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10 résultats trouvés.
  • Development of detection method of hydrolysed rapid-acting insulin analogues in human urine by ion trap mass spectrometry

    Development of detection method of hydrolysed rapid-acting insulin analogues in human urine by ion trap mass spectrometry

    By

    Investigateur principal
    C. Ayotte

    Institut Armand-Frapier (INRS)

    Canada   ―   2007   ―   Complété

    Sommaire

    Code: 07C28CA

    Insulin issued from the recombinant technology present the same amino acid sequence as the human endogenous hormone and a molecular weight of 5807 Da. Different analogues have been commercialized with slight amino acid modifications affecting their molecular weight, except for Humalog (Eli Lily) that presents only two interchanged amino acids resulting in a polypeptide chain of same molecular weight than human insulin. A LCMS/MS detection method for rapid-acting analogues in plasma and urine was recently published (Thevis et al., 2005; Thevis et al., 2006). The urine method proposes an immunoaffinity purification from a 25 mL urine aliquot and a top-down sequencing based mass spectrometric approach on a triple quadrupole instrument. The study of the lowest molecular weight ions after fragmentation in the collision cell allows differentiation of the analogues, even if their precursor mass is identical. This approach is innovative but can not be adapted on regular 3D ion trap as fragmentation of large molecule is difficult. As a result, no low molecular weight ions can be observed. Preliminary works have shown that a bottom-up approach using peptide hydrolysis can release smaller fragments that can easily fragment to the desired diagnostic ions. It is proposed that hydrolysis can be performed prior to analysis on an ion trap to monitor the smaller peptide containing the susceptible amino acid interchange, and then fragmentation pattern can qualify the analogues. The goal of this project is to develop a detection method for hydrolysis products of insulin and rapid-acting analogues using an ion trap mass spectrometer. Complementarily, a simpler purification method using single-use immunoprecipitation will be tentatively developed and compared with the 3steps approach.

    Main Findings

    Insulin testing is not widespread; as a matter of fact, in 2012 it is available in only a handful of laboratories. This method consuming a quite important volume of the urine sample and requiring cumbersome sample preparation must be applied aside from those routinely employed, the testing organizations have been reluctant as well to request insulin testing considering the costs involved. Whilst research is still ongoing (LIVE), this relatively pragmatic approach was put in place for the analysis of the 2010 Olympic Games samples. The simplified purification with immunoprecipitation allowed the analysis of a greater number of specimens. As a result, for the first time during Olympic Games, over 200 samples, i.e. 10% of samples could be analyzed. With current advancements in LC-MS/MS technologies (nanoflow, nanospray ionization, selexION, Qtrap 6500 etc), this method could be further improved as extraction volumes could be reduced to a more practical volume in the low mL range and as well, lower injection volumes would reduce ion suppression.

    Voir le projet à propos de Development of detection method of hydrolysed rapid-acting insulin analogues in human urine by ion trap mass spectrometry
  • Development of tests for detecting hypoxia-inducible gene doping to enhance athletic performance

    Development of tests for detecting hypoxia-inducible gene doping to enhance athletic performance

    By

    Investigateur principal
    S. Lahiri

    University of Pennsylvania

    États-Unis   ―   2007   ―   Complété

    Sommaire

    Code: 07D02SL

    Numerous pharmacological and/or genetic strategies exist that simulate the effects of hypoxia at the cellular level and increase expression of hypoxia-induced genes such as hypoxia-inducible factor (HIF), its downstream targets such as erythropoietin (EPO) and consequently increase red blood cell production. Many of these strategies / molecules were developed to treat diseases such as the anemia associated with chronic renal failure and indeed are mainstays in the medical management of these conditions. However, these strategies have great potential to be abused by elite athletes seeking to gain a (unfair) competitive advantage, since they are, 1) currently available and 2) not efficiently detectable by current anti-doping protocols (particularly the newer molecular / gene-based strategies that are subject of this proposal). Prime amongst the pharmacological and / or genetic strategies that have great doping potential are those aimed at modulating hypoxia-induced genes by inhibiting HIF-prolyl hydroxylase (HIF-PHD), a key regulatory enzyme that regulates HIF. Both small molecule inhibitors against HIF-PHD (such as iron chelators or small molecules are able to efficiently inhibit HIF-PHD) and direct gene transfer (i.e. RNAi-based) strategies knocking down HIF have been shown be effective. Of particular concern regarding 'doping' by athletes is the availability drugs/small molecules such as clinically used iron chelators (desferrioxamine-DFO, ciclopirox olamine-CPX) and small molecules (e.g. FG-2216, FG-4519) developed by FibroGen, that are currently in human Phase II/III trials. Currently, tests do not exist to detect hypoxia induced gene 'doping' with pharmacological and/or genetic strategies such as those listed above. The fact that a number of web-based resources and pharmaceutical firms currently offer 'HIF-PHD inhibitory reagents, underscores the need for rapidly developing a test to detect hypoxia induced-gene doping not just the currently described reagents but also those that would be used in the near future, such as gene transfer using RNA-based inhibitors (such as RNAi molecules against HIF). Thus, the challenge is to develop standardized detection tests that would be specific, sensitive and standardized enough to hold up to legal challenges that anti-doping agencies would almost certainly face by athletes caught using these tests. These challenges are not insurmountable; we propose to develop a robust and standardized, blood-based test using 'molecular signatures' of hypoxia that will detect all the different forms (of small molecule and gene-based) hypoxia-induced gene doping that are currently in use (or likely to be developed in the near future) with great sensitivity and specificity to serve this need.

