2,042 research outputs found
Osso e infiammazione
Negli ultimi due decenni molti studiosi hanno
messo in evidenza le complesse interazioni tra tessuto osseo
e sistema immunitario, le quali hanno portato allo sviluppo
di una branca di ricerca classificata come Osteoimmunologia.
La ricerca in questo campo ha un grande potenziale,
quello di poter fornire una migliore comprensione
della patogenesi di numerose malattie che colpiscono entrambi
i sistemi, osseo e immunitario, chiarendo così le basi
molecolari per sviluppare nuove strategie terapeutiche
Beamlike models for the analyses of curved, twisted and tapered horizontal-axis wind turbine (HAWT) blades undergoing large displacements
Abstract. Continuous ongoing efforts to better predict the mechanical behaviour of complex beamlike structures, such as wind turbine blades, are motivated by the need to improve their performance and reduce the costs. However, new design approaches and the increasing flexibility of such structures make their aeroelastic modelling ever more challenging. For the structural part of this modelling, the best compromise between computational efficiency and accuracy can be obtained via schematizations based on suitable beamlike elements. This paper addresses the modelling of the mechanical behaviour of beamlike structures which are curved, twisted and tapered in their unstressed state and undergo large displacements, in- and out-of-plane cross-sectional warping, and small strains. A suitable model for the problem at hand is proposed. Analytical and numerical results obtained by its application are presented and compared with results from 3D FEM analyses
Tadalafil modulates aromatase activity and androgen receptor expression in a human osteoblastic cell in vitro model
Purpose Phosphodiesterase type-5 inhibitor (PDE5i)
tadalafil administration in men with erectile dysfunction is
associated with increased testosterone/estradiol ratio, leading
to hypothesize a potential increased effect of androgen
action on target tissues. We aimed to characterize, in a cellular
model system in vitro, the potential modulation of
aromatase and sex steroid hormone receptors upon exposure
to tadalafil (TAD).
Methods Human osteoblast-like cells SAOS-2 were chosen
as an in vitro model system since osteoblasts are target
of steroid hormones. Cells were tested for viability upon
TAD exposure, which increased cell proliferation. Then,
cells were treated with/without TAD for several times to
evaluate potential modulation in PDE5, aromatase (ARO),
androgen (AR) and estrogen (ER) receptor expression.
Results Osteoblasts express significant levels of both PDE5
mRNA and protein. Exposure of cells to increasing concentrations
of TAD (10−8–10−7 M) decreased PDE5 mRNA and
protein expression. Also, TAD inhibited ARO mRNA and
protein expression leading to an increase in testosterone levels
in the supernatants. Interestingly, TAD increased total AR mRNA and protein expression and decreased ERα, with an
increased ratio of AR/ER, suggesting preferential androgenic
vs estrogenic pathway activation.
Conclusions Our results demonstrate for the first time
that TAD decreases ARO expression and increases AR
protein expression in human SAOS-2, strongly suggesting
a new control of steroid hormones pathway by PDE5i.
These findings might represent the first evidence of translational
actions of PDE5i on AR, which leads to hypothesize
a growing relevance of this molecule in men with
prostate cancer long-term treated with TAD for sexual
rehabilitation.
Keywords Tadalafil · Osteoblasts · Aromatase · Androgen
receptor · Estrogen recepto
Components of Purity to Describe the Polarimetric State of a 3-D Field Within the Reverberating Chamber
Reverberating chambers (RCs) are electrically large microwave enclosures in which a random electromagnetic 3-D, i.e., nonplanar, field is generated. To characterize such 3-D fields, a proper polarimetric decomposition is requested. In this article, a new set of parameters, namely the components of purity (CP), first proposed to the electromagnetic compatibility community, is presented. The CP parameters, which stem for the so-called trivial decomposition, are able to classify any 3-D polarimetric field into two states: regular and nonregular. Such characterization is of practical relevance, e.g., for RC isotropy testing
Tissue and circulating microRNAs as biomarkers of response to obesity treatment strategies
Background: Obesity, characterized by an increased amount of adipose tissue, is a metabolic chronic alteration which has reached pandemic proportion. Lifestyle changes are the first line therapy for obesity and a large variety of dietary approaches have demonstrated efficacy in promoting weight loss and improving obesity-related metabolic alterations. Besides diet and physical activity, bariatric surgery might be an effective therapeutic strategy for morbid obese patients. Response to weight-loss interventions is characterised by high inter-individual variability, which might involve epigenetic factors. microRNAs have critical roles in metabolic processes and their dysregulated expression has been reported in obesity. Aim: The aim of this review is to provide a comprehensive overview of current studies evaluating changes in microRNA expression in obese patients undergoing lifestyle interventions or bariatric surgery. Results: A considerable number of studies have reported a differential expression of circulating microRNAs before and after various dietary and bariatric surgery approaches, identifying several candidate biomarkers of response to weight loss. Significant changes in microRNA expression have been observed at a tissue level as well, with entirely different patterns between visceral and subcutaneous adipose tissue. Interestingly, relevant differences in microRNA expression have emerged between responders and non-responders to dietary or surgical interventions. A wide variety of dysregulated microRNA target pathways have also been identified, helping to understand the pathophysiological mechanisms underlying obesity and obesity-related metabolic diseases. Conclusions: Although further research is needed to draw firm conclusions, there is increasing evidence about microRNAs as potential biomarkers for weight loss and response to intervention strategies in obesity
Physical activity and hypocaloric diet recovers osteoblasts homeostasis in women affected by abdominal obesity.
Obesity is a multifactorial disease linked to metabolic chronic disorders such as diabetes, and hypertension. Also, it has recently been associated with skeletal alterations and low bone mineral density. We previously demonstrated that exposure of osteoblasts to sera of sedentary subjects affected by obesity alters cell homeostasis in vitro, leading to disruption of intracellular differentiation pathways and cellular activity. Thus, the purpose of the present study has been to evaluate whether sera of sedentary obese women, subjected to physical activity and hypocaloric diet, could recover osteoblast homeostasis in vitro as compared to the sera of same patients before intervention protocol. To this aim, obese women were evaluated at time 0 and after 4, 6, and 12 months of individualized prescribed physical activity and hypocaloric diet. Dual-energy-X-ray absorptiometry measurements were performed at each time point, as well as blood was collected at the same points. Cells were incubated with sera of subjects before and after physical activity as described: obese at baseline and after for 4, 6, and 12 months of physical activity and nutritional protocol intervention. Osteoblasts exposed to sera of patients, who displayed increased lean and decreased fat mass (from 55.5 ± 6.5 to 57.1 ± 5.6% p ≤ 0.05; from 44.5 ± 1.1 to 40.9 ± 2.6% p ≤ 0.01 respectively), showed a time-dependent increase of Wnt/β-catenin signaling, versus cells exposed to sera of obese patients before intervention protocol, suggesting recovery of osteoblast homeostasis upon improvement of body composition. An increase in β-catenin nuclear accumulation and nuclear translocation was also observed, accompanied by an increase in Adiponectin receptor 1 protein expression, suggesting positive effect on cell differentiation program. Furthermore, a decrease in sclerostin amount and an increase of type 1 procollagen amino-terminal-propeptide were depicted as compared to baseline, proportionally to the time of physical activity, suggesting a recovery of bone remodeling modulation and an increase of osteoblast activity induced by improvement of body composition. In conclusion, our results show for the first time that sera of obese sedentary women who increased lean mass and decreased fat mass, by physical activity and hypocaloric diet, rescue osteoblasts differentiation and activity likely due to a reactivation of Wnt/β-catenin-pathway, suggesting that a correct life style can improve skeletal metabolic alteration induced by obesity
Fetal-Perinatal Exposure to Bisphenol-A Affects Quality of Spermatozoa in Adulthood Mouse
Bisphenol-A (BPA) is considered an endocrine disruptor with estrogenic activity. It is described as an environment-polluting industrial chemical whose adverse effects on the male reproductive system depend on the period of exposure (i.e., fetal, prepubertal, or adult life). We exposed male mice to BPA during the fetal-perinatal period (from 10 days post coitum to 31 days post partum) and investigated the impact of this early-life exposure on gamete health in adulthood animals at 78 days of age. Both in control and BPA-exposed mice, viability and motility of spermatozoa, as well as sperm motility acquisition and chromatin condensation of spermatozoa, have been evaluated. Results reveal harmful effect of BPA on viability and motility of sperm cells as well as on chromatin condensation status during epididymal maturation of spermatozoa. In particular, BPA exposure interferes with biochemical mechanism useful to stabilize sperm chromatin condensation, as it interferes with oxidation of thiol groups associated to chromatin
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