Evo-devo of human adolescence: beyond disease models of early puberty

Despite substantial heritability in pubertal development, much variation remains to be explained, leaving room for the influence of environmental factors to adjust its phenotypic trajectory in the service of fitness goals. Utilizing evolutionary development biology (evo-devo), we examine adolescence as an evolutionary life-history stage in its developmental context. We show that the transition from the preceding stage of juvenility entails adaptive plasticity in response to energy resources, other environmental cues, social needs of adolescence and maturation toward youth and adulthood. Using the evolutionary theory of socialization, we show that familial psychosocial stress fosters a fast life history and reproductive strategy rather than early maturation being just a risk factor for aggression and delinquency. Here we explore implications of an evolutionary-developmental-endocrinological-anthropological framework for theory building, while illuminating new directions for research

Sexual precocity after immigration from developing countries to Belgium: evidence of previous exposure to organochlorine pesticides.

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Human exposure to endocrine disrupters: consequences of gastroplasty on plasma concentration of toxic pollutants

BACKGROUND: Body weight loss occurring after a hypoenergetic diet or a gastroplasty could be followed by an increase in blood concentration of potentially toxic pollutants that can interfere with the hormonal system (endocrine disrupters). DESIGN: Thirty obese individuals recruited for gastroplasty were compared before and after treatment with 45 normal-weight people. MEASUREMENTS: Blood samples were analyzed for DDT, DDE, HCB and PCBs no. 28, 52, 101, 118, 138, 153 and 180, by gas chromatography-mass spectrometry. RESULTS: The results indicate clearly that body weight loss occurring after gastroplasty increases plasma concentration of lipophilic pollutants. CONCLUSION: Gastroplasty increases plasma concentration of organochlorine pesticides and PCBs, which could be a risk factor of endocrine disruption. Future longitudinal research will have to determine if the advantages of body weight loss are reduced by this potentially harmful effect

¿Existen relaciones entre los factores ambientales rurales y la salud reproductiva en la Pampa Húmeda Argentina? Is there any relationship between rural environmental factors and reproductive health in the Pampa Humeda in Argentina?

La relación entre factores ambientales y salud es un hecho reconocido. La influencia de ambientes rurales sobre la salud reproductiva ha sido fehacientemente probada en diferentes regiones del mundo, tanto en la fauna como en humanos. En América Latina pocas investigaciones han sido realizadas en este campo. El presente proyecto se establece sobre la base de la describir las relaciones entre salud reproductiva y factores ambientales en poblaciones rurales, caracterizada por aspectos ambientales particulares. Tres variables han sido evaluadas: relación de nacimientos masculinos/femeninos; incidencia de malformaciones uro-genitales masculinas (hipospadias y criptorquidias); e incidencia de cánceres hormono-dependientes. Se seleccionaron cinco comunidades rurales de la Pampa Húmeda de Argentina, comparándose los datos obtenidos con medias nacionales. Los datos bio-médicos y las fuentes ambientales de riesgo fueron relacionados entre sí a través de un sistema de geo-referenciación. La relación de nacimientos no mostró significación. Las malformaciones presentaron una muy significativa incidencia. Los cánceres hormono-dependientes presentaron incidencia mayores a las medias nacionales, particularmente en algunas de las comunidades estudiadas. Se concluye que existe una relación entre condiciones de salud reproductiva y factores ambientales en esta región.<br>The relationship between environmental factors and health is well known. Rural environmental influences on reproductive health have been properly proved, both in animals and humans. In Latin America, few studies have been conducted in this area. The current project is based on the description of relationships between reproductive health and environmental factors in rural populations, characterized by specific environmental characteristics. Three variables were evaluated: male-to-female birth ratio, male urogenital malformations (cryptorchidism and hypospadias), and endocrine-related cancer incidence. Five rural communities in the Pampa Humeda in Argentina were selected, and the data were compared to the national mean. Biomedical data and environmental risk factors were correlated through a geographic information system. The ratio of male to female births did not show any differences. Malformations showed very significant differences. Endocrine-related cancers showed higher incidence rates compared to the national mean, particularly in some communities. In conclusion, there is a relationship between environmental factors and reproductive health conditions in this region

Early onset of puberty: Tracking genetic and environmental factors

Under physiological conditions, factors affecting the genetic control of hypothalamic functions are predominant in determining the individual variations in timing of pubertal onset. In pathological conditions, however, these variations can involve different genetic susceptibility and the interaction of environmental factors. The high incidence of precocious puberty in foreign children migrating to Belgium and the detection in their plasma of a long-lasting 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) residue suggest the potential role of environmental endocrine disrupting chemicals in the early onset of puberty. This hypothesis was confirmed by experimental data showing thattemporary exposure of immature female rats to DDT in vivo results in early onset of puberty. We compared the gene expression profile of hypothalamic hamartoma associated or not with precocious puberty in order to identify gene networks responsible for both hamartoma-dependent sexual precocity and the onset of normal human puberty. In conclusion, pathological variations in the timing of puberty may provide unique information about the interactions of either environmental conditions or genetic susceptibility with the hypothalamic mechanism controlling the onset of sexual maturation, as shown by examples of precocious puberty following exposure to endocrine disrupters or due to hypothalamic hamartoma. Copyright (c) 2005 S. Karger AG, Basel