Vol. 5 No. 3 September 2000

Volume 5 (2000) pp 295 -313
Title THE INTRACELLULAR FATE OF NON-VIRAL DNA CARRIERS.
Authors Marek Langner
Abstract Rapid progress in molecular biology and genetic engineering techniques has made the induction of cell behavior modifications by altering genetic material possible. This allows us to think about the medical application of gene therapy as an alternative to classical pharmacology and as a means of introducing a new approach to treating hereditary diseases. The major obstacle that prevents the application of this method in clinical practice is the difficulty of delivering genetic material to its destination. The fragile DNA molecule (very unstable in in vivo) requires the assistance of supramolecular structures in order to ensure its extended lifetime in circulation. A number of DNA delivery methods have been considered. One of them, a viral carrier, has been extensively studied as a potential candidate for this purpose. Unfortunately, a number of serious problems exist associated with this approach. The risk of accidental infection has not been eliminated and virus presentation causes the immune system to activate. Transfection efficiency achieved with viral vectors is superior to that of other methods, but safety concerns and financial considerations have stimulated studies aimed at the development of non-viral DNA carriers. At present, the transfection efficiency of such carriers is very low. This paper discusses problems encountered when developing a stable and efficient lipid-DNA aggregate, capable of delivering genetic material into the targeted cell nucleus. Discussion is limited to aggregate interaction with the cellular plasma membrane and its fate in the cytosol.
Address and Contact Information Institute of Physics, Wrocław University of Technology, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland
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Volume 5 (2000) pp 315-324
Title A QUATERNARY AMMONIUM SALT AS AN INHIBITOR OF PLASMA MEMBRANE H+-ATPase IN YEAST Saccharomyces cerevisiae.
Authors Ewa Obłąk, Joanna Bącal and Tadeusz M Lachowicz
Abstract A quaternary ammonium salt, dodecyloxycarboxymethyl N, N, N - trimethyl ammonium chloride (IM), inhibits glucose-stimulated proton extrusion in yeast cells. The IM-resistant mutant (IMR ) and pma1 mutant are less sensitive to this inhibition. The inhibition of amino acids uptake by IM depends on repressed or derepressed conditions. IM treatment of yeast cells leads to a change of internal pH in a quinacrine fluorescence test.
Address and Contact Information 1 Institute of Microbiology, University of Wrocław, Przybyszewskiego 65/7, 51-148 Wrocław, Poland,
2 Institute of Biotechnology and Environmental Protection Higher Pedagogical School, Monte Casino 3a, 65-561 Zielona Góra, Poland
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Volume 5 (2000) pp 327-348
Title ELASTIN: STRUCTURE, PROPERTIES AND METABOLISM.
Authors Marek Gacko
Abstract Soluble tropoelastin is a precursor of elastin. It is transported by elastin binding protein (EBP) into intercellular space. The EBP-tropoelastin complex undergoes disintegration in the intercellular space. EBP returns to the cell and tropoelastin joins with microfibril proteins. Lysine residues of tropoelastin undergo oxidative deamination. Desmosine, isodesmosine and cross bonds arise. Thus tropoelastin loses solubility and transforms to elastin. The elastic fiber created consists of microfibrils on the periphery and an elastin core inside. Elastin provides blood vessels, lungs, cartilage and skin with the ability to reverse deformations. A decrease of elastin content or changes in this protein structure results in pathological conditions such as aneurysms and pulmonary emphysema.
Address and Contact Information
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Volume 5 (2000) pp 349-356
Title POTENTIAL PESTICIDE EFFICIENCY OF NEW BIFUNCTIONAL SURFACTANTS.
Authors Janusz Sarapuk, Halina Kleszczyłska, Hanna Radecka and Małgorzata Oświęcimska
Abstract Two series of new bifunctional surfactants were synthesized for potential use as antioxidants or as pesticides, depending on their concentration. At a low concentration, the surfactants can be incorporated into the membranes with no damage to these membranes, while surfactants` antioxidant functional group, localized in its polar part, protrudes outside thus effectively protecting the membranes. If the concentration of the incorporated surfactant is high enough it can destroy membranes acting as a common biocide. The aim of this paper was to determine the concentration level at which surfactants can be possibly used as biocides. The surfactants studied differed in the polar head and/or in the length of their alkyl chain. One of the investigated series consisted of pyrolidinium chlorides (PC), whereas the other series consisted of the respective bromides (PB). PB salts were found to be more destructive to model membranes studied (erythrocytes - RBC and planar lipid membranes - BLM) than PC salts. Also, the results of BLM experiments indicate the existence of a maximum of the interaction between planar lipid membranes and surfactants when they have about twelve carbon atoms in the alkyl chain. It may be possible that interdigitation phenomena are responsible for this effect.
