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Результаты 1501-1510 из 4,938
Di-(2-ethylhexyl) phthalate induced an increase in blood pressure via activation of ACE and inhibition of the bradykinin-NO pathway Полный текст
2019
Deng, Ting | Xie, Xiaoman | Duan, Jiufei | Chen, Mingqing
Epidemiological studies and animal experiments have suggested that exposure to Di-(2-ethylhexyl) phthalate (DEHP) is strongly associated with an increase in blood pressure. However, the mechanisms that result in the detrimental effects of DEHP exposure on blood pressure are unclear. In our study, mice were orally exposed to DEHP dosages of 0.1, 1, 10 mg/kg/day for 6 weeks. The results showed that DEHP could induce a significant increase in systolic blood pressure (SBP) and heart rate, and a significant thickening of the ventricular wall. To explore the underlying mechanism, we measured the level of: angiotensin converting enzyme (ACE); bradykinin B2 receptor (BK2R); endothelial nitric oxide synthase (eNOS); bradykinin and Ca²⁺ in cardiac cytoplasm as well as in serum nitric oxide (NO). The results suggested that DEHP could induce an increase in ACE levels, and a decrease in bradykinin levels. Moreover, BK2R, Ca²⁺, eNOS and NO decreased when mice were exposed to 10 mg/kg/day DEHP. Interestingly, 5 mg/kg/day angiotensin converting enzyme inhibitor (ACEI) treatment inhibited the increase in blood pressure, and inhibited the decrease in the levels of BK2R, Ca²⁺, eNOS, and NO, that were induced by DEHP exposure. Our results suggest that DEHP might increase blood pressure by activating ACE expression, and inhibiting the bradykinin-NO pathway.
Показать больше [+] Меньше [-]Examining the responses of the zebrafish (Danio rerio) gastrointestinal system to the suspected obesogen diethylhexyl phthalate Полный текст
2019
Buerger, Amanda N. | Schmidt, Jordan | Chase, Amanda | Paixao, Carla | Patel, Tejas N. | Brumback, Babette A. | Kane, Andrew S. | Martyniuk, Christopher J. | Bisesi, Joseph H.
Epidemiological evidence suggests that phthalate plasticizers may act as “obesogens”, which are chemicals that exacerbate obesity. The gastrointestinal (GI) system is the primary exposure route for phthalates, however, the relationship between phthalate-driven perturbations of GI system functions that can influence obesity has yet to be examined. To address this knowledge gap, we exposed Danio rerio (zebrafish) for 60 days to either (1) Control feeding (5 mg/fish/day), (2) Overfeeding (20 mg/fish/day) or (3) Overfeeding with diethyl-hexyl phthalate (DEHP) (20 mg/fish/day with 3 mg/kg DEHP). After 60 days, Overfed and Overfed + DEHP zebrafish had elevated body mass, and hepatosomatic and gonadosomatic indices. RNAseq analysis of the GI revealed enrichment of gene networks related to lipid metabolism in the Overfed + DEHP group. Many of the enriched networks were under transcriptional control of peroxisome proliferator activated receptor alpha (pparα), a known modulator of lipid metabolism, immune function, and GI function. Real-time PCR confirmed that pparα was overexpressed in the Overfed + DEHP zebrafish, further revealing a pathway by which DEHP may influence lipid metabolism via the GI. These data increase our understanding of phthalate-driven effects on GI function and lipid metabolism, identifying gut-specific gene networks that may drive phthalate-exacerbated obesity.
Показать больше [+] Меньше [-]Variation in rhizosphere microbiota correlates with edaphic factor in an abandoned antimony tailing dump Полный текст
2019
Xiao, Enzong | Ning, Zengping | Xiao, Tangfu | Sun, Weimin | Qiu, Yaqun | Zhang, Yu | Chan, Kit-Yee | Gou, Zilun | Chen, Yuxiao
The distribution pattern of root-associated bacteria in native plant growth in tailing dumps with extreme conditions remains poorly understood and largely unexplored. Herein we chose a native plant, Bidens bipinnata, growing on both an Sb tailing dump (WKA) and adjacent normal soils (WKC) to in-depth understand the distribution pattern of root-associated bacteria and their responses on environmental factors. We found that the rhizosphere microbial diversity indices in the tailing dump were significantly different from that in the adjacent soil, and that such variation was significantly related with soil nutrients (TC, TOC, TN) and metal(loid) concentrations (Sb and As). Some dominant genera were significant enriched in WKA, suggesting their adaption to harsh environments. Notably, these genera are proposed to be involved in nutrient and metal(liod) cycling, such as nitrogen fixing (Devosia, Cellvibrio, Lysobacter, and Cohnella), P solubilizing (Flavobacterium), and Sb and As oxidation (Paenibacillus, Bacillus, Pseudomonas, and Thiobacillus). Our results suggest that certain root-associated bacteria in tailing dump were governed by soil edaphic factors and play important ecological roles in nutrient amendments and metal cycling for the successful colonization of Bidens bipinnata in this tailing dump.
