highly conserved between fish and mammals in both sequence and expression pattern. This includes osteonectin, the major non-collagenous component of the mammalian bone matrix. Medaka osteonectin is expressed in osteoblasts and chondrocytes, e.g. in the developing vertebrae. For functional characterization of all these skeletal factors, they are ectopically expressed after gene transfer into fish embryos and their effect on bone formation is analyzed by Calcein staining in developing fish in vivo. Alternatively, the activity of these factors can be blocked by antisense oligonucleotide mediated gene knock-down. In addition, the Medaka offers the unique opportunity to study biomineralization processes in fish in vitro by using embryonic stem (ES) cells. In an approach to study calcification events at the cellular level, candidate genes will be ectopically expressed in these ES cells, thereby driving differentiation of stem cells into the osteoblast lineage. Acknowledgement: This work is supported by the German Aerospace Center (DLR) (50 WB 0152) and the European Space Agency (AO-LS-99-MAP-LSS-003).

  6. Generation of a transgenic medaka (Oryzias latipes) strain for visualization of nuclear dynamics in early developmental stages.

    PubMed

    Inoue, Takanobu; Iida, Atsuo; Maegawa, Shingo; Sehara-Fujisawa, Atsuko; Kinoshita, Masato

    2016-12-01

    In this study, we verified nuclear transport activity of an artificial nuclear localization signal (aNLS) in medaka fish (Oryzias latipes). We generated a transgenic medaka strain expresses the aNLS tagged enhanced green fluorescent protein (EGFP) driven by a medaka beta-actin promoter. The aNLS-EGFP was accumulated in the nuclei of somatic tissues and yolk nuclei of oocytes, but undetectable in the spermatozoa. The fluorescent signal was observed from immediately after fertilization by a maternal contribution. Furthermore, male and female pronuclei were visualized in fertilized eggs, and nuclear dynamics of pronuclear fusion and subsequent cleavage were captured by time-lapse imaging. In contrast, SV40NLS exhibited no activity of nuclear transport in early embryos. In conclusion, the aNLS possesses a strong nuclear localization activity and is a useful probe for fluorescent observation of the pronuclei and nuclei in early developmental stage of medaka.

  7. The Japanese Medakafish (Oryzias latipes) as Animal Model for Space-related Bone Research

    NASA Astrophysics Data System (ADS)

    Renn, J.; Schaedel, M.; Elmasri, H.; Wagner, T.; Goerlich, R.; Furutani-Seiki, M.; Kondoh, H.; Schartl, M.; Winkler, C.

    Long-term space flight leads to bone loss due to reduced mechanical load. Animal models are needed to support the analysis of the underlying mechanisms at the molecular and cellular level that are presently largely unclear. For this, small laboratory fish offer many experimental advantages as in vivo models to study disease related processes. They produce large numbers of completely transparent embryos, are easy to keep under laboratory and space conditions and have relatively compact genomes. We are using the Japanese Medaka to characterize the genetic networks regulating bone formation and to study bone formation and remodeling under microgravity. We showed that despite the large evolutionary distance many known factors regulating bone formation are conserved between fish and humans. This includes osteoprotegerin (opg), a key regulator of bone resorption that is altered at the transcriptional level by simulated microgravity in mammals in vitro (Kanematsu et al., Bone 30, 2002). To monitor, how opg is regulated by altered gravity in vivo in fish and how fish react to microgravity, we isolated the Medaka opg regulatory region and produced transgenic fish that carry the green fluorescent protein reporter under the control of the Medaka opg promoter. This model will be useful to monitor gravity-induced changes at the molecular level in vivo. Fish also provide the opportunity to identify novel genes involved in bone formation by using large-scale mutagenesis screens. We have characterized several lines of mutant fish subjected to ENU mutagenesis that show morphological defects in the formation of the bone precursor cell compartment of the axial skeleton, the sclerotome. Using this genetic approach, the identification of the mutated genes is expected to reveal novel components of the genetic cascades that regulate bone formation. In an attempt to identify genes specifically expressed in the sclerotome in Medaka, we identified and characterized dmrt2, a gene that so far

  8. Association between the frequency of meals combining "Shushoku, Shusai, and Hukusai" (Staple food, main dish, and side dish) and intake of nutrients and food groups among Japanese young adults aged 18-24 years: a cross-sectional study.

    PubMed

    Kakutani, Yuya; Kamiya, Saori; Omi, Naomi

    2015-01-01

    "Shushoku," "Shusai," and "Hukusai" are staple food, main dish, and side dish, respectively. The recommended meal in Japan is a combination of "Shushoku," "Shusai," and "Hukusai"; however, it remains unclear whether there is an association between the frequency of these meals and intake of nutrients and food groups. This cross-sectional study examined the association between the frequency of meals combining "Shushoku, Shusai, and Hukusai" and intake of nutrients and food groups among 664 Japanese young adults aged 18-24 y. The dietary habits of the subjects during the preceding month were assessed using a validated brief-type self-administered diet history questionnaire. The frequency of meals combining "Shushoku, Shusai, and Hukusai" was self-reported according to four categories: "less than 1 d or 1 d/wk," "2 or 3 d/wk," "4 or 5 d/wk," and "every day." In both women and men, there was an association between the higher frequency of these meals and higher intake of the following food groups: pulses, green and yellow vegetables, other vegetables, mushrooms, seaweeds, fish and shellfish, and eggs. Moreover, there was an association with higher intake of protein, polyunsaturated fat, n-6 and n-3 polyunsaturated fat, total dietary fiber, soluble and insoluble dietary fiber, β-carotene, α-tocopherol, vitamin K, thiamin, riboflavin, folate, pantothenic acid, vitamin C, potassium, calcium, magnesium, iron, and copper, and lower intake of carbohydrate in both women and men. Our findings support the hypothesis that the meals combining "Shushoku, Shusai, and Hukusai" may be associated with intake of many food groups and nutrients among Japanese young adults.

  9. Energy density of the diets of Japanese adults in relation to food and nutrient intake and general and abdominal obesity: a cross-sectional analysis from the 2012 National Health and Nutrition Survey, Japan.

    PubMed

    Murakami, Kentaro; Livingstone, M Barbara E; Okubo, Hitomi; Sasaki, Satoshi

    2017-01-01

    The associations of dietary energy density with dietary intake and obesity have been largely unexplored in non-Western populations. The present cross-sectional study examined the associations using data from the 2012 National Health and Nutrition Survey, Japan. Dietary intake was assessed using a 1-d semi-weighed dietary record in 15 618 Japanese adults aged ≥20 years. Mean dietary energy density (calculated on the basis of foods only) was 5·98 (sd 1·20) kJ/g in men and 5·72 (sd 1·16) kJ/g in women. Dietary energy density was positively associated with intakes of bread, noodles (only men), meat, fats and oils, and sugar and confectionery but inversely with intakes of white rice (only men), potatoes, pulses, vegetables, fruits, and fish and shellfish. For nutrient intake, dietary energy density was positively associated with total fat and SFA but inversely associated with all other nutrients examined such as protein, carbohydrate, alcohol (only women), dietary fibre, and several vitamins and minerals, including Na. After adjustment for potential confounding factors, dietary energy density was positively associated with abdominal obesity (waist circumference ≥80 cm) in women (adjusted prevalence ratio between the extreme tertiles 1·07; 95 % CI 1·02, 1·12; P for trend=0·003). Dietary energy density was also positively but non-significantly associated with general obesity (BMI≥25 kg/m2) in women (P for trend=0·08). There were no such associations in men. In conclusion, lower energy density of the diets of Japanese adults was associated with favourable food and nutrient intake patterns, except for higher Na, and, in only women, a lower prevalence of abdominal obesity.

  10. Motivational Factors Affecting Online Learning by Japanese MBA Students

    ERIC Educational Resources Information Center

    Kikuchi, Hisayo

    2006-01-01

    In Japan, Internet based learning is still at an early stage. However, adult learners in Japanese society expect the development of flexible e-learning programs. This case study examines motivational factors affecting online learning in a Japanese and Australian MBA program, using observations, interviews and a questionnaire survey. The data were…

  11. Development of the Gerotranscendence Scale Type 2: Japanese Version

    ERIC Educational Resources Information Center

    Hoshino, Kazumi; Zarit, Steven H.; Nakayama, Makoto

    2012-01-01

    This study developed the Japanese version of the Gerotranscendence Scale Type 2 (the GST2) and examined reliability and validity of the scale. In Japan, 525 community-dwelling older adults (Male = 260, Female = 265) answered a questionnaire. An exploratory factor analysis of the Japanese version of the GST2 revealed the same three-factor structure…

  12. Sequence analysis of choriogenin H gene of medaka (Oryzias latipes) and mRNA expression.

    PubMed

    Lee, Chulwoo; Jeon, Seong Hwan; Na, Jin Gyun; Park, Kwangsik

    2002-08-01

    Zona radiata proteins of medaka (Oryzias latipes) consist of two major subunit groups, ZI-1,2 and ZI-3. The precursor of ZI-1,2, which is a glycoprotein with a molecular weight of 74,000 to 76,000 Da, is called choriogenin H, and the precursor of ZI-3, with a molecular weight of 49,000 Da, is called choriogenin L. The precursor proteins are synthesized in the liver in response to estrogen in sexually mature female medaka. However, they are also induced in the male medaka when fish are exposed to estrogenic chemicals. Therefore, choriogenin is known as a possible sensitive biomarker for endocrine disruption in fish. In this study, the choriogenin H cDNA sequence was reanalyzed and the genomic DNA sequence was newly analyzed. This was done for the selection of proper reverse transcription-polymerase chain reaction (RT-PCR) primers to measure the choriogenin mRNA induction by estrogenic chemicals. In the results, the full cDNA sequence was found to be 2,109 bp long and the size of the open reading frame (ORF) was found to be a total of 1,998 bp encoding 666 predicted amino acids, which was found to be different from previously reported cDNA sequence of medaka choriogenin. In the choriogenin H cDNA, a repetitive domain and a nonrepetitive domain were shown. Regarding the repetitive domain, seven complete repeats of the 45 bp of 5'-ccc cag tac cca tca aag cct cag ccc cct cag aat cct cag gtc-3' encoding PQYPSKPQPPQNPQV were found. Medaka choriogenin H gene was found to possess seven exons and six introns, and the total length was 2,643 bp long. The seven repetitive nucleotide residues described above existed in exon 1, which was found to be 1,033 bp long. Based on the full sequence information, proper primers were synthesized for RT-PCR to detect choriogenin H mRNA induction in male and juvenile medaka by 17alpha-ethinylestradiol, and this type of measurement system was found to be effective as a simple tool for the screening of endocrine-disrupting chemicals.

  13. Effects of new dietary fiber from Japanese Apricot (Prunus mume Sieb. et Zucc.) on gut function and intestinal microflora in adult mice.

    PubMed

    Tamura, Motoi; Ohnishi, Yuriko; Kotani, Tatsuya; Gato, Nobuki

    2011-01-01

    Much attention has been focused recently on functional foods. Ume, the Japanese name for the apricot of Prunus mume Sieb. et Zucc., is an example of a Japanese traditional functional food. There are, however, few reports on the effects of fiber from this fruit on bowel function. With this objective, we prepared ume fiber to test the hypothesis that it can change gut function and intestinal flora in mice. Mice were fed an ume fiber (UF) or cellulose (CF) diet (control) for 40 days. The fecal weight, fecal lipids, plasma lipids and cecal composition of the microflora were analyzed. The amount of feces was significantly greater in the UF group than in the CF group (p < 0.01). The fecal lipids content (% DW) of the feces sampled on the final day of the experiment were significantly greater in the UF group than in the CF group (p < 0.01). Plasma non-esterified fatty acids (NEFA) concentrations tended to be lower in the UF compared to the CF group (p = 0.058). Occupation ratios of Bacteroides and Clostridium cluster IV were significantly greater in the cecal flora of the UF group. Our results suggest that ume fiber possesses the fecal lipid excretion effects and feces bulking effects.

  14. ASSESSMENT OF THE REPRODUCTIVE AXIS: COMPARING CRITICAL PERIODS OF HORMONE SENSITIVITY.

    EPA Science Inventory

    Japanese medaka (Oryzias latipes) have been developed as a model species to compare the effects of endocrine active chemicals at critical life-stage periods of hormonal sensitivity, specifically as reproductively active adults, during the developmental period of differentiation, ...

  15. Sulfidation as a natural antidote to metallic nanoparticles is overestimated: CuO sulfidation yields CuS nanoparticles with increased toxicity in medaka (Oryzias latipes) embryos.

    PubMed

    Li, Lingxiangyu; Hu, Ligang; Zhou, Qunfang; Huang, Chunhua; Wang, Yawei; Sun, Cheng; Jiang, Guibin

    2015-02-17

    Sulfidation is considered as a natural antidote to toxicity of metallic nanoparticles (NPs). The detoxification contribution from sulfidation, however, may vary depending on sulfidation mechanisms. Here we present the dissolution-precipitation instead of direct solid-state-shell mechanism to illustrate the process of CuO-NPs conversion to CuS-NPs in aqueous solutions. Accordingly, the CuS-NPs at environmentally relevant concentrations showed much stronger interference on Japanese medaka (Oryzias latipes) embryo hatching than CuO-NPs, which was probably due to elevated free copper ions released from CuS-NPs, leading to significant increase in oxidative stress and causing toxicity in embryos. The larval length was significantly reduced by CuS-NPs, however, no other obviously abnormal morphological features were identified in the hatched larvae. Co-introduction of a metal ion chelator [ethylene diamine tetraacetic acid (EDTA)] could abolish the hatching inhibition induced by CuS-NPs, indicating free copper ions released from CuS-NPs play an important role in hatching interference. This work documents for the first time that sulfidation as a natural antidote to metallic NPs is being overestimated, which has far reaching implications for risk assessment of metallic NPs in aquatic environment.

  16. The Japanese Mind: Understanding Contemporary Japanese Culture.

    ERIC Educational Resources Information Center

    Davies, Roger J., Ed.; Ikeno, Osamu, Ed.

    This collection of essays offers an overview of contemporary Japanese culture, and can serve as a resource for classes studying Japan. The 28 essays offer an informative, accessible look at the values, attitudes, behavior patterns, and communication styles of modern Japan from the unique perspective of the Japanese people. Filled with examples…

  17. Bullying in Japanese Schools.

    ERIC Educational Resources Information Center

    Kobayashi, Futoshi

    Noting that although many Western educators praise the Japanese educational system because of its students' academic achievements, schools in Japan have developed severe and prevalent problems with student bullying. This paper examines the problem of bullying in Japanese schools. Part 1 of the paper reviews bullying incidents in Japanese schools…

  18. Microgravity promotes osteoclast activity in medaka fish reared at the international space station.

    PubMed

    Chatani, Masahiro; Mantoku, Akiko; Takeyama, Kazuhiro; Abduweli, Dawud; Sugamori, Yasutaka; Aoki, Kazuhiro; Ohya, Keiichi; Suzuki, Hiromi; Uchida, Satoko; Sakimura, Toru; Kono, Yasushi; Tanigaki, Fumiaki; Shirakawa, Masaki; Takano, Yoshiro; Kudo, Akira

    2015-09-21

    The bone mineral density (BMD) of astronauts decreases specifically in the weight-bearing sites during spaceflight. It seems that osteoclasts would be affected by a change in gravity; however, the molecular mechanism involved remains unclear. Here, we show that the mineral density of the pharyngeal bone and teeth region of TRAP-GFP/Osterix-DsRed double transgenic medaka fish was decreased and that osteoclasts were activated when the fish were reared for 56 days at the international space station. In addition, electron microscopy observation revealed a low degree of roundness of mitochondria in osteoclasts. In the whole transcriptome analysis, fkbp5 and ddit4 genes were strongly up-regulated in the flight group. The fish were filmed for abnormal behavior; and, interestingly, the medaka tended to become motionless in the late stage of exposure. These results reveal impaired physiological function with a change in mechanical force under microgravity, which impairment was accompanied by osteoclast activation.

  19. Microgravity promotes osteoclast activity in medaka fish reared at the international space station

    PubMed Central

    Chatani, Masahiro; Mantoku, Akiko; Takeyama, Kazuhiro; Abduweli, Dawud; Sugamori, Yasutaka; Aoki, Kazuhiro; Ohya, Keiichi; Suzuki, Hiromi; Uchida, Satoko; Sakimura, Toru; Kono, Yasushi; Tanigaki, Fumiaki; Shirakawa, Masaki; Takano, Yoshiro; Kudo, Akira

    2015-01-01

    The bone mineral density (BMD) of astronauts decreases specifically in the weight-bearing sites during spaceflight. It seems that osteoclasts would be affected by a change in gravity; however, the molecular mechanism involved remains unclear. Here, we show that the mineral density of the pharyngeal bone and teeth region of TRAP-GFP/Osterix-DsRed double transgenic medaka fish was decreased and that osteoclasts were activated when the fish were reared for 56 days at the international space station. In addition, electron microscopy observation revealed a low degree of roundness of mitochondria in osteoclasts. In the whole transcriptome analysis, fkbp5 and ddit4 genes were strongly up-regulated in the flight group. The fish were filmed for abnormal behavior; and, interestingly, the medaka tended to become motionless in the late stage of exposure. These results reveal impaired physiological function with a change in mechanical force under microgravity, which impairment was accompanied by osteoclast activation. PMID:26387549

  20. Targeted disruption of exogenous EGFP gene in medaka using zinc-finger nucleases.

    PubMed

    Ansai, Satoshi; Ochiai, Hiroshi; Kanie, Yuta; Kamei, Yasuhiro; Gou, Yuki; Kitano, Takeshi; Yamamoto, Takashi; Kinoshita, Masato

    2012-06-01

    Zinc-finger nucleases (ZFNs) are artificial enzymes that create site-specific double-strand breaks and thereby induce targeted genome editing. Here, we demonstrated successful gene disruption in somatic and germ cells of medaka (Oryzias latipes) using ZFN to target exogenous EGFP genes. Embryos that were injected with an RNA sequence pair coding for ZFNs showed mosaic loss of green fluorescent protein fluorescence in skeletal muscle. A number of mutations that included both deletions and insertions were identified within the ZFN target site in each embryo, whereas no mutations were found at the non-targeted sites. In addition, ZFN-induced mutations were introduced in germ cells and efficiently transmitted to the next generation. The mutation frequency varied (6-100%) in the germ cells from each founder, and a founder carried more than two types of mutation in germ cells. Our results have introduced the possibility of targeted gene disruption and reverse genetics in medaka.

  1. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish.

    PubMed

    Hong, Ni; Li, Mingyou; Yuan, Yongming; Wang, Tiansu; Yi, Meisheng; Xu, Hongyan; Zeng, Huaqiang; Song, Jianxing; Hong, Yunhan

    2016-03-08

    Primordial germ cell (PGC) specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes). Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model.

  2. Different Modulatory Mechanisms of Renal FXYD12 for Na+-K+-ATPase between Two Closely Related Medakas upon Salinity Challenge

    PubMed Central

    Yang, Wen-Kai; Kang, Chao-Kai; Hsu, An-Di; Lin, Chia-Hao; Lee, Tsung-Han

    2016-01-01

    Upon salinity challenge, the Na+-K+-ATPase (NKA) of fish kidney plays a crucial role in maintaining ion and water balance. Moreover, the FXYD protein family was found to be a regulator of NKA. Our preliminary results revealed that fxyd12 was highly expressed in the kidneys of the two closely related euryhaline medaka species (Oryzias dancena and O. latipes) from different natural habitats (brackish water and fresh water). In this study, we investigated the expression and association of renal FXYD12 and NKA α-subunit as well as potential functions of FXYD12 in the two medakas. These findings illustrated and compared the regulatory roles of FXYD12 for NKA in kidneys of the two medakas in response to salinity changes. In this study, at the mRNA and/or protein level, the expression patterns were similar for renal FXYD12 and NKA in the two medakas. However, different patterns of NKA activities and different interaction levels between FXYD12 and NKA were found in the kidneys of these two medakas. The results revealed that different strategies were used in the kidneys of the two medaka species upon salinity challenge. On the other hand, gene knockdown experiments demonstrated that the function of O. dancena FXYD12 allowed maintenance of a high level of NKA activity. The results of the present study indicated that the kidneys of the examined euryhaline medakas originating from brackish water and fresh water exhibited different modulatory mechanisms through which renal FXYD12 enhanced NKA activity to maintain internal homeostasis. Our findings broadened the knowledge of expression and functions of FXYD proteins, the modulators of NKA, in vertebrates. PMID:27194950

  3. Nutritional intakes in community-dwelling older Japanese adults: high intakes of energy and protein based on high consumption of fish, vegetables and fruits provide sufficient micronutrients.

    PubMed

    Watanabe, Reiko; Hanamori, Kiyoko; Kadoya, Hiroko; Nishimuta, Mamoru; Miyazaki, Hideo

    2004-06-01

    The purpose of this study was to obtain detailed data on the dietary intake of energy, macronutrients, and micronutrients, especially minerals and vitamins, of healthy free-living people over the age of 70 in Japan and to clarify the correlations among nutrient intakes. The survey was conducted in November 2001 for 57 persons (men: 31, women: 26) aged 74 y (born in 1927) living in Niigata City, Japan. A precise weighing method was used to record food intake for three consecutive days. Nutrient intake was calculated based on the Standard Tables of Food Composition in Japan (5th ed.). The intakes of energy and total protein were 44.8+/-7.7 kcal/kg/d and 1.80+/-0.35 g/kg/d for men and 38.1+/-7.6 kcal/ kg/d and 1.51+/-0.26 g/kg/d for women. These values are significantly higher than those proposed by the current Recommended Dietary Allowances (RDAs) and the data by the 2001 National Nutrition Survey in Japan. The energy intake ratios from protein, carbohydrate and fat for men were 16 : 58 : 22, respectively, and the residual part was alcohol. For women, the ratios were 16 : 62 : 22. The proportion of total protein intake that consisted of animal protein was 57.8% for men and 52.8% for women. For both sexes, all of the mean daily intakes of nine minerals and 12 vitamins were higher than those prescribed for elderly Japanese people (> or =70 y) in the RDAs. Significant strong correlations were found between total protein intake and intakes of vitamins D, B2 and B6, as well as niacin and pantothenic acid (p<0.0001). Among the nine minerals, the correlations were very strong between potassium and magnesium, calcium and phosphorus, magnesium and iron, magnesium and copper, iron and copper, and zinc and copper (r's>0.700). For vitamins, strong correlations were found between vitamin A and folic acid, vitamin B2 and pantothenic acid, and folic acid and pantothenic acid. Furthermore, strong relationships were observed between potassium and folic acid, potassium and pantothenic

  4. Molecular cloning and biochemical characterization of medaka (Oryzias latipes) lysosomal neu4 sialidase.

    PubMed

    Shiozaki, Kazuhiro; Ryuzono, Sena; Matsushita, Naoto; Ikeda, Asami; Takeshita, Kazuki; Chigwechokha, Petros Kingstone; Komatsu, Masaharu; Miyagi, Taeko

    2014-10-01

    Glycoconjugates are known to be involved in many physiological events in vertebrates. Sialidase is one of the glycosidases, which removes sialic acid from glycoconjugates. In mammals, the properties and physiological functions of sialidases have been investigated, while there is little understanding of fish sialidase. Here, to investigate the significance of fish neu4 sialidase, neu4 gene was cloned from medaka brain mRNA and identified. Sialidase-specific motifs (GPG, YRVP and Asp-Box) were well conserved in the medaka neu4 polypeptide. Optimal pH of medaka neu4 sialidase was 4.6, but its activity was sustained even at neutral and weak alkaline pH. The neu4 considerably cleaved sialic acid from 4-methylumbelliferyl-N-acetyl-α-D-neuraminic acid and sialyllactose, but not from ganglioside and fetuin, which are good substrates for human NEU4. neu4 activity was mostly detected in mitochondria/lysosome fraction after biochemical fractionation, and indirect immunofluorescence assays revealed neu4 localization in lysosome in neu4 overexpressed cells. Next, developmental change in medaka neu4 and other sialidase mRNA levels were estimated by real-time PCR. Each sialidases showed different expression patterns in embryonic development: neu4 was up-regulated at late developmental stage in embryo, and neu3a mRNA level was quite high in 0.5 dpf. On the other hand, neu3b expression was drastically increased after hatching, suggesting that each sialidase may play a different role in embryonic development.

