The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Belsy Guerrero - One of the best experts on this subject based on the ideXlab platform.
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Isolation and characterization of two new non-hemorrhagic metalloproteinases with Fibrinogenolytic activity from the mapanare (Bothrops colombiensis) venom
Archives of Toxicology, 2013Co-Authors: María E. Girón, Alexis Rodríguez-acosta, Ana María Salazar, Elda E. Sánchez, Jacob Galán, Carlos Ibarra, Belsy GuerreroAbstract:Colombienases are acidic, low molecular weight metalloproteinases (Mr of 23,074.31 Da colombienase-1 and 23,078.80 Da colombienase-2; p I of 6.0 and 6.2, respectively) isolated from Bothrops colombiensis snake venom. The chromatographic profile in RP-HPLC and its partial sequence confirmed its high homogeneity. Both colombienases present Fibrino(geno)lytic activity, but did not show any hemorrhagic, amidolytic, plasminogen activator or coagulant activities, and no effect on platelet aggregation induced by collagen or ADP. Both enzymes were strongly active on Fibrinogen Aα chains followed by the Bβ chains, and colombienases-2, at high doses, also degraded the γ chains. This activity was stable at temperatures ranging between 4 and 37 °C, with a maximum activity at 25 °C, and at pHs between 7 and 9. The homology demonstrated by the comparison of sequences, with zinc-dependent metalloproteinases, as well as the metal chelant effects on, confirmed that the colombienases were metalloproteinases, particularly to α-Fibrinogenases belonging to the P-I class of SVPMs (20–30 kDa), which contain only the single-domain proteins. The biological characteristics of the colombienases confer a therapeutic potential, since they contain a high Fibrino(geno)lytic activity, devoid of hemorrhagic activity. These metalloproteinases might be explored as thrombolytic agents given that they dissolve Fibrin clots or prevent their formation.
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discreplasminin a plasmin inhibitor isolated from tityus discrepans scorpion venom
Archives of Toxicology, 2009Co-Authors: Josmary Brazon, Gina Dsuze, Maria Lucia Derrico, C L Arochapinango, Belsy GuerreroAbstract:Tityus discrepans venom (TdV) produces digestive hemorrhages, disseminated intravascular coagulation, alveoli Fibrin deposition and/or prothrombin and partial thromboplastin time alterations in humans. T. discrepans venom presents an in vitro tissue plasminogen activator-like (tPA-like), Fibrino(geno)lytic and plasmin inhibitory activities. The plasmin inhibitor, called discreplasminin, was isolated from TdV. Discreplasminin has a pI of 8.0 and a relative molecular weight of <6,000 Da. Discreplasminin and aprotinin strongly inhibited plasmin activity and moderately tPA activity, while epsilon amino caproic acid (EACA) moderately inhibited both enzymes. In presence and absence of Fibrin, the plasmin generation by tPA was completely inhibited by aprotinin and discreplasminin. EACA in the absence of Fibrin partially inhibited plasmin generation (37%); however, it produced a total inhibition of plasmin generation on a Fibrin surface. The tPA-clot lysis assay showed that discreplasminin acts like aprotinin inducing a slight delay in lysis time and lysis rate; in contrast, EACA presented a total inhibitory effect on Fibrin lysis. These results suggest that discreplasminin presents an anti-Fibrinolytic mechanism similar to aprotinin. Discreplasminin probably interacts with the active sites of plasmin and tPA. The presence of discreplasminin and other similar components in scorpion venom could partially explain the generalized Fibrin deposition which was found previously in rams.
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Discreplasminin, a plasmin inhibitor isolated from Tityus discrepans scorpion venom
Archives of Toxicology, 2008Co-Authors: Josmary Brazon, Gina D’suze, Maria Lucia D’errico, Carmen L. Arocha-piñango, Belsy GuerreroAbstract:Tityus discrepans venom ( TdV ) produces digestive hemorrhages, disseminated intravascular coagulation, alveoli Fibrin deposition and/or prothrombin and partial thromboplastin time alterations in humans. T. discrepans venom presents an in vitro tissue plasminogen activator-like (tPA-like), Fibrino(geno)lytic and plasmin inhibitory activities. The plasmin inhibitor, called discreplasminin, was isolated from TdV . Discreplasminin has a pI of 8.0 and a relative molecular weight of
Josmary Brazon - One of the best experts on this subject based on the ideXlab platform.
