Epigenetic assessment of environmental chemicals detected in maternal peripheral and cord blood samples     

Arai Y  Ohgane J  Yagi S  Ito R  Iwasaki Y  Saito K  Akutsu K  Takatori S  Ishii R  Hayashi R  Izumi S  Sugino N  Kondo F  Horie M  Nakazawa H  Makino T  Shiota K 《The Journal of reproduction and development》2011,57(4):507-517

Epigenetic alteration is an emerging paradigm underlying the long-term effects of chemicals on gene functions. Various chemicals, including organophosphate insecticides and heavy metals, have been detected in the human fetal environment. Epigenetics by DNA methylation and histone modifications, through dynamic chromatin remodeling, is a mechanism for genome stability and gene functions. To investigate whether such environmental chemicals may cause epigenetic alterations, we studied the effects of selected chemicals on morphological changes in heterochromatin and DNA methylation status in mouse ES cells (ESCs). Twenty-five chemicals, including organophosphate insecticides, heavy metals and their metabolites, were assessed for their effect on the epigenetic status of mouse ESCs by monitoring heterochromatin stained with 4￠,6-diamino-2-phenylindole (DAPI). The cells were surveyed after 48 or 96 h of exposure to the chemicals at the serum concentrations of cord blood. The candidates for epigenetic mutagens were examined for the effect on DNA methylation at genic regions. Of the 25 chemicals, five chemicals (diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se) and octachlorodipropyl ether (S-421)) caused alterations in nuclear staining, suggesting that they affected heterochromatin conditions. Hg and Se caused aberrant DNA methylation at gene loci. Furthermore, DEP at 0.1 ppb caused irreversible heterochromatin changes in ESCs, and DEP-, Hg- and S-421-exposed cells also exhibited impaired formation of the embryoid body (EB), which is an in vitro model for early embryos. We established a system for assessment of epigenetic mutagens. We identified environmental chemicals that could have effects on the human fetus epigenetic status.  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   

戊型肝炎病毒(HEV)猪间传播的动力学分析——对人类感染的潜在影响     

Kunio Satou  朱于敏  孙旭涵 《国外畜牧学(猪与禽)》2007,27(5):53-57,63

【目的】戊型肝炎病毒(Hepatitis Evirus,HEV)感染是一种人畜共患病,而猪是HEV的病毒储库。在日本,HEV感染已成为猪的地方性猪病。阐明HEV在猪场中的详细传播机制,将有利于人们掌握特定年龄段猪群的感染状况,尤其是肉猪在屠宰前的感染状况。【结果】本文,作者重新分析了源于日本猪场的一个大型猪HEV血清阳性率数据集,以此评估HEV的感染力。结果表明,北海道、本州和九州三个地区猪场中的猪HEV感染力分别为3.45×10-2/d(95%的置信区间(下同):3.17～3.75×10-2/d)、2.68×10-2/d(2.28～3.14×10-2/d)和3.11×10-2/d(2.76～3.50×10-2/d)。利用作者建立的模型得到的估测结果表明,猪感染HEV的平均日龄在59.0～67.3d之间,其基本传染数R0按4.02～5.17的数量级递增。对特定年龄猪群在不同感染力下的敏感性分析显示,HEV感染力下降将提高猪感染HEV的年龄,而且会增加180日龄时散毒猪的数量。【结论】尽管作者的研究表明95%以上的猪是在150日龄前被感染的,但该模型显示感染力下降可以增加感染猪将HEV传播给人的风险。如果感染力开始下降,就有必要采取基本的应对策略(如在哺乳期末将未感染猪与感染猪分开)以最大限度地减少肥育阶段的HEV阳性猪数量。  相似文献   

Serological characterization of viruses isolated from experimental mucosal disease   总被引：2，自引：0，他引：2  

M Shimizu  K Satou  N Nishioka  T Yoshino  E Momotani  Y Ishikawa 《Veterinary microbiology》1989,19(1):13-21

Four cattle persistently infected with non-cytopathogenic bovine viral diarrhoea-mucosal disease (BVD-MD) virus and 3 normal controls were challenge exposed to cytopathogenic BVD-MD viruses that are antigenically different from the persistent viruses. Two of the persistently infected cattle developed mucosal disease and became moribund on postinoculation days (PID) 28 and 14, respectively; one developed severe and chronic diarrhoea and became moribund on PID 32; and the other remained healthy until the end of the experiment (PID 150). All control cattle showed transient fever, but no diarrhoea, and recovered from infection. Cytopathogenic viruses were isolated from blood of all cattle early in infection (PID 5-10) and from carcasses at necropsy. The former viruses were antigenically identical with the challenge viruses. On the other hand, the antigenicity of the cytopathogenic viruses isolated from carcasses at necropsy were different from that of the challenge viruses but similar to that of the non-cytopathogenic persistent viruses. Three of 4 persistently infected cattle, but not the calf which became moribund on PID 14, produced serum neutralizing (SN) antibodies to the challenge viruses, but not to the persistent viruses and the cytopathogenic viruses isolated from carcasses at necropsy. Control cattle produced SN antibodies to both the challenge and persistent viruses.  相似文献   

Improved method for culturing the swimming crab Portunus trituberculatus larvae to prevent mass mortality during seed production     

Shigeki Dan  Masakazu Ashidate  Katsuyuki Hamasaki 《Fisheries Science》2016,82(1):113-126