Показать больше [+] Меньше [-]An integrated assessment and spatial-temporal variation analysis of neonicotinoids in pollen and honey from noncrop plants in Zhejiang, China Полный текст
2019
Tang, Tao | Cui, Wang | Wei, Dai | Shuqing, Yu | Zhengbiao, Lu | Quan, Zhang
Recent studies have shown that neonicotinoids in pollen and honey (collected by honeybees) are likely to pose risks to honeybees. However, data on the integrated residue and spatial-temporal variation of neonicotinoids from noncrop plants, the principle sources of pollen for honey bees, are very limited, especially in China. In this study, we employed a novel assessment method based on the relative potency factor to calculate the integrated residue of seven neonicotinoids in pollen and honey samples collected from noncrop plants in 12 stations of Zhejiang province in three consecutive months. The integrated concentration of neonicotinoids (IMIRPF) ranged from no detected (ND) to 34.93 ng/g in pollen and ND to 8.51 ng/g in honey. Acetamiprid showed the highest detection frequency of 41.7%, followed by clothianidin (33.3%) and dinotefuran (22.2%). The highest IMIRPF occurred in April for stations in the fringe areas of Zhejiang province, whereas for stations in the central areas of Zhejiang province, the IMIRPF in May was relatively higher than the other two months. In terms of spatial change, the pollution variation of pollen samples in Lin'an—Tonglu—Pujiang was relative highly polluted—lightly polluted—highly polluted. For honey samples, spatial variation showed a single trend, and peak values were found in Wenzhou, which may be attributed to the local climate and farming practices. This fundamental information will be helpful to understand the effects of neonicotinoids on honeybees foraging habits.
Показать больше [+] Меньше [-]Retrotransposon methylation and activity in wild fish (A. anguilla): A matter of size Полный текст
2019
Pierron, Fabien | Daffe, Guillemine | Lambert, Patrick | Couture, Patrice | Baudrimont, Magalie
Retrotransposon methylation and activity in wild fish (A. anguilla): A matter of size Полный текст
2019
Pierron, Fabien | Daffe, Guillemine | Lambert, Patrick | Couture, Patrice | Baudrimont, Magalie
Understanding how organisms cope with global change is a major question in many fields of biology. Mainly, understanding the molecular mechanisms supporting rapid phenotypic changes of organisms in response to stress and linking stress-induced molecular events to adaptive or adverse outcomes at the individual or population levels remain a major challenge in evolutionary biology, ecology or ecotoxicology. In this view, the present study aimed to test (i) whether environmental factors, especially pollutants, can trigger changes in the activity of retrotransposons (RTs) in wild fish and (ii) if changes in RT DNA methylation or transcription levels can be linked to modifications at the individual level. RTs are genetic elements that have the ability to replicate and integrate elsewhere in the genome. Although RTs are mainly quiescent during normal development, they can be experimentally activated under life-threatening conditions, affecting the fitness of their host. Wild eels were collected in four sampling sites presenting differing levels of contamination. The methylation level and the transcriptional activity of two RTs and two genes involved in development and cell differentiation were analyzed in fish liver in addition to the determination of fish contaminants levels and diverse growth and morphometric indices. An up-regulation of RTs associated to lower methylation levels and lower growth indices were observed in highly contaminated fish. Our results suggest that RT activation in fish experiencing stress conditions could have both detrimental and beneficial implications, affecting fish growth but promoting resistance to environmental stressors such as pollutants.
