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Pubertal Maturation (pubertal + maturation)
Selected Abstracts[Commentary] EARLY PUBERTAL MATURATION AND DRUG USE: UNDERLYING MECHANISMSADDICTION, Issue 1 2009RUTGER C. M. E. ENGELS No abstract is available for this article. [source] Growth and Lipid Metabolism in Girls and Young Women with Epilepsy during Pubertal MaturationEPILEPSIA, Issue 7 2005Kirsi Mikkonen Summary:,Purpose: To assess growth and the serum lipid profile in girls with epilepsy receiving monotherapy at a mean age of 12.6 years and approximately 6 years later. Methods: A population-based cohort of 77 girls with epilepsy and 49 healthy controls participated in this follow-up study including two cross-sectional evaluations (age range, 8,18.5 years on the first evaluation, and 12.5,25.8 years on the second evaluation). Forty of the patients were initially taking valproate (VPA), 19, carbamazepine (CBZ), and 18, oxcarbazepine (OXC). Growth data were compiled, body mass index (BMI) was calculated, and serum total (TC), and high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) cholesterol and triglyceride concentrations were analyzed. Results: Linear growth and final height did not differ between the patients and the controls. At follow-up, the mean BMI of the patients who were off medication (61%) was similar to that of the controls, whereas the patients initially treated with VPA who were still taking any medication had a higher BMI. On the first evaluation, the patients taking VPA had low serum HDL-C, and those taking CBZ or OXC had high serum TC and LDL-C concentrations. At follow-up, serum lipid levels were similar in the patients off medication and the controls. Conclusions: Neither epilepsy nor antiepileptic therapy affects linear growth or final height, but they may have unfavorable effects on body weight and serum lipid concentrations. Lipid-profile impairment seems to be transient if the medication is discontinued. Overweight is common in patients treated with VPA during puberty if epilepsy and medication continue into adulthood. [source] Pubertal maturation modifies the regulation of insulin-like growth factor-I receptor signaling by estradiol in the rat prefrontal cortexDEVELOPMENTAL NEUROBIOLOGY, Issue 8 2008Amaya Sanz Abstract The transition from adolescence to adulthood is accompanied by substantial plastic modifications in the cerebral cortex, including changes in the growth and retraction of neuronal processes and in the rate of synaptic formation and neuronal loss. Some of these plastic changes are prevented in female rats by prepubertal ovariectomy. The ovarian hormone estradiol modulates neuronal differentiation and survival and these effects are in part mediated by the interaction with insulin-like growth factor-I (IGF-I). In this study, we have explored whether the activation by estradiol of some components of IGF-I receptor signaling is altered in the prefrontal cortex during puberty. Estradiol administration to rats ovariectomized after puberty resulted, 24 h after the hormonal administration, in a sustained phosphorylation of Akt and glycogen synthase kinase 3, in the prefrontal cortex. However, this hormonal effect was not observed in animals ovariectomized before puberty. These findings suggest that during pubertal maturation there is a programming by ovarian hormones of the future regulatory actions of estradiol on IGF-I receptor signaling in the prefrontal cortex. The modification in the regulation of IGF-I receptor signaling by estradiol during pubertal maturation may have implications for the developmental changes occurring in the prefrontal cortex in the transition from adolescence to adulthood. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008. [source] Early pubertal maturation in the prediction of early adult substance use: a prospective studyADDICTION, Issue 1 2009Mohammad R. Hayatbakhsh ABSTRACT Aims To examine whether self-reporting a later stage of pubertal development in early adolescence predicts young adults' use of illicit drugs. Design Population-based prospective birth cohort study. Setting Follow-up of a cohort of mothers and their children, recruited between 1981 and 1983. Participants Cohort of 2710 young adults who completed a self-report questionnaire about their use of cannabis and amphetamines at the 21-year follow-up. Measurements Young adults' use of cannabis and amphetamines were measured at the 21-year follow-up. Stage of pubertal development was assessed at the 14-year follow-up. Potential confounding and mediating variables were assessed between birth and when the child was 14 years. Findings Of 2710 young adults, 49.9% (47.3 females and 52.7% males) reported that they had used cannabis and 21.0% (18.9% females and 23.3% males) reported that they had used amphetamines and cannabis by 21 years. In multivariate analyses, adolescents with a later stage of puberty were more likely to use cannabis or amphetamines in young adulthood. This association was not confounded by mother's education or child's gender and age. Part of the relationship was explained by the higher frequency of child externalizing behaviour at 14 years. Conclusions The findings warrant further attention to puberty as a sensitive period in an individual's development. With regard to prevention, there is a need to understand more about the pathways between pubertal development, child behaviour problems and substance use. [source] Pubertal Maturation Characteristics and the Rate of Bone Mass Development Longitudinally Toward MenarcheJOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2001Silvia C. C. M. Van Coeverden Abstract To assess risks for osteoporosis and to compare bone mass in different groups of healthy children or children with diseases, it is important to have knowledge of their sexual maturation status during puberty. The aim of our study was to evaluate bone mass formation longitudinally in relation to pubertal maturation characteristics in healthy white girls. We investigated the bone mineral content (BMC) and the bone mineral density (BMD) at different skeletal sites in 151 girls with increasing pubertal stages in relation with their chronological age and with an early or late onset of puberty or menarche and with a slow or fast maturation. Bone mass was measured at the onset of puberty, during puberty, and at menarche. We conclude the following: (1) from midpuberty to menarche, the increase in bone