Defining Potential Vaccine Targets of Haemophilus ducreyi Trimeric Autotransporter Adhesin DsrA

PubMed Central

Fusco, William G.; Choudhary, Neelima R.; Stewart, Shelley M.; Alam, S. Munir; Sempowski, Gregory D.; Elkins, Christopher

2015-01-01

Haemophilus ducreyi is the causative agent of the sexually transmitted genital ulcer disease chancroid. Strains of H. ducreyi are grouped in two classes (I and II) based on genotypic and phenotypic differences, including those found in DsrA, an outer membrane protein belonging to the family of multifunctional trimeric autotransporter adhesins. DsrA is a key serum resistance factor of H. ducreyi that prevents binding of natural IgM at the bacterial surface and functions as an adhesin to fibronectin, fibrinogen, vitronectin, and human keratinocytes. Monoclonal antibodies (MAbs) were developed to recombinant DsrA (DsrAI) from prototypical class I strain 35000HP to define targets for vaccine and/or therapeutics. Two anti-DsrAI MAbs bound monomers and multimers of DsrA from genital and non-genital/cutaneous H. ducreyi strains in a Western blot and reacted to the surface of the genital strains; however, these MAbs did not recognize denatured or native DsrA from class II strains. In a modified extracellular matrix protein binding assay using viable H. ducreyi, one of the MAbs partially inhibited binding of fibronectin, fibrinogen, and vitronectin to class I H. ducreyi strain 35000HP, suggesting a role for anti-DsrA antibodies in preventing binding of H. ducreyi to extracellular matrix proteins. Standard ELISA and surface plasmon resonance using a peptide library representing full-length, mature DsrAI revealed the smallest nominal epitope bound by one of the MAbs to be MEQNTHNINKLS. Taken together, our findings suggest that this epitope is a potential target for an H. ducreyi vaccine. PMID:25897604

Defining Potential Vaccine Targets of Haemophilus ducreyi Trimeric Autotransporter Adhesin DsrA.

PubMed

Fusco, William G; Choudhary, Neelima R; Stewart, Shelley M; Alam, S Munir; Sempowski, Gregory D; Elkins, Christopher; Leduc, Isabelle

2015-04-01

Haemophilus ducreyi is the causative agent of the sexually transmitted genital ulcer disease chancroid. Strains of H. ducreyi are grouped in two classes (I and II) based on genotypic and phenotypic differences, including those found in DsrA, an outer membrane protein belonging to the family of multifunctional trimeric autotransporter adhesins. DsrA is a key serum resistance factor of H. ducreyi that prevents binding of natural IgM at the bacterial surface and functions as an adhesin to fibronectin, fibrinogen, vitronectin, and human keratinocytes. Monoclonal antibodies (MAbs) were developed to recombinant DsrA (DsrA(I)) from prototypical class I strain 35000HP to define targets for vaccine and/or therapeutics. Two anti-DsrAI MAbs bound monomers and multimers of DsrA from genital and non-genital/cutaneous H. ducreyi strains in a Western blot and reacted to the surface of the genital strains; however, these MAbs did not recognize denatured or native DsrA from class II strains. In a modified extracellular matrix protein binding assay using viable H. ducreyi, one of the MAbs partially inhibited binding of fibronectin, fibrinogen, and vitronectin to class I H. ducreyi strain 35000HP, suggesting a role for anti-DsrA antibodies in preventing binding of H. ducreyi to extracellular matrix proteins. Standard ELISA and surface plasmon resonance using a peptide library representing full-length, mature DsrAI revealed the smallest nominal epitope bound by one of the MAbs to be MEQNTHNINKLS. Taken together, our findings suggest that this epitope is a potential target for an H. ducreyi vaccine.

Passive participation of fixed platelets in aggregation facilitated by covalently bound fibrinogen.

PubMed

Agam, G; Livne, A

1983-01-01

The role of fibrinogen in interplatelet recognition during aggregation was examined by combining two cell types: fresh platelets (in limiting density) activated by thrombin or A23187, and formaldehyde-fixed platelets, bearing cross-linked fibrinogen. The fixed platelets did not aggregate by themselves, nor with resting platelets, but were capable of interacting with activated platelets and of participating passively in aggregation. The participation, expressed by enhanced aggregation, was assayed by the conventional turbidometric traces and by cosedimentation of fixed 3H-platelets with aggregates of fresh platelets. Platelet suspensions, prepared without special means to avert spontaneous activation, retained plasma fibrinogen to the extent of 50 micrograms/ml of a suspension containing 10(8) platelets, and the derived fixed platelets participated in aggregation, independently of added fibrinogen. The capability of such fixed platelets to participate in aggregation was sensitive to proteolytic digestion and to massive acetylation. When platelet separation was aided by apyrase or aspirin, PGE1 and gel filtration, the residual plasma fibrinogen was limited to 0.4 micrograms/ml of 10(8) platelet suspension. The derived fixed platelets were incapable of participating in aggregation unless fibrinogen was added prior to fixation. The affixed fibrinogen could not be replaced by soluble fibrinogen or affixed albumin. It is concluded that fibrinogen, which binds to platelets upon activation or is linked to them covalently, is a recognition site for platelet-platelet interaction during aggregation.

Detection of Nisin and Fibrinogen Adsorption on Poly(ethylene Oxide) Coated Polyurethane Surfaces by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

PubMed Central

Schilke, Karl F.; McGuire, Joseph

2011-01-01

Stable, pendant polyethylene oxide (PEO) layers were formed on medical-grade Pellethane® and Tygon® polyurethane surfaces, by adsorption and gamma-irradiation of PEO-polybutadiene-PEO triblock surfactants. Coated and uncoated polyurethanes were challenged individually or sequentially with nisin (a small polypeptide with antimicrobial activity) and/or fibrinogen, and then analyzed with time-of-flight secondary ion mass spectrometry (TOF-SIMS). Data reduction by robust principal components analysis (PCA) allowed detection of outliers, and distinguished adsorbed nisin and fibrinogen. Fibrinogen-contacted surfaces, with or without nisin, were very similar on uncoated polymer surfaces, consistent with nearly complete displacement or coverage of previously-adsorbed nisin by fibrinogen. In contrast, nisin-loaded PEO layers remained essentially unchanged upon challenge with fibrinogen, suggesting that the adsorbed nisin is stabilized within the pendant PEO layer, while the peptide-loaded PEO layer retains its ability to repel large proteins. Coatings of PEO loaded with therapeutic polypeptides on medical polymers have the potential to be used to produce anti-fouling and biofunctional surfaces for implantable or blood-contacting devices. PMID:21440897

Stimulation of fibrinogen synthesis in cultured rat hepatocytes by fibrinogen degradation product fragment D

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaDuca, F.M.; Tinsley, L.A.; Dang, C.V.

The direct stimulation of fibrinogen biosynthesis by fibrinogen degradation produces (FDPs) was studied in rat hepatocyte cultures. Pure rat FDP fragment D (FDP-D) (Mr 90,000) and FDP fragment E (FDP-E) (Mr 40,000) and mixtures of the two (FDP-DE) were added to rat hepatocytes cultured in serum-free hormonally defined medium. Hydrocortisone (20 microM) significantly increased synthesis of fibrinogen, as determined by incorporation of (35S)methionine. FDP-D and FDP-E did not increase fibrinogen synthesis in the presence of hydrocortisone. However, hepatocytes cultured without hydrocortisone displayed increased fibrinogen synthesis (2.0- to 2.8-fold) with FDP-D (2.6-6.7 microM) but not with FDP-E (5.7 microM). At thesemore » FDP concentrations the synthesis of albumin, haptoglobin, and transferrin was not increased. FDP-D-induced fibrinogen synthesis was inhibited (greater than 90%) by actinomycin D and cycloheximide, indicating that the increase in (35S)methionine incorporation was from de novo protein synthesis. The role of FDP-D was further substantiated by showing that FDP-D, but not FDP-E, bound to the hepatocytes. These data indicate that FDP-D, but not FDP-E, directly and specifically stimulates fibrinogen synthesis in rat hepatocytes; this stimulation does not require any additional serum or protein cofactors.« less

Protein corona formation in bronchoalveolar fluid enhances diesel exhaust nanoparticle uptake and pro-inflammatory responses in macrophages.

PubMed

Shaw, Catherine A; Mortimer, Gysell M; Deng, Zhou J; Carter, Edwin S; Connell, Shea P; Miller, Mark R; Duffin, Rodger; Newby, David E; Hadoke, Patrick W F; Minchin, Rodney F

2016-09-01

In biological fluids nanoparticles bind a range of molecules, particularly proteins, on their surface. The resulting protein corona influences biological activity and fate of nanoparticle in vivo. Corona composition is often determined by the biological milieu encountered at the entry portal into the body, and, can therefore, depend on the route of exposure to the nanoparticle. For environmental nanoparticles where exposure is by inhalation, this will be lung lining fluid. This study examined plasma and bronchoalveolar fluid (BALF) protein binding to engineered and environmental nanoparticles. We hypothesized that protein corona on nanoparticles would influence nanoparticle uptake and subsequent pro-inflammatory biological response in macrophages. All nanoparticles bound plasma and BALF proteins, but the profile of bound proteins varied between nanoparticles. Focusing on diesel exhaust nanoparticles (DENP), we identified proteins bound from plasma to include fibrinogen, and those bound from BALF to include albumin and surfactant proteins A and D. The presence on DENP of a plasma-derived corona or one of purified fibrinogen failed to evoke an inflammatory response in macrophages. However, coronae formed in BALF increased DENP uptake into macrophages two fold, and increased nanoparticulate carbon black (NanoCB) uptake fivefold. Furthermore, a BALF-derived corona increased IL-8 release from macrophages in response to DENP from 1720 ± 850 pg/mL to 5560 ± 1380 pg/mL (p = 0.014). These results demonstrate that the unique protein corona formed on nanoparticles plays an important role in determining biological reactivity and fate of nanoparticle in vivo. Importantly, these findings have implications for the mechanism of detrimental properties of environmental nanoparticles since the principle route of exposure to such particles is via the lung.

Label-Free Quantitative Immunoassay of Fibrinogen in Alzheimer Disease Patient Plasma Using Fiber Optical Surface Plasmon Resonance

NASA Astrophysics Data System (ADS)

Kim, Jisoo; Kim, SeJin; Nguyen, Tan Tai; Lee, Renee; Li, Tiehua; Yun, Changhyun; Ham, Youngeun; An, Seong Soo A.; Ju, Heongkyu

2016-05-01

We present a real-time quantitative immunoassay to detect fibrinogen in the blood plasma of Alzheimer's disease patients using multimode fiber optical sensors in which surface plasmon resonance (SPR) was employed. Nanometer-thick bimetals including silver and aluminum were coated onto the core surface of the clad-free part (5 cm long) of the fiber for SPR excitation at the He-Ne laser wavelength of 632.8 nm. The histidine-tagged peptide was then coated on the metal surface to immobilize the fibrinogen antibody for the selective capture of fibrinogen among the proteins in the patient blood plasma. The SPR fiber optical sensor enabled quantitative detection of concentrations of fibrinogen from the different human patient blood at a detection limit of ˜20 ng/ml. We also observed a correlation in the fibrinogen concentration measurement between enzyme-linked immunosorbent assay and our SPR fiber-based sensors. This suggests that the presented SPR fiber-based sensors that do not rely on the use of labels such as fluorophores can be used for a real-time quantitative assay of a specific protein such as fibrinogen in a human blood that is known to contain many other kinds of proteins together.

SPM analysis of fibrinogen adsorption on solid surfaces

NASA Astrophysics Data System (ADS)

Choukourov, A.; Grinevich, A.; Saito, N.; Takai, O.

2007-09-01

The adsorption kinetics, adhesion and orientation of human fibrinogen on solid surfaces have been studied by surface probe microscopy (SPM) and quartz crystal microbalance techniques (QCM). CF 3-, NH 2-terminated organo-silane self-assembled monolayers (SAM) and OH-terminated silicon dioxide have been used as model surfaces. Furthermore, the interaction of fibrinogen with nanocomposite Ti/hydrocarbon plasma polymer films (Ti/ppCH) deposited by dc magnetron sputtering has also been studied.

Procoagulant Platelets Form an α-Granule Protein-covered “Cap” on Their Surface That Promotes Their Attachment to Aggregates*

PubMed Central

Abaeva, Anastasia A.; Canault, Matthias; Kotova, Yana N.; Obydennyy, Sergey I.; Yakimenko, Alena O.; Podoplelova, Nadezhda A.; Kolyadko, Vladimir N.; Chambost, Herve; Mazurov, Aleksei V.; Ataullakhanov, Fazoil I.; Nurden, Alan T.; Alessi, Marie-Christine; Panteleev, Mikhail A.

2013-01-01

Strongly activated “coated” platelets are characterized by increased phosphatidylserine (PS) surface expression, α-granule protein retention, and lack of active integrin αIIbβ3. To study how they are incorporated into thrombi despite a lack of free activated integrin, we investigated the structure, function, and formation of the α-granule protein “coat.” Confocal microscopy revealed that fibrin(ogen) and thrombospondin colocalized as “cap,” a single patch on the PS-positive platelet surface. In aggregates, the cap was located at the point of attachment of the PS-positive platelets. Without fibrin(ogen) retention, their ability to be incorporated in aggregates was drastically reduced. The surface fibrin(ogen) was strongly decreased in the presence of a fibrin polymerization inhibitor GPRP and also in platelets from a patient with dysfibrinogenemia and a fibrinogen polymerization defect. In contrast, a fibrinogen-clotting protease ancistron increased the amount of fibrin(ogen) and thrombospondin on the surface of the PS-positive platelets stimulated with collagen-related peptide. Transglutaminases are also involved in fibrin(ogen) retention. However, platelets from patients with factor XIII deficiency had normal retention, and a pan-transglutaminase inhibitor T101 had only a modest inhibitory effect. Fibrin(ogen) retention was normal in Bernard-Soulier syndrome and kindlin-3 deficiency, but not in Glanzmann thrombasthenia lacking the platelet pool of fibrinogen and αIIbβ3. These data show that the fibrin(ogen)-covered cap, predominantly formed as a result of fibrin polymerization, is a critical mechanism that allows coated (or rather “capped”) platelets to become incorporated into thrombi despite their lack of active integrins. PMID:23995838

Surface structural conformations of fibrinogen polypeptides for improved biocompatibility.

PubMed

Yaseen, Mohammed; Zhao, Xiubo; Freund, Amy; Seifalian, Alexander M; Lu, Jian R

2010-05-01

This work reports on how incorporation of silica nanocages into poly(urethane) copolymers (PU) affects conformational orientations of adsorbed fibrinogen and how different surfaces subsequently influenced HeLa cell attachment and proliferation. Incorporation of 2 wt% silica nanocages into poly(urethane) (PU4) substantially altered the surface topography of the films and some 50% of the surface was covered with the nanocages due to their preferential exposure. AFM studies revealed the deposition of a dense protein network on the soft polymeric domains of PU4 and much reduced fibrinogen adsorption on the hard nanocage domains. As on the bare SiO(2) control surface, fibrinogen molecules adsorbed on top of the hard nanocages mainly took the dominant trinodular structures in monomeric and dimeric forms. In addition, net positively charged long alpha chains were prone to being hidden beneath the D domains whilst gamma chains predominantly remained exposed. Dynamic interfacial adsorption as probed by spectroscopic ellipsometry revealed fast changes in interfacial conformation induced by electrostatic interactions between different segments of fibrinogen and the surface, consistent with the AFM imaging. On the PU surfaces without nanocage incorporation (PUA), however, adsorbed fibrinogen molecules formed beads-like chain networks, consistent with the structure featured on the soft PU4 domains, showing very different effects of surface chemical nature. Monoclonal antibodies specific to the alpha and gamma chains showed reduced alpha but increased gamma chain binding at the silicon oxide control and PU4 surfaces, whilst on the PUA, C18 and amine surfaces (organic surface controls) the opposite binding trend was detected with alpha chain binding dominant, showing different fibrinogen conformations. Cell attachment studies revealed differences in cell attachment and proliferation, consistent with the different polypeptide conformations on the two types of surfaces, showing a strong preference to the extent of exposure of gamma chains. Crown Copyright 2010. Published by Elsevier Ltd. All rights reserved.

Supramolecular Structures with Blood Plasma Proteins, Sugars and Nanosilica

NASA Astrophysics Data System (ADS)

Turov, V. V.; Gun'ko, V. M.; Galagan, N. P.; Rugal, A. A.; Barvinchenko, V. M.; Gorbyk, P. P.

Supramolecular structures with blood plasma proteins (albumin, immunoglobulin and fibrinogen (HPF)), protein/water/silica and protein/water/ silica/sugar (glucose, fructose and saccharose) were studied by NMR, adsorption, IR and UV spectroscopy methods. Hydration parameters, amounts of weakly and strongly bound waters and interfacial energy (γ S) were determined over a wide range of component concentrations. The γ S(C protein,C silica) graphs were used to estimate the energy of protein-protein, protein-surface and particle-particle interactions. It was shown that interfacial energy of self-association (γ as) of protein molecules depends on a type of proteins. A large fraction of water bound to proteins can be displaced by sugars, and the effect of disaccharide (saccharose) was greater than that of monosugars. Changes in the structural parameters of cavities in HPF molecules and complexes with HPF/silica nanoparticles filled by bound water were analysed using NMR-cryoporometry showing that interaction of proteins with silica leads to a significant decrease in the amounts of water bound to both protein and silica surfaces. Bionanocomposites with BSA/nanosilica/sugar can be used to influence states of living cells and tissues after cryopreservation or other treatments. It was shown that interaction of proteins with silica leads to strong decrease in the volume of all types of internal cavities filled by water.

Distinct Adsorption Configurations and Self-Assembly Characteristics of Fibrinogen on Chemically Uniform and Alternating Surfaces including Block Copolymer Nanodomains

PubMed Central

2015-01-01

Understanding protein–surface interactions is crucial to solid-state biomedical applications whose functionality is directly correlated with the precise control of the adsorption configuration, surface packing, loading density, and bioactivity of protein molecules. Because of the small dimensions and highly amphiphilic nature of proteins, investigation of protein adsorption performed on nanoscale topology can shed light on subprotein-level interaction preferences. In this study, we examine the adsorption and assembly behavior of a highly elongated protein, fibrinogen, on both chemically uniform (as-is and buffered HF-treated SiO2/Si, and homopolymers of polystyrene and poly(methyl methacrylate)) and varying (polystyrene-block-poly(methyl methacrylate)) surfaces. By focusing on high-resolution imaging of individual protein molecules whose configurations are influenced by protein–surface rather than protein–protein interactions, fibrinogen conformations characteristic to each surface are identified and statistically analyzed for structural similarities/differences in key protein domains. By exploiting block copolymer nanodomains whose repeat distance is commensurate with the length of the individual protein, we determine that fibrinogen exhibits a more neutral tendency for interaction with both polystyrene and poly(methyl methacrylate) blocks relative to the case of common globular proteins. Factors affecting fibrinogen–polymer interactions are discussed in terms of hydrophobic and electrostatic interactions. In addition, assembly and packing attributes of fibrinogen are determined at different loading conditions. Primary orientations of fibrinogen and its rearrangements with respect to the underlying diblock nanodomains associated with different surface coverage are explained by pertinent protein interaction mechanisms. On the basis of two-dimensional stacking behavior, a protein assembly model is proposed for the formation of an extended fibrinogen network on the diblock copolymer. PMID:24708538

An improved layer-by-layer self-assembly technique to generate biointerfaces for platelet adhesion studies: Dynamic LbL

NASA Astrophysics Data System (ADS)

Lopez, Juan Manuel

Layer-by-layer self-assembly (LbL) is a technique that generates engineered nano-scale films, coatings, and particles. These nanoscale films have recently been used in multiple biomedical applications. Concurrently, microfabrication methods and advances in microfluidics are being developed and combined to create "Lab-on-a-Chip" technologies. The potential to perform complex biological assays in vitro as a first-line screening technique before moving on to animal models has made the concept of lab on a chip a valuable research tool. Prior studies in the Biofluids Laboratory at Louisiana Tech have used layer-by-layer and in vitro biological assays to study thrombogenesis in a controlled, repeatable, engineered environment. The reliability of these previously established techniques was unsatisfactory for more complex cases such as chemical and shear stress interactions. The work presented in this dissertation was performed to test the principal assumptions behind the established laboratory methodologies, suggest improvements where needed, and test the impact of these improvements on accuracy and repeatability. The assumptions to be tested were: (1) The fluorescence microscopy (FM) images of acridine orange-tagged platelets accurately provide a measure of percent area of surface covered by platelets; (2) fibrinogen coatings can be accurately controlled, interact with platelets, and do not interfere with the ability to quantify platelet adhesion; and (3) the dependence of platelet adhesion on chemical agents, as measured with the modified methods, generally agrees with results obtained from our previous methods and with known responses of platelets that have been documented in the literature. The distribution of fibrinogen on the final LbL surface generated with the standard, static process (s-LbL) was imaged by tagging the fibrinogen with an anti-fibrinogen antibody bound to fluorescein isothiocyanate (FITC). FITC FM images and acridine orange FM images were taken sequentially at selected surface locations to generate a composite overlap of presumed platelet adhesion as a function of fibrinogen distribution. The method was unable to distinguish the surface from the adhered cells. The surface inhomogeneity and porosity retained a large amount of acridine orange stain, even in the absence of platelets, and components in the platelet-rich plasma (PRP) were found to fix acridine orange in a mode that fluoresced in the FITC imaging FM. Both of these problems obfuscated the platelet adhesion FM results when using s-LbL surfaces and acridine orange staining of platelets. A dynamic process (d-LbL) was developed in which a solution of the molecule to be layered was constantly washed over the surface, and was constantly mixed to maintain a more homogeneous distribution of solute relative to the surface during the layering process. The d-LbL surfaces were tested as described above, and found to reduce the size and number of regions of anomalous acridine orange pooling trapped by the surface, providing a greater consistency and reliability in identifying platelets. The improved surface was then used in a series of platelet adhesion experiments under static and dynamic flow conditions, and with and without the chemical additive L-arginine. The complex microcharmel system used in prior studies was replaced with a simpler system involving fewer nuisance variables for these tests. The tests were performed on both collagen and fibrinogen surfaces. Collagen has been used as a thrombogenic surface in multiple studies in the literature, but produces additional variables in thrombogenesis control that are avoided when fibrinogen is used. In these tests, fibrinogen was found to be as thrombogenic as collagen, and platelet coverage of both biointerfaces was reduced by L-arginine in a manner similar to previously reported work. The simpler system differed from the previous microchannel system in important factors: (1) It exposed the platelets to much lower shear stresses; (2) It introduced an oscillatory flow, which introduced a higher degree of variability in the adhesion than previously reported; (3) the previous work had not removed the acridine orange surface problems. Therefore, a direct comparison between results was not possible. The new d-LbL surface process was successful in testing the basic assumptions. Testing showed that the new process eliminated the anomalous acridine orange retention problem during fluorescence imaging. This improvement in fluorescence response meant that the FM results matched the platelet adhesion on plain glass slides and adhesion reported by others in microfluidic flows. The chemical additive responses behaved as expected, with an increase in L-arginine contributing to a decrease in thrombogenesis under dynamic conditions, but not under static conditions.

Fibrinogen Brescia

PubMed Central

Brennan, Stephen O.; Wyatt, Jane; Medicina, Daniela; Callea, Francesco; George, Peter M.

2000-01-01

The proposita suffered from liver cirrhosis and biopsy showed type 1 membrane-bound fiberglass inclusions. The hepatic inclusion bodies were weakly periodic acid-Schiff diastase-positive, and on immunoperoxidase staining reacted specifically with anti-fibrinogen antisera. Coagulation investigations revealed low functional and antigenic fibrinogen together with a prolonged thrombin time of 37 seconds (normal, 17 to 22 seconds) suggestive of a hypodysfibrinogenemia. DNA sequencing of all three fibrinogen genes showed a single heterozygous mutation of GGG (Gly)→CGG (Arg) at codon 284 of the γ-chain gene. However, examination of purified fibrinogen chains by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, reverse-phase high-performance liquid chromatography, ion-exchange high-performance liquid chromatography, and isoelectric focusing, failed to show any evidence of the mutant γBr chain in plasma fibrinogen. This finding was substantiated by electrospray ionization mass spectrometry, which showed only a normal γ (and Bβ) chain mass, but a large increase in the portion of their disialo isoforms. We speculate that misfolding of the variant protein causes hepatic retention and the subsequent hypofibrinogenemia, and that the functional defect (dysfibrinogenemia) results from hypersialylation of otherwise normal Bβ and γ chains consequent to the liver cirrhosis. These conclusions were supported by studies on six other family members with hypofibrinogenemia, and essentially normal clotting times, who were heterozygous for the γ284 Gly→Arg mutation. PMID:10880389

Coated platelets function in platelet-dependent fibrin formation via integrin αIIbβ3 and transglutaminase factor XIII

PubMed Central

Mattheij, Nadine J.A.; Swieringa, Frauke; Mastenbroek, Tom G.; Berny-Lang, Michelle A.; May, Frauke; Baaten, Constance C.F.M.J.; van der Meijden, Paola E.J.; Henskens, Yvonne M.C.; Beckers, Erik A.M.; Suylen, Dennis P.L.; Nolte, Marc W.; Hackeng, Tilman M.; McCarty, Owen J.T.; Heemskerk, Johan W.M.; Cosemans, Judith M.E.M.

2016-01-01

Coated platelets, formed by collagen and thrombin activation, have been characterized in different ways: i) by the formation of a protein coat of α-granular proteins; ii) by exposure of procoagulant phosphatidylserine; or iii) by high fibrinogen binding. Yet, their functional role has remained unclear. Here we used a novel transglutaminase probe, Rhod-A14, to identify a subpopulation of platelets with a cross-linked protein coat, and compared this with other platelet subpopulations using a panel of functional assays. Platelet stimulation with convulxin/thrombin resulted in initial integrin αIIbβ3 activation, the appearance of a platelet population with high fibrinogen binding, (independently of active integrins, but dependent on the presence of thrombin) followed by phosphatidylserine exposure and binding of coagulation factors Va and Xa. A subpopulation of phosphatidylserine-exposing platelets bound Rhod-A14 both in suspension and in thrombi generated on a collagen surface. In suspension, high fibrinogen and Rhod-A14 binding were antagonized by combined inhibition of transglutaminase activity and integrin αIIbβ3. Markedly, in thrombi from mice deficient in transglutaminase factor XIII, platelet-driven fibrin formation and Rhod-A14 binding were abolished by blockage of integrin αIIbβ3. Vice versa, star-like fibrin formation from platelets of a patient with deficiency in αIIbβ3 (Glanzmann thrombasthenia) was abolished upon blockage of transglutaminase activity. We conclude that coated platelets, with initial αIIbβ3 activation and high fibrinogen binding, form a subpopulation of phosphatidylserine-exposing platelets, and function in platelet-dependent star-like fibrin fiber formation via transglutaminase factor XIII and integrin αIIbβ3. PMID:26721892

Histamine release and fibrinogen adsorption mediate acute inflammatory responses to biomaterial implants in humans

PubMed Central

Zdolsek, Johann; Eaton, John W; Tang, Liping

2007-01-01

Background Medical implants often fail as a result of so-called foreign body reactions during which inflammatory cells are recruited to implant surfaces. Despite the clinical importance of this phenomenon, the mechanisms involved in these reactions to biomedical implants in humans are not well understood. The results from animal studies suggest that both fibrinogen adsorption to the implant surface and histamine release by local mast cells are involved in biomaterial-mediated acute inflammatory responses. The purpose of this study was to test this hypothesis in humans. Methods Thirteen male medical student volunteers (Caucasian, 21–30 years of age) were employed for this study. To assess the importance of fibrinogen adsorption, six volunteers were implanted with polyethylene teraphthalate disks pre-coated with their own (fibrinogen-containing) plasma or (fibrinogen-free) serum. To evaluate the importance of histamine, seven volunteers were implanted with uncoated disks with or without prior oral administration of histamine receptor antagonists. The acute inflammatory response was estimated 24 hours later by measuring the activities of implant-associated phagocyte-specific enzymes. Results Plasma coated implants accumulated significantly more phagocytes than did serum coated implants and the recruited cells were predominantly macrophage/monocytes. Administration of both H1 and H2 histamine receptor antagonists greatly reduced the recruitment of macrophages/monocytes and neutrophils on implant surfaces. Conclusion In humans – as in rodents – biomaterial-mediated inflammatory responses involve at least two crucial events: histamine-mediated phagocyte recruitment and phagocyte accumulation on implant surfaces engendered by spontaneously adsorbed host fibrinogen. Based on these results, we conclude that reducing fibrinogen:surface interactions should enhance biocompatibility and that administration of histamine receptor antagonists prior to, and shortly after, medical device implantation should improve the functionality and longevity of medical implants. PMID:17603911

Plasmin cleaves fibrinogen and the human complement proteins C3b and C5 in the presence of Leptospira interrogans proteins: A new role of LigA and LigB in invasion and complement immune evasion.

PubMed

Castiblanco-Valencia, Mónica Marcela; Fraga, Tatiana Rodrigues; Pagotto, Ana Helena; Serrano, Solange Maria de Toledo; Abreu, Patricia Antonia Estima; Barbosa, Angela Silva; Isaac, Lourdes

2016-05-01

Plasminogen is a single-chain glycoprotein found in human plasma as the inactive precursor of plasmin. When converted to proteolytically active plasmin, plasmin(ogen) regulates both complement and coagulation cascades, thus representing an important target for pathogenic microorganisms. Leptospira interrogans binds plasminogen, which is converted to active plasmin. Leptospiral immunoglobulin-like (Lig) proteins are surface exposed molecules that interact with extracellular matrix components and complement regulators, including proteins of the FH family and C4BP. In this work, we demonstrate that these multifunctional molecules also bind plasminogen through both N- and C-terminal domains. These interactions are dependent on lysine residues and are affected by ionic strength. Competition assays suggest that plasminogen does not share binding sites with C4BP or FH on Lig proteins at physiological molar ratios. Plasminogen bound to Lig proteins is converted to proteolytic active plasmin in the presence of urokinase-type plasminogen activator (uPA). Lig-bound plasmin is able to cleave the physiological substrates fibrinogen and the complement proteins C3b and C5. Taken together, our data point to a new role of LigA and LigB in leptospiral invasion and complement immune evasion. Plasmin(ogen) acquisition by these versatile proteins may contribute to Leptospira infection, favoring bacterial survival and dissemination inside the host. Copyright © 2016. Published by Elsevier GmbH.

Human fibrinogen adsorption on positively charged latex particles.

PubMed

Zeliszewska, Paulina; Bratek-Skicki, Anna; Adamczyk, Zbigniew; Cieśla, Michał

2014-09-23

Fibrinogen (Fb) adsorption on positively charged latex particles (average diameter of 800 nm) was studied using the microelectrophoretic and the concentration depletion methods based on AFM imaging. Monolayers on latex were adsorbed from diluted bulk solutions at pH 7.4 and an ionic strength in the range of 10(-3) to 0.15 M where fibrinogen molecules exhibited an average negative charge. The electrophoretic mobility of the latex after controlled fibrinogen adsorption was systematically measured. A monotonic decrease in the electrophoretic mobility of fibrinogen-covered latex was observed for all ionic strengths. The results of these experiments were interpreted according to the three-dimensional electrokinetic model. It was also determined using the concentration depletion method that fibrinogen adsorption was irreversible and the maximum coverage was equal to 0.6 mg m(-2) for ionic strength 10(-3) M and 1.3 mg m(-2) for ionic strength 0.15 M. The increase of the maximum coverage was confirmed by theoretical modeling based on the random sequential adsorption approach. Paradoxically, the maximum coverage of fibrinogen on positively charged latex particles was more than two times lower than the maximum coverage obtained for negative latex particles (3.2 mg m(-2)) at pH 7.4 and ionic strength of 0.15 M. This was interpreted as a result of the side-on adsorption of fibrinogen molecules with their negatively charged core attached to the positively charged latex surface. The stability and acid base properties of fibrinogen monolayers on latex were also determined in pH cycling experiments where it was observed that there were no irreversible conformational changes in the fibrinogen monolayers. Additionally, the zeta potential of monolayers was more positive than the zeta potential of fibrinogen in the bulk, which proves a heterogeneous charge distribution. These experimental data reveal a new, side-on adsorption mechanism of fibrinogen on positively charged surfaces and confirmed the decisive role of electrostatic interactions in this process.

Scanning probe microscopy for the analysis of composite Ti/hydrocarbon plasma polymer thin films

NASA Astrophysics Data System (ADS)

Choukourov, A.; Grinevich, A.; Slavinska, D.; Biederman, H.; Saito, N.; Takai, O.

2008-03-01

Composite Ti/hydrocarbon plasma polymer films with different Ti concentration were deposited on silicon by dc magnetron sputtering of titanium in an atmosphere of argon and hexane. As measured by Kelvin force microscopy and visco-elastic atomic force microscopy, respectively, surface potential and hardness increase with increasing Ti content. Adhesion force to silicon and to fibrinogen molecules was stronger for the Ti-rich films as evaluated from the AFM force-distance curves. Fibrinogen forms a very soft layer on these composites with part of the protein molecules embedded in the outermost region of the plasma polymer. An increase of the surface charge due to fibrinogen adsorption has been observed and attributed to positively charged αC domains of fibrinogen molecule.

Single Cell Force Spectroscopy for Quantification of Cellular Adhesion on Surfaces

NASA Astrophysics Data System (ADS)

Christenson, Wayne B.

Cell adhesion is an important aspect of many biological processes. The atomic force microscope (AFM) has made it possible to quantify the forces involved in cellular adhesion using a technique called single cell force spectroscopy (SCFS). AFM based SCFS offers versatile control over experimental conditions for probing directly the interaction between specific cell types and specific proteins, surfaces, or other cells. Transmembrane integrins are the primary proteins involved in cellular adhesion to the extra cellular matix (ECM). One of the chief integrins involved in the adhesion of leukocyte cells is alpha Mbeta2 (Mac-1). The experiments in this dissertation quantify the adhesion of Mac-1 expressing human embryonic kidney (HEK Mac-1), platelets, and neutrophils cells on substrates with different concentrations of fibrinogen and on fibrin gels and multi-layered fibrinogen coated fibrin gels. It was shown that multi-layered fibrinogen reduces the adhesion force of these cells considerably. A novel method was developed as part of this research combining total internal reflection microscopy (TIRFM) with SCFS allowing for optical microscopy of HEK Mac-1 cells interacting with bovine serum albumin (BSA) coated glass after interacting with multi-layered fibrinogen. HEK Mac-1 cells are able to remove fibrinogen molecules from the multi-layered fibrinogen matrix. An analysis methodology for quantifying the kinetic parameters of integrin-ligand interactions from SCFS experiments is proposed, and the kinetic parameters of the Mac-1 fibrinogen bond are quantified. Additional SCFS experiments quantify the adhesion of macrophages and HEK Mac-1 cells on functionalized glass surfaces and normal glass surfaces. Both cell types show highest adhesion on a novel functionalized glass surface that was prepared to induce macrophage fusion. These experiments demonstrate the versatility of AFM based SCFS, and how it can be applied to address many questions in cellular biology offering quantitative insights.

Evaluation of the ability of Streptococcus agalactiae strains isolated from genital and neonatal specimens to bind to human fibrinogen and correlation with characteristics of the fbsA and fbsB genes.

PubMed

Rosenau, Agnès; Martins, Karine; Amor, Souheila; Gannier, François; Lanotte, Philippe; van der Mee-Marquet, Nathalie; Mereghetti, Laurent; Quentin, Roland

2007-03-01

The ability of 111 Streptococcus agalactiae strains to bind to human fibrinogen was quantified. We correlated the percentages of bacteria that bound to immobilized fibrinogen with fibrinogen-binding (fbs) gene characteristics of strains and with clinical origin, serotypes, and phylogenetic positions of strains. Percentages varied from 0.4 to 29.9%. Fifty-five strains (49.5%) had the fbsB gene sensu stricto described by Gutekunst et al. (Infect. Immun., 72:3495-3504, 2004), allowing adhesion to human fibrinogen, and all of the other strains had an fgag variant gene. Ninety strains (81.1%) had a fbsA gene and 55 of them also had the fbsB gene. The other 21 strains (18.9%) had a truncated form of fbsA without the fbsB gene sensu stricto. The numbers of 48-nucleotide repeat sequences (rs) in the fbsA gene varied from 2 to 26. The population of strains with the highest ability to bind to human fibrinogen significantly more frequently had the fbsB gene sensu stricto and 4 to 7 rs in the fbsA gene (P < 0.05). However, the single strain that carried the highest number of rs (26 rs) in the fbsA gene showed high fibrinogen-binding activity (24.3%). Strains exhibiting significantly higher levels of binding to human fibrinogen belonged to a phylogenetic group of strains associated with neonatal meningitis, currently known as the ST-17 clone, that is mostly composed of serotype III strains. These findings indicate that S. agalactiae strains possess a wide variety of fbs gene content that markedly influences the ability of strains to bind to human fibrinogen. Variations in the configuration and the expression of the Fbs proteins may therefore partly explain the variability of virulence in S. agalactiae species.

Adsorption and covalent binding of fibrinogen as a method for probing the chemical composition of poly(styrene/α-tert-butoxy-ω-vinylbenzyl-polyglycidol) microsphere surfaces.

PubMed

Gosecka, Monika; Chehimi, Mohamed M; Basinska, Teresa; Slomkowski, Stanislaw; Makowski, Tomasz

2017-12-01

We investigated the distribution of polyglycidol and polystyrene on the surface of poly(styrene/α-tert-butoxy-ω-vinylbenzyl-polyglycidol) microspheres (random distribution or segregated into hydrophilic and hydrophobic patches), using fibrinogen (Fb) as a macromolecular probe. The fibrinogen was adsorbed or covalently attached to the surface of the poly(styrene-co-α-tert-butoxy-ω-vinylbenzyl-polyglycidol) (P(S/PGLy)) microspheres. The P(S/PGLy) particles were prepared by emulsion copolymerization of styrene and α-tert-butoxy-ω-vinylbenzyl-polyglycidol (PGLy) macromonomer initiated with potassium persulfate. The polymerizations yielded P(S/PGLy) particles with various surface fractions of polyglycidol, depending on the amount of added macromonomer and the addition process. In some syntheses, the entire macromonomer amount was added once at the beginning of the polymerization, while in others, the macromonomer was added gradually after the formation of particle seeds from pure polystyrene. XPS studies revealed that the fraction of polyglycidol in the interfacial layer of the microspheres was larger when the entire amount of macromonomer was added at the beginning of the polymerization than when it was added after formation of the polystyrene seeds. Studies of fibrinogen adsorption provided the first evidence of segregation of the hydrophobic (polystyrene) and hydrophilic (polyglycidol) components at the surface of the composite P(S/PGLy) microspheres into patches. The hydrophobic patches are composed mainly of polystyrene. However, they also contain a small amount of polyglycidol chains, making the adsorption of fibrinogen weaker than the adsorption onto the pure polystyrene. Studies of covalent immobilization of fibrinogen on the microspheres via 1,3,5-trichlorotriazine confirmed these findings. Copyright © 2017 Elsevier B.V. All rights reserved.

Expression, immunogenicity and variation of iron-regulated surface protein A from bovine isolates of Staphylococcus aureus.

PubMed

Misra, Neha; Wines, Tyler F; Knopp, Colton L; McGuire, Mark A; Tinker, Juliette K

2017-05-01

Staphylococcus aureus iron-regulated surface protein A (IsdA) is a fibrinogen and fibronectin adhesin that also contributes to iron sequestration and resistance to innate immunity. IsdA is conserved in human isolates and has been investigated as a human vaccine candidate. Here we report the expression of isdA, the efficacy of anti-IsdA responses and the existence of IsdA sequence variants from bovine Staphylococcus. Clinical staphylococci were obtained from US dairy farms and assayed by PCR for the presence and expression of isdA. isdA-positive species from bovines included S. aureus, S. haemolyticus and S. chromogenes. Immunoassays on bovine milk and serum confirmed the induction and opsonophagocytic activity of anti-IsdA humoral responses. The variable region of isdA was sequenced and protein alignments predicted the presence of two main variants consistent with those from human S. aureus. Mouse antibodies against one IsdA variant reduced staphylococcal binding to fibronectin in vitro in an isotype-dependent manner. Purified IsdA variants bound distinctly to fibronectin and fibrinogen. Our findings demonstrate that variability within the C-terminus of this adhesin affects immune reactivity and binding specificity, but are consistent with the significance of IsdA in bovine disease and relevant for vaccine development. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Adsorption of fibrinogen on a biomedical-grade stainless steel 316LVM surface: a PM-IRRAS study of the adsorption thermodynamics, kinetics and secondary structure changes.

PubMed

Desroches, Marie-Josee; Omanovic, Sasha

2008-05-14

Polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) was employed to investigate the interaction of serum protein fibrinogen with a biomedical-grade 316LVM stainless steel surface, in terms of the adsorption thermodynamics, kinetics and secondary structure changes of the protein. Apparent Gibbs energy of adsorption values indicated a highly spontaneous and strong adsorption of fibrinogen onto the surface. The kinetics of fibrinogen adsorption were successfully modeled using a pseudo first-order kinetic model. Deconvolution of the amide I bands indicated that the adsorption of fibrinogen on 316LVM results in significant changes in the protein's secondary structure that occur predominantly within the first minute of adsorption. Among the investigated structures, the alpha-helix structure undergoes the smallest changes, while the beta-sheet and beta-turns structures undergo significant changes. It was shown that lateral interactions between the adsorbed molecules do not play a role in controlling the secondary structure changes. An increase in temperature induced changes in the secondary structure of the protein, characterized by a loss of the alpha-helical content and its transformation into the beta-turns structure.

Apparent Activation Energies Associated with Protein Dynamics on Hydrophobic and Hydrophilic Surfaces

PubMed Central

Langdon, Blake B.; Kastantin, Mark; Schwartz, Daniel K.

2012-01-01

With the use of single-molecule total internal reflection fluorescence microscopy (TIRFM), the dynamics of bovine serum albumin (BSA) and human fibrinogen (Fg) at low concentrations were observed at the solid-aqueous interface as a function of temperature on hydrophobic trimethylsilane (TMS) and hydrophilic fused silica (FS) surfaces. Multiple dynamic modes and populations were observed and characterized by their surface residence times and squared-displacement distributions (surface diffusion). Characteristic desorption and diffusion rates for each population/mode were generally found to increase with temperature, and apparent activation energies were determined from Arrhenius analyses. The apparent activation energies of desorption and diffusion were typically higher on FS than on TMS surfaces, suggesting that protein desorption and mobility were hindered on hydrophilic surfaces due to favorable protein-surface and solvent-surface interactions. The diffusion of BSA on TMS appeared to be activationless for several populations, whereas diffusion on FS always exhibited an apparent activation energy. All activation energies were small in absolute terms (generally only a few kBT), suggesting that most adsorbed protein molecules are weakly bound and move and desorb readily under ambient conditions. PMID:22713578

Association of Factor V Secretion with Protein Kinase B Signaling in Platelets from Horses with Atypical Equine Thrombasthenia.

PubMed

Norris, J W; Pombo, M; Shirley, E; Blevins, G; Tablin, F

2015-01-01

Two congenital bleeding diatheses have been identified in Thoroughbred horses: Glanzmann thrombasthenia (GT) and a second, novel diathesis associated with abnormal platelet function in response to collagen and thrombin stimulation. Platelet dysfunction in horses with this second thrombasthenia results from a secretory defect. Two affected and 6 clinically normal horses. Ex vivo study. Washed platelets were examined for (1) expression of the αIIb-β3 integrin; (2) fibrinogen binding capacity in response to ADP and thrombin; (3) secretion of dense and α-granules; (4) activation of the mammalian target of rapamycin (mTOR)-protein kinase B (AKT) signaling pathway; and (5) cellular distribution of phosphatidylinositol-4-phosphate-3-kinase, class 2B (PIK3C2B) and SH2 containing inositol-5'-phosphatase 1 (SHIP1). Platelets from affected horses expressed normal amounts of αIIb-β3 integrin and bound fibrinogen normally in response to ADP, but bound 80% less fibrinogen in response to thrombin. α-granules only released 50% as much Factor V as control platelets, but dense granules released their contents normally. Protein kinase B (AKT) phosphorylation was reduced after thrombin activation, but mTOR Complex 2 (mTORC2) and phosphoinositide-dependent kinase 1 (PDK1) signaling were normal. SH2-containing inositol-5'-phosphatase 1 (SHIP1) did not localize to the cytoskeleton of affected platelets and was decreased overall consistent with reduced AKT phosphorylation. Defects in fibrinogen binding, granule secretion, and signal transduction are unique to this thrombasthenia, which we designate as atypical equine thrombasthenia. Copyright © The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of American College of Veterinary Internal Medicine.

Effects of calcium binding and of EDTA and CaEDTA on the clotting of bovine fibrinogen by thrombin.

PubMed

Perizzolo, K E; Sullivan, S; Waugh, D F

1985-03-01

Studies were carried out at pH 7.0 and gamma/2 0.15 before addition of CaCl2 or EDTA. Clotting time, tau, at 3.03 microM fibrinogen and 0.91 u/ml thrombin was determined for equilibrium systems. With added Ca2+, tau decreases, from tau 0 at 0 added Ca2+ (mean, 29.7 +/- 3 s), by approximately 3 s at 5 mM added Ca2+. With added EDTA, tau increases sigmoidally from tau 0 at 0 EDTA to a maximum (mean tau m = 142 +/- 23 s) at approximately 200 microM EDTA. tau then decreases slightly to a minimum at approximately 1.3 mM and finally increases to infinity at approximately 10 mM EDTA. Between 0 and 1.3 mM EDTA, effects on clotting time are completely reversed by adding Ca2+ and, after equilibration at 400 microM EDTA, tau is independent of EDTA concentration. Thus, up to 400 microM EDTA, effects on clotting time are attributed to decreasing fibrinogen bound Ca2+. Between 5 mM Ca2+ and 200 microM EDTA it is assumed that an equilibrium distribution of fibrinogen species having 3, 2, 1, or 0 bound calcium ions is established and that a clotting time is determined by the sum of products of species fractional abundance and pure species clotting time. Analysis indicates that pure species clotting times increase proportionately with decreasing Ca2+ binding, binding sites are nearly independent, and the microscopic association constant for the first bound Ca2+ is approximately 4.9 X 10(6) M-1. Effects of adding Ca2+ at times t1 after thrombin addition to systems initially equilibrated at 200 microM EDTA were determined. Analysis of the relation between tau and t1 indicates that as Ca2+ binding decreases, rate constants for release of B peptides decrease less than those for release of A peptides. As EDTA concentration is increased above 1.3 mM, inhibitory effects of EDTA and CaEDTA progressively increase.

Trimeric autotransporter DsrA is a major mediator of fibrinogen binding in Haemophilus ducreyi.

PubMed

Fusco, William G; Elkins, Christopher; Leduc, Isabelle

2013-12-01

Haemophilus ducreyi is the etiologic agent of the sexually transmitted genital ulcer disease chancroid. In both natural and experimental chancroid, H. ducreyi colocalizes with fibrin at the base of the ulcer. Fibrin is obtained by cleavage of the serum glycoprotein fibrinogen (Fg) by thrombin to initiate formation of the blood clot. Fg binding proteins are critical virulence factors in medically important Gram-positive bacteria. H. ducreyi has previously been shown to bind Fg in an agglutination assay, and the H. ducreyi Fg binding protein FgbA was identified in ligand blotting with denatured proteins. To better characterize the interaction of H. ducreyi with Fg, we examined Fg binding to intact, viable H. ducreyi bacteria and identified a novel Fg binding protein. H. ducreyi bound unlabeled Fg in a dose-dependent manner, as measured by two different methods. In ligand blotting with total denatured cellular proteins, digoxigenin (DIG)-Fg bound only two H. ducreyi proteins, the trimeric autotransporter DsrA and the lectin DltA; however, only the isogenic dsrA mutant had significantly less cell-associated Fg than parental strains in Fg binding assays with intact bacteria. Furthermore, expression of DsrA, but not DltA or an empty vector, rendered the non-Fg-binding H. influenzae strain Rd capable of binding Fg. A 13-amino-acid sequence in the C-terminal section of the passenger domain of DsrA appears to be involved in Fg binding by H. ducreyi. Taken together, these data suggest that the trimeric autotransporter DsrA is a major determinant of Fg binding at the surface of H. ducreyi.

Hydroxyl radical-modified fibrinogen as a marker of thrombosis: the role of iron.

PubMed

Lipinski, B; Pretorius, E

2012-07-01

Excessive free iron in blood and in organ tissues (so called iron overload) has been observed in degenerative diseases such as atherosclerosis, cancer, neurological, and certain autoimmune diseases, in which fibrin-like deposits are also found. Although most of the body iron is bound to hemoglobin and myoglobin in a divalent ferrous form, a certain amount of iron exists in blood as a trivalent (ferric) ion. This particular chemical state of iron has been shown to be toxic to the human body when not controlled by endogenous and/or dietary chelating agents. Experiments described in this paper show for the first time that ferric ions (Fe(3+)) can generate hydroxyl radicals without participation of any redox agent, thus making it a special case of the Fenton reaction. Ferric chloride was also demonstrated to induce aggregation of purified fibrinogen at the same molar concentrations that were used for the generation of hydroxyl radicals. Iron-aggregated fibrinogen, by contrast to native molecule, could not be dissociated into polypeptide subunit chains as shown in a polyacrylamide gel electrophoresis. The mechanism of this phenomenon is very likely based on hydroxyl radical-induced modification of fibrinogen tertiary structure with the formation of insoluble aggregates resistant to enzymatic and chemical degradations. Soluble modified fibrinogen species can be determined in blood of thrombotic patients by the reaction with protamine sulfate and/or by scanning electron microscopy. In view of these findings, it is postulated that iron-induced alterations in fibrinogen structure is involved in pathogenesis of certain degenerative diseases associated with iron overload and persistent thrombosis. It is concluded that the detection of hydroxyl radical-modified fibrinogen may be utilized as a marker of a thrombotic condition in human subjects.

Mice lacking the extracellular matrix protein MAGP1 display delayed thrombotic occlusion following vessel injury

PubMed Central

Werneck, Claudio C.; Vicente, Cristina P.; Weinberg, Justin S.; Shifren, Adrian; Pierce, Richard A.; Broekelmann, Thomas J.; Tollefsen, Douglas M.

2008-01-01

Mice lacking the extracellular matrix protein microfibril-associated glycoprotein-1 (MAGP1) display delayed thrombotic occlusion of the carotid artery following injury as well as prolonged bleeding from a tail vein incision. Normal occlusion times were restored when recombinant MAGP1 was infused into deficient animals prior to vessel wounding. Blood coagulation was normal in these animals as assessed by activated partial thromboplastin time and prothrombin time. Platelet number was lower in MAGP1-deficient mice, but the platelets showed normal aggregation properties in response to various agonists. MAGP1 was not found in normal platelets or in the plasma of wild-type mice. In ligand blot assays, MAGP1 bound to fibronectin, fibrinogen, and von Willebrand factor, but von Willebrand factor was the only protein of the 3 that bound to MAGP1 in surface plasmon resonance studies. These findings show that MAGP1, a component of microfibrils and vascular elastic fibers, plays a role in hemostasis and thrombosis. PMID:18281502

Interaction of Leptospira Elongation Factor Tu with Plasminogen and Complement Factor H: A Metabolic Leptospiral Protein with Moonlighting Activities

PubMed Central

Abe, Cecília M.; Monaris, Denize; Morais, Zenaide M.; Souza, Gisele O.; Vasconcellos, Sílvio A.; Isaac, Lourdes; Abreu, Patrícia A. E.; Barbosa, Angela S.

2013-01-01

The elongation factor Tu (EF-Tu), an abundant bacterial protein involved in protein synthesis, has been shown to display moonlighting activities. Known to perform more than one function at different times or in different places, it is found in several subcellular locations in a single organism, and may serve as a virulence factor in a range of important human pathogens. Here we demonstrate that Leptospira EF-Tu is surface-exposed and performs additional roles as a cell-surface receptor for host plasma proteins. It binds plasminogen in a dose-dependent manner, and lysine residues are critical for this interaction. Bound plasminogen is converted to active plasmin, which, in turn, is able to cleave the natural substrates C3b and fibrinogen. Leptospira EF-Tu also acquires the complement regulator Factor H (FH). FH bound to immobilized EF-Tu displays cofactor activity, mediating C3b degradation by Factor I (FI). In this manner, EF-Tu may contribute to leptospiral tissue invasion and complement inactivation. To our knowledge, this is the first description of a leptospiral protein exhibiting moonlighting activities. PMID:24312361

Platelet Adhesion and Activation on Chiral Surfaces: The Influence of Protein Adsorption.

PubMed

Fan, Yonghong; Luo, Rifang; Han, Honghong; Weng, Yajun; Wang, Hong; Li, Jing'an; Yang, Ping; Wang, Yunbing; Huang, Nan

2017-10-03

Adsorbed proteins and their conformational change on blood-contacting biomaterials will determine their final hemocompatibility. It has frequently been reported that surface chirality of biomaterials may highly influence their protein adsorption behavior. Here, lysine and tartaric acid with different chirality were immobilized onto TiO 2 films respectively, and the influence of surface chirality on protein adsorption, platelet adhesion, and activation was also investigated. It showed that the l- and d-molecule grafted samples had almost the same grafting density, surface topography, chemical components, and hydrophilicity in this study. However, biological behaviors such as protein adsorption, platelet adhesion, and activation were quite different. The d-lysine grafted surface had a greater ability to inhibit both bovine serum albumin and fibrinogen adsorption, along with less degeneration of fibrinogen compared to the l-lysine anchored surface. However, the d-tartaric acid grafted surface adsorbed more protein but with less denatured fibrinogen compared to the l-tartaric acid grafted one. Further studies showed that the secondary structural change of the adsorbed albumin and fibrinogen on all surfaces with deduction of the α-helix content and increase of disordered structure, while the changing degree was apparently varied. As a result, the d-lysine immobilized surface absorbed less platelets and red blood cells and achieved slightly increased platelet activation. For tartaric acid anchored surfaces, a larger number of platelets adhered to the D-surface but were less activated compared to the L-surface. In conclusion, the surface chirality significantly influenced the adsorption and conformational change of blood plasma protein, which in turn influenced both platelet adhesion and activation.

Interaction of fibrinogen and albumin with titanium dioxide nanoparticles of different crystalline phases

NASA Astrophysics Data System (ADS)

Marucco, Arianna; Fenoglio, Ivana; Turci, Francesco; Fubini, Bice

2013-04-01

TiO2 nanoparticles (NPs) are contained in different kinds of industrial products including paints, self-cleaning glasses, sunscreens. TiO2 is also employed in photocatalysis and it has been proposed for waste water treatment. Micrometric TiO2 is generally considered a safe material, while there is concern on the possible health effects of nanometric titania. Due to their small size NPs may migrate within the human body possibly entering in the blood stream. Therefore studies on the interaction of NPs with plasma proteins are needed. In fact, the interaction with proteins is believed to ultimately influences the NPs biological fate. Fibrinogen and albumin are two of the most abundant plasma proteins. They are involved in several important physiological functions. Furthermore, fibrinogen is known to trigger platelet adhesion and inflammation. For these reasons the study of the interaction between these protein and nanoparticles is an important step toward the understanding of the behavior of NPs in the body. In this study we investigated the interaction of albumin and fibrinogen with TiO2 nanoparticles of different crystal phases (rutile and anatase) using an integrated set of techniques. The amount of adsorbed fibrinogen and albumin for each TiO2 surface was investigated by using the bicinchoninic acid assay (BCA). The variation of the surface charge of the NP-protein conjugates respect to the naked NPs was used to indirectly estimate both surface coverage and reversibility of the adsorption upon dilution. Surface charge was monitored by measuring the ζ potential with a conventional electrophoretic light scattering (ELS) system. The extent of protein deformation was evaluated by Raman Spectroscopy. We found that both proteins adsorb irreversibly against electrostatic repulsion, likely undergoing conformational changes or selective orientation upon adsorption. The size of primary particles and the particles aggregation rather than the crystal phase modulate the affinity of fibrinogen for the TiO2 surfaces.

Bioactivity evolution of the surface functionalized bioactive glasses.

PubMed

Magyari, Klára; Baia, Lucian; Vulpoi, Adriana; Simon, Simion; Popescu, Octavian; Simon, Viorica

2015-02-01

The formation of a calcium phosphate layer on the surface of the SiO2 -CaO-P2 O5 glasses after immersion in simulated body fluid (SBF) generally demonstrates the bioactivity of these materials. Grafting of the surface by chemical bonding can minimize the structural changes in protein adsorbed on the surface. Therefore, in this study our interest was to evaluate the bioactivity and blood biocompatibility of the SiO2 -CaO-P2 O5 glasses after their surface modification by functionalization with aminopropyl-triethoxysilane and/or by fibrinogen. It is shown that the fibrinogen adsorbed on the glass surfaces induces a growing of the apatite-like layer. It is also evidenced that the protein content from SBF influences the growth of the apatite-like layer. Furthermore, the good blood compatibility of the materials after fibrinogen and bovine serum albumin adsorption is proved from the assessment of the β-sheet-β-turn ratio. © 2014 Wiley Periodicals, Inc.

The Haemophilus ducreyi trimeric autotransporter adhesin DsrA protects against an experimental infection in the swine model of chancroid.

PubMed

Fusco, William G; Choudhary, Neelima R; Routh, Patty A; Ventevogel, Melissa S; Smith, Valerie A; Koch, Gary G; Almond, Glen W; Orndorff, Paul E; Sempowski, Gregory D; Leduc, Isabelle

2014-06-24

Adherence of pathogens to cellular targets is required to initiate most infections. Defining strategies that interfere with adhesion is therefore important for the development of preventative measures against infectious diseases. As an adhesin to host extracellular matrix proteins and human keratinocytes, the trimeric autotransporter adhesin DsrA, a proven virulence factor of the Gram-negative bacterium Haemophilus ducreyi, is a potential target for vaccine development. A recombinant form of the N-terminal passenger domain of DsrA from H. ducreyi class I strain 35000HP, termed rNT-DsrAI, was tested as a vaccine immunogen in the experimental swine model of H. ducreyi infection. Viable homologous H. ducreyi was not recovered from any animal receiving four doses of rNT-DsrAI administered with Freund's adjuvant at two-week intervals. Control pigs receiving adjuvant only were all infected. All animals receiving the rNT-DsrAI vaccine developed antibody endpoint titers between 3.5 and 5 logs. All rNT-DsrAI antisera bound the surface of the two H. ducreyi strains used to challenge immunized pigs. Purified anti-rNT-DsrAI IgG partially blocked binding of fibrinogen at the surface of viable H. ducreyi. Overall, immunization with the passenger domain of the trimeric autotransporter adhesin DsrA accelerated clearance of H. ducreyi in experimental lesions, possibly by interfering with fibrinogen binding. Copyright © 2014 Elsevier Ltd. All rights reserved.

