This study examined links between adolescent depressive symptoms, actual pubertal development, perceived pubertal timing relative to one’s peers, adolescent-maternal relationship satisfaction, and couple sexual behavior. Assessments of these variables were made on each couple member separately and then these variables were used to predict the sexual activity of the couple. Participants were drawn from the National Longitudinal Study of Adolescent Health (Add Health; Bearman et al., 1997; Udry, 1997) data set (N = 20,088; aged 12-18 years). Dimensions of adolescent romantic experiences using the total sample were described and then a subsample of romantically paired adolescents (n = 1,252) were used to test a risk and protective model for predicting couple sexual behavior using the factors noted above. Relevant measures from the Wave 1 Add Health measures were used. Most of the items used in Add Health to assess romantic relationship experiences, adolescent depressive symptoms, pubertal development (actual and perceived), adolescent-maternal relationship satisfaction, and couple sexual behavior were drawn from other national surveys or from scales with well documented psychometric properties. Results demonstrated that romantic relationships are part of most adolescents’ lives and that adolescents’ experiences with these relationships differ markedly by age, sex, and race/ethnicity. Further, each respective couple member’s pubertal development, perceived pubertal timing, and maternal relationship satisfaction were useful in predicting sexual risk-promoting and risk-reducing behaviors in adolescent romantic couples. Findings in this dissertation represent an initial step toward evaluating explanatory models of adolescent couple sexual behavior.

Age at the initiation of puberty and at menarche are key maturational indicators. They reflect health both within and between populations; in that a declining average age is associated with improving health, nutrition, and socio-economic conditions. Knowledge of the timing of pubertal development and menarche is important as earlier development within a population, in particular, has been linked with an increased risk of negative sequelae including overweight and obesity, development of risk factors for non-communicable diseases such as hypertension and insulin resistance, and engagement in risk behaviours such as early sexual debut and substance abuse. The main aims of this study were to investigate the timing of, and the early life factors (such as body composition and growth velocities) associated with pubertal development and age at menarche in Black and White urban South African adolescents. Mixed-longitudinal data (n = 401) from the Birth to Twenty (Bt20) birth-cohort study, initiated in 1990 and set in SowetoJohannesburg, South Africa were used. Median age at the initation of puberty and at menarche was derived by fitting logistic curves to cumulative frequency plots. Logistic regression models were constructed to examine the early life predictors of the timing of puberty and menarche. Data were also collected from adolescents and Bt20 staff (n = 72) using focus groups to explore views on the pubertal development questionnaire used in the Bt20 study. Median age at the initiation of genitalia development was 10.4 years (95% Cl = 8.4, 12.4) for Black boys and 9.8 years (95% Cl = 9.4, 10.2) for White boys. Median age for the initiation of pubic hair development for Black males was 10.8 years (95% Cl = 9.6, 12.0) compared to White males, which was 10.2 years (95% Cl = 8.4, 12.0). Median age at the initiation of breast development in Black females was 10.1 years (95% Cl = 9.3, 10.9) compared to White females which was 10.2 years (95% Cl = 8.2, 12.2). Median age for the initiation of pubic hair was 10.3 years (95% Cl = 9.3, 11.3) and 10.5 years (95% Cl = 8.7, 12.3) for Black and White girls, respectively. Results from logistic regression showed that a greater weight and height velocity in late childhood significantly increased the odds of achieving early breasU genitalia development. Furthermore, a low socio-economic status (SES) index at 9/10 years significantly reduced the odds of achieving early breasUgenitalia development. A greater weight, height, body mass index (BM I), and growth rate during infancy and childhood significantly increased the odds of achieving early pubic hair development. Median age at menarche for Black females was 12.4 years (95% Cl = 12.2, 12.6) and 12.5 . years (95% Cl = 11.7,13.3) for White females. Average menarcheal age for Black girls has declined by 0.56 years per decade and 0.32 years for White girls in South Africa, when comparing the current study findings with those from previous studies. Results from logistic regression showed that being taller, fatter and heavier in late childhood significantly increased the odds of achieving earlier menarche. The focus groups provided a range of opinions relating to the Bt20 pubertal development questionnaire and procedure. The majority of views were positive and included the ease of understanding and completion of the tool. Negative views revolved around the language used and privacy issues. These qualitative results provided a unique insight into the way in which pubertal development data are assessed and how these methods can potentially be improved to enhance the reliability and accuracy of pubertal development data collection. The results from this study provide the most recent estimates of age at the. initiation of puberty and age at menarche for urban Black and White South African adolescents. This is particularly important given the social, nutritional, and economic transition currently occurring in this country as these key maturity indicators reflect population health. This study has also added to our knowledge of the factors that are associated with pubertal development, showing that proximate rather than distal factors are the most sensitive indicators in this urban transitioning environment. In addition, the results from the focus groups provided a unique insight into how pubertal development data are assessed and how these methods could be improved. The negative health outcomes which have been associated with earlier pubertal development and age at menarche are major public health concerns, particularly in the South African context given the HIV/AIDS epidemic and rising levels of obesity. This study highlights the need for renewed research and resources for intervention strategies and policy programmes which target appropriate sex and obesity education in urban South African children.

