The shift to group-housing of the breeding herd makes it difficult to manage animals individually. To maximize sow longevity and reproductive performance, gilts must be bred on second heat weighing between 135 and 160 kg. As gilts are typically fed ad libitum (AD), they often exceed targeted breeding weights, leading to structural and other problems resulting in culling at early parities. Thus, utilization of an electronic sow feeder (ESF) enables caretakers to manage animals individually in group-housing situations, by allotting predetermined amounts of feed. The specific objectives of this study were to: 1) to determine the effects of AD or restricted (RS) feeding bases (FB) on growth and sexual development in replacement gilts using an ESF; 2) to determine the growth and reproductive responses to gonadotropins in gilts fed on either AD or RS feeding bases using an ESF; and 3) to ascertain the effects of short-term increases in feed allowances on growth and sexual development in previously feed-restricted gilts using an ESF. Gilts employed in all studies were acclimated to an ESF (ACCUTEAM, Osborne Industries, Osborne, KS) beginning at 150 d of age, during a 10-d training period. Across all experiments, treatments were assigned at 160 d of age. In experiments 1 and 2, gilts received feed on either AD (5.00 kg/d) or RS (2.72 kg/d) bases. In the first study, estrus detection began at 160 d of age. In experiment 2, gilts assigned to receive gonadotropins were treated at 170 d of age, with estrus detection beginning the next d. Gilts fed on the RS basis were observed to have improved feed conversion efficiency compared to AD-fed gilts in experiments 1 and 2 (both P < 0.01); and flushed gilts in experiment 3 had G: F similar to RS gilts. Average daily gain was not affected by FB in the first and third experiments, however AD-fed gilts gained weight at a faster rate (P = 0.02) than RS gilts in experiment 2. Gilts fed AD consumed their allotments across more meals than those fed RS. Age at puberty onset was not affected by FB in any of the experiments. Further, P.G. 600 did not hasten the onset of puberty, irrespective of FB in experiment 2. In experiment 3, ovulation rate was numerically greatest for flushed gilts, and was significantly greater than RS gilts (P = 0.05). The ovulation rate for flushed gilts was similar to AD gilts. Across all experiments, feed disappearance was observed to decrease as AD-fed gilts approached estrus. In this series of experiments, FB did not alter puberty onset, however ovulation rate was increased when gilts were allocated short-term increases in feed allowances. Further, utilizing an ESF may augment current industry estrus detection methods by monitoring feeding behavior. / Doctor of Philosophy / On commercial swine operations in the U.S. sow removal rates due to death and culling exceed 40% annually. On average, sows are culled at parity 3 or 4, while at least this many parities are required before investment costs are recouped. Gilts are typically fed AD until BW of 135 kg are attained by approximately 200 d of age. Oftentimes, gilts fed on AD basis exceed targeted breeding weights, leading to structural and other problems resulting in culling at early parities. To improve sustainability and competitiveness of pork production systems, the industry must focus on proper gilt management practices to facilitate successful entry into the breeding herd and increase longevity and lifetime performance as sows. A series of 3 experiments were conducted to evaluate different feeding bases on growth and sexual development in gilts. The first experiment evaluated the impact of AD or RS feeding on growth and sexual development in gilts using an ESF. Age at puberty was not different in limit-fed gilts. Limit-fed gilts also grew at a similar rate accompanied with improved feed conversion compared to AD fed gilts. Results from this experiment indicate that gilts can be limit-fed prior during the period around puberty until entering the breeding herd without negative impacts to growth or sexual development. In the second experiment, the same feeding bases were utilized, but within feeding basis groups, gilts either received or did not receive treatment with exogenous gonadotropins. Age at puberty was similar, regardless of feeding basis or gonadotropin treatment. Feed conversion was improved in limit-fed gilts, however daily gain was improved for gilts receiving feed AD. Results from this experiment imply that limit feeding gilts has no negative impacts on sexual development, but daily gain is reduced. In the third experiment, previous feeding bases were used, and a third, nutritional flushing, was also studied, when gilts received AD feed 7 d after first estrus. Flushed gilts had feed conversion like that of limit-fed gilts with daily gain similar to that of AD gilts. Gilts which were flushed had ovulation rates which were similar to gilts receiving feed AD but was greater compared with limit-fed gilts. Results indicate that flush feeding can achieve daily gain similar to ad libitum feeding and feed conversion similar to limit-feeding, while improving ovulation rate compared to limit-feeding. Across all studies, feed disappearance decreased for AD fed gilts as they neared estrus. Overall, using an ESF allows for precise feeding of replacement gilts and allows producers to implement various feeding strategies across multiple animals on an individual basis. Monitoring feed behavior with an ESF may enhance current estrus detection practices.

