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| Registros recuperados: 11 | |
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| MIYAMOTO, Akio; SHIRASUNA, Koumei; HAYASHI, Ken-Go; KAMADA, Daichi; KAWASHIMA, Chiho; KANEKO, Etsushi; ACOSTA, Tomas J.; MATSUI, Motozumi; 宮本, 明夫; 白砂, 孔明; 川島, 千帆; 松井, 基純. |
| Ultrasonography (US) has been applied to the ovary and the uterus of domestic animals from the late 1980s, and established in 1990s as a practical tool for animal production. US made it possible to detect pregnancy at a very early stage and, most importantly, to observe the real-time dynamics of follicular development and hence the discovery of follicular waves. This has greatly contributed to our understanding of ovarian physiology and helped us to develop several "pin-point" protocols for hormonal treatment. While US may not seem to fit preconceived ideas of a "green" technology, it does not contravene environmental priorities, and it is non-invasive ("ethical") and non-hormonal ("clean"). Using the US technology that is now commercially available at a... |
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Palavras-chave: Color Doppler ultrasound; Blood flow; Ovary; Reproduction; Cow. |
| Ano: 2006 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2983 |
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| KOWSAR, Rasoul; JIEMTAWEEBOON, Sineenard; SHIRASUNA, Koumei; SHIMIZU, Takashi; SASAKI, Motoki; KITAMURA, Nobuo; MIYAMOTO, Akio; 清水, 隆; 佐々木, 基樹; 宮本, 明夫. |
| This study was to investigate the localization and distribution of eosinophils (EOS) in the bovine oviduct throughout the estrous cycle. Histological studies revealed more abundant EOS in the infundibula of the oviducts ipsilateral to the preovulatory dominant follicle and the ovulated ovary. The number of EOS was higher in the infundibula of the oviducts ipsilateral to the ovulated ovary than those of the oviducts contralateral to the ovulated ovary. The infundibula of the oviducts ipsilateral to the preovulatory dominant follicle had higher number of EOS than those of the oviducts ipsilateral to the mid-cycle corpus luteum. The number of EOS in the isthmus, but not in the ampulla, was higher in the outer layers (tunica muscularis and tunica serosa) than... |
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Palavras-chave: Bovine; Eosinophil; Oviduct; Ovulation. |
| Ano: 2014 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3947 |
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| SHIRASUNA, Koumei; ASAHI, Takayuki; SASAKI, Motoki; SHIMIZU, Takashi; MIYAMOTO, Akio; 白砂, 孔明; 佐々木, 基樹; 清水, 隆; 宮本, 明夫. |
| We have shown that luteal blood flow increases in the peripheral vasculature of the mature corpus luteum (CL) prior to the onset of luteolysis in response to prostaglandin F2α (PGF2α) in the cow, but this phenomenon does not occur in the early CL. We therefore hypothesize that this acute increase of luteal blood flow occurs by vasodilation of large blood vessels due to local release of nitric oxide (NO). In the present study, we characterized the CL vasculature together with endothelial NO synthase (eNOS) expression during the estrous cycle in the cow. Immunohistochemistry was used to quantify the number of arteriolovenous vessels (surrounded with smooth muscle actin-positive smooth muscle cells), capillaries (with von Willebrand Factor-positive... |
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Palavras-chave: Blood vessels; Corpus luteum; ENOS; Luteolysis. |
| Ano: 2010 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2989 |
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| SHIRASUNA, Koumei; WATANABE, Sho; NAGAI, Kaya; SASAHARA, Kiemi; SHIMIZU, Takashi; RICKEN, Albert M.; SPANEL-BOROWSKI, Katharina; MIYAMOTO, Akio; 白砂, 孔明; 清水, 隆; 宮本, 明夫. |
