Immunitat und Infektion最新文献

In order to evaluate potential health effects on days with elevated ozone concentrations, lung function parameters and subjective votes on irritations of eyes and airways were taken repeatedly from subjects belonging to four assumed ozone risk groups and one control group (at least 40 subjects each) - senior citizens, juvenile asthmatics, forestry workers, athletes and clerks - in comparison of days with elevated (at least 100 micrograms/m3) and low ozone concentrations (at most 80 micrograms/m3). The results show no relevant ozone effects for the groups, "senior citizens" and "athletes", only minor pulmonary effects for "juvenile asthmatics", but significantly higher airway resistances on "ozone days" for "forestry workers" (by 21%) and "clerks" (by 16%). On days with moderately elevated levels of ozone in the environment it is assumed that ozone itself has minor influence on pulmonary responses compared to that of other constituents of the air in certain location like forest or indoors.

Immunoadsorption (IMAD) is a particle extracorporeal therapy in treatment of various autoimmune diseases which differs from plasmapheresis. In the case presented here IMAD was helpful in the therapy of an acute renal failure due to an antiglomerular basement membrane disease. IMAD resulted in a quick recovery and stabilisation of the renal function. In addition to IMAD, the patient was treated with steroids, an immunosuppressive therapy was started immediately after IMAD. Considering the course of this patient's disease, we are convicted that IMAD was a major factor in the therapeutic success. IMAD was well tolerated by the patient, no side effects were seen.

Free radicals and reactive oxygen species can damage cells and tissues of biological organisms. Due to the fact that these compounds are generated continuously in living cells defense mechanisms must exist. This so-called antioxidative system ensures that the formation of free radicals during different physiological processes does not result in cellular damage. Free radicals (oxidants) are produced form the immune system. The purpose of this immune cell products is to destroy invading organisms and damaged tissue. Oxidants enhance IL-1, IL-8 and TNF production in response to inflammatory stimuli. Sophisticated antioxidant defense systems like enzymes or vitamins protect directly and indirectly the host against the damaging influence of oxidants. While endogenous systems can hardly be influenced, exogenous antioxidants, delivered by the diet, can be upregulated in the body. By this way the pro-/antioxidative capacity can be balanced or even unbalanced.

There is increasing evidence that reactive oxygen substances are involved in the pathogenesis and/or progression of differ diseases. A short introduction to the biochemistry of reactive oxygen substances will be given in this review. Subsequently, the role of reactive oxygen substances will be discussed exemplarily on pathophysiological aspects of neutrophil granulocytes and of neurodegenerative diseases.

In experimental exposure studies with ozone or nitrogen dioxide a change in lung function and unspecific airway sensitivity was observed. These effects were paralleled by an induction of cellular and biochemical changes. The exposure of isolated cells in vitro led to a decrease in vitality, an increase in permeability and the secretion of mediators very similar to the composition found in bronchoalveolar lavage after in vivo exposure. The cell culture model, therefore, allows the study of the mechanism of these oxidative air pollutants and allows further the understanding of the influence of different cell types on the observed effects in vivo.

At least 15% of the human cancer incidence is caused by an infection with human tumor viruses. The recent progress of experimental cancer research led to important new concepts about the pathomechanisms of viral carcinogenesis. The functional inactivation of cellular tumor suppressor proteins by viral factors appears to be a key event in the process of virus-associated malignant cell transformation. This review summarizes the current concepts about the interaction between viral oncoproteins and cellular tumor suppressor proteins and evaluates their significance for individual tumor viruses and their associated cancers.

The activation of polymorphonuclear leukocytes by stimulants from host or parasites leads to various metabolic processes and to enhanced oxygen uptake. Oxygen is enzymatically processed to from reactive oxygen compounds and metabolites of arachidonic acid which are involved in killing of microbial pathogens and influence many processes in inflammation. Their activities are regulated intracellularly by antioxidants. A lack or exhaustion of these systems may lead to cell and organ damage in which DNA, proteins, lipids and sugars may be involved. Antioxidants and inhibitors of the arachidonic acid metabolism are applied to reduce these pathological changes. An essential aspect of microbial pathogenicity is the multifold modification of the formation of reactive oxygen compounds and arachidonic acid metabolites.

Increasing resistance of pneumococci against antimicrobial agents in several parts of the world is reported. We observed a probably nosocomial transmission of a pneumococcal strain with reduced susceptibility to penicillin (capsular type 6A). Recommendations for diagnostic procedures in the laboratory and therapy are given.