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991.
Renée Claire Le Bayon Virginie Matera Roxane Kohler-Milleret Claudia Degen Jean-Michel Gobat 《Pedobiologia》2011
Environmental pollution due to arsenic (As) has been well studied and most investigations have focused on inorganic As coming from industrial areas. However, the natural rock-borne contamination of this metalloid has been underestimated and few studies focusing on annelids have addressed the question of geogenic As distribution in earthworm biogenic structures. Our study concentrated on the earthworm drilosphere and investigated the distribution of As in surface-casts and burrow-linings. In this context, we assumed that the concentration of geogenic As should differ in biogenic structures (faeces, burrow-linings) compared to non-ingested soil. To test our hypothesis, microcosms in controlled conditions were filled with soil containing 157 mg As kg?1 from a geogenic origin. The soil was collected from a meadow in the Jura Mountains. The earthworm Aporrectodea giardi was selected because of its natural presence in the meadow and its anecic behaviour.We found that while earthworm surface-casts were enriched in carbon, nitrogen and available phosphorus compared to non-ingested soil, no enrichment was found for geogenic arsenic. The coarse sand fraction contained 3.5 times more As than silt and clay fractions but no significant difference existed between surface-casts and non-ingested soil. Iron was shown to be the main mineral bearing phase for As and predominated in the coarse sand fraction. No retention effect of organic matter on geogenic arsenic was observed. In conclusion, it appeared that geogenic As did not affect biological components and environmental aspects. These findings are particularly encouraging considering that most of the environments at an altitude of 1330 m in the Jura Mountains have exposed rocks, especially on meadows that are regularly grazed by cattle. 相似文献
992.
Cakir-Kiefer C Miclo L Balandras F Dary A Soligot C Le Roux Y 《Journal of agricultural and food chemistry》2011,59(22):11956-11965
α-Casozepine and f91-97, peptides from α(s1)-casein, display anxiolytic activity in rats and may have to cross the intestinal epithelium to exert this central effect. We evaluated their resistance to hydrolysis by the peptidases of Caco-2 cells and their ability to cross the cell monolayer. To mimic physiological conditions, two preparations of bile salts were used in noncytotoxic concentrations: porcine bile extract and an equimolar mixture of taurocholate, cholate, and deoxycholate. The presence and composition of bile salts appeared to modulate the peptidase activities of the Caco-2 cells involved (i) in the hydrolysis of α-casozepine, leading to much higher formation of fragments f91-99, f91-98, and f91-97, and (ii) in the hydrolysis of f91-97, leading to lower degradation of this peptide. Transport of α-casozepine across Caco-2 monolayer increased significantly, in the presence of bile extract, and of fragment f91-97, in the presence of bile salts. 相似文献
993.
Kim KH Choi SU Choi SZ Son MW Lee KR 《Journal of agricultural and food chemistry》2011,59(13):6980-6984
Edible yams are tropical crops that serve as important staple foods in many parts of the world. The rhizome of Dioscorea japonica , well-known as "Japanese yam", is a food and medicinal source known as "San Yak" in Korea. Bioassay-guided fractionation and chemical investigation of the extract of this yam resulted in the identification of two new withanolides, named dioscorolide A (1) and dioscorolide B (2). The structures of these new compounds were determined by spectroscopic methods, including 1D and 2D nuclear magnetic resonance (NMR) techniques, high-resolution mass spectrometry (HRMS), and chemical methods. The cytotoxic activities of the isolates (1 and 2) were evaluated by determining their inhibitory effects on four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT15) and a human normal cell line (HUVEC) using a sulforhodamine B (SRB) bioassay. Compounds 1 and 2 showed cytotoxicity against tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT15) with IC(50) values ranging from 6.3 to 26.9 μM and exhibited lower activity against the normal cell line (HUVEC) with IC(50) values ranging from 27.1 to 28.8 μM, suggesting selective toxicity among tumor and normal cells. 相似文献
994.