  5. Osteoblast and osteoclast behaviors in the turnover of attachment bones during medaka tooth replacement.

    PubMed

    Mantoku, Akiko; Chatani, Masahiro; Aono, Kazushi; Inohaya, Keiji; Kudo, Akira

    2016-01-15

    Tooth replacement in polyphyodont is a well-organized system for maintenance of homeostasis of teeth, containing the dynamic structural change in skeletal tissues such as the attachment bone, which is the supporting element of teeth. Histological analyses have revealed the character of tooth replacement, however, the cellular mechanism of how skeletal tissues are modified during tooth replacement is largely unknown. Here, we showed the important role of osteoblasts for controlling osteoclasts to modify the attachment bone during tooth replacement in medaka pharyngeal teeth, coupled with an osterix-DsRed/TRAP-GFP transgenic line to visualize osteoblasts and osteoclasts. In the turnover of the row of attachment bones, these bones were resorbed at the posterior side where most developed functional teeth were located, and generated at the anterior side where teeth were newly erupted, which caused continuous tooth replacement. In the cellular analysis, osteoclasts and osteoblasts were located at attachment bones separately, since mature osteoclasts were localized at the resorbing side and osteoblasts gathered at the generating side. To demonstrate the role of osteoclasts in tooth replacement, we established medaka made deficient in c-fms-a by TALEN. c-fms-a deficient medaka showed hyperplasia of attachment bones along with reduced bone resorption accompanied by a low number of TRAP-positive osteoclasts, indicating an important role of osteoclasts in the turnover of attachment bones. Furthermore, nitroreductase-mediated osteoblast-specific ablation induced disappearance of osteoclasts, indicating that osteoblasts were essential for maintenance of osteoclasts for the proper turnover. Taken together, our results suggested that the medaka attachment bone provides the model to understand the cellular mechanism for tooth replacement, and that osteoblasts act in the coordination of bone morphology by supporting osteoclasts.

  6. Multicentre, randomised, placebo-controlled trial of extract of Japanese herbal medicine Daikenchuto to prevent bowel dysfunction after adult liver transplantation (DKB 14 Study)

    PubMed Central

    Kaido, Toshimi; Shimamura, Tsuyoshi; Sugawara, Yasuhiko; Sadamori, Hiroshi; Shirabe, Ken; Yamamoto, Michio; Uemoto, Shinji

    2015-01-01

    Introduction This multicentre randomised controlled clinical trial will aim to determine the ability of an extract (TJ-100) of Daikenchuto (traditional Japanese herbal medicine; Kampo) to prevent bowel dysfunction in at least 110 patients after liver transplantation (LT). Methods and analysis The following co-primary end points will be evaluated on postoperative day 7: total oral and enteral caloric intake, abdominal distension and abdominal pain. The secondary end points will comprise sequential changes of total oral and enteral caloric intake after LT, sequential changes in numeric rating scales for abdominal distension and pain, elapsed time to the first postoperative passage of stool, quality of life assessment using the Gastrointestinal Symptom Rating Scale score (Japanese version), postoperative liver function, liver regeneration rate, incidence of bacteraemia and bacterial strain, trough level of immunosuppressants, occurrence of acute cellular rejection, discharge or not within 2 months after LT, sequential changes of portal venous flow to the graft and ascites discharge. The two arms of the study will comprise 55 patients per arm. Ethics and dissemination The study has been conducted according to the CONSORT statement. All participants signed a written consent form, and the study has been approved by the institutional review board of each participating institute and conducted in accordance with the Declaration of Helsinki of 1996. The findings will be disseminated through scientific and professional conferences, and in peer-reviewed journals. Trial registration number The DKB 14 Study was registered in the University Hospital Medical Information Network Clinical Trial Registration (UMIN-CTR), Japan (registration number: UMIN000014326) during 2014. PMID:26419681

  7. Morphometric Characteristics and Fin Dimorphism between Male and Female on the Marine Medaka, Oryzias dancena

    PubMed Central

    Im, Jae Hyun; Gil, Hyun Woo; Lee, Tae Ho; Kong, Hee Jeong; Ahn, Cheol Min; Kim, Bong Seok; Kim, Dong Soo; Zhang, Chang Ik; Park, In-Seok

    2016-01-01

    ABSTRACT Sexual dimorphism is the most conspicuous difference between the sexes. This study examines possible sexual dimorphism and the relative growth patterns of morphometric characteristics in the marine medaka, Oryzias dancena for their potential to help differentiate between males and females of this species. The von Bertalanffy growth parameters estimated by a non-linear regression method were L∞=30.2 mm, K=3.22/year, and τ0=-0.05. All 18 characteristics measured showed a difference between males and females from 70 days after hatching. Each of these characteristics were significantly different between sexes (ANCOVA, P<0.05), and the ratio of standard length between sexes showed that males were larger than females for all five morphometric measurements. Fin length measurements were taken for 21 distances of anal fin and 7 distances of dorsal fin between landmarks. There were all differences for all dorsal fin rays between the males and the females and there is significant difference in 70 days after their hatch when the sexual dimorphism is presented. The significant difference (P<0.05) in fin ray for male and female was more greatly seen as they grow. Male marine medaka showed more rapid growth than females, with longer length, dorsal fins and anal fins. Differences in these characteristics will be useful during experiments when it is necessary to differentiate between sexes of marine medaka. PMID:28144638

  8. Right-elevated expression of charon is regulated by fluid flow in medaka Kupffer's vesicle.

    PubMed

    Hojo, Motoki; Takashima, Shigeo; Kobayashi, Daisuke; Sumeragi, Akira; Shimada, Atsuko; Tsukahara, Tatsuya; Yokoi, Hayato; Narita, Takanori; Jindo, Tomoko; Kage, Takahiro; Kitagawa, Tadao; Kimura, Tetsuaki; Sekimizu, Koshin; Miyake, Akimitsu; Setiamarga, Davin; Murakami, Ryohei; Tsuda, Sachiko; Ooki, Shinya; Kakihara, Ken; Naruse, Kiyoshi; Takeda, Hiroyuki

    2007-06-01

    Recent studies have revealed that a cilium-generated liquid flow in the node has a crucial role in the establishment of the left-right (LR) axis in the mouse. In fish, Kupffer's vesicle (KV), a teleost-specific spherical organ attached to the tail region, is known to have an equivalent role to the mouse node during LR axis formation. However, at present, there has been no report of an asymmetric gene expressed in KV under the control of fluid flow. Here we report the earliest asymmetric gene in teleost KV, medaka charon, and its regulation. Charon is a member of the Cerberus/DAN family of proteins, first identified in zebrafish. Although zebrafish charon was reported to be symmetrically expressed in KV, medaka charon displays asymmetric expression with more intense expression on the right side. This asymmetric expression was found to be regulated by KV flow because symmetric and up-regulated charon expression was observed in flow-defective embryos with immotile cilia or disrupted KV. Taken together, medaka charon is a reliable gene marker for LR asymmetry in KV and thus, will be useful for the analysis of the early steps downstream of the fluid flow.

  9. Effects of CO2-driven ocean acidification on early life stages of marine medaka (Oryzias melastigma)

    NASA Astrophysics Data System (ADS)

    Mu, J.; Jin, F.; Wang, J.; Zheng, N.; Cong, Y.

    2015-01-01

    The potential effects of elevated CO2 level and reduced carbonate saturation state in marine environment on fishes and other non-calcified organisms are still poorly known. In present study, we investigated the effects of ocean acidification on embryogenesis and organogenesis of newly hatched larvae of marine medaka (Oryzias melastigma) after 21 d exposure of eggs to different artificially acidified seawater (pH 7.6 and 7.2, respectively), and compared with those in control group (pH 8.2). Results showed that CO2-driven seawater acidification (pH 7.6 and 7.2) had no detectable effect on hatching time, hatching rate, and heart rate of embryos. However, the deformity rate of larvae in pH 7.2 treatment was significantly higher than that in control treatment. The left and right sagitta areas did not differ significantly from each other in each treatment. However, the mean sagitta area of larvae in pH 7.6 treatment was significantly smaller than that in the control (p = 0.024). These results suggest that although marine medaka might be more tolerant of elevated CO2 than some other fishes, the effect of elevated CO2 level on the calcification of otolith is likely to be the most susceptibly physiological process of pH regulation in early life stage of marine medaka.

  10. Cloning and localization of immediate early response 2 (ier2) gene in the brain of medaka.

    PubMed

    Moriya, Shogo; Chourasia, Dipti; Ng, Kai We; Khel, Nazmina Bahadur; Parhar, Ishwar S

    2016-11-01

    Immediate early response (IER) 2 gene, a member of the IER family, is a gene of unknown function which is affected by external stimuli in the brain. In the present study, the full length sequence and localization of medaka (Oryzias latipes) ier2 was investigated in the brain to understand the functions of Ier2 in the future studies. The full length sequence of medaka ier2 was identified using a 3'-, 5'- rapid amplification of cDNA ends method, and distribution in the brain was identified using in situ hybridization. The identified full length ier2 mRNA consisted of 939 nucleotides spanning along 1 exon. The deduced amino acid sequence consisted of 171 amino acid residues which contains a highly conserved sequence, nuclear localization signal. ier2 mRNA was distributed in the telencephalon, midbrain and the hypothalamus. This highly conserved primary response gene Ier2 can be used to visualize and map functionally activated neuronal circuitry in the brain of medaka.

  11. Production of the medaka derived from vitrified whole testes by germ cell transplantation

    PubMed Central

    Seki, Shinsuke; Kusano, Kazunari; Lee, Seungki; Iwasaki, Yoshiko; Yagisawa, Masaru; Ishida, Mariko; Hiratsuka, Tadashi; Sasado, Takao; Naruse, Kiyoshi; Yoshizaki, Goro

    2017-01-01

    The medaka (Oryzias latipes) is a teleost model distinguished from other model organisms by the presence of inbred strains, wild stocks, and related species. Cryopreservation guarantees preservation of these unique biological resources. However, because of their large size, cryopreservation techniques for their eggs and embryos have not been established. In the present study, we established a methodology to produce functional gametes from cryopreserved testicular cells (TCs). Whole testes taken from medaka were cryopreserved by vitrification. After thawing, the cells dissociated from cryopreserved testicular tissues were intraperitoneally transplanted into sterile triploid hatchlings. Some cells, presumably spermatogonial stem cells, migrated into the genital ridges of recipients and resulted in the production of eggs or sperm, based on sex of the recipient. Mating of recipients resulted in successful production of cryopreserved TC-derived offspring. We successfully produced individuals from the Kaga inbred line, an endangered wild population in Tokyo, and a sub-fertile mutant (wnt4b−/−) from cryopreserved their TCs. This methodology facilitates semi-permanent preservation of various medaka strains. PMID:28256523

  12. Tooth replacement and putative odontogenic stem cell niches in pharyngeal dentition of medaka (Oryzias latipes).

    PubMed

    Abduweli, Dawud; Baba, Otto; Tabata, Makoto J; Higuchi, Kazunori; Mitani, Hiroshi; Takano, Yoshiro

    2014-04-01

    The small-sized teleost fish medaka, Oryzias latipes, has as many as 1000 pharyngeal teeth undergoing continuous replacement. In this study, we sought to identify the tooth-forming units and determine its replacement cycles, and further localize odontogenic stem cell niches in the pharyngeal dentition of medaka to gain insights into the mechanisms whereby continuous tooth replacement is maintained. Three-dimensional reconstruction of pharyngeal epithelium and sequential fluorochrome labeling of pharyngeal bones and teeth indicated that the individual functional teeth and their successional teeth were organized in families, each comprising up to five generations of teeth and successional tooth germs, and that the replacement cycle of functional teeth was approximately 4 weeks. BrdU label/chase experiments confirmed the existence of clusters of label-retaining epithelial cells at the posterior end of each tooth family where the expression of pluripotency marker Sox2 was confirmed by in situ hybridization. Label-retaining cells were also identified in the mesoderm immediately adjacent to the posterior end of each tooth family. These data suggest the importance of existence of slow-cycling dental epithelial cells and Sox2 expressions at the posterior end of each tooth family to maintain continuous tooth formation and replacement in the pharyngeal dentition of medaka.

  13. Disruption of dmc1 Produces Abnormal Sperm in Medaka (Oryzias latipes)

    PubMed Central

    Chen, Ji; Cui, Xiaojuan; Jia, Shaoting; Luo, Daji; Cao, Mengxi; Zhang, Yunsheng; Hu, Hongling; Huang, Kaiyao; Zhu, Zuoyan; Hu, Wei

    2016-01-01

    DMC1 is a recombinase that is essential for meiotic synapsis. Experiments in extensive species of eukaryotes have indicated the independent role of DMC1 in repairing double strand breaks (DSBs) produced during meiosis I. Mutation of dmc1 in mice and human often leads to obstacles in spermatogenesis and male sterility. Here, we report on the disruption of dmc1 in male medaka (Oryzias latipes). Synapsis was disturbed in the mutant medaka testis nuclei, as observed in mice and other organisms. Unexpectedly, the mutant medaka could produce a few sperm and, although most of these had multiple tail or multiple head malformations, some of them could swim, and few of them even had insemination ability. Our transcriptome analysis showed that there was not a remarkable change in the expression of most of the genes involved in the pathways associated with the meiotic DNA repair and flagella assembly. Our results provided an indication of the accessory mechanisms that might be involved in the repair of DSBs during meiosis. In a species besides humans, we provided evidence that disorders in meiosis recombination might lead to the malformation of sperm. PMID:27480068

  14. Ethanol Disrupts Chondrification of the Neurocranial Cartilages in Medaka Embryos without Affecting Aldehyde Dehydrogenase 1A2 (Aldh1A2) Promoter Methylation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Medaka (Oryzias latipes) embryos at different developmental stages were exposed to ethanol for 48 h, then allowed to hatch. Teratogenic effects were evaluated in hatchlings after examining chondrocranial cartilage deformities. Ethanol disrupted cartilage development in medaka in a dose and developme...

  15. Deaf Life on Isolated Japanese Islands.

    ERIC Educational Resources Information Center

    Torigoe, Takashi; And Others

    1995-01-01

    Interviewed 38 adults with deafness and little schooling in Okinawa concerning their social and language environment. Many of the individuals used an indigenous gestural system shared with hearing people that enabled them to participate in the hearing community. Most had only limited contact with the deaf community and Japanese Sign Language.…

  16. TALENs-mediated gene disruption of myostatin produces a larger phenotype of medaka with an apparently compromised immune system.

    PubMed

    Chiang, Yi-An; Kinoshita, Masato; Maekawa, Shun; Kulkarni, Amod; Lo, Chu-Fang; Yoshiura, Yasutoshi; Wang, Han-Ching; Aoki, Takashi

    2016-01-01

    Although myostatin, a suppressor of skeletal muscle development and growth, has been well studied in mammals, its function in fish remains unclear. In this study, we used a popular genome editing tool with high efficiency and target specificity (TALENs; transcription activator-like effector nucleases) to mutate the genome sequence of myostatin (MSTN) in medaka (Oryzias latipes). After the TALEN pair targeting OlMyostatin was injected into fertilized medaka eggs, mutant G0 fish carrying different TALENs-induced frameshifts in the OlMSTN coding sequence were mated together in order to transmit the mutant sequences to the F1 generation. Two F1 mutants with frameshifted myostatin alleles were then mated to produce the F2 generation, and these F2 OlMSTN null (MSTN(-/-)) medaka were evaluated for growth performance. The F2 fish showed significantly increased body length and weight compared to the wild type fish at the juvenile and post-juvenile stages. At the post-juvenile stage, the average body weight of the MSTN(-/-) medaka was ∼25% greater than the wild type. However, we also found that when the F3 generation were challenged with red spotted grouper nervous necrosis virus (RGNNV), the expression levels of the interferon-stimulated genes were lower than in the wild type, and the virus copy number was maintained at a high level. We therefore conclude that although the MSTN(-/-) medaka had a larger phenotype, their immune system appeared to be at least partially suppressed or undeveloped.

  17. An Approach to Elucidate NBS1 Function in DNA Repair Using Frequent Nonsynonymous Polymorphism in Wild Medaka (Oryzias latipes) Populations.

    PubMed

    Igarashi, Kento; Kobayashi, Junya; Katsumura, Takafumi; Urushihara, Yusuke; Hida, Kyohei; Watanabe-Asaka, Tomomi; Oota, Hiroki; Oda, Shoji; Mitani, Hiroshi

    2017-01-01

    Nbs1 is one of the genes responsible for Nijmegen breakage syndrome, which is marked with high radiosensitivity. In human NBS1 (hNBS1), Q185E polymorphism is known as the factor to cancer risks, although its DSB repair defect has not been addressed. Here we investigated the genetic variations in medaka (Oryzias latipes) wild populations, and found 40 nonsynonymous single nucleotide polymorphisms (SNPs) in medaka nbs1 (olnbs1) gene within 5 inbred strains. A mutation to histidine in Q170 residue in olNbs1, which corresponds to Q185 residue of hNBS1, was widely distributed in the closed colonies derived from the eastern Korean population of medaka. Overexpression of H170 type olNbs1 in medaka cultured cell lines resulted in the increased accumulation of olNbs1 at laser-induced DSB sites. Autophosphorylation of DNA-dependent protein kinase at T2609 was suppressed after the γ-ray irradiation, which was followed by prolonged formation of γ-H2AX foci and delayed DSB repair. These findings suggested that the nonsynonymous SNP (Q170H) in olnbs1, which induced DSB repair defects, is specifically distributed in the eastern Korean population of medaka. Furthermore, examination using the variation within wild populations might provide a novel method to characterize a driving force to spread the disease risk alleles.

  18. Multiple cocaine- and amphetamine-regulated transcript (CART) genes in medaka, Oryzias latipes: cloning, tissue distribution and effect of starvation.

    PubMed

    Murashita, Koji; Kurokawa, Tadahide

    2011-02-01

    The neuropeptide cocaine- and amphetamine-regulated transcript (CART) is important in the regulation of food intake in mammals and fish. The tissue distributions of six CART cDNAs (cart ch3, ch4, ch6, ch9, ch11, and ch22) from medaka, Oryzias latipes, were cloned and the effect of starvation on their expression was examined. As in other species, medaka cart ch3, ch4, ch6, ch9, and ch22 consisted of three exons, while medaka cart ch11 contained four. The six cysteine residues at the C-terminal end of the CART motif and three-dimensional structure were well conserved in all medaka CART peptides. Tissue distribution analysis revealed that cart ch3, ch4, ch6, ch11, and ch22 were primarily expressed in the brain, but that the highest rates of cart ch9 expression occurred in the skin, suggesting different functions among the homologous genes. Although CART ch3 mRNA levels decreased in response to 17 days starvation, these levels were restored by re-feeding. However, the finding that the five other CART mRNAs did not respond to starvation suggests that only CART ch3 has an anorexigenic function in medaka.

  19. An Approach to Elucidate NBS1 Function in DNA Repair Using Frequent Nonsynonymous Polymorphism in Wild Medaka (Oryzias latipes) Populations

    PubMed Central

    Igarashi, Kento; Kobayashi, Junya; Katsumura, Takafumi; Urushihara, Yusuke; Hida, Kyohei; Watanabe-Asaka, Tomomi; Oota, Hiroki; Oda, Shoji

    2017-01-01

    Nbs1 is one of the genes responsible for Nijmegen breakage syndrome, which is marked with high radiosensitivity. In human NBS1 (hNBS1), Q185E polymorphism is known as the factor to cancer risks, although its DSB repair defect has not been addressed. Here we investigated the genetic variations in medaka (Oryzias latipes) wild populations, and found 40 nonsynonymous single nucleotide polymorphisms (SNPs) in medaka nbs1 (olnbs1) gene within 5 inbred strains. A mutation to histidine in Q170 residue in olNbs1, which corresponds to Q185 residue of hNBS1, was widely distributed in the closed colonies derived from the eastern Korean population of medaka. Overexpression of H170 type olNbs1 in medaka cultured cell lines resulted in the increased accumulation of olNbs1 at laser-induced DSB sites. Autophosphorylation of DNA-dependent protein kinase at T2609 was suppressed after the γ-ray irradiation, which was followed by prolonged formation of γ-H2AX foci and delayed DSB repair. These findings suggested that the nonsynonymous SNP (Q170H) in olnbs1, which induced DSB repair defects, is specifically distributed in the eastern Korean population of medaka. Furthermore, examination using the variation within wild populations might provide a novel method to characterize a driving force to spread the disease risk alleles. PMID:28107384

  20. Early warning signs of endocrine disruption in adult fish from the ingestion of polyethylene with and without sorbed chemical pollutants from the marine environment.

    PubMed

    Rochman, Chelsea M; Kurobe, Tomofumi; Flores, Ida; Teh, Swee J

    2014-09-15

    Plastic debris is associated with several chemical pollutants known to disrupt the functioning of the endocrine system. To determine if the exposure to plastic debris and associated chemicals promotes endocrine-disrupting effects in fish, we conducted a chronic two-month dietary exposure using Japanese medaka (Oryzias latipes) and environmentally relevant concentrations of microplastic (<1mm) and associated chemicals. We exposed fish to three treatments: a no-plastic (i.e. negative control), virgin-plastic (i.e. virgin polyethylene pre-production pellets) and marine-plastic treatment (i.e. polyethylene pellets deployed in San Diego Bay, CA for 3 months). Altered gene expression was observed in male fish exposed to the marine-plastic treatment, whereas altered gene expression was observed in female fish exposed to both the marine- and virgin-plastic treatment. Significant down-regulation of choriogenin (Chg H) gene expression was observed in males and significant down-regulation of vitellogenin (Vtg I), Chg H and the estrogen receptor (ERα) gene expression was observed in females. In addition, histological observation revealed abnormal proliferation of germ cells in one male fish from the marine-plastic treatment. Overall, our study suggests that the ingestion of plastic debris at environmentally relevant concentrations may alter endocrine system function in adult fish and warrants further research.

  1. Effects of Madagascar yam extracts, Dioscorea antaly, on embryo-larval development of medaka fish, Oryzias latipes.

    PubMed

    Rakotobe, Lolona; Berkal, Miassa; Huet, Hélène; Djediat, Chakib; Jeannoda, Victor; Bodo, Bernard; Mambu, Lengo; Crespeau, François; Edery, Marc

    2010-01-01

    The yams edible starchy tubers, are of cultural, economic and nutritional importance in tropical and subtropical regions. The present study concerns the analysis at different levels of Dioscorea antaly toxicity to medaka embryo-larval development. The incubation of medaka fish embryos in a medium containing Dioscorea antaly extract resulted in a dose dependent reduction in survival rate. Survival rates were reduced up to 100% with extract concentrations of 4mg mL(-1). The LD(50) was estimated to be 0.86mg mL(-1)Dioscorea antaly. Anatomopathological studies did not show any caustic effects, irritation to mouth, throat or intestinal tract in surviving embryos but rather an inflammatory reaction in the liver. The data presented in this paper thus extends the use of medaka embryos as a valuable model to analyze the effects of food toxins.

  2. The Effects of the Habitual Consumption of Miso Soup on the Blood Pressure and Heart Rate of Japanese Adults: A Cross-sectional Study of a Health Examination

    PubMed Central

    Ito, Koji; Miyata, Kenji; Mohri, Masahiro; Origuchi, Hideki; Yamamoto, Hideo

    2017-01-01

    Objective It is recommended that middle-aged and elderly individuals reduce their salt intake because of the high prevalence of hypertension. The consumption of miso soup is associated with salt intake, and the reduced consumption of miso soup has been recommended. Recent studies have demonstrated that the consumption of miso soup can attenuate an autonomic imbalance in animal models. However, it is unclear whether these results are applicable to humans. This study examined the cross-sectional association between the frequency of miso soup consumption and the blood pressure and heart rate of human subjects. Methods A total of 527 subjects of 50 to 81 years of age who participated in our hospital health examination were enrolled in the present study and divided into four groups based on the frequency of their miso soup consumption ([bowl(s) of miso soup/week] Group 1, <1; Group2, <4; Group3, <7; Group4, ≥7). The blood pressure levels and heart rates of the subjects in each group were compared. Furthermore, a multivariable analysis was performed to determine whether miso soup consumption was an independent factor affecting the incidence of hypertension or the heart rate. Results The frequency of miso soup consumption was not associated with blood pressure. The heart rate was, however, lower in the participants who reported a high frequency of miso soup consumption. A multivariable analysis revealed that the participants who reported a high frequency of miso soup consumption were more likely to have a lower heart rate, but that the consumption of miso soup was not associated with the incidence of hypertension. Conclusion These results indicate that miso soup consumption might decrease the heart rate, but not have a significant effect on the blood pressure of in middle-aged and elderly Japanese individuals. PMID:28049996

  3. The Effects of the Habitual Consumption of Miso Soup on the Blood Pressure and Heart Rate of Japanese Adults: A Cross-sectional Study of a Health Examination.

