997 resultados para Stone age.


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OBJECTIVES The effects of advancing paternal age on the male reproductive system are well known, but its effects on fecundity remain controversial. Although oxidative stress is associated with poor semen quality and function, a relationship with advancing male age has not been established. The objective of this study was to analyze the relationship between male age and seminal reactive oxygen species (ROS) levels in men presenting for voluntary sterilization. METHODS We prospectively evaluated 98 fertile men who were candidates for vasectomy. These were divided into 2 age groups: less than 40 years (n = 78) and 40 or more years (n = 20). We used 46 infertile patients as positive controls. Standard semen analysis, seminal leukocyte count and ROS levels were measured in all samples. Fertile men with leukocytospermia were excluded. RESULTS The mean age of the men was 35.1 +/- 5.6 years. Men 40 years and older had significantly higher ROS levels compared with younger men (P < 0.001). We observed a positive correlation between seminal ROS levels and age (r = 0.20; P = 0.040). In addition, ROS was negatively correlated with sperm concentration (r = -0-48; P < 0.001) and motility (r = -0.21; P = 0.030). CONCLUSIONS Reactive oxygen species levels are significant higher in seminal ejaculates of healthy fertile men older than 40 years. ROS levels in whole ejaculate are significantly correlated to age among fertile men. Because ROS are clearly implicated in the pathogenesis of male infertility, these data suggest that delayed fatherhood may reduce the chances of pregnancy as men become progressively less fertile with age.

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Adolescence is popularly understood as a transitional phase of turbulence and extremes. It is also often associated with 'trouble'. Criminal justice statistics, however, reveal that youth criminality remains a relatively rare phenomenon, less than one percent of the total adolescent population in any given year. This exceptional book is based upon a major Australian research programme to consider the key social factors impacting upon the lives of young people. A sample of 1,300 young people was divided into three major subgroups: a 'control' group, drawn from state secondary schools and closely approximating the general population; a chronically marginalized cohort representing a 'vulnerable group', and a group of offenders, most of whom were incarcerated at the time of the research.

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Objective(s): We intend to verify if fetal volume and crown-rump length were different between singletons and twins in pregnancies aged from 7 to 10 weeks and to evaluate if fetal volume is more accurate to determine the gestational age than crown-rump length at this gestational age. Study design: From 52 days (7 weeks and 3 days) to 73 days (10 weeks and 3 days) weekly three-dimensional Ultrasonography was per-formed in 20 twin fetuses and 20 singletons. Crown-rump length and fetal volume using VOCAL were assessed in all examinations. The `true` gestational age was based on oocyte retrieval. Results: At the age of 52 days, the crown-rump length was 11.74 +/- 0.27 mm (mean +/- S.D.) and 11.48 +/- 0.22 mm (singletons and twins, respectively), while the fetal volume was 0.354 +/- 0.015 cm(3) and 0.324 +/- 0.012 cm(3). At the gestational age of 73 days, the crown-rump length was 36.19 +/- 0.90 mm and 35.87 +/- 0.54 mm and the fetal volume was 6.204 +/- 0.090 cm(3) and 6.083 +/- 0.081 cm(3). The total relative increase observed was much higher for fetal volume than for CRL: 1705 +/- 301% vs. 210 +/- 33% in singletons and 1827 +/- 305% vs. 214 +/- 25% in twins. The 95% limits of agreement (+/- 2.3 days vs. +/- 3.2 days, fetal volume vs. crown-rump length) and the intraclass correlation coefficients (0.989 vs. 0.978) between the ""true"" gestational age and that predicted by fetal volume were better than those predicted by crown-rump length. No significant difference was identified between singletons and twins for both fetal volume and crown-rump length. Conclusion(s): Twins and singletons had similar fetal volume and crown-rump length between the 7th and 10th week of gestational age. Additionally, fetal volume assessed by VOCAL was better than crown-rump length to estimate the gestational age at the evaluated period. However, the improvement was small and probably without clinical significance. Condensation: Fetal volume and crown-rump length were similar between singletons and twins. Fetal volume relative increase was higher and the predicted gestational age was better. (c) 2009 Elsevier Ireland Ltd. All rights reserved.

