Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
J Chromatogr A ; 1628: 461445, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822984

RESUMO

Anabolic androgenic steroids (AAS) have been the most commonly abused substances taken by not only professional sportsmen but also recreational bodybuilders. The detection of micro-dose testosterone (T) misuse is particularly challenging as it possesses pseudo-endogenous origin and is sometimes impossible to be identified in urine samples. Dried blood (DB) obtained by finger pricking has been proven to be an alternative matrix for better correlating to physiological responses. Moreover, the introduction of the volumetric absorptive microsampling (VAMS) technology allows overcoming some major limitations of spotting blood onto a filter paper card. In this work, a fast and sensitive GC-MS/MS method was developed and validated for the quantification of AAS in DB collected by means of VAMS. T and the eight top abused synthetic AAS, namely nandrolone, boldenone, mesterolone, drostanolone, metenolone, metandienone, oxandrolone, and dehydrochloromethyl T were selected as the target analytes. The method based on VAMS exhibited good precision, accuracy as well as stability, and superior extraction recoveries over the punched DB spots reported in the literature. The chromatographic separation was achieved within 6.4 min and the detection limit is as little as 50 fg (i.e. able to detect 0.10 ng mL-1 in 20 µL of DB). Confirmed by forty real blood samples, the Deming regression and Bland-Altman analysis revealed that the VAMS DB could be employed for quantifying blood T level in agreement with using the serum specimen. The feasibility of the method was then successfully proven by the analysis of samples collected from a three-arm T administration trial. Our results highlighted that DB total T was a sensitive indicator for identifying transdermal micro-dosing of T. In the groups of receiving T gel administration, T concentrations could rise up to ten times higher than the baseline at 9 h after the application. As a future step, this approach is being expanded to a large cohort screening of bodybuilders at gym and ultimately may allow universal applications on monitoring sports drug misuse.


Assuntos
Androgênios/sangue , Teste em Amostras de Sangue Seco/métodos , Monitoramento de Medicamentos/métodos , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas em Tandem , Congêneres da Testosterona/sangue , Testosterona/análise , Humanos
2.
Drug Test Anal ; 10(11-12): 1722-1727, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30381908

RESUMO

Anabolic androgenic steroids (AAS) are the most widely abused class of drugs by athletes and thus represent a significant problem to the anti-doping community. Confirmation of a doping violation for AAS cannot always be based on their presence alone due to the endogenous production of some steroids. Both testosterone (and its metabolites) and the major diagnostic metabolite of nandrolone (19-norandrosterone) are produced endogenously. Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) is used in such cases to differentiate between the administration of a synthetic preparation and endogenous steroid production by measurement of their differing carbon isotope (13 C/12 C) ratio. The purpose of this study was to investigate the availability of steroid preparations in the UK with a 13 C content analytically indistinguishable from that of endogenous steroids. Fourteen preparations containing nandrolone (n = 9) and testosterone (n = 5) were analyzed. The δ13 C values were determined using GC-C-IRMS and the identity of the steroid preparations was confirmed using gas chromatography-mass spectrometry (GC-MS). Ten steroid preparations displayed δ13 C values within the range expected for synthetic steroids (less than -27‰). However, four nandrolone preparations displayed δ13 C values that overlap with the values considered to be endogenous in origin (range: -26 to -16‰). Misuse of these preparations could prevent the confirmation of nandrolone administration using GC-C-IRMS in anti-doping cases.


