Biomedical subjects

Radosław Kowalewski

Publications and source records attributed to Radosław Kowalewski.

3 recordsLinked to original sources

PubMed2006

[Antiheparin activity of the aneurysm wall and parietal thrombus and blood plasma of patients with aortic aneurysm].

Aneurysm dilatation is filled by parietal thrombus. Its magnitude is determined by the ratio of coagulative to anticoagulative activities above all. The aim of the study was to assess antiheparin activity, contents of heparin neutralizing chemical compounds and glycosaminoglycans with anticoagulative activity as well in the aneurysm wall, parietal thrombus filling the aneurysm dilatation and blood plasma/blood serum of patients with aortic aneurysm. The studied material consisted of aneurysm walls and parietal thrombi extracts, as well as of blood plasma/serum of patients with aortic aneurysm. Extracts of normal aorta from organ donors and blood plasma/serum of healthy subjects were the control material. Antiheparin and antithrombin III activities, as well as contents of heparin neutralizing compounds and heparin-like acting glycosaminoglycans were evaluated in the investigated material with chemical methods. The aneurysm wall, parietal thrombus filling the aneurysm dilatation and blood plasma of patients with aortic aneurysm show high antiheparin activity and increased content of heparin neutralizing compounds. However differences in glycosaminoglycans content were not demonstrated. That can predispose to formation and enlargement of parietal thrombus in aneurysm dilatation.

Aorta, Abdominal↗

PubMed2005

Evaluation of enzymes involved in proteoglycan degradation in the wall of abdominal aortic aneurysms.

The abdominal aortic aneurysm (AAA) wall represents an extreme example of arterial remodeling with disturbed elastin, collagen and proteoglycan metabolism. The aim of this study was to evaluate enzymes involved in the degradation of glycosaminoglycan chains and core proteins of proteoglycans in the AAA wall. The study material consisted of wall samples from 10 AAA. Fragments of 5 normal abdominal aortas from organ donors were used as a control. The activity of endoglycosidases, exoglycosidases and sulfatases was measured using colorimetric methods. To assess matrix metalloproteinases (MMPs), Western blot and zymography were performed. The activity of endoglycosidase degrading chondroitin-4-sulfate was lower in the AAA wall. Endoglycosidase degrading heparan sulfate and dermatan sulfate, arylosulfatase B, as well as all the exoglycosidases assessed demonstrated higher activities in the AAA wall. Furthermore, increased expression of MMP1, MMP2 and MMP9 was also shown in the AAA wall. Zymography revealed decreased activity of pro-MMP2 and presence of pro-MMP9 in the AAA wall compared to the wall of normal aorta. Extensive changes in the activity of glycosaminoglycan-degrading enzymes and MMPs may influence the organization of the extracellular matrix network and lead to previously demonstrated changes in the proteoglycan and glycosaminoglycan content in the AAA wall.

Aorta, Abdominal↗

PubMed2005

Decrease of force capabilities as an index of upper limb fatigue.

The aim of the study was to assess upper limb fatigue on the basis of the force change index (FCI), which expresses changes in developed force, and to demonstrate that this index differentiates muscle fatigue of the upper limb depending on external load. The study was performed on ten young men in 12 conditions of external load. Ten conditions characterized repetitive work in a two-period cycle, in which both or one of the periods were loaded, and two conditions characterized continuous work with constant load. The participants tried to maintain hand-grip force at an imposed level during a determined time in the standard upper limb posture. Changes in values of recorded force exerted during successive cycles were approximated by a regression function. In most cases there was a strong correlation between the measurement data and the logarithmic regression curve. However, several cases of lower external load showed absence of such correlation. In 75% of the cases, there were statistically significant differences between the values of FCI calculated for individual conditions of external load. That means that FCI not only expresses muscle fatigue quantitatively but also points to the differences in upper limb fatigue resulting from differences in the external load. The study results have shown that the developed index (FCI) can be applied for fatigue assessment and discrimination with a more sophisticated model of a repetitive task than just a simple two-period work and rest model.

Adult↗