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1.
J Hazard Mater ; 422: 126749, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34390953

RESUMO

Although (-)-α-hexabromocyclododecane (HBCDD) and (+)-γ-HBCDD are preferentially enriched in chickens, the key factors contributing to their selective bioaccumulation in hens and their potential biotransformation in developing chicken embryos remain unclear. Herein, in vivo and in ovo exposure experiments using hens and fertilized eggs were conducted to investigate the absorption, excretion, and biotransformation of HBCDDs in chickens. γ-HBCDD (76%) exhibited a higher absorption efficiency than α- (22%) and ß- (69%) HBCDDs. However, α-HBCDD was dominant in hen tissues, although γ-HBCDD accounted for >75% in the spiked feed. Moreover, chicken embryos biotransformed approximately 9.5% and 11.7% of absorbed α- and γ-HBCDDs, respectively, implying that diastereomer-selective elimination causes the predominance of α-HBCDD in hens. The concentration and enantiomer fraction (EF) of α-HBCDD in laid eggs were significantly positively correlated, suggesting enantioselective elimination. The EFs of α- and γ-HBCDDs varied between feces from the exposure and depuration periods, indicating the preferred excretion of (+)-α- and (-)-γ-HBCDDs. Furthermore, the enantioselective biotransformation of (-)-γ-HBCDD was confirmed in developing chicken embryos. These results show that excretion and biotransformation contribute to the diastereomer- and enantiomer-selective bioaccumulation of HBCDDs in chickens; The results may improve our understanding of the environmental fate and ecological risks of HBCDDs in biota.


Assuntos
Galinhas , Animais , Bioacumulação , Biotransformação , Embrião de Galinha , Feminino , Hidrocarbonetos Bromados , Estereoisomerismo
2.
Lab Invest ; 101(5): 588-599, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33526807

RESUMO

NOD-like receptor protein 3 (NLRP3) promotes the inflammatory response during progression of nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). This study aimed to further delineate the role of NLRP3 in NASH development by abolishing its expression in mice. A high-fat and calorie diet plus high fructose and glucose in drinking water (HFCD-HF/G) was used to establish NASH in both wild-type (WT) and NLRP3 knock-out (KO) mice. Hepatocellular injury, hepatic steatosis and fibrosis, as well as inflammatory response and insulin resistance in the liver and epidydimal white adipose tissue (eWAT) were determined. Elevated body weight, liver weight and serum alanine transaminase level, increased hepatic triglyceride accumulation and collagen deposition, and worsened systemic insulin resistance were observed in Nlrp3-/- mice compared to WT mice under HFCD-HF/G feeding. Upregulated hepatic transcription of tumor necrosis factor-α (TNF-α) and monocyte chemotactic protein-1 (MCP-1), and enhanced infiltration of inducible nitric oxide synthase-positive (iNOS+) M1 macrophages were also documented in HFCD-HF/G-fed Nlrp3-/- mice in comparison to HFCD-HF/G-fed WT mice. Moreover, transcription of TNF-α and MCP-1 and infiltration of iNOS+ M1 macrophages were increased in the liver of Nlrp3-/- mice under control diet. NLRP3 deficiency did not attenuate, but instead aggravated NASH development under HFCD-HF/G feeding. The worsened extent of NASH might be attributed to enhanced hepatic MCP-1 expression and M1 macrophage infiltration in Nlrp3-/- mice. Our study points to additional caution when NLRP3 blockade is considered as a therapeutic strategy in the treatment of human NASH.


Assuntos
Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Hepatopatia Gordurosa não Alcoólica/etiologia , Animais , Colágeno/metabolismo , Dieta Hiperlipídica/efeitos adversos , Frutose/efeitos adversos , Glucose/efeitos adversos , Resistência à Insulina , Metabolismo dos Lipídeos , Fígado/imunologia , Fígado/metabolismo , Masculino , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
3.
Clin Mol Hepatol ; 27(2): 329-345, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33465844

