143 research outputs found
Drug Use on Mont Blanc: A Study Using Automated Urine Collection
No full textMont Blanc, the summit of Western Europe, is a popular but demanding high-altitude ascent. Drug use is thought to be widespread among climbers attempting this summit, not only to prevent altitude illnesses, but also to boost physical and/or psychological capacities. This practice may be unsafe in this remote alpine environment. However, robust data on medication during the ascent of Mont Blanc are lacking. Individual urine samples from male climbers using urinals in mountain refuges on access routes to Mont Blanc (Goûter and Cosmiques mountain huts) were blindly and anonymously collected using a hidden automatic sampler. Urine samples were screened for a wide range of drugs, including diuretics, glucocorticoids, stimulants, hypnotics and phosphodiesterase 5 (PDE-5) inhibitors. Out of 430 samples analyzed from both huts, 35.8% contained at least one drug. Diuretics (22.7%) and hypnotics (12.9%) were the most frequently detected drugs, while glucocorticoids (3.5%) and stimulants (3.1%) were less commonly detected. None of the samples contained PDE-5 inhibitors. Two substances were predominant: the diuretic acetazolamide (20.6%) and the hypnotic zolpidem (8.4%). Thirty three samples were found positive for at least two substances, the most frequent combination being acetazolamide and a hypnotic (2.1%). Based on a novel sampling technique, we demonstrate that about one third of the urine samples collected from a random sample of male climbers contained one or several drugs, suggesting frequent drug use amongst climbers ascending Mont Blanc. Our data suggest that medication primarily aims at mitigating the symptoms of altitude illnesses, rather than enhancing performance. In this hazardous environment, the relatively high prevalence of hypnotics must be highlighted, since these molecules may alter vigilance
Seasonal variations of haematological parameters in athletes
No full textThe influence of training and competition workloads is crucial for evaluation of longitudinal haematological data in athletes. There are only a few papers on the variation of haematological parameters during long-lasting periods and, especially, during an entire competitive season. We summarized that some haematological parameters can be influenced by long-term training and competition periods. Haemoglobin (Hb) and haematocrit (Ht) are decreased during the more intense periods of training, throughout the season. In different sport disciplines, the decline of Hb ranges from 3 to 8% during the competition season, while the range of reticulocytes (Ret%) varies from 5 to 21%. Reticulocytes are also decreased after long periods of training and competitions, but their variation is not necessarily associated with that of Hb. The qualitative variations (trend of modifications) of haematological parameters are roughly independent of the sport discipline, but quantitatively (amount of modifications) dependent on sport discipline. The modifications are more evident in cycling, running, swimming than they are in football and rugby. The variations of haematological parameters within the same sport discipline are qualitatively concordant and quantitatively different among separate but consecutive competitive seasons. These findings are described in aerobic and team sports sportsmen. The definition of reliable reference ranges in sportsmen would only be possible by following the best laboratory practices. For antidoping purposes more studies investigating haematological modifications during the season are advisable
A multi-targeted liquid chromatography-mass spectrometry screening procedure for the detection in human urine of drugs non-prohibited in sport commonly used by the athletes
