Cytoskeletal abnormalities in relation with meiotic competence and ageing in porcine and bovine oocytes during in vitro maturation     

Somfai T  Kikuchi K  Kaneda M  Akagi S  Watanabe S  Mizutani E  Haraguchi S  Dang-Nguyen TQ  Inaba Y  Geshi M  Nagai T 《Anatomia, histologia, embryologia》2011,40(5):335-344

We investigated the frequencies of cytoskeletal anomalies in metaphase-II (M-II) and incompetent [arrested at an immature metaphase (IM) stage] porcine and bovine oocytes during in vitro maturation (IVM) in relation with ageing by immunostaining and confocal microscopy. In porcine oocytes, meiotic arrest at the IM stage was associated with abnormalities of cortical actin but not with abnormal spindles. Prolongation of IVM culture to 52 h did not affect microfilament and spindle abnormalities, but reduced the microfilament-rich area overlaying the spindle. Meiotic arrest of bovine oocytes at the IM stage was associated with degenerations of microfilaments, and the frequencies of abnormal spindles were also higher than those of M-II oocytes. Ageing of bovine oocytes (IVM for 30 h) did not affect cortical microfilaments but increased the frequency of spindle alterations in both M-II and IM bovine oocytes. These results suggest that, in both species, altered ability of oocytes to polymerize F-actin might be a possible reason for the failure of polar body extrusion during IVM. Also, there seem to be differences between the two species in the sensitivity of oocytes to suffer ageing-related spindle damages.  相似文献   

Diagnostic significance of serum glycated albumin in diabetic dogs   总被引：1，自引：0，他引：1  

Toshinori Sako  Akihiro Mori  Peter Lee  Tomoya Takahashi  Takehito Izawa  Sino Karasawa  Miho Furuuchi  Daigo Azakami  Mina Mizukoshi  Hisashi Mizutani  Yoshio Kiyosawa  Toshiro Arai 《Journal of veterinary diagnostic investigation》2008,20(5):634-638

Measurements of serum fructosamine, glycated hemoglobin, and glycated albumin (GA) are increasingly used to complement serum glucose concentration for better management of diabetes mellitus. Fructosamine tests are currently not performed in veterinary medicine in Japan. As such, the measurement of GA may serve as a replacement test. Therefore, in the current study, serum GA and fructosamine were evaluated for a positive correlation in dogs, and, depending on the correlation, a reference range of GA percentage would also be determined from healthy control dogs. The degree of glycemic control in diabetic dogs was determined by fructosamine concentration. A positive correlation between GA and fructosamine was observed with both normal and diabetic animals. In addition, the reference interval of serum GA percentage in control dogs was determined to be 11.4-11.9% (95% confidence interval). Interestingly, no significant difference in serum GA percentages was observed between samples from diabetic dogs with excellent glycemic control and control dogs. However, good, fair, and poor glycemic control diabetic dogs resulted in a significant increase in serum GA percentages in comparison with control dogs. These results suggest that serum GA may be a useful diagnostic indicator, substituting for fructosamine, to monitor glycemic control in diabetic dogs.  相似文献   

Enhanced Growth and nodule occupancy of red kidney bean and soybean inoculated with soil aggregate-based inoculant     

Keishi Senoo  Maki Kaneko  Rikako Taguchi  Jun Murata  Choochad Santasup  Akiyoshi Tanaka 《Soil Science and Plant Nutrition》2013,59(2):251-259

Volcanic ash soil, which is widely distributed in Japan, contains a large amount of well-structured soil aggregates. By using these aggregates as carrier materials, we prepared (brady)rhizobial inoculants for red kidney bean (Phaseolus vulgaris) and soybean (Glycine max). Autoclaved soil aggregates were inoculated with Rhizobium tropici CIATS99R or Bradyrhizobium japonicum USDA110R, incubated for 15 or 21 d at 30°C, slowly air-dried at 20°C to prepare the aggregate-based inoculants, and stored at various temperatures. The populations of CIATS99R and USDA110R in the aggregate-based inoculants were maintained during several months of storage at 20°C. When the aggregate-based inoculants were mixed with soil, CIATS99R and USDA110R cells showed a remarkably improved survival in soils compared with those mixed with soil without carrier material. The effect of the aggregate-based inoculants on the growth of red kidney bean and soybean was examined in pot experiments. By placing a small amount of the inoculant just beneath the seeds at the time of sowing, plant growth was significantly enhanced compared with the use of traditional peat-based inoculant. In addition, nodule formation on the upper part of soybean roots and nodule occupancy by the inoculated strain were remarkably enhanced by the aggregate-based inoculant. It is suggested that soil aggregates might be suitable carrier materials for preparing cheap and effective (brady)rhizobial inoculants.  相似文献   