Trimeric Autotransporter DsrA Is a Major Mediator of Fibrinogen Binding in Haemophilus ducreyi

PubMed Central

Fusco, William G.; Elkins, Christopher

2013-01-01

Haemophilus ducreyi is the etiologic agent of the sexually transmitted genital ulcer disease chancroid. In both natural and experimental chancroid, H. ducreyi colocalizes with fibrin at the base of the ulcer. Fibrin is obtained by cleavage of the serum glycoprotein fibrinogen (Fg) by thrombin to initiate formation of the blood clot. Fg binding proteins are critical virulence factors in medically important Gram-positive bacteria. H. ducreyi has previously been shown to bind Fg in an agglutination assay, and the H. ducreyi Fg binding protein FgbA was identified in ligand blotting with denatured proteins. To better characterize the interaction of H. ducreyi with Fg, we examined Fg binding to intact, viable H. ducreyi bacteria and identified a novel Fg binding protein. H. ducreyi bound unlabeled Fg in a dose-dependent manner, as measured by two different methods. In ligand blotting with total denatured cellular proteins, digoxigenin (DIG)-Fg bound only two H. ducreyi proteins, the trimeric autotransporter DsrA and the lectin DltA; however, only the isogenic dsrA mutant had significantly less cell-associated Fg than parental strains in Fg binding assays with intact bacteria. Furthermore, expression of DsrA, but not DltA or an empty vector, rendered the non-Fg-binding H. influenzae strain Rd capable of binding Fg. A 13-amino-acid sequence in the C-terminal section of the passenger domain of DsrA appears to be involved in Fg binding by H. ducreyi. Taken together, these data suggest that the trimeric autotransporter DsrA is a major determinant of Fg binding at the surface of H. ducreyi. PMID:24042118

Fibrin(ogen) mediates acute inflammatory responses to biomaterials

PubMed Central

1993-01-01

Although "biocompatible" polymeric elastomers are generally nontoxic, nonimmunogenic, and chemically inert, implants made of these materials may trigger acute and chronic inflammatory responses. Early interactions between implants and inflammatory cells are probably mediated by a layer of host proteins on the material surface. To evaluate the importance of this protein layer, we studied acute inflammatory responses of mice to samples of polyester terephthalate film (PET) that were implanted intraperitoneally for short periods. Material preincubated with albumin is "passivated," accumulating very few adherent neutrophils or macrophages, whereas uncoated or plasma- coated PET attracts large numbers of phagocytes. Neither IgG adsorption nor surface complement activation is necessary for this acute inflammation; phagocyte accumulation on uncoated implants is normal in hypogammaglobulinemic mice and in severely hypocomplementemic mice. Rather, spontaneous adsorption of fibrinogen appears to be critical: (a) PET coated with serum or hypofibrinogenemic plasma attracts as few phagocytes as does albumin-coated material; (b) in contrast, PET preincubated with serum or hypofibrinogenemic plasma containing physiologic amounts of fibrinogen elicits "normal" phagocyte recruitment; (c) most importantly, hypofibrinogenemic mice do not mount an inflammatory response to implanted PET unless the material is coated with fibrinogen or the animals are injected with fibrinogen before implantation. Thus, spontaneous adsorption of fibrinogen appears to initiate the acute inflammatory response to an implanted polymer, suggesting an interesting nexus between two major iatrogenic effects of biomaterials: clotting and inflammation. PMID:8245787

Construction of a multifunctional coating consisting of phospholipids and endothelial progenitor cell-specific peptides on titanium substrates

NASA Astrophysics Data System (ADS)

Chen, Huiqing; Li, Xiaojing; Zhao, Yuancong; Li, Jingan; Chen, Jiang; Yang, Ping; Maitz, Manfred F.; Huang, Nan

2015-08-01

A phospholipid/peptide polymer (PMMDP) with phosphorylcholine groups, endothelial progenitor cell (EPC)-specific peptides and catechol groups was anchored onto a titanium (Ti) surface to fabricate a biomimetic multifunctional surface. The PMMDP coating was characterized by X-ray photoelectron spectroscopy (XPS), water contact angle measurements and atomic force microscopy (AFM), respectively. The amount of PMMDP coating on the Ti surface was quantified by using the quartz crystal microbalance with dissipation (QCM-D). Interactions between blood components and the coated and bare Ti substrates were evaluated by platelet adhesion and activation assays and fibrinogen denaturation test using platelet rich plasma (PRP). The results revealed that the PMMDP-modified surface inhibited fibrinogen denaturation and reduced platelet adhesion and activation. EPC cell culture on the PMMDP-modified surface showed increased adhesion and proliferation of EPCs when compared to the cells cultured on untreated Ti surface. The inhibition of fibrinogen denaturation and platelet adhesion and support of EPCs attachment and proliferation indicated that this coating might be beneficial for future applications in blood-contacting implants, such as vascular stents.

Astrocytes Specifically Remove Surface-Adsorbed Fibrinogen and Locally Express Chondroitin Sulfate Proteoglycans

PubMed Central

Hsiao, Tony W.; Swarup, Vimal P.; Kuberan, Balagurunathan; Tresco, Patrick A.; Hlady, Vladimir

2013-01-01

Surface-adsorbed fibrinogen (FBG) was recognized by adhering astrocytes and removed from the substrates in vitro by a two-phase removal process. The cells removed adsorbed FBG from binary proteins surface patterns (FBG + laminin, or FBG + albumin) while leaving the other protein behind. Astrocytes preferentially expressed chondroitin sulfate proteoglycan (CSPG) at the loci of fibrinogen stimuli; however no differences in overall CSPG production as a function of FBG surface coverage were identified. Removal of FBG by astrocytes was also found to be independent of transforming growth factor type β (TGF-β) receptor based signaling as cells maintained CSPG production in the presence of TGF-β receptor kinase inhibitor, SB 431542. The inhibitor decreased CSPG expression, but did not abolicsh it entirely. Because blood contact and subsequent FBG adsorption are unavoidable in neural implantations, the results indicate that implant-adsorbed FBG may contribute to reactive astrogliosis around the implant as astrocytes specifically recognize adsorbed FBG. PMID:23499985

Multi-Step Fibrinogen Binding to the Integrin αIIbβ3 Detected Using Force Spectroscopy

PubMed Central

Litvinov, Rustem I.; Bennett, Joel S.; Weisel, John W.; Shuman, Henry

2005-01-01

The regulated ability of integrin αIIbβ3 to bind fibrinogen plays a crucial role in platelet aggregation and hemostasis. We have developed a model system based on laser tweezers, enabling us to measure specific rupture forces needed to separate single receptor-ligand complexes. First of all, we performed a thorough and statistically representative analysis of nonspecific protein-protein binding versus specific αIIbβ3-fibrinogen interactions in combination with experimental evidence for single-molecule measurements. The rupture force distribution of purified αIIbβ3 and fibrinogen, covalently attached to underlying surfaces, ranged from ∼20 to 150 pN. This distribution could be fit with a sum of an exponential curve for weak to moderate (20–60 pN) forces, and a Gaussian curve for strong (>60 pN) rupture forces that peaked at 80–90 pN. The interactions corresponding to these rupture force regimes differed in their susceptibility to αIIbβ3 antagonists or Mn2+, an αIIbβ3 activator. Varying the surface density of fibrinogen changed the total binding probability linearly >3.5-fold but did not affect the shape of the rupture force distribution, indicating that the measurements represent single-molecule binding. The yield strength of αIIbβ3-fibrinogen interactions was independent of the loading rate (160–16,000 pN/s), whereas their binding probability markedly correlated with the duration of contact. The aggregate of data provides evidence for complex multi-step binding/unbinding pathways of αIIbβ3 and fibrinogen revealed at the single-molecule level. PMID:16040750

Protein-targeted corona phase molecular recognition

PubMed Central

Bisker, Gili; Dong, Juyao; Park, Hoyoung D.; Iverson, Nicole M.; Ahn, Jiyoung; Nelson, Justin T.; Landry, Markita P.; Kruss, Sebastian; Strano, Michael S.

2016-01-01

Corona phase molecular recognition (CoPhMoRe) uses a heteropolymer adsorbed onto and templated by a nanoparticle surface to recognize a specific target analyte. This method has not yet been extended to macromolecular analytes, including proteins. Herein we develop a variant of a CoPhMoRe screening procedure of single-walled carbon nanotubes (SWCNT) and use it against a panel of human blood proteins, revealing a specific corona phase that recognizes fibrinogen with high selectivity. In response to fibrinogen binding, SWCNT fluorescence decreases by >80% at saturation. Sequential binding of the three fibrinogen nodules is suggested by selective fluorescence quenching by isolated sub-domains and validated by the quenching kinetics. The fibrinogen recognition also occurs in serum environment, at the clinically relevant fibrinogen concentrations in the human blood. These results open new avenues for synthetic, non-biological antibody analogues that recognize biological macromolecules, and hold great promise for medical and clinical applications. PMID:26742890

Fibrinogen adsorption onto 316L stainless steel under polarized conditions.

PubMed

Gettens, Robert T T; Gilbert, Jeremy L

2008-04-01

Adsorption of the plasma protein fibrinogen onto electrically polarized 316L stainless steel was observed and quantified using both in situ and ex situ atomic force microscopy (AFM) techniques. Significant differences in fibrinogen adsorption were observed across voltages. Ex situ studies showed significantly lower area coverage (theta) and height of adsorbed Fb on cathodically polarized surfaces when compared to anodically polarized surfaces. Conformational differences in the protein may explain the distinctions in Fb surface area coverage (theta) and height between the anodic and cathodic cases. In situ studies showed significantly slower kinetics of Fb adsorption onto surfaces below -100 mV (vs. Ag/AgCl) compared to surfaces polarized above -100 mV. Electrochemical current density data showed large charge transfer processes (approximately 1 x 10(-5) to 1 x 10(-4) A/cm(2)) taking place on the 316L SS surfaces at voltages below -100 mV (vs. Ag/AgCl). These relatively large current densities point to flux of ionic species away from the surface as a major source of the reduction in adsorption kinetics rather than just hydrophilic or electrostatic effects. Copyright 2007 Wiley Periodicals, Inc.

Fibrinogen adsorption, platelet adhesion and activation on mixed hydroxyl-/methyl-terminated self-assembled monolayers.

PubMed

Rodrigues, Sofia N; Gonçalves, Inês C; Martins, M C L; Barbosa, Mário A; Ratner, Buddy D

2006-11-01

The effect of surface wettability on fibrinogen adsorption, platelet adhesion and platelet activation was investigated using self-assembled monolayers (SAMs) containing different ratios of longer chain methyl- and shorter chain hydroxyl-terminated alkanethiols (C15CH3 vs. C11OH) on gold. Protein adsorption studies were performed using radiolabeled human fibrinogen (HFG). Platelet adhesion and activation studies with and without pre-adsorbed fibrinogen, albumin and plasma were assessed using scanning electron microscopy (SEM) and a glutaraldehyde-induced fluorescence technique (GIFT). Results demonstrated a linear decrease of HFG adsorption with the increase of OH groups on the monolayer (increase of the hydrophilicity). Platelet adhesion and activation also decrease with increase of hydrophilicity of surface. Concerning SAMs pre-immersed in proteins, fibrinogen adsorption was related with high platelet adhesion and activation. The passivant effect of albumin on platelet adhesion and activation was only demonstrated on SAMs contained C11OH. When all the blood proteins are present (plasma) platelet adhesion was almost absent on SAMs with 65% and 100% C11OH. This could be explained by the higher albumin affinity of the SAMs with 65% C11OH and the lower total protein adsorption associated with SAMs with 100% C11OH.

Analysis of aggregation of platelets in thrombosis

NASA Astrophysics Data System (ADS)

Ahuja, Suresh

Platelets are key players in thrombus formation by first rolling over collagen bound von Willebrand factor followed by formation of a stable interaction with collagen. The first adhered platelets bind additional platelets until the whole injury is sealed off by a platelet aggregate. The coagulation system stabilizes the formed platelet plug by creating a tight fibrin network, and then wound contraction takes place because of morphological changes in platelets. Coagulation takes place by platelet activation and aggregation mainly through fibrinogen polymerization into fibrin fibers. The process includes multiple factors, such as thrombin, plasmin, and local shear-rate which regulate and control the process. Coagulation can be divided into two pathways: the intrinsic pathway and the extrinsic pathway. The intrinsic pathway is initiated by the exposure of a negatively charged. It is able to activate factor XII, using a complex reaction that includes prekallikrein and high-molecular-weight kininogen as cofactors.. Thrombin is the final enzyme that is needed to convert fibrinogen into fibrin. The extrinsic pathway starts with the exposure of tissue factor to the circulating blood, which is the major initiator of coagulation. There are several feedback loops that reinforce the coagulation cascade, resulting in large amounts of thrombin. It is dependent on the presence of pro-coagulant surfaces of cells expressing negatively charged phospholipids--which include phosphatidylserine (PS)--on their outer membrane. PS-bearing surfaces are able to increase the efficiency of the reactions by concentrating and co-localizing coagulation factors.. Aggregation of platelets are analyzed and compared to adhesion of platelet to erythrocyte and to endothelial cells. This abstract is replacing MAR16-2015-020003.

The down-regulation of the mitogenic fibrinogen receptor (MFR) in serum-containing medium does not occur in defined medium.

PubMed

Levesque, J P; Hatzfeld, A; Domart, I; Hatzfeld, J

1990-02-01

Normal human hemopoietic cells such as early bone marrow progenitors, or lymphoma-derived cell lines such as Raji or JM cells, possess a low-affinity receptor specific for fibrinogen. This receptor triggers a mitogenic effect. It differs from the glycoprotein IIb-IIIa which is involved in fibrinogen-induced platelet aggregation. We demonstrate here that this mitogenic fibrinogen receptor (MFR) can be internalized or reexpressed, depending on culture conditions. Internalization was temperature-dependent. At 37 degrees C in the presence of cycloheximide or actinomycin D, the half-life of cell surface MFRs was 2 h, independent of receptor occupancy. Binding of fibrinogen to the MFR resulted in a down-regulation which was fibrinogen dose-dependent. This occurred in serum-supplemented medium but not in defined medium supplemented with fatty acids. Reexpression of MFRs could be induced in 28 to 42 h by serum removal. The down-regulation of mitogenic receptors in plasma or serum could explain why normal cells do not proliferate in the peripheral blood.

Clumping factor A-mediated virulence during Staphylococcus aureus infection is retained despite fibrinogen depletion.

PubMed

Palmqvist, Niklas; Josefsson, Elisabet; Tarkowski, Andrzej

2004-02-01

Clumping factor A (ClfA), a fibrinogen-binding protein expressed on the Staphylococcus aureus cell surface, has previously been shown to act as a virulence factor in experimental septic arthritis. Although the interaction between ClfA and fibrinogen is assumed to be of importance for the virulence of S. aureus, this has not been demonstrated in any in vivo model of infection. Therefore, the objective of this study was to investigate the contribution of this interaction to ClfA-mediated virulence in murine S. aureus-induced arthritis. Ancrod, a serine protease with thrombin-like activity, was used to induce in vivo depletion of fibrinogen in mice. Ancrod treatment significantly aggravated septic arthritis following inoculation with a ClfA-expressing strain (Newman) compared to control treatment. Also, ancrod treatment tended to enhance the arthritis induced by a clfA mutant strain (DU5876), indicating that fibrinogen depletion exacerbates septic arthritis in a ClfA-independent manner. Most importantly, the ClfA-expressing strain was much more arthritogenic than the isogenic clfA mutant, following inoculation of fibrinogen-depleted mice. This finding indicates that the interaction between ClfA and free fibrinogen is not required for ClfA-mediated functions contributing to S. aureus virulence. It is conceivable that ClfA contributes to the virulence of S. aureus through interactions with other host ligands than fibrinogen.

The Staphylococcus aureus polysaccharide capsule and Efb-dependent fibrinogen shield act in concert to protect against phagocytosis

PubMed Central

Kuipers, Annemarie; Stapels, Daphne A. C.; Weerwind, Lleroy T.; Ko, Ya-Ping; Ruyken, Maartje; Lee, Jean C.; van Kessel, Kok P. M.

2016-01-01

Staphylococcus aureus has developed many mechanisms to escape from human immune responses. To resist phagocytic clearance, S. aureus expresses a polysaccharide capsule, which effectively masks the bacterial surface and surface-associated proteins, such as opsonins, from recognition by phagocytic cells. Additionally, secretion of the extracellular fibrinogen binding protein (Efb) potently blocks phagocytic uptake of the pathogen. Efb creates a fibrinogen shield surrounding the bacteria by simultaneously binding complement C3b and fibrinogen at the bacterial surface. By means of neutrophil phagocytosis assays with fluorescently labelled encapsulated serotype 5 (CP5) and serotype 8 (CP8) strains we compare the immune-modulating function of these shielding mechanisms. The data indicate that, in highly encapsulated S. aureus strains, the polysaccharide capsule is able to prevent phagocytic uptake at plasma concentrations <10 %, but loses its protective ability at higher concentrations of plasma. Interestingly, Efb shows a strong inhibitory effect on both capsule-negative and encapsulated strains at all tested plasma concentrations. Furthermore, the results suggest that both shielding mechanisms can exist simultaneously and collaborate to provide optimal protection against phagocytosis at a broad range of plasma concentrations. As opsonizing antibodies will be shielded from recognition by either mechanism, incorporating both capsular polysaccharides and Efb in future vaccines could be of great importance. PMID:27112346

The Staphylococcus aureus polysaccharide capsule and Efb-dependent fibrinogen shield act in concert to protect against phagocytosis.

PubMed

Kuipers, Annemarie; Stapels, Daphne A C; Weerwind, Lleroy T; Ko, Ya-Ping; Ruyken, Maartje; Lee, Jean C; van Kessel, Kok P M; Rooijakkers, Suzan H M

2016-07-01

Staphylococcus aureus has developed many mechanisms to escape from human immune responses. To resist phagocytic clearance, S. aureus expresses a polysaccharide capsule, which effectively masks the bacterial surface and surface-associated proteins, such as opsonins, from recognition by phagocytic cells. Additionally, secretion of the extracellular fibrinogen binding protein (Efb) potently blocks phagocytic uptake of the pathogen. Efb creates a fibrinogen shield surrounding the bacteria by simultaneously binding complement C3b and fibrinogen at the bacterial surface. By means of neutrophil phagocytosis assays with fluorescently labelled encapsulated serotype 5 (CP5) and serotype 8 (CP8) strains we compare the immune-modulating function of these shielding mechanisms. The data indicate that, in highly encapsulated S. aureus strains, the polysaccharide capsule is able to prevent phagocytic uptake at plasma concentrations <10 %, but loses its protective ability at higher concentrations of plasma. Interestingly, Efb shows a strong inhibitory effect on both capsule-negative and encapsulated strains at all tested plasma concentrations. Furthermore, the results suggest that both shielding mechanisms can exist simultaneously and collaborate to provide optimal protection against phagocytosis at a broad range of plasma concentrations. As opsonizing antibodies will be shielded from recognition by either mechanism, incorporating both capsular polysaccharides and Efb in future vaccines could be of great importance.

Hydrodynamic effects and receptor interactions of platelets and their aggregates in linear shear flow.

PubMed Central

Tandon, P; Diamond, S L

1997-01-01

We have modeled platelet aggregation in a linear shear flow by accounting for two body collision hydrodynamics, platelet activation and receptor biology. Considering platelets and their aggregates as unequal-sized spheres with DLVO interactions (psi(platelet) = -15 mV, Hamaker constant = 10(-19) J), detailed hydrodynamics provided the flow field around the colliding platelets. Trajectory calculations were performed to obtain the far upstream cross-sectional area and the particle flux through this area provided the collision frequency. Only a fraction of platelets brought together by a shearing fluid flow were held together if successfully bound by fibrinogen cross-bridging GPIIb/IIIa receptors on the platelet surfaces. This fraction was calculated by modeling receptor-mediated aggregation using the formalism of Bell (Bell, G. I. 1979. A theoretical model for adhesion between cells mediated by multivalent ligands. Cell Biophys. 1:133-147) where the forward rate of bond formation dictated aggregation during collision and was estimated from the diffusional limited rate of lateral association of receptors multiplied by an effectiveness factor, eta, to give an apparent rate. For a value of eta = 0.0178, we calculated the overall efficiency (including both receptor binding and hydrodynamics effects) for equal-sized platelets with 50,000 receptors/platelet to be 0.206 for G = 41.9 s(-1), 0.05 for G = 335 s(-1), and 0.0086 for G = 1920 s(-1), values which are in agreement with efficiencies determined from initial platelet singlet consumption rates in flow through a tube. From our analysis, we predict that bond formation proceeds at a rate of approximately 0.1925 bonds/microm2 per ms, which is approximately 50-fold slower than the diffusion limited rate of association. This value of eta is also consistent with a colloidal stability of unactivated platelets at low shear rates. Fibrinogen was calculated to mediate aggregation quite efficiently at low shear rates but not at high shear rates. Although secondary collisions (an orbitlike trajectory) form only a small fraction of the total number of collisions, they become important at high shear rates (>750 s(-1)), as these are the only collisions that provide enough time to result in successful aggregate formation mediated by fibrinogen. The overall method provides a hydrodynamic and receptor correction of the Smoluchowski collision kernel and gives a first estimate of eta for the fibrinogen-GPIIb/IIIa cross-bridging of platelets. We also predict that secondary collisions extend the shear rate range at which fibrinogen can mediate successful aggregation. Images FIGURE 2 PMID:9370476

Investigating the effect of an arterial hypertension drug on the structural properties of plasma protein.

PubMed

Hassan, Natalia; Maldonado-Valderrama, Julia; Gunning, A Patrick; Morris, V J; Ruso, Juan M

2011-10-15

Propanolol is a betablocker drug used in the treatment of arterial hypertension related diseases. In order to achieve an optimal performance of this drug it is important to consider the possible interactions of propanolol with plasma proteins. In this work, we have used several experimental techniques to characterise the effect of addition of the betablocker propanolol on the properties of bovine plasma fibrinogen (FB). Differential scanning calorimeter (DSC), circular dichroism (CD), dynamic light scattering (DLS), surface tension techniques and atomic force microscopy (AFM) measurements have been combined to carry out a detailed physicochemical and surface characterization of the mixed system. As a result, DSC measurements show that propranolol can play two opposite roles, either acting as a structure stabilizer at low molar concentrations or as a structure destabilizer at higher concentrations, in different domains of fibrinogen. CD measurements have revealed that the effect of propanolol on the secondary structure of fibrinogen depends on the temperature and the drug concentration and the DLS analysis showed evidence for protein aggregation. Interestingly, surface tension measurements provided further evidence of the conformational change induced by propanolol on the secondary structure of FB by importantly increasing the surface tension of the system. Finally, AFM imaging of the fibrinogen system provided direct visualization of the protein structure in the presence of propanolol. Combination of these techniques has produced complementary information on the behavior of the mixed system, providing new insights into the structural properties of proteins with potential medical interest. Copyright © 2011 Elsevier B.V. All rights reserved.

The long term immunological response of swine after two exposures to a salmon thrombin and fibrinogen hemostatic bandage

PubMed Central

Rothwell, Stephen W.; Settle, Timothy; Wallace, Shannon; Dorsey, Jennifer; Simpson, David; Bowman, James R.; Janmey, Paul; Sawyer, Evelyn

2014-01-01

Experimental salmon thrombin/fibrinogen dressings have been shown to provide effective hemostasis in severe hemorrhage situations. The hypothesis for this study was that swine would still remain healthy without coagulopathy six months after exposure to salmon thrombin/fibrinogen dressings. Initial exposure was by insertion of the salmon dressing into the peritoneal cavity. Three months after the initial exposure, the same animals were subjected to two full thickness dermal wounds on the dorsal surface. One wound was bandaged with the salmon thrombin/fibrinogen bandage and the other wound was dressed with a standard bandage. The animals were monitored for an additional three months. Blood was drawn every 14 days over the six months for immunological and coagulation function analysis. All of the animals (8 pigs) remained healthy during the six month period and the dermal wounds healed without incidence. Lymph nodes and spleen showed signs of normal immune response and Western blots showed development of antibodies against salmon fibrinogen, but none of the animals made antibodies that recognized any species of thrombin. Coagulation parameters (fibrinogen concentration, thrombin time, PT and aPTT) and hematological parameters remained normal over the course of the study when compared to initial values of the subject swine. PMID:20705479

A comparative study of fibrinogen adsorption onto metal oxide thin films

NASA Astrophysics Data System (ADS)

Silva-Bermudez, P.; Muhl, S.; Rodil, S. E.

2013-10-01

One of the first events occurring upon foreign material-biological medium contact is the adsorption of proteins, which evolution greatly determines the cells response to the material. Protein-surface interactions are a complex phenomenon driven by the physicochemical properties of the surface, protein(s) and liquid medium involve in the interaction. In this article the adsorption of fibrinogen (Fbg) onto Ta2O5, Nb2O5, TiO2 and ZrO2 thin films is reported. The adsorption kinetics and characteristics of the adsorbed fibrinogen layer were studied in situ using dynamic and spectroscopic ellipsometry. The films wettability, surface energy (γLW/AB) and roughness were characterized aiming to elucidate their correlations with Fbg adsorption. The adsorption rate changed accordingly to the film; the fastest adsorption rate and highest Fbg surface mass concentration (Γ) was observed on ZrO2. The hydrophobic/hydrophilic character of the oxide highly influenced Fbg adsorption. On Ta2O5, Nb2O5 and TiO2, which were either hydrophilic or in the breaking-point between hydrophilicity and hydrophobicity, Γ was correlated to the polar component of γLW/AB and roughness of the surface. On ZrO2, clearly hydrophobic, Γ increased significantly off the correlation observed for the other films. The results indicated different adsorption dynamics and orientations of the Fbg molecules dependent on the surface hydrophobic/hydrophilic character.

Platelet adhesion in breast cancer: development and application of a novel assay.

PubMed

Caine, Graham J; Nadar, Sunil K; Lip, Gregory Y H; Stonelake, Paul S; Blann, Andrew D

2004-09-01

The increased risk of thromboembolism in cancer may be related to a prothrombotic or hypercoagulable state, with abnormalities of haemostasis and platelet activation. To further investigate the role of platelets in this disease, we developed and applied a new assay to detect and quantify platelet adhesion to the well-defined subendothelial substrate, fibrinogen. Platelet-rich plasma was obtained from 31 females with breast cancer (13 metastatic, 18 benign), and 30 healthy female controls, re-suspended to 2 x 10(8) cells/ml and 100 microl and incubated for 1 h in microtitre plates pre-coated with fibrinogen (5 mg/ml). The supernatant was carefully aspirated, lysed with Triton X-100 and stored at -70 degrees C as supernatant-platelet lysate. The microtitre wells were carefully washed with saline, bound platelets lysed with Triton, and the lysate stored at -70 degrees C as bound-platelet lysate. P-selectin was determined in supernatant-platelet lysate and bound-platelet lysate for each patient by enzyme-linked immunosorbent assay. Interpreting differences in P-selectin in different lysates as reflective of adhesion, patients with cancer had increased platelet adhesion (absolute and percentage, both P < 0.001) compared with healthy controls. There was also more adhesion (P < 0.001) in metastatic disease compared with non-metastatic disease. Patients with breast carcinomas, and, in particular, those with metastatic disease, have a higher degree of platelet adhesion, which may by quantified by a novel method based on cell lysis. This increase in platelet adhesiveness may be related to an increased risk of thromboembolism in these patients.

The effect of mucin, fibrinogen and IgG on the corrosion behaviour of Ni-Ti alloy and stainless steel.

PubMed

Chao, Zhang; Yaomu, Xiao; Chufeng, Liu; Conghua, Liu

2017-06-01

In this study, Ni-Ti alloy and stainless steal were exposed to artificial saliva containing fibrinogen, IgG or mucin, and the resultant corrosion behavior was studied. The purpose was to determine the mechanisms by which different types of protein contribute to corrosion. The effect of different proteins on the electrochemical resistance of Ni-Ti and SS was tested by potentiodynamic polarization, and the repair capacity of passivation film was tested by cyclic polarization measurements. The dissolved corrosion products were determined by ICP-OES, and the surface was analyzed by SEM and AFM. The results showed fibrinogen, IgG or mucin could have different influences on the susceptibility to corrosion of the same alloy. Adding protein lead to the decrease of corrosion resistance of SS, whereas protein could slow down the corrosion process of Ni-Ti. For Ni-Ti, adding mucin could enhance the corrosion stability and repair capacity of passivation film. The susceptibility to pitting corrosion of Ni-Ti and stainless steal in fibrinogen AS is not as high as mucin and IgG AS. There are different patterns of deposition formation on the metal surface by different types of protein, which is associated with their effects on the corrosion process of the alloys.

Effect of SanOrg123781A, a synthetic hexadecasaccharide, on clot-bound thrombin and factor Xa in vitro and in vivo.

PubMed

Hérault, J-P; Cappelle, M; Bernat, A; Millet, L; Bono, F; Schaeffer, P; Herbert, J-M

2003-09-01

Factor (F)Xa and thrombin bound to the clot during its formation contribute to the propensity of thrombi to activate the coagulation system. The aim of this work was to study the inhibition of clot-bound FXa and clot-bound thrombin by SanOrg123781A, a synthetic hexadecasaccharide that enhances the inhibition of thrombin and FXa by antithrombin (AT). SanOrg123781A, designed to exhibit low non-specific binding to proteins other than AT, was compared with heparin. In buffer, heparin and SanOrg123781A inhibited FXa and thrombin at similar concentrations [concentration inhibiting 50% (IC50) of Xa and IIa activity were, respectively: heparin 120 +/- 7 and 3 +/- 1 ng mL-1; SanOrg123781A 77 +/- 5 and 4 +/- 1 ng mL-1]. In human plasma, the activity of both compounds was reduced, although the activity of heparin was much more affected than that of SanOrg123781A (IC50 values for inhibition of FXa and FIIa activity were, respectively: heparin 100 +/- 5 and 800 +/- 40 ng mL-1; SanOrg123781A 10 +/- 5 and 30 +/- 3 ng mL-1). We demonstrated, in agreement with our previous results, that the procoagulant activity of the clot is essentially due to clot-bound FXa and to some extent to clot-bound thrombin. We showed that heparin and SanOrg123781A were able to inhibit fragment F1+2 generation induced by clot-bound FXa with IC50 values of 2 +/- 0.5 micro g mL-1 and 0.6 +/- 0.2 micro g mL-1, respectively. Both compounds also inhibited clot-bound thrombin activity, the IC50 values of heparin and SanOrg123781A being 1 +/- 0.01 micro g mL-1 and 0.1 +/- 0.1 micro g mL-1, respectively. Moreover, both heparin and SanOrg123781A significantly inhibited fibrinopeptide A generated by the action of clot-bound thrombin on fibrinogen but also by free thrombin generated from prothrombin by clot-bound FXa with IC50 values of 4 +/- 0.6 and 1 +/- 0.1 micro g mL-1, respectively. As with clot-bound enzymatic activities, SanOrg123781A was three times more active than heparin in vivo on fibrinogen accretion onto a pre-existing thrombus and as activators of recombinant tissue-type plasminogen activator-induced thrombolysis. In conclusion, due to the specific activities of SanOrg123781A, this compound is much more active than heparin in the presence of plasma proteins, on clot-bound enzymes and in in vivo models of thrombosis/thrombolysis.

Lessons from the Crystal Structure of the S. aureus Surface Protein Clumping Factor A in Complex With Tefibazumab, an Inhibiting Monoclonal Antibody.

PubMed

Ganesh, Vannakambadi K; Liang, Xiaowen; Geoghegan, Joan A; Cohen, Ana Luisa V; Venugopalan, Nagarajan; Foster, Timothy J; Hook, Magnus

2016-11-01

The Staphylococcus aureus fibrinogen binding MSCRAMM (Microbial Surface Components Recognizing Adhesive Matrix Molecules), ClfA (clumping factor A) is an important virulence factor in staphylococcal infections and a component of several vaccines currently under clinical evaluation. The mouse monoclonal antibody aurexis (also called 12-9), and the humanized version tefibazumab are therapeutic monoclonal antibodies targeting ClfA that in combination with conventional antibiotics were effective in animal models but showed less impressive efficacy in a limited Phase II clinical trial. We here report the crystal structure and a biochemical characterization of the ClfA/tefibazumab (Fab) complex. The epitope for tefibazumab is located to the "top" of the N3 subdomain of ClfA and partially overlaps with a previously unidentified second binding site for fibrinogen. A high-affinity binding of ClfA to fibrinogen involves both an interaction at the N3 site and the previously identified docking of the C-terminal segment of the fibrinogen γ-chain in the N2N3 trench. Although tefibazumab binds ClfA with high affinity we observe a modest IC 50 value for the inhibition of fibrinogen binding to the MSCRAMM. This observation, paired with a common natural occurring variant of ClfA that is not effectively recognized by the mAb, may partly explain the modest effect tefibazumab showed in the initial clinic trail. This information will provide guidance for the design of the next generation of therapeutic anti-staphylococcal mAbs targeting ClfA. Copyright © 2016. Published by Elsevier B.V.

Control of Fibrinogen Assembly by Changing a Polarity of Surfaces

NASA Astrophysics Data System (ADS)

Koo, Jaseung; Liu, Ying; Snow, Sara; Rambhia, Pooja; Koga, Tadanori; Rafailovich, Miriam; Galanakis, Dennis

2009-03-01

Thrombogenesis causes various problems associated with an interruption in the blood flow (e.g., myocardial and cerebral infarction), and a hindrance to use of blood-contact vascular biomaterials (e.g., hemodialysis and cardiopulmonary bypass) with long-term patency since undesired adsorption of blood components occurs on vessels or biomaterials, such as surface-induced thrombosis. we showed that this clotting procedure can be occurred on hydrophobic polymeric surfaces without thrombin cleavage. However, the fibrinogen fibers were not formed on the polar surface such as spun-cast polymer film with pyridine and phenol groups. We also found that αC domains play an important role in initiation of polymerization on surface. Therefore, molecular association was inhibited on the polar surfaces due to confinement of αC chains on the surfaces. These findings were directly applied to stent surface modification. The commercial stent consist of Co-Cr alloy forms undesired fiber formation. However, PS-r-PVPh (13% phenol) coated stent surfaces completely prevent fiber formation.

Mechanical fibrinogen-depletion supports heparin-free mesenchymal stem cell propagation in human platelet lysate.

PubMed

Laner-Plamberger, Sandra; Lener, Thomas; Schmid, Doris; Streif, Doris A; Salzer, Tina; Öller, Michaela; Hauser-Kronberger, Cornelia; Fischer, Thorsten; Jacobs, Volker R; Schallmoser, Katharina; Gimona, Mario; Rohde, Eva

2015-11-10

Pooled human platelet lysate (pHPL) is an efficient alternative to xenogenic supplements for ex vivo expansion of mesenchymal stem cells (MSCs) in clinical studies. Currently, porcine heparin is used in pHPL-supplemented medium to prevent clotting due to plasmatic coagulation factors. We therefore searched for an efficient and reproducible medium preparation method that avoids clot formation while omitting animal-derived heparin. We established a protocol to deplete fibrinogen by clotting of pHPL in medium, subsequent mechanical hydrogel disruption and removal of the fibrin pellet. After primary culture, bone-marrow and umbilical cord derived MSCs were tested for surface markers by flow cytometry and for trilineage differentiation capacity. Proliferation and clonogenicity were analyzed for three passages. The proposed clotting procedure reduced fibrinogen more than 1000-fold, while a volume recovery of 99.5 % was obtained. All MSC types were propagated in standard and fibrinogen-depleted medium. Flow cytometric phenotype profiles and adipogenic, osteogenic and chondrogenic differentiation potential in vitro were independent of MSC-source or medium type. Enhanced proliferation of MSCs was observed in the absence of fibrinogen but presence of heparin compared to standard medium. Interestingly, this proliferative response to heparin was not detected after an initial contact with fibrinogen during the isolation procedure. Here, we present an efficient, reproducible and economical method in compliance to good manufacturing practice for the preparation of MSC media avoiding xenogenic components and suitable for clinical studies.

Fibrinogen Induces RUNX2 Activity and Osteogenic Development from Human Pluripotent Stem Cells

PubMed Central

Kidwai, Fahad; Edwards, Jessica; Zou, Li; Kaufman, Dan S.

2016-01-01

Pluripotent stem cells, both human embryonic stem cells (hESC) and induced pluripotent stem cells (iPSC), provide an important resource to produce specialized cells such as osteogenic cells for therapeutic applications such as repair or replacement of injured, diseased or damaged bone. hESCs and iPSCs can also be used to better define basic cellular and genetic mechanisms that regulate the earliest stages of human bone development. However, current strategies to mediate osteogenic differentiation of hESC and iPSC are typically limited by the use of xenogeneic components such as fetal bovine serum (FBS) that make defining specific agents that mediate human osteogenesis difficult. Runt-related transcription factor 2 (RUNX2) is a key regulator required for osteogenic differentiation. Here, we used a RUNX2-YFP reporter system to characterize the novel ability of fibrinogen to mediate human osteogenic development from hESC and iPSC in defined (serum-free) conditions. These studies demonstrate that fibrinogen mediates significant osteo-induction potential. Specifically, fibrinogen binds to the surface integrin (α9β1) to mediate RUNX2 gene expression through the SMAD1/5/8 signaling pathway. Additional studies characterize the fibrinogen-induced hESC/iPSC-derived osteogenic cells to demonstrate these osteogenic cells retain the capacity to express typical mature osteoblastic markers. Together, these studies define a novel fibrinogen-α9β1-SMAD1/5/8-RUNX2 signaling axis can efficiently induce osteogenic differentiation from hESCs and iPSCs. PMID:27331788

Protein FOG--a streptococcal inhibitor of neutrophil function.

PubMed

Johansson, Helena M; Mörgelin, Matthias; Frick, Inga-Maria

2004-12-01

Several strains of group G streptococci (GGS) form aggregates when grown in vitro. Aggregating strains interact with fibrinogen, and this study reports the isolation of a novel self-associating and fibrinogen-binding protein of GGS, denoted protein FOG. Sequencing of the fog gene revealed structural similarity with M proteins of both GGS and group A streptococci (GAS). Analogous to GAS, GGS were found to multiply in human blood. All strains of GGS express protein G, a protein known to interact with the constant region of immunoglobulin G and albumin. Surprisingly, a clinical isolate expressing protein G, but lacking protein FOG, was killed in human whole blood; however, the addition of intact soluble protein FOG restored the ability of the bacteria to survive and multiply in human blood. This is believed to be the first report of a soluble M-like protein salvaging an M-negative strain from being killed. The antibactericidal property of protein FOG is dependent on its fibrinogen-binding activity. Thus, in plasma, FOG precipitates fibrinogen, and when added to whole blood, protein FOG triggers the formation of visible aggregates comprising fibrinogen and neutrophils that are disabled in their killing of the bacteria. Moreover, the results emphasize the importance of an intact FOG molecule, as presented on the bacterial surface, for full protective effect.

Fibrinogen-like protein 1, a hepatocyte derived protein is an acute phase reactant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Zhilin; Ukomadu, Chinweike

2008-01-25

Fibrinogen-like protein 1 (FGL1) is a hepatocyte derived protein that is upregulated in regenerating rodent livers following partial hepatectomy. It has been implicated as a mitogen for liver cell proliferation. In this study, we show that recombinant human IL-6 induces FGL1 expression in Hep G2 cells in a pattern similar to those of acute phase reactants. Following induction of acute inflammation in rats by subcutaneous injection of turpentine oil, serum FGL1 levels are also enhanced. Although, a recent report suggests that FGL1 associates almost exclusively with the fibrin matrix, we report here that approximately 20% of the total plasma FGL1more » remains free. The enhancement of FGL1 levels in vitro by IL-6 and its induction after turpentine oil injection suggest that it is an acute phase reactant. Its presence in bound and free forms in the blood also implies biological roles that extend beyond the proposed autocrine effect it has on hepatocytes during regeneration.« less

Plasminogen associates with phosphatidylserine-exposing platelets and contributes to thrombus lysis under flow

PubMed Central

Whyte, Claire S.; Swieringa, Frauke; Mastenbroek, Tom G.; Lionikiene, Ausra S.; Lancé, Marcus D.; van der Meijden, Paola E. J.; Heemskerk, Johan W. M.

2015-01-01

The interaction of plasminogen with platelets and their localization during thrombus formation and fibrinolysis under flow are not defined. Using a novel model of whole blood thrombi, formed under flow, we examine dose-dependent fibrinolysis using fluorescence microscopy. Fibrinolysis was dependent upon flow and the balance between fibrin formation and plasminogen activation, with tissue plasminogen activator-mediated lysis being more efficient than urokinase plasminogen activator-mediated lysis. Fluorescently labeled plasminogen radiates from platelet aggregates at the base of thrombi, primarily in association with fibrin. Hirudin attenuates, but does not abolish plasminogen binding, denoting the importance of fibrin. Flow cytometry revealed that stimulation of platelets with thrombin/convulxin significantly increased the plasminogen signal associated with phosphatidylserine (PS)-exposing platelets. Binding was attenuated by tirofiban and Gly-Pro-Arg-Pro amide, confirming a role for fibrin in amplifying plasminogen binding to PS-exposing platelets. Confocal microscopy revealed direct binding of plasminogen and fibrinogen to different platelet subpopulations. Binding of plasminogen and fibrinogen co-localized with PAC-1 in the center of spread platelets. In contrast, PS-exposing platelets were PAC-1 negative, and bound plasminogen and fibrinogen in a protruding “cap.” These data show that different subpopulations of platelets harbor plasminogen by diverse mechanisms and provide an essential scaffold for the accumulation of fibrinolytic proteins that mediate fibrinolysis under flow. PMID:25712989

Fibrinogen variant B[beta]D432A has normal polymerization but does not bind knob 'B'

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowley, Sheryl R.; Lord, Susan T.; UNC)

2009-10-23

Fibrinogen residue B{beta}432Asp is part of hole 'b' that interacts with knob 'B,' whose sequence starts with Gly-His-Arg-Pro-amide (GHRP). Because previous studies showed B{beta}D432A has normal polymerization, we hypothesized that B{beta}432Asp is not critical for knob 'B' binding and that new knob-hole interactions would compensate for the loss of this Asp residue. To test this hypothesis, we solved the crystal structure of fragment D from B{beta}D432A. Surprisingly, the structure (rfD-B{beta}D432A+GH) showed the peptide GHRP was not bound to hole 'b.' We then re-evaluated the polymerization of this variant by examining clot turbidity, clot structure, and the rate of FXIIIa cross-linking.more » The turbidity and the rate of - dimer formation for B{beta}D432A were indistinguishable compared with normal fibrinogen. Scanning electron microscopy showed no significant differences between the clots of B{beta}D432A and normal, but the thrombin-derived clots had thicker fibers than clots obtained from batroxobin, suggesting that cleavage of FpB is more important than 'B:b' interactions. We conclude that hole 'b' and 'B:b' knob-hole binding per se have no influence on fibrin polymerization.« less

Pathophysiologic roles of the fibrinogen gamma chain.

PubMed

Farrell, David H

2004-05-01

Fibrinogen binds through its gamma chains to cell surface receptors, growth factors, and coagulation factors to perform its key roles in fibrin clot formation, platelet aggregation, and wound healing. However, these binding interactions can also contribute to pathophysiologic processes, including inflammation and thrombosis. This review summarizes the latest findings on the role of the fibrinogen gamma chain in these processes, and illustrates the potential for therapeutic intervention. Novel gamma chain epitopes that bind platelet integrin alpha IIbbeta3 and leukocyte integrin alphaMbeta2 have been characterized, leading to the revision of former dogma regarding the processes of platelet aggregation, clot retraction, inflammation, and thrombosis. A series of studies has shown that the gamma chain serves as a depot for fibroblast growth factor-2 (FGF-2), which is likely to play an important role in wound healing. Inhibition of gamma chain function with the monoclonal antibody 7E9 has been shown to interfere with multiple fibrinogen activities, including factor XIIIa crosslinking, platelet adhesion, and platelet-mediated clot retraction. The role of the enigmatic variant fibrinogen gamma chain has also become clearer. Studies have shown that gamma chain binding to thrombin and factor XIII results in clots that are mechanically stiffer and resistant to fibrinolysis, which may explain the association between gammaA/gamma' fibrinogen levels and cardiovascular disease. The identification of new interactions with gamma chains has revealed novel targets for the treatment of inflammation and thrombosis. In addition, several exciting studies have shown new functions for the variant gamma chain that may contribute to cardiovascular disease.

Platelet adhesion in hypertension: application of a novel assay of platelet adhesion.

PubMed

Nadar, Sunil K; Caine, Graham J; Blann, Andrew D; Lip, Gregory Y H

2005-01-01

The increased risk of thromboembolism in hypertension may be related to a prothrombotic or hypercoagulable state, with abnormalities in haemostasis and platelet function. To investigate the role of platelets in the pathogenesis of thrombosis in hypertension, we applied a novel new assay to detect and quantify the degree of platelet adhesion to a defined coagulation molecule. Platelet-rich plasma (PRP) and citrated plasma (CP) were obtained from 50 patients with hypertension (25 treated, and 25 untreated) and 30 healthy controls. A suspension of 2 x 10(7) platelets were incubated for one hour in microtitre plates pre-coated with 5mg/mL fibrinogen. The supernatant was carefully aspirated, lysed with 5% tween and stored at -70 degrees C as supernatant platelet lysate (SPL). The wells were carefully washed with saline and bound platelets lysed as before, and stored at -70 degrees C as bound-platelet lysate (BPL). Soluble P-selectin (sP-sel) was determined in CP, SPL and BPL by enzyme-linked immunosorbent assay (ELISA). Patients with hypertension (both treated and previously untreated) had increased platelet adhesion, as determined by increased lysate sP-sel (P=0.002) in BPL, with no change in SPL (P=0.5) compared to healthy controls. There was no significant difference between treated and previously untreated hypertensives. Platelets from patients with hypertension display increased adhesion to an important coagulation factor (fibrinogen). This may, in part, account for the increased risk of thrombosis seen in these patients.

Interaction of platelets, fibrinogen and endothelial cells with plasma deposited PEO-like films

NASA Astrophysics Data System (ADS)

Yang, Zhilu; Wang, Jin; Li, Xin; Tu, Qiufen; Sun, Hong; Huang, Nan

2012-02-01

For blood-contacting biomedical implants like retrievable vena cava filters, surface-based diagnostic devices or in vivo sensors, limiting thrombosis and cell adhesion is paramount, due to a decrease even failure in performance. Plasma deposited PEO-like films were investigated as surface modifications. In this work, mixed gas composed of tetraethylene glycol dimethyl ether (tetraglyme) vapor and oxygen was used as precursor. It was revealed that plasma polymerization under high ratio of oxygen/tetraglyme led to deposition of the films that had high content of ether groups. This kind of PEO-like films had good stability in phosphate buffer solution. In vitro hemocompatibility and endothelial cell (EC) adhesion revealed low platelet adhesion, platelet activation, fibrinogen adhesion, EC adhesion and proliferation on such plasma deposited PEO-like films. This made it a potential candidate for the applications in anti-fouling surfaces of blood-contacting biomedical devices.

Fibrinogen binding sites P336 and Y338 of clumping factor A are crucial for Staphylococcus aureus virulence.

PubMed

Josefsson, Elisabet; Higgins, Judy; Foster, Timothy J; Tarkowski, Andrej

2008-05-21

We have earlier shown that clumping factor A (ClfA), a fibrinogen binding surface protein of Staphylococcus aureus, is an important virulence factor in septic arthritis. When two amino acids in the ClfA molecule, P(336) and Y(338), were changed to serine and alanine, respectively, the fibrinogen binding property was lost. ClfAP(336)Y(338) mutants have been constructed in two virulent S. aureus strains Newman and LS-1. The aim of this study was to analyze if these two amino acids which are vital for the fibrinogen binding of ClfA are of importance for the ability of S. aureus to generate disease. Septic arthritis or sepsis were induced in mice by intravenous inoculation of bacteria. The clfAP(336)Y(338) mutant induced significantly less arthritis than the wild type strain, both with respect to severity and frequency. The mutant infected mice developed also a much milder systemic inflammation, measured as lower mortality, weight loss, bacterial growth in kidneys and lower IL-6 levels. The data were verified with a second mutant where clfAP(336) and Y(338) were changed to alanine and serine respectively. When sepsis was induced by a larger bacterial inoculum, the clfAP(336)Y(338) mutants induced significantly less septic death. Importantly, immunization with the recombinant A domain of ClfAP(336)SY(338)A mutant but not with recombinant ClfA, protected against septic death. Our data strongly suggest that the fibrinogen binding activity of ClfA is crucial for the ability of S. aureus to provoke disease manifestations, and that the vaccine potential of recombinant ClfA is improved by removing its ability to bind fibrinogen.

The research and preparation of a novel nano biodegradable polymer external reinforcement

NASA Astrophysics Data System (ADS)

Zhang, Xiangman; Chen, Bin; Fu, Weiguo; Fang, Zhengdong; Liu, Zhenjie; Lu, Weifeng; Shi, Zhengyu; Chen, Lili; Chen, Tao

2011-10-01

The use of current drug-loaded vascular scaffolds is limited in sustained drug release and stability studies in clinical and preclinical trials. We found that poly( L-glutamic acid)-b-poly(propylene oxide)-b-poly( L-glutamic acid) (PLGA-b-PPO-b-PLGA) triblock copolymers can deliver multiple poorly water-soluble drugs (e.g., Paclitaxel) at clinically relevant doses. In this study, we synthesized a new drug-loaded vascular external graft with electrospun nanofibrous scaffolds [poly( L-lactide-co-ɛ-caprolactone) (PLCL):fibrinogen; 2:1 (w/w)] and drug-loaded PLGA-b-PPO-b-PLGA micelles. Cell proliferation and viability assay results showed that beagle smooth muscle cells grew well on the surface of vascular graft-coated micelles at a percentages of 10% (w/w) GPG:PLCL-fibrinogen. This study demonstrates that micelle-coated electrospun PLCL-fibrinogen vascular scaffolds have potential applications in vascular tissue engineering.

Haem-assisted dityrosine-cross-linking of fibrinogen under non-thermal plasma exposure: one important mechanism of facilitated blood coagulation

PubMed Central

Ke, Zhigang; Huang, Qing

2016-01-01

Although blood coagulation facilitated by non-thermal plasma has been reported several years ago, the insight to the involved mechanisms is still rather limited. In this work, we report our discovery of a new mechanism for the haem-promoted blood-coagulation caused by non-thermal plasma treatment. The reason for the haem role is due to that its oxidized form, namely, hematin, can promote the dityrosine cross-linking of fibrinogen, the most important coagulation protein, to form a membrane-like layer on the surface of the treated blood with plasma exposure. Both haem and non-thermal-plasma generated hydrogen peroxide are requisite for the cross-linking process. We confirmed that fibrinogen can coordinate with the haem iron to form a protein-haem complex which shows pseudo-peroxidase activity, and in the presence of hydrogen peroxide, the complex can induce the dityrosine formation between fibrinogen molecules, leading to the fibrin network necessary for the blood coagulation. Understanding of such an underlying mechanism can be useful to guide more efficient application of non-thermal plasma in the management of hemostasis, thrombosis and etc. PMID:27229173

The effect of reagents mimicking oxidative stress on fibrinogen function.

PubMed

Štikarová, Jana; Kotlín, Roman; Riedel, Tomáš; Suttnar, Jiří; Pimková, Kristýna; Chrastinová, Leona; Dyr, Jan E

2013-01-01

Fibrinogen is one of the plasma proteins most susceptible to oxidative modification. It has been suggested that modification of fibrinogen may cause thrombotic/bleeding complications associated with many pathophysiological states of organism. We exposed fibrinogen molecules to three different modification reagents-malondialdehyde, sodium hypochlorite, and peroxynitrite-that are presented to various degrees in different stages of oxidative stress. We studied the changes in fibrin network formation and platelet interactions with modified fibrinogens under flow conditions. The fastest modification of fibrinogen was caused by hypochlorite. Fibers from fibrinogen modified with either reagent were thinner in comparison with control fibers. We found that platelet dynamic adhesion was significantly lower on fibrinogen modified with malondialdehyde and significantly higher on fibrinogen modified either with hypochlorite or peroxynitrite reflecting different prothrombotic/antithrombotic properties of oxidatively modified fibrinogens. It seems that, in the complex reactions ongoing in living organisms at conditions of oxidation stress, hypochlorite modifies proteins (e.g., fibrinogen) faster and more preferentially than malondialdehyde. It suggests that the prothrombotic effects of prior fibrinogen modifications may outweigh the antithrombotic effect of malondialdehyde-modified fibrinogen in real living systems.

The Effect of Reagents Mimicking Oxidative Stress on Fibrinogen Function

PubMed Central

Štikarová, Jana; Kotlín, Roman; Riedel, Tomáš; Suttnar, Jiří; Pimková, Kristýna; Chrastinová, Leona; Dyr, Jan E.

2013-01-01

Fibrinogen is one of the plasma proteins most susceptible to oxidative modification. It has been suggested that modification of fibrinogen may cause thrombotic/bleeding complications associated with many pathophysiological states of organism. We exposed fibrinogen molecules to three different modification reagents—malondialdehyde, sodium hypochlorite, and peroxynitrite—that are presented to various degrees in different stages of oxidative stress. We studied the changes in fibrin network formation and platelet interactions with modified fibrinogens under flow conditions. The fastest modification of fibrinogen was caused by hypochlorite. Fibers from fibrinogen modified with either reagent were thinner in comparison with control fibers. We found that platelet dynamic adhesion was significantly lower on fibrinogen modified with malondialdehyde and significantly higher on fibrinogen modified either with hypochlorite or peroxynitrite reflecting different prothrombotic/antithrombotic properties of oxidatively modified fibrinogens. It seems that, in the complex reactions ongoing in living organisms at conditions of oxidation stress, hypochlorite modifies proteins (e.g., fibrinogen) faster and more preferentially than malondialdehyde. It suggests that the prothrombotic effects of prior fibrinogen modifications may outweigh the antithrombotic effect of malondialdehyde-modified fibrinogen in real living systems. PMID:24235886

Structure and hemocompatibility of nanocrystalline titanium nitride produced under glow-discharge conditions

NASA Astrophysics Data System (ADS)

Sowińska, Agnieszka; Czarnowska, Elżbieta; Tarnowski, Michał; Witkowska, Justyna; Wierzchoń, Tadeusz

2018-04-01

Significant efforts are being made towards developing novel antithrombotic materials. The purpose of the presented study was to characterize two variants of nitrided surface layers produced on alloy Ti-6Al-4V in different areas of low-temperature plasma - at the plasma potential (TiNp) or at the cathode potential (TiNc). The layers were characterized in terms of their microstructure, surface topography and wettability, and platelet response to the environment of different pH. The produced layers were of the TiN + Ti2N + αTiN-type, but the layer produced at the plasma potential was thinner, smoother and had lower surface free energy compared with that produced at the cathode potential. Biological evaluation demonstrated more fibrinogen buildup, less platelet adhesion and aggregation, and fewer strongly activated platelets on the TiNp surface compared with those parameters on the TiNc surface and on the titanium alloy in its initial state. Interestingly, both surface types were significantly resistant to fibrinogen adsorption and platelet adhesion in the environment of lower pH. In conclusion, the nitrided surface layer produced at the plasma potential is a promising material and this basic information is critical for further development of hemocompatible materials.

Orphan nuclear receptor ERRγ is a key regulator of human fibrinogen gene expression

PubMed Central

Zhang, Yaochen; Kim, Don-Kyu; Lu, Yan; Jung, Yoon Seok; Lee, Ji-min; Kim, Young-Hoon; Lee, Yong Soo; Kim, Jina; Dewidar, Bedair; Jeong, Won-IL; Lee, In-Kyu; Cho, Sung Jin; Dooley, Steven; Lee, Chul-Ho; Li, Xiaoying

2017-01-01

Fibrinogen, 1 of 13 coagulation factors responsible for normal blood clotting, is synthesized by hepatocytes. Detailed roles of the orphan nuclear receptors regulating fibrinogen gene expression have not yet been fully elucidated. Here, we identified estrogen-related receptor gamma (ERRγ) as a novel transcriptional regulator of human fibrinogen gene expression. Overexpression of ERRγ specially increased fibrinogen expression in human hepatoma cell line. Cannabinoid receptor types 1(CB1R) agonist arachidonyl-2'-chloroethylamide (ACEA) up-regulated transcription of fibrinogen via induction of ERRγ, whereas knockdown of ERRγ attenuated fibrinogen expression. Deletion analyses of the fibrinogen γ (FGG) gene promoter and ChIP assays revealed binding sites of ERRγ on human fibrinogen γ gene promoter. Moreover, overexpression of ERRγ was sufficient to increase fibrinogen gene expression, whereas treatment with GSK5182, a selective inverse agonist of ERRγ led to its attenuation in cell culture. Finally, fibrinogen and ERRγ gene expression were elevated in liver tissue of obese patients suggesting a conservation of this mechanism. Overall, this study elucidates a molecular mechanism linking CB1R signaling, ERRγ expression and fibrinogen gene transcription. GSK5182 may have therapeutic potential to treat hyperfibrinogenemia. PMID:28750085

Serum protein adsorption and platelet adhesion on aspartic-acid-immobilized polysulfone membranes.