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discreplasminin a plasmin inhibitor isolated from tityus discrepans scorpion venom
Archives of Toxicology, 2009Co-Authors: Josmary Brazon, Gina Dsuze, Maria Lucia Derrico, C L Arochapinango, Belsy GuerreroAbstract:Tityus discrepans venom (TdV) produces digestive hemorrhages, disseminated intravascular coagulation, alveoli Fibrin deposition and/or prothrombin and partial thromboplastin time alterations in humans. T. discrepans venom presents an in vitro tissue plasminogen activator-like (tPA-like), Fibrino(geno)lytic and plasmin inhibitory activities. The plasmin inhibitor, called discreplasminin, was isolated from TdV. Discreplasminin has a pI of 8.0 and a relative molecular weight of <6,000 Da. Discreplasminin and aprotinin strongly inhibited plasmin activity and moderately tPA activity, while epsilon amino caproic acid (EACA) moderately inhibited both enzymes. In presence and absence of Fibrin, the plasmin generation by tPA was completely inhibited by aprotinin and discreplasminin. EACA in the absence of Fibrin partially inhibited plasmin generation (37%); however, it produced a total inhibition of plasmin generation on a Fibrin surface. The tPA-clot lysis assay showed that discreplasminin acts like aprotinin inducing a slight delay in lysis time and lysis rate; in contrast, EACA presented a total inhibitory effect on Fibrin lysis. These results suggest that discreplasminin presents an anti-Fibrinolytic mechanism similar to aprotinin. Discreplasminin probably interacts with the active sites of plasmin and tPA. The presence of discreplasminin and other similar components in scorpion venom could partially explain the generalized Fibrin deposition which was found previously in rams.
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Discreplasminin, a plasmin inhibitor isolated from Tityus discrepans scorpion venom
Archives of Toxicology, 2008Co-Authors: Josmary Brazon, Gina D’suze, Maria Lucia D’errico, Carmen L. Arocha-piñango, Belsy GuerreroAbstract:Tityus discrepans venom ( TdV ) produces digestive hemorrhages, disseminated intravascular coagulation, alveoli Fibrin deposition and/or prothrombin and partial thromboplastin time alterations in humans. T. discrepans venom presents an in vitro tissue plasminogen activator-like (tPA-like), Fibrino(geno)lytic and plasmin inhibitory activities. The plasmin inhibitor, called discreplasminin, was isolated from TdV . Discreplasminin has a pI of 8.0 and a relative molecular weight of
Antonella Motta - One of the best experts on this subject based on the ideXlab platform.
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outgrowth endothelial cells isolated and expanded from human peripheral blood progenitor cells as a potential source of autologous cells for endothelialization of silk fibroin biomaterials
Biomaterials, 2006Co-Authors: Sabine Fuchs, Antonella Motta, Claudio Migliaresi, C. J. KirkpatrickAbstract:One challenge of particular importance in tissue engineering is to improve vascularization of larger size defects, which would then facilitate a sufficient supply with oxygen and nutrients to the central regions of a larger tissue-engineered construct or in highly vascularized tissues. In this study, we show that outgrowth endothelial cells (OECs) derived from human peripheral blood can serve as a source of human autologous endothelial cells and can be used in combination with fibroin silk fiber meshes for applications in tissue engineering. OEC reveal a highly differentiated endothelial phenotype as well as a high phenotypic stability during their expansion. Furthermore, OEC showed very promising results in the endothelialization of fibroin silk fiber meshes, maintaining their endothelial characteristics and functions. On the fibroin fiber meshes OECs formed differentiated endothelial cell layers covering the single fibers as shown by data from scanning electron microscopy, immunofluorescence, and gene expression analysis. After embedding in a wound-healing matrix, mimicked by Fibrin gels, OEC migrated from the fibroin scaffolds into the Fibrin and formed a microvessel-like network. Thus, we conclude that OEC could serve as a valuable source of autologous endothelial cells, supporting pro-angiogenic therapies in combination with silk fibroin-based scaffolding materials in the field of tissue engineering and regenerative medicine.