The objective of this study was to determine the onset of puberty by using progesterone profiles and anterior pituitary gonadotropin releasing hormone (GnRH) challenges in purebred and crossbred Holstein and Jersey heifers. In experiment 1, fifty prepubertal heifers by four sire - dam classifications (18 HH, 11 JJ, 10 JH, and 11 HJ) were used. The HH heifers attained puberty at an older age than the HJ, JH or JJ heifers, and these three classifications were not different from each other. There were significant differences in weight and wither height at puberty and average daily weight gain (ADWG) between all four sire - dam classifications. Season of birth had a significant effect on age and weight at puberty. In experiment 2, four prepubertal heifers from each sire - dam classification in experiment 1 were used at 3, 6, 9 and 12 mo of age to determine the effects of administering 200 μg GnRH on LH secretion. The effects of breed, age at challenge, and their interaction were only significant for time to LH peak. In conclusion, age at puberty in crossbred Holstein X Jersey heifers is regulated by breed and season of birth, and further research with larger sample sizes is needed to establish the relationship of pituitary maturation and the capacity to secrete LH in response to GnRH stimulation as related to onset of puberty in purebred and crossbred dairy heifers. / Master of Science

Bakgrund: Puberteten är den period i livet då kroppen förändras och utvecklas till att bli vuxen. I skolsköterskans uppdrag ingår hälsosamtal och hälsobesök med tillväxtkontroller. Här har skolsköterskan möjlighet att pubertetsskatta eleverna och upptäcka avvikande pubertet. På många skolor används Tannerskalan som skattningsinstrument. Syfte: Att utforska skolsköterskors upplevelse av att samtala om och skatta elevers pubertet. Metod: En kvalitativ studie med induktiv ansats. Materialet analyserades enligt en latent kvalitativ innehållsanalys. Resultat: Fyra huvudkategorier framkom: Pubertetsskattning, Aspekter på positiva och negativa samtal, Skolsköterskornas upplevelser av pubertetsskattning samt Förslag till förbättringar av elevers pubertetssamtal och skattningar. Temat som framkom var: Vikten av relationsskapande. Konklusion: Studien visar att det ser olika ut gällande hur och på vilket sätt skolsköterskor samtalar om och skattar elevers pubertet. Tannerskalan upplevs omodern och icke inkluderande och tankar på ett nationellt stöd för pubertetskattningar framkommer. Sammanfattningsvis har vikten av att skapa goda relationer en stor och avgörande betydelse för att mötet med eleven ska bli framgångsrikt och pubertetsskattningen så korrekt som möjligt. / Background: Puberty is the period in life when the body changes and develops into adulthood. The school nurse's duties include health conversations and health visits, with growth assessments. Here, the school nurse has the opportunity to assess puberty in pupils and detect abnormal puberty. Many schools use the Tanner scale as an assessment tool. Aim: To explore the experience of school nurses in discussing and assessing pupils' puberty. Method: A qualitative study with an inductive approach. The material was analyzed using latent qualitative content analysis. Findings: Four main categories emerged: Puberty assessment, Aspects of positive and negative conversations, School nurses' experiences of puberty assessment, and Suggestions for improving pupils' puberty conversations and assessments. The theme that emerged were: The importance of relationship building. Conclusion: The study shows that there are differences in how and in what way school nurses discuss and assess pupils' puberty. The Tanner scale is perceived as outdated and non-inclusive, and ideas for national support for puberty assessments emerge. To summarise, the importance of creating good relationships is of great and crucial importance for the meeting with the pupil to be successful and the puberty assessment as accurate as possible.

