1,721,851 research outputs found
On the qualitative analysis of the solutions of a mathematical model of social dynamics
Full text linkThis work deals with a family of dynamical systems which were introduced in [M.L. Bertotti, M. Delitala, From discrete kinetic and stochastic game theory to modelling complex systems in applied sciences, Math. Models Methods Appl. Sci. 7 (2004) 1061–1084], modelling the evolution of a population of interacting individuals, distinguished by their social state. The existence of certain uniform distribution equilibria is proved and the asymptotic trend is investigate
Growth hormone, menopause and ageing: no definite evidence for 'rejuvenation' with growth hormone
No full textEstrogens regulate growth hormone (GH) secretion and modulate the tissue responsiveness to GH. After the menopause, and during ageing, a decline in GH secretion (somatopause) is physiologically observed. This article (i) provides a brief overview of the different regulators of GH secretion, (ii) reviews the mechanisms involved in age-related changes in GH concentrations, with particular emphasis on the interrelationships between menopause and GH, and (iii) discusses the interventions aimed at the restoration of GH and insulin-like growth factor (IGF-1) circulating levels.
A systematic literature search was conducted in the PubMed database using the search terms 'Growth Hormone', 'Somatopause' and 'Menopause'. The search included full English articles covering the period 1972-2008. We selected 234 relevant citations. We also included three chapters from books.
Estrogen deficiency may contribute, through its action on GH, to the complex physical and metabolic alterations of menopause. Several attempts have been made to restore the GH and IGF-1 levels within the young adult range.
There is no definite evidence that elderly subjects really benefit from treatment with GH or GH secretagogues. Strategies aimed at enhancing spontaneous GH secretion such as sleep and exercise are safer and certainly less expensive than GH supplementation regimen
Subclinical Hyperthyroidism and the Cardiovascular Disease
No full textAbstractThyroid hormone excess has complex metabolic effects, particularly on the cardiovascular system. Treatment of these conditions is universally suggested by international guidelines. Subclinical hyperthyroidism, defined by reduced or suppressed TSH levels in the presence of normal free thyroxine and free triiodothyronine values, is common in the general population and progressively increases with aging, being as high as 15.4% in subjects more than 75 years old and more frequent in subjects with nodular goiter. Subclinical hyperthyroidism is often asymptomatic and the diagnosis is incidentally made during screening exams. However, this form of thyroid disorder has gained attention in the last years for its association with cardiovascular disease, in particular with atrial fibrillation. Less clear are the effects of subclinical hyperthyroidism on blood pressure, stroke, or heart failure. The decision to treat subclinical hyperthyroidism is made on the clinical judge, particularly in elderly patients and/or in the presence of comorbidities.</jats:p
The assessment of self and collective efficacy in volleyball
No full textSelf–efficacy is defined as belief in one’s capabilities to organize and execute the courses of actions required
to produce given attainments. Perceived Collective efficacy is defined as a group's shared belief in its conjoint
capabilities to organize and execute the courses of action required to produce given levels of attainments
(Bandura, 1997). To evaluate self and collective efficacy in Italian volleyball players at different competitive
levels we have constructed some non-hierarchical scales to assess specific aspects relevant for this sport, as
emotions regulation, approach to training, technical/tactical capabilities and communication. A preliminary
version was administrated to different samples using two_formats of rating scales: an 11-point and a 5-point
Likert scale. Statistical analysis led us to choose the 5-point scale format (Guicciardi, Fadda and Delitala, 2010)
and revealed a factorial structure composed of four dimensions. Based on the results of this study a new
version of the questionnaires was created and it was named VEBS (volleyball efficacy beliefs scales).Efficacy
scales were administered to an élite sample (n=133) along with other psychological tests (TEOSQ, GEQ, BIG
FIVE) to verify the structural validity. The scales showed adequate values of skewness and kurtosis and values
of Cronbach‘s alpha ranging from .69 to .95. Good fit indices emerged in CFA for self-efficacy (÷2=74.4, df=59,
CFI=.97, TLI=.97, RMSEA=.05) confirming the four factors model. In conclusion, the structural validity of