No full textThis work presents an analytical method for the simultaneous analysis in human urine of 38 pharmacologically active compounds (19 benzodiazepine-like substances, 7 selective serotonin reuptake inhibitors, 4 azole antifungal drugs, 5 inhibitors of the phosphodiesterases type 4 and 3 inhibitors of the phosphodiesterase type 5) by liquid-chromatography coupled with tandem mass spectrometry. The above substances classes include both the most common "non banned" drugs used by the athletes (based on the information reported on the "doping control form") and those drugs who are suspected to be performance enhancing and/or act as masking agents in particular conditions. The chromatographic separation was performed by a reverse-phase octadecyl column using as mobile phases acetonitrile and ultra-purified water, both with 0.1% formic acid. The detection was carried out using a triple quadrupole mass spectrometric analyser, positive electro-spray as ionization source and selected reaction monitoring as acquisition mode. Sample pre-treatment consisted in an enzymatic hydrolysis followed by a liquid-liquid extraction in neutral field using tert-butyl methyl-ether. The analytical procedure, once developed, was validated in terms of sensitivity (lower limits of detection in the range of 1-50 ng mL(-1)), specificity (no interferences were detected at the retention time of all the analytes under investigation), recovery (≥60% with a satisfactory repeatability, CV % lower than 10), matrix effect (lower than 30%) and reproducibility of retention times (CV% lower than 0.1) and of relative abundances (CV% lower than 15). The performance and the applicability of the method was evaluated by analyzing real samples containing benzodiazepines (alprazolam, diazepam, zolpidem or zoplicone) or inhibitors of the phosphodiesterases type 5 (sildenafil or vardenafil) and samples obtained incubating two of the phosphodiesterases type 4 studied (cilomilast or roflumilast) with pooled human liver microsomes. All the parent compounds, together with their main phase I metabolites, were clearly detected using the analytical procedures here developed
Recovery processes after repeated supramaximal exercise at the altitude of 4,350 m
No full text Robach, Paul, Daniel Biou, Jean-Pierre Herry, Denis Deberne, Murielle Letournel, Jenny Vaysse, and Jean-Paul Richalet. Recovery processes after repeated supramaximal exercise at the altitude of 4,350 m. J. Appl. Physiol. 82(6): 1897–1904, 1997.—We tested the hypothesis that prolonged exposure to high altitude would impair the restoration of muscle power during repeated sprints. Seven subjects performed two 20-s Wingate tests (WT1 and WT2) separated by 5 min of recovery, at sea level (N) and after 5–6 days at 4,350 m (H). Mean power output (MPO) and O2 deficit were measured during WT. O2 uptake (V˙o 2) and ventilation (V˙e) were measured continuously. Blood velocity in the femoral artery (FBV) was recorded by Doppler ultrasound during recovery. Arterialized blood pH and concentrations of bicarbonate ([[Formula: see text]]), venous plasma lactate ([La−]), norepinephrine ([NE]), and epinephrine ([Epi]) were measured before and after WT1 and WT2. MPO decreased between WT1 and WT2 by 6.9% in N ( P < 0.05) and by 10.7% in H ( P < 0.01). H did not further decrease MPO. O2 deficit decreased between WT1 and WT2 in H only ( P < 0.01). PeakV˙o 2 after WT was reduced by 30–40% in H ( P < 0.01), but excess postexercise O2 consumption was not significantly lowered in H. During recovery in H compared with N, V˙e, exercise-induced acidosis, and [NE] were higher, [Epi] tended to be higher, [La−] was not altered, and [[Formula: see text]] and FBV were lower. The similar [La−] accumulation was associated with a higher exercise-induced acidosis and a larger increase in [NE] in H. We concluded from this study that prolonged exposure to high altitude did not significantly impair the restoration of muscle power during repeated sprints, despite a limitation of aerobic processes during early recovery. </jats:p
Social Dimensions of Private Well Testing: Why Don’t People Test their Well Water?
