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11.
Fuminori TANIHARA Michiko NAKAI Hiroyuki KANEKO Junko NOGUCHI Takeshige OTOI Kazuhiro KIKUCHI 《The Journal of reproduction and development》2013,59(4):385-392
In porcine oocytes, the function of the zona pellucida (ZP) with regard to sperm
penetration or prevention of polyspermy is not well understood. In the present study, we
investigated the effects of the ZP on sperm penetration during in vitro
fertilization (IVF). We collected in vitro-matured oocytes with a first
polar body (ZP+ oocytes). Some of them were freed from the ZP (ZP− oocytes) by two
treatments (pronase and mechanical pipetting), and the effects of these treatments on
sperm penetration parameters (sperm penetration rate and numbers of penetrated sperm per
oocyte) were evaluated. There was no evident difference in the parameters between the two
groups. Secondly, we compared the sperm penetration parameters of ZP+ and ZP− oocytes
using frozen-thawed epididymal spermatozoa from four boars. Sperm penetration into ZP+
oocytes was found to be accelerated relative to ZP− oocytes. Thirdly, we evaluated the
sperm penetration of ZP+ and ZP− oocytes at 1−10 h after IVF (3 h gamete co-incubation).
The proportions of oocytes penetrated by sperm increased significantly with time in both
groups; however, the number of penetrated sperm per oocyte did not increase in ZP−
oocytes. Finally, we performed IVF using ZP− oocytes divided into control (3 h) and
prolonged gamete co-incubation (5 h) groups. Greater numbers of sperm penetrated in the 5
h group than in the control group. These results suggest that the ZP and oolemma are not
competent factors for prevention of polyspermy in our present porcine IVF system. However,
it appears that ZP removal is one of the possibilities for reducing polyspermic
penetration in vitro in pigs. 相似文献
12.
Fujisawa H Suma K Origuchi K Kumagai H Seki T Ariga T 《Journal of agricultural and food chemistry》2008,56(11):4229-4235
This study verifies the instability of garlic ( Allium sativum L.)-derived allyl 2-propenylthiosulfinate (allicin) in various aqueous and ethanolic solutions as well as in vegetable oil through chemical and biological analyses performed simultaneously. Crushed fresh garlic cloves generated antibacterial activity and chemically detectable allicin, a major antibacterial principle, and both declined on a daily basis in aqueous and ethanolic solutions at room temperature, showing biological and chemical half-lives of about 6 and 11 days, respectively. Allicin was more stable in 20% alcohol than in water, but surprisingly unstable in vegetable oil, with an activity half-life 0.8 h, as estimated from its antibacterial activity toward Escherichia coli, and a chemical half-life of 3.1 h, based on chromatographic quantification. In alcoholic and aqueous extracts, the biological half-life of allicin tended to be longer than the chemical one, suggesting the occurrence of bioactive compounds other than allicin in the extracts. 相似文献
13.
Ichimi Kazuhiko Honda Miyuki Okada Yuka Tsuzuki Kana Yamaguchi Hitomi 《Fisheries Science》2019,85(3):417-427
Fisheries Science - We carried out surveys to clarify how the density (no. of individuals/m2) and condition factor (CF) of Manila clam Ruditapes philippinarum differ between estuarine tidal flats... 相似文献
14.
Kana Yamashita Yasuhiko Hirakawa Hiroshi Nakatani Motoyoshi Ikeda 《Journal of Wood Science》2009,55(3):161-168
The transverse shrinkage variation within trees was examined for five sugi cultivars. The within-tree trends of tangential
shrinkage (α
T) were different by cultivar, whereas radial shrinkage (α
R) increased from pith to bark in most cultivars. The tangential/radial shrinkage ratio (α
T/α
R) decreased from pith to bark in most cultivars, because the radial variation of α
R was larger than that of α
T. The cultivars showed significant differences among cultivars in α
T, α
R, and α
T/α
R, but the difference among cultivars for α
T/α
R was smaller. The relationships between transverse shrinkage and microfi bril angle (MFA), basic density (BD), tree ring parameters,
and modulus of elasticity were examined. The α
T and α
R showed positive relationships with BD, latewood percentage, latewood density, and modulus of elasticity, and negative relationships
with MFA and ring width. The relationships with earlywood density were weak. Sugi exhibited variation in transverse shrinkage
within stem and among cultivars, with the variation affected by MFA, density, and tree ring parameters.
Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, Japan, August 2006,
and the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, Japan, August 2007 相似文献
15.
Makoto NISHIZAWA Nobuaki TAKAHASHI Kumiko SHIMOZAWA Takako AOYAMA Kouichi JINBOW Yukari NOGUCHI Kiyoshi HORITA Hideo BANDO Takashi YAMAGISHI 《Fisheries Science》2003,69(3):639-643
ABSTRACT: Four steroidal ketones were isolated from the holdfast of cultivated Laminaria japonica . The structures were characterized as ergosta-4,24(28)-diene-3-one (1), ergosta-4,24(28)-diene-3,6-dione (2), stigmasta-4,24(28)-diene-3-one (3) and stigmasta-4,24(28)-diene-3,6-dione (4), by spectral data. Compounds 2 and 4 were shown to be cytotoxic against the MCF-7 human breast cancer cell, and the growth of MCF-7 was inhibited by 96% and 79%, respectively, at 10 µg/mL. It is the first report on the isolation of cytotoxic steroidal ketones from the kelp in the genus of Laminaria. 相似文献
16.
