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Michał Wozniak

Publications and source records attributed to Michał Wozniak.

2 recordsLinked to original sources

[Mast cells, their adenosine receptors and reactive oxygen species in chronic inflammatory pathologies of childhood].

Mast cells were described by Erhlich at the end of XIX-th century. Their role was deeply investigated in asthma and allergy. The massive degranulation of mast cells in allergy can lead to anaphylactic shock. Recently, mast cells have been recognized again as a very interesting topic for investigation, due to their possible role in chronic inflammation. Moreover, through adenosine receptors, mast cells can be activated or inactivated. That is why these cells are regarded as a potential target of new drugs. It has been reported, that mast cells generate intracellular reactive oxygen species (ROS) in response to stimulation with divergent physiologically relevant stimulants. The intensification of ROS production may be measured by the level of carbonyl groups, as a marker of protein peroxidation. However, the role of mast cells in other than asthma diseases with chronic inflammation needs further investigation. It was found out that the information about mast cell distribution in colonic mucosa may serve as help in differentiation between inflammatory bowel disease and collagenous colitis. Moreover, its accumulation in focal active gastritis was confirmed in patients with Crohn's disease. An important role in regulation of inflammatory process seems to be reserved for adenosine receptors present on mastocytes. The activation of mast cells through the adenosine receptor is connected with 11-8 release, which stimulate the migration of leukocytes and oxidation reactions. The detection of mast cells in tissues should not be limited only to the simple histologic examination. It should be completed by the detection of products of degranulation, e.g. tryptase. This is the way to find out their actual function and state of activation.

Adult↗

Oxidative stress during oxygen tolerance test.

Reactive oxygen species, including oxygen free radicals are normally generated in human cells during aerobic metabolism. Their production may increase during breathing of hyperoxic mixtures. The 'oxidative stress' has been postulated to be an important contributor to CNS oxygen toxicity. One of the highest partial pressure of oxygen used in healthy humans is 280 kPa(a) during 30 min of 'oxygen tolerance tests' (OTT). This test is conducted in order to detect some individuals with an increased sensitivity to high partial pressures of oxygen leading them to develop CNS oxygen toxicity earlier than others. The purpose of this study was to investigate whether the OTT (30 min of breathing pure oxygen at 280 kPa(a)) would significantly induce oxidative stress in healthy population. The first group consisted of 52 subjects, in whom total antioxidant status (TAS) was measured. The second group consisted of 44 subjects, in whom protein carbonyls (PC), total thiol (t-SH) and heat shock proteins (HSP70) were measured. All measurements were done just before and immediately after the OTT. There was no statistically significant change of TAS. We observed a small, however statistically significant increase of PC and decrease of t-SH. A significant decrease of HSP70 was detected, however false positives of initial measurements are suspected. In summary, in young healthy subjects 30 min of breathing oxygen under pressure of 280 kPa(a) induces oxidative stress which can be detected by increase of protein carbonyls and by decrease of total thiol. In our study this stress was not reflected in measurement of total oxidative status and heat shock proteins.

Adult↗