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1.
Prev Vet Med ; 167: 90-100, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31027728

RESUMO

Veterinary antimicrobials can spread via manure onto agricultural fields, representing an emission of these products or their active metabolites into the environment. This causes concerns regarding the role of antimicrobial residues in the development, selection and spread of resistance. Aiming to approach this issue quantitatively, first a literature review was performed on the bioavailability and extent of in vivo biotransformation of twelve antimicrobials commonly used in pigs orally, and on the level of their persistence in manure. This information was then used in a model estimating the level of each of these administered antimicrobials that is present in manure at the end of common storage durations in pits and, thus, readily applied onto soil. From the studied antimicrobials, the highest level of residues in stored manure was estimated for doxycycline (55% of the initial amount of doxycycline administered orally to pigs after six months of manure storage), as a combining result of its high use in pigs, low bioavailability and high stability in manure. Other antimicrobials (e.g. amoxicillin) are readily degraded and therefore pose less threat. The results of this study highlight the importance of rational antimicrobial use and of further research on pharmacokinetics of antimicrobials and their degraded products in different environmental compartments, to efficiently control the spread of residues and/or resistance genes from manure to these matrices.


Assuntos
Anti-Infecciosos/química , Esterco/análise , Poluentes do Solo , Suínos , Administração Oral , Animais , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/metabolismo , Bélgica , Monitoramento Ambiental , Modelos Teóricos , Fatores de Risco
2.
Poult Sci ; 97(4): 1134-1140, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29381781

RESUMO

Florfenicol (FF) is registered for treatment of bovine and swine respiratory diseases. Although, turkeys often suffer from bacterial respiratory tract infections, there is no registered formulation based on FF for poultry available in Europe. The aim of this study was to evaluate the pharmacokinetic behavior of FF in turkeys in plasma, lung tissue, and pulmonary epithelial lining fluid (PELF).The concentration and pharmacokinetic characteristics of FF in plasma, lung tissue, and PELF in turkeys were determined, either after a single oral bolus (30 mg/kg body weight, BW) or during and after continuous drinking water medication (30 mg/kg BW/d for 5 d). Plasma, lung tissue, and PELF samples were collected at different intervals after administration, and FF was quantified by liquid chromatography-tandem mass spectrometry. After single bolus administration, FF was rapidly absorbed in plasma (the time to maximum concentration, tmax, was 1.02 h) and distributed to the respiratory tract (mean tmax = 1.00 h). The mean t1/2el in plasma and lung tissue was similar, around 6 h, whereas it was slightly higher in PELF, namely, 8.7 hours. After oral bolus dosing, the mean maximum concentration in plasma was twice as high as in the lung tissue, 4.26 µg/mL and 2.64 µg/g, respectively, while in PELF it was much lower, 0.39 µg/mL. During continuous drinking water medication, lung FF concentrations were slightly higher than plasma concentrations, with lung/plasma ratios of 2.01 and 1.27 after 24 h and 72 h, respectively. FF was not detected in PELF during continuous drinking water medication.


Assuntos
Antibacterianos/farmacocinética , Tianfenicol/análogos & derivados , Perus/fisiologia , Animais , Antibacterianos/sangue , Cromatografia Líquida/veterinária , Vias de Administração de Medicamentos/veterinária , Feminino , Pulmão/química , Mucosa Respiratória/química , Espectrometria de Massas em Tandem/veterinária , Tianfenicol/sangue , Tianfenicol/farmacocinética , Distribuição Tecidual
3.
Equine Vet J ; 50(3): 377-383, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29023952

