105 resultados para In-doping


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Since 2004, cannabis has been prohibited by the World Anti-Doping Agency for all sports competitions. In the years since then, about half of all positive doping cases in Switzerland have been related to cannabis consumption. In doping urine analysis, the target analyte is 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH), the cutoff being 15 ng/mL. However, the wide urinary detection window of the long-term metabolite of Delta(9)-tetrahydrocannabinol (THC) does not allow a conclusion to be drawn regarding the time of consumption or the impact on the physical performance. The purpose of the present study on light cannabis smokers was to evaluate target analytes with shorter urinary excretion times. Twelve male volunteers smoked a cannabis cigarette standardized to 70 mg THC per cigarette. Plasma and urine were collected up to 8 h and 11 days, respectively. Total THC, 11-hydroxy-Delta(9)-tetrahydrocannabinol (THC-OH), and THC-COOH were determined after hydrolysis followed by solid-phase extraction and gas chromatography/mass spectrometry. The limits of quantitation were 0.1-1.0 ng/mL. Eight puffs delivered a mean THC dose of 45 mg. Plasma levels of total THC, THC-OH, and THC-COOH were measured in the ranges 0.2-59.1, 0.1-3.9, and 0.4-16.4 ng/mL, respectively. Peak concentrations were observed at 5, 5-20, and 20-180 min. Urine levels were measured in the ranges 0.1-1.3, 0.1-14.4, and 0.5-38.2 ng/mL, peaking at 2, 2, and 6-24 h, respectively. The times of the last detectable levels were 2-8, 6-96, and 48-120 h. Besides high to very high THC-COOH levels (245 +/- 1,111 ng/mL), THC (3 +/- 8 ng/mL) and THC-OH (51 +/- 246 ng/mL) were found in 65 and 98% of cannabis-positive athletes' urine samples, respectively. In conclusion, in addition to THC-COOH, the pharmacologically active THC and THC-OH should be used as target analytes for doping urine analysis. In the case of light cannabis use, this may allow the estimation of more recent consumption, probably influencing performance during competitions. However, it is not possible to discriminate the intention of cannabis use, i.e., for recreational or doping purposes. Additionally, pharmacokinetic data of female volunteers are needed to interpret cannabis-positive doping cases of female athletes.

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BACKGROUND AND OBJECTIVES: Urinary steroid profiling is used in doping controls to detect testosterone abuse. A testosterone over epitestosterone (T/E) ratio exceeding 4.0 is considered as suspicious of testosterone administration, irrespectively of individual heterogeneous factors such as the athlete's ethnicity. A deletion polymorphism in the UGT2B17 gene was demonstrated to account for a significant part of the interindividual variability in the T/E between Caucasians and Asians. Here, the variability of urinary steroid profiles was examined in a widely heterogeneous cohort of professional soccer players. Method: The steroid profile of 57 Africans, 32 Asians, 50 Caucasians and 32 Hispanics was determined by gas chromatography-mass spectrometry. RESULTS: Significant differences have been observed between all ethnic groups. After estimation of the prevalence of the UGT2B17 deletion/deletion genotype (African: 22%; Asian: 81%; Caucasian: 10%; Hispanic: 7%), ethnic-specific thresholds were developed for a specificity of 99% for the T/E (African: 5.6; Asian: 3.8; Caucasian: 5.7; Hispanic: 5.8). Finally, another polymorphism could be hypothesised in Asians based on specific concentration ratio of 5alpha-/5beta-androstane-3alpha,17beta-diol in urine. CONCLUSION: These results demonstrate that a unique and non-specific threshold to evidence testosterone misuse is not fit for purpose. An athlete's endocrinological passport consisting of a longitudinal follow-up together with the ethnicity and/or the genotype would strongly enhance the detection of testosterone abuse. Finally, additional genotyping studies should be undertaken to determine whether the remaining unexplained disparities have an environmental or a genetic origin.

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Haemoglobin (Hb) and haematocrit (Hct) are measured as indirect markers of doping in athletes. We studied the effect of posture on these parameters in a typical antidoping setting. Venous blood samples were obtained from nine endurance athletes (six males, three females) and nine control subjects (six males, three females) immediately and after 5, 10, 15, 20 and 30 min after having adopted a seated position from normal daily activity. Hb (CV 0.72%) and Hct (CV 0.87%) were determined using an automated cell counter, plasma volume changes were calculated. Differences between the time points, gender and groups were calculated using a mixed-model procedure. Significant changes were observed in the first 10 min after sitting down but no further changes were noted between 10 and 30 min. Mean directional change for Hb and Hct between 0 min and the average of the period from 10 to 30 min was -2.4% (-0.35 g/dl) for Hb and -2.7% (-1.2%) for Hct. Plasma volume increased accordingly. Neither group nor gender had significant effects. Under typical conditions encountered during blood testing in doping control, a period of 10 min in a seated position is sufficient for the vascular volumes to re-equilibrate and to adapt to the new posture.

