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1.
Food Chem ; 266: 9-16, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30381230

RESUMO

A novel method for the simultaneous identification and quantification of twelve aminoglycosides (AGs) and two colistins in meat and bovine milk has been developed. The analysis was carried out using liquid chromatography coupled to quadrupole-Orbitrap mass spectrometry (LC-Q-Orbitrap). Among the HILIC (Hydrophilic Interaction Liquid Chromatography) stationary phases tested, the bare silica Poroshell 120 provided the best results. The samples were extracted with an aqueous solution followed by an SPE clean up based on the weak cation exchange mechanism. The validation study was performed carrying out 72 experiments per matrix at six different concentrations in a range encompassing the Maximum Residue Limits. The recoveries were from 72 to 87% in meat (except colistins) and from 82 to 96% in milk. Repeatabilities and intra-lab reproducibilities were lower than 10 and 15%, respectively. Limits of detection were lower than or equal to 33 µg kg-1. Finally, test materials containing AGs prepared for interlaboratory studies were successfully analysed.


Assuntos
Aminoglicosídeos/análise , Colistina/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Animais , Bovinos , Limite de Detecção , Carne/análise , Leite/química , Fatores de Tempo
2.
Toxicol In Vitro ; 40: 124-133, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28062356

RESUMO

The expression of CYP4F2, a form of cytochrome P-450 with proposed role in α-tocopherol and long-chain fatty acid metabolism, was explored in HepG2 and HepaRG human hepatocytes during ethanol toxicity. Cytotoxicity, ROS production, and JNK and ERK1/2 kinase signaling increased in a dose and time-dependent manner during ethanol treatments; CYP4F2 gene expression decreased, while other CYP4F forms, namely 4F11 and 12, increased along with 3A4 and 2E1 isoforms. α-Tocopherol antagonized the cytotoxicity and CYP4F2 gene repression effect of ethanol in HepG2 cells. Ethanol stimulated the tocopherol-ω-hydroxylase activity and the other steps of vitamin E metabolism, which points to a minor role of CYP4F2 in this metabolism of human hepatocytes. PPAR-γ and SREBP-1c followed the same expression pattern of CYP4F2 in response to ethanol and α-tocopherol treatments. Moreover, the pharmacological inhibition of PPAR-γ synergized with ethanol in decreasing CYP4F2 protein expression, which suggests a role of this nuclear receptor in CYP4F2 transcriptional regulation. In conclusion, ethanol toxicity modifies the CYP expression pattern of human hepatic cells impairing CYP4F2 transcription and protein expression. These changes were associated with a lowered expression of the fatty acid biosynthesis regulators PPAR-γ and SREBP-1c, and with an increased enzymatic catabolism of vitamin E. CYP4F2 gene repression and a sustained vitamin E metabolism appear to be independent effects of ethanol toxicity in human hepatocytes.


Assuntos
Antioxidantes/metabolismo , Inibidores das Enzimas do Citocromo P-450/toxicidade , Sistema Enzimático do Citocromo P-450/metabolismo , Etanol/toxicidade , Hepatócitos/efeitos dos fármacos , alfa-Tocoferol/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Sistema Enzimático do Citocromo P-450/genética , Células Hep G2 , Hepatócitos/metabolismo , Humanos , PPAR gama/metabolismo , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
3.
Vet J ; 208: 70-5, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26681138

RESUMO

The aim of this study was to evaluate the safety of intra-articular (IA) lidocaine plus adrenaline for improving peri-operative analgesia in anaesthetized dogs undergoing arthroscopy of the elbow. A solution of lidocaine (L) 1.98% plus adrenaline 1:100.000 was administered via the IA route and its safety evaluated in terms of cardio-, neuro-, and chondro-toxicity. No bradycardia or hypotension was recorded from induction to the last observational time point. Signs of toxicity of the nervous system could have been masked by the general anaesthesia but lidocaine concentrations detected in the blood were lower than those thought to be capable of producing toxicity. The assessment of in vitro chondrotoxicity showed a dose- and time-dependent effect of lidocaine on the viability of articular cells. Adrenaline appeared to reduce the chondrotoxicity of 1% lidocaine, following an exposure of up to 30 min.


Assuntos
Analgesia/veterinária , Cães/metabolismo , Epinefrina/toxicidade , Lidocaína/toxicidade , Anestésicos Locais/farmacocinética , Anestésicos Locais/toxicidade , Animais , Artroscopia/veterinária , Cães/cirurgia , Epinefrina/farmacocinética , Feminino , Injeções Intra-Articulares/veterinária , Lidocaína/farmacocinética , Masculino , Distribuição Aleatória , Vasoconstritores/farmacocinética , Vasoconstritores/toxicidade
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