Effects of hypothyroidism on the mesenteric and omental adipose tissue in rats.

To characterize the influence of hypothyroidism on the endocrine activity of mesenteric and omental adipose tissue (MOAT) and the peripheral regulation of energy balance (EB) in rats, we analyzed food intake (FI); basal metabolic rate (BMR); locomotor activity; body weight (BW); serum hormone concentrations and the expression of their receptors in MOAT. We evaluated the morphology and differentiation of adipocytes. Hypothyroidism decreased FI, BMR and BW. The percentage of visceral white adipose tissue (WAT) depots and the morphology of adipocytes were similar to euthyroid rats. Serum leptin and adiponectin expression in MOAT were altered by hypothyroidism. The expression of Perilipin 1, HSL, UCP1 and PRDM16 was significantly lower in MOAT of hypothyroid animals. Hypothyroidism in rats leads to a compensated EB by inducing a white adipocyte dysfunction and a decrease in BW, BMR, FI and adipokine secretions without changing the percentage of WAT depots and the morphology of the MOAT.

High maternal milk intake in the postnatal life reduces the incidence of breast cancer during adulthood in rats.

Environmental factors during perinatal life can lead to changes in the mammary gland, making it susceptible to cancer in adulthood. Breastfeeding has a special importance since it takes place at a critical period of growth and development of the newborn. We aimed to analyze if an appropriate lactation protects the offspring against mammary carcinogenesis during adult life and explore the mechanisms involved in the protective effect. One-day-old Sprague-Dawley female rats were randomly distributed in litters of three (L3), eight (L8) or 12 (L12) pups per dam, to induce a differential consumption of breast milk. At 55 days of age, the animals were treated with a single dose of dimethylbenzanthracene to study tumor latency, incidence and progression. Histological, immunohistochemical and Western blot studies were performed. We observed lower incidence and higher latency in L3 compared to the other groups. The mitotic index and expression of proliferating cell nuclear antigen (PCNA) was significantly augmented in tumors of L12 rats compared to L3 and L8, while the apoptotic index was augmented in tumors of L3 v. L12. Cleaved caspase 8 was significantly higher in tumors from L3 compared to L12. Tumors developed in L3 have a greater number of apoptotic bodies and a greater expression of caspase 8. These results demonstrate that the animals that maintained a higher intake of maternal milk (L3) presented lower incidence and greater tumor latency. Lower consumption of breast milk (L12) would increase tumor mitosis and the expression of PCNA, explaining the higher tumor incidence observed in this group.

Hypothyroidism reduces mammary tumor progression via Β-catenin-activated intrinsic apoptotic pathway in rats.

Experimental hypothyroidism retards mammary carcinogenesis promoting apoptosis of tumor cells. ß-catenin plays a critical role in cell adhesion and intracellular signaling pathways conditioning the prognosis of breast cancer. However, the mechanistic connections associated with the expression of ß-catenin in thyroid status and breast cancer are not known. Therefore, we studied the relationship between the expression and localization of ß-catenin and apoptosis in mammary tumors induced by 7,12-dimethylbenz(a)anthracene (DMBA) in hypothyroid (Hypot) and euthyroid (EUT) rats. Female Sprague Dawley rats were treated with a dose of DMBA (15 mg/rat) at 55 days of age and were then divided into two groups: HypoT (0.01% 6-N-propyl-2-thiouracil in drinking water, n = 54) and EUT (untreated control, n = 43). Latency, incidence and progression of tumors were determined. At sacrifice, tumors were obtained for immunohistological studies and Western Blot. The latency was longer (p < 0.05), the incidence was lower (p < 0.0001) and tumor growth was slower (p < 0.01) in HypoT rats compared to EUT. The expression of Bax, cleaved caspase-9 and caspase-3 was significantly higher in tumors of HypoT than in EUT (p < 0.05) indicating the activation of the intrinsic pathway. In this group, ß-catenin was expressed in the plasma membrane and with less intensity, while its expression was nuclear and with greater intensity in the EUT (p < 0.05). Moreover, the expression of survivin was reduced in tumors of HypoT rats (p < 0.05). In conclusion, decreased expression of ß-catenin and its normal location in membrane of mammary tumors are associated with augmented apoptosis via activation of the intrinsic pathway in HypoT rats.

[Relation between selenium plasma levels and different prostatic pathologies]. / Relación entre los niveles plasmáticos de selenio y las diferentes enfermedades prostáticas.

UNLABELLED: Several studies have demonstrated an inverse relation between serum selenium levels (Se) and advanced prostate cancer (PCa). OBJECTIVE: To determine and compare selenium plasma levels in patients with different prostatic pathologies. MATERIAL AND METHODS: It is a transversal, descriptive and comparative study. A sample of 64 men between 50 and 80 years old were selected for the study between 2007 and 2009. All volunteers underwent a digital rectal examination, prostate specific antigen level, ultrasound and transrectal prostate biopsy (12-14 chips). Prostate cancer was subclassified according to Gleason Score. Selenium was determined indirectly by serum Glutathione peroxidase (Kit Ransel, Randox SRL, Crumlin, UK). Statistical analysis was performed using ANOVA I (p<0.05). RESULTS: Glutathione Peroxidase level was 33.75+/-2.36 mg/ml in control patients. A decrease of 31.6% was observed in patients with BPH (23.08+/-1.57 mg/ml) and of (63.6%) in subjects with prostate cancer (12.28+/-1.03 mg/ml) (p<0,0001). There was no correlation with the Gleason Score. CONCLUSION: Serum Seleniun is lower in patients with prostatic pathologies being even more important in cancer patients regardless the Gleason Score.

[Comparison between two methods to estimate physical activity in obese women: accelerometry and self-administered questionnaire]. / Comparación de la estimación de la actividad física en una población de mujeres obesas por acelerometría y con cuestionario.

The aims of this study were to describe a female obese population according to their food intake and physical activity, and to compare two methods to estimate physical activity (PA). The study included a nutritional interview where a detailed dietary history was done, an initial clinical day in which measurements of body composition and basal metabolic rate (BMR) were carried out and an estimation of PA by means of a triaxial accelerometer and a PA questionnaire. The group of volunteers showed a mean BMI of 37.15 kg/m2, a waist/hip ratio of 0.82 and a mean body fat mass of 43.34%. The average of BMR was 1720 Kcal/d and the CRNP of 0.79. The total caloric intake was 3344 Kcal/d with a energy-distribution of 43.1% Carbohydrates, 16.4% Proteins, 40.3% Lipids. Weight and BMI showed a positive correlation (p < 0.05) with the sedentary index (SI). Also, weight presented a positive correlation with the heart rate (p < 0.05). The estimates of PA derived from the questionnaire showed a positive correlation with the triaxial accelerometer (p < 0.01); and this one, revealed a negative correlation with the SI (p < 0.01). Anthropometric, metabolic and food intake variables are comparable to the results found in obese women from similar socioeconomic background. The estimates of PA according to the questionnaire were significantly correlated to the results of the triaxial accelerometer, thus confirming the validity of the questionnaire to assess PA in an obese population.