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Studies Worldwide (studies + worldwide)
Selected AbstractsEtiopathogenic role of HLA-B27 alleles in ankylosing spondylitisINTERNATIONAL JOURNAL OF RHEUMATIC DISEASES, Issue 3 2005Nurullah AKKOC Abstract HLA-B27 is the major genetic susceptibility factor for ankylosing spondylitis (AS). However, its precise role in the pathogenesis of AS still remains unclear, even though its gene has been cloned and sequenced, and its crystallographic structure has been defined. Arthritogenic peptide and molecular mimicry hypotheses propose mechanisms related to an antigen-presenting function of HLA-B27 to be responsible for disease development. However, peculiar aspects of its immunobiology, such as its misfolding and heavy chain dimerization raise the possibility of involvement of pathogenic mechanisms unrelated to its physiological function. Moreover, HLA-B27 is not a single allele, but a family of 31 different alleles, named HLA-B*2701 to HLA-B*2727. Studies worldwide indicate that the relatively common alleles (subtypes) HLA-B*2705, B*2704, and B*2702 are strongly associated with AS, whereas HLA-B*2706 which is prevalent in South-east Asia and HLA-B*2709 which is prevalent on the Italian island of Sardinia, seem to lack such an association. The distinction between the disease-associated subtypes and those that are not associated, may provide clues to the actual role of HLA-B27 in disease pathogenesis. B*2706 differs from B*2704 by only two residues, and B*2709 differs from B*2705 by only one residue. Moreover, both B*2706 and B*2709 bind an endogenous peptide (derived from vasoactive intestinal peptide type 1 receptor) and also an exogenous peptide (latent membrane protein 2 of Epstein-Barr virus) but in two drastically diverse conformations. These recent X-ray diffraction studies of individual peptides in the context of different HLA-B27 alleles broaden our perception of the possible pathogenetic role of this molecule in the development of AS and related spondyloarthopathies. In summary, the pathogenetic role of HLA-B27 in AS seem to be quite heterogenous, and cannot be explained by a single mechanism, and new ideas have been raised based on the aberrant immunobiologic features of HLA-B27. [source] Scientific rationale for the Finnish Allergy Programme 2008,2018: emphasis on prevention and endorsing toleranceALLERGY, Issue 5 2009L. C. Von Hertzen ,In similarity to many other western countries, the burden of allergic diseases in Finland is high. Studies worldwide have shown that an environment rich in microbes in early life reduces the subsequent risk of developing allergic diseases. Along with urbanization, such exposure has dramatically reduced, both in terms of diversity and quantity. Continuous stimulation of the immune system by environmental saprophytes via the skin, respiratory tract and gut appears to be necessary for activation of the regulatory network including regulatory T-cells and dendritic cells. ,Substantial evidence now shows that the balance between allergy and tolerance is dependent on regulatory T-cells. Tolerance induced by allergen-specific regulatory T-cells appears to be the normal immunological response to allergens in non atopic healthy individuals. Healthy subjects have an intact functional allergen-specific regulatory T-cell response, which in allergic subjects is impaired. Evidence on this exists with respect to atopic dermatitis, contact dermatitis, allergic rhinitis and asthma. Restoration of impaired allergen-specific regulatory T-cell response and tolerance induction has furthermore been demonstrated during allergen-specific subcutaneous and sublingual immunotherapy and is crucial for good therapeutic outcome. However, tolerance can also be strengthened unspecifically by simple means, e.g. by consuming farm milk and spending time in nature. ,Results so far obtained from animal models indicate that it is possible to restore tolerance by administering the allergen in certain circumstances both locally and systemically. It has become increasingly clear that continuous exposure to microbial antigens as well as allergens in foodstuffs and the environment is decisive, and excessive antigen avoidance can be harmful and weaken or even prevent the development of regulatory mechanisms. ,Success in the Finnish Asthma Programme was an encouraging example of how it is possible to reduce both the costs and morbidity of asthma. The time, in the wake of the Asthma Programme, is now opportune for a national allergy programme, particularly as in the past few years, fundamentally more essential data on tolerance and its mechanisms have been published. In this review, the scientific rationale for the Finnish Allergy Programme 2008,2018 is outlined. The focus is on tolerance and how to endorse tolerance at the population level. [source] Would the elderly be better off if they were given more placebos?GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 2 2010E Paul Cherniack Placebos are useful in the medical care of the elderly, although the exact definition of a "placebo" or "placebo effect" is difficult to define precisely. They have an important role as control treatments in research trials, but a non-specific "placebo effect" may also be beneficial part of many physician,patient interactions. Physicians also give them deliberately according to several studies worldwide to satisfy patient demands or because they believe in a "placebo effect" among other reasons. A significant placebo effect has been observed among older patients in clinical trials of antidepressants (12,15%), and in treatments of Parkinson's disease (16%). Placebos activate serotonergic pathways in the brain used by antidepressants. In Parkinson's disease, the administration of a placebo stimulates dopamine release in the dorsal (resulting in motor effects) and ventral striatum (which influences expectation of reward). Much of our understanding of the placebo effect comes from studies of placebo analgesia which is influenced by conditioning, expectation, meaning and context of the treatment for the patient, and patient,physician interaction. It is anatomically medicated by brain opioid pathways. Response to "sham" acupuncture in osteoarthritis may be an example of its use in the elderly. Placebos have often been considered a deception and thus unethical. On the other hand, some physicians and ethicists have suggested conditions for appropriate uses for placebos. A placebo might offer the theoretical advantage of an inexpensive treatment that would not cause adverse drug reactions or interactions with other medications, potentially avoiding complications of polypharmacy. [source] A systematic review of trend studies of women seeking termination of pregnancyJOURNAL OF CLINICAL NURSING, Issue 22 2008Wendy Abigail Aims and objectives., This article reports a systematic review of trend studies (1995,2006) which answers five questions: What are the patterns of: 1,Age of women seeking termination of pregnancy; 2,First ever pregnancy ending in a termination; 3,Contraception usage at the time of conception; 4,Contraception chosen immediately postoperatively; and 5,Referral sources to termination of pregnancy services. Background., Fertility patterns are changing and there is evidence to indicate that the numbers of older women conceiving for the first time are increasing. At the same time, there are new methods of contraception widely available. Little is known about the implications of these changes on termination patterns. Design., An extensive electronic search of databases such as CINAHL, MEDLINEŽ In-Process (OVID) and was conducted from January 1995,June 2006 for trend studies in pregnancy terminations. Methods., Articles chosen were based on trend studies greater than five years, contained primary quantitative research and official government statistical reports. Results., Results of the search showed age that was unable to be compared because of the many variations in measurements and time periods, and there was only limited research worldwide of trends in contraception at the time of conception in relation to a termination of pregnancy. Additionally, there were no studies worldwide in the past 11 years, which specifically examined trends in the characteristics of the number of first-ever pregnancies which ended in a termination, contraception choices postoperative to a termination of pregnancy, or referral source to a termination of pregnancy provider. Conclusion., Little is reported in the literature on trends in the five characteristics related to pregnancy termination. Relevance to clinical practice., Evidence about the changing patterns of women seeking pregnancy termination is needed to inform policy and practice, and to ensure that health promotion strategies are underpinned by accurate information that reflects the needs of the populations of women in relation to their reproductive health. [source] | ||||||||||