Made available in DSpace on 2016-01-26T18:55:45Z (GMT). No. of bitstreams: 1 Dissertacao Fernando.pdf: 431045 bytes, checksum: 5ae1b35993c556c6871734dee523f3dc (MD5) Previous issue date: 2008-06-26 / Libido is an important component of a bull s breeding ability; however it is difficult to make as assessment of libido during a breeding soundness examination. It is best assessed in young bulls and scrotal circumference is favorably correlated with semen traits. Sixteen Brangus and eight Brown-Swiss bulls, with 36 months old, extensively managed were evaluated. The objective of this work is to study the relationship between scrotal circumference, libido, hormones and semen characteristics in Brangus and Brown-Swiss bulls. Bulls were divided into two experimental groups: group 1, with 16 bulls Brangus, and group 2, with 8 bulls Brown-Swiss, evaluated for sexual soundness using physical and morphological characteristics of semen, sexual behavior, testosterone and cortisol serum concentrations. There was a difference in the serum testosterone (P<0,05) and cortisol (P<0,01) concentrations between groups. No correlation (P>0,05) between libido, scrotal circumference, motility , concentration, testosterone and major defects were obtained. It was observed correlation among motility and mass movement (0,50; P<0,01), vigor and mass movement (0,58; P<0,01), libido and vigor (0,55; P<0,01), libido and cortisol (-0,41; P<0,05). In conclusion, were not correlations between libido and sperm quality, libido and scrotal circumference, libido and testosterone. / A libido é um importante componente da habilidade de procriação dos touros, todavia, não é fácil realizar a mensuração da mesma durante o exame do aparelho reprodutor. A libido é melhor traduzida em touros jovens e a circunferência escrotal está favoravelmente correlacionada com o perfil do sêmen. Dezesseis touros Brangus e oito Pardos-suiços, com 36 meses de idade, criados extensivamente, foram avaliados. O objetivo deste trabalho foi estudar as relações entre circunferência escrotal, libido, hormônios e características do sêmen em touros Brangus e Pardos-suiços. Os touros foram divididos em dois grupos experimentais: grupo 1, com 16 touros Brangus e grupo 2, com 8 touros Pardos-suiços, avaliados sexualmente por meio de exame físico e das características morfológicas do sêmen, comportamento sexual e concentrações séricas de testosterona e cortisol. Houve diferença nas concentrações séricas de testosterona (P>0,05) entre libido, circunferência escrotal, motilidade, concentração, testosterona e defeitos maiores foi obtida. Observou-se correlação entre motilidade e turbilhão (0,50: P<0,05), vigor e turbilhão (0,58: P<0,01), libido e vigor (0,55; p<0,01) e para libido e cortisol (-0,41; P<0,05). Conclui-se que não há correlações entre libido e qualidade espermática, libido e circunferência escrotal e entre libido e testosterona.

Made available in DSpace on 2016-07-18T17:53:08Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 371163 bytes, checksum: 00d67c3200895b27fd357306527c561c (MD5) Previous issue date: 2011-03-18 / The objective of this work was to study the seasons influence (spring, summer, autumn and winter) on semen characteristics and hormones (testosterone and cortisol) in Nelore and Simental bulls. Five Nelore and five Simental bulls were 48-72 months old, extensively managed, were evaluated for sexual soundness using physical and morphological characteristics of semen and hormonal serum levels. There was decreased motility and vigor semen (P<0.05) during winter in Simental bulls. There was correlation between serum testosterone and cortisol (P<0.01) to motility and vigor in either Nelore and Simental bulls. In conclusion, these results showed a hormonal and semen characteristics variation throughout the season change the semen quality. Bulls from Nelore breed differed from Simental, demonstrating adaptability to the field conditions. / O objetivo desse trabalho foi estudar a influência das quatro estações do ano: (primavera, verão, outono e inverno), nas características do sêmen e nos níveis de testosterona e cortisol em touros Nelore e Simental. Cinco touros Nelore e cinco Simental com 48-72 meses de idade, criados extensivamente, foram avaliados andrologicamente por meio de exame físico e das características morfológicas do sêmen, concentrações séricas de testosterona e cortisol. Houve queda na motilidade e vigor do sêmen no inverno (p<0,05) para a raça Simental. Houve correlação entre a concentração sérica de testosterona e cortisol (P<0,01) para a motilidade e vigor espermático para os touros Nelore e Simental. Conclui-se que houve variação hormonal e nas características do sêmen ao longo das estações modificando a qualidade do sêmen. Os touros da raça Nelore diferiram dos da raça Simental, demonstrando adaptabilidade às condições do campo.

