Several possible spawning sites of the Japanese eel determined from collections of their eggs and preleptocephali     

Takeuchi  Aya  Higuchi  Takatoshi  Watanabe  Shun  Miller  Michael J.  Yama  Ritsuno  Fukuba  Tatsuhiro  Okamura  Akihiro  Okino  Tatsufumi  Miwa  Tetsuya  Tsukamoto  Katsumi 《Fisheries Science》2021,87(3):339-352

The spawning area of the Japanese eel is located at the southern part of the West Mariana Ridge in the western North Pacific, but their spawning events have not been observed. To further understand Japanese eel spawning ecology, an interdisciplinary research survey by the R/V NATSUSHIMA (NT14-09, 14 May–4 June 2014) was conducted to detect spawning sites based on the seamount, salinity front, new moon and third quadrant (spawning south of front, west of ridge) hypotheses. Attempts were made to film spawning events with underwater camera systems and to consider if eels might be detected in hydroacoustic observations. Although no Japanese eels or spawning events were video-recorded and no eel aggregations could be clearly identified acoustically, three eggs were collected at two stations in the third quadrant region at or just south of 13° N on 26 and 27 May. Three or four days later, newly hatched preleptocephali were collected at two stations far to the south, including 224 at a station > 160 km southwest of the egg catches, and a few preleptocephali were caught at two stations closer to the egg stations. The eggs and southern preleptocephali were from discrete spawning events, which indicated that at least two spawning sites occurred in May 2014.

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The beneficial effects of horse trekking on autonomic nervous activity in experienced rider with no disability          下载免费PDF全文

Akihiro Matsuura  Haruhiro Maruta  Tomohiko Iwatake  Takashi Kumagai  Toshihiko Nakanowatari  Koichi Hodate 《Animal Science Journal》2017,88(1):173-179

The aim of this study was to determine whether autonomic nervous activity of a rider with no disability was altered by one practical and applicable horse trekking (HT) exercise. Changes in autonomic nervous activity were analyzed by heart rate variability (HRV). Twenty‐three participants with no disability rode horses along a predetermined HT course at trotting and walking for 60 min. HRV was sampled at 60 min before and immediately, following 60 min, and 120 min after HT. As a control, the same measurements were performed for 22 age‐matched participants during their rest. Only in the HT group, the value of normalized unit in high frequency component (HF nu), an index of parasympathetic nervous activity, was higher at 120 min after treatment than before HT (P < 0.05). The low / high frequency ratio (LF / HF), believed to reflect sympathetic nervous activity, was lower in the HT group than those in the control group at 60 min (P < 0.05) and 120 min after treatment (P < 0.01). These findings suggest that a single HT shifted the autonomic nervous balance of a rider toward parasympathetic dominance. The results obtained by the present study could accelerate the use of horses for human health.  相似文献   

Oligoarray analysis of gene expression in ripening Japanese pear fruit     

Chikako Nishitani  Tokurou Shimizu  Hiroshi Fujii  Fumiko Hosaka  Shingo Terakami  Yuri Nakamura  Akihiro Itai  Ayako Yamaguchi-Nakamura  Toshiya Yamamoto 《Scientia Horticulturae》2010

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Concordance between Results of Medium-term Liver Carcinogenesis Bioassays and Long-term Findings for Carcinogenic 2-Nitropropane and Non-carcinogenic1-Nitropropane in F344 Rats     

Doi Y  Tamano S  Kawabe M  Sano M  Imai N  Nakashima H  Furukawa F  Hagiwara A  Otsuka M  Shirai T 《Journal of toxicologic pathology》2011,24(4):207-213

This study was conducted to determine the concordance of results for a pair of structural isomers, 2-nitropropane (2-NP) and 1-nitropropane (1-NP), using the rat medium-term liver carcinogenesis bioassay (Ito test) and previously published long-term carcinogenicity tests. Male F344 rats were given a single intraperitoneal injection of DEN (200 mg/kg b.w.) to initiate hepatocarcinogenesis. After 2 weeks, they received per os 0, 0.8, 4 or 20 mg/kg/day of 2-NP or 1-NP six times a week and were subjected to two-thirds partial hepatectomy at week 3. Non-initiated groups receiving 0 or 20 mg/kg/day were also included. The animals were sacrificed for quantitative analysis of GST-P-positive foci at week 8. With the highest dose of 2-NP, significantly increased numbers and areas of GST-P-positive foci were demonstrated as compared with the respective control but were not noted with 1-NP. In the non-DEN-initiated groups, many small GST-P-positive foci of less than 0.2 mm in diameter were also induced in the rats treated with 2-NP at 20 mg/kg/day but were lacking with 1-NP. These results strongly support that 2-NP is a complete hepatocarcinogen with a potent initiation activity, whereas 1-NP is not.  相似文献   

Letter to the editor     

Lee P  Mori A 《Veterinary research communications》2011,35(3):131-132

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Establishment and characterization of a canine sebaceous epithelial cell line derived from an eyelid mass     

Akira MATSUDA  Ikki MITSUI  Yuki SHIMIZU  Teppei KANDA  Akihiro OHNISHI  Masahiro MIYABE  Yoshiki ITOH 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2020,82(11):1577