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domain driven binding of Fibrin ogen onto silk fibroin biomaterials
Journal of Bioactive and Compatible Polymers, 2002Co-Authors: Matteo Santin, Stephen Paul Denyer, Andrew W Lloyd, Antonella MottaAbstract:Studies have demonstrated that serum protein adsorption onto silk fibroin-based biomaterials dramatically changes when the conformation of this natural polymer is rearranged by engineering procedures. In the present study, attention was paid to the binding of Fibrin(ogen) to fibroin fibers and regenerated films. The fibroin specimens were incubated either in human plasma or in a Fibrinogen solution to which thrombinwas added to activate the polymerization of the precursor into the final product, Fibrin. The experiments were carried out in the presence and absence of calcium to investigate the role of calcium-dependent enzymes in the binding process. The two types of samples were analyzed by SEM, the micrographs showed completely different interactions with Fibrinogen. Films did not show any visible Fibrin polymerization, whereas the fibers were bound to the Fibrin bundles by calcium-independent mechanisms.
Srivatsan Kidambi - One of the best experts on this subject based on the ideXlab platform.
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A totally recombinant Fibrin matrix for mesenchymal stem cell culture and delivery
Journal of Biomedical Materials Research Part A, 2018Co-Authors: Ou Wang, Ayman E.a. Ismail, Frank M. Fabian, Christian Elowsky, Wilson H. Burgess, Mark A. Carlson, William H. Velander, Qiang Li, Srivatsan KidambiAbstract:Mesenchymal stem cells (MSCs) have been widely studied for tissue engineering and treating diseases in laboratories, clinical trials, and clinics. Fibrin matrices are often used to culture MSCs or increase the retention of MSCs at the injection site. However, Fibrins made with the human plasma derived Fibrinogen have high cost and risk of human pathogen transmission. In this article, we studied if Fibrin matrices made with recombinant human Fibrinogen, recombinant human thrombin, and recombinant human factor XIII could be used to culture and deliver MSCs. We systematically investigated the relationships between the Fibrin matrix formulation, its nanostructure, and the behaviors of the cells in the matrix including the cell morphology, viability, and growth. We found that the Fibrinogen concentration significantly affected the matrix structure and cell behaviors. We then used an optimized Fibrin matrix to deliver human MSCs into mice subcutaneously. We found that the matrix could significantly enhance the retention of MSCs at the injection site. To our best knowledge, this is the first study on using Fibrin matrices made with entirely recombinant proteins for culturing and delivering MSCs. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3135-3142, 2018.
Gina Dsuze - One of the best experts on this subject based on the ideXlab platform.
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discreplasminin a plasmin inhibitor isolated from tityus discrepans scorpion venom
Archives of Toxicology, 2009Co-Authors: Josmary Brazon, Gina Dsuze, Maria Lucia Derrico, C L Arochapinango, Belsy GuerreroAbstract:Tityus discrepans venom (TdV) produces digestive hemorrhages, disseminated intravascular coagulation, alveoli Fibrin deposition and/or prothrombin and partial thromboplastin time alterations in humans. T. discrepans venom presents an in vitro tissue plasminogen activator-like (tPA-like), Fibrino(geno)lytic and plasmin inhibitory activities. The plasmin inhibitor, called discreplasminin, was isolated from TdV. Discreplasminin has a pI of 8.0 and a relative molecular weight of <6,000 Da. Discreplasminin and aprotinin strongly inhibited plasmin activity and moderately tPA activity, while epsilon amino caproic acid (EACA) moderately inhibited both enzymes. In presence and absence of Fibrin, the plasmin generation by tPA was completely inhibited by aprotinin and discreplasminin. EACA in the absence of Fibrin partially inhibited plasmin generation (37%); however, it produced a total inhibition of plasmin generation on a Fibrin surface. The tPA-clot lysis assay showed that discreplasminin acts like aprotinin inducing a slight delay in lysis time and lysis rate; in contrast, EACA presented a total inhibitory effect on Fibrin lysis. These results suggest that discreplasminin presents an anti-Fibrinolytic mechanism similar to aprotinin. Discreplasminin probably interacts with the active sites of plasmin and tPA. The presence of discreplasminin and other similar components in scorpion venom could partially explain the generalized Fibrin deposition which was found previously in rams.