RESUMO

BACKGROUND/AIMS: Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) characterized by hepatic steatosis, inflammation, hepatocellular injury, and fibrosis. We aimed to investigate the usefulness of a key biomarker, lipocalin-2 (LCN2), for the detection of NASH progression. METHODS: A mouse NASH model was established using a high-fat diet and a high-sugar drinking water. Gene expression profile of the NASH model was analyzed using RNA sequencing. Moreover, 360 NAFLD patients (steatosis, 83; NASH, 277), 40 healthy individuals, and 87 patients with alcoholic fatty liver disease were recruited. RESULTS: Inflammatory infiltration, focal necrosis in the leaflets, steatosis, and fibrosis were documented in the mouse liver. In total, 504 genes were differentially expressed in the livers of NASH mice, and showed significant functional enrichment in the inflammation-related category. Upregulated liver LCN2 was found to be significantly interactive with various interleukins and toll-like receptors. Serum LCN2 levels were significantly increased in NAFLD patients. Serum LCN2 levels were correlated with steatosis, intralobular inflammation, semiquantitative fibrosis score, and nonalcoholic fatty liver disease activity score. The area under the curve of serum LCN2 was 0.987 with a specificity of 100% and a sensitivity of 93.5% for NASH diagnosis, and 0.977 with almost the same specificity and sensitivity for steatosis. CONCLUSION: LCN2 might be involved in the transition from NAFL to NASH by mediating inflammation. Serum LCN2 levels might be a novel biomarker for the diagnosis of NASH.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Adulto , Animais , Biomarcadores , Feminino , Humanos , Inflamação , Lipocalina-2 , Fígado , Masculino , Camundongos , Pessoa de Meia-Idade
4.
Environ Pollut ; 270: 116157, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33321435

RESUMO

Many studies have reported maternal transfer of organic contaminants in oviparous species, with inconsonant results. Egg-laying sequence and selected maternal tissues may impact on assessment of potential maternal transfer of contaminants. Here, this hypothesis was verified by exposing chickens (Gallus domesticus) to polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dechlorane plus (DPs). Concentrations in eggs laid during exposure exhibited periodic fluctuations (conforming to egg-laying cycles) and a decreasing trend during depuration. Fluctuation patterns of DPs and BDE209 differed from those of other compounds. The PBDE congener profiles in eggs were dominated by BDE209 during exposure and by BDE100 and 153 during depuration. The abundance of PCB congener (CB138) which is recalcitrant to metabolism increased with laying sequence. Maternal transfer potential was negatively correlated (P = 0.0014, R2 = 0.7874) to the log KOW of chemicals (log KOW >7) when the muscle, heart, lung, or stomach was used. No correlations were found when the liver, fat, kidneys, or intestine was used (log KOW >7), although DPs and BDE209 showed the highest maternal transfer potential. Different fluctuation patterns of DPs and BDE209 in eggs and increased abundance of BDE209 in eggs laid in the initial egg-laying period imply that the liver, fat, kidney, or intestinal tissues could be more appropriate in assessing maternal transfer of the target analytes.


Assuntos
Poluentes Ambientais , Bifenilos Policlorados , Animais , Galinhas , Monitoramento Ambiental , Poluentes Ambientais/análise , Éteres Difenil Halogenados/análise , Projetos Piloto , Bifenilos Policlorados/análise
5.
Environ Pollut ; 247: 550-555, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30708317

RESUMO

Although isomer-specific bioaccumulation of dechlorane plus (DP) has been addressed in many studies, it remains unclear which factors determine this process and whether biotransformation of DP occurs in organisms. Comparative experiments were conducted in both in vivo and in ovo incubation using hens and eggs to identify the dominant factors determining the bioaccumulation of DP. Hens and fertilized eggs were exposed to DP isomers (syn- and anti-DP) by feeding and spiking, respectively, to investigate absorption, elimination, and metabolism. No significant differences were found between absorption efficiencies of DP isomers in the adult hens. Following first-order kinetics, anti-DP exhibited a slightly longer half-life than syn-DP as well as an elevated anti-DP fraction in laid eggs, thereby suggesting selective enrichment of anti-DP in adult hens. However, chicken embryos metabolized approximately 12% and 28% of the absorbed syn- and anti-DP, respectively, thereby verifying that anti-DP was preferably metabolized. This result indicated that stereo-selective excretion of syn-DP, rather than preferred metabolism of anti-DP, played a more prominent role in isomer-specific bioaccumulation of DP in chickens. Further studies on metabolites of DP are crucial to understanding the fate of DP in organisms.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais/metabolismo , Retardadores de Chama/metabolismo , Hidrocarbonetos Clorados/metabolismo , Compostos Policíclicos/metabolismo , Animais , Biotransformação , Galinhas/metabolismo , Ovos , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário , Retardadores de Chama/análise , Hidrocarbonetos Clorados/análise , Cinética , Compostos Policíclicos/análise
6.
Org Lett ; 20(15): 4641-4644, 2018 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-30043613