Показать больше [+] Меньше [-]Retrotransposon methylation and activity in wild fish (A. anguilla): A matter of size Полный текст
2019
Pierron, Fabien | Daffe, Guillemine | Lambert, Patrick | Couture, Patrice | Baudrimont, Magalie | Environnements et Paléoenvironnements OCéaniques (EPOC) ; École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) | Ecosystèmes aquatiques et changements globaux (UR EABX) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Centre Eau Terre Environnement [Québec] (INRS - ETE) ; Institut National de la Recherche Scientifique [Québec] (INRS) | ANR-16-CE34-0008,TRACE,Effets transgénérationnels des polluants chez les poissons: l'épigénétique et son implication en écotoxicologie(2016)
[Departement_IRSTEA]Eaux [ADD1_IRSTEA]Systèmes aquatiques soumis à des pressions multiples | International audience | Understanding how organisms cope with global change is a major question in many fields of biology. Mainly, understanding the molecular mechanisms supporting rapid phenotypic changes of organisms in response to stress and linking stress-induced molecular events to adaptive or adverse outcomes at the individual or population levels remain a major challenge in evolutionary biology, ecology or ecotoxicology. In this view, the present study aimed to test (i) whether environmental factors, especially pollutants, can trigger changes in the activity of retrotransposons (RTs) in wild fish and (ii) if changes in RT DNA methylation or transcription levels can be linked to modifications at the individual level. RTs are genetic elements that have the ability to replicate and integrate elsewhere in the genome. Although RTs are mainly quiescent during normal development, they can be experimentally activated under life-threatening conditions, affecting the fitness of their host. Wild eels were collected in four sampling sites presenting differing levels of contamination. The methylation level and the transcriptional activity of two RTs and two genes involved in development and cell differentiation were analyzed in fish liver in addition to the determination of fish contaminants levels and diverse growth and morphometric indices. An up-regulation of RTs associated to lower methylation levels and lower growth indices were observed in highly contaminated fish. Our results suggest that RT activation in fish experiencing stress conditions could have both detrimental and beneficial implications, affecting fish growth but promoting resistance to environmental stressors such as pollutants. Retrotransposons could represent interesting environment-sensitive molecular markers allowing to link stress-induced molecular events to adverse outcomes at higher levels.
Показать больше [+] Меньше [-]Essential and non-essential trace elements in fish consumed by indigenous peoples of the European Russian Arctic Полный текст
2019
Sobolev, Nikita | Aksenov, Andrey | Sorokina, Tatiana | Chashchin, Valery | Ellingsen, Dag G. | Nieboer, Evert | Varakina, Yulia | Veselkina, Elena | Kotsur, Dmitry | Thomassen, Yngvar
Essential and non-essential trace elements in fish consumed by indigenous peoples of the European Russian Arctic Полный текст
2019
Sobolev, Nikita | Aksenov, Andrey | Sorokina, Tatiana | Chashchin, Valery | Ellingsen, Dag G. | Nieboer, Evert | Varakina, Yulia | Veselkina, Elena | Kotsur, Dmitry | Thomassen, Yngvar
In present study, the analyses of essential [copper (Cu), cobalt (Co), selenium (Se) and zinc (Zn)] and non-essential elements [mercury (Hg), lead (Pb), cadmium (Cd) and arsenic (As)] in 7 fish species consumed by the indigenous people of the European Russia Arctic were conducted. The Nenets Autonomous Region, which is located in the north-eastern part of European Russia, was chosen as a Region of interest. Within it, the Nenets indigenous group (n = 6000) constitutes approximately 10% of the total population. Nearly all of the Nenets live a traditional life with fish caught in the local waters as a subsistence resource.We found that northern pike contained twice the amount of Hg compared with roach, and 3–4 times more than other fish species commonly consumed in the Russian Arctic (namely, Arctic char, pink salmon, navaga, humpback whitefish and inconnu). Fish Hg concentrations were relatively low, but comparable to those reported in other investigations that illustrate a decreasing south-to-north trend in fish Hg concentrations. In the current study, northern pike is the only species for which Hg bioaccumulated significantly. In all fish species, both Cd and Pb were present in considerably lower concentrations than Hg. The total As concentrations observed are similar to those previously published, and it is assumed to be present primarily in non-toxic organic forms. All fish tissues were rich in the essential elements Se, Cu and Zn and, dependent on the amount fish consumed, may contribute significantly to the nutritional intake by indigenous Arctic peoples. We observed large significant differences in the molar Se/Hg ratios, which ranged from 2.3 for northern pike to 71.1 for pink salmon. Values of the latter <1 may increase the toxic potential of Hg, while those >1 appear to enhance the protection against Hg toxicity.