    Main Findings

    Numerous physical, pharmacological and/or genetic strategies exist that simulate the effects of hypoxia at the molecular and cellular level and increase expression of hypoxia-induced genes such as hypoxia-inducible factor (HIF), its downstream targets such as erythropoietin (EPO) and consequently increase red blood cell production. While hypoxia was classically achieved by exposure to high altitude (hypobaric hypoxic exposure), there are currently numerous methodologies for achieving hypoxia-induced gene doping including chambers (normobaric hypoxia), chemicals and genetic manipulation. Our basic hypothesis is that exposure to different types of hypoxia lead to both a unique 'molecular signature' specific to the type of hypoxia as well as core 'molecular signature' irrespective of the type of hypoxia. Testing the 'molecular signatures of hypoxia' using blood samples from athletes will detect all the different forms (of physical, small molecule and gene-based) hypoxia-induced gene doping that are currently in use (or likely to be developed in the near future) with great sensitivity and specificity. Identification and definition of these molecular signatures would allow detection of hypoxia-inducible gene doping and preclude abuse by elite athletes seeking to gain a (unfair) competitive advantage using this strategy. The project was funded to provide proof of concept that the 'molecular signatures' (in peripheral blood) are distinct for different types of hypoxiainduced doping. We have been able to demonstrate that different hypoxic conditions tested experimentally (hypobaric/high-altitude, normobaric/ chambers or tents and chemical) have both a unique 'molecular signature' specific to the type of hypoxia as well as core 'molecular signature' irrespective of the type of hypoxia. To be comprehensive and rigorous experiments were conducted both in laboratory conditions and in field studies on Mt. Everest at altitudes up to c. 8400 mts. The 'molecular signature' generated during the pilot studies have been deposited into the WADA Informatics website and GEO databases (GEO Accession Numbers GSE 15894, 15901 and 15902). Further we have been able to validate the data by Taqman based qPCR assays. These findings are of great relevance for development of anti-doping efforts as it provide the first evidence that sensitive and specific anti-doping tests to detect hypoxia-inducible gene doping can indeed be developed using the bioinformatically generated 'molecular signatures' we have identified. Based on the progress and tangible resources that we have generated, we are confident of achieving our overall goals to develop sensitive and specific tests to comprehensively and rigorously detect hypoxia induced gene doping and preclude abuse by elite athletes seeking to gain a (unfair) competitive advantage using these strategies.

    Voir le projet à propos de Development of tests for detecting hypoxia-inducible gene doping to enhance athletic performance
  • Glucocoricoid and performance: Possible mechanisms of action

