László Kohidai

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Chemotactic properties of the leukocyte chemoattractant N-formyl-Norleucine-Leucine-Phenylalanine (NLP) and its antagonist N-t-BOC-Norleucine-Leucine-Phenylalanine (BOC-NLP) were investigated in unicellular Tetrahymena pyriformis cells. NLP express its attractant character in a two-peak profile of concentration course (maximum at 10(-8)-10(-7) M and 10(-11)(More)
NGR peptides that recognize CD13 receptors in tumor neovasculature are of high interest, in particular due to their potential applications in drug targeting. Here we report the synthesis and structural analysis of novel thioether bond-linked cyclic NGR peptides. Our results show that their chemostability (resistance against spontaneous decomposition forming(More)
An increasing attention is paid to the potential harmful effects of aquatic contaminant pharmaceuticals exerted on both biosystems and humans. In the present work the effects of 14 pharmaceuticals including NSAIDs, antibiotics, β-blockers and a frequently used X-ray contrast media on the proliferation and migratory behavior of the freshwater ciliate(More)
The formyl peptide receptors (FPRs) are a family of chemoattractant receptors with important roles in host defense and the regulation of inflammatory reactions. In humans, three FPR paralogs have been identified (FPR1, FPR2, and FPR3) and may have functionally diversified by gene duplication and adaptive evolution. However, the evolutionary mechanisms(More)
The chemotactic character of the nonapeptide bradykinin (BK1-9) and its derivatives was studied in the eukaryotic ciliated model Tetrahymena pyriformis. The results demonstrate that BK1-9 has a direct and ligand-specific chemoattractant effect (maximal at 10(-11) m) without any intermediate substance as is essential in some mammalian test systems.(More)
Chemotactic selection is a method by which populations of cells exposed to ligands can be isolated and subsequently cultivated. We used Tetrahymena pyriformis GL cultures selected by chemotactic selection to insulin (10 nM), histamine (0.1 nM) and di-iodotyrosine (T2, 10 nM) to study the phagocytotic capacity under the induction of selector hormones. Our(More)
The unicellular Tetrahymena pyriformis was studied for chemotaxis, chemotactic selection, phagocytosis, growth and body shape changes in the presence of water soluble (beta-cyclodextrin-coupled) steroid hormones (testosterone, estradiol, progesterone, hydrocortisone and dexamethasone). Testosterone was chemoattractant over a wide range of concentrations,(More)
The chemotactic effects of six formylated, putatively bacterial peptides (fMLP, fMLPP, fMMM, fMP, fMV, and fMS) were studied. From the set of six peptides, only fMLP (one of the most effective chemoattractant peptides in mammals) elicited a significant positive chemotactic response in the eukaryotic ciliate Tetrahymena pyriformis, while the other formylated(More)