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C.E.R.A., a continuous erythropoietin receptor activator, is a new third-generation erythropoiesis-stimulating agent (ESA) that has recently been linked with abuse in endurance sports. In order to combat this new form of doping, we examined an enzyme-linked immunosorbent assay (ELISA) designed to detect the presence of C.E.R.A. in serum samples. The performance of the assay was evaluated using a pilot excretion study that involved six subjects receiving C.E.R.A. Validation data demonstrated an excellent reproducibility and ensured the applicability of the assay for anti-doping purposes. To maximize the chances of detecting the drug in serum samples, we propose the use of this specific ELISA test as a high-throughput screening method, combined with a classic isoelectric focusing test as a confirmatory assay. This strategy should make C.E.R.A. abuse relatively easy to detect, thereby preventing the future use of this drug as a doping agent.

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Background: Urinary human chorionic gonadotropin (hCG) concentration is routinely measured in all anti-doping laboratories to exclude the misuse of recombinant or urinary hCG preparations. In this study, extended validation of two commercial immunoassays for hCG measurements in urine was performed. Both tests were initially designed for hCG determination in human serum/plasma. Methods: Access (R) and Elecsys (R) 1010 are two automated immunoanalysers for central laboratories. The limits of detection and quantification, as well as intra-laboratory and inter-technique correlation, precision, and accuracy, were determined. Stability studies of hCG in urine following freezing and thawing cycles (n = 3) as well as storage conditions at room temperature, 4 degrees C and 20 degrees C, were performed. Results: Statistical evaluation of hCG concentrations in male urine samples (n = 2429) measured with the Elecsys (R) 1010 system enabled us to draw a skewed frequency histogram and establish a far outside value equal to 2.3 IU/L. This decision limit corresponds to the concentration at which a sportsman will be considered positive for hCG. Intra-assay precision for the Access (R) analyser was less than 4.0 A, whereas the inter-assay precision was closer to 4.5 % (concentrations of the official external controls contained between 5.5 and 195.0 IU/L). Intra and inter-assay precision for the Elecsys (R) 1010 analyser was slightly better. A good inter-technique correlation was obtained when measuring various urine samples (male and female). No urinary hCG loss was observed after two freeze/thaw cycles. On the other hand, time and inappropriate storage conditions, such as temperatures above 10 degrees C for more than 5 days, can deteriorate urinary hCG. Conclusions: Both analysers showed acceptable performances and are suitable for screening urine for anti-doping analyses. Each laboratory should validate and establish its own reference values because hCG concentrations measured in urine can be different from one immunoassay to another. The time delay between urine collection and analysis should be reduced as much as possible, and urine samples should be transported in optimal conditions to avoid a loss of hCG immunoreactivity.

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For doping control, analyses of samples are generally achieved in two steps: a rapid screening and, in the case of a positive result, a confirmatory analysis. A two-step methodology based on ultra-high-pressure liquid chromatography coupled to a quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was developed to screen and confirm 103 doping agents from various classes (e.g., beta-blockers, stimulants, diuretics, and narcotics). The screening method was presented in a previous article as part I (i.e., Fast analysis of doping agents in urine by ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry. Part I: screening analysis). For the confirmatory method, basic, neutral and acidic compounds were extracted by a dedicated solid-phase extraction (SPE) in a 96-well plate format and detected by MS in the tandem mode to obtain precursor and characteristic product ions. The mass accuracy and the elemental composition of precursor and product ions were used for compound identification. After validation including matrix effect determination, the method was considered reliable to confirm suspect results without ambiguity according to the positivity criteria established by the World Anti-Doping Agency (WADA). Moreover, an isocratic method was developed to separate ephedrine from its isomer pseudoephedrine and cathine from phenylpropanolamine in a single run, what allowed their direct quantification in urine.

