Structural changes in intramuscular connective tissue during the fattening of Japanese black cattle: effect of marbling on beef tenderization   总被引：2，自引：0，他引：2  

Nishimura T  Hattori A  Takahashi K 《Journal of animal science》1999,77(1):93-104

We investigated changes in structures and mechanical properties of the intramuscular connective tissue during the fattening of Japanese Black steers, using the cell maceration method for scanning electron microscopy. During the early fattening period, from 9 to 20 mo of age, collagen fibrils of the endomysium in longissimus muscle associated more closely with each other, and collagen fibers in the perimysium increased in thickness and their wavy pattern became more regular. These changes were closely related to the increase in mechanical strength of the intramuscular connective tissue and resulted in a toughening of the beef during the period. The shear force value of longissimus muscle decreased after 20 mo of age, concomitantly with the rapid increase in the crude fat content. Scanning electron micrographs of the longissimus muscle dissected from 32-mo-old steers clearly showed that the adipose tissues were formed between muscle fiber bundles, that the honeycomb structure of endomysia was partially broken, and that the perimysium separated into thinner collagen fibers. In semitendinosus muscle, in which the crude fat content was lower (P<.05) than that in longissimus muscle, the structure of the intramuscular connective tissue remained rigid at 32 mo of age. The shear force value of the muscle increased even in the late fattening period, from 20 to 32 mo of age. Thus, the development of adipose tissues in longissimus muscle appears to disorganize the structure of the intramuscular connective tissue and contributes to tenderization of highly marbled beef from Japanese Black cattle during the late fattening period.  相似文献   

Evaluation of high sensitive DNA probe for the detection of Theileria sergenti infection in cattle.   总被引：2，自引：0，他引：2  

A Hirano  R Kirisawa  T Matsuba  R Komatsu  M Tanaka  K Takahashi  Y Kawakami  M Onuma 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(5):933-935

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Morphology and size of embryos recovered from superovulated cows.     

A Nakagawa  T Suzuki  T Suga  T Inoue  Y Takahashi  H Kanagawa 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(2):287-290

A total of 691 normal embryos were recovered from 183 superovulated donor cows on the 5th and 6th days after the first insemination, and were examined for their morphology and size in relation to their developmental stage. There was no significant difference in the thickness of the zona pellucida, the diameter of the cell mass, and the overall diameter of the embryos among zygotes, 2-, 4-, 8- and 16-cell embryos, and morulae. In the blastocyst stage, however, the diameter of the cell mass and the overall embryo diameter were significantly greater and the zona pellucida was significantly thinner than in the earlier-stage embryos. The volume of the blastomere significantly decreased from zygote to morula in proportion to the increase in the number of blastomeres. The volume of the cell mass of 2-cell embryos was decreased by about 30% compared with that of zygotes and no increase in the volume of the cell mass was observed during the progression from 2-cell stage to morula. The diameter of the cell mass and the overall diameter of morulae recovered on the 6th day after the first insemination were significantly greater than those of morulae recovered on the 5th day.  相似文献   

Isolation and monolayer culture of bovine oviduct epithelial cells   总被引：3，自引：0，他引：3  

M Hishinuma  Y Takahashi  H Kanagawa 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1989,51(6):1201-1208

Oviduct epithelia obtained from 32 cows were cultured. The oviducts were classified into follicular and luteal phases and divided into ampulla and isthmus regions. The epithelial cells were dissociated by enzyme digestion and cultured in plastic dishes with Dulbecco's modified Eagle's medium/Ham's F12 (1:1) containing 10% calf serum. After enzyme treatment, the epithelial suspension showed free ciliated and non-ciliated cells, and cell mass. The non-ciliated cells contained secretory granules in the cytoplasm. The cell mass was composed of ciliated and secretory cells. The cell mass adhered to the dish within 12-24 hr, while the free ciliated cells attached on Day 2 of the culture. The cells grew into confluent monolayers on Day 4. The cell monolayers contained ciliated and non-ciliated cells. The monolayered non-ciliated cells showed a few secretory granules. When the cells were further cultured without subculturing, ciliary activity diminished on Day 5 and was rarely detected on Day 9. When the cells were subcultured on Day 3, ciliary movement was detected on the monolayers for only 2 days. Cell mass that did not adhere to the dish and remained floating in the medium formed ball-like structures on Day 2. Active ciliary beating was observed on the cells that were cultured in the medium supplemented with 10(-5) and 10(-9) M estradiol-17 beta, however, the ciliary activity diminished on Day 5. No difference in the cell growth was observed between the follicular and luteal phases or between the ampulla and isthmus regions.  相似文献   

Immunohistochemical analysis of pseudorabies virus spread through neurons innervating the eyeball     