    PubMed

    Ito, Koji; Miyata, Kenji; Mohri, Masahiro; Origuchi, Hideki; Yamamoto, Hideo

    Objective It is recommended that middle-aged and elderly individuals reduce their salt intake because of the high prevalence of hypertension. The consumption of miso soup is associated with salt intake, and the reduced consumption of miso soup has been recommended. Recent studies have demonstrated that the consumption of miso soup can attenuate an autonomic imbalance in animal models. However, it is unclear whether these results are applicable to humans. This study examined the cross-sectional association between the frequency of miso soup consumption and the blood pressure and heart rate of human subjects. Methods A total of 527 subjects of 50 to 81 years of age who participated in our hospital health examination were enrolled in the present study and divided into four groups based on the frequency of their miso soup consumption ([bowl(s) of miso soup/week] Group 1, <1; Group2, <4; Group3, <7; Group4, ≥7). The blood pressure levels and heart rates of the subjects in each group were compared. Furthermore, a multivariable analysis was performed to determine whether miso soup consumption was an independent factor affecting the incidence of hypertension or the heart rate. Results The frequency of miso soup consumption was not associated with blood pressure. The heart rate was, however, lower in the participants who reported a high frequency of miso soup consumption. A multivariable analysis revealed that the participants who reported a high frequency of miso soup consumption were more likely to have a lower heart rate, but that the consumption of miso soup was not associated with the incidence of hypertension. Conclusion These results indicate that miso soup consumption might decrease the heart rate, but not have a significant effect on the blood pressure of in middle-aged and elderly Japanese individuals.

  4. Comparative analysis of her genes during fish somitogenesis suggests a mouse/chick-like mode of oscillation in medaka.

    PubMed

    Gajewski, Martin; Elmasri, Harun; Girschick, Manuel; Sieger, Dirk; Winkler, Christoph

    2006-06-01

    Somitogenesis is the key developmental step, which divides the vertebrate body axis into segmentally repeated structures. It requires an intricate process of pre-patterning, which is driven by an oscillator mechanism consisting of the Delta-Notch pathway and various hairy- and Enhancer of split-related (her) genes. The subset of her genes, which are necessary to set up the segmentation clock, reveal a complex scenario of interactions. To understand which her genes are essential core players in this process, we compared the expression patterns of somitogenesis-relevant her genes in zebrafish and medaka (Oryzias latipes). Most of the respective medaka genes (Ol-her) are duplicated like what has been shown for zebrafish (Dr-her) and pufferfish genes (Fr-her). However, zebrafish genes show some additional copies and significant differences in expression patterns. For the paralogues Dr-her1 and Dr-her11, only one copy exists in the medaka (Ol-her1/11), which combines the expression patterns found for both zebrafish genes. In contrast to Dr-her5, the medaka orthologue appears to play a role in somitogenesis because it is expressed in the presomitic mesoderm (PSM). PSM expression also suggests a role for both Ol-her13 genes, homologues of mouse Hes6 (mHes6), in this process, which would be consistent with a conserved mHes6 homologue gear in the segmentation clock exclusively in lower vertebrates. Members of the mHes5 homologue group seem to be involved in somite formation in all vertebrates (e.g. Dr- and Ol-her12), although different paralogues are additionally recruited in zebrafish (e.g. Dr-her15) and medaka (e.g. Ol-her4). We found that the linkage between duplicates is strongly conserved between pufferfish and medaka and less well conserved in zebrafish. Nevertheless, linkage and orientation of several her duplicates are identical in all three species. Therefore, small-scale duplications must have happened before whole genome duplication occurred in a fish ancestor

  5. A study to investigate changes in the levels of biomarkers of exposure to selected cigarette smoke constituents in Japanese adult male smokers who switched to a non-combustion inhaler type of tobacco product.

    PubMed

    Miura, Naoki; Yuki, Dai; Minami, Naoki; Kakehi, Aoi; Futamura, Yasuyuki

    2015-04-01

    In a clinical study, changes in 14 biomarkers of exposures (BOEs) from 10 tobacco smoke constituents and mutagens detected by the urine mutagenicity test were investigated using a non-combustion inhaler type of tobacco product (NCIT) by switching from a conventional cigarette. This study was conducted in 80 Japanese healthy adult males with a 4-week residential, controlled, open-label, parallel group design. After randomization, 40 smokers used NCIT with approximately 750 aspirations, other 20 smokers smoked approximately 20 pieces of an assigned 1-mg ISO tar conventional cigarette (CC1) every day. Twenty non-smokers (NS) did not use any tobacco product. Under this study condition, switching from cigarette to NCIT showed significant reduction in all BOEs measured. On day 29, the levels of these BOEs were almost the same as those in the NS group, except BOEs of nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). This suggested that the exposure to 8 constituents and mutagens in the NCIT group was similar to that in the NS group, while the exposure to nicotine was higher. Although the precise exposure level to NNK was not estimated because of the long half-life of its BOE, it would be substantially lower in the NCIT group than in the CC1 group.

  6. Effects of a Lifestyle-Based Physical Activity Intervention on Medical Expenditure in Japanese Adults: A Community-Based Retrospective Study

    PubMed Central

    2016-01-01

    Background. This study aimed to investigate whether a lifestyle-based physical activity program could contribute to reduced medical expenditure. Methods. The study participants were 60 adults aged 63.1 (standard deviation, 4.4) years in the intervention group; the case-control group consisted of 300 adults who were randomly selected from Japan's national health insurance system. This community-based retrospective study incorporated a 3-year follow-up. Results. The total and outpatient medical expenditure in the intervention group were significantly lower than in the control group: total expenditure, $US640.4/year; outpatient expenditure, $369.1/year. The odds ratio for outpatient visiting was 6.47-fold higher in the control than in the intervention group. Conclusion. Our study suggests that a health program to promote physical activity can result in reduced total medical expenditure, outpatient medical expenditure, and possibly also inpatient medical expenditure. PMID:27493963

  7. Lifestyle characteristics assessment of Japanese in Pittsburgh, USA.

    PubMed

    Hirooka, Nobutaka; Takedai, Teiichi; D'Amico, Frank

    2012-04-01

    Lifestyle-related chronic diseases such as cancer and cardiovascular disease are the greatest public health concerns. Evidence shows Japanese immigrants to a westernized environment have higher incidence of lifestyle-related diseases. However, little is known about lifestyle characteristics related to chronic diseases for Japanese in a westernized environment. This study is examining the gap in lifestyle by comparing the lifestyle prevalence for Japanese in the US with the Japanese National Data (the National Health and Nutrition Survey in Japan, J-NHANS) as well as the Japan National Health Promotion in the twenty-first Century (HJ21) goals. Japanese adults were surveyed in Pittsburgh, USA, regarding their lifestyle (e.g., diet, exercise, smoking, stress, alcohol, and oral hygiene). The prevalence was compared with J-NHANS and HJ21 goals. Ninety-three responded (response rate; 97.9%). Japanese men (n = 38) and women (n = 55) in Pittsburgh smoke less than Japanese in Japan (P < 0.001 for both genders). Japanese in Pittsburgh perform less physical activity in daily life and have lower prevalence of walking more than 1 h per day (P < 0.001 for both genders). Japanese women in Pittsburgh have significantly higher prevalence of stress than in Japan (P = 0.004). Japanese men in Pittsburgh do not reach HJ21 goal in weight management, BMI, use of medicine or alcohol to sleep, and sleep quality. Japanese women in Pittsburgh do not reach HJ21 goal in weight management and sleep quality. In conclusion, healthy lifestyle promotion including exercise and physical activity intervention for Japanese living in a westernized environment is warranted.

  8. Japanese Interest in "Hotaru" (Fireflies) and "Kabuto-Mushi" (Japanese Rhinoceros Beetles) Corresponds with Seasonality in Visible Abundance.

    PubMed

    Takada, Kenta

    2012-04-10

    Seasonal changes in the popularity of fireflies [usually Genji-fireflies (Luciola cruciata Motschulsky) in Japan] and Japanese rhinoceros beetles [Allomyrina dichotoma (Linne)] were investigated to examine whether contemporary Japanese are interested in visible emergence of these insects as seasonal events. The popularity of fireflies and Japanese rhinoceros beetles was assessed by the Google search volume of their Japanese names, "Hotaru" and "Kabuto-mushi" in Japanese Katakana script using Google Trends. The search volume index for fireflies and Japanese rhinoceros beetles was distributed across seasons with a clear peak in only particular times of each year from 2004 to 2011. In addition, the seasonal peak of popularity for fireflies occurred at the beginning of June, whereas that for Japanese rhinoceros beetles occurred from the middle of July to the beginning of August. Thus seasonal peak of each species coincided with the peak period of the emergence of each adult stage. These findings indicated that the Japanese are interested in these insects primarily during the time when the two species are most visibly abundant. Although untested, this could suggest that fireflies and Japanese rhinoceros beetles are perceived by the general public as indicators or symbols of summer in Japan.

  9. Air Writing as a Technique for the Acquisition of Sino-japanese Characters by Second Language Learners

    ERIC Educational Resources Information Center

    Thomas, Margaret

    2015-01-01

    This article calls attention to a facet of the expertise of second language (L2) learners of Japanese at the intersection of language, memory, gesture, and the psycholinguistics of a logographic writing system. Previous research has shown that adult L2 learners of Japanese living in Japan (similarly to native speakers of Japanese) often…

  10. A first generation physical map of the medaka genome in BACs essential for positional cloning and clone-by-clone based genomic sequencing.

    PubMed

    Khorasani, Maryam Zadeh; Hennig, Steffen; Imre, Gabriele; Asakawa, Shuichi; Palczewski, Stefanie; Berger, Anja; Hori, Hiroshi; Naruse, Kiyoshi; Mitani, Hiroshi; Shima, Akihiro; Lehrach, Hans; Wittbrodt, Jochen; Kondoh, Hisato; Shimizu, Nobuyoshi; Himmelbauer, Heinz

    2004-07-01

    In order to realize the full potential of the medaka as a model system for developmental biology and genetics, characterized genomic resources need to be established, culminating in the sequence of the medaka genome. To facilitate the map-based cloning of genes underlying induced mutations and to provide templates for clone-based genomic sequencing, we have created a first-generation physical map of the medaka genome in bacterial artificial chromosome (BAC) clones. In particular, we exploited the synteny to the closely related genome of the pufferfish, Takifugu rubripes, by marker content mapping. As a first step, we clustered 103,144 public medaka EST sequences to obtain a set of 21,121 non-redundant sequence entities. Avoiding oversampling of gene-dense regions, 11,254 of EST clusters were successfully matched against the draft sequence of the fugu genome, and 2363 genes were selected for the BAC map project. We designed 35mer oligonucleotide probes from the selected genes and hybridized them against 64,500 BAC clones of strains Cab and Hd-rR, representing 14-fold coverage of the medaka genome. Our data set is further supplemented with 437 results generated from PCR-amplified inserts of medaka cDNA clones and BAC end-fragment markers. Our current, edited, first generation medaka BAC map consists of 902 map segments that cover about 74% of the medaka genome. The map contains 2721 markers. Of these, 2534 are from expressed sequences, equivalent to a non-redundant set of 2328 loci. The 934 markers (724 different) are anchored to the medaka genetic map. Thus, genetic map assignments provide immediate access to underlying clones and contigs, simplifying molecular access to candidate gene regions and their characterization.

  11. Osterix/Sp7 regulates biomineralization of otoliths and bone in medaka (Oryzias latipes).

    PubMed

    Renn, Jörg; Winkler, Christoph

    2014-02-01

    Osterix/Sp7 is a zinc finger transcription factor and critical regulator of osteoblast differentiation, maturation and activity. Osterix expression has also been described in non-skeletal tissues but functional analyses are lacking. In the present study, we show that in the teleost model medaka, osterix is present as two alternatively spliced transcripts, osx_tv1 and osx_tv2. Knock-down of osx_tv1 and/or osx_tv2 results in mineralization loss in early intramembranous bones while cartilage formation is mostly unaffected. Formation of the parasphenoid, the earliest mineralized bone in the medaka skeleton, is impaired and fails to recover at later stages. Ossification of later bones, such as the operculum and cleithrum, is delayed but recovers during further development. In the axial skeleton, formation of the neural arches and centra is strongly delayed. In vivo analyses using osterix:nlGFP and osteocalcin:GFP transgenic medaka and whole mount in situ hybridization suggest that bone defects observed after knock-down of osterix are caused by a delay of osteoblast maturation and activity. Furthermore, we analyzed expression profile and function of osterix during ear and otolith formation. We show that osterix is expressed in otic placodes at the otic vesicle stage and that its knock-down results in a loss of otoliths. Taken together, we show that osterix is required for bone formation in a teleost fish and that its important regulatory functions are conserved between teleosts and mammals. Furthermore, we provide the first functional evidence for a role of Osterix in a non-skeletal tissue, i.e. the otoliths.

  12. Analysis of the Ush2a Gene in Medaka Fish (Oryzias latipes)

    PubMed Central

    Aller, Elena; Sánchez-Sánchez, Ana V.; Chicote, Javier U.; García-García, Gema; Udaondo, Patricia; Cavallé, Laura; Piquer-Gil, Marina; García-España, Antonio; Díaz-Llopis, Manuel; Millán, José M.; Mullor, José L.

    2013-01-01

    Patients suffering from Usher syndrome (USH) exhibit sensorineural hearing loss, retinitis pigmentosa (RP) and, in some cases, vestibular dysfunction. USH is the most common genetic disorder affecting hearing and vision and is included in a group of hereditary pathologies associated with defects in ciliary function known as ciliopathies. This syndrome is clinically classified into three types: USH1, USH2 and USH3. USH2 accounts for well over one-half of all Usher cases and mutations in the USH2A gene are responsible for the majority of USH2 cases, but also for atypical Usher syndrome and recessive non-syndromic RP. Because medaka fish (Oryzias latypes) is an attractive model organism for genetic-based studies in biomedical research, we investigated the expression and function of the USH2A ortholog in this teleost species. Ol-Ush2a encodes a protein of 5.445 aa codons, containing the same motif arrangement as the human USH2A. Ol-Ush2a is expressed during early stages of medaka fish development and persists into adulthood. Temporal Ol-Ush2a expression analysis using whole mount in situ hybridization (WMISH) on embryos at different embryonic stages showed restricted expression to otoliths and retina, suggesting that Ol-Ush2a might play a conserved role in the development and/or maintenance of retinal photoreceptors and cochlear hair cells. Knockdown of Ol-Ush2a in medaka fish caused embryonic developmental defects (small eyes and heads, otolith malformations and shortened bodies with curved tails) resulting in late embryo lethality. These embryonic defects, observed in our study and in other ciliary disorders, are associated with defective cell movement specifically implicated in left-right (LR) axis determination and planar cell polarity (PCP). PMID:24086419

  13. Hypoxia alters testicular functions of marine medaka through microRNAs regulation.

    PubMed

    Tse, Anna Chung-Kwan; Li, Jing-Woei; Wang, Simon Yuan; Chan, Ting-Fung; Lai, Keng Po; Wu, Rudolf Shiu-Sun

    2016-11-01

    Hypoxia is a global environmental concern and poses a significant threat to aquatic ecosystems, including the sustainability of natural fish populations. The deleterious effects of hypoxia on fish reproductive fitness, as mediated by disruption of sex hormones and gene expression along the Brain-Pituitary-Gonad axis, have been well documented. Recently, we further demonstrated that the observed disruption of steroidogenesis in the ovary of marine medaka Oryzias melastigma is mediated through microRNAs (miRNAs). More importantly, we reported the transgenerational epigenetic effect of hypoxia on the male reproductive impairment of marine medaka. This study attempts to elucidate the function of miRNAs and its potential role in the transgenerational effect of hypoxia in the male medaka testis, using small RNA sequencing. A total of 558 miRNAs were found in the testis, of which 9 were significant upregulated and 5 were downregulated by hypoxia. Bioinformatics analysis further revealed that among the 2885 genes targeted by the hypoxia-responsive miRNAs, many are closely related to stress response, cell cycle, epigenetic modification, sugar metabolism and cell motion. Furthermore, the integrated analysis of transcriptome data and the result of target gene prediction demonstrated 108 genes and 65 genes were concordantly upregulated and downregulated, respectively. In which, euchromatic histone-lysine N-methyltransferase 2, the epigenetic regulator of transgenerational reproductive impairment caused by hypoxia, is found to be targeted by miR-125-5p. The present findings not only reveal that miRNAs are crucial downstream mediators of hypoxic stress in fish male gonad, but also shed light on the underlying epigenetic mechanism for the reproductive impairments of hypoxia on male fish, including the observed transgenerational effects.

  14. Functional and comparative genomics analyses of pmp22 in medaka fish

    PubMed Central

    Itou, Junji; Suyama, Mikita; Imamura, Yukio; Deguchi, Tomonori; Fujimori, Kazuhiro; Yuba, Shunsuke; Kawarabayasi, Yutaka; Kawasaki, Takashi

    2009-01-01

    Background Pmp22, a member of the junction protein family Claudin/EMP/PMP22, plays an important role in myelin formation. Increase of pmp22 transcription causes peripheral neuropathy, Charcot-Marie-Tooth disease type1A (CMT1A). The pathophysiological phenotype of CMT1A is aberrant axonal myelination which induces a reduction in nerve conduction velocity (NCV). Several CMT1A model rodents have been established by overexpressing pmp22. Thus, it is thought that pmp22 expression must be tightly regulated for correct myelin formation in mammals. Interestingly, the myelin sheath is also present in other jawed vertebrates. The purpose of this study is to analyze the evolutionary conservation of the association between pmp22 transcription level and vertebrate myelin formation, and to find the conserved non-coding sequences for pmp22 regulation by comparative genomics analyses between jawed fishes and mammals. Results A transgenic pmp22 over-expression medaka fish line was established. The transgenic fish had approximately one fifth the peripheral NCV values of controls, and aberrant myelination of transgenic fish in the peripheral nerve system (PNS) was observed. We successfully confirmed that medaka fish pmp22 has the same exon-intron structure as mammals, and identified some known conserved regulatory motifs. Furthermore, we found novel conserved sequences in the first intron and 3'UTR. Conclusion Medaka fish undergo abnormalities in the PNS when pmp22 transcription increases. This result indicates that an adequate pmp22 transcription level is necessary for correct myelination of jawed vertebrates. Comparison of pmp22 orthologs between distantly related species identifies evolutionary conserved sequences that contribute to precise regulation of pmp22 expression. PMID:19534778

  15. A free calcium wave traverses the activating egg of the medaka, Oryzias latipes

    PubMed Central

    Gilkey, J. C.; Jaffe, L. F.; Ridgway, E. B.; Reynolds, G. T.

    1978-01-01

    Aequorin-injected eggs of the medaka (a fresh water fish) show an explosive rise in free calcium during fertilization, which is followed by a slow return to the resting level. Image intensification techniques now show a spreading wave of high free calcium during fertilization. The wave starts at the animal pole (where the sperm enters) and then traverses the egg as a shallow, roughly 20 degrees-wide band which vanishes at the antipode some minutes later. The peak free calcium concentration within this moving band is estimated to be about 30 microM (perhaps 100-1,000 times the resting level). Eggs activated by ionophore A23187 may show multiple initiation sites. The resulting multiple waves never spread through each other; rather, they fuse upon meeting so as to form spreading waves of compound origin. The fertilization wave is nearly independent of extracellular calcium because it is only slightly slowed (by perhaps 15%) in a medium containing 5 mM ethylene glycol-bis[beta-aminoethyl ether]N,N'-tetraacetic acid (EGTA) and no deliberately added calcium. It is also independent of the large cortical vesicles, which may be centrifugally displaced. Normally, however, it distinctly precedes the well-known wave of cortical vesicle exocytosis. We conclude that the fertilization wave in the medaka egg is propagated by calcium-stimulated calcium release, primarily from some internal sources other than the large cortical vesicles. A comparison of the characteristics of the exocytotic wave in the medaka with that in other eggs, particularly in echinoderm eggs, suggests that such a propagated calcium wave is a general feature of egg activation. PMID:10605450

  16. Bioconcentration, Metabolism and Excretion of Triclocarban in larval Qurt Medaka (Oryzias latipes)

    PubMed Central

    Schebb, Nils Helge; Flores, Ida; Kurobe, Tomofumi; Franze, Bastian; Ranganathan, Anupama; Hammock, Bruce D.; Teh, Swee

    2011-01-01

    The antimicrobial triclocarban (TCC) is frequently found in personal care products and commonly observed in surface waters and sediments. Due to its long environmental persistence TCC accumulates in sewage sludge. It also shows a high unintended biological activity as a potent inhibitor of the soluble epoxide hydrolase (sEH) and may be an endocrine disruptor. In this study, we investigated bioconcentration, metabolism and elimination of TCC in fish using Medaka (Oryzias latipes) as a model. Medaka larvae (7±1 days post hatching) were exposed to 63 nM (20 µg/L) TCC water for 24 hours. The LC-MS/MS analysis of water and tissues provided bioconcentration of TCC and its metabolites in fish body and rapid excretion into culture water. Results from tissue samples showed a tissue concentration of 34 µmol/kg and a log bioconcentration factor (BCF) of 2.86. These results are slightly lower than previous findings in snails and algae. A significant portion of the absorbed TCC was oxidatively metabolized by the fish to hydroxylated products. These metabolites underwent extensive phase II metabolism to yield sulfate and glucuronic acid conjugates. The most abundant metabolite in fish tissue was the glucuronide of 2’-OH-TCC. Elimination of TCC after transferring the fish to fresh water was rapid, with a half-life of 1 hour. This study shows that larval medaka metabolize TCC similarly to mammals. The rapid rate of metabolism results in a lower bioconcentration than calculated from the n-octanol/water partition coefficient of TCC. PMID:21872556

  17. The transition of adult patients with childhood-onset chronic diseases from pediatric to adult healthcare systems: a survey of the perceptions of Japanese pediatricians and child health nurses

    PubMed Central

    2012-01-01

    Background Advances in medical science have enabled many children with chronic diseases to survive to adulthood. The transition of adult patients with childhood-onset chronic diseases from pediatric to adult healthcare systems has received attention in Europe and the United States. We conducted a questionnaire survey among 41 pediatricians at pediatric hospitals and 24 nurses specializing in adolescent care to compare the perception of transition of care from pediatric to adult healthcare services for such patients. Findings Three-fourths of the pediatricians and all of the nurses reported that transition programs were necessary. A higher proportion of the nurses realized the necessity of transition and had already developed such programs. Both pediatricians and nurses reported that a network covering the transition from pediatric to adult healthcare services has not been established to date. Conclusions It has been suggested that spreading the importance of a transition program among pediatricians and developing a pediatric-adult healthcare network would contribute to the biopsychosocial well-being of adult patients with childhood-onset chronic disease. PMID:22433283

  18. Relationship Between Ice Nucleation Temperature Depression and Equilibrium Melting Points Depression of Medaka (Oryzias latipes) Embryos

    NASA Astrophysics Data System (ADS)

    Kimizuka, Norihito; Suzuki, Toru

    We measured the ice nucleation temperature depression , ΔTf , and equilibrium melting points depression, ΔTm, of Medaka (Oryzias latipes) embryos with different cryoprotectant (ethylene glycol, 1.3-propanediol, 1.4-butanediol, glycerol aqueous solutions) treatments. Our obtained results showed the good relationship between the ΔTf ,and ΔTm all samples. In addition the value of λ , which can be obtained from the linear relationship, ΔTf =λ ΔTm, were confirmed to show correlation with the value of λ , as obtained by the W/O emulsion method.

  19. Japanese American Identity Dilemma.

    ERIC Educational Resources Information Center

    Maykovich, Minako K.

    The major theme of this book is the label "Quiet American" for the Japanese American. In order to locate Japanese Americans sociologically and psychologically in the structure of American society, various concepts such as "marginal man,""alienation," and "inauthenticity" are examined, specifying these…

  20. Incarcerating Japanese Americans.

    ERIC Educational Resources Information Center

    Daniels, Roger

    2002-01-01

    Presents the history of the Japanese American incarceration during World War II. Focuses on issues such as Executive Order 9066, what happened to the Japanese Americans during the war, and the forms of resistance that occurred. Questions whether something like this could ever happen again. (CMK)

  1. The Japanese American Story.

    ERIC Educational Resources Information Center

    Fukei, Budd

    This book presents a view of the Japanese American experience from the time of their immigration to this country in the 1800s to their acculturation into American society in the 1970s. Topics dealt with include the prejudice and mistrust experienced by the Japanese immigrants in this country, particularly their evacuation and internment in…

  2. The Japanese containerless experiments

    NASA Technical Reports Server (NTRS)

    Azuma, Hisao

    1990-01-01

    There are three sets of Japanese containerless experiments. The first is Drop dynamics research. It consists of acoustic levitation and large amplitude drop oscillation. The second is Optical materials processing in an acoustic levitation furnace. And the third is Electrostatic levitator development by two different Japanese companies.

