205 resultados para sexual differentiation
Resumo:
Male infertility affects one man in twenty and a genetic basis seems likely in at least 30% of those men. Genetic regulation of fertility involves the inter-related processes of testicular development, spermatogenesis (involving germ cell mitosis, meiosis and spermatid maturation), and their endocrine and paracrine regulation. In regard to spermatogenesis, particular attention has been given to the Yq11 region, where some spermatogenesis genes ('azoospermia factors') appear to be located. Several candidate genes have been identified but have not been shown to have a defined or essential role in spermatogenesis. Microdeletions of Yq11 are found in approximately 15% of azoospermic or severely oligospermic men. The complexity of the genetic control of male fertility is demonstrated by the evidence for genes involved in spermatogenesis and sexual differentiation on the X chromosome and autosomes. Better understanding of the genetic regulation of normal spermatogenesis will provide new probes for clinical studies; however, at present the majority of spermatogenic failure remains without an identified genetic linkage. The advent of intracytoplasmic sperm injection permits fertility in many previously sterile men and presents the possibility of their transmission of infertility; appropriate counselling is required.
Resumo:
Molecular marker studies reported here, involving allozymes, mitochondrial DNA and microsatellites, demonstrate that ferox brown trout Salmo trutta in Lochs Awe and Laggan, Scotland, are reproductively isolated and genetically distinct from co-occurring brown trout. Ferox were shown to spawn primarily, and possibly solely, in a single large river in each lake system making them particularly vulnerable to environmental changes. Although a low level of introgression seems to have occurred with sympatric brown trout, possibly as a result of human-induced habitat alterations and stocking, ferox trout in these two lakes meet the requirements for classification as a distinct biological, phylogenetic and morphological species. It is proposed that the scientific name Salmo ferox Jardine, 1835, as already applied to Lough Melvin (Ireland) ferox, should be extended to Awe and Laggan ferox.
Resumo:
This article explores the use of shaming mechanisms with sexual offenders, particularly those who offend against children. Shaming, a central concept in the broader theory of restorative justice, may be of two varieties. The first, ‘disintegrative shaming’, characterises the traditional retributive framework of justice and is evident in recent state led and popular responses to the risk posed by released sexual offenders. Far from ensuring offender integration, the net result is often labelling, stigmatisation, ostracism and a return to offending behaviour. The second, ‘reintegrative shaming’, affirms the offender’s membership within law abiding society. This has been used in several jurisdictions as the basis of restorative support and treatment networks for sexual offenders where the community works in partnership with state and voluntary agencies. Contrary to arguments put forward by critics of restorative justice, this article argues that such cases may be particularly suitable for a restorative approach.
Resumo:
The term ‘grooming’ has been used to describe the offender’s actions during the preparatory stage of sexual abuse. This paper will argue that current discourses on grooming have created ambiguities and misunderstandings about child sexual abuse. In particular, the popular focus on ‘stranger danger’ belies the fact that the majority of children are abused by someone well known to them, where grooming can also occur. Current discourses also neglect other important facets of the sex offending pattern. They fail to consider that offenders may groom not only the child but also their family and even the local community who may act as the gatekeepers of access. They also ignore what can be termed ‘institutional grooming’ – that sex offenders may groom criminal justice and other institutions into believing that they present no risk to children. A key variable in the grooming process is the creation and subsequent abuse of trust. Given that the criminal law may be somewhat limited in its response to this type of behaviour, ultimately concerted efforts must be made to foster social and organisational awareness of such processes in order to reduce the offender’s opportunity for abuse.
Resumo:
Two National Surveys of Sexual Attitudes and Lifestyles in Britain (Natsal) were conducted, one in 1990 and one in 2000. Northern Ireland was excluded from both studies. Now, for the first time, comparable data about sexual attitudes and lifestyles of young people (14- to 25-year-olds) in Northern Ireland are available. Data were collected through self-administered questionnaires, one-to-one interviews and focus-group discussions. As in Natsal 1990 and 2000, young people were asked about their sexual attitudes towards sex, experiences of sex education, knowledge of sexually transmitted infections (STIs) and, if sexually active, about the circumstances in which sexual intercourse occurred. A total of 1013 young people in the target age group completed the self-administered questionnaire. Young people in Northern Ireland do not differ significantly from their counterparts in Britain in terms of sexual lifestyles and attitudes. Some 53.3% of all respondents reported that they had had sexual intercourse. Condom use at first sex was reported by 64% of sexually active respondents; 27.4% said they used no contraception; 26.7% of all respondents said they had sex before age 16. Respondents who first had sex when they were 15 or 16 years were more likely than other respondents to say that 'being drunk' was the main reason why intercourse occurred. Peer pressure to engage in sex was more prevalent among males than females. Young people in Northern Ireland regard friends as their most important source of sex education. School is the second most important source but most respondents wanted more sex education in school. It is important that it is needs focused and includes potentially sensitive and contentious information.
Resumo:
INTRODUCTION: In addition to its role in apoptosis suppression, Bcl-2 has been reported to be co-expressed with neuroendocrine markers in several tissues, leading to speculation that this oncoprotein may promote neuroendocrine differentiation. AIM: This study investigated whether Bcl-2 modulated neuroendocrine biopeptide expression. METHODS: Levels of chromogranin A, neurone specific enolase, protein gene peptide 9.5, pancreatic polypeptide, and the chromogranin-derived peptides, intervening peptide and vasostatin-1 were examined by immunocytochemistry in rat phaeochromocytoma (PC12) cell lines genetically engineered to over-express Bcl-2 and their mock-transfected controls. Intensity of fluorescence was graded using a semi-quantitative scale from (-) indicating negative expression to (+++) indicating intense positivity. RESULTS: Mann-Whitney U analysis indicated that no significant differences in expression existed between control and Bcl2 over-expressing cell lines for any of the six peptides examined. CONCLUSIONS: The results of this study do not support the hypothesis that Bcl-2 promotes the acquisition of a neuroendocrine phenotype.