Made available in DSpace on 2016-07-18T17:53:18Z (GMT). No. of bitstreams: 1 Dissertacao Fernando.pdf: 431045 bytes, checksum: 5ae1b35993c556c6871734dee523f3dc (MD5) Previous issue date: 2008-06-26 / Libido is an important component of a bull s breeding ability; however it is difficult to make as assessment of libido during a breeding soundness examination. It is best assessed in young bulls and scrotal circumference is favorably correlated with semen traits. Sixteen Brangus and eight Brown-Swiss bulls, with 36 months old, extensively managed were evaluated. The objective of this work is to study the relationship between scrotal circumference, libido, hormones and semen characteristics in Brangus and Brown-Swiss bulls. Bulls were divided into two experimental groups: group 1, with 16 bulls Brangus, and group 2, with 8 bulls Brown-Swiss, evaluated for sexual soundness using physical and morphological characteristics of semen, sexual behavior, testosterone and cortisol serum concentrations. There was a difference in the serum testosterone (P<0,05) and cortisol (P<0,01) concentrations between groups. No correlation (P>0,05) between libido, scrotal circumference, motility , concentration, testosterone and major defects were obtained. It was observed correlation among motility and mass movement (0,50; P<0,01), vigor and mass movement (0,58; P<0,01), libido and vigor (0,55; P<0,01), libido and cortisol (-0,41; P<0,05). In conclusion, were not correlations between libido and sperm quality, libido and scrotal circumference, libido and testosterone. / A libido é um importante componente da habilidade de procriação dos touros, todavia, não é fácil realizar a mensuração da mesma durante o exame do aparelho reprodutor. A libido é melhor traduzida em touros jovens e a circunferência escrotal está favoravelmente correlacionada com o perfil do sêmen. Dezesseis touros Brangus e oito Pardos-suiços, com 36 meses de idade, criados extensivamente, foram avaliados. O objetivo deste trabalho foi estudar as relações entre circunferência escrotal, libido, hormônios e características do sêmen em touros Brangus e Pardos-suiços. Os touros foram divididos em dois grupos experimentais: grupo 1, com 16 touros Brangus e grupo 2, com 8 touros Pardos-suiços, avaliados sexualmente por meio de exame físico e das características morfológicas do sêmen, comportamento sexual e concentrações séricas de testosterona e cortisol. Houve diferença nas concentrações séricas de testosterona (P>0,05) entre libido, circunferência escrotal, motilidade, concentração, testosterona e defeitos maiores foi obtida. Observou-se correlação entre motilidade e turbilhão (0,50: P<0,05), vigor e turbilhão (0,58: P<0,01), libido e vigor (0,55; p<0,01) e para libido e cortisol (-0,41; P<0,05). Conclui-se que não há correlações entre libido e qualidade espermática, libido e circunferência escrotal e entre libido e testosterona.

Hormis leur implication dans les fonctions de reproduction, de développement et du maintien des caractères mâles, les androgènes (principalement la testostérone et la dihydrotestostérone, DHT) sont des hormones stéroïdiennes capables d’influencer plusieurs structures et fonctions du système nerveux. En effet, durant le développement, les androgènes ont un effet masculinisant sur le système nerveux central (SNC) le rendant sexuellement dimorphique. Chez les rongeurs mâles adultes, la substance blanche est plus volumineuse et les oligodendrocytes, cellules myélinisantes du SNC, sont plus nombreux. Cette différence est abolie après castration des mâles ; ce qui suggère l'implication de la testostérone dans le dimorphisme des oligodendrocytes et de la myéline.D’une part, mon travail de thèse visait à démontrer l’implication des androgènes et de leur récepteur (AR) dans l’établissement de ce dimorphisme. Nos résultats confirment l'implication de la testostérone et démontrent que son effet est médié par AR. En effet les corps calleux (CC) des souris mâles adultes ayant un AR non fonctionnel dans l'ensemble de l'organisme (souris Tfm) ou invalidé spécifiquement dans les cellules neurales (souris ARNesCre), présentent 20 à 30% moins d'oligodendrocytes et de surfaces myélinisées que ceux des contrôles. En outre, nos résultats montrent que ce dimorphisme apparait dès le dixième jour postnatal. De manière intéressante, le traitement pharmacologique des souriceaux mâles par un antagoniste du AR (flutamide) et des souriceaux femelles par l’agoniste d'AR (la DHT), pendant les dix premiers jours après la naissance inverse respectivement leurs profils oligodendrocytaires, suggérant un rôle organisationnel d'AR dans la substance blanche.D’autre part, mon sujet consistait à montrer l'importance de la testostérone et du AR dans la réparation de la myéline dans un modèle de démyélinisation de la moelle épinière des souris par injection stéréotaxique de lysolécithine. Nos résultats montrent que le traitement pendant 4 semaines des animaux par la testostérone permet le recrutement des oligodendrocytes et la réparation de la myéline dans les zones lésées. Il est à noter (1) qu’en absence de la testostérone ou d'AR, la réparation de la myéline est inefficace et se fait par des composants de la myéline périphérique et (2)que la présence des astrocytes semble nécessaire pour l’effet remyélinisant de la testostérone. Afin de mieux comprendre le ou les mécanisme(s) d'action(s) de la testostérone et du AR dans les processus de myélinisation et de remyélinisation, nous avons réalisé une étude transcriptomique comparative entre les animaux lésés et traités ou non avec la testostérone pour déterminer les gènes cibles et les voies de signalisations impliquées dans ces processus. Les résultats permettront probablement de définir une nouvelle cible thérapeutique pour les maladies démyélinisantes telle que la sclérose en plaques. / Androgens (mainly testosterone and dihydrotestosterone, DHT) are steroid hormones that are involved in reproduction functions, development and maintenance of male characteristics. They can also influence several structures and functions of the nervous system. Indeed, during development, androgens have a masculinizing effect on the central nervous system (CNS) making it sexually dimorphic. In addition, in adult male rodents,the white matter is larger and presents more oligodendrocytes, myelinating cells of the CNS. This difference is abolished after castration of males ; witch suggests the involvement of testosterone in the dimorphism of oligodendrocytes and myelin.One aim of my thesis was to study the involvement of androgens and their receptor (AR) in the establishment of this dimorphism. Our results confirm that testosterone is involved and demonstrate that its effect is mediated by AR. Indeed, the corpus callosum (CC) of adult male mice having a non-functional AR in the entire body (Tfm mice) or invalidated specifically in neural cells, (ARNesCre mice) have 20 to 30% fewer oligodendrocytes and myelinated area than those of controls. Moreover, our results show that this dimorphism appears early during postnatal life. Interestingly, pharmacological treatment of male pups with an AR antagonist (flutamide) and female ones with an AR agonist (DHT) during the first ten days after the birth reverses their oligodendrocytic profiles. These results suggest an organizational role of the AR in the white matter development.The aim of the second part of my study was to investigate the importance of testosterone and the AR in myelin repair in a rodent model of spinal cord demyelinationby stereotactic injection of lysolecithin. Our results show that a 4 weeks testosterone treatment allows the recruitment of oligodendrocyte and myelin repair. Interestingly, in the absence of testosterone or the AR, myelin repair was ineffeciant and was done by components of peripheral myelin. Moreover, the presence of astrocytes seems necessary for the remyelinating effect of testosterone since myelin repair was confined to astrocyte populated area.An important goal of my work is to better understand the mechanism of action of testosterone and the AR in the process of myelin formation and repair. For this, we performed a comparative transcriptomic study between animals injected or not with LPC than treated or not with testosterone to determine new target genes and signaling pathways involved in these processes. The results will probably define a new therapeutic target for demyelinating diseases such as multiple sclerosis.

Daily undulating periodization (DUP), using daily alterations in repetitions, has been advocated as a superior method of resistance training, while traditional forms of programming for periodization (Block) have been questioned. Nineteen Division I track and field athletes were assigned to either a 10-week Block or DUP training group. Year and event were controlled. Over the course of the study, there were four testing sessions, which were used to evaluate a variety of strength characteristics, including maximum isometric strength, rate of force development, and one repetition maximum (1RM). Although, performance trends favored the Block group for strength and rate of force development, no statistical differences were found between the two groups. However, different (p ≤ 0.05) estimated volumes of work (VL) and amounts of improvement per VL were found between groups. Based upon calculated training efficiency scores, these data indicate that a Block training model is more efficient in producing strength gains than a DUP model. Additionally, alterations in testosterone (T), cortisol (C) and the T:C ratio were measured. Although there were no statistically (p ≤ 0.05) different hormone alterations between groups, relationships between training variables and hormone concentrations including the T:C ratio, indicate that Block may be more efficacious in terms of fatigue management.

It is generally believed that the presence of male traits is regulated by androgens. This thesis is designed to reveal the influence of testosterone on male traits in the leopard gecko, Eublepharis macularius. The noninvasive skin application mixture of vegetable oil and testosterone was used to manipulate the hormonal status of females and castrated males. This method has proven to be an effective alternative to the widely used hormonal implants. Manipulation was successfully validated, and there was apparent progressive increase of male sexual behavior in both groups. In females, the onset lasted much longer time, but both groups were able to perform all components of males sexual behaviour. Furthermore, I found that, contrary to widespread view, male sexual behavior persisted several weeks after reduction of testosterone levels in both manipulated groups. These results bring new evidence for temporary organization of male sexual behaviour by testosterone. Powered by TCPDF (www.tcpdf.org)

In der Schweiz wird die Diskussion um eine Testosteron-Behandlung gerade beim älteren Mann sehr konservativ und mit vielen Vorbehalten geführt. In der schweizerischen Fachliteratur finden sich keine nationalen Guidelines zu diesem Thema. In Zeitungsartikeln in schweizerischen Fachzeitschriften wird die Testosteron-Behandlung befürwortet, aber mit vielen Einschränkungen und Vorbehalten versehen. Daraus lässt sich eine Gruppe von „offenen Fragen“ zusammenstellen, die in der Folge aufgrund der aktuellen internationalen Fachliteratur diskutiert werden. / The discussion about testosterone therapy is hold in Switzerland in a conservative way and with many objections. In the Swiss medical literature there are no national guidelines published about this object. In publications in Swiss medical papers the testosterone therapy is approved but with many restrictions and reservations. There are some "open questions" collected together and discussed comparing the actual international medical literature.