Distribution of a bacterium (γ-1,2,3,4,5,6-hexachlorocyclohexane-decomposing Sphingomonas paucimobilis) among soil aggregates     

Keishi Senoo  Ken-ichiro Izumi  Masaya Nishiyama  Satoshi Matsumoto 《Soil Science and Plant Nutrition》2013,59(2):463-468

A great variety of microorganisms lives in soil with a heterogeneous structure. Identification and characterization of microhabitats for survival of individual soil microorganisms are important not only for gaining a better understanding of soil microbial ecology, but also for controling the biological functions of soil such as increase in nitrogen fixation, prevention of soil-borne diseases, and microbial degradation of hazardous waste materials.  相似文献   

Peach seedling growth in replant and non-replant soils after inoculation with arbuscular mycorrhizal fungi     

Kipkoriony L. Rutto  Fusao Mizutani 《Soil biology & biochemistry》2006,38(9):2536-2542

The effect of pre-inoculation with arbuscular mycorrhizal fungi (AMF) on post-transplant growth of peach seedlings in replant and non-replant soils was studied for two successive seasons. Seedlings raised in sterile media and pre-inoculated with soil-based Gigaspora margarita inoculum were transplanted in replant and non-replant field soils alongside non-inoculated controls. Pre-inoculated seedlings transplanted in non-replant soils showed greater initial growth in the first year. Plant height, and lateral shoot length and number was highest in non-replant soils irrespective of mycorrhizal pre-inoculation. Similarly, biomass yield was significantly higher in seedlings in non-replant soils, though there were no significant differences in shoot/root ratios, and in tissue mineral content between and within treatments. Seedling infection by indigenous AMF was high in both replant and non-replant soils, and even non-inoculated seedlings recorded high infection levels after the first season. Generally, mycorrhizal activity was lower, and spore populations higher in replant soils, while the opposite was true in non-replant soils. It seems that soil sickness has a negative impact on plant metabolism and limits the capacity of the plant host to support the mycorrhizal symbiosis.  相似文献   

Decontamination of Chlorate in Longan Plantation Soils by Bio-Stimulation with Molasses Amendment     

Pathipan Sutigoolabud  Keishi Senoo  Somchai Ongprasert  Takafumi Mizuno  Takashi Mishima  Makoto Hisamatsu  Hitoshi Obata 《Soil Science and Plant Nutrition》2005,51(4):583-588

Potassium chlorate is widely used as an active substance for flower induction in longan plantation fields for off-season production of longan fruits in northern Thailand. Contamination of groundwater with residual chlorate in soil is a cause for concern because of its toxicity to human health. Based on our previous finding that the addition of glucose or sucrose to soil was effective for accelerating the disappearance of residual chlorate in soil, the effect of the addition of molasses, which contains a high concentration of sucrose, as a substitute for glucose or sucrose was examined in laboratory and pot experiments. Under laboratory conditions, the addition of molasses to soil at the concentrations of 100 to 200 g kg⁻¹ soil strikingly enhanced the rate of disappearance of chlorate applied at 341 mg kg⁻¹ soil. Addition of diluted molasses was also effective for the accelerated disappearance of chlorate in soil when 33 g kg⁻¹ soil of molasses was added repeatedly. The effect of repeated addition of diluted molasses to soil on the decontamination of residual chlorate in soil was also confirmed in an outdoor pot experiment. These results may lead to the development of a practical method of cleaning-up chlorate-polluted soil in longan plantation fields.  相似文献   

Comparison of visual acuity and visual axis of three flatfish species with different ecotypes     

