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Selected AbstractsAtypical nevi of the scalp in adolescentsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 5 2007Giujeppe Fabrizi Background:, A few reports in the literature point out that in special areas of the body, nevi can have peculiar pseudomelanomatous features. In our routine work, we have met few examples of atypical nevi with peculiar features on the scalp of teenagers. To evaluate the frequency and the biological behaviour of these lesions, we have conducted a complete survey on melanocytic lesions on the scalp in a significant group of patients. Materials and methods:, Thirty-nine nevi of the scalp were from adolescents (12,18 years), 160 from adults, and 30 from children below the age of 12 years. Results:, About 10% of the melanocytic nevi of the scalp of adolescents have atypical cytological and architectural aspects that are different from those seen in Clark's dysplastic nevus. The most striking features were the presence of large bizarrely shaped nests scattered disorderly along the junction with follicular involvement. Other findings were pagetoid spread of cells above the junction and the discohesive pattern of the melanocytes in the nests. Mild cytological atypia was present but less significant. Such distinctive aspects are not found in nevi of the same site in adults or younger children. The general pattern of these atypical nevi of the scalp of adolescents closely recalls that of the so-called atypical nevi on special sites, i.e. nevi on mammary line, genitalia and body's folds. Despite the architectural and cytological atypia, clinical follow-up does not show any tendency to recur or proclivity to malignant behaviour. Conclusions:, Despite their similarities with melanoma, the nevi with atypical features of the scalp of adolescents are probably an entirely benign entity, at least at the moment of their excision. However, although benign, the relationship of this peculiar group of nevi with melanomas developed in adulthood remains entirely unknown, and the complete excision with conservative margins seems a recommendable procedure. [source] The use of leukocyte profiles to measure stress in vertebrates: a review for ecologistsFUNCTIONAL ECOLOGY, Issue 5 2008A. K. Davis Summary 1A growing number of ecologists are turning to the enumeration of white blood cells from blood smears (leukocyte profiles) to assess stress in animals. There has been some inconsistency and controversy in the ecological literature, however, regarding their interpretation. The inconsistencies may stem partly from a lack of information regarding how stress affects leukocytes in different taxa, and partly from a failure on the part of researchers in one discipline to consult potentially informative literature from another. 2Here, we seek to address both issues by reviewing the literature on the leukocyte response to stress, spanning the taxa of mammals (including humans), birds, amphibians, reptiles and fish. 3We show that much of the early literature points to a close link between leukocyte profiles and glucocorticoid levels. Specifically, these hormones act to increase the number and percentage of neutrophils (heterophils in birds and reptiles), while decreasing the number and percentage of lymphocytes. This phenomenon is seen in all five vertebrate taxa in response to either natural stressors or exogenous administration of stress hormones. For the ecologist, therefore, high ratios of heterophils or neutrophils to lymphocytes (,H : L' or ,N : L' ratios) in blood samples reliably indicate high glucocorticoid levels. Furthermore, this close relationship between stress hormones and N : L or H : L ratios needs to be highlighted more prominently in haematological assessments of stress, as it aids the interpretation of results. 4As with hormone assays, there are challenges to overcome in the use of leukocytes profiles to assess levels of stress; however, there are also advantages to this approach, and we outline each. Given the universal and consistent nature of the haematological response to stress, plus the overwhelming evidence from the veterinary, biomedical and ecological literature reviewed here, we conclude that this method can provide a reliable assessment of stress in all vertebrate taxa. [source] Principal-agent relationships on the stewardship-agency axisNONPROFIT MANAGEMENT & LEADERSHIP, Issue 1 2006Ralf Caers This article provides an overview of the literature on nonprofit principal-agent relationships. It depicts the nature of agency theory and stewardship theory, analyzes the origin of their struggle within the nonprofit structure, and marks directions for a conciliatory approach. We open with an introduction to agency theory and discuss the two main components of its mathematical branch. We thereby contrast it with stewardship theory and elaborate on the arguments that can affect the position of nonprofit principal-agent relationships on the stewardship-agency axis. Analysis of the existing literature points to a lack of consensus as to which theory should be applied. We argue that the division of nonprofit principalagent relationships into board-manager and manageremployee interactions may help to clarify the balance between agency theory and stewardship theory and may lead to the establishment of a strongly founded theory on nonprofit principal-agent relationships. We close with a discussion of how this article may prove valuable to nonprofit policymakers and other empirical researchers. [source] The prediction of coronary atherosclerosis employing artificial neural networksCLINICAL CARDIOLOGY, Issue 6 2000Jacob George M.D. Abstract Background: Atherosclerosis is a complex histopathologic process that is analogous to chronic inflammatory conditions. Several factors have been shown to correlate with the extent of atherosclerosis. Whereas hypertension, obesity, hyperlipidemia, diabetes, smoking, and family history are all well documented, recent literature points to additional associated factors. Thus, antibodies to oxidized low-density lipoprotein (oxLDL), cytomegalovirus (CMV), Chlamydia pneumonia, Helicobacter pylori, as well as homocysteine and C-reactive protein (CRP) levels have all been implicated as independent markers of accelerated atherosclerosis. Hypothesis: In the current study we attempted to formulate a system by which to predict the extent of coronary atherosclerosis as assessed by angiographic vessel occlusion. Methods: The 81 patients were categorized as having single-, double-, triple-, or no vessel involvement. The clinical data concerning the "classic" risk factors were obtained from clinical records, and sera were drawn from the patients for determination of the various parameters that are thought to be associated with atherosclerosis. Results: Using four artificial neural networks, we have found the most effective parameters predictive of coronary vessel involvement were (in decreasing order of importance) antibodies to oxLDL, to cardiolipin, to CMV, to Chlamydia pneumonia, and to ,2-glycoprotein I (,2GPI). Although important in the prediction of vessel occlusion, hyperlipidemia, hypertension, CRP levels, and diabetes were less accurate. Conclusion: The results of the current study, if reproduced in a larger population, may establish an integrated system based on the creation of artificial neural networks by which to predict the extent of atherosclerosis in a given subject fairly and noninvasively. [source] |