PubMed

Higuchi, Akon; Hashiba, Hirokazu; Hayashi, Rika; Yoon, Boo Ok; Sakurai, Masaru; Hara, Mariko

2004-01-01

Polysulfone (PSf) membranes that covalently conjugated with aspartic acid (ASP-PSf) were prepared and analyzed for hemocompatability. Compared to PSf or other types of surface-modified PSf membranes, the ASP-PSf membranes had a reduced ability to adsorb protein from either a plasma solution or a mixed solution of albumin, globulin and fibrinogen. This appears to be due to the creation of a hydrophilic surface by the aspartic acid zwitterion immobilized on the ASP-PSf membranes. Furthermore, the analyses of membrane protein adsorption showed that a mixed protein solution recapitulates the cooperative adsorption of proteins that occurs in plasma. We also found that the number of adhering platelets was the lowest on the ASP-PSf membranes and, in general, that platelet adhesion decreased in parallel with fibrinogen adsorption. In summary, aspartic acid immobilized on the ASP-PSf membranes, which have zwitterions with a net zero charge, effectively contributes to the hydrophilic and hemocompatible sites on the surface of the hydrophobic PSf membranes.

Laboratory and Genetic Investigation of Mutations Accounting for Congenital Fibrinogen Disorders.

PubMed

Neerman-Arbez, Marguerite; de Moerloose, Philippe; Casini, Alessandro

2016-06-01

Congenital fibrinogen disorders are classified into two types of plasma fibrinogen defects: type I (quantitative fibrinogen deficiencies), that is, hypofibrinogenemia or afibrinogenemia, in which there are low or absent plasma fibrinogen antigen levels, respectively, and type II (qualitative fibrinogen deficiencies), that is, dysfibrinogenemia or hypodysfibrinogenemia, in which there are normal or reduced antigen levels associated with disproportionately low functional activity. These disorders are caused by mutations in the three fibrinogen-encoding genes FGA, FGB, and FGG. Afibrinogenemia is associated with mild to severe bleeding, whereas hypofibrinogenemia is often asymptomatic. For these quantitative disorders, the majority of mutations prevent protein production. However, in some cases, missense or late-truncating nonsense mutations allow synthesis of the mutant fibrinogen chain, but intracellular fibrinogen assembly and/or secretion are impaired. Qualitative fibrinogen disorders are associated with bleeding, thrombosis, or both thrombosis and bleeding, but many dysfibrinogenemias are asymptomatic. The majority of cases are caused by heterozygous missense mutations. Here, we review the laboratory and genetic diagnosis of fibrinogen gene anomalies with an updated discussion of causative mutations identified. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Leptospira Immunoglobulin-Like Protein B (LigB) Binds to Both the C-Terminal 23 Amino Acids of Fibrinogen αC Domain and Factor XIII: Insight into the Mechanism of LigB-Mediated Blockage of Fibrinogen α Chain Cross-Linking.

PubMed

Hsieh, Ching-Lin; Chang, Eric; Tseng, Andrew; Ptak, Christopher; Wu, Li-Chen; Su, Chun-Li; McDonough, Sean P; Lin, Yi-Pin; Chang, Yung-Fu

2016-09-01

The coagulation system provides a primitive but effective defense against hemorrhage. Soluble fibrinogen (Fg) monomers, composed of α, β and γ chains, are recruited to provide structural support for the formation of a hemostatic plug. Fg binds to platelets and is processed into a cross-linked fibrin polymer by the enzymatic clotting factors, thrombin and Factor XIII (FXIII). The newly formed fibrin-platelet clot can act as barrier to protect against pathogens from entering the bloodstream. Further, injuries caused by bacterial infections can be confined to the initial wound site. Many pathogenic bacteria have Fg-binding adhesins that can circumvent the coagulation pathway and allow the bacteria to sidestep containment. Fg expression is upregulated during lung infection providing an attachment surface for bacteria with the ability to produce Fg-binding adhesins. Fg binding by leptospira might play a crucial factor in Leptospira-associated pulmonary hemorrhage, the main factor contributing to lethality in severe cases of leptospirosis. The 12th domain of Leptospira immunoglobulin-like protein B (LigB12), a leptospiral adhesin, interacts with the C-terminus of FgαC (FgαCC). In this study, the binding site for LigB12 was mapped to the final 23 amino acids at the C-terminal end of FgαCC (FgαCC8). The association of FgαCC8 with LigB12 (ELISA, KD = 0.76 μM; SPR, KD = 0.96 μM) was reduced by mutations of both charged residues (R608, R611 and H614 from FgαCC8; D1061 from LigB12) and hydrophobic residues (I613 from FgαCC8; F1054 and A1065 from LigB12). Additionally, LigB12 bound strongly to FXIII and also inhibited fibrin formation, suggesting that LigB can disrupt coagulation by suppressing FXIII activity. Here, the detailed binding mechanism of a leptospiral adhesin to a host hemostatic factor is characterized for the first time and should provide better insight into the pathogenesis of leptospirosis.

Leptospira Immunoglobulin-Like Protein B (LigB) Binds to Both the C-Terminal 23 Amino Acids of Fibrinogen αC Domain and Factor XIII: Insight into the Mechanism of LigB-Mediated Blockage of Fibrinogen α Chain Cross-Linking

PubMed Central

Hsieh, Ching-Lin; Chang, Eric; Tseng, Andrew; Ptak, Christopher; Wu, Li-Chen; Su, Chun-Li; McDonough, Sean P.; Lin, Yi-Pin; Chang, Yung-Fu

2016-01-01

The coagulation system provides a primitive but effective defense against hemorrhage. Soluble fibrinogen (Fg) monomers, composed of α, β and γ chains, are recruited to provide structural support for the formation of a hemostatic plug. Fg binds to platelets and is processed into a cross-linked fibrin polymer by the enzymatic clotting factors, thrombin and Factor XIII (FXIII). The newly formed fibrin-platelet clot can act as barrier to protect against pathogens from entering the bloodstream. Further, injuries caused by bacterial infections can be confined to the initial wound site. Many pathogenic bacteria have Fg-binding adhesins that can circumvent the coagulation pathway and allow the bacteria to sidestep containment. Fg expression is upregulated during lung infection providing an attachment surface for bacteria with the ability to produce Fg-binding adhesins. Fg binding by leptospira might play a crucial factor in Leptospira-associated pulmonary hemorrhage, the main factor contributing to lethality in severe cases of leptospirosis. The 12th domain of Leptospira immunoglobulin-like protein B (LigB12), a leptospiral adhesin, interacts with the C-terminus of FgαC (FgαCC). In this study, the binding site for LigB12 was mapped to the final 23 amino acids at the C-terminal end of FgαCC (FgαCC8). The association of FgαCC8 with LigB12 (ELISA, KD = 0.76 μM; SPR, KD = 0.96 μM) was reduced by mutations of both charged residues (R608, R611 and H614 from FgαCC8; D1061 from LigB12) and hydrophobic residues (I613 from FgαCC8; F1054 and A1065 from LigB12). Additionally, LigB12 bound strongly to FXIII and also inhibited fibrin formation, suggesting that LigB can disrupt coagulation by suppressing FXIII activity. Here, the detailed binding mechanism of a leptospiral adhesin to a host hemostatic factor is characterized for the first time and should provide better insight into the pathogenesis of leptospirosis. PMID:27622634

Insertional inactivation of Eap in Staphylococcus aureus strain Newman confers reduced staphylococcal binding to fibroblasts.

PubMed

Hussain, Muzaffar; Haggar, Axana; Heilmann, Christine; Peters, Georg; Flock, Jan-Ingmar; Herrmann, Mathias

2002-06-01

To initiate invasive infection, Staphylococcus aureus must adhere to host substrates, such as the extracellular matrix or eukaryotic cells, by virtue of different surface proteins (adhesins). Recently, we identified a 60-kDa cell-secreted extracellular adherence protein (Eap) of S. aureus strain Newman with broad-spectrum binding characteristics (M. Palma, A. Haggar, and J. I. Flock, J. Bacteriol. 181:2840-2845, 1999), and we have molecularly confirmed Eap to be an analogue of the previously identified major histocompatibility complex class II analog protein (Map) (M. Hussain, K. Becker, C. von Eiff, G. Peter, and M. Herrmann, Clin. Diagn. Lab. Immunol. 8:1281-1286, 2001). Previous analyses of the Eap/Map function performed with purified protein did not allow dissection of its precise role in the complex situation of the staphylococcal whole cell presenting several secreted and wall-bound adhesins. Therefore, the role of Eap was investigated by constructing a stable eap::ermB deletion in strain Newman and by complementation of the mutant. Patterns of extracted cell surface proteins analyzed both by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by Western ligand assays with various adhesive matrix molecules clearly confirmed the absence of Eap in the mutant. However, binding and adhesion tests using whole staphylococcal cells demonstrated that both the parent and mutant strains bound equally well to fibronectin- and fibrinogen-coated surfaces, possibly due to their recognition by other staphylococcal adhesins. Furthermore, Eap mediated staphylococcal agglutination of both wild-type and mutant cells. In contrast, the mutant adhered to a significantly lesser extent to cultured fibroblasts (P < 0.001) than did the wild type, while adherence was restorable upon complementation. Furthermore, adherence to both epithelial cells (P < 0.05) and fibroblasts (not significant) could be blocked with antibodies against Eap, whereas preimmune serum was not active. In conclusion, Eap may contribute to pathogenicity by promoting adhesion of whole staphylococcal cells to complex eukaryotic substrates.

Fibrinogen blood test

MedlinePlus

Serum fibrinogen; Plasma fibrinogen; Factor I; Hypofibrinogenemia test ... Chernecky CC, Berger BJ. Fibrinogen (factor I) - plasma. In: ... Louis, MO: Elsevier Saunders; 2013:525. Schmaier AH. Laboratory ...

Two novel mutations in the fibrinogen γ nodule.

PubMed

Kotlín, Roman; Pastva, Ondřej; Stikarová, Jana; Hlaváčková, Alžběta; Suttnar, Jiří; Chrastinová, Leona; Riedel, Tomáš; Salaj, Peter; Dyr, Jan E

2014-10-01

Congenital dysfibrinogenemia and hypofibrinogenemia are rare diseases characterized by inherited abnormality in the fibrinogen molecule, resulting in functional defects (dysfibrinogenemia) or low fibrinogen plasma levels (hypofibrinogenemia). We have described two abnormal fibrinogens - fibrinogen Hranice (γ Phe204Val) and Praha IV (γ Ser313Gly). The carrier of the Hranice mutation was a 40-year-old female with low fibrinogen levels. The carrier of the Praha IV mutation was a 42-year-old man with a history of idiopathic thrombosis, low functional fibrinogen levels, and a prolonged thrombin time. Fibrin polymerization kinetics measurement was normal in both cases (after the addition of either thrombin or reptilase), as well as was fibrinolysis. Scanning electron microscopy and confocal microscopy revealed significantly wider fibers in both cases, when compared with fibers prepared from healthy control samples. Although both cases are situated in the γ-nodule, they manifested differently. While the γ Ser313Gly mutation manifested as dysfibrinogenemia with a thrombotic background, the γ Phe204Val mutation manifested as hypofibrinogenemia without clinical symptoms. The mutation sites of both fibrinogens are in highly conserved regions of the fibrinogen γ chains. γ Ser313 is situated in a class 16:18 β hairpin and is involved in hydrogen bonding with γ Asp320. γ Phe204 is situated in an inverse γ turn and may be involved in π-π interactions. Both mutations cause conformational changes in fibrinogen, which lead either to impaired fibrinogen assembly (fibrinogen Hranice) or abnormal fibrinogen function (fibrinogen Praha IV). Copyright © 2014 Elsevier Ltd. All rights reserved.

Biofunctionalization on alkylated silicon substrate surfaces via "click" chemistry.

PubMed

Qin, Guoting; Santos, Catherine; Zhang, Wen; Li, Yan; Kumar, Amit; Erasquin, Uriel J; Liu, Kai; Muradov, Pavel; Trautner, Barbara Wells; Cai, Chengzhi

2010-11-24

Biofunctionalization of silicon substrates is important to the development of silicon-based biosensors and devices. Compared to conventional organosiloxane films on silicon oxide intermediate layers, organic monolayers directly bound to the nonoxidized silicon substrates via Si-C bonds enhance the sensitivity of detection and the stability against hydrolytic cleavage. Such monolayers presenting a high density of terminal alkynyl groups for bioconjugation via copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC, a "click" reaction) were reported. However, yields of the CuAAC reactions on these monolayer platforms were low. Also, the nonspecific adsorption of proteins on the resultant surfaces remained a major obstacle for many potential biological applications. Herein, we report a new type of "clickable" monolayers grown by selective, photoactivated surface hydrosilylation of α,ω-alkenynes, where the alkynyl terminal is protected with a trimethylgermanyl (TMG) group, on hydrogen-terminated silicon substrates. The TMG groups on the film are readily removed in aqueous solutions in the presence of Cu(I). Significantly, the degermanylation and the subsequent CuAAC reaction with various azides could be combined into a single step in good yields. Thus, oligo(ethylene glycol) (OEG) with an azido tag was attached to the TMG-alkyne surfaces, leading to OEG-terminated surfaces that reduced the nonspecific adsorption of protein (fibrinogen) by >98%. The CuAAC reaction could be performed in microarray format to generate arrays of mannose and biotin with varied densities on the protein-resistant OEG background. We also demonstrated that the monolayer platform could be functionalized with mannose for highly specific capturing of living targets (Escherichia coli expressing fimbriae) onto the silicon substrates.

Two novel fibrinogen variants in the C-terminus of the Bβ-chain: fibrinogen Rokycany and fibrinogen Znojmo.

PubMed

Kotlín, Roman; Reicheltová, Zuzana; Suttnar, Jirí; Salaj, Peter; Hrachovinová, Ingrid; Riedel, Tomás; Malý, Martin; Oravec, Milan; Kvasnicka, Jan; Dyr, Jan Evangelista

2010-10-01

Hereditary dysfibrinogenemia is a rare disorder wherein an inherited abnormality in fibrinogen structure may result in defective fibrin function and/or structure. Congenital hypofibrinogenemia is a rare autosomal bleeding disorder, either recessive or dominant, characterized by a low fibrinogen plasma level. A 28-year-old asymptomatic woman (fibrinogen Rokycany) and a 54-year-old man with thrombosis and pulmonary embolism (fibrinogen Znojmo) were investigated for a suspected fibrinogen mutation after abnormal coagulation tests results were obtained. DNA sequencing showed the heterozygous point mutation Bβ Asn351Lys in fibrinogen Rokycany and the heterozygous point mutation Bβ Arg237Ser in fibrinogen Znojmo, respectively. The kinetics of fibrinopeptide release was found to be normal in both cases. Fibrinolysis was impaired in the Znojmo variant. The average fibril diameters of Znojmo fibrin was slightly increased, but not differing significantly from normal; formed by less fibrils with abrupt fibril terminations. Rheological studies revealed a softer clot. Rokycany fibrin was formed by significantly narrower fibrils than normal fibrin; and the clot was denser than the control clot. Rheological studies revealed a stiffer clot. Impaired fibrinolysis and abnormal clot morphology may be the cause of thrombotic episodes in the patient with Znojmo mutation. New cases of hypofibrinogenemia and dysfibrinogenemia, found by routine coagulation testing, were genetically identified as a novel fibrinogen variants Bβ Asn351Lys (fibrinogen Rokycany) and Bβ Arg237Ser (fibrinogen Znojmo), respectively.

Endothelialization of polyurethanes: Surface silanization and immobilization of REDV peptide.

PubMed

Butruk-Raszeja, Beata A; Dresler, Magdalena S; Kuźmińska, Aleksandra; Ciach, Tomasz

2016-08-01

The paper presents method for chemical immobilization of arginine-glutamic acid-aspartic acid-valine (REDV) peptide on polyurethane surface. The peptide has been covalently bonded using silanes as a spacer molecules. The aim of this work was to investigate the proposed modification process and assess its biological effectiveness, especially in contact with blood and endothelial cells. Physicochemical properties were examined in terms of wettability, atomic composition and density of introduced functional groups and peptide molecules. Experiments with blood showed that material coating reduced number of surface-adhered platelets and fibrinogen molecules. In contrast to polyurethane (PU), there were no blood components deposited on REDV-modified materials (PU-REDV); fibrinogen adsorption on PU-REDV surface has been strongly reduced compared to PU. Analysis of cell adhesion after 1, 2, 3, 4, and 5 days of culture showed a significant increase of the cell-coated area on PU-REDV compared to PU. However, an intense cell growth appeared also on the control surface modified without the addition of REDV. Thus, the positive effect of REDV peptide on the adhesion of HUVEC could not be unequivocally confirmed. Copyright © 2016 Elsevier B.V. All rights reserved.

Fabrication of Semiordered Nanopatterned Diamond-like Carbon and Titania Films for Blood Contacting Applications.

PubMed

Nandakumar, Deepika; Bendavid, Avi; Martin, Philip J; Harris, Kenneth D; Ruys, Andrew J; Lord, Megan S

2016-03-23

Biomaterials with the ability to interface with, but not activate, blood components are essential for a multitude of medical devices. Diamond-like carbon (DLC) and titania (TiO2) have shown promise for these applications; however, both support platelet adhesion and activation. This study explored the fabrication of nanostructured DLC and TiO2 thin film coatings using a block copolymer deposition technique that produced semiordered nanopatterns with low surface roughness (5-8 nm Rrms). These surfaces supported fibrinogen and plasma protein adsorption that predominantly adsorbed between the nanofeatures and reduced the overall surface roughness. The conformation of the adsorbed fibrinogen was altered on the nanopatterned surfaces as compared with the planar surfaces to reveal higher levels of the platelet binding region. Planar DLC and TiO2 coatings supported less platelet adhesion than nanopatterned DLC and TiO2. However, platelets on the nanopatterned DLC coatings were less spread indicating a lower level of platelet activation on the nanostructured DLC coatings compared with the planar DLC coatings. These data indicated that nanostructured DLC coatings may find application in blood contacting medical devices in the future.

Computational modeling of in vitro biological responses on polymethacrylate surfaces

PubMed Central

Ghosh, Jayeeta; Lewitus, Dan Y; Chandra, Prafulla; Joy, Abraham; Bushman, Jared; Knight, Doyle; Kohn, Joachim

2011-01-01

The objective of this research was to examine the capabilities of QSPR (Quantitative Structure Property Relationship) modeling to predict specific biological responses (fibrinogen adsorption, cell attachment and cell proliferation index) on thin films of different polymethacrylates. Using 33 commercially available monomers it is theoretically possible to construct a library of over 40,000 distinct polymer compositions. A subset of these polymers were synthesized and solvent cast surfaces were prepared in 96 well plates for the measurement of fibrinogen adsorption. NIH 3T3 cell attachment and proliferation index were measured on spin coated thin films of these polymers. Based on the experimental results of these polymers, separate models were built for homo-, co-, and terpolymers in the library with good correlation between experiment and predicted values. The ability to predict biological responses by simple QSPR models for large numbers of polymers has important implications in designing biomaterials for specific biological or medical applications. PMID:21779132

Fibrinogen Reduction During Selective Plasma Exchange due to Membrane Fouling.

PubMed

Ohkubo, Atsushi; Okado, Tomokazu; Miyamoto, Satoko; Hashimoto, Yurie; Komori, Shigeto; Yamamoto, Motoki; Maeda, Takuma; Itagaki, Ayako; Yamamoto, Hiroko; Seshima, Hiroshi; Kurashima, Naoki; Iimori, Soichiro; Naito, Shotaro; Sohara, Eisei; Uchida, Shinichi; Rai, Tatemitsu

2017-06-01

Fibrinogen is substantially reduced by most plasmapheresis modalities but retained in selective plasma exchange using Evacure EC-4A10 (EC-4A). Although EC-4A's fibrinogen sieving coefficient is 0, a session of selective plasma exchange reduced fibrinogen by approximately 19%. Here, we investigated sieving coefficient in five patients. When the mean processed plasma volume was 1.15 × plasma volume, the mean reduction of fibrinogen during selective plasma exchange was approximately 15%. Fibrinogen sieving coefficient was 0 when the processed plasma volume was 1.0 L, increasing to 0.07 when the processed plasma volume was 3.0 L, with a mean of 0.03 during selective plasma exchange. When fibrinogen sieving coefficient was 0, selective plasma exchange reduced fibrinogen by approximately 10%. Scanning electron microscopy images revealed internal fouling of EC-4A's hollow fiber membrane by substances such as fibrinogen fibrils. Thus, fibrinogen reduction by selective plasma exchange may be predominantly caused by membrane fouling rather than filtration. © 2017 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.

The significance of variations in immunoreactive and clottable fibrinogen in health and following thrombosis

PubMed Central

Wolf, P.; Farrell, G. W.; Walton, K. W.

1972-01-01

In individuals in a steady state of fibrinogen metabolism, immunoreactive and clottable fibrinogen estimates of plasma fibrinogen show close agreement. These estimates also detect any increase of plasma fibrinogen (due to increased synthesis) following metabolic stresses but in certain circumstances discrepancies between immunoreactive and clottable fibrinogen values occur which are of diagnostic assistance. During extensive thrombosis, circulating `cryoprofibrin' (fibrin intermediates) may be formed. These fail to give full quantitative immunodiffusion reactions with antifibrinogen. Values for immunoreactive are therefore lower than for clottable fibrinogen. When intravascular catabolism (due to plasmin action) accompanies increased synthesis, since some of the molecular breakdown products of fibrin or fibrinogen react with antifibrinogen but are not clottable, immunoreactive values exceed those for clottable fibrinogen. This discrepancy is therefore an indicator of thrombolysis. Each discrepancy in turn may be encountered during the alternating predominance of thrombosis or thrombolysis in vivo: (a) physiologically, in association with the menstrual cycle; (b) pathologically, following surgical operations or extensive intravascular thrombosis. Images PMID:4259368

Pulsed laser deposited metal oxide thin films mediated controlled adsorption of proteins

NASA Astrophysics Data System (ADS)

Kim, Se Jin

Several metal oxide thin films were grown on Si substrate by pulsed laser deposition for controlling adsorption of proteins. No intentional heating of substrate and introduction of oxygen gas during growth were employed. Additionally, fibrinogen, bovine serum albumin (BSA), and lysozyme were used as model protein in this study. The film properties such as cyratllinity, surface roughness, surface electrical charge and chemistry were investigated by many techniques in order to obtain the relationship with protein adsorption. Firstly, as grown Ta2O5 and ZnO thin film were used to study the effects of surface charge on the behaviors of BSA and lysozyme adsorption. The protein thickness results by ellipsometry showed that negatively charged Ta2O5 had a stronger affinity to positively charged lysozyme, while positively charged ZnO had a stronger affinity to negatively charged BSA. The results confirmed electrostatic interaction due to surface charge is one of main factors for determining adsorption of proteins. Furthermore, annealing studies were performed by heat treatment of as grown Ta2O5 and ZnO at 800°C in air ambience. Annealed Ta2O5 thin film had almost wetting property (from 10.02° to less than 1˜2°) and the change of cystallinity (from amorphous to cyrsalline) while annealed ZnO thin film had a reduced contact angle (from 75.65° to 39.41°) and remained to crystalline structure. The fibrinogen thickness on annealed Ta2O5 film was increased compared with as grown sample, while heat treated ZnO film showed much reduction of fibrinogen adsorption. Binary Ta-Zn oxide thin films (TZ) were grown by preparing PLD target composed of 50 wt% Ta2O5 and 50 wt% ZnO. This binary film had IEP pH 7.1 indicating nearly neutral charge in pH 7.4 PBS solution, and hydrophilic property. Ellipsometrical results showed that TZ film had the lowest fibrinogen, BSA and lysozyme thickness after 120 min adsorption compared with Ta2O5 and ZnO. Other samples, bilayer oxide films in which Ta2O5 and ZnO coexist were also employed to study adsorption behaviors. Especially, Ta2O 5-based bilayer films revealed zero adsorption of lysozyme.

Network of Surface-Displayed Glycolytic Enzymes in Mycoplasma pneumoniae and Their Interactions with Human Plasminogen

PubMed Central

Gründel, Anne; Pfeiffer, Melanie; Jacobs, Enno

2015-01-01

In different bacteria, primarily cytosolic and metabolic proteins are characterized as surface localized and interacting with different host factors. These moonlighting proteins include glycolytic enzymes, and it has been hypothesized that they influence the virulence of pathogenic species. The presence of surface-displayed glycolytic enzymes and their interaction with human plasminogen as an important host factor were investigated in the genome-reduced and cell wall-less microorganism Mycoplasma pneumoniae, a common agent of respiratory tract infections of humans. After successful expression of 19 glycolytic enzymes and production of polyclonal antisera, the localization of proteins in the mycoplasma cell was characterized using fractionation of total proteins, colony blot, mild proteolysis and immunofluorescence of M. pneumoniae cells. Eight glycolytic enzymes, pyruvate dehydrogenases A to C (PdhA-C), glyceraldehyde-3-phosphate dehydrogenase (GapA), lactate dehydrogenase (Ldh), phosphoglycerate mutase (Pgm), pyruvate kinase (Pyk), and transketolase (Tkt), were confirmed as surface expressed and all are able to interact with plasminogen. Plasminogen bound to recombinant proteins PdhB, GapA, and Pyk was converted to plasmin in the presence of urokinase plasminogen activator and plasmin-specific substrate d-valyl-leucyl-lysine-p-nitroanilide dihydrochloride. Furthermore, human fibrinogen was degraded by the complex of plasminogen and recombinant protein PdhB or Pgm. In addition, surface-displayed proteins (except PdhC) bind to human lung epithelial cells, and the interaction was reduced significantly by preincubation of cells with antiplasminogen. Our results suggest that plasminogen binding and activation by different surface-localized glycolytic enzymes of M. pneumoniae may play a role in successful and long-term colonization of the human respiratory tract. PMID:26667841

Clinical and Prognostic Effect of Plasma Fibrinogen in Renal Cell Carcinoma: A Meta-Analysis.

PubMed

Tian, Yuejun; Hong, Mei; Jing, Suoshi; Liu, Xingchen; Wang, Hanzhang; Wang, Xinping; Kaushik, Dharam; Rodriguez, Ronald; Wang, Zhiping

2017-01-01

Background . Although numerous studies have shown that plasma fibrinogen is linked to renal cell carcinoma (RCC) risk, the consistency and magnitude of the effect of plasma fibrinogen are unclear. The aim of the study was to explore the association between plasma fibrinogen and RCC prognosis. Methods . An electronic search of Embase, PubMed/MEDLINE, and the Cochrane databases was performed to identify relevant studies published prior to June 1, 2016. Results . A total of 3744 patients with RCC from 7 published studies were included in the meta-analysis. The prognostic and clinical relevance of plasma fibrinogen are evaluated in RCC patients. Statistical significance of the combined hazard ratio (HR) was detected for overall survival, cancer-specific survival, and disease-free survival. Our pooled results showed that elevated plasma fibrinogen was significantly associated with clinical stage and Fuhrman grading. The level of plasma fibrinogen was not found to be associated with tumor type and gender. Conclusions . Elevated plasma fibrinogen is a strong indicator of poorer prognosis of patients with RCC, whereas the plasma fibrinogen is not significantly associated with tumor type. Therefore, plasma fibrinogen could be used in patients with RCC for risk stratification and decision providing a proper therapeutic strategy.

Three cases of congenital dysfibrinogenemia in unrelated Chinese families: heterozygous missense mutation in fibrinogen alpha chain Argl6His

PubMed Central

Luo, Meiling; Deng, Donghong; Xiang, Liqun; Cheng, Peng; Liao, Lin; Deng, Xuelian; Yan, Jie; Lin, Faquan

2016-01-01

Abstract Congenital dysfibrinogenemia (CD) is a qualitative fibrinogen disorder caused by an abnormal fibrinogen molecule structure, leading to dysfunctional blood coagulation. This study describes 3 cases of dysfibrinogenemia identified in the unrelated Chinese pedigrees. Routine coagulation screening tests were performed on the probands and their families. The antigens and functionality of fibrinogen was measured using an immunoturbidimetry assay and the Clauss method, respectively. To identify the genetic mutation responsible for these dysfibrinogens, genomic DNA extracted from the blood was analyzed using PCR amplification and direct sequencing. The presence of the mutant chains was determined using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectroscopy. Purified plasma fibrinogen of 3 probands was analyzed using SDS–PAGE, fibrinogen clottability, fibrin polymerization, fibrinopeptide release, and scanning electron microscopy (SEM). The 3 probands had a long thrombin time. Levels of functional fibrinogen were found to be very low, while the fibrinogen antigen was within the normal range. DNA sequencing revealed a heterozygous Arg16His substitution in the fibrinogen Aα chain (FGA). The mutant chains were found to be expressed using MALDI-TOF mass spectroscopy. SDS–PAGE did not reveal any difference in the molecular weights of 3 polypeptide chains between normal and abnormal fibrinogens. Fibrinogen clottability showed a slower fibrin clot formation than the healthy control. Fibrin polymerization, after addition of thrombin, showed a prolonged lag phase and decreased final turbidity. The kinetics of fibrinopeptides release revealed a decreased amount of the released fibrinopeptide A. SEM of the patient's fibrin clot was found to be abnormal. Results indicate that the 3 probands with dysfibrinogenemia were caused by mutations of Aα chain Arg16His. Mutation of this fibrinogen induced dysfunction of plasma fibrinogen. PMID:27684817

Substitution of the human αC region with the analogous chicken domain generates a fibrinogen with severely impaired lateral aggregation: fibrin monomers assemble into protofibrils but protofibrils do not assemble into fibers.†

PubMed Central

Ping, Lifang; Huang, Lihong; Cardinali, Barbara; Profumo, Aldo; Gorkun, Oleg V.; Lord, Susan T.

2011-01-01

Fibrin polymerization occurs in two steps: the assembly of fibrin monomers into protofibrils and the lateral aggregation of protofibrils into fibers. Here we describe a novel fibrinogen that apparently impairs only lateral aggregation. This variant is a hybrid, where the human αC region has been replaced with the homologous chicken region. Several experiments indicate this hybrid human-chicken (HC) fibrinogen has an overall structure similar to normal. Thrombin-catalyzed fibrinopeptide release from HC fibrinogen was normal. Plasmin digests of HC fibrinogen produced fragments that were similar to normal D and E; further, as with normal fibrinogen, the knob ‘A’ peptide, GPRP, reversed the plasmin cleavage associated with addition of EDTA. Dynamic light scattering and turbidity studies with HC fibrinogen showed polymerization was not normal. Whereas early small increases in hydrodynamic radius and absorbance paralleled the increases seen during the assembly of normal protofibrils, HC fibrinogen showed no dramatic increase in scattering as observed with normal lateral aggregation. To determine whether HC and normal fibrinogen could form a copolymer, we examined mixtures of these. Polymerization of normal fibrinogen was markedly changed by HC fibrinogen, as expected for mixed polymers. When the mixture contained 0.45 μM normal and 0.15 M HC fibrinogen, the initiation of lateral aggregation was delayed and the final fiber size was reduced relative to normal fibrinogen at 0.45 μM. Considered altogether our data suggest that HC fibrin monomers can assemble into protofibrils or protofibril-like structures but these either cannot assemble into fibers or assemble into very thin fibers. PMID:21932842

Utilisation of Quartz Crystal Microbalance Sensors with Dissipation (QCM-D) for a Clauss Fibrinogen Assay in Comparison with Common Coagulation Reference Methods.

PubMed

Oberfrank, Stephanie; Drechsel, Hartmut; Sinn, Stefan; Northoff, Hinnak; Gehring, Frank K

2016-02-24

The determination of fibrinogen levels is one of the most important coagulation measurements in medicine. It plays a crucial part in diagnostic and therapeutic decisions, often associated with time-critical conditions. The commonly used measurement is the Clauss fibrinogen assay (CFA) where plasma is activated by thrombin reagent and which is conducted by mechanical/turbidimetric devices. As quartz crystal microbalance sensors with dissipation (QCM-D) based devices have a small footprint, can be operated easily and allow measurements independently from sample transportation time, laboratory location, availability and opening hours, they offer a great opportunity to complement laboratory CFA measurements. Therefore, the objective of the work was to (1) transfer the CFA to the QCM-D method; (2) develop an easy, time- and cost-effective procedure and (3) compare the results with references. Different sensor coatings (donor's own plasma; gold surface) and different QCM-D parameters (frequency signal shift; its calculated turning point; dissipation signal shift) were sampled. The results demonstrate the suitability for a QCM-D-based CFA in physiological fibrinogen ranges. Results were obtained in less than 1 min and in very good agreement with a standardized reference (Merlin coagulometer). The results provide a good basis for further investigation and pave the way to a possible application of QCM-D in clinical and non-clinical routine in the medical field.

Utilisation of Quartz Crystal Microbalance Sensors with Dissipation (QCM-D) for a Clauss Fibrinogen Assay in Comparison with Common Coagulation Reference Methods

PubMed Central

Oberfrank, Stephanie; Drechsel, Hartmut; Sinn, Stefan; Northoff, Hinnak; Gehring, Frank K.

2016-01-01

The determination of fibrinogen levels is one of the most important coagulation measurements in medicine. It plays a crucial part in diagnostic and therapeutic decisions, often associated with time-critical conditions. The commonly used measurement is the Clauss fibrinogen assay (CFA) where plasma is activated by thrombin reagent and which is conducted by mechanical/turbidimetric devices. As quartz crystal microbalance sensors with dissipation (QCM-D) based devices have a small footprint, can be operated easily and allow measurements independently from sample transportation time, laboratory location, availability and opening hours, they offer a great opportunity to complement laboratory CFA measurements. Therefore, the objective of the work was to (1) transfer the CFA to the QCM-D method; (2) develop an easy, time- and cost-effective procedure and (3) compare the results with references. Different sensor coatings (donor’s own plasma; gold surface) and different QCM-D parameters (frequency signal shift; its calculated turning point; dissipation signal shift) were sampled. The results demonstrate the suitability for a QCM-D-based CFA in physiological fibrinogen ranges. Results were obtained in less than 1 min and in very good agreement with a standardized reference (Merlin coagulometer). The results provide a good basis for further investigation and pave the way to a possible application of QCM-D in clinical and non-clinical routine in the medical field. PMID:26927107

Analysis of the safety and pharmacodynamics of human fibrinogen concentrate in animals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beyerle, Andrea, E-mail: andrea.beyerle@cslbehring.com; Nolte, Marc W.; Solomon, Cristina

Fibrinogen, a soluble 340 kDa plasma glycoprotein, is critical in achieving and maintaining hemostasis. Reduced fibrinogen levels are associated with an increased risk of bleeding and recent research has investigated the efficacy of fibrinogen concentrate for controlling perioperative bleeding. European guidelines on the management of perioperative bleeding recommend the use of fibrinogen concentrate if significant bleeding is accompanied by plasma fibrinogen levels less than 1.5–2.0 g/l. Plasma-derived human fibrinogen concentrate has been available for therapeutic use since 1956. The overall aim of the comprehensive series of non-clinical investigations presented was to evaluate i) the pharmacodynamic and pharmacokinetic characteristics and ii)more » the safety and tolerability profile of human fibrinogen concentrate Haemocomplettan P® (RiaSTAP®). Pharmacodynamic characteristics were assessed in rabbits, pharmacokinetic parameters were determined in rabbits and rats and a safety pharmacology study was performed in beagle dogs. Additional toxicology tests included: single-dose toxicity tests in mice and rats; local tolerance tests in rabbits; and neoantigenicity tests in rabbits and guinea pigs following the introduction of pasteurization in the manufacturing process. Human fibrinogen concentrate was shown to be pharmacodynamically active in rabbits and dogs and well tolerated, with no adverse events and no influence on circulation, respiration or hematological parameters in rabbits, mice, rats and dogs. In these non-clinical investigations, human fibrinogen concentrate showed a good safety profile. This data adds to the safety information available to date, strengthening the current body of knowledge regarding this hemostatic agent. - Highlights: • A comprehensive series of pre-clinical investigations of human fibrinogen concentrate. • Human fibrinogen concentrate was shown to be pharmacodynamically active. • Human fibrinogen concentrate was well tolerated, with no adverse events. • Overall, human fibrinogen concentrate demonstrated a good safety profile. • This data adds to the safety information available to date on this hemostatic agent.« less

Clumping factor B, a fibrinogen-binding MSCRAMM (microbial surface components recognizing adhesive matrix molecules) adhesin of Staphylococcus aureus, also binds to the tail region of type I cytokeratin 10.

PubMed

Walsh, Evelyn J; O'Brien, Louise M; Liang, Xiaowen; Hook, Magnus; Foster, Timothy J

2004-12-03

The primary habitat of Staphylococcus aureus in humans is the moist squamous epithelium of the anterior nares. We showed previously that S. aureus adheres to desquamated epithelial cells and that clumping factor B (ClfB), a surface-located MSCRAMM (microbial surface components recognizing adhesive matrix molecules) known for its ability to bind to the alpha-chain of fibrinogen, is partly responsible (O'Brien, L. M., Walsh, E. J., Massey, R. C., Peacock, S. J., and Foster, T. J. (2002) Cell. Microbiol. 4, 759-770). We identified cytokeratin 10 (K10) as the ligand recognized by ClfB. Here we have shown that purified recombinant human and murine K10 immobilized on a plastic surface supports adherence of S. aureus in a ClfB-dependent manner. Furthermore, the recombinant A domain of ClfB (rClfB 45-542) bound to immobilized K10 dose-dependently and saturably. Subdomains of human and murine K10 were expressed and purified. The N-terminal head domain (residues 1-145) did not support the binding of rClfB or adherence of S. aureus ClfB+. In contrast, the C-terminal tail domains (human rHK10 452-593, mouse rMK10 454-570) promoted avid binding and adherence. Isothermal titration microcalorimetry and intrinsic tryptophan fluorescence experiments gave dissociation constants for rClfB 45-542 binding to rMK10 454-570 of 1.4 and 1.7 microM, respectively. The tail region of K10 is composed largely of quasi-repeats of Tyr-(Gly/Ser)n. A synthetic peptide corresponding to a typical glycine loop (YGGGSSGGGSSGGY; Y-Y loop peptide) inhibited the adherence of S. aureus ClfB+ to immobilized MK10 to a level of 80%, whereas control peptides had no effect. The KD of rClfB 45-542 for the Y-Y loop peptide was 5.3 microm by intrinsic tryptophan fluorescence. Thus ClfB binds to the glycine loop region of the tail domain of keratin 10 where there are probably multiple binding sites. Binding is discussed in the context of the dock-lock-latch model for MSCRAMM-ligand interactions. We provide an explanation for the molecular basis for S. aureus adherence to the squamous epithelium and suggest that nasal colonization might be prevented by reagents that inhibit this interaction.

Fibrinogen Vicenza and Genova II: two new cases of congenital dysfibrinogenemia with isolated defect of fibrin monomer polymerization and inhibitory activity on normal coagulation.

PubMed

Rodeghiero, F; Castaman, G C; Dal Belin Peruffo, A; Dini, E; Galletti, A; Barone, E; Gastaldi, G

1987-06-03

Two new cases of congenital dysfibrinogenemia are presented in which defective fibrin monomer polymerization and inhibitory activity on normal coagulation were observed. They have been tentatively called fibrinogen Vicenza and Genova II. The first was discovered in a family with mild bleeding diathesis, the second in an asymptomatic family. In almost all reported cases of fibrinogens with defective fibrin monomer polymerization, additional functional or structural defects have been detected. In our cases, on the contrary, detailed investigations failed to show any other abnormality. Fibrinogen Genova II is apparently identical to fibrinogen Baltimore IV, whereas fibrinogen Vicenza is similar to fibrinogen Troyes and Genova I, but also exerts an evident inhibitory activity on normal coagulation and differs from fibrinogen Genova II and Baltimore IV showing a different kinetic pattern of fibrin monomer polymerization.

Antibody-Based Therapy for Enterococcal Catheter-Associated Urinary Tract Infections.

PubMed

Flores-Mireles, Ana L; Walker, Jennifer N; Potretzke, Aaron; Schreiber, Henry L; Pinkner, Jerome S; Bauman, Tyler M; Park, Alyssa M; Desai, Alana; Hultgren, Scott J; Caparon, Michael G

2016-10-25

Gram-positive bacteria in the genus Enterococcus are a frequent cause of catheter-associated urinary tract infection (CAUTI), a disease whose treatment is increasingly challenged by multiantibiotic-resistant strains. We have recently shown that E. faecalis uses the Ebp pilus, a heteropolymeric surface fiber, to bind the host protein fibrinogen as a critical step in CAUTI pathogenesis. Fibrinogen is deposited on catheters due to catheter-induced inflammation and is recognized by the N-terminal domain of EbpA (EbpA NTD ), the Ebp pilus's adhesin. In a murine model, vaccination with EbpA NTD confers significant protection against CAUTI. Here, we explored the mechanism of protection using passive transfer of immune sera to show that antisera blocking EbpA NTD -fibrinogen interactions not only is prophylactic but also can act therapeutically to reduce bacterial titers of an existing infection. Analysis of 55 clinical CAUTI, bloodstream, and gastrointestinal isolates, including E. faecalis, E. faecium, and vancomycin-resistant enterococci (VRE), revealed a diversity of levels of EbpA expression and fibrinogen-binding efficiency in vitro Strikingly, analysis of 10 strains representative of fibrinogen-binding diversity demonstrated that, irrespective of EbpA levels, EbpA NTD antibodies were universally protective. The results indicate that, despite diversity in levels of fibrinogen binding, strategies that target the disruption of EbpA NTD -fibrinogen interactions have considerable promise for treatment of CAUTI. Urinary catheterization is a routine medical procedure, and it has been estimated that 30 million Foley catheters are used annually in the United States. Importantly, placement of a urinary catheter renders the patient susceptible to developing a catheter-associated urinary tract infection, accounting for 1 million cases per year. Additionally, these infections can lead to serious complications, including bloodstream infection and death. Enterococcus strains are a common cause of these infections, and management of enterococcal infections has been more difficult in recent years due to the development of antibiotic resistance and the ability of strains to disseminate, resulting in a major threat in hospital settings. In this study, we developed an antibiotic-sparing treatment that is effective against diverse enterococcal isolates, including vancomycin-resistant enterococci, during catheter-associated urinary tract infections. Copyright © 2016 Flores-Mireles et al.

Time and force dependence of the rupture of glycoprotein IIb-IIIa-fibrinogen bonds between latex spheres.

PubMed Central

Goldsmith, H L; McIntosh, F A; Shahin, J; Frojmovic, M M

2000-01-01

We studied the shear-induced breakup of doublets of aldehyde/sulfate (A/S) latex spheres covalently linked with purified platelet GPIIb-IIIa receptor, and cross-linked by fibrinogen. Flow cytometry with fluorescein isothiocyanate-fibrinogen showed than an average of 22,500 molecules of active GPIIb-IIIa were captured per sphere, with a mean K(d) = 56 nM for fibrinogen binding. The spheres, suspended in buffered 19% Ficoll 400 containing 120 or 240 pM fibrinogen, were subjected to Couette flow in a counter-rotating cone-plate rheoscope. Doublets, formed by two-body collisions at low shear rate (G = 8 s(-1)) for < or =15 min, were subjected to shear stress from 0.6 to 2.9 Nm(-2), their rotations recorded until they broke up or were lost to view. Although breakup was time dependent, occurring mostly in the first 2 rotations after the onset of shear, the percentage of doublets broken up after 10 rotations were almost independent of normal hydrodynamic force, F(n): at 240 pN, 15.6, 16.0, and 17.0% broke up in the force range 70-150 pN, 150-230 pN, and 230-310 pN. Unexpectedly, at both [fibrinogen], the initial rate of breakup was highest in the lowest force range, and computer simulation using a stochastic model of breakup was unable to simulate the time course of breakup. When pre-sheared at low G for >15 min, no doublets broke up within 10 rotations at 70 < F(n) < 310 pN; it required >3 min shear (>1110 rotations) at F(n) = 210 pN for significant breakup to occur. Other published work has shown that binding of fibrinogen to GPIIb-IIIa immobilized on plane surfaces exhibits an initial fast reversible process with relative low affinity succeeded by transformation of GPIIb-IIIa to a stable high-affinity complex. We postulate that most doublet breakups observed within 10 rotations were from a population of young doublets having low numbers of bonds, by dissociation of the initial receptor complex relatively unresponsive to force. The remaining, older doublets with GPIIb-IIIa in the high-affinity complex were not broken up in the time or range of forces studied. PMID:10692309

Rapid measurement of fibrinogen concentration in whole blood using a steel ball coagulometer

PubMed Central

Schlimp, Christoph J.; Khadem, Anna; Klotz, Anton; Solomon, Cristina; Hochleitner, Gerald; Ponschab, Martin; Redl, Heinz; Schöchl, Herbert

2015-01-01

BACKGROUND Fibrinogen plays a key role in hemostasis and is the first coagulation factor to reach critical levels in bleeding patients. Current European guidelines on the management of traumatic or perioperative bleeding recommend fibrinogen supplementation at specific threshold levels. Whole blood viscoelastic tests provide fast evaluation of fibrin deficits. Fast measurement of plasma fibrinogen concentration is not yet available. We investigated a method to rapidly determine whole blood fibrinogen concentration using standard Clauss assays and a steel ball coagulometer and provide an estimate of the “plasma-equivalent” fibrinogen concentration within minutes by adjustment of the measured whole blood fibrinogen concentration with a quickly measureable hemoglobin-derived hematocrit. METHODS The feasibility of this approach was tested with a Clauss assay using multiple porcine fresh blood samples obtained during in vivo bleeding, hemodilution, and after treatment with hemostatic therapy. Two different Clauss assays were then tested using multiple human volunteers’ blood samples diluted in vitro and supplemented with fibrinogen concentrate. Comparative measurements with fibrin-based thromboelastometry tests were performed. RESULTS Regression and Bland-Altman analyses of derived “plasma-equivalent” fibrinogen and measured plasma fibrinogen concentration was excellent in porcine and human blood samples, especially in the ranges relevant to traumatic or perioperative bleeding. CONCLUSION Fast whole blood fibrinogen measurements could be considered as an alternative to plasma fibrinogen measurement for acute bleeding management in trauma and perioperative care settings. Further studies are needed to prove this concept and determine the turnaround times for its clinical application in emergency departments and operating theaters. PMID:25742256

Multielement surface plasmon resonance immunosensor for monitoring of blood circulation system

NASA Astrophysics Data System (ADS)

Kostyukevych, Sergey A.; Kostyukevych, Kateryna V.; Khristosenko, Roman V.; Lysiuk, Viktor O.; Koptyukh, Anastasiya A.; Moscalenko, Nadiya L.

2017-12-01

The problems related to the development of a multielement immunosensor device with the prism type of excitation of a surface plasmon resonance in the Kretschmann configuration and with the scanning of the incidence angle of monochromatic light aimed at the reliable determination of the levels of three molecular markers of the system of hemostasis (fibrinogen, soluble fibrin, and D-dimer) are considered. We have analyzed the influence of a technology for the production of a gold coating, modification of its surface, and noise effects on the enhancement of sensitivity and stability of the operation of devices. A means of oriented immobilization of monoclonal antibodies on the surface of gold using a multilayer film of copper aminopentacyanoferrate is developed. For the model proteins of studied markers, the calibrating curves (maximum sensitivity of 0.5 μg/ml) are obtained, and the level of fibrinogen in blood plasma of donors is determined. A four-channel modification of the device with an application of a reference channel for comparing the elimination of the noise of temperature fluctuations has been constructed. This device allows one to execute the express-diagnostics of prethrombotic states and the monitoring of the therapy of diseases of the blood circulation system.

Plasma-deposited tetraglyme surfaces greatly reduce total blood protein adsorption, contact activation, platelet adhesion, platelet procoagulant activity, and in vitro thrombus deposition.

PubMed

Cao, Lan; Chang, Mark; Lee, Chi-Ying; Castner, David G; Sukavaneshvar, Sivaprasad; Ratner, Buddy D; Horbett, Thomas A

2007-06-15

The ability of tetraethylene glycol dimethyl ether (tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Willebrand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagulant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that tetraglyme surfaces strongly resisted the adsorption of all proteins from human plasma. The clotting time in the presence of tetraglyme surfaces was lengthened compared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on tetraglyme-coated materials, compared with uncoated and Biospan-coated glass slides. In the in vitro disturbed blood flow model, tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme-coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood compatibility of plasma-deposited tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions. (c) 2007 Wiley Periodicals, Inc.

The adhesion of blood platelets on fibrinogen surface: comparison of two biochemical microplate assays.

PubMed

Vanícková, Martina; Suttnar, Jirí; Dyr, Jan Evangelista

2006-11-01

The biocompatibility of materials is frequently assessed by blood platelet adhesion, since platelet adhesion plays a considerable role in blood interaction with artificial surfaces. Blood platelets adhesion is an essential event in haemostatic and thrombotic processes. The aim of this study was to simultaneously compare simple biochemical assays widely used for evaluation of platelet static adhesion based on the determination of enzymatic activity of either lactate dehydrogenase (LDH) or acid phosphatase (ACP) in lysates of adhered platelets. Adhesion of platelets from platelet-rich plasma and washed platelets activated by either ADP or thrombin on surfaces covered with fibrinogen and well defined fibrin was studied. The results demonstrated that the amounts of adhered platelets estimated by the LDH method were significantly lower as compared with the amount obtained by ACP method. LDH but not ACP release from platelets during adhesion was shown to take place. It suggests that the LDH method should be used rather as an assay of platelet integrity. The ACP method is much more suitable for quantitative determination of platelet adhesion especially in the development and evaluation of haemocompatibility of new biomaterials.

A liver enhancer in the fibrinogen gene cluster.

PubMed

Fort, Alexandre; Fish, Richard J; Attanasio, Catia; Dosch, Roland; Visel, Axel; Neerman-Arbez, Marguerite

2011-01-06

The plasma concentration of fibrinogen varies in the healthy human population between 1.5 and 3.5 g/L. Understanding the basis of this variability has clinical importance because elevated fibrinogen levels are associated with increased cardiovascular disease risk. To identify novel regulatory elements involved in the control of fibrinogen expression, we used sequence conservation and in silico-predicted regulatory potential to select 14 conserved noncoding sequences (CNCs) within the conserved block of synteny containing the fibrinogen locus. The regulatory potential of each CNC was tested in vitro using a luciferase reporter gene assay in fibrinogen-expressing hepatoma cell lines (HuH7 and HepG2). 4 potential enhancers were tested for their ability to direct enhanced green fluorescent protein expression in zebrafish embryos. CNC12, a sequence equidistant from the human fibrinogen alpha and beta chain genes, activates strong liver enhanced green fluorescent protein expression in injected embryos and their transgenic progeny. A transgenic assay in embryonic day 14.5 mouse embryos confirmed the ability of CNC12 to activate transcription in the liver. While additional experiments are necessary to prove the role of CNC12 in the regulation of fibrinogen, our study reveals a novel regulatory element in the fibrinogen locus that is active in the liver and may contribute to variable fibrinogen expression in humans.

Creation of fibrinogen-enhanced experimental blood clots to evaluate mechanical thrombectomy devices for treatment of acute stroke: an in vitro study.

PubMed

Luo, Zhong Hua; Chung, Alex; Choi, Gibok; Lin, Yih Huie; Uchida, Barry T; Pavcnik, Dusan; Loriaux, Marc M; Nesbit, Gary M; Keller, Frederick S; Rösch, Josef

2012-08-01

To explore if addition of fibrinogen to the most commonly used experimental blood clot (EBC) model would improve its mechanical properties and histologic structure. Fresh blood from three swine was used to create four EBC types. The Gralla model of thrombin-induced barium-opaque EBC served as the control. In three other EBC types, 50 mg, 100 mg, and 200 mg of bovine fibrinogen were added. Evaluation of EBCs was done with three tests: manual elongation, injection through an 8-F catheter, and an opacity test. Thirty EBCs of each type were evaluated with each test. Histologic evaluation followed. The control EBCs had low tensile strength and broke at 165% elongation. However, they were elastic and returned to their original length after catheter injection. The EBCs with fibrinogen exhibited increased tensile strength with increasing fibrinogen doses and withstood elongation to 213% (P < .01). Their elasticity decreased with increased tensile strength, and they remained elongated after catheter injection (P < .01 for EBC with 100 mg and 200 mg fibrinogen). Histologic examination showed more thorough mixing of blood with barium and a significantly increased amount of fibrin after addition of fibrinogen. Addition of fibrinogen to a Gralla EBC model changes its mechanical properties proportionately to the fibrinogen dose. Fibrinogen increases EBC tensile strength but decreases its elasticity. Fibrinogen also significantly increases the binding of blood cells with fibrin on histologic slides. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

Tracheal anastomosis using indocyanine green dye enhanced fibrinogen with a near-infrared diode laser

NASA Astrophysics Data System (ADS)

Auteri, Joseph S.; Jeevanandam, Valluvan; Oz, Mehmet C.; Libutti, Steven K.; Kirby, Thomas J.; Smith, Craig R.; Treat, Michael R.

1990-06-01

A major obstacle to lung transplantation and combined heart- lung transplantation is dehiscence of the tracheobronchial anastomosis. We explored the possibility of laser welded anastomoses in canine tracheas in vivo. Laser anastomoses were performed on three-quarter circumferential anterior tracheotomies. A continous wave diode laser (808 +1 nm) at a power density of 9.6 watts/cm was used. Human fibrinogen was mixed with indocyanine green dye (ICG, max absorbance 805 nm) and applied to the anastomosis site prior to laser exposure. Animals were sacrificed at 0, 21 and 28 days post-operatively. At sacrifice weld bursting pressures were measured by raising intratracheal pressure using forced ventilation via an endotracheal tube. Sutured and laser welded anastomoses had similar bursting pressures, and exhibited satisfactory histologic evidence of healing. However, compared to polypropylene sutured controls, the laser welded anastomoses exhibited less peritracheal inflammatory reaction and showed visibly smoother luminal surfaces at 21 and 28 days post- operatively. Tracheal anastomosis using ICG dye enhanced fibrinogen combined with the near-infrared diode laser is a promising extension of the technology of laser tissue fusion and deserves further study.

In vitro pleural fluid clottability and fibrinogen content.

PubMed

Glauser, F L; Otis, P T; Levine, R I; Smith, W R

1975-08-01

Twenty-three specimens of pleural fluid from 23 patients were examined for quantitative fibrinogen, total protein levels, and for clottability in vitro using the recalcification time. Of the 19 specimens of pleural fluid from patients without loculation, 11 (seven exudates) had no detectable fibrinogen; another 8 (six exudates) had a mean fibrinogen level of 55.0 +/- 10.2 mg percent, and a mean recalcification time of 19.4 +/- 2.6 minutes. The pleural fluids from the four patients with loculation had no detectable fibrinogen. The only fluids containing fibrinolytic activity were from the nonloculated non-fibrinogen-containing group. No correlation existed between pleural fluid/plasma total protein ratios and pleural fluid/plasma fibrinogen ratios. In vitro clottability in this study did not reflect the in vivo tendency for coagulation and loculation.

Fibrinogen Nový Jicín and Praha II: cases of hereditary Aalpha 16 Arg-->Cys and Aalpha 16 Arg-->His dysfibrinogenemia.

PubMed

Kotlín, Roman; Chytilová, Martina; Suttnar, Jirí; Riedel, Tomás; Salaj, Peter; Blatný, Jan; Santrůcek, Jirí; Klener, Pavel; Dyr, Jan E

2007-01-01

Various dysfibrinogenemias have been described worldwide. This paper describes two new cases of dysfibrinogenemia identified in the Czech Republic. The proposita of fibrinogen Nový Jicín, a 12-year-old girl, presented with hemorrhagic complications, low Clauss fibrinogen level (0.3 g/l) and prolonged both thrombin (70.8 s) and reptilase (>180 s) time. Her mother and sister both presented with normal coagulation tests, normal fibrinogen level and reported no history of bleeding. The carriers of the fibrinogen Praha II were a 31-year-old man and his 11-year-old daughter. They both presented with low fibrinogen Clauss level (0.88 g/l) and prolonged thrombin and reptilase time. To identify the genetic mutation responsible for these dysfibrinogens, genomic DNA extracted from the blood was analyzed. The presence of the mutant chains in the circulation was determined by MALDI-TOF mass spectroscopy. Scanning electron micrographs of the patients' fibrin clots were obtained. The kinetics of fibrinopeptide release and fibrin polymerization were impaired for both fibrinogen Nový Jicín and Praha II. DNA sequencing showed heterogeneous fibrinogen Aalpha R16C mutation in the fibrinogen Nový Jicín case and heterogeneous fibrinogen Aalpha R16H in the fibrinogen Praha II case. The mutant chains were found to be expressed to the circulation by MALDI-TOF mass spectroscopy. Scanning electron micrographs of the patient's fibrin clot were found to be abnormal. The case of dysfibrinogenemia Aalpha R16C-fibrinogen Nový Jicín and the case of dysfibrinogenemia Aalpha R16H were found by routine coagulation testing and were genetically identified.

Fibrinogen deficiency suppresses the development of early and delayed radiation enteropathy

PubMed Central

Wang, Junru; Pathak, Rupak; Garg, Sarita; Hauer-Jensen, Martin

2017-01-01

AIM To determine the mechanistic role of fibrinogen, a key regulator of inflammation and fibrosis, in early and delayed radiation enteropathy. METHODS Fibrinogen wild-type (Fib+/+), fibrinogen heterozygous (Fib+/-), and fibrinogen knockout (Fib-/-) mice were exposed to localized intestinal irradiation and assessed for early and delayed structural changes in the intestinal tissue. A 5-cm segment of ileum of mice was exteriorized and exposed to 18.5 Gy of x-irradiation. Intestinal tissue injury was assessed by quantitative histology, morphometry, and immunohistochemistry at 2 wk and 26 wk after radiation. Plasma fibrinogen level was measured by enzyme-linked immunosorbent assay. RESULTS There was no difference between sham-irradiated Fib+/+ and Fib+/- mice in terms of fibrinogen concentration in plasma and intestinal tissue, intestinal histology, morphometry, intestinal smooth muscle cell proliferation, and neutrophil infiltration. Therefore, Fib+/- mice were used as littermate controls. Unlike sham-irradiated Fib+/+ and Fib+/- mice, no fibrinogen was detected in the plasma and intestinal tissue of sham-irradiated Fib-/- mice. Moreover, fibrinogen level was not elevated after irradiation in the intestinal tissue of Fib-/- mice, while significant increase in intestinal fibrinogen level was noticed in irradiated Fib+/+ and Fib+/- mice. Importantly, irradiated Fib-/- mice exhibited substantially less overall intestinal structural injury (RIS, P = 0.000002), intestinal wall thickness (P = 0.003), intestinal serosal thickness (P = 0.009), collagen deposition (P = 0.01), TGF-β immunoreactivity (P = 0.03), intestinal smooth muscle proliferation (P = 0.046), neutrophil infiltration (P = 0.01), and intestinal mucosal injury (P = 0.0003), compared to irradiated Fib+/+ and Fib+/- mice at both 2 wk and 26 wk. CONCLUSION These data demonstrate that fibrinogen deficiency directly attenuates development of early and delayed radiation enteropathy. Fibrinogen could be a novel target in treating intestinal damage. PMID:28765691

The Effects of Hypothermia on Fibrinogen Metabolism and Coagulation Function in Swine

DTIC Science & Technology

2007-01-01

blanket with circulating water at 48C. Fibrinogen synthesis and breakdown were quantified using a 6-hour stable isotope infusion with subsequent gas...tion and sufficient fibrinogen in the circulation . The effects of hypothermia on the coagulation process have been estimated 0026-0495/$ – see front...and released to circulation in 1 hour. Fibrinogen breakdown rate is the total loss of fibrinogen (expressed as milligram per kilogram of body weight

Fibrinogen and associated risk factors in a high-risk population: urban Indigenous Australians, the DRUID Study.

