Long-term preservation of mouse spermatozoa as frozen testicular sections   总被引：1，自引：0，他引：1  

Ohta H  Sakaide Y  Wakayama T 《The Journal of reproduction and development》2008,54(4):295-298

We previously demonstrated that testicular spermatozoa can be preserved as frozen testicular sections, allowing us to preserve male gametes in less space than conventional methods. However, it remains unclear whether the testicular spermatozoa can be preserved for a long period using this procedure. In this study, we examined the function of testicular spermatozoa preserved as frozen testicular sections for l year at -30 or -80 C. Testicular spermatozoa were successfully retrieved from frozen testicular sections preserved at either -30 or -80 C, and their function was assessed using intracytoplasmic sperm injection (ICSI). Over 90% of the oocytes injected with long-term preserved testicular spermatozoa formed pronuclei, which was a frequency similar to that obtained with spermatozoa preserved for a short term, indicating that the testicular spermatozoa retained oocyte activation factor(s). Approximately 70% of the fertilized oocytes developed to 2-cell stage embryos, and 9.3 to 12.8% of the embryos developed to term after transfer into pseudopregnant females, regardless of the preservation temperatures examined. These results indicate that the birthrates of progeny did not differ between the preservation temperatures examined. They also indicate that male gametes can be preserved in testicular frozen sections for at least 1 year without loss of function.  相似文献   

Investigation into the dosage of dietary sphingomyelin concentrate in relation to the improvement of epidermal function in hairless mice     

Yuko HARUTA-ONO  Hiroshi UENO  Noriko UEDA  Ken KATO  Toshimitsu YOSHIOKA 《Animal Science Journal》2012,83(2):178-183

We previously found that dietary sphingomyelin (SPM) concentrate from bovine milk improved epidermal function. In this study, we investigated the dosage of dietary SPM concentrate from bovine milk in relation to the improvement of epidermal function. Thirteen-week-old hairless male mice were separated into four experimental groups, each fed one of four types of experimental diet: the control group, the low SPM group, the medium SPM group and the high SPM group. The mice were each fed the experimental diet for 6 weeks. The stratum corneum hydration and the transepidermal water loss (TEWL) were measured using a Corneometer and a Tewameter at 3 weeks and 6 weeks. After the feeding period, ceramides in the stratum corneum were analyzed. We found that the stratum corneum hydration in all the SPM groups was significantly higher than that in the control group, whereas TEWL in all the SPM groups was significantly lower than that in the control group. Ceramides increased significantly in mice fed the medium SPM diet and statistically tended to increase in mice fed the high SPM diet. Our results indicate that a daily intake of 17 mg SPM concentrate is enough to improve epidermal function in hairless mice.  相似文献   

Potential contributions of forestry and wood use to climate change mitigation in Japan     

Mitsuo Matsumoto  Hiroyasu Oka  Yasushi Mitsuda  Shoji Hashimoto  Chihiro Kayo  Yuko Tsunetsugu  Mario Tonosaki 《Journal of Forest Research》2016,21(5):211-222

By considering trade-offs and complementarity between carbon removal from the atmosphere by forests and emission reduction by wood use, we developed a forest-sector carbon integrated model for Japan. We discuss mitigation measures for Japan based on model projections. The integrated model included the forest model and the wood use model. Based on three scenarios (baseline, moderate increase, and rapid increase) of harvesting and wood use, the integrated model projected mitigation effects including carbon removal by forests and emission reduction through the wider use of wood, until 2050. Results indicate that forests will not become a source of net carbon emissions under the three scenarios considered. The baseline scenario is most effective for mitigating climate change, for most periods. However, the sum total of carbon removal in forests and carbon emission reductions by wood use under the rapid increase scenario exceeded the one of the moderate increase scenario after 2043. This was because of strong mitigation activities: promoting replanting, using new high-yield varieties, and wood use. The results also indicated that increases in emission reduction due to greater wood use compensated for 67.9 % of the decrease of carbon removal in 2050, for the rapid increase scenario. The results show that carbon removal in forests is most important in the short term because of the relative youth of the planted forests in Japan, and that mitigation effects by material and energy substitution may become greater over the longer term.  相似文献   

