Effect of Methotrexate on Neuroepithelium in the Rat Fetal Brain     

Jing SUN  Akihiko SUGIYAMA  Shota INOUE  Takashi TAKEUCHI  Satoshi FURUKAWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(3):347-354

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A Comparison of the Histological Structure of the Placenta in Experimental Animals     

Satoshi Furukawa  Yusuke Kuroda  Akihiko Sugiyama 《Journal of toxicologic pathology》2014,27(1):11-18

The primary function of the placenta is to act as an interface between the dam and fetus. The anatomic structure of the chorioallantoic placenta in eutherian mammals varies between different animal species. The placental types in eutherian mammals are classified from various standpoints based on the gross shape, the histological structure of the materno-fetal interface, the type of materno-fetal interdigitation, etc. Particularly, the histological structure is generally considered one of the most useful and instructive classifications for functionally describing placental type. In this system, three main types are recognized according to the cell layers comprising the interhemal area: (1) epitheliochorial type (horses, pigs and ruminants), (2) endotheliochorial type (carnivores) and (3) hemochorial type (primates, rodents and rabbits). The number of cell layers in the interhemal area is considered to modify the transfer of nutrients between maternal and fetal blood and is one of the important factors with respect to the difference in placental permeability between animal species. Therefore, in reproductive and developmental toxicity studies, careful attention should be paid to the histological structure of the interhemal area when extrapolating information concerning placental transfer characteristics to different animal species.  相似文献   

Estrogenic activity in coastal areas around Japan evaluated by measuring male serum vitellogenins in Japanese common goby Acanthogobius flavimanus   总被引：1，自引：0，他引：1  

Nobuyuki  OHKUBO  Kazuhiko  MOCHIDA  Shinji  ADACHI  Akihiko  HARA  Komei  HOTTA  Yukio  NAKAMURA  Takahiro  MATSUBARA 《Fisheries Science》2003,69(6):1135-1145

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Regulation of gonadotropin subunit genes expression by 11-ketotestosterone during early spermatogenesis in male red seabream, Pagrus major     

S. Yamaguchi  K. Gen  K. Okuzawa  N. Kumakura  H. Kagawa  M. Matsuyama 《Fish physiology and biochemistry》2003,28(1-4):111-112

To examine the roles of gonadal steroids in the regulation of expression of gonadotropin subunit genes, male red seabream were gonadectomized and a sub-group was treated with 11-ketotestosterone (11-KT). Castration of males during the early stage of spermatogenesis elicited a significant increase in FSHβ mRNA levels, which was prevented by 11-KT replacement. By contrast, LHβ mRNA levels were not changed by castration or 11-KT replacement. In addition, administration of 11-KT to sham-operated males suppressed the steady-state FSHβ and LHβ mRNA levels. These results indicate that 11-KT may function as a negative feedback regulator of FSHβ gene expression, and may act through the testis to down-regulate LHβ mRNA levels in male red seabream during this period.  相似文献   

Quality aspect of fish sauce prepared from underutilized fatty Japanese anchovy and rabbit fish     

Kazufumi?OsakoEmail author  Mohammed?Anwar?Hossain  Koichi?Kuwahara  Akira?Okamoto  Atsuko?Yamaguchi  Yukinori?Nozaki 《Fisheries Science》2005,71(6):1347-1355

ABSTRACT:   To explore the potential utility of underutilized fish in the fish sauce industry, fish sauces were prepared from both raw and heat-induced meat of Japanese anchovy Engraulis japonica and rabbit fish Siganus fuscescens using wheat malt, and their quality aspects and sensory properties were assessed. Proximate composition of the fish meat represents protein as the major component (16.0–17.8%), other than moisture. Analyses of free amino acids, peptides including oligopeptides, and organic acids contents in fish sauces revealed suitability of both raw and heat-induced meat of the selected species in commercial fish sauce production. The variations in taste of raw meat fish sauces were species-specific, but the taste of fish sauces from heat-induced meat were similar.  相似文献   

