Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Top Companion Anim Med ; 43: 100521, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33556641

RESUMEN

Dietary exogenous thyrotoxicosis is infrequently observed in pet food. A retrospective evaluation of pet food investigations (PFI) was conducted for 17 dogs, including review of medical records, dietary and environmental exposure interviews, food testing, and regulatory action. Five PFIs occurring between 2016 and 2018 involved 7 food products including 2 food types, jerky treats or canned food, made from beef or bison. The dogs' serum thyroid hormone concentrations were evaluated before and after diet change. The foods were tested for active thyroid hormones and hormone precursors using high performance liquid chromatography with inductively coupled plasma mass spectrometry detection. The foods were also examined microscopically. Serum thyroid hormone concentrations of thyroxine (T4) varied depending on the food type consumed. Dogs that consumed dried jerky containing greater T4 concentrations often had increased serum T4 concentrations, whereas dogs that consumed canned products containing greater and 3,4,5- and 3,5,3'-triiodothyronine (T3) concentrations often had decreased serum T4 concentrations. After the diets were changed, serum T4 and T3 concentrations normalized at 1 month. Seven foods containing beef or bison had iodine concentrations greater than 11 mg/kg, and iodine speciation identified variable concentrations of iodide, T4, T3, monoiodotyrosine (MIT), and di-iodotyrosine (DIT). Thyroid gland was found in microscopic sections from one finished food and one ingredient, gullet. FDA performed Health Hazard Evaluations to categorize the exposure risk, and 5 foods were recalled for which the product packaging had not been discarded. Dietary exogenous thyrotoxicosis should be considered in dogs exhibiting clinical signs compatible with hyperthyroidism, especially if consuming beef-based food. A thyroid panel that includes serum iodine, coupled with a thorough feeding history can aid in diagnosis. Thyrotoxicosis is typically reversible after removing the contaminated food from the diet.


Asunto(s)
Alimentación Animal , Enfermedades de los Perros , Tirotoxicosis , Animales , Dieta , Perros , Estudios Retrospectivos , Tirotoxicosis/veterinaria , Tiroxina , Triyodotironina
2.
Artículo en Inglés | MEDLINE | ID: mdl-27107244

RESUMEN

An analytical method for determination of the iodine species 3-monoiodotyrosine (MIT), iodide, 3,5-diiodotyrosine (DIT), 3,5-diiodothyronine (3, 5-T2), 3,5,3'-triiodothyronine (T3), and thyroxine (T4) in dog foods and treats is reported. Iodine speciation was carried out using a HPLC method capable of both anion-exchange and reversed-phase retention coupled with inductively coupled plasma mass spectrometry detection (LC-ICP-MS). The method was evaluated by the analysis of the iodine species concentrations in twelve dog foods and treats following enzymatic digestion. The concentrations of MIT, iodide, DIT, T3, and T4 in the samples ranged from 0.64-59.5µg/g, 0.86-4.05µg/g,

Asunto(s)
Alimentación Animal/análisis , Cromatografía Líquida de Alta Presión/métodos , Compuestos de Yodo/análisis , Compuestos de Yodo/química , Yodo/química , Espectrometría de Masas/métodos , Animales , Perros , Límite de Detección , Modelos Lineales , Reproducibilidad de los Resultados
3.
Forensic Sci Int ; 226(1-3): 81-7, 2013 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-23313601