Master of Science / Department of Kinesiology / Craig A. Harms / Expiratory flow limitation (EFL) during exercise can limit exercise tolerance. We have recently reported a high prevalence of EFL independent of sex in prepubescent children (Swain et al. 2010) that greatly exceeds that reported in adults. It is unknown how maturation and growth from pre- to post-puberty affects pulmonary function, specifically EFL, during exercise. The purpose of this longitudinal study was to investigate the changes in cardiopulmonary function from pre- to post-puberty in boys and girls. We hypothesized that EFL prevalence would decrease from pre- to post-puberty (with boys exhibiting a greater decrease than girls) and that the decrement could be explained by an increase in pulmonary function and a decrease in VE/VCO2. Twenty-one children (ages 12-16 yrs; 11 boys, 10 girls) were recruited from 40 prepubescent children who completed testing in our laboratory ~5 years ago. Subjects completed pulmonary function tests before and after an incremental exercise test to exhaustion (VO2max) on a cycle ergometer. EFL was determined using the percent tidal volume (VT) overlap method. Nineteen of the 21 subjects (10 boys, 9 girls; 90%) exhibited EFL pre-puberty, while only 7 of the 21 subjects (5 boys, 2 girls; 33%) exhibited EFL post-puberty. Of the subjects who experienced EFL post-puberty, all had experienced EFL pre-puberty. Boys had a significantly greater vital capacity (VC) than girls both pre- (~15%) and post-puberty (B: 4.73 ± 0.53; G: 3.80 ± 0.29 L). Maximal aerobic capacity (VO2max) significantly increased (~110% in girls and ~120% in boys) from pre- to post-puberty and was greater (p<0.05) in boys post-puberty (B: 2.76 ± 0.43; G: 1.94 ± 0.35 L/min). VE/VCO2 also significantly decreased (~13%) in both boys and girls. Post-puberty subjects regulated tidal breathing at higher lung volumes (greater ERV/FVC and lower IRV/FVC) during exercise compared to pre-puberty. None of the subjects experienced significant arterial desaturation pre-puberty or post-puberty. Our findings suggest that the prevalence of EFL declines as children mature from pre- to post-puberty, likely due to increases in lung size, decreases in VE/VCO2, and/or changes in breathing mechanics that are greater than increases in maximal ventilation that occur with increased pulmonary gas exchange.

Almost all African societies have female initiation rites to mark the process of growing up. Initiation rites signal the transition from one stage in life to another. Between the two levels is “the camp,” the liminal phase, in which the initiate is secluded in order to be initiated into the mysteries of life. Through female initiation rites, positions of power and social relations within the society are demonstrated. The Bemba people of Zambia perform the Chisungu female initiation rites in which young women are initiated into adulthood through the ritual process. Chisungu female initiation rites remain an important source of traditional education on sex and the social and religious leadership roles of women in Zambia although they are now being modified and performed in a shortened form. This study builds on the scholarly work undertaken by African women theologians particularly in the last decade, to engage theologically with the subject of HIV and AIDS on the African continent. Their theoretical insights and analysis provide the critical lenses for this thesis. The objective of the thesis is to offer a gendered analysis of Chisungu initiation rites among the Bemba people, in order to retrieve the values of indigenous female initiation rites which can critique patriarchy in the context of HIV and AIDS. This objective is achieved in the following steps. Firstly the function, the form and the practices of indigenous female Chisungu initiation rites are explained. Secondly, the gendered cultural values of indigenous female Chisungu initiation rites are demonstrated while simultaneously providing details of the symbolic meaning of the rites and the interpretation of the initiation songs and the sacred emblems (imbusa). Thirdly, how gendered cultural values of indigenous Chisungu initiation rites can be retrieved for HIV prevention is illustrated. Finally the importance of inculturating the values of indigenous female Chisungu initiation rites in the UCZ with regards to empowering women in the context of HIV and AIDS is explored. / Thesis (M.Th.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Many phenotypes are controlled by factors which include the genes, the environment, interactions between genes and interaction between the genotypes and the environment. Great strides have been made to understand how these various factors affect traits of agricultural, medical and environmental importance. The chicken is regarded as a model organism whose study would not only assist efforts towards increased agricultural productivity but also provide insight into the genetic determination of traits with potential application in understanding human health and disease. Detection of genomic regions or loci responsible for controlling quantitative traits (QTL) in poultry has focussed mainly on growth and production traits with limited information on reproductive traits. Most of the reported results have used additive-dominance models which are easy to