Epidemiology and unique aspects of aging and infectious diseases.
(49/1873)
The elderly population will grow rapidly over the next 25 years. The majority of patients with serious or life-threatening infections will be old. It is imperative that primary care physicians and infectious diseases specialists become aware of and knowledgeable about the special and unique aspects of infections in the geriatric population. (+info)
Exercise and the immune system: regulation, integration, and adaptation.
(50/1873)
Stress-induced immunological reactions to exercise have stimulated much research into stress immunology and neuroimmunology. It is suggested that exercise can be employed as a model of temporary immunosuppression that occurs after severe physical stress. The exercise-stress model can be easily manipulated experimentally and allows for the study of interactions between the nervous, the endocrine, and the immune systems. This review focuses on mechanisms underlying exercise-induced immune changes such as neuroendocrinological factors including catecholamines, growth hormone, cortisol, beta-endorphin, and sex steroids. The contribution of a metabolic link between skeletal muscles and the lymphoid system is also reviewed. The mechanisms of exercise-associated muscle damage and the initiation of the inflammatory cytokine cascade are discussed. Given that exercise modulates the immune system in healthy individuals, considerations of the clinical ramifications of exercise in the prevention of diseases for which the immune system has a role is of importance. Accordingly, drawing on the experimental, clinical, and epidemiological literature, we address the interactions between exercise and infectious diseases as well as exercise and neoplasia within the context of both aging and nutrition. (+info)
Management of patients with community-acquired pneumonia in a primary care hospital: a critical evaluation.
(51/1873)
The aim of the study was to evaluate routine management of patients with community-acquired pneumonia (CAP) with regard to severity patterns, diagnostic approaches and results, as well as initial empiric antimicrobial treatment and its impact on outcome. Two hundred and thirty-two consecutive patients with CAP admitted to a primary care hospital were studied prospectively. Patients were classified according to Fine's severity score. Severe pneumonia was defined as admission at the ICU. Diagnostic approaches and initial antimicrobial treatment were judged according to the guidelines of the European Respiratory Society (ERS). Fifty-five patients (24%) had mild, 156 (67%) moderate, and 21 (9%) severe CAP. At least one microbial examination was performed in 124 patients (54%). There was no association between microbial investigation and severity of CAP. Inadequate initial antimicrobial treatment was significantly more frequent in severe (18/21, 86%), than in mild (5/55, 9%) and moderate CAP (39/156, 25%, P < 0.0001). Conversely, antimicrobial overtreatment occurred significantly more often in mild (30/55, 55%) and moderate (77/156, 49%) than in severe CAP (0/21, 0%, P < 0.0001). Inadequate initial antimicrobial treatment was more frequent in non-responders [18/62 (29%) vs. 31/170, (18%), RR 1.6 95% CI 0.9-2.6, P = 0.07] and was associated with a longer duration of hospitalization (17 +/- 11 vs. 14 +/- 8 days, P = 0.03). Mortality was not affected by inadequate initial antimicrobial treatment [5/62 (8%) vs. 10/170 (6%), RR 1.4 95% CI 0.5-3.9, P=0.55]. Principal conceptual weaknesses which might be subject to intervention were (1) the hospitalization of patients with mild pneumonia at low risk of mortality; (2) the lack of association between microbial investigation and severity of CAP; (3) antimicrobial overtreatment of patients with non-severe CAP; and (4) inadequate antimicrobial treatment with increased number of primary treatment failures and duration of hospitalization. (+info)
Does social medicine still matter in an era of molecular medicine?
(52/1873)
To ask whether social medicine still matters may seem to be in poor taste at a symposium to honor Martin Cherkasky, but social medicine has always had the courage to take on difficult questions. There is all the more reason to do so when its legitimacy is challenged. The extraordinary findings emerging from the human genome project will revolutionize diagnostic and therapeutic methods in medicine. The power of medical interventions, for good and for harm, will increase enormously. However, in the next millennium, as in this one, social factors will continue to be decisive for health status. The distribution of health and disease in human populations reflects where people live, what they eat, the work they do, the air and the water they consume, their activity, their interconnectedness with others, and the status they occupy in the social order. Virchow's aphorism is as true today as it was in 1848: "If disease is an expression of individual life under unfavorable conditions, then epidemics must be indicative of mass disturbances of mass life." Increasing longevity resulting from major economic transformations has made ours the age of chronic disease. Changes in diet and behavior transform genes that once conferred selective biologic advantage into health hazards. Although disease risk varies with social status, medical care makes an important difference for health outcomes. Access to care and the quality of care received are functions of social organization, the way care is financed, and political beliefs about the "deserving" and the "underserving" poor. It is a moral indictment of the US that ours is the only industrialized society without universal health care coverage. In educating the American public about the social determinants of health, a goal Martin Cherkasky championed, the very power of the new molecular biology will help make our case. Social medicine is alive and well. (+info)
Sickness absence and early retirement on health grounds in the construction industry in Ireland.