RESUMEN

The identification of a predominate metabolite found in urine specimens which test positive for naphthoylindole-based synthetic cannabinoids is reported. The presence of this new metabolite was detected at the Air Force Drug Testing Lab Investigations Division during screening analysis for metabolites of JWH-018 and JWH-073, because it shares the same MRM transitions as the JWH-073 N-(3-hydroxybutyl) metabolite. However, the detected peak is chromatographically distinguished from other metabolites due to differences in retention time. This metabolite appears to be a common metabolite for select naphthoylindole-based synthetic cannabinoids that could potentially be used as a common biomarker for their qualitative and quantitative analyses. The new metabolite has been successfully identified as 3-(3-(1-naphthoyl)-1H-indol-1-yl) propanoic acid (1, JWH 072 N-propanoic acid metabolite, Fig. 1) by using various mass spectrometric and liquid chromatographic techniques as well as chemical derivatization. The metabolite identity was confirmed through the comparison of authentic positive urine and a chemically synthesized metabolite standard. Both materials shared the same chromatographic retention time on two separate chromatographic systems, mass fragmentation pattern and exact mass. Full characterization of the synthetic reference material and intermediates by (1)H NMR, (13)C NMR, IR and HRMS was also conducted.

4.
Artículo en Inglés | MEDLINE | ID: mdl-23153643

RESUMEN

Herbal smoking mixtures which are sold as incense or potpourri and often referred to as 'Spice' are actually inactive plant matter adulterated with alkylamino indole based synthetic cannabinoids such as JWH-018 and JWH-073. Due to the inclusion of five synthetic cannabinoids, including JWH-018 and JWH-073, as Schedule I drugs by the Drug Enforcement Agency (DEA) in March 2011, it has become necessary for forensic laboratories to develop analytical methods to test for the presence of metabolites of synthetic cannabinoids. When a new analyte of interest emerges, most laboratories strive to develop a sample preparation procedure and validate an analytical method as quickly as possible and therefore, rely on effective but time consuming traditional protocols such as solid phase and liquid-liquid extraction. This research focuses on the examination of all aspects of sample preparation and analytical method development to streamline the analysis of four urinary metabolites of JWH-018 and JWH-073. A detailed evaluation of the ß-glucuronide hydrolysis step lead to the reduction of time required for hydrolysis from 1h at 50°C to only 10min at room temperature. By utilizing a salting-out assisted liquid-liquid extraction (SALLE) in place of traditional liquid-liquid extraction with a volatile solvent, processing time was saved and waste was reduced. The analysis run time was also shortened to one-third of a typical published run time by utilizing UPLC with isocratic conditions in place of conventional HPLC running a gradient method.


Asunto(s)
Cannabinoides/orina , Cromatografía Líquida de Alta Presión/métodos , Ensayos Analíticos de Alto Rendimiento/métodos , Indoles/orina , Extracción Líquido-Líquido/métodos , Naftalenos/orina , Cannabinoides/química , Humanos , Hidrólisis , Drogas Ilícitas/química , Drogas Ilícitas/orina , Indoles/química , Naftalenos/química , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrometría de Masas en Tándem/métodos
5.
Anal Chem ; 74(1): 107-13, 2002 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-11795777

RESUMEN

Various Brassica species accumulate Se into the thousands of ppm. This suggests some of them as candidates for Se phytoremediation. Brassica juncea (Indian mustard) was used to accumulate selenium by growing with sodium selenite as the selenium source under hydroponic conditions resulting in Se accumulation of up to hundreds of ppm in various parts of the plant. To date, few selenium speciation studies have been done in plants, with most studies reporting total selenium concentration in various parts of the plant. Se species extraction was evaluated by several digestion/extraction procedures, including the use of HCl, Tris-HCl buffer, and enzymatic hydrolysis (using proteinase K and protease XIV). The best extraction was obtained with proteinase K (extracting approximately 75% of the total Se present in the plant). Some of the species produced by the plant, such as selenomethionine, can be identified at ppb levels by RP-HPLC-ICPMS, since standards are readily available. Others needed to be further characterized by ES-MS. Enzymatic hydrolysis releases mostly Se-methionine from juncea leaves, although other Se-containing species can also be observed by HPLC-ICPMS. In this initial study, the possible identification (by ES-MS) of a small chromatographic peak containing a Se-S bridged seleno amino acid with a structure similar to cystine is suggested.


Asunto(s)
Brassica/química , Selenio/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Estructura Molecular , Plantas Comestibles/química , Selenio/química , Espectrometría de Masa por Ionización de Electrospray
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA