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Congenital melanocytic naevi (CMN) are a known risk factor for melanoma, with the greatest risk currently thought to be in childhood. There has been controversy over the years about the incidence of melanoma, and therefore over the clinical management of CMN, due partly to the difficulties of histological diagnosis and partly to publishing bias towards cases of malignancy. Large cohort studies have demonstrated that melanoma risk in childhood is related to the severity of the congenital phenotype. New understanding of the genetics of CMN offers the possibility of improvement in diagnosis of melanoma, identification of those at highest risk, and new treatment options. We review the world literature and our centre's experience over the last 25 years, including the molecular characteristics of melanoma in these patients and new melanoma incidence and outcome data from our prospective cohort. Management strategies are proposed for presentation of suspected melanoma of the skin and the central nervous system in patients with CMN, including use of oral mitogen‐activated protein kinase kinase inhibitors in NRAS‐mutated tumours.  相似文献   
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A case of maternal uniparental disomy of chromosome 13 is described. The subject is a phenotypically normal male who inherited a t(13;13)(p11.2;p11.2) from his mother who is a carrier of this translocation. The mother was ascertained through a history of recurrent abortion and is phenotypically normal. The translocation in both subjects was studied by cytogenetic and DNA analysis and appears to be a true dicentric isochromosome. These findings show that maternal uniparental disomy of chromosome 13 has had no pathological consequences and suggests that there is no imprinting of genes on maternally derived chromosome 13.  相似文献   
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OBJECTIVE: Women are more likely to receive breast and cervical cancer screening if they see female physicians. We studied whether this is due to differences between male and female physicians, or to differences in their patients. SETTING: Large midwestern, independent practice association style of health plan. DESIGN: We surveyed male and female primary care physicians matched for age and specialty and a stratified random sample of three of each physician's women patients. Physicians reported on their practice setting, their attitudes and practices regarding prevention, and their comfort and skill with various examinations. Patients reported on their sociodemographic characteristics, their attitudes and practices regarding prevention, and their preferences for physician gender. Claims data were used to calculate mammography and Pap smear screening rates for the physicians PARTICIPANTS: We studied 154 female and 190 male internists and family physicians and 794 of their patients. MEASUREMENTS AND MAIN RESULTS: We compared the responses of male and female physicians and their patients and used multivariable analysis to identify the patient and physician factors that accounted for the differences in screening rates between male and female physicians. Female physicians were more likely to ask new patients about components of prevention, to believe in the effectiveness of mammography, to feel more personal responsibility for ensuring that their patients received screening, and to report more comfort in performing Pap smears and breast examinations. Patients of female physicians were more educated and less likely to be married, but did not differ in other sociodemographic characteristics. They had similar attitudes and practices regarding prevention, except that patients of male physicians were more likely to smoke. Significantly more patients of female physicians preferred a female for some component of care. In multivariable analyses, practice organization, patient preference for a female physician, and prevention orientation of female physicians accounted for up to 40% of screening rate differences between female and male physicians for Pap smears, and 33% for mammography. CONCLUSIONS: Differences in beliefs of male and female physicians and patient preference for a female provider contribute independently to the higher rate of breast and cervical cancer screening by female physicians.  相似文献   
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X-linked hyper-IgM syndrome (XHIM) results from mutations in the gene encoding for CD40 ligand (CD154). Patients with the syndrome suffer from infections with opportunistic pathogens such as Cryptosporidium and Pneumocystis carinii. In this study, we demonstrate that activated T cells from patients with XHIM produce markedly reduced levels of IFN-gamma, fail to induce antigen-presenting cells to synthesize IL-12, and induce greatly reduced levels of TNF-alpha. In addition, we show that the patients' circulating T lymphocytes of both the CD4(+) and CD8(+) subsets contain a markedly reduced antigen-primed population, as determined by CD45RO expression. Finally, we demonstrate that the defects in antigen priming are likely due to the lack of CD154 expression and insufficient costimulation of T cells by CD80/CD86 interactions. Taken together, this study offers a basis for the increased susceptibility of patients with XHIM to certain opportunistic infections.  相似文献   
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This paper is focused on selected items from an exploratory study of nurse tutor-student nurse role-relationships. Aspects of the teacher-student and counsellor-client dimensions of the relationship are reported. The research was conducted from a sociological perspective using role theory as the organizing theoretical framework. An 'ideal type' tutor-student relationship was proposed from the findings. There was concensus between tutors and students that tutors acted in a caring way towards students but many constraints were identified which inhibited students with problems from seeking help from tutors and prevented tutors from offering all the help which they wished to give to students.  相似文献   
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