295 research outputs found
Proliferative and apoptotic pathways in the testis of quail coturnix coturnix during the seasonal reproductive cycle
The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17ÎČâestradiol (E2) and androgens are higher during the reproductive period compared to the nonâreproductive period, which led us to hypothesize that estrogens and androgens may act synergistically to initiate spermatogenesis. The present study was, therefore, aimed to investigate the estrogen responsive system in quail testis in relation to the reproduction seasonality, with a focus on the molecular pathways elicited in both active and regressive quail testes. Western blotting and immunohistochemistry analysis revealed that the expression of ERα, which is the predominant form of estrogen receptors in quail testis, was correlated with E2 concentration, suggesting that increased levels of E2âinduced ERα could play a key role in the resumption of spermatogenesis during the reproductive period, when both PCNA and SYCP3, the mitotic and meiotic markers, respectively, were also increased. In the reproductive period we also found the activation of the ERK1/2 and Aktâ1 kinase pathways and an increase in second messengers cAMP and cGMP levels. In the nonâreproductive phase, when the E2/ERα levels were low, the inactivation of ERK1/2 and Aktâ1 pathways favored apoptotic events due to an increase in the levels of Bax and cytochrome C, with a consequent regression of the gonad
Bell correlation depth in many-body systems
We address the question of assessing the number of particles sharing genuinely nonlocal correlations in a multipartite system. While the interest in multipartite nonlocality has grown in recent years, its existence in large quantum systems is difficult to confirm experimentally. This is mostly due to the inadequacy of standard multipartite Bell inequalities to many-body systems: Such inequalities usually rely on expectation values involving many parties, usually all, and require individual addressing of each party. In addition, known Bell inequalities for genuine nonlocality are composed of a number of expectation values that scales exponentially with the number of observers, which makes such inequalities impractical from the experimental point of view. In a recent work [Tura et al., Science 344, 1256 (2014)], it was shown that it is possible to detect nonlocality in multipartite systems using Bell inequalities with only two-body correlators. This opened the way for the detection of Bell correlations with trusted collective measurements through Bell correlation witnesses [Schmied et al., Science 352, 441 (2016)]. These witnesses were recently tested experimentally in many-body systems such as Bose-Einstein condensate or thermal ensembles, hence demonstrating the presence of Bell correlations with assumptions on the statistics. Here, we address the problem of detecting nonlocality depth, a notion that quantifies the number of particles sharing nonlocal correlation in a multipartite system. We introduce a general framework allowing us to derive Bell-like inequalities for nonlocality depth from symmetric two-body correlators. We characterize all such Bell-like inequalities for a finite number of parties and we show that they reveal Bell correlation depth k <= 6 in arbitrarily large systems. We then show how Bell correlation depth can be estimated using quantities that are within reach in current experiments. On one hand, we use the standard multipartite Bell inequalities such the Mermin and Svetlichny ones to derive Bell correlations witnesses of any depth that involves only two collective measurements, one of which being the parity measurement. On the other hand, we show that our two-body Bell inequalities can be turned into witnesses of depth k <= 6 that require measuring total spin components in certain directions. Interestingly, such a witness is violated by existing data from an ensemble of 480 atoms
Use of hormones in doping and cancer risk
Hormones with anabolic properties such as growth hormone (GH) and insulin-like growth factor-1 (IGF-1) are commonly abused among professional and recreational athletes to enhance physical ability. Despite their adverse effects are well-documented, the use of GH and IGF-1 has recently grown. This article highlights the anabolic activity related to mechanisms of cancer development and progression. GH/IGF-1 axis is able to activate cellular mechanisms that modulate every key stage of cancer formation and progression, such as inhibition of apoptosis, resistance to treatments, and induction of angiogenesis, metastatic process and cell proliferation. Results from pre-clinical studies and epidemiological observations in patients with an excess of GH and IGF-1 production or treated with these hormones showed a positive association with the risk to develop several types of cancer. In conclusion, athletes should be made aware that long-term treatment with doping agents might increase the risk of developing cancer, especially if associated with other licit or illicit drugs and/or high-protein diet
Multimodal investigation of melanopsin retinal ganglion cells in Alzheimer's disease
Objective: In Alzheimer's disease (AD), the presence of circadian dysfunction is well-known and may occur early in the disease course. The melanopsin retinal ganglion cell (mRGC) system may play a relevant role in contributing to circadian dysfunction. In this study, we aimed at evaluating, through a multimodal approach, the mRGC system in AD at an early stage of disease. Methods: We included 29 mildâmoderate AD (70.9 ± 11 years) and 26 (70.5 ± 8 years) control subjects. We performed an extensive neurophtalmological evaluation including optical coherence tomography with ganglion cell layer segmentation, actigraphic evaluation of the rest-activity rhythm, chromatic pupillometry analyzed with a new data-fitting approach, and brain functional MRI combined with light stimuli assessing the mRGC system. Results: We demonstrated a significant thinning of the infero-temporal sector of the ganglion cell layer in AD compared to controls. Moreover, we documented by actigraphy the presence of a circadian-impaired AD subgroup. Overall, circadian measurements worsened by age. Chromatic pupillometry evaluation highlighted the presence of a pupil-light response reduction in the rod condition pointing to mRGC dendropathy. Finally, brain fMRI showed a reduced occipital cortex activation with blue light particularly for the sustained responses. Interpretation: Overall, the results of this multimodal innovative approach clearly document a dysfunctional mRGC system at early stages of disease as a relevant contributing factor for circadian impairment in AD providing also support to the use of light therapy in AD
The prevention of doping and the improper use of drugs and food supplements in sports and physical activities: a survey on the activity of the prevention departments of Italian local health authorities
Doping is an important public health problem widespread not only among elite athletes, but also among amateur and recreational athletes and the general population. In Italy the introduction of doping prevention within the Essential Levels of Care (LEA) with the DPCM 12/1/2017 represents a crucial step towards the implementation of education and health promotion interventions. In this context, the Departments of Prevention (DP) of the Local Health Authorities (LHA) have to play a fundamental role, becoming the cultural and operational reference on this issue. As part of the "Doping prevention: development of a permanent educational tool coordinated by the National Health Service Prevention Departments" project, funded by the Italian Ministry of Health, a survey was conducted on the activities carried out by the DP regarding doping prevention and improper use and abuse of drugs and food supplements in sports and physical activities, as a basis for the harmonization of organizational structures and prevention programs and the creation of a collaboration network at a regional and national level
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