Effects of delayed first feeding on the survival and growth of tiger grouper,Epinephelus fuscoguttatus (Forsskål, 1775), larvae     

Fui Fui Ching  Yoshizumi Nakagawa  Keitaro Kato  Osamu Murata  Shigeru Miyashita 《Aquaculture Research》2012,43(2):303-310

The effects of delayed first feeding on the survival and growth of tiger grouper, Epinephelus fuscoguttatus (Forsskål 1775), larvae were examined under controlled conditions. The total length, yolk sac volume, oil globule volume, yolk sac absorption time and nutritional transition period (NTP) of the larvae fed at different first times (0, 6, 12, 18 and 24 h after the mouth opening stage; h AMO) were compared. Larval first feed intake was observed at 54 h after hatching (h AH) at 27.5 ± 0.5 °C. The yolk sac was consumed more rapidly with an increase in delayed first feeding and was significantly different among treatments (P<0.05). Larvae first fed at 0 h AMO had the longest yolk sac absorption (72 h AH) and NTP (20 h) times and had the highest survival and growth rates at the end of the experimental period (360 h AH), being significantly higher (P<0.05) than the other treatments. First mortality was observed at 69 h AH, approximately 2 h after point of no return (PNR) occurred. This study suggests that first feeding of tiger grouper larvae should commence at 0 h AMO for enhancement of larval survival and growth.  相似文献   

Preliminary observation of growth‐promoting effects of alginate hydrolysates on juvenile Manila clams,Ruditapes philippinarum          下载免费PDF全文

Yasuhiro Yamasaki  Shigeru Taga  Masanobu Kishioka 《Aquaculture Research》2015,46(4):1013-1017

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A method for visualizing cesium ions adsorbed on wood charcoal using SEM–EDX     

Takayuki?YamagishiEmail author  Yasuji?Kurimoto  Shigeru?Yamauchi 《Wood Science and Technology》2017,51(2):413-429

A new method based on scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDX) was developed for visualizing the distribution of cesium ions (Cs⁺) adsorbed by Japanese cedar charcoal. After being soaked in saturated aqueous CsCl solutions, wood charcoal and regular wood samples were embedded in resin, and thin sections of sample were prepared for the Cs⁺ observations. The Cs⁺ ions on charcoal could be seen in EDX mapping images and also in line profiles with enough contrast to identify differences between the various carbonized cell wall regions. On the other hand, Cs⁺ could not be observed in the EDX mapping images of wood samples, despite having been soaked in a saturated aqueous CsCl solution. These results indicate that Cs⁺ adsorbed on charcoal can be visualized using this method, but not Cs⁺ in wood. Additionally, oxygen detected on the charcoal by EDX can be regarded as an indicator of the presence of surface functional groups.  相似文献   

Formation of a complex with aluminum by ozone-treated kraft lignins and their low molecular weight fragments     

Hikaru Aimi  Ko Tahara  Yasuji Kurimoto  Shigeru Yamauchi 《Journal of Wood Science》2010,56(2):133-139

The formation of a complex with aluminum by low molecular weight compounds and saponified ozone-treated kraft lignins was evaluated based on the decrease in pH of their solutions on the addition of 0.1 M AlCl₃. Decreases in pH were observed with the solutions containing compounds having adjacent carboxyl groups (oxalic acid), carboxyl/alcoholic hydroxyl groups (glycolic acid), carboxyl/formyl groups (glyoxylic acid), and phenolic hydroxyl groups (protocatechuic acid) on the addition of 0.1 M AlCl₃. The malonic and phthalic acids, having two carboxyl groups, were also effective. These results show that the compounds were effective in forming complexes with aluminum. This finding corresponds to the fact that aluminum toxicity is reduced by formation of a complex with aluminum, except in phthalic acid. The chemical structures stated above in ozone-treated kraft lignins contribute, at least partly, to the complex with aluminum. The pH of solutions containing saponified ozone-treated kraft lignins and alkaline-treated kraft lignin decreased more than that without modified kraft lignins on the addition of 0.1 M AlCl₃, showing that they were effective in forming a complex with aluminum. The high molecular weight part of saponified ozone-treated kraft lignin was effective in forming a complex with aluminum and in reducing its toxicity.  相似文献   

Effect of a Large Dose of Di (2-ethylhexyl) phthalate (DEHP) on Hepatic Peroxisome in Cynomolgus Monkeys (Macaca Fascicularis)     

Satake S  Nakamura C  Minamide Y  Kudo S  Maeda H  Chihaya Y  Kamimura Y  Miyajima H  Sasaki J  Goryo M  Okada K 《Journal of toxicologic pathology》2010,23(2):75-83