PubMed

Maple-Brown, Louise J; Cunningham, Joan; Nandi, Nirjhar; Hodge, Allison; O'Dea, Kerin

2010-10-29

Epidemiological evidence suggests that fibrinogen and CRP are associated with coronary heart disease risk. High CRP in Indigenous Australians has been reported in previous studies including our 'Diabetes and Related diseases in Urban Indigenous population in Darwin region' (DRUID) Study. We studied levels of fibrinogen and its cross-sectional relationship with traditional and non-traditional cardiovascular risk factors in an urban Indigenous Australian cohort. Fibrinogen data were available from 287 males and 628 females (aged ≥ 15 years) from the DRUID study. Analysis was performed for associations with the following risk factors: diabetes, HbA1c, age, BMI, waist circumference, waist-hip ratio, total cholesterol, triglyceride, HDL cholesterol, C-reactive protein, homocysteine, blood pressure, heart rate, urine ACR, smoking status, alcohol abstinence. Fibrinogen generally increased with age in both genders; levels by age group were higher than those previously reported in other populations, including Native Americans. Fibrinogen was higher in those with than without diabetes (4.24 vs 3.56 g/L, p < 0.001). After adjusting for age and sex, the following were significantly associated with fibrinogen: BMI, waist, waist-hip ratio, systolic blood pressure, heart rate, fasting triglycerides, HDL cholesterol, HbA1c, CRP, ACR and alcohol abstinence. On multivariate regression (age and sex-adjusted) CRP and HbA1c were significant independent predictors of fibrinogen, explaining 27% of its variance; CRP alone explained 25% of fibrinogen variance. On factor analysis, both CRP and fibrinogen clustered with obesity in women (this factor explained 20% of variance); but in men, CRP clustered with obesity (factor explained 18% of variance) whilst fibrinogen clustered with HbA1c and urine ACR (factor explained 13% of variance). Fibrinogen is associated with traditional and non-traditional cardiovascular risk factors in this urban Indigenous cohort and may be a useful biomarker of CVD in this high-risk population. The apparent different associations of fibrinogen with cardiovascular disease risk markers in men and women should be explored further.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kielmas, Martyna; Szewczuk, Zbigniew; Stefanowicz, Piotr, E-mail: Piotr.stefanowicz@chem.uni.wroc.pl

Highlights: •The glycation of fibrinogen was investigated by isotopic labeling method. •The potential glycation sites in fibrinogen were identified. •Human serum albumin (HSA) inhibits the glycation of fibrinogen. •The effect of HSA on fibrinogen glycation is sequence-dependent. -- Abstract: Although in vivo glycation proceeds in complex mixture of proteins, previous studies did not take in consideration the influence of protein–protein interaction on Maillard reaction. The aim of our study was to test the influence of human serum albumin (HSA) on glycation of fibrinogen. The isotopic labeling using [{sup 13}C{sub 6}] glucose combined with LC-MS were applied as tool for identificationmore » possible glycation sites in fibrinogen and for evaluation the effect of HSA on the glycation level of selected amino acids in fibrinogen. The obtained data indicate that the addition of HSA protects the fibrinogen from glycation. The level of glycation in presence of HSA is reduced by 30–60% and depends on the location of glycated residue in sequence of protein.« less

A novel fibrinogen variant--Liberec: dysfibrinogenaemia associated with gamma Tyr262Cys substitution.

PubMed

Kotlín, Roman; Sobotková, Alzbeta; Suttnar, Jirí; Salaj, Peter; Walterová, Lenka; Riedel, Tomás; Reicheltová, Zuzana; Dyr, Jan Evangelista

2008-08-01

A 22-yr-old woman had abnormal preoperative coagulation test results and congenital dysfibrinogenaemia was suspected. The patient from Liberec (Czech Republic) had a low fibrinogen plasma level as determined by Clauss method, normal fibrinogen level as determined by immunoturbidimetrical method, and prolonged thrombin time. To identify the genetic mutation responsible for this dysfibrinogen, genomic DNA extracted from the blood was analysed. Fibrin polymerisation measurement, kinetics of fibrinopeptide release, fibrinogen clottability measurement and scanning electron microscopy were performed. DNA sequencing showed the heterozygous fibrinogen gamma Y262C mutation. Kinetics of fibrinopeptide release was normal, however fibrin polymerisation was impaired. Fibrinogen clottability measurement showed that only about 45% molecules of fibrinogen are involved in the clot formation. Scanning electron microscopy revealed thicker fibres, which were significantly different from the normal control. A case of dysfibrinogenaemia, found by routine coagulation testing, was genetically identified as a novel fibrinogen variant (gamma Y262C) that has been named Liberec.

Does fibrinogen add to prediction of cardiovascular disease? Results from the Scottish Heart Health Extended Cohort Study.

PubMed

Woodward, Mark; Tunstall-Pedoe, Hugh; Rumley, Ann; Lowe, Gordon D O

2009-08-01

Plasma fibrinogen is an established risk factor for cardiovascular disease (CVD), but it has not been established whether it adds predictive value to risk scores. In the Scottish Heart Health Extended Cohort Study, we measured plasma fibrinogen in 13 060 men and women, aged 30-74 years, initially free of CVD. After follow-up for a median of 19.2 years, 2626 subjects had at least one CVD event. After adjusting for classical CVD risk factors and socio-economic status, the hazard ratios (95% confidence interval) for a one unit (g/l) increase in plasma fibrinogen were 1.09 (1.02, 1.16) for men and 1.10 (1.02, 1.19) for women. Although fibrinogen added significantly to the discrimination of the Framingham risk score for women, it failed to do so for men. Fibrinogen did not add significantly to the ASSIGN risk score. Fibrinogen added between 1.3% and 3.2% to the classification of CVD status by the existing risk scores. We conclude that the added value of fibrinogen to two currently used risk scores is low; hence population screening with fibrinogen for this purpose is unlikely to be clinically useful or cost-effective.

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fibrinogen/fibrin degradation products assay. 864.7320 Section 864.7320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....7320 Fibrinogen/fibrin degradation products assay. (a) Identification. A fibrinogen/fibrin degradation...

A novel natural mutation AαPhe98Ile in the fibrinogen coiled-coil affects fibrinogen function.

PubMed

Riedelová-Reicheltová, Zuzana; Kotlín, Roman; Suttnar, Jiří; Geierová, Véra; Riedel, Tomáš; Májek, Pavel; Dyr, Jan Evangelista

2014-01-01

The aim of this study was to investigate the structure and function of fibrinogen obtained from a patient with normal coagulation times and idiopathic thrombophilia. This was done by SDS-PAGE and DNA sequence analyses, scanning electron microscopy, fibrinopeptide release, fibrin polymerisation initiated by thrombin and reptilase, fibrinolysis, and platelet aggregometry. A novel heterozygous point mutation in the fibrinogen Aα chain, Phe98 to Ile, was found and designated as fibrinogen Vizovice. The mutation, which is located in the RGDF sequence (Aα 95-98) of the fibrinogen coiled-coil region, significantly affected fibrin clot morphology. Namely, the clot formed by fibrinogen Vizovice contained thinner and curled fibrin fibers with reduced length. Lysis of the clots prepared from Vizovice plasma and isolated fibrinogen were found to be impaired. The lysis rate of Vizovice clots was almost four times slower than the lysis rate of control clots. In the presence of platelets agonists the mutant fibrinogen caused increased platelet aggregation. The data obtained show that natural mutation of Phe98 to Ile in the fibrinogen Aα chain influences lateral aggregation of fibrin protofibrils, fibrinolysis, and platelet aggregation. They also suggest that delayed fibrinolysis, together with the abnormal fibrin network morphology and increased platelet aggregation, may be the direct cause of thrombotic complications in the patient associated with pregnancy loss.

The preoperative plasma fibrinogen level is an independent prognostic factor for overall survival of breast cancer patients who underwent surgical treatment.

PubMed

Wen, Jiahuai; Yang, Yanning; Ye, Feng; Huang, Xiaojia; Li, Shuaijie; Wang, Qiong; Xie, Xiaoming

2015-12-01

Previous studies have suggested that plasma fibrinogen contributes to tumor cell proliferation, progression and metastasis. The current study was performed to evaluate the prognostic relevance of preoperative plasma fibrinogen in breast cancer patients. Data of 2073 consecutive breast cancer patients, who underwent surgery between January 2002 and December 2008 at the Sun Yat-sen University Cancer Center, were retrospectively evaluated. Plasma fibrinogen levels were routinely measured before surgeries. Participants were grouped by the cutoff value estimated by the receiver operating characteristic (ROC) curve analysis. Overall survival (OS) was assessed using Kaplan-Meier analysis, and multivariate Cox proportional hazards regression model was performed to evaluate the independent prognostic value of plasma fibrinogen level. The optimal cutoff value of preoperative plasma fibrinogen was determined to be 2.83 g/L. The Kaplan-Meier analysis showed that patients with high fibrinogen levels had shorter OS than patients with low fibrinogen levels (p < 0.001). Multivariate analysis suggested preoperative plasma fibrinogen as an independent prognostic factor for OS in breast cancer patients (HR = 1.475, 95% confidence interval (CI): 1.177-1.848, p = 0.001). Subgroup analyses revealed that plasma fibrinogen level was an unfavorable prognostic parameter in stage II-III, Luminal subtypes and triple-negative breast cancer patients. Elevated preoperative plasma fibrinogen was independently associated with poor prognosis in breast cancer patients and may serve as a valuable parameter for risk assessment in breast cancer patients. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The fibrous form of intracellular inclusion bodies in recombinant variant fibrinogen-producing cells is specific to the hepatic fibrinogen storage disease-inducible variant fibrinogen.

PubMed

Arai, Shinpei; Ogiwara, Naoko; Mukai, Saki; Takezawa, Yuka; Sugano, Mitsutoshi; Honda, Takayuki; Okumura, Nobuo

2017-06-01

Fibrinogen storage disease (FSD) is a rare disorder that is characterized by the accumulation of fibrinogen in hepatocytes and induces liver injury. Six mutations in the γC domain (γG284R, γT314P, γD316N, the deletion of γG346-Q350, γG366S, and γR375W) have been identified for FSD. Our group previously established γ375W fibrinogen-producing Chinese hamster ovary (CHO) cells and observed aberrant large granular and fibrous forms of intracellular inclusion bodies. The aim of this study was to investigate whether fibrous intracellular inclusion bodies are specific to FSD-inducible variant fibrinogen. Thirteen expression vectors encoding the variant γ-chain were stably or transiently transfected into CHO cells expressing normal fibrinogen Aα- and Bβ-chains or HuH-7 cells, which were then immunofluorescently stained. Six CHO and HuH-7 cell lines that transiently produced FSD-inducible variant fibrinogen presented the fibrous (3.2-22.7 and 2.1-24.5%, respectively) and large granular (5.4-25.5 and 7.7-23.9%) forms of intracellular inclusion bodies. Seven CHO and HuH-7 cell lines that transiently produced FSD-non-inducible variant fibrinogen only exhibit the large granular form. These results demonstrate that transiently transfected variant fibrinogen-producing CHO cells and inclusion bodies of the fibrous form may be useful in non-invasive screening for FSD risk factors for FSD before its onset.

Fibrinogen concentration and its role in CVD risk in black South Africans--effect of urbanisation.

PubMed

Pieters, Marlien; de Maat, Moniek P M; Jerling, Johann C; Hoekstra, Tiny; Kruger, Annamarie

2011-09-01

The aim of this study was to investigate correlates of fibrinogen concentration in black South Africans, as well as its association with cardiovascular disease (CVD) risk and whether urbanisation influences this association. A total of 1,006 rural and 1,004 urban black South Africans from the PURE study were cross-sectionally analysed. The association of fibrinogen with CVD risk was determined by investigating the association of fibrinogen with other CVD risk markers as well as with predicted CVD risk using the Reynolds Risk score. The rural group had a significantly higher fibrinogen concentration than the urban group, despite higher levels of risk factors and increased predicted CVD risk in the urban group. Increased levels of CVD risk factors were, however, still associated with increased fibrinogen concentration. Fibrinogen correlated significantly, but weakly, with overall predicted CVD risk. This correlation was stronger in the urban than in the rural group. Multiple regression analysis showed that a smaller percentage of the variance in fibrinogen is explained by the traditional CVD risk factors in the rural than in the urban group. In conclusion, fibrinogen is weakly associated with CVD risk (predicted overall risk as well with individual risk factors) in black South Africans, and is related to the degree of urbanisation. Increased fibrinogen concentration, in black South Africans, especially in rural areas, is largely unexplained, and likely not strongly correlated with traditional CVD-related lifestyle and pathophysiological processes. This does, however, not exclude the possibility that once increased, the fibrinogen concentration contributes to future development of CVD.

Expanding Cancer Detection Using Molecular Imprinting for a Novel Point-of-Care Diagnostic Device

NASA Astrophysics Data System (ADS)

Yu, Yingjie; Rafailovich, Miriam; Wang, Yantian; Kang, Yeona; Zhang, Lingxi; Rigas, Basil; Division of Gastroenterology, School of Medicine Team

2013-03-01

We propose the use of a potentiometric biosensor that incorporates the efficient and specific molecular imprinting (MI) method with a self-assembled monolayer (SAM). We first tested the biosensor using carcinoembryonic antigen, CEA, a biomarker associated with pancreatic cancer. No change in detection efficiency was observed, indicating that the sensor is able to discriminate for the template analyte even in concentrated solution of similar substances. In addition, we use biosensor to discriminate normal fibrinogen and damaged fibrinogen, which is critical for the detection of bleeding disorder. Computer simulations of the protein structure were performed in order to estimate the changes in morphology and determine the sensitivity of the biosensor to conformational changes in the proteins. We found that even small changes in PH can generate rotation of the surface functional groups. Yet, the results show that only when the detection and imprinting conditions are similar, robust signals occurs. Hence we concluded that both morphology and surface chemistry play a role in the recognition.

Cationic PAMAM Dendrimers Aggressively Initiate Blood Clot Formation

PubMed Central

Jones, Clinton F.; Campbell, Robert A.; Brooks, Amanda E.; Assemi, Shoeleh; Tadjiki, Soheyl; Thiagarajan, Giridhar; Mulcock, Cheyanne; Weyrich, Andrew S.; Brooks, Benjamin D.; Ghandehari, Hamidreza; Grainger, David W.

2012-01-01

Poly(amidoamine) (PAMAM) dendrimers are increasingly studied as model nanoparticles for a variety of biomedical applications, notably in systemic administrations. However, with respect to blood contacting applications, amine-terminated dendrimers have recently been shown to activate platelets and cause a fatal, disseminated intravascular coagulation (DIC)-like condition in mice and rats. We here demonstrate that, upon addition to blood, cationic G7 PAMAM dendrimers induce fibrinogen aggregation, which may contribute to the in vivo DIC-like phenomenon. We demonstrate that amine-terminated dendrimers act directly on fibrinogen in a thrombin-independent manner to generate dense, high-molecular-weight fibrinogen aggregates with minimal fibrin fibril formation. In addition, we hypothesize this clot-like behavior is likely mediated through electrostatic interactions between the densely charged cationic dendrimer surface and negatively charged fibrinogen domains. Interestingly, cationic dendrimers also induced aggregation of albumin, suggesting that many negatively charged blood proteins may be affected by cationic dendrimers. To investigate this further, zebrafish embryos (ZFE) were employed to more specifically determine the speed of this phenomenon and the pathway- and dose-dependency of the resulting vascular occlusion phenotype. These novel findings show that G7 PAMAM dendrimers significantly and adversely impact many blood components to produce rapid coagulation and strongly suggest that these effects are independent of classic coagulation mechanisms. These results also strongly suggest the need to fully characterize amine-terminated PAMAM dendrimers in regards to their adverse effects on both coagulation and platelets, which may contribute to blood toxicity. PMID:23062017

The Primary Role of Fibrinogen-Related Proteins in Invertebrates Is Defense, Not Coagulation

PubMed Central

Hanington, Patrick C.; Zhang, Si-Ming

2010-01-01

In vertebrates, the conversion of fibrinogen into fibrin is an essential process that underlies the establishment of the supporting protein framework required for coagulation. In invertebrates, fibrinogen-domain-containing proteins play a role in the defense response generated against pathogens; however, they do not function in coagulation, suggesting that this role has been recently acquired. Molecules containing fibrinogen motifs have been identified in numerous invertebrate organisms, and most of these molecules known to date have been linked to defense. Moreover, recent genome projects of invertebrate animals have revealed surprisingly high numbers of fibrinogen-like loci in their genomes, suggesting important and perhaps diverse functions of fibrinogen-like proteins in invertebrates. The ancestral role of molecules containing fibrinogen-related domains (FReDs) with immunity is the focus of this review, with emphasis on specific FReDs called fibrinogen-related proteins (FREPs) identified from the schistosome-transmitting mollusc Biomphalaria glabrata. Herein, we outline the range of invertebrate organisms FREPs can be found in, and detail the roles these molecules play in defense and protection against infection. PMID:21063081

In vitro sealing of iatrogenic fetal membrane defects by a collagen plug imbued with fibrinogen and plasma.

PubMed

Engels, A C; Hoylaerts, M F; Endo, M; Loyen, S; Verbist, G; Manodoro, S; DeKoninck, P; Richter, J; Deprest, J A

2013-02-01

We aimed to demonstrate local thrombin generation by fetal membranes, as well as its ability to generate fibrin from fibrinogen concentrate. Furthermore, we aimed to investigate the efficacy of collagen plugs, soaked with plasma and fibrinogen, to seal iatrogenic fetal membrane defects. Thrombin generation by homogenized fetal membranes was measured by calibrated automated thrombography. To identify the coagulation caused by an iatrogenic membrane defect, we analyzed fibrin formation by optical densitometry, upon various concentrations of fibrinogen. The ability of a collagen plug soaked with fibrinogen and plasma was tested in an ex vivo model for its ability to seal an iatrogenic fetal membrane defect. Fetal membrane homogenates potently induced thrombin generation in amniotic fluid and diluted plasma. Upon the addition of fibrinogen concentrate, potent fibrin formation was triggered. Measured by densiometry, fibrin formation was optimal at 1250 µg/mL fibrinogen in combination with 4% plasma. A collagen plug soaked with fibrinogen and plasma sealed an iatrogenic membrane defect about 35% better than collagen plugs without these additives (P = 0.037). These in vitro experiments suggest that the addition of fibrinogen and plasma may enhance the sealing efficacy of collagen plugs in closing iatrogenic fetal membrane defects. © 2013 John Wiley & Sons, Ltd.

Fibrinogen is not elevated in the cerebrospinal fluid of patients with multiple sclerosis

PubMed Central

2011-01-01

Background Elevated plasma fibrinogen levels are a well known finding in acute infectious diseases, acute stroke and myocardial infarction. However its role in the cerebrospinal fluid (CSF) of acute and chronic central (CNS) and peripheral nervous system (PNS) diseases is unclear. Findings We analyzed CSF and plasma fibrinogen levels together with routine parameters in patients with multiple sclerosis (MS), acute inflammatory diseases of the CNS (bacterial and viral meningoencephalitis, BM and VM) and PNS (Guillain-Barré syndrome; GBS), as well as in non-inflammatory neurological controls (OND) in a total of 103 patients. Additionally, MS patients underwent cerebral MRI scans at time of lumbar puncture. CSF and plasma fibrinogen levels were significantly lower in patients with MS and OND patients as compared to patients with BM, VM and GBS. There was a close correlation between fibrinogen levels and albumin quotient (rho = 0.769, p < 0.001) which strongly suggests passive transfer of fibrinogen through the blood-CSF-barrier during acute inflammation. Hence, in MS, the prototype of chronic neuroinflammation, CSF fibrinogen levels were not elevated and could not be correlated to clinical and neuroradiological outcome parameters. Conclusions Although previous work has shown clear evidence of the involvement of fibrinogen in MS pathogenesis, this is not accompanied by increased fibrinogen in the CSF compartment. PMID:22029888

Fibrin network changes in neonates after cardiopulmonary bypass

PubMed Central

Brown, Ashley C.; Hannan, Riley; Timmins, Lucas H.; Fernandez, Janet D.; Barker, Thomas H.; Guzzetta, Nina A.

2016-01-01

Background Quantitative and qualitative differences exist between the hemostatic systems of neonates and adults, among them the presence of ‘fetal’ fibrinogen, a qualitatively dysfunctional form of fibrinogen that exists until one year of age. The consequences of ‘fetal’ fibrinogen on clot structure in neonates, particularly in the context of surgical associated bleeding, have not been well characterized. Here we examine the sequential changes in clotting components and resultant clot structure in a small sample of neonates undergoing cardiac surgery and cardiopulmonary bypass (CPB). Methods Blood samples were collected from neonates (n=10) before surgery, immediately after CPB and following the transfusion of cryoprecipitate (i.e. adult fibrinogen component). Clots were formed from patient samples or purified neonatal and adult fibrinogen. Clot structure was analyzed using confocal microscopy. Results Clots formed from plasma obtained after CPB and after transfusion were more porous than baseline clots. Analysis of clots formed from purified neonatal and adult fibrinogen, demonstrated that at equivalent fibrinogen concentrations, neonatal clots lack three-dimensional structure while adult clots were denser with significant three-dimensional structure. Clots formed from a combination of purified neonatal and adult fibrinogen were less homogenous than those formed from either purified adult or neonatal fibrinogen. Conclusions Our results confirm that significant differences exist in clot structure between neonates and adults, and that neonatal and adult fibrinogen may not integrate well. These findings suggest that differential treatment strategies for neonates should be pursued to reduce the demonstrated morbidity of blood product transfusion. PMID:26914227

Recovery of fibrinogen concentrate after intraosseous application is equivalent to the intravenous route in a porcine model of hemodilution

PubMed Central

Schlimp, Christoph J.; Solomon, Cristina; Keibl, Claudia; Zipperle, Johannes; Nürnberger, Sylvia; Öhlinger, Wolfgang; Redl, Heinz; Schöchl, Herbert

2014-01-01

BACKGROUND Fibrinogen concentrate is increasingly considered as a hemostatic agent for trauma patients experiencing bleeding. Placing a venous access is sometimes challenging during severe hemorrhage. Intraosseous access may be considered instead. Studies of intraosseous infusion of coagulation factor concentrates are limited. We investigated in vivo recovery following intraosseous administration of fibrinogen concentrate and compared the results with intravenous administration. METHODS This study was performed on 12 pigs (mean [SD] body weight, 34.1 [2.8] kg). Following controlled blood loss (35 mL/kg) and fluid replacement with balanced crystalloid solution, intraosseous (n = 6) administration of fibrinogen concentrate (80 mg per kilogram of bodyweight) in the proximal tibia was compared with intravenous (n = 6) administration of the same dose (fibrinogen infusion time approximately 5 minutes in both groups). The following laboratory parameters were assessed: blood cell count, prothrombin time index, activated partial thromboplastin time, and plasma fibrinogen concentration (Clauss assay). Coagulation status was also assessed by thromboelastometry. RESULTS All tested laboratory parameters were comparable between the intraosseous and intravenous groups at baseline, hemodilution, and 30 minutes after fibrinogen concentrate administration. In vivo recovery of fibrinogen was also similar in the two groups (89% [23%] and 91% [22%], respectively). There were no significant between-group differences in any of the thromboelastometric parameters. Histologic examination indicated no adverse effects on the tissue surrounding the intraosseous administration site. CONCLUSION This study suggests that intraosseous administration of fibrinogen concentrate results in a recovery of fibrinogen similar to that of intravenous administration. The intraosseous route of fibrinogen concentrate could be a valuable alternative in situations where intravenous access is not feasible or would be time consuming. LEVEL OF EVIDENCE Prospective, randomized, therapeutic feasibility study in an animal model, level V. PMID:24747454

Evaluation of plasma fibrinogen concentration as a diagnostic indicator of inflammation in red-eared sliders (Trachemys scripta elegans).

PubMed

Moore, A Russell; Allender, Matthew C; Mitchell, Mark A; MacNeill, Amy L

2015-01-15

To critically evaluate plasma fibrinogen concentration as a diagnostic indicator of inflammation in red-eared sliders (Trachemys scripta elegans). Prospective induced-disease model and prospective cross-sectional study. Plasma samples from 12 purpose-bred red-eared sliders and 153 farm-raised red-eared sliders. A modification of the Jacobsson method was developed to measure fibrinogen concentration in platelet-poor plasma from red-eared sliders. Purpose-bred turtles had been inoculated with a ranavirus (n = 4) or sterile PBS solution (8) as part of another study. Farm-raised red-eared sliders were categorized as healthy (n = 138) or overtly ill (15) on the basis of physical examination findings at the time of blood sample collection. Samples from 124 of the 138 healthy red-eared sliders were used to establish a fibrinogen concentration reference interval as measured by the modified Jacobsson method. Fibrinogen concentrations in ranavirus-infected and physically ill turtles were compared with those of healthy turtles to determine whether fibrinogen concentration would be a useful diagnostic indicator of inflammation in red-eared sliders. The modified Jacobsson method was reliably used to measure fibrinogen concentration. The fibrinogen concentration reference interval from healthy reproductively active female red-eared sliders was right skewed. Fibrinogen concentration did not differ significantly between healthy red-eared sliders and ranavirus-infected or overtly ill red-eared sliders. A reference interval for red-eared slider plasma fibrinogen concentration was established and partitioned by sex to account for considerable right skewing observed for females. Fibrinogen concentration was not a useful indicator of inflammation in red-eared sliders with ranavirus infection or other overt illnesses.

Early fibrinogen degradation coagulopathy: a predictive factor of parenchymal hematomas in cerebral rt-PA thrombolysis.

PubMed

Sun, Xuhong; Berthiller, Julien; Trouillas, Paul; Derex, Laurent; Diallo, Laho; Hanss, Michel

2015-04-15

The purpose of this study was to systematically determine the correlations between the post-thrombolytic changes of hemostasis parameters and the occurrence of early intracerebral hemorrhage (ICH). In 72 consecutive patients with cerebral infarcts treated with rt-PA, plasma levels of fibrinogen, plasminogen, alpha2-antiplasmin, factor XIII, fibrin(ogen) degradation products (FDPs) and d-Dimers were measured at baseline, 2 and 24h after thrombolysis. Correlations were studied between the hemostasis events and early (less than 24h) hemorrhagic infarcts (HIs) or parenchymatous hematomas (PH). Of 72 patients, 6 patients (8.3%) had early PHs, 11 (15.3%) had early HIs, and 55 (76.4%) had no bleeding. Early HIs were not linked to any hemostasis parameter at any time. Univariate comparison of patients having early PHs with non-bleeding patients showed hemostasis abnormalities at 2h: high FDP (p=0.01), high Log FDP (p=0.01), low fibrinogen (p=0.01), and low Log fibrinogen (p=0.01). Logistic regression adjusted for age, NIHSS and diabetes confirmed these 2hour predictors: Log FDP (OR: 7.50; CI: 1.26 to 44.61, p=0.03), and Log fibrinogen (OR: 19.32; CI: 1.81 to 205.98, p=0.01). The decrease in fibrinogen less than 2g/L multiplies the odds of early PH by a factor 12.82. An early fibrinogen degradation coagulopathy involving an increase of FDP and a massive consumption of circulating fibrinogen is predictive of early parenchymal hematomas, indicating the occurrence of a particularly intense lysis of circulating fibrinogen. These results, if confirmed by future studies, suggest that early assays of fibrinogen and FDP may be useful in predicting the risk of post-thrombolytic intracerebral hematoma. Copyright © 2015 Elsevier B.V. All rights reserved.

Prognostic value of plasma fibrinogen levels in patients with localized upper tract urothelial carcinoma.

PubMed

Tanaka, Nobuyuki; Kikuchi, Eiji; Matsumoto, Kazuhiro; Hayakawa, Nozomi; Ide, Hiroki; Miyajima, Akira; Nakamura, So; Oya, Mototsugu

2013-05-01

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Upper tract urothelial carcinoma (UTUC) is relatively uncommon, accounting for only ~5% of urothelial malignancies and 10% of all renal tumours. Radical nephroureterectomy (RNU) with bladder cuff excision is the surgical standard of care for treating localized UTUC, but the prognosis for patients who undergo RNU remains poor. Evidence suggests that an interactive relationship exists between haemostatic factors and tumour biology. A number of procoagulant and fibrinolytic factors have been found to be overexpressed in tumours. One of these factors is plasma fibrinogen. Recent studies have shown that elevated pre-therapeutic plasma fibrinogen levels are associated with worse outcome in various malignancies; however, the prognostic value of plasma fibrinogen levels for UTUC has not yet been reported. To the best of our knowledge, this is the first paper to evaluate the prognostic impact of preoperative plasma fibrinogen levels in patients with localized UTUC treated surgically. We believe that the present results may assist in decision-making with respect to the need for lymph node dissection and neoadjuvant chemotherapy. To investigate the prognostic value of plasma fibrinogen levels as a predictor of patient outcome in upper tract urothelial carcinoma (UTUC). A total of 218 patients who underwent radical nephroureterectomy (RNU) for localized UTUC (pTa-4N0M0) were identified between 1995 and 2009. The association between preoperative plasma fibrinogen levels and clinicopathological variables was analysed. Forty-five patients experienced tumour recurrence, and 36 died from disease during the mean follow-up of 51 months. The mean (sd) preoperative plasma fibrinogen level was 362 (103) mg/dL. Kaplan-Meier curves showed that subsequent tumour recurrence was strongly predicted in patients with preoperative plasma fibrinogen levels ≥450 mg/dL, and similar results were observed for cancer-specific survival. On multivariate analysis we found that a preoperative plasma fibrinogen level of ≥450 mg/dL was an independent risk factor for subsequent tumour recurrence and cancer-specific survival. The 5-year recurrence-free survival rate was 56.9% in patients with plasma fibrinogen levels ≥450 mg/dL and 81.5% in patients with plasma fibrinogen levels <450 mg/dL (P < 0.001). The 5-year cancer-specific survival rate was 59.5% in patients with plasma fibrinogen levels of ≥450 mg/dL and 84.8% in patients with plasma fibrinogen levels <450 mg/dL (P < 0.001). On multivariate analysis, controlling for preoperative indicators, a preoperative plasma fibrinogen level of ≥450 mg/dL predicted worse pathological features, such as ≥pT3 disease and positive lymphovascular invasion, in surgical specimens. Preoperative elevated plasma fibrinogen level was an independent predictor for poor survival after RNU and for worse pathological features. Plasma fibrinogen levels may become a useful biomarker, particularly because of its low associated cost and easy accessibility. © 2012 BJU International.

Circulating immune complexes contain citrullinated fibrinogen in rheumatoid arthritis

PubMed Central

Zhao, Xiaoyan; Okeke, Nwora Lance; Sharpe, Orr; Batliwalla, Franak M; Lee, Annette T; Ho, Peggy P; Tomooka, Beren H; Gregersen, Peter K; Robinson, William H

2008-01-01

Introduction There is increasing evidence that autoantibodies and immune complexes (ICs) contribute to synovitis in rheumatoid arthritis (RA), yet the autoantigens incorporated in ICs in RA remain incompletely characterised. Methods We used the C1q protein to capture ICs from plasma derived from human RA and control patients. Antibodies specific for immunoglobulin were used to detect ICs, and fibrinogen antibodies were used to detect fibrinogen-containing ICs. RA and control plasma were separated by liquid chromatography, and fractions then characterised by ELISA, immunoblotting and mass spectrometry. Immunohistochemical staining was performed on rheumatoid synovial tissue. Results C1q-immunoassays demonstrated increased levels of IgG (p = 0.01) and IgM (p = 0.0002) ICs in plasma derived from RA patients possessing anti-cyclic citrullinated peptide (CCP+) autoantibodies as compared with healthy controls. About one-half of the anti-CCP+ RA possessed circulating ICs containing fibrinogen (p = 0.0004). Fractionation of whole RA plasma revealed citrullinated fibrinogen in the high molecular weight fractions that contained ICs. Positive correlations were observed between fibrinogen-containing ICs and anti-citrullinated fibrinogen autoantibodies, anti-CCP antibody, rheumatoid factor and certain clinical characteristics. Immunohistochemical staining demonstrated co-localisation of fibrinogen, immunoglobulin and complement component C3 in RA pannus tissue. Mass spectrometry analysis of immune complexes immunoprecipitated from RA pannus tissue lysates demonstrated the presence of citrullinated fibrinogen. Conclusion Circulating ICs containing citrullinated fibrinogen are present in one-half of anti-CCP+ RA patients, and these ICs co-localise with C3 in the rheumatoid synovium suggesting that they contribute to synovitis in a subset of RA patients. PMID:18710572

Circulating fibrinogen but not D-dimer level is associated with vital exhaustion in school teachers.

PubMed

Kudielka, Brigitte M; Bellingrath, Silja; von Känel, Roland

2008-07-01

Meta-analyses have established elevated fibrinogen and D-dimer levels in the circulation as biological risk factors for the development and progression of coronary artery disease (CAD). Here, we investigated whether vital exhaustion (VE), a known psychosocial risk factor for CAD, is associated with fibrinogen and D-dimer levels in a sample of apparently healthy school teachers. The teaching profession has been proposed as a potentially high stressful occupation due to enhanced psychosocial stress at the workplace. Plasma fibrinogen and D-dimer levels were measured in 150 middle-aged male and female teachers derived from the first year of the Trier-Teacher-Stress-Study. Log-transformed levels were analyzed using linear regression. Results yielded a significant association between VE and fibrinogen (p = 0.02) but not D-dimer controlling for relevant covariates. Further investigation of possible interaction effects resulted in a significant association between fibrinogen and the interaction term "VE x gender" (p = 0.05). In a secondary analysis, we reran linear regression models for males and females separately. Gender-specific results revealed that the association between fibrinogen and VE remained significant in males but not females. In sum, the present data support the notion that fibrinogen levels are positively related to VE. Elevated fibrinogen might be one biological pathway by which chronic work stress may impact on teachers' cardiovascular health in the long run.

Influence of a constant magnetic field on the fibrinogen-fibrin system. [in blood coagulation process

NASA Technical Reports Server (NTRS)

Matskevichene, V. B.; Platonova, A. T.

1974-01-01

The effect of a constant magnetic field with a strength of 2500 oersteds on the fibrinogen-fibrin system was studied in the organism of healthy rabbits with exposure times of 1 and 5 hours. The results obtained indicate disruptions in the stage of conversion of fibrinogen to fibrin and an increase in the amount of fibrinogen.

The multifunctional LigB adhesin binds homeostatic proteins with potential roles in cutaneous infection by pathogenic Leptospira interrogans.

PubMed

Choy, Henry A; Kelley, Melissa M; Croda, Julio; Matsunaga, James; Babbitt, Jane T; Ko, Albert I; Picardeau, Mathieu; Haake, David A

2011-02-09

Leptospirosis is a potentially fatal zoonotic disease in humans and animals caused by pathogenic spirochetes, such as Leptospira interrogans. The mode of transmission is commonly limited to the exposure of mucous membrane or damaged skin to water contaminated by leptospires shed in the urine of carriers, such as rats. Infection occurs during seasonal flooding of impoverished tropical urban habitats with large rat populations, but also during recreational activity in open water, suggesting it is very efficient. LigA and LigB are surface localized proteins in pathogenic Leptospira strains with properties that could facilitate the infection of damaged skin. Their expression is rapidly induced by the increase in osmolarity encountered by leptospires upon transition from water to host. In addition, the immunoglobulin-like repeats of the Lig proteins bind proteins that mediate attachment to host tissue, such as fibronectin, fibrinogen, collagens, laminin, and elastin, some of which are important in cutaneous wound healing and repair. Hemostasis is critical in a fresh injury, where fibrinogen from damaged vasculature mediates coagulation. We show that fibrinogen binding by recombinant LigB inhibits fibrin formation, which could aid leptospiral entry into the circulation, dissemination, and further infection by impairing healing. LigB also binds fibroblast fibronectin and type III collagen, two proteins prevalent in wound repair, thus potentially enhancing leptospiral adhesion to skin openings. LigA or LigB expression by transformation of a nonpathogenic saprophyte, L. biflexa, enhances bacterial adhesion to fibrinogen. Our results suggest that by binding homeostatic proteins found in cutaneous wounds, LigB could facilitate leptospirosis transmission. Both fibronectin and fibrinogen binding have been mapped to an overlapping domain in LigB comprising repeats 9-11, with repeat 11 possibly enhancing binding by a conformational effect. Leptospirosis patient antibodies react with the LigB domain, suggesting applications in diagnosis and vaccines that are currently limited by the strain-specific leptospiral lipopolysaccharide coats.

The Multifunctional LigB Adhesin Binds Homeostatic Proteins with Potential Roles in Cutaneous Infection by Pathogenic Leptospira interrogans

PubMed Central

Choy, Henry A.; Kelley, Melissa M.; Croda, Julio; Matsunaga, James; Babbitt, Jane T.; Ko, Albert I.; Picardeau, Mathieu; Haake, David A.

2011-01-01

Leptospirosis is a potentially fatal zoonotic disease in humans and animals caused by pathogenic spirochetes, such as Leptospira interrogans. The mode of transmission is commonly limited to the exposure of mucous membrane or damaged skin to water contaminated by leptospires shed in the urine of carriers, such as rats. Infection occurs during seasonal flooding of impoverished tropical urban habitats with large rat populations, but also during recreational activity in open water, suggesting it is very efficient. LigA and LigB are surface localized proteins in pathogenic Leptospira strains with properties that could facilitate the infection of damaged skin. Their expression is rapidly induced by the increase in osmolarity encountered by leptospires upon transition from water to host. In addition, the immunoglobulin-like repeats of the Lig proteins bind proteins that mediate attachment to host tissue, such as fibronectin, fibrinogen, collagens, laminin, and elastin, some of which are important in cutaneous wound healing and repair. Hemostasis is critical in a fresh injury, where fibrinogen from damaged vasculature mediates coagulation. We show that fibrinogen binding by recombinant LigB inhibits fibrin formation, which could aid leptospiral entry into the circulation, dissemination, and further infection by impairing healing. LigB also binds fibroblast fibronectin and type III collagen, two proteins prevalent in wound repair, thus potentially enhancing leptospiral adhesion to skin openings. LigA or LigB expression by transformation of a nonpathogenic saprophyte, L. biflexa, enhances bacterial adhesion to fibrinogen. Our results suggest that by binding homeostatic proteins found in cutaneous wounds, LigB could facilitate leptospirosis transmission. Both fibronectin and fibrinogen binding have been mapped to an overlapping domain in LigB comprising repeats 9–11, with repeat 11 possibly enhancing binding by a conformational effect. Leptospirosis patient antibodies react with the LigB domain, suggesting applications in diagnosis and vaccines that are currently limited by the strain-specific leptospiral lipopolysaccharide coats. PMID:21347378

Characterization of the Modular Design of the Autolysin/Adhesin Aaa from Staphylococcus Aureus

PubMed Central

Hirschhausen, Nina; Schlesier, Tim; Peters, Georg; Heilmann, Christine

2012-01-01

Background Staphylococcus aureus is a frequent cause of serious and life-threatening infections, such as endocarditis, osteomyelitis, pneumonia, and sepsis. Its adherence to various host structures is crucial for the establishment of diseases. Adherence may be mediated by a variety of adhesins, among them the autolysin/adhesins Atl and Aaa. Aaa is composed of three N-terminal repeated sequences homologous to a lysin motif (LysM) that can confer cell wall attachment and a C-terminally located cysteine, histidine-dependent amidohydrolase/peptidase (CHAP) domain having bacteriolytic activity in many proteins. Methodology/Principal Findings Here, we show by surface plasmon resonance that the LysM domain binds to fibrinogen, fibronectin, and vitronectin respresenting a novel adhesive function for this domain. Moreover, we demonstrated that the CHAP domain not only mediates the bacteriolytic activity, but also adherence to fibrinogen, fibronectin, and vitronectin, thus demonstrating for the first time an adhesive function for this domain. Adherence of an S. aureus aaa mutant and the complemented aaa mutant is slightly decreased and increased, respectively, to vitronectin, but not to fibrinogen and fibronectin, which might at least in part result from an increased expression of atl in the aaa mutant. Furthermore, an S. aureus atl mutant that showed enhanced adherence to fibrinogen, fibronectin, and endothelial cells also demonstrated increased aaa expression and production of Aaa. Thus, the redundant functions of Aaa and Atl might at least in part be interchangeable. Lastly, RT-PCR and zymographic analysis revealed that aaa is negatively regulated by the global virulence gene regulators agr and SarA. Conclusions/Significance We identified novel functions for two widely distributed protein domains, LysM and CHAP, i.e. the adherence to the extracellular matrix proteins fibrinogen, fibronectin, and vitronectin. The adhesive properties of Aaa might promote S. aureus colonization of host extracellular matrix and tissue, suggesting a role for Aaa in the pathogenesis of S. aureus infections. PMID:22768285

Characterization of the modular design of the autolysin/adhesin Aaa from Staphylococcus aureus.

PubMed

Hirschhausen, Nina; Schlesier, Tim; Peters, Georg; Heilmann, Christine

2012-01-01

Staphylococcus aureus is a frequent cause of serious and life-threatening infections, such as endocarditis, osteomyelitis, pneumonia, and sepsis. Its adherence to various host structures is crucial for the establishment of diseases. Adherence may be mediated by a variety of adhesins, among them the autolysin/adhesins Atl and Aaa. Aaa is composed of three N-terminal repeated sequences homologous to a lysin motif (LysM) that can confer cell wall attachment and a C-terminally located cysteine, histidine-dependent amidohydrolase/peptidase (CHAP) domain having bacteriolytic activity in many proteins. Here, we show by surface plasmon resonance that the LysM domain binds to fibrinogen, fibronectin, and vitronectin respresenting a novel adhesive function for this domain. Moreover, we demonstrated that the CHAP domain not only mediates the bacteriolytic activity, but also adherence to fibrinogen, fibronectin, and vitronectin, thus demonstrating for the first time an adhesive function for this domain. Adherence of an S. aureus aaa mutant and the complemented aaa mutant is slightly decreased and increased, respectively, to vitronectin, but not to fibrinogen and fibronectin, which might at least in part result from an increased expression of atl in the aaa mutant. Furthermore, an S. aureus atl mutant that showed enhanced adherence to fibrinogen, fibronectin, and endothelial cells also demonstrated increased aaa expression and production of Aaa. Thus, the redundant functions of Aaa and Atl might at least in part be interchangeable. Lastly, RT-PCR and zymographic analysis revealed that aaa is negatively regulated by the global virulence gene regulators agr and SarA. We identified novel functions for two widely distributed protein domains, LysM and CHAP, i.e. the adherence to the extracellular matrix proteins fibrinogen, fibronectin, and vitronectin. The adhesive properties of Aaa might promote S. aureus colonization of host extracellular matrix and tissue, suggesting a role for Aaa in the pathogenesis of S. aureus infections.

Reusable hydroxyapatite nanocrystal sensors for protein adsorption.

PubMed

Tagaya, Motohiro; Ikoma, Toshiyuki; Hanagata, Nobutaka; Chakarov, Dinko; Kasemo, Bengt; Tanaka, Junzo

2010-08-01

The repeatability of the adsorption and removal of fibrinogen and fetal bovine serum on hydroxyapatite (HAp) nanocrystal sensors was investigated by Fourier transform infrared (FTIR) spectroscopy and quartz crystal microbalance with dissipation (QCM-D) monitoring technique. The HAp nanocrystals were coated on a gold-coated quartz sensor by electrophoretic deposition. Proteins adsorbed on the HAp sensors were removed by (i) ammonia/hydrogen peroxide mixture (APM), (ii) ultraviolet light (UV), (iii) UV/APM, (iv) APM/UV and (v) sodium dodecyl sulfate (SDS) treatments. FTIR spectra of the reused surfaces revealed that the APM and SDS treatments left peptide fragments or the proteins adsorbed on the surfaces, whereas the other methods successfully removed the proteins. The QCM-D measurements indicated that in the removal treatments, fibrinogen was slowly adsorbed in the first cycle because of the change in surface wettability revealed by contact angle measurements. The SDS treatment was not effective in removing proteins. The APM or UV treatment decreased the frequency shifts for the reused HAp sensors. The UV/APM treatment did not induce the frequency shifts but decreased the dissipation shifts. Therefore, we conclude that the APM/UV treatment is the most useful method for reproducing protein adsorption behavior on HAp sensors.

Reusable hydroxyapatite nanocrystal sensors for protein adsorption

NASA Astrophysics Data System (ADS)

Tagaya, Motohiro; Ikoma, Toshiyuki; Hanagata, Nobutaka; Chakarov, Dinko; Kasemo, Bengt; Tanaka, Junzo

2010-08-01

The repeatability of the adsorption and removal of fibrinogen and fetal bovine serum on hydroxyapatite (HAp) nanocrystal sensors was investigated by Fourier transform infrared (FTIR) spectroscopy and quartz crystal microbalance with dissipation (QCM-D) monitoring technique. The HAp nanocrystals were coated on a gold-coated quartz sensor by electrophoretic deposition. Proteins adsorbed on the HAp sensors were removed by (i) ammonia/hydrogen peroxide mixture (APM), (ii) ultraviolet light (UV), (iii) UV/APM, (iv) APM/UV and (v) sodium dodecyl sulfate (SDS) treatments. FTIR spectra of the reused surfaces revealed that the APM and SDS treatments left peptide fragments or the proteins adsorbed on the surfaces, whereas the other methods successfully removed the proteins. The QCM-D measurements indicated that in the removal treatments, fibrinogen was slowly adsorbed in the first cycle because of the change in surface wettability revealed by contact angle measurements. The SDS treatment was not effective in removing proteins. The APM or UV treatment decreased the frequency shifts for the reused HAp sensors. The UV/APM treatment did not induce the frequency shifts but decreased the dissipation shifts. Therefore, we conclude that the APM/UV treatment is the most useful method for reproducing protein adsorption behavior on HAp sensors.

Fibrinogen Motif Discriminates Platelet and Cell Capture in Peptide-Modified Gold Micropore Arrays.

PubMed

Adamson, Kellie; Spain, Elaine; Prendergast, Una; Moran, Niamh; Forster, Robert J; Keyes, Tia E

2018-01-16

Human blood platelets and SK-N-AS neuroblastoma cancer-cell capture at spontaneously adsorbed monolayers of fibrinogen-binding motifs, GRGDS (generic integrin adhesion), HHLGGAKQAGDV (exclusive to platelet integrin α IIb β 3 ), or octanethiol (adhesion inhibitor) at planar gold and ordered 1.6 μm diameter spherical cap gold cavity arrays were compared. In all cases, arginine/glycine/aspartic acid (RGD) promoted capture, whereas alkanethiol monolayers inhibited adhesion. Conversely only platelets adhered to alanine/glycine/aspartic acid (AGD)-modified surfaces, indicating that the AGD motif is recognized preferentially by the platelet-specific integrin, α IIb β 3 . Microstructuring of the surface effectively eliminated nonspecific platelet/cell adsorption and dramatically enhanced capture compared to RGD/AGD-modified planar surfaces. In all cases, adhesion was reversible. Platelets and cells underwent morphological change on capture, the extent of which depended on the topography of the underlying substrate. This work demonstrates that both the nature of the modified interface and its underlying topography influence the capture of cancer cells and platelets. These insights may be useful in developing cell-based cancer diagnostics as well as in identifying strategies for the disruption of platelet cloaks around circulating tumor cells.

Mechanisms of fibrin polymerization and clinical implications

PubMed Central

Litvinov, Rustem I.

2013-01-01

Research on all stages of fibrin polymerization, using a variety of approaches including naturally occurring and recombinant variants of fibrinogen, x-ray crystallography, electron and light microscopy, and other biophysical approaches, has revealed aspects of the molecular mechanisms involved. The ordered sequence of fibrinopeptide release is essential for the knob-hole interactions that initiate oligomer formation and the subsequent formation of 2-stranded protofibrils. Calcium ions bound both strongly and weakly to fibrin(ogen) have been localized, and some aspects of their roles are beginning to be discovered. Much less is known about the mechanisms of the lateral aggregation of protofibrils and the subsequent branching to yield a 3-dimensional network, although the αC region and B:b knob-hole binding seem to enhance lateral aggregation. Much information now exists about variations in clot structure and properties because of genetic and acquired molecular variants, environmental factors, effects of various intravascular and extravascular cells, hydrodynamic flow, and some functional consequences. The mechanical and chemical stability of clots and thrombi are affected by both the structure of the fibrin network and cross-linking by plasma transglutaminase. There are important clinical consequences to all of these new findings that are relevant for the pathogenesis of diseases, prophylaxis, diagnosis, and treatment. PMID:23305734

Binding host proteins to the M protein contributes to the mortality associated with influenza-Streptococcus pyogenes superinfections.

PubMed

Herrera, Andrea L; Suso, Kuta; Allison, Stephanie; Simon, Abby; Schlenker, Evelyn; Huber, Victor C; Chaussee, Michael S

2017-09-25

The mortality associated with influenza A virus (IAV) is often due to the development of secondary bacterial infections known as superinfections. The group A streptococcus (GAS) is a relatively uncommon cause of IAV superinfections, but the mortality of these infections is high. We used a murine model to determine whether the surface-localized GAS M protein contributes to the outcome of IAV-GAS superinfections. A comparison between wild-type GAS and an M protein mutant strain (emm3) showed that the M3 protein was essential to virulence. To determine whether the binding, or recruitment, of host proteins to the bacterial surface contributed to virulence, GAS was suspended with BALF collected from mice that had recovered from a sub-lethal infection with IAV. Following intranasal inoculation of naïve mice, the mortality associated with the wild-type strain, but not the emm3 mutant strain, was greater compared to mice inoculated with GAS suspended with either BALF from uninfected mice or PBS. Further analyses showed that both albumin and fibrinogen (Fg) were more abundant in the respiratory tract 8 days after IAV infection, that M3 bound both proteins to the bacterial surface, and that suspension of GAS with either protein increased GAS virulence in the absence of antecedent IAV infection. Overall, the results showed that M3 is essential to the virulence of GAS in an IAV superinfection and suggested that increased abundance of albumin and Fg in the respiratory tract following IAV infection enhanced host susceptibility to secondary GAS infection.

Thrombin-inhibiting nanoparticles rapidly constitute versatile and detectable anticlotting surfaces

NASA Astrophysics Data System (ADS)

Wheatley Myerson, Jacob; He, Li; Allen, John Stacy; Williams, Todd; Lanza, Gregory; Tollefsen, Douglas; Caruthers, Shelton; Wickline, Samuel

2014-09-01

Restoring an antithrombotic surface to suppress ongoing thrombosis is an appealing strategy for treatment of acute cardiovascular disorders such as erosion of atherosclerotic plaque. An antithrombotic surface would present an alternative to systemic anticoagulation with attendant risks of bleeding. We have designed thrombin-targeted nanoparticles (NPs) that bind to sites of active clotting to extinguish local thrombin activity and inhibit platelet deposition while exhibiting only transient systemic anticoagulant effects. Perfluorocarbon nanoparticles (PFC NP) were functionalized with thrombin inhibitors (either D-phenylalanyl-L-prolyl-L-arginyl-chloromethyl ketone or bivalirudin) by covalent attachment of more than 15 000 inhibitors to each PFC NP. Fibrinopeptide A (FPA) ELISA demonstrated that thrombin-inhibiting NPs prevented cleavage of fibrinogen by both free and clot-bound thrombin. Magnetic resonance imaging (MRI) confirmed that a layer of thrombin-inhibiting NPs prevented growth of clots in vitro. Thrombin-inhibiting NPs were administered in vivo to C57BL6 mice subjected to laser injury of the carotid artery. NPs significantly delayed thrombotic occlusion of the artery, whereas an equivalent bolus of free inhibitor was ineffective. For thrombin-inhibiting NPs, only a short-lived (˜10 min) systemic effect on bleeding time was observed, despite prolonged clot inhibition. Imaging and quantification of in vivo antithrombotic NP layers was demonstrated by MRI of the PFC NP. 19F MRI confirmed colocalization of particles with arterial thrombi, and quantitative 19F spectroscopy demonstrated specific binding and retention of thrombin-inhibiting NPs in injured arteries. The ability to rapidly form and image a new antithrombotic surface in acute vascular syndromes while minimizing risks of bleeding would permit a safer method of passivating active lesions than current systemic anticoagulant regimes.

Fibrinogen Gamma Chain Mutations Provoke Fibrinogen and Apolipoprotein B Plasma Deficiency and Liver Storage

PubMed Central

Callea, Francesco; Giovannoni, Isabella; Sari, Sinan; Guldal, Esendagli; Dalgic, Buket; Akyol, Gulen; Sogo, Tsuyoshi; Al-Hussaini, Abdulrahman; Maggiore, Giuseppe; Bartuli, Andrea; Boldrini, Renata; Francalanci, Paola; Bellacchio, Emanuele

2017-01-01

p.R375W (Fibrinogen Aguadilla) is one out of seven identified mutations (Brescia, Aguadilla, Angers, Al du Pont, Pisa, Beograd, and Ankara) causing hepatic storage of the mutant fibrinogen γ. The Aguadilla mutation has been reported in children from the Caribbean, Europe, Japan, Saudi Arabia, Turkey, and China. All reported children presented with a variable degree of histologically proven chronic liver disease and low plasma fibrinogen levels. In addition, one Japanese and one Turkish child had concomitant hypo-APOB-lipoproteinemia of unknown origin. We report here on an additional child from Turkey with hypofibrinogenemia due to the Aguadilla mutation, massive hepatic storage of the mutant protein, and severe hypo-APOB-lipoproteinemia. The liver biopsy of the patient was studied by light microscopy, electron microscopy (EM), and immunohistochemistry. The investigation included the DNA sequencing of the three fibrinogen and APOB–lipoprotein regulatory genes and the analysis of the encoded protein structures. Six additional Fibrinogen Storage Disease (FSD) patients with either the Aguadilla, Ankara, or Brescia mutations were investigated with the same methodology. A molecular analysis revealed the fibrinogen gamma p.R375W mutation (Aguadilla) but no changes in the APOB and MTTP genes. APOB and MTTP genes showed no abnormalities in the other study cases. Light microscopy and EM studies of liver tissue samples from the child led to the demonstration of the simultaneous accumulation of both fibrinogen and APOB in the same inclusions. Interestingly enough, APOB-containing lipid droplets were entrapped within the fibrinogen inclusions in the hepatocytic Endoplasmic Reticulum (ER). Similar histological, immunohistochemical, EM, and molecular genetics findings were found in the other six FSD cases associated with the Aguadilla, as well as with the Ankara and Brescia mutations. The simultaneous retention of fibrinogen and APOB-lipoproteins in FSD can be detected in routinely stained histological sections. The analysis of protein structures unraveled the pathomorphogenesis of this unexpected phenomenon. Fibrinogen gamma chain mutations provoke conformational changes in the region of the globular domain involved in the “end-to-end” interaction, thus impairing the D-dimer formation. Each monomeric fibrinogen gamma chain is left with an abnormal exposure of hydrophobic patches that become available for interactions with APOB and lipids, causing their intracellular retention and impairment of export as a secondary unavoidable phenomenon. PMID:29244742

A Multi-Ethnic Meta-Analysis of Genome-Wide Association Studies in Over 100,000 Subjects Identifies 23 Fibrinogen-Associated Loci but no Strong Evidence of a Causal Association between Circulating Fibrinogen and Cardiovascular Disease

PubMed Central

Sabater-Lleal, Maria; Huang, Jie; Chasman, Daniel; Naitza, Silvia; Dehghan, Abbas; Johnson, Andrew D; Teumer, Alexander; Reiner, Alex P; Folkersen, Lasse; Basu, Saonli; Rudnicka, Alicja R; Trompet, Stella; Mälarstig, Anders; Baumert, Jens; Bis, Joshua C.; Guo, Xiuqing; Hottenga, Jouke J; Shin, So-Youn; Lopez, Lorna M; Lahti, Jari; Tanaka, Toshiko; Yanek, Lisa R; Oudot-Mellakh, Tiphaine; Wilson, James F; Navarro, Pau; Huffman, Jennifer E; Zemunik, Tatijana; Redline, Susan; Mehra, Reena; Pulanic, Drazen; Rudan, Igor; Wright, Alan F; Kolcic, Ivana; Polasek, Ozren; Wild, Sarah H; Campbell, Harry; Curb, J David; Wallace, Robert; Liu, Simin; Eaton, Charles B.; Becker, Diane M.; Becker, Lewis C.; Bandinelli, Stefania; Räikkönen, Katri; Widen, Elisabeth; Palotie, Aarno; Fornage, Myriam; Green, David; Gross, Myron; Davies, Gail; Harris, Sarah E; Liewald, David C; Starr, John M; Williams, Frances M.K.; Grant, P.J.; Spector, Timothy D.; Strawbridge, Rona J; Silveira, Angela; Sennblad, Bengt; Rivadeneira, Fernando; Uitterlinden, Andre G; Franco, Oscar H; Hofman, Albert; van Dongen, Jenny; Willemsen, G; Boomsma, Dorret I; Yao, Jie; Jenny, Nancy Swords; Haritunians, Talin; McKnight, Barbara; Lumley, Thomas; Taylor, Kent D; Rotter, Jerome I; Psaty, Bruce M; Peters, Annette; Gieger, Christian; Illig, Thomas; Grotevendt, Anne; Homuth, Georg; Völzke, Henry; Kocher, Thomas; Goel, Anuj; Franzosi, Maria Grazia; Seedorf, Udo; Clarke, Robert; Steri, Maristella; Tarasov, Kirill V; Sanna, Serena; Schlessinger, David; Stott, David J; Sattar, Naveed; Buckley, Brendan M; Rumley, Ann; Lowe, Gordon D; McArdle, Wendy L; Chen, Ming-Huei; Tofler, Geoffrey H; Song, Jaejoon; Boerwinkle, Eric; Folsom, Aaron R.; Rose, Lynda M.; Franco-Cereceda, Anders; Teichert, Martina; Ikram, M Arfan; Mosley, Thomas H; Bevan, Steve; Dichgans, Martin; Rothwell, Peter M.; Sudlow, Cathie L M; Hopewell, Jemma C.; Chambers, John C.; Saleheen, Danish; Kooner, Jaspal S.; Danesh, John; Nelson, Christopher P; Erdmann, Jeanette; Reilly, Muredach P.; Kathiresan, Sekar; Schunkert, Heribert; Morange, Pierre-Emmanuel; Ferrucci, Luigi; Eriksson, Johan G; Jacobs, David; Deary, Ian J; Soranzo, Nicole; Witteman, Jacqueline CM; de Geus, Eco JC; Tracy, Russell P.; Hayward, Caroline; Koenig, Wolfgang; Cucca, Francesco; Jukema, J Wouter; Eriksson, Per; Seshadri, Sudha; Markus, Hugh S.; Watkins, Hugh; Samani, Nilesh J; Wallaschofski, Henri; Smith, Nicholas L.; Tregouet, David; Ridker, Paul M.; Tang, Weihong; Strachan, David P.; Hamsten, Anders; O’Donnell, Christopher J.

