Reduction of primordial follicles caused by maternal treatment with busulfan promotes endometrial adenocarcinoma development in donryu rats     

Yoshida M  Watanabe G  Shirota M  Maekawa A  Taya K 《The Journal of reproduction and development》2005,51(6):707-714

Ovarian dysfunction leading to hormonal imbalance plays a crucial role in uterine carcinogenesis in rats as well as women. However, the effects of a reduction in primordial follicles at birth on uterine adenocarcinoma development have hitherto not been determined. The present study was therefore conducted using female Donryu rats, a high incidence rat strain of uterine adenocarcinoma. The animals were maternally exposed to 2.5 or 5.0 mg/kg of busulfan on gestation day 14 to reduce primordial follicles, and were then initiated by intrauterine treatment with N-ethyl-N'-nitro-N-nitrosoguanidine at 11 weeks of age. Both busulfan treatment doses caused earlier occurrence of persistent estrus, with dose-dependence as compared to controls. At 15 months of age, the rats were euthanized. The incidence of uterine adenocarcinomas and multiplicity of uterine neoplastic lesions were significantly increased by the 5.0 mg/kg, but not the 2.5 mg/kg busulfan treatment. Morphologically, the ovaries exposed to busulfan treatment exhibited severe atrophy, with few or no follicles and corpus lutea. Serum 17beta-estradiol (E2), progesterone, and inhibin levels were significantly decreased in the busulfan treatment groups, with a clear dose-relation. Interestingly, only the 5.0 mg/kg busulfan treatment elevated the E2/progesterone ratio. These results provide evidence that the reduction of primordial follicles promotes uterine adenocarcinoma development in rats in association with an earlier occurrence of the persistent estrus status.  相似文献   

Prevalence of fowl glioma-inducing virus in chickens of zoological gardens in Japan and nucleotide variation in the env gene   总被引：1，自引：0，他引：1  

Hatai H  Ochiai K  Murakami M  Imanishi S  Tomioka Y  Toyoda T  Ohashi K  Umemura T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(5):469-474

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Interspecies nuclear transfer embryos reconstructed from cat somatic cells and bovine ooplasm     

Thongphakdee A  Kobayashi S  Imai K  Inaba Y  Tasai M  Tagami T  Nirasawa K  Nagai T  Saito N  Techakumphu M  Takeda K 《The Journal of reproduction and development》2008,54(2):142-147

This study was conducted to investigate the developmental capacity of domestic cat-bovine reconstructed embryos via interspecies somatic cell nuclear transfer (iSCNT) and to observe the mitochondrial DNA (mtDNA) content of the iSCNT embryos. The iSCNT embryos were generated using mixed-breed domestic cat fibroblasts as donor cells and enucleated bovine oocytes as the recipient cytoplasm. When the developmental capacities of iSCNT embryos and parthenogenic bovine embryos were compared, there was no difference (P>0.05) in the rates of cleavage and development to the 8-cell stage (86.6 vs. 84.0% and 32.2 vs. 36.2%, respectively). However, in contrast to development of parthenogenic embryos to the morula and blastocyst stages, no iSCNT embryos (0/202) developed beyond the 8-cell stage. For mtDNA analysis, iSCNT embryos at the 1-cell, 2-cell, 4-cell and 8-cell stages were randomly selected. Both cat and bovine mtDNA quantification analysis were performed using quantitative PCR. The levels of both cat and bovine mtDNA in cat-bovine iSCNT embryos varied at each stage of development. The cat mtDNA concentration in the iSCNT embryos was stable from the 1-cell to 8-cell stages. The bovine mtDNA in the iSCNT embryos at the 8-cell stage was significantly lower than that at the 4-cell stage (P<0.05). No difference in the proportions of cat mtDNA in the iSCNT embryos was found in any of the observed developmental stages (1- through 8-cell stages). In conclusion, bovine cytoplasm supports domestic cat nucleus development through the 8-cell stage. The mtDNA genotype of domestic cat-bovine iSCNT embryos illustrates persistence of heteroplasmy, and the reduction in mtDNA content might reflect a developmental block at the 8-cell stage.  相似文献   

Trans-endothelial and trans-epithelial transfer of lactoferrin into the brain through BBB and BCSFB in adult rats     

Kamemori N  Takeuchi T  Sugiyama A  Miyabayashi M  Kitagawa H  Shimizu H  Ando K  Harada E 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(3):313-315

The transportation of intravenously administered bovine lactoferrin (bLF) into the cerebrospinal fluid (CSF) was immunohistochemically investigated in adult rats. Administered bLF was detected in the vesicular membranes of endothelial cells in cerebral blood vessels 10 min after the infusion. Numerous immunoreactive small vesicles were also detected at the ependymal cells in the choroid plexus. Moreover, the bLF concentration in the CSF was significantly increased at 1-2 hr after the intravenous infusion of bLF (10 or 30 mg/kg). These findings clearly demonstrate that LF is possibly transported into the brain matter even in adult animals.  相似文献   