    Glucocoricoid and performance: Possible mechanisms of action

    By

    Investigateur principal
    K. Collomp

    Laboratoire LAPSEP

    France   ―   2007   ―   Complété

    Sommaire

    Code: 07E06KC

    It is generally accepted in the sporting world that glucocorticoid use enhance maximal performance, and, as a consequence, this pharmacological class is banned by the World Antidoping Agency (WADA) after systemic administration. Literature on the ergogenic effects of glucocorticoid intake appears, however, very scarce. Indeed, as a matter of fact, research is limited to a few studies for both acute and short-term administration. Using an animal model, Gorostiaga et al. (1988) showed that a single injection of glucocorticoids (cortisol acetate, 100 mg.kg body wt-1) is capable of improving endurance in female rats. In contrast, Soetens et al. (1995) did not find any significant increase of maximal performance with 1 mg ACTH injection in professional cyclists. Similarly, we showed previously (2005, submitted) that an acute therapeutic administration of oral prednisolone (20 mg) does not improve the time of cycling until exhaustion during submaximal exercise (70-75% VO2 max and 80-85%VO2 max) in healthy moderately trained male volunteers, despite a probable increase in lipid oxidation and decrease in CHO oxidation (in press). Regarding published studies following short-term administration of glucosteroids, only one study has focused on the effects of short-term dexamethasone intake (0,5 and 1,5 mg per day for 4.5 days) (Marquet et al., 1999) during maximal exercise without demonstrating any ergogenic effect of the treatment. We recently demonstrated (in press), however, that short-term therapeutic prednisolone intake (60 mg per day for 7 days), contrarily to acute intake, significantly improved performance in healthy men during submaximal exercise (70-75% VO2 max). The concomitant alterations in the hormonal and metabolic exercise parameters analyzed showed that shortterm administration of this drug had both central and peripheral effects. Further studies will, however, be necessary to elucidate the mechanisms of these hormonal and metabolic changes in particular after short-term intake in order to determine which changes may be associated with the marked performance improvement obtained only after this mode of administration. Moreover, to our knowledge, no study has focused on women and a specific gender response to glucocorticoid can be questioned. We therefore propose to contribute to a wider knowledge of glucocorticoid action mechanisms during exercise with in particular investigation of: 1) the ergogenic impact of these drugs in women; 2) the endocrine and metabolic responses after short-term glucocorticoid administration during longer exercise (3 hours), with regard to the gender status of the subjects in order to elucidate the mechanism(s) of action involved in the improvement in performance.

    Main Findings

    We showed in the first study that short-term therapeutic prednisolone (Cor) intake (50 mg per day for 7 days) improves significantly performance in healthy recreationally women during submaximal exercise (70-75% VO2 max). ACTH and DHEA remained completely blunted throughout the experiment with Cor vs. Placebo (Pla), whereas growth hormone and prolactin were significantly decreased with Cor during exercise. No significant difference in insulin or blood glucose values was found between the two treatments, suggesting that women may be less sensitive than men to glucocorticoid-induced insulin-resistance. These data indicate that short-term glucocorticoid intake improved endurance performance in women, but further investigation is needed to determine whether these results are applicable to elite female athletes. In parallel, during a long-lasting exercise (2 hrs), no significant difference in glucagon, insulin or free fatty acid values was found between the treatments. However, essential amino acids (in particular BCAA) and blood glucose were significantly higher after Cor vs Pla during the second part of exercise. It appears therefore that proteolysis probably increases with glucocorticoid during long-lasting exercise and that the related higher plasma EAA concentrations may contribute as energy substrates. Regarding saliva DHEA and cortisol concentrations, they decreased strongly immediately after the start of prednisone treatment, demonstrating a rapid suppression of the HPA axis. However, it is only a short-lasting suppression, as 3 days after concluding prednisone administration, both saliva DHEA and cortisol had returned to pretreatment levels. We can therefore conclude that: 1) this is no high risk of adrenal insufficiency after such treatment (i.e., 1 week at high therapeutic dosage). 2) non invasive saliva samples may offer a practical approach to assessing pituitary-adrenal function continuously during and after short-term corticosteroid therapy. No significant change was found in body weight, body composition or food intake after 7 days of glucocorticoid treatment, which induces however a significant leptin increase. In parallel, no significant physiological repercussions were noted. Such glucocorticoid treatment does not promote obesity in recreationally trained women. However, further studies are necessary to understand its stimulating effects on the metabolically active hormone leptin.

    Publications

    Short-term glucocorticoid intake improves exercise endurance in healthy recreationally trained women. Le Panse B, Thomasson R, Jollin L, Lecoq AM, Amiot V, Rieth N, De Ceaurriz J, Collomp K. Eur J Appl Physiol 107(4): 437-443, 2009.

    Saliva DHEA and cortisol responses following short-term corticosteroid intake. Jollin L, Thomasson R, Le Panse B, Baillot A, Vibarel-Rebot N, Lecoq AM, Amiot V, De Ceaurriz J, Collomp K. Eur J Clin Invest 40(2): 183-186, 2010.