  3. Use of gene expression data to determine effects on gonad phenotype in Japanese medaka after exposure to trenbolone or estradiol

    EPA Science Inventory

    Various aquatic bioassays using one of several fish species have been developed or are in the process of being developed by organizations like the US Environmental Protection Agency and the Office of Economic Cooperation and Development for testing potential endocrine disrupting ...

  4. Phototoxicity of TiO2 Nanoparticles under Solar Radiation to Two Aquatic Species: Daphnia magna and Japanese Medaka

    EPA Science Inventory

    One target of development and application of TiO2 nanoparticles (nano-TiO2) is photochemical degredation of contaminants and photo-killing of microbes and fouling organisms. However, few ecotoxicological studies have focused on this aspect of nano-TiO2, specifically whether this ...

  5. EFFECTS OF ETHINYLESTRADIOL ON REPRODUCTION AND ENDOCRINE FUNCTION IN JAPANESE MEDAKA (ORYZIAS LATIPES): II. TRANSGENERATIONAL EXPOSURE. (R827098)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  6. EFFECTS OF ETHINYLESTRADIOL ON REPRODUCTION AND ENDOCRINE FUNCTION IN JAPANESE MEDAKA (ORYZIAS LATIPES): I. DEVELOPMENTAL EXPOSURE. (R827098)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  7. EFFECTS OF CADMIUM ON THE HYPOTHALAMUS-PITUITARY-GONADAL AXIS IN JAPANESE MEDAKA (ORYZIAS LATIPES): CONSEQUENCES FOR REPRODUCTION AND DEVELOPMENT

    EPA Science Inventory

    Cadmium (Cd) is an important inorganic pollutant that exists from both natural and anthropogenic emission. Concentrations measured in the aquatic environment vary considerably from 0.05 to 1,000 ppb depending on contamination, but even range in drinking water from 1 to 10 ppb. C...

  8. RESPONSE OF JAPANESE MEDAKA TO 17B-ESTRADIOL: A TIME COURSE OF ENDOCRINE-MEDIATED EFFECTS

    EPA Science Inventory

    Estrogenic compounds have been measured in the aquatic environment in concentrations subsequently found to affect reproduction and development in fish. Further investigations have described several endocrine-mediated events that indicate exposure of organisms to estrogens and/or ...

  9. Children's On-Line Processing of Scrambling in Japanese

    ERIC Educational Resources Information Center

    Suzuki, Takaaki

    2013-01-01

    This study investigates the on-line processing of scrambled sentences in Japanese by preschool children and adults using a combination of self-paced listening and speeded picture selection tasks. The effects of a filler-gap dependency, reversibility, and case markers were examined. The results show that both children and adults had difficulty in…

  10. MODERN JAPANESE, A BASIC READER. VOLUME II, JAPANESE TEXTS.

    ERIC Educational Resources Information Center

    HIBBETT, HOWARD; ITASAKA, GEN

    VOLUME II OF THIS INTRODUCTION TO WRITTEN JAPANESE CONTAINS 60 READING PASSAGES IN JAPANESE SCRIPT TO BE USED WITH THE VOCABULARY AND NOTES IN VOLUME I. THE READINGS ARE GRADED AND HAVE BEEN SELECTED TO REPRESENT GOOD MODERN JAPANESE USAGE. THE BEGINNING LESSONS ARE IN EASY INFORMAL STYLES AND ARE CONCERNED WITH THE JAPANESE LANGUAGE AND CULTURE.…

  11. Evolutionary Conservation of pou5f3 Genomic Organization and Its Dynamic Distribution during Embryogenesis and in Adult Gonads in Japanese Flounder Paralichthys olivaceus

    PubMed Central

    Gao, Jinning; Wang, Xubo; Zhang, Quanqi

    2017-01-01

    Octamer-binding transcription factor 4 (Oct4) is a member of POU (Pit-Oct-Unc) transcription factor family Class V that plays a crucial role in maintaining the pluripotency and self-renewal of stem cells. Though it has been deeply investigated in mammals, its lower vertebrate homologue, especially in the marine fish, is poorly studied. In this study, we isolated the full-length sequence of Paralichthys olivaceus pou5f3 (Popou5f3), and we found that it is homologous to mammalian Oct4. We identified two transcript variants with different lengths of 3′-untranslated regions (UTRs) generated by alternative polyadenylation (APA). Quantitative real-time RT-PCR (qRT-PCR), in situ hybridization (ISH) and immunohistochemistry (IHC) were implemented to characterize the spatial and temporal expression pattern of Popou5f3 during early development and in adult tissues. Our results show that Popou5f3 is maternally inherited, abundantly expressed at the blastula and early gastrula stages, then greatly diminishes at the end of gastrulation. It is hardly detectable from the heart-beating stage onward. We found that Popou5f3 expression is restricted to the adult gonads, and continuously expresses during oogenesis while its dynamics are downregulated during spermatogenesis. Additionally, numerous cis-regulatory elements (CRE) on both sides of the flanking regions show potential roles in regulating the expression of Popou5f3. Taken together, these findings could further our understanding of the functions and evolution of pou5f3 in lower vertebrates, and also provides fundamental information for stem cell tracing and genetic manipulation in Paralichthys olivaceus. PMID:28124980

  12. Effects of triclosan on the early life stages and reproduction of medaka Oryzias latipes and induction of hepatic vitellogenin.

    PubMed

    Ishibashi, Hiroshi; Matsumura, Naomi; Hirano, Masashi; Matsuoka, Munekazu; Shiratsuchi, Hideki; Ishibashi, Yasuhiro; Takao, Yuji; Arizono, Koji

    2004-04-14

    Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) is widely used as antibacterial agent in various industrial products, such as textile goods, soap, shampoo, liquid toothpaste and cosmetics, and often detected in wastewater effluent. In this study, the effects of TCS on the early life stages and reproduction of medaka (Oryzias latipes) were investigated. The 96-h median lethal concentration value of TCS for 24-h-old larvae was 602 microg/l. The hatchability and time to hatching in fertilized eggs exposed to 313 microg/l TCS for 14 days were significantly decreased and delayed, respectively. An assessment of the effects of a TCS 21-day exposure period on the reproduction of paired medaka showed no significant differences in the number of eggs produced and fertility among the control and 20, 100 and 200 microg/l TCS treatment groups. However, concentrations of hepatic vitellogenin were increased significantly in males treated with TCS at 20 and 100 microg/l. In the F(1) generations, although the hatching of embryos in the 20 microg/l treatment showed adverse effects, there was no dose-response relationship between hatchability and TCS treatment levels. These results suggest that TCS has high toxicity on the early life stages of medaka, and that the metabolite of TCS may be a weak estrogenic compound with the potential to induce vitellogenin in male medaka but with no adverse effect on reproductive success and offspring.

  13. Rescue from oculocutaneous albinism type 4 using medaka slc45a2 cDNA driven by its own promoter.

    PubMed

    Fukamachi, Shoji; Kinoshita, Masato; Tsujimura, Taro; Shimada, Atsuko; Oda, Shoji; Shima, Akihiro; Meyer, Axel; Kawamura, Shoji; Mitani, Hiroshi

    2008-02-01

    Patients and vertebrate mutants with oculocutaneous albinism type 4 (OCA4) have mutations in the solute carrier family 45 member 2 (slc45a2) gene. However, there is no empirical evidence for this gene-phenotype relationship. There is a unique OCA4 mutant in medaka (b) that exhibits albinism only in the skin, but the mechanism underlying this phenotype is also unknown. In this study, we rescued medaka OCA4 phenotypes, in both the eyes and the skin, by micro-injection of an slc45a2-containing genomic fragment or slc45a2 cDNA driven by its own 0.9-kb promoter. We also identified a spontaneous nucleotide change of 339 bp in the promoter as the b mutation. There are multiple transcription start sites in medaka slc45a2, as in its human ortholog, and only the shortest and eye-specific mRNA is transcribed with the b mutation. Interestingly, we further revealed a conserved pyrimidine (Py)-rich sequence of approximately 10 bp in the promoter by medaka-pufferfish comparative genomics and verified that it plays an indispensable role for expression of slc45a2 in the skin. Further studies of the 0.9-kb promoter identified in this study should provide insights into the cis/trans-regulatory mechanisms underlying the ocular and cutaneous expression of slc45a2.

  14. Zebrafish and medaka: model organisms for a comparative developmental approach of brain asymmetry

    PubMed Central

    Signore, Iskra A.; Guerrero, Néstor; Loosli, Felix; Colombo, Alicia; Villalón, Aldo; Wittbrodt, Joachim; Concha, Miguel L.

    2008-01-01

    Comparison between related species is a successful approach to uncover conserved and divergent principles of development. Here, we studied the pattern of epithalamic asymmetry in zebrafish (Danio rerio) and medaka (Oryzias latipes), two related teleost species with 115–200 Myr of independent evolution. We found that these species share a strikingly conserved overall pattern of asymmetry in the parapineal–habenular–interpeduncular system. Nodal signalling exhibits comparable spatial and temporal asymmetric expressions in the presumptive epithalamus preceding the development of morphological asymmetries. Neuroanatomical asymmetries consist of left-sided asymmetric positioning and connectivity of the parapineal organ, enlargement of neuropil in the left habenula compared with the right habenula and segregation of left–right habenular efferents along the dorsoventral axis of the interpeduncular nucleus. Despite the overall conservation of asymmetry, we observed heterotopic changes in the topology of parapineal efferent connectivity, heterochronic shifts in the timing of developmental events underlying the establishment of asymmetry and divergent degrees of canalization of embryo laterality. We offer new tools for developmental time comparison among species and propose, for each of these transformations, novel hypotheses of ontogenic mechanisms that explain interspecies variations that can be tested experimentally. Together, these findings highlight the usefulness of zebrafish and medaka as comparative models to study the developmental mechanisms of epithalamic asymmetry in vertebrates. PMID:19064351

  15. Effects of CO2-driven ocean acidification on early life stages of marine medaka (Oryzias melastigma)

    NASA Astrophysics Data System (ADS)

    Mu, J.; Jin, F.; Wang, J.; Zheng, N.; Cong, Y.

    2015-06-01

    The potential effects of high CO2 and associated ocean acidification (OA) in marine fishes and other non-calcified organisms are less well understood. In this study, we investigated the responses of early life stages (ELS) of marine medaka (Oryzias melastigma) exposed to a series of experimental manipulation of CO2 levels. Results showed that CO2-driven seawater acidification (pH 7.6 and pH 7.2) had no detectable effect on hatching time, hatching rate, or heart rate of embryos. However, the deformity rate of larvae in the pH 7.2 treatment was significantly higher than that in the control treatment. There is no significant difference between the left and right otolith areas in each treatment. However, the average otolith area of larvae in the pH 7.6 treatment was significantly smaller than that in the control. Such alterations in the developmental abnormalities and otolith size of marine medaka larvae due to elevated-CO2 levels suggests that this species will be increasingly challenged by future OA. Further studies of the impacts of OA on marine fish to assess whether or not the environmental influence in one generation can affect the later life history and the phenotype of subsequent generations are needed.

  16. Marine medaka ATP-binding cassette (ABC) superfamily and new insight into teleost Abch nomenclature

    PubMed Central

    Jeong, Chang-Bum; Kim, Bo-Mi; Kang, Hye-Min; Choi, Ik-Young; Rhee, Jae-Sung; Lee, Jae-Seong

    2015-01-01

    The ABC gene family is recognized as one of the largest gene families in all kingdoms of life. Although many genes involved in the ABC superfamily have been annotated from several fish species, information on large sets of the ABC superfamily and their evolutionary characterization are still unclear. In the marine medaka Oryzias melastigma, 50 ABC transporters were identified with bioinformatics-aided in silico analyses, and their full-length cDNA sequences were characterized. Phylogenetic analysis revealed that they could be classified into the eight subfamilies (A–H) that include all members of all ABC subfamilies. Interestingly, several teleosts’ Abcg members were closely clustered with Abch members in a distinctive clade. The abch gene was also observed in the coelacanth and the spotted gar, suggesting that this gene was retained from a bilaterian ancestor and that a gene loss event recently occurred in the tetrapod lineage. In teleosts, the nomenclature of previously annotated abcg genes should be considered carefully, as they form a distinctive clade with the marine medaka abch subfamily and other teleost abch genes, but not with the members of the Abcg subfamily. PMID:26472499

  17. Mechanistic studies of pericardial edema in early life stages (ELS) of medaka (Oryzias latipes)

    SciTech Connect

    Villalobos, S.A.; Fan, T.W.M.; Higashi, R.M.; Hinton, D.E.

    1995-12-31

    Pericardial edema (PE), a manifestation of developmental toxicity in fish ELS, may compromise stock recruitment and survival. However, the mechanism underlying this common lesion is unknown. Possible mechanisms for PE in ELS of medaka were studied by metabolic and morphologic methods. In the laboratory, medaka embryos readily develop PE after brief exposure to dioxin, trichloroethylene (TCE) soot extract, or thiobencarb. Histopathological analyses, regardless of agent, indicated widespread edema without cellular infiltrates in pericardial and peritoneal cavities and in subepithelial spaces of skin. Additionally, endothelia of sinus venosus and adjacent atrium were enlarged. Walls of dilated sinoatrial compartments showed subendothelial fluid accumulation. Ethoxyresorufin O-deethylase activity (indicator of CYPL A induction), considerably higher in embryos exposed to dioxin and TCE soot, was suppressed by thiobencarb. In vivo {sup 31}P nuclear magnetic resonance (NMR) spectroscopy of living embryos (pregastrula through hatching) previously treated with thiobencarb, showed a temporary depression of ATP and phosphocreatine levels, with an apparent transient alkalinization in intracellular (possibly yolk sac) pH. Results indicate that induction of CYP1A is not a requirement for development of PE, and that ionic imbalances and/or metabolic disorders following exposure may be causative factor(s).

  18. Calculation of pressure drop in the developmental stages of the medaka fish heart and microvasculature

    NASA Astrophysics Data System (ADS)

    Chakraborty, Sreyashi; Vlachos, Pavlos

    2016-11-01

    Peristaltic contraction of the developing medaka fish heart produces temporally and spatially varying pressure drop across the atrioventricular (AV) canal. Blood flowing through the tail vessels experience a slug flow across the developmental stages. We have performed a series of live imaging experiments over 14 days post fertilization (dpf) of the medaka fish egg and cross-correlated the red blood cell (RBC) pattern intensities to obtain the two-dimensional velocity fields. Subsequently we have calculated the pressure field by integrating the pressure gradient in the momentum equation. Our calculations show that the pressure drop across the AV canal increases from 0.8mm Hg during 3dpf to 2.8 mm Hg during 14dpf. We have calculated the time-varying wall shear stress for the blood vessels by assuming a spatially constant velocity magnitude in each vessel. The calculated wall shear stress matches the wall shear stress sensed by human endothelial cells (10-12 dyne/sq. cm). The pressure drop per unit length of the vessel is obtained by doing a control volume analysis of flow in the caudal arteries and veins. The current results can be extended to investigate the effect of the fluid dynamic parameters on the vascular and cardiac morphogenesis.

  19. Regulatory back-up circuit of medaka Wt1 co-orthologs ensures PGC maintenance.

    PubMed

    Klüver, Nils; Herpin, Amaury; Braasch, Ingo; Driessle, Julia; Schartl, Manfred

    2009-01-01

    In mammals, the Wilms' tumor suppressor gene, Wt1, encodes a transcription factor critical for development of the urogenital system. In teleost fish, however, two wt1 genes have been identified. In medaka wt1a is expressed in the lateral plate mesoderm during early embryogenesis. Later in development, wt1a is additionally expressed in the somatic cells of the gonadal primordium. We show here for the first time that in teleosts wt1 gene expression is observed during gonad development. Wt1b is expressed later during embryogenesis and is not expressed in the gonadal primordium. Analysis of morpholino knockdown experiments revealed functions of wt1 genes in pronephros development. Unexpectedly, by down-regulating Wt1a protein we observed wt1b expression during embryogenesis in the wildtype wt1a expression domains including somatic cells of the gonadal primordium. Interestingly, neither wt1a nor wt1b morphants showed effects on the gonad development, whereas the double knockdown of wt1a and wt1b displayed strong influences on the number of primordial germ cell (PGC) during gonad development. Our results indicate that medaka wt1 co-orthologs show genetic redundancy in PGC maintenance or survival through responsive backup circuits. This provides first evidence for a conditional co-regulation of these genes within a transcriptional network.

  20. Zebrafish and medaka: model organisms for a comparative developmental approach of brain asymmetry.

    PubMed

    Signore, Iskra A; Guerrero, Néstor; Loosli, Felix; Colombo, Alicia; Villalón, Aldo; Wittbrodt, Joachim; Concha, Miguel L

    2009-04-12

    Comparison between related species is a successful approach to uncover conserved and divergent principles of development. Here, we studied the pattern of epithalamic asymmetry in zebrafish (Danio rerio) and medaka (Oryzias latipes), two related teleost species with 115-200 Myr of independent evolution. We found that these species share a strikingly conserved overall pattern of asymmetry in the parapineal-habenular-interpeduncular system. Nodal signalling exhibits comparable spatial and temporal asymmetric expressions in the presumptive epithalamus preceding the development of morphological asymmetries. Neuroanatomical asymmetries consist of left-sided asymmetric positioning and connectivity of the parapineal organ, enlargement of neuropil in the left habenula compared with the right habenula and segregation of left-right habenular efferents along the dorsoventral axis of the interpeduncular nucleus. Despite the overall conservation of asymmetry, we observed heterotopic changes in the topology of parapineal efferent connectivity, heterochronic shifts in the timing of developmental events underlying the establishment of asymmetry and divergent degrees of canalization of embryo laterality. We offer new tools for developmental time comparison among species and propose, for each of these transformations, novel hypotheses of ontogenic mechanisms that explain interspecies variations that can be tested experimentally. Together, these findings highlight the usefulness of zebrafish and medaka as comparative models to study the developmental mechanisms of epithalamic asymmetry in vertebrates.

  1. Contaminated sediments from tributaries of the Great Lakes: Chemical characterization and carcinogenic effects in medaka (Oryzias latipes)

    USGS Publications Warehouse

    Besser, John M.; Schmitt, Christopher J.; Harshbarger, John C.; Peterman, Paul H.; Lebo, Jon A.

    1991-01-01

    Sediments from four inshore industrial sites and a reference site in the Great Lakes were extracted with organic solvents to produce a crude extract, which was separated on alumina into two fractions: predominantly polycyclic aromatic hydrocarbons; and predominantly nitrogencontaining polycyclic aromatic compounds. Crude extracts were redissolved in acetone and analyzed by gas chromatography and gas chromatography-mass spectrometry. The acetone-redissolved crude extracts from the four industrialized sites contained 5.6–313.3 μg total polycyclic aromatic compounds/g sediment and 3.0–36.4 μg other compounds/g sediment. In addition to the typical EPA priority pollutants, a substantial amount (228.7 μg/g sediment) of alkyl-polycyclic-aromatic compounds was detected in sediments from one of the industrialized sites. Extracts from the reference site contained 1.55 μg total polycyclic aromatic compounds/ g sediment. Medaka (Oryzias latipes) were exposed to multiple pulse doses of acetone-redissolved extracts and fractions. Medaka were also exposed to a known carcinogen, methylazoxymethanol acetate, to verify that chemicals produced tumors in the test fish. Acetone-redissolved extracts and fractions from contaminated sediments were toxic to medaka. Fin erosion and non-neoplastic liver abnormalities were more prevalent in medaka after exposure to acetoneredissolved extracts and fractions from contaminated sediments. Neoplasms previously associated with chemical exposure in wild fishes were induced in medaka exposed to acetone-redissolved extracts and fractions from two of the contaminated sites, but not from the reference site or controls. These findings further support the hypothesis that chemical contaminants in sediments are involved in epizootics of neoplasms in wild fishes at contaminated sites.

  2. Differential GFP expression patterns induced by different heavy metals in Tg(hsp70:gfp) transgenic medaka (Oryzias latipes).

    PubMed

    Ng, Grace Hwee Boon; Xu, Hongyan; Pi, Na; Kelly, Barry C; Gong, Zhiyuan

    2015-06-01

    Heat shock protein 70 (Hsp70) is one of the most widely used biomarker for monitoring environment perturbations in biological systems. To facilitate the analysis of hsp70 expression as a biomarker, we generated a Tg(hsp70:gfp) transgenic medaka line in which green fluorescence protein (GFP) reporter gene was driven by the medaka hsp70 promoter. Here, we characterized Tg(hsp70:gfp) medaka for inducible GFP expression by seven environment-relevant heavy metals, including mercury, arsenic, lead, cadmium, copper, chromium, and zinc. We found that four of them (mercury, arsenic, lead, and cadmium) induced GFP expression in multiple and different organs. In general, the liver, kidney, gut, and skin are among the most frequent organs to show induced GFP expression. In contrast, no detectable GFP induction was observed to copper, chromium, or zinc, indicating that the transgenic line was not responsive to all heavy metals. RT-qPCR determination of hsp70 mRNA showed similar induction and non-induction by these metals, which also correlated with the levels of metal uptake in medaka exposed to these metals. Our observations suggested that these heavy metals have different mechanisms of toxicity and/or differential bioaccumulation in various organs; different patterns of GFP expression induced by different metals may be used to determine or exclude metals in water samples tested. Furthermore, we also tested several non-metal toxicants such as bisphenol A, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 4-introphenol, and lindane; none of them induced significant GFP expression in Tg(hsp70:gfp) medaka, further suggesting that the inducibility of Tg(hsp70:gfp) for GFP expression is specific to a subset of heavy metals.

  3. ALTERED GENE EXPRESSION AND DEVELOPMENT OF POTENTIAL BIOMARKERS IN MEDAKA (ORYZIAS LATIPES) BRAIN, LIVER AND TESTIS FOLLOWING EXPOSURE TO FIBRATE PHARMACEUTICALS

    EPA Science Inventory

    To help address the consequences of increasing levels of environmental contaminants and to identify potentially novel markers of toxicity, we examined gene expression profiles from medaka (Oryzias latipes) exposed to a prototypical fibrate pharmaceutical. Changes in gene express...

  4. Cross talk between germ cells and gonadal somatic cells is critical for sex differentiation of the gonads in the teleost fish, medaka (Oryzias latipes).

    PubMed

    Tanaka, Minoru; Saito, Daisuke; Morinaga, Chikako; Kurokawa, Hiromi

    2008-05-01

    To evaluate the possible role of germ cells on sex differentiation of the gonads in vertebrates, the teleost fish, medaka (Oryzias latipes), was used to generate a gonad without germ cells. The germ cell-deficient medaka reveals multiple effects of germ cells on the process of sex differentiation. The previously isolated mutant medaka, hotei, with the excessive number of germ cells may support the contention that the proliferation of germ cells is related to feminization of the gonad. Futhermore, we show that two modes of proliferation for either maintenance of germ cells or commitment to gametogenesis are important components of the sex differentiation of medaka developing gonads. An intimate cross talk between germ cells and gonadal somatic cells during the sex differentiation will be discussed.

  5. Burden of herpes zoster and postherpetic neuralgia in Japanese adults 60 years of age or older: Results from an observational, prospective, physician practice-based cohort study.

    PubMed

    Sato, Keiko; Adachi, Koichi; Nakamura, Hiroyuki; Asano, Kazuhiro; Watanabe, Akihiro; Adachi, Riri; Kiuchi, Mariko; Kobayashi, Keiju; Matsuki, Taizo; Kaise, Toshihiko; Gopala, Kusuma; Holl, Katsiaryna

    2016-12-05

    Approximately one in three persons will develop herpes zoster during their lifetime, and it can lead to serious complications such as postherpetic neuralgia. However, evidence on burden of herpes zoster and postherpetic neuralgia in Japan is limited. This prospective, observational, multicenter, physician practice-based cohort study was conducted in Kushiro, Hokkaido, Japan (Clinicaltrials.gov identifier NCT01873365) to assess the incidence and hospitalization rates of herpes zoster, and the proportion, clinical burden and risk factors for postherpetic neuralgia in adults aged 60 years or more. Within the study area, 800 subjects developed herpes zoster and 412 were eligible for the study. Herpes zoster incidence was 10.2/1000 person-years and higher among women and older subjects. Subjects with herpes zoster required on average 5.7 outpatient consultations. Herpes zoster-associated hospitalization rate was 3.4% (27/800). The proportion of postherpetic neuralgia and other complications was 9.2% (38/412) and 26.5% (109/412), respectively. Statistically significant association with the development of postherpetic neuralgia was male sex (odds ratio [OR], 2.51; 95% confidence interval [CI], 1.17-5.38), age of 70-74 years (OR, 3.51; 95% CI, 1.09-11.3), immunosuppressive therapy (OR, 6.44; 95% CI, 1.26-32.9), severe herpes zoster pain at first consultation (OR, 3.08; 95% CI, 1.10-8.62) and rash on upper arms (vs no rash on upper arms; OR, 3.46; 95% CI, 1.10-10.9). Considerable herpes zoster and postherpetic neuralgia burden exists among elderly in Japan, and there may be predictive factors at the first visit which could be indicative of the risk of developing postherpetic neuralgia.