Bovine mastitis is typically caused by microbial infection of the udder, but the factors responsible for this condition are varied. One potential cause is the milking system, and although previous studies have investigated various methods for inspecting these devices, most have not assessed methods for evaluating the milking units. With this in mind, we analyzed the factors that affect the vacuum inside the milking claw by using a simulated milking device and by measuring milking claw vacuum when adjusting the flow rate in five stages. The factors analyzed in each milking system were the vacuum pressure settings (high and low line system) , milk tube length (200‐328 cm), aperture diameter (14‐22.2 mm), constricted aperture diameter (12 mm), tubing configurations, lift formation (0‐80 cm), claw type (bottom and top flow) and use or non‐use of a milk sampler. The study findings demonstrated that all of these variables had a significant impact on claw vacuum and suggest that a diagnostic method using a simulated milking device should be considered when inspecting modern milking systems. 相似文献
17.
Age-related histological changes in the canine substantia nigra 总被引:2,自引:0,他引:2
Uchida K Kihara N Hashimoto K Nakayama H Yamaguchi R Tateyama S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(2):179-185
Age-related changes in the canine substantia nigra, were examined using immunostaining for tyrosine hydroxylase (TH), glial fibrillary acidic protein (GFAP), neurofilament (NF), ubiquitin, single stranded DNA (ssDNA), and alpha-synuclein (alphaSN). Brain sections from 34 necropsied dogs, ranging from 2 months to 18 years old, were used for this study. On general histological examinations, several age-related changes, including lipofuscin deposition, polyglucosan bodies, amorphous basophilic inclusions and eosinophilic crystal inclusions, were found in the aged dogs. Immunohistochemically, TH-positive neurons were located only in the substantia nigra. The number of TH-positive neurons was well preserved in all dogs examined, however, the ratio of TH-positive neurons to GFAP-positive glial cells tended to show slight decrease in aged dogs. By ssDNA immunostaining for apoptotic cells, there were no significant results in the number of ssDNA-positive neurons. The number of ubiquitin- and NF-positive swollen neurites was increased markedly in aged dogs. Ubiquitin immunostaining revealed a small number of basophilic and eosinophilic inclusions, although both types of inclusions were negative for NF. By alphaSN immunostaining, no neurons were immunoreactive and no basophilic or eosinophilic intracytoplasmic inclusions were revealed. These results indicate that in the substantia nigra of aged dogs the dopaminergic neurons are well preserved, but intracytoplasmic inclusions and ubiquitin-positive degenerative neurites are commonly found. 相似文献
18.
Methyl‐mannosylerythritol lipid (MEL), a new sugar esterified lipid synthesized by Pseudozyma aphidis, was assessed for its functionality in modulating rumen fermentation and microbiota toward more propionate and less methane production. A pure culture study using rumen representatives showed that MEL selectively inhibited the growth of most Gram‐positive bacteria including Streptococcus bovis, ruminococci, and Fibrobacter succinogenes, but not Gram‐negative bacteria such as Megasphaera elsdenii, Succinivibrio dextrinosolvens, and Selenomonas ruminantium. A batch culture study revealed that MEL significantly decreased methane production in a dose‐dependent manner with accumulation of hydrogen, while propionate production was enhanced. A continuous culture (Rusitec) study confirmed all of these changes. A feeding study revealed that sheep fed a MEL diet showed an increased proportion of propionate, while proportions of acetate and butyrate were decreased without affecting total VFA level. These changes disappeared after cessation of MEL feeding. Based on these results, dietary application of MEL can favorably modify rumen fermentation in terms of the efficiency of dietary energy utilization. 相似文献
19.
Neurotoxin tetrodotoxin as attractant for toxic snails 总被引:1,自引:1,他引:1
ABSTRACT: The attracting effect of a small dose of tetrodotoxin (TTX) on eight toxic snail species ( Polinices didyma, Natica lineata, Natica vitellus, Zeuxis sufflatus, Niotha clathrata, Oliva miniacea, Oliva mustelina and Oliva hirasei ) and two non-toxic species ( Pomacea canaliculata and Satsuma bairdi ) was investigated. Each toxic snail species was determined to contain TTX. The minimum lethal dose of TTX for most toxic snails was estimated to be >44.5 µg TTX/20 g body weight, but for non-toxic snails it was <3.6 µg TTX/20 g body weight. After the attracting test, it was found that for all toxic snails there was a significantly positive relationship between the comparative attracting variation and the toxicity reported, and this relationship was linear ( y = 5.895 x + 3.443, r = 0.806). The relationship between TTX resistance ability and toxicity also had a positive correlation ( y = 0.113 x + 52.447, r = 0.814). However, non-toxic species showed a negative response. The more toxic snails appeared to prefer TTX, indicating that TTX is an attractant for toxic snails. 相似文献
20.
Makoto Ueno Yumiko Kumura Kana Ueda Junichi Kihara Sakae Arase 《Journal of General Plant Pathology》2011,77(3):209-213
In leaves pretreated with an indole derivative [indole-3-acetic acid (IAA) tryptamine, or tryptophan], blast lesion formation
was suppressed compared to those treated with distilled water (DW) as a control. Phenylalanine ammonia-lyase (PAL) activity
and PAL expression were significantly enhanced in the IAA- or tryptophan-pretreated leaves, but not in tryptamine-pretreated leaves.
This induction of resistance was inhibited by pretreatment with a PAL inhibitor, α-aminooxyacetic acid, in IAA- and in tryptophan-treated
leaves, but not in tryptamine-treated leaves. This study strongly shows that the indole derivatives IAA tryptamine and tryptophan
can enhance a disease resistance mechanism that is supported by different metabolic pathways. 相似文献