    Short-term glucocorticoid and metabolic responses during long-lasting exercise Thomasson R, Rieth N, Jollin L, Lecoq AM, Amiot V, Lasne F, Collomp K. Eur J Appl Physiol

    Congress Presentations

    Short-term glucocorticoid intake improves exercise endurance in healthy recreationally trained women. Collomp K, Le Panse B, Thomasson R, Jollin L, Lecoq AM, Amiot V, Rieth N, De Ceaurriz J. Abstract accepted (April 2010) in European Congress of Sport Science (ECSS) congress, Antalya, July 2010

    Saliva DHEA and cortisol responses following short-term corticosteroid intake. Jollin L, Thomasson R, Le Panse B, Baillot A, Vibarel-Rebot N, Lecoq AM, Amiot V, De Ceaurriz J, Collomp K. Abstract accepted (April 2010) in European Congress of Sport Science (ECSS) congress, Antalya, July 2010

    Voir le projet à propos de Glucocoricoid and performance: Possible mechanisms of action
  • Harmonisation of uncertainty calculations of the quantitative doping control analytical procedures

    Harmonisation of uncertainty calculations of the quantitative doping control analytical procedures

    By

    Investigateur principal
    C. Georgakopoulos

    Doping Control Laboratory of Athens

    Grèce   ―   2007   ―   Complété

    Sommaire

    Code: 07C26CG

    Uncertainty is an important analytical and legal issue for reporting WADA Prohibited List threshold substances. Threshold substances require quantitative analysis to compare analytical signal and concentration of the substance of interest in the athlete’ sample to the threshold value. The importance of the uncertainty parameter in reporting an adverse analytical finding of a threshold substance is the fact that the uncertainty value is used as an, among others, additional protection for the athlete from a highly improbable false positive report. On the other hand, a high value of uncertainty can guide to false negative results. For that reason, uncertainty has been found in the middle of court evidence arguments. Consequently, a correct and harmonized calculation of uncertainty is required not only for legal reasons but also to reveal probable analytical drawbacks. More specifically, the current project proposes:

    1. To evaluate uncertainty estimation for isotope ratio mass spectrometry and hematological analyzers technologies, where pour literature has been published so far.

    2. To survey within the WADA Accredited Doping Control Laboratories various ways for uncertainty estimation of the quantitative procedures.

    3. To incorporate uncertainty specifications from the under preparation WADA technical document on uncertainty

    4. To develop a software tool for uncertainty evaluation, specific for the WADA Accredited Doping Control Laboratories based on the 1-3 above paragraphs

    5. To distribute a first version of the software tool to WADA Accredited Doping Control Laboratories to perform a first evaluation.

    6. To collect evaluation points, apply a second software version and distribute the software to the WADA Accredited Doping Control Laboratories.

    Main Findings

    Uncertainty is an important analytical gauge for the quality of the analytical data that are produced from a quantitative procedure. Uncertainty estimation is based mainly on validation data for the ISO 17025 accredited analytical methodologies. Moreover, uncertainty is added or subtracted to the concentration of the, according to the WADA List, threshold substances found in doping control urine or blood samples in order to decide to report for an adverse analytical finding or not, i.e. uncertainty is a major decision parameter. According to the International Standard for Laboratories, measurement uncertainty reporting for the prohibited substances required quantification is mandatory and WADA Accredited Laboratories are obliged to comply with this specification. WADA will bring into force by September 1st, 2010, the technical document TD2010DL entitled “DECISION LIMITS FOR THE CONFIRMATORY QUANTIFICATION OF THRESHOLD SUBSTANCES”, where a full description of the uncertainty estimation scheme is included. Facilitating and harmonising the way that Accredited Doping Control Laboratories estimate uncertainty to their quantitative methodologies will add one more ring in the WADA lab network chain. The project has concentrated information for the various ways of uncertainty estimation within the WADA Accredited Laboratories, the WADA Technical Document and from literature sources and it has provided with a friendly software tool called MUADS for this purpose.

    Voir le projet à propos de Harmonisation of uncertainty calculations of the quantitative doping control analytical procedures
  • Identification and Characterization of Transcriptional Markers Diagnostic of Autologous Blood Doping

    Identification and Characterization of Transcriptional Markers Diagnostic of Autologous Blood Doping

    By

    Investigateur principal
    J. Rupert

    University of British Columbia

    Canada   ―   2007   ―   Complété

    Sommaire

    Code: 07A01JR

    As autologous blood doping augments the athlete’s blood with their own cells, detecting the procedure is challenging. Blood cell shape and distribution are being explored as potential markers for; however, changes in the transcript (the mRNA intermediate in the DNA-to-protein pathway) complement of the blood may be a more informative indicator of reinfused blood cells in an athlete. The transcript complement of a tissue is extremely sensitive to the environment, so blood cells that have been removed, processed and stored may show changes in transcript frequencies that could be diagnostic for autologous blood doping. RNA is an excellent candidate for doping tests as it is stable when stored correctly, quantifiable using commercially supported techniques, and measurable in very small blood samples. This proposal describes a one year pilot project using high-resolution transcription profiling of blood to identify transcripts with the potential to be used as a diagnostic test for autologous blood doping. The project has three phases: 1) identification of transcripts in whole and leuko-depleted blood that represent genes that are activated or up-regulated in blood cells in response to post-withdrawal processing and/or short-term storage, 2) use of simulated autologous blood doping to determine if these transcripts could be detected in a “doped” athlete; and 3) characterization of the inter- and intra-individual variation of the transcripts shown to have potential test utility under a variety of conditions experienced by athletes (e.g. physical exertion, hypoxia/altitude, time of day, and time in menstrual cycle). The ultimate goal of the project is to identify transcripts that are characteristic of stored blood, that are of sufficient quantity as to be identifiable in a recipient’s circulation following reinfusion, and have patterns of expression that are consistent, predictable, and informative in athletes, which believe could form the basis for a blood-based, gene-expression test for autologous blood doping.

    Main Findings

    The aim of this study was to determine if there were genes overexpressed in blood in response to refrigerated storage that could be used as markers for the presence of stored blood in an athlete’s circulation. To be considered a potential transcript for follow-up, there had to be a minimum of a 10 fold expression difference (as this represented he the typical dilution that would occur in an autologous reintroduction of a unit of blood into the ‘doper’s’ circulation. We also felt that the overexpressed transcripts needed to be part of a unique pathway and not a variant of other commonly expressed pathways, as those would be unlikely sufficiently robust to serve as a diagnostic tool. Outcome: Transcriptional analysis identified only a single non-hemoglobin gene that met the criteria for being a candidate for a test for blood storage. The gene was GADD45G (encoding: Growth arrest and DNA-damage-inducible protein GADD45 gamma). This gene is a stress response gene that has been shown to be up-regulated in circulating cells in response to ‘behavioral stress’ in animal models (e.g. restraint, Flint at al., J Neuroimmunol. 2005; 167:34-44). This response would likely make it an unpromising candidate for a doping control assay as expression levels would likely fluctuate between athletes due to differential responses to perceived stress (e.g. doing control, imminent or recent competition). The only other genes that fit the candidacy profile were ‘rare’ hemoglobins (delta and zeta). As the adult blood transcriptome is overwhelmingly made up of hemoglobin alpha and beta transcripts, it is unlikely that an assay sufficiently specific and sensitive could be developed based on differentiating between the highly homologous hemoglobin transcripts against this background. Overall, the results of the project do not support the use of transcriptomic analysis of athletes' blood as a method for detecting the inclusion of stored blood (i.e. autologous blood doping).

    Voir le projet à propos de Identification and Characterization of Transcriptional Markers Diagnostic of Autologous Blood Doping
  • Identification and Mass Spectrometric Characterization of Urinary Proteins other than EPO Binding to Clone AE7A5 Anti-Human EPO Antibody

    Identification and Mass Spectrometric Characterization of Urinary Proteins other than EPO Binding to Clone AE7A5 Anti-Human EPO Antibody

    By

    Investigateur principal
    C. Reichel

    Seibersdorf Laboratory GmbH

    Autriche   ―   2007   ―   Complété

    Sommaire

    Code: 07A04CR

    Non-specific binding of the monoclonal anti-human EPO antibody (clone AE7A5; R&D Systems, Inc.) used for the detection of doping with recombinant human erythropoietin by the worldwide practised isoelectric focusing (IEF) and Western double blotting method has been in discussion for several years. Publications in peer-reviewed journals addressed this subject in 2005 and 2006 and led to some scientific argumentation on the specificity of the employed detection antibody. However, under experienced users of the Epo-method several additional bands (usually two to four) in the basic region of the pH 2-6 IEF-gel caused scientific interest, because theses bands could only be occasionally detected among the tested urinary samples. Their relationship to Epo remained unclear for years. Nevertheless, it was obvious that these bands did not interfere with the endogenous urinary and recombinant Epo-IEF profiles and thus the evaluation of the profiles was not disturbed or questioned at all. We were able to identify the protein causing these basic IEF-bands by means of carrier ampholyte IEF-PAGE, SDS-PAGE, Western blotting, and nano-ESI high resolution mass spectrometry and presented the results at the 2007 Cologne Workshop on Dope Analysis. The name of the protein is Zinc-alpha-2-glycoprotein. It is a high abundant urinary protein. The purpose of this project is a detailed study on the specificity of the clone AE7A5 antibody. According to the WADA technical document on the “Harmonization of the method for the identification of epoetin alfa and beta (Epo) and darbepoetin alfa (NESP) by IEF-double blotting and chemiluminescent detection” the IEF-method “relies on the particular specificity of the monoclonal antibody with which it was developed (clone AE7A5)” and “this antibody is considered a critical reagent and shall not be changed”. However, during SDS-PAGE experiments we were able to show that AE7A5 also binds to urinary proteins other than erythropoietin and Zinc-alpha-2-glycoprotein. These proteins might interfere with the interpretation of the Epo-IEF profiles.

