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81.
The aim of the present study was to clarify the overall efficiency of porcine somatic cell nuclear transfer (SCNT) by incorporating cryopreservation of the cloned embryos before transfer. The SCNT embryos reconstructed with preadipocytes and in vitro-matured (IVM) oocytes were cultured to harvest morula stage embryos; they were then subjected to delipation (removal of cytoplasmic lipid droplets) and vitrification. After warming and culture, the embryos developing to blastocysts were transferred to recipients to obtain cloned piglets. From 372 reconstructed embryos, 188 (50.5%) reached the morula stage and 117 (31.5%) developed to blastocysts after vitrification. Transfer of 98 (26.3%) morphologically normal blastocysts gave rise to 6 (1.6%) piglets, including 1 stillborn. The efficiency of the cloned piglet production was comparable with that obtained using SCNT embryos without cryopreservation (2.7%, 17/635). Here, we demonstrate that porcine somatic cell cloning can be performed without a significant reduction in efficiency even when the SCNT embryos are cryopreserved before transfer.  相似文献   
82.
The aim of the present study was to optimize the conditions for in vitro development and postvitrification survival of somatic cell cloned feline embryos. To determine the effects of cell cycle synchronization of the nuclear donor cells, we cultured preadipocytes under serum starvation or conventional conditions. After two days in serum starvation culture, the proportion of synchronized donor cells at the G0/G1 phase was 91.6%. This was significantly higher than the proportion of non-synchronized cells in the proliferative phase (72.6%, P<0.05). The in vitro development of somatic cell nuclear transfer (SCNT) embryos reconstructed using donor cells treated under serum starvation conditions (normal cleavage rate of 65.7%, 46/70, and blastocyst formation rate of 20.0%, 14/70) was comparable to that of the serum supplemented group (52.5%, 31/59, and 20.3%, 12/59). Use of in vitro or in vivo matured oocytes as recipient cytoplasts equally supported development of the SCNT embryos to the blastocyst stage (11.9%, 5/42, vs. 9.5%, 2/21). SCNT-derived blastocysts were vitrified using the original minimum volume cooling (MVC) or the modified (stepwise) MVC method. Although none (n=10) of the SCNT blastocysts survived following vitrification by the original MVC method, the stepwise MVC method resulted in 100% survival after rewarming (n=11). In conclusion, we demonstrated that feline somatic cell cloned embryos with a high developmental ability can be produced irrespective of cell cycle synchronization of donor cells using either in vivo or in vitro matured oocytes. Furthermore, by utilizing a stepwise vitrification method, we showed that it is possible to cryopreserve cloned feline blastocysts.  相似文献   
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84.
In this study, we report the features of an adenocarcinoma with giant cell formation spontaneously occurring in the accessory sex glands of a male 10-month-old Sprague-Dawley rat. A milky white mass was found in the region corresponding to the left seminal vesicle and the left coagulating gland. Histologically, tumor cells exhibited diverse growth patterns, including glandular/trabecular, cystic, and sheet-like growth areas. The tumor cells were pleomorphic, with round- or oval-shaped nuclei and abundant eosinophilic cytoplasm. Mitotic figures were occasionally observed. Giant cells were also prominent in the sheet-like growth area, with intracytoplasmic vacuoles containing eosinophilic material. The stroma was rich in collagen fibers and fibroblasts. Numerous inflammatory cells were observed in the glandular and cystic lumina and stroma. Immunohistochemically, the tumor cells were positive for cytokeratin AE1/AE3 and proliferating cell nuclear antigen. In the sheet-like growth area, some of the tumor cells and giant cells were positive for vimentin in the cytoplasm adjacent to the nucleus. Electron microscopy revealed that the tumor cells contained a small number of mitochondria and rough endoplasmic reticulum, and had no basement membrane or desmosome. The giant cells occasionally contained variably sized intracytoplasmic lumina and globular filamentous bodies, probably corresponding to vimentin. Considering these morphological features, the tumor was diagnosed as an adenocarcinoma with the formation of giant tumor cells originating from the male accessory sex glands.  相似文献   
85.