Hiromi Takahashi  Chieko Kai  Yasuhiro Yoshikawa  Kazuya Yamanouchi 《Comparative immunology, microbiology and infectious diseases》1995,18(4):275-281

Pseudorabies virus (PRV) was inoculated intraocularly into BALB/c mice, and the distribution pattern of cells positive for several neurotransmitters and viral antigens in the eyeball, trigeminal nerve ganglia, and superior cervical ganglia was examined immunohistochemically to clarify the neural route of the virus spread. In the eyeball, substance P (SP)- and calcitonin gene-related peptide (CGRP)-positive cells were detected in the ipsilateral iris and ciliary body, neuropeptide tyrosine (NPY)-positive cells were detected in the choloid membrane, and tyrosine hydroxylase (TH)-positive cells were detected in the ipsilateral inner nuclear layer of the retina; all these cells contained viral antigens. In the superior cervical ganglia, viral antigen-positive cells containing TH or NPY were found at bilateral sites. In the trigeminal nerve ganglia, viral antigen-positive cells containing SP or CGRP were found at bilateral sites. These findings indicated that the SP- and CGRP-positive ganglion cells of the trigeminal nerve ganglia innervating the iris or ciliary body, and the NPY-positive ganglion cells of the superior cervical ganglia innervating the iris, ciliary body, and choroid membrane served as the route for the virus spread. These findings also suggested that dopaminergic neurons, such as the TH-positive retinal cells and TH-positive ganglion cells of the superior cervical ganglia, served as the route for virus spread.  相似文献   

Nephroblastoma with liver and lung metastases in an adult dog     

H Nakayama  T Hayashi  R Takahashi  K Fujiwara 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1984,46(6):897-900

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Pathological observations of feline mast cell tumor   总被引：1，自引：0，他引：1  

N Goto  M Ozasa  R Takahashi  K Ishida  K Fujiwara 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1974,36(6):483-494

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Physicochemical properties of akabane virus: A member of the simbu arbovirus group of the family bunyaviridae     

E. Takahashi  Y. Inaba  H. Kurogi  K. Sato  Y. Goto  Y. Ito  T. Omori  M. Matumoto 《Veterinary microbiology》1978,3(1):45-54

The multiplication of Akabane virus was not inhibited in the presence of 5-iodo-2′-deoxyuridine, indicating the presence of RNA. The virus was considered to have an envelope, as it was sensitive to ether and chloroform. It was readily inactivated by deoxycholate and trypsin, but was not precipitated by protamine sulphate. The virus was very labile at pH 3 and also rather heat-labile. Akabane virus was readily filtered through membrane filters of 200 or 100-nm pore size, but not through 50-nm filters. Equilibrium centrifugation in a CsCl density gradient gave a peak of infectivity and hemagglutinin at a density of 1.22 g/ml. The peak fractions thus obtained contained numerous virus particles, roughly spherical, variable in size, 70 to 130 nm in diameter, and mostly having a ragged, closely adherent envelope with projections, when examined, following phosphotungstic acid negative staining, in an electron microscope.  相似文献   

Use of DNA array to screen blastocyst genes potentially involved in the process of murine implantation     

Qin J  Takahashi Y  Imai M  Yamamoto S  Takakura K  Noda Y  Imakawa K 《The Journal of reproduction and development》2003,49(6):473-484

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Matrix-metalloproteinases-2 and -9 production in bovine endometrial cell culture   总被引：1，自引：0，他引：1  

Hashizume K  Takahashi T  Shimizu M  Todoroki J  Shimada A  Hirata M  Sato T  Ito A 《The Journal of reproduction and development》2003,49(1):45-53

In vitro cell culture is a convenient tool for studying cellular mechanisms. In the present study, production of matrix-metalloproteinases (MMPs) in bovine endometrial (containing both epithelial and stromal cells) monolayer cells was examined. Blastocysts attached to the endometrial cells in a monolayer culture were examined for their effects on MMP-2 production. Initial attachment of blastocysts to the monolayer inhibited MMP-2 production by endometrial cells. But once trophoblast cells began to migrate into the endometrial cell layer, MMP-2 production increased, and at the same time MMP-9 production also became evident in the medium. In order to understand how blastocysts affected MMP-2 production, we examined the effect of progesterone, estradiol, insulin-like growth factors (IGFs), tumor necrosis factors (TNFs), and interferon-tau (IFN-tau) supplementation. It was IFN-tau that inhibited the production of MMP-2. In addition, progesterone at a lower dose appeared to inhibit MMP-2 production. Both TNF-alpha and TNF-beta strongly stimulated the production of MMP-2 and MMP-9, whereas IGFs had no effect. Based on these findings, it appears that conceptus has the capacity to inhibit MMP activity.  相似文献