RESUMO

BACKGROUND: Arrhythmias in horses may require long-term anti-arrhythmic therapy. Unfortunately, oral anti-arrhythmic drugs for use in horses are currently scarce. In human patients and small animals, sotalol, a ß-blocker with class III anti-arrhythmic properties, is often used for long-term treatment. OBJECTIVES: To determine the pharmacokinetics of sotalol at multiple oral dosages in unfasted horses, as well as the effects on electro- and echocardiographic measurements, right atrial and ventricular monophasic action potential (MAP) and effective refractory period (ERP). STUDY DESIGN: Placebo controlled, double-blinded experiment. MATERIALS AND METHODS: Six healthy, unfasted Warmblood horses were given either 0, 2, 3 or 4 mg/kg bodyweight (bwt) sotalol orally (PO) twice daily (bid) for 9 days in a randomised cross-over design. Echocardiography and surface electrocardiography were performed and plasma concentrations of sotalol and right atrial and right ventricular MAPs and ERPs were determined at steady-state conditions. Statistical analysis was performed using a repeated measures univariate analysis with post hoc Bonferroni corrections. RESULTS: Calculated mean steady-state plasma concentrations determined by nonlinear mixed-effect modelling were 287 (range 234-339), 409 (359-458) and 543 (439-646) ng/mL for 2, 3 and 4 mg/kg bwt sotalol PO bid respectively. Sotalol significantly increased the QT interval and ERPs, but, despite increasing plasma concentrations, higher dosages did not result in a progressive increase in QT interval or ERPs. Echocardiographic and other electrocardiographic measurements did not change significantly. MAP durations at 90% repolarisation were not significantly different during sotalol treatment. Besides transient local sweating, no side effects were noted. MAIN LIMITATIONS: Study size and ad libitum feeding of hay. CONCLUSIONS: Sotalol at a dose of 2, 3 and 4 mg/kg bwt PO bid increases the QT interval and ERP and might be a useful drug for long-term anti-arrhythmic therapy in horses.


Assuntos
Antiarrítmicos/farmacocinética , Eletrocardiografia/veterinária , Cavalos , Período Refratário Eletrofisiológico/efeitos dos fármacos , Sotalol/farmacocinética , Animais , Antiarrítmicos/administração & dosagem , Estudos Cross-Over , Relação Dose-Resposta a Droga , Ecocardiografia/veterinária , Feminino , Masculino , Sotalol/administração & dosagem , Sotalol/sangue
4.
Poult Sci ; 96(7): 2137-2144, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28160001

RESUMO

The presence of mycotoxins in broiler feed can have deleterious effects on the wellbeing of the animals and their performance. Mycotoxin binders are feed additives that aim to adsorb mycotoxins in the intestinal tract and thereby prevent the oral absorption of the mycotoxin. The simultaneous administration of coccidiostats and/or antimicrobials with mycotoxin binders might lead to a reduced oral bioavailability of these veterinary medicinal products. This paper describes the influence of 3 mycotoxin binders (i.e., clay 1 containing montmorillonite, mica, and feldspars; clay 2 containing montmorillonite and quartz; and yeast 1 being a modified glucomannan fraction of inactivated yeast cells) and activated carbon on the oral bioavailability and pharmacokinetic parameters of the antimicrobials doxycycline and tylosin, and the coccidiostats diclazuril and salinomycin. A feeding study with 40 15 day-old broilers was performed evaluating the effects of long-term feeding 2 g mycotoxin binder/kg of feed. The birds were randomly divided into 5 groups of 8 birds each, i.e., a control group receiving no binder and 4 test groups receiving either clay 1, clay 2, yeast 1, or activated carbon mixed in the feed. After 15 d of feeding, both the control and each test group were administered doxycycline, tylosin, diclazuril, and salinomycin, consecutively, respecting a wash-out period of 2 to 3 d between each administration. The 4 medicinal products were dosed using a single bolus administration directly in the crop. After each bolus administration, blood was collected for plasma analysis and calculation of the main pharmacokinetic parameters and relative oral bioavailability (F = area under the plasma concentration-time curve (AUC0-8 h) in the test groups/AUC0-8 h in the control group)*100). No effects were observed of any of the mycotoxin binders on the relative oral bioavailability of the coccidiostats (i.e., F between 82 and 101% and 79 and 93% for diclazuril and salinomycin, respectively). Also, no significant effects could be noticed of any of the mycotoxin binders on the relative oral bioavailability of the antimicrobials doxycycline and tylosin (i.e., F between 67 and 83% and between 43 and 104%, respectively).


Assuntos
Antibacterianos/farmacocinética , Galinhas/metabolismo , Coccidiostáticos/farmacocinética , Micotoxinas/antagonistas & inibidores , Administração Oral , Animais , Disponibilidade Biológica , Doxiciclina/farmacocinética , Nitrilas/farmacocinética , Piranos/farmacocinética , Distribuição Aleatória , Triazinas/farmacocinética , Tilosina/farmacocinética
5.
Poult Sci ; 96(1): 14-17, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27591283

RESUMO

The aim of the present study was to evaluate the effect of the Fusarium mycotoxins deoxynivalenol (DON) and fumonisins (FBs) on the stress response in broiler chickens, using corticosterone (CORT) in plasma as a biomarker. Chickens were fed either a control diet, a DON contaminated diet, a FBs contaminated diet, or a DON and FBs contaminated diet for 15 d at concentrations close to the European Union maximum guidance levels for DON and FBs in poultry. Mean plasma CORT levels were significantly higher in broiler chickens fed a DON contaminated and a DON and FBs contaminated diet compared to birds fed a control diet. A similar trend was observed for animals fed a FBs contaminated diet. Consequently, feeding broilers a diet contaminated with DON and/or FBs induced a CORT stress response, which may indicate a negative effect on animal welfare.