Cooked rice quality is based on a number of factors including texture. Texture and structure of foods are closely related and aspects of the relationship can be explored by correlating compression measurements to structural observations of the compressed material. To obtain compression measurements, single cooked, milled rice grains were compressed in a texture analyzer to a specific percentage (% compression) of the original grain; the uncompressed grain is 0%. The experiment, using single grains in each case, was repeated multiple times. Compression percentages of 20, 30, 40, 50, 60, and 70% were measured against a constant resistance force in the texture analyzer. Structures of cooked rice grains at the various compression levels were compared by brightfield and fluorescence microscopy. The outside of an uncompressed, intact, cooked rice grain is swollen and distorted while the interior has three or more odd‐shaped holes (voids). Each void is largest in the center of the grain and decreases in size toward the peripheral edges becoming fine cracks toward the outermost portion of the void. The voids tended to increase in area up to 40% compression and then decrease in area upon further compression. Percent compression versus resistance force was a curvilinear relationship. With increasing % compression, cell shapes became increasingly more rounded, although there wasn't much effect on the integrity of cell walls with increasing % compression. The degree to which grain structure changed during the various compression tests, combined with the curvilinear behavior of resistance force versus % compression, indicates that the voids and cell walls have an effect on texture.  相似文献   
86.
An attempt was made to examine the possible connection between the various ratios of calcium/aluminum (Ca/Al) in the nutrient solution of plant cultures and the active oxygen scavenging system of hinoki cypress (Chamaecyparis obtusa) seedlings. The hinoki cypress seedlings were transferred to nutrient solutions containing 5 mM AlCl3 together with various concentrations of Ca(NO3)2 in pots containing glass beads and Teflon tips. The activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) in the needles were estimated at several stages during the 7-day treatment. The samples treated with the lower Ca/Al solutions show the highest SOD activities. The activities of APX and GR, both of them involved in the ascorbate-glutathione cycle, showed the same tendency with decrease to higher Ca/Al ratio. These results indicate that rhizospheric Ca might compete with Al and ameliorate Al toxicity on and in the roots, the Al stress is not transformed to the needles after a few days, and the ascorbate-glutathione cycle in the hinoki cypress needles might fluctuate and be suppressed by the rhizospheric Al stress during the 7 days. This work was supported in part by funding from the Japan Science & Technology Corporation, the CREST program 1996–2001, and the Center for Forest Decline Studies.  相似文献   
87.
The objectives of this study were to estimate genetic parameters and to perform a genome‐wide association study (GWAS) for predicted methane‐related traits in Japanese Black steers. The methane production and yield traits were predicted using on‐farm measurable traits, such as dry matter intake and average daily gain. A total of 4,578 Japanese Black steers, which were progenies of 362 sires genotyped with imputed 551,995 single nucleotide polymorphisms (SNPs), had phenotypes of predicted methane‐related traits during the total fattening period (52 weeks). For the estimation of genetic parameters, the estimated heritabilities were moderate (ranged from 0.57 to 0.60). In addition, the estimated genetic correlations of methane production traits with most of carcass traits and feed‐efficiency traits were unfavorable, but those of methane yield traits were favorable or low. For the GWAS, no genome‐wide significant SNP was detected, but a total of four quantitative trait locus (QTL) regions that explained more than 5.0% of genetic variance were localized on the genome, and some candidate genes associated with growth and feed‐efficiency traits were located on the regions. Our results suggest that the predicted methane‐related traits are heritable and some QTL regions for the traits are localized on the genome in Japanese Black steers.  相似文献   
88.
We characterised cultured canine mammary gland adenocarcinoma cells by exhaustive step protein expression analysis to identify factors associated with tumour progression or metastasis of canine mammary gland tumour. Cultured adenocarcinoma cells derived from a total of 3 primary and 3 metastatic lesions from 3 dogs (CHMp/m, CIPp/m and CNMp/m, where CHM, CIP, and CNM indicate the 3 animals) were used in this study. The expression of 24 proteins reported to be related to tumourigenesis or malignancy of human breast cancers were examined by Western blot analysis using 24 antibodies. The expression of sialyl Lewis X [sLe(x)] was only observed in CHMm cells, which were derived from pleural effusion. This expression was further confirmed by immunohistochemistry. The levels of some factors, such as 14-3-3sigma, cyclinD1 and Rb, differed among cells or between the primary and metastatic cells in the pair. Though the difference in their expression was not consistent within the cells from primary and metastatic origin, this characterisation should provide useful information for further molecular analysis of these cultured cells. Since some of the factors, such as sLe(x), 14-3-3sigma, cyclinD1 and Rb, showed different levels of expression in the pair, these cultured cells might be meaningful tools for clarification of distant metastasis in canine mammary gland tumours.  相似文献   
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