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J A Czyrski

Publications and source records attributed to J A Czyrski.

8 recordsLinked to original sources
PubMed1992

The interaction of a glycosaminoglycan, heparin, with HIV-1 major envelope glycoprotein.

We demonstrate in vitro the occurrence of a specific but low-affinity interaction between soluble tetrameric rgp160 or soluble monomeric or tetrameric rgp120 and heparin-agarose (HA). This interaction is saturable, pH and temperature-dependent, and can be inhibited by soluble heparin, but not by soluble dextran. In buffer supplemented with 10 mM CaCl2, the C50 of soluble heparin, i.e., the concentration of soluble heparin which leads to 50% inhibition of the binding of [125I]rgp160 or of [125I]rgp120 to HA, is 1.1 x 10(-4) disaccharidic molar concentration for rgp160 and 3.2 x 10(-4) dissacharidic molar concentration for rgp120, which indicates low-affinity interactions. Upon chromatography on HA, [125I]rgp160 is repeatedly eluted as a retarded fraction when compared to the elution volume of [125I]rgp160-soluble heparin complex. Under the same experimental conditions, [125I]rgp120 is also eluted, but as a less retarded fraction than [125I]rgp160. Taken together, these results suggest that, at least part of the described anti HIV-1 activity of heparin might be mediated by interaction with HIV-1 major envelope glycoprotein.

Dextrans↗
PubMed1991

Mitogenic activity of selenoorganic compounds in human peripheral blood leukocytes.

A variety of organoselenium compounds were originally described as antiinflammatory, antioxidant or glutathione-peroxidase-like agents, and as inhibitors of prostaglandin and leukotriene synthesis. Recently, the compounds have also been found to be inducers of interferon gamma and tumor necrosis factor in human peripheral blood leukocytes (PBL). We evaluated the effects of bis [2-(N-phenylcarboxamido)phenyl] diselenide and Ebselen; 2-phenyl-1,2-benzisoselenazol-3(2H)one, on the incorporation of tritiated thymidine into the DNA of PBL cultured in vitro. Both compounds were mitogenic and this effect was correlated with the expression of interleukin 2 receptor in T-lymphocytes. Therefore, we suggest that the selenoorganic compounds may induce mitogenic cytokines.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1987

Activity of human, bovine and porcine platelet-derived growth factor in a radioreceptor assay with human placental membrane protein.

Radioiodinated human platelet-derived growth factor (125I-PDGF), and unlabeled human (Hu), bovine (Bo), and porcine (Po) PDGF were used to study PDGF receptors in human term placental membrane preparations. The binding of 125I-Hu-PDGF was inhibited by unlabeled preparations. Half-maximal occupancy of the binding sites occurred at 7-9 nM of Hu-, Bo- or Po-PDGF. Scatchard analysis of the binding data indicated a single class of receptors having a Kd value of about 1.1-1.2 X 10(-10) M. Thus, the sensitive radioreceptor assay does not detect any species specificity of PDGF.

Animals↗
PubMed1987

Partial purification of porcine platelet-derived growth factor (PDGF).

Fresh porcine blood platelets, subjected to ethanol acid extraction and purification on DEAE-Sephadex A-50 and CM-Sephadex C-50, were used to obtain partially purified, cationic PDGF (pI 8.5-10) of Mr 38,000 and biological activity 10(4) U/ml. Reduction of porcine PDGF with 2-mercaptoethanol revealed the presence of two polypeptides with Mr 18,000-22,000.

Animals↗
PubMed1985

Properties of purified bovine platelet-derived growth factor stimulating proliferation of human and mouse fibroblasts.

Platelet-derived growth factor (PDGF) was isolated from platelets obtained from fresh bovine blood. The platelet lysates were extracted with acid-ethanol, according to the classic procedure that has been applied to the preparation of various protein hormones and transforming growth factors, but not until now to PDGF isolation. Bovine PDGF was further purified by ion-exchange chromatography on DEAE-Sephadex, CM-Sephadex, and finally by molecular sieving on Sephadex G-100. Bovine PDGF has an isoelectric point of 9.45-10.6 and a molecular weight ranging from 28 000 to 31 000. Reduction of bovine PDGF with 2-mercaptoethanol revealed the presence of two polypeptides with molecular weights of approximately 14 000 and 15 000. A simple biologic microassay of cell multiplication-stimulating activity has been developed in our laboratory. Purified bovine PDGF stimulated the proliferation of BALB/c 3T3 or human fibroblasts at minimal concentrations of 0.36-1.5 ng/mL.

Animals↗
PubMed1985

Interaction of sodium salt of 9-oxo-10-acridineacetic acid (CMA) and its analogs with serum albumin. A model for study on binding of the interferon inducer with receptor.

Equilibrium dialysis, gel filtration and SDS polyacrylamide gel electrophoresis were used to study the interaction of sodium salt of 9-oxo-10-acridineacetic acid (CMA) as well as its analogs 7, 8, 11, 13 - 16 with proteins. The compounds were found to bind mainly to serum albumins. Several other proteins had no affinity to the compounds. The close analogs 7 and 8 (sodium salt of 2,7-dibromo-9-oxo-10-acridineacetic acid and sodium salt of 9-oxo-10-acridinebutyric acid) which were inactive as interferon inducers were found to have greater affinity to bovine, mouse or human albumin than the active IFN inducer--CMA. The mechanism of interaction of CMA as well as its close analogs with albumin resembled the first phase of reaction of pharmacologically active ligands with their specific receptor or acceptor proteins. CMA and some of its close analogs were also shown to stabilize the human erythrocyte membrane against hemolysis in the hypotonic solution. However, the activity of the compounds was much weaker than that of other so called membrane active drugs.

Acridines↗
PubMed1984

New procedure for purification of human platelet-derived growth factor.

A new simple procedure was developed for purification of human platelet-derived growth factor (PDGF). PDGF was isolated and concentrated by acid/ethanol extraction of platelet lysate. Purification of this extract was accomplished by initial ion-exchange chromatography on DEAE-Sephadex and subsequent separation of "cationic" unadsorbed fraction on CM-Sephadex and controlled-pore glass--CPG-10. The product migrated as two biologically active homogeneous fractions, PDGF I (Mr = 34 000) and PDGF II (Mr = 31 000) in analytical gel electrophoresis in the presence of SDS. PDGF had isoelectric point ranging from 9.5-10.6. Multiplication-stimulating activity of PDGF was estimated using the clone of Balb/c 3T3 cells propagated in microplates in Eagle's minimal essential medium supplemented with 2% of platelet poor plasma serum. Purified PDGF was active in stimulating 3T3 cell proliferation at 0.4 ng/ml.

Biological Assay↗