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The present study was carried to develop and analyze the consequences of hypercaloric pellet-diet cycle that promotes obesity in rats. Male Wistar rats were randomly distributed into two groups that received either normal diet (ND; n =32; 3,5 Kcal/g) or a hypercaloric diet (HD; n =32; 4,6 Kcal/g). The ND group received commercial Labina rat feeding while the HD animals received a cycle of five hypercaloric diets over a 14-week period. The effects of the diets were analyzed in terms of body weight, body composition, hormone-metabolite levels, systolic arterial pressure and glucose tolerance at the 5% significance level. The hypercaloric pellet diet cycle promoted an increase in body weight and fat, systolic arterial pressure and a high serum level of glucose, triacylglycerol, insulin and leptin. The HD group also presented an impaired glucose tolerance. In conclusion, the results of this study show that the hypercaloric pellet-diet cycle promoted obesity in Wistar rats and displayed several characteristics that are commonly associated with human obesity, such as high arterial pressure, insulin resistance, hyperglycaemia, hyperinsulinaemia, hyperleptinaemia and dyslipidaemia.

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Estrogen involvement in breast cancer has been established; however, the association between breast cancer and thyroid diseases is controversial. Estrogen-like effects of thyroid hormone on breast cancer cell growth in culture have been reported. The objective of the present study was to determine the profile of thyroid hormones in breast cancer patients. Serum aliquots from 26 patients with breast cancer ranging in age from 30 to 85 years and age-matched normal controls (N = 22) were analyzed for free triiodothyronine (T 3 F), free thyroxine (T 4 F), thyroid-stimulating hormone (TSH), antiperoxidase antibody (TPO), and estradiol (E 2 ). Estrogen receptor ß (ERß) was determined in tumor tissues by immunohistochemistry. Thyroid disease incidence was higher in patients than in controls (58 vs 18%, P < 0.05). Subclinical hyperthyroidism was the most frequent disorder in patients (31%); hypothyroidism (8%) and positive anti-TPO antibodies (19%) were also found. Subclinical hypothyroidism was the only dysfunction (18%) found in controls. Hyperthyroidism was associated with postmenopausal patients, as shown by significantly higher mean T 3 and T 4 values and lower TSH levels in this group of breast cancer patients than in controls. The majority of positive ERß tumors were clustered in the postmenopausal patients and all cases presenting subclinical hyperthyroidism in this subgroup concomitantly exhibited Erß-positive tumors. Subclinical hyperthyroidism was present in only one of 6 premenopausal patients. We show here that postmenopausal breast cancer patients have a significantly increased thyroid hormone/ E 2 ratio (P < 0.05), suggesting a possible tumor growth-promoting effect caused by this misbalance.

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The effect of cachexia on insulin secretion was examined in adult male rats. Isolated islets of Langerhans from Walker 256 tumor-bearing rats secreted less insulin by glucose stimuli as compared with the control group; this was accompanied by significant change in 45Ca2+ outflow rate. Reduced insulin secretion to glucose stimuli in tumor-bearing rats probably led to low insulinemia (one-third). These findings indicate that reduced insulin secretion is probably an important factor for the development of cachexia in Walker 256 tumor-bearing rats.

Cabergoline and bromocriptine are the most used drugs in the treatment of hyperprolactinemia, they are able to normalize the prolactin levels, restore gonadal function and promote tumor reduction in the majority of patients. We undertake a systematic review and meta-analysis of randomized controlled trials to compare cabergoline versus bromocriptine in the treatment of patients with idiopathic hyperprolactinemia and prolactinomas. The data sources were: Embase, Pubmed, Lilacs and Cochrane Central. The outcome measures were: normalization of prolactin secretion, restoration of gonadal function, reduction of tumoral volume, quality of life and adverse drug effects. Were identified 418 references and after screening by title and abstract, we obtained complete copies of 34 articles potentially eligible for inclusion in the review. From this total, 19 were selected to be included, but fifteen of them were excluded due to the following reasons: one randomized study compared cabergoline versus placebo and other randomized study compared different doses of cabergoline; five references were cases series; four were only controlled studies; three were retrospectives series and; one was a cohort study. Therefore, four publications were included in the review and in the final analysis. The meta-analysis of normalization of serum prolactin levels and menstruation with return of ovulatory cycle showed a significant difference in favor of cabergoline group (RR 0.67 [CI 95% 0.57, 0.80]) e (RR 0.74 [CI 95% 0.67, 0.83]), respectively. The number of adverse effects was significantly higher in the bromocriptine number than in cabergoline group (RR 1.43 [CI 95% 1.03, 1.98]). The meta-analysis showed new evidence favoring the use of cabergoline in comparison with bromocriptine for the treatment of prolactinomas and idiopathic hyperprolactinemia.

Congenital hypothyroidism associated with thyroid hypoplasia can be caused by several genetic defects, including mutations in the TSHbeta-subunit, the TSH receptor, the G(s)alpha-subunit, and the transcription factor PAX8. Four girls with sporadic congenital hypothyroidism and hypoplastic thyroid glands were analyzed for mutations in PAX8 and TTF2 (FKHL15). Mutations in the coding region of the TSHbeta-subunit gene, the TSH receptor gene, and exons 8 and 9 of G(s)alpha had been excluded previously. Serum TSH concentrations were 150 mU/liter or more, TG levels were within normal limits, and thyroid autoantibodies were absent. Technetium scintigraphies did not reveal the presence of thyroid tissue, but ultrasonography documented hypoplastic, normally located glands. One patient was found to harbor a heterozygous transversion 119A-->C in exon 3 of PAX8 replacing a conserved glutamine by proline in the paired box domain (Q40P). Analysis of her family members revealed that her mother, who has a thyroid gland of normal size and mild, adult-onset autoimmune hypothyroidism, is also heterozygous for this mutation. Functional analyses of the PAX8 Q40P mutation showed impaired binding to a PAX8 response element and absent trans-activation of a thyroid peroxidase promoter luciferase reporter gene. These findings confirm the important role of PAX8 in the development of the thyroid, but they indicate that PAX8 gene mutations may have a variable penetrance or expressivity. The absence of mutations in the coding sequences of the analyzed genes in the three other patients supports the concept that the pathogenesis of congenital hypothyroidism associated with thyroid hypoplasia is diverse.