Assuntos
Galinhas/fisiologia , Corticosterona/sangue , Microbiologia de Alimentos , Fusarium/química , Micotoxinas/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Ração Animal/análise , Animais , Biomarcadores/sangue , Feminino , Fumonisinas/toxicidade , Masculino , Tricotecenos/toxicidade
6.
Vet J ; 208: 60-4, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26670333

RESUMO

Arrhythmias are common in horses. Some, such as frequent atrial or ventricular premature beats, may require long-term anti-arrhythmic therapy. In humans and small animals, sotalol hydrochloride (STL) is often used for chronic oral anti-arrhythmic therapy. STL prolongs repolarization and the effective refractory period in all cardiac tissues. No information on STL pharmacokinetics or pharmacodynamics in horses is available and the aim of this study was to evaluate the pharmacokinetics of intravenously (IV) and orally (PO) administered STL and the effects on surface electrocardiogram and left ventricular systolic function. Six healthy horses were given 1 mg STL/kg bodyweight either IV or PO. Blood samples to determine plasma STL concentrations were taken before and at several time points after STL administration. Electrocardiography and echocardiography were performed at different time points before and after IV STL administration. Mean peak plasma concentrations after IV and PO administration of STL were 1624 ng/mL and 317 ng/mL, respectively. The oral bioavailability was intermediate (48%) with maximal absorption after 0.94 h, a moderate distribution and a mean elimination half-life of 15.24 h. After IV administration, there was a significant increase in QT interval, but no significant changes in other electrocardiographic and echocardiographic parameters. Transient transpiration was observed after IV administration, but no adverse effects were noted after a single oral dose of 1 mg/kg STL in any of the horses. It was concluded that STL has an intermediate oral bioavailability in the horse and might be useful in the treatment of equine arrhythmias.


Assuntos
Eletrocardiografia/veterinária , Cavalos/metabolismo , Sotalol/farmacologia , Sotalol/farmacocinética , Função Ventricular Esquerda/efeitos dos fármacos , Administração Intravenosa/veterinária , Administração Oral , Animais , Antiarrítmicos/farmacocinética , Antiarrítmicos/farmacologia , Disponibilidade Biológica , Eletrocardiografia/efeitos dos fármacos
7.
Artigo em Inglês | MEDLINE | ID: mdl-25264912

RESUMO

This study aims to develop an LC-MS/MS method allowing the determination of 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol, deoxynivalenol and its main in vivo metabolite, deepoxy-deoxynivalenol, in broiler chickens and pigs. These species have a high exposure to these toxins, given their mainly cereal based diet. Several sample cleanup strategies were tested and further optimized by means of fractional factorial designs. A simple and straightforward sample preparation method was developed consisting out of a deproteinisation step with acetonitrile, followed by evaporation of the supernatant and reconstitution in water. The method was single laboratory validated according to European guidelines and found to be applicable for the intended purpose, with a linear response up to 200ngml(-1) and limits of quantification of 0.1-2ngml(-1). As a proof of concept, biological samples from a broiler chicken that received either deoxynivalenol, 3- or 15-acetyl-deoxynivalenol were analyzed. Preliminary results indicate nearly complete hydrolysis of 3-acetyl-deoxynivalenol to deoxynivalenol; and to a lesser extent of 15-acetyl-deoxynivalenol to deoxynivalenol. No deepoxy-deoxynivalenol was detected in any of the plasma samples. The method will be applied to study full toxicokinetic properties of deoxynivalenol, 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol in broiler chickens and pigs.