implement because they ignore epistatic gene action despite indications that it may be important for traits with low heritability and high heterosis. The thesis presents results on the detection of loci and genetic mechanisms involved in sexual maturity traits through modelling both additive-dominance gene actions and epistasis. The study was conducted on an F2 broiler x White Leghorn layer cross for QTL detection for age, weight, abdominal fat, ovary weight, oviduct weight, comb weight, number of ovarian yellow follicles, a score for the persistence of the right oviduct and bone density. In addition, body weight QTL at 3, 6, 12, 24, 48 and 72 weeks of age, QTL for growth rate between the successive ages and QTL for the parameters of the growth curve were also detected. Most of the QTL for traits at sexual maturity acted additively. A few of the QTL explained a modest proportion of the phenotypic variation with most of the QTL explaining a small component of the cumulative proportion of the variation explained by the QTL. Body weight QTL were critical in determining the attainment of puberty. The broiler allele had positive effects on weight at first egg and negative effects on age at first egg. Most QTL affecting weight at first egg overlapped with QTL for age at first egg and for early growth rate (6-9 weeks) suggesting that growth rate QTL are intimately related to the onset of puberty. Specific QTL for early and adult growth were detected but most QTL had varying influence on growth throughout life. Chromosome 4 harboured most of QTL for the assessed traits which explained the highest proportion of the phenotypic variation in the traits confirming its critical role in influencing traits of economic importance. There was no evidence for epistasis for almost all the studied traits. Evidence for role of epistasis was significant for ovary weight and suggestive for both growth rate and abdominal fat.

The general aims of the thesis were to study GH responsiveness by estimation of pharmacokinetics and bioavailability of injected recombinant human GH (rhGH), of growth response as gain in heightSDS during childhood and puberty, and IGF-I response as change in circulating IGF-ISDS and IGFBP3SDS. Methods Short children were recruited during 1988–1999 into two national randomized multicentre clinical trials on growth until adult height. A group of 117 GHD patients who had been treated from prepuberty with a single GH dose of 33μg/kg/day for at least 1 year were randomized at onset of puberty either to remain on this dose regimen or to an increased dose, GH67μg/kg/day, administered once daily or divided into two doses, GH33x2μg/kg/day. Data on IGF-ISDS and IGF binding protein 3 (IGFBP3)SDS were available from 111 patients and analysed as stated below. The 151 short prepubertal non-GHD patients were randomized into three groups: untreated controls, GH33 or GH67μg/kg/day. A subpopulation from both trials, 128 patients examined annually in Gothenburg, formed the study sample on GH uptake. They received sc GH injections to obtain 16–24 hour GH curves and the GH pharmacokinetics and bioavailability was calculated. Results: A dose-dependent effect on Cmax was found with great intra- and inter-individual variability. Of the Cmax variability, 43% was explained by the rhGH dose and proxies for injection depth. Median bioavailability of the injected dose was 71%, with great variation, mainly dependent on injection depth. In the IGHD group a dose-dependent difference in pubertal gain in heightSDS was found, with mean of 0.8 for the GH67 group and 0.4 for GH33, p&lt;0.01. The mean total gain in heightSDS during treatment was 1.9 for GH67 and 1.4 for GH33, p&lt;0.01. A dose-dependent pubertal ΔIGF-ISDS was 0.5 vs −0.1, p=0.007, correlating to pubertal gain in heightSDS, p=0.003; and was the most important variable to explain the variation in pubertal gain in heightSDS. In the non-GHD group the ΔIGF-ISDS from baseline to mean study level was dose-dependent 2.07 vs 1.20, p=0.001; and correlated negatively with baseline values of IGF-ISDS, rho= -0.56 for GH67, p=0.001, vs rho= -0.82 for GH33, p=0.0001, and correlated positively with gain in heightSDS in both GH-treated groups, rho= 0.42, p&lt;0.001. In multivariable regression analyses, ΔIGF-ISDS was always an important explanatory variable for long-term growth response from the prepubertal period until adult height, while the IGF-ISDS study level per se was not. Conclusion: Growth response to GH treatment was dose dependent with great variability between patients. More pubertal growth was attained by an increased rhGH dose, mimicking the physiology of healthy children, in whom GH secretion rate increases during puberty. This resulted in a gain in IGF-ISDS closely correlating to pubertal gain in heightSDS in both IGHD and non-GHD patients. A broad range in GH responsiveness was found for both growth and IGF response in both diagnostic groups, but lower in the non-GHD group. Higher uptake of a given GH dose was observed after a deep injection and a higher GH concentration. These results are clinically applicable for individuals who remain short close to onset of puberty; by identifying and deeply injecting a rhGH dose that accounts for individual responsiveness, we can stimulate an increment in IGF-ISDS that correlates to gain in heightSDS during puberty.