Fatigue of structural plywood under cyclic shear through thickness II: a new method for fatigue life prediction     

Takanori Sugimoto  Yasutoshi Sasaki  Mariko Yamasaki 《Journal of Wood Science》2007,53(4):303-308

For plywood specimens under shear through the thickness, a fatigue life prediction method based on strain energy has been newly developed with the fatigue process and failure criterion applicable to various loading conditions. Once the fatigue process and failure criterion of the plywood specimen were determined by the fatigue data measured under a loading condition other than the square loading waveform, the fatigue life of a specimen under various loading conditions could be predicted easily and accurately by the first cycle loading test. The relationship between stress level and the predicted fatigue life was also similar to that between stress level and the experimentally determined fatigue life. The fatigue life prediction method proposed may be widely applicable to the prediction of the fatigue life of solid wood and wood composites.  相似文献   

Combined hepatocellular and cholangiocellular carcinoma in a dog     

Shiga A  Shirota K  Enomoto M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(4):483-486

A transitional type of combined hepatocellular and cholangiocellular carcinoma developed in a 12-year-old male Yorkshire terrier dog. The tumor was histologically composed of both hepatocellular carcinoma and cholangiocellular carcinoma components, and both elements were closely intermingled. Intraluminal mucin accumulation in cytokeratin-positive tubular/glandular structures was observed within the cholangiocellular carcinoma components and this feature was useful histological marker for a differential diagnosis between combined hepatocellular and cholangiocellular carcinoma and a pseudoglandular type of hepatocellular carcinoma. This primary hepatic tumor is extremely rare in dogs.  相似文献   

Tyzzer's disease in a neonatal rainbow lorikeet (Trichoglossus haematodus)     

Raymond JT  Topham K  Shirota K  Ikeda T  Garner MM 《Veterinary pathology》2001,38(3):326-327

A captive-born 8-day-old male rainbow lorikeet (Trichoglossus haematodus) was found dead. Histologically, there were necrotizing hepatitis, myocarditis, and ventriculitis. Silver stain revealed argyrophilic filamentous bacilli within hepatocytes, smooth myofibers of the gizzard, and cardiac myofibers surrounding foci of necrosis. Immunohistochemistry using anti-Clostridium piliforme RT and MSK strain antisera reacted positively against bacilli within hepatocytes, cardiac myofibers, smooth myofibers of the gizzard, and splenic and intestinal macrophages. Polymerase chain reaction (PCR) assay of paraffin-embedded liver, heart, gizzard, spleen, and small intestine amplified the 196-bp DNA fragment specific to 16S ribosomal RNA of C. piliforme. The results of histopathology, immunohistochemistry, and PCR are consistent with C. piliforme infection in this lorikeet.  相似文献   

Vimentin/cytokeratin coexpression foci in a well-differentiated canine hepatocellular carcinoma     

Shiga A  Shirota K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(2):199-202

A number of pale-stained cell foci were observed within a well-differentiated hepatocellular carcinoma which developed in a 10-year-old male mongrel dog. The foci were composed of hepatocyte-like cells, but did not contain glycogen granules in their cytoplasm. Immunohistochemically, the focus cells coexpressed both bile duct type cytokeratin and vimentin. Electronmicroscopically, they were abundant in cytoplasmic organelles and contained bile pigments. Bile canaliculi were noted between the focus cells. The focus cells in the present case were considered to be neoplastic hepatocytes expressed bipotential features of hepatic stem cells.  相似文献   

Immunocytochemical evaluation of epithelial–mesenchymal transition in epithelial tumors of dogs and cats     

Yu FURUSAWA  Masashi TAKAHASHI  Mariko SHIMA-SAWA  Hitoshi HATAI  Noriaki MIYOSHI  Osamu YAMATO  Akira YABUKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(9):1363

Epithelial–mesenchymal transition (EMT) plays a crucial role in metastasis of epithelial tumors; however, it is challenging to detect EMT by cytology. In the present study, EMT was visualized by fluorescence-immunocytochemistry (FICC). Air-dried smears from epithelial tumors of dogs (n=22) and cats (n=9) were stained using mouse monoclonal anti-E-cadherin and rabbit monoclonal anti‐vimentin antibodies. Enzymatic immunohistochemistry (IHC) revealed that 51.6% (8/22 in dogs, 8/9 in cats) of the cases showed EMT. In dogs, FICC could detect EMT in 62.5% (5/8) of those cases. In cats, FICC could detect EMT in 100% (8/8) of the cases. In conclusion, the present FICC method could successfully detect EMT using conventional air-dried cytology smear slides.  相似文献   

Corneal-Protective Effects of an Artificial Tear Containing Sodium Hyaluronate and Castor Oil on a Porcine Short-Term Dry Eye Model     

Takashi HASEGAWA  Hideki AMAKO  Takeshi YAMAMOTO  Mariko TAZAWA  Yuji SAKAMOTO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(9):1219-1224

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