    Main Findings

    A comprehensive study on the non-specific binding behaviour of monoclonal anti-EPO antibody clone AE7A5, which has to be used according to the technical document on EPO-analysis of WADA (TD2009EPO) for the detection of EPO-doping, was performed. Human urine and serum were used as matrices, since both are also used for EPO-testing. Additionally, E. coli and S. cerevisiae lysates were investigated. Aside from zinc-alpha2-glycoprotein (ZAG) a weak interaction with transferrin was detected (urine, serum). However, the non-specific interaction of the four proteins, which were mentioned by Khan et al. (2005) [1] in the context of 2D-PAGE (Tamm Horsfall glycoprotein, alpha-1antichymotrypsin, alpha-2-thiol proteinase inhibitor, alpha-2-HS-glycoprotein precursor), could not be confirmed – neither on carrier ampholyte IEF- nor SDS-PAGE. Strong binding was observed for thioredoxin reductase of E. coli, but no interaction occured with human thioredoxin reductases 1 and 2. Another strong non-specific binding was found for enolase from S. cerevisiae. Contrary to E. coli thioredoxin reductase, human enolases (tested were two enolases from human brain) were also non-specifically detected by the antibody. E. coli thioredoxin reductase as well as human and S. cerevisiae enolases are also non-specifically bound on IEF-PAGE. However, due to their higher isoelectric points (pI) these proteins focus outside the region of the gel used for EPO evaluation and therefore have no influence on the analysis results. Due to the observed non-specific interactions of the clone AE7A5 anti-EPO antibody with proteins other than EPO, immunoaffinity purification is mandatory for SDS-PAGE analyses. This pre-cleaning step has already been performed in the past, since the high protein content of urinary retentates and serum samples impedes the accurate detection of EPO by SDS-PAGE. This step is mandatory due to the non-specific binding of the antibody to thioredoxin reductase of E. coli. The molecular mass of this protein is within the range of rhEPOs on SDS-PAGE. An interference with the detection of rhEPO-doping is excluded by the combined usage of (1) two monoclonal antibodies directed against different epitopes for the immunoaffinity purification step, (2) the Western double blotting procedure, and (3) the usage of IEF- and SDS-PAGE for the interpretation of analysis results. This strategy has already been implemented in TD2009EPO. Reference: [1] Khan A, Grinyer J, Truong ST, Breen EJ, Packer NH (2005) New urinary EPO drug testing method using two-dimensional gel electrophoresis. Clin Chim Acta 358:119-30.

    Voir le projet à propos de Identification and Mass Spectrometric Characterization of Urinary Proteins other than EPO Binding to Clone AE7A5 Anti-Human EPO Antibody
  • Identification/detection of novel anaemia drugs

    Identification/detection of novel anaemia drugs

    By

    Investigateur principal
    M. Ashenden

    SIAB Research Ltd.

    Australie   ―   2007   ―   Complété

    Sommaire

    Code: 07A14MA

    Despite a committed antidoping movement, abuse of recombinant human erythropoietin (rHuEPO) continues. Clandestine use extends to the use of novel rHuEPO products in the hope these may be undetectable via the electrophoresis test which distinguishes endogenous EPO from the synthetic versions based on different electric charges on the respective molecules. Recombinant erythropoietins are the number one revenue-generating class of biological products on the market, with worldwide sales exceeding US $12 billion. The lapse of European patents in 2004 has opened the door for approval of biosimilar versions of rHuEPO, and multiple pharmaceutical companies are now embarked on the development of viable alternatives for this lucrative market. In order to maintain an effective screening process it is vital for laboratories to obtain pre-emptive information regarding the structure and detectability of these novel anaemia drugs. Several classes of products are being developed: biosimilar rHuEPOs (same molecular structure but produced using different procedures), long lasting EPOs (molecule modified to extend half-life in circulation), synthetic EPO receptor agonists (completely different molecular structure which nonetheless stimulates the EPO receptor) and EPO replacements (stimulate red cell production via non-EPO receptor pathways). The aim of this research is to validate the capacity for isoelectric focussing to discriminate between novel anaemia drugs and endogenous EPO, and where this proves impractical to develop new detection methodologies. We will enter collaborative arrangements with the pharmaceutical companies to seek access to their products prior to commercial release in order to thwart attempts to use novel drugs before an appropriate test has been introduced by antidoping authorities. The drugs will be screened at the WADA-accredited laboratory in Paris who developed the isoelectric test and are world leaders in its application to doping control.

