14,114 research outputs found
Thyroid hormone receptors and ligand, tissue distribution and sexual behavior
The thyroid hormones (THs) triiodothyronine (T3) and tetraiodothyronine,
or thyroxine (T4), not only dramatically impact on
development and differentiation, but also on the sexual and
reproductive function. There is large body of literature, in fact, on
the effects of THs on the reproductive function in both humans
(Poppe and Velkeniers, 2004; Wajner et al., 2009) and animals
(Hapon et al., 2010; Nelson et al., 2011).
For a long time the gonads were thought to be unresponsive to
THs, but TH receptors (TR) were discovered in rat (Jannini et al.,
1990; Palmero et al., 1988) and then in human testis (Jannini
et al., 2000). In women, the association of menstrual disturbance
with thyroid disease was described as early as 1840 by von Basedow,
but the discovery of TRs in the ovary was carried out at the
end of last century (Wakim et al., 1994b). Therefore, the link between
thyroid and reproductive function was well established.
Since then, research has shown that thyroid dysfunction is associated
with an adverse effect on fertility, both in men (Wagner et al.,
2009) and women (Dittrich et al., 2011). There is also evidence that
THs can affect the sex steroid hormone axis (Bagamasbad and
Denver, 2011), consequently sexual hormones and the pituitary
gland can mediate the action of THs on the reproductive
physiology.
While the effects of THs on fertility have been widely studied,
little is known about their influence on sexual function. In the last
few years, an increasing number of evidences have shown the influence
of THs on male sexual function, particularly on ejaculation
control as well on desire and erectile function (Carani et al., 2005;
Corona et al., 2012b; Di Sante et al., 2016). The female sexual
function and the relationship with thyroid function is still less
studied. Furthermore, studies conducted on animals have shown
the presence of TRs in the male (Carosa et al., 2010) and female
genitalia (Rodriguez-Castelan et al., 2017). Moreover, knockout
mice for TRs showed alterations in sexual behavior (Dellovade et al.,
2000).
The purpose of this review is to summarize and discuss the
available data on the influence of THs on male and female sexual
function to understand the molecular mechanisms of the influence
of the thyroid gland on sexual behavior and function
Quantum Statistical Mechanics for Nonextensive Systems II
In this paper, the Green function theory of quantum many-particle systems
recently presented is reworked within the framework of nonextensive statistical
mechanics with a new normalized -expectation values. This reformulation
introduces a renormalization of temperature of the earlier theory and a
self-consistency condition. The linear response theory is also presented, along
with its two-particle Green function version. Finally, a Boltzmann
transport-like equation is also developed here.Comment: RevTeX 16 page
Scaling dependence on time and distance in nonlinear fractional diffusion equations and possible applications to the water transport in soils
Recently, fractional derivatives have been employed to analyze various
systems in engineering, physics, finance and hidrology. For instance, they have
been used to investigate anomalous diffusion processes which are present in
different physical systems like: amorphous semicondutors, polymers, composite
heterogeneous films and porous media. They have also been used to calculate the
heat load intensity change in blast furnace walls, to solve problems of control
theory \ and dynamic problems of linear and nonlinear hereditary mechanics of
solids. In this work, we investigate the scaling properties related to the
nonlinear fractional diffusion equations and indicate the possibilities to the
applications of these equations to simulate the water transport in unsaturated
soils. Usually, the water transport in soils with anomalous diffusion, the
dependence of concentration on time and distance may be expressed in term of a
single variable given by In particular, for the
systems obey Fick's law and Richards' equation for water transport. We show
that a generalization of Richards' equation via fractional approach can
incorporate the above property.Comment: 9 page
Excitation of the GDR and the Compressional Isoscalar Dipole State by alpha scattering
The excitation of the isovector giant dipole resonance (GDR) by alpha
scattering is investigated as a method of probing the neutron excess in exotic
nuclei. DWBA calculations are presented for 28O and 70Ca and the interplay of
Coulomb and nuclear excitation is discussed. Since the magnitude of the Coulomb
excitation amplitude is strongly influenced by the Q-value, the neutron excess
plays an important role, as it tends to lower the energy of the GDR. The
excitation of the compressional isoscalar dipole state in 70Ca by alpha
scattering is also investigated. It is shown that the population of this latter
state may be an even more sensitive probe of the neutron skin than the
isovector GDR.Comment: 7 pages, 5 figures, Latex2
Symbolic Sequences and Tsallis Entropy
We address this work to investigate symbolic sequences with long-range
correlations by using computational simulation. We analyze sequences with two,
three and four symbols that could be repeated times, with the probability
distribution . For these sequences, we verified that
the usual entropy increases more slowly when the symbols are correlated and the
Tsallis entropy exhibits, for a suitable choice of , a linear behavior. We