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The present study aimed investigate the age and gender influence on maximal molar bite force and at outlining the criteria for normal masticatory muscle development in a sample of 177 Brazilian Caucasian dentate individuals aged 7-80 years divided into five age groups: I(7-12 years), II (13-20 years), III (21-40 years), IV (41-60 years), and V (61-80 years). Except for Group V, which comprised nine women and eight men, all groups were equally divided in respect to gender (20 M/20 F). Bite force was recorded with a mouth-adapted 1000 N dynamometer and the highest out of three records was regarded as the maximal bite force. The data were submitted to multivariate statistical analysis (SPSS 17.0 p < 0.05). Effects of group and gender were found, but no interactions between them. The ANOVA showed significant differences between groups bilaterally. Bonferroni`s test showed that group I had significantly lower bite force means at both sides as compared to all groups, except group V. No differences were found between the left and right sides. In all the groups, gender was found to be a significant factor associated with maximal bite force. A global comparison including all the subjects and measures showed that the means of men were approximately 30% higher than those of women, within-group comparisons yielded similar results in all groups. Muscle thickness was measured with a SonoSite Titan ultrasound tool using a high-resolution real-time 56 mm/10 MHz linear-array transducer. Three ultrasound images were obtained from the bilateral masseter and temporal muscles at rest and at maximal voluntary contraction. The means of the three measures in each clinical condition were analyzed with multivariate statistical analysis (SPSS 17.0 p < 0.05). A gradual increase in thickness of the masseter and temporal muscles was found both at rest and maximal voluntary contraction for groups I to IV, whereas a decrease in muscle thickness was observed in group V. Multivariate analysis showed that in both conditions there was an effect of group and gender. The study of the development of the stomatognathic system in relation to age and gender can provide useful data for the identification of normal and impaired functioning patterns. The results of this study indicate that age and gender are associated with structural and functional alterations in the muscles of the stomatognathic system. (C) 2010 Elsevier Ltd. All rights reserved.

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Context The association between large for gestational age (LGA) phenotype, postnatal growth and cardiometabolic risk (CMR) in adult life remains unclear. The role of IGF1 genotype on LGA-related outcomes in adult life is unknown. Aim To assess the postnatal growth, IGF-I levels, CMR and the influence of the 737.738 IGF1 in adults born LGA. Subjects Case-control study (n = 515) nested in a population-based prospective cohort (n = 2063); 117 LGA and 398 gender-matched controls appropriate for gestational age (AGA) subjects. Methods Anthropometry was evaluated at birth, at 9-10 and at 23-25 years old. At the age of 23-25 years, blood pressure (BP), glycaemia, insulinaemia, homeostasis model assessment - insulin resistance, lipids, fibrinogen, and plasma IGF-I and 737.738 IGF1 polymorphism were assessed. Results Large for gestational age subjects remained heavier and taller than AGA at 9-10 and 23-25 years (P < 0.05); at 23-25 years, LGA had greater waist circumference (WC; P < 0.05) and higher BP (P < 0.05) than controls. Body proportionality at birth did not predict metabolic outcome. LGA subjects presenting catch-down of weight in childhood had lower body mass index (BMI; P = 0.001), lower WC (P < 0.05) and lower BP (P < 0.05) at 2325 years. 737.738 IGF-I genotype differed between groups (P < 0.001). Homozygosis for polymorphic alleles was associated with increased odds of LGA (OR: 3.2; 95% CI: 1.5-6.9), higher IGF-I (56.9 +/- 16.4 vs 37.7 +/- 16.0 nm; P < 0.01) and lower BP (114/68 vs 121/73 mmHg; P < 0.05). Conclusions Young adults born LGA presented higher BMI, WC and BP and appear to be at higher CMR risk than AGA subjects. The 737.738 IGF1 polymorphism appears to play a role on birth size and LGA-related metabolic outcomes.