Address and Contact Information Department of Physics and Biophysics, Agricultural University, Norwida 25, 50-375 Wrocław, Poland,
1 Institute of Animal Reproduction and Food Sciences, Polish Academy of Sciences, Tuwima 10, 10-747, Olsztyn, Poland, 2 Institute of Organic and Polymer Technology, Technical University, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland
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Volume 5 (2000) pp 357-366
Title PRODUCTION OF UREASE FROM Helicobacter pylori IN TRANSGENIC TOBACCOPLANTS.
Authors Robert Brodzik1, Hilary Koprowski2, Vidadi Yusibov2 and Agnieszka Sirko1
Abstract H. pylori ureA and ureB genes encoding both subunits of urease were expressed transgenically in a low-alkaloid line of tobacco (LA Burley 21). Analysis of transgene expression at both the mRNA and protein levels revealed a significant increase (up to 8-fold) in ammonia concentration correlated with an amount of UreB protein detected in the leaves, and an increase (up to 2-fold) in urease activity in transformants as compared to control plants.
Address and Contact Information 1 Institute of Biochemistry and Biophysics, Polish Academy of Sciences, ul. Pawinskiego 5A, 02-106 Warsaw, Poland,
2 Biotechnology Foundation Laboratories at Thomas Jefferson University, 1020 Locust Street, Room 346 JAH, Philadelphia, PA 19107, USA
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Volume 5 (2000) pp 367-371
Title ON THE TRANSPORT OF PESTICIDE LONTREL THROUGH LIPOSOMAL MEMBRANES.
Authors Elena A. Saratovskikh*, Tatiana A. Kondratieva and Boris L. Psikha
Abstract he process of ecotoxicant transfer through membrane was studied on the example of the pesticide lontrel (3,6-DCPA**). 3,6-DCPA is able to penetrate through the model liposomal membrane. The mathematical model of mass-transfer process was established. It was found that the transfer rate of 3,6- DCPA through lipid membrane equals (5-8)d'—10-10 M/s for all 3,6-DCPA concentrations.
Address and Contact Information Institute of Problems of Chemical Physics Chernogolovka, Moscow region, 142432 Russia
* Corresponding author
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Volume 5 (2000) pp 373-379
Title DFF40/CAD HYPERSENSITNE SITES ARE POTENTIALLY INVOLVED IN HIGH MOLECULAR WEIGHT DNA FRAGMENTATION DURING APOPTOSIS.
Authors Piotr Widłak
Abstract Sequential cleavage of genomic DNA into large-scale DNA fragments of 50-300-kb, followed by formation of mono- and oligonucleosomal DNA fragments, is a biochemical hallmark of programmed cell death (apoptosis). The endonuclease DFF40/CAD mediates regulated inter- nucleosomal DNA fragmentation and chromatin condensation in cells undergoing apoptosis. DFF40 hypersensitive sites were detected in purified HeLa cell nuclei, and excision of 50-kb DNA fragments preceded formation of oligonucleosomal DNA ladders in nuclei treated with the nuclease. Topoisomerase II, but not topoisomerase I, stimulates DFF40 activity on plasmid DNA substrates. This suggests that interactions of DFF with the nuclear matrix-bound topoisomerase II may be involved in formation of DFF40 hypersensitive sites.
Address and Contact Information Department of Experimental and Clinical Radiobiology, Center of Oncology, 44-100 Gliwice, Poland.
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Volume 5 (2000) pp 381-396
Title THE SMAD PATHWAY IN TGF-β SIGNALLING.
Authors Dagmara Piestrzeniewicz, Magdalena Bryś and Wanda M Krajewska
Abstract The recent identification of the Smad proteins has allowed the delineation of a mechanism by which TGF-β and related growth and differentiation factors convey their signals from transmembrane receptors into nucleus. Following receptor-induced activation heteromeric Smad complexes translocate into the nucleus where they act as transcription factors. Smad proteins modulate target genes through interaction with DNA and with other nuclear factors. Disruption of signalling cascade by Smad gene aberrations may cause loss of cellular responsiveness to TGF-β and thus contribute to development of cancer.
Address and Contact Information University of Łódź, Department of Cytobiochemistry, Banacha 12/16 90-237 Łódź, Poland
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Volume 5 (2000) pp 397-403
Title ANTIMUT AGENIC ACTNITY OF TODRALAZINE AND FLUPHENAZINE. A COMPARISON OF THE RESULTS FROM SHORT-TERM CYTOGENETIC TESTS.
authors Kazimierz Gąsiorowski
Abstract The multicriterial analysis proved that the antimutagenic effect fluphenazine exerted on human blood cells cultured in the presence of the standard mutagens was 60-time stronger than the effect exerted by todralazine. Future attempts to obtain chemical derivatives of fluphenazine should yield compounds which possess the antimutagenic activity but manifest a low or none psychotropic action.
Address and Contact Information Wrocław Medical University, Department of Basic Medical Sciences 14 Kochanowskiego Str., 51-601 Wrocław, Poland
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