To elucidate the effect of a large dose of di (2-ethylhexyl) phthalate (DEHP), a plasticizer and peroxisome proliferator-activated receptor-α (PPARα) agonist, on hepatic peroxisomes, we orally administered 1,000 mg/kg/day, once daily, to 3 male and 4 female cynomolgus monkeys for 28 days consecutively. Light-microscopic and electron microscopic examinations of the liver were carried out in conjunction with measurement of the hepatic fatty acid β-oxidation system (FAOS), carnitine acetyltransferase (CAT) and carnitine palmitoyltransferase (CPT) activities, which are peroxisomal and/or mitochondrial enzyme activities. Electron microscopically, enlargement of the mitochondria was observed with lamellar orientation of the cristae along the major axis. Although the number of peroxisomes showed a tendency to increase when compared with those in a biopsied specimen before treatment, no abnormality in morphology was observed. A slight increase in CPT activity was noted at termination. No changes were noted in hepatic FAOS or CAT activity. In conclusion, although repeated oral treatment of cynomolgus monkeys with a large dose of DEHP induced a subtle increase in the numbers of peroxisomes with slight enlargements of the mitochondria, this low-sensitivity response to peroxisome proliferators in cynomolgus monkeys was considered to be closer to the response in humans than that in rodents.  相似文献   

Induction of apoptotic lesions in liver and lymphoid tissues and modulation of cytokine mRNA expression by acute exposure to deoxynivalenol in piglets     

Osamu Mikami  Hiroyuki Yamaguchi  Hideo Murata  Yasuyuki Nakajima  Shigeru Miyazaki 《Journal of veterinary science (Suw?n-si, Korea)》2010,11(2):107-113

Six 1-month-old piglets were intravenously injected with deoxynivalenol (DON) at the concentration of 1 mg/kg body weight, with three pigs each necropsied at 6 and 24 h post-injection (PI) for investigation of hepatotoxicity and immunotoxicity with special attention to apoptotic changes and cytokine mRNA expression. Histopathological examination of the DON-injected pigs revealed systemic apoptosis of lymphocytes in lymphoid tissues and hepatocytes. Apoptosis of lymphocytes and hepatocytes was confirmed by the TdT-mediated dUTP-biotin nick end-labeling (TUNEL) method and immunohistochemical staining against single-stranded DNA and cleaved caspase-3. The number of TUNEL-positive cells in the thymus and Peyer''s patches of the ileum was increased at 24 h PI compared to 6 h PI, but the peak was at 6 h PI in the liver. The mRNA expression of interleukin (IL)-1β, IL-6, IL-18, and tumor necrosis factor (TNF)-α in the spleen, thymus and mesenteric lymph nodes were determined by semi-quantitative RT-PCR, and elevated expression of IL-1β mRNA at 6 h PI and a decrease of IL-18 mRNA at 24 h PI were observed in the spleen. IL-1β and IL-6 mRNA expressions increased significantly at 6 h PI in the thymus, but TNF-α decreased at 6 h PI in the mesenteric lymph nodes. These results show the apoptosis of hepatocytes suggesting the hepatotoxic potential of DON, in addition to an immunotoxic effect on the modulation of proinflammatory cytokine genes in lymphoid organs with extensive apoptosis of lymphocytes induced by acute exposure to DON in pigs.  相似文献   

Construction of a system for exploring mitotic homologous recombination in the genome of Pyricularia oryzae     

Takayuki Arazoe  Shuichi Ohsato  Tsutomu Arie  Katsuyoshi Yoneyama  Shigeru Kuwata 《Journal of General Plant Pathology》2013,79(6):422-430

To investigate mitotic homologous recombination (HR) in Pyricularia oryzae, we created an HR detection system. The system consists of two non-functional enhanced yellow fluorescent protein (YFP) and blasticidin S deaminase (BSD) fusion genes (YFP::BSD). If mitotic HR occurs between the two non-functional genes in the genome, restoration of the functional YFP::BSD gene can be expected. The expression of the functional YFP::BSD gene can be detected by both YFP fluorescence and resistance against BS. When the P. oryzae genome was transformed simultaneously with two non-functional genes, all six lines of transformants with both genes had some portion of their hyphae exhibiting YFP fluorescence and BS resistance during growth. Up to ca. 10 % of conidia harvested from the mycelium of each of the six lines had YFP fluorescence, suggesting that HR consistently occurs during mycelium growth. To determine whether and how the HR-mediated phenotypic changes occurred at the DNA level, we analyzed the genomic DNA of BS-resistant mycelia by PCR-RFLP and sequencing and were able to confirm the existence of a restored functional YFP::BSD gene and a non-functional recombinant gene. Collectively, these findings demonstrate that we established a successful HR detection system for P. oryzae, which can be used for other plant pathogens, and that mitotic HR actually occurs in P. oryzae and constitute the first experimental evidence for mitotic HR in a fungus.  相似文献   

