Alicja K. Olejnik

Tumor necrosis factor alpha (TNF-α) modulates rat mast cell reactivity

Abstract Nowadays there is growing evidence that some cytokines regulate biological functions of the mature mast cells. Therefore, we have studied whether TNF- α , the cytokine of multifunctional activities, could directly stimulate rat peritoneal mast cells to histamine secretion and whether it could modulate rat mast cell reactivity in anaphylactic (with ConA) and anaphylactoid (with compound 48/80) reactions. We have established that rat recombinant TNF- α does not activate rat mast cells to histamine release. However, TNF- α -treatment causes the decrease of spontaneous histamine release up to 85% (TNF- α concentration: 2×10 −9 M). Pretreatment of mast cells with TNF- α inhibits ConA-stimulate release of histamine with the percent release decreasing up to 33.7% of the control value (TNF- α concentration: 5×10 −9 M) and this decrease is statistically significant. Pretreatment of mast cells with TNF- α reduces compound 48/80-dependent histamine release as well and the percent release of histamine fell to 64.7% of the control value. We have concluded that TNF- α may play a significant role in regulation of mast cell secretory activity.

Does quercetin protect human red blood cell membranes against γ-irradiation?

Abstract Objectives Radioprotective potential of quercetin, a powerful free radical scavenger, was investigated in human red blood cells (RBCs) and in isolated RBC membranes exposed to γ-irradiation-induced oxidative stress. Methods RBCs and RBC membrane suspensions were irradiated (50 Gy) in the presence of quercetin (2–50 µM). Oxidative damage of the membranes was analysed by protein carbonyl measurement (enzyme-linked immunosorbent assay). In RBCs, the concentration of glutathione (GSH) was determined. Lipid peroxidation in RBCs, and for comparison in plasma and peripheral lymphocytes, was quantified by the amount of thiobarbituric acid-reactive substances (TBARS). Radiation-induced damage of the RBC membrane integrity was evaluated by the degree of haemolysis. Results Quercetin (50 µM) brought back the level of carbonyls to normal in γ-irradiated RBC membrane proteins and inhibited radiation-induced lipid peroxidation in plasma and lymphocytes, by 75 and 96%, respectively. However, it moderately decreased reduced/oxidized glutathione (GSH/GSSG) ratio and significantly increased TBARS concentrations, by 60 and 28% in irradiated and non-irradiated RBCs, respectively. Haemolysis rate was much higher in RBCs irradiated in the presence of quercetin vs. non antioxidant. Discussion In non-cellular systems (RBC membranes or plasma) and in lymphocytes, quercetin shows antioxidative/radioprotective activity but in whole RBCs it acts as a pro-oxidant and a cytotoxic substance. The possible mechanisms of such action are discussed.

Can the 1,5-disubstituted tetrazole ring modify the co-ordinating ability and biological activity of opiate-like peptides?

The copper(II) complexing ability and the biological activity of beta-casomorphin-7 tetrazole analogues have been investigated. Potentiometric and spectroscopic (UV-Vis, CD and EPR) studies have been used to establish the thermodynamic stability, speciation and structure of Cu(II) complexes with YP-psi(CN4)-FPGPI-NH2 (1), YPF-psi(CN4)-AGPI-NH2 (2) and YPFP-psi(CN4)-GPI-NH2 (3). Comparison of the binding ability of the tetrazole analogues reveals that the most effective ligand for copper(II) is YPF-psi(CN4)-AGPI-NH2. The effectiveness of this ligand comes from its particular conformation suited for the Cu(II) 2N co-ordination mode in the physiological pH region. The ability of casomorphin tetrazole analogues to activate rat mast cells to histamine release in vitro in the presence of copper(II) has been studied.

Polyphenolic-polysaccharide conjugates from plants of Rosaceae/Asteraceae family as potential radioprotectors.