Antiproliferative effect of neoxanthin and fucoxanthin on cultured cells   总被引：1，自引：0，他引：1  

Eiichi?Kotake-Nara  Tatsuya?Sugawara  Akihiko?NagaoEmail author 《Fisheries Science》2005,71(2):459-461

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Reproductive parameters of the chub mackerel <Emphasis Type="Italic">Scomber japonicus</Emphasis> estimated from human chorionic gonadotropin-induced final oocyte maturation and ovulation in captivity     

Tetsuro?Shiraishi  Kohei?Ohta  Akihiko?Yamaguchi  Mari?Yoda  Hisashi?Chuda  Michiya?MatsuyamaEmail author 《Fisheries Science》2005,71(3):531-542

ABSTRACT:   Final oocyte maturation and ovulation of captive chub mackerel Scomber japonicus with fully yolk-accumulated oocytes were induced by a single injection of human chorionic gonadotropin. Reproductive parameters, including spawning frequency and batch fecundity, which are required to estimate spawning biomass in pelagic fish by the daily egg production method, were analyzed. Germinal vesicle migration (GVM) occurred at 18–24 h post-injection, and the hydration and ovulation of oocytes were completed at 30 and 36 h post-injection, respectively. The results of the maturation process suggest that fish with GVM-stage ovaries captured in the daytime from the field are capable of spawning on the night following their capture. The oocytes used in the oocyte size-frequency distribution method for batch fecundity estimates should be at late GVM and more advanced stages. The results of sequential artificial insemination showed that the quality of ovulated eggs held in the ovarian lumen rapidly deteriorated as time progressed after ovulation. This indicates that the fertilization window for the ovulated eggs of chub mackerel lasts only a few hours, and spawning behavior should be performed within a few hours after ovulation in the wild population.  相似文献   

Mottled coloration of haploid-diploid and diploid-triploid mosaic amago salmon Oncorhynchus masou ishikawae     

Masaru Yamaki  Satoshi Yamaguchi  Katsutoshi Arai 《Fisheries Science》2006,72(1):157-165

ABSTRACT:   Mottled amago salmon Oncorhynchus masou ishikawe with both yellow- and dark-pigmented skin occurred together with typical albino individuals in a commercial farm. Out of 12 mottled fish examined by DNA content flow-cytometry and erythrocytic nucleus size, three were diploid, eight were haploid-diploid mosaic and one was diploid-triploid mosaic. This fact indicates that the mottled coloration might link to polyploid mosaicism. Genotype of diploid and non-diploid cells at the albino locus was estimated in nine mature mottled fish by observing the frequency of wild-type and albino progeny when mating to homozygous albino ( aa ). One diploid and three haploid-diploid mosaic mottled fish were presumed to have mosaic genotype with both hemizygous ' a ' and heterozygous ' Aa ' cells ( a/Aa ), because the segregation ratio between two phenotypes was 1 : 1. Three other haploid-diploid mosaic fish were presumed to have mosaic genotype with both hemizygous ' a ' and homozygous ' AA ' cells ( a/AA ), because of exclusive occurrence of wild-type phenotype in the progeny. The diploid-triploid mosaic mottled fish was presumed to have mosaic genotypes ' aa / AAA ', ' aa/AAa ' or ' aa / Aaa ', because this fish yielded only albino progeny. One diploid mottled fish produced both two phenotypes but albino embryos appeared with much more frequency than the expectation, when assuming the genotype ' Aa '. Thus, this fish was considered to have mosaic genotype ' Aa/aa '.  相似文献   

Characterization of cystathionine λ-lyase in the liver of rainbow trout <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>     

Takanobu?GotoEmail author  Yuko?Osada  Hiroyuki?Funatsu  Hiroki?Sugiyama  Shusaku?Takagi  Akihiko?Mochizuki 《Fisheries Science》2005,71(1):245-247

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Reproductive biology of the cardinalfish Apogon lineatus in Tokyo Bay, Japan     

Gen Kume  Atsuko Yamaguchi  Ichiro Aoki and  Toru Taniuchi 《Fisheries Science》2000,66(5):947-954

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