849 resultados para Hormones and Behaviour
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The melanocortin system is implicated in the expression of many phenotypic traits. Activation of the melanocortin MC(1) receptor by melanocortin hormones induces the production of brown/black eumelanic pigments, while activation of the four other melanocortin receptors affects other physiological and behavioural functions including stress response, energy homeostasis, anti-inflammatory and sexual activity, aggressiveness and resistance to oxidative stress. We recently proposed the hypothesis that some melanocortin-physiological and -behavioural traits are correlated within individuals. This hypothesis predicts that the degree of eumelanin production may, in some cases, be associated with the regulation of glucocorticoids, immunity, resistance to oxidative stress, energy homeostasis, sexual activity, and aggressiveness. A review of the zoological literature and detailed experimental studies in a free-living population of barn owls (Tyto alba) showed that indeed melanic coloration is often correlated with the predicted physiological and behavioural traits. Support for predictions of the hypothesis that covariations between coloration and other phenotypic traits stem from pleiotropic effects of the melanocortin system raises a number of theoretical and empirical issues from evolutionary and pharmacological point of views.
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Objective: To provide prevalence data on several key mental health indicators for young people aged 15 to 24 years. Methods: A cross-sectional household survey, using telephone recruitment followed by a postal pencil-and-paper questionnaire. The overall response rate was 67.3%. Results: Difficulties with interpersonal relationships are common causes of distress for young people, in particular problems with parents, problems with friends and relationship break-ups. Depressive symptomatology is common among young people with approximately one in eight males and one in four females reporting current depressive symptomatology. One in three young people reported that they had had suicidal thoughts at some time in the past, 1.2% of young people reported that they had made a plan on how to kill themselves in the four-week period prior to completing the survey and 6.9% of young people reported that they had tried to kill themselves at some time during their life time (4.2% of males and 9.0% of females). Conclusions and implications: The prevalence figures for the various mental health indicators presented in this paper represent good baseline information upon which to examine the progress over time of interventions designed to improve the mental health of young people.
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The acetohydroxamic acid synthesis reaction was studied using whole cells, cell-free extract and purified amidase from the strains of Pseudomonas aeruginosa L10 and A13 entrapped in a reverse micelles system composed of cationic surfactant tetradecyltrimethyl ammonium bromide. The specific activity of amidase, yield of synthesis and storage stability were determined for the reversed micellar system as well as for free amidase in conventional buffer medium. The results have revealed that amidase solutions in the reverse micelles system exhibited a substantial increase in specific activity, yield of synthesis and storage stability. In fact, whole cells from P. aeruginosa L10 and AI3 in reverse micellar medium revealed an increase in specific activity of 9.3- and 13.9-fold, respectively, relatively to the buffer medium. Yields of approximately 92% and 66% of acetohydroxamic acid synthesis were obtained for encapsulated cell free extract from P. aeruginosa L10 and A13, respectively. On the other hand, the half-life values obtained for the amidase solutions encapsulated in reverse micelles were overall higher than that obtained for the free amidase solution in buffer medium. Half-life values obtained for encapsulated purified amidase from P. aeruginosa strain L10 and encapsulated cell-free extract from P. aeruginosa strain AI3 were of 17.0 and 26.0 days, respectively. As far as the different sources biocatalyst are concerned, the data presented in this work has revealed that the best results, in both storage stability and biocatalytic efficiency, were obtained when encapsulated cell-free extract from P. aeruginosa strain AI3 at 14/0 of 10 were used. Conformational changes occurring upon encapsulation of both strains enzymes in reverse micelles of TAB in heptane/octanol were additionally identified by FTIR spectroscopy which clarified the biocatalysts performances.
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Magdeburg, Univ., Fak. für Mathematik, Diss., 2009
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After peripheral nerve injury in adult mammals, reestablishment of functional connections depends on several parameters including neurotrophic factors, the extracellular matrix, and hormones. However, little is known about the contribution of hormones to peripheral nerve regeneration. Thyroid hormones, which are required for the development and maturation of the central nervous system, are also important for the development of peripheral nerves. The action of triiodothyronine (T3) on responsive cells is mediated through nuclear thyroid hormone receptors (TRs) which modulate the expression of specific genes in target cells. Thus, to study the effect of T3, it is first necessary to know whether the target tissues possess TRs. The fact that sciatic nerve cells possess functional TRs suggests that these cells can respond to T3 and, as a consequence, that thyroid hormone may be involved in peripheral nerve regeneration. The silicone nerve guide model provides an excellent system to study the action of local administration of T3. Evidence from such studies demonstrate that animals treated locally with T3 at the level of transection have more complete regeneration of sciatic nerve and better functional recovery. Among the possible regulatory mechanisms by which T3 enhances peripheral nerve regeneration is rapid action on both axotomized neurons and Schwann cells which, in turn, produce a lasting and stimulatory effect on peripheral nerve regeneration. It is probable that T3 up- or down-regulates gene expression of one or more growth factors, extracellular matrix, or cell adhesion molecules, all of which stimulate peripheral nerve regeneration. This could explain the greater effect of T3 on nerve regeneration compared with the effect of any one growth factor or adhesion molecule.