STUDENT NUMBER: 0301561E MASTERS OF EDUCATION FACULTY OF HUMANITIES-DISCIPLINE OF SPECIALISED EDUCATION / The purpose of this study was to examine whether: actual and ideal body mass index (BMI) scores, perception of a weight problem, racial identity, physical exercise, weight control behaviour and stage of pubertal development predict levels of global self-esteem in average academic achieving English speaking middle-class adolescent females. The sample consisted of 90 females, ranging in age from 13 years 3 months to 18 years 7 months who were attending Benoni High School. BMI was measured and desired BMI based on self-reported weight and height. Self-perception of having a weight problem was evaluated by one question: “Do you see yourself as having a weight problem?” Self-esteem was measured in two ways: firstly participants completed the Rosenburg Self-esteem Scale and secondly homeroom teachers were asked to give a score of global self-esteem. A significant association was found between global self-esteem and: a perceived weight problem, actual BMI and race. No significant association was found between global self-esteem and: weight control behaviour; physical exercise, age of menarcheal onset and ideal BMI. KEY WORDS Global self-esteem, adolescent females, BMI, racial identity, weight control behaviour, physical exercise and pubertal development

<p>This thesis tested and extended the peer socialization hypothesis, a psychosocial model that identifies the interpersonal and contextual conditions in which pubertal development is linked to delinquent behavior such as alcohol use. Although there is support for the hypothesis in early empirical work, particularly for female adolescents, more recent work has shown mixed results. Furthermore, there are gaps within the peer socialization hypothesis: a) the theory does not discuss if the mediation process pertains to male adolescents, b) it does not address the role of pubertal tempo, and c) it implies, but does not explicitly model, a role for tempo with regards to including other-sex friendships into the friend group. Using the Internet Surveys About You (iSAY) study (<em>n</em>=1020), the peer socialization hypothesis and proposed extensions were tested separately by sex. Female adolescents initiated inclusion of other-sex friends into the friend group earlier than male adolescents. However, there were no observed sex differences in the tempo of other-sex friendships. Female adolescents’ pubertal development was not related to their other-sex friendship development nor was pubertal development and other-sex friendship development related to their alcohol use. Male adolescents’ pubertal timing was associated with the timing of other-sex friendship uptake in that later maturing adolescents displayed earlier initiation of other-sex friendships. Male adolescents’ other-sex friendship development was not related to their alcohol use. Implications of this work are that other-sex friendships may no longer be a context of increased risk for alcohol use for early maturing adolescents and interventions targeting this social context may not be as effective. </p>

A crescente prevalência de diabetes mellitus (DM) em nível mundial, a sua incidência cada vez maior em crianças e adolescentes e resultados prévios obtidos em nosso laboratório (piora do quadro diabético em ratos na puberdade) nos levaram a investigar o metabolismo de glicose em tecido adiposo branco na puberdade em ratos controle (CO) e intolerantes à glicose (STZ). Parâmetros de desenvolvimento corporal e maturação sexual foram estudados entre a 5ª e a 10ª semanas de vida dos animais, identificando-se a 6ª e 7ª semanas como importante fase da puberdade. Desta forma, os estudos metabólicos foram realizados neste período. Os animais CO apresentaram franca resistência à insulina no período da puberdade, com prejuízos no metabolismo de glicose em adipócitos isolados. A injeção de estreptozotocina no quinto dia de vida produziu um quadro de intolerância à glicose em nossos animais, resultando em atraso no início do estirão de crescimento e desenvolvimento sexual. A resistência fisiológica à insulina da puberdade não produziu piora da resposta à insulina no tecido adiposo branco. / The growth in the prevalence of diabetes mellitus (DM), a larger incidence of type 1 and 2 DM in children and adolescents and the previous results of our laboratory (worsening of the metabolic picture in diabetic rats during puberty) motivate us to study the glucose metabolism in the puberty in order to assess the possible influence of the physiological insulin resistance characteristic of this period on the course of the diabetic status. Five-day old male Wistar rats were divided into two experimental groups: control group (CO) and streptozotocin group (STZ). Body development and sexual maturation were weekly evaluated between the 5th and 10th weeks of life. We identify the 6th and 7th weeks as an important early phase of the puberty. The insulin resistance and a slight degree of glucose intolerance were determined in non-diabetic rats. On the other hand, STZ group showed insulin resistance and it was impaired in the course of puberty suggesting that the developing of this resistance during the puberty presents a different characteristic of that seen in normal rats.