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Since the 1990's, cheating athletes have abused substances to increase their oxygen transport capabilities; among these substances, recombinant EPO is the most well known. Currently, other investigational pharmaceutical products are able to produce an effect similar to EPO but without having chemical structures related to EPO; these are the synthetic erythropoiesis stimulating agents (ESAs). Peginesatide (also known as Hematide?) is being developed by Affymax and Takeda and, if approved by regulatory authorities, could soon be released on the international market. To detect potential athletic abuse of this product and deter athletes who consider cheating, we initiated a collaboration to implement a detection test for anti-doping purposes. Peginesatide is a synthetic, PEGylated, investigational, peptide-based erythropoiesis-stimulating agent that is designed and engineered to stimulate specifically the erythropoietin receptor dimer that governs erythropoiesis. It is undetectable using current anti-doping tests due to its lack of sequence homology to EPO. To detect and deter potential abuse of peginesatide, we initiated an industry/antidoping laboratory collaboration to develop and validate screening and confirmation assays so that they would be available before peginesatide reaches the market. We describe a screening ELISA and a confirmation assay consisting of immune-purification followed by separation with SDS-PAGE and revelation with Western double blotting. Both assays can detect 0.5 ng/mL concentrations of peginesatide in blood samples, enabling detection for several days after administration of a physiologically relevant dose. This initial report describes experimental characterization of these assays, including testing with a blinded set of samples from a clinical study conducted in healthy volunteers.

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The misuse of human growth hormone (hGH) in sport is deemed to be unethical and dangerous because of various adverse effects. Thus, it has been added to the International Olympic Committee list of banned substances. Until now, the very low concentration of hGH in the urine made its measurement difficult using classical methodology. Indeed, for routine diagnosis, only plasma measurements were available. However, unlike blood samples, urine is generally provided in abundant quantities and is, at present, the only body fluid allowed to be analysed in sport doping controls. A recently developed enzyme-linked immunosorbent assay (Norditest) makes it now possible, without any extraction, to measure urinary hGH (u-hGH) in a dynamic range of 2-50 ng hGH/l. In our protocol, untreated and treated non-athlete volunteers were followed. Some of them received therapeutical doses of recombinant hGH (Norditropin) for one week either intramuscularly (three increasing doses) or subcutaneously (12 i.u. every day). The u-hGH excretion after treatment showed dramatic increases of 50-100 times the basal values and returned to almost the mean normal level after 24 h. u-hGH was also measured in samples provided by the anti-doping controls at major and minor competitions. Depending on the type of efforts made during the competition, the hGH concentration in urine was dramatically increased. Insulin-like growth factor binding proteins and beta 2-microglobulins in urine and/or in blood could be necessary for the correct investigation of any hGH doping test procedure.

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Objectives This article presents a psychological approach to substance use in sport using a dynamic and situated activity framework. The aim was to analyze the various relationships between activity and the consumption of substances during the sporting life course of athletes who recognized doping violation. Design Data were collected from secondary sources and biographical and self-confrontational interviews to build traces of the past activity. Method Twelve doping athletes or those admitting to having used banned substances volunteered to participate. The data were coded and compared to identify typical activities and their intrinsic dynamics. Results Six activities were identified: "Agree to use," "Drop out of a non-viable state," Return to a former state," "Prevent a potential deficiency," "Maintain an acquired state," and "Balance the sporting life with substance use," comprising 11 patterns. Conclusions The athletes' activity embedded substance use in reciprocal relationships that consisted of freezing, exploring and exploiting fields of possible actions created and offered by the situation dynamics. Recommendations for situated and dynamic prevention are provided.

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Today's approach to anti-doping is mostly centered on the judicial process, despite pursuing a further goal in the detection, reduction, solving and/or prevention of doping. Similarly to decision-making in the area of law enforcement feeding on Forensic Intelligence, anti-doping might significantly benefit from a more extensive gathering of knowledge. Forensic Intelligence might bring a broader logical dimension to the interpretation of data on doping activities for a more future-oriented and comprehensive approach instead of the traditional case-based and reactive process. Information coming from a variety of sources related to doping, whether directly or potentially, would feed an organized memory to provide real time intelligence on the size, seriousness and evolution of the phenomenon. Due to the complexity of doping, integrating analytical chemical results and longitudinal monitoring of biomarkers with physiological, epidemiological, sociological or circumstantial information might provide a logical framework enabling fit for purpose decision-making. Therefore, Anti-Doping Intelligence might prove efficient at providing a more proactive response to any potential or emerging doping phenomenon or to address existing problems with innovative actions or/and policies. This approach might prove useful to detect, neutralize, disrupt and/or prevent organized doping or the trafficking of doping agents, as well as helping to refine the targeting of athletes or teams. In addition, such an intelligence-led methodology would serve to address doping offenses in the absence of adverse analytical chemical evidence.