Little is known about the pathological roles of sebaceous glands in canine skin diseases, as most examinations have been conducted with cultured human sebaceous epithelial cell lines. To our knowledge, there is no available canine sebaceous epithelial cell line. The purpose of this study was to establish a canine sebaceous epithelial cell line and characterize it. An eyelid mass in a dog was surgically resected for treatment, and it was histologically diagnosed as sebaceous epithelioma. Collected tissue was conducted for culture, and the growing epithelial-like cells were passaged. The cells showed continuous proliferation for over 6 months. After 40 passages, the cells were named CMG-1. Lipid droplets in the cytoplasm of CMG-1 cells were confirmed by Oil Red O staining. As reported in studies with human sebaceous epithelial cell lines, lipogenesis in CMG-1 cells was promoted by linoleic acid, whereas transforming growth factor-β (TGF-β) suppressed it. Additionally, real-time PCR revealed that the expression levels of chemokines and cytokines, including CC chemokine ligand (CCL)-2, CCL-20, CXCL-10, Tumor necrosis factor-α (TNF-α), Interleukin (IL)-1α, IL-1β, and IL-8, were significantly increased in CMG-1 cells following treatment with lipopolysaccharide. In conclusion, we successfully established a new canine sebaceous epithelial cell line. Our data indicated that lipogenesis and inflammatory responses were quantitatively evaluable in this cell line. CMG-1 cells could be useful for the pathological analysis of sebaceous gland diseases in dogs.  相似文献   

Invertase Activities in Sheath-blight Infected Rice Selection Lines and Fungus Culture Filtrates   总被引：2，自引：0，他引：2  

Jedidah DANSON  Kikuo WASANO  Akihiro NOSE 《Journal of General Plant Pathology》2000,66(3):202-205

Infection of rice plants with Rhizoctonia solani, the sheath blight fungus, at the flowering stage resulted in an increase in acid invertase activity. Activity of the invertase(s) with optimum pH at 3.5 and 4.5 was higher in the susceptible plants compared to resistant plants. Healthy control plants had no change in invertase activity. An invertase of fungal origin produced in sheath blight fungus culture filtrates had an optimum acidic pH of 3.5. The increase in invertase activity observed in the later stages of infection in the susceptible plants compared to the resistant plants demonstrated a relation to fungal growth. These results suggested that the fungus produced an invertase for the hydrolysis of sucrose that resulted in alterations of source-sink relationships in the colonized cells. Thus, the increased invertase activity in the susceptible plants regulated the ratio of hexose to sucrose. This observation is further supported by the lack of a significant invertase increase in the resistant plants. Received 14 July 1999/ Accepted in revised form 9 December 1999  相似文献   

断奶后多系统衰竭综合征病猪中存在沙门氏菌和猪繁殖与呼吸系统综合征病毒共感染     

Akihiro O GAWA  Noriko ITO  Takashi NAKANE  魏晓锋  李春华 《国外畜牧学(猪与禽)》2007,27(1):46-48

调查了曾经暴发沙门氏菌病的四个猪场的14头病猪,发现在这些猪的肿胀淋巴结中出现带有淋巴细胞排空的肉芽肿性炎症。应用免疫标记和PCR方法在病变部位检测到猪圆环病毒2(PCV2)抗原和PCV2DNA。此外,在这些病猪的肺脏中检测出猪繁殖与呼吸综合征病毒(PRRSV),分离到猪霍乱沙门氏菌。在9头沙门氏菌感染猪中,有5头为沙门氏菌、PMWS与PRRSV并发感染,其数量(55.6%)远远高于沙门氏菌与PMWS感染猪(22.2%)或沙门氏菌与PRRSV感染猪(22.2%)。  相似文献   

Effects of silvering state on induced maturation and spawning in wild female Japanese eel <Emphasis Type="Italic">Anguilla japonica</Emphasis>     

Akihiro Okamura  Yoshiaki Yamada  Noriyuki Horie  Tomoko Utoh  Naomi Mikawa  Satoru Tanaka  Katsumi Tsukamoto 《Fisheries Science》2008,74(3):642-648

ABSTRACT:   The effects of silvering state of wild female Japanese eels Anguilla japonica on the success of induced maturation and the following spawning were examined. Thirty-eight females, collected in Mikawa Bay, were divided into four stages based on their silvering state: yellow (Y1), late-yellow (Y2), silver (S1) and late silver eels (S2). Despite injections of salmon pituitary extract (SPE) through the standard technique, Y1 and Y2 eels did not respond to the treatment with undeveloped gonad (gonad-somatic index [GSI]: 0.3–0.9), and all these females died by 5 weeks, probably due to an abnormal physiological condition. Most S1 (81%) and S2 eels (100%) matured completely (GSI: 17.8–51.4), and finally spawned successfully (69% for S1, 89% for S2). S2 eels fully matured with oocytes of over 750 μm in diameter by significantly smaller number of injections of SPE (5–6 times) than the case of S1 eels (6–8 times). The amount of eggs released by S2 eels (0.65 ± 0.11 g/fish per body weight [BW]) was significantly larger than those by S1 eels (0.54 ± 0.09 g/fish per BW). There was no difference in fertilization and hatching rates between eggs released by S1 eels and those of S2 eels. These results indicate that the success of induced maturation and spawning in wild female Japanese eels depends on their silvering state, and matured eggs can be obtained efficiently through the use of S2 eels rather than other stages.  相似文献   

Cytological studies on artificially induced gynogenesis in the Pacific abalone   总被引：17，自引：0，他引：17  

Qi Li  Makoto Osada  Masaru Kashihara  Ken Hirohashi and  Akihiro Kijima 《Fisheries Science》2000,66(4):701-707

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