<p>Fifty children with hematologic malignancies have been treated with autologous BMT in Uppsala. The aim was to describe late effects in this group with special reference to cataracts, reduced final height, and to hepatic, renal, and pulmonary late effects. </p><p>Cataracts: All patients who received TBI in their conditioning developed posterior subcapsular cataract after BMT. A few patients with visual impairment affecting daily life needed cataract surgery, whereas the visual acuity was well preserved in most of the other patients.</p><p>Final height: There was a decrease in final height relative both to height at BMT and to target height. This decrease was significant both in those who had received TBI only and in those who had been given cranial irradiation. Cranial irradiation, young age at BMT, and short duration of GH treatment were predictors of height loss. </p><p>Hepatic function: Hepatic function was well preserved over a period of 10 years after BMT. TBI did not appear to be a risk factor for hepatic impairment. </p><p>Renal function: Six months after BMT there was a decrease in renal function in patients who had received TBI. It then recovered, albeit incompletely, and stabilized. After the first year there was little change over a period of 10 years after BMT. TBI appeared to be the most important risk factor for the development of chronic renal impairment in a number of patients. Nephrotoxic antibiotics may have contributed.</p><p>Pulmonary function: Six months after BMT there was a decrease in pulmonary function in those who received TBI. It then recovered and stabilized at the pretransplant level. After the first year there was little change over a period of 10 years after BMT. TBI appeared to be the most important risk factor for restrictive pulmonary disease in a number of patients whereas chemotherapy might also have been of importance for impaired gas exchange.</p>

Fifty children with hematologic malignancies have been treated with autologous BMT in Uppsala. The aim was to describe late effects in this group with special reference to cataracts, reduced final height, and to hepatic, renal, and pulmonary late effects. Cataracts: All patients who received TBI in their conditioning developed posterior subcapsular cataract after BMT. A few patients with visual impairment affecting daily life needed cataract surgery, whereas the visual acuity was well preserved in most of the other patients. Final height: There was a decrease in final height relative both to height at BMT and to target height. This decrease was significant both in those who had received TBI only and in those who had been given cranial irradiation. Cranial irradiation, young age at BMT, and short duration of GH treatment were predictors of height loss. Hepatic function: Hepatic function was well preserved over a period of 10 years after BMT. TBI did not appear to be a risk factor for hepatic impairment. Renal function: Six months after BMT there was a decrease in renal function in patients who had received TBI. It then recovered, albeit incompletely, and stabilized. After the first year there was little change over a period of 10 years after BMT. TBI appeared to be the most important risk factor for the development of chronic renal impairment in a number of patients. Nephrotoxic antibiotics may have contributed. Pulmonary function: Six months after BMT there was a decrease in pulmonary function in those who received TBI. It then recovered and stabilized at the pretransplant level. After the first year there was little change over a period of 10 years after BMT. TBI appeared to be the most important risk factor for restrictive pulmonary disease in a number of patients whereas chemotherapy might also have been of importance for impaired gas exchange.

A crescente prevalência de diabetes mellitus (DM) em nível mundial, a sua incidência cada vez maior em crianças e adolescentes e resultados prévios obtidos em nosso laboratório (piora do quadro diabético em ratos na puberdade) nos levaram a investigar o metabolismo de glicose em tecido adiposo branco na puberdade em ratos controle (CO) e intolerantes à glicose (STZ). Parâmetros de desenvolvimento corporal e maturação sexual foram estudados entre a 5ª e a 10ª semanas de vida dos animais, identificando-se a 6ª e 7ª semanas como importante fase da puberdade. Desta forma, os estudos metabólicos foram realizados neste período. Os animais CO apresentaram franca resistência à insulina no período da puberdade, com prejuízos no metabolismo de glicose em adipócitos isolados. A injeção de estreptozotocina no quinto dia de vida produziu um quadro de intolerância à glicose em nossos animais, resultando em atraso no início do estirão de crescimento e desenvolvimento sexual. A resistência fisiológica à insulina da puberdade não produziu piora da resposta à insulina no tecido adiposo branco. / The growth in the prevalence of diabetes mellitus (DM), a larger incidence of type 1 and 2 DM in children and adolescents and the previous results of our laboratory (worsening of the metabolic picture in diabetic rats during puberty) motivate us to study the glucose metabolism in the puberty in order to assess the possible influence of the physiological insulin resistance characteristic of this period on the course of the diabetic status. Five-day old male Wistar rats were divided into two experimental groups: control group (CO) and streptozotocin group (STZ). Body development and sexual maturation were weekly evaluated between the 5th and 10th weeks of life. We identify the 6th and 7th weeks as an important early phase of the puberty. The insulin resistance and a slight degree of glucose intolerance were determined in non-diabetic rats. On the other hand, STZ group showed insulin resistance and it was impaired in the course of puberty suggesting that the developing of this resistance during the puberty presents a different characteristic of that seen in normal rats.

