1,720,974 research outputs found
ANABOLIC-ANDROGENIC STEROIDS SIGNALING
Full text linkAndrogens exert their effects on various parts of the body, including muscles, bones, hair follicles in the skin, liver and kidney, reproductive, hematic, immune and nervous systems. The effects are modulated by specific cellular "steroid-converting" enzymes, located inside target tissues. All the anabolic steroids currently used are derivates of testosterone or changes of its structure. The most important esterified forms of testosterone include the propionate, cipionate, enhantate and undecanoate ones. The mechanism of action of AAS has not been fully elucidated and it is currently subject of many studies. Several mechanism of action have been proposed to identify the path activated by AAS. Some, like oximetholone, does not bind the androgen receptors: it is assumed that these steroids act after a biological transformation into more active
compounds. The 5 alpha-reductase, for example, plays a central role in their mechanism of action; on the other hand, aromatase is responsible for the conversion of AAS in female sex hormones such as estradiol and estrone, which bind to the estrogen receptor, forming estrogen-receptor complex. Steroid hormone receptors (SHRs) are members of the superfamily of nuclear and steroid receptors. In particolar, the functions of the androgen receptors (hAR) involving transciption factors are generally regulated by specific steroid ligands, that is androgens and selective androgen receptor modulators (SARMs)
Total genetic score: An instrument to improve the performance in the elite athletes
No full textIntroduction: The purpose of this study was to demonstrate the effectiveness of the TGS calculation method to identify genetic athletic predisposition in two groups of basketball and soccer players based on genetics analysis. Through the genetic profile we calculated, by an algorithm, the TGS (Total Genetic Score) in both groups; this idea comes from the concept that it's better to personalized workout based on athlete genetic profile. Identifying specifically performance demands (based on the metabolism system used during performance, aerobic or anaerobic) and paying attention to the performance- enhancing genes and their polymorphisms, is important focus it in order to build personalized and successful training for every single athlete. Materials and methods: We considered two groups of professional athletes: 21 basketball players and 21 soccer players both involved in professional championships. For the genetic analysis a saliva sample was taken from athletes, and the polymorphisms ..
TREND OF DRUG ABUSE IN 2011–2014 IN ITALY
Full text linkDoping, although was born as a medication and not with the purpose of enhancing performance, is a widespread practice
in all sports, between amateur and gym-goers. The Italian sports federations were in second place worldwide for positive doping-test,
after Russia.
This review focuses on the analysis of data collected by Italian National Olympic Committee (CONI) in the 2012–2014 period, showing
that the most commonly used substances were anabolic androgenic agents, glucocorticoids, diuretics and stimulants.
Prevention in doping could be a key to limit the damage caused by this harmful practice both, for the physical health and the athlete’s
moral integrity and anti-doping campaigns should be direct as much as possible to young people, since about two-thirds of adolescents
appear to be dissatisfied with their body. Even coordination between the various professionals that surround athletes could help fight
doping by planning specific training and adapted to the individual athlete, taking into account the actual physical limitations and physical
features of each
Does a specific genetic background influence endurance or power-orientated phenotypes?
No full textThe purpose of this study was to determine the probability of individuals having the “best” mitochondrial biogenesis related polygenic profile that could increase performance.
We compared polygenic profile analyzing several polymorphisms on sixty professional italian soccer players, considered “power-oriented athletes” and thirty sedentary volunteers. Samples of venous blood were obtained by standard clinical procedures and anticoagulant-treated blood was used to prepare genomic DNA. The polymorphic sites were scanned using PCR-RFLP protocols with different enzyme. Furthermore, a cloted part of venus blood sample was used to obtain serum from which we analyzed total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol and triglycerides, by using a kit in a chinetic enzyme analyzer.
We computed an “endurance genotype score” (EGS), related to mitochondrial biogenesis, from 0 to 100, from the accumulated combination of the polymorphisms in the PPARα-PPARGC1A-NRF2 (A/G; C/T) pathway; moreover, we analyzed the ACTN3 polymorphism. Particularly, as regards PPARα we also analyzed the lipid profile (total cholesterol, triglycerides, HDL and LDL) because it is an important factor that regulate the balance between fatty acid and glucose metabolism.