Seasonal changes of nitrate concentrations in baseflow headwaters of coniferous forests in Japan: A significant indicator for N saturation     

Zhao Zhang  Takehiko Fukushima  Peijun Shi  Fulu Tao  Yuichi Onda  Takashi Gomi  Shigeru Mizugaki  Yuko Asano  Ken'ichirou Kosugi  Shinya Hiramatsu  Hikaru Kitahara  Koichiro Kuraji  Tomomi Terajima  Kazuo Matsushige 《CATENA》2008

Understanding the seasonal and regional patterns of nitrogen (N) components in the headwaters of forested watersheds is important for forests management. Here, we investigated the NO₃-N concentration and its seasonal variations in the baseflow headwaters in Japanese coniferous forests with different N saturation status in five regions (i.e., Nagano, Tokyo, Aichi, Kochi and Mie). We found that the ratios of NO₃-N to DON were significantly higher in the N-saturated regions including Nagano (14.1 ± 2.2) and Tokyo (16.5 ± 4.1), compared with the regions, which didn't experience N saturation including Aichi (1.4 ± 0.2), Kochi (5.1 ± 1.8), and Mie (2.2 ± 0.5). In comparison with the regions without experiencing N saturation, the relatively higher NO₃-N concentration, as well as its contrastive variation between growing season and dormant season, was also characteristic of the seasonal NO₃-N concentration in the N-saturated regions. Our findings have indicated that NO₃-N concentration, its seasonal variations, and the ratio of NO₃-N to DON, are the better and applicable indicators for evaluating N saturation status in Japanese coniferous forests.  相似文献   

Quantitative estimation of carbon removal effects due to wood utilization up to 2050 in Japan: effects from carbon storage and substitution of fossil fuels by harvested wood products     

Yuko Tsunetsugu  Mario Tonosaki 《Journal of Wood Science》2010,56(4):339-344

Carbon absorbed by forests remains stored in the timber used for wood products, and a change in wood product stock can be evaluated as substantial removal/emission of atmospheric carbon. Since the carbon storage effect due to harvested wood products (HWP) might be taken into account in the future framework of carbon mitigation, it is crucial to estimate the carbon fl ow and stock concerning HWP for the next commitment period. In the present study, we developed a model for estimating the fl ow and stock of wood products in Japan’s building, furniture, and paper sectors. The HWP carbon storage effect and substitution effect (carbon reduction by substituting fossil fuels and energy-intensive materials with HWP) up to 2050 were quantitatively estimated by lifetime analysis. Our model simulation revealed that (i) the carbon stock change in Japan due to HWP would be evaluated as a large emission if the atmospheric-fl ow approach is adopted, (ii) carbon removal would not significantly increase if the ratio of newly constructed wooden buildings/furniture remains stable, and (iii) the carbon storage effect together with the substitution effect would have a significant impact on climate change mitigation if the ratio of newly constructed wooden buildings/furniture is gradually improved to 70% by 2050.  相似文献   

Relationship between crack propagation and the stress intensity factor in cutting parallel to the grain of hinoki (<Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis>)     

Masumi Minagawa  Yosuke Matsuda  Yuko Fujiwara  Yoshihisa Fujii 《Journal of Wood Science》2018,64(6):758-766

The method of digital image correlation (DIC) was applied to the digital image of orthogonal cutting parallel to the grain of hinoki, and the strain distribution near the cutting edge was evaluated. The wood fracture associated with chip generation was considered as mode I fracture, and the stress intensity factor K_I for fracture mode I was calculated from the strain distribution according to the theory of linear elastic fracture mechanics for the anisotropic material. The calculated K_I increased prior to crack propagation and decreased just after the crack propagation. The change in K_I before and after crack propagation, ΔK_I, decreased in accordance with the crack propagation length, although the variance in ΔK_I should depend on the relationships between the resolution of DIC method and the dimensions of cellular structure. The calculated K_I in this study was almost on the same order as reported in the literatures. It was also revealed, for the case of chip generation Type 0 or I, the stress intensity factor for fracture mode II could be negligible due to the higher longitudinal elastic properties of wood in the tool feed direction than the one radial ones, and the mode I fracture was dominant.  相似文献   