| Cell-to-cell interaction via cell contact-dependent pathway is essentially important for maintenance and regulation of corpus luteum (CL) integrity and its physiological actions. The objective of the present study was to evaluate the mRNA expression of the cell adhesion molecules (CAMs) that are constituent factors of gap junctions [connexin (Cx) 43] and adherence junctions (VE-, E-, N-cadherin) in two types of endothelial cells from the mid CL and in CL tissue during the estrous cycle and PGF2α-induced luteolysis in the cow. Specific mRNA expression for Cx43 and N-cadherin was detected in cytokeratin-positive (CK+) and cytokeratin-negative (CK-) luteal endothelial cells (EC) and fully luteinized granulosa cells (LGC). E-cadherin mRNA was expressed in... |
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Palavras-chave: Cadherin; Connexin; Corpus luteum; Cow; Luteolysis. |
| Ano: 2007 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2988 |
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| MAGATA, Fumie; SHIRASUNA, Koumei; STRÜVE, Klaas; HERZOG, Kathrin; SHIMIZU, Takashi; BOLLWEIN, Heinrich; MIYAMOTO, Akio; 清水, 隆; 宮本, 明夫. |
| Persistence of the corpus luteum (CL) in cattle usually occurs during the puerperium and is associated with interference of prostaglandin (PG) F2α release from the uterus. The objective of the present study was to determine for the first time the gene expressions in the persistent CL compared with the CL of pregnancy and cyclic CL. Three types of CL biopsy samples were collected from 32 lactating Holstein cows: (1) CL persisting for 29 to 33 days after the first ovulation postpartum (persistent CL, n=9), (2) CL between days 29 and 33 of early pregnancy (CL of pregnancy, n=8) and (3) CL between days 10 and 13 of the estrous cycle (cyclic CL, n=27). mRNA expression of 2',5'-oligoadenylate synthetase-1 was upregulated only in the CL of pregnancy, confirming... |
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Palavras-chave: Dairy cow; Early pregnancy; Persistent corpus luteum; MRNA expression. |
| Ano: 2012 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3938 |
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| SHIRASUNA, Koumei; SASAHARA, Kiemi; MATSUI, Motozumi; SHIMIZU, Takashi; MIYAMOTO, Akio; 白砂, 孔明; 松井, 基純; 清水, 隆; 宮本, 明夫. |
| Administration of prostaglandin (PG) F2α in cattle during the mid-luteal phase (Days 8-12 of the estrous cycle) drastically reduces the plasma progesterone concentrations and the volume of the corpus luteum (CL). However, PGF2α does not induce luteolysis during the early luteal phase (up to Day 5 of the estrous cycle). To characterize the possible distinct difference in acute response to a luteolytic dose of PGF2α administration, we determined various mRNA expressions in the early and mid CL relating to angiogenesis, vasoactivation and PG-related factors at 30 min after PGF2α injection in cyclic cows. The experiments were conducted on Day 4 (early CL) and Days 10-12 (mid CL). Cows were either injected with 500 μg PGF2α analogue or saline as the control... |
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Palavras-chave: Corpus luteum; Cow; Luteolysis; Prostaglandin F2α. |
| Ano: 2010 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2812 |
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| SHIRASUNA, Koumei; KAWASHIMA, Chiho; MURAYAMA, Chiaki; AOKI, Yuka; MASUDA, Yutaka; KIDA, Katsuya; MATSUI, Motozumi; SHIMIZU, Takashi; MIYAMOTO, Akio; 白砂, 孔明; 川島, 千帆; 増田, 豊; 木田, 克弥; 松井, 基純; 清水, 隆; 宮本, 明夫. |
| The decrease in fertility and conception rates of high-producing dairy cows is one of the major negative impacts for today's producers. The recovery of ovarian activity postpartum is affected by the status of immunity, metabolism and reproduction and plays a critical role in subsequent fertility after parturition in the cow. In the present study we investigated the relationships between polymorphisms in genes relating to the above functions and the first postpartum ovulation as a marker of the recovery of ovarian function in the cow. In immune function related-factors, the occurrence of first postpartum ovulation within 3 weeks in the C/C genotypes of tumor necrosis factor α (TNFα) exon (55.4%) and the A/G genotypes of TNFα promoter (55.4%) was... |