2013-01-01

Background Estimates of the heritability of plasma fibrinogen concentration, an established predictor of cardiovascular disease (CVD), range from 34 to 50%. Genetic variants so far identified by genome-wide association (GWA) studies only explain a small proportion (< 2%) of its variation. Methods and Results We conducted a meta-analysis of 28 GWA studies, including more than 90,000 subjects of European ancestry, the first GWA meta-analysis of fibrinogen levels in 7 African Americans studies totaling 8,289 samples, and a GWA study in Hispanic-Americans totaling 1,366 samples. Evaluation for association of SNPs with clinical outcomes included a total of 40,695 cases and 85,582 controls for coronary artery disease (CAD), 4,752 cases and 24,030 controls for stroke, and 3,208 cases and 46,167 controls for venous thromboembolism (VTE). Overall, we identified 24 genome-wide significant (P<5×10−8) independent signals in 23 loci, including 15 novel associations, together accounting for 3.7% of plasma fibrinogen variation. Gene-set enrichment analysis highlighted key roles in fibrinogen regulation for the three structural fibrinogen genes and pathways related to inflammation, adipocytokines and thyrotrophin-releasing hormone signaling. Whereas lead SNPs in a few loci were significantly associated with CAD, the combined effect of all 24 fibrinogen-associated lead SNPs was not significant for CAD, stroke or VTE. Conclusion We identify 23 robustly associated fibrinogen loci, 15 of which are new. Clinical outcome analysis of these loci does not support a causal relationship between circulating levels of fibrinogen and CAD, stroke or VTE. PMID:23969696

Recombinant γT305A fibrinogen indicates severely impaired fibrin polymerization due to the aberrant function of hole 'A' and calcium binding sites.

PubMed

Ikeda, Minami; Kobayashi, Tamaki; Arai, Shinpei; Mukai, Saki; Takezawa, Yuka; Terasawa, Fumiko; Okumura, Nobuo

2014-08-01

We examined a 6-month-old girl with inherited fibrinogen abnormality and no history of bleeding or thrombosis. Routine coagulation screening tests showed a markedly low level of plasma fibrinogen determined by functional measurement and also a low level by antigenic measurement (functional/antigenic ratio=0.295), suggesting hypodysfibrinogenemia. DNA sequence analysis was performed, and γT305A fibrinogen was synthesized in Chinese hamster ovary cells based on the results. We then functionally analyzed and compared with that of nearby recombinant γN308K fibrinogen. DNA sequence analysis revealed a heterozygous γT305A substitution (mature protein residue number). The γT305A fibrinogen indicated markedly impaired thrombin-catalyzed fibrin polymerization both in the presence or absence of 1mM calcium ion compared with that of γN308K fibrinogen. Protection of plasmin degradation in the presence of calcium ion or Gly-Pro-Arg-Pro peptide (analogue for so-called knob 'A') and factor XIIIa-catalyzed fibrinogen crosslinking demonstrated that the calcium binding sites, hole 'a' and D:D interaction sites were all markedly impaired, whereas γN308Kwas impaired at the latter two sites. Molecular modeling demonstrated that γT305 is localized at a shorter distance than γN308 from the high affinity calcium binding site and hole 'a'. Our findings suggest that γT305 might be important for construction of the overall structure of the γ module of fibrinogen. Substitution of γT305A leads to both dysfibrinogenemic and hypofibrinogenemic characterization, namely hypodysfibrinogenemia. We have already reported that recombinant γT305A fibrinogen was synthesized normally and secreted slightly, but was significantly reduced. Copyright © 2014 Elsevier Ltd. All rights reserved.

Integrin-associated protein (CD47) is a putative mediator for soluble fibrinogen interaction with human red blood cells membrane.

PubMed

De Oliveira, S; Vitorino de Almeida, V; Calado, A; Rosário, H S; Saldanha, C

2012-03-01

Fibrinogen is a multifunctional plasma protein that plays a crucial role in several biological processes. Elevated fibrinogen induces erythrocyte hyperaggregation, suggesting an interaction between this protein and red blood cells (RBCs). Several studies support the concept that fibrinogen interacts with RBC membrane and this binding, due to specific and non-specific mechanisms, may be a trigger to RBC hyperaggregation in inflammation. The main goals of our work were to prove that human RBCs are able to specifically bind soluble fibrinogen, and identify membrane molecular targets that could be involved in this process. RBCs were first isolated from blood of healthy individuals and then separated in different age fractions by discontinuous Percoll gradients. After isolation RBC samples were incubated with human soluble fibrinogen and/or with a blocking antibody against CD47 followed by fluorescence confocal microscopy, flow cytometry acquisitions and zeta potential measurements. Our data show that soluble fibrinogen interacts with the human RBC membrane in an age-dependent manner, with younger RBCs interacting more with soluble fibrinogen than the older cells. Importantly, this interaction is abrogated in the presence of a specific antibody against CD47. Our results support a specific and age-dependent interaction of soluble fibrinogen with human RBC membrane; additionally we present CD47 as a putative mediator in this process. This interaction may contribute to RBC hyperaggregation in inflammation. Copyright © 2011 Elsevier B.V. All rights reserved.

Fibrinogen adsorption mechanisms at the gold substrate revealed by QCM-D measurements and RSA modeling.

PubMed

Kubiak, Katarzyna; Adamczyk, Zbigniew; Cieśla, Michał

2016-03-01

Adsorption kinetics of fibrinogen at a gold substrate at various pHs was thoroughly studied using the QCM-D method. The experimental were interpreted in terms of theoretical calculations performed according to the random sequential adsorption model (RSA). In this way, the hydration functions and water factors of fibrinogen monolayers were quantitatively evaluated at various pHs. It was revealed that for the lower range of fibrinogen coverage the hydration function were considerably lower than previously obtained for the silica sensor [33]. The lower hydration of fibrinogen monolayers on the gold sensor was attributed to its higher roughness. However, for higher fibrinogen coverage the hydration functions for both sensors became identical exhibiting an universal behavior. By using the hydration functions, the fibrinogen adsorption/desorption runs derived from QCM-D measurements were converted to the Γd vs. the time relationships. This allowed to precisely determine the maximum coverage that varied between 1.6mgm(-2) at pH 3.5 and 4.5mgm(-2) at pH 7.4 (for ionic strength of 0.15M). These results agree with theoretical eRSA modeling and previous experimental data derived by using ellipsometry, OWLS and TIRF. Various fibrinogen adsorption mechanisms were revealed by exploiting the maximum coverage data. These results allow one to develop a method for preparing fibrinogen monolayers of well-controlled coverage and molecule orientation. Copyright © 2015 Elsevier B.V. All rights reserved.

Dysfibrinogenemia in childhood: two cases of congenital dysfibrinogens.

PubMed

Kotlín, Roman; Blažek, Bohumír; Suttnar, Jiří; Malý, Martin; Kvasnička, Jan; Dyr, Jan E

2010-10-01

A 2-year-old asymptomatic boy and his relatives were investigated for a suspected fibrinogen mutation after coagulation tests revealed a decreased functional fibrinogen level (family A). Eight-year-old and 1-year-old asymptomatic brothers were investigated for a suspected fibrinogen mutation after coagulation tests revealed a decreased functional fibrinogen level and prolonged thrombin time (family B). To identify whether genetic mutations were responsible for these dysfibrinogens, DNA extracted from the blood was analyzed. Fibrin polymerization and fibrinolysis were measured by a turbidimetric method at 450 nm. DNA analysis was performed by the Sanger method. Mass spectroscopy was performed on a Biflex IV mass spectrometer. DNA sequencing showed the heterozygous point mutation Aα Arg16His in the fibrinogen of family A and the heterozygous point mutation Aα Arg16Cys in the fibrinogen of family B. Kinetics of fibrinopeptide release, fibrinolysis, and fibrin polymerization were impaired in the carriers of the mutations in both families. Mass spectroscopy showed the presence of mutant fibrinogen chains in circulation. Scanning electron microscopy revealed thicker fibrin fibers, differing significantly from the normal control in both cases. Two cases of asymptomatic dysfibrinogenemias, found by routine coagulation testing, were genetically identified as new cases of fibrinogen variants Aα Arg16His and Aα Arg16Cys.

Polymorphism in beta fibrinogen -455 g/a gene was associated with diabetic in severe ischemic stroke patients

NASA Astrophysics Data System (ADS)

Ritarwan, Kiking; Kadri, Alfansuri; Juwita Sembiring, Rosita

2018-03-01

There is a association of polymorphism in the promoter region of the beta fibrinogen gene -455 G/A with enhancement plasma fibrinogen level. Diabetes mellitus is a risk factor for early neurologic deterioration in acute ischemic stroke. The prothrombotic fibrinogen protein is frequently elevated in patients with diabetes and may be association with poorer prognosis. This study evaluated the association of beta fibrinogen gene -455 G/A promoter polymorphism on modified Ranking Scale of Ischemic Stroke patients treated with diabetic and nondiabetic group. In a Cohort study design comprises 200 consecutive patients diabetic and a nondiabetic who, three months using completed a detailed outcome stroke. Of 200 samples genotype distribution were 27.1% for GG+GA and 0% for AA with diabetic and than 4.4% for GG+GA and 0.05% diabetic patients. Fibrinogen levels were higher in diabetic than nondiabetic group patients (307.7 + 106.3 vs 278 + 84 gr/dl, p=0.002). Fibrinogen level was found to be an independent predictor for diabetic patients. On Genotype GG+GA were associated wth diabetic and nondiabetic group patients. Modified Rankin Scale on day 90 were found associated with diabetic and nondiabetic patients. Conclusion: Elevated fibrinogen level is dose-dependently associated with 90 days outcome severity stroke with diabetic following ischemic stroke

Fibrinogen Is at the Interface of Host Defense and Pathogen Virulence in Staphylococcus aureus Infection

PubMed Central

Ko, Ya-Ping; Flick, Matthew J.

2017-01-01

Fibrinogen not only plays a pivotal role in hemostasis but also serves key roles in antimicrobial host defense. As a rapidly assembled provisional matrix protein, fibrin(ogen) can function as an early line of host protection by limiting bacterial growth, suppressing dissemination of microbes to distant sites, and mediating host bacterial killing. Fibrinogen-mediated host antimicrobial activity occurs predominantly through two general mechanisms, namely, fibrin matrices functioning as a protective barrier and fibrin(ogen) directly or indirectly driving host protective immune function. The potential of fibrin to limit bacterial infection and disease has been countered by numerous bacterial species evolving and maintaining virulence factors that engage hemostatic system components within vertebrate hosts. Bacterial factors have been isolated that simply bind fibrinogen or fibrin, promote fibrin polymer formation, or promote fibrin dissolution. Staphylococcus aureus is an opportunistic gram-positive bacterium, the causative agent of a wide range of human infectious diseases, and a prime example of a pathogen exquisitely sensitive to host fibrinogen. Indeed, current data suggest fibrinogen serves as a context-dependent determinant of host defense or pathogen virulence in Staphylococcus infection whose ultimate contribution is dictated by the expression of S. aureus virulence factors, the path of infection, and the tissue microenvironment. PMID:27056151

A Novel Role for Pro-Coagulant Microvesicles in the Early Host Defense against Streptococcus pyogenes

PubMed Central

Oehmcke, Sonja; Westman, Johannes; Malmström, Johan; Mörgelin, Matthias; Olin, Anders I.; Kreikemeyer, Bernd; Herwald, Heiko

2013-01-01

Previous studies have shown that stimulation of whole blood or peripheral blood mononuclear cells with bacterial virulence factors results in the sequestration of pro-coagulant microvesicles (MVs). These particles explore their clotting activity via the extrinsic and intrinsic pathway of coagulation; however, their pathophysiological role in infectious diseases remains enigmatic. Here we describe that the interaction of pro-coagulant MVs with bacteria of the species Streptococcus pyogenes is part of the early immune response to the invading pathogen. As shown by negative staining electron microscopy and clotting assays, pro-coagulant MVs bind in the presence of plasma to the bacterial surface. Fibrinogen was identified as a linker that, through binding to the M1 protein of S. pyogenes, allows the opsonization of the bacteria by MVs. Surface plasmon resonance analysis revealed a strong interaction between pro-coagulant MVs and fibrinogen with a KD value in the nanomolar range. When performing a mass-spectrometry-based strategy to determine the protein quantity, a significant up-regulation of the fibrinogen-binding integrins CD18 and CD11b on pro-coagulant MVs was recorded. Finally we show that plasma clots induced by pro-coagulant MVs are able to prevent bacterial dissemination and possess antimicrobial activity. These findings were confirmed by in vivo experiments, as local treatment with pro-coagulant MVs dampens bacterial spreading to other organs and improved survival in an invasive streptococcal mouse model of infection. Taken together, our data implicate that pro-coagulant MVs play an important role in the early response of the innate immune system in infectious diseases. PMID:23935504

Fibrinogen signal transduction as a mediator and therapeutic target in inflammation: lessons from multiple sclerosis.

PubMed

Adams, R A; Schachtrup, C; Davalos, D; Tsigelny, I; Akassoglou, K

2007-01-01

The blood protein fibrinogen as a ligand for integrin and non-integrin receptors functions as the molecular nexus of coagulation, inflammation and immunity. Studies in animal models and in human disease have demonstrated that extravascular fibrinogen that is deposited in tissues upon vascular rupture is not merely a marker, but a mediator of diseases with an inflammatory component, such as rheumatoid arthritis, multiple sclerosis, sepsis, myocardial infarction and bacterial infection. The present article focuses on the recent discoveries of specific cellular targets and receptors for fibrinogen within tissues that have extended the role of fibrinogen from a coagulation factor to a regulator of inflammation and immunity. Fibrinogen has the potential for selective drug targeting that would target its proinflammatory properties without affecting its beneficial effects in hemostasis, since it interacts with different receptors to mediate blood coagulation and inflammation. Strategies to target receptors for fibrinogen and fibrin within the tissue microenvironment could reveal selective and disease-specific agents for therapeutic intervention in a variety of human diseases associated with fibrin deposition.

Plasma Fibrinogen in Patients With Bell Palsy.

PubMed

Zhao, Hua; Zhang, Xin; Tang, Yinda; Li, Shiting

2016-10-01

To determine the plasma fibrinogen level in patients with Bell palsy and explore the significances of it in Bell palsy. One hundred five consecutive patients with facial paralysis were divided into 3 groups: group I (Bell palsy), group II (temporal bone fractures), and group III (facial nerve schwannoma). In addition, 22 volunteers were defined as control group. Two milliliters fasting venous blood from elbow was collected, and was evaluated by CA-7000 Full-Automatic Coagulation Analyzer. The plasma fibrinogen concentration was significantly higher in the group of patients with Bell palsy (HB IV-VI) than that in the control group (P <0.05). There was no significant difference between group II and control group (P >0.05); similarly, there was also no marked difference between group III and control group (P >0.05). In group I, the plasma fibrinogen levels became higher with the HB grading increase. The plasma fibrinogen level of HB-VI was highest. Plasma fibrinogen has an important clinical meaning in Bell palsy, which should be used as routine examination items. Defibrinogen in treatment for patients with high plasma fibrinogen content also should be suggested.

ESTABLISHMENT OF A FIBRINOGEN REFERENCE INTERVAL IN ORNATE BOX TURTLES (TERRAPENE ORNATA ORNATA).

PubMed

Parkinson, Lily; Olea-Popelka, Francisco; Klaphake, Eric; Dadone, Liza; Johnston, Matthew

2016-09-01

This study sought to establish a reference interval for fibrinogen in healthy ornate box turtles ( Terrapene ornata ornata). A total of 48 turtles were enrolled, with 42 turtles deemed to be noninflammatory and thus fitting the inclusion criteria and utilized to estimate a fibrinogen reference interval. Turtles were excluded based upon physical examination and blood work abnormalities. A Shapiro-Wilk normality test indicated that the noninflammatory turtle fibrinogen values were normally distributed (Gaussian distribution) with an average of 108 mg/dl and a 95% confidence interval of the mean of 97.9-117 mg/dl. Those turtles excluded from the reference interval because of abnormalities affecting their health had significantly different fibrinogen values (P = 0.313). A reference interval for healthy ornate box turtles was calculated. Further investigation into the utility of fibrinogen measurement for clinical usage in ornate box turtles is warranted.

Association of fibrinogen with HbA1C in diabetic foot ulcer

NASA Astrophysics Data System (ADS)

Pase, M. A.; Gatot, D.; Lindarto, D.

2018-03-01

Fibrinogen is one of the inflammatory markers of vascular changes and endothelial dysfunction in diabetic patients. The aim of this study to associate serum fibrinogen levels with HbA1C in diabetic foot ulcer (DFU). This study was cross-sectional and retrospective in DFU patients from January to July 2017 in Haji Adam Malik Central General Hospital. The patients enrolled in the study were T2DM with DFU as a complication. The grading of DFU was evaluated according to the Wagner’s Classification. Serum fibrinogen level, HbA1C and ankle-brachial index (ABI) were carried out directly in the patients. Fibrinogen serum levels were found significantly with HbA1C (P=0.001, r=0.387) and ABI (P=0.008, r=-0.454). Fibrinogen serum levels in DFU patients were positively correlated with HbA1C and significantly higher in patients with poor glycemic control.

Prediction of extravasation in pelvic fracture using coagulation biomarkers.

PubMed

Aoki, Makoto; Hagiwara, Shuichi; Tokue, Hiroyuki; Shibuya, Kei; Kaneko, Minoru; Murata, Masato; Nakajima, Jun; Sawada, Yusuke; Isshiki, Yuta; Ichikawa, Yumi; Oshima, Kiyohiro

2016-08-01

To evaluate the usefulness of coagulation biomarkers, which are easy and quick to analyze in emergency settings, for prediction of arterial extravasation due to pelvic fracture. The medical records of pelvic fracture patients transferred to the emergency department of Gunma University Hospital between December 2009 and May 2015 were reviewed. Patients were divided into two groups, those with (Extra(+)) and without (Extra(-)) arterial extravasation on enhanced CT or angiography. Levels of fibrin degradation products (FDP), D-dimer, fibrinogen, the ratio of FDP to fibrinogen, the ratio of D-dimer to fibrinogen, systolic blood pressure, heart rate, the Glasgow Coma Scale, pH, base excess, hemoglobin and lactate levels, the pattern of pelvic injury, and injury severity score were measured at hospital admission, and compared between the two groups. Parameters with a significant difference between the two groups were used to construct receiver operating characteristic (ROC) curves. The study included 29 patients with pelvic fracture. FDP, D-dimer, the ratio of FDP to fibrinogen and the ratio of D-dimer to fibrinogen were the most useful parameters for predicting arterial extravasation due to pelvic fracture. FDP, D-dimer, the ratio of FDP to fibrinogen, the ratio of D-dimer to fibrinogen, and hemoglobin and lactate levels were significantly higher in the Extra(+) group than in the Extra(-) group (FDP, 354.8μg/mL [median] versus 96.6μg/mL; D-dimer, 122.3μg/mL versus 42.1μg/mL; the ratio of FDP to fibrinogen, 3.39 versus 0.42; the ratio of D-dimer to fibrinogen, 1.14 versus 0.18; hemoglobin, 10.5g/dL versus 13.5g/dL; lactate, 3.5mmol/L versus 1.7mmol/L). The area under the ROC curves for FDP, D-dimer, the ratio of FDP to fibrinogen, the ratio of D-dimer to fibrinogen, hemoglobin and lactate levels were 0.900, 0.882, 0.918, 0.900, 0.815 and 0.765, respectively. Coagulation biomarkers, and hemoglobin and lactate levels could be useful to predict the existence of arterial extravasation due to pelvic fracture. The ratio of FDP to fibrinogen and the ratio of D-dimer to fibrinogen were the most accurate markers. Coagulation biomarkers may enable more rapid and specific treatment for pelvic fracture. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Management of congenital quantitative fibrinogen disorders: a Delphi consensus.

PubMed

Casini, A; de Moerloose, P

2016-11-01

No evidence-based guidelines for the management of patients suffering from afibrinogenaemia and hypofibrinogenaemia are available. The aim of this study was to harmonize patient's care among invited haemophilia experts from Belgium, France and Switzerland. A Delphi-like methodology was used to reach a consensus on: prophylaxis, bleeding, surgery, pregnancy and thrombosis management. The main final statements are as follows: (i) a secondary fibrinogen prophylaxis should be started after a first life-threatening bleeding in patients with afibrinogenaemia; (ii) during prophylaxis the target trough fibrinogen level should be 0.5 g L -1 ; (iii) if an adaptation of dosage is required, the frequency of infusions rather than the fibrinogen amount should be modified; (iv) afibrinogenaemic patients undergoing a surgery at high bleeding risk should receive fibrinogen concentrates regardless of the personal or family history of bleeding; (v) moderate hypofibrinogenaemic patients (i.e. ≥0.5 g L -1 ) without previous bleeding (despite haemostatic challenges) undergoing a surgery at low bleeding risk may not receive fibrinogen concentrates as prophylaxis; (vi) monitoring the trough fibrinogen levels should be performed at least once a month throughout the pregnancy and a foetal growth and placenta development close monitoring by ultrasound is recommended; (vii) fibrinogen replacement should be started concomitantly to the introduction of anticoagulation in afibrinogenaemic patients suffering from a venous thromboembolic event; and (viii) low-molecular-weight heparin is the anticoagulant of choice in case of venous thromboembolism. The results of this initiative should help clinicians in the difficult management of patients with congenital fibrinogen disorders. © 2016 John Wiley & Sons Ltd.

Force measurements on the molecular interactions between ligand (RGD) and human platelet α IIbβ 3 receptor system

NASA Astrophysics Data System (ADS)

Lee, ImShik; Marchant, Roger E.

2001-10-01

The peptide sequence arginine-glycine-aspartate (RGD) found in fibrinogen, von Willebrand factor, fibronectin, and vitronectin, plays a critical role in platelet adhesion and thrombus formation, when bound to the platelet α IIbβ 3 integrin receptor. Using atomic force microscopy (AFM), we have measured the debonding interaction between an RGD peptide-modified AFM probe tip and a human platelet surface from pN to nN levels of force. The peptide sequence, GSSSGRGDSPA, which contains the biologically active RGDSP sequence with a hydrophilic spacer sequence (GSSSG), was covalently coupled to AFM probe tips. Direct measurements on the debonding force for the RGD ligand - α IIbβ 3 platelet receptor system were carried out in Tyrode buffer at room temperature. Our results show three distinct distributions of debonding forces at a loading rate of 12 nN/s, from which we estimate the debonding force for the single ligand-receptor to be ˜93 pN. The results also show evidence for considerable extension in the flexible sample surface during the debonding process, and a linear correlation between the debonding force and the logarithm of the rate of loading. From our analysis, the zero kinetic off-rate Koff(0), the single molecular binding energy Eb, and the transition state xB, assuming rigid binding, were extracted from the data, and estimated to be 22.6 s -1, -2.64×10 -20 J and 0.1 nm, respectively.

Gallium nitrate induces fibrinogen flocculation: an explanation for its hemostatic effect?

PubMed

Bauters, A; Holt, D J; Zerbib, P; Rogosnitzky, M

2013-12-01

A novel hemostatic effect of gallium nitrate has recently been discovered. Our aim was to perform a preliminary investigation into its mode of action. Thromboelastography® showed no effect on coagulation but pointed instead to changes in fibrinogen concentration. We measured functional fibrinogen in whole blood after addition of gallium nitrate and nitric acid. We found that gallium nitrate induces fibrinogen precipitation in whole blood to a significantly higher degree than solutions of nitric acid alone. This precipitate is not primarily pH driven, and appears to occur via flocculation. This behavior is in line with the generally observed ability of metals to induce fibrinogen precipitation. Further investigation is required into this novel phenomenon.

Tailoring of the titanium surface by immobilization of heparin/fibronectin complexes for improving blood compatibility and endothelialization: an in vitro study.

PubMed

Li, Guicai; Yang, Ping; Liao, Yuzhen; Huang, Nan

2011-04-11

To improve the blood compatibility and endothelialization simultaneously and to ensure the long-term effectiveness of the cardiovascular implants, we developed a surface modification method, enabling the coimmobilization of biomolecules to metal surfaces. In the present study, a heparin and fibronectin mixture (Hep/Fn) covalently immobilized on a titanium (Ti) substrate for biocompatibility was investigated. Different systems [N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide and N-hydroxysuccinimide, electrostatic] were used for the formation of Hep/Fn layers. Atomic force microscopy (AFM) showed that the roughness of the silanized Ti surface decreased after the immobilization of Hep/Fn. Fourier transform infrared spectroscopy (FTIR), Toluidine Blue O (TBO) test, and immunochemistry assay showed that Hep/Fn mixture was successfully immobilized on Ti surface. Blood compatibility tests (hemolysis rate, APTT, platelet adhesion, fibrinogen conformational change) showed that the coimmobilized films of Hep/Fn mixture reduced blood hemolysis rate, prolonged blood coagulation time, reduced platelets activation and aggregation, and induced less fibrinogen conformational change compared with a bare Ti surface. Endothelial cell (EC) seeding showed more EC with better morphology on pH 4 samples than on pH 7 and EDC/NHS samples, which showed rounded and aggregated cells. Systematic evaluation showed that the pH 4 samples also had much better blood compatibility. All results suggest that the coimmobilized films of Hep/Fn can confer excellent antithrombotic properties and with good endothelialization. We envisage that this method will provide a potential and effective solution for the surface modification of cardiovascular implant materials.

Fibrinogen catabolism within the procoagulant VX-2 tumor of rabbit lung in vivo: Effluxing fibrin(ogen) fragments contain antiangiogenic activity.

PubMed

Hatton, Mark W C; Southward, Suzanne M R; Legault, Kimberly J; Ross, Bonnie L; Clarke, Bryan J; Bajzar, Laszlo; Blajchman, Morris A; Singh, Gurmit; Richardson, Mary

2004-04-01

Many types of solid tumors are known to be procoagulant environments. This is partly because a hyperpermeable vascular system within the tumor allows plasma hemostatic factors to accumulate in relatively high concentrations in the stroma, and many solid-tumor cells express tissue factor or a procoagulant factor. These circumstances appear to exist in the VX-2 lung tumor of the New Zealand White (NZW) rabbit, and they sustain a measurable turnover of stromal deposits of fibrin(ogen). We have measured the turnover of fibrinogen within tumors of the VX-2 tumor-burdened rabbit and analysed the catabolic products of fibrin(ogen) and the status of fibrinolysis in tumor-derived interpleural effusate. Using intravenously injected (125)I-labeled rabbit fibrinogen as a marker, we found that fibrinogen (approximate blood concentration 1740 microg/mL) passed from blood to VX-2 tumor stroma, saturating the tumor at a concentration of approximately 348 microg fibrinogen/g in approximately 12 hours. We measured fibrin(ogen) fragments, at a concentration of approximately 292 microg/mL, in interpleural effusates that we recovered from 13% of the VX-2-burdened rabbits. Unreduced fibrin(ogen) fragments consisted of 4 major components with a relative molecular mass of approximately 250,000 (assumed to be fragment X; approximately 9% of total fragments from densitometry of immunoblots), 200,000 (d-dimer; 41%), 110,000 (fragment D; 49%), and 50,000 to 55,000 (fragment E; 1%-2%) kD. Total fibrin(ogen) fragments immunopurified from effusates exhibited an antiangiogenic effect when subjected to a chick embryo chorioallantoic membrane procedure. Interpleural effusates were devoid of plasmin activity or active plasminogen activator inhibitor-1 but contained plasmin complexes and active urokinase-like plasminogen activator (uPA), alpha(2)-antiplasmin, and thrombin-activatable fibrinolysis inhibitor. We speculate that VX-2 cells release uPA to activate fibrinolysis within the tumor stroma. Catabolic products of hemostasis (eg, fibrinolytic fragments, angiostatin) flux from the stroma into the interpleural space, thereby providing a net antiangiogenic property to the effusate and ultimately to the lymphatic and circulatory systems.

M-Ficolin Binds Selectively to the Capsular Polysaccharides of Streptococcus pneumoniae Serotypes 19B and 19C and of a Streptococcus mitis Strain

PubMed Central

Kjaer, Troels R.; Hansen, Annette G.; Sørensen, Uffe B. S.; Holm, Anne T.; Sørensen, Grith L.; Jensenius, Jens C.

2013-01-01

The three human ficolins (H-, L-, and M-ficolins) and mannan-binding lectin are pattern recognition molecules of the innate immune system mediating activation of the lectin pathway of the complement system. These four human proteins bind to some microorganisms and may be involved in the resolution of infections. We investigated binding selectivity by examining the binding of M-ficolin to a panel of more than 100 different streptococcal strains (Streptococcus pneumoniae and Streptococcus mitis), each expressing distinct polysaccharide structures. M-ficolin binding was observed for three strains only: strains of the pneumococcal serotypes 19B and 19C and a single S. mitis strain expressing a similar polysaccharide structure. The bound M-ficolin, in association with MASP-2, mediated the cleavage of complement factor C4. Binding to the bacteria was inhibitable by N-acetylglucosamine, indicating that the interaction with the bacterial surface takes place via the fibrinogen-like domain. The common N-acetylmannosamine residue present in the structures of the four capsular polysaccharides of group 19 is linked via a phosphodiester bond. This residue is apparently not a ligand for M-ficolin, since the lectin binds to two of the group 19 polysaccharides only. M-ficolin bound strongly to serotype 19B and 19C polysaccharides. In contrast to those of serotypes 19A and 19F, serotype 19B and 19C polysaccharides contain an extra N-acetylmannosamine residue linked via glycoside linkage only. Thus, this extra residue seems to be the M-ficolin ligand. In conclusion, we were able to demonstrate specific binding of M-ficolin to some capsular polysaccharides of the opportunistic pathogen S. pneumoniae and of the commensal bacterium S. mitis. PMID:23184524

Surface modification of blood-contacting biomaterials by plasma-polymerized superhydrophobic films using hexamethyldisiloxane and tetrafluoromethane as precursors

NASA Astrophysics Data System (ADS)

Hsiao, Chaio-Ru; Lin, Cheng-Wei; Chou, Chia-Man; Chung, Chi-Jen; He, Ju-Liang

2015-08-01

This paper proposes a plasma polymerization system that can be used to modify the surface of the widely used biomaterial, polyurethane (PU), by employing low-cost hexamethyldisiloxane (HMDSO) and tetrafluoromethane (CF4) as precursors; this system features a pulsed-dc power supply. Plasma-polymerized HMDSO/CF4 (pp-HC) with coexisting micro- and nanoscale morphology was obtained as a superhydrophobic coating material by controlling the HMDSO/CF4 (fH) monomer flow ratio. The developed surface modification technology can be applied to medical devices, because it is non-cytotoxic and has favorable hemocompatibility, and no blood clots form when the device surface direct contacts. Experimental results reveal that the obtained pp-HC films contained SiOx nanoparticles randomly dispersed on the micron-scale three-dimensional network film surface. The sbnd CF functional group, sbnd CF2 bonding, and SiOx were detected on the film surface. The maximal water contact angle of the pp-HC coating was 161.2°, apparently attributable to the synergistic effect of the coexisting micro- and nanoscale surface morphology featuring a low surface-energy layer. The superhydrophobic and antifouling characteristics of the coating were retained even after it was rubbed 20 times with a steel wool tester. Results of in vitro cytotoxicity, fibrinogen adsorption, and platelet adhesion tests revealed favorable myoblast cell proliferation and the virtual absence of fibrinogen adsorption and platelet adhesion on the pp-HC coated specimens. These quantitative findings imply that the pp-HC coating can potentially prevent the formation of thrombi and provide an alternative means of modifying the surfaces of blood-contacting biomaterials.

The role of complement C3 and fibrinogen in monocyte adhesion to PEO like plasma deposited tetraglyme

PubMed Central

Szott, Luisa M.; Horbett, Thomas A.

2010-01-01

The role of complement C3 in mediating adhesion of monocytes to plasma deposited tetraglyme surfaces was studied. Although fibrinogen (Fg) is usually considered the main factor in mediating phagocyte attachment, plasma deposited PEO-like tetraethylene glycol dimethyl ether (tetraglyme) coatings that have ultra-low Fg adsorption (< 10 ng/cm2) from low concentration solutions and low monocyte adhesion in vitro still show high phagocyte adhesion after short implantations and later become encapsulated when tested in vivo. To test whether higher Fg adsorption under in vivo conditions could explain the higher in vivo reactivity, we again measured the resistance of tetraglyme films to Fg adsorption. We found a surprising and previously unreported increased amount of adsorbed Fg on tetraglyme surfaces from higher concentration protein solutions. However, monocyte adhesion to tetraglyme did not markedly increase despite the increased Fg adsorption. We thus suspected proteins other than Fg must be responsible for the increased in vivo reactivity. We found that on tetraglyme pre-adsorbed with C3-depleted serum, monocyte adhesion was greatly reduced as compared to samples adsorbed with normal serum. Addition of exogenous pure C3 to the serum used to pre-adsorb the surfaces restored monocyte adhesion to tetraglyme coatings. While Fg clearly plays an important role in mediating monocyte adhesion to tetraglyme surfaces, the results show an additional role for adsorbed C3 in monocyte adhesion. PMID:20939050

Conditioned media from (pre)adipocytes stimulate fibrinogen and PAI-1 production by HepG2 hepatoma cells

PubMed Central

Faber, D R; Kalkhoven, E; Westerink, J; Bouwman, J J; Monajemi, H M; Visseren, F L J

2012-01-01

Background: Obesity is associated with a prothrombotic state, which may contribute to the increased risk of thrombotic events. Objective: To assess the effects of (pre)adipocyte-derived adipokines on fibrinogen, plasminogen activator inhibitor-1 (PAI-1) and tissue factor (TF) production by hepatocytes. Methods: HepG2 hepatocytes were incubated with conditioned media (CM) derived from preadipocytes and adipocytes, which had been untreated or prestimulated with tumor necrosis factor (TNF)-α, interleukin (IL)-1β or IL-6. After 24 h, supernatants and cell lysates were harvested for measurement of fibrinogen, PAI-1 and TF. Results: (Pre)adipocyte CM significantly enhanced the production of PAI-1 by HepG2 cells 2.5- to 4.4-fold. CM from cytokine-stimulated (pre)adipocytes significantly induced fibrinogen secretion 1.5- to 4.2-fold. TF production was not affected by the CM. After specific depletion of TNF-α, IL-1β or IL-6 from the CM, IL-6 was shown to be the most prominent stimulus of fibrinogen secretion and IL-1β of PAI-1 secretion. In addition, fibrinogen, PAI-1 and tissue factor production was evaluated by direct stimulation of HepG2 cells with TNF-α, IL-1β or IL-6. IL-6 enhanced fibrinogen synthesis 4.3-fold (P<0.01), whereas IL-1β induced PAI-1 production 5.0-fold (P<0.01). Gene expression analyses showed that TNF-α and IL-1β stimulate the adipocyte expression of TNF-α, IL-1β and IL-6. Cytokine stimulation of adipocytes may thus have induced an inflammatory response, which may have stimulated fibrinogen and PAI-1 production by HepG2 cells more potently. Conclusions: SGBS (pre)adipocytes release cytokines that increase the production of fibrinogen and PAI-1 by HepG2 cells. IL-6 and IL-1β produced by (pre)adipocytes were the strongest inducers of fibrinogen and PAI-1 secretion, respectively. PMID:23208413

Role of serum fibrinogen levels in patients with rotator cuff tears.

PubMed

Longo, Umile Giuseppe; Petrillo, Stefano; Berton, Alessandra; Spiezia, Filippo; Loppini, Mattia; Maffulli, Nicola; Denaro, Vincenzo

2014-01-01

Although rotator cuff (RC) tendinopathy is a frequent pathology of the shoulder, the real understanding of its aetiopathogenesis is still unclear. Several studies showed that RC tendinopathy is more frequent in patients with hyperglycemia, diabetes, obesity, or metabolic syndrome. This paper aims to evaluate the serum concentration of fibrinogen in patients with RC tears. Metabolic disorders have been related to high concentration of serum fibrinogen and the activity of fibrinogen has been proven to be crucial in the development of microvascular damage. Thus, it may produce progression of RC degeneration by reducing the vascular supply of tendons. We report the results of a cross-sectional frequency-matched case-control study comparing the serum concentration of fibrinogen of patients with RC tears with that of a control group of patients without history of RC tears who underwent arthroscopic meniscectomy. We choose to enrol in the control group patients with pathology of the lower limb with a likely mechanic, not metabolic, cause, different from tendon pathology. We found no statistically significant differences in serum concentration of fibrinogen when comparing patients with RC tears and patients who underwent arthroscopic meniscectomy (P = 0.5). Further studies are necessary to clarify the role of fibrinogen in RC disease.

Acute hyperfibrinogenemia impairs cochlear blood flow and hearing function in guinea pigs in vivo.

PubMed

Ihler, Fritz; Strieth, Sebastian; Pieri, Nicos; Göhring, Peter; Canis, Martin

2012-03-01

Impairment of microcirculation is a possible cause of sudden sensorineural hearing loss (SSNHL). Fibrinogen is known as a risk factor for both microvascular dysfunction and SSNHL. Therefore, the aim of this study was to investigate the effect of elevated serum levels of fibrinogen on cochlear blood flow and hearing function in vivo. One group of guinea pigs received two consecutive injections of 100 mg fibrinogen while a control group received equimolar doses of albumin. Measurements of cochlear microcirculation by intravital microscopy and of hearing thresholds by auditory brainstem response (ABR) recordings were carried out before, after first and after second injection. Ten healthy guinea pigs were randomly assigned to a treatment group or a control group of five animals each. Serum fibrinogen levels were elevated after the first and second injections of fibrinogen compared to basal values and control group respectively. Increasing levels of fibrinogen were paralleled by decreasing cochlear blood flow as well as increasing hearing thresholds. Hearing threshold correlated negatively with cochlear blood flow. The effect of microcirculatory impairment on hearing function could be explained by a malfunction of the cochlear amplifier. Further investigation is needed to quantify cochlear potentials under elevated serum fibrinogen levels.

Influence of Ficoll on urea induced denaturation of fibrinogen

NASA Astrophysics Data System (ADS)

Sankaranarayanan, Kamatchi; Meenakshisundaram, N.

2016-03-01

Ficoll is a neutral, highly branched polymer used as a molecular crowder in the study of proteins. Ficoll is also part of Ficoll-Paque used in biology laboratories to separate blood to its components (erythrocytes, leukocytes etc.,). Role of Ficoll in the urea induced denaturation of protein Fibrinogen (Fg) has been analyzed using fluorescence, circular dichroism, molecular docking and interfacial studies. Fluorescence studies show that Ficoll prevents quenching of Fg in the presence of urea. From the circular dichroism spectra, Fg shows conformational transition to random coil with urea of 6 M concentration. Ficoll helps to shift this denaturation concentration to 8 M and thus constraints by shielding Fg during the process. Molecular docking studies indicate that Ficoll interacts favorably with the protein than urea. The surface tension and shear viscosity analysis shows clearly that the protein is shielded by Ficoll.

Method for estimating protein binding capacity of polymeric systems.

PubMed

Sharma, Vaibhav; Blackwood, Keith A; Haddow, David; Hook, Lilian; Mason, Chris; Dye, Julian F; García-Gareta, Elena

2015-01-01

Composite biomaterials made from synthetic and protein-based polymers are extensively researched in tissue engineering. To successfully fabricate a protein-polymer composite, it is critical to understand how strongly the protein binds to the synthetic polymer, which occurs through protein adsorption. Currently, there is no cost-effective and simple method for characterizing this interfacial binding. To characterize this interfacial binding, we introduce a simple three-step method that involves: 1) synthetic polymer surface characterisation, 2) a quick, inexpensive and robust novel immuno-based assay that uses protein extraction compounds to characterize protein binding strength followed by 3) an in vitro 2D model of cell culture to confirm the results of the immuno-based assay. Fibrinogen, precursor of fibrin, was adsorbed (test protein) on three different polymeric surfaces: silicone, poly(acrylic acid)-coated silicone and poly(allylamine)-coated silicone. Polystyrene surface was used as a reference. Characterisation of the different surfaces revealed different chemistry and roughness. The novel immuno-based assay showed significantly stronger binding of fibrinogen to both poly(acrylic acid) and poly(allylamine) coated silicone. Finally, cell studies showed that the strength of the interaction between the protein and the polymer had an effect on cell growth. This novel immuno-based assay is a valuable tool in developing composite biomaterials of synthetic and protein-based polymers with the potential to be applied in other fields of research where protein adsorption onto surfaces plays an important role.

The acute phase reactant, fibrinogen, as a guide to plasma exchange therapy for acute Guillain-Barré syndrome.

PubMed

Sanjay, Rashmi; Flanagan, Janice; Sodano, Donata; Gorson, Kenneth C; Ropper, Allan H; Weinstein, Robert

2006-07-01

The Guillian Barré syndrome is an acute inflammatory disorder for which plasma exchange is effective treatment. Up to 10% relapse after plasma exchange suggesting that treatment sometimes finishes before disease activity has resolved. We studied whether plasma fibrinogen, an inflammatory marker, might be used to determine when to discontinue plasma exchange in patients with acute Guillain-Barré syndrome. We conducted a post-hoc analysis of apheresis database and hospital records of patients treated with plasma exchange for acute Guillain-Barré syndrome during 1999-2004. Data were analyzed from 28 patients who underwent a total of 29 courses of plasma exchange for acute Guillain-Barré syndrome. The mean (+/-SD) plasma fibrinogen concentration was 422.5 (+/-96.4) mg/dl at the time of presentation and, in 17 of the 29, it was above 400 mg/dl (reference range 200-400). Twenty of the 21 patients whose fibrinogen fell by more than 30% from baseline by the time of the final plasma exchange treatment had neurological improvement. There was improvement in only 3 of the 8 instances where fibrinogen decreased by less than 30% by the end of plasma exchange therapy. A > or =30% decrease in fibrinogen by the conclusion of plasma exchange was significantly associated with sustained neurological improvement (P = 0.0025). The plasma fibrinogen level appears to reflect disease activity in acute Guillain-Barré syndrome. A <30% fall in fibrinogen level despite plasma exchange may indicate the need to continue plasma exchange to maximize the benefit of treatment or minimize the risk of relapse. Therapeutic plasma exchange need not be extended when plasma fibrinogen remains > or =30% below its level at presentation by the time of the final planned plasma exchange procedure.

The in vivo effect of fibrinogen and factor XIII on clot formation and fibrinolysis in Glanzmann's thrombasthenia.

PubMed

Shenkman, Boris; Livnat, Tami; Misgav, Mudi; Budnik, Ivan; Einav, Yulia; Martinowitz, Uriel

2012-01-01

Glanzmann's thrombasthenia (GT) is characterized by increased bleeding risk. The treatment options in GT are limited. The aim of this study was to test the effect of GT blood supplementation with fibrinogen and factor XIII on thrombin generation, blood clotting, and fibrinolysis. Whole blood samples of GT patients and normal donors treated with eptifibatide (GT model) were subjected to clotting by CaCl(2) and tissue factor. Thrombin generation was measured in platelet-rich plasma. Clot formation and tPA-induced fibrinolysis were evaluated in whole blood by rotation thromboelastometry (ROTEM). Blood was supplemented with fibrinogen (3 g/L) and/or FXIII (2 IU/mL). Thrombin generation analysis of blood derived from GT model and GT patients revealed decreased endogenous thrombin potential and peak height and extended lag time compared to control. However, this method was not sensitive to blood spiking with fibrinogen and FXIII. ROTEM revealed lower maximum clot firmness (MCF) and area under curve (AUC) in the blood of GT model and GT patients. In the absence of exogenous tPA, blood spiking with fibrinogen markedly enhanced clot quality while FXIII had no effect. Combination of fibrinogen and FXIII did not add to the effect of fibrinogen. In contrast, by the addition of tPA, both fibrinogen and FXIII separately and, to more extent, in combination enhanced clot quality as well as resistance against tPA-induced fibrinolysis (increasing MCF, AUC, and lysis onset time). In conclusion, fibrinogen and FXIII exerted stimulation of blood clotting and inhibition of fibrinolysis. Treating normal blood with eptifibatide mimics the changes of coagulopathy in GT blood.

Use of human fibrinogen concentrate during proximal aortic reconstruction with deep hypothermic circulatory arrest.

PubMed

Hanna, Jennifer M; Keenan, Jeffrey E; Wang, Hanghang; Andersen, Nicholas D; Gaca, Jeffrey G; Lombard, Frederick W; Welsby, Ian J; Hughes, G Chad

2016-02-01

Human fibrinogen concentrate (HFC) is approved by the Food and Drug Administration for use at 70 mg/kg to treat congenital afibrinogenemia. We sought to determine whether this dose of HFC increases fibrinogen levels in the setting of high-risk bleeding associated with aortic reconstruction and deep hypothermic circulatory arrest (DHCA). This was a prospective, pilot, off-label study in which 22 patients undergoing elective proximal aortic reconstruction with DHCA were administered 70 mg/kg HFC upon separation from cardiopulmonary bypass (CPB). Fibrinogen levels were measured at baseline, just before, and 10 minutes after HFC administration, on skin closure, and the day after surgery. The primary study outcome was the difference in fibrinogen level immediately after separation from CPB, when HFC was administered, and the fibrinogen level 10 minutes following HFC administration. Additionally, postoperative thromboembolic events were assessed as a safety analysis. The mean baseline fibrinogen level was 317 ± 49 mg/dL and fell to 235 ± 39 mg/dL just before separation from CPB. After HFC administration, the fibrinogen level rose to 331 ± 41 mg/dL (P < .001) and averaged 372 ± 45 mg/dL the next day. No postoperative thromboembolic complications occurred. Administration of 70 mg/kg HFC upon separation from CPB raises fibrinogen levels by approximately 100 mg/dL without an apparent increase in thrombotic complications during proximal aortic reconstruction with DHCA. Further prospective study in a larger cohort of patients will be needed to definitively determine the safety and evaluate the efficacy of HFC as a hemostatic adjunct during these procedures. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

The place of fibrinogen concentrates in the management of perioperative bleeding: A position paper from the Francophone Working Group on Perioperative Haemostasis (GIHP).

PubMed

Samama, Charles Marc; Ickx, Brigitte; Ozier, Yves; Steib, Annick; Susen, Sophie; Godier, Anne

2018-04-13

The consumption of fibrinogen concentrates has been increasing steadily for several years in surgery, trauma and obstetrics. However, data from the literature are conflicting. The French Working Group on Perioperative Haemostasis (GIHP) proposes a position paper based on a narrative review of the literature, and addresses the following questions: What is the exact role of fibrinogen in haemostasis? Which rational support for the use of perioperative fibrinogen? Which thrombotic risk? What are the most recent professional recommendations on the use of fibrinogen concentrates? Then, evidence-based recommendations are proposed: 1) it is suggested not to administer prophylactic FC to prevent haemorrhage; 2) it is suggested not to use FC alone. Haemostatic treatment must be comprehensive, include other haemostatic treatments and must be limited in cases of severe active haemorrhage; 3) the GIHP suggests urgent measurement of fibrinogen plasma concentration in a biology laboratory or functional fibrinogen by viscoelastic methods. The choice between the two methods must be guided by the time to receive the results from a certified organisation with, in particular, authorisation to perform delocalised biologic examinations; 4) it is suggested not to administer FC when the fibrinogen concentration is superior to 1.5g/L or when there is a functional fibrinogen deficit (with the possible exception in obstetrics where the threshold could be 2.0g/L); 5) if FC are administered, an initial dose of 25-50mg/kg is proposed. Copyright © 2018 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

The combination of recombinant factor VIIa and fibrinogen correct clotting ex vivo in patient samples obtained following cardiopulmonary bypass surgery.

PubMed

Sørensen, Benny; Asvaldsdottir, Hanna S; Gudmundsdottir, Brynja R; Onundarson, Pall T

2009-12-01

Cardiac surgery involving cardio pulmonary bypass (CPB) may be associated with development of a coagulopathy that increases risk of bleeding. In the present ex vivo study we investigated the influence of fibrinogen and rFVIIa, alone or in combination, on whole blood coagulation thromboelastometry using pre- and postoperative blood samples from 18 consecutive adult patients undergoing CPB surgery. Dynamic thromboelastometric clotting profiles were recorded using citrated whole blood activated with trace amounts of tissue factor (Innovin, final dilution 1:17000). Blood samples were collected before surgery (control) and postoperative samples were obtained following in vivo neutralization of heparin with protamine sulphate. All blood samples were treated with heparinase to ensure neutralization of possible residual heparin effect. The post-operative blood samples were spiked with buffer, rFVIIa (2 microg/mL), fibrinogen (1 mg/mL), or the combination of rFVIIa and fibrinogen. Despite neutralization of heparin, CPB surgery left a measurable coagulopathy that was thromboelastometrically characterized by prolonged onset of clotting, reduced maximum velocity of clot formation (MaxVel), and decreased maximum clot firmness (MCF). Ex vivo spiking of the postoperative samples with rFVIIa shortened the clotting time. Fibrinogen also shortened the clotting time and, in addition, improved the MaxVel, and MCF. Finally, adding the combination of rFVIIa and fibrinogen to the postoperative samples corrected all thromboelastometric parameters to the preoperative range. In conclusion, the correction of whole blood clotting abnormalities that occurs with rFVIIa and/or fibrinogen suggests that future clinical trials on treatment of bleeding during CPB surgery should study the haemostatic effect of fibrinogen or possibly the combination of rFVIIa and fibrinogen.

Neutropenia fails to prevent the acute phase stimulation of fibrinogen synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kernoff, L.; Colman, J.

This study evaluates the role of neutrophil granulocytes in mediating acute phase stimulation of fibrinogen synthesis. Turpentine was administered to neutropenic and non-neutropenic rats and fibrinogen synthetic rates measured in an isolated liver perfusion system. Using the (/sup 14/C) carbonate technique for the measurement of the absolute synthetic rates of liver produced plasma proteins it was observed that the rates of fibrinogen synthesis of the neutropenic and non-neutropenic rats were significantly greater (p less than 0.01) than those of normal control animals, but were not significantly different from each other. These results suggest that the neutrophil granulocyte may not bemore » of major importance in mediating acute phase stimulation of fibrinogen synthesis.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gencoglu, Maria F.; Spurri, Amanda; Franko, Mitchell

We report that soft-templated mesoporous carbon is morphologically a non-nano type of carbon. It is a relatively newer variety of biomaterial, which has already demonstrated its successful role in drug delivery applications. To investigate the toxicity and biocompatibility, we introduced three types of mesoporous carbons with varying synthesis conditions and pore textural properties. We compared the Brunauer–Emmett–Teller (BET) surface area and pore width and performed cytotoxicity experiments with HeLa cells, cell viability studies with fibroblast cells and hemocomapatibility studies. Cytotoxicity tests reveal that two of the carbons are not cytotoxic, with cell survival over 90%. The mesoporous carbon with themore » highest surface area showed slight toxicity (~70% cell survival) at the highest carbon concentration of 500 μg/mL. Fibroblast cell viability assays suggested high and constant viability of over 98% after 3 days with no apparent relation with materials property and good visible cell-carbon compatibility. No hemolysis (<1%) was confirmed for all the carbon materials. Protein adsorption experiments with bovine serum albumin (BSA) and fibrinogen revealed a lower protein binding capacity of 0.2–0.6 mg/m 2 and 2–4 mg/m 2 for BSA and fibrinogen, respectively, with lower binding associated with an increase in surface area. The results of this study confirm the biocompatibility of soft-templated mesoporous carbons.« less

Staphylococcus aureus aggregation and coagulation mechanisms, and their function in host-pathogen interactions

PubMed Central

Crosby, Heidi A.; Kwiecinski, Jakub; Horswill, Alexander R.

2017-01-01

The human commensal bacterium Staphylococcus aureus can cause a wide range of infections ranging from skin and soft tissue infections to invasive diseases like septicemia, endocarditis, and pneumonia. Muticellular organization almost certainly contributes to S. aureus pathogenesis mechanisms. While there has been considerable focus on biofilm formation and its role in colonizing prosthetic joints and indwelling devices, less attention has been paid to non-surface attached group behavior like aggregation and clumping. S. aureus is unique in its ability to coagulate blood, and it also produces multiple fibrinogen-binding proteins that facilitate clumping. Formation of clumps, which are large, tightly-packed groups of cells held together by fibrin(ogen), has been demonstrated to be important for S. aureus virulence and immune evasion. Clumps of cells are able to avoid detection by the host’s immune system due to a fibrin(ogen) coat that acts as a shield, and the size of the clumps facilitates evasion of phagocytosis. In addition, clumping could be an important early step in establishing infections that involve tight clusters of cells embedded in host matrix proteins, such as soft tissue abscesses and endocarditis. In this review we discuss clumping mechanisms and regulation, as well as what is known about how clumping contributes to immune evasion. PMID:27565579

Fibrinogen storage disease in a Chinese boy with de novo fibrinogen Aguadilla mutation: Incomplete response to carbamazepine and ursodeoxycholic acid.

PubMed

Zhang, Mei-Hong; Knisely, A S; Wang, Neng-Li; Gong, Jing-Yu; Wang, Jian-She

2016-08-12

Fibrinogen storage disease (FSD) is a rare autosomal-dominant disorder caused by mutation in FGG, encoding the fibrinogen gamma chain. Here we report the first Han Chinese patient with FSD, caused by de novo fibrinogen Aguadilla mutation, and his response to pharmacologic management. Epistaxis and persistent clinical-biochemistry test-result abnormalities prompted liver biopsy in a boy, with molecular study of FGG in him and his parents. He was treated with the autophagy enhancer carbamazepine, reportedly effective in FSD, and with ursodeoxycholic acid thereafter. Inclusion bodies in hepatocellular cytoplasm stained immune-histochemically for fibrinogen. Selective analysis of FGG found the heterozygous mutation c.1201C > T (p.Arg401Trp), absent in both parents. Over more than one year's follow-up, transaminase and gamma-glutamyl transpeptidase activities have lessened but not normalized. This report expands the epidemiology of FSD and demonstrates idiosyncrasy in response to oral carbamazepine and/or ursodeoxycholic acid in FSD.

Contribution of the Interaction of Streptococcus mutans Serotype k Strains with Fibrinogen to the Pathogenicity of Infective Endocarditis

PubMed Central

Nomura, Ryota; Otsugu, Masatoshi; Naka, Shuhei; Teramoto, Noboru; Kojima, Ayuchi; Muranaka, Yoshinori; Matsumoto-Nakano, Michiyo; Ooshima, Takashi

2014-01-01

Streptococcus mutans, a pathogen responsible for dental caries, is occasionally isolated from the blood of patients with bacteremia and infective endocarditis (IE). Our previous study demonstrated that serotype k-specific bacterial DNA is frequently detected in S. mutans-positive heart valve specimens extirpated from IE patients. However, the reason for this frequent detection remains unknown. In the present study, we analyzed the virulence of IE from S. mutans strains, focusing on the characterization of serotype k strains, most of which are positive for the 120-kDa cell surface collagen-binding protein Cbm and negative for the 190-kDa protein antigen (PA) known as SpaP, P1, antigen I/II, and other designations. Fibrinogen-binding assays were performed with 85 clinical strains classified by Cbm and PA expression levels. The Cbm+/PA− group strains had significantly higher fibrinogen-binding rates than the other groups. Analysis of platelet aggregation revealed that SA31, a Cbm+/PA− strain, induced an increased level of aggregation in the presence of fibrinogen, while negligible aggregation was induced by the Cbm-defective isogenic mutant SA31CBD. A rat IE model with an artificial impairment of the aortic valve created using a catheter showed that extirpated heart valves in the SA31 group displayed a prominent vegetation mass not seen in those in the SA31CBD group. These findings could explain why Cbm+/PA− strains are highly virulent and are related to the development of IE, and the findings could also explain the frequent detection of serotype k DNA in S. mutans-positive heart valve clinical specimens. PMID:25287921

Contribution of the interaction of Streptococcus mutans serotype k strains with fibrinogen to the pathogenicity of infective endocarditis.