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There is evidence that intrauterine growth restriction, resulting in newborn girls that are small for gestational age (SGA), may be related to the onset of polycystic ovary syndrome (PCOS). Thus, we studied whether women born SGA have a higher prevalence of PCOS than women born appropriate for gestational age (AGA). This was a prospective birth cohort study of 384 women born at term between June 1, 1978, and May 31, 1979, in Ribeirao Preto, Brazil. After exclusion, 165 women effectively participated in this study, of whom 43 were SGA and 122 were AGA. The prevalence of PCOS was analysed. At a mean age of 29 years, the women agreed to follow the study protocol, which included: anamnesis, physical examination, serum tests [follicle stimulating hormone, luteinizing hormone, total and free testosterone, dehydroepiandrostenedione sulphate, 17-OH-progesterone, fasting insulin, sex steroid-binding globulin (SHBG) and fasting glucose] and pelvic ultrasound. Data regarding gestational age, birthweight, age at menarche and maternal data were obtained from the files of the cohort. The adjusted relative risk (RR) values of the SGA, insulin resistance, body mass index, maternal smoking and parity variables were analysed using Poisson regression with robust adjustment of variance for the prediction of PCOS. The prevalence of PCOS was higher in the SGA group than in the AGA group [adjusted RR = 2.44, 95% CI (1.39-4.28)]. Hyperandrogenism was more prevalent in the SGA women than in the AGA women (P = 0.011). Circulating SHBG was lower in the SGA women than in the AGA women (P = 0.041), but fasting insulinemia was similar in both groups. The prevalence of PCOS in SGA women was twice as high as in AGA women in our study population.

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Objective: To assess whether the -11391G > A polymorphism in the regulatory region of the adiponectin gene (ADIPOQ) is associated with birth size, postnatal growth, adiponectinemia, and cardiometabolic risk in adult life. Design: Case-control study nested within a prospective cohort of 2063 community subjects born in 1978/1979 and followed since birth to date. Methods: ADIPOQ -11391G > A genotype-phenotype associations were evaluated in 116 subjects born large for gestational age (LGA) and 392 gender-matched controls at birth (birth size), at 8-10 years (catch-down growth), and at 23-25 years of age (cardiometabolic profile). Results: The -11391A variant allele frequency was higher in LGA subjects (P=0.04). AA genotype was associated with augmented probability of being born LGA (odds ratio=4.14; 95% confidence interval: 1.16-16.7; P=0.03). This polymorphism was associated neither with body composition nor with postnatal growth pattern. At the age of 23-25 years, the -11391A variant allele was associated with higher serum adiponectin levels (GG: 10.7 +/- 6.2 versus GA: 12.2 +/- 6.5 versus AA: 14.2 +/- 6.8 mu g/ml; P < 0.01). Subjects born LGA presented higher body mass index (BMI; P=0.01), abdominal circumference (P=0.04), blood pressure (P=0.04), and homeostasis assessment model for insulin resistance (P=0.01) than adequate for gestational age. Symmetry at birth did not influence these variables. The occurrence of catch-down of weight was associated with lower BMI and abdominal circumference (P < 0.001) at 23-25 years. Conclusions: The -11391A ADIPOQ gene variant was associated with increased chance of being born LGA and with higher adiponectin levels in early adult life.

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Objective: This study aimed to assess the relative validity of a food frequency questionnaire.(FFQ), previously validated to measure usual intakes in adults, for measuring dietary intakes in children 5 to 10 y of age. Methods: Dietary intakes were measured using an FFQ and a 3-d dietary record. Healthy children, 5 to 10 y old (n = 151), were recruited from public schools and asked to answer the questions in the FFQ and to provide non-consecutive 3-d dietary records based on reported estimated portion sizes. Paired sample t tests and Pearson`s correlation coefficients were conducted to determine whether the two instruments reported similar values for energy and nutrients. The agreement of quartile categorization between the two instruments was also examined. Results: Estimated energy and nutrient intakes derived from the FFQ were significantly higher than those derived from 3-d dietary records. As expected, Pearson`s correlations increased after adjusting for residual measurement error, presumably due to exclusion of the high within-person variability in intake of these nutrients. Moderate to high (r > 0.50) correlation coefficients were verified for some nutrients such as calcium, folate, vitamin 132, vitamin A, and vitamin C. Conclusion: This FFQ, originally developed for use in adults, appears to overestimate usual energy and nutrient intakes in children 5 to 10 y of age. Further work is necessary to conduct a calibration study to establish adequate portion sizes before instrument adoption in this population. (c) 2008 Elsevier Inc. All rights reserved.