Evaluation of bone toxicity in various bones of aged rats     

Noguchi C  Miyata H  Sato Y  Iwaki Y  Okuyama S 《Journal of toxicologic pathology》2011,24(1):41-48

The aim of the present study was to provide a method for evaluating bone toxicity induced by drugs in various bones in aged rats. Male Crl:CD (SD) rats at 46 weeks of age were administered 15 mg/m(2) body surface area of doxorubicin, which effects the growth plate in weanling rats, weekly for 9 weeks by intravenous injection, and the femur, sternum, humerus and tibia were examined histopathologically. In the doxorubicin-treated group, thinning of the growth plate was remarkably observed in the proximal tibia and humerus; however, these changes were not observed in other regions. In addition, the osteoclast number per bone perimeter in the proximal tibia was significantly higher than others in control aged rat. Thus, recognizing the various histological reactions related to the time of epiphyseal closure is important for evaluating bone toxicity in aged rats.  相似文献   

How different or similar are nematode communities between a paddy and an upland rice fields across a flooding-drainage cycle?     

Hiroaki Okada  Shigeru Niwa  Masakazu Komatsuzaki 《Soil biology & biochemistry》2011,43(10):2142-2151

The paddy field is being recognised as a biodiversity hotspot fostering a variety of organisms. However, there are few studies on the ecology of paddy field nematodes. We characterised nematode communities in rice paddy fields by comparing them with upland fields of rice or soybean. We examined nematode communities of the top (0-15 mm) and second (15-50 mm) soil layers before flooding (March or April), during flooding (June or July) and during the draining period (October) 2007-2009. We found that the nematode community in the paddy was different than that in the upland fields during all periods. Rhabdolaimus, Tobrilus, Mesodorylaims and Monhysteridae characterised the top of the paddy and Hirschmanniella characterised the second layer of the paddy. Total nematode density was generally lower in the paddy than in the upland field. However, the density in the paddy top layer increased with time from the flooding period to the draining period, during which time it was about the same as (or even greater than) the peak density in the upland fields. The density in the second layer of the paddy remained lower than that in the top layer of the paddy throughout the time course. Community diversity values were generally greater in the paddy top layer than in the paddy second layer across the six sampling periods, but periodic differences between the paddy and upland fields or between soil layers were not significant. During the flooding period, the F/(F + B) (13-37) and Enrichment Index (17-38) values were lower in the paddy than in the upland fields (32-47, 37-74, respectively) to reflect that bacteria dominate over fungi with slow decomposition due to anaerobic conditions in the flooded paddy field. In addition, particularly in the top layer, the Maturity (2.0-2.4) and Structure Index (23-72) values were greater in the paddy than in the upland fields (1.7-2.1, 9-15, respectively), indicating a well-developed ecosystem under water. These unique nematode communities persisted during the draining period, but there was a rapid increase in opportunistic bacterivores, which increased the EI values. We suggest that bactivorous nematodes in the families Cephalobidae and Chronogasteridae, herbivores in the genus Hirschmanniella, and fungivores in the genus Filenchus may be specific to paddy field soil rather than to pond and lake sediments.  相似文献   

Effects of Saccharomyces cerevisiae supplementation on growth performance,plasma metabolites and hormones,and rumen fermentation in Holstein calves during pre‐ and post‐weaning periods     

Kei Takemura  Hiroyuki Shingu  Kentaro Ikuta  Shigeru Sato  Shiro Kushibiki 《Animal Science Journal》2020,91(1)

This study aimed to evaluate the effects of supplementing Saccharomyces cerevisiae (SC) during the pre‐ and post‐weaning periods on growth, metabolic and hormonal responses, and rumen fermentation in calves. Three‐week‐old Holstein calves were assigned to either control (n = 12) or SC group (n = 12), the latter of which received 2 × 10⁹ cfu/day of SC. The experiment was conducted over a period of 7 weeks around weaning. Daily gain (DG) in the SC group was higher (p < .05) than that in the control group. In the SC group, plasma glucose, insulin, and growth hormone (GH) concentrations were higher (p < .05) and concentrations of glucagon and insulin‐like growth factor 1 (IGF‐1) tended to be higher (p < .1) than in the control group. Proportion of rumen propionate and concentration of rumen ammonia nitrogen at 10 weeks of age were greater (p < .05) in the SC group than that in the control group. Supplementation of SC around weaning may improve dietary nutrient and energy availability and increase plasma GH and IGF‐1 concentrations. These changes observed in SC‐supplemented calves could be closely related to the improvement of DG.  相似文献