also study the chain as a random walk-like process and observe a nonusual
diffusive behavior depending on the values of the parameter .Comment: Published in the Brazilian Journal of Physic
High serum osteopontin levels are associated with prevalent fractures and worse lipid profile in post-menopausal women with type 2 diabetes
Purpose: Patients with type 2 diabetes (T2DM) have increased fracture risk. Osteopontin (OPN) is a protein involved in bone remodeling and inflammation. The aim of this study was to evaluate the association of OPN with fracture prevalence and with metabolic parameters in post-menopausal women with T2DM. Methods: Sixty-four post-menopausal women with T2DM (age 67.0 ± 7.8 years, diabetes duration 8.9 ± 6.7 years), enrolled in a previous study, were followed up (3.6 ± 0.9 years). Previous fragility fractures were recorded. The FRAX score (without BMD) was calculated and biochemical parameters (plasma glucose, HbA1c, lipid profile and renal function) were assessed. Serum 25OH-vitamin D, calcium, PTH and OPN were evaluated at baseline. The association between OPN and fracture prevalence at baseline was evaluated by a logistic model. Results: OPN levels were higher in patients with previous fractures (n.25) than in patients without previous fractures at baseline (n.39) (p = 0.006). The odds of having fractures at baseline increased by 6.7 (1.9–31.4, 95% CI, p = 0.007) for each increase of 1 ng/ml in OPN levels, after adjustment for vitamin D and HbA1c levels. Fracture incidence was 4.7%. Higher OPN associated with a decrease in HDL-cholesterol (p = 0.048), after adjustment for age, basal HDL-cholesterol, basal and follow-up HbA1c and follow-up duration. 25OH-vitamin D associated with an increase in FRAX-estimated probability of hip fracture at follow-up (p = 0.029), after adjustment for age, 25OH-vitamin D and time. Conclusions: In post-menopausal women with T2DM, OPN might be a useful marker of fracture and worse lipid profile
Circulating SIRT1 inversely correlates with epicardial fat thickness in patients with obesity
Background and aim: Obesity is increasing worldwide and is related to undesirable cardiovascular outcomes. Epicardial fat (EF), the heart visceral fat depot, increases with obesity and correlates with cardiovascular risk. SIRT1, an enzyme regulating metabolic circuits linked with obesity, has a cardioprotective effect and is a predictor of cardiovascular events. We aimed to assess the relationship of EF thickness (EFT) with circulating SIRT1 in patients with obesity.
Methods and results: Sixty-two patients affected by obesity and 23 lean controls were studied. Plasma SIRT1 concentration was determined by enzyme-linked immunosorbent assay (ELISA). EFT was measured by echocardiography. Body mass index (BMI), waist circumference, heart rate (HR), blood pressure, and laboratory findings (fasting glucose, insulin, HbA1c, cholesterol, and triglycerides) were assessed. SIRT1 was significantly lower (P = 0.002) and EFT was higher (P < 0.0001) in patients with obesity compared with lean controls. SIRT1 showed a negative correlation with EFT and HR in the obesity group (rho = -0.350, P = 0.005; rho = -0.303, P = 0.008, respectively). After adjustment for obesity-correlated variables, multiple linear regression analysis showed that EFT remained the best correlate of SIRT1 (beta = -0.352, P = 0.016).
Conclusions: Circulating SIRT1 correlates with the visceral fat content of the heart. Serum SIRT1 levels might provide additional information for risk assessment of coronary artery disease in patients with obesity. (C) 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved
Are the therapeutic strategies in anorexia of ageing effective on nutritional status? A systematic review with meta-analysis
BACKGROUND:
Anorexia of ageing (AA) may be considered as a risk factor for frailty and has an important impact on quality of life, morbidity and mortality.
METHODS:
A systematic review and a meta-analysis were performed to summarise the results from several trials on the effectiveness of treatments in AA, as associated with depression, sensory impairment of taste and smell, decreased appetite or early satiety, and disability. Eligible studies were required to report baseline and follow-up values, the mean change (∆-change) from baseline, and/or the mean difference among intervention groups versus control group, concerning food intake (kcal/daily) and/or nutritional outcomes, such as body weight, body mass index, albumin and Mini Nutritional Assessment.
RESULTS:
The systematic review included 20 papers based on different therapeutic approaches concerning food intake and/or nutritional outcomes. The results of the meta-analysis indicate that the interventions for AA have an important impact on body weight [+1.59 kg; 95% confidence interval (CI) = 1.48-+1.71 kg; P < 0.001) and on energy intake (+56.09 kcal; 95% CI = -54.05 to +166.25 kcal; P = 0.32). Regarding secondary outcomes, it was not possible to meta-analyse the limited amount of data availab le.
CONCLUSIONS:
The different variants of AA need to be defined because diverse therapeutic approaches are available. A more precise definition of the functional impairments associated with AA may allow a more correct decision about the most appropriate therapy to be prescribed. Moreover, this may allow for a more effective performance of the different therapeutic approaches once they are better targeted to the different scenarios of AA
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