Показать больше [+] Меньше [-]Essential and non-essential trace elements in fish consumed by indigenous peoples of the European Russian Arctic Полный текст
2019
In present study, the analyses of essential [copper (Cu), cobalt (Co), selenium (Se) and zinc (Zn)] and non-essential elements [mercury (Hg), lead (Pb), cadmium (Cd) and arsenic (As)] in 7 fish species consumed by the indigenous people of the European Russia Arctic were conducted. The Nenets Autonomous Region, which is located in the north-eastern part of European Russia, was chosen as a Region of interest. Within it, the Nenets indigenous group (n = 6000) constitutes approximately 10% of the total population. Nearly all of the Nenets live a traditional life with fish caught in the local waters as a subsistence resource. We found that northern pike contained twice the amount of Hg compared with roach, and 3–4 times more than other fish species commonly consumed in the Russian Arctic (namely, Arctic char, pink salmon, navaga, humpback whitefish and inconnu). Fish Hg concentrations were relatively low, but comparable to those reported in other investigations that illustrate a decreasing south-to-north trend in fish Hg concentrations. In the current study, northern pike is the only species for which Hg bioaccumulated significantly. In all fish species, both Cd and Pb were present in considerably lower concentrations than Hg. The total As concentrations observed are similar to those previously published, and it is assumed to be present primarily in non-toxic organic forms. All fish tissues were rich in the essential elements Se, Cu and Zn and, dependent on the amount fish consumed, may contribute significantly to the nutritional intake by indigenous Arctic peoples. We observed large significant differences in the molar Se/Hg ratios, which ranged from 2.3 for northern pike to 71.1 for pink salmon. Values of the latter <1 may increase the toxic potential of Hg, while those >1 appear to enhance the protection against Hg toxicity. | Essential and non-essential trace elements in fish consumed by indigenous peoples of the European Russian Arctic
Показать больше [+] Меньше [-]Linking hydrophobicity of biochar to the water repellency and water holding capacity of biochar-amended soil Полный текст
2019
Mao, Jiefei | Zhang, Kun | Chen, Baoliang
Biochar addition to soil may change the hydrophobicity of amended soil and influence soil hydraulic properties. Soil hydrophobicity, i.e. soil water repellency (SWR) can interrupt water infiltration and form preferential flow leading to a potential risk of soil erosion or groundwater pollution. Up to date, the effect of different biochars on soil hydrophobicity remains unclear and the association of SWR with soil hydraulic properties is still unknown. To link the biochar hydrophobicity to SWR and soil water holding capacity (WHC), the surface structure and chemical composition of 27 biochars with different feedstocks and pyrolysis temperatures were characterized, and the SWR and soil WHC of biochar-added soil were investigated. Carboxylic groups on the biochar surface, surface area and pore volume were mostly influenced by pyrolysis temperature, which suggested the dominant factor determining the severity of biochar hydrophobicity was pyrolysis temperature. Hydrophilic soil became hydrophobic after biochar amendment. A higher addition rate led to a stronger SWR of hydrophilic soil. Biochar addition increased soil WHC of hydrophilic soil with low total organic carbon (TOC) content. Biochar did not have significant influence on SWR and soil WHC of hydrophobic soil with high TOC content. It implied that the influence of biochar on SWR and soil hydraulic properties mainly depended on soil original hydrophobicity and TOC content. Therefore, the properties of biochar and influence on soil hydrophobicity and hydraulic properties should be considered before processing biochar application.