Objective: Although associations between testosterone and cardiovascular (CV) morbidity in women have been proposed, no large prospective study has evaluated potential associations between testosterone and mortality in women. The objective was to determine whether baseline testosterone levels in women are associated with future overall or CV morbidity and mortality. Design: Prospective cohort study with a 4.5-year follow-up period. Methods: From a representative sample of German primary care practices, 2914 female patients between 18 and 75 years were analyzed for the main outcome measures: CV risk factors, CV diseases, and all-cause mortality. Results: At baseline, the study population was aged 57.96±14.37 years with a mean body mass index of 26.71±5.17 kg/m2. No predictive value of total testosterone for incident CV risk factors or CV diseases was observed in logistic regressions. Patients with total testosterone levels in the lowest quintile Q1, however, had a higher risk to die of any cause or to develop a CV event within the follow-up period compared to patients in the collapsed quintiles Q2–Q5 in crude and adjusted Cox regression models (all-cause mortality: Q2–Q5 versus Q1: crude hazard ratios (HR) 0.49, 95% confidence interval (CI) 0.33–0.74; adjusted HR 0.62, 95% CI 0.42–0.939; CV events: Q2–Q5 versus Q1: crude HR 0.54, 95% CI 0.38–0.77; adjusted HR 0.68, 95% CI 0.48–0.97). Kaplan–Meier curves revealed similar data. Conclusions: Low baseline testosterone in women is associated with increased all-cause mortality and incident CV events independent of traditional risk factors.

The second (index finger) to fourth (ring finger) digit length ratio (2D:4D) is known to be a putative marker of prenatal exposure to the testosterone. It has been reported that fetal testosterone may be critical for development of morphological and psychological traits such as quality of the cardiovascular system, visuo-spatial ability, risk-taking behavior and behavioral masculinity. Testosterone-driven attributes are associated with success in male-to- male physical competition, which may be proxied by ability in sports. Many studies have found that 2D:4D is sexually dimorphic and low (male-typical) 2D:4D ratio is associated with athletic performance. This study aims to investigate possible associations of performance in sport with 2D:4D ratio, personality characteristics (Big Five model), willing to take risks and training habits, in a sample of 57 top and 57 recreational snowboard racers. We did not find any associations between 2D:4D ratio and sport performance, no significant differences were found in 2D:4D ratio between samples. We found negative associations between agreeableness and sport performance; individuals with low agreeableness achieved higher results in the real competition of freestyle snowboarding. Low agreeableness used to be associated with aggressiveness, emulation and...

Weltweit ist eine rasante Zunahme des Artensterbens auch bei der Klasse Aves zu verzeichnen. Durch Umweltveränderungen und unzählige andere menschliche Einflüsse (z.B. illegaler Handel) ist fast ein Drittel der Papageienpopulation (Psittaciformes) vom Aussterben bedroht. Eine Möglichkeit, diesen Trend aufzuhalten, besteht in der gezielten und effektiven Nachzucht bedrohter Arten in der Obhut von Menschen mit dem Ziel der späteren Wiederauswilderung. Leider waren bisher solche Bemühungen oft erfolglos. Dies ist der Tatsache geschuldet, dass fundierte wissenschaftliche Untersuchungen zum Reproduktionsstatus nahezu fehlen und ein Transfer der hormonanalytischen Methoden vom Säugetier zum Vogel nicht so einfach möglich ist. Ziel der vorliegenden Arbeit war die Etablierung von Methoden zur Hormonbestimmung in verschiedenen Medien beim männlichen Papagei, mit deren Hilfe eine Einordnung des Reproduktionsstatus möglich