Effects of vegetation type on soil resistance to erosion: Relationship between aggregate stability and shear strength 总被引:5,自引:0,他引:5
M. Fattet Y. Fu M. Ghestem W. Ma M. Foulonneau J. Nespoulous Y. Le Bissonnais A. Stokes 《CATENA》2011
Soil water erosion and shallow landslides depend on aggregate stability and soil shear strength. We investigated the effect of vegetation on both soil aggregate stability and shear strength (through direct shear tests) in former croplands converted to vegetated erosion protection areas within the context of China's sloping land conversion programme. Four treatments were analysed in plots comprised of (i) 4 year old crop trees, Vernicia fordii, where understory vegetation was removed; (ii) V. fordii and the dominant understory species Artemisia codonocephala; (iii) only A. codonocephala and (iv) no vegetation. Soil samples were taken at depths of 0–5 cm and 45–50 cm. Root length density (RLD) in five diameter classes was measured, soil organic carbon (SOC), hot water extractable carbon (HWEC), texture and Fe and Al oxides were also measured. We found that mean weight diameter after slow wetting (MWDSW) in the A-horizon, was significantly greater (0.94–1.01 mm) when A. codonocephala was present compared to plots without A. codonocephala (0.57–0.59 mm). SOC and RLD in the smallest diameter class (< 0.5 mm), were the variables which best explained variability in MWDSW. A significant positive linear relationship existed between MWDSW and soil cohesion but not with internal angle of friction. As herbaceous vegetation was more efficient than trees in improving aggregate stability, this result suggests that the mechanisms involved include modifications of the cohesive forces between soil particles adjacent to plant roots and located in the enriched in SOC rhizosphere, thus also affecting shear strength of the corresponding soil volume. Thus, vegetation stabilised soil under different hierarchical levels of aggregate organisation, i.e. intra- and inter-aggregate. Our results have implications for the efficacy of techniques used in land conversion programs dedicated to control of soil erosion and shallow landslides. We suggest that mixtures of different plant functional types would improve soil conservation on slopes, by reducing both surface water erosion and shallow substrate mass movement. Planting trees for cropping or logging, and removing understory vegetation is most likely detrimental to soil conservation. 相似文献
995.
996.
Lim JH Kim TW Park SJ Song IB Kim MS Kwon HJ Cho ES Son HY Lee SW Suh JW Kim JW Yun HI 《Journal of toxicologic pathology》2011,24(4):223-228
The aim of the present study was to evaluate the protective activity of aqueous extract
from Platycodon grandiflorum (BC703) on thioacetamide (TA)-induced
hepatotoxicity in mice. We found that BC703 significantly decreased mortality and the
change in serum transaminase following TA administration. The group treated with BC703 at
doses of 1, 5, and 10 mg/kg produced significant hepatoprotective effects against
TA-induced liver damage by decreasing the activities of serum enzymes, nitric oxide and
lipid peroxidation in dose-dependent manners. Histopathological studies further
substantiated the protective effect of BC703. These results show the hepatoprotective
activity of aqueous extract from Platycodon grandiflorum on
thioacetamide-induced fulminant hepatic failure. 相似文献
997.
Viet Linh N Kikuchi K Nakai M Noguchi J Kaneko H Dang-Nguyen TQ Maedomari N Nguyen BX Nagai T Manabe N 《The Journal of reproduction and development》2011,57(5):620-626
We have shown in pigs that oocytes denuded of cumulus cells at 24 h of in vitro maturation culture and subsequently matured for a total of 46 h (DO24 oocytes) have lower cytoplasmic maturity than those matured with cumulus cells for 46 h and then denuded (DO46 oocytes). In the present study, DO24 zona-free oocytes were fused with one (1C) or two (2C) cytoplasmic fragments produced by serial centrifugation ("centri-fusion") of DO46 oocytes (DO24+1C and DO24+2C oocytes, respectively). Groups of (1) DO46 (a control), (2) DO24, (3) DO24+1C and (4) DO24+2C oocytes were partheno-activated by an electrical pulse or fertilized in vitro and subsequently cultured for 6 days. In the fused groups, female pronucleus (FPN) formation rates were higher than that in the DO24 group after parthenogenetic activation (PA); however, the blastocyst rates were intermediate between those of the control and DO24 groups. After in vitro fertilization, the male pronucleus (MPN) formation rates in the fused groups were similar to that in the control group and higher than that in the DO24 group; the normal fertilization rate in the DO24+2C group was higher than that in the DO24 group and similar to that in the control group, resulting in significantly higher blastocyst rates in the DO24+2C and control groups than that in the DO24 group. These results suggest that centri-fusion using ooplasm from fully matured DO46 oocytes can offer a potentially novel approach for restoration of cytoplasmic maturity to oocytes with low developmental ability and subsequent improvement of fertilization and developmental competence. 相似文献
998.