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Palavras-chave: Cow; Ovulation; Polymorphism; Tumor necrosis factor α (TNFα). |
| Ano: 2011 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2990 |
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| KAWASAKI, Yurie; AOKI, Yuka; MAGATA, Fumie; MIYAMOTO, Akio; KAWASHIMA, Chiho; HOJO, Takuo; OKUDA, Kiyoshi; SHIRASUNA, Koumei; SHIMIZU, Takashi; 宮本, 明夫; 清水, 隆. |
| The present study aimed to assess the effect of polymorphisms in the tumor necrosis factor α (TNF-α) promoter (A/A, A/G and G/G) and exons (T/T, T/C and C/C) on immune function and reproductive performance in dairy cows. The occurrence of the first postpartum ovulation within 3 weeks in the cows with the TNF-α promoter A/G and G/G genotypes was higher than in the A/A group. Among the different TNF-α exon genotypes, the occurrence of early first postpartum ovulation was higher in the T/C and C/C genotype groups than in the T/T group. Single nucleotide polymorphisms (SNPs) in the TNF-α gene did not affect the rate of artificial insemination (AI) or duration from parturition to next conception (days open). The apoptosis rate of polymorphonuclear leukocytes... |
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Palavras-chave: Cattle; Immune function; Polymorphism; Reproductive performance; Tumor necrosis factor α (TNF-α). |
| Ano: 2014 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3934 |
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| MAGATA, Fumie; SHIRASUNA, Koumei; STRÜVE, Klaas; HERZOG, Kathrin; SHIMIZU, Takashi; BOLLWEIN, Heinrich; MIYAMOTO, Akio; 清水, 隆; 宮本, 明夫. |
| Persistence of the corpus luteum (CL) in cattle usually occurs during the puerperium and is associated with interference of prostaglandin (PG) F2α release from the uterus. The objective of the present study was to determine for the first time the gene expressions in the persistent CL compared with the CL of pregnancy and cyclic CL. Three types of CL biopsy samples were collected from 32 lactating Holstein cows: (1) CL persisting for 29 to 33 days after the first ovulation postpartum (persistent CL, n=9), (2) CL between days 29 and 33 of early pregnancy (CL of pregnancy, n=8) and (3) CL between days 10 and 13 of the estrous cycle (cyclic CL, n=27). mRNA expression of 2',5'-oligoadenylate synthetase-1 was upregulated only in the CL of pregnancy, confirming... |
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Palavras-chave: Dairy cow; Early pregnancy; Persistent corpus luteum; MRNA expression. |
| Ano: 2012 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4039 |
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| BEINDORFF, Nicola; NAGAI, Kaya; SHIRASUNA, Koumei; HERZOG, Kathrin; HOEFFMANN, Katharina; SASAKI, Motoki; BOLLWEIN, Heinrich; MIYAMOTO, Akio; 佐々木, 基樹; 宮本, 明夫; 白砂, 孔明. |
| The present study determined vascular changes in the bovine corpus luteum (CL) at Day 16 (early maternal recognition period) and Day 40 in early pregnancy and compared them to the CL from Day 12 and Day 16 of the estrous cycle. The CLs were analyzed in the central and peripheral regions, where site-depending features of vessels and angiogenic factors are evident. The same protein level of the endothelial cell marker von Willebrand factor was retained in the CL from Day 16 of the estrous cycle to Day 40 of early pregnancy. The protein level of pericytes and smooth muscle cells was determined using smooth muscle α-actin; the level decreased at Day 40 of early pregnancy in both regions of the CL. No significant change in the expressions of vascular... |
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Palavras-chave: Corpus luteum; Cow; Early pregnancy; Endothelial cells. |
| Ano: 2010 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2811 |
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| Registros recuperados: 11 | |
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