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1.
Sasakii K Kimura K Kitaguchi Y Onoue T Ogura H Aoyagi Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(8):925-927
Changes in ascorbate content in primary cultured rat hepatocytes exposed to oxidative stress derived from water soluble radical initiator 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) were examined. Cells were exposed to 0.05 and 5 mg/ml of AAPH as 'mild' and severe' oxidative stresses, respectively. Lipid peroxidation in hepatocytes was induced by 'severe' oxidative stress, but not by 'mild' oxidative stress. Ascorbate decreased at 6 hr after administration of both mild' and severe' oxidative stresses, and recovered to the control level after a further 6 hr. In cells treated with 'severe oxidative stress, however, total ascorbate (reduced form plus oxidized form) had increased 24 hr after administration. These results indicated that consumption alone did not account for the increase of ascorbate in hepatocytes under oxidative stress. 相似文献
2.
Neurotoxins in a toxic red tide of Heterosigma akashiwo (Raphidophyceae) in Kagoshima Bay, Japan 总被引：3，自引：0，他引：3
In April 1995, an unusual large-scale red tide of Heterosigma akashiwo (Hada) Hada occurred, causing massive fish kills in Kagoshima Bay, Japan. Four neurotoxic components, HaTx-i , HaTx-ii a, HaTx-ii b and HaTx-iii , which corresponded to brevetoxin components. PbTx-2. PbTx-9, PbTx-3 and oxidized PbTx-2, were inferred from analysis of Heterosigma red tide toxins on TLC and HPLC. 相似文献
3.
Nilton G. Marengoni Yoshio Onoue Tetsuo Oyama 《Journal of the World Aquaculture Society》1998,29(1):108-113
Hybridization between Nile tilapia Oreochromis niloticus (Local and Stirling University strains) and blue tilapia O. aureus was found to be a tool to produce monosex populations. In order to select a purebred that produces all- or nearly all-male hybrids with high productivity, O. niloticus females and their diploid gynogenetics (meiogynes and mitogynes) were hybridized with O. aureus males. The sex ratio of progenies was evaluated from inter- and intraspecific crosses of two strains of Nile tilapia. Single-pair matings and group spawns under hatchery conditions showed no deviation ( P > 0.01) from the expected sex ratio of intraspecific crosses among two strains of Nile tilapia. However, a higher proportion of male progenies in blue tilapia was observed in group spawns in pond ( P < 0.004) and hatchery conditions ( P < 0.01). Only the Stirling strain and mitogynes produced all-male progenies under laboratory conditions. There were significant differences ( P < 0.05) in growth among hybrid progeny groups, when gynogens and their regular O. niloticus (Local strain) females were crossed with O. aureus males. Six-month hybrid offspring from mitogyne female parents grew better than those from regular and meiogyne female broods. 相似文献
4.
Fertilization of ultraviolet (UV) irradiated oocytes of Nile tilapia, Oreochromis niloticus (L.), with sperm from O, niloticus or blue tilapia, O, aureus (Steindachner), and subsequent suppression of the first cleavage of fertilized eggs successfully induced androgenesis in Nile and blue tilapia. The optimal doses of UV irradiation to denucleate a female genome of Nile tilapia prior to androgenesis ranged from 5940 to 6930 erg mm?2 for 54-63 s at a fixed intensity of 110 erg mm?2 s?1. Putative androgenetic fish were created from eggs which were irradiated at various times and several durations of heat-shock. Eggs which were treated for 5 min at 41.6 oC at 2 7.5 min after fertilization were the most successful at suppressing the first cleavage and producing viable androgenetic diploids in Nile or hybrid Nile X blue tilapia. The maximal survivals of putative androgenetic diploids in relation to the control were 1.60% and 0.90% in Nile and hybrid Nile X blue tilapia, respectively. The androgenetic offspring established exhibited active feeding and normal growth. 相似文献
5.
The effects of temperature, salinity, light intensity and pH on the growth and morphology of Chattonella marina (Subrahmanyan) Hara & Chihara were examined. Optimal growth was observed at temperatures of 20-25°C, salinities of 20-30%o, light intensities of 60-140 μE m?2 s_1 and pH 7.5-8.5. Growth did not occur at temperatures below 15°C or above 30°C, and at salinities below 10%o. The morphology (shape) of the cells was strongly affected by temperature. At 20°C and 25°C, the population occurred mostly in a spindle-like form, whereas at 10°C, 90% of the cells became spherical within 10 days of inoculation and stationary phase cultures consisted entirely of spherical cells. Morphology was also markedly affected at 30°C. The number of spindle-like cells was highest at 20-30%o and was less at lower salinities. Light intensity and pH did not influence morphology markedly under the range of light intensities (20-180 μE m ?2 s-?1) and pH (6.5-8.5) tested. 相似文献
6.