Assuntos
Anabolizantes/análise , Androgênios/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Nandrolona/análise , Testosterona/análise , Isótopos de Carbono/análise , Dopagem Esportivo , Estranos/análise , Humanos , Esteroides/análise , Detecção do Abuso de Substâncias/métodos
4.
Anal Chem ; 89(16): 8343-8350, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28714673

RESUMO

γ-Hydroxybutyric acid (GHB) is a popular drug increasingly associated with cases of drug-facilitated sexual assault (DFSA). Currently, expanding procedures of analysis and having forensic evidence of GHB intake in a long term are mandatory. Up to now, most studies have been performed using GC/MS and LC-MS as analytical platforms, which involve significant manipulation of the sample and, often, indirect measurements. In this work, procedures used in NMR-based metabolomics were applied to a GHB clinical trial on urine and serum. Detection, identification, and quantification of the drug by NMR methods were surveyed, as well as the use of NMR-based metabolomics for the search of potential surrogate biomarkers of GHB consumption. Results demonstrated the suitability of NMR spectroscopy, as a robust nondestructive technique, to fast and directly monitor (detect, identify, and quantify) exogenous GHB in almost intact body fluids and its high potential in the search for metabolites associated with GHB intake.


Assuntos
Hidroxibutiratos/sangue , Hidroxibutiratos/urina , Detecção do Abuso de Substâncias/métodos , Adulto , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Feminino , Humanos , Masculino , Metabolômica/métodos , Espectroscopia de Prótons por Ressonância Magnética , Adulto Jovem
5.
Anal Chem ; 89(14): 7431-7437, 2017 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-28613840

RESUMO

The combination of field asymmetric waveform ion mobility spectrometry with liquid chromatography-mass spectrometry (LC-FAIMS-MS) has been developed for the analysis of glucuronide and sulfate metabolites of seven anabolic-androgenic steroids in urine. Separation by FAIMS-MS was investigated in positive ion mode for selected cationic adducts (H+, NH4+, Na+, K+, and Cs+). LC-FAIMS-MS analysis of the doubly sodiated adducts ([M + 2Na - H]+) of isobaric and coeluting steroid metabolites allowed their rapid (8 min) qualitative and quantitative determination in spiked urine using hydrophilic interaction liquid chromatography prior to FAIMS-MS separation, with discrimination >95% achieved between the steroids investigated. A quantitative evaluation of the LC-FAIMS-MS method was performed giving limits of detection in the range 1-6 ng mL-1, limits of quantification in the range 3-20 ng mL-1, with reproducibility (%RSD < 10%; n = 6) and linearity (R2 > 0.99). The LC-FAIMS-MS method demonstrates increases in signal-to-noise ratios for the doubly sodiated steroid metabolites in unspiked urine (>250%) by the reduction of isobaric interferences from the matrix. An alternative or additional tool for identification of the steroid metabolites is based on the observations of different patterns of sodium acetate clusters that are characteristic for each metabolite.


Assuntos
Congêneres da Testosterona/urina , Cromatografia Líquida , Humanos , Espectrometria de Mobilidade Iônica , Espectrometria de Massas em Tandem , Congêneres da Testosterona/metabolismo
6.
J Anal Toxicol ; 41(1): 54-59, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27744373

RESUMO

The administration of gamma-hydroxybutyrate (GHB) has been reported to augment the increase in growth hormone (GH) secretion associated with the onset of sleep. The ability of GHB to stimulate GH production in the absence of sleep in both male and female volunteers was investigated as part of a GHB administration study. Twelve healthy volunteers (six men and six women) were given a small oral dose (25 mg/kg) of GHB (as Xyrem®) at 10:00 h. Basal blood samples (as serum) were taken 10 min prior to GHB administration, with additional samples taken at 10, 15, 20, 25, 30, 45, 60, 90, 120, 150, 180, 240, 360 and 480 min post-administration. The serum concentrations of GHB were measured by GC-MS and GH by immunometric assay. Following GHB administration, volunteers exhibited effects consistent with mild sedation, i.e., relaxed with normal responses to verbal stimuli. Despite none being asleep, an increase in serum GH concentration occurred in 11 out of the 12 volunteers (5 women and 6 men). In these volunteers, peak GH concentrations occurred 45-60 min post-administration compared with a mean serum tmax for GHB of 23 min (SD = 5.4 min). The absolute increase in GH was similar for men and women, averaging 3.4 and 3.7 ng/mL, respectively. The mean intra-individual increase in GH was much greater in males (29 times) compared with females (2 times), as males had (as expected) smaller basal GH concentrations (mean = 0.26 ng/mL) compared with females (mean = 5.4 ng/mL). After maximizing, the GH concentration decreased rapidly (in agreement with GHB concentrations), returning to basal concentrations at ~90-120 min post-administration. GHB administration at a small therapeutic dose results in increases in serum GH concentrations in healthy male and female volunteers in the absence of sleep onset.