Les défauts d’odeurs, liés à l’accumulation d’androsténone et de scatol dans le tissu adipeux, sont le frein majeur à l’élevage des porcs mâles entiers. L’androsténone est produite par les testicules et le scatol dans le colon. En dehors de la génétique et de l’alimentation, les facteurs de variation ont été peu étudiés.La thèse aborde le problème des odeurs sexuelles sous quatre angles : 1) estimer l’héritabilité des composés odorants du tissu gras et leurs corrélations génétiques avec des indicateurs de santé, du développement sexuel et de l’agressivité ; 2) étudier l’effet de la dominance sur ces composés ; 3) déterminer l’impact d’un état inflammatoire chronique modéré sur le développement sexuel et la concentration en androsténone ; 4) rechercher les effets de conditions d’hygiène contrastées sur la teneur en scatol et analyser l’implication du microbiote intestinalNos résultats confirment l’héritabilité forte des teneurs en composés odorants mais les corrélations génétiques avec les paramètres de santé sont faibles. Une sélection pour réduire la concentration plasmatique en œstradiol et testostérone permettrait de réduire à la fois les teneurs en composés odorants et l’agressivité des porcs. Les porcs de rang de dominance élevé ont une teneur en androsténone supérieure dans le gras. Un état inflammatoire chronique modéré ne semble pas affecter la teneur en androsténone. Enfin, la dégradation de l’hygiène du logement augmente fortement la concentration en scatol, probablement via des changements de composition du microbiote intestinal. / Boar taint, due to the accumulation of androstenone and skatole in the fat tissue, is the major constraint to the production of entire male pigs. Androstenone is produced by the testes. Its synthesis increases during pubertal development. Skatole is produced in the hind gut. Its hepatic catabolism is inhibited by sexual steroids. Apart from genetics and feeding, the factors affecting boar taint have been little studied.The current thesis approaches four aspects of the boar taint problem: 1) the heritability of the fat content of odorous compounds in the fat tissue and their genetic correlations with indicators of health, sexual development and aggressiveness; 2) to study the effect of dominance on the fat content of boar taint compounds; 3) to determine the influence of a moderate chronic inflammatory status on the sexual development and the fat concentration in androstenone; 4) to evaluate the effect of contrasting hygiene conditions on the fat concentration in skatole and, to analyOur results confirm the high heritability of the fat concentrations of boar taint compounds but their genetic correlations with health indicators are low. A selection to decrease the plasma concentrations in estradiol and testosterone should decrease both boar taint compound concentrations and aggressiveness of boars. Boars with a high dominance rank have a higher fat concentration in androstenone. Lastly, the degradation of the housing hygiene conditions strongly increases the concentration in skatole, probably through modifications in gut microbiota composition

El estudio KIDSCREEN Seguimiento analizó los cambios en la calidad de vida relacionada con la salud (CVRS) en una muestra representativa de niños y adolescentes españoles de 8 a 18 años de edad y sus padres, que contestaron un cuestionario inicial vía postal en 2003 y el de seguimiento en 2006. Además se estudiaron los cambios en salud mental y su impacto sobre la CVRS, así como los factores predictivos del uso de servicios sanitarios. La mayoría de dimensiones de la CVRS presentó un empeoramiento moderado y generalizado, sobre todo en las niñas y en la etapa puberal. El empeoramiento en la salud mental se asoció a un mayor deterioro de la CVRS. En general, la declaración de morbilidad fue el factor con mayor poder predictivo del uso de servicios sanitarios a los 3 años de seguimiento. Algunos factores socioeconómicos fueron determinantes del acceso al especialista y el dentista. / The KIDSCREEN Follow-up study analysed changes in health-related quality of life (HRQL) in a representative sample of Spanish children and adolescents from 8 to 18 years old and their parents and who answered a mail-posted questionnaire at the baseline (2003) and follow-up (2006). In addition changes in mental health and its impact on changes on HRQL and predictors of healthcare services use were analysed. Most of the dimensions of HRQL showed a generalized and moderate worsening, especially amongst girls at the pubertal phase. The worsening in mental health was associated with a higher deterioration in HRQL. In general, the strongest predictive factor on the use of healthcare services was reporting morbidity. Some socioeconomic factors determined the access to specialists and dentist.