The results evidence an higher EGS and a variation of genotype distribution of the analyzed polymorphisms in professional soccer players compared with sedentary healty volunteers. Moreover, our study shows that PPARα genotype distribution is not related with a variation in the values of the lipid profile.
In conclusion professional soccer players possess “theoretically” a genetic background that is more suitable for mitochondrial biogenesis
OXIDATIVE STRESS MARKERS ASSOCIATED WITH MIDDLE DISTANCE RUNNING PERFORMANCE
Full text linkThe aim of this study was to understand the mechanism underlying the physiological adaptation of a kind purely aerobic workout. Particular attention has also been given to the analysis of oxidative stress by detecting some enzymatic blood parameters.
We investigate the effect of 2 months of training on middle distance running (800 meters and 1500 meters) agonistic athletes; nine active specifically trained males of mean (± SD) age 19,9 years.
The physiological characteristics of middle runners are different from those sprinters and long distance runners because include a variety of aerobic and anaerobic capabilities.
Two weeks prior to the 2 months period of exercise, subjects were tested for VO2max during a graded, treadmill test with the Cosmed FitMate metabolic device (Cosmed, Italy). Antropometric parameters were detected used a Bioimpedance analyzer (BF 302 Ormon BIA). A blood sample was collected in the morning and were collected by a clinical specialized center to analyze: triglycerides, total cholesterol, G.O.T. and G.P.T. transaminase, γ-GT, CPK and CK-MB, as well as lipid profile.
All these tests were performed before and after the two months of training period.
The results obtained suggest that the endurance training, as it is high oxygen consumption, should increase reactive oxygen species (ROS), but it has been shown that exercise leads to increased activation of antioxidant defenses. Infact, serum levels of gamma-glutamyltransferase (GGT) enzyme, which plays a key role in the metabolism of extracellular reduced glutathione (2) was not increased. However, a classic cardiac biomarkers (1), CK-MB as well as total CK was analyzed and while the total CK after two months of training increased, the CK-MB isoform decrease, in a significant statistical way.
Even the emathological parameters were analyzed and there were the variations overall on neutrophils and monocytes value. These two cell type are involved in the infection respons.
An antropometric parameter that changed after two months of training, was the weight. Infact after statistical analysis, the P value was < 0,0001, considered extremely significant (59,3±5,4 Kg before training; 58,1±5,2 Kg after training).
Finally, put together all the results, we can say that middle distance runners are subject at not high oxidative and biological stress; infact there were no change in γ-GT value, that usually is involved in the oxidative stress as well as a decrease of CK-MB value, that usually associated with cardiac injury. These are preliminary results that need to confirm with other studies using a larger sample of subjects or comparing with the runners that are involved in a different running distance (sprinters or long distance runners)
PPARα gene variation and phisycal performance in italian soccer players
No full textPURPOSE: One of the genes of the health-related fitness phenotype is a PPARα coding
for peroxisome proliferator activator receptor alpha, a central regulator of expression
of genes involved in fatty acid metabolism. The aim of our research was to study the
role of polymorphism of PPARα gene in performance enhancing in Italian soccer
players.
METHODS: Sixty professional soccer players and thirty sedentary volunteers were
enrolled in the study. Samples of venous blood were obtained at rest in the morning by
conventional clinical procedures. Serum was collected and lipid profile was measured
by using a commercial kit. An aliquote of anticoagulant-treated blood was used to
prepare genomic DNA from mononuclear cells. The polymorphic site in PPARα intron 7
was scanned by using PCR-RFLP protocol with Taq I enzyme.
RESULTS: We found variations among genotype distribution of PPARα in professional
soccer players versus sedentary volunteers. To enphatyzed this correlation, we also
investigated lipidic profile variation.
CONCLUSIONS: Our results evidenced an high expression of G allele as well as GG
genotype in accordance with other studies that associate this genotype with
endurance performance. So PPARα G allele may be considered an endurance relates
allele. We can explain this one because PPARα is an important factor that regulate the
balance between fatty acid and glucose metabolism. Moreover, we analyzed the
correlation between G allele distribution and athletes lipid profile but we didn’t find
any correlation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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