Assuntos
Hormônio do Crescimento/sangue , Oxibato de Sódio/administração & dosagem , Administração Oral , Adulto , Índice de Massa Corporal , Relação Dose-Resposta a Droga , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Sono , Oxibato de Sódio/sangue , Adulto Jovem
7.
Neuropsychopharmacology ; 41(7): 1742-50, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26552847

RESUMO

Pathological gambling is a psychiatric disorder and the first recognized behavioral addiction, with similarities to substance use disorders but without the confounding effects of drug-related brain changes. Pathophysiology within the opioid receptor system is increasingly recognized in substance dependence, with higher mu-opioid receptor (MOR) availability reported in alcohol, cocaine and opiate addiction. Impulsivity, a risk factor across the addictions, has also been found to be associated with higher MOR availability. The aim of this study was to characterize baseline MOR availability and endogenous opioid release in pathological gamblers (PG) using [(11)C]carfentanil PET with an oral amphetamine challenge. Fourteen PG and 15 healthy volunteers (HV) underwent two [(11)C]carfentanil PET scans, before and after an oral administration of 0.5 mg/kg of d-amphetamine. The change in [(11)C]carfentanil binding between baseline and post-amphetamine scans (ΔBPND) was assessed in 10 regions of interest (ROI). MOR availability did not differ between PG and HV groups. As seen previously, oral amphetamine challenge led to significant reductions in [(11)C]carfentanil BPND in 8/10 ROI in HV. PG demonstrated significant blunting of opioid release compared with HV. PG also showed blunted amphetamine-induced euphoria and alertness compared with HV. Exploratory analysis revealed that impulsivity positively correlated with caudate baseline BPND in PG only. This study provides the first evidence of blunted endogenous opioid release in PG. Our findings are consistent with growing evidence that dysregulation of endogenous opioids may have an important role in the pathophysiology of addictions.


Assuntos
Anfetamina/administração & dosagem , Analgésicos Opioides/metabolismo , Estimulantes do Sistema Nervoso Central/administração & dosagem , Jogo de Azar/diagnóstico por imagem , Jogo de Azar/metabolismo , Administração Oral , Adulto , Anfetamina/sangue , Analgésicos Opioides/farmacocinética , Análise de Variância , Isótopos de Carbono/farmacocinética , Estimulantes do Sistema Nervoso Central/sangue , Feminino , Fentanila/análogos & derivados , Fentanila/farmacocinética , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Tomografia por Emissão de Pósitrons
8.
Int J Neuropsychopharmacol ; 17(12): 2069-74, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24807268

RESUMO

This study aimed to replicate a previous study which showed that endogenous opioid release, following an oral dose of amphetamine, can be detected in the living human brain using [11C]carfentanil positron emission tomography (PET) imaging. Nine healthy volunteers underwent two [11C]carfentanil PET scans, one before and one 3 h following oral amphetamine administration (0.5 mg/kg). Regional changes in [11C]carfentanil BPND from pre- to post-amphetamine were assessed. The amphetamine challenge led to significant reductions in [11C]carfentanil BPND in the putamen, thalamus, frontal lobe, nucleus accumbens, anterior cingulate, cerebellum and insula cortices, replicating our earlier findings. None of the participants experienced significant euphoria/'high', supporting the use of oral amphetamine to characterize in vivo endogenous opioid release following a pharmacological challenge. [11C]carfentanil PET is able to detect changes in binding following an oral amphetamine challenge that reflects endogenous opioid release and is suitable to characterize the opioid system in neuropsychiatric disorders.


