Vol. 1 No. 4 December 1996

Volume 1 (1996) pp 357-361
Title IN VITRO ANTIBACTERIAL ACTIVITY OF LIPOSOMAL POLYMYXIN B INCORPORATED INTO COLLAGEN SPONGE
Authors E. A. Trafny, M. Antos-Bielska, J. Grzybowski
Abstract The new antibacterial collagen dressing/implant was constructed. The dressing was composed of collagen sponge saturated with liposomal polymyxin B (Lip-PolB). As a control an alternative dressing composed of collagen sponge saturated with free polymyxin (Free-PolB) was used. The release of the antibiotic from the Lip-PolB was measured by diffusion of the drug into polyurethane sponge saturated with sterile broth employing "polyurethane sponge model" published previously. The antibiotic was released from Lip-PolB four times slower than from Free-PolB. Antibacterial activity of the dressing was tested using also polyurethane sponge model, with polyurethane sponge saturated with the bacterial broth culture of P. aeruginosa (10 8 CFU/ml). After 1, 2 and 3 days of incubation at 370C, polyurethane sponges were sonicated in the tubes with PBS; then the CFU number was examined by plating. The Lip-PolB proved again to be several times less effective than Free-PolB. We can draw a conclusion that collagen sponge with liposomal polymyxin B can serve as an effective reservoir of the drug for control of infection in superficial wounds. However, the concentration of liposomal drug applied topically should be several times higher than the concentration of free drug.
Address and Contact Information Military Institute of Hygiene and Epidemiology, Department of Microbiology, 01-163 Warsaw, Poland
[Rozmiar: 1332 bajtów]

Volume 1 (1996) pp 363-371
Title IMMUNOSPECIFIC NUCLEAR PROTEINS OF COLORECTAL TUMORS
Authors P. Szymczyk1, W.M. Krajewska1, J. Jakubik2, A. Berner2, J. Berner2, M. Brocki3, B. Rajczyk3 and Z.M. Kilianska1
Abstract Electrophoretically specific nuclear proteins of human colon adenocarcinoma with mol.wt of 35-40 kDa were used as immunogen to produce rabbit antiserum. Expression of cancer-specific antigens was investigated by Western blot technique among nuclear proteins from normal and cancerous mucosa. Obtained antiserum crossreacted mainly with 36 kDa polypeptide in 23 of 26 (88,5%) colorectal tumor nuclear fractions but not with any of normal cells. It was also observed that this antiserum recognized 36 kDa antigen in 10 of 12 and 6 of 7 nuclear fractions from other cancers, i.e. gastric and lung, respectively. In part of studied tumors antiserum crossreacted also with the antigens of 38 and 32-33 kDa. Expression of 36 and 32-33 kDa components seems to be correlated with colorectal cancer procession from A to B stage of disease according to the classification of Dukes. Immunoblot analysis revealed that cancer-specific 36 kDa polypeptide, mainly associated with nuclear compartment, can be also detected within 10P and 100P fractions of colorectal tumors.
Address and Contact Information 1Department of Cytobiochemistry, University of Lodz, Banacha 12/16, 90-237 Lodz
2Department of Surgical Oncology, Medical University of Lodz, Paderewskiego 4, 93-509 Lodz
3Department of Surgery, Military Medical Academy, Zeromskiego 113, 90-549 Lodz
[Rozmiar: 1332 bajtów]

Volume 1 (1996) pp 373-376
Title A RAPID METHOD OF AGAROSE GEL ELECTROPHORESIS FOR SEPARATION OF DIFFERENT CONFORMATIONAL FORMS OF DNA
Authors Ewa Ciesielska and Leszek Szmigiero
Abstract A fast two step method of agarose gel electrophoresis for separation of different conformational forms of DNA is described. In the first step the gel is run in the buffer without ethidium bromide and then the gel is stained with this dye. After staining the second step of electrophoresis is performed in the buffer without ethidium bromide. This two step procedure allows one to receive very good resolution between bands corresponding to relaxed, supercoiled, open circular, and liner forms of DNA.
Address and Contact Information Medical University of Lodz, Institute of Physiology & Biochemistry, Department of General Chemistry
[Rozmiar: 1332 bajtów]

