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101.
102.
Hiroki Yasuma Ryo Nakagawa Takashi Yamakawa Kazushi Miyashita Ichiro Aoki 《Fisheries Science》2009,75(3):545-552
Sound-speed and density contrasts (h and g, respectively), important acoustic material properties, of Japanese sandeel Ammodytes personatus were measured to estimate theoretical target strength (TS). The measured sound-speed contrast of adult fish varied between
1.016 and 1.023 (mean 1.020), and showed temperature dependence. The measured density contrast differed significantly between
juvenile and adult. The density contrast of juvenile varied between 1.017 and 1.024 (1.021), and that of adult varied between
1.026 and 1.038 (1.032). Using these results, TS at 38 and 120 kHz in the fishing season were estimated by an empirical sound
scattering model. TS of an individual fish varied significantly with change of tilt angle. TS of near-dorsal aspect (TSmax) and tilt-averaged TS (TSave) differed by up to 7 dB. At both frequencies, two different TSave−length relationships (TSave = a log L + b) were obtained for adult and juvenile. The coefficients of log L of adult were close to 20, suggesting that backscattering strength was proportional to square of body length. These values
were larger in juvenile (34.0 at 120 kHz, 56.5 at 38 kHz), suggesting that backscattering strength varied drastically with
the cube or fifth power of body length. 相似文献
103.
Takanori NISHIMURA Eiko FUTAMI Jun-ichi WAKAMATSU Akihito HATTORI 《Animal Science Journal》2003,74(5):407-416
In order to provide background for understanding biological roles of proteoglycans (PG) in developing skeletal muscle, we have isolated and characterized PG in bovine neonatal skeletal muscle. Two types of PG were isolated from skeletal muscle by density gradient ultracentrifugation and ion‐exchange chromatography. One was a small PG (PG‐S) with a molecular size of 100–130 kDa, another was a large PG (PG‐L) with a molecular size of 300–500 kDa. The glycosaminoglycan chains of PG‐S and PG‐L were dermatan sulfate and chondroitin sulfate, respectively, judged by cellulose acetate membrane electrophoresis. Immunoblot assays revealed that both PG bound to type I, II, III and IV collagen, laminin and fibronectin. Unlike PG‐S, PG‐L bound to type V collagen and hyaluronic acid. Small proteoglycans had a core protein of 45 kDa, which reacted with the antibody against the decorin core protein. The N‐terminal amino acid sequence of the PG‐S core protein was consistent with that of decorin from bovine bone and tendon. Thus, PG‐S from neonatal skeletal muscle was identified as decorin in bovines. Immunohistochemical analysis with antibodies against PG‐L and PG‐S demonstrated that PG‐L was located both in the perimysium and endomysium, but PG‐S was localized exclusively in the perimysium. These findings suggest that the characterized PG may have distinct roles in the ECM construction of developing skeletal muscle. 相似文献
104.
Hisao IWAMOTO Takafumi GOTOH Shoji TABATA Shotaro NISHIMURA Satoru OKAMOTO 《Animal Science Journal》2003,74(2):111-118
The histochemical profiles of myofibers in Musculus pectoralis (PT) and M. supracoracoideus (SC) fasciculi were compared among Japanese quail strains with large, normal and small body sizes. In male and female adults, both the PT and SC muscles had attained a 2.5–2.7-fold weight gain in the large strain and conversely a 0.43–0.50-fold change in the small strain relative to those of the normal size. The muscles were composed of fasciculi with a central cluster of type IIA fibers surrounded by a peripheral layer of type IIB fibers. In the large strain, the cross sectional area (CSA) of the fasciculus and CSA of the fibers in each type were significantly enlarged compared with those in the normal size, with the exception of the fasciculus in the deep region of the male PT muscle. The hypertrophied type IIA fibers in the large strain showed considerable variation in nicotinamide adenine dinucleotide dehydrogenase activity, some of which might represent a transitional form into type IIB fibers. In the small strain, the fasciculus CSA did not significantly differ from that of the normal size except for the PT surface region of the male. However, fiber atrophy was observed in type IIB fibers of the PT surface region in both sexes, and type IIA fibers of the PT deep region and SC muscle in the small strain male quails. The relative fiber type composition of a fasciculus in each region showed only a slight change across the strains. These results indicate that breast muscle hypertrophy in the large strain could be based mainly on fasciculus and fiber hypertrophy, but muscle atrophy in the small strain is not induced by fasciculus and fiber atrophy. 相似文献
105.