    Main Findings

    An extensive network including pharmaceutical company representatives and their expert consultants was activated in order to identify and detect novel anaemia drugs. A comprehensive market appraisal and de novo interrogation of literature and websites dramatically expanded upon the initial estimate made in 2007 that around one dozen copy EPOs were available. The most recent estimate suggests this number to be in excess of 100 in 2010. A significant number of these products have been procured and analysed by an anti-doping laboratory; several unusual profiles, and in a small number of cases inexplicable characteristics, have been reported. An important emphasis of the project has been to facilitate collaboration between pharmaceutical manufacturers and the WADA. Introductions were made to different pharmaceutical and biotechnology companies which enabled WADA to commence discussions and in several cases in-depth collaboration to develop detection methods for novel ESAs considered of high interest. In 2009 the ESA industry experienced considerable upheaval following the publication of results (‘TREAT” study) indicating that administration of exogenous EPO posed previously unrecognised health risks. Subsequently it is anticipated that substantially greater research emphasis will be placed in the foreseeable future on development of novel ESA agents.

    Voir le projet à propos de Identification/detection of novel anaemia drugs
  • Immunological detection of tetracosactide in serum for anti-doping control purpose

    Immunological detection of tetracosactide in serum for anti-doping control purpose

    By

    Investigateur principal
    J. De Ceaurriz

    Agence Francaise de Lutte contre le Dopage

    France   ―   2007   ―   Complété

    Sommaire

    Code: 07C17JD

    The project deals with the developpment of immunological methods for the screening and the confirmation analysis of tetracosactide in serum. In vitro and in vivo immunological studies will be performed to develop immunological tools and their performance will be compared to that of a spectrophysical method using a Q trap instrument. Immunoextraction from serum prior to immunological analysis will be scheduled for confirmation analysis but not for screening analysis. The aim is the specific detection of tetracosactide in serum at concentration level as low as 100 pg/ml or less in order to offer a relevant detection window.

    Main Findings

    Tetracosactide is a synthetic peptide which exercises the same biological effects as endogenous Adreno CorticoTropin Hormone (ACTH) produced by anterior pituitary gland. Its structure reproduces the first 24 amino acids of ACTH which is composed of 39 ones. A screening method by ELISA was developed and validated for detection of Tetracosactide in plasma. The principle of the method was to use an ELISA kit (Enzyme Immunossay Kit from Peninsula Laboratories, San Carlos, USA), that reacts with the part 1-24 of ACTH (and thus Tetracosactide), after total elimination of endogenous ACTH from the tested plasma samples. In such conditions, ELISA became specific for Tetracosactide. The sample preparation consisted in removing most of the proteins and any trace of ACTH from plasma. This was achieved by cation-exchange chromatography (CM Sephadex ®). The preanalytical conditions were shown to be very important. Only EDTA plasma samples must be analysed and if the plasma samples could not be frozen just after collection, it was essential to quickly ship them to the laboratory in refrigerated conditions. The detection limit of the method was 13 pg/mL. In parallel, a confirmation method by LC-MS/MS (Thermo) Triple Quad, ESI was developed and validated. The preparation of plasma included cation exchange chromatography (CM Sephadex ®) and solid-phase extraction (Oasis® HLB). The detection limit of the method was < 50 pg/mL.

    Voir le projet à propos de Immunological detection of tetracosactide in serum for anti-doping control purpose
  • Pilot Project for a WADA Bioinformatics Core Facility

    Pilot Project for a WADA Bioinformatics Core Facility

    By

    Investigateur principal
    R. Bhasker

    University of California at San Diego

    États-Unis   ―   2007   ―   Complété

    Sommaire

    Code: T07D01RB 

    Many studies are being carried out to develop methods for identifying exposure to growth factors such as human growth hormone, IGF1 and other related factors with potential application in sport doping. A number of these studies are based on the hypothesis that identification of genes and their protein products abnormally expressed in tissues treated with these factors can provide definitive evidence – i.e., signatures - for exposure to such growth factors. A number of related parallel studies are being conducted under the sponsorship of WADA and an enormous amount of information is being accumulated. However, to date no concerted effort has been made to collate and compare these large data sets and results to identify factors common to these studies that would represent the markers most likely to be informative in a drug testing setting. We propose to carry out a pilot informatics study to compare results from several completed and on-going WADA-sponsored studies.