mass formation is highest at all skeletal sites in white girls; (2) early mature girls at the onset of puberty have slightly but definitely lower bone masses at all skeletal sites and at all pubertal stages than late mature girls, whereas the average bone mass formation from the onset of puberty to menarche is similar in both groups; (3) girls with a slow rate of pubertal maturation have lower bone mass values 2 years after the onset of puberty, but at menarche bone mass is similar compared with fast maturers; and (4) it cannot be confirmed that there is an effect of menarcheal age on bone mass values at menarche. [source] Is puberty starting earlier in urban South Africa?AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2009Laura L. Jones Age at the initation of pubertal development was estimated for 401 Black (212 boys) and 206 White (100 boys) urban South African adolescents born in Soweto-Johannesburg in 1990. Average age at the initation of puberty, assessed by age at the transition from Tanner Stage 1 to Tanner Stage 2 for breast/genitalia or pubic hair development ranged between 9.8 and 10.5 years. There were no statistically significant differences in age at initiation between genders or ethnic groups. Age at the initation of pubertal development has remained stable over the last 10 to 15 years, with the exception of pubic hair in boys which has declined on average 1.3 years over a decade. There is evidence to suggest that the tempo of pubertal maturation is increasing in girls born in the Soweto-Johannesburg area, however, the evidence is less clear for boys. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. [source] Association of maturation, sex, and body fat in cardiorespiratory fitnessAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 6 2002Jorge Mota The aims of this cross-sectional study were 1) to estimate changes in body composition and cardiorespiratory fitness across stages of pubertal maturation, and 2) to describe the relationship between maturity status and body fatness, regional fat distribution, and cardiorespiratory fitness. The sample consisted of 494 children (254 males, 240 females), 8,16 years of age. Height and weight were measured with standard anthropometric methods. Percentage of fat (%F) was estimated from two skinfold thicknesses and regional fat distribution was estimated by the ratio of the subscapular to the triceps skinfold (S/T ratio). Biological maturity was based on self-assessment of breast stages in females and pubic hair stages in males. A maximal multistage 20-m shuttle run was used to predict maximal aerobic capacity from maximal aerobic speed. Both VO2max and 20SRT-time were used as indicators of cardiorespiratory fitness. ANCOVA with age as the covariate was used. There were significant differences among girls across pubertal stages. Among boys, only weight and height differed significantly by stage of maturity. When adjusted for maturity status, cardiorespiratory fitness expressed either as VO2/kg body mass or 20SRT-time was inversely associated with %F in both sexes. This suggests that sexual maturity status alone accounts for a small portion of the variance in aerobic fitness. Height, %F and the S/T ratio were also significantly associated with VO2/kg body mass and 20SRT-time. Am. J. Hum. Biol. 14:707,712, 2002. © 2002 Wiley-Liss, Inc. [source] Estrogen/isoflavone interactions in cynomolgus macaques (Macaca fascicularis)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 9 2009J. Mark Cline Abstract Soy isoflavones are phytoestrogenic components of dietary soy, which are widely consumed for their potential health benefits. Soy isoflavones appear to decrease breast and endometrial cancer risk in human observational studies, but paradoxically stimulate growth of breast cancer cells in culture and uterine enlargement in rodents. We have shown that these compounds are not estrogenic in cynomolgus monkeys even at relatively high doses, but that they reduce estrogen-induced proliferative responses of the breast and endometrium. This effect may be mediated through estrogen receptor interactions and/or modulation of endogenous estrogen metabolism. Interindividual variation in isoflavone absorption and metabolism contributes to the degree of estrogen antagonistic effect. Our recent studies have also shown that individual isoflavone metabolites such as glyceollins may have unique selective estrogen receptor modulator-like activity, acting as tissue-specific antagonists without agonist activity. Rodent studies and human epidemiologic data suggest that timing of exposure and dose relative to endogenous estrogen concentrations are important determinants of effect, and studies of dietary soy on breast development and pubertal maturation are under way. Because soy isoflavones are both abundant in standard monkey chow diets and widely available as dietary supplements for human beings, these findings have broad relevance to the health of human and nonhuman primates. Am. J. Primatol. 71:722,731, 2009. © 2009 Wiley-Liss, Inc. [source] Psychosocial Antecedents of Variation in Girls' Pubertal Timing: Maternal Depression, Stepfather Presence, and Marital and Family StressCHILD DEVELOPMENT, Issue 2 2000Bruce J. Ellis Drawing on Belsky, Steinberg, and Draper's evolutionary theory of the development of reproductive strategies, we tested a model of individual differences in girls' pubertal timing. This model posits that a history of psychopathology in mothers results in earlier pubertal maturation in daughters, and that this effect is mediated by discordant family relationships and father absence/stepfather presence. The model was supported in a short-term longitudinal study of 87 adolescent girls. In the primary test of the model, it was found that a history of mood disorders in mothers predicted earlier pubertal timing in daughters, and this relation was fully mediated by dyadic stress and biological father absence. In families in which the mother's romantic partner was not the biological father, dyadic stress accounted for almost half of the variation in daughters' pubertal timing. Stepfather presence, rather than biological father absence, best accounted for earlier pubertal maturation in girls living apart from their biological fathers. We propose that stepfather presence and stressful family relationships constitute separate paths to early pubertal maturation in girls. 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