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BACKGROUND: The role of estrogen and progesterone in the development of endometrial cancer is well documented. Few studies have examined the association of genetic variants in sex hormone-related genes with endometrial cancer risk. METHODS: We conducted a case-control study nested within three cohorts to examine the association of endometrial cancer risk with polymorphisms in hormone-related genes among 391 cases (92% postmenopausal at diagnosis) and 712 individually-matched controls. We also examined the association of these polymorphisms with circulating levels of sex hormones and SHBG in a cross-sectional analysis including 596 healthy postmenopausal women at blood donation (controls from this nested case-control study and from a nested case-control study of breast cancer in one of the three cohorts). RESULTS: Adjusting for endometrial cancer risk factors, the A allele of rs4775936 in CYP19 was significantly associated (OR(per allele)=1.22, 95% CI=1.01-1.47, p(trend)=0.04), while the T allele of rs10046 was marginally associated with increased risk of endometrial cancer (OR(per allele)=1.20, 95% CI=0.99-1.45, p(trend)=0.06). PGR rs1042838 was also marginally associated with risk (OR(per allele)=1.25, 95% CI=0.96-1.61, p(trend)=0.09). No significant association was found for the other polymorphisms, i.e. CYP1B1 rs1800440 and rs1056836, UGT1A1 rs8175347, SHBG rs6259 and ESR1 rs2234693. Rs8175347 was significantly associated with postmenopausal levels of estradiol, free estradiol and estrone and rs6259 with SHBG and estradiol. CONCLUSION: Our findings support an association between genetic variants in CYP19, and possibly PGR, and risk of endometrial cancer.
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The Kilkenny post-primary school survey was carried out in the spring of 1987 on a stratified random sample of 445 post-primary school children in county Kilkenny. The study was designed as the basis for evaluation of the Kilkenny Health Project's school health education programme. The study examined knowledge, attitudes and behaviour relevant to non-communicable disease. The results showed that levels of adolescent alcohol and tobacco use were similar to those found in neighbouring countries. Smoking and drinking increased during adolescence and were more prevalent in males. Physical activity decreased throughout adolescence and a high intake of 'snack' foods was found. Health related knowledge levels were high but were not related to behaviour; however attitudes were found to be consistent with behaviour. These and other results are discussed. Literature relevant to school health education and the aetiology of non-communicable disease is described, with particular reference to Ireland. The evidence supporting health promotion intervention programmes against non-communicable disease is examined and WHO and Irish policies on health promotion outlined. The importance of health and disease prevention programmes commencing in youth is emphasised and the suitability and efficacy of school health education programmes are noted. A number of school health education programmes world-wide are described. The role of the community physician in relation to such programmes is discussed. Finally recommendations are made and areas for further research are made.This resource was contributed by The National Documentation Centre on Drug Use.
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If we create the space in which children and young people can talk openly and in their own language even upon challenging subjects such as sex, then we are likely to learn more from what they tell usâ?T proposes the final UNICEF Ireland report which examines adolescent perspectives on sexual health and behaviour. Key findings in the report included: 63%, and 1 in 5 sixteen year old respondents, reported that they have had sex; 1 in 5 sexually active respondents reported that they did not use a condom the first time that they had sex; 2 in 5 girls who were sexually active reported that they had consumed alcohol before their first sexual experience, compared to 3 in 10 boys; The majority of respondents (54%) reported that they had watched pornography on the internet, and more than one third of the respondents who had watched pornography on the internet believed that it was accurate or educational; Only 1 in 5 respondents reported that they ever speak to their parents about sex. Noting â?~the broad spectrum from which young people living in Ireland draw down information about sexâ?T the UNICEF Ireland report concludes that â?~we must be sure that when a young person is making decisions about their sexual health and behaviour, every opportunity is afforded them in terms of open discussion, understanding, support, information and adviceâ?T Commenting on the Report, Amel Yucef a Youth Health Coordinator at the Base Youth Centre, Ballyfermot said â?oAs the participants in UNICEF Irelandâ?Ts survey have shown, many young people do not feel equipped with the information and support they need to make informed choices about their sexual health. Providing those supports is a priority for us at the Base.â? The Youth Health Programme, that Amel co-ordinates is a HSE funded initiative which was created to respond to the health needs of young people, as identified by the young people of the Dublin 10 area themselves. The Programme delivers community-based and youth-friendly health responses, based upon a harm-reduction model. The Youth Health Programme works towards building the capacity of young people to access health services, while also encouraging those services to deliver in an accessible and youth-friendly way.This resource was contributed by The National Documentation Centre on Drug Use.
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This is the second paper in a series, Kicking Bad Habits, on how people can be encouraged to adopt healthy behaviour. Looking at interventions targeted specifically at low-income groups, this paper asks which interventions are effective in getting people to quit smoking, eat healthily and exercise. It reveals that the most frequently used techniques are providing information and encouraging people to set goals, which can be particularly effective at changing behaviour in disadvantaged groups.
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In the urinary bladder of the toad Bufo marinus triiodothyronine selectively inhibits the late effect of aldosterone on Na+ transport. We have investigated whether T3 might mediate its antimineralocorticoid action by controlling: i) the level of aldosterone binding sites in the soluble (cytosolic) pool isolated from tissues treated with T3 (60 nM) for up to 20 hr of incubation; ii) the kinetics of uptake of 3H-aldosterone into cytoplasmic and nuclear fractions after 2 or 20 hr of exposure to T3. The number and the affinity of Type I (high affinity, low capacity) and Type II (low affinity, high capacity) cytosolic binding sites (measured at 0 degrees C) did not vary significantly after 18 hr of exposure to T3, while aldosterone-dependent Na+ transport was significantly inhibited. In addition, T3 did not modify the kinetics of uptake (90 min) of 3H-aldosterone into cytoplasmic and nuclear fractions of toad bladder incubated in vitro at 25 degrees C. By contrast, aldosterone itself was able to down-regulate its cytosolic and nuclear binding sites after an 18-hr exposure to the steroid hormone (10 or 80 nM). T3 slightly (20%) but significantly potentiated the down regulation of nuclear binding sites. In conclusion, T3 does not appear to have major effects on the regulation of the aldosterone receptor, which could explain in a simple manner its antimineralocorticoid action.
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Selostus: Kasvatushäkin ympäristön vaikutus hopeakettujen käyttäytymiseen