efficacy scales (of VEBS) has been confirmed, as well as their relationships with the task-orientation, cohesion
and some personality traits (energy and openness)
Libro raro y curioso. Poesías de José Delitala y Castelví (1672). Un clásico olvidado
No full textSerís Homero. Libro raro y curioso. Poesías de José Delitala y Castelví (1672). Un clásico olvidado. In: Bulletin Hispanique, tome 43, n°2, 1941. pp. 171-181
Thyroid hormone analogs for the treatment of dyslipidemia: past, present, and future
No full textObjective: Treatment of dyslipidemia is a major burden for public health. Thyroid hormone regulates lipid metabolism by binding the thyroid hormone receptor (TR), but the use of thyroid hormone to treat dyslipidemia is not indicated due to its deleterious effects on heart, bone, and muscle. Thyroid hormone analogs have been conceived to selectively activate TR in the liver, thus reducing potential side-effects. Methods: The authors searched the PubMed database to review TR and the action of thyromimetics in vitro and in animal models. Then, all double-blind, placebo controlled trials that analyzed the use of thyroid hormone analog for the treatment of dyslipidemia in humans were included. Finally, the ongoing research on the use of TR agonists was searched, searching the US National Institutes of Health Registry and the WHO International Clinical Trial Registry Platform (ICTRP). Results: Thyromimetics were tested in humans for the treatment of dyslipidemia, as a single therapeutic agent or as an add-on therapy to the traditional lipid-lowering drugs. In most trials, thyromimetics lowered total cholesterol, low-density lipoprotein cholesterol, and triglycerides, but their use has been associated with adverse side-effects, both in pre-clinical studies and in humans. Conclusions: The use of thyromimetics for the treatment of dyslipidemia is not presently recommended. Future possible clinical applications might include their use to promote weight reduction. Thyromimetics might also represent an interesting alternative, both for the treatment of non-alcoholic steatohepatitis, and type 2 diabetes due to their positive effects on insulin sensitivity. Finally, additional experimental and clinical studies are needed for a better comprehension of the effect(s) of a long-term therapy
Nonlinear models of vehicular traffic flow - new frameworks of the mathematical kinetic theory
Full text linkPrimary symptomatic adrenal insufficiency induced by megestrol acetate
No full textMegestrol acetate (MA) is a progestational agent for the treatment of metastatic breast cancer and endometrial cancer. MA has also been used to promote weight gain in malnourished elderly patients, in patients with immunodeficiency virus and in cancer-induced cachexia. In addition to thromboembolic disease, MA may induce hyperglycaemia, osteoporosis, suppression of the gonadal axis, and Cushing's syndrome. MA has also been shown to cause symptomatic suppression of the hypothalamic-pituitary-adrenal (HPA) axis owing to its intrinsic glucocorticoid-like effect. Three additional patients are presented who developed symptomatic adrenal insufficiency while they were receiving 160-320 mg MA daily. The patients were treated with cortisone acetate supplements, had clear evidence of HPA-axis suppression but recovered fully after MA was discontinued. Patients receiving MA might have an inadequate adrenal response during stressful conditions, possibly because 160-320 mg MA daily may not provide adequate protection to prevent the symptoms of adrenal insufficiency. The adverse MA effect on the HPA axis is probably not well recognised in clinical practice, and clinicians need an increased awareness of the endocrine complications secondary to MA treatment. © Van Zuiden Communications B.V. All rights reserved
Subclinical hypothyroidism, lipid metabolism and cardiovascular disease
No full textSubclinical hypothyroidism is defined by elevated serum thyrotropin in presence of normal free thyroid hormones. Lipid metabolism is influenced by thyroid hormone and many reports showed that lipids status worsen along with TSH level. Subclinical hypothyroidism has been also linked to other cardiovascular risk factors such as alteration in blood pressure and increased atherosclerosis. Further evidences suggested that mild dysfunction of thyroid gland is associated with metabolic syndrome and heart failure. Thyrotropin level seems the best predictor of cardiovascular disease, in particular when its levels are above 10à ̄¿Â1⁄2mU/L. However, despite these observations, there is no clear evidence that levothyroxine therapy in subjects with milder form of subclinical hypothyroidism could improve lipid status and the other cardiovascular risk factors. In this review, we address the effect of thyroid hormone and cardiovascular risk, with a focus on lipid metabolism
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