Search

This study investigated the impact of low‐volume blood withdrawal on the hematological biomarkers currently considered for anti‐doping purposes. After baseline measurement (D − 7), a 140 mL blood withdrawal was completed (D + 0) on 12 healthy volunteers, followed by weekly monitoring for 21 days (D + 7 – 21). Each visit consisted of a full blood count (Sysmex XN‐1000) and duplicate blood volume measurements by CO‐rebreathing. A significant decrease in total hemoglobin mass (Hbmass) (−2.3%, p = 0.007) and red blood cell volume (RBCV) (−2.8%, p = 0.028) was reported at D + 7. Despite no atypical passport finding (ATPF) when considering the athlete biological passport adaptive longitudinal model, hemoglobin concentration ([Hb]) increased significantly at D + 21 (+3.8%, p = 0.031). Besides, ferritin (FERR) was significantly downregulated at all points following blood withdrawal, with the largest decrease occurring at D + 7 (−26.6%, p < 0.001). Regardless of the presumable effect of blood reinfusion on ABP biomarkers, these results illustrate the challenge of monitoring hematological variables for the detection of low‐volume blood withdrawal. Finally, this study outlines the sensitivity of FERR to altered erythropoiesis to support the implementation of iron markers as complementary variables for the longitudinal monitoring of blood doping, despite the potential influence of confounding factors (e.g., iron supplementations). [ABSTRACT FROM AUTHOR]

Hemoglobin concentration ([Hb]) is used for the clinical diagnosis of anemia, and in sports as a marker of blood doping. [Hb] is however subject to significant variations mainly due to shifts in plasma volume (PV). This study proposes a newly developed model able to accurately predict total hemoglobin mass (Hbmass) and PV from a single complete blood count (CBC) and anthropometric variables in healthy subject. Seven hundred and sixty‐nine CBC coupled to measures of Hbmass and PV using a CO‐rebreathing method were used with a machine learning tool to calculate an estimation model. The predictive model resulted in a root mean square error of 33.2 g and 35.6 g for Hbmass, and 179 mL and 244 mL for PV, in women and men, respectively. Measured and predicted data were significantly correlated (p < 0.001) with a coefficient of determination (R2) ranging from 0.76 to 0.90 for Hbmass and PV, in both women and men. The Bland–Altman bias was on average 0.23 for Hbmass and 4.15 for PV. We herewith present a model with a robust prediction potential for Hbmass and PV. Such model would be relevant in providing complementary data in contexts such as the epidemiology of anemia or the individual monitoring of [Hb] in anti‐doping. [ABSTRACT FROM AUTHOR]

Increasing numbers of dietary supplements with ecdysteroids are marketed as "natural anabolic agents". Results of recent studies suggested that their anabolic effect is mediated by estrogen receptor (ER) binding. Within this study the anabolic potency of ecdysterone was compared to well characterized anabolic substances. Effects on the fiber sizes of the soleus muscle in rats as well the diameter of C2C12 derived myotubes were used as biological readouts. Ecdysterone exhibited a strong hypertrophic effect on the fiber size of rat soleus muscle that was found even stronger compared to the test compounds metandienone (dianabol), estradienedione (trenbolox), and SARM S 1, all administered in the same dose (5 mg/kg body weight, for 21 days). In C2C12 myotubes ecdysterone (1 µM) induced a significant increase of the diameter comparable to dihydrotestosterone (1 µM) and IGF 1 (1.3 nM). Molecular docking experiments supported the ERβ mediated action of ecdysterone. To clarify its status in sports, ecdysterone should be considered to be included in the class "S1.2 Other Anabolic Agents" of the list of prohibited substances of the World Anti-Doping Agency. [ABSTRACT FROM AUTHOR]

The covariant form of entropy change (or balance) is expressed in the metric of the Schwarzschild line element. In this metric the rate of entropy change depends only on the time component of the metric tensor; it is then different at different points in space and appears to be slower in the presence than in the absence of a gravitational field. The linear equations originated by the internal entropy sources depend on both the time and radial components of the metric tensor and the transport processes behave anisotropically, being slower along the radial coordinate than in the directions of the others. The extent of rate reduction is expressed by the kinetic (transport) quantities which assume different values at different points in space. [ABSTRACT FROM AUTHOR]