No full textIn March 2007, 2600 surveys about well water testing were mailed to private well owners
in Michigan, Wisconsin, and Minnesota. Goals of the study were to learn what well owners
need to make informed decisions and to understand social factors that explain well-testing behavior. The survey (43 questions) assessed water use, testing behaviors, perceptions about risk, reasons for testing/not testing, and preferences for getting information. Results (68% response rate) indicated most respondents felt their well water was safe or very safe (67%). Over 50% were not worried about the safety of their water; however, 48% believed there was a serious or very serious problem with ground water safety in their township. About 20% of respondents had never had their well water tested. People said they would get their water tested if they learned that a neighbor’s well was contaminated (86%), if
there was a change in taste or appearance (86%), or if their family had unexplained health problems (63%). The most common reasons for not testing well water were “have been drinking it years without problems” (53%), “don’t know what to test for” (41%), and “don’t know how to test” (35%). Results suggest strategies for providing information to private well owners and coordinating water testing clinics.Funding from Extension Great Lakes Regional Water Program, 2006-2008Healthier Wisconsin Partnership Program, Medical College of WisconsinImpactsLiukkonen, Barbara; Severtson, Lori; Kline-Robach, Ruth. (2009). Social Dimensions of Private Well Testing: Why Don’t People Test their Well Water?. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/58540
Setup for human sera MALDI profiling: The case of rhEPO treatment
No full textThe implementation of high-throughput technologies based on qualitative and quantitative methodologies for the characterization of complex protein mixtures is increasingly required in clinical laboratories. MALDI profiling is a robust and sensitive technology although the serum high dynamic range imposes a major limitation hampering the identification of less abundant species decreasing the quality of MALDI profiling. A setup to improve these parameters has been performed for recombinant human erythropoietin (rhEPO) monitoring in serum, analyzing the effects of two commercially available columns (MARS Hu7 and Hu14) for immunodepletion, and two matrices (α-cyano-4-hydroxycinnamic acid and 2′,4′-dihydroxyacetophenone) for peak quality improvement. The immunodepletion capability of both columns was determined by 2-D DIGE, which precisely revealed the efficacy of Hu14 in protein removal and the serum dynamic range decrement. In addition, the type of matrix, the sample dilution, and the efficacy of optimized parameters were used for serum profiling of ten healthy subjects before and after rhEPO treatment. The principal component analysis indicates that a combination of Hu14 column and 2′,4′-dihydroxyacetophenone matrix increases data quality allowing the discrimination between treated and untreated samples, making serum MALDI profiling suitable for clinical monitoring of rhEP
Effets d'un entraînement en altitude de type "Live high - Train low" sur la performance athlétique et mécanismes de contrôle : une étude en double insu contre groupe placebo: Implications directes pour l’entraînement et l’optimisation de la performance
No full textRésider en altitude tout en s’entraînant en plaine (live high-train low, LHTL) est susceptibled’améliorer la performance en endurance chez l’athlète. Cependant, à ce jour, aucune étudene peut exclure l’éventuelle contribution d’un potentiel effet placebo, expliquant en partie legain de performance. A partir d’une méthodologie en double insu versus groupe placebo,nous avons formulé l’hypothèse que les gains de performance induits par LHTL sont liés àdes mécanismes physiologiques et non à un effet placebo. Pour cela, seize cyclistesd’endurance de haut niveau ont suivi un programme d’entraînement de huit semaines àbasse altitude (< 1200 m). Après deux semaines de phase préparatoire, les athlètes ontséjourné 16h/jour durant les quatre semaines suivantes dans des chambres ventilées soitavec de l’air normal (groupe placebo, n = 6), soit avec de l’hypoxie normobarecorrespondant à une altitude de 3000 m (groupe LHTL, n = 10). Les mesures physiologiquesont été réalisées deux fois durant la période préparatoire, après trois et quatre semainesd’intervention LHTL puis encore une et deux semaines après l’intervention LHTL. Lesquestionnaires ont révélés que les sujets ignoraient le traitement qui leur était administré.La charge d’entraînement hebdomadaire était similaire entre les groupes. La masse totaled’hémoglobine, la consommation maximale d’O2 en normoxie et à l’altitude simulée de 2500m, ainsi que la puissance moyenne durant une épreuve simulée de compétition cycliste de26,15 km (« contre la montre »), sont restés inchangés dans les deux groupes, tout au longde l’étude. L’efficience musculaire (consommation d’O2 mesurée à 200 W) n’a pas étémodifiée lors de l’intervention LHTL dans aucun des deux groupes. En conclusion, ni laperformance en endurance, ni les variables physiologiques associées n’ont été améliorées àl’issue de quatre semaines d’intervention LHTL