PubMed

Nomura, Ryota; Otsugu, Masatoshi; Naka, Shuhei; Teramoto, Noboru; Kojima, Ayuchi; Muranaka, Yoshinori; Matsumoto-Nakano, Michiyo; Ooshima, Takashi; Nakano, Kazuhiko

2014-12-01

Streptococcus mutans, a pathogen responsible for dental caries, is occasionally isolated from the blood of patients with bacteremia and infective endocarditis (IE). Our previous study demonstrated that serotype k-specific bacterial DNA is frequently detected in S. mutans-positive heart valve specimens extirpated from IE patients. However, the reason for this frequent detection remains unknown. In the present study, we analyzed the virulence of IE from S. mutans strains, focusing on the characterization of serotype k strains, most of which are positive for the 120-kDa cell surface collagen-binding protein Cbm and negative for the 190-kDa protein antigen (PA) known as SpaP, P1, antigen I/II, and other designations. Fibrinogen-binding assays were performed with 85 clinical strains classified by Cbm and PA expression levels. The Cbm(+)/PA(-) group strains had significantly higher fibrinogen-binding rates than the other groups. Analysis of platelet aggregation revealed that SA31, a Cbm(+)/PA(-) strain, induced an increased level of aggregation in the presence of fibrinogen, while negligible aggregation was induced by the Cbm-defective isogenic mutant SA31CBD. A rat IE model with an artificial impairment of the aortic valve created using a catheter showed that extirpated heart valves in the SA31 group displayed a prominent vegetation mass not seen in those in the SA31CBD group. These findings could explain why Cbm(+)/PA(-) strains are highly virulent and are related to the development of IE, and the findings could also explain the frequent detection of serotype k DNA in S. mutans-positive heart valve clinical specimens. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Proinflammatory and prothrombotic state in subjects with different glucose tolerance status before cardiovascular disease.

PubMed

Isordia-Salas, Irma; Galván-Plata, María Eugenia; Leaños-Miranda, Alfredo; Aguilar-Sosa, Eberth; Anaya-Gómez, Francisco; Majluf-Cruz, Abraham; Santiago-Germán, David

2014-01-01

Inflammation has been associated with insulin resistance, type 2 diabetes mellitus (T2DM), and atherothrombosis. To determine differences in levels of proinflammatory and prothrombotic markers such as high sensitivity C-reactive protein (hs-CRP) and fibrinogen in subjects with normal glucose tolerance (NGT), prediabetes, and T2DM and to establish their relationship with other cardiovascular risk factors before clinical manifestations of cardiovascular disease. We conducted a nonrandomized, cross-sectional assay in a hospital at México City. The levels of hs-CRP and fibrinogen were measured and compared according to glucose tolerance status. We enrolled 1047 individuals and they were distributed into NGT n = 473, pre-DM n = 250, and T2DM n = 216. There was a statistical difference between NGT and T2DM groups for fibrinogen (P = 0.01) and hs-CRP (P = 0.05). Fibrinogen and hs-CRP showed a significant positive correlation coefficient (r = 0.53, P<0.0001). In a multiple stepwise regression analysis, the variability in fibrinogen levels was explained by age, HbA1c, and hs-CRP (adjusted R² = 0.31, P<0.0001), and for hs-CRP it was explained by BMI and fibrinogen (adjusted R² = 0.33, P<0.0001). Inflammation and prothrombotic state are present in people with T2DM lacking cardiovascular disease. Fibrinogen and Hs-CRP are positively correlated. Fibrinogen and hs-CRP concentrations are predominantly determined by BMI rather than glucose levels.

Proinflammatory and Prothrombotic State in Subjects with Different Glucose Tolerance Status before Cardiovascular Disease

PubMed Central

Isordia-Salas, Irma; Galván-Plata, María Eugenia; Leaños-Miranda, Alfredo; Aguilar-Sosa, Eberth; Anaya-Gómez, Francisco; Majluf-Cruz, Abraham; Santiago-Germán, David

2014-01-01

Background. Inflammation has been associated with insulin resistance, type 2 diabetes mellitus (T2DM), and atherothrombosis. Aim. To determine differences in levels of proinflammatory and prothrombotic markers such as high sensitivity C-reactive protein (hs-CRP) and fibrinogen in subjects with normal glucose tolerance (NGT), prediabetes, and T2DM and to establish their relationship with other cardiovascular risk factors before clinical manifestations of cardiovascular disease. Methods. We conducted a nonrandomized, cross-sectional assay in a hospital at México City. The levels of hs-CRP and fibrinogen were measured and compared according to glucose tolerance status. Results. We enrolled 1047 individuals and they were distributed into NGT n = 473, pre-DM n = 250, and T2DM n = 216. There was a statistical difference between NGT and T2DM groups for fibrinogen (P = 0.01) and hs-CRP (P = 0.05). Fibrinogen and hs-CRP showed a significant positive correlation coefficient (r = 0.53, P<0.0001). In a multiple stepwise regression analysis, the variability in fibrinogen levels was explained by age, HbA1c, and hs-CRP (adjusted R 2 = 0.31, P<0.0001), and for hs-CRP it was explained by BMI and fibrinogen (adjusted R 2 = 0.33, P<0.0001). Conclusion. Inflammation and prothrombotic state are present in people with T2DM lacking cardiovascular disease. Fibrinogen and Hs-CRP are positively correlated. Fibrinogen and hs-CRP concentrations are predominantly determined by BMI rather than glucose levels. PMID:24772446

Fibrinogen: cardiometabolic risk marker in obese or overweight children and adolescents.

PubMed

Azevedo, Waldeneide F; Cantalice, Anajás S C; Gonzaga, Nathalia C; Simões, Mônica O da S; Guimarães, Anna Larissa V; Carvalho, Danielle F de; Medeiros, Carla Campos Muniz

2015-01-01

To determine the prevalence of increased serum fibrinogen levels and its association with cardiometabolic risk factors in overweight or obese children and adolescents. Cross-sectional study with 138 children and adolescents (overweight or obese) followed at a reference outpatient clinic of the public health care network. Fibrinogen concentration was divided into quartiles, and values above or equal to the third quartile were considered high. The association between high fibrinogen values and cardiometabolic risk factors was assessed using Pearson's chi-squared test or Fisher's exact test, as necessary. Logistic regression was used to adjust variables predictive of fibrinogen levels. Analyses were performed using SPSS version 22.0 and SAS software, considering a confidence interval of 95%. Serum fibrinogen levels were elevated in 28.3% of individuals, showing association with the presence of high CRP (p=0.003, PR: 2.41, 95% CI: 1.30-4.46) and the presence of four or more risk factors (p=0.042; PR: 1.78, 95% CI: 1.00-3.17). After a logistic regression, only elevated CRP remained associated with altered fibrinogen levels (p=0.024; PR: 1.32; 95% CI: 1.09-5.25). Increased fibrinogen was prevalent in the study population and was associated with ultrasensitive C-reactive protein and the presence of four or more cardiovascular risk factors; it should be included in the assessment of individuals at risk. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

The Enterococcus faecalis EbpA Pilus Protein: Attenuation of Expression, Biofilm Formation, and Adherence to Fibrinogen Start with the Rare Initiation Codon ATT

PubMed Central

Montealegre, Maria Camila; La Rosa, Sabina Leanti; Roh, Jung Hyeob; Harvey, Barrett R.

2015-01-01

ABSTRACT The endocarditis and biofilm-associated pili (Ebp) are important in Enterococcus faecalis pathogenesis, and the pilus tip, EbpA, has been shown to play a major role in pilus biogenesis, biofilm formation, and experimental infections. Based on in silico analyses, we previously predicted that ATT is the EbpA translational start codon, not the ATG codon, 120 bp downstream of ATT, which is annotated as the translational start. ATT is rarely used to initiate protein synthesis, leading to our hypothesis that this codon participates in translational regulation of Ebp production. To investigate this possibility, site-directed mutagenesis was used to introduce consecutive stop codons in place of two lysines at positions 5 and 6 from the ATT, to replace the ATT codon in situ with ATG, and then to revert this ATG to ATT; translational fusions of ebpA to lacZ were also constructed to investigate the effect of these start codons on translation. Our results showed that the annotated ATG does not start translation of EbpA, implicating ATT as the start codon; moreover, the presence of ATT, compared to the engineered ATG, resulted in significantly decreased EbpA surface display, attenuated biofilm, and reduced adherence to fibrinogen. Corroborating these findings, the translational fusion with the native ATT as the initiation codon showed significantly decreased expression of β-galactosidase compared to the construct with ATG in place of ATT. Thus, these results demonstrate that the rare initiation codon of EbpA negatively regulates EbpA surface display and negatively affects Ebp-associated functions, including biofilm and adherence to fibrinogen. PMID:26015496

[Lipid changes of fibrinogen and of platelet aggregation induced by etofibrate].

PubMed

Fonseca, F A; Novazzi, J P; Cendoroglo, M S; Duarte, M; Almeida Pinto, L E; Rabelo, L M; da Rocha Martinez, T L

1996-01-01

To evaluate modifications on lipid profile, fibrinogen and platelet aggregation induced by etofibrate. Twenty-one adult patients were studied. They all had primary hyperlipidemia and had already been on the AHA step I diet and placebo. Etofibrate (500mg/day) was administered for 60 days in the active phase, when lipid parameters, fibrinogen and platelet aggregation were measured. The % significant reductions were: total cholesterol (-9.50%), LDL-cholesterol (-7.88%), triglycerides (-19.07%), total cholesterol/HDL-cholesterol(-11.90%), LDL-cholesterol/HDL-cholesterol (-10.20%), fibrinogen (-12.79%), platelet aggregation with adrenaline (-24.02%), with ADP 1 mumol (-30.13%), and ADP 3 mumol (-24.51%). The beneficial effects of etofibrate were observed not only on the lipid profile but also on the thrombogenic parameters measured by fibrinogen and platelet aggregation.

The fibrinogen/CRP ratio as a new parameter for the diagnosis of disseminated intravascular coagulation in patients with HELLP syndrome and as a predictive factor for neonatal outcome.

PubMed

Windsperger, Karin; Lehner, Rainer

2013-02-01

The aim of this study was to determine if the fibrinogen/C-reactive protein (CRP) ratio could be used in obstetrics as a predictor for a disseminated intravascular coagulation. One hundred eleven patients with hemolysis, elevated liver enzymes, and low platelet count syndrome at the Department of Obstetrics and Fetomaternal Medicine (General Hospital, Vienna, Austria) were selected and divided into 2 groups (overt disseminated intravascular coagulation, no overt disseminated intravascular coagulation). The classical parameters and the fibrinogen/CRP ratio were compared. The analysis was carried out using IBM SPSS statistical package (SPSS, Inc, Cary, NC). The fibrinogen/CRP ratio showed significant differences. The receiver-operating characteristic analysis showed for the ratio (area under the curve, 0.74) significantly better discriminative power than for fibrinogen (area under curve, 0.59). The odds ratio for the fibrinogen/CRP ratio was 7.04. Finally, significant correlations between the ratio and the neonatal outcome were found. We suggest the implementation of the fibrinogen/CRP ratio within patients with hemolysis, elevated liver enzymes, and low platelet count syndrome as a diagnostic and prognostic factor for the occurrence of disseminated intravascular coagulation. Copyright © 2013 Mosby, Inc. All rights reserved.

Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Svensson, Jan, E-mail: jan.svensson@ki.se; Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm; Bergman, Ann-Charlotte

Highlights: Black-Right-Pointing-Pointer Fibrinogen was incubated in vitro with glucose or aspirin. Black-Right-Pointing-Pointer Acetylations and glycations were found at twelve lysine sites by mass spectrometry. Black-Right-Pointing-Pointer The labeling by aspirin and glucose occurred dose-dependently. Black-Right-Pointing-Pointer No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent - a phenomenon called 'aspirin resistance'. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirinmore » in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to 'aspirin resistance' in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5-10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the {alpha}-chain: {alpha}K191, {alpha}K208, {alpha}K224, {alpha}K429, {alpha}K457, {alpha}K539, {alpha}K562, in the {beta}-chain: {beta}K233, and in the {gamma}-chain: {gamma}K170 and {gamma}K273. Glycations were found at {beta}K133 and {gamma}K75, alternatively {gamma}K85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [{sup 14}C-acetyl]salicylic acid and [{sup 14}C]glucose, a labeling of 0.013-0.084 and 0.12-0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9-100 {mu}M aspirin) and physiologically (2-8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of fibrinogen. This may mechanistically explain why aspirin facilitates fibrin degradation. We find no support for the idea that glycation of fibrin(ogen) interferes with acetylation of fibrinogen.« less

Differential regulation of macrophage inflammatory activation by fibrin and fibrinogen.

PubMed

Hsieh, Jessica Y; Smith, Tim D; Meli, Vijaykumar S; Tran, Thi N; Botvinick, Elliot L; Liu, Wendy F

2017-01-01

Fibrin is a major component of the provisional extracellular matrix formed during tissue repair following injury, and enables cell infiltration and anchoring at the wound site. Macrophages are dynamic regulators of this process, advancing and resolving inflammation in response to cues in their microenvironment. Although much is known about how soluble factors such as cytokines and chemokines regulate macrophage polarization, less is understood about how insoluble and adhesive cues, specifically the blood coagulation matrix fibrin, influence macrophage behavior. In this study, we observed that fibrin and its precursor fibrinogen elicit distinct macrophage functions. Culturing macrophages on fibrin gels fabricated by combining fibrinogen with thrombin stimulated secretion of the anti-inflammatory cytokine, interleukin-10 (IL-10). In contrast, exposure of macrophages to soluble fibrinogen stimulated high levels of inflammatory cytokine tumor necrosis factor alpha (TNF-α). Macrophages maintained their anti-inflammatory behavior when cultured on fibrin gels in the presence of soluble fibrinogen. In addition, adhesion to fibrin matrices inhibited TNF-α production in response to stimulation with LPS and IFN-γ, cytokines known to promote inflammatory macrophage polarization. Our data demonstrate that fibrin exerts a protective effect on macrophages, preventing inflammatory activation by stimuli including fibrinogen, LPS, and IFN-γ. Together, our study suggests that the presentation of fibrin(ogen) may be a key switch in regulating macrophage phenotype behavior, and this feature may provide a valuable immunomodulatory strategy for tissue healing and regeneration. Fibrin is a fibrous protein resulting from blood clotting and provides a provisional matrix into which cells migrate and to which they adhere during wound healing. Macrophages play an important role in this process, and are needed for both advancing and resolving inflammation. We demonstrate that culture of macrophages on fibrin matrices exerts an anti-inflammatory effect, whereas the soluble precursor fibrinogen stimulates inflammatory activation. Moreover, culture on fibrin completely abrogates inflammatory signaling caused by fibrinogen or known inflammatory stimuli including LPS and IFN-γ. Together, these studies show that the presentation of fibrin(ogen) is important for regulating a switch between macrophage pro- and anti-inflammatory behavior. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Association between job characteristics and plasma fibrinogen in a normal working population: a cross sectional analysis in referents of the SHEEP Study. Stockholm Heart Epidemiology Program.

PubMed

Tsutsumi, A; Theorell, T; Hallqvist, J; Reuterwall, C; de Faire, U

1999-06-01

To explore the association between job characteristics and plasma fibrinogen concentrations. Cross sectional design. The Greater Stockholm area. A total of 1018 men and 490 women aged 45-70 who were randomly selected from the general population during 1992-1994. They were all employed and had no history of myocardial infarction. The self reported job characteristics were measured by a Swedish version of the Karasek demand-control questionnaire. For inferred scoring of job characteristics, psychosocial exposure categories (job control and psychological demands) were assigned by linking each subject's occupational history with a work organisation exposure matrix. Job strain was defined as the ratio between demands and control. In univariate analyses, expected linear trends were found in three of four tests of association between high plasma fibrinogen and low control (the self reported score for women and the inferred score for both sexes), in one of four tests of association between high plasma fibrinogen and high demands (the inferred score for women) and in two of four tests of association between high plasma fibrinogen and job strain (the inferred score for both sexes). Multiple logistic regression analyses showed that men in the inferred job strain group have an increased risk of falling into the increased plasma fibrinogen concentration group (above median level of the distribution) (odds ratio (OR) 1.2; 95% CI 1.0, 1.5) after adjustment for the variables that were associated with plasma fibrinogen in the univariate analyses. In women, low self reported control, high inferred demand, and inferred job strain were significantly associated with increased plasma fibrinogen concentration (OR 1.3; 95% CI 1.0, 1.8, OR 1.5; 95% CI 1.0, 2.2, OR 1.5; 95% CI 1.1, 2.2, respectively). These results indicate that adverse job characteristics may be related to plasma fibrinogen concentrations and this relation is more relevant in female workers. The clearest evidence for psychosocial effects on plasma fibrinogen seems to be with job control and the associations are clearer for the objective than for the self report variables.

Variability of fibrinogen measurements in post-myocardial infarction patients. Results from the AIRGENE study center Augsburg.

PubMed

Baumert, Jens; Karakas, Mahir; Greven, Sonja; Rückerl, Regina; Peters, Annette; Koenig, Wolfgang

2012-05-01

Elevated fibrinogen levels are strongly and consistently associated with incident coronary heart disease (CHD). A possible causal contribution of fibrinogen in the pathway leading to atherothrombotic cardiovascular disease complications has been suggested. However, for implementation in clinical practice, data on validity and reliability, which are still scarce, are needed that are still scarce, especially in subjects with a history of CHD. For the present study, levels of plasma fibrinogen were measured in 200 post-myocardial infarction (post-MI) patients aged 39-76 years, with approximately six blood samples collected at monthly intervals between May 2003 and March 2004, giving a total of 1,144 samples. Inter-individual variability (between-subject variance component, VCb and coefficient of variation, CVb), intra-individual and analytical variability (VCw+a and CVw+a), intraclass correlation coefficient (ICC) and the number of measurements required for an ICC of 0.75 were estimated to assess the reliability of serial fibrinogen measurements. Mean fibrinogen concentration of all subjects over all samples was 3.34 g/l (standard deviation 0.67). Between-subject variation for fibrinogen was VCb = 0.34 (CVb'=17.5%) whereas within-subject and analytical variation was estimated as VCw+a = 0.14 (CVw+a=11.0%). The variation was mainly explained by between-subject variability, shown by the proportion of total variance of 71.3%. Two different measurements were required to reach sufficient reliability, if subjects with extreme values were not excluded. The present study indicates a fairly good reproducibility of serial individual fibrinogen measurements in post-MI subjects.

Prognostic significance of hyperfibrinogenemia in patients with esophageal squamous cell carcinoma.

PubMed

Suzuki, Takashi; Shimada, Hideaki; Nanami, Tatsuki; Oshima, Yoko; Yajima, Satoshi; Washizawa, Naohiro; Kaneko, Hironori

2017-06-01

Preoperative hyperfibrinogenemia is associated with inflammatory mediators and a poor prognosis in several types of cancer. However, there is no published information on the monitoring of patients with preoperative hyperfibrinogenemia after surgery. The aim of the study reported here was to assess the clinicopathological and prognostic significance of plasma fibrinogen levels in patients with esophageal squamous cell carcinoma before and after surgical treatment. Plasma fibrinogen levels were analyzed before surgical treatment (endoscopic submucosal dissection and surgery) in 82 patients with esophageal squamous cell carcinoma. The clinicopathological significance of plasma fibrinogen levels and the relationship of plasma fibrinogen levels with several biomarkers were evaluated. The cutoff value for hyperfibrinogenemia was 321 mg/dl. Univariate and multivariate analysis using the Cox proportional hazards model were performed to evaluate the prognostic significance of plasma fibrinogen levels. The changing patterns of plasma fibrinogen were monitored after surgical treatment to evaluate prognostic impact. Hyperfibrinogenemia was significantly associated with advanced pathological stage of cancer and high C-reactive protein levels. Plasma fibrinogen levels significantly decreased after surgical treatment in recurrence-free patients but did not decrease in patients with recurrence. The multivariate analysis indicated that preoperative hyperfibrinogenemia was an independent prognostic factor for poor survival (hazard ratio 1.005, 95% confidence interval 1.000-1.010; P = 0.039). Preoperative hyperfibrinogenemia was associated with inflammatory mediators, tumor progression, and poor survival in patients with esophageal squamous cell carcinoma. The absence of a decrease in plasma fibrinogen levels after surgical treatment may indicate the possibility of tumor recurrence.

Reduced Transfusion During OLT by POC Coagulation Management and TEG Functional Fibrinogen: A Retrospective Observational Study.

PubMed

De Pietri, Lesley; Ragusa, Francesca; Deleuterio, Annalisa; Begliomini, Bruno; Serra, Valentina

2016-01-01

Patients undergoing orthotopic liver transplantation are at high risk of bleeding complications. Several Authors have shown that thromboelastography (TEG)-based coagulation management and the administration of fibrinogen concentrate reduce the need for blood transfusion. We conducted a single-center, retrospective cohort observational study (Modena Polyclinic, Italy) on 386 consecutive patients undergoing liver transplantation. We assessed the impact on resource consumption and patient survival after the introduction of a new TEG-based transfusion algorithm, requiring also the introduction of the fibrinogen functional thromboelastography test and a maximum amplitude of functional fibrinogen thromboelastography transfusion cutoff (7 mm) to direct in administering fibrinogen (2012-2014, n = 118) compared with a purely TEG-based algorithm previously used (2005-2011, n = 268). After 2012, there was a significant decrease in the use of homologous blood (1502 ± 1376 vs 794 ± 717 mL, P < 0.001), fresh frozen plasma (537 ± 798 vs 98 ± 375 mL, P < 0.001), and platelets (158 ± 280 vs 75 ± 148 mL, P < 0.005), whereas the use of fibrinogen increased (0.1 ± 0.5 vs 1.4 ± 1.8 g, P < 0.001). There were no significant differences in 30-day and 6-month survival between the 2 groups. The implementation of a new coagulation management method featuring the addition of the fibrinogen functional thromboelastography test to the TEG test according to an algorithm which provides for the administration of fibrinogen has helped in reducing the need for transfusion in patients undergoing liver transplantation with no impact on their survival.

A novel fibrinogen variant--Praha I: hypofibrinogenemia associated with gamma Gly351Ser substitution.

PubMed

Kotlín, Roman; Chytilová, Martina; Suttnar, Jirí; Salaj, Peter; Riedel, Tomás; Santrůcek, Jirí; Klener, Pavel; Dyr, Jan Evangelista

2007-05-01

A 25-yr-old man from Prague had abnormal bleeding after several surgical operations with low fibrinogen level and hypofibrinogenemia was suspected. The patient, 25 yr-old male had a low fibrinogen concentration as determined by the thrombin time and immunoturbidimetrical method. His 48-yr-old mother presented with normal coagulation tests, normal fibrinogen level and reported no history of bleeding. To identify the genetic mutation responsible for this hypofibrinogen, genomic DNA extracted from the blood was analyzed. Fibrin polymerization measurement, kinetics of fibrinopeptide release, fibrinogen clottability measurement, mass spectroscopy, and scanning electron microscopy were performed. DNA sequencing showed heterogeneous fibrinogen gammaG351S mutation in the propositus. The mutant chain was found not to be expressed to the circulation by matrix-assisted laser desorption/ionization time of flight mass spectrometry. Scanning electron micrographs of the patient's fibrin clot as well as kinetics of fibrinopeptide release and fibrin polymerization were found to be normal. A case of hypofibrinogenemia gammaG351S was found by routine coagulation testing and was genetically identified.

Antibody functionalized graphene biosensor for label-free electrochemical immunosensing of fibrinogen, an indicator of trauma induced coagulopathy.

PubMed

Saleem, Waqas; Salinas, Carlos; Watkins, Brian; Garvey, Gavin; Sharma, Anjal C; Ghosh, Ritwik

2016-12-15

An antibody, specific to fibrinogen, has been covalently attached to graphene and deposited onto screen printed electrodes using a chitosan hydrogel binder to prepare an inexpensive electrochemical fibrinogen biosensor. Fourier Transform Infrared (FT-IR) spectroscopy has been utilized to confirm the presence of the antibody on the graphene scaffold. Electrochemical Impedance Spectroscopy (EIS) has been utilized to demonstrate that the biosensor responds in a selective manner to fibrinogen in aqueous media even in the presence of plasminogen, a potentially interfering molecule in the coagulopathy cascade. Furthermore, the biosensor was shown to reliably sense fibrinogen in the presence of high background serum albumin levels. Finally, we demonstrated detection of clinically relevant fibrinogen concentrations (938-44,542μg/dL) from human serum and human whole blood samples using this biosensor. This biosensor can potentially be used in a point-of-care device to detect the onset of coagulopathy and monitor response following therapeutic intervention in trauma patients. Thus this biosensor may improve the clinical management of patients with trauma-induced coagulopathy. Copyright © 2016 Elsevier B.V. All rights reserved.

THE EFFECT OF ORALLY ADMINISTERED EPSILON AMINOCAPROIC ACID ON THE DEPOSITION AND/OR RETENTION OF RADIOIODINATED FIBRINOGEN AND ANTIBODIES TO FIBRINOGEN IN SUBCUTANEOUS RAT PLASMA CLOTS AND TURPENTINE-INDUCED ABSCESSES OF THE RAT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mutschler, L.E.

1963-01-25

Treatment of metastatic cancer through the use of highly radioactive labeled tumor-localizing antibodies would have the advantage over conventional radiation therapy techniques of delivering large doses of radiation to areas of malignancy while at the same time sparing vital normal tissue from excessive radiation. Intravenously administered I/sup 131/-labeled rat fibrinogen and antibodies to rat fibrin or fibrinogen were found to localize with considerable specificity in the rat-carried Murphy-Sturm lymphosarcoma. lt was suggested that fibrin deposition in tumors is a phenomenon associated with the growth of these tumors and may be of significance in rapidly growing tumors. An apparent lack ofmore » I/sup 131/-fibrinogen localization was observed in some transplantable rat tumors, such as the Walker carcinoma 256. The hypothesis that fibrin deposition is masked by its subsequent rapid removal by fibrinolytic processes was investigated. Data are presented from an investigation of the in vivo antifibrinolytic properties of epsilon aminocapronic acid (EACA), a potent in vitro fibrinolytic inhibitor. Two basic test systems, both using the rat as an experimental animal, were employed. The first involved measuring the effect of orally administered EACA on the retention of subcutaneous clots labeled with either I/sup 131/-fibrinogen or I/sup 131/-antibody against rat fibrinogen. The second system involved measuring the effect of EACA treatment on the deposition and retention of intravenously injected I/sup 131/-fibrinogen and I/sup 131/- antibody in subcutaneous turpentine-induced abscesses. Data indicate that EACA is a potent in vivo anti-fibrinolytic agent and that the mechanism by which EACA treatment brings about increased tumor localization of I/sup 131/-fibrinogen and I/sup 131/antibody is the inhibition of their subsequent removal by fibrinolytic processes. (C.H.)« less

High fibrin/fibrinogen degradation product to fibrinogen ratio is associated with 28-day mortality and massive transfusion in severe trauma.

PubMed

Lee, D H; Lee, B K; Noh, S M; Cho, Y S

2018-04-01

There is a lack of association between coagulation biomarkers and long-term mortality in severe trauma. We aimed to investigate the association between coagulation biomarkers on admission and outcome of late stage of trauma. This retrospective observational study included patients admitted with severe trauma between 2012 and 2015. We used the area under the receiver operating characteristic curve (AUROC) of coagulation biomarkers to determine 28-day mortality. Head Abbreviated Injury Scale scores greater than 3 were defined as traumatic brain injury (TBI). The primary outcome was 28-day mortality and the secondary outcome was massive transfusion. Of the 1266 patients included in the study, 28-day mortality rate was 19.7% (n = 249) and 7.9% (n = 100) of patients received massive transfusion. The AUROC of fibrin/fibrinogen degradation product (FDP) to fibrinogen ratio had a significantly higher prognostic performance than other markers. Multivariate analysis revealed that D-dimer level [odds ratio (OR) 1.033; 95% confidence interval (CI) 1.016-1.051] and FDP/fibrinogen ratio (OR 1.007; 95% CI 1.001-1.013) were independently associated with 28-day mortality. D-dimer (OR 1.028; 95% CI 1.003-1.055) and FDP/fibrinogen ratio (OR 1.035; 95% CI 1.012-1.058) were associated with 28-day mortality in the TBI group. In the non-TBI group, D-dimer was associated with 28-day mortality (OR 1.033; 95% CI 1.008-1.059), but the FDP/fibrinogen ratio was not. FDP/fibrinogen ratio, not D-dimer level, was an independent predictor for massive transfusion (OR 1.005; 95% CI 1.001-1.010). High FDP/fibrinogen ratio on arrival is a predictor of 28-day mortality and the requirement for massive transfusion in severe trauma.

The N-terminal domain of the thermo-regulated surface protein PrpA of Enterococcus faecium binds to fibrinogen, fibronectin and platelets

PubMed Central

Guzmán Prieto, Ana M.; Urbanus, Rolf T.; Zhang, Xinglin; Bierschenk, Damien; Koekman, C. Arnold; van Luit-Asbroek, Miranda; Ouwerkerk, Janneke P.; Pape, Marieke; Paganelli, Fernanda L.; Wobser, Dominique; Huebner, Johannes; Hendrickx, Antoni P. A.; Bonten, Marc J. M.; Willems, Rob J. L.; van Schaik, Willem

2015-01-01

Enterococcus faecium is a commensal of the mammalian gastrointestinal tract, but is also found in non-enteric environments where it can grow between 10 °C and 45 °C. E. faecium has recently emerged as a multi-drug resistant nosocomial pathogen. We hypothesized that genes involved in the colonization and infection of mammals exhibit temperature-regulated expression control and we therefore performed a transcriptome analysis of the clinical isolate E. faecium E1162, during mid-exponential growth at 25 °C and 37 °C. One of the genes that exhibited differential expression between 25 °C and 37 °C, was predicted to encode a peptidoglycan-anchored surface protein. The N-terminal domain of this protein is unique to E. faecium and closely related enterococci, while the C-terminal domain is homologous to the Streptococcus agalactiae surface protein BibA. This region of the protein contains proline-rich repeats, leading us to name the protein PrpA for proline-rich protein A. We found that PrpA is a surface-exposed protein which is most abundant during exponential growth at 37 °C in E. faecium E1162. The heterologously expressed and purified N-terminal domain of PrpA was able to bind to the extracellular matrix proteins fibrinogen and fibronectin. In addition, the N-terminal domain of PrpA interacted with both non-activated and activated platelets. PMID:26675410

The N-terminal domain of the thermo-regulated surface protein PrpA of Enterococcus faecium binds to fibrinogen, fibronectin and platelets.

PubMed

Guzmán Prieto, Ana M; Urbanus, Rolf T; Zhang, Xinglin; Bierschenk, Damien; Koekman, C Arnold; van Luit-Asbroek, Miranda; Ouwerkerk, Janneke P; Pape, Marieke; Paganelli, Fernanda L; Wobser, Dominique; Huebner, Johannes; Hendrickx, Antoni P A; Bonten, Marc J M; Willems, Rob J L; van Schaik, Willem

2015-12-17

Enterococcus faecium is a commensal of the mammalian gastrointestinal tract, but is also found in non-enteric environments where it can grow between 10 °C and 45 °C. E. faecium has recently emerged as a multi-drug resistant nosocomial pathogen. We hypothesized that genes involved in the colonization and infection of mammals exhibit temperature-regulated expression control and we therefore performed a transcriptome analysis of the clinical isolate E. faecium E1162, during mid-exponential growth at 25 °C and 37 °C. One of the genes that exhibited differential expression between 25 °C and 37 °C, was predicted to encode a peptidoglycan-anchored surface protein. The N-terminal domain of this protein is unique to E. faecium and closely related enterococci, while the C-terminal domain is homologous to the Streptococcus agalactiae surface protein BibA. This region of the protein contains proline-rich repeats, leading us to name the protein PrpA for proline-rich protein A. We found that PrpA is a surface-exposed protein which is most abundant during exponential growth at 37 °C in E. faecium E1162. The heterologously expressed and purified N-terminal domain of PrpA was able to bind to the extracellular matrix proteins fibrinogen and fibronectin. In addition, the N-terminal domain of PrpA interacted with both non-activated and activated platelets.

Concurrent application of charge using a novel circuit prevents heat-related coagulum formation during radiofrequency ablation.

PubMed

Lim, Bernard; Venkatachalam, Kalpathi L; Jahangir, Arshad; Johnson, Susan B; Asirvatham, Samuel J

2008-08-01

Thromboembolism resulting from coagulum formation on the catheter and electrode surfaces is a serious complication with radiofrequency ablation procedures for heart rhythm disorders. Why coagulum occurs despite therapeutic heparinization is unclear. In this report, we demonstrate a novel approach to minimize coagulum formation based on the electromolecular characteristics of fibrinogen. Atomic force microscopy was used to establish that fibrinogen deposited on surfaces underwent conformational changes that resulted in spontaneous clot formation. We then immersed ablation catheters that were uncharged, negatively, or positively charged in heparinized blood for 30 minutes and noted the extent of clot formation. In separate experiments, ablation catheters were sutured to the ventricle of an excised porcine heart immersed in whole, heparinized blood and radiofrequency ablation performed for 5 minutes with and without charge delivered to the catheter tips. Electron microscopy of the catheter tips showed surface coverage of fibrin clot of the catheter to be 33.8% for negatively charged catheters, compared with 84.7% (P = 0.01) in noncharged catheters. There was no significant difference in surface coverage of fibrin clot between positively charged catheters (93.8%) and noncharged catheters (84.7%, P = ns). In contrast, the thickness of surface clot coverage for positively charged catheters was 87.5%, compared with 28.45% (P= 0.03) for noncharged catheters and 11.25% (P = 0.03) for negatively charged catheters, compared with noncharged catheters. We describe a novel method of placing negative charge on electrodes during ablation that reduced coagulum formation. This may decrease thromboembolism-related complications with radiofrequency ablation procedures.

Steric and electrostatic surface forces on sulfonated PEG graft surfaces with selective albumin adsorption.

PubMed

Bremmell, Kristen E; Britcher, Leanne; Griesser, Hans J

2013-06-01

Addition of ionized terminal groups to PEG graft layers may cause additional interfacial forces to modulate the net interfacial interactions between PEG graft layers and proteins. In this study we investigated the effect of terminal sulfonate groups, characterizing PEG-aldehyde (PEG-CHO) and sulfonated PEG (PEG-SO3) graft layers by XPS and colloid probe AFM interaction force measurements as a function of ionic strength, in order to determine surface forces relevant to protein resistance and models of bio-interfacial interaction of such graft coatings. On the PEG-CHO surface the measured interaction force does not alter with ionic strength, typical of a repulsive steric barrier coating. An analogous repulsive interaction force of steric origin was also observed on the PEG-SO3 graft coating; however, the net interaction force changed with ionic strength. Interaction forces were modelled by steric and electrical double layer interaction theories, with fitting to a scaling theory model enabling determination of the spacing and stretching of the grafted chains. Albumin, fibrinogen, and lysozyme did not adsorb on the PEG-CHO coating, whereas the PEG graft with terminal sulfonate groups showed substantial adsorption of albumin but not fibrinogen or lysozyme from 0.15 M salt solutions. Under lower ionic strength conditions albumin adsorption was again minimized as a result of the increased electrical double-layer interaction observed with the PEG-SO3 modified surface. This unique and unexpected adsorption behaviour of albumin provides an alternative explanation to the "negative cilia" model used by others to rationalize observed thromboresistance on PEG-sulfonate coatings. Copyright © 2013 Elsevier B.V. All rights reserved.

Friction Stir Processing of Stainless Steel for Ascertaining Its Superlative Performance in Bioimplant Applications.

PubMed

Perumal, G; Ayyagari, A; Chakrabarti, A; Kannan, D; Pati, S; Grewal, H S; Mukherjee, S; Singh, S; Arora, H S

2017-10-25

Substrate-cell interactions for a bioimplant are driven by substrate's surface characteristics. In addition, the performance of an implant and resistance to degradation are primarily governed by its surface properties. A bioimplant typically degrades by wear and corrosion in the physiological environment, resulting in metallosis. Surface engineering strategies for limiting degradation of implants and enhancing their performance may reduce or eliminate the need for implant removal surgeries and the associated cost. In the current study, we tailored the surface properties of stainless steel using submerged friction stir processing (FSP), a severe plastic deformation technique. FSP resulted in significant microstructural refinement from 22 μm grain size for the as-received alloy to 0.8 μm grain size for the processed sample with increase in hardness by nearly 1.5 times. The wear and corrosion behavior of the processed alloy was evaluated in simulated body fluid. The processed sample demonstrated remarkable improvement in both wear and corrosion resistance, which is explained by surface strengthening and formation of a highly stable passive layer. The methylthiazol tetrazolium assay demonstrated that the processed sample is better in supporting cell attachment, proliferation with minimal toxicity, and hemolysis. The athrombogenic characteristic of the as-received and processed samples was evaluated by fibrinogen adsorption and platelet adhesion via the enzyme-linked immunosorbent assay and lactate dehydrogenase assay, respectively. The processed sample showed less platelet and fibrinogen adhesion compared with the as-received alloy, signifying its high thromboresistance. The current study suggests friction stir processing to be a versatile toolbox for enhancing the performance and reliability of currently used bioimplant materials.

Prognostic and diagnostic impact of fibrinogen, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio on thymic epithelial tumors outcome

PubMed Central

Janik, Stefan; Raunegger, Thomas; Hacker, Philipp; Ghanim, Bahil; Einwallner, Elisa; Müllauer, Leonhard; Schiefer, Ana-Iris; Moser, Julia; Klepetko, Walter; Ankersmit, Hendrik Jan; Moser, Bernhard

2018-01-01

Background Peripheral blood-derived inflammation-based markers, such as Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), and Fibrinogen have been identified as prognostic markers in various solid malignancies. Here we aimed to investigate the prognostic and diagnostic impact of NLR, PLR, and Fibrinogen in patients with thymic epithelial tumors (TETs). Results Pretreatment Fibrinogen serum concentrations, NLRs and PLRs were highest in patients with TCs and advanced tumor stages. High pretreatment Fibrinogen serum concentration (≥452.5 mg/dL) was significantly associated with worse cause specific survival (CSS; p = 0.001) and freedom from recurrence (FFR; p = 0.043), high NLR (≥4.0) with worse FFR (p = 0.008), and high PLR (≥136.5) with worse CSS (p = 0.032). Longitudinal analysis revealed that compared to patients without tumor recurrence, patients with tumor recurrence had significantly higher NLR (11.8 ± 4.0 vs. 4.70 ± 0.5; p = 0.001) and PLR (410.8 ± 149.1 vs. 228.3 ± 23.7; p = 0.031). Conclusion Overall, Fibrinogen serum concentrations, NLRs, and PLRs were associated with higher tumor stage, more aggressive tumor behavior, recurrence, and worse outcome. Prospective multicenter studies of the diagnostic and prognostic potential of Fibrinogen, NLR, and PLR are warranted. Methods This retrospective analysis included 122 patients with TETs who underwent surgical resection between 1999-2015. Fibrinogen serum concentrations, NLRs, and PLRs were measured in patients preoperatively, postoperatively, and later during follow-up. These markers were analyzed for association with several clinical variables, including tumor stage, tumor subtype, FFR, and CSS and to evaluate their prognostic and diagnostic impact for detecting tumor recurrence. PMID:29774108

Randomised clinical trial of an intensive intervention in the primary care setting of patients with high plasma fibrinogen in the primary prevention of cardiovascular disease

PubMed Central

2012-01-01

Background We have studied the possible effects of an intensive lifestyle change program on plasma fibrinogen levels, in patients with no cardiovascular disease, with elevated levels of fibrinogen, normal cholesterol levels, and a moderate estimated risk of coronary heart disease (CHD) and we have also analysed whether the effect on fibrinogen is independent of the effect on lipids. Results This clinical trial was controlled, unblinded and randomized, with parallel groups, done in 13 Basic Health Areas (BHA) in l'Hospitalet de Llobregat (Barcelona) and Barcelona city. The study included 436 patients, aged between 35 and 75 years, with no cardiovascular disease, elevated levels of fibrinogen (> 300 mg/dl), cholesterol < 250 mg/dl, 218 of whom received a more intensive intervention consisting of advice on lifestyle and treatment. The follow-up frequency of the intervention group was every 2 months. The other 218 patients followed their standard care in the BHAs. Fibrinogen, plasma cholesterol and other clinical biochemistry parameters were assessed. The evaluation of the baseline characteristics of the patients showed that both groups were homogenous. Obesity and hypertension were the most prevalent risk factors. After 24 months of the study, statistically significant changes were seen between the adjusted means of the two groups, for the following parameters: fibrinogen, plasma cholesterol, systolic and diastolic blood pressure and body mass index. Conclusion Intensive intervention to achieve lifestyle changes has shown to be effective in reducing some of the estimated CHD factors. However, the effect of intensive intervention on plasma fibrinogen levels did not correlate with the variations in cholesterol. Trial Registration ClinicalTrials.gov: NCT01089530 PMID:22381072

Fibrinogen concentrate as a treatment for postpartum haemorrhage-induced coagulopathy: A study protocol for a randomised multicentre controlled trial. The fibrinogen in haemorrhage of DELivery (FIDEL) trial.

PubMed

Ducloy-Bouthors, Anne-Sophie; Mignon, Alexandre; Huissoud, Cyril; Grouin, Jean-Marie; Mercier, Frédéric J

2016-08-01

Postpartum haemorrhage (PPH) remains the leading cause for maternal mortality worldwide. Hypofibrinogenaemia has been identified as a major risk factor for progress towards severe PPH. The efficacy of fibrinogen concentrate supplementation in PPH has been shown in various clinical settings but the level of evidence is not sufficient to prove the benefit, evaluate the risks, and determine the value, timing and dose of fibrinogen supplementation in PPH. The FIDEL trial objective is to evaluate the impact of a therapeutic strategy based on the early administration of human fibrinogen concentrate compared to the current practice based on late administration in severe PPH patients requiring second line uterotonics. This is a prospective multicentre, randomised, double-blind, placebo-controlled trial. A total of 412 patients will be randomised if they meet the following criteria: female patients≥18 years old, vaginal delivery, PPH requiring IV administration of prostaglandins (sulprostone) after 20 to 30minutes of oxytocin failure. The participants are assigned to receive either fibrinogen 3g or placebo infusions. The primary endpoint is a composite endpoint defined as the percentage of patients losing at least 4g/dL of Hb, and/or requiring a transfusion of at least 2 units of packed red blood cells, within the 48hours following fibrinogen administration. The purpose of this study is to demonstrate the efficacy and safety of an early fibrinogen concentrate infusion in uncontrolled active PPH. Copyright © 2016 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

Fibrinogen concentrate as first-line therapy in aortic surgery reduces transfusion requirements in patients with platelet counts over or under 100×109/L

PubMed Central

Solomon, Cristina; Rahe-Meyer, Niels

2015-01-01

Background Administration of fibrinogen concentrate, targeting improved maximum clot firmness (MCF) of the thromboelastometric fibrin-based clot quality test (FIBTEM) is effective as first-line haemostatic therapy in aortic surgery. We performed a post-hoc analysis of data from a randomised, placebo-controlled trial of fibrinogen concentrate, to investigate whether fibrinogen concentrate reduced transfusion requirements for patients with platelet counts over or under 100×109/L. Material and methods Aortic surgery patients with coagulopathic bleeding after cardiopulmonary bypass were randomised to receive either fibrinogen concentrate (n=29) or placebo (n=32). Platelet count was measured upon removal of the aortic clamp, and coagulation and haematology parameters were measured peri-operatively. Transfusion of allogeneic blood components was recorded and compared between groups. Results After cardiopulmonary bypass, haemostatic and coagulation parameters worsened in all groups; plasma fibrinogen level (determined by the Clauss method) decreased by 43–58%, platelet count by 53–64%, FIBTEM maximum clot firmness (MCF) by 38–49%, FIBTEM maximum clot elasticity (MCE) by 43–54%, extrinsically activated test (EXTEM) MCF by 11–22%, EXTEM MCE by 25–41% and the platelet component of the clot by 23–39%. Treatment with fibrinogen concentrate (mean dose 7–9 g in the 4 groups) significantly reduced post-operative allogeneic blood component transfusion requirements when compared to placebo both for patients with a platelet count ≥100×109/L and for patients with a platelet count <100×109/L. Discussion FIBTEM-guided administration of fibrinogen concentrate reduced transfusion requirements when used as a first-line haemostatic therapy during aortic surgery in patients with platelet counts over or under 100×109/L. PMID:25369608

Effects of fibrinogen concentration on fibrin glue and bone powder scaffolds in bone regeneration.

PubMed

Kim, Beom-Su; Sung, Hark-Mo; You, Hyung-Keun; Lee, Jun

2014-10-01

Fibrin polymers are widely used in the tissue engineering field as biomaterials. Although numerous researchers have studied the fabrication of scaffolds using fibrin glue (FG) and bone powder, the effects of varied fibrinogen content during the fabrication of scaffolds on human mesenchymal stem cells (hMSCs) and bone regeneration remain poorly understood. In this study, we formulated scaffolds using demineralized bone powder and various fibrinogen concentrations and analyzed the microstructure and mechanical properties. Cell proliferation, cell viability, and osteoblast differentiation assays were performed. The ability of the scaffold to enhance bone regeneration was evaluated using a rabbit calvarial defect model. Micro-computed tomography (micro-CT) showed that bone powders were uniformly distributed on the scaffolds, and scanning electron microscopy (SEM) showed that the fibrin networks and flattened fibrin layers connected adjacent bone powder particles. When an 80 mg/mL fibrinogen solution was used to formulate scaffolds, the porosity decreased 41.6 ± 3.6%, while the compressive strength increased 1.16 ± 0.02 Mpa, when compared with the values for the 10 mg/mL fibrinogen solution. Proliferation assays and SEM showed that the scaffolds prepared using higher fibrinogen concentrations supported and enhanced cell adhesion and proliferation. In addition, mRNA expression of alkaline phosphatase and osteocalcin in cells grown on the scaffolds increased with increasing fibrinogen concentration. Micro-CT and histological analysis revealed that newly formed bone was stimulated in the scaffold implantation group. Our results demonstrate that optimization of the fibrinogen content of fibrin glue/bone powder scaffolds will be beneficial for bone tissue engineering. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Severe Bleeding In a Woman Heterozygous for the Fibrinogen γR275C Mutation

PubMed Central

Rein, Chantelle M.; Anderson, Brian L; Ballard, Morgan M.; Domes, Christopher M.; Johnston, Joshua M.; Madsen, R. Jared; Wolper, Kathryn K. M.; Terker, Andrew S.; Strother, John M.; Deloughery, Thomas G.; Farrell, David H.

2010-01-01

The dysfibrinogen γR275C can be a clinically silent mutation, with only two out of seventeen cases in the literature reporting a hemorrhagic presentation, and four cases reporting a thrombotic presentation. We describe here a particularly severe presentation in 54-year-old female patient who required a hysterectomy at 47 years of age due to heavy menstrual bleeding. Coagulation studies revealed a prolonged prothrombin time and thrombin time, a normal fibrinogen antigen level, and a low fibrinogen activity level. Molecular analysis of the patient’s DNA revealed a γ chain gene mutation resulting in an amino acid substitution at residue 275 (γR275C). Protein sequencing of the fibrinogen γ chain confirmed this mutation, which was named Fibrinogen Portland I. This case demonstrates that the γR275C mutation can lead to a severe hemorrhagic phenotype. PMID:20386430

Natural hidden autoantibodies to tissue transglutaminase cross-react with fibrinogen.

PubMed

Zöller-Utz, Ingrid M; Esslinger, Birgit; Schulze-Krebs, Anja; Dieterich, Walburga

2010-03-01

Patients with celiac disease display autoantibodies against tissue transglutaminase (TG2), and the high sensitivity and specificity of these autoantibodies render them a reliable tool for diagnosis. However, we found that denatured sera from healthy persons also showed reactivity against TG2. To further examine the specificity of this phenomenon, sera of healthy individuals and celiac patients were denatured by heat or pH shift. Denatured sera of all individuals showed autoantibodies against TG2 in ELISA that could be specifically inhibited by TG2, but the biological role of these autoantibodies remains unknown. The alpha fibrinogen precursor could be isolated as serum protein that reacts with TG2 antibodies and treated sera reacted with fibrinogen in Western blotting. Cross-reactivity of TG2 antibodies with fibrinogen and vice versa was observed. We hypothesise that denaturation of sera reveals hidden autoantibodies against TG2, which might be normally masked by fibrinogen.

Unique surface adsorption behaviors of serum proteins on chemically uniform and alternating surfaces

NASA Astrophysics Data System (ADS)

Song, Sheng

With increasing interests of studying proteins adsorption on the surfaces with nanoscale features in biomedical field, it is crucial to have fundamental understandings on how the proteins are adsorbed on such a surface and what factors contribute to the driving forces of adsorption. Besides, exploring more available nanoscale templates would greatly offer more possibilities one could design surface bio-detection methods with favorable protein-surface interactions. Thus, to fulfill the purpose, the work in this dissertation has been made into three major sections. First, to probe the intermediate states which possibly exist between stable and unstable phases described in mean-field theory diagram, a solvent vapor annealing method is chosen to slowly induce the copolymer polystyrene-block-polyvinylpyridine (PS-b-PVP)'s both blocks undergoing micro-phase separations from initial spherical nanodomains into terminal cylindrical nanodomains. During this process, real time atomic force microscopy (AFM) has been conducted to capture other six intermediate states with different morphologies on the polymeric film surfaces. Secondly, upon recognizing each intermediate state, the solution of immunoglobulin gamma (IgG) proteins has been deposited on the surface and been rinsed off with buffer solution before the protein-bounded surface is imaged by AFM. It has been found IgG showing a strong adsorption preference on PS over P4VP block. Among all the six intermediate states, the proteins are almost exclusively adsorbed on PS nanodomains regardless the concentration and deposition time. Thirdly, a trinodular shape protein fibrinogen (Fg) is selected for investigating how geometry and surface charge of proteins would interplay with cylindrical nanodomains on a surface developed from Polystyrene -block-Poly-(methyl methacrylate) PS-b-PMMA. Also, Fg adsorptions on chemically homogeneous surfaces are included here to have a better contrast of showing how much difference it can make by using it on a nanoscale surface. Interestingly, higher concentration of protein solution promotes the occurrences of single phase packed Fg on the PS domain. The densely packed network has formed where each Fg keeps its main body in PS domain and leaves its two alpha C chains on nearby PMMA domain. We believe this conformation and orientation would maximize both the hydrophobic and electrostatic interactions between Fg and the underlying surface.

Importance of fibrinogen in dilutional coagulopathy after neurosurgical procedures: A descriptive study.

PubMed

Nair, Shalini; Nair, Bijesh Ravindran; Vidyasagar, Ajay; Joseph, Mathew

2016-08-01

The routine management of coagulopathy during surgery involves assessing haemoglobin, prothrombin time (PT), activated partial thromboplastin time (aPTT) and platelets. Correction of these parameters involves administration of blood, fresh frozen plasma and platelet concentrates. The study was aimed at identifying the most common coagulation abnormality during neurosurgical procedures and the treatment of dilutional coagulopathy with blood components. During 2 years period, all adult patients undergoing neurosurgical procedures who were transfused two or more units of red cells were prospectively evaluated for the presence of a coagulopathy. PT, aPTT, platelet count and fibrinogen levels were estimated before starting a component therapy. After assessing PT, aPTT, platelet count and fibrinogen levels following two or more blood transfusions, thirty patients were found to have at least one abnormal parameter that required administration of a blood product. The most common abnormality was a low fibrinogen level, seen in 26 patients; this was the only abnormality in three patients. No patient was found to have an abnormal PT or aPTT without either the fibrinogen concentration or platelet count or both being low. Low fibrinogen concentration was the most common coagulation abnormality found after blood transfusions for neurosurgical procedures.

Transport of nattokinase across the rat intestinal tract.

PubMed

Fujita, M; Hong, K; Ito, Y; Misawa, S; Takeuchi, N; Kariya, K; Nishimuro, S

1995-09-01

Intraduodenal administration of nattokinase (NK) at a dose of 80 mg/kg, resulted in the degradation of fibrinogen in plasma suggesting transport of NK across the intestinal tract in normal rats. The action of NK on the cleavage of fibrinogen in the plasma from blood samples drawn at intervals after intraduodenal administration of the enzyme was investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting analysis with an anti-fibrinogen gamma chain antibody. The 270 kDa fragment carrying antigenic sites for the binding of the anti-fibrinogen gamma chain antibody appeared within 0.5 h and was then degraded gradually to a 105 kDa fragment via a 200 kDa fragment. This suggests that fibrinogen was degraded to a 105 kDa fragment via several intermediates (270 and 200 kDa). In parallel with the degradation process, plasma recalcification times were remarkably prolonged NK was also detected in the plasma from blood samples drawn 3 and 5 h after administration of the enzyme by SDS-PAGE and Western blotting analysis with an anti-NK antibody. The results indicate that NK is absorbed from the rat intestinal tract and that NK cleaves fibrinogen in plasma after intraduodenal administration of the enzyme.

Examination of the relation between periodontal health status and cardiovascular risk factors: serum total and high density lipoprotein cholesterol, C-reactive protein, and plasma fibrinogen.

PubMed

Wu, T; Trevisan, M; Genco, R J; Falkner, K L; Dorn, J P; Sempos, C T

2000-02-01

Using data from the Third National Health and Nutrition Examination Survey (1988-1994), the authors examined the relation between periodontal health and cardiovascular risk factors: serum total and high density lipoprotein cholesterol, C-reactive protein, and plasma fibrinogen. A total of 10,146 participants were included in the analyses of cholesterol and C-reactive protein and 4,461 in the analyses of fibrinogen. Periodontal health indicators included the gingival bleeding index, calculus index, and periodontal disease status (defined by pocket depth and attachment loss). While cholesterol and fibrinogen were analyzed as continuous variables, C-reactive protein was dichotomized into two levels. The results show a significant relation between indicators of poor periodontal status and increased C-reactive protein and fibrinogen. The association between periodontal status and total cholesterol level is much weaker. No consistent association between periodontal status and high density lipoprotein cholesterol was detectable. Similar patterns of association were observed for participants aged 17-54 years and those 55 years and older. In conclusion, this study suggests that total cholesterol, C-reactive protein, and fibrinogen are possible intermediate factors that may link periodontal disease to elevated cardiovascular risk.

Association between job characteristics and plasma fibrinogen in a normal working population: a cross sectional analysis in referents of the SHEEP Study. Stockholm Heart Epidemiology Program

PubMed Central

Tsutsumi, A.; Theorell, T.; Hallqvist, J.; Reuterwall, C.; de Faire, U.

1999-01-01

STUDY OBJECTIVE: To explore the association between job characteristics and plasma fibrinogen concentrations. DESIGN: Cross sectional design. SETTING: The Greater Stockholm area. SUBJECTS: A total of 1018 men and 490 women aged 45-70 who were randomly selected from the general population during 1992-1994. They were all employed and had no history of myocardial infarction. MAIN RESULTS: The self reported job characteristics were measured by a Swedish version of the Karasek demand-control questionnaire. For inferred scoring of job characteristics, psychosocial exposure categories (job control and psychological demands) were assigned by linking each subject's occupational history with a work organisation exposure matrix. Job strain was defined as the ratio between demands and control. In univariate analyses, expected linear trends were found in three of four tests of association between high plasma fibrinogen and low control (the self reported score for women and the inferred score for both sexes), in one of four tests of association between high plasma fibrinogen and high demands (the inferred score for women) and in two of four tests of association between high plasma fibrinogen and job strain (the inferred score for both sexes). Multiple logistic regression analyses showed that men in the inferred job strain group have an increased risk of falling into the increased plasma fibrinogen concentration group (above median level of the distribution) (odds ratio (OR) 1.2; 95% CI 1.0, 1.5) after adjustment for the variables that were associated with plasma fibrinogen in the univariate analyses. In women, low self reported control, high inferred demand, and inferred job strain were significantly associated with increased plasma fibrinogen concentration (OR 1.3; 95% CI 1.0, 1.8, OR 1.5; 95% CI 1.0, 2.2, OR 1.5; 95% CI 1.1, 2.2, respectively). CONCLUSIONS: These results indicate that adverse job characteristics may be related to plasma fibrinogen concentrations and this relation is more relevant in female workers. The clearest evidence for psychosocial effects on plasma fibrinogen seems to be with job control and the associations are clearer for the objective than for the self report variables.   PMID:10396481

Two-Component System RgfA/C Activates the fbsB Gene Encoding Major Fibrinogen-Binding Protein in Highly Virulent CC17 Clone Group B Streptococcus

PubMed Central

Safadi, Rim Al; Mereghetti, Laurent; Salloum, Mazen; Lartigue, Marie-Frédérique; Virlogeux-Payant, Isabelle; Quentin, Roland; Rosenau, Agnès

2011-01-01

Group B streptococcus (GBS) strains with the highest ability to bind to human fibrinogen belong to the highly invasive clonal complex (CC) 17. To investigate the fibrinogen-binding mechanisms of CC17 strains, we determined the prevalence of fibrinogen-binding genes (fbsA and fbsB), and fbs regulator genes (rogB encoding an fbsA activator, rovS encoding an fbsA repressor and rgf encoding a two-component system [TCS] whose role on fbs genes was not determined yet) in a collection of 134 strains representing the major CCs of the species. We showed that specific gene combinations were related to particular CCs; only CC17 strains contained the fbsA, fbsB, and rgf genes combination. Non polar rgfAC deletion mutants of three CC17 serotype III strains were constructed. They showed a 3.2- to 5.1-fold increase of fbsA transcripts, a 4.8- to 6.7-fold decrease of fbsB transcripts, and a 52% to 68% decreased fibrinogen-binding ability, demonstrating that the RgfA/RgfC TCS inhibits the fbsA gene and activates the fbsB gene. The relative contribution of the two fbs genes in fibrinogen-binding ability was determined by constructing isogenic fbsA, fbsB, deletion mutants of the three CC17 strains. The ability to bind to fibrinogen was reduced by 49% to 57% in ΔfbsA mutants, and by 78% to 80% in ΔfbsB mutants, suggesting that FbsB protein plays a greater role in the fibrinogen-binding ability of CC17 strains. Moreover, the relative transcription level of fbsB gene was 9.2- to 12.7-fold higher than that of fbsA gene for the three wild type strains. Fibrinogen-binding ability could be restored by plasmid-mediated expression of rgfAC, fbsA, and fbsB genes in the corresponding deletion mutants. Thus, our results demonstrate that a specific combination of fbs genes and fbs regulator genes account for the high fibrinogen-binding ability of CC17 strains that may participate to their enhanced invasiveness for neonates as compared to strains of other CCs. PMID:21326613

[Relationship of fibrinogen with cardiovascular risk factors in healthy men from Maracaibo, Venezuela].

