Leptin and leptin receptor polymorphisms are associated with increased risk and poor prognosis of breast carcinoma

BACKGROUND: Leptin (LEP) has been consistently associated with angiogenesis and tumor growth. Leptin exerts its physiological action through its specific receptor (LEPR). We have investigated whether genetic variations in LEP and LEPR have implications for susceptibility to and prognosis in breast carcinoma. METHODS: We used the polymerase chain reaction and restriction enzyme digestion to characterize the variation of the LEP and LEPR genes in 308 unrelated Tunisian patients with breast carcinoma and 222 healthy control subjects. Associations of the clinicopathologic parameters and these genetic markers with the rates of the breast carcinoma-specific overall survival (OVS) and the disease free survival (DFS) were assessed using univariate and multivariate analyses. RESULTS: A significantly increased risk of breast carcinoma was associated with heterozygous LEP (-2548) GA (OR = 1.45; P = 0.04) and homozygous LEP (-2548) AA (OR = 3.17; P = 0.001) variants. A highly significant association was found between the heterozygous LEPR 223QR genotype (OR = 1.68; P = 0.007) or homozygous LEPR 223RR genotype (OR = 2.26; P = 0.001) and breast carcinoma. Moreover, the presence of the LEP (-2548) A allele showed a significant association with decreased disease-free survival in breast carcinoma patients, and the presence of the LEPR 223R allele showed a significant association with decreased overall survival. CONCLUSION: Our results indicated that the polymorphisms in LEP and LEPR genes are associated with increased breast cancer risk as well as disease progress, supporting our hypothesis for leptin involvement in cancer pathogenesis

El ambiente entre representación y ecología - Un estudio de caso en Guatemala, siglo XIX The environment: between representation and ecology - A case study of Guatemala, 19th century

<abstract language="por">A Guatemala - onde a cultura do café assumiu papel relevante - foi alvo de intensa idealização de sua natureza, ao mesmo tempo em que foi exaltada como uma nação essencialmente agrícola. Tais imagens se construíram tanto sobre bases naturais como sobre representa ções sociais e históricas. Muitos estudos apontam a existência de duas macro-regiões homogêneas no seu território. Entretanto, cada uma delas apresenta uma composição ecológica muito mais variada do que se supõe tradicionalmente, o que se configura como um dos principais fatores de compreensão da constituição histórica das regiões de plantio do café naquele país.<br>Guatemala - where the culture of coffee became relevant - was the target of intense idealization of its nature, at the same time that it was exalted as an essentially agricultural nation. Such images were built upon natural bases as well as upon social and historical representations. Many studies point to the existence of two homogeneous macroregions in the territory. However, each one of them presents an ecological composition much more varied than is traditionally supposed, which is one of the main factors for understanding the historical constitution of coffee plantation regions in that country