Tetsuro Shiraishi Kumiko Okamoto Michio Yoneda Takeshi Sakai Seiji Ohshimo Shizumasa Onoe Akihiko Yamaguchi Michiya Matsuyama 《Fisheries Science》2008,74(5):947-954
The age and growth of chub mackerel Scomber japonicus collected from the East China Sea and the northern waters off Kyushu between June 2000 and June 2001 were determined by observing
the otolith surface after dipping it in xylene. The translucent and opaque zones on the otolith surface were identified, and
the number of translucent zones was counted. Monthly changes in the frequency of fish with translucent zones on the otolith
margin, and in the marginal increments, indicated that the translucent zones were formed between April and June. The seasonal
pattern of annulus formation on the otolith became clear by observing the otoliths of fish with known ages, and the otolith
formation in wild fish was consistent with that of fish with known ages. The mean gonadosomatic index of male and female fish
was high from March to May, and spawning females were observed from mid-March to mid-May. The estimated ages were 1–5 years
for males and 1–6 years for females. The von Bertalanffy growth parameters did not significantly differ between male and female.
The model was obtained as FL
t=406×{1−exp[−0.372×(t+1.68)] 相似文献
7.
A mucinous histochemical study on malignancy of aberrant crypt foci (ACF) in rat colon 总被引：2，自引：0，他引：2
Uchida K Kado S Ando M Nagata Y Takagi A Onoue M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(2):145-149
The relationship between malignancy and number of crypts (crypt multiplicity) comprising aberrant crypt foci (ACF) was investigated, by studying changes in the mucous nature of ACF with 5 crypts or less, ACF with 6-13 crypts, adenomas and invasive adenocarcinomas induced by 1,2-dimethylhydrazine in distal colon of rats. A paradoxical Con A-staining was performed for goblet cell mucins. Of the sulfomucin-dominant ACF with 1-3 crypts, 82.6% had labile class III mucin, similar to the distal colon in the normal rats. However, in most of the goblet cell mucin produced by the ACF with 4-5 crypts with an indicated relation to colorectal carcinoma or the sialomucin (SiM) -dominant ACF with 1-3 crypts, mucin types other than class I were rarely present. The incidence of class I mucin decreased with the increase in crypt multiplicity of ACF or in the degree of histological malignancy, with the lowest incidence of 40% in adenocarcinomas. In contrast, the incidence of class II mucin increased markedly with the increase in crypt multiplicity of ACF or in the degree of histological malignancy, with the highest incidence in adenocarcinomas (95%). The ACF with 6-13 crypts had a mucous profile similar to that of adenomas. These results suggested that malignancy of ACF related to the crypt multiplicity. In the ACF with 1-3 crypts, SiM-dominant ACF had the potential to progress to malignant lesions. 相似文献
8.
The effects of temperature and light intensity on the growth and toxicity of Heterosigma akashiwo (Hada) were studied in the laboratory. The growth and toxicity of this organism were found to be greatly influenced by temperature and light intensity. The best growth was found at 25 °C where the toxicity was very low. On the other hand, cells were found to be most toxic at 20 °C (0.087 ± 0.005 FU), although the growth was much less than at 25 °C. The lowest toxicity was observed at 30 °C with a toxicity of 0.011 ± 0.005 FU. The toxicity of this species also differed markedly at different light intensities. It gave the maximum toxicity at 200 μE m?2 s?1, but poor growth. The best growth occurred at 100 μE m?2 s?1, but with a marked toxicity drop. In toxin composition studies, the amounts of most of the toxic fractions were lower at 25 °C and 100 μE m?2 s?1 where the growth was most conspicuous. 相似文献
9.
10.
Immunoglobulin M antibodies with ten combining sites 总被引：2，自引：0，他引：2
Immunoglobulin M rabbit antibodies to a hapten are shown to have ten binding sites per molecule. The affinity for the specific hapten is approximately 100 times greater for one-half of the sites than for the other half. All sites are retained in the five 7S subunits produced by reduction and alkylation of the immunoglobulin M. Each of the 7S subunits of the IgM molecule apparently has one strong and one weak site. 相似文献