Relationship between prey utilization and growth variation in hatchery‐reared Pacific bluefin tuna,Thunnus orientalis (Temminck et Schlegel), larvae estimated using nitrogen stable isotope analysis     

Yosuke Tanaka  Hiroshi Minami  Yuka Ishihi  Kazunori Kumon  Kentaro Higuchi  Takeshi Eba  Akefumi Nishi  Hideki Nikaido  Satoshi Shiozawa 《Aquaculture Research》2014,45(3):537-545

In mass culture of Pacific bluefin tuna Thunnus orientalis, a marked growth variation is observed after they start feeding at 6–7 mm in body length (BL) on yolk‐sac larvae of other species, and the growth variation in tuna larvae is a factor leading to the prevalence of cannibalism. To examine the relationship between prey utilization and growth variation, nitrogen stable isotope ratios (δ¹⁵N) of individual larvae were analysed. A prey switch experiment was conducted under two different feeding regimes: a group fed rotifers (rotifer fed group), and a group fed yolk‐sac larvae of spangled emperor, Lethrinus nebulosus (fish fed group) from 15 days after hatching (6.87 mm BL). The fish fed group showed significantly higher growth than the rotifer fed group. Changes in the δ¹⁵N of the fish fed group were expressed as an exponential model and showed different patterns from those of the rotifer fed group. The δ¹⁵N of fast‐growing tuna larvae collected in an actual mass culture tank after the feeding of yolk‐sac larvae was significantly higher than those of the slow‐growing larvae, indicating that slow glowing larvae depended largely on rotifers rather than the yolk‐sac larvae.  相似文献   

Suppression of feline coronavirus replication in vitro by cyclosporin A     

Tanaka Y  Sato Y  Osawa S  Inoue M  Tanaka S  Sasaki T 《Veterinary research》2012,43(1):41

ABSTRACT: The feline infectious peritonitis virus (FIPV) is a member of the feline coronavirus family that causes FIP, which is incurable and fatal in cats. Cyclosporin A (CsA), an immunosuppressive agent that targets the nuclear factor pathway of activated T-cells (NF-AT) to bind cellular cyclophilins (CyP), dose-dependently inhibited FIPV replication in vitro. FK506 (an immunosuppressor of the pathway that binds cellular FK506-binding protein (FKBP) but not CyP) did not affect FIPV replication. Neither cell growth nor viability changed in the presence of either CsA or FK506, and these factors did not affect the NF-AT pathway in fcwf-4 cells. Therefore, CsA does not seem to exert inhibitory effects via the NF-AT pathway. In conclusion, CsA inhibited FIPV replication in vitro and further studies are needed to verify the practical value of CsA as an anti-FIPV treatment in vivo.  相似文献   

Prevalence of avian haematozoa in wild birds in a high-altitude forest in Japan     

Imura T  Suzuki Y  Ejiri H  Sato Y  Ishida K  Sumiyama D  Murata K  Yukawa M 《Veterinary parasitology》2012,183(3-4):244-248

The infection dynamics of avian haematozoa, which includes the genera Plasmodium, Haemoproteus, and Leucocytozoon, are complicated by a variety of environmental factors and host-parasite interactions. In Japan, the prevalence of haematozoa in wild birds has recently been determined in several local areas. However, no information on the annual prevalence of avian haematozoa in a single study site has been reported. Here, we investigated the long-term infection dynamics of haematozoa in wild birds inhabiting a mountain forest of Japan. Blood samples were collected from 415 wild birds captured in the Chichibu mountains in Saitama Prefecture at an altitude of 1650 m between 2007 and 2010. All obtained samples were examined for haematozoan infection using nested polymerase chain reaction (PCR) of the cytochrome b (cytb) genes of haematozoa. A total of 62 out of 415 (14.9%) forest birds were PCR positive for haematozoa. Relatively high infection rates of Leucocytozoon were found among several bird species (Parus ater, 64.3%; Parus montanus, 81.8%) and may be due to the host preference of vector black flies and host nestling pattern in this forest. Phylogenetic analysis of amplified cytb sequences revealed for the first time that a variety of lineages of avian haematozoa are distributed among wild bird hosts in a high-altitude forest stand in Japan. Notably, significant seasonal changes of the prevalence of avian haematozoa were not observed; however, continuous investigation will likely provide detailed information on host-parasite interactions, including local environmental factors, that influence the dynamics of avian haematozoan infections.  相似文献   

Bromocriptine inhibits salsolinol‐induced prolactin release in male goats     

Tsutomu HASHIZUME  Tatsuru SAWADA  Yuka NAKAJIMA  Tomoyoshi YAEGASHI  Hayato SAITO  Yuki GOTO  Jin JIN  Ferenc FÜLÖP  György Miklos NAGY 《Animal Science Journal》2012,83(1):63-67

The secretion of prolactin (PRL) is under the dominant and tonic inhibitory control of dopamine (DA); however, we have recently found that salsolinol (SAL), an endogenous DA‐derived compound, strongly stimulated the release of PRL in ruminants. The aim of the present study was to clarify the inhibitory effect of DA on the SAL‐induced release of PRL in ruminants. The experiments were performed from late June to early July. Male goats were given a single intravenous (i.v.) injection of SAL (5 mg/kg body weight (BW)), a DA receptor antagonist (sulpiride, 0.1 mg/kg BW), or thyrotropin‐releasing hormone (TRH, 1 µg/kg BW) before and after treatment with a DA receptor agonist (bromocriptine), and the effect of DA on SAL‐induced PRL release was compared to that on sulpiride‐ or TRH‐induced release. Bromocriptine completely inhibited the SAL‐induced release of PRL (P < 0.05), and the area under the response curve (AUC) for a 120‐min period after the treatment with bromocriptine was 1/28 of that for before the treatment (P < 0.05). Bromocriptine also completely inhibited the sulpiride‐induced release (P < 0.05). The AUC post‐treatment was 1/17 that of pre‐treatment with bromocriptine (P < 0.05). Bromocriptine also inhibited the TRH‐induced release (P < 0.05), though not completely. The AUC post‐treatment was 1/3.8 that of pre‐treatment (P < 0.05). These results indicate that DA inhibits the SAL‐induced release of PRL in male goats, and suggest that SAL and DA are involved in regulating the secretion of PRL. They also suggest that in terms of the regulatory process for the secretion of PRL, SAL resembles sulpiride but differs from TRH.  相似文献   

