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Related Subjects (relate + subject)
Selected AbstractsMultiple pathology and tails of disability: Space,time structure of disability in longevityGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 4 2003Satoru Matsushita Disability and the resulting lowered quality of life are serious issues accompanying increased longevity. Curiously, despite its potential contribution to aging theory, complete statistical and etiological structures of this common and unwelcome aging phenotype before death have not been well identified. Another neglected issue in aging and disability is the principles of phylogenesis and morphogenesis, which contemporary life science invariably starts with. In the present review these two related subjects are addressed, with an introduction of an analysis on patients and published data. Statistically rigorous log,normal and normal distributions distinguish disability for its duration and age-wise distribution, respectively. Multiple pathology and diverse effects of various endogenous diseases on disability are confirmed. The robust long-tailed log,normal distribution for various phases of disability validates the fact that patients in disability undergo series of stochastic subprocesses of many independent endogenous diseases until death. For 60% of patients, the log,normal distribution is mimicked by a random walk model. Diseases of core organs are major causes of the long tails. A declining force of natural selection after reproduction and trade-off of life history through pleiotropy of the genes are considered to be the roots of aging. The attenuated selection pressure and the resulting decrease of genetic constraints produce an increased opportunity for chance and stochastics. Elucidated stochastic behaviors of disability underscore the key role of chance in aging. Evolutionary modifications in the development of the structure tend to favor developmentally later stages first. Distal parts are developmentally last, therefore most subject to modification. The rate of molecular evolution of the genes is also found to be relatively slow at the core and rapid at the edge of cells and organs. Therefore, systems at the core must be relatively slow and inactive to comply with pleiotropy and trade-offs in comparison with systems at the edge. Hence, against flat and probabilistic aging, the core organs must be moulded to be more robust with a lower threshold for dysfunction, to age relatively slowly, and should have less of a disease quota in aging. The principle of core protective aging assures possibilities not only to reduce disability but also to accomplish the Third Age as well. Finally, it must also be acknowledged that the principle is a double-edged sword. Paradoxically, the developed biological and societal organization provides protection for the injured core, and so develops long tails of disability. The principle of core protective aging re-emphasizes the key role of prevention in order to reduce the amount of disability. [source] Mutational analysis of HOXD13 and HOXA13 genes in the triphalangeal thumb,brachyectrodactyly syndromeJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2002A. Pérez-Cabrera Abstract The triphalangeal thumb-brachyectrodactyly syndrome is a very rare autosomal dominant disorder of unknown etiology characterized by an unusual pattern of limb malformations: triphalangeal thumbs and brachyectrodactyly in the hands, and ectrodactyly in the feet. In a previous report, we described the clinical and radiographical features of three related subjects with the disease and suggest that due to the unusual combination of limb defects and to its phenotypic similarity with the limb malformative pattern induced by disrupting the Hoxd13 gene in mouse, the triphalangeal thumb-brachyectrodactyly syndrome might be caused by mutations in a HOX gene. After sequencing the entire coding region of HOXD13 and the highly conserved homeodomain encoding region of HOXA13, we do not detect any deleterious mutation in any of the patients excluding that alterations at these sequences are responsible for the disease. Mutations in regulatory regions of these genes or in other genes involved in limb development might be responsible for the disease. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Mesothelioma in blood related subjects: Report of 11 clusters among 1954 Italy cases and review of the literatureAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 5 2007Valeria Ascoli Abstract Background Malignant mesothelioma is a sporadic tumor related to asbestos. Its occurrence in blood relatives raises the question of potential contribution of predisposing factors. Methods The study analyses the features of mesothelioma in blood relatives that might explain the disease clustering. Data sources of familial clusters were three population-based Mesothelioma Registries in Italy (Veneto and Apulia Regions, Brescia province; 1978,2005) and Medline, Toxline, and Oshline/Hseline databases for a review of the literature (1968,2006). Results Eleven clusters (22 cases) were identified among 1954 Italy mesothelioma cases, and 51 clusters (120 cases) were extracted from 33 studies. The proportion of Italy familial cases was 1.4 per 100 mesothelioma cases; the ratio between the number of familial clusters and the number of non-familial mesothelioma cases was 1:148. The mesothelioma profile in consanguineous is the same as in non-consanguineous subjects (male prevalence; pleural site; age at diagnosis >50 years; asbestos exposure). Most clusters occurred in asbestos workers (shipyard, asbestos-cement production/processing, and insulation) and household-exposed blood relatives. Others were related to asbestos-cement factory pollution, asbestos-in-place, and handling asbestos-contaminated textiles. Two clusters were without any known exposure. Cancer family history revealed lung cancer cases in eight clusters. Conclusions Available data support asbestos exposure as the main risk factor in mesothelioma cases among blood relatives. Our finding of a low proportion of familial cases would not suggest the influence of a large genetic component for mesothelioma in blood relatives. Am. J. Ind. Med. 50:357,369, 2007. © 2007 Wiley-Liss, Inc. [source] Additive preconditioning in matrix computationsPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2007V. Y. Pan We combine our novel SVD-free additive preconditioning with aggregation and other relevant techniques to facilitate the solution of a linear system of equations and other fundamental matrix computations. Our analysis and experiments show the power of our algorithms, guide us in selecting most effective policies of preconditioning and aggregation, and provide some new insights into these and related subjects. Compared to the popular SVD-based multiplicative preconditioners, our additive preconditioners are generated more readily and for a much larger class of matrices. Furthermore, they better preserve matrix structure and sparseness and have a wider range of applications (e.g., they facilitate the solution of a consistent singular linear system of equations and of the eigen-problem). (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The Relevance of student seminars on clinically related subjects in a biochemistry course for medical and nutrition students,BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 1 2002Marcelo Hermes-Lima Abstract The aim of this study was to determine the value of a system of seminars on clinically related biochemistry topics for undergraduate students in medicine and nutrition at the University of Brasília, Brazil. During the second semester of 1998 (1998,2), the teaching staff decided to establish new and stricter rules for the seminar method and to adopt a system of peer tutoring, whereby former good to excellent students of the class Bioquímica e Biofísica helped in the planning and preparation of the oral presentations. The average performance grades for the seminars in the first semester of 1998 (1998,1) (7.19 ± 1.42) were significantly lower than those for the following semesters (ranging from 8.10 to 8.91), indicating some degree of success with the new system. We also conducted, by means of questionnaires, an evaluation (scores ranging from 0 to 4) of each student seminar (14 topics) in relation to the overall biochemistry learning experience connected to the clinical expectations of the students. All seminars but one averaged above 3.0. Moreover, when asked whether (i) the seminars were relevant to a more clinical approach to biochemistry and whether (ii) the oral presentations could be viewed as valid tools for the understanding of biochemistry, 96% (n = 188) and 80.6% (n = 150) of the students, respectively, answered, "yes." The students also scored the work of the peer tutors high (ranging from 3.38 to 3.90, out of 4). A seminar system for a clinically related biochemistry course may also open the minds of students about the relevance of biochemistry to their future medical or nutritional practices. [source] | ||||||||||