PubMed

Campos, Gilberto; Diez-Ewald, María; Ryder, Elena; Torres-Guerra, Enrique; Fernández, Virginia; Rivero, Francisco; Arocha-Piñango, Carmen Luisa

2008-09-01

The purpose of this paper was to determine the relationship between fibrinogen concentration and cardiovascular ischaemic risk factors in a group of apparently healthy men from Maracaibo, Venezuela. Two hundred and forty six individuals, ages 31 to 65 years were evaluated by means of clinical and laboratory examination. In each person plasma fibrinogen concentration was measured by coagulometry, serum glucose and lipids by enzymatic methods and insulin by radioimmunoanalysis. 31.7% of subjects had fibrinogen values in the highest tertil of the whole group (> or = 311 mg/dL), they also showed significantly higher values of total cholesterol (p < 0.03) and LDL-C (p < 0.01). In addition, the individuals in this tertil showed a significant and positive correlation between the values of triglycerides with insulin (p < 0.02) and with HOMA-IR (p < 0.01). On the other hand, correlation analysis also showed a positive significant association between the fibrinogen levels and total cholesterol (p < 0.02), dependent of individuals with family history of ischaemic cardiovascular disease (total cholesterol: p < 0.02 and LDL-C: p < 0.003). In consideration of the high concentrations of fibrinogen found in 31.7% of apparently healthy men and their significant positive correlation with total cholesterol and LDL-C, on the group of men with a family history of ischaemic cardiovascular disease, it would be advisable to include the determination of fibrinogen in the cardiovascular evaluation of these particular subjects.

Comparison of fibrinogen- and collagen-based treatments for penetrating wounds with comminuted femur fractures in a Swine model.

PubMed

Rothwell, Stephen W; Sawyer, Evelyn; Lombardini, Eric; Royal, Joseph; Tang, Haiyin; Selwyn, Reed; Bodo, Michael; Settle, Timothy L

2013-01-01

Military servicemembers in combat operations often sustain injuries to the extremities from highspeed projectiles, resulting in bleeding and comminuted open fractures. Severe injury with bone fragmentation can result in limb amputation. Surgical treatment options include materials that promote osteogenesis and bone proliferation, such as growth hormones, stem cells, or mineralized matrix adjuncts. However, none of these are amenable to use by the first responder, nor do they address the question of hemorrhage control, which is a common problem in traumatic injuries. Our hypothesis was that treatment with a fibrinogen-based protein mixture at the time of the bone injury will provide both hemostasis and a supportive environment for preservation of injured bone. A comminuted femur fracture was produced in 28 female Yorkshire swine, and one of four treatments was instilled into the wound immediately after injury. Each animal was evaluated for the following parameters: inflammation, new bone growth, osteoclast proliferation, callus formation, and femur wound cavity fill, using post-mortem computed tomography and analysis of histological sections. Overall, salmon fibrinogen?thrombin and porcine fibrinogen?thrombin showed a trend for improved healing based on bone filling and calcification. However, statistically significant differences could not be established between treatment groups. These findings indicate that a fibrinogen?thrombin matrix may be a useful as an immediate response product to enhance fracture healing. Salmon fibrinogen?thrombin has the advantages of cost and a pathogen profile compared to mammalian fibrinogens. 2013.

Cushing`s disease: Fibrinogen and D-dimer levels fail to normalize despite early postoperative remission - a prospective, controlled study.

PubMed

Witek, Przemysław; Zieliński, Grzegorz; Szamotulska, Katarzyna; Witek, Joanna; Kamiński, Grzegorz

2016-01-01

Effective transsphenoidal surgery (TSS) for Cushing`s disease (CD) normalizes cortisol levels and reduces complications of hypercortisolism. However, there is evidence of increased cardiovascular morbidity even after successful surgery. A prospective, controlled study on the dynamics of fibrinogen and D-dimer levels with a six-month follow-up after an effective TSS for CD. Forty patients with CD and forty healthy age- and sex-matched subjects were included. We assessed ACTH, urinary and serum cortisol, and fibrinogen and D-dimer levels before TSS and during follow-up. Baseline BMI (P < 0.001), fibrinogen (P = 0.002), and D-dimer (P = 0.001) levels in CD patients were significantly higher than those in healthy controls. High fibrinogen levels in the CD group were independent of BMI, and were positively associated with hsCRP (rS = 0.61, P < 0.001) and arterial hypertension (P = 0.029). After the six-month follow-up we confirmed a sustained difference between the remission group and controls in fibrinogen and D-dimer levels (P = 0.001 and P = 0.017, respectively). Despite early biochemical remission of CD the levels of fibrinogen and D-dimer failed to decrease. This probably contributes to the high risk of thrombotic events and indicates the need for a close follow-up for signs of thromboembolic and cardiovascular complications in patients with early CD remission. (Endokrynol Pol 2016; 67 (3): 283-291).

Familial hypofibrinogenaemia associated with heterozygous substitution of a conserved arginine residue; Bbeta255 Arg-->His (Fibrinogen Merivale).

PubMed

Maghzal, Ghassan J; Brennan, Stephen O; Fellowes, Andrew P; Spearing, Ruth; George, Peter M

2003-02-21

Sequencing of all three fibrinogen genes from an individual with hypofibrinogenaemia led to the identification of two new point mutations in the Bbeta gene. Family studies showed the mutations Bbeta255 Arg-->His (Fibrinogen Merivale) and Bbeta148 Lys-->Asn (Fibrinogen Merivale II) were on different alleles and that only the Bbeta255 Arg-->His mutation segregated with hypofibrinogenaemia. Three simple heterozygotes for this mutation had mean fibrinogen concentrations of 1.4 mg/ml, while heterozygotes for the Bbeta148 Lys-->Asn mutation had normal fibrinogen concentrations. ESI MS analysis of endoproteinase Asp-N digests of Bbeta chains showed that the Bbeta255 Arg-->His substitution was not expressed in plasma, confirming it as the cause of the hypofibrinogenaemia. The Bbeta148 Lys-->Asn chains, on the other hand, were equally expressed with wild-type Bbeta chains in simple heterozygotes. Genotype analysis failed to detect either substitution in 182 healthy controls. Arg(255) is located in the first strand of the five-stranded sheet that forms the main feature of the betaD domain and appears to form an essential H bond with Gly(414). Both the Arg and Gly are absolutely conserved, not only in all known Bbeta chains, but also in all homologous alphaE and gamma chains and in all fibrinogen-related proteins. Protein instability from loss of this contact could easily explain the association of this mutation with hypofibrinogenaemia.

Blood-brain barrier dysfunction and cerebral small vessel disease (arteriolosclerosis) in brains of older people.

PubMed

Bridges, Leslie R; Andoh, Joycelyn; Lawrence, Andrew J; Khoong, Cheryl H L; Poon, Wayne; Esiri, Margaret M; Markus, Hugh S; Hainsworth, Atticus H

2014-11-01

The blood-brain barrier protects brain tissue from potentially harmful plasma components. Small vessel disease (SVD; also termed arteriolosclerosis) is common in the brains of older people and is associated with lacunar infarcts, leukoaraiosis, and vascular dementia. To determine whether plasma extravasation is associated with SVD, we immunolabeled the plasma proteins fibrinogen and immunoglobulin G, which are assumed to reflect blood-brain barrier dysfunction, in deep gray matter (DGM; anterior caudate-putamen) and deep subcortical white matter (DWM) in the brains of a well-characterized cohort of donated brains with minimal Alzheimer disease pathology (Braak Stages 0-II) (n = 84; aged 65 years or older). Morphometric measures of fibrinogen labeling were compared between people with neuropathologically defined SVD and aged control subjects. Parenchymal cellular labeling with fibrinogen and immunoglobulin G was detectable in DGM and DWM in many subjects (>70%). Quantitative measures of fibrinogen were not associated with SVD in DGM or DWM; SVD severity was correlated between DGM and DWM (p < 0.0001). Fibrinogen in DGM showed a modest association with a history of hypertension; DWM fibrinogen was associated with dementia and cerebral amyloid angiopathy (all p < 0.05). In DWM, SVD was associated with leukoaraiosis identified in life (p < 0.05), but fibrinogen was not. Our data suggest that, in aged brains, plasma extravasation and hence local blood-brain barrier dysfunction are common but do not support an association with SVD.

Dysfibrinogen Kagoshima with the amino acid substitution gammaThr-314 to Ile: analyses of molecular abnormalities and thrombophilic nature of this abnormal molecule.

PubMed

Niwa, Kazuki; Mimuro, Jun; Miyata, Masaaki; Sugo, Teruko; Ohmori, Tsukasa; Madoiwa, Seiji; Tei, Chuwa; Sakata, Yoichi

2008-01-01

Emerging lines of evidence have suggested that certain dysfibrinogens present a significant risk of thrombosis. The thrombophilic nature of a new-type of dysfibrinogen Kagoshima identified in a 36-year-old female with deep vein thrombosis during the postpartum period was studied. Based on the analyses of the patient fibrinogen and the fibrinogen genes, fibrinogen Kagoshima was shown to have the amino acid substitution of gammaThr-314 to Ile that resulted in impaired function and hypofibrinogenemia. Polymerization of fibrin monomers derived from patient fibrinogen was severely impaired with a partial correction in the presence of calcium ions, causing very low clottability and delayed cross-linking of patient fibrin catalyzed by activated factor XIII. Because of the low clottability, a large amount of soluble fibrin was formed upon thrombin treatment, resulting in an increase of thrombin in the soluble fraction. Additionally, tPA-mediated plasmin generation on fibrin was impaired and calcium-ion-dependent integrity of the gamma-chain D domain of Kagoshima fibrinogen was perturbed. The presence of many tapered-fiber ends inside the tangled fibrin networks, observed by scanning electron microscopy, suggested early termination of fibrin polymerization and the structural alteration. These data suggest that fibrinogen Kagoshima is dysfunctional, giving rise to formation of fibrinolysis-resistant soluble fibrin polymers and entrance of soluble fibrin associating with thrombin to the circulation, partly accounting for the thrombophilic nature of the affected fibrinogen and fibrin molecules.

Fibrinogen Bastia (gamma 318 Asp-->Tyr) a novel abnormal fibrinogen characterized by defective fibrin polymerization.

PubMed

Lounes, K C; Soria, C; Valognes, A; Turchini, M F; Soria, J; Koopman, J

1999-12-01

A new congenital dysfibrinogen, Fibrinogen Bastia, was discovered in a 20-year-old woman with no clinical symptoms. The plasma thrombin-clotting time was severely prolonged. The functional plasma fibrinogen concentration was low (0.2 mg/ml), whereas the immunological concentration was normal (2.9 mg/ml). Purified fibrinogen Bastia displayed a markedly prolonged thrombin-clotting time related to a delayed thrombin-induced fibrin polymerization. Both the thrombin-clotting time and the fibrin polymerization were partially corrected by the addition of calcium ions. The anomaly of fibrinogen Bastia was found to be located in the gamma-chain since by SDS-PAGE performed according to the method of Laemmli two gamma-chains were detected, one normal and one with an apparently lower molecular weight. Furthermore, analysis of plasmin degradation products demonstrated that calcium ions only partially protect fibrinogen Bastia gamma-chain against plasmin digestion, suggesting that the anomaly is located in the C-terminal part of the gamma-chain. Sequence analysis of PCR-amplified genomic DNA fragments of the propositus demonstrated a single base substitution (G-->T) in the exon VIII of the gamma chain gene, resulting in the amino acid substitution 318 Asp (GAC)-->Tyr (TAC). The PCR clones were recloned and 50% of them contained the mutation, indicating that the patient was heterozygous. These data indicate that residue Asp 318 is important for normal fibrin polymerization and the protective effect of calcium ions against plasmin degradation of the C-terminal part of the gamma-chain.

Surface morphology of platelet adhesion influenced by activators, inhibitors and shear stress

NASA Astrophysics Data System (ADS)

Watson, Melanie Groan

Platelet activation involves multiple events, one of which is the generation and release of nitric oxide (NO), a platelet aggregation inhibitor. Platelets simultaneously send and receive various agents that promote a positive and negative feedback control system during hemostasis. Although the purpose of platelet-derived NO is not fully understood, NO is known to inhibit platelet recruitment. NO's relatively large diffusion coefficient allows it to diffuse more rapidly than platelet agonists. It may thus be able to inhibit recruitment of platelets near the periphery of a growing thrombus before agonists have substantially accumulated in those regions. Results from two studies in our laboratory differed in the extent to which platelet-derived NO decreased platelet adhesion. Frilot studied the effect of L-arginine (L-A) and NG-Methyl-L-arginine acetate salt (L-NMMA) on platelet adhesion to collagen under static conditions in a Petri dish. Eshaq examined the percent coverage on collagen-coated and fibrinogen-coated microchannels under shear conditions with different levels of L-A and Adenosine Diphosphate (ADP). Frilot's results showed no effect of either L-A or L-NMMA on surface coverage, thrombus size or serotonin release, while Eshaq's results showed a decrease in surface coverage with increased levels of L-A. A possible explanation for these contrasting results is that platelet-derived NO may be more important under flow conditions than under static conditions. For this project, the effects of L-A. ADP and L-NMMA on platelet adhesion were studied at varying shear stresses on protein-coated glass slides. The surface exposed to platelet-rich-plasma in combination with each chemical solution was observed under AFM, FE-SEM and fluorescence microscopy. Quantitative and qualitative comparisons of images obtained with these techniques confirmed the presence of platelets on the protein coatings. AFM images of fibrinogen and collagen-coated slides presented characteristic differences. Adhered platelets were identified, particularly with the AFM. The effects of chemical additives were examined under the same microscopy techniques. The resulting fluorescent microscopy data suggests statistical differences between the percent surface coverage of different shear regions on the glass slides. No statistically significant change in surface coverage was found with the addition of ADP on fibrinogen-coated slides, but showed differences on collagen with all chemicals. However, in high shear regions. L-A produced a significant decrease in platelet adhesion and L-NMMA produced a statistically significant increase in platelet adhesion on fibrinogen and collagen-coated slides. The AFM images of the chemical additives provided no differences between one another except with ADP. The no shear and low shear conditions provided no variations between AFM images via visual confirmation and statistical significance. The only AFM image shear region differences were obtained from low to high shear regions and static to high shear regions comparisons. The objective of this project was to determine whether the static conditions used by Frilot and the dynamic conditions used by Eshaq could explain the different effects of L-A observed in those studies. In addition, the ability of the fluorescent imaging technique to quantify platelet adhesion was examined by comparison of fluorescent imaging to AFM and FE-SEM. The results of this study were consistent with both the lack of an effect of chemical additives under static conditions reported by Frilot and the reduction of platelet adhesion in response to L-A reported by Eshaq.

Does Bicarbonate Correct Coagulation Function Impaired by Acidosis in Swine?

DTIC Science & Technology

2006-07-01

requires sufficient fibrinogen available in the circulation . At any time, fibrinogen availabil- Fig. 4. Thrombin generation kinetics at baseline (T0... circulation can potentially impact physiologic function. As the precursor in the coagulation process, fibrinogen is primarily involved in maintaining...with different proteins. It is also possible that following acidosis insult, some of the albumin loss from the circulation was compensated for by

Discriminatory bio-adhesion over nano-patterned polymer brushes

NASA Astrophysics Data System (ADS)

Gon, Saugata

Surfaces functionalized with bio-molecular targeting agents are conventionally used for highly-specific protein and cell adhesion. This thesis explores an alternative approach: Small non-biological adhesive elements are placed on a surface randomly, with the rest of the surface rendered repulsive towards biomolecules and cells. While the adhesive elements themselves, for instance in solution, typically exhibit no selectivity for various compounds within an analyte suspension, selective adhesion of targeted objects or molecules results from their placement on the repulsive surface. The mechanism of selectivity relies on recognition of length scales of the surface distribution of adhesive elements relative to species in the analyte solution, along with the competition between attractions and repulsions between various species in the suspension and different parts of the collecting surface. The resulting binding selectivity can be exquisitely sharp; however, complex mixtures generally require the use of multiple surfaces to isolate the various species: Different components will be adhered, sharply, with changes in collector composition. The key feature of these surface designs is their lack of reliance on biomolecular fragments for specificity, focusing entirely on physicochemical principles at the lengthscales from 1 - 100 nm. This, along with a lack of formal patterning, provides the advantages of simplicity and cost effectiveness. This PhD thesis demonstrates these principles using a system in which cationic poly-L-lysine (PLL) patches (10 nm) are deposited randomly on a silica substrate and the remaining surface is passivated with a bio-compatible PEG brush. TIRF microscopy revealed that the patches were randomly arranged, not clustered. By precisely controlling the number of patches per unit area, the interfaces provide sharp selectivity for adhesion of proteins and bacterial cells. For instance, it was found that a critical density of patches (on the order of 1000/mum 2) was required for fibrinogen adsorption while a greater density comprised the adhesion threshold for albumin. Surface compositions between these two thresholds discriminated binding of the two proteins. The binding behavior of the two proteins from a mixture was well anticipated by the single- protein binding behaviors of the individual proteins. The mechanism for protein capture was shown to be multivalent: protein adhesion always occurred for averages spacings of the adhesive patches smaller than the dimensions of the protein of interest. For some backfill brush architectures, the spacing between the patches at the threshold for protein capture clearly corresponded to the major dimension of the target protein. For more dense PEG brush backfills however, larger adhesion thresholds were observed, corresponding to greater numbers of patches involved with the adhesion of each protein molecule. . The thesis demonstrates the tuning of the position of the adhesion thresholds, using fibrinogen as a model protein, using variations in brush properties and ionic strength. The directions of the trends indicate that the brushes do indeed exert steric repulsions toward the proteins while the attractions are electrostatic in nature. The surfaces also demonstrated sharp adhesion thresholds for S. Aureus bacteria, at smaller concentrations of adhesive surfaces elements than those needed for the protein capture. The results suggest that bacteria may be captured while proteins are rejected from these surfaces, and there may be potential to discriminate different bacterial types. Such discrimination from protein-containing bacterial suspensions was investigated briefly in this thesis using S. Aureus and fibrinogen as a model mixture. However, due to binding of fibrinogen to the bacterial surface, the separation did not succeed. It is still expected, however, that these surfaces could be used to selectively capture bacteria in the presence of non-interacting proteins. The interaction of these brushes with two different cationic species PLL and lysozyme were studied. The thesis documents rapid and complete brush displacement by PLL, highlighting a major limitation of using such brushes in some applications. Also unanticipated, lysozyme, a small cationic protein, was found to adhere to the brushes in increasing amounts with the PEG content of the brush. This finding contradicts current understanding of protein-brush interactions that suggests increases in interfacial PEG content increase biocompatibility.

[Correlation between the changes of fibrinogen and the treatment effect of all-frequency sudden deafness].

PubMed

Fang, X; Yu, L S; Ma, X; Xia, R M; Jiang, Y H; Liu, H X; Jing, Y Y

2018-01-07

Objective: To analyze the correlation between the changes of fibrinogen and the treatment effect of all-frequency sudden deafness, and to explore the individualized treatment strategy for the use of Batroxobin. Methods: Patients with all-frequency sudden deafness who were admitted to Department of Otorhinolaryngology, People's Hospital of Peking University, from January 2010 to September 2016 were selected. All patients were given standard treatment and regular use of Batroxobin. Value of fibrinogen on D1 (before treatment) / D3 / D7 (±1) and D14 (±2) were recorded, at the same time, the correlation between the changes of fibrinogen and prognosis of all-frequency sudden deafness by the audiograms of onset and after-treatment of all patients were analyzed. Independent t -test was used to analyze normal distributed measurement data and chi square linear trend test was used to analyze the curative effect of different fibrinogen groups. Results: A total of 148 patients were included, the outcomes were worst when the patient's fibrinogen was below 2 g/L or above 4 g/L before treatment, ineffective rate were both 50%. The fibrinogen was lowest when the treatment came to the third day. Normally, the patient's prognosis was best when this value waved between 0.7 and 0.9 g/L, with a total effective rate between 73.9% and 83.3%. The fibrinogen value of the 7th day was a good indicator of the outcome, and Fib7 value was significant lower in patients of effective group than ineffective ones ((1.25±0.37)g/L vs (1.38±0.35) g/L, t =-0.27, P =0.04). Patients found a best recovery when Fib7 was below 1 g/L, and the higher the Fib7 value, the higher the inefficiency (χ(2)=7.55, P =0.01). Batroxobin showed safety during the treatment and found no complications. Conclusion: The change of fibrinogen in the process of all-frequency sudden deafness is closely related to the curative effect.

Fibronectin alters the rate of formation and structure of the fibrin matrix.

PubMed

Ramanathan, Anand; Karuri, Nancy

2014-01-10

Plasma fibronectin is a vital component of the fibrin clot; however its role on clot structure is not clearly understood. The goal of this study was to examine the influence of fibronectin on the kinetics of formation, structural characteristics and composition of reconstituted fibrin clots or fibrin matrices. Fibrin matrices were formed by adding thrombin to 1, 2 or 4 mg/ml fibrinogen supplemented with 0-0.4 mg/ml fibronectin. The rate of fibrin matrix formation was then monitored by measuring light absorbance properties at different time points. Confocal microscopy of fluorescein conjugated fibrinogen was used to visualize the structural characteristics of fibrin matrices. The amount of fibronectin in fibrin matrices was determined through electrophoresis and immunoblotting of solubilized matrices. Fibronectin concentration positively correlated with the initial rate of fibrin matrix formation and with steady state light absorbance values of fibrin matrices. An increase in fibronectin concentration resulted in thinner and denser fibers in the fibrin matrices. Electrophoresis and immunoblotting showed that fibronectin was covalently and non-covalently bound to fibrin matrices and in the form of high molecular weight multimers. The formation of fibronectin multimers was attributed to cross-linking of fibronectin by trace amounts Factor XIIIa. These findings are novel because they link results from light absorbance studies to microcopy analyses and demonstrate an influence of fibronectin on fibrin matrix structural characteristics. This data is important in developing therapies that destabilize fibrin clots. Copyright © 2014. Published by Elsevier Inc.

Preoperative serum fibrinogen is an independent prognostic factor in operable esophageal cancer

PubMed Central

Zhang, Shui-Shen; Lei, Yi-Yan; Cai, Xiao-Li; Yang, Hong; Xia, Xin; Luo, Kong-Jia; Su, Chun-Hua; Zou, Jian-Yong; Zeng, Bo; Hu, Yi; Luo, Hong-He

2016-01-01

In order to fully elucidate the association between serum fibrinogen and prognosis of esophageal cancer, we examined serum fibrinogen concentrations in 1512 patients who underwent esophagectomy by the Clauss method. The impact of fibrinogen on overall survival and disease-free survival was analyzed using the Kaplan-Meier method and Cox proportional hazard models. Hyperfibrinogenemia was significantly associated with older age, male gender, smoking, alcohol consumption, weight loss, advanced pathological T stage and lymph node metastasis. Patients with hyperfibrinogenemia exhibited poor OS (HR=1.20, 95%CI: 1.04-1.38, P=0.012) and DFS (HR=1.18, 95%CI: 1.03-1.35, P=0.019). Subgroup analysis further exhibited an significant association between hyperfibrinogenemia and poor OS (P<0.001), DFS (P<0.001) in esophageal squamous cell carcinoma (P<0.001) and early pathological stage (I-II) (P=0.001). Collectively, this study indicates that preoperative serum fibrinogen is an independent prognostic factor for survival in esophageal cancer. PMID:27009857

Fibrin deposited in the Alzheimer’s disease brain promotes neuronal degeneration

PubMed Central

Cortes-Canteli, Marta; Mattei, Larissa; Richards, Allison T.; Norris, Erin H.; Strickland, Sidney

2014-01-01

Alzheimer’s disease (AD) is the most common form of dementia and has no effective treatment. Besides the well-known pathological characteristics, this disease also has a vascular component, and substantial evidence shows increased thrombosis as well as a critical role for fibrin(ogen) in AD. This molecule has been implicated in neuroinflammation, neurovascular damage, blood brain barrier permeability, vascular amyloid deposition, and memory deficits that are observed in AD. Here we present evidence demonstrating that fibrin deposition increases in the AD brain and correlates with the degree of pathology. Moreover, we show that fibrin(ogen) is present in areas of dystrophic neurites and that a modest decrease in fibrinogen levels improves neuronal health and ameliorates amyloid pathology in the subiculum of AD mice. Our results further characterize the important role of fibrin(ogen) in this disease and support the design of therapeutic strategies aimed at blocking the interaction between fibrinogen and Aβ and/or normalizing the increased thrombosis present in AD. PMID:25475538

Differential roles of fibrinogen and von Willebrand factor on clot formation and platelet adhesion in reconstituted and immune thrombocytopenia.

PubMed

Misgav, Mudi; Shenkman, Boris; Budnik, Ivan; Einav, Yulia; Martinowitz, Uri

2011-05-01

Bleeding tendencies in immune thrombocytopenia (ITP) do not always correlate with the number of platelets, suggesting platelet function variation. We used a model of normal whole blood thrombocytopenia to compare platelet function and other hemostatic variables with ITP patients. We further investigated the effect of in vitro spiking with von Willebrand factor (vWF) and fibrinogen on platelet function and hemostatic variables. The Cone and Plate(let) Analyzer was used to measure platelet adhesion (surface coverage [SC], %) and aggregation (average size, μm(2)) under defined shear rate (1200 s(-1)). Rotational thromboelastometry was used to determine variables of clot formation triggered by CaCl(2) and tissue factor. In both the model of thrombocytopenia as well as in ITP, the SC and to some extent the average size were correlated to the platelet number over a range of 5 to 80 × 10(6)/mL. The results obtained for most ITP samples were within the boundaries of the lower and upper limits set by the whole blood model of thrombocytopenia. The addition of 2 U/mL vWF (Haemate-P) to whole blood (calculated to plasma volume) results in an increase in the SC and average size without affecting clot formation. Spiking with fibrinogen (100 and 300 mg/dL) did not affect platelet deposition but improved clot formation. Using a model of whole blood thrombocytopenia enables us to establish reference variables for the Cone and Plate(let) Analyzer and rotational thromboelastometry and to assess platelet function and clot formation in the presence of severe thrombocytopenia. We demonstrated that in most cases of ITP, platelet function is comparable to normal platelets. This work also suggests that vWF and fibrinogen differentially affect primary and secondary hemostasis and therefore both may perform a function in the bleeding phenotype and possibly may be considered for treatment in patients with ITP. © 2011 International Anesthesia Research Society

An evaluation of fibrin tissue adhesive concentration and application thickness on skin graft survival.

PubMed

O'Grady, K M; Agrawal, A; Bhattacharyya, T K; Shah, A; Toriumi, D M

2000-11-01

To examine the effects of fibrinogen concentration and application thickness of fibrin tissue adhesive on skin graft survival. Prospective controlled study. Ten domestic pigs were included in the study. A 20 x 5-cm area of skin was harvested bilaterally along the flanks of the animals using a Padgett dermatome. The harvested grafts were trimmed into four 4 x 4-cm squares. Donor sites were treated according to group assignment and the non-meshed grafts were placed on the side opposite their initial orientation and secured with staples. Both single- and multiple-donor human fibrin tissue adhesive preparations, with low and high average fibrinogen concentrations of 30 mg/mL and 60 mg/ mL, were used. Adhesive preparations were applied in either a thin layer (0.015 mL/cm2) or a thick layer (0.06 mL/cm2) using a spray applicator. A constant thrombin concentration of 10 U/mL was used in the study. No adhesive was used in the control group and grafts were stabilized with staples. No topical dressings were applied to any of the treatment sites. Animals were sacrificed 4 weeks after graft application. Based on statistical analysis, thickness of adhesive application had a significant effect on skin graft survival. Percent mean graft survival in the control and thin application groups was found to be 92% and 97.8% respectively; the mean survival rate in the thick application group was 63.1%. Fibrinogen concentration, when evaluated independently within the thin and thick application groups, was found to have no significant effect on graft survival. Independent of fibrinogen concentration, a thin layer of fibrin tissue adhesive, when applied between two opposing surfaces, does not interfere with and may support the healing process, whereas a thick layer of adhesive inhibits skin graft healing.

Fibrinogen Šumperk II: dysfibrinogenemia in an individual with two coding mutations.

PubMed

Kotlín, Roman; Suttnar, Jiří; Cápová, Irena; Hrachovinová, Ingrid; Urbánková, Marie; Dyr, Jan Evangelista

2012-05-01

Fibrinogen—a 340-kDa glycoprotein—plays a crucial role in blood coagulation, platelet aggregation, wound healing, and other physiological processes. A mutation in fibrinogen may lead to congenital dysfibrinogenemia,a rare disease characterized by the functional deficiency of fibrinogen. About 580 cases of abnormal fibrinogens have been reported worldwide; thereof 335 cases in the fibrinogen Aa chain[1]. To our knowledge, only five cases of abnormal fibrinogens with two mutations [2–6] and one case of two different mutations in the same family [7] have been described earlier. A 52-year-old female was examined for bleeding. Routine hemostasis screening resulted in a diagnosis of dysfibrinogenemia. Functional testing revealed prolonged fibrin polymerization, prolonged lysis of the clot, abnormal fibrin morphology,and fibrinopeptides release. Genetic analysis showed two heterozygous nonsense mutations—previously described mutation AaGly13Glu and a novel mutation Aa Ser314Cys. The mutation Aa Gly13-Glu was found in her brother and niece, but there was no evidence in either of the mutation Aa Ser314Cys. While mutation Aa Gly13Glu is responsible for abnormal fibrinopeptide release and prolonged thrombin time, the novel mutation Aa Ser314Cys seems to affect fibrin morphology and fibrinolysis.

Psychosocial job characteristics and plasma fibrinogen in Japanese male and female workers: the Jichi Medical School cohort study.

PubMed

Hirokawa, Kumi; Tsutsumi, Akizumi; Kayaba, Kazunori

2008-06-01

The aim of the study was to explore the association between psychosocial job characteristics and plasma fibrinogen levels among 1588 male and 1677 female Japanese workers aged 65 and younger. Sociodemographic and behavioral variables were obtained by a standardized questionnaire, which included the Japanese version of the demand-control questionnaire. Fibrinogen levels were determined with a one-stage clotting assay kit. Job strain - a ratio of demand to control - was positively associated with plasma fibrinogen (p for trend<0.05) but ANCOVA showed that the main effect was only marginally statistically significant in men. Analyses by individual job characteristics components revealed that men with a high level of job demand (Age-adjusted geometric mean (mg/dl)=234.6, 95% CI: 230.9-238.2) showed a higher fibrinogen level than those with other levels (middle; 227.9, 223.6-232.3, low; 224.8, 220.5-229.1) (F (2, 1584)=6.63, p<0.001). Adjustment for potential confounders including total cholesterol and CRP did not reduce the association. No significant association was found between psychosocial job characteristics and fibrinogen in women. The findings appear to imply a mechanism through which adverse psychosocial job characteristics lead to cardiovascular diseases in men.

Levels of plasma fibrinogen and D-dimer in subjects with subclinical hyperthyroidism.

PubMed

Coban, Erkan; Aydemir, Mustafa

2008-01-01

During the last 15 years, several risk markers for atherosclerosis, such as fibrinogen and D-dimer, have been identified. The role of elevated fibrinogen levels as an independent risk factor for coronary, cerebral, and peripheral vascular disease is well established on the basis of clinical and epidemiological studies. Increased D-dimer levels are associated with increased risk of future myocardial infarction, stroke, and peripheral vascular disease. The aim of this study was to evaluate the alterations in fibrinogen and D-dimer, which indicates overall thrombotic activity, in subjects with subclinical hyperthyroidism. Thirty-six subclinical hyperthyroidic subjects and 36 euthyroidic control subjects matched for age, gender, and body mass index were selected. The levels of plasma fibrinogen and D-dimer in all subjects were measured. The level of fibrinogen was significantly higher in the subclinical hyperthyroidic group than in the euthyroidic group (296.9+/-74.3 mg/dl vs. 255.0+/-41.7 mg/dl, p<0.001). The level of D-dimer was significantly higher in the subclinical hyperthyroidic group than in the euthyroidic group (261.9+/-47.8 mg/dl vs. 216.4+/-32.1 mg/dl, p<0.000). The results suggest that subjects with subclinical hyperthyroidism present a relatively hypercoagulable state. This state could contribute to increased thromboembolic risk in subclinical hyperthyroidism.

Identification of fibrinogen-binding proteins of Aspergillus fumigatus using proteomic approach.

PubMed

Upadhyay, Santosh Kumar; Gautam, Poonam; Pandit, Hrishikesh; Singh, Yogendra; Basir, Seemi Farhat; Madan, Taruna

2012-03-01

Aspergillus fumigatus, the main etiological agent for various forms of human aspergillosis, gets access to the respiratory system of human host by inhalation of airborne conidia. These conidia possibly adhere to extracellular matrix (ECM) proteins. Among the ECM proteins involved in adherence, fibrinogen is thought to be crucial. Here, we studied whether A. fumigatus three-week culture filtrate (3wcf) proteins promote binding of A. fumigatus to ECM proteins and promote fungal growth. We observed that incubation of ECM with 3wcf proteins led to dose- and time-dependent increase in adherence of conidia to the ECM. In order to identify the catalogue of fibrinogen-binding A. fumigatus proteins, we carried out fibrinogen affinity blotting using two-dimensional gel electrophoresed 3wcf proteins. A total of 15 fibrinogen-binding protein spots corresponding to 7 unique proteins were identified in 3wcf using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF-TOF). Among these, 4 proteins, namely, beta-glucosidase, alpha-mannosidase, pectate lyase A and oryzin precursor were predicted to have cell wall or extracellular localization, whereas amidase family protein and two hypothetical proteins did not display the signal sequence. This study reports seven novel fibrinogen-binding proteins of A. fumigatus, some of which could be further explored for targeting the adhesion phenomenon as antifungal strategy.

COMMERCIAL EXTRACT FROM ARONIA AS A MODULATOR OF ADHESIVE PROPERTIES OF FIBRINOGEN TREATED WITH HOMOCYSTEINE AND ITS THIOLACTONE IN VITRO.

PubMed

Olas, Beata; Kontek, Bogdan; Oleszek, Wieslaw; Stochmal, Anna

2016-11-01

Research has confirmed the positive effect of berries of Aivnia melanocarpa on the cardiovascular system. The protective effects of polyphenol-rich extract from berries of A. melanocarpa against changes in biological properties of fibrinogen were studied. In in vino model of hyperhomocysteinemia the capability of fibrinogen to interact with human blood platelets was measured by platelet adhesion in the presence of extract fromA. nelanocapa. We induced hyperhomocystenemia using a reduced form of homocysteine (Hey, at a final concentration of 0.01. 0.1 and 1 μM) and the most reactive form of Hey - its cyclic thioester, homocysteine thiolactone (HTL, at a final concentration of 0.1, 0.5 and I μM). It was observed that Hey or HTL-treated fibrinogen, in comparison with untreated molecule, had a distinct capability to mediate blood platelet adhesion. The experiments also indicate that polyphenol-rich extract from black chokeberries (at final concentrations of 2.5-10 pM/mL) reduced the toxic action of Hey and HTL on the adhesive properties of fibrinogen. The possible protection exerted by black chokeberry extract, through restoring the platelet adhesion of Hey or HTL treated fibrinogen, may be important for vascular diseases.

Aronia melanocarpa as a protector against nitration of fibrinogen.

PubMed

Bijak, Michał; Saluk, Joanna; Antosik, Adam; Ponczek, Michał B; Żbikowska, Halina M; Borowiecka, Marta; Nowak, Paweł

2013-04-01

Fibrinogen (Fg) also known as coagulation factor I represents about 4% of the total human plasma proteins. The main function of Fg is its involvement in last phase of blood coagulation cascade, when thrombin-induced conversion of dissolved plasma fibrinogen into an insoluble fibrin clot occurs. The reaction of fibrinogen with peroxynitrite causes both structural modifications and changes of the biological properties of this plasma glycoprotein. Recently, there is an increased interest in the screening of natural products present in fruits, vegetables and herbs for their possible antioxidative activities. Therefore, the aim of our study was to estimate the effect of extract from berries of Aronia melanocarpa against nitrative and oxidative damage induced by peroxynitrite. The extract from A. melanocarpa (0.5-50 μg/ml) added to Fg 10 min before peroxynitrite (100 μM) significantly inhibited both the formation of the high molecular weight protein aggregates and nitration of Fg molecule. The extract also abolished peroxynitrite-induced inhibition of fibrinogen polymerization (by 95% at 50 μg/ml). The obtained results indicate that natural extract from berries of A. melanocarpa has protective effects against peroxynitrite-induced nitrative damage of plasma fibrinogen, and therefore may contribute in the prevention of peroxynitrite-related cardiovascular or inflammatory diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

Relationship between visceral obesity and plasma fibrinogen in obese children.

PubMed

Hafez, Mona; El-Masry, Sahar; Musa, Noha; Fathy, Marwa; Hassan, Mona; Hassan, Nayera; El Husseiny, Mohamed; Tareef, Mahmoud

2016-03-01

The prevalence of obesity in children and adolescents has increased significantly worldwide with an alarming rise of its co-morbidities. The excess of visceral adipose tissue is associated with hypertension, prothrombotic and pro-inflammatory states. Our aim was to find a possible association between visceral obesity and plasma fibrinogen, as one of the cardiovascular risk factors, in obese children. Forty-three obese children and 40 non-obese controls were studied regarding their history, complete physical examination, anthropometric assessment, body composition analysis, ultrasonographic measurement of visceral adipose tissue and subcutaneous fat as well as laboratory measurement of plasma fibrinogen. Our study revealed significant higher levels of fibrinogen in obese children than controls (14.5+5.1 and 2.9+0.52 mg/mL, respectively) with p-value <0.01. Moreover, the obese group had statistically significant difference in visceral fat (5.96+0.77 cm) and subcutaneous fat (2.66+0.70 cm) than controls (2.45+0.65 and 0.70+0.18 mg/mL, respectively) with p-value <0.01. In addition, fibrinogen had significant positive correlation with body mass index (r=0.327), waist/hip ratio (r=0.394), fat percentage (r=0.301), visceral adipose tissue (r=0.323) and subcutaneous fat (r=0.301). There was highly significant increase in the fibrinogen level, visceral and subcutaneous abdominal fat in the obese group with insignificant sex differences. Fibrinogen had a significant positive correlation with the different adiposity markers, blood pressure, visceral and subcutaneous fat. Visceral adipose tissue is a stronger predictor for cardiovascular risk compared to subcutaneous fat.

Plasma levels of thrombomodulin, plasminogen activator inhibitor-1 and fibrinogen in elderly, diabetic patients with depressive symptoms.

PubMed

Gorska-Ciebiada, Malgorzata; Saryusz-Wolska, Malgorzata; Borkowska, Anna; Ciebiada, Maciej; Loba, Jerzy

2016-10-01

Diabetes, depression and aging have been associated with pro-inflammatory and prothrombotic state. The aim of the study was to determine the plasma levels of thrombomodulin, plasminogen activator inhibitor-1 (PAI-1) and fibrinogen in elderly diabetic patients with and without depressive symptoms and to examine factors (including thrombomodulin, PAI-1, fibrinogen levels) associated with depressive symptoms in elderly patients with type 2 diabetes (T2DM). A total of 276 T2DM elders were evaluated: 82 subjects with depressive symptoms and 194 controls. Data were collected concerning biochemical parameters and biomarkers. Plasma thrombomodulin, PAI-1 and fibrinogen were elevated in patients with depressive symptoms compared to controls. Thrombomodulin level was correlated with fibrinogen and PAI-1 levels. All parameters were correlated with the Geriatric Depression Scale-30 score. The univariate logistic regression models revealed that variables which increased the likelihood of diagnosis of depressive symptoms in elderly patients with T2DM were: female sex, smoking habit, longer duration of T2DM, hyperlipidemia, neuropathy, increased number of co-morbidities, higher BMI, and higher levels of total and LDL cholesterol, thrombomodulin, PAI-1 and fibrinogen. In addition, the multivariable analysis indicated that female sex, smoking habit, increased number of co-morbidities, higher BMI, and higher levels of LDL cholesterol and thrombomodulin are the predisposing factors for depressive symptoms. Elderly diabetic patients with depressive symptoms have higher levels of thrombomodulin, PAI-1 and fibrinogen. Further prospective larger studies are needed to provide potential directions for the research, treatment and prevention of co-morbid depression and diabetes.

Two cases of congenital dysfibrinogenemia associated with thrombosis - Fibrinogen Praha III and Fibrinogen Plzen.

PubMed

Kotlín, Roman; Reicheltová, Zuzana; Malý, Martin; Suttnar, Jirí; Sobotková, Alzbeta; Salaj, Peter; Hirmerová, Jana; Riedel, Tomás; Dyr, Jan E

2009-09-01

Congenital dysfibrinogenemia is a rare disease characterised by inherited abnormality in the fibrinogen molecule, resulting in functional defects. Two patients, a 26-year-old woman and a 61-year-old man, both with history of thrombotic events, had abnormal coagulation test results. DNA sequencing showed the heterozygous gamma Y363N mutation (Fibrinogen Praha III) and the heterozygous Aalpha N106D mutation (Fibrinogen Plzen), respectively. Fibrin polymerisation, after addition of either thrombin or reptilase, showed remarkably delayed polymerisation in both cases. Fibrinolysis experiments showed slower tPA initiated lysis of clots. SDS-PAGE did not show any difference between normal and Praha III and Plzen fibrinogens. Both mutations had a significant effect on platelet aggregation. In the presence of either ADP or TRAP, both mutations caused the decrease of platelet aggregation. SEM revealed abnormal clot morphology, with a large number of free ends and narrower fibres of both fibrin Praha III and Plzen. Praha III mutation was situated in the polymerisation pocket "a". The replacement of the bulky aromatic side chain of tyrosine by the polar uncharged small side chain of asparagine may lead to a conformational change, possibly altering the conformation of the polymerisation pocket. The Plzen mutation is situated in the coiled-coil connector and this replacement of polar uncharged asparagine residue by polar acidic aspartate changes the alpha-helical conformation of the coiled-coil connector; and may destabilise hydrogen bonds in its neighborhood. Although both mutations are situated in different regions of the molecule, both mutations have a very similar effect on fibrinogen functions and both are connected with thromboses.

C-reactive protein and fibrinogen of bedridden older patients in a six-month vitamin D supplementation trial.

PubMed

Bjorkman, M P; Sorva, A J; Tilvis, R S

2009-05-01

To elucidate the association between vitamin D status, C-reactive protein (CRP) and fibrinogen. Secondary analysis of a randomised double-blind placebo controlled trial. Four longterm care hospitals (1215 beds) in Helsinki, Finland. 218 long-term inpatients aged over 65 years. Eligible patients (n = 218) were randomized to receive 0 IU/d, 400 IU/d, or 1200 IU/d cholecalciferol for six months. Plasma 25-hydroxyvitamin D (25-OHD), parathyroid hormone (PTH), high sensitive CRP, fibrinogen, amino-terminal propeptide of type I procollagen (PINP), and carboxy-terminal telopeptide of type I collagen (ICTP) were measured. The patients were aged (84.5 +/- 7.5 years), vitamin D deficient (25-OHD = 23 +/- 10 nmol/l), chronically bedridden and in stable general condition. The mean baseline CRP and fibrinogen were 10.86 mg/l (0.12 mg/l - 125.00 mg/l) and 4,7 g/l (2.3 g/l - 8.6 g/l), respectively. CRP correlated with ICTP (r = 0.217, p = 0.001), but not with vitamin D status. Supplementation significantly increased 25-OHD concentrations, but the changes in CRP and fibrinogen were insignificant and inconsistent. The post-trial CRP concentrations (0.23 mg/l -138.00 mg/l) correlated with ICTP (r = 0.156, p < 0.001), but no association was found with vitamin D status. The baseline and post-trial fibrinogen correlated with CRP, only. CRP concentrations are associated with bone turnover, but not with vitamin D status, and vitamin D supplementation has no major effect on CRP or fibrinogen concentrations in bedridden older patients.

Fibrin Formation, Structure and Properties

PubMed Central

Weisel, John W.; Litvinov, Rustem I.

2017-01-01

Fibrinogen and fibrin are essential for hemostasis and are major factors in thrombosis, wound healing, and several other biological functions and pathological conditions. The X-ray crystallographic structure of major parts of fibrin(ogen), together with computational reconstructions of missing portions and numerous biochemical and biophysical studies, have provided a wealth of data to interpret molecular mechanisms of fibrin formation, its organization, and properties. On cleavage of fibrinopeptides by thrombin, fibrinogen is converted to fibrin monomers, which interact via knobs exposed by fibrinopeptide removal in the central region, with holes always exposed at the ends of the molecules. The resulting half-staggered, double-stranded oligomers lengthen into protofibrils, which aggregate laterally to make fibers, which then branch to yield a three-dimensional network. Much is now known about the structural origins of clot mechanical properties, including changes in fiber orientation, stretching and buckling, and forced unfolding of molecular domains. Studies of congenital fibrinogen variants and post-translational modifications have increased our understanding of the structure and functions of fibrin(ogen). The fibrinolytic system, with the zymogen plasminogen binding to fibrin together with tissue-type plasminogen activator to promote activation to the active proteolytic enzyme, plasmin, results in digestion of fibrin at specific lysine residues. In spite of a great increase in our knowledge of all these interconnected processes, much about the molecular mechanisms of the biological functions of fibrin(ogen) remains unknown, including some basic aspects of clotting, fibrinolysis, and molecular origins of fibrin mechanical properties. Even less is known concerning more complex (patho)physiological implications of fibrinogen and fibrin. PMID:28101869

An in vitro study of the effects of t-PA and tranexamic acid on whole blood coagulation and fibrinolysis.

PubMed

Godier, Anne; Parmar, Kiran; Manandhar, Karuna; Hunt, Beverley J

2017-02-01

Acute traumatic coagulopathy is characterised by fibrinolysis and low fibrinogen. It is unclear how much fibrinogenolysis contributes to reduce fibrinogen levels. The study aim was to: investigate in vitro the effects of tissue-plasminogen activator (t-PA) and tranexamic acid (TXA) on coagulation and fibrinolysis. Whole blood was spiked with varying t-PA concentrations. Clauss fibrinogen levels and thrombelastography (TEG, Haemonetics) were performed, including functional fibrinogen level (FLEV). TXA effects were assessed using four TXA concentrations. Recorded parameters from kaolin activated TEG included maximal amplitude (MA), clot strength (G), percentage lysis (LY). Plasmin-antiplasmin complex (PAP), endogenous thrombin potential (ETP), prothrombin fragment 1+2 (PF1+2), factor V and factor VIII levels were all measured. t-PA induced fibrinolysis: it increased PAP and LY, but decreased MA and G. t-PA induced fibrinogenolysis, with a concentration-dependant decrease in fibrinogen from 2.7 (2.6-3.1) to 0.8 (0.8-0.9) g/L with 60 nM t-PA. FLEV and fibrinogen levels were well correlated. High t-PA doses increased PF1+2, decreased ETP of 19% and FVIII of 63% but not FV. TXA had no effect on plasmin generation as evidenced by no change in PAP. It corrected LY, MA and G and partly protected fibrinogen against fibrinogenolysis: 0.03 mg/mL TXA reduced the fibrinogen fall induced by t-PA 20 nM from 43% to 14%. TXA halved the FVIII fall and increased ETP. t-PA induced plasminogen activation and fibrinogenolysis in a concentration-dependant manner. TXA did not affect plasmin activation but reduced fibrinogenolysis. These results suggest that TXA given early in bleeding patients may prevent fibrinogenolysis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Fibrin-based tissue engineering: comparison of different methods of autologous fibrinogen isolation.

PubMed

Dietrich, Maren; Heselhaus, Johanna; Wozniak, Justyna; Weinandy, Stefan; Mela, Petra; Tschoeke, Beate; Schmitz-Rode, Thomas; Jockenhoevel, Stefan

2013-03-01

This study is focussed on the optimal method of autologous fibrinogen isolation with regard to the yield and the use as a scaffold material. This is particularly relevant for pediatric patients with strictly limited volumes of blood. The following isolation methods were evaluated: cryoprecipitation, ethanol (EtOH) precipitation, ammonium sulfate [(NH(4))(2)SO(4))] precipitation, ammonium sulfate precipitation combined with cryoprecipitation, and polyethylene glycol precipitation combined with cryoprecipitation. Fibrinogen yields were quantified spectrophotometrically and by electrophoretic analyses. To test the influence of the different isolation methods on the microstructure of the fibrin gels, scanning electron microscopy (SEM) was used and the mechanical strength of the cell-free and cell-seeded fibrin gels was tested by burst strength measurements. Cytotoxicity assays were performed to analyze the effect of various fibrinogen isolation methods on proliferation, apoptosis, and necrosis. Tissue development and cell migration were analyzed in all samples using immunohistochemical techniques. The synthesis of collagen as an extracellular matrix component by human umbilical cord artery smooth muscle cells in fibrin gels was measured using hydroxyproline assay. Compared to cryoprecipitation, all other considered methods were superior in quantitative analyses, with maximum fibrinogen yields of ∼80% of total plasma fibrinogen concentration using ethanol precipitation. SEM imaging demonstrated minor differences in the gel microstructure. Ethanol-precipitated fibrin gels exhibited the best mechanical properties. None of the isolation methods had a cytotoxic effect on the cells. Collagen production was similar in all gels except those from ammonium sulfate precipitation. Histological analysis showed good cell compatibility for ethanol-precipitated gels. The results of the present study demonstrated that ethanol precipitation is a simple and effective method for isolation of fibrinogen and a suitable alternative to cryoprecipitation. This technique allows minimization of the necessary blood volume for fibrinogen isolation, particularly important for pediatric applications, and also has no negative influence on microstructure, mechanical properties, cell proliferation, or tissue development.

Gallibacterium elongation factor-Tu possesses amyloid-like protein characteristics, participates in cell adhesion, and is present in biofilms.

PubMed

López-Ochoa, Jaqueline; Montes-García, J Fernando; Vázquez, Candelario; Sánchez-Alonso, Patricia; Pérez-Márquez, Victor M; Blackall, Patrick J; Vaca, Sergio; Negrete-Abascal, Erasmo

2017-09-01

Gallibacterium, which is a bacterial pathogen in chickens, can form biofilms. Amyloid proteins present in biofilms bind Congo red dye. The aim of this study was to characterize the cell-surface amyloid-like protein expressed in biofilms formed by Gallibacterium strains and determine the relationship between this protein and curli, which is an amyloid protein that is commonly expressed by members of the Enterobacteriaceae family. The presence of amyloid-like proteins in outer membrane protein samples from three strains of G. anatis and one strain of Gallibacterium genomospecies 2 was evaluated. A protein identified as elongation factor-Tu (EF-Tu) by mass spectrometric analysis and in silico analysis was obtained from the G. anatis strain F149 T . This protein bound Congo red dye, cross-reacted with anti-curli polyclonal serum, exhibited polymerizing properties and was present in biofilms. This protein also reacted with pooled serum from chickens that were experimentally infected with G. anatis, indicating the in vivo immunogenicity of this protein. The recombinant EF-Tu purified protein, which was prepared from G. anatis 12656-12, polymerizes under in vitro conditions, forms filaments and interacts with fibronectin and fibrinogen, all of which suggest that this protein functions as an adhesin. In summary, EF-Tu from G. anatis presents amyloid characteristics, is present in biofilms and could be relevant for the pathogenesis of G. anatis.

Biocompatible and biodegradable fibrinogen microspheres for tumor-targeted doxorubicin delivery

PubMed Central

Joo, Jae Yeon; Park, Gil Yong; An, Seong Soo A

2015-01-01

In the development of effective drug delivery carriers, many researchers have focused on the usage of nontoxic and biocompatible materials and surface modification with targeting molecules for tumor-specific drug delivery. Fibrinogen (Fbg), an abundant glycoprotein in plasma, could be a potential candidate for developing drug carriers because of its biocompatibility and tumor-targeting property via arginine–glycine–aspartate (RGD) peptide sequences. Doxorubicin (DOX), a chemotherapeutic agent, was covalently conjugated to Fbg, and the microspheres were prepared. Acid-labile and non-cleavable linkers were used for the conjugation of DOX to Fbg, resulting in an acid-triggered drug release under a mild acidic condition and a slow-controlled drug release, respectively. In vitro cytotoxicity tests confirmed low cytotoxicity in normal cells and high antitumor effect toward cancer cells. In addition, it was discovered that a longer linker could make the binding of cells to Fbg drug carriers easier. Therefore, DOX–linker–Fbg microspheres could be a suitable drug carrier for safer and effective drug delivery. PMID:26366073

Critical role for the mitochondrial permeability transition pore and cyclophilin D in platelet activation and thrombosis

PubMed Central

Wilson, Katina M.; Leo, Lorie; Raimondi, Alejandro; Molkentin, Jeffery D.; Lentz, Steven R.; Di Paola, Jorge

2008-01-01

Many of the cellular responses that occur in activated platelets resemble events that take place following activation of cell-death pathways in nucleated cells. We tested the hypothesis that formation of the mitochondrial permeability transition pore (MPTP), a key signaling event during cell death, also plays a critical role in platelet activation. Stimulation of murine platelets with thrombin plus the glycoprotein VI agonist convulxin resulted in a rapid loss of mitochondrial transmembrane potential (Δψm) in a subpopulation of activated platelets. In the absence of cyclophilin D (CypD), an essential regulator of MPTP formation, murine platelet activation responses were altered. CypD-deficient platelets exhibited defects in phosphatidylserine externalization, high-level surface fibrinogen retention, membrane vesiculation, and procoagulant activity. Also, in CypD-deficient platelet-rich plasma, clot retraction was altered. Stimulation with thrombin plus H2O2, a known activator of MPTP formation, also increased high-level surface fibrinogen retention, phosphatidylserine externalization, and platelet procoagulant activity in a CypD-dependent manner. In a model of carotid artery photochemical injury, thrombosis was markedly accelerated in CypD-deficient mice. These results implicate CypD and the MPTP as critical regulators of platelet activation and suggest a novel CypD-dependent negative-feedback mechanism regulating arterial thrombosis. PMID:17989312

Redox proteomic analysis of serum from aortic anerurysm patients: insights on oxidation of specific protein target.

PubMed

Spadaccio, Cristiano; Coccia, Raffaella; Perluigi, Marzia; Pupo, Gilda; Schininà, Maria Eugenia; Giorgi, Alessandra; Blarzino, Carla; Nappi, Francesco; Sutherland, Fraser W; Chello, Massimo; Di Domenico, Fabio

2016-06-21

oxidative stress is undoubtedly one of the main players in abdominal aortic aneurysm (AAA) pathophysiology. Recent studies in AAA patients reported an increase in the indices of oxidative damage at the tissue level and in biological fluids coupled with the loss of counter-regulatory mechanisms of protection from oxidative stress. We recently reported, in a proteomic analysis of AAA patient sera, changes in the expression of several proteins exerting important modulatory activities on cellular proliferation, differentiation and response to damage. This study aimed to explore the involvement of protein oxidation, at peripheral levels, in AAA. a redox proteomic approach was used to investigate total and specific protein carbonylation and protein-bound 4-hydroxy-2-nonenal (HNE) in the serum of AAA patients compared with age-matched controls. our results show increased oxidative damage to protein as indexed by the total carbonyl levels and total protein-bound HNE. By redox proteomics we identified specific carbonylation of three serum proteins: serum retinol-binding protein, vitamin D-binding protein and fibrinogen α-chain HNE. We also identified increased protein-bound HNE levels for hemopexin, IgK chain C region and IgK chain V-III region SIE. In addition we found a high correlation between specific protein carbonylation and protein-bound HNE and the aortic diameter. Moreover the analysis of serum proteins with antioxidant activity demonstrates the oxidation of albumin together with the overexpression of transferrin, haptoglobin and HSPs 90, 70, 60 and 32. this study support the involvement of oxidative stress in the pathogenesis of AAA and might provide a further degree of knowledge in the cause-effect role of oxidative stress shedding new light on the molecular candidates involved in the disease.

NCO-sP(EO-stat-PO) coatings on gold sensors--a QCM study of hemocompatibility.

PubMed

Sinn, Stefan; Eichler, Mirjam; Müller, Lothar; Bünger, Daniel; Groll, Jürgen; Ziemer, Gerhard; Rupp, Frank; Northoff, Hinnak; Geis-Gerstorfer, Jürgen; Gehring, Frank K; Wendel, Hans P

2011-01-01

The reliability of implantable blood sensors is often hampered by unspecific adsorption of plasma proteins and blood cells. This not only leads to a loss of sensor signal over time, but can also result in undesired host vs. graft reactions. Within this study we evaluated the hemocompatibility of isocyanate conjugated star shaped polytheylene oxide-polypropylene oxide co-polymers NCO-sP(EO-stat-PO) when applied to gold surfaces as an auspicious coating material for gold sputtered blood contacting sensors. Quartz crystal microbalance (QCM) sensors were coated with ultrathin NCO-sP(EO-stat-PO) films and compared with uncoated gold sensors. Protein resistance was assessed by QCM measurements with fibrinogen solution and platelet poor plasma (PPP), followed by quantification of fibrinogen adsorption. Hemocompatibility was tested by incubation with human platelet rich plasma (PRP). Thrombin antithrombin-III complex (TAT), β-thromboglobulin (β-TG) and platelet factor 4 (PF4) were used as coagulation activation markers. Furthermore, scanning electron microscopy (SEM) was used to visualize platelet adhesion to the sensor surfaces. Compared to uncoated gold sensors, NCO-sP(EO-stat-PO) coated sensors revealed significant better resistance against protein adsorption, lower TAT generation and a lower amount of adherent platelets. Moreover, coating with ultrathin NCO-sP(EO-stat-PO) films creates a cell resistant hemocompatible surface on gold that increases the chance of prolonged sensor functionality and can easily be modified with specific receptor molecules.