Effets d'un entraînement en altitude de type "Live high - Train low" sur la performance athlétique et mécanismes de contrôle : une étude en double insu contre groupe placebo: Implications directes pour l’entraînement et l’optimisation de la performance
No full textRésider en altitude tout en s’entraînant en plaine (live high-train low, LHTL) est susceptibled’améliorer la performance en endurance chez l’athlète. Cependant, à ce jour, aucune étudene peut exclure l’éventuelle contribution d’un potentiel effet placebo, expliquant en partie legain de performance. A partir d’une méthodologie en double insu versus groupe placebo,nous avons formulé l’hypothèse que les gains de performance induits par LHTL sont liés àdes mécanismes physiologiques et non à un effet placebo. Pour cela, seize cyclistesd’endurance de haut niveau ont suivi un programme d’entraînement de huit semaines àbasse altitude (< 1200 m). Après deux semaines de phase préparatoire, les athlètes ontséjourné 16h/jour durant les quatre semaines suivantes dans des chambres ventilées soitavec de l’air normal (groupe placebo, n = 6), soit avec de l’hypoxie normobarecorrespondant à une altitude de 3000 m (groupe LHTL, n = 10). Les mesures physiologiquesont été réalisées deux fois durant la période préparatoire, après trois et quatre semainesd’intervention LHTL puis encore une et deux semaines après l’intervention LHTL. Lesquestionnaires ont révélés que les sujets ignoraient le traitement qui leur était administré.La charge d’entraînement hebdomadaire était similaire entre les groupes. La masse totaled’hémoglobine, la consommation maximale d’O2 en normoxie et à l’altitude simulée de 2500m, ainsi que la puissance moyenne durant une épreuve simulée de compétition cycliste de26,15 km (« contre la montre »), sont restés inchangés dans les deux groupes, tout au longde l’étude. L’efficience musculaire (consommation d’O2 mesurée à 200 W) n’a pas étémodifiée lors de l’intervention LHTL dans aucun des deux groupes. En conclusion, ni laperformance en endurance, ni les variables physiologiques associées n’ont été améliorées àl’issue de quatre semaines d’intervention LHTL
Effets d'un entraînement en altitude de type "Live high - Train low" sur la performance athlétique et mécanismes de contrôle : une étude en double insu contre groupe placebo: Implications directes pour l’entraînement et l’optimisation de la performance
No full textRésider en altitude tout en s’entraînant en plaine (live high-train low, LHTL) est susceptibled’améliorer la performance en endurance chez l’athlète. Cependant, à ce jour, aucune étudene peut exclure l’éventuelle contribution d’un potentiel effet placebo, expliquant en partie legain de performance. A partir d’une méthodologie en double insu versus groupe placebo,nous avons formulé l’hypothèse que les gains de performance induits par LHTL sont liés àdes mécanismes physiologiques et non à un effet placebo. Pour cela, seize cyclistesd’endurance de haut niveau ont suivi un programme d’entraînement de huit semaines àbasse altitude (< 1200 m). Après deux semaines de phase préparatoire, les athlètes ontséjourné 16h/jour durant les quatre semaines suivantes dans des chambres ventilées soitavec de l’air normal (groupe placebo, n = 6), soit avec de l’hypoxie normobarecorrespondant à une altitude de 3000 m (groupe LHTL, n = 10). Les mesures physiologiquesont été réalisées deux fois durant la période préparatoire, après trois et quatre semainesd’intervention LHTL puis encore une et deux semaines après l’intervention LHTL. Lesquestionnaires ont révélés que les sujets ignoraient le traitement qui leur était administré.La charge d’entraînement hebdomadaire était similaire entre les groupes. La masse totaled’hémoglobine, la consommation maximale d’O2 en normoxie et à l’altitude simulée de 2500m, ainsi que la puissance moyenne durant une épreuve simulée de compétition cycliste de26,15 km (« contre la montre »), sont restés inchangés dans les deux groupes, tout au longde l’étude. L’efficience musculaire (consommation d’O2 mesurée à 200 W) n’a pas étémodifiée lors de l’intervention LHTL dans aucun des deux groupes. En conclusion, ni laperformance en endurance, ni les variables physiologiques associées n’ont été améliorées àl’issue de quatre semaines d’intervention LHTL
- …