Introdução - A puberdade precoce verdadeira ou dependente de GnRH apresenta importante morbidade: a baixa estatura, conseqüência da rápida progressão da idade óssea, além das seqüelas psico-emocionais do desenvolvimento sexual secundário precoce. Daí a importância da realização de um diagnóstico precoce e preciso, a fim de que a terapêutica adequada seja instituída o quanto antes. O uso do análogo do GnRH (aGnRH) em teste diagnóstico vem sendo utilizado com este objetivo. Neste estudo avaliou-se os valores de corte para o diagnóstico de puberdade precoce verdadeira, usando-se o teste do aGnRH. Material e métodos - Estudo prospectivo, com 44 meninas, com desenvolvimento dos caracteres sexuais secundários antes dos 8 anos de idade, atendidas no Ambulatório de Ginecologia Infanto-Puberal do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo. Realizou-se, em todos os casos, o teste do aGnRH, que consistiu na coleta de amostra sanguínea basal para dosagem de FSH e LH, seguida da aplicação subcutânea de 500µg de acetato de leuprolida (Lupron®). Novas amostras sanguíneas foram realizadas após 3 horas, para dosagem de FSH e LH, e após 24 horas da aplicação, para dosagem de estradiol Compararam-se os níveis de LH e FSH basais, de 3 horas e a relação LH/FSH obtida, além do estradiol de 24h, com a evolução clínica das pacientes. Este foi o padrão ouro utilizado para análise do teste, sendo que, após 6 meses, as pacientes foram divididas em 2 grupos: puberdade progressiva (puberdade precoce verdadeira) e não-progressiva. Para análise estatística, utilizou-se curvas ROC, estabelecendo-se sensibilidade, especificidade e melhor nível de corte para o diagnóstico de puberdade precoce verdadeira, para os diferentes critérios analisados. Além disso, avaliou-se a concordância entre os diversos tipos de análise do teste, através do coeficiente kappa. Resultados - O LH de 3 horas apresentou valor de corte > 4,5 mUI/mL, sensibilidade 59,1% e especificidade 86,4%, com área sobre a curva de 0,723. O valor de kappa foi de 0,45, com concordância de 0,73. O estradiol de 24 horas apresentou valor de corte > 40,6 pg/mL, sensibilidade 70% e especificidade 73,7%, com área sobre a curva de 0,703. O valor de kappa foi de 0,436, com concordância de 0,718. Dentre todos os critérios analisados, o melhor deles foi a relação LH/FSH de 3 horas, com valor de corte > 0,14, sensibilidade 72,7% e especificidade 77,3%, com área sobre a curva de 0,771. O valor de kappa foi de 0,5, com concordância de 0,75. Conclusões - Em nossa avaliação, a relação LH/FSH de 3 horas foi superior ao valor de LH de 3 horas ou estradiol de 24 horas, que haviam sidos os melhores critérios diagnósticos no trabalho pioneiro na utilização deste teste. / Introduction - True or GnRH-dependent precocious puberty involves important morbidity such as short stature due to the rapid progression of bone age, as well as psycho-emotional sequels of precocious secondary sexual development. Thus, it is important to make an early and precise diagnosis so that appropriate treatment can be instituted as early as possible. The GnRH analogue (aGnRH) in the diagnostic test has been used for this purpose. In the present study, the sensitivity and specificity of different laboratory criteria for the diagnosis of true precocious puberty were compared using the aGnRH test. Material and methods - This was a prospective study conducted on 44 girls with the development of secondary sexual traits before 8 years of age attended at the Childhood-Pubertal Gynecology Outpatient Clinic of the University Hospital, Faculty of Medicine of Ribeirão Preto, University of São Paulo. The aGnRH test was performed in all cases, consisting of collection of a basal blood sample for the determination of FSH and LH, followed by subcutaneous application of 500 µg leuprolide acetate (Lupron®). New blood samples were obtained after 3 hours, for the determination of FSH and LH, and after 24hours of application, for determination of estradiol. Basal LH and FSH levels and levels after 3 hours, the LH/FSH ratio obtained 3 hours after the administration of 500 µg Lupron®, and 24 hour estradiol levels were compared with the clinical course of the patients. This was the gold standard used for