    Main Findings: 

    Most of the current methods to detect doping rely on the use of chemical tests to identify drugs in the body. These methods are very powerful and often highly effective. Recent advances have enabled scientists to develop entirely new and potentially even more effective kinds of tests that are based on the detection of the broad changes that drugs cause in the genes and the proteins of affected tissues. These new methods can examine the ways in which all of the 25,000 human genes are affected by exposure to drugs and how those changes in genes affect the content of the even larger number of proteins in human cells. WADA has mounted a major research effort to use these approaches to develop detection methods for doping and is supporting work in more than a dozen laboratories scattered around the world aimed at finding genetic and protein changes in blood, urine and other body fluids and tissues that can definitively identify exposure to given drugs. Very promising results are coming from this effort and potentially useful "signature" gene and protein changes are being identified. A feature of these approaches is that they produce enormous amounts of information that require unified methods of analysis that are generally beyond the computing and informatics capabilities of individual laboratories. To ensure that the data are being evaluated in a consistent and effective manner, WADA has established a centralized bioinformatics laboratory that uses the most modern computational and analytical methods to harmonize the results of all the separate research laboratories to ensure that tests coming from this approach are highly sensitive, accurate and specific. The facility has succeeded in establishing an effective infrastructure and operating procedures and is beginning to obtain and analyze data from the research laboratories. WADA is confident that this more unified and centralized approach to doping detection will lead to far more effective tests that are rigorous, accurate and sensitive and that provide an effective and fair approach to protect athletes and Sport from doping.

    Voir le projet à propos de Pilot Project for a WADA Bioinformatics Core Facility
  • Molecular signatures of IGF-1 gene doping after AAV-mediated gene transfer

    Molecular signatures of IGF-1 gene doping after AAV-mediated gene transfer

    By

    Investigateur principal
    M. Giacca

    International Centre for Genetic Engineering and Biotechnology

    Italie   ―   2006   ―   Complété

    Sommaire

    Code: 06B06MG

    This is a highly interdisciplinary and coordinated project that is aimed at understanding the molecular modifications induced by prolonged IGF-1 gene expression in the skeletal muscle after viral mediated gene transfer in rodent animals. The project will exploit the availability of AAV vectors expressing different IGF-1 isoforms to transduce skeletal muscles, a unique system that permites the long-term evaluation of the effects induced by the growth factor in vivo. In the treated animals, the signatures of these modifications will be analyzed by detecting the presence of the delivered transgenes in serum by quantitative real-time PCR and by analyzing the modifications of the proteomic pattern in muscle by advanced proteomics and mass spectrometry. These studies will be complemented by a parallel evaluation of the proteomic modifications induced by IGF-1 gene transfer in skeletal muscle satellite cells in vitro.

    The project will be divided into three tasks.

    Task 1. The overall purpose of this task will be the identification of a proteomic signature of IGF-1 gene transfer in muscle cells. The project will involve the development of animal models for AAV-mediated IGF-1 gene transfer. In particular, viral vectors expressing different IGF-1 isoforms will be produced and used to inoculate the tibialis anterior and femoral quadriceps muscles of mice and rats. At different times after transduction, proteomic analysis of the transduced muscles will be performed. These studies will take advantage of state-of-the-art technology 2-DE DIGE and will have the ultimate purpose of identifying protein patterns specific to the IGF-1 expressing muscles. These studies will be paralleled by the analysis of proteomic changes in human skeletal myoblasts after ex vivo gene transfer of the IGF-1 cDNAs.

    Task 2. This task is aimed at the identification of novel peptides markers that might be exploited for anti-doping purposes. In particular, the project is aimed at the indentifications, quantification and qualitative assessment of the proteins differential expressed in muscle transduced with IGF-1. Differentially expressed or modified proteins will be analyzed using advanced mass spectrometry instrumentation, including MALDI-TOF/TOF, ESI-linear quarupole ion trap and high resolution FT-MS instrumentation.

    Task 3. This task is aimed at the assessment of gene doping by monitoring the presence of exogenous gene fragments in animal serum. This possibility is based on different experimental and clinical reports that indicate that muscle exercise determines signficant damage to muscle cells, with the release of intracellular content into the bloodstream. At different times after in vivo IGF-1 gene transfer, both in resting conditions and during muscle exercise, serum will be analyzed for the presence of promoter-, vectore backbone- or cDNA-specific gene fragments by TaqMan-based Real Time quantitative PCR.

    Main findings

    The main findings are not available due to the sensitivity of the information and results developed in this project.

    Voir le projet à propos de Molecular signatures of IGF-1 gene doping after AAV-mediated gene transfer
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