  6. Transgenic medaka that overexpress growth hormone have a skin color that does not indicate the activation or inhibition of somatolactin-α signal.

    PubMed

    Komine, Ritsuko; Nishimaki, Toshiyuki; Kimura, Tetsuaki; Oota, Hiroki; Naruse, Kiyoshi; Homma, Noriko; Fukamachi, Shoji

    2016-06-10

    Teleosts have two paralogous growth-hormone receptors (GHRs). In vitro studies demonstrated that both receptors bind to and transmit the signal of the growth hormone (GH). However, one of the GHRs (GHR1) was shown to bind more strongly to somatolactin-α (SLα), a fish-specific peptide hormone that is closely related to GH, and is, therefore, termed somatolactin receptor (SLR). In this study, we questioned whether the dual binding of GHR1/SLR causes a crosstalk (reciprocal activation or inhibition) between GH and SLα signals in vivo. For this purpose, we newly established a transgenic medaka that overexpresses GH (Actb-GH:GFP) and assessed its phenotype. The body weight of these transgenic medaka is about twice that of wild-type fish, showing that functional GH was successfully overexpressed in Actb-GH:GFP fish. The transgenic medaka, especially female fish, showed severe infertility, which was a common side effect in GH transgenesis. The skin color, which reflects the effects of SLα most conspicuously in medaka, was similar to that of neither the SLα-overexpressing nor the SLα-deficient medaka, indicating that GH overexpression does not enhance or suppress the SLα signal. We also verified that a transgenic medaka that overexpressed SLα grew and reproduced normally. Therefore, regardless of the in vitro binding relationships, the GH and SLα signals seem not to crosstalk significantly in vivo even when these hormones are overexpressed.

  7. 2011 Japanese Nuclear Incident

    EPA Pesticide Factsheets

    EPA’s RadNet system monitored the environmental radiation levels in the United States and parts of the Pacific following the Japanese Nuclear Incident. Learn about EPA’s response and view historical laboratory data and news releases.

  8. Effects of Kisspeptin1 on Electrical Activity of an Extrahypothalamic Population of Gonadotropin-Releasing Hormone Neurons in Medaka (Oryzias latipes)

    PubMed Central

    Zhao, Yali; Wayne, Nancy L.

    2012-01-01

    Kisspeptin (product of the kiss1 gene) is the most potent known activator of the hypothalamo-pituitary-gonadal axis. Both kiss1 and the kisspeptin receptor are highly expressed in the hypothalamus of vertebrates, and low doses of kisspeptin have a robust and long-lasting stimulatory effect on the rate of action potential firing of hypophysiotropic gonadotropin releasing hormone-1 (GnRH1) neurons in mice. Fish have multiple populations of GnRH neurons distinguished by their location in the brain and the GnRH gene that they express. GnRH3 neurons located in the terminal nerve (TN) associated with the olfactory bulb are neuromodulatory and do not play a direct role in regulating pituitary-gonadal function. In medaka fish, the electrical activity of TN-GnRH3 neurons is modulated by visual cues from conspecifics, and is thought to act as a transmitter of information from the external environment to the central nervous system. TN-GnRH3 neurons also play a role in sexual motivation and arousal states, making them an important population of neurons to study for understanding coordination of complex behaviors. We investigated the role of kisspeptin in regulating electrical activity of TN-GnRH3 neurons in adult medaka. Using electrophysiology in an intact brain preparation, we show that a relatively brief treatment with 100 nM of kisspeptin had a long-lasting stimulatory effect on the electrical activity of an extrahypothalamic population of GnRH neurons. Dose-response analysis suggests a relatively narrow activational range of this neuropeptide. Further, blocking action potential firing with tetrodotoxin and blocking synaptic transmission with a low Ca2+/high Mg2+ solution inhibited the stimulatory action of kisspeptin on electrical activity, indicating that kisspeptin is acting indirectly through synaptic regulation to excite TN-GnRH3 neurons. Our findings provide a new perspective on kisspeptin's broader functions within the central nervous system, through its regulation

  9. Effects of kisspeptin1 on electrical activity of an extrahypothalamic population of gonadotropin-releasing hormone neurons in medaka (Oryzias latipes).

    PubMed

    Zhao, Yali; Wayne, Nancy L

    2012-01-01

    Kisspeptin (product of the kiss1 gene) is the most potent known activator of the hypothalamo-pituitary-gonadal axis. Both kiss1 and the kisspeptin receptor are highly expressed in the hypothalamus of vertebrates, and low doses of kisspeptin have a robust and long-lasting stimulatory effect on the rate of action potential firing of hypophysiotropic gonadotropin releasing hormone-1 (GnRH1) neurons in mice. Fish have multiple populations of GnRH neurons distinguished by their location in the brain and the GnRH gene that they express. GnRH3 neurons located in the terminal nerve (TN) associated with the olfactory bulb are neuromodulatory and do not play a direct role in regulating pituitary-gonadal function. In medaka fish, the electrical activity of TN-GnRH3 neurons is modulated by visual cues from conspecifics, and is thought to act as a transmitter of information from the external environment to the central nervous system. TN-GnRH3 neurons also play a role in sexual motivation and arousal states, making them an important population of neurons to study for understanding coordination of complex behaviors. We investigated the role of kisspeptin in regulating electrical activity of TN-GnRH3 neurons in adult medaka. Using electrophysiology in an intact brain preparation, we show that a relatively brief treatment with 100 nM of kisspeptin had a long-lasting stimulatory effect on the electrical activity of an extrahypothalamic population of GnRH neurons. Dose-response analysis suggests a relatively narrow activational range of this neuropeptide. Further, blocking action potential firing with tetrodotoxin and blocking synaptic transmission with a low Ca(2+)/high Mg(2+) solution inhibited the stimulatory action of kisspeptin on electrical activity, indicating that kisspeptin is acting indirectly through synaptic regulation to excite TN-GnRH3 neurons. Our findings provide a new perspective on kisspeptin's broader functions within the central nervous system, through its

  10. How the Japanese work.

    PubMed

    Chambers, D W

    1998-01-01

    The Japanese do not work harder or even use different approaches so much as they aim for a different result--one that balances process and results and extends the definition of quality beyond the product itself to include cost and convenience to the customer as well. Ten methods of the Japanese kaizen culture of work are presented with applications and contrasts to American dentistry.

  11. Six3, a medaka homologue of the Drosophila homeobox gene sine oculis is expressed in the anterior embryonic shield and the developing eye.

    PubMed

    Loosli, F; Köster, R W; Carl, M; Krone, A; Wittbrodt, J

    1998-06-01

    homologue Six3 (Oliver, G., Mailhos, A., Wehr, R., Copeland, N.G., Jenkins, N.A., Gruss, P., 1995. Six3, a murine homologue of the sine oculis gene, demarcates the most anterior border of the developing neural plate and is expressed during eye development. Development 121, 4045-4055). sine oculis (so) is essential for the development of the larval and adult visual system (Cheyette, B.N.R., Green, P.J., Martin, K., Garren, H., Hartenstein, V., Zipursky, S.L., 1994. The Drosophila sine oculis locus encodes a homeodomain-containing protein required for the development of the entire visual system. Neuron l2, 977-996). Six3 is expressed in the anterior neural plate and optic vesicles, lens, olfactory placodes and ventral forebrain (Oliver, G., Mailhos, A., Wehr, R., Copeland, N.G., Jenkins, N.A., Gruss, P., 1995. Six3, a murine homologue of the sine oculis gene, demarcates the most anterior border of the developing neural plate and is expressed during eye development. Development 121, 4045-4055). Overexpression of mouse Six3 gene in medaka fish embryos (Orvzias latipes) results in the formation of an ectopic lens, indicating that Six3 activity can trigger the genetic pathway leading to lens formation (Oliver, G., Loosli, F., Koster, R., Wittbrodt, J., Gruss, P., 1996. Ectopic lens induction in fish in response to the murine homeobox gene Six3. Mech. Dev. 60, 233-239). We isolated the medaka Six3 homologue and analyzed its expression pattern in the medaka embryo. It is expressed initially in the anterior embryonic shield and later in the developing eye and prosencephalon. The early localized expression of Six3 suggests a role in the regionalization of the rostral head.

  12. The embryotoxicity of ZnO nanoparticles to marine medaka, Oryzias melastigma.

    PubMed

    Cong, Yi; Jin, Fei; Wang, Juying; Mu, Jingli

    2017-04-01

    The negative effects of metal oxide nanoparticles on aquatic environment and organisms have caused much concern. In this study, the embryotoxicity of zinc oxide nanoparticles (ZnO NP) to marine medaka, Oryzias melastigma, was explored and compared with that of aqueous Zn (ZnSO4·7H2O). The Zn(2+) released from ZnO NP in artificial seawater at exposure concentrations was also measured. Results showed that zinc ion release percentage (%) decreased with increasing concentration, which was 44%, 41% and 25% at 0.1, 1 and 10mg/L of ZnO NP suspension, respectively. After 20 d exposure of medaka embryos to ZnO NP, we observed increased mortality and heart rate, reduced percent total hatching success, delayed hatching of embryos and increased malformation% of newly-hatched larvae in ZnO NP treatment compared to the control group. Furthermore, ZnO NPs have significantly greater effects than the aqueous Zn for mortality and heart rate, indicating that ZnO NPs themselves, in particulate or aggregate form, contribute to the observed toxicity. Edema was the most commonly found malformation in newly-hatched larvae after ZnO NP exposure. Overall, our findings suggest that the embryonic stage of marine medaka is sensitive to ZnO NP exposure. Studies of the toxic mechanism of ZnO NPs should not ignore the impact of NPs since the greater effects of ZnO NPs than of aqueous Zn ions observed in this study cannot be explained by the ZnO NP dissolution. The ion release profile of ZnO NPs in marine environment is related to both NP and seawater characteristics, which should be analyzed on a case-by-case basis. The ZnO NP-related Zn speciation may play an important role in the dissolution and toxicity processes of ZnO NPs in marine environment, and further speciation study may contribute to the interpretation of ZnO NP toxicity.

  13. Testosterone content of developing eggs and sex reversal in the medaka (Oryzias latipes).

    PubMed

    Iwamatsu, Takashi; Kobayashi, Hirokuni; Sagegami, Reiko; Shuo, Takuya

    2006-01-01

    To understand the effect of testosterone on sex differentiation, the quantities of testosterone (T) and estradiol-17beta (E2) in developing eggs of medaka (Oryzias latipes) were measured by radioimmunoassay, and the influence on sex differentiation of treating embryos with exogenous androgens was also examined. Endogenous T of eggs dispersed into the environmental water at spawning, and precipitously declined to a minimum level during incubation for 2 days post-fertilization (dpf). It did not significantly increase during development. The E2 content of fertilized eggs increased when eggs were incubated in medium containing exogenous T at the concentrations of 100 and 500 ng/ml, but not in low concentrations of 10 ng/ml or less. The presence of 500 ng/ml 17alpha-methyltestosterone (MT) in the incubation medium also induced an increase in the E2 content of embryos. Exposure of embryos to exogenous 1 ng/ml T that corresponded with the level of T in eggs shortly after fertilization was enough to induce sex reversal of genotypic females to functional males. The co-existence of T and aromatase inhibitor in incubation medium inhibited not only the T-induced increase in the embryonic E2 content, but also the estrogenic effect of T in causing the paradoxical sex reversal from genotypic males to phenotypic females. However, treatment of embryos with the non-aromatizable androgen, 17alpha-methyldihydrotestosterone, induced no detectable increase in the E2 content of embryos, but still brought about sex reversal of genotypic males into females. This contradictory result suggests that the conversion of androgens to E2 may not always be the cause for induction of paradoxical sex reversal by T treatment. Consequently, these results on sex reversal induced by treatment of embryos with exogenous androgens suggest that endogenous T of developing medaka embryos may not act as the natural andro-inducer, and that genotypic sex can be modified by exogenous sex steroids at early

  14. Medaka Fish Embryo Developed for STS-78 Life and Microgravity Spacelab (LMS)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Launched on June 20, 1996, the STS-78 mission's primary payload was the Life and Microgravity Spacelab (LMS), which was managed by the Marshall Space Flight Center (MSFC). During the 17 day space flight, the crew conducted a diverse slate of experiments divided into a mix of life science and microgravity investigations. In a manner very similar to future International Space Station operations, LMS researchers from the United States and their European counterparts shared resources such as crew time and equipment. Five space agencies (NASA/USA, European Space Agency/Europe (ESA), French Space Agency/France, Canadian Space Agency /Canada, and Italian Space Agency/Italy) along with research scientists from 10 countries worked together on the design, development and construction of the LMS. This photo represents the development of Medaka Fish Embryos, one of the many studies of the LMS mission.

  15. Transcriptional response of marine medaka (Oryzias javanicus) on exposure to toxaphene.

    PubMed

    Woo, Seonock; Yum, Seungshic

    2011-04-01

    Differential gene expression profiles were established from the head and liver tissues of the marine medaka fish (Oryzias javanicus) after its exposure to toxaphene, a persistent organic pollutant and insecticide, using differential display polymerase chain reaction. Twenty-seven differentially expressed genes were identified, which were associated with the cytoskeleton, development, metabolism, nucleic acid/protein binding, and signal transduction. Among these genes, those encoding molecular biomarkers known to be involved in metabolism, ATP hydrolysis, and protein regulation were strongly induced at the transcription level, and genes encoding one structural protein subunit or involved in lipid metabolism were strongly downregulated. The same trends in gene expression changes were observed with real-time PCR analysis of 12 selected clones. The genes identified could be used as molecular biomarkers of biological responses to polychlorinated camphene contamination in aquatic environments.

  16. Current Status of Sperm Cryopreservation in Biomedical Research Fish Models: Zebrafish, Medaka, and Xiphophorus*

    PubMed Central

    Yang, Huiping; Tiersch, Terrence R.

    2009-01-01

    Aquarium fishes are becoming increasingly important because of their value in biomedical research and the ornamental fish trade, and because many have become threatened or endangered in the wild. This review summarizes the current status of sperm cryopreservation in three fishes widely used in biomedical research: zebrafish, medaka, and live-bearing fishes of the genus Xiphophorus, and will focus on the needs and opportunities for future research and application of cryopreservation in aquarium fish. First, we summarize the basic biological characteristics regarding natural habitat, testis structure, spermatogenesis, sperm morphology, and sperm physiology. Second, we compare protocol development of sperm cryopreservation. Third, we emphasize the importance of artificial fertilization in sperm cryopreservation to evaluate the viability of thawed sperm. We conclude with a look to future research directions for sperm cryopreservation and the application of this technique in aquarium species. PMID:18691673

  17. Structural and functional characterization of recombinant medaka fish alpha-amylase expressed in yeast Pichia pastoris.

    PubMed

    Mizutani, Kimihiko; Toyoda, Mayuko; Otake, Yuichiro; Yoshioka, Soshi; Takahashi, Nobuyuki; Mikami, Bunzo

    2012-08-01

    The medaka fish α-amylase was expressed and purified. The expression systems were constructed using methylotrophic yeast Pichia pastoris, and the recombinant proteins were secreted into the culture medium. Purified recombinant α-amylase exhibited starch hydrolysis activity. The optimal pH, denaturation temperature, and K(M) and V(max) values were determined; chloride ions were essential for enzyme activity. The purified protein was also crystallized and examined by X-ray crystallography. The structure has the (α/β)(8) barrel fold, as do other known α-amylases, and the overall structure is very similar to the structure of vertebrate (human and pig) α-amylases. A novel expression plasmid was developed. Using this plasmid, high-throughput construction of an expression system by homologous recombination in P. pastoris cells, previously reported for membrane proteins, was successfully applied to the secretory protein.

  18. Medaka osmotic stress transcription factor 1b (Ostf1b/TSC22D3-2) triggers hyperosmotic responses of different ion transporters in medaka gill and human embryonic kidney cells via the JNK signalling pathway.

    PubMed

    Tse, William K F; Lai, K P; Takei, Y

    2011-12-01

    Eukaryotic cells undergo rapid regulatory processes to maintain cellular homeostasis upon osmotic stress. In fishes, gill epithelial cells play main roles in these processes. Although osmoregulatory functions of fish gills have been well studied, little is known about the underlying mechanisms, particularly the hypertonic-induced signalling pathways during osmotic stress. This study reports for the first time on the osmo-sensing signal cascade that related to the medaka osmotic stress transcription factor 1 (Ostf1), a hypertonic induced immediate early gene, under hypertonic stress. Quantitative real-time PCR showed the rapid increase of Ostf1 in gill after transfer of medaka from fresh water to 50% seawater; particularly Ostf1b whose mRNA expression increased to 4 folds at 0.5h and reached to 10 folds at 6h after the transfer. The in vivo knockdown of Ostf1b profoundly inhibited SEK and JNK phosphorylation, but not p38 and ERK phosphorylation in the medaka gill tissue. To further investigate the possible role of Ostf1b in the JNK pathway, Ostf1b was ectopically expressed in HEK293 cells. Results indicated that Ostf1b is a downstream target of SEK and JNK and exerts a positive feedback loop on the JNK signalling pathway via activation of GCK and/or MLK3 proteins. Additionally, MAPK inhibitors experiments suggested that activation of the JNK pathway by hypertonicity is involved in the maintenance of Ostf1b stability, which in turn provides continuous stimulation of GCK for JNK phosphorylation. Lastly, changes in transcription levels of different water/ion transporters were found in knockdown or ecoptic over-expression of Ostf1b in medaka gills and human embryonic kidney cells, suggesting the role of Ostf1b in modulation of critical water channel/ion transporters during osmotic stress.

  19. Positive regulation of myoblast differentiation by medaka Neu3b sialidase through gangliosides desialylation.

    PubMed

    Shiozaki, Kazuhiro; Harasaki, Yusuke; Fukuda, Midori; Yoshinaga, Ayana; Ryuzono, Sena; Chigwechokha, Petros Kingstone; Komatsu, Masaharu; Miyagi, Taeko

    2016-04-01

    Sialidase Neu3b is an unique enzyme conserved in medaka and tilapia, but not in mammals. Previous study revealed that medaka Neu3b is localized at cytosol and is a ganglioside-specific sialidase. Neu3b functions, however, have not been understood, while Neu3a sialidase, which is widely conserved from human to fish, is known as a regulator of neurite formation. Here, we investigated the biological function of Neu3b for C2C12 myoblast cell differentiation. Bioinformatics analysis using genome browser revealed the presence of neu3b gene in some orders of fish species such as Beloniformes, Perciformes and Cyprinodontiformes. With the treatment of 2% horse serum, Neu3b-overexpression accelerated myoblast cell differentiation to myotubes accompanied with up-regulation of myogenesis biomarkers mRNA, myod and myog. Neu3b altered ganglioside composition in C2C12 cells results showing a decrease in GM2, and the increase of Lac-Cer, while desialylation of glycoproteins were not detected. Contrary to cell differentiation, Neu3b cell proliferation was suppressed in normal growth medium. To understand the mechanism of the alteration of cell differentiation and proliferation, phosphorylation of signal molecules in EGFR/ERK pathway was investigated. Neu3b induced a decline in phosphorylation of ERK and EGFR. Surprisingly, immuno-blot and real-time PCR analysis revealed that down-regulation of egfr gene could be involved in the acceleration of cell differentiation by Neu3b. These results suggested that Neu3b sialidase is a positive regulator for myoblast differentiation, similar with mammalian cytosolic sialidase Neu2.

  20. Anchoring Ethinylestradiol Induced Gene Expression Changes with Testicular Morphology and Reproductive Function in the Medaka

    PubMed Central

    Miller, Hilary D.; Clark, Bryan W.; Hinton, David E.; Whitehead, Andrew; Martin, Stan; Kwok, Kevin W.; Kullman, Seth W.

    2012-01-01

    Environmental estrogens are ubiquitous in the environment and can cause detrimental effects on male reproduction. In fish, a multitude of effects from environmental estrogens have been observed including altered courting behavior and fertility, sex reversal, and gonadal histopathology. However, few studies in fish assess the impacts of estrogenic exposure on a physiological endpoint, such as reproduction, as well as the associated morphologic response and underlying global gene expression changes. This study assessed the implications of a 14 day sub-chronic exposure of ethinylestradiol (EE2; 1.0 or 10.0 µg/L EE2) on male medaka fertility, testicular histology and testicular gene expression. The findings demonstrate that a 14 day exposure to EE2 induced impaired male reproductive capacity and time- and dose-dependent alterations in testicular morphology and gene expression. The average fertilization rate/day following the exposure for control, 1.0 and 10.0 µg/L EE2 was 91.3% (±4.4), 62.8% (±8.3) and 28.8% (±5.8), respectively. The testicular morphologic alterations included increased germ cell apoptosis, decreased germinal epithelium and thickening of the interstitium. These changes were highly associated with testicular gene expression changes using a medaka-specific microarray. A pathway analysis of the differentially expressed genes emphasized genes and pathways associated with apoptosis, cell cycle and proliferation, collagen production/extracellular matrix organization, hormone signaling, male reproduction and protein ubiquitination among others. These findings highlight the importance of anchoring global gonadal gene expression changes with morphology and ultimately with tissue/organ function. PMID:23300682

  1. Comparative Study of Growth and Gonad Maturation in Diploid and Triploid Marine Medaka, Oryzias dancena

    PubMed Central

    Park, In-Seok; Gil, Hyun Woo; Lee, Tae Ho; Nam, Yoon Kwon; Kim, Dong Soo

    2016-01-01

    ABSTRACT The marine medaka, Oryzias dancena is a suitable sample as a laboratory animal because it has a small size and clearly distinguishes between female and male. Data on the growth and maturity of the diploid and triploid sea cucurbit species suitable for laboratory animals are very useful for studying other species. Triploidy was induced in the marine medaka by cold shock treatment (0°C) of fertilized eggs for 45 min, applied two minutes after fertilization. The diploid and triploid male fish were larger than their female counterparts (P<0.05), and the concentrations of thyroid stimulating hormone (TSH) and thyroxine (T4) were higher in the induced triploids over 1 year (P<0.05). In both the diploid and tri-ploid groups the concentrations of TSH and T4 were higher in the male fish than in the females (P<0.05), while the testo-sterone and estradiol-17ß concentrations in the induced triploids were lower than in the diploids (P<0.05). The gonadosomatic index (GSI) of the triploid fish was lower than that for the diploids, and the GSI for females in each ploidy group were higher than that for the males. For both groups the GSI was highest at 4 months of age, and decreased thereafter to 12 months. Analysis of the gonads of one-year-old triploid fish suggested that the induction of triploidy probably causes sterility in this species; this effect was more apparent in females than in males. PMID:28144636

  2. Overview: Japanese encephalitis.

    PubMed

    Misra, Usha Kant; Kalita, Jayantee

    2010-06-01

    Japanese encephalitis (JE) is one of the most important endemic encephalitis in the world especially in Eastern and Southeastern Asia. JE affects over 50,000 patients and results in 15,000 deaths annually. JE virus is a single stranded positive sense RNA virus belonging to family flaviviridae. JE virus is transmitted through a zoonotic cycle between mosquitoes, pigs and water birds. Humans are accidentally infected and are a dead end host because of low level and transient viremia. In the northern region, large epidemics occur during summers whereas in the southern region JE tends to be endemic: cases occur throughout the year with a peak in the rainy season. Occurrence of JE is more closely related to temperature than to humidity. JE is regarded as a disease of children in the endemic areas but in the newly invaded areas, it affects both the adults and children because of the absence of protective antibodies. For every patient of JE, there are large numbers of subclinical cases (25-1000). Symptomatic JEV infection manifests with nonspecific febrile illness, aseptic meningitis or encephalitis. Encephalitis manifests with altered sensorium, seizures and focal neurological deficit. Acute flaccid paralysis may occur due to anterior horn cell involvement. A wide variety of movement disorders especially transient Parkinsonian features and dystonia (limb, axial, orofacial) are reported in 20-60% patients. JE mainly affects thalamus, corpus striatum, brainstem and spinal cord as revealed by MRI and on autopsy studies. Coinfection of JE and cysticercosis occurs because of the important role of pigs in the life cycle of both JEV and cysticercosis. Laboratory diagnosis of JE is by IgM capture ELISA, which has high sensitivity and specificity. In the absence of specific antiviral therapy, JE is managed by symptomatic and supportive therapies and preventive measures. Purified formalin inactivated mouse brain derived vaccine and live attenuated vaccine (SA 14-14-2) are

  3. Establishment and maintenance of sexual preferences that cause a reproductive isolation between medaka strains in close association

    PubMed Central

    Ikawa, Mayuka; Ohya, Emi; Shimada, Hiroka; Kamijo, Makiko

    2017-01-01

    ABSTRACT Animals choose reproductive partners based on their sexual preferences which are established at a certain time point before, during, or after sexual maturation. The preferences are often divergent within a species, which suppresses gene flow between populations and may promote speciation. There are two strains of medaka (Oryzias latipes) that differ by a single transgene and mate assortatively depending on skin color. Here, we demonstrate that symmetrically biased (mutually exclusive) sexual preferences are (1) gradually established during growth depending on skin color and the color of surrounding fish, (2) strong enough to minimize gene flow between the strains at a population level, and (3) inflexibly retained after sexual maturation, even after weeks of daily mating with partners of the other strain. Thus, these laboratory strains of medaka are under premating isolation with the simplest genomic structure. They provide an empirical platform for assessing the complex and hypothetical mechanisms of speciation by mate choice. PMID:28202469

  4. Homology-modeled ligand-binding domains of medaka estrogen receptors and androgen receptors: A model system for the study of reproduction

    SciTech Connect

    Cui Jianzhou Shen Xueyan; Yan Zuowei; Zhao Haobin; Nagahama, Yoshitaka

    2009-02-27

    Estrogen and androgen and their receptors play critical roles in physiological processes such as sexual differentiation and development. Using the available structural models for the human estrogen receptors alpha and beta and androgen receptor as templates, we designed in silico agonist and antagonist models of medaka estrogen receptor (meER) alpha, beta-1, and beta-2, and androgen receptor (meAR) alpha and beta. Using these models, we studied (1) the structural relationship between the ligand-binding domains (LBDs) of ERs and ARs of human and medaka, and (2) whether medaka ER and AR can be potential models for studying the ligand-binding activities of various agonists and antagonists of these receptors by docking analysis. A high level of conservation was observed between the sequences of the ligand-binding domains of meER{alpha} and huER{alpha}, meER{beta}1 and huER{beta}, meER{beta}2, and huER{beta} with 62.8%, 66.4%, and 65.1% identity, respectively. The sequence conservation between meAR{alpha} and huAR, meAR{beta}, and huAR was found with 70.1% and 61.0% of identity, respectively. Thirty-three selected endocrine disrupting chemicals (EDCs), including both agonists and antagonists, were docked into the LBD of ER and AR, and the corresponding docking score for medaka models and human templates were calculated. In order to confirm the conservation of the overall geometry and the binding pocket, the backbone root mean square deviation (RMSD) for C{alpha} atoms was derived from the structure superposition of all 10 medaka homology models to the six human templates. Our results suggested conformational conservation between the ERs and ARs of medaka and human, Thus, medaka could be highly useful as a model system for studies involving estrogen and androgen interaction with their receptors.