Assuntos
Galinhas/sangue , Cromatografia Líquida de Alta Pressão/métodos , Sus scrofa/sangue , Espectrometria de Massas em Tandem/métodos , Tricotecenos/sangue , Animais , Masculino , Projetos Piloto , Sensibilidade e Especificidade , Toxicocinética , Tricotecenos/toxicidade
8.
J Vet Pharmacol Ther ; 36(6): 621-4, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23701633

RESUMO

The aim of this study was to investigate whether T-2 toxin, a potent Fusarium mycotoxin, affects the oral absorption of the antibiotic chlortetracycline in pigs. Animals were allocated to blank feed without T-2 toxin (controls), feed containing 111 µg T-2/kg feed, T-2-contaminated feed supplemented with a yeast-derived feed additive, or blank feed supplemented solely with the feed additive, respectively. After 21 days, an intragastric bolus of chlortetracycline was given to assess potential alterations in the pharmacokinetics of this commonly used antibiotic. A significantly higher area under the plasma concentration-time curve and maximal plasma concentration of chlortetracycline was observed after intake of T-2-contaminated feed compared with control. Thus, exposure to T-2-contaminated feed can influence the oral bioavailability of chlortetracycline. This effect could have consequences for the withdrawal time of the drug and the occurrence of undesirable residues in edible tissues.


Assuntos
Clortetraciclina/farmacocinética , Micotoxinas/toxicidade , Suínos/metabolismo , Absorção , Administração Oral , Animais , Área Sob a Curva , Clortetraciclina/administração & dosagem , Clortetraciclina/metabolismo , Meia-Vida
9.
Food Chem Toxicol ; 57: 54-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23524315

RESUMO

Mycotoxins are toxic metabolites produced by fungi that readily colonize crops. After ingestion, these mycotoxins can compromise intestinal health, and once entering the blood stream, even affect the liver and its metabolizing enzymes. It was therefore the aim of the present study to investigate the effect of T-2 toxin, an emerging and potent Fusarium mycotoxin, on the enzymatic activity of cytochrome P4503A (CYP3A) metabolizing enzymes in the liver of pigs. In addition, a yeast-derived feed additive that claims to bind T-2 toxin was included in the study to evaluate its efficacy. Our results demonstrated that a 14-days intake of T-2 toxin contaminated feed at a dose of 903 µg/kg feed, whether or not combined with the mycotoxin binder, results in a substantial inhibition of the CYP3A activity in the liver of pigs. This result may be of importance for animal health, the pharmacokinetics and the withdrawal time of drugs that are substrate of CYP3A enzymes, and consequently can be a threat for public health with respect to tissue residues of these drugs.


Assuntos
Inibidores do Citocromo P-450 CYP3A , Fígado/efeitos dos fármacos , Toxina T-2/toxicidade , Ração Animal , Animais , Contaminação de Alimentos , Fusarium/química , Fígado/metabolismo , Masculino , Suínos
10.
Food Chem Toxicol ; 55: 150-5, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23313610

RESUMO

The effects of the mycotoxin T-2 on hepatic and intestinal drug-metabolizing enzymes (cytochrome P450) and drug transporter systems (MDR1 and MRP2) in poultry were investigated during this study. Broiler chickens received either uncontaminated feed, feed contaminated with 68µg/kg or 752µg/kg T-2 toxin. After 3weeks, the animals were euthanized and MDR1, MRP2, CYP1A4, CYP1A5 and CYP3A37 mRNA expression were analyzed using qRT-PCR. Along the entire length of the small intestine no significant differences were observed. In the liver, genes coding for CYP1A4, CYP1A5 and CYP3A37 were significantly down-regulated in the group exposed to 752µg/kg T-2. For CYP1A4, even a contamination level of 68µg/kg T-2 caused a significant decrease in mRNA expression. Expression of MDR1 was not significantly decreased in the liver. In contrast, hepatic MRP2 expression was significantly down-regulated after exposure to 752µg/kg T-2. Hepatic and intestinal microsomes were prepared to test the enzymatic activity of CYP3A. In the ileum and liver CYP3A activity was significantly increased in the group receiving 752µg/kg T-2 compared to the control group. The results of this study show that drug metabolizing enzymes and drug transporter mechanisms can be influenced due to prolonged exposure to relevant doses of T-2.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Dieta , Intestinos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Toxina T-2/toxicidade , Animais , Sequência de Bases , Biotransformação , Peso Corporal/efeitos dos fármacos , Galinhas , Primers do DNA , Mucosa Intestinal/metabolismo , Intestinos/enzimologia , Fígado/enzimologia , Fígado/metabolismo , Reação em Cadeia da Polimerase , Membro 4 da Subfamília B de Transportadores de Cassetes de Ligação de ATP
11.
Anal Chim Acta ; 756: 37-48, 2012 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-23176738