RESUMO

An efficient Fe(TPP)Cl catalyzed insertion reaction of in situ generated benzylic carbenes from N-tosylhydrazones into X-H (X = Si, Sn, Ge) was developed. Silanes bearing tertiary, secondary, and primary (3°, 2°, and 1°) Si-H bonds all reacted well to afford insertion products in moderate to high yields (up to 97%), and the reaction time could be significantly shortened to 1 h under microwave irradiation. A programmable stepwise double insertion strategy was developed for the synthesis of unsymmetrical tetrasubstituted silanes.

7.
Sci Rep ; 6: 36597, 2016 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-27819361

RESUMO

Fertilized chicken eggs were injected with environmental doses of 4 chiral polychlorinated biphenyls (PCBs) and 8 polybrominated biphenyl ethers (PBDEs) to investigate their uptake, metabolism in the embryo, and distribution in the neonate chicken. PCB95 uptake was the most efficient (80%) whereas BDE209 was the least (56%). Embryos metabolized approximately 52% of the PCBs absorbed. Though some degree of metabolism in the first 18 days, most of the PCBs and PBDEs was metabolized in the last three days, when BDE85, 99, 153, and 209 decrease by 11-37%. Enantioselective metabolism of the (+) enantiomers of PCB95, 149, and 132 and the (-) enantiomer of PCB91 was observed. The enantioselective reactivity was higher with the two penta-PCBs than the two tetra-PCBs. Liver, exhibited high affinity for high lipophilic chemicals, enrich all chemicals that was deflected in other tissues except for some special chemicals in a given tissues. Lipid composition, time of organ formation, and metabolism contribute to the distribution of chemicals in the neonate chicken. The result of this study will improve our understanding on the fate and potential adverse effects of PCBs and PBDEs in the neonate chicken.


Assuntos
Galinhas/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Éteres Difenil Halogenados/efeitos adversos , Bifenilos Policlorados/efeitos adversos , Animais , Transporte Biológico/efeitos dos fármacos , Embrião de Galinha , Monitoramento Ambiental/métodos , Poluentes Ambientais/efeitos adversos , Distribuição Tecidual
8.
Chemosphere ; 159: 449-456, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27341148

RESUMO

Metabolites of polychlorinated biphenyls (PCBs) in fish are difficult to detect in vivo due to the complexity of biometabolism. In the present study, atropisomeric fraction analysis of chiral PCB congeners and compound-specific isotopic analysis (CSIA) were applied to trace the biotransformation of PCBs in fish by exposure of common carp (Cryprinus carpio) to the commercial PCB mixture Aroclor 1242. Stereoselective elimination of the chiral PCB congeners 91, 95, and 136 was observed, indicating a stereoselective biotransformation process. The δ(13)C values of PCBs 5/8, 18, and 20/33 in fish were increased compared with those in the spiked food, while PCBs 47/48 and 49 showed significant heavy isotope depletion. These results suggested a significant biotransformation of the corresponding individual PCB congeners although the potential PCB metabolites, hydroxylated PCBs (OH-PCBs) and methylsulfone PCBs (MeSO2-PCBs), were not detected in the fish tissue samples throughout this experiment. The results of the present study demonstrated that a combination of chiral analysis and CSIA is a promising new approach for investigating the biotransformation of PCBs in biota.