  5. Neurocytotoxic effects of iron-ions on the developing brain measured in vivo using medaka (Oryzias latipes), a vertebrate model

    PubMed Central

    Yasuda, Takako; Oda, Shoji; Yasuda, Hiroshi; Hibi, Yusuke; Anzai, Kazunori; Mitani, Hiroshi

    2011-01-01

    Purpose: Exposure to heavy-ion radiation is considered a critical health risk on long-term space missions. The developing central nervous system (CNS) is a highly radiosensitive tissue; however, the biological effects of heavy-ion radiation, which are greater than those of low-linear energy transfer (LET) radiation, are not well studied, especially in vivo in intact organisms. Here, we examined the effects of iron-ions on the developing CNS using vertebrate organism, fish embryos of medaka (Oryzias latipes). Materials and methods: Medaka embryos at developmental stage 28 were irradiated with iron-ions at various doses of 0-1.5 Gy. At 24 h after irradiation, radiation-induced apoptosis was examined using an acridine orange (AO) assay and histo-logically. To estimate the relative biological effectiveness (RBE), we quantified only characteristic AO-stained rosette-shaped apoptosis in the developing optic tectum (OT). At the time of hatching, morphological abnormalities in the irradiated brain were examined histologically. Results: The dose-response curve utilizing an apoptotic index for the iron-ion irradiated embryos was much steeper than that for X-ray irradiated embryos, with RBE values of 3.7-4.2. Histological examinations of irradiated medaka brain at 24 h after irradiation showed AO-positive rosette-shaped clusters as aggregates of condensed nuclei, exhibiting a circular hole, mainly in the marginal area of the OT and in the retina. However, all of the irradiated embryos hatched normally without apparent histological abnormalities in their brains. Conclusion: Our present study indicates that the medaka embryo is a useful model for evaluating neurocytotoxic effects on the developing CNS induced by exposure to heavy iron-ions relevant to the aerospace radiation environment. PMID:21770703

  6. Effects of dietary 2,2', 4,4'-tetrabromodiphenyl ether (BDE-47) exposure in growing medaka fish (Oryzias latipes).

    PubMed

    González-Doncel, Miguel; Carbonell, Gregoria; García-Mauriño, José Enrique; Sastre, Salvador; Beltrán, Eulalia María; Fernàndez Torija, Carlos

    2016-09-01

    In this research work, we addressed the effects of a diet fortified with BDE-47 (0, 10, 100, 1000ng/g) dosed to 4-7 day-old post-hatch medaka fish for 40 days, followed by an 80-day depuration period. BDE-47 accumulation and overall growth were evaluated throughout the dosing period, and its elimination was quantified over the following 60 days. The histological condition of the thyroid gland, liver and gonads from the 1000ng BDE-47-treated fish were assessed 5 and 70days after exposures finished. The phenotypic males to females ratio was also quantified 70days after treatments finished. Sixty days after the BDE-47 exposures, reproductive capacity (i.e. fecundity, fertility and hatchability) was evaluated in mating groups for a 20-day period. BDE-47 exposure via food from larval through juvenile life stages of medaka fish resulted in steady accumulation with time dose-dependently. This accumulation tendency rapidly decreased after dosing ended. The growth rates showed a significant increase only at the highest concentration 70days after exposures finished. The histological survey did not reveal BDE-47-related alterations in the condition of the potential target organs. However, a morphometrical approach suggested BDE-47-related differences in the thickness of the epithelium that lines thyroid follicles. The reproduction studies showed comparable values for the fecundity, fertility and hatching rates. Dietary BDE-47 dosed for 40days to growing medaka fish did not alter the phenotypic sex ratios at maturity. The dietary approach used herein could not provide conclusive evidence of effects on medaka development and thriving despite the fact that BDE-47 underwent rapid accumulation in whole fish during the 40-day treatment.

  7. Non invasive in vivo investigation of hepatobiliary structure and function in STII medaka (Oryzias latipes): methodology and applications

    PubMed Central

    Hardman, Ron C; Kullman, Seth W; Hinton, David E

    2008-01-01

    Background A novel transparent stock of medaka (Oryzias latipes; STII), recessive for all pigments found in chromatophores, permits transcutaneous imaging of internal organs and tissues in living individuals. Findings presented describe the development of methodologies for non invasive in vivo investigation in STII medaka, and the successful application of these methodologies to in vivo study of hepatobiliary structure, function, and xenobiotic response, in both 2 and 3 dimensions. Results Using brightfield, and widefield and confocal fluorescence microscopy, coupled with the in vivo application of fluorescent probes, structural and functional features of the hepatobiliary system, and xenobiotic induced toxicity, were imaged at the cellular level, with high resolution (< 1 μm), in living individuals. The findings presented demonstrate; (1) phenotypic response to xenobiotic exposure can be investigated/imaged in vivo with high resolution (< 1 μm), (2) hepatobiliary transport of solutes from blood to bile can be qualitatively and quantitatively studied/imaged in vivo, (3) hepatobiliary architecture in this lower vertebrate liver can be studied in 3 dimensions, and (4) non invasive in vivo imaging/description of hepatobiliary development in this model can be investigated. Conclusion The non-invasive in vivo methodologies described are a unique means by which to investigate biological structure, function and xenobiotic response with high resolution in STII medaka. In vivo methodologies also provide the future opportunity to integrate molecular mechanisms (e.g., genomic, proteomic) of disease and toxicity with phenotypic changes at the cellular and system levels of biological organization. While our focus has been the hepatobiliary system, other organ systems are equally amenable to in vivo study, and we consider the potential for discovery, within the context of in vivo investigation in STII medaka, as significant. PMID:18838008

  8. The acetylcholinesterase (AChE) inhibition analysis of medaka (Oryzias latipes) in the exposure of three insecticides.

    PubMed

    Zhu, Jianping; Huan, Cheng; Si, Guiyun; Yang, Haitang; Yin, Li; Ren, Qing; Ren, Baixiang; Fu, Rongshu; Miao, Mingsheng; Ren, Zongming

    2015-03-01

    The continuous effects on Acetylcholinesterase (AChE) activity of medaka (Oryzias latipes) caused by dichlorvos, methomyl and deltamethrin in vivo were investigated, and the trends of AChE activity inhibition due to the influence of these insecticides were discussed. The LC50-24h of dichlorvos, methomyl and deltamethrin on medaka were 2.3 mg/L, 0.2 mg/L, and 2.9×10(-3) mg/L respectively. The result suggested that at the beginning of the exposure, the AChE activity might increase, and the AChE activity in dead individuals was obviously lower than the live individuals. Though the de novo synthesis of AChE in medaka might help the AChE activity recover, the trends during the exposure in different treatments were downward, and it showed both exposure time and concentration dependent. Meanwhile, higher temperature might cause the AChE inhibition earlier due to the higher metabolic rate. Therefore, as a specific biomarker for organophosphate, carbamate pesticides and pyrethroids, the degree of the AChE inhibition with in vivo conditions is a good tool in continuous monitoring of insecticides, which may induce the nerve conduction disorders.

  9. A Trial to Cryopreserve Immature Medaka (Oryzias latipes) Oocytes after Enhancing Their Permeability by Exogenous Expression of Aquaporin 3

    PubMed Central

    VALDEZ JR, Delgado M.; TSUCHIYA, Ryoma; SEKI, Shinsuke; SAIDA, Naoya; NIIMI, Saori; KOSHIMOTO, Chihiro; MATSUKAWA, Kazutsugu; KASAI, Magosaburo; EDASHIGE, Keisuke

    2013-01-01

    Abstract Fish oocytes have not been cryopreserved successfully, probably because it is difficult to prevent intracellular ice from forming. Previously, we have shown in medaka that immature oocytes are more suitable for cryopreservation than mature oocytes or embryos, in terms of permeability. We have also shown in immature medaka oocytes that the exogenous expression of aquaporin 3 (AQP3), a water/cryoprotectant channel, promotes the movement of water and cryoprotectants through the plasma membrane. In the present study, we attempted to cryopreserve immature medaka oocytes expressing AQP3. We first examined effects of hypertonic stress and the chemical toxicity of cryoprotectants on the survival of the AQP3-expressing oocytes. Exposure to hypertonic solutions containing sucrose decreased the survival of oocytes, but the expression of AQP3 did not affect sensitivity to hypertonic stress. Also, AQP3 expression did not markedly increase sensitivity to the toxicity of cryoprotectants. Of the four cryoprotectants tested, propylene glycol was the least toxic. Using a propylene glycol-based solution, therefore, we tried to cryopreserve immature oocytes by vitrification. During cooling with liquid nitrogen, all intact oocytes became opaque, but many AQP3-expressing oocytes remained transparent. This indicates that the expression of AQP3 is effective in preventing intracellular ice from forming during cooling. During warming, however, all the AQP3-expressing oocytes became opaque, indicating that intracellular ice formed. Therefore, the dehydration and permeation by propylene glycol were still insufficient. Further studies are necessary to realize the cryopreservation of fish oocytes. PMID:23337101

  10. Spontaneous germline excision of Tol1, a DNA-based transposable element naturally occurring in the medaka fish genome.

    PubMed

    Watanabe, Kohei; Koga, Hajime; Nakamura, Kodai; Fujita, Akiko; Hattori, Akimasa; Matsuda, Masaru; Koga, Akihiko

    2014-04-01

    DNA-based transposable elements are ubiquitous constituents of eukaryotic genomes. Vertebrates are, however, exceptional in that most of their DNA-based elements appear to be inactivated. The Tol1 element of the medaka fish, Oryzias latipes, is one of the few elements for which copies containing an undamaged gene have been found. Spontaneous transposition of this element in somatic cells has previously been demonstrated, but there is only indirect evidence for its germline transposition. Here, we show direct evidence of spontaneous excision in the germline. Tyrosinase is the key enzyme in melanin biosynthesis. In an albino laboratory strain of medaka fish, which is homozygous for a mutant tyrosinase gene in which a Tol1 copy is inserted, we identified de novo reversion mutations related to melanin pigmentation. The gamete-based reversion rate was as high as 0.4%. The revertant fish carried the tyrosinase gene from which the Tol1 copy had been excised. We previously reported the germline transposition of Tol2, another DNA-based element that is thought to be a recent invader of the medaka fish genome. Tol1 is an ancient resident of the genome. Our results indicate that even an old element can contribute to genetic variation in the host genome as a natural mutator.

  11. Japanese Interest in “Hotaru” (Fireflies) and “Kabuto-Mushi” (Japanese Rhinoceros Beetles) Corresponds with Seasonality in Visible Abundance

    PubMed Central

    Takada, Kenta

    2012-01-01

    Seasonal changes in the popularity of fireflies [usually Genji-fireflies (Luciola cruciata Motschulsky) in Japan] and Japanese rhinoceros beetles [Allomyrina dichotoma (Linne)] were investigated to examine whether contemporary Japanese are interested in visible emergence of these insects as seasonal events. The popularity of fireflies and Japanese rhinoceros beetles was assessed by the Google search volume of their Japanese names, “Hotaru” and “Kabuto-mushi” in Japanese Katakana script using Google Trends. The search volume index for fireflies and Japanese rhinoceros beetles was distributed across seasons with a clear peak in only particular times of each year from 2004 to 2011. In addition, the seasonal peak of popularity for fireflies occurred at the beginning of June, whereas that for Japanese rhinoceros beetles occurred from the middle of July to the beginning of August. Thus seasonal peak of each species coincided with the peak period of the emergence of each adult stage. These findings indicated that the Japanese are interested in these insects primarily during the time when the two species are most visibly abundant. Although untested, this could suggest that fireflies and Japanese rhinoceros beetles are perceived by the general public as indicators or symbols of summer in Japan. PMID:26466535

  12. Effect of hypergravity on expression of the immediate early gene, c-fos, in central nervous system of medaka (Oryzias latipes)

    NASA Astrophysics Data System (ADS)

    Sayaka, Shimomura-Umemura; Ijiri, Kenichi

    2006-01-01

    Immediate-early genes serve as useful neurobiological tools for mapping brain activity induced by a sensory stimulation. In this study, we have examined brain activity related to gravity perception of medaka (Oryzias latipes) by use of c-fos. The gene, which is homologous to the c-fos genes of other vertebrates, was identified in medaka. Functionally important domains are highly conserved among all the vertebrate species analyzed. Intraperitoneal administration of kainic acid transiently induced the c-fos mRNAs in medaka brains. The results indicate that the expression of c-fos can be utilized as a suitable anatomical marker for the increased neural activities in the central nervous system of medaka. Fish were continuously exposed to 3 g hypergravity by centrifugation. Investigation of c-fos mRNA expression indicated that c-fos mRNA significantly increased 30 min after a start of 3 g exposure. The distribution of its transcripts within the brains was analyzed by an in situ hybridization method. The 3-g treated medakas displayed c-fos positive cells in their brainstem regions, which are related to vestibular function, such as torus semicircularis, nucleus tangentialis, posterior octavu nucleus, and inferior olive. Our results established a method to follow the effect of gravity stimulation, which can be used to investigate gravity perception.

  13. Japanese Temple Geometry

    ERIC Educational Resources Information Center

    Vincent, Jill; Vincent, Claire

    2004-01-01

    Between the 17th and 19th centuries, the Japanese government closed its borders to the outside world in an attempt to become more powerful. Foreign books were banned, people could not travel, and foreigners were not allowed to enter the country. One result of this isolation was the flourishing of sangaku--wooden tablets inscribed with intricately…

  14. Reciprocal Predicates in Japanese.

    ERIC Educational Resources Information Center

    Ishii, Yasuo

    A study of reciprocals in Japanese compares two kinds: (1) a verbal suffix "aw"; and (2) an NP argument "otagai." Although "otagai" appears to be taken care of by syntactic binding theory, it is proposed that there is no evidence for the existence of a syntactic position of the object NP in the case of "aw." The suffix can be characterized as…

  15. Reflexives in Japanese

    ERIC Educational Resources Information Center

    Kishida, Maki

    2011-01-01

    The purpose of this dissertation is to reconsider reflexives in Japanese through the following three steps: (a) separation of genuine reflexive elements from elements that are confounded as reflexives, (b) classification of reflexive anaphors into subtypes based on their semantic difference, and (c) classification of predicates that occur with…

  16. JAPANESE READERS (TITLE SUPPLIED).

    ERIC Educational Resources Information Center

    THREE JAPANESE READERS ARE PRESENTED WHICH CONTAIN VOCABULARY, NOTES, AND DRILL SENTENCES. THE THREE READERS--(1) ARU SARARIIMAN NO ITI-NITI, (2) OTOOSAN WA KAMI-SAMA, AND (3) ARU GAKUSEI NO HANNITI--ARE WRITTEN IN THE ROMAJI ALPHABET. EACH READER HAS A VOCABULARY LISTING WITH ENGLISH EXPLANATIONS AND DRILL SENTENCES. AN ENGLISH WORD DEFINITION…

  17. On Japanese Children's Books.

    ERIC Educational Resources Information Center

    Watanare, Shigeo

    This report, given at a special meeting held in Tehran, presents data and facts concerning yearly publications (books, magazines, and textbooks), translations, and illustrations of Japanese children's literature. The report then discusses at length recent trends in children's literature and library activities for children in the past, present, and…

  18. Reconstruction of Japanese Vowels.

    ERIC Educational Resources Information Center

    Aoki, Haruo

    1972-01-01

    This paper discusses the relationship between linguistic reconstructions and their historical validity using the case of Old Japanese (8th century A.D.) vowels as an example. Reconstructions throughout the paper include only those cases in which the modern reflexes and phonological correspondences between two or more genetically related languages…

  19. Japanese Experiences: "Hentai" Narratives

    ERIC Educational Resources Information Center

    Kama, Amit

    2011-01-01

    For those acquainted with Japanese lesbian, gay, bisexual, and transgender (LGBT) issues, "Queer Voices from Japan" can be good reading. But with only 1 of its 22 chapters informative for researchers, those interested in LGBT youth studies will only indirectly gain insight into a non-Western perspective on youth and sexuality.

  20. The Effect of Estradiol-17(beta), Goitrogen (T3), and Flutamide on Gene Expression in Medaka, Oryzias latipes

    SciTech Connect

    E.Haut, J

    2005-09-06

    Concern has been generated over the discovery of endocrine disrupting chemicals in rivers near sewage outflows. The presence of endocrine disrupting chemicals such as estradiol-17{beta} has been associated with a reduction of reproductive success in fish and an increase in the female phenotype and gonadal intersex in fish downstream of sewage treatment facilities. Such effects are believed to result from a disruption in the normal estrogenic pathways since estrogen plays a vital role in reproduction, sexual differentiation, the developments of secondary sex characteristics, and ovulation. Most studies have focused on the effect of a single endocrine disruptor on a single gene which does not provide for the interaction between genes. Microarray technology has made it possible to put an entire genome on a single chip so that researchers can get a clearer picture of the interaction of genes expressed in a cell and changes of said interactions when those cells are exposed to various conditions. Medaka males were exposed to known endocrine disruptors, estradial-17{beta} and goitrogen, and medaka females were exposed to flutamide. All treatments were then compared to controls. Total RNA was extracted from the livers of both treated and untreated males and hybridized to a microarray chip designed to have EST sequences specific to medaka. ESTs were identified through two-channel microarray analysis and compared to GenBank using blastn searches to identify up regulated genes. Choriogenins H and L, zona radiata, and vitellogenin, previously shown to be estrogen-induced in male fish were identified. Heat shock proteins (hsp70, hsp90, and hsp8) were also induced by estradiol-17{beta}, as was choriogenin Hminor. Exposure to goitrogen (T3) resulted in the induced expression of glutathione S-transferase and a GABA receptor protein in male medaka. Treatment with flutamide, an antiandrogen, caused the up regulation of choriogenin L, choriogenin Hminor, and zona radiata-2 in female

  1. Theoretical Implications of Contemporary Brain Science for Japanese EFL Learning

    ERIC Educational Resources Information Center

    Clayton, John Lloyd

    2015-01-01

    Recent advances in brain science show that adult native Japanese speakers utilize a different balance of language processing routes in the brain as compared to native English speakers. Biologically this represents the remarkable flexibility of the human brain to adapt universal human cognitive processes to fit the specific needs of linguistic and…

  2. Japanese Women's Perceptions of Intimate Partner Violence (IPV)

    ERIC Educational Resources Information Center

    Nagae, Miyoko; Dancy, Barbara L.

    2010-01-01

    Intimate partner violence (IPV) is a problem in Japan. The purpose is to describe IPV as perceived by a purposive sample of 11 Japanese adult females who were in a heterosexual marriage at the time of IPV. We used a cross-sectional, retroactive, qualitative description research design with individual, fact-to-face in depth interviews. At the time…

  3. Experimental Analysis of Japanese Martial Art Nihon-Kempo

    ERIC Educational Resources Information Center

    Kuragano, Tetsuzo; Yokokura, Saburo

    2012-01-01

    With a male, adult subject, this study measured the punch force and kick force of the Japanese martial art Nihon-Kempo, the movements of the dominant (right) arm, leg, and the movements of the legs using timed synchronization. Using an electromyogram (EMG), the relationship between the variation of punch force and the variation of the electrical…

  4. Japanese and American Children's Moral Evaluations of Reporting on Transgressions

    ERIC Educational Resources Information Center

    Chiu Loke, Ivy; Heyman, Gail D.; Itakura, Shoji; Toriyama, Rie; Lee, Kang

    2014-01-01

    American and Japanese children's evaluations of the reporting of peers' transgressions to authority figures were investigated. Seven-, 9-, and 11-year-old children (N = 160) and adults (N = 62) were presented with vignettes and were asked to evaluate the decisions of child observers who reported their friend's either major or relatively minor…

  5. Acquisition and Generalization of Japanese Locatives by English Speakers.

    ERIC Educational Resources Information Center

    Weber-Olsen, Marcia; Ruder, Kenneth F.

    1980-01-01

    Presents a comparison study of language learning in American children and adults using various Japanese locatives. The subjects were pre- and posttested to determine if locatives that were semantically similar to their English equivalents would yield better transfer than terms that deviated in meaning and phonemic structure in English. (BK)

  6. Creating a Global Cultural Consciousness in a Japanese EFL Classroom

    ERIC Educational Resources Information Center

    Aubrey, Scott

    2009-01-01

    Recently, culture has taken an important role in language education. In this view, creating a global cultural consciousness among second language (L2) students can help bridge the gap between linguistic ability and functional intercultural communication. This paper, which makes reference to Japanese adult EFL learners, justifies the body of…

  7. Immunotoxicity of trenbolone acetate in Japanese quail

    USGS Publications Warehouse

    Quinn, M.J.; McKernan, M.; Lavoie, E.T.; Ottinger, M.A.