RESUMO

A sensitive and specific method for the quantitative determination of zearalenone (ZEN) and its major metabolites (α-zearalenol (α-ZEL), ß-zearalenol (ß-ZEL), α-zearalanol (α-ZAL), ß-zearalanol (ß-ZAL) and zearalanone (ZAN)) in animal plasma using liquid chromatography combined with heated electrospray ionization (h-ESI) tandem mass spectrometry (LC-MS/MS) and high-resolution Orbitrap(®) mass spectrometry ((U)HPLC-HR-MS) is presented. The sample preparation was straightforward, and consisted of a deproteinization step using acetonitrile. Chromatography was performed on a Hypersil Gold column (50 mm × 2.1 mm i.d., dp: 1.9 µm, run-time: 10 min) using 0.01% acetic acid in water (A) and acetonitrile (B) as mobile phases. Both mass spectrometers were operated in the negative h-ESI mode. The method was in-house validated for all analytes: matrix-matched calibration graphs were prepared and good linearity (r≥0.99) was achieved over the concentration range tested (0.2-200 ng mL(-1)). Limits of quantification (LOQ) in plasma were between 0.2 and 5 ng mL(-1) for all compounds. Limits of detection in plasma ranged from 0.004 to 0.070 ng mL(-1). The results for the within-day and between-day precision, expressed as relative standard deviation (RSD), fell within the maximal RSD values (within-day precision: RSD(max)=2((1-0.5logConc)) x 2/3; between-day precision: RSD(max)=2((1-0.5logConc))). The accuracy fell within -50% to +20% (concentrations <1 ng mL(-1)), -30% to +10% (concentrations between 1 and 10 ng mL(-1)) or -20% to +10% (concentrations >10 ng mL(-1)) of the theoretical concentration. The method has been successfully used for the quantitative determination of ZEN in plasma samples from broiler chickens and pigs. α-ZEL and ß-ZEL were the only metabolites that could be detected, but the concentrations were around the LOQ levels. The intact ZEN-glucuronide conjugate could be detected using the (U)HPLC-HR-MS instrument. A good correlation (r(2)=0.9979) was observed between the results for ZEN obtained with the LC-MS/MS and (U)HPLC-HR-MS instruments. The results prove the usefulness of the developed method for application in the field of toxicokinetic analysis and for exposure assessment of mycotoxins.


Assuntos
Técnicas de Química Analítica/métodos , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas em Tandem , Zearalenona/sangue , Animais , Galinhas , Limite de Detecção , Suínos , Zearalenona/metabolismo
12.
Poult Sci ; 91(8): 2046-54, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22802203

RESUMO

Contamination of feeds with mycotoxins is a worldwide problem and mycotoxin-detoxifying agents are used to decrease their negative effect. The European Food Safety Authority recently stated guidelines and end-points for the efficacy testing of detoxifiers. Our study revealed that plasma concentrations of deoxynivalenol and deepoxy-deoxynivalenol were too low to assess efficacy of 2 commercially available mycotoxin-detoxifying agents against deoxynivalenol after 3 wk of continuous feeding of this mycotoxin at concentrations of 2.44±0.70 mg/kg of feed and 7.54±2.20 mg/kg of feed in broilers. This correlates with the poor absorption of deoxynivalenol in poultry. A safety study with 2 commercially available detoxifying agents and veterinary drugs showed innovative results with regard to the pharmacokinetics of 2 antibiotics after oral dosing in the drinking water. The plasma and kidney tissue concentrations of oxytetracycline were significantly higher in broilers receiving a biotransforming agent in the feed compared with control birds. For amoxicillin, the plasma concentrations were significantly higher for broilers receiving an adsorbing agent in comparison to birds receiving the biotransforming agent, but not to the control group. Mycotoxin-detoxifying agents can thus interact with the oral bioavailability of antibiotics depending on the antibiotic and detoxifying agent, with possible adverse effects on the health of animals and humans.