Volume 1 (1996) pp 377-389
Title THREE-DIMENSIONAL DYNAMIC STRUCTURE OF THE LIPID BILAYER MEMBRANES: AN EPR SPIN LABEL STUDY
Authors Witold K. Subczynski1,2 and Anna Wisniewska1
Abstract Over the last decade we have investigated the effects of cholesterol, polar carotenoids, and integral proteins (peptides) on the structure, dynamics, and hydrophobicity of saturated and unsaturated phosphatidylcholine (PC) membranes. The major results obtained in our studies can be summarized as follows: (1) The effect of unsaturation on the membrane alkyl chain order and reorientational motion is negligibly small; (2) The translational diffusion of lipids (lateral or vertical) as well as the diffusion of lipid-soluble small molecules is significantly decreased in cis- and trans-unsaturated PC membranes: (3) cis-unsaturated alkyl chains greatly decrease the ordering effect of membrane modifiers (cholesterol, polar carotenoids) as well as their effect on alkyl chain reorientational motion; (4) Introduction of a double bond into the alkyl chain increases the hydrophobicity ( decreases water penetration) at all locations in the membrane; (5) Incorporation of cholesterol (30 mol%) decreases hydrophobicity ( increases water penetration) from the polar headgroup to a depth of approximately C7 and C9 for saturated and unsaturated PC membranes, respectively. Membrane hydrophobicity sharply increases at these positions from the level of methanol to the level of pure hexane, and hydrophobicity is constant in the inner region of the membrane.
Address and Contact Information 1Department of Biophysics, Institute of Molecular Biology, Jagiellonian University, Al. Mickiewicza 3, 31-120 Krakow, Poland
2Biophysics Research Institute, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226-0509 USA
[Rozmiar: 1332 bajtów]

Volume 1 (1996) pp 391-415
Title THE 14-3-3 PROTEIN BINDS TO THE NUCLEAR MATRIX ENDONUCLEASE AND HAS A POSSIBLE FUNCTION IN THE CONTROL OF PLANT SENESCENCE
Authors Ewa Markiewicz, Grzegorz Wilczynski, Ryszard Rzepecki, Anna Kulma and Jan Szopa
Abstract The nuclear matrices of plant cell nuclei display an intrinsic nuclease activity which is capable of nicking supercoiled DNA. Recently a cDNA encoding the 14-3-3 protein from Cucurbita pepo has been cloned and sequenced. The evidence that the recombinant 14-3-3 protein associates with DNase I and endogenous plant nuclease is presented. Evidence is also presented that the cloned 14-3-3 protein isoform, unique in its binding to nuclease within the 14-3-3 family, is located in the nuclei and in the nuclear matrix. Transgenic potato plants were created where the 14-3-3 protein derived from Cucurbita was overexpressed. An increase in tuber number and a decrease in tuber size in the transformants was also observed. The adenine nucleotide pool in leaves of transgenic plants was significantly reduced and they contain more chlorophyll and loose it slower when grown in the dark. A decrease in 14-3-3 protein content concomitant with an increase in nuclease activity in senescent plants was detected and this was markedly delayed in transgenic potato plants which overexpressed the 14-3-3 protein. It is proposed that a function of the isolated 14-3-3 isoform is the control of the nuclease activity and hence senescence.
Address and Contact Information Institute of Biochemistry, University of Wroclaw, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland
[Rozmiar: 1332 bajtów]

Volume 1 (1996) pp 417-427
Title BASIC STUDY ON FUNCTIONAL LIPOSOMES AND THEIR APPLICATION
Authors N. Oku
Abstract Liposomes have been used as models of biomembranes and tools in the field of drug delivery systems. Liposomalization of various drugs has been revealed to enhance their efficacy and to reduce the side effect of the drugs. For site-specific delivery, intracellular targeting, and controlled release of drugs, many functional liposomes have been developed based on their nature as models of biomembranes. In this paper, preparation and characterization of three kinds of functional liposomes are presented, namely, thermosensitive liposomes for delivering macromolecules, pH-sensitive liposomes for cytosolic delivery of the encapsulated materials, and reticuloendothelial system (RES)-avoiding liposomes for passive targeting to tumor tissues. The actual usefulness of RES-avoiding liposomes modified with a uronic acid derivative, palmityl-D-glucuronide, for tumor imaging and therapy was demonstrated. Recently, a method to analyze liposomal trafficking in living animals, which is important in the use of liposomes as drug carriers, was developed by use of positron emission tomography. In this paper, liver accumulation of liposomes having various charges is shown.
Address and Contact Information School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka, 422, Japan
[Rozmiar: 1332 bajtów]