Wood structure of <Emphasis Type="Italic">Populus alba</Emphasis> formed in a shortened annual cycle system     

Kei’ichi Baba  Yuko Kurita  Tetsuro Mimura 《Journal of Wood Science》2018,64(1):1-5

Wood formation of trees that grow along the seasons has an annual rhythm. Due to this rhythm, physiological research on the mechanism of wood formation has been difficult to conduct in a typical experimental room. In the present study, we observed the wood tissue formation in a shortened annual cycle system, which was developed for poplar trees grown in a growth chamber with dormant and non-dormant cycles. Poplar trees were grown in this system by repeating the cycle three times. The resulting wood tissue consisted of three growth rings and very similar structures were observed around the ring boundary of the wood in a field-grown stem. This result suggests that the shortened annual cycle system can be adopted as a model for physiological, cell biological and molecular research of wood and annual ring formation.  相似文献   

Molecular detection of five cherry viruses from sweet cherry trees in Japan   总被引：5，自引：0，他引：5  

Masamichi?IsogaiEmail author  Jun?Aoyagi  Megumi?Nakagawa  Yuko?Kubodera  Kenji?Satoh  Tomohiro?Katoh  Mikio?Inamori  Kazuo?Yamashita  Nobuyuki?Yoshikawa 《Journal of General Plant Pathology》2004,70(5):288-291

  相似文献   

Differential expression of bone morphogenetic protein 4-6 (BMP-4, -5, and -6) and growth differentiation factor-9 (GDF-9) during ovarian development in neonatal pigs     

Shimizu T  Yokoo M  Miyake Y  Sasada H  Sato E 《Domestic animal endocrinology》2004,27(4):397-405

Growth differentiation factor-9 (GDF-9) and bone morphogenetic proteins (BMPs), comprise the largest subgroups of ligands in the TGF-β superfamily, and have been shown to be involved in follicle development in mammals. However, whether these factors are involved in folliculogenesis in pigs is still unknown. The present study was performed to determine the relationships between early folliculogenesis and the expression of GDF-9 and BMP (BMP-4, -5 and -6) mRNAs in neonatal pigs. Ovaries were removed at 5, 16, 28 and 39 days after birth to examine the follicular population (the right ovary of each animal) and to detect mRNA expression (the left ovary of each animal). Primordial follicles accounted for >80% of the ovarian follicles from 5 days until 39 days after birth. A marked increase in primary follicles and the appearance of secondary follicles were observed in the ovaries at 28 days after birth. BMP-4, -5, and -6 and GDF-9 mRNAs were expressed by ovaries at 5-, 16-, 28- and 39-day-old pigs. The peak expression of BMP-4, -5, and -6 and GDF-9 mRNAs was observed in the ovaries at 5, 39, 28 and 16 days, respectively, after birth. These data demonstrate that folliculogenesis in piglets might be controlled by the interaction with these factors. We conclude that BMPs and GDF-9 may have distinct functions in several stages of follicle development in neonatal pig ovaries.  相似文献   

Hypercalcemia in a dog with resolution of iatrogenic Cushing's syndrome     

Nakamura M  Kawamura Y  Minegishi M  Momoi Y  Iwasaki T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(3):329-331

A six-year-old spayed Pug was presented with crust formation and ulcer on the skin. The patient had received long-term glucocorticoid therapy for treatment of tentatively diagnosed panniculitis. Severe calcification and pyoderma was observed and the patient was diagnosed with iatrogenic Cushing's syndrome and predonisolone was gradually withdrawn. After the withdrawal, the patient developed marked hypercalcemia (15.3 mg/dl) and finally died from renal failure. It is postulated that the eluted calcium from the calcified lesions may have contributed to the high serum calcium level as the underlying disease was not identified on necropsy.  相似文献