25 research outputs found
Effects of 28-days ingestion of a slow-release energy supplement versus placebo on hematological and cardiovascular measures of health
Concentrations of Nandrolone metabolites in urine after the therapeutic administration of an ophthalmic solution
Nandrolone, an anabolic steroid, is used for the treatment of several diseases and is available in various pharmaceutical formulations. The most widely used pharmaceutical formulation is Deca-Durabolin (R), but other products, such as Keratyl (R) eye drops solution, are also currently administered. Nandrolone is one of the most abused anabolic steroid in sports. Analyses for this anabolic steroid according to the World Anti-Doping Agency (WADA) protocol are based on the identification of the nandrolone two main urinary metabolites which, in humans, are glucuronides of 19-norandrosterone and 19-noretiocholanolone. A positive cut off limit of 2ng/mL has been set by the anti-doping code for the first metabolite, 19-norandrosterone. In this preliminary study, an eye drops solution (Keratyl (R)) containing a therapeutic dose of a nandrolone sodium sulphate was administered to several male volunteers during 3 days and urines were collected during 3 weeks. Surprisingly, contrary to all expectations, the urinary concentrations measured in urines reached 450 ng/mL and 70 ng/mL for norandrosterone and noretiocholanolone, respectively. Moreover, concentration levels near to 2 ng/mL were found, more than 2 weeks after the last administration, depending on individual metabolism. Inter-variability as well as intra-variability of nandrolone excretion kinetic, regarding this particular administration mode, were also evaluated. Quantification of nandrolone metabolites was performed by GC-MS. The method was previously validated in terms of specificity, precision, linearity, LOD, LOQ, robustness, accuracy and the expanded uncertainty was also evaluated
Use of ion trap gas chromatography-multiple mass spectrometry for the detection and confirmation of 3 ' hydroxystanozolol at trace levels in urine for doping control
Stanozolol, a synthetic anabolic androgenic steroid, is often abused in sports to enhance performance. Consequently, the anti-doping laboratories daily screen for its metabolites (3'hydroxystanozolol and 4beta hydroxystanozolol) in all urines, mainly by GC-MS, after enzymatic hydrolysis and TMS derivatization. A sensitive and specific method by GC-MS3 has been developed for the identification in urine of 3'hydroxystanozolol at trace levels. Full mass spectra and diagnostic ions are presented and a case report is commented. In this case, it was possible to attest the presence of a low concentration of stanozolol metabolite in a sample obtained from a competition test. This would have not been possible with other analytical techniques used in the laboratory. Through this case report, it was also possible to demonstrate the importance of sampling and the difficulties that has to face the laboratory when the pre-analytical step is not correctly performed
Development and validation of a capillary zone electrophoresis method for the determination of ephedrine and related compounds in urine without extraction
A capillary zone electrophoresis (CZE) method, with UV detection and in the presence of dimethyl-beta-CD, was optimized by means of an experimental design for the separation and the simultaneous quantitation of ephedrine, pseudoephedrine, norephedrine (phenylpropanolamine) and norpseudoephedrine (cathine) in urine without any extraction. In this application, the optimization of the analytical conditions with an experimental design was preferred to a univariate study. Therefore, a central composite design was used and the following factors were investigated and varied simultaneously: buffer concentration, buffer pH and dimethyl-beta-CD concentration. In order to evaluate the influence of each experimental parameter on the analytical separation, the resolutions between the four compounds, as well as the separation time and generated current were observed and established as responses of the experimental design. A model was obtained for each response by linear multiple regression of a second-degree mathematical expression. After acceptance of the mathematical models, the most favorable conditions were determined by maximizing the resolutions between the four compounds and by setting the other responses at threshold values. Successful results were obtained with a 260 mM Tris-phosphate buffer at pH 3.5 in the presence of 13.3 mM dimethyl-beta-CD at 25degreesC and with an applied voltage of 30 W Under these optimized conditions, a baseline separation of the four compounds was achieved in less than 6 min. The method was validated in terms of precision, linearity, accuracy and successfully applied for the determination of these compounds in urine samples without any extraction as well as in nutritional supplements
Short-timescale variability of picophytoplankton abundance and cellular parameters in surface waters of the Alboran Sea (western Mediterranean)
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Human growth hormone doping in sport
BACKGROUND AND OBJECTIVES: Recombinant human growth hormone (rhGH) has been on the list of forbidden substances since availability of its recombinant form improved in the early 1990s. Although its effectiveness in enhancing physical performance is still unproved, the compound is likely used for its potential anabolic effect on the muscle growth, and also in combination with other products (androgens, erythropoietin, etc.). The degree of similarity between the endogenous and the recombinant forms, the pulsatile secretion and marked interindividual variability makes detection of doping difficult. Two approaches proposed to overcome this problem are: the indirect method, which measures a combination of several factors in the biological cascade affected by administration of GH; and the direct method, which measures the difference between the circulating and the recombinant (represented by the unique 22 kD molecule) forms of GH. This article gives an overview of what is presently known about hGH in relation to sport. The available methods of detection are also evaluated. METHODS: Review of the literature on GH in relation to exercise, and its adverse effects and methods of detection when used for doping. RESULTS AND CONCLUSION: The main effects of exercise on hGH production and the use and effects of rhGH in athletes are discussed. Difficulties encountered by laboratories to prove misuse of this substance by both indirect and direct analyses are emphasised. The direct method currently seems to have the best reliability, even though the time window of detection is too short. hGH doping is a major challenge in the fight against doping. The effect of exercise on hGH and its short half-life are still presenting difficulties during doping analysis. To date the most promising method appears to be the direct approach utilising immunoassays
Central nervous system stimulants and sport practice
BACKGROUND AND OBJECTIVES: Central nervous system (CNS) stimulants may be used to reduce tiredness and increase alertness, competitiveness, and aggression. They are more likely to be used in competition but may be used during training to increase the intensity of the training session. There are several potential dangers involving their misuse in contact sports. This paper reviews the three main CNS stimulants, ephedrine, amfetamine, and cocaine, in relation to misuse in sport. METHODS: Description of the pharmacology, actions, and side effects of amfetamine, cocaine, and ephedrine. RESULTS: CNS stimulants have psychotropic effects that may be perceived to be ergogenic. Some are prescription drugs, such as Ephedra alkaloids, and there are issues regarding their appropriate therapeutic use. Recently attention has been given to their widespread use by athletes, despite the lack of evidence regarding any ergogenic or real performance benefit, and their potentially serious side effects. Recreational drugs, some of which are illegal (cocaine, amfetamines), are commonly used by athletes and cause potential ergolytic effects. Overall, these drugs are important for their frequent use and mention in anti-doping laboratories statistics and the media, and their potentially serious adverse effects. CONCLUSIONS: Doping with CNS stimulants is a real public health problem and all sports authorities should participate in its prevention. Dissemination of information is essential to prevent doping in sport and to provide alternatives. Adequate training and education in this domain should be introduced