Volume 1 (1996) pp 429-437
Title INTRAVENOUS TREATMENT OF LEISHMANIA DONOVANI INFECTED MICE WITH LIPOSOMAL HEXADECYLPHOSPHOCHOLINE
Authors P. Kaufmann-Kolle*1, A. Kuhlencord2 and H. Eibl1
Abstract Visceral leishmaniasis is protozoan born disease, which when left untreated, leads to morbidity and mortality in humans. It was demonstrated that orally applied non-liposomal hexadecylphosphocholine exhibits remarkable therapeutic efficacy against leishmanial infections in BALB/c mice. With the added benefit that liposomal hexadecylphosphocholine is better tolerated after oral application and can be repeatedly injected intravenously without causing thrombophlebitis, we show that liposomal hexadecyphosphocholine is much more effective against visceral leishmaniasis than therapy with conventional drugs such as Pentostam (.Most important, the iv. treatment of infected mice with liposomal hexadecylphosphocholine was the only therapy that was curative.
Address and Contact Information 1Max-Planck- Institut fur biophysical. Chemie, D-37077 Gottingen
2Labor fur experimentelle Parasitologie, D-33102 Paderborn
* Corresponding author: Dr. Petra Kaufmann-Kolle, MPI biophys. Chemie, D-37077 Goettingen, FRG
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Volume 1 (1996) pp 439-446
Title ANION TRANSPORT ACROSS THE RED BLOOD CELL MEMBRANE IN THE PRESENCE OF MALATHION AND PARATHION AND THEIR MAIN METABOLITES
Authors Janusz Blasiak
Abstract The effect of organophosphorus insecticides malathion and parathion as well as their main metabolites malaoxon and paraoxon on chloride (36 Cl-) and sulfate (35 SO4 2- ) equilibrium exchange in pig erythrocytes was investigated using an isotope labelling technique. Efflux of both radioactive isotopes vs. time followed a single exponential. Parathion and paraoxon inhibited the chloride equilibrium exchange in intact cells in a dose- and time-dependent manner. These was no difference between effects evoked by these two compounds. Neither malathion nor malaoxon affected the chloride transport. Parathion and paraoxon inhibited sulfate efflux from resealed ghosts. The effect was also dose- and time-dependent. Again there was no difference between action and the agents. No effect of malathion and malaoxon on sulfate efflux was observed. Dixon analysis revealed noncompetitive character of the inhibition of the exchange of both anions with the apparent Ki values 68 and 73 (M for parathion and paraoxon, respectively in the case of chloride transport; for sulfate exchange these values were 341 and 340 (M, respectively. It was suggested that structural similarity between parent agents and their metabolites is responsible for the identity of their effects. Parathion and paraoxon could inhibit the anion exchange indirectly by changing the fluidity of the erythrocyte membrane or directly by binding the Band 3 protein and evoking conformational changes leading to the inhibition of the anion transport. The insecticides, due to their ability to phosphorylate, could also disturb some regulation processes in the Band 3 protein.
Address and Contact Information University of Lodz, Institute of Biochemistry, Banacha 12/16, 90-237 Lodz, Poland
[Rozmiar: 1332 bajtów]

Volume 1 (1996) pp 447-457
Title PREPARATION AND PROPERTIES OF ALKYLPHOSPHOLIPID LIPOSOMES: A REVIEW
Authors R. Zeisig, I. Fichtner and D. Arndt
Abstract Alkylphospholipids are synthetic compounds with relatively simple structures combining amphiphilic character and anticancer properties. It is possible to prepare different types of liposomes from APL if a high amount of cholesterol and a charged component is added. The biological relevant properties can be changed by sterical stabilization of these vesicles by the incorporation of up to 10 mol% poly(ethylenglycol) derivatives of phosphoethanolamine. This incorporation increased the fixed aqueous layer thickness from 0.83 nm to 3.57 nm. As a result of this changed property the uptake of such liposomes by macrophages was reduced compared to liposomes without a sterical stabilization. APL liposomes are remarkably stable in buffer and in plasma. APL liposomes are able to induce the release of tumoricidal factors like TNF and NO from different macrophage cell lines. The strongest release was induced by a synergistic action of liposomal APC and lipopolysaccharide. Sterical stabilization prevents such an activation process likely as a result of significantly reduced uptake and internalization by the macrophages. APL are highly therapeutically active in a number of hormone-independent human mammary carcinomas. Using the MaTu mammary carcinoma xenotransplanted to nude mice the sterically stabilized HPC-SUV have the strongest cancerostatic formulation.
Address and Contact Information Max Delbruck Center for Molecular Medicine, AG Phospholipids, R.-Rossle-Str. 10, 13122 Berlin- Buch, Germany
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Volume 1 (1996) pp 459-468
Title ELABORATION AND SPECIFIC PROPERTIES OF FLUORINATED LIPOSOMES AND RELATED SUPRAMOLECULAR SYSTEMS
Authors M.P. Krafft and J.G. Riess
Abstract A range of well defined, pure, highly surface-active but non-hemolyzing fluorinated amphiphiles has recently been synthesized. Fluorocarbon chains strongly enhance the hydrophobic effect that induces the organization of amphiphiles into bilayer membranes, and supplement it with a lipophobic effect as well. This leads to an augmented tendency for fluorinated amphiphiles to self-assemble into vesicles (liposomes), tubules and other supramolecular aggregates when dispersed in water and other solvents. Fluorinated bilayers and vesicles are generally more stable and less permeant than those made from hydrocarbon analogs. The presence of a fluorinated film inside the liposomal membrane also has significant repercussion on the behaviour of the liposomes in a biological milieu and on their in vivo recognition.
Address and Contact Information Laboratoire de Chimie Moleculaire, Unite Associee au CNRS, Universite de Nice-Sophia Antipolis, Faculte des Sciences, 06108 Nice Cedex 02, France
[Rozmiar: 1332 bajtów]