The effect of a herbal paste and oil extract on the lipid content of canine hair fibres          下载免费PDF全文

Yutaka Momota  Kenichiro Shimada  Chihiro Kadoya  Azusa Gin  Jun Kobayashi  Yuka Nakamura  Takako Matsubara  Toshinori Sako 《Veterinary dermatology》2017,28(4):337-e73

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Hypoxanthine enhances the cured meat taste          下载免费PDF全文

Sayaka Ichimura  Yukinobu Nakamura  Yuka Yoshida  Akihito Hattori 《Animal Science Journal》2017,88(2):379-385

We evaluated the enhancement of cured meat taste during maturation by sensory analysis. We focused on the heat‐stable sarcoplasmic fraction (HSSF) to identify the factors related to cured meat taste. Because the dry matter of HSSF contained more than 30% nitrogen, nitrogen compounds such as free amino acids, small peptides and adenosine triphosphate‐related compounds seemed to be the important components of HSSF. The samples cured with HSSF for 2 h exhibited the same taste profile as ones cured without HSSF for 168 h. Therefore, the changes in the amount and fractions of nitrogen compounds were examined in HSSF during incubation from 0 to 168 h. The concentration of hypoxanthine (Hx) gradually increased, while inosine‐5′‐monophosphate decreased during the incubation. The samples cured with pickles containing various concentrations of Hx were subjected to sensory analysis. The addition of Hx, in a dose‐dependent fashion, enhanced cured meat taste by maturation for 2 h. It was concluded that Hx is essential for the enhancement of cured meat taste.  相似文献   

Electrotonic junctions between teleost spinal neurons: electrophysiology and ultrastructure     

BENNETT MV  ALJURE E  NAKAJIMA Y  PAPPAS GD 《Science (New York, N.Y.)》1963,141(3577):262-264

Electrotonic transmission between spinal neurons is correlated with distinctive apposition of cell processes involving membrane fusion. In the same neurons, postsynaptic potentials appear to arise at typical synaptic knobs where there is an intercellular space.  相似文献   

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for mtDNA typing in hokkaido brown bear (Ursus arctos yesoensis)     

Satoh Y  Mano T  Tsuruga H  Masuda R  Matsuhashi T  Onuma M  Suzuki M  Ohtaishi N 《The Japanese journal of veterinary research》2003,50(4):195-199

To develop an easy method of typing of mitochondrial DNA (mtDNA) in Hokkaido brown bears (Ursus arctos yesoensis), the PCR-RFLP technique was improved using four restriction enzymes: Mbo 1, Cfr 13 I, TspE 1, and Fok 1. This approach identified seven groups of mtDNA haplotypes, HB1/2/5-7, HB 3, HB4, HB8/9, HB10/11, HB12 and HB13 from 102 brown bears of northern, central and eastern Hokkaido.  相似文献   

Characterization of a monoclonal antibody against desmoplakin 1 for use in dogs     

Nakamura Y  Nakashima K  Kano R  Watanabe S  Hasegawa A 《Veterinary dermatology》2002,13(3):165-167

Abstract Skin biopsy specimens from face, axilla, abdomen and thigh, mucocutaneous tissues from anus and vagina, and oral mucosa from six healthy Beagle dogs were examined for desmoplakin (Dsp) immunoreactivity using immunoblotting and immunohistochemical analysis. With immunoblotting using mouse antihuman Dsp 1 monoclonal antibody (DP2.17), a band was detected at 250 kDa in all the extracts as in normal human skin samples, although no band was detected at 210 kDa, suggesting that monoclonal antibody DP2.17 recognizes canine Dsp 1 but not Dsp 2. Moreover, the desmosome regions of all specimens were stained with DP2.17 using immunohistochemical analysis. From these results, DP2.17, developed for the examination of human skin, might be suitable for the investigation of Dsp-related skin disorders in dogs.  相似文献   

Computed tomography and magnetic resonance imaging of thoracic chordoma in a Bengal tiger (Panthera tigris tigris)     

Toshie ISERI  Junichiro SHIMIZU  Hideo AKIYOSHI  Kayo KUSUDA  Akiyoshi HAYASHI  Keiichiro MIE  Takeshi IZAWA  Mitsuru KUWAMURA  Jyoji YAMATE  Yuka FUJIMOTO  Fumihito OHASHI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):857-860

A Bengal tiger was presented for evaluation of weakness, ataxia and inappetance. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass extending from the T7-8 vertebral body to the left rib and compressing the spinal cord. On CT, the bone destruction and sequestrum were shown. On MRI, the multilobulated mass appeared hypo- to isointense in T1-weighted and hyperintense in T2-weighted images. The tiger died after imaging, most likely from renal failure. Chordoma without metastasis was diagnosed on necropsy. The imaging characteristics were similar to those found in chordoma in humans. This report describes the use of CT and MRI in an exotic species.  相似文献