Assuntos
Anfetamina/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/diagnóstico por imagem , Estimulantes do Sistema Nervoso Central/farmacologia , Peptídeos Opioides/metabolismo , Adulto , Anfetamina/sangue , Encéfalo/metabolismo , Mapeamento Encefálico , Radioisótopos de Carbono , Estimulantes do Sistema Nervoso Central/sangue , Estudos de Coortes , Fentanila/análogos & derivados , Humanos , Imageamento por Ressonância Magnética , Masculino , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos
9.
J Anal Toxicol ; 36(2): 88-95, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22337777

RESUMO

Over the last 10-15 years, γ-hydroxybutyrate (GHB) and γ-butyrolactone have become increasingly popular "club drugs", but they have also gained attention as potential agents of drug-facilitated sexual assault (DFSA). Several studies have attempted to characterize GHB's pharmacokinetic properties in humans, and the aim of this paper is to build on this research with an emphasis on DFSA cases. A 25 mg/kg dose of GHB was given to 12 GHB-naïve volunteers (6 men and 6 women). Urine and blood samples (serum and whole blood) were collected and analyzed by gas chromatography-mass spectrometry following liquid-liquid extraction. The urinary T(max) was 1 h in 11 volunteers with a mean C(max) of 67.6 mg/L (32.6-161.3 mg/L). Urinary concentrations rapidly decreased to < 10 mg/L (interpretive limit) for 11 volunteers after just 4 h. Data derived from whole blood (mean C(max) = 48.0 mg/L, T(max) = 24.6 min) closely matched that from serum (mean C(max) = 59.4 mg/L, T(max) = 23.3 min), suggesting GHB is distributed into erythrocytes. All 12 volunteers had GHB concentrations of less than 5 mg/L in both whole blood and serum after 3 h. Results verify the rapid elimination of GHB and the limited retrospective power of a concentration-based approach to prove GHB administration in blood and urine and confirm that, in DFSA cases, samples should be collected as soon as possible.


Assuntos
Oxibato de Sódio/sangue , Oxibato de Sódio/farmacocinética , Oxibato de Sódio/urina , 4-Butirolactona/sangue , 4-Butirolactona/urina , Administração Oral , Adulto , Calibragem , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Extração Líquido-Líquido , Masculino , Controle de Qualidade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
10.
Drug Test Anal ; 3(7-8): 417-25, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21548140

RESUMO

Gamma-hydroxybutyrate (GHB) has been used as a recreational drug since the 1990s and over the last few years there has been increasing use of its analogues gamma-butyrolactone (GBL) and to a lesser extent 1,4-butanediol (1,4BD). This review will summarize the literature on the pharmacology of these compounds; the patterns and management of acute toxicity associated with their use; and the clinical patterns of presentation and management of chronic dependency associated with GHB and its analogues.


Assuntos
4-Butirolactona/toxicidade , Butileno Glicóis/toxicidade , Drogas Ilícitas/toxicidade , Oxibato de Sódio/toxicidade , Síndrome de Abstinência a Substâncias/terapia , 4-Butirolactona/análise , 4-Butirolactona/farmacologia , Animais , Butileno Glicóis/análise , Butileno Glicóis/farmacologia , Humanos , Drogas Ilícitas/análise , Drogas Ilícitas/farmacologia , Oxibato de Sódio/análise , Oxibato de Sódio/farmacologia , Síndrome de Abstinência a Substâncias/diagnóstico
11.
Steroids ; 76(5): 478-83, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21255594