Polyphenolic-polysaccharide macromolecular, water-soluble glycoconjugates, isolated from the selected medicinal plants of Rosaceae/Asteraceae family: from leaves of Fragaria vesca L., Rubus plicatus Whe. et N. E., and from flowering parts of Sanguisorba officinalis L., and Erigeron canadensis L., were investigated for their ability to protect proteins and lipids of human plasma against γ-radiation-induced oxidative damage. Treatment of plasma with plant conjugates (6, 30, 150 μg/ml) prior exposure to 100 Gy radiation resulted in a significant inhibition of lipid peroxidation, evaluated by TBARS levels; conjugates isolated from E. canadensis and R. plicatus and a reference flavonoid quercetin showed similar high potential (approx. 70% inhibition, at 6 μg/ml). The conjugates prevented radiation-induced oxidation of protein thiols and significantly improved plasma total antioxidant capacity, estimated with Ellmans reagent and ABTS(.+) assay, respectively. The results demonstrate by the first time a significant radioprotective capability of the polyphenolic-polysaccharide conjugates isolated from E. canadensis, R. plicatus, S. officinalis and to the less extent from F. vesca. The abilities of these substances to inhibit radiation-induced lipid peroxidation and thiol oxidation in plasma seems to be mediated, but not limited to ROS scavenging activity.

Biocompatibility of Modified Bionanocellulose and Porous Poly(ϵ-caprolactone) Biomaterials

Biocompatibility of modified bionanocellulose (BC) and porous poly(ϵ caprolactone) (PCL) were compared to UHMWPE. For all the materials lack of cytotoxic effect to mouse fibroblasts was observed in vitro. In vivo study, subcutaneous implantations in Wistar rats, lasted for seven, 14, and 30 days. Subsequently the composition of surrounding tissue and explants surface changes was evaluated. No symptoms of acute inflammation were observed. Surrounding tissue thickness, the number of granulocytes, lymphocytes, macrophages, and blood vessels differed in time and revealed regular healing process. It is concluded that investigated PCL and BC are the materials with superior biocompatibility with high application potential.

Polyphenolic glycoconjugates from medical plants of Rosaceae/Asteraceae family protect human lymphocytes against γ-radiation-induced damage

Radioprotective effects of the water-soluble polyphenolic glycoconjugates, isolated from flowers of Sanguisorba officinalis L.(SO) and Erigeron canadensis L.(EC), and from leaves of Fragaria vesca L. (FV) and Rubus plicatus Whe. Et N. E. (RP), against γ-radiation-induced toxicity in human peripheral blood lymphocytes were investigated. Cell treatment with glycoconjugates (1, 5 and 25μg/mL) prior exposure to 10/15Gy radiation resulted in concentration-dependent reduction of DNA damage including oxidative DNA lesions (comet assay), substantial inhibition of lipid peroxidation (TBARS) and restoration of superoxide dismutase and S-glutathione transferase activities. Glycoconjugates isolated from SO and EC ensured better protection versus these from RP and FV, with the SO product potential comparable to that of the reference quercetin. Strong antioxidant/radioprotective activity of the SO and EC glycoconjugates could be attributed to high abundance of syringol-type and ferulic acid units in their matrices, respectively. Moreover, polyphenolic glycoconjugates (25μg/mL), including RP and FV products, significantly decreased DNA damage when applied post-radiation suggesting their modulating effects on DNA repair pathways. Preliminary data on the glycoconjugate phenolic structural units, based on GLC/MS of the products of pyrolysis and in situ methylation, in relation to application of plant products as potential radioprotectors is promising and deserves further investigation.

A comparative study on the radioprotective potential of the polyphenolic glycoconjugates from medicinal plants of Rosaceae and Asteraceae families versus their aglycones

Radioprotective potential of the polyphenolic glycoconjugates, isolated from flowers of Sanguisorba officinalis L. (So) and Erigeron canadensis L. (Ec), and from leaves of Fragaria vesca L. (Fv) and Rubus plicatus Whe. Et N. E. (Rp) as well as their aglycones (SoA, EcA, FvA and RpA, respectively), against γ-radiation-induced lipid peroxidation in human plasma and DNA damage in lymphocytes, were investigated in vitro. These properties were assessed by measuring the concentration of thiobarbituric acid reactive substances (TBARS) and using the alkaline comet assay, and were compared to the protective effects of rutin (R) and quercetin (Q). Cytotoxicity of the glycoconjugates/aglycones towards L929 mouse fibroblasts and human lymphocytes were also measured. Plant products from S. officinalis, similar to Q, were able to reduce the most radiation-induced lipid peroxidation as well as DNA damage and extent of oxidative damage to the DNA basis. Contrary to the pure flavonoids, where Q was shown to be significantly more effective than its glycoside R, the results did not show more benefit with application of SoA/EcA over So/Ec in terms of lipid peroxidation inhibition. Moreover, glycoconjugates Ec and So showed much higher capacity in protecting lymphocytes against radiation-induced genotoxicity which may suggest that between the polyphenolic and polysaccharide parts exist some synergistic effects. There were no significant differences between Fv versus FvA or Rp versus RpA in terms of the provided radioprotection. Summarizing, plant glycoconjugates isolated by the multi-step method offered sufficient radioprotection. In addition, they possess many advantages, compared to the synthetic polyphenolic compounds or the plant extracts, such as water-solubility and minor toxicity.