Somfai T Imai K Kaneda M Akagi S Watanabe S Haraguchi S Mizutani E Dang-Nguyen TQ Inaba Y Geshi M Nagai T 《The Journal of reproduction and development》2011,57(6):723-730
Since BSE testing of slaughtered cattle is obligatory in Japan, storage of ovaries at 15-20 C overnight in phosphate buffered saline has become a routine protocol in in vitro production (IVP) of cattle embryos. Ovary storage is known to reduce developmental competence of oocytes; however, its effects on oocyte gene expression have not been clarified yet. This study compared oocytes collected from stored slaughterhouse-derived ovaries with those collected by Ovum Pick-Up (OPU) in terms of the expression of 20 selected genes to determine if ovary storage affects cellular processes at the molecular level. Expression of mRNA in oocytes was assayed before and after in vitro maturation (IVM) by real-time quantitative PCR. Maternal mRNA levels of genes were investigated in 2-cell stage embryos obtained from slaughterhouse oocytes to assess their roles for blastocyst formation. In immature OPU oocytes, genes related to metabolism (GAPDH), transporters (GLUT8, ATP1A1) and stress resistance protein (HSP70) showed significantly higher expression compared with oocytes derived from stored ovaries. During IVM, the expression of GDF9, GLUT8, CTNNB1 and PMSB1 was significantly decreased irrespective of oocyte source. Two-cell stage embryos cleaving at 22-25 h after in vitro fertilization (IVF) showed a significantly higher blastocyst formation rate and ATP1A1 gene expression level compared with those cleaving at 27-30 h after IVF. Our results reveal that storage of ovaries alters mRNA levels in oocytes. Correlation of Na/K ATPase ATP1A1 expression in IVP embryos at the 2-cell and 8-cell stages with their developmental ability to the blastocyst stage may suggest the importance of maternal mRNA of this gene during blastulation in embryos derived from slaughterhouse oocytes. 相似文献
999.
本研究旨在探讨不同能量和蛋白质水平日粮对石岐杂仔鸡器官指数和血液生化指标的影响。选用21日龄健康石岐杂鸡120只,随机分为4组,每组3个重复,每个重复10只,饲喂4种蛋白质(CP)和能量(DE)水平不同的玉米-豆饼型日粮,分别为:Ⅰ组(12.09 MJ/kg;18.07%)、Ⅱ组(13.09 MJ/kg;18.01%)、Ⅲ组(12.09 MJ/kg;20.08%)和Ⅳ组(13.09 MJ/kg;19.93%)。试验期为21 d。结果显示:(1)Ⅱ、Ⅳ组较Ⅰ组能显著提高胸腺、脾脏和法氏囊等免疫器官指数(P<0.05);Ⅲ组较Ⅰ组能显著提高胸腺和脾脏指数(P<0.05)。(2)Ⅱ组较Ⅰ、Ⅲ组能显著提高肝脏指数(P<0.05);(3)Ⅱ组能显著提高葡萄糖和总胆固醇的含量(P<0.05);Ⅲ组能显著提高血清总蛋白、甘油三酯和尿酸的含量(P<0.05);Ⅳ组能显著提高血清总蛋白和葡萄糖的含量(P<0.05),并提高总胆固醇、甘油三酯和尿酸含量(P>0.05)。对于22~42日龄的石岐杂鸡,以免疫器官指数作为衡量标准,能量13.09 MJ/kg、蛋白质19.93%较为适宜;以血液葡萄糖和尿酸(或其他指标)为衡量指标,能量... 相似文献
1000.
为了研究蒙药三子汤对热应激小鼠的CD3+T/CD19+B细胞的作用,160只小鼠随机分4组:灌水组、热应激组、低剂量热应激组和高剂量热应激组,热应激后眼前房采血,流式细胞仪检测CD3+T/CD19+B细胞变化。结果:热应激0h的4组小鼠CD3+T/CD19+B细胞差异不显著;热应激组CD3+细胞2h、7d均显著低于灌药、灌水组(p<0.05);灌药组1h、2h、7d小鼠CD19+细胞量显著高于热应激、灌水组。表明三子汤可以维持热应激小鼠CD3+T细胞量无显著变化,并可显著提高CD19+B细胞量。 相似文献