Assuntos
Carbono/química , Carbono/metabolismo , Carpas/metabolismo , Bifenilos Policlorados/metabolismo , Animais , Biotransformação , Isótopos de Carbono , Hidroxilação , Bifenilos Policlorados/farmacocinética , Estereoisomerismo
9.
Sci Total Environ ; 544: 77-84, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26657357

RESUMO

Twelve organophosphorus flame retardants (PFRs) were identified in the sediments and the sediment core collected from the rivers and the estuary in the Pearl River Delta, with the aim of investigating their spatial and vertical distributions. The concentrations of PFRs ranged from 8.3 to 470 ng/g dry weight with high levels of PFRs in the urban area and the e-waste recycling region. Generally, TPhP, TCPP, TEHP, TCEP, and TBEP were the dominant compounds of the PFRs, the composition of which varied across the different regions, reflecting the different sources of PFRs. In the estuary, the PFRs mainly derived from the Xijiang River and the Shunde sections. Increased concentrations of halogen-containing PFRs have been observed in the upper layers of the sediment core. Conversely, relatively high concentrations of halogen-free PFRs were observed in the lower layers of the sediment core, indicating different usage patterns or environmental behaviors between the halogen and the non-halogen PFRs in the study area.


Assuntos
Monitoramento Ambiental , Estuários , Retardadores de Chama/análise , Compostos Organofosforados/análise , Poluentes Químicos da Água/análise , China , Rios/química
10.
Chemosphere ; 139: 565-71, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26318119

RESUMO

A suite of legacy and emerging halogenated organic pollutants (HOPs) were measured in marine organisms (coastal fish and invertebrates) from the Pearl River Estuary, South China, to investigate the current contamination status after the Stockholm Convention was implemented in China. Dichlorodiphenyltrichloroethane and its metabolites (DDTs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were detected in all samples at concentrations of 54-1500, 16-700, and 0.56-59ng/g lipid weight, respectively. Dechlorane Plus (DP), decabromodiphenyl ethane (DBDPE), 2,3,5,6-tetrabromo-p-xylene (pTBX), and pentabromotoluene (PBT) were also found at concentrations of ND (non-detectable) to 37ng/g lipid weight. The concentrations of these investigated contaminants in the present study were at moderate levels, as compared with those reported in other regions. Significant interspecies differences were found in the levels of DDTs, PCBs, PBDEs and the alternative halogenated flame retardants (AHFRs). DDTs were the predominant HOPs in those species and represented >50% of the total HOPs, followed by PCBs, PBDEs, and AHFRs. The total estimated daily intakes (EDIs) of DDTs, PCBs, PBDEs, and AHFRs were 28, 12, 1.0, and 0.18 (ng/kg)/d, respectively, via seafood consumption. These concentrations are not expected to pose health risks to humans.


Assuntos
Organismos Aquáticos/química , Monitoramento Ambiental , Estuários , Hidrocarbonetos Halogenados/análise , Rios/química , Poluentes Químicos da Água/análise , Animais , China , Peixes , Humanos , Invertebrados/química , Alimentos Marinhos
11.
Mar Pollut Bull ; 93(1-2): 61-7, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25769908

RESUMO

Dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), 2,3,5,6-tetrabromo-p-xylene (pTBX) and pentabromotoluene (PBT) were measured in baby croaker (Collichthys lucidus) and mullet (Osteomugil ophuyseni) collected in 2005 and 2013 from the Pearl River Estuary. DDTs, HCHs, PCBs, and PBDEs were detected in two fish species at concentrations of 150-8100, 1.4-120, 22-560, 2.2-280 ng/g lipid wt., respectively. The levels of these chemicals were significantly lower in 2013 than in 2005. The compositions for DDTs, HCHs, and PBDEs in 2013 differed from those in 2005, indicating source changes between the two sampling periods. DP, pTBX and PBT were detected at concentrations of ND-130 ng/g lipid wt. No clear temporal trends were found for these contaminants. Overall, these results indicated the effectiveness of regulations and source controls in substantively reducing inputs of these contaminants to the Pearl River Estuary.


Assuntos
Monitoramento Ambiental , Estuários , Peixes/metabolismo , Poluentes Químicos da Água/metabolismo , Poluição Química da Água/estatística & dados numéricos , Animais , China , DDT/análise , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/metabolismo , Hexaclorocicloexano/análise , Hexaclorocicloexano/metabolismo , Hidrocarbonetos Clorados/metabolismo , Bifenilos Policlorados/análise , Bifenilos Policlorados/metabolismo , Rios/química , Alimentos Marinhos/estatística & dados numéricos , Xilenos/análise , Xilenos/metabolismo
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