Keishi Matsuda  Shinsuke Torisawa  Tomonori Hiraishi  Katsutaro Yamamoto 《Fisheries Science》2008,74(3):562-572

ABSTRACT:   The visual acuity, visual axis and visual accommodation of pointhead flounder, slime flounder, and red halibut were determined to obtain basic knowledge for developing appropriate fishing gear and fishing methods for sustainable fisheries. Each of these species has a different ecotype in terms of habitat, depth and prey species. Thus, it was hypothesized that they may differ in terms of visual acuity, visual axis and visual accommodation. Few studies have compared these characters in flatfishes from different ecotypes. We used histological methods to determine visual acuity (i.e. cone cell density) and visual axis (i.e. cone cell distribution) in each of these species. The maximum visual acuity was 0.127 in pointhead flounder (total length, TL 344 mm), 0.092 in slime flounder (TL 372 mm) and 0.109 in red halibut (TL 336 mm). Based on the cone cell distribution in the retina, the visual axis was upward and forward in pointhead flounder, forward and downward in slime flounder, and downward in red halibut. Finally, the mean angle of lens movement was −2° in pointhead flounder, −13° in slime flounder and −32° in red halibut. This measurement of lens movement indicated that the average near-point distance was 0.87 × TL in pointhead flounder, 0.65 × TL in slime flounder and 1.02 × TL in red halibut. At similar TL (336–355 mm), the visual acuity of these species differs depending on the direction in which they are looking.  相似文献   

A single-tube RT-PCR method for the detection of Borna disease viral genomic RNA     

Mizutani T  Ogino M  Nishino Y  Kimura T  Kariwa H  Tsujimura K  Inagaki H  Takashima I 《The Japanese journal of veterinary research》1998,46(2-3):73-81

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Borna disease virus infection in domestic cats: evaluation by RNA and antibody detection     

Nishino Y  Funaba M  Fukushima R  Mizutani T  Kimura T  Iizuka R  Hirami H  Hara M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(10):1167-1170

Borna disease virus (BDV) infection has been suggested to cause spontaneous neurological disease in cats referred to as staggering disease. However the evaluation of BDV infection in neurologically asymptomatic cats remained unclear. In the present study, BDV infected, asymptomatic cats in Tokyo were surveyed both by the presence of plasma antibodies against BDV-p24 and -p40 and by RNA detection in peripheral blood mononuclear cells. Seven of 32 domestic cats (21.9%) were serologically or genetically judged to be BDV-infected. Six cats were positive for anti-BDV antibody and two cats were positive for BDV RNA. Within the 2 RNA-positive cats, only one was positive for anti-BDV antibodies. Furthermore, the findings of anti-BDV-p40 and anti-BDV-p24 antibody-positive cats did not completely overlap. These results suggest that there are neurologically asymptomatic domestic cats infected with BDV present in the Tokyo area.  相似文献   

Eye structure and function in the giant freshwater prawn Macrobrachium rosenbergii     

Keishi Matsuda  Marcy N. Wilder 《Fisheries Science》2014,80(3):531-541

We used histological and electroretinogram methods to investigate eye structure and function in Macrobrachium rosenbergii. M. rosenbergii was demonstrated to have superposition compound eyes with a clear zone. Rhabdom volume dramatically increased only under dark-adapted conditions at night. The eyes were assumed to be dark adapted after about 50 min under dark conditions, and to be light adapted after about 4 min under light conditions during the day. The mean angle between receptor units was 1.75°. The slope of the visual sensitivity (V/log I) curve of M. rosenbergii was 0.40 and the K value (stimulus irradiance eliciting half of the maximum response) was 16.1 log photons cm^?2 s^?1. The mean dynamic range was 4.06, ranging from 13.91 to 17.97 log photons cm^?2 s^?1. The response latency was 19.6 ± 7.5 ms (mean ± SD). Analysis of the visual spectral sensitivity of dark-adapted specimens indicated that the sensitivity maximum was centered at a wavelength of 563 nm in the yellow–green region of the spectrum. The critical flicker fusion frequency increased as stimulus irradiance increased, up to a maximum of 44.3 Hz at almost the same stimulus irradiance of the K value.  相似文献