The multipotent action of electromagnetic field

Abstract The use of electromagnetic field in the treatment of diseases has already been known for centuries. Low hazard, wide applicability, good clinical effect and the relatively low cost enable the electromagnetic field therapy to be widely used. The biological effect of the electromagnetic field is based on inter alia, analgesic, anti-inflammatory, osteogenetic and regenerative actions, which are associated with the changes in cellular signal transmission, action on biological membranes, ion transport processes, protein synthesis, cell proliferation and apoptosis. In addition, the electromagnetic field increases quantity of collagen content elevating its density and a more regular arrangement. Furthermore, it induces the activation of glutathione peroxidase and intensification of the process of erythropoiesis leading to better use of oxygen in the tissues around the wound. The electromagnetic field is used in rehabilitation of patients with diseases of skeletal, nervous and respiratory systems. Moreover, electromagnetic field may be used in the course of most inflammatory diseases and in the case of concomitant pain. The objective of this paper is to present the actual state of knowledge on selected applications of electromagnetic field in the biomedical treatment area.

Experimental reconstruction of an abdominal wall defect with electrospun polycaprolactone-ureidopyrimidinone mesh conserves compliance yet may have insufficient strength

PURPOSE Electrospun meshes mimic the extracellular matrix, which may improve their integration. We aimed to compare polycaprolactone (PCL) modified with ureidopyrimidinone (UPy) electrospun meshes with ultra-lightweight polypropylene (PP; Restorelle) reference textile meshes for in vivo compliance. We chose UPy-PCL because we have shown it does not compromise biomechanical properties of native tissue, and because it potentially can be bioactivated. METHODS We performed ex vivo biomechanical cyclic loading in wet conditions and in vivo overlay of full-thickness abdominal wall defects in rats and rabbits. Animals were sacrificed at 7, 42 and 54 days (rats; n = 6/group) and 30 and 90 days (rabbits; n = 3/group). Outcomes were herniation, mesh degradation and mesh dimensions, explant compliance and histology. High failure rates prompted us to provide additional material strength by increasing fiber diameter and mesh thickness, which was further tested in rabbits as a biomechanically more challenging model. RESULTS Compliance was tested in animals without herniation. In both species, UPy-PCL-explants were as compliant as native tissue. In rats, PP-explants were stiffer. Contraction was similar in UPy-PCL and PP-explants. However, UPy-PCL-meshes macroscopically degraded from 30 days onwards, coinciding with herniation in up to half of animals. Increased fiber and mesh thickness did not improve outcome. Degradation of UPy-PCL is associated with an abundance of foreign body giant cells until UPy-PCL disappears. CONCLUSION Abdominal wall reconstruction with electrospun UPy-PCL meshes failed in 50%. Degradation coincided with a transient vigorous foreign body reaction. Non-failing UPy-PCL-explants were as compliant as native tissue. Despite that, the high failure rate forces us to explore electrospun meshes based on other polymers.

Spatial Approach to Diseases of Affluence Epidemiology and Regional Economic Development

Abstract Diseases of affluence (of the 21st c.) by definition should have higher prevalence and/or mortality rates in richer and more developed countries than in poorer, underdeveloped states (where diseases of poverty are more common). Therefore, it has been indicated that it is civilizational progress that makes us sick. On the other hand, substantial financial resources, highly qualified medical personnel, and the cutting-edge technology of richer states, should allow for effective preventions, diagnostics, and treatment of diseases of poverty and of affluence. Therefore, a dilemma arises: is progress making us sick or curing us? To evaluate the influence of country socioeconomic and technological development on population health, a spatial analysis of the epidemiology of diseases of affluence and distribution of economic resources for European NUTS 2 has been performed. The main aim of this paper is to assess, how regional diversity in the prevalence of diseases of affluence is related to the regional development of regions.