Показать больше [+] Меньше [-]Long-term exposure to greenspace and metabolic syndrome: A Whitehall II study Полный текст
2019
de Keijzer, Carmen | Basagaña, Xavier | Tonne, Cathryn | Valentín, Antònia | Alonso, J. (Jordi) | Antó, Josep M. | Nieuwenhuijsen, Mark J. | Kivimäki, Mika | Singh-Manoux, Archana | Sunyer, Jordi | Dadvand, Payam
Metabolic syndrome is an important risk factor for non-communicable diseases, particularly type 2 diabetes, coronary heart disease, and stroke. Long-term exposure to greenspace could be protective of metabolic syndrome, but evidence for such an association is lacking. Accordingly, we investigated the association between long-term exposure to greenspace and risk of metabolic syndrome.The present longitudinal study was based on data from four clinical examinations between 1997 and 2013 in 6076 participants of the Whitehall II study, UK (aged 45–69 years at baseline). Long-term exposure to greenspace was assessed by satellite-based indices of greenspace including Normalized Difference Vegetation Index (NDVI) and Vegetation Continuous Field (VCF) averaged across buffers of 500 and 1000 m surrounding the participants’ residential location at each follow-up. The ascertainment of metabolic syndrome was based on the World Health Organization (WHO) definition. Hazard ratios for metabolic syndrome were estimated using Cox proportional hazards regression models, controlling for age, sex, ethnicity, lifestyle factors, and socioeconomic status.Higher residential surrounding greenspace was associated with lower risk of metabolic syndrome. An interquartile range increase in NDVI and VCF in the 500 m buffer was associated with 13% (95% confidence interval (CI): 1%, 23%) and 14% (95% CI: 5%, 22%) lower risk of metabolic syndrome, respectively. Greater exposure to greenspace was also associated with each individual component of metabolic syndrome, including a lower risk of high levels of fasting glucose, large waist circumference, high triglyceride levels, low HDL cholesterol, and hypertension. The association between residential surrounding greenspace and metabolic syndrome may have been mediated by physical activity and exposure to air pollution.The findings of the present study suggest that middle-aged and older adults living in greener neighbourhoods are at lower risk of metabolic syndrome than those living in neighbourhoods with less greenspace.
Показать больше [+] Меньше [-]Emission inventory of carbonyl sulfide (COS) from primary anthropogenic sources in China Полный текст
2019
Yan, Yulong | Li, Rumei | Peng, Lin | Yang, Chao | Liu, Chenglong | Cao, Jingyuan | Yang, Fan | Li, Yinghui | Wu, Jing
An emission inventory of carbonyl sulfide (COS) from primary anthropogenic sources in China was compiled from 2010 to 2015. The national total emission was estimated at 174 Gg S yr⁻¹ in 2015, with an annually average sustainable growth rate of 7.2% from 2010 to 2015. Industrial sources, biomass burning, coal combustion, agricultural sources and vehicle exhaust contributed 68.2%, 22.0%, 6.1%, 2.2%, and 1.5%, respectively, of total COS emissions in 2015. Aluminum production, carbon black production, titania production, coke production, pulp and paper industry, were the main industrial sources of COS, with the emission about 118 Gg S yr⁻¹ COS in 2015, accounting for 98.5% of total direct emissions from the Chinese industry. The distribution of COS emissions in China showed significant differences at the provincial level. In Shandong and Xinjiang province, they were much bigger than other provinces, with total emissions of 31 and 15 Gg S yr⁻¹, respectively. Uncertainty analysis of COS emission inventories showed that the emission range was 70–267 Gg S yr⁻¹ at a 95% confidence interval. In this study, COS emissions in China were much higher than prior underestimated estimations, even for Asian and global emissions, which could be resolved part of missing sources in the global COS budget.
Показать больше [+] Меньше [-]The impacts of urbanization on fine particulate matter (PM2.5) concentrations: Empirical evidence from 135 countries worldwide Полный текст
2019
Wang, Qiang | Kwan, Mei-po | Zhou, Gan | Fan, Jie | Wang, Yafei | Zhan, Dongsheng
Few attempts have been made to systematically investigate the impacts of urbanization on PM₂.₅ concentrations in countries at different stages of economic development. In this study, a broad concept of urbanization that considers the transformations in the urban economy and the transport sector induced by urbanization is proposed to investigate the influence of urbanization on national PM₂.₅ concentrations for underdeveloped, developing and developed countries during 1998–2014. The results indicate that urbanization has a significant relationship with PM₂.₅ concentrations, but the magnitude of its influence varies among groups of countries with different development levels. First, the positive response of PM₂.₅ concentrations to increased urbanization and transport-related emissions in underdeveloped countries are noticeably stronger than that in developing and developed countries. Second, for developing countries, urbanization, transport-related emissions and industrialization all have a significant positive effect on national PM₂.₅ concentrations increase, although their impacts are unexpectedly smaller than those in the other groups of countries. Finally, increasing urbanization and the decrease in CO₂ emissions from manufacturing industry appear to reduce national average PM₂.₅ concentrations in developed countries, while the decrease in transport-related CO₂ emission is likely to cause the rise in national average PM₂.₅ concentrations.
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