    2007-01-01

    Trenbolone acetate is a synthetic androgen that is currently used as a growth promoter in many meat-exporting countries. Despite industry laboratories classifying trenbolone as nonteratogenic, data showed that embryonic exposure to this androgenic chemical altered development of the immune system in Japanese quail. Trenbolone is lipophilic, persistent, and released into the environment in manure used as soil fertilizer. This is the first study to date to assess this chemical's immunotoxic effects in an avian species. A one-time injection of trenbolone into yolks was administered to mimic maternal deposition, and subsequent effects on the development and function of the immune system were determined in chicks and adults. Development of the bursa of Fabricius, an organ responsible for development of the humoral arm of the immune system, was disrupted, as indicated by lower masse, and smaller and fewer follicles at day 1 of hatch. Morphological differences in the bursas persisted in adults, although no differences in either two measures of immune function were observed. Total numbers of circulating leukocytes were reduced and heterophil-lymphocyte ratios were elevated in chicks but not adults. This study shows that trenbolone acetate is teratogenic and immunotoxic in Japanese quail, and provides evidence that the quail immune system may be fairly resilient to embryonic endocrine-disrupting chemical-induced alterations following no further exposure posthatch.

  8. Genome-wide SNP identification for the construction of a high-resolution genetic map of Japanese flounder (Paralichthys olivaceus): applications to QTL mapping of Vibrio anguillarum disease resistance and comparative genomic analysis.

    PubMed

    Shao, Changwei; Niu, Yongchao; Rastas, Pasi; Liu, Yang; Xie, Zhiyuan; Li, Hengde; Wang, Lei; Jiang, Yong; Tai, Shuaishuai; Tian, Yongsheng; Sakamoto, Takashi; Chen, Songlin

    2015-04-01

    High-resolution genetic maps are essential for fine mapping of complex traits, genome assembly, and comparative genomic analysis. Single-nucleotide polymorphisms (SNPs) are the primary molecular markers used for genetic map construction. In this study, we identified 13,362 SNPs evenly distributed across the Japanese flounder (Paralichthys olivaceus) genome. Of these SNPs, 12,712 high-confidence SNPs were subjected to high-throughput genotyping and assigned to 24 consensus linkage groups (LGs). The total length of the genetic linkage map was 3,497.29 cM with an average distance of 0.47 cM between loci, thereby representing the densest genetic map currently reported for Japanese flounder. Nine positive quantitative trait loci (QTLs) forming two main clusters for Vibrio anguillarum disease resistance were detected. All QTLs could explain 5.1-8.38% of the total phenotypic variation. Synteny analysis of the QTL regions on the genome assembly revealed 12 immune-related genes, among them 4 genes strongly associated with V. anguillarum disease resistance. In addition, 246 genome assembly scaffolds with an average size of 21.79 Mb were anchored onto the LGs; these scaffolds, comprising 522.99 Mb, represented 95.78% of assembled genomic sequences. The mapped assembly scaffolds in Japanese flounder were used for genome synteny analyses against zebrafish (Danio rerio) and medaka (Oryzias latipes). Flounder and medaka were found to possess almost one-to-one synteny, whereas flounder and zebrafish exhibited a multi-syntenic correspondence. The newly developed high-resolution genetic map, which will facilitate QTL mapping, scaffold assembly, and genome synteny analysis of Japanese flounder, marks a milestone in the ongoing genome project for this species.

  9. Detraditionalisation: Japanese Students in the USA.

    ERIC Educational Resources Information Center

    Ueno, Junko

    2001-01-01

    Focuses on the identity formation of Japanese students temporarily living in the United States. The students were enrolled in Japanese Saturday school and in American public schools. Student interviews reveal a mixture of Japanese and American characteristics. Suggests Japanese students do not reject either culture--Japanese or American--but that…

  10. Developmental Sentence Scoring for Japanese (DSSJ)

    PubMed Central

    Miyata, Susanne; MacWhinney, Brian; Otomo, Kiyoshi; Sirai, Hidetosi; Oshima-Takane, Yuriko; Hirakawa, Makiko; Shirai, Yasuhiro; Sugiura, Masatoshi; Itoh, Keiko

    2014-01-01

    This paper reports on the development and use of the Developmental Sentence Scoring for Japanese (DSSJ), a new morpho-syntactical measure for Japanese constructed after the model of the English Developmental Sentence Scoring model (Lee, 1974). Using this measure, we calculated DSSJ scores for 84 children divided into six age groups between 2;8 and 5;2 on the basis of 100-sentence samples collected from free-play child-adult conversations. The analysis showed a high correlation of the DSSJ overall score with the Mean Length of Utterance. The analysis of the DSSJ subarea scores revealed large variations between these subarea scores for children with similar overall DSSJ scores. When investigating the high-scoring children (over 1 SD over group average), most children scored high in three to five subareas, but the combination of scores for these subareas varied from child to child. It is concluded that DSSJ is a valuable tool especially for the language acquisition research. The overall DSSJ score reliably reflects the overall morpho-syntactic development of Japanese children, and the subarea scores provide specific information on individual acquisition patterns. PMID:25414535

  11. Developmental toxicity from exposure to various forms of mercury compounds in medaka fish (Oryzias latipes) embryos

    PubMed Central

    Liu, Jie; Wei, Lixin; Jingfeng, Yang; Chernick, Melissa; Hinton, David E.

    2016-01-01

    This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes) embryos were exposed to 0.001–10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha), and β-HgS (Zuotai) from stage 10 (6–7 hpf) to 10 days post fertilization (dpf). Of the forms of mercury in this study, the organic form (MeHg) proved the most toxic followed by inorganic mercury (HgCl2), both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM), HgCl2 (1 µM), α-HgS (10 µM), or β-HgS (10 µM) to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT) and heme oxygenase-1 (Ho-1), while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity. PMID:27635309

  12. Influence of water hardening of the chorion on cadmium accumulation in medaka (Oryzias latipes) eggs.

    PubMed

    González-Doncel, Miguel; Larrea, Maite; Sánchez-Fortún, Sebastián; Hinton, David E

    2003-07-01

    This report describes a study in which in vitro fertilization methods were used to expose medaka (Oryzias latipes) eggs to cadmium (Cd(2+)). This approach was applied to address the differential sensitivity and cumulative potential of Cd(2+) when exposure was initiated early (before fertilization and water hardening of the chorion) versus later during embryo development (i.e., well after the chorion has undergone water hardening). Following range finding exposures (2.5, 10, 20, 40 or 80 mg/l) under artificially controlled experimental procedures, results from hatching success and embryo malformations showed the earlier exposure interval more sensitive than the assay involving only the embryonated egg. Subsequent accumulation studies have shown that the exposure initiated before fertilization apparently led to more Cd(2+) deposition in the chorion compared to the exposure during embryonated stages of the eggs. Similarly, values for total Cd(2+) indicated higher concentrations in those eggs exposed prior to--and during--water hardening. Results suggest an alteration of the properties of the zona radiata in the early-stage eggs, making it more permeable to the potential exit or entrance of waterborne agents even after water hardening. Ongoing studies must now address the development of more realistic exposure conditions of the gametes by using incubation media with osmolarities similar to surface waters, and by shortening duration for gamete exposure. Also, sensitive methods to localize Cd(2+) and to delineate the transfer from the chorion to the embryo are needed.

  13. Autosomal gsdf acts as a male sex initiator in the fish medaka

    PubMed Central

    Zhang, Xi; Guan, Guijun; Li, Mingyou; Zhu, Feng; Liu, Qizhi; Naruse, Kiyoshi; Herpin, Amaury; Nagahama, Yoshitaka; Li, Jiale; Hong, Yunhan

    2016-01-01

    Sex is pivotal for reproduction, healthcare and evolution. In the fish medaka, the Y-chromosomal dmy (also dmrt1bY) serves the sex determiner, which activates dmrt1 for male sex maintenance. However, how dmy makes the male decision via initiating testicular differentiation has remained unknown. Here we report that autosomal gsdf serves a male sex initiator. Gene addition and deletion revealed that gsdf was necessary and sufficient for maleness via initiating testicular differentiation. We show that gsdf transcription is activated directly by dmy. These results establish the autosomal gsdf as the first male sex initiator. We propose that dmy determines maleness through activating gsdf and dmrt1 without its own participation in developmental processes of sex initiation and maintenance. gsdf may easily become a sex determiner or other autosomal genes can be recruited as new sex determiners to initiate gsdf expression. Our findings offer new insights into molecular mechanisms underlying sex development and evolution of sex-controlling genes in vertebrates. PMID:26813267

  14. Characterization of assortative mating in medaka: Mate discrimination cues and factors that bias sexual preference.

    PubMed

    Utagawa, Umi; Higashi, Shoichi; Kamei, Yasuhiro; Fukamachi, Shoji

    2016-08-01

    Somatolactin alpha (SLα) is a peptide hormone that regulates skin color, and SLα-deficient and SLα-excess strains have been established in medaka (Oryzias latipes). Their skin colors differ conspicuously and males prefer to mate with females from the same strain. Pre-mating sexual isolation in this model vertebrate provides an ideal platform for investigating the molecular mechanisms of mate choice. Thus, we studied the sensory cues utilized by these fish to discriminate the same and different strains. When males were given a choice under monochromatic light, where the skin colors differed only in terms of brightness but not in hue, mating occurred but it was not assortative. This suggests that: (1) a visual cue is essential for mate discrimination rather than odor or acoustic cues; (2) the visual cue is color and not shape, size, or motion; and (3) the color cue needs to be perceived as the relative balance of brightness at multiple wavelengths rather than the brightness at a specific wavelength. In addition, we introduced another skin-color mutation into the SLα-excess strain and found that this new strain and the original SLα-excess strain, which also overexpressed SLα but exhibited distinct skin colors, preferred different colors. This demonstrates that SLα is not a primary determinant of sexual preference. The symmetrically biased sexual preferences of the SLα-deficient and SLα-excess strains may be acquired postnatally depending on their individual skin color or that of tank mates.

  15. Somatolactin selectively regulates proliferation and morphogenesis of neural-crest derived pigment cells in medaka

    PubMed Central

    Fukamachi, Shoji; Sugimoto, Masazumi; Mitani, Hiroshi; Shima, Akihiro

    2004-01-01

    Species-specific colors and patterns on animal body surfaces are determined primarily by neural-crest-derived pigment cells in the skin (chromatophores). However, even closely related species display widely differing patterns. These contrasting aspects of chromatophores (i.e., the fixed developmental control within species and extreme diversity among species) seem to be a curious and suitable subject for understanding evolution and diversity of organisms. Here we identify a gene responsible for medaka “color interfere” mutants by positional cloning. These mutants do not show any obvious morphological and physiological defects other than defects in chromatophore proliferation and morphogenesis. The mutation has been identified as an 11-base deletion in somatolactin, which causes truncation 91 aa upstream of the C terminus of the protein's 230 aa. Somatolactin transcription changed dramatically during morphological body color adaptation to different backgrounds. This genetic evidence explains somatolactin function. Studying this mutant will provide further insights into the development and regulation of chromatophores and clues for reassessing other functions of somatolactin suggested in other fish. PMID:15249680

  16. Developmental toxicity from exposure to various forms of mercury compounds in medaka fish (Oryzias latipes) embryos.

    PubMed

    Dong, Wu; Liu, Jie; Wei, Lixin; Jingfeng, Yang; Chernick, Melissa; Hinton, David E

    2016-01-01

    This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes) embryos were exposed to 0.001-10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha), and β-HgS (Zuotai) from stage 10 (6-7 hpf) to 10 days post fertilization (dpf). Of the forms of mercury in this study, the organic form (MeHg) proved the most toxic followed by inorganic mercury (HgCl2), both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM), HgCl2 (1 µM), α-HgS (10 µM), or β-HgS (10 µM) to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT) and heme oxygenase-1 (Ho-1), while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity.

  17. Genetic analysis of vertebral regionalization and number in medaka (Oryzias latipes) inbred lines.

    PubMed

    Kimura, Tetsuaki; Shinya, Minori; Naruse, Kiyosi

    2012-11-01

    Vertebral number is the most variable trait among vertebrates. In addition to the vertebral number, the ratio of abdominal to caudal vertebrae is a variable trait. The vertebral number and the ratio of abdominal to caudal vertebrae contribute to vertebrate diversity. It is very interesting to know how to determine the vertebral number and the ratio of abdominal to caudal vertebrae. In this study, we identify differences in the vertebral number and the ratio of abdominal vertebrae to vertebral number between two inbred lines of medaka, namely, Hd-rRII1 and Kaga. To identify the genetic factor of those differences, we performed quantitative trait locus (QTL) analysis for vertebral number and the ratio of abdominal vertebrae to vertebral number using 200 F(2) fish. Our results show a suggestive QTL of the ratio of abdominal vertebrae to vertebral number on chromosome 15, and five QTL of vertebral number on chromosomes 1, 10, 11, 17, and 23. The QTL on chromosome 15 contains hoxDb cluster genes. The QTL of vertebral number include some genes related to the segmentation clock and axial elongation. In addition, we show that the difference in vertebral number between two inbred lines is derived from differences in the anteroposterior length of somites. Our results emphasize that the developmental process should be considered in genetic analyses for vertebral number.

  18. Targeted Inactivation of DNA Photolyase Genes in Medaka Fish (Oryzias latipes).

    PubMed

    Ishikawa-Fujiwara, Tomoko; Shiraishi, Eri; Fujikawa, Yoshihiro; Mori, Toshio; Tsujimura, Tohru; Todo, Takeshi

    2017-01-01

    Proteins of the cryptochrome/photolyase family (CPF) exhibit sequence and structural conservation, but their functions are divergent. Photolyase is a DNA repair enzyme that catalyzes the light-dependent repair of ultraviolet (UV)-induced photoproducts, whereas cryptochrome acts as a photoreceptor or circadian clock protein. Two types of DNA photolyase exist: CPD photolyase, which repairs cyclobutane pyrimidine dimers (CPDs), and 6-4 photolyase, which repairs 6-4 pyrimidine-pyrimidone photoproducts (6-4PPs). Although the Cry-DASH protein is classified as a cryptochrome, it also has light-dependent DNA repair activity. To determine the significance of the three light-dependent repair enzymes in recovering from solar UV-induced DNA damage at the organismal level, we generated mutants in each gene in medaka using the CRISPR genome editing technique. The light-dependent repair activity of the mutants was examined in vitro in cultured cells and in vivo in skin tissue. Light-dependent repair of CPD was lost in the CPD photolyase-deficient mutant, whereas weak repair activity against 6-4PPs persisted in the 6-4 photolyase-deficient mutant. These results suggest the existence of a heretofore unknown 6-4PP repair pathway and thus improve our understanding of the mechanisms of defense against solar UV in vertebrates.

  19. Directory of Japanese researchers available

    NASA Astrophysics Data System (ADS)

    The National Center for Science Information System Japanese Scientific and Engineering Database Access Project, sponsored by the National Science Foundation and Japan's NACSIS, has added four new databases to its free service, bringing the total number of available databases to 13.The new Directory of Japanese Researchers covers researchers affiliated with Japanese universities and academic research centers. Each researcher is listed by name, date of birth, organizational affiliation, education and degrees, memberships and awards, areas of specialization, and representative publications. Non-Japanese researchers are also covered.

  20. A Dual Role for Melatonin in Medaka Ovulation: Ensuring Prostaglandin Synthesis and Actin Cytoskeleton Rearrangement in Follicular Cells.

    PubMed

    Ogiwara, Katsueki; Takahashi, Takayuki

    2016-03-01

    Understanding the direct effects of melatonin on vertebrate ovulation remains a challenge. The present study provides the first characterization of the role of melatonin in ovulation using the teleost medaka. The melatonin receptor antagonist luzindole inhibited in vitro follicle ovulation. In the preovulatory follicles, arylalkylamine N-acetyltransferase 1a and hydroxyindole-O-methyltransferase 2, the enzymes responsible for melatonin synthesis, were expressed in the granulosa cells throughout the 24 h spawning cycle. The granulosa cells of the follicle also expressed the melatonin receptor 1a-a. An in vitro characterization study using medaka OLHNI-2 cells revealed that melatonin and luzindole act as an agonist and an antagonist, respectively, of the melatonin receptor. The intracellular cAMP levels in these cells were reduced after melatonin treatment. The expression of cytosolic phospholipase A2 group 4a (Pla2g4a), the enzyme producing arachidonic acid (cyclooxygenase-2 substrate), was inhibited in the granulosa cells in luzindole-treated follicles. Follicular prostaglandin E2 levels and in vitro follicle ovulation were suppressed in follicles isolated at 12 h prior to ovulation and incubated with the Pla2g4a inhibitor AACOCF3. The G-actin:F-actin ratios in follicular cells increased with approaching ovulation, but this increase was suppressed after luzindole treatment. The phosphorylation of moesin, an ezrin-radixin-moesin protein, was inhibited in the follicular cells in luzindole-treated follicles. These results indicate a dual role for melatonin in medaka ovulation: melatonin ensures prostaglandin E2 synthesis throughout the spawning cycle and induces actin cytoskeleton rearrangement in the follicular cells at ovulation.

  1. Issei: Japanese Immigrants in Hawaii.

    ERIC Educational Resources Information Center

    Kimura, Yukiko

    Coming to Hawaii before July 1, 1924, when the Japanese Exclusion Act became effective, the experiences of the Issei or first generation are described. Divided into four parts, this book examines the experiences of Japanese immigrants in Hawaii from 1885 through 1970. Part 1, "The Formation and Stabilization of the Issei Community,"…

  2. Developmental Sentence Scoring for Japanese

    ERIC Educational Resources Information Center

    Miyata, Susanne; MacWhinney, Brian; Otomo, Kiyoshi; Sirai, Hidetosi; Oshima-Takane, Yuriko; Hirakawa, Makiko; Shirai, Yasuhiro; Sugiura, Masatoshi; Itoh, Keiko

    2013-01-01

    This article reports on the development and use of the Developmental Sentence Scoring for Japanese (DSSJ), a new morpho-syntactical measure for Japanese constructed after the model of Lee's English Developmental Sentence Scoring model. Using this measure, the authors calculated DSSJ scores for 84 children divided into six age groups between 2;8…

  3. Asian Pacific Perspectives: Japanese Americans.

    ERIC Educational Resources Information Center

    Los Angeles Unified School District, CA.

    These instructional materials on Japanese Americans for elementary students were developed through the K.E.Y.S. project (Knowledge of English Yields Success). Information is included on early immigrants, their historical and cultural background, and current problems of Japanese Americans. Resource guides describe the purpose of the unit, how to…

  4. The modern Japanese color lexicon.

    PubMed

    Kuriki, Ichiro; Lange, Ryan; Muto, Yumiko; Brown, Angela M; Fukuda, Kazuho; Tokunaga, Rumi; Lindsey, Delwin T; Uchikawa, Keiji; Shioiri, Satoshi

    2017-03-01

    Despite numerous prior studies, important questions about the Japanese color lexicon persist, particularly about the number of Japanese basic color terms and their deployment across color space. Here, 57 native Japanese speakers provided monolexemic terms for 320 chromatic and 10 achromatic Munsell color samples. Through k-means cluster analysis we revealed 16 statistically distinct Japanese chromatic categories. These included eight chromatic basic color terms (aka/red, ki/yellow, midori/green, ao/blue, pink, orange, cha/brown, and murasaki/purple) plus eight additional terms: mizu ("water")/light blue, hada ("skin tone")/peach, kon ("indigo")/dark blue, matcha ("green tea")/yellow-green, enji/maroon, oudo ("sand or mud")/mustard, yamabuki ("globeflower")/gold, and cream. Of these additional terms, mizu was used by 98% of informants, and emerged as a strong candidate for a 12th Japanese basic color term. Japanese and American English color-naming systems were broadly similar, except for color categories in one language (mizu, kon, teal, lavender, magenta, lime) that had no equivalent in the other. Our analysis revealed two statistically distinct Japanese motifs (or color-naming systems), which differed mainly in the extension of mizu across our color palette. Comparison of the present data with an earlier study by Uchikawa & Boynton (1987) suggests that some changes in the Japanese color lexicon have occurred over the last 30 years.

  5. Counseling Japanese Men on Fathering

    ERIC Educational Resources Information Center

    Seto, Atsuko; Becker, Kent W.; Akutsu, Motoko

    2006-01-01

    The authors review an article (J. Yamamoto & F. Tagami, 2004) published in the "Japanese Journal of Counseling Science" that described changes in contemporary Japanese family structures and illustrated a therapy process with a father to enhance the father-son relationship. Implications for the counseling profession in working with…

  6. Altered brain activity for phonological manipulation in dyslexic Japanese children.

    PubMed

    Kita, Yosuke; Yamamoto, Hisako; Oba, Kentaro; Terasawa, Yuri; Moriguchi, Yoshiya; Uchiyama, Hitoshi; Seki, Ayumi; Koeda, Tatsuya; Inagaki, Masumi

    2013-12-01

    Because of unique linguistic characteristics, the prevalence rate of developmental dyslexia is relatively low in the Japanese language. Paradoxically, Japanese children have serious difficulty analysing phonological processes when they have dyslexia. Neurobiological deficits in Japanese dyslexia remain unclear and need to be identified, and may lead to better understanding of the commonality and diversity in the disorder among different linguistic systems. The present study investigated brain activity that underlies deficits in phonological awareness in Japanese dyslexic children using functional magnetic resonance imaging. We developed and conducted a phonological manipulation task to extract phonological processing skills and to minimize the influence of auditory working memory on healthy adults, typically developing children, and dyslexic children. Current experiments revealed that several brain regions participated in manipulating the phonological information including left inferior and middle frontal gyrus, left superior temporal gyrus, and bilateral basal ganglia. Moreover, dyslexic children showed altered activity in two brain regions. They showed hyperactivity in the basal ganglia compared with the two other groups, which reflects inefficient phonological processing. Hypoactivity in the left superior temporal gyrus was also found, suggesting difficulty in composing and processing phonological information. The altered brain activity shares similarity with those of dyslexic children in countries speaking alphabetical languages, but disparity also occurs between these two populations. These are initial findings concerning the neurobiological impairments in dyslexic Japanese children.

  7. Divergent Expression Regulation of Gonad Development Genes in Medaka Shows Incomplete Conservation of the Downstream Regulatory Network of Vertebrate Sex Determination

    PubMed Central

    Herpin, Amaury; Adolfi, Mateus C.; Nicol, Barbara; Hinzmann, Maria; Schmidt, Cornelia; Klughammer, Johanna; Engel, Mareen; Tanaka, Minoru; Guiguen, Yann; Schartl, Manfred

    2013-01-01

    Genetic control of male or female gonad development displays between different groups of organisms a remarkable diversity of “master sex-determining genes” at the top of the genetic hierarchies, whereas downstream components surprisingly appear to be evolutionarily more conserved. Without much further studies, conservation of sequence has been equalized to conservation of function. We have used the medaka fish to investigate the generality of this paradigm. In medaka, the master male sex-determining gene is dmrt1bY, a highly conserved downstream regulator of sex determination in vertebrates. To understand its function in orchestrating the complex gene regulatory network, we have identified targets genes and regulated pathways of Dmrt1bY. Monitoring gene expression and interactions by transgenic fluorescent reporter fish lines, in vivo tissue-chromatin immunoprecipitation and in vitro gene regulation assays revealed concordance but also major discrepancies between mammals and medaka, notably amongst spatial, temporal expression patterns and regulations of the canonical Hedgehog and R-spondin/Wnt/Follistatin signaling pathways. Examination of Foxl2 protein distribution in the medaka ovary defined a new subpopulation of theca cells, where ovarian-type aromatase transcriptional regulation appears to be independent of Foxl2. In summary, these data show that the regulation of the downstream regulatory network of sex determination is less conserved than previously thought. PMID:23883523

  8. Development of Cultural Strategies of Attention in North American and Japanese Children

    ERIC Educational Resources Information Center

    Duffy, Sean; Toriyama, Rie; Itakura, Shoji; Kitayama, Shinobu

    2009-01-01

    Recent studies suggest that North American adults exhibit a focused strategy of attention that emphasizes focal information about objects, whereas Japanese adults exhibit a divided strategy of attention that emphasizes contextual information about objects. The current study investigated whether 4- and 5-, 6- to 8-, and 9- to 13-year-old North…

  9. Japanese Children's Awareness of the Effects of Psychological Taste Experiences on Biological Processes

    ERIC Educational Resources Information Center

    Toyama, Noriko

    2016-01-01

    The present study examined Japanese children's and adults' awareness of the effects of psychological taste experiences on biological processes such as growth and illness. Studies 1 and 2 showed the following: (1) preschoolers tended to assume that good-tasting experiences would make one grow taller and gain more weight, while adults seldom…

  10. Japanese risk behaviors and their HIV/AIDS-preventive behaviors.

    PubMed

    Munakata, T; Tajima, K

    1996-04-01

    This study is to identify the risk behaviors of the Japanese that may lead to HIV infection and the behaviors that prevent such infection, as well as their background factors. Two behavioral surveys were conducted for the present study. (1) For international comparison on knowledge, attitudes, beliefs, and practices (KABP) related to HIV/AIDS, we conducted a survey on a sample of 10,000 adults, randomly selected from a nationwide population in Japan; and (2) for sexual partner relation, we conducted a survey on a sample of 10,000 adults randomly selected from a population in five major cities of Japan. Our main findings include: (1) Most of the Japanese adult did not regard AIDS as a major threat in the area where they lived; (2) People in their twenties are too casual about "having sex without using a condom with someone they've met for the first time and know little about"; (3) Thirteen percent (19% male, 8% female) of those with a steady sex partner including a spouse, on average, had sex with 2.4 non-steady partners in the previous year; and (4) Only 25 percent used condoms always when they engaged in casual sex during the previous four weeks. These risk behaviors of the Japanese adults might lead to an explosive rise in the number of HIV-infected in the near future unless steps are taken immediately to prevent it.