(53/1873)
OBJECTIVE: To establish a detailed pattern of the nature and extent of illnesses and injuries among construction workers in Ireland which cause temporary absence from work, and to identify diseases and disabilities which lead to premature retirement from the industry on health grounds. METHODS: The population base for the study consisted of construction workers who were members of the Construction Federation operatives pension and sick pay scheme. Records of sickness absence since 1981, stored on computer disks, and records of early retirement on health grounds since 1972, stored on microfiche film, were examined. Pertinent data were extracted and transferred to a database; after cleaning and the exclusion of unvalidated data, records of 28 792 absences and 3098 records of early retirement were available for analysis. Data were analysed with Access 97 and Epi Info. RESULTS: Over the period of the study the mean annual absences were 7.8/100 workers. Three quarters of absences were among younger workers; however, the rate of absence increased with age, as did the mean duration of absence. Injury was the most frequent reason for absence, followed by infectious disease, then musculoskeletal disorders. The mean annual rate of early retirement on health grounds was 5.3/1000 workers. The median age at retirement was 58 years. Cardiovascular disease and musculoskeletal disorders each accounted for nearly one third of the conditions leading to permanent disability on the grounds of which early retirement was granted. During the period of the study, over 677 000 working days were lost due to sickness absence, and over 24 000 potential years of working lives were lost due to early retirement on health grounds. CONCLUSIONS: The study has shown patterns of sickness absence and early retirement on health grounds in the Irish construction industry which will contribute to the further development of health promotion strategies for construction workers. (+info)
Micronutrients and infectious diseases: thoughts on integration of mechanistic approaches into micronutrient research.
(54/1873)
Results of field and laboratory studies provide convincing evidence that micronutrient deficiencies contribute to the mortality and morbidity of infectious diseases. Despite encouraging results in large trials, understanding the mechanisms by which micronutrients contribute to the outcome of the encounter between an individual and an infectious agent requires additional hypothesis-driven research. Presumably, such understanding should lead to translational studies with targeted nutritional therapy. Although these mechanistic studies are varied and complex, they must be done systematically and should include examination of the mechanisms by which micronutrients affect host-pathogen interactions, development of appropriate animal models and reliable methods for the assessment of micronutrient levels, and translation of the results of basic research findings into clinical studies. Moving the frontiers of micronutrient research from the laboratory to the field will be challenging. However, sound scientific research should lead toward better human health. (+info)
Effects of zinc deficiency on Th1 and Th2 cytokine shifts.
(55/1873)
Nutritional deficiency of zinc is widespread throughout developing countries, and zinc-deficient persons have increased susceptibility to a variety of pathogens. Zinc deficiency in an experimental human model caused an imbalance between Th1 and Th2 functions. Production of interferon-gamma and interleukin (IL)-2 (products of Th1) were decreased, whereas production of IL-4, IL-6, and IL-10 (products of Th2) were not affected during zinc deficiency. Zinc deficiency decreased natural killer cell lytic activity and percentage of precursors of cytolytic T cells. In HuT-78, a Th0 cell line, zinc deficiency decreased gene expression of thymidine kinase, delayed cell cycle, and decreased cell growth. Gene expression of IL-2 and IL-2 receptors (both alpha and beta) and binding of NF-kappaB to DNA were decreased by zinc deficiency in HuT-78. Decreased production of IL-2 in zinc deficiency may be due to decreased activation of NF-kappaB and subsequent decreased gene expression of IL-2 and IL-2 receptors. (+info)
Vitamin A supplementation: implications for morbidity and mortality in children.
(56/1873)
Vitamin A deficiency impairs epithelial integrity and systemic immunity and increases the incidence and severity of infections during childhood. However, findings from vitamin A supplementation trials are not consistent. Supplementation has resulted in significant reductions in mortality in several (but not all) large community-based trials among apparently healthy children. In hospital-based studies, vitamin A supplements have been consistently found to reduce the severity of measles infection, but no effect on nonmeasles respiratory infections has been observed. In some cases, the supplements were associated with an apparently increased risk of lower respiratory infection. Vitamin A supplements also reduced the severity of diarrhea in most (but not all) trials. Potential explanations for the differences in efficacy across trials are reviewed. While vitamin A supplementation is effective in reducing total mortality and complications from measles infections, it is likely to be more effective in populations suffering from nutritional deficiencies. (+info)