the analysis of the test and after 6 months the patients were divided into 2 groups: progressive puberty (true precocious puberty) and non-progressive puberty. ROC curves were used for statistical analysis, with the determination of the sensitivity, specificity and best cut-off value for the diagnosis of true precocious puberty of the different criteria analyzed. In addition, the agreement of the various types of test analysis was evaluated using the kappa coefficient. Results - Three hour LH presented a cut-off value of > 4.5 mIU/mL, 59.1% sensitivity and 86.4% specificity, with an area under the curve of 0.723. The kappa value was 0.45, with 0.73 agreement. Twenty-four hour estradiol presented a cut-off value of > 40.6 pg/mL, 70% sensitivity and 73.7% specificity, with an area under the curve of 0.703. The kappa value was 0.436, with 0.718 agreement. The best of all criteria used was the 3 hour LH/FSH ratio, with a cut-off value of > 0.14, 72.7% sensitivity and 77.3% specificity, with an area under the curve of 0.771. The kappa value was 0.5, with 0.75 agreement. Conclusions - In the present evaluation, the 3 hour LH/FSH ratio was superior to the 3 hour LH value and the 24 hour estradiol value, which had been the best diagnostic criteria in the pioneering study using this test.

Foi estudada a atividade ovariana de fêmeas de onça-pintada (Panthera onca; adultas n=2 e pré-púberes n=3) mantidas em cativeiro, pela extração e quantificação de estrógenos e progestinas fecais. Foram colhidas amostras fecais de 2-7 vezes por semana durante 16-18 meses. Foi realizada a validação dos radioimunoensaios em fase sólida, progesterona e 17&beta;-estradiol, para uso em extratos fecais em onça-pintada. A duração média (±EPM) do ciclo ovariano (n=7) definido por dois picos consecutivos de estrógenos fecais foi de 38,28 ±2,52dias (variando de 25 a 44 dias). A fase de estro teve duração média de 10,42 ±1,15dias (variando de 7 a 15dias) e a fase de inter-estro durou em média 28,00 ±1,43dias (variando de 28 a 31 dias). O nível basal médio de estrógenos fecais no período de inter-estro foram de 31,26 ±1,34ng/g de fezes secas. No período de estro, os valores médios encontrados foram de 115,91 ±8,82ng/g de fezes secas, foi observado um pico entre o D-5 e o D-2, com valores médios de 164,45 ±3,49ng/g de fezes secas. As progestinas fecais apresentaram valores médios de 0,44 ±0,05&micro;g/g de fezes secas, não apresentando variações significantes durante todo o ciclo. Os dados obtidos durante a avaliação do perfil longitudinal das concentrações de estrógenos fecais, no grupo dos animais pré-púberes, permitem indicar um possível início da atividade ovariana a partir do bimestre agosto-setembro, onde os valores médios dos picos detectados para estrógenos fecais, foram de 135,31 ±3,16ng/g de fezes secas. Todos os animais entraram na fase peripuberal com idade aproximada de 20 meses. / Ovarian function of captive jaguars (Panthera onca; adults n=2 and pre-pubertal n=3) was assessed by extraction and quantification of fecal estrogens and progestins. Fecal samples were obtained 2-7 times per week during 16-18 months. Validation of solid phase radioimmunoassay for progesterone and 17&beta;-estradiol was performed for jaguar fecal extracts. Ovarian cycle mean duration (±SEM), defined by two consecutive peaks of fecal estrogens, was 38.28 ±2.52days (range, 25 - 44days; n=7). Mean estrous phase duration was 10.42 ± 1.15days (range, 7 - 15days), and inter-estrous phase mean duration was 28.00 ±1.43days (range, 28 - 31days). Basal fecal estrogen mean concentration in inter-estrous period was 31.26 ± 1.34ng/g of dry feces. During estrous period mean value was 115.91 ±8.82ng/ g of dry feces, and was observed a mean peak (164.45 ±3.49 ng/g of dry feces) between D-5 and D-2. Fecal progestins had a mean concentration of 0,44 ± 0.05&micro;g/g of dry feces, with no significant variations during the cycles. Data obtained during the evaluation of fecal estrogen longitudinal profiles in the pre-pubertal group, allow to indicate the beginning of ovarian activity in August-September bimester with fecal estrogen mean peaks of 135.31 ± 3.16ng/ g of dry feces. AlI animaIs started pre-pubertal phase around 20 months of age.