RESUMO

A series of molecularly imprinted polymers have been prepared and investigated as stationary phases in high performance liquid chromatography for the separation of testosterone and epitestosterone using non-polar mobile phases. The polymers were imprinted using 5α-dihydrotestosterone as template, and all retain testosterone more strongly than its 17α-OH epimer. The best polymer was prepared using trifluoromethylacrylic acid as functional monomer (interacting with the template via hydrogen bonds), divinylbenzene as 'inert' cross-linker, and chloroform as porogen. It also included a steroid-based cross-linker, which may interact with the template via van der Waals interactions to lend additional 'shape selectivity'. A 250×4.6mm column packed with this polymer gave baseline resolution of testosterone and epitestosterone (15 µg each) in under 20 min. Preparation of the steroid based cross-linker included the selective reduction of 5α-dihydrotestosterone (17ß-hydroxy-5α-androstan-3-one) to the 3α,17ß-diol using K-selectride.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Epitestosterona/isolamento & purificação , Impressão Molecular/métodos , Polímeros , Testosterona/isolamento & purificação , Reagentes de Ligações Cruzadas/química , Métodos , Esteroides
12.
J Anal Toxicol ; 34(9): 555-61, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21073808

RESUMO

γ-Hydroxybutyrate (GHB) and its metabolic precursor γ-butyrolactone (GBL) are often implicated in cases of drug-facilitated sexual assault (DFSA), although definitive confirmation of GHB/GBL ingestion is complicated by GHB's endogenous nature and rapid elimination following ingestion. Multiple studies have attempted to establish a discriminant limit (generally 10 mg/L) above which urinary GHB concentrations can be considered consistent with GHB/GBL consumption. To supplement the currently available data, a rapid gas chromatography-mass spectrometry method was developed and validated for the analysis of GHB (following acidic conversion to GBL) and used to analyze urine samples collected from 1126 women (mean = 0.84 mg/L, median = 0.68 mg/L, range = 0.00-5.5 mg/L). GHB concentrations were shown to be independent of urinary pH (within the range 4.6-9.3), age (within the range 18-35 years), body mass index (within the range 13.8-36.3), and race. Adjusting GHB concentrations with respect to urinary specific gravity had little effect on the mean value (0.91 mg/L) and range (0.0-7.76 mg/L), although a statistically significant trend of increasing GHB concentration with specific gravity could be observed. Our results can be taken to offer further support for the 10 mg/L discriminant limit for GHB administration in antemortem urine samples.


Assuntos
Oxibato de Sódio/urina , Adolescente , Adulto , Envelhecimento , Algoritmos , Métodos Analíticos de Preparação de Amostras , Índice de Massa Corporal , Calibragem , Feminino , Medicina Legal/métodos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Concentração de Íons de Hidrogênio , Valores de Referência , Gravidade Específica , Adulto Jovem
13.
Bioanalysis ; 1(5): 1001-13, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21083067

RESUMO

Reported incidences of drug-facilitated sexual assault (DFSA) are on the increase worldwide. These cases represent a particular challenge for the forensic toxicologist due to the difficulty in obtaining adequate evidence of drug administration. Primarily, this is due to the nature and diversity of the drugs involved, their pharmacology and sampling timescales. Evaluating whether a drug has been administered to a victim for the purpose of sexual assault can often be difficult, if not impossible. This review draws attention to this burgeoning crime and focuses on the unique challenges DFSA cases present in terms of evidential analysis. Current analytical methodologies for investigating DFSA are highlighted and discussed along with developments in improving analytical procedures. In particular, enlarging detection windows by adopting emerging LC-MS techniques is also discussed. This review also highlights the use of cutting-edge technologies such as ultra-HPLC and the use of alternative matrices for addressing the problem of improved retrospective drug detection.


Assuntos
Toxicologia Forense/métodos , Hipnóticos e Sedativos/análise , Delitos Sexuais , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Feminino , Flunitrazepam/análise , Humanos , Masculino , Oxibato de Sódio/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA