38 research outputs found

    Metformin inhibits androgen-induced IGF-IR up-regulation in prostate cancer cells by disrupting membrane-initiated androgen signaling.

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    We have previously demonstrated that, in prostate cancer cells, androgens up-regulate IGF-I receptor (IGF-IR) by inducing cAMP-response element-binding protein (CREB) activation and CREB-dependent IGF-IR gene transcription through androgen receptor (AR)-dependent membrane-initiated effects. This IGF-IR up-regulation is not blocked by classical antiandrogens and sensitizes cells to IGF-I-induced biological effects. Metformin exerts complex antitumoral functions in various models and may inhibit CREB activation in hepatocytes. We, therefore, evaluated whether metformin may affect androgen-dependent IGF-IR up-regulation. In the AR(+) LNCaP prostate cancer cells, we found that metformin inhibits androgen-induced CRE activity and IGF-IR gene transcription. CRE activity requires the formation of a CREB-CREB binding protein-CREB regulated transcription coactivator 2 (CRTC2) complex, which follows Ser133-CREB phosphorylation. Metformin inhibited Ser133-CREB phosphorylation and induced nuclear exclusion of CREB cofactor CRTC2, thus dissociating the CREB-CREB binding protein-CRTC2 complex and blocking its transcriptional activity. Similarly to metformin action, CRTC2 silencing inhibited IGF-IR promoter activity. Moreover, metformin blocked membrane-initiated signals of AR to the mammalian target of rapamycin/p70S6Kinase pathway by inhibiting AR phosphorylation and its association with c-Src. AMPK signals were also involved to some extent. By inhibiting androgen-dependent IGF-IR up-regulation, metformin reduced IGF-I-mediated proliferation of LNCaP cells. These results indicate that, in prostate cancer cells, metformin inhibits IGF-I-mediated biological effects by disrupting membrane-initiated AR action responsible for IGF-IR up-regulation and suggest that metformin could represent a useful adjunct to the classical antiandrogen therapy

    Impact of a mediterranean dietary pattern and its components on cardiovascular risk factors, glucose control, and body weight in people with type 2 diabetes: A real-life study

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    This study evaluates the relation of a Mediterranean dietary pattern and its individual components with the cardiovascular risk factors profile, plasma glucose and body mass index (BMI) in people with type 2 diabetes. We studied 2568 participants at 57 diabetes clinics. Diet was assessed with the EPIC (European Prospective Investigation into Cancer and Nutrition) questionnaire, adherence to the Mediterranean diet was evaluated with the relative Mediterranean diet score (rMED). A high compared to a low score was associated with a better quality of diet and a greater adherence to the nutritional recommendations for diabetes. However, even in the group achieving a high score, only a small proportion of participants met the recommendations for fiber and saturated fat (respectively 17% and 30%). Nonetheless, a high score was associated with lower values of plasma lipids, blood pressure, glycated hemoglobin, and BMI. The relationship of the single food items components of the rMED score with the achievement of treatment targets for plasma lipids, blood pressure, glucose, and BMI were also explored. The study findings support the Mediterranean dietary model as a suitable model for type 2 diabetes and the concept that the beneficial health effects of the Mediterranean diet lie primarily in its synergy among various nutrients and foods rather than on any individual component

    Secular Trends in the Prevalence of Overweight and Obesity in Sicilian Schoolchildren Aged 11–13 Years During the Last Decade

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    The present study evaluates trends in the prevalence of overweight and obesity in relation to gender and area of residence between two cohorts of students aged 11–13 years in Sicily. The analysis was performed on 1,839 schoolchildren, with 924 and 915 children being studied in 1999–2001 and 2009–2010, respectively. The children who were enrolled during 2009–2010 had significantly higher body mass indexes (BMI), BMI z-scores, and waist circumferences than the children who were studied during 1999–2001 (p<0.0001 for all); these differences was also observed when the cohort was subdivided according to gender or residence area The prevalence of obesity increased significantly from 7.9% in 1999–2001 to 13.7% in 2009–2010 (p<0.0001), whereas thinness decreased significantly from 10.1% to 2.3% (p<0.0001) in the same periods. The increase of trends in the prevalence of obesity was significantly higher in males (9.7% vs. 17.6%, p = 0.0006) than in females (6.3% vs. 9.8%, p = 0.04) and was slightly higher in urban areas (8.8% vs. 14.3%, p = 0.002) than in rural areas (7.8% vs. 13.0%, p = 0.012). The male gender was associated with a higher risk of being overweight or obese (odds ratio: 1.63; 95% confidence intervals: 1.24–2.15; p = 0.0005) in 2009–2010 than in 1999–2001, after adjusting for age and the residence area. In conclusion, this study showed an increasing trend in the prevalence of overweight and obesity in Sicilian schoolchildren during the last decade and that this trend was related to gender, age and the area of residence. More specifically, our data indicated that the prevalence of obesity increased by 5.8%, the prevalence of thinness decreased by 7.8% and the prevalence of normal-weight children did not change over the course of a decade. These results suggest a shift in the body weights of Sicilian children toward the upper percentiles

    Worldwide Increasing Incidence of Thyroid Cancer: Update on Epidemiology and Risk Factors

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    Background. In the last decades, thyroid cancer incidence has continuously and sharply increased all over the world. This review analyzes the possible reasons of this increase. Summary. Many experts believe that the increased incidence of thyroid cancer is apparent, because of the increased detection of small cancers in the preclinical stage. However, a true increase is also possible, as suggested by the observation that large tumors have also increased and gender differences and birth cohort effects are present. Moreover, thyroid cancer mortality, in spite of earlier diagnosis and better treatment, has not decreased but is rather increasing. Therefore, some environmental carcinogens in the industrialized lifestyle may have specifically affected the thyroid. Among potential carcinogens, the increased exposure to medical radiations is the most likely risk factor. Other factors specific for the thyroid like increased iodine intake and increased prevalence of chronic autoimmune thyroiditis cannot be excluded, while other factors like the increasing prevalence of obesity are not specific for the thyroid. Conclusions. The increased incidence of thyroid cancer is most likely due to a combination of an apparent increase due to more sensitive diagnostic procedures and of a true increase, a possible consequence of increased population exposure to radiation and to other still unrecognized carcinogens

    The effect of short-term triiodothyronine administration on thyroxine response to exogenous TSH in man.

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    In order to examine whether thyroid hormone concentration interfere with the thyroid gland responsivity to TSH, paired studies on the effect of short-term T3 treatment on T4 response to exogenous TSH ( 5 I.U. i.m.) were carried out in 10 euthyroid volunteers. During T3 administration ( 120 mcg/day for 4 days starting 48 hr before TSH injection) a significant decrease in T4 concentrations was observed both prior to and after TSH, with an inhibition of the T4 response ranging from 36-77% as calculated from the area under the response curve. The present data are in agreement with the existence of a "short-loop" thyroid-thyroid regulatory mechanism in man. In fact, the decreased percent rise of T4 after TSH suggests an inhibitory effect of T4 release following TSH, even though a modification of T4 kinetic parameters during T3 administration may account for a portion of the lowering of T4 blood concentrations

    Endemic cretinism in Sicily

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    This work reports the presence of endemic cretinism in a small district located inside an endemic goiter area in north-eastern Sicily, personally described. The study covers 19 mental defectives (11 females and 8 males, mean age 35.8 ± 15.5 yr) selected on the basis of severe mental retardation recognized by the local doctors. No systematic survey for cretinism was carried out in the total population. Marked mental retardation was evident in all subjects. Nine of them exhibited clinical and biochemical signs of hypothyroidism (myxedematous cretins). The 10 others were clinically euthyroid and had deaf-mutism and/or pyramidal tract dysfunction (neurological cretinism). Familial aggregation of cretinism was also observed. In both myxedematous and neurological cretins the urinary iodine excretion was very low, but not significantly different from that recorded in the euthyroid controls of the same area. The data available do not clarify the pathogenesis of endemic cretinism in Sicily. However, the marked height retardation, the observation of delayed bone maturation and the severity of mental deficiency suggest that thyroid failure was present in early life. The presence of endemic cretinism today in Sicily constitutes a strong argument in favour of the immediate introduction of adequate iodine prophylaxis. © 1981, Italian Society of Endocrinology (SIE). All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Effect of dexamethasone on thyroid hormone response to TSH.

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    The effect of short-term dexamethasone administration (8 mg daily for 3 days) on thyroid hormone response to exogenous TSH (bovine TSH, 5 IU i.m.) was studied in 16 euthyroid volunteers. Serum T3 and T4 concentrations were measured by radio-immunoassay prior to and 2, 6, 12, 24, and 49 hr after bTSH injection, both under basal conditions and during dexamethasone treatment. In all subjects bTSH administration raised both T3 and T4 concentrations significantly. Dexamethasone treatment induced a slight depression of endogenous TSH (m +/- SEM = 2.0 +/- 0.4 versus 1.6 +/- 0.3 muU/ml) and T4 (6.8 +/- 0.4 versus 6.1 +/- 0.2 mug/100 ml) basal values and a significant decrease in T3 value (1.16 +/- 0.09 versus 0.64 +/- 0.06 ng/ml, p = 0.005). The mean increment of both T3 and T4 after bTSH injection was percentually unchanged during dexamethasone treatment but, due to lowered basal value, T3 levels at each time interval after TSH + dexamethasone were significantly lower than the corresponding values observed after TSH alone. The present data show that high dexamethasone doses decrease T3 serum levels significantly without inhibiting T3 response to TSH stimulation. Only a slight lowering was observed in T4 levels

    Growth hormone levels in diabetes; correlation with the clinical control of the disease

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    The authors carried out simultaneous daytime blood sugar and growth hormone (HGH) determinations in eight juvenile and six middle aged diabetics under both poor and good metabolic control. A continuous blood sampling technic was used. The following results were obtained: HGH values in poorly controlled diabetics were higher and more fluctuating than in normals of a corresponding age. After good control was reached, a significant HGH decrease was observed in all patients but one. In this condition HGH levels were normalized in middle aged diabetics but not in juvenile ones. In the latter group HGH values, even if decreased, were persistently higher than in controls of the same age. No difference was observed between newly diagnosed diabetics and patients known to have had diabetes for some years. Our data support the suggestion that HGH abnormalities in diabetes are a consequence of the metabolic disturbance
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