INTRODUÇÃO: Os fatores genéticos que influenciam o início da puberdade precoce ainda não são totalmente conhecidos. Assim, investigar os mecanismos gênicos que estariam envolvidos na sua gênese é muito importante, pois, além de possibilitar o diagnóstico em fases iniciais, pode contribuir para o desenvolvimento de novas terapias, com melhora do prognóstico. Para alguns investigadores, o estradiol também seria um fator contribuinte no determinismo da puberdade. OBJETIVOS: Estudar três genes que codificam enzimas relacionadas à esteroidogênese (CYP1A1, CYP1B1 e CYP17) em meninas com puberdade precoce central. Avaliar a associação entre variações na sequência desses genes e a puberdade precoce central. MÉTODOS: Foram incluídas 177 pacientes, divididas em dois grupos: Grupo Controle - formado por 104 meninas sem puberdade precoce, acompanhadas no Setor de Ginecologia da Infância e da Adolescência da Divisão de Clínica Ginecológica do HC-FMUSP por outros diagnósticos; Grupo Caso - composto por 73 meninas com diagnóstico de puberdade precoce central, acompanhadas no mesmo setor. Foi avaliada a presença de mutação em genes envolvidos no metabolismo do estrogênio (CYP1A1, CYP1B1 e CYP17) pela técnica de RFLP (Restriction Fragment Length Polymorphism), utilizando DNA obtido a partir de sangue periférico. RESULTADOS: A distribuição dos genótipos de CYP1A1 MspI (p=0,86) e CYP17 (p=0,12) não apresentou diferença significante entre os grupos. Para o CYP1B1 Eco571, o genótipo mutado C/C foi mais frequente no Grupo Controle que no Grupo Caso (p=0,03). CONCLUSÃO: Nossos dados sugerem que a variação do gene CYP1B1 Eco571 poderia estar associada ao determinismo da puberdade / INTRODUCTION: The genetic factors influencing onset of precocious puberty are not as yet fully known. Therefore, it is very important to investigate the genetic mechanisms involved in its genesis, for the resulting knowledge would not only enable diagnosis in the early stages but also contribute to the development of new therapies for improvement in prognosis. According to some researchers, estradiol would also be a contributory factor in puberty timing. OBJECTIVES: To investigate three genes which codify enzymes associated with steroidogenesis (CYP1A1, CYP1B1, and CYP17) in girls with central precocious puberty by focusing on the association between the sequence variation of these genes and central precocious puberty. METHODS: A total of 177 patients was included and divided into two groups: Control Group with 104 girls without precocious puberty who were being treated for other diagnoses at the Sector of Gynecology of Childhood and Adolescence, Division of Gynecology Clinic, HC-FMUSP; Case Group with 73 girls diagnosed with central precocious puberty. Mutations in genes involved in estrogen metabolism (CYP1A1, CYP1B1, and CYP17) were assessed by the RFLP (restriction fragment length polymorphism) technique using DNA obtained from peripheral blood. RESULTS: No significant difference in the distribution of the CYP1A1 MspI (p=0.86) and CYP17 (p=0.12) genotypes was detected between the two study groups. As for CYP1B1 Eco571, the mutated C/C genotype was found to be more frequent in the Control Group than in the Case Group (p=0.03). CONCLUSION: Our data suggest the CYP1B1 Eco571 gene variation is associated with puberty timing