Assuntos
Amoxicilina/uso terapêutico , Galinhas , Oxitetraciclina/uso terapêutico , Doenças das Aves Domésticas/induzido quimicamente , Tricotecenos/antagonistas & inibidores , Amoxicilina/efeitos adversos , Animais , Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Bile/química , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Europa (Continente) , Feminino , Masculino , Oxitetraciclina/efeitos adversos , Doenças das Aves Domésticas/prevenção & controle , Tricotecenos/sangue , Tricotecenos/metabolismo
13.
Artigo em Inglês | MEDLINE | ID: mdl-22497259

RESUMO

In this study, three new models were developed for efficacy testing of mycotoxin-detoxifying agents in relation to recent European guidelines. In the first model, deoxynivalenol was given to broiler chickens as an intra-crop bolus together with a mycotoxin-detoxifying agent in order to study the plasma concentration-time profile of deoxynivalenol. In the second model, the same oral bolus was given, preceded by an oral bolus of mycotoxin-detoxifying agent, to make sure the detoxifying agent was present in the whole intestinal tract when the mycotoxin was administered. In the third model, the mycotoxin-detoxifying agent was mixed in the feed of broiler chickens, and after 1 week's feeding, deoxynivalenol was given as an oral bolus. In order to evaluate the efficacy of these agents, plasma concentration-time profiles were set up and the main toxicokinetic parameters were compared. Two commercially available mycotoxin-detoxifying agents were tested, but they were not able to lower the oral availability of deoxynivalenol. As a positive control, activated carbon was used. We showed that activated carbon significantly reduces the absorption and oral availability of deoxynivalenol in all three models. Therefore, it can be concluded that these models are able to demonstrate the efficacy of mycotoxin-detoxifying agents in relation to European Food Safety Authority guidelines.


Assuntos
Guias como Assunto , Micotoxinas/toxicidade , Tricotecenos/química , Animais , Galinhas , Limite de Detecção , Testes de Toxicidade
14.
J Chromatogr B Analyt Technol Biomed Life Sci ; 879(24): 2403-15, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21767999

RESUMO

A sensitive and specific method for the quantitative determination of deoxynivalenol (DON), deepoxy-deoxynivalenol (DOM-1), T-2 toxin (T-2) and HT-2 toxin (HT-2) in animal body fluids (plasma and bile) using liquid chromatography combined with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) is presented. The extraction of plasma consisted of a deproteinization step using methanol, followed by a clean-up using an Oasis HLB solid-phase extraction column. For bile analysis, an extraction using a methanol/water mixture (70/30, v/v), followed by a liquid-liquid extraction using ethyl acetate, was performed. Chromatographic separation was achieved on a reversed-phase Nucleosil (100-5 C18 G100 × 3.0 mm) column. For the analysis of DON and DOM-1, a mixture of 0.1% acetic acid in water and methanol was used as the mobile phase. T-2 and its metabolite HT-2 were separated using 5mM ammonium acetate in a mixture of water/methanol/acetic acid. The mass spectrometer was operated in the negative or positive ESI selected reaction monitoring mode for DON and T-2 analysis, respectively. Calibration graphs (1-250 ng mL(-1)) were prepared for all matrices and correlation and goodness-of-fit coefficients were between 0.9978-1.000 and 2.96-11.77%, respectively. Limits of quantification were between 1 and 2.5 ng mL(-1) for all compounds. Limits of detection ranged from 0.01 to 0.63 ng mL(-1). The results for the within-day precision and accuracy fell within the ranges specified. The method has been successfully used for the quantitative determination of DON, DOM-1, T-2 and HT-2 in plasma and the semi-quantitative determination of the same compounds in bile from broiler chickens and pigs, respectively.


Assuntos
Bile/química , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Toxina T-2/análogos & derivados , Toxina T-2/análise , Tricotecenos/análise , Animais , Galinhas , Suínos , Toxina T-2/sangue , Espectrometria de Massas em Tandem/métodos , Tricotecenos/sangue
15.
Bull Soc Belge Ophtalmol ; 241: 105-11, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1840991

RESUMO

As an alternative treatment, we performed a cyclocryotherapy in a series of 27 eyes with chronic narrow angle and chronic open angle glaucoma. Intraocular pressure control was achieved in 91% of the eyes after a mean follow-up period of 38 months. Topical anti-glaucoma medication was needed in 65%. The complications were minor and transient. No serious complications were seen.


Assuntos
Criocirurgia/métodos , Glaucoma/cirurgia , Idoso , Corpo Ciliar/cirurgia , Feminino , Glaucoma Neovascular/cirurgia , Glaucoma de Ângulo Aberto/cirurgia , Humanos , Masculino , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos
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