  11. Design, evaluation, and screening methods for efficient targeted mutagenesis with transcription activator-like effector nucleases in medaka.

    PubMed

    Ansai, Satoshi; Inohaya, Keiji; Yoshiura, Yasutoshi; Schartl, Manfred; Uemura, Norihito; Takahashi, Ryosuke; Kinoshita, Masato

    2014-01-01

    Genome editing using engineered nucleases such as transcription activator-like effector nucleases (TALENs) has become a powerful technology for reverse genetics. In this study, we have described efficient detection methods for TALEN-induced mutations at endogenous loci and presented guidelines of TALEN design for efficient targeted mutagenesis in medaka, Oryzias latipes. We performed a heteroduplex mobility assay (HMA) using an automated microchip electrophoresis system, which is a simple and high-throughput method for evaluation of in vivo activity of TALENs and for genotyping mutant fish of F1 or later generations. We found that a specific pattern of mutations is dominant for TALENs harboring several base pairs of homologous sequences in target sequence. Furthermore, we found that a 5' T, upstream of each TALEN-binding sequence, is not essential for genomic DNA cleavage. Our findings provide information that expands the potential of TALENs and other engineered nucleases as tools for targeted genome editing in a wide range of organisms, including medaka.

  12. Ammonium chloride and tunicamycin are novel toxins for dopaminergic neurons and induce Parkinson's disease-like phenotypes in medaka fish.

    PubMed

    Matsui, Hideaki; Ito, Hidefumi; Taniguchi, Yoshihito; Takeda, Shunichi; Takahashi, Ryosuke

    2010-12-01

    Perturbations in protein folding and degradation are key pathological mechanisms in neurodegenerative diseases, including Parkinson's disease (PD). Recent evidence suggests that mishandling of proteins may play an important role in the pathogenesis of PD. We have utilized medaka fish to monitor the effects of injecting neurotoxins into the CSF space. In this study, ammonium chloride, tunicamycin, and lactacystin were tested for their ability to disturb lysosomal proteolysis, N-glycosylation in the endoplasmic reticulum, and proteasomal degradation, respectively. All of the substances tested induced selective loss of dopaminergic neurons, movement disorders and inclusion bodies. Among them, the features of the inclusion bodies that developed after ammonium chloride injection mimicked those of PD: co-localization of ubiquitin and phosphorylated α-synuclein, as well as the presence of LC3 protein in the inclusion bodies. Our study demonstrated that medaka fish are useful for examining the effects of environmental toxins and lysosome inhibition, and lysosome inhibitors may be factors in the development of PD.

  13. Transgenerational effects from early developmental exposures to bisphenol A or 17α-ethinylestradiol in medaka, Oryzias latipes

    USGS Publications Warehouse

    Bhandari, Ramji K.; vom Saal, Frederick S.; Tillitt, Donald E.

    2015-01-01

    The transgenerational consequences of environmental contaminant exposures of aquatic vertebrates have the potential for broad ecological impacts, yet are largely uninvestigated. Bisphenol A (BPA) and 17α-ethinylestradiol (EE2) are two ubiquitous estrogenic chemicals present in aquatic environments throughout the United States and many other countries. Aquatic organisms, including fish, are exposed to varying concentrations of these chemicals at various stages of their life history. Here, we tested the ability of embryonic exposure to BPA or EE2 to cause adverse health outcomes at later life stages and transgenerational abnormalities in medaka fish. Exposures of F0 medaka to either BPA (100 μg/L) or EE2 (0.05 μg/L) during the first 7 days of embryonic development, when germ cells are differentiating, did not cause any apparent phenotypic abnormalities in F0 or F1 generations, but led to a significant reduction in the fertilization rate in offspring two generations later (F2) as well as a reduction of embryo survival in offspring three generations later (F3). Our present observations suggest that BPA or EE2 exposure during development induces transgenerational phenotypes of reproductive impairment and compromised embryonic survival in fish of subsequent generations. These adverse outcomes may have negative impacts on populations of fish inhabiting contaminated aquatic environments.

  14. Developmental toxicity and molecular responses of marine medaka (Oryzias melastigma) embryos to ciguatoxin P-CTX-1 exposure.

    PubMed

    Yan, Meng; Leung, Priscilla T Y; Ip, Jack C H; Cheng, Jin-Ping; Wu, Jia-Jun; Gu, Jia-Rui; Lam, Paul K S

    2017-04-01

    Ciguatoxins are produced by toxic benthic dinoflagellates and cause ciguatera fish poisoning worldwide, but the toxic effects on developing marine fish have not been well investigated. The Pacific ciguatoxin (P-CTX-1), is a potent sodium channel agonist, which is one of the most toxic members among all CTXs. This study evaluated the toxic effects of microinjecting purified Pacific ciguatoxin-1 (P-CTX-1) on embryonic development of marine medaka Oryzias melastigma. A lower 96h-LD50 value was estimated for eleuthero-embryos (1.32ngg(-1)) than that for embryos (1.71ngg(-1)), indicating that P-CTX-1 is more lethal to newly hatched medaka larvae. P-CTX-1 induced detrimental effects during embryonic development, including hatching failure, abnormalities in physical development (caudal fin malformation and spinal deformities), internal damage (green coloration of the gall bladder and hemorrhaging), immune dysfunction, and altered muscle physiology (bradycardia and hyperkinetic twitching). The results of a transcriptional expression analysis of genes related to the stress/immune responses, cardiac and bone development, and apoptosis supported the observed developmental abnormalities. This study advanced the understanding of P-CTX-1 mediated toxic mechanisms in the development of early life stages of a fish, and thus contributed to the toxicity assessment of CTXs in marine ecosystems.

  15. Quantitative analysis of fish schooling behavior with different numbers of medaka ( Oryzias latipes) and goldfish ( Carassius auratus)

    NASA Astrophysics Data System (ADS)

    Leem, Joo-Baek; Jeon, Wonju; Yun, Chi-Young; Lee, Sang-Hee

    2012-12-01

    Fish form schools of various sizes, according to species or environmental conditions, to attain several advantages, such as protection from predators or to improve efficiency in searching for prey. Thus, quantifying the mechanisms of how group size affects schooling behavior may contribute to better understanding fish biology and the evolution of the collective behavior of fishes. In the present study, we explored how school size affected the behavior of medaka ( Oryzias latipes) and goldfish ( Carassius auratus). Size groups of 10 to 40 individuals were placed in a circular aquarium (100 cm diameter, 30 cm height, 5 cm water depth) and videoed for 4 hours. Eight to 10 video clips of 3 seconds in length for each group size were evaluated for 6 physical parameters of fish schooling behavior. Regardless of species, the mean distance among individuals increased with increasing school size. However, due to variations in certain physical parameters, the schooling pattern of goldfish was more elongated than medaka, possibly related to body size, or indicating species-specific differences in schooling characteristics. Our experimental datasets could be incorporated into theoretical mathematical models of fish schooling behavior, by contributing new information about school size and species differences.

  16. A trans-Regulatory Code for the Forebrain Expression of Six3.2 in the Medaka Fish*

    PubMed Central

    Beccari, Leonardo; Marco-Ferreres, Raquel; Tabanera, Noemi; Manfredi, Anna; Souren, Marcel; Wittbrodt, Beate; Conte, Ivan; Wittbrodt, Jochen; Bovolenta, Paola

    2015-01-01

    A well integrated and hierarchically organized gene regulatory network is responsible for the progressive specification of the forebrain. The transcription factor Six3 is one of the central components of this network. As such, Six3 regulates several components of the network, but its upstream regulators are still poorly characterized. Here we have systematically identified such regulators, taking advantage of the detailed functional characterization of the regulatory region of the medaka fish Six3.2 ortholog and of a time/cost-effective trans-regulatory screening, which complemented and overcame the limitations of in silico prediction approaches. The candidates resulting from this search were validated with dose-response luciferase assays and expression pattern criteria. Reconfirmed candidates with a matching expression pattern were also tested with chromatin immunoprecipitation and functional studies. Our results confirm the previously proposed direct regulation of Pax6 and further demonstrate that Msx2 and Pbx1 are bona fide direct regulators of early Six3.2 distribution in distinct domains of the medaka fish forebrain. They also point to other transcription factors, including Tcf3, as additional regulators of different spatial-temporal domains of Six3.2 expression. The activity of these regulators is discussed in the context of the gene regulatory network proposed for the specification of the forebrain. PMID:26378230

  17. Developmental exposures to waterborne abused drugs alter physiological function and larval locomotion in early life stages of medaka fish.

    PubMed

    Liao, Pei-Han; Hwang, Chiu-Chu; Chen, Te-Hao; Chen, Pei-Jen

    2015-08-01

    Environmental pollution by neuroactive pharmaceuticals from wastewater discharge is a major threat to aquatic ecosystems. However, the ecotoxicologic effect of waterborne abused drugs remains unclear. Embryos of medaka fish (Oryzias latipes) were exposed to aqueous solutions of 2 hallucinogenic drugs, ketamine (KET) and methamphetamine (MET) (0.004-40μM) to assess developmental toxicity, oxidative stress and behavioral alteration in early life stages. The environmentally relevant concentration (0.004μM) of both KET and MET significantly delayed blood circulation and hatching time in embryos and altered larval swimming behavior (e.g., maximum velocity and relative turn angle). KET and MET induced similar oxidative stress responses in embryos, which were unrecoverable in hatchlings in drug-free solutions. Early life exposure to the 2 drugs conferred distinct patterns in larval locomotion: KET induced hyperactivity and a less tortuous swimming path, but MET-treated larvae showed hypoactivity and a clockwise swimming direction at high doses. The alteration in locomotor responses were generally similar in mammals and zebrafish. We report sensitive biomarkers (e.g., heartbeat, hatching and swimming behavior) by developmental stage of medaka that reflect environmentally relevant exposures of abused drugs. They could be useful for ecological risk assessment of waterborne neuroactive drugs. The toxicity results implicate a potential ecotoxicological impact of controlled or abused drugs on fish development and populations in aquatic environments.

  18. Non Invasive High Resolution In Vivo Imaging of α-napthylisothiocyanate (ANIT) Induced Hepatobiliary Toxicity in STII Medaka

    PubMed Central

    Hardman, Ron; Kullman, Seth; Yuen, Bonny; Hinton, David E.

    2009-01-01

    A novel transparent stock of medaka (Oryzias latipes; STII), homozygous recessive for all four pigments (iridophores, xanthophores, leucophores, melanophores), permits transcutaneous, high resolution ( < 1μm) imaging of internal organs and tissues in living individuals. We applied this model to in vivo investigation of α-napthylisothiocyanate (ANIT) induced hepatobiliary toxicity. Distinct phenotypic responses to ANIT involving all aspects of intrahepatic biliary passageways (IHBPs), particularly bile preductular epithelial cells (BPDECs), associated with transitional passageways between canaliculi and bile ductules, were observed. Alterations included: attenuation/dilation of bile canaliculi, bile preductular lesions, hydropic vacuolation of hepatocytes and BPDECs, mild BPDEC hypertrophy, and biliary epithelial cell (BEC) hyperplasia. Ex vivo histological, immunohistochemical, and ultrastructural studies were employed to aid in interpretation of, and verify, in vivo findings. 3D reconstructions from in vivo investigations provided quantitative morphometric and volumetric evaluation of ANIT exposed and untreated livers. The findings presented show for the first time in vivo evaluation of toxicity in the STII medaka hepatobiliary system, and, in conjunction with prior in vivo work characterizing normalcy, advance our comparative understanding of this lower vertebrate hepatobiliary system and its response to toxic insult. PMID:18022256

  19. Transgenerational effects from early developmental exposures to bisphenol A or 17α-ethinylestradiol in medaka, Oryzias latipes

    PubMed Central

    Bhandari, Ramji K.; vom Saal, Frederick S.; Tillitt, Donald E.

    2015-01-01

    The transgenerational consequences of environmental contaminant exposures of aquatic vertebrates have the potential for broad ecological impacts, yet are largely uninvestigated. Bisphenol A (BPA) and 17α-ethinylestradiol (EE2) are two ubiquitous estrogenic chemicals present in aquatic environments throughout the United States and many other countries. Aquatic organisms, including fish, are exposed to varying concentrations of these chemicals at various stages of their life history. Here, we tested the ability of embryonic exposure to BPA or EE2 to cause adverse health outcomes at later life stages and transgenerational abnormalities in medaka fish. Exposures of F0 medaka to either BPA (100 μg/L) or EE2 (0.05 μg/L) during the first 7 days of embryonic development, when germ cells are differentiating, did not cause any apparent phenotypic abnormalities in F0 or F1 generations, but led to a significant reduction in the fertilization rate in offspring two generations later (F2) as well as a reduction of embryo survival in offspring three generations later (F3). Our present observations suggest that BPA or EE2 exposure during development induces transgenerational phenotypes of reproductive impairment and compromised embryonic survival in fish of subsequent generations. These adverse outcomes may have negative impacts on populations of fish inhabiting contaminated aquatic environments. PMID:25790734

  20. Comparative Analysis of Genome and Epigenome in Closely Related Medaka Species Identifies Conserved Sequence Preferences for DNA Hypomethylated Domains.

    PubMed

    Uno, Ayako; Nakamura, Ryohei; Tsukahara, Tatsuya; Qu, Wei; Sugano, Sumio; Suzuki, Yutaka; Morishita, Shinichi; Takeda, Hiroyuki

    2016-08-01

    The genomes of vertebrates are globally methylated, but a small portion of genomic regions are known to be hypomethylated. Although hypomethylated domains (HMDs) have been implicated in transcriptional regulation in various ways, how a HMD is determined in a particular genomic region remains elusive. To search for DNA motifs essential for the formation of HMDs, we performed the genome-wide comparative analysis of genome and DNA methylation patterns of the two medaka inbred lines, Hd-rRII1 and HNI-II, which are derived from northern and southern subpopulations of Japan and exhibit high levels of genetic variations (SNP, ∼ 3%). We successfully mapped > 70% of HMDs in both genomes and found that the majority of those mapped HMDs are conserved between the two lines (common HMDs). Unexpectedly, the average genetic variations are similar in the common HMD and other genome regions. However, we identified short well-conserved motifs that are specifically enriched in HMDs, suggesting that they may play roles in the establishment of HMDs in the medaka genome.

  1. [Expression of elongation factor-1 alpha-A and beta-actin promoters in embryos of transgenic Medaka (Oryzias latipes)].

    PubMed

    Long, Hua

    2003-06-01

    Two expression vectors with the promoter of either Medaka (Oryzias latipes) elongation factor gene or beta-actin gene were constructed based on pBluescript SK+. Both of them are linked with green-fluorescent protein (GFP) gene. And they are named as pB-EF and pB-BA, respectively. The microinjection experiments were conducted with fertilized Medaka eggs at one-cell stage. The expression of two vectors, pB-EF and pB-BA, was observed under stereo-fluorescence microscope. The detection results showed that both EF-1 alpha-A promoter and beta-actin promoter are strong. In the process of embryo development, the activity of beta-actin promoter became stronger while that of EF-1 alpha-A promoter weaker gradually. beta-actin promoter was but EF-1 alpha-A promoter distributed throughout fish body uniformly. The expression rate of two vectors, pB-EF and pB-BA, are 8.23% and 6.10%, respectively.

  2. Pathogenicity of the pinewood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings.

    PubMed

    Mamiya, Y; Shoji, T

    2009-06-01

    Pathogenicity of the pine wood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings was tested with inoculation experiments under nursery conditions. Water suspensions of nematodes (mixed stages cultured on Botrytis cinerea or dispersal fourth-stage juveniles (DJ4) extracted from the adult Japanese pine sawyer, Monochamus alternatus) were injected into the stems of 2- and 3-year-old Japanese larch and Japanese black pine, Pinus thunbergii, seedlings growing in a nursery. In another treatment, Japanese pine sawyer adults holding DJ4 were released under a net that covered the upper half of the seedlings. Regardless of nematode inoculation method, Japanese larch seedlings were as susceptible as Japanese black pine seedlings to B. xylophilus under nursery conditions. The rate of disease development was similar on larch and pine seedlings. Nematode population densities were lower in the stems of dead larch seedlings than in the stems of dead pine seedlings. Histopathological observations revealed that the distribution of nematodes in the stems of dead larch seedlings was mostly limited to the cortex, phloem and cambial zone. Traumatic resin canal formation was one of the most characteristic symptoms in larch seedlings which was dissimilar to that in pine seedlings.

  3. Identification and expression profiling of microRNAs in the brain, liver and gonads of marine medaka (Oryzias melastigma) and in response to hypoxia.

    PubMed

    Lau, Karen; Lai, Keng Po; Bao, Jessie Yun Juan; Zhang, Na; Tse, Anna; Tong, Amy; Li, Jing Woei; Lok, Si; Kong, Richard Yuen Chong; Lui, Wing Yee; Wong, Alice; Wu, Rudolf Shiu Sun

    2014-01-01

    The marine medaka (Oryzias melastigma) has been increasingly used as a fish model for detecting environmental stresses and chemical contaminants in the marine environment. Recent mammalian studies have shown that environmental stresses can alter the expression profiles of microRNAs (miRNAs), leading to transgenerational effects. Here, we use high-throughput Illumina RNA sequencing (RNA-Seq) for miRNA transcriptome analysis of brain, liver, and gonads from sexually mature male and female marine medaka. A total of 128,883,806 filtered sequence reads were generated from six small RNA libraries, identifying a total of 2,125,663 non-redundant sequences. These sequences were aligned and annotated to known animal miRNAs (miRBase) using the BLAST method. A total of 223 distinct miRNA types were identified, with the greatest number expressed in brain tissue. Our data suggested that 55 miRNA types from 34 families are common to all tested tissues, while some of the miRNAs are tissue-enriched or sex-enriched. Quantitative real-time PCR analysis further demonstrated that let-7a, miR-122, and miR-9-3p were downregulated in hypoxic female medaka, while miR-2184 was specifically upregulated in the testis of hypoxic male fish. This is the first study to identify miRNAs in O. melastigma using small RNA deep sequencing technology. Because miRNA expression is highly conserved between marine medaka and other vertebrates, marine medaka may serve as a good model for studies on the functional roles of miRNAs in hypoxia stress response and signaling in marine fish.

  4. Influence of awareness of the Japanese Food Guide Spinning Top on eating behavior and obesity.

    PubMed

    Takaizumi, Kanae; Harada, Kazuhiro; Shibata, Ai; Nakamura, Yoshio

    2011-01-01

    The purpose of the present study was to investigate the influence of awareness of the Japanese Food Guide Spinning Top on eating behavior and obesity in Japan. Participants were 1,558 Japanese male and female adults (40.2±12.2 years) who had been registered with a social research company. The cross-sectional questionnaire survey was conducted via the Internet in November 2007. Potential respondents were invited to complete the survey via e-mail, which contained a link to the survey Uniform Resource Locator (URL). The measures were awareness of the Japanese Food Guide Spinning Top, eating knowledge scores, eating attitude scores, and eating behaviors scores, according to the recommendations of the Health Japan 21 and the Food Balance Guide Spinning Top. Obesity was assessed by self-reported body mass index (BMI) and waist circumference. The relationships between awareness of the Japanese Food Guide Spinning Top, eating knowledge scores, eating attitude scores, eating behavior scores, and obesity were analyzed using path analysis. Path analysis revealed that awareness of the Japanese Food Guide Spinning Top was associated with BMI and waist circumference via eating behavior scores. In addition, eating knowledge scores and eating attitude scores were mediators of the association between awareness of the Japanese Food Guide Spinning Top and eating behavior scores. These results suggest that promotion of the Japanese Food Guide Spinning Top would be a useful strategy to encourage healthy eating and prevent obesity in the Japanese population.

  5. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    SciTech Connect

    Webb, Carol F.; Ratliff, Michelle L.; Powell, Rebecca; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

    2015-08-07

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights: • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.

  6. Valproate-induced teratogenesis in Japanese rice fish (Oryzias latipes) embryogenesis.

    PubMed

    Wu, Mengmeng; Khan, Ikhlas A; Dasmahapatra, Asok K

    2012-04-01

    Fertilized eggs of Japanese rice fish (medaka) at three developmental stages (Iwamatsu stages 4-30) were exposed to waterborne valproic acid (VPA) (0-80 mM) in hatching solution for 48 h. The amount of valproate to cause 50% mortality (IC(50)) is found to be developmental stage-specific. The embryos were more sensitive to valproate at early stages of development (Iwamatsu stages 4-10) than in the embryos in late stages (Iwamatsu stages 17-30). Valproate exposed embryos have microcephaly and disrupted cardiovasculature with delayed vessel circulation, thrombus formation, and slow heart rate. The hatching efficiency is also reduced by valproate exposure due to developmental delay. The mRNA analysis of nine genes belong to oxidative stress (catalase, gsr, gst), neurogenesis (iro3, wnt1, shh, otx2, nlgn3b) and cell cycle regulation (ccna2) have been done. It was observed that the genes belong to oxidative stress remained unaltered after valproate exposure. However, some of the genes belong to neurogenesis (wnt1,shh, otx2 and nlgn3b) and cell cycle (ccna2) showed developmental stage-specific alteration after valproate exposure. This study indicates that valproate is able to induce some of the phenotypic features which are analogous to human fetal valproate syndrome (FVS). Modulation of genes expressed in neural tissues indicates that this fish can be used to analyze the mechanisms of many neurobehavioral disorders like Autism spectrum disorder (ASD) in human.

  7. Japanese viral encephalitis

    PubMed Central

    Tiroumourougane, S; Raghava, P; Srinivasan, S

    2002-01-01

    One of the leading causes of acute encephalopathy in children in the tropics is Japanese encephalitis (JE). Transmitted by the culex mosquito, this neurotropic virus predominately affects the thalamus, anterior horns of the spinal cord, cerebral cortex, and cerebellum. It mainly affects children <15 years and is mostly asymptomatic. The occasional symptomatic child typically presents with a neurological syndrome characterised by altered sensorium, seizures, and features of intracranial hypertension. Aetiological diagnosis is based on virus isolation or demonstration of virus specific antigen or antibodies in the cerebrospinal fluid/blood. Though no antiviral drug is available against JE, effective supportive management can improve the outcome. Control of JE involves efficient vector control and appropriate use of vaccines. PMID:11930023

  8. Japanese Experiment Module (JEM)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Japanese Experiment Module (JEM) pressure module is removed from its shipping crate and moved across the floor of the Space Station Processing Facility at Kennedy Space Center (KSC) to a work stand. A research laboratory, the pressurized module is the first element of the JEM, named 'Kibo' (Hope) to arrive at KSC. Japan's primary contribution to the International Space Station, the module will enhance unique research capabilities of the orbiting complex by providing an additional environment in which astronauts will conduct experiments. The JEM also includes an exposed facility or platform for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

  9. Anthropophobia and Japanese performance.

    PubMed

    Takano, R

    1977-08-01

    Actors are not the only people who act on a regular basis--everyone does some "acting" in his everyday life. The merchant is acting when he pays compliments to his annoying customers. Neurotics often exaggerate their sufferings and assume poses in order to impress their therapists with the seriousness of their illness. When this acting is done so poorly that everyone but the person himself perceives its penny-dreadful nature, the neurosis might be designated a hysteria. Such dramatics can be observed not only in the demeanor of neurotics, but also in their symptoms. The unconscious and concealed acting revealed in the symptoms of neurotics, especially in those of anthropophobiacs, whose main concern is with their appearance in the eyes of others, is what I would like to examine in this paper. I will attempt to eludicate the psychopathology of a large element in Japanese neurosis--that is, of anthropophobia--in relation to unconscious acting.

  10. Japanese Management: An American Challenge.

    ERIC Educational Resources Information Center

    Rehder, Robert R.

    1979-01-01

    In contrast to the American system of management, Japanese management motivates its employees by challenging them with high goals an