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The smell and odorous components of dried shiitake mushroom, Lentinula edodes III: substances that increase the odorous compound content     

Masakazu Hiraide 《Journal of Wood Science》2006,52(3):265-269

This study formed part of an effort to improve the quality of dried shiitake mushroom [Lentinula edodes (Berk.) Pegler], in accordance with consumer preferences, and deals with the search for substances that increase the odorous component content. From analysis of sulfur and sulfur-containing substances in the culture substrate, rice bran was found to be the main source of sulfur, and 75% of this was present as cysteine and methionine. The sulfur-containing substances were added to a sawdust medium containing only rice bran and sawdust as a substrate; shiitake mushrooms were cultivated in the medium, the fruiting bodies were dried, and the 1,2,4-trithiolane content in the fruiting bodies was measured as an indicator of the odorous compounds. Of the sulfur-containing substances, those that increased odorous compounds the most were cysteine and methionine. The efficiency of cysteine in this regard was higher than that of methionine. It was also noted that the amount of glutamic acid increased the odorous compounds in combination with cysteine and methionine. Furthermore, the addition of both amino acids and glutamic acid had no negative effect on the yield. These results showed that it is possible to produce dried shiitake mushrooms with a smell suitable for particular consumer preferences.  相似文献   

The impact of forest clear-cutting on soil temperature: a comparison between before and after cutting,and between clear-cut and control sites   总被引：2，自引：0，他引：2  

Shoji?HashimotoEmail author  Masakazu?Suzuki 《Journal of Forest Research》2004,9(2):125-132

Soil temperature is one of the most important factors governing biological activity in the soil. This study was conducted to investigate how forest clear-cutting changes soil temperature. Soil temperatures at 0.5, 1.0, 2.0, and 3.0m depths were measured in two neighboring forest watersheds (35°12N, 140°06E) in Chiba Prefecture, Japan, from 1994 to 2000. One watershed was clear-cut 5 years after the observations began. After clear-cutting, the annual mean soil temperature at 0.5, 1.0, 2.0, and 3.0m depths rose by about 2.2, 2.0, 1.7, and 1.4°C, respectively. The maximum respective soil temperatures rose by about 3.2, 3.0, 2.2, and 1.8°C. The minimum soil temperature rose slightly (1°C). The range of temperatures increased by 3.0, 2.4, 1.6, and 1.4°C, respectively. In our study, forest clear-cutting raised maximum and average soil temperatures but hardly changed minimum soil temperature. This is probably because solar radiation dominated in the summer season and increased soil temperature; on the other hand, net long-wave radiation, and releases of latent and sensible heat from the soil surface, were predominant in the cool season.  相似文献   

The smell and odorous components of dried shiitake mushroom, <Emphasis Type="Italic">Lentinula edodes</Emphasis> I: relationship between sensory evaluations and amounts of odorous components     

Masakazu?HiraideEmail author  Yoshifumi?Miyazaki  Yasushi?Shibata 《Journal of Wood Science》2004,50(4):358-364

The smell of food is one of the most important factors in assessing its quality. Concerning the smell of dried shiitake mushrooms [Lentinula edodes (Berk.) Pegler], 1,2,3,5,6-pentathiepane, commonly known as lenthionine, has been reported as a key compound. However, other compounds have not been studied sufficiently in connection with smell. From the results of sensory intensity studies and sensory evaluations of dried shiitake mushrooms, a positive significant correlation at 1% risk was observed between sensory intensity and sulfur perception. This showed that the smell of dried shiitake mushrooms was characterized by a sulfurous smell. Also, comparing the sensory intensity with the amounts of volatile components showed positive significant correlations at 1% risk between sensory intensity and three compounds: 1,2,4-trithiolane, 1,2,4,6-tetrathiepane, and lenthionine. Furthermore, significant correlations at 5% risk were obtained between the amounts of these three compounds and sensory intensity by multiple regression analysis. This showed that the smell of dried shiitake mushrooms depended on these compounds. The partial regression coefficient of 1,2,4-trithiolane was larger than those of the others, and so it was proposed that 1,2,4-trithiolane could serve as an indicator to estimate the smell of dried shiitake mushroom.  相似文献   

Adsorption of mercury by sugi wood carbonized at 1000°C     

Lilibeth Pulido-Novicio  Yasuji Kurimoto  Masakazu Aoyama  Kazuto Seki  Shuichi Doi  Toshimitsu Hata  Shigehisa Ishihara  Yuji Imamura 《Journal of Wood Science》2001,47(2):159-162

The ability of sugi wood carbonized at 1000°C to adsorb mercury was examined using aqueous solutions of mercuric chloride. Parameters studied include contact time, pH, adsorption temperature, and initial concentration of mercury in solution. Results showed that sugi wood carbonized at 1000°C could effectively remove mercury from aqueous solutions. The carbonized wood showed high adsorption ability for mercury at a wide pH range (pH 3–9), but its ability drastically decreased at pH 11. Adsorption decreased with increases in adsorption temperatures, indicating that the processes were exothermic in nature. Adsorption was found to follow the Freundlich isotherm model. The adsorption capacity of carbonized sugi wood was comparable to that of commercial activated carbon.  相似文献   

Cis-acting transcriptional repression establishes a sharp boundary in chordate embryos     

KS Imai  Y Daido  TG Kusakabe  Y Satou 《Science (New York, N.Y.)》2012,337(6097):964-967

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