ist. Im Vordergrund standen dabei vor allem nicht-invasive Techniken, die mit deutlich geringerem Stress für die Tiere verbunden sind. Als Vertreter für die Gruppe der Papageienartigen wurden Wellensittiche (Melopsittacus undulatus, n=11), Nymphensittiche (Nymphicus hollandicus, n=9) und Halsbandsittiche (Psittacula krameri, n=7) ausgewählt und endokrinologisch untersucht. Diese Vögel wurden vom Bundesverband für fachgerechten Natur- und Artenschutz e.V. (BNA) zur Verfügung gestellt. Die Hormonanalyse erfolgte in den regelmäßig gesammelten Blut-, Speichel- und Kotproben der männlichen Psittaziden. Neben dem Sexualhormon Testosteron wurden die Blutspiegel des Stresshormons Corticosteron bestimmt, da eine mögliche Beziehung zwischen Stress und Testosteronsekretion besteht. In den Vorversuchen wurden zunächst geeignete Methoden für die Hormonanalyse in den verschiedenen Medien beim Papagei entwickelt. Zur Extraktion von Testosteron aus den Blut- und Kotproben erwies sich Diethylether als gut geeignet, während Speichel direkt ohne Extraktion im Testosteron-Enzymimmunoassay eingesetzt wurde. Da Papageien hauptsächlich primär konjugierte Testosteronmetabolite (85%) ausscheiden, wurden die Kotproben nach dem Trocknen und Einwiegen mit Hilfe der β-Glucuronidase/Arylsulfatase hydrolysiert und dann mit Diethyether extrahiert. Die Corticosteronanalyse im Plasma der Papageien erfolgte durch Fällung der Proteine mittels absolutem Alkohol und Einsatz der Plasmaextrakte in den Radioimmunoassay. Bei den verschiedenen Papageienspezies traten während der Untersuchungsperiode vergleichbare Plasma-Testosteronkonzentrationen auf. Die höchsten Plasmaspiegel (0,36 ng/ml) wiesen die Wellensittiche im März 2007 auf, ähnliche Konzentrationen (0,34 ng/ml) erreichten die Nymphensittiche im Februar 2007. Demgegenüber zeigten die Halsbandsittiche geringere maximale Konzentrationen (0,26 ng/ml) im November 2007. Im Kot der Papageien wurden erwartungsgemäß deutlich höhere Testosteronwerte gemessen, weil die Steroidausscheidung im Kot kumulativ eine zurückliegende Zeitperiode und Blut den aktuellen Hormonstatus zum Zeitpunkt der Probennahme widerspiegelt. Bezüglich der Haltungs- und Umweltbedingungen zeigten die Papageien maximale Testosteronspiegel während der kalten Jahreszeit, bei kurzer (Halsbandsittich) bzw. zunehmender Tageslichtlänge (Wellen- und Nymphensittich) und Haltung in der Innenvoliere. Dabei spielte die Niederschlagsmenge in der gemäßigten Klimazone offenbar weniger eine Rolle in der aviären Reproduktion. Die Verlaufsuntersuchungen des Stresshormons Corticosteron im Blut der Papageien ergaben speziesspezifische Unterschiede hinsichtlich der Konzentrationen, zeitlichen Verläufe und in Bezug zum Testosteronspiegel. Auffällig hohe Corticosteronkonzentrationen zeigten die nicht domestizierten Halsbandsittiche (15,9 – 35,6 ng/ml) im Vergleich zu den Wellensittichen (1,76 – 17,1 ng/ml) und Nymphensittichen (4,06 – 12,1 ng/ml), bei denen sich vermutlich im Laufe der Domestikation eine verminderte Sensibilität der HPA-Achse ausgebildet hat. In Bezug zum Plasma-Testosteronspiegel war bei den Wellen- und Halsbandsittichen ein gegenläufiger Zusammenhang erkennbar, wobei beim Nymphensittich eine positive Korrelation zwischen der Testosteron- und Corticosteronkonzentrationim Plasma bestand. Zusammenfassend lässt sich sagen, dass durch die Testosteronanalyse in Kot und Plasma eine Einordnung des Reproduktionsstatus beim Wellen-, Nymphen- und Halsbandsittich möglich ist. Es ist jedoch sinnvoll, Proben zu verschiedenen Zeitpunkten vergleichend zu betrachten, um die tierindividuellen Unterschiede zu berücksichtigen. Offensichtlich stehen die Steroidhormone der Gonaden und der Nebenniere zueinander in Beziehung, sodass auch Corticosteron in der Reproduktionsdiagnostik von männlichen Psittaziden Anwendung finden sollte.