Satoshi Kitao Takatsugu Yamada Takefumi Ishikawa Hiroo Madarame Mitsuru Furuichi Sakurako Neo Ryo Tsuchiya Kosaku Kobayashi 《Journal of veterinary diagnostic investigation》2006,18(3):291-295
Serum alpha-fetoprotein (AFP) concentrations were measured before and after surgical removal of tumor masses in four dogs with hepatocellular carcinoma (HCC). Localization of AFP was also examined immunohistochemically in tumor tissues. In three cases, the serum AFP concentration was 10 to 20 times higher than that of normal dogs. One to two months after surgery, the serum AFP concentration had decreased to normal range. AFP was localized in the tumor tissues in these three cases. One case, which had a low serum AFP, did not show AFP localization in tumor tissue. 相似文献
106.
TOSHIE ISERI KAZUTAKA YAMADA KOUSAKU CHIJIWA RYOHEI NISHIMURA SATORU MATSUNAGA REINA FUJIWARA NOBUO SASAKI 《Veterinary radiology & ultrasound》2007,48(4):328-331
To establish optimal imaging conditions for enhanced computed tomography (CT) for canine pancreatic tumors, 10 healthy beagles were subjected to dynamic CT. This technique was then applied to a dog with suspected insulinoma. The changes in mean peak enhancement and the delay time of the aorta and pancreas were determined. In normal beagles, maximal arterial and pancreatic CT enhancement was observed at 15 +/- 2 s (795 +/- 52 Housfield unit [HU]) and 28 +/- 9 s (118 +/- 16HU) after contrast medium injection, respectively. Multiphase enhanced CT was performed in a pug with suspected insulinoma using the CT protocol defined for the normal beagles with some parameters modified; the images were acquired at the arterial (14 s after contrast medium injection), pancreatic (after 28 s), and equilibrium (after 90 s) phases; scanning was followed by exploratory laparotomy. CT images were characterized by an enhanced mass in the left pancreatic lobe at the arterial phase, during which the difference between the CT values of the mass and normal pancreas was the highest. Histopathologic diagnosis of the pancreatic mass was insulinoma. Thus, it appears that enhanced CT imaging can be used to delineate the pancreas from a pancreatic mass, and it may be helpful in deciding the need for surgery. 相似文献
107.
Ichiro OSHIMA Hisao IWAMOTO Shoji TABATA Yoshitaka ONO Akira ISHIBASHI Nobuya SHIBA Hideyuki MIYACHI Takafumi GOTOH Shotaro NISHIMURA 《Animal Science Journal》2007,78(6):619-630
Growth‐related changes in the histochemical properties and collagen architecture of the Musculus pectoralis were compared among Silky, layer‐type and meat‐type cockerels. Histochemical and immunohistochemical methods were used and collagen architecture was studied using scanning electron microscopy. The total amount of collagen present was also measured. The diameter of type IIB myofibers was similar or rather larger in the layer‐type birds compared with the meat‐type. The collagen content was generally low for 5–10 weeks across the breeds and then increased in the other breeds except for Silky. In the perimysium, the collagen bundles gradually increased in size and the density of the fibrils also increased during growth. At 30 weeks of age, the layer‐type birds showed compact collagen bundles while the meat‐type had loose bundles. The endomysial collagen network appeared relatively denser in the meat‐type chicks compared to the others at week 1. At 30 weeks of age, compact and felt‐like structure of endomysium was shown by Silky and layer‐type chickens, while the meat‐type showed a relatively loose arrangement of tissue in the endomysial collagen. From these results, it appears that the meat‐type chicken can produce a large M. pectoralis with many, relatively thinner myofibers and a relatively undeveloped form of intramuscular collagen structure. 相似文献
108.
Progesterone stimulation by LH involves the phospholipase-C pathway in bovine luteal cells 总被引:2,自引:0,他引:2
Nishimura R Shibaya M Skarzynski DJ Okuda K 《The Journal of reproduction and development》2004,50(2):257-261
Luteinizing hormone (LH)-stimulated steroidogenesis in luteal cells is known to be mediated through the activation of cyclic AMP (cAMP)-dependent protein kinase, and to be also modulated by calcium-dependent mechanisms. In the present study, we tested the hypothesis that LH stimulates progesterone (P4) production in bovine luteal cells through activation of phospholipase (PL) C by using a cell culture system. Bovine mid-luteal cells (Days 8-12 of the estrous cycle) were cultured for 24 h and then exposed to a PLC inhibitor (U-73122; 10 microM) with or without LH (10 ng/ml) for 4 h. U-73122 blocked LH-stimulated P4 production without affecting cAMP accumulation. Moreover, exposure of luteal cells to PLC increased P4 production in a dose-dependent manner. These results support the hypothesis that the luteotropic action of LH in bovine luteal cells is mediated not only by activation of adenylate cyclase but also by activation of PLC. 相似文献
109.
110.