NCO-sP(EO-stat-PO) Coatings on Gold Sensors—a QCM Study of Hemocompatibility

PubMed Central

Sinn, Stefan; Eichler, Mirjam; Müller, Lothar; Bünger, Daniel; Groll, Jürgen; Ziemer, Gerhard; Rupp, Frank; Northoff, Hinnak; Geis-Gerstorfer, Jürgen; Gehring, Frank K.; Wendel, Hans P.

2011-01-01

The reliability of implantable blood sensors is often hampered by unspecific adsorption of plasma proteins and blood cells. This not only leads to a loss of sensor signal over time, but can also result in undesired host vs. graft reactions. Within this study we evaluated the hemocompatibility of isocyanate conjugated star shaped polytheylene oxide—polypropylene oxide co-polymers NCO-sP(EO-stat-PO) when applied to gold surfaces as an auspicious coating material for gold sputtered blood contacting sensors. Quartz crystal microbalance (QCM) sensors were coated with ultrathin NCO-sP(EO-stat-PO) films and compared with uncoated gold sensors. Protein resistance was assessed by QCM measurements with fibrinogen solution and platelet poor plasma (PPP), followed by quantification of fibrinogen adsorption. Hemocompatibility was tested by incubation with human platelet rich plasma (PRP). Thrombin antithrombin-III complex (TAT), β-thromboglobulin (β-TG) and platelet factor 4 (PF4) were used as coagulation activation markers. Furthermore, scanning electron microscopy (SEM) was used to visualize platelet adhesion to the sensor surfaces. Compared to uncoated gold sensors, NCO-sP(EO-stat-PO) coated sensors revealed significant better resistance against protein adsorption, lower TAT generation and a lower amount of adherent platelets. Moreover, coating with ultrathin NCO-sP(EO-stat-PO) films creates a cell resistant hemocompatible surface on gold that increases the chance of prolonged sensor functionality and can easily be modified with specific receptor molecules. PMID:22163899

Effects of fibrinogen concentrate after shock/resuscitation – A comparison between in vivo microvascular clot formation and thromboelastometry

PubMed Central

Martini, Judith; Cabrales, Pedro; Fries, Dietmar; Intaglietta, Marcos; Tsai, Amy G.

2014-01-01

Objective Dilutional coagulopathy after resuscitation with crystalloids/colloids clinically often appears as diffuse microvascular bleeding. Administration of fibrinogen reduces bleeding and increases maximum clot firmness (MCF), measured by thromboelastometry. Study objective was to implement a model where microvascular bleeding can be directly assessed by visualizing clot formation in microvessels, and correlations can be made to thromboelastometry. Design Randomized animal study. Setting University research laboratory. Subjects Male Syrian Golden hamsters. Interventions Microvessels of Syrian Golden hamsters fitted with a dorsal window chamber were studied using videomicroscopy. After 50% hemorrhage followed by 1 hr of hypovolemia resuscitation with 35% of blood volume using a high molecular weight (MW) HES solution (Hextend®, Hospira, MW 670 kD) occurred. Animals were then treated with 250 mg/kg fibrinogen iv (Laboratoire français du Fractionnement et des Biotechnologies (LFB), Paris, France) or an equal volume of saline before venular vessel wall injuries were made by directed laser irradiation and the ability of microthrombus formation was assessed. Measurements and main results Thromboelastometric measurements of MCF were performed at the beginning and at the end of the experiment. Resuscitation with HES and sham treatment significantly decreased FIBTEM MCF from 32 ± 9 at baseline vs. 13 ± 5 mm after sham treatment (p < 0.001). Infusion of fibrinogen concentrate significantly increased MCF, restoring baseline levels (baseline 32 ± 9 mm; after fibrinogen administration 29 ± 2 mm). In vivo microthrombus formation in laser injured vessels significantly increased in fibrinogen treated animals compared with sham (77% vs. 18%). Conclusions Fibrinogen treatment leads to increased clot firmness in dilutional coagulopathy as measured with thromboelastometry. At the microvascular level this increased clot strength, corresponds to an increased incidence of thrombus formation in vessels injured by focused laser irradiation. PMID:23978812

Serum bilirubin levels are inversely associated with PAI-1 and fibrinogen in Korean subjects.

PubMed

Cho, Hyun Sun; Lee, Sung Won; Kim, Eun Sook; Shin, Juyoung; Moon, Sung Dae; Han, Je Ho; Cha, Bong Yun

2016-01-01

Oxidative stress may contribute to atherosclerosis and increased activation of the coagulation pathway. Bilirubin may reduce activation of the hemostatic system to inhibit oxidative stress, which would explain its cardioprotective properties shown in many epidemiological studies. This study investigated the association of serum bilirubin with fibrinogen and plasminogen activator inhibitor-1 (PAI-1), respectively. A cross-sectional analysis was performed on 968 subjects (mean age, 56.0 ± 11.2 years; 61.1% men) undergoing a general health checkup. Serum biochemistry was analyzed including bilirubin subtypes, insulin resistance (using homeostasis model of assessment [HOMA]), C-reactive protein (CRP), fibrinogen, and PAI-1. Compared with subjects with a total bilirubin (TB) concentration of <10.0 μmol/L, those with a TB concentration of >17.1 μmol/L had a smaller waist circumference, a lower triglyceride level, a lower prevalence of metabolic syndrome, and decreased HOMA-IR and CRP levels. Correlation analysis revealed linear relationships of fibrinogen with TB and direct bilirubin (DB), whereas PAI-1 was correlated with DB. After adjustment for confounding factors, bilirubin levels were inversely associated with fibrinogen and PAI-1 levels, respectively. Multivariate regression models showed a negative linear relationship between all types of bilirubin and fibrinogen, whereas there was a significant linear relationship between PAI-1 and DB. High bilirubin concentrations were independently associated with low levels of fibrinogen and PAI-1, respectively. The association between TB and PAI-1 was confined to the highest TB concentration category whereas DB showed a linear association with PAI-1. Bilirubin may protect against the development of atherothrombosis by reducing the hemostatic response. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Detection of fibrin generation alterations in dogs with haemangiosarcoma using resonance thrombography.

PubMed

Mischke, R; Wohlsein, P; Schoon, H-A

2005-01-01

The objective of the study was to examine the alterations of fibrin generation in dogs with haemangiosarcoma using resonance thrombography. The second objective was to evaluate the sensitivity of this method for the detection of hypofibrinogenaemia and/or increased fibrin(ogen) degradation product (FDP) concentration. Resonance thrombogram (RTG) measurements with two different instruments were performed in 30 unselected dogs with haemangiosarcoma, 14 of which had decreased fibrinogen and 28 of which had an increased FDP concentration (p<0.0001). The RTG-reaction time was less sensitive than the fibrin formation time (RTG-f) and fibrin amplitude (RTG-F). The RTG-f and RTG-F indicated reliably a decrease in fibrinogen concentration (sensitivity: 0.93). The sensitivity of detection of increased FDP levels was considerably higher than that of thrombin time. However, false-negative results were found even at FDP concentrations > or =120 mg/l, especially in cases with high fibrinogen level. Both machines showed similar sensitivity. The results of this study indicate that canine haemangiosarcoma is frequently associated with severe alterations of fibrin generation due to low fibrinogen and high FDP levels leading to distinct RTG abnormalities. The global test RTG reacts sensitively to a decreased fibrinogen level whereas its accuracy to detect FDP concentrations occurring under pathophysiological conditions is limited. A significant alteration of fibrin generation induced by FDPs may not occur until the serum FDP concentration exceeds 60 mg/l.

Prognostic significance of blood coagulation tests in carcinoma of the lung and colon.

PubMed

Wojtukiewicz, M Z; Zacharski, L R; Moritz, T E; Hur, K; Edwards, R L; Rickles, F R

1992-08-01

Blood coagulation test results were collected prospectively in patients with previously untreated, advanced lung or colon cancer who entered into a clinical trial. In patients with colon cancer, reduced survival was associated (in univariate analysis) with higher values obtained at entry to the study for fibrinogen, fibrin(ogen) split products, antiplasmin, and fibrinopeptide A and accelerated euglobulin lysis times. In patients with non-small cell lung cancer, reduced survival was associated (in univariate analysis) with higher fibrinogen and fibrin(ogen) split products, platelet counts and activated partial thromboplastin times. In patients with small cell carcinoma of the lung, only higher activated partial thromboplastin times were associated (in univariate analysis) with reduced survival in patients with disseminated disease. In multivariate analysis, higher activated partial thromboplastin times were a significant independent predictor of survival for patients with non-small cell lung cancer limited to one hemithorax and with disseminated small cell carcinoma of the lung. Fibrin(ogen) split product levels were an independent predictor of survival for patients with disseminated non-small cell lung cancer as were both the fibrinogen and fibrinopeptide A levels for patients with disseminated colon cancer. These results suggest that certain tests of blood coagulation may be indicative of prognosis in lung and colon cancer. The heterogeneity of these results suggests that the mechanism(s), intensity, and pathophysiological significance of coagulation activation in cancer may differ between tumour types.

Effect of Metformin on Plasma Fibrinogen Concentrations: A Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials.

PubMed

Simental-Mendia, Luis E; Pirro, Matteo; Atkin, Stephen L; Banach, Maciej; Mikhailidis, Dimitri P; Sahebkar, Amirhossein

2018-01-01

Fibrinogen is a key mediator of thrombosis and it has been implicated in the pathogenesis of atherosclerosis. Because metformin has shown a potential protective effect on different atherothrombotic risk factors, we assessed in this meta-analysis its effect on plasma fibrinogen concentrations. A systematic review and meta-analysis was carried out to identify randomized placebo-controlled trials evaluating the effect of metformin administration on fibrinogen levels. The search included PubMed-Medline, Scopus, ISI Web of Knowledge and Google Scholar databases (by June 2, 2017) and quality of studies was performed according to Cochrane criteria. Quantitative data synthesis was conducted using a random-effects model and sensitivity analysis by the leave-one-out method. Meta-regression analysis was performed to assess the modifiers of treatment response. Meta-analysis of data from 9 randomized placebo-controlled clinical trials with 2302 patients comprising 10 treatment arms did not suggest a significant change in plasma fibrinogen concentrations following metformin therapy (WMD: -0.25 g/L, 95% CI: -0.53, 0.04, p = 0.092). The effect size was robust in the leave-one-out sensitivity analysis and remained non-significant after omission of each single study from the meta-analysis. No significant effect of metformin on plasma fibrinogen concentrations was demonstrated in the current meta-analysis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A sensitive HPLC-MS/MS method for the simultaneous detection of microbial transglutaminase, and bovine and porcine fibrinogen/thrombin in restructured meat.

PubMed

Jira, Wolfgang; Schwägele, Fredi

2017-12-15

A sensitive HPLC-MS/MS method for the simultaneous detection of microbial transglutaminase (TG) from Streptomyces mobaraensis, and bovine and porcine fibrinogen/thrombin in restructured meat was developed using tryptic marker peptides of TG (five markers), and bovine and porcine fibrinogen (six markers each). Meat binding experiments with beef and pork were performed using a technical TG mixture (Activa, Ajinomoto), and bovine and porcine plasmapowder FG (PPFG; Sonac B.V.). The method developed allows the simultaneous detection of the use of these cold-set binders in raw and heated samples. The peak areas of the fibrinogen marker peptides were increased by a factor of about 100, compared to blank values originating from the occurrence of residual blood in meat, using a concentration of 0.6% bovine and porcine PPFG. A differentiation between the use of blood plasma powder and PPFG using the ratios of fibrinogen to serotransferrin peptide peak areas seems to be possible. Copyright © 2017 Elsevier Ltd. All rights reserved.

CONNECTION BETWEEN THE INCREASED FIBRINOGEN CONCENTRATION IN DOGS WITH RADIATION SICKNESS AND THE FIBRINOGENASE ACTIVITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gordeeva, K.V.

1963-11-01

A study was made of the concentration of blood plasma fibrinogen in relation to the changes of fibrinogenase activity. Dogs with radiation sickness (severe, moderately severe, and mild) served as experimental animals. A rise of the blood plasma fibrinogen content was observed in dogs with severe and moderately severe radiation sickness. This phenomenon is especially pronounced at the height of radiation sickness. The activity of fibrinogenase in severe radiation sickness was considerably decreased at the initial period and at the height of the disease. The rise of fibrinogen content in severe and moderately severe radiation sickness should be regarded asmore » an adaptive reaction directed to control hemorrhages, not as the sequence of raduced fibrinogenase activity. (auth)« less

Mechanisms of fibrinogen-acebutolol interactions: Insights from DSC, CD and LS.

PubMed

Hassan, Natalia; Ruso, Juan M; Somasundaran, P

2011-02-01

The complex formed due to the interaction of the amphiphilic betablocker acebutolol with fibrinogen in a buffer solution (50mN glycine, pH of 8.5) has been investigated using a multipronged physicochemical approach. Differential scanning calorimetry measurements of the complexes have shown no reversibility of thermal denaturation as indicated by the three observed peaks and the opposite role that acebutolol plays in the folding different domains of the fibrinogen molecule and the stability of such domains. While circular dichroism measurements have revealed that interaction of acebutolol with fibrinogen affects the protein secondary structure to a different extent depending on the temperature and drug concentration, dynamic light scattering analysis showed evidence for protein aggregation mainly to tetramers and dimers. Copyright © 2010 Elsevier B.V. All rights reserved.

Assessment of the Dual Role of Clumping Factor A in S. Aureus Adhesion to Endothelium in Absence and Presence of Plasma.

PubMed

Claes, Jorien; Ditkowski, Bartosz; Liesenborghs, Laurens; Veloso, Tiago Rafael; Entenza, Jose M; Moreillon, Philippe; Vanassche, Thomas; Verhamme, Peter; Hoylaerts, Marc F; Heying, Ruth

2018-06-17

Adhesion of Staphylococcus aureus to endothelial cells (ECs) is paramount in infective endocarditis. Bacterial proteins such as clumping factor A (ClfA) and fibronectin binding protein A (FnbpA) mediate adhesion to EC surface molecules and (sub)endothelial matrix proteins including fibrinogen (Fg), fibrin, fibronectin (Fn) and von Willebrand factor (vWF). We studied the influence of shear flow and plasma on the binding of ClfA and FnbpA (including its sub-domains A, A 16+ , ABC, CD) to coverslip-coated vWF, Fg/fibrin, Fn or confluent ECs, making use of Lactococcus lactis , expressing these adhesins heterologously. Global adherence profiles were similar in static and flow conditions. In the absence of plasma, L. lactis-clfA binding to Fg increased with shear forces, whereas binding to fibrin did not. The degree of adhesion of L. lactis-fnbpA to EC-bound Fn and of L. lactis-clfA to EC-bound Fg, furthermore, was similar to that of L. lactis-clfA to coated vWF domain A1, in the presence of vWF-binding protein (vWbp). Yet, in plasma, L. lactis-clfA adherence to activated EC-vWF/vWbp dropped over 10 minutes by 80% due to vWF-hydrolysis by a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13 and that of L. lactis-fnbpA likewise by > 70% compared to the adhesion in absence of plasma. In contrast, plasma Fg supported high L. lactis-clfA binding to resting and activated ECs. Or, in plasma S. aureus adhesion to active endothelium occurs mainly via two complementary pathways: a rapid but short-lived vWF/vWbp pathway and a stable integrin-coupled Fg-pathway. Hence, the pharmacological inhibition of ClfA-Fg interactions may constitute a valuable additive treatment in infective endocarditis. Schattauer GmbH Stuttgart.

Hyperfibrinogenaemia and hyperviscosity in sickle-cell crisis.

PubMed Central

Richardson, S G; Breeze, G R; Stuart, J

1976-01-01

Plasma fibrinogen concentration and whole-blood viscosity, the latter measured at two shear rates (23 and 230 sec-1), were estimated during eight episodes of sickle-cell crisis and compared with values in 26 sickle-cell anaemia patients who were not in crisis. Painful crisis was associated with a significant increase in both plasma fibrinogen and whole-blood viscosity. Increased fibrinogen-erythrocyte interaction in vivo may be a significant contributory factor to raising blood viscosity and precipitating vaso-occlusive crisis in sickle-cell disease. PMID:977763

MECHANISMS INVOLVED IN FIBRIN FORMATION

PubMed Central

Boyles, Paul W.; Ferguson, John H.; Muehlke, Paul H.

1951-01-01

That the role of thrombin in the conversion of fibrinogen to fibrin is essentially enzymatic, is established not only by the minute amounts of thrombin which are effective but also by the complete independence of fibrin yields and thrombin concentrations over a very wide range of thrombin dilutions and clotting times. The thrombin-fibrinogen reaction, in the phase beyond the "latent period" at least, seems fundamentally "first order." Technical requirements of the experiments leading to these conclusions include: (1) a highly purified (e.g. 97 per cent "clottable") fibrinogen, (2) absence of traces of thrombic impurities in the fibrinogen, (3) absence of fibrinolytic protease contaminant of the thrombin and the fibrinogen, and (4) sufficient stability of the thrombin even at very high dilutions. Four conditions affecting thrombin stability have been investigated. Fibrin yields are not significantly modified by numerous experimental circumstances that influence the clotting time, such as (1) temperature, (2) pH, (3) non-specific salt action due to electrical (ionic) charges, which alter the Coulomb forces involved in the fibrillar aggregation, (4) specific ion effects, whether clot-accelerating (e.g. Ca++) or clot-inhibitory (e.g. Fe(CN)6''''), (5) occluding (adsorptive) colloids, which have a "fibrinoplastic" action, e.g. (a) acacia and probably (b) fibrinogen which has been mildly "denatured" by salt-heating, acidification, etc. The data with which several European workers have attempted to substantiate the idea of a two-stage thrombin-fibrinogen reaction with an intermediary "profibrin" (allegedly partly "denatured") have been reanalyzed with controls which lead us to very different conclusions, viz. (1) denaturation and fibrin formation are independent; (2) partial denaturation is "fibrinoplastic" (see above); and (3) conditions of strong salinity and acid pH (5.1) usually do not completely prevent the thrombin-fibrinogen reaction but merely prolong the "latent" phase and lessen the time required for completion of essentially the same reaction (fibrin polymerization) when more favorable clotting conditions are restored. Thus, our experiments advance the modern concepts concerning the coagulation mechanisms along lines that, for the most part, agree with those of the Harvard physical chemists, and we oppose the European views concerning a two-stage reaction, "profibrin," and "the denaturase theory" of clotting. PMID:14832433

Effects of tibolone on fibrinogen and antithrombin III: A systematic review and meta-analysis of controlled trials.

PubMed

Bała, Małgorzata; Sahebkar, Amirhossein; Ursoniu, Sorin; Serban, Maria-Corina; Undas, Anetta; Mikhailidis, Dimitri P; Lip, Gregory Y H; Rysz, Jacek; Banach, Maciej

2017-10-01

Tibolone is a synthetic steroid with estrogenic, androgenic and progestogenic activity, but the evidence regarding its effects on fibrinogen and antithrombin III (ATIII) has not been conclusive. We assessed the impact of tibolone on fibrinogen and ATIII through a systematic review and meta-analysis of available randomized controlled trials (RCTs). The search included PUBMED, Web of Science, Scopus, and Google Scholar (up to January 31st, 2016) to identify controlled clinical studies investigating the effects of oral tibolone treatment on fibrinogen and ATIII. Overall, the impact of tibolone on plasma fibrinogen concentrations was reported in 10 trials comprising 11 treatment arms. Meta-analysis did not suggest a significant reduction of fibrinogen levels following treatment with tibolone (WMD: -5.38%, 95% CI: -11.92, +1.16, p=0.107). This result was robust in the sensitivity analysis and not influenced after omitting each of the included studies from meta-analysis. When the studies were categorized according to the duration of treatment, there was no effect in the subsets of trials lasting either <12months (WMD: -7.64%, 95% CI: -16.58, +1.29, p=0.094) or ≥12months (WMD: -0.62%, 95% CI: -8.40, +7.17, p=0.876). With regard to ATIII, there was no change following treatment with tibolone (WMD: +0.74%, 95% CI: -1.44, +2.93, p=0.505) and this effect was robust in sensitivity analysis. There was no differential effect of tibolone on plasma ATIII concentrations in trials with either <12months (WMD: +2.26%, 95% CI: -3.14, +7.66, p=0.411) or≥12months (WMD: +0.06%, 95% CI: -1.16, +1.28, p=0.926) duration. Consistent with the results of subgroup analysis, meta-regression did not suggest any significant association between the changes in plasma concentrations of fibrinogen (slope: +0.40; 95% CI: -0.39, +1.19; p=0.317) and ATIII (slope: -0.17; 95% CI: -0.54, +0.20; p=0.374) with duration of treatment. In conclusion, meta-analysis did not suggest a significant reduction of fibrinogen and ATIII levels following treatment with tibolone. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reactive polymer coatings: A robust platform towards sophisticated surface engineering for biotechnology

NASA Astrophysics Data System (ADS)

Chen, Hsien-Yeh

Functionalized poly(p-xylylenes) or so-called reactive polymers can be synthesized via chemical vapor deposition (CVD) polymerization. The resulting ultra-thin coatings are pinhole-free and can be conformally deposited to a wide range of substrates and materials. More importantly, the equipped functional groups can served as anchoring sites for tailoring the surface properties, making these reactive coatings a robust platform that can deal with sophisticated challenges faced in biointerfaces. In this work presented herein, surface coatings presenting various functional groups were prepared by CVD process. Such surfaces include aldehyde-functionalized coating to precisely immobilize saccharide molecules onto well-defined areas and alkyne-functionalized coating to click azide-modified molecules via Huisgen 1,3-dipolar cycloaddition reaction. Moreover, CVD copolymerization has been conducted to prepare multifunctional coatings and their specific functions were demonstrated by the immobilization of biotin and NHS-ester molecules. By using a photodefinable coating, polyethylene oxides were immobilized onto a wide range of substrates through photo-immobilization. Spatially controlled protein resistant properties were characterized by selective adsorption of fibrinogen and bovine serum albumin as model systems. Alternatively, surface initiator coatings were used for polymer graftings of polyethylene glycol) methyl ether methacrylate, and the resultant protein- and cell- resistant properties were characterized by adsorption of kinesin motor proteins, fibrinogen, and murine fibroblasts (NIH3T3). Accessibility of reactive coatings within confined microgeometries was systematically studied, and the preparation of homogeneous polymer thin films within the inner surface of microchannels was demonstrated. Moreover, these advanced coatings were applied to develop a dry adhesion process for microfluidic devices. This process provides (i) excellent bonding strength, (ii) extended storage time prior to bonding, and (iii) well-defined surface functionalities for subsequent surface modifications. Finally, we have also prepared surface microstructures and surface patterns using reactive coatings via photopatterning, projection lithography, supramolecular nanostamping (SuNS), and vapor-assisted micropatterning in replica structures (VAMPIR). These patterning techniques can be complimentarily used and provide access to precisely confined microenvironments on flat and curved geometries. Reactive coatings provide a technology platform that creates active, long-term control and may lead to improved mimicry of biological systems for effective bio-functional modifications.

Rapid evaluation of fibrinogen levels using the CG02N whole blood coagulation analyzer.

PubMed

Hayakawa, Mineji; Gando, Satoshi; Ono, Yuichi; Mizugaki, Asumi; Katabami, Kenichi; Maekawa, Kunihiko; Miyamoto, Daisuke; Wada, Takeshi; Yanagida, Yuichiro; Sawamura, Atsushi

2015-04-01

Rapid evaluation of fibrinogen (Fbg) levels is essential for maintaining homeostasis in patients with massive bleeding during severe trauma and major surgery. This study evaluated the accuracy of fibrinogen levels measured by the CG02N whole blood coagulation analyzer (A&T Corporation, Kanagawa, Japan) using heparinized blood drawn for blood gas analysis (whole blood-Fbg). A total of 100 matched pairs of heparinized blood samples and citrated blood samples were simultaneously collected from patients in the intensive care unit. Whole blood-Fbg results were compared with those of citrated plasma (standard-Fbg). The whole blood coagulation analyzer measured fibrinogen levels within 2 minutes. Strong correlations between standard-Fbg and whole blood-Fbg were observed (ρ = 0.91, p < 0.001). Error grid analysis showed that 88% of the values were clinically acceptable, and 12% were in a range with possible effects on clinical decision-making; none were in a clinically dangerous range without appropriate treatment. Using a fibrinogen cutoff value of 1.5 g/L for standard-Fbg, the area under the receiver operating characteristic curve of whole blood-Fbg was 0.980 (95% confidence interval 0.951-1.000, p < 0.001). The whole blood coagulation analyzer can rapidly measure fibrinogen levels in heparinized blood and could be useful in critical care settings where excessive bleeding is a concern. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Association between PSA Levels and Biomarkers of Subclinical Systemic Inflammation in Middle-Aged Healthy Men from the General Population.

PubMed

Elzanaty, Saad; Rezanezhad, Babak; Borgquist, Rasmus

2016-10-01

This study was aimed to determine the association between PSA levels and biomarkers of subclinical systemic inflammation based on data from 119 middle-aged healthy men from the general population. Serum levels of PSA and biomarkers of systemic inflammation (CRP and fibrinogen) were measured. Demographic data were also collected. Subjects were divided into two groups according to PSA levels; < 2 ng/ml and ≥ 2 ng/ml. The mean (SD) age of men was 55 ± 4.0 years. We found a positive significant correlation between PSA and fibrinogen levels (r = 0.20, p = 0.04), and between CRP and fibrinogen levels (r = 0.60, p = 0.01). On the other hand, no significant correlation between PSA and CRP levels was found. Men with PSA values ≥ 2 ng/ml had significantly higher levels of fibrinogen as compared to those with PSA < 2 ng/ml (2.9 ng/ml vs. 2.4 ng/ml, p = 0.01). In a multivariate regression analysis model adjusted for the age of subjects, BMI, marital status, smoking, snuff, and alcohol intake with serum levels of PSA as a dependent variable, serum level of fibrinogen predicted higher PSA-values (odds ratio = 3.30, 95% CI = 1.05-10.20, p = 0.042). The present results indicate that serum fibrinogen is a biomarker of subclinical systemic inflammation associated with PSA elevation among middle-aged healthy men from the general population.

Peptides derived from central turn motifs within integrin αIIb and αV cytoplasmic tails inhibit integrin activation.

PubMed

Li, Xinlei; Liu, Yongqing; Haas, Thomas A

2014-12-01

We previously found that peptides derived from the full length of integrin αIIb and αV cytoplasmic tails inhibited their parent integrin activation, respectively. Here we showed that the cell-permeable peptides corresponding to the conserved central turn motif within αIIb and αV cytoplasmic tails, myr-KRNRPPLEED (αIIb peptide) and myr-KRVRPPQEEQ (αV peptide), similarly inhibited both αIIb and αV integrin activation. Pre-treatment with αIIb or αV peptides inhibited Mn(2+)-activated αIIbβ3 binding to soluble fibrinogen as well as the binding of αIIbβ3-expressing Chinese Hamster Ovary cells to immobilized fibrinogen. Our turn peptides also inhibited adhesion of two breast cancer cell lines (MDA-MB-435 and MCF7) to αV ligand vitronectin. These results suggest that αIIb and αV peptides share a same mechanism in regulating integrin function. Using αIIb peptide as a model, we found that replacement of RPP with AAA significantly attenuated the inhibitory activity of αIIb peptide. Furthermore, we found that αIIb peptide specifically bound to β-tubulin in cells. Our work suggests that the central motif of α tails is an anchoring point for cytoskeletons during integrin activation and integrin-mediated cell adhesion, and its function depends on the turn structure at RPP. However, post-treatment of peptides derived from the full-length tail or from the turn motif did not reverse αIIb and αV integrin activation. Copyright © 2014 Elsevier Inc. All rights reserved.

Bioadhesive control of plasma proteins and blood cells from umbilical cord blood onto the interface grafted with zwitterionic polymer brushes.

PubMed

Chang, Yu; Chang, Yung; Higuchi, Akon; Shih, Yu-Ju; Li, Pei-Tsz; Chen, Wen-Yih; Tsai, Eing-Mei; Hsiue, Ging-Ho

2012-03-06

In this work, bioadhesive behavior of plasma proteins and blood cells from umbilical cord blood (UCB) onto zwitterionic poly(sulfobetaine methacrylate) (polySBMA) polymer brushes was studied. The surface coverage of polySBMA brushes on a hydrophobic polystyrene (PS) well plate with surface grafting weights ranging from 0.02 mg/cm(2) to 0.69 mg/cm(2) can be effectively controlled using the ozone pretreatment and thermal-induced radical graft-polymerization. The chemical composition, grafting structure, surface hydrophilicity, and hydration capability of prepared polySBMA brushes were determined to illustrate the correlations between grafting properties and blood compatibility of zwitterionic-grafted surfaces in contact with human UCB. The protein adsorption of fibrinogen in single-protein solutions and at complex medium of 100% UCB plasma onto different polySBMA brushes with different grafting coverage was measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. The grafting density of the zwitterionic brushes greatly affects the PS surface, thus controlling the adsorption of fibrinogen, the adhesion of platelets, and the preservation of hematopoietic stem and progenitor cells (HSPCs) in UCB. The results showed that PS surfaces grafted with polySBMA brushes possess controllable hydration properties through the binding of water molecules, regulating the bioadhesive and bioinert characteristics of plasma proteins and blood platelets in UCB. Interestingly, it was found that the polySBMA brushes with an optimized grafting weight of approximately 0.1 mg/cm(2) at physiologic temperatures show significant hydrated chain flexibility and balanced hydrophilicity to provide the best preservation capacity for HSPCs stored in 100% UCB solution for 2 weeks. This work suggests that, through controlling grafting structures, the hemocompatible nature of grafted zwitterionic polymer brushes makes them well suited to the molecular design of regulated bioadhesive interfaces for use in the preservation of HSPCs from human UCB.

Beta-fibrinogen allele frequencies in Peruvian Quechua, a high-altitude native population.

PubMed

Rupert, J L; Devine, D V; Monsalve, M V; Hochachka, P W

1999-06-01

Elevated hematocrits, which are found in many high-altitude populations, increase the oxygen-carrying capacity of blood and may represent an adaptation to hypoxic environments. However, as high hematocrit increases blood viscosity, which in turn is associated with hypertension and heart disease, it may be advantageous for high-altitude populations to limit other factors that contribute to increased blood viscosity. One such factor is the plasma concentration of the coagulation protein fibrinogen. Several common polymorphisms in the beta-fibrinogen gene have been identified that affect fibrinogen concentrations. We determined the allele frequencies of three of these polymorphisms (G/A-455(HaeIII), C/T-148(HindIII), and G/A+448(MnlI)) in sample groups drawn from three populations: Quechua-speaking natives living at over 3,200 m in the Peruvian Andes, North American natives (Na-Dene) from coastal British Columbia, and Caucasian North Americans. The frequencies of the alleles previously shown to be associated with increased fibrinogen levels were so low in the Quechuas that their presence could be accounted for solely by genetic admixture with Caucasians. Frequencies in the Na-Dene, a Native American group unrelated to the Quechua, were not significantly different from those in Caucasians.

The importance of selecting a proper biological milieu for protein corona analysis in vitro: Human plasma versus human serum.

PubMed

Mirshafiee, Vahid; Kim, Raehyun; Mahmoudi, Morteza; Kraft, Mary L

2016-06-01

Nanoparticle (NP) exposure to biological fluids in the body results in protein binding to the NP surface, which forms a protein coating that is called the "protein corona". To simplify studies of protein-NP interactions and protein corona formation, NPs are incubated with biological solutions, such as human serum or human plasma, and the effects of this exposure are characterized in vitro. Yet, how NP exposure to these two different biological milieus affects protein corona composition and cell response has not been investigated. Here, we explore the differences between the protein coronas that form when NPs are incubated in human serum versus human plasma. NP characterization indicated that NPs that were exposed to human plasma had higher amounts of proteins bound to their surfaces, and were slightly larger in size than those exposed to human serum. In addition, significant differences in corona composition were also detected with gel electrophoresis and liquid chromatography-mass spectrometry/mass spectrometry, where a higher fraction of coagulation proteins and complement factors were found on the plasma-exposed NPs. Flow cytometry and confocal microscopy showed that the uptake of plasma-exposed NPs was higher than that of serum-exposed NPs by RAW 264.7 macrophage immune cells, but not by NIH 3T3 fibroblast cells. This difference is likely due to the elevated amounts of opsonins, such as fibrinogen, on the surfaces of the NPs exposed to plasma, but not serum, because these components trigger NP internalization by immune cells. As the human plasma better mimics the composition of the in vivo environment, namely blood, in vitro protein corona studies should employ human plasma, and not human serum, so the biological phenomena that is observed is more similar to that occurring in vivo. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rare coagulation disorders: fibrinogen, factor VII and factor XIII.

PubMed

de Moerloose, P; Schved, J-F; Nugent, D

2016-07-01

Rare coagulation disorders (RCDs) include the inherited deficiencies of fibrinogen, factor (F) II, FV, combined FV and VIII, FVII, FX, combined FVII and X, FXI, FXIII and combined congenital deficiency of vitamin K-dependent factors (VKCFDs). Despite their rarity, a deep comprehension of all these disorders is essential to really understand haemostasis. Indeed, even if they share some common features each RCD has some particularity which makes it unique. In this review, we focus on three disorders: fibrinogen, FVII and FXIII. © 2016 John Wiley & Sons Ltd.

Identification and phenotypic characterization of a second collagen adhesin, Scm, and genome-based identification and analysis of 13 other predicted MSCRAMMs, including four distinct pilus loci, in Enterococcus faecium

PubMed Central

Sillanpää, Jouko; Nallapareddy, Sreedhar R.; Prakash, Vittal P.; Qin, Xiang; Hook, Magnus; Weinstock, George M.; Murray, Barbara E.

2009-01-01

SUMMARY Attention has recently been drawn to Enterococcus faecium because of an increasing number of nosocomial infections caused by this species and its resistance to multiple antibacterial agents. However, relatively little is known about pathogenic determinants of this organism. We have previously identified a cell wall anchored collagen adhesin, Acm, produced by some isolates of E. faecium, and a secreted antigen, SagA, exhibiting broad spectrum binding to extracellular matrix proteins. Here, we analyzed the draft genome of strain TX0016 for potential MSCRAMMs (microbial surface component recognizing adhesive matrix molecules). Genome-based bioinformatics identified 22 predicted cell wall anchored E. faeciumsurface proteins (Fms) of which 15 (including Acm) have typical characteristics of MSCRAMMs including predicted folding into a modular architecture with multiple immunoglobulin-like domains. Functional characterization of one (Fms10, redesignated Scm for second collagen adhesin of E. faeciu m) revealed that recombinant Scm65 (A- and B-domains) and Scm36 (A-domain) bound efficiently to collagen type V in a concentration dependent manner, bound considerably less to collagen type I and fibrinogen, and differed from Acm in their binding specificities to collagen types IV and V. Results from far-UV circular dichroism of recombinant Scm36 and of Acm37 indicated that these proteins are rich in β-sheets, supporting our folding predictions. Whole-cell ELISA and FACS analyses unambiguously demonstrated surface expression of Scm in most E. faecium isolates. Strikingly, 11 of the 15 predicted MSCRAMMs clustered in four loci, each with a class C sortase gene; 9 of these showed similarity to Enterococcus faecalis Ebp pilus subunits and also contained motifs essential for pilus assembly. Antibodies against one of the predicted major pilus proteins, Fms9 (redesignated as EbpCfm), detected a “ladder” pattern of high-molecular weight protein bands in a Western blot analysis of cell surface extracts from E. faecium, suggesting that EbpCfm is polymerized into a pilus structure. Further analysis of the transcripts of the corresponding gene cluster indicated that fms1 (ebpAfm), fms5 (ebpBfm) and ebpCfm are co-transcribed, consistent with pilus-encoding gene clusters of other gram-positive bacteria. All 15 genes occurred frequently in 30 clinically-derived diverse E. faecium isolates tested. The common occurrence of MSCRAMM and pilus-encoding genes and the presence of a second collagen-binding protein may have important implications for our understanding of this emerging pathogen. PMID:18832325

Fibrinogen, viscosity, and white blood cell count are major risk factors for ischemic heart disease. The Caerphilly and Speedwell collaborative heart disease studies.

PubMed

Yarnell, J W; Baker, I A; Sweetnam, P M; Bainton, D; O'Brien, J R; Whitehead, P J; Elwood, P C

1991-03-01

Recent studies have suggested that hemostatic factors and white blood cell count are predictive of ischemic heart disease (IHD). The relations of fibrinogen, viscosity, and white blood cell count to the incidence of IHD in the Caerphilly and Speedwell prospective studies are described. The two studies have a common core protocol and are based on a combined cohort of 4,860 middle-aged men from the general population. The first follow-up was at a nearly constant interval of 5.1 years in Caerphilly and 3.2 years in Speedwell; 251 major IHD events had occurred. Age-adjusted relative odds of IHD for men in the top 20% of the distribution compared with the bottom 20% were 4.1 (95% confidence interval, 2.6-6.5) for fibrinogen, 4.5 (95% confidence interval, 2.8-7.4) for viscosity, and 3.2 (95% confidence interval, 2.0-4.9) for white blood cell count. Associations with IHD were similar in men who had never smoked, exsmokers, and current smokers, and the results suggest that at least part of the effect of smoking on IHD is mediated through fibrinogen, viscosity, and white blood cell count. Multivariate analysis shows that white blood cell count is an independent risk factor for IHD as is either fibrinogen or viscosity, or possibly both. Jointly, these three variables significantly improve the fit of a logistic regression model containing all the main conventional risk factors. Further, a model including age, smoking habits, fibrinogen, viscosity, and white blood cell count predicts IHD as well as one in which the three hemostatic/rheological variables are replaced by total cholesterol, diastolic pressure, and body mass index. Jointly, fibrinogen, viscosity, and white blood cell count are important risk factors for IHD.

Paradoxical bleeding and thrombosis in a patient with afibrinogenemia and fibrinogen Mumbai mutation.

PubMed

Mukaddam, Alfiya; Patil, Rucha; Jadli, Anshul; Chandrakala, S; Ghosh, Kanjaksha; Shetty, Shrimati

2015-05-01

Thrombosis is rarely reported in cases of afibrinogenemia and is generally associated with thrombophilia or replacement therapy. Often, it is difficult to predict whether the patients will bleed or whether they are exposed to the risk of thrombosis. We report a patient with afibrinogenemia who presented with complete thrombosis of right hepatic, portal, and splenic veins and who described a lifelong history of bleeding. Direct sequencing of the three fibrinogen genes was performed to identify the mutation. DNA sequencing showed the presence of a homozygous for G8017A substitution in exon 8 of the fibrinogen β-chain gene, resulting in a G434D missense mutation (Fibrinogen Mumbai). Presence of both bleeding and thrombotic manifestations in a patient with afibrinogenemia in the presence of other associated risk factors warrants a very careful individualized approach in the management of patients with afibrinogenemia. Copyright© by the American Society for Clinical Pathology.

[Assessment of local and systemic inflammatory parameters of peripheral burn in an animal model].

PubMed

Torres, Wilmary; Mendoza, Liseth; Vicci, Hember; Eblen-Zajjur, Antonio; Navarro, María

2016-01-01

To evaluate the edema volume and leukocyte, platelet, and fibrinogen count of peripheral burn in an animal model. The back left leg of Rattus norvegicus (experimental group) was placed in water at 60 °C for 60 seconds or at room temperature (control group). An analysis was carried out before and after the induced burn (at 4, 8, 12, and 24 h). The edema volume was determined by an orthogonal photo, the leukocyte and platelet counts were determined using automated equipment, and the fibrinogen count was determined using the gravimetric method. The maximum value of the edema was recorded at 4 h and leukocytes at 24 h. The platelet count did not vary at different post-edema time intervals. The fibrinogen level increased at 4 h and 24 h. In this animal model we induced systemic inflammation characterized by leukocytosis and elevated fibrinogen levels, combined with edema located at the induction area.

Adsorption and conformational modification of fibronectin and fibrinogen adsorbed on hydroxyapatite. A QCM-D study.

PubMed

Fernández-Montes Moraleda, Belén; San Román, Julio; Rodríguez-Lorenzo, Luís M

2016-10-01

Hydroxyapatite is a bioactive ceramic frequently used for bone engineering/replacement. One of the parameters that influence the biological response to implanted materials is the conformation of the first adsorbed protein layer. In this work, the adsorption and conformational changes of two fibroid serum proteins; fibronectin and fibrinogen adsorbed onto four different hydroxyapatite powders are studied with a Quartz Crystal Microbalance with Dissipation (QCM-D). Each of the calcined apatites adsorbs less protein than their corresponding synthesized samples. Adsorption on synthesized samples yields always an extended conformation whereas a reorganization of the layer is observed for the calcined samples. Fg acquires a "Side on" conformation in all the samples at the beginning of the experiment except for one of the synthesized samples where an "End-on" conformation is obtained during the whole experiment. The Extended conformation is the active conformation for Fn. This conformation is favored by apatites with large specific surface area (SSA) and on highly concentrated media. Apatite surface features should be considered in the selection or design of materials for bone regeneration, since it is possible to control the conformation mode of attachment of Fn and Fg by an appropriate selection of them. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2585-2594, 2016. © 2016 Wiley Periodicals, Inc.

Biphasic regulation of polymorphonuclear leukocyte spreading by polyphenolic compounds with pyrogallol moieties.

PubMed

Kori, Soichiro; Namiki, Hideo; Suzuki, Kingo

2009-09-01

Green tea polyphenols have been reported to have anti-inflammatory activities, although the molecular mechanisms responsible for this effect remain unclear. In the present study, we examined the effect of green tea extract and a variety of polyphenolic compounds on spreading of peripheral blood polymorphonuclear leukocytes (PMNs) over fibrinogen-coated surfaces. Green tea extract exerted a biphasic effect on PMN spreading; it induced or suppressed spreading at low and high concentrations, respectively. We also found that pyrogallol-bearing compounds have spreading induction activity. Among the compounds tested, tannic acid (TA) had the strongest activity; the concentrations required for induction of maximal spreading were 2 microM for TA, 200 microM for (-)-epigallocatechin gallate, and 2000 microM for the other active compounds. Furthermore, TA was the only compound showing a biphasic effect similar to that of green tea extract; TA at 20 or 200 microM suppressed spreading. The spreading-stimulatory signal was still latent during PMN exposure to TA at concentrations that inhibited spreading, because the pre-exposed PMNs underwent spreading when plated after removal of free TA by centrifugation. The spreading-inhibitory effect of TA at high concentrations overcame the induction of spreading by other stimuli, including phorbol 12-myristate 13-acetate, hydrogen peroxide, denatured fibrinogen surfaces, and naked plastic surfaces. These results suggest that TA as well as green tea extract is bi-functional, having pro-inflammatory and anti-inflammatory effects at low and high concentrations, respectively. Pharmacological use of TA may thus provide new strategies aimed at regulation of PMN spreading for control of inflammation.

Adsorption of human fibrinogen and albumin onto hydrophobic and hydrophilic Ti6Al4V powder

NASA Astrophysics Data System (ADS)

Rodríguez-Sánchez, Jesús; Gallardo-Moreno, Amparo M.; Bruque, José M.; González-Martín, M. Luisa

2016-07-01

Adsorption of proteins on solid surfaces has been widely studied because of its importance in various biotechnological, medical and technical applications, such as medical implants or biosensors. One of the main problems is the adsorption-induced conformational changes because they often modify the biological activity of the proteins, which is believed to be a key factor on the subsequent cellular adhesion. The aim of this work is the study of the adsorption of human fibrinogen (Fg) and human serum albumin (HSA) onto Ti6Al4V particles, commercially available on different size, that are used to elaborate scaffolds to provide structural support to cell proliferation, promoting tissue development and bone regeneration among others. The study was done through the analysis of the adsorption isotherms and the electrical characterization of surfaces after adsorption in terms of the zeta potential (ζ). From this analysis it seems that Fg adsorbs preferentially vertically oriented (end-on) and HSA moves sequentially over the surface of the Ti6Al4V particles through dimmer formation, allowing adsorption progress over this initial bilayer. The zeta potential values of both proteins remain constant when the monolayer is formed. The study also extends the analysis of both adsorption behaviour and ζ potential characterization factors to the influence of the substrate hydrophobicity as this property can be modified for the Ti6Al4V by irradiating it with ultraviolet light (UV-C) without changes on its chemical composition [1,2]. Differences at low protein concentrations were found for both isotherms and zeta-potential values.

Competitive Protein Adsorption on Polysaccharide and Hyaluronate Modified Surfaces

PubMed Central

Ombelli, Michela; Costello, Lauren; Postle, Corinne; Anantharaman, Vinod; Meng, Qing Cheng; Composto, Russell J.; Eckmann, David M.

2011-01-01

We measured adsorption of bovine serum albumin (BSA) and fibrinogen (Fg) onto six distinct bare and dextran- and hyaluronate-modified silicon surfaces created using two dextran grafting densities and three hyaluronic acid (HA) sodium salts derived from human umbilical cord, rooster comb and streptococcus zooepidemicus. Film thickness and surface morphology depended on HA molecular weight and concentration. BSA coverage was enhanced on surfaces upon competitive adsorption of BSA:Fg mixtures. Dextranization differentially reduced protein adsorption onto surfaces based on oxidation state. Hyaluronization was demonstrated to provide the greatest resistance to protein coverage, equivalent to that of the most resistant dextranized surface. Resistance to protein adsorption was independent of the type of hyaluronic acid utilized. With changing bulk protein concentration from 20 to 40 µg ml−1 for each species, Fg coverage on silicon increased by 4×, whereas both BSA and Fg adsorption on dextran and HA were far less dependent of protein bulk concentration. PMID:21623481

Fabrication and physical and biological properties of fibrin gel derived from human plasma.

PubMed

Zhao, Haiguang; Ma, Lie; Zhou, Jie; Mao, Zhengwei; Gao, Changyou; Shen, Jiacong

2008-03-01

The fast development of tissue engineering and regenerative medicine drives the old biomaterials, for example, fibrin glue, to find new applications in these areas. Aiming at developing a commercially available hydrogel for cell entrapment and delivery, in this study we optimized the fabrication and gelation conditions of fibrin gel. Fibrinogen was isolated from human plasma by a freeze-thaw circle. Gelation of the fibrinogen was accomplished by mixing with thrombin. Absorbance of the fibrinogen/thrombin mixture at 550 nm as a function of reaction time was monitored by UV-VIS spectroscopy. It was found that the clotting time is significantly influenced by the thrombin concentration and the temperature, while less influenced by the fibrinogen concentration. After freeze-drying, the fibrin gel was characterized by scanning electron microscopy (SEM), revealing fibrous microstructure. Thermal gravimetric analysis found that the degradation temperature of the crosslinked fibrin gel starts from 288 degrees C, which is about 30 degrees C higher than that of the fibrinogen. The hydrogel has an initial water-uptake ratio of approximately 50, decreased to 30-40 after incubation in water for 11 h depending on the thrombin concentration. The fibrin gels lost their weights in PBS very rapidly, while slowly in DMEM/fetal bovine serum and DMEM. In vitro cell culture found that human fibroblasts could normally proliferate in the fibrin gel with spreading morphology. In conclusion, the fibrin gel containing higher concentration of fibrinogen (20 mg ml(-1)) and thrombin (5 U ml(-1)) has suitable gelation time and handling properties, and thus is applicable as a delivery vehicle for cells such as fibroblasts.

Fabrication and physical and biological properties of fibrin gel derived from human plasma

NASA Astrophysics Data System (ADS)

Zhao, Haiguang; Ma, Lie; Zhou, Jie; Mao, Zhengwei; Gao, Changyou; Shen, Jiacong

2008-03-01

The fast development of tissue engineering and regenerative medicine drives the old biomaterials, for example, fibrin glue, to find new applications in these areas. Aiming at developing a commercially available hydrogel for cell entrapment and delivery, in this study we optimized the fabrication and gelation conditions of fibrin gel. Fibrinogen was isolated from human plasma by a freeze-thaw circle. Gelation of the fibrinogen was accomplished by mixing with thrombin. Absorbance of the fibrinogen/thrombin mixture at 550 nm as a function of reaction time was monitored by UV-VIS spectroscopy. It was found that the clotting time is significantly influenced by the thrombin concentration and the temperature, while less influenced by the fibrinogen concentration. After freeze-drying, the fibrin gel was characterized by scanning electron microscopy (SEM), revealing fibrous microstructure. Thermal gravimetric analysis found that the degradation temperature of the crosslinked fibrin gel starts from 288 °C, which is about 30 °C higher than that of the fibrinogen. The hydrogel has an initial water-uptake ratio of ~50, decreased to 30-40 after incubation in water for 11 h depending on the thrombin concentration. The fibrin gels lost their weights in PBS very rapidly, while slowly in DMEM/fetal bovine serum and DMEM. In vitro cell culture found that human fibroblasts could normally proliferate in the fibrin gel with spreading morphology. In conclusion, the fibrin gel containing higher concentration of fibrinogen (20 mg ml-1) and thrombin (5 U ml-1) has suitable gelation time and handling properties, and thus is applicable as a delivery vehicle for cells such as fibroblasts.

A G-to-A mutation in IVS-3 of the human gamma fibrinogen gene causing afibrinogenemia due to abnormal RNA splicing.

PubMed

Margaglione, M; Santacroce, R; Colaizzo, D; Seripa, D; Vecchione, G; Lupone, M R; De Lucia, D; Fortina, P; Grandone, E; Perricone, C; Di Minno, G

2000-10-01

Congenital afibrinogenemia is a rare autosomal recessive disorder characterized by a hemorrhagic diathesis of variable severity. Although more than 100 families with this disorder have been described, genetic defects have been characterized in few cases. An investigation of a young propositus, offspring of a consanguineous marriage, with undetectable levels of functional and quantitative fibrinogen, was conducted. Sequence analysis of the fibrinogen genes showed a homozygous G-to-A mutation at the fifth nucleotide (nt 2395) of the third intervening sequence (IVS) of the gamma-chain gene. Her first-degree relatives, who had approximately half the normal fibrinogen values and showed concordance between functional and immunologic levels, were heterozygtes. The G-to-A change predicts the disappearance of a donor splice site. After transfection with a construct, containing either the wild-type or the mutated sequence, cells with the mutant construct showed an aberrant messenger RNA (mRNA), consistent with skipping of exon 3, but not the expected mRNA. Sequencing of the abnormal mRNA showed the complete absence of exon 3. Skipping of exon 3 predicts the deletion of amino acid sequence from residue 16 to residue 75 and shifting of reading frame at amino acid 76 with a premature stop codon within exon 4 at position 77. Thus, the truncated gamma-chain gene product would not interact with other chains to form the mature fibrinogen molecule. The current findings show that mutations within highly conserved IVS regions of fibrinogen genes could affect the efficiency of normal splicing, giving rise to congenital afibrinogenemia.

Varieties of Anger and the Inverse Link between Education and Inflammation: Toward an Integrative Framework

PubMed Central

Boylan, Jennifer Morozink; Ryff, Carol D.

2013-01-01

Objective To examine multiple aspects of anger experience and expression (frequency, outward expression, suppression, control) as moderators of the association of social inequality as measured by educational status with inflammation and coagulation markers. Methods Following survey assessments via telephone and mail, MIDUS (Midlife in the U.S.) respondents (N = 1,054) participated in an overnight clinic visit, where they completed anger questionnaires and provided a fasting blood sample to measure IL-6, C-reactive protein (CRP), and fibrinogen. Results Educational status was linked to higher anger-control among men (B = .14, p = .001). Significant inverse correlations emerged between education and IL-6, CRP, and fibrinogen (r's ≥ -.09, p's < .004) and between anger-control and IL-6 and CRP (r's = -.07, p's <. 03). Controlling for demographic and health status covariates, anger-in predicted lower fibrinogen (p = .031). Interactions between education and anger measures were significant for education and trait anger as related to fibrinogen (p = .023), education and anger-out as related to IL-6 (p = 0.05) and fibrinogen (p = .05). As predicted, the inverse relationships between education and IL-6 and fibrinogen were stronger among individuals reporting high anger. Anger-control also moderated the association of education with IL-6 in women (p = .026), such that the link between education and IL-6 was attenuated among women with high anger-control. Conclusion Varieties of anger moderated educational gradients in inflammation: The inverse relationships between education and inflammation markers were strongest among individuals with high anger, and were attenuated among those with high anger control. PMID:23766379

Relative effects of plasma, fibrinogen concentrate, and factor XIII on ROTEM coagulation profiles in an in vitro model of massive transfusion in trauma.

PubMed

Schmidt, David E; Halmin, Märit; Wikman, Agneta; Östlund, Anders; Ågren, Anna

2017-10-01

Massive traumatic haemorrhage is aggravated through the development of trauma-induced coagulopathy, which is managed by plasma transfusion and/or fibrinogen concentrate administration. It is yet unclear whether these treatments are equally potent in ensuring adequate haemostasis, and whether additional factor XIII (FXIII) administration provides further benefits. In this study, we compared ROTEM whole blood coagulation profiles after experimental massive transfusion with different transfusion regimens in an in vitro model of dilution- and transfusion-related coagulopathy. Healthy donor blood was mixed 1 + 1 with six different transfusion regimens. Each regimen contained RBC, platelet concentrate, and either fresh frozen plasma (FFP) or Ringer's acetate (RA). The regimens were further augmented through addition of a low- or medium-dose fibrinogen concentrate and FXIII. Transfusion with FFP alone was insufficient to maintain tissue-factor activated clot strength, coincidental with a deficiency in fibrin-based clot strength. Fibrinogen concentrate conserved, but did not improve coagulation kinetics and overall clot strength. Only combination therapy with FFP and low-dose fibrinogen concentrate improved both coagulation kinetics and fibrin-based clot strength. Administration of FXIII did not result in an improvement of clot strength. In conclusion, combination therapy with both FFP and low-dose fibrinogen concentrate improved clotting time and produced firm clots, representing a possible preferred first-line regimen to manage trauma-induced coagulopathy when RBC and platelets are also transfused. Further research is required to identify optimal first-line transfusion fluids for massive traumatic haemorrhage.

A genome-wide search for genes affecting circulating fibrinogen levels in the Framingham Heart Study.

PubMed

Yang, Qiong; Tofler, Geoffrey H; Cupples, L Adrienne; Larson, Martin G; Feng, DaLi; Lindpaintner, Klaus; Levy, Daniel; D'Agostino, Ralph B; O'Donnell, Christopher J

2003-04-15

Circulating levels of fibrinogen are associated with atherosclerosis and predict future coronary heart disease and stroke. Levels of fibrinogen are correlated among family members, suggesting a heritable component. Variants of the beta-fibrinogen gene subunit on 4q28 are associated with fibrinogen levels but explain only a small proportion of the total genetic variability. It remains unknown what role, if any, is played by other genetic variants in the inter-individual variability in levels of fibrinogen in the general population. We conducted a 10-cM spaced genome-wide scan using 402 original cohort subjects and 1193 offspring subjects from 330 extended families of the Framingham Heart Study. Heritability and linkage analyses were carried out using variance component methods. Regression analyses were performed to adjust for traditional risk factors and HindIII beta-148 genotypes. The total heritability was estimated as 0.24. The highest and second highest LOD scores of linkage were found on chromosomes 2 (LOD=1.5 at 243 cM) and 10 (LOD=2.4 at 87 cM) using only offspring subjects in the analysis, and on chromosomes 2 (LOD=2.1 at 242 cM) and 10(LOD=1.4 at 86 cM), 17 (LOD=1.4 at 96 cM) and 20 (LOD=1.4 at 80 cM) using both original cohort and offspring. These results suggest that there may be influential genetic regions on these chromosomes. While no linkage with genome-wide significance was detected, further research to confirm our findings is warranted.

Varieties of anger and the inverse link between education and inflammation: toward an integrative framework.

PubMed

Boylan, Jennifer Morozink; Ryff, Carol D

2013-01-01

To examine multiple aspects of anger experience and expression (frequency, outward expression, suppression, and control) as moderators of the association of social inequality, as measured by educational status, with inflammation and coagulation markers. After survey assessments via telephone and mail, Midlife in the United States respondents (N = 1054) participated in an overnight clinic visit, where they completed anger questionnaires and provided a fasting blood sample to measure interleukin-6 (IL-6), C-reactive protein (CRP), and fibrinogen. Educational status was linked to higher anger control among men (B = 0.14, p = .001). Significant inverse correlations emerged between education and IL-6, CRP, and fibrinogen (r values ≥ -0.09, p values <.004) and between anger control and IL-6 and CRP (r values = -0.07, p values < .03). Controlling for demographic and health status covariates, anger-in predicted lower fibrinogen (p = .03). Interactions between education and anger measures were significant for education and trait anger as related to fibrinogen (p = .02) and education and anger-out as related to IL-6 (p = .05) and fibrinogen (p = .05). As predicted, the inverse relationships between education and IL-6 and fibrinogen were stronger among individuals reporting high anger. Anger control also moderated the association of education with IL-6 in women (p = .026), such that the link between education and IL-6 was attenuated among women with high anger control. Varieties of anger moderated educational gradients in inflammation: The inverse relationships between education and inflammation markers were strongest among individuals with high anger and were attenuated among those with high anger control.

Does Topology Drive Fiber Polymerization?

PubMed Central

2015-01-01

We have developed new procedures to examine the early steps in fibrin polymerization. First, we isolated fibrinogen monomers from plasma fibrinogen by gel filtration. Polymerization of fibrinogen monomers differed from that of plasma fibrinogen. The formation of protofibrils was slower and the transformation of protofibrils to fibers faster for the fibrinogen monomers. Second, we used formaldehyde to terminate the polymerization reactions. The formaldehyde-fixed products obtained at each time point were examined by dynamic light scattering and transmission electron microscopy (TEM). The data showed the formaldehyde-fixed products were stable and representative of the reaction intermediates. TEM images showed monomers, short oligomers, protofibrils, and thin fibers. The amount and length of these species varied with time. Short oligomers were less than 5% of the molecules at all times. Third, we developed models that recapitulate the TEM images. Fibrin monomer models were assembled into protofibrils, and protofibrils were assembled into two-strand fibers using Chimera software. Monomers were based on fibrinogen crystal structures, and the end-to-end interactions between monomers were based on D-dimer crystal structures. Protofibrils assembled from S-shaped monomers through asymmetric D:D interactions were ordered helical structures. Fibers were modeled by duplicating a protofibril and rotating the duplicate 120° around its long axis. No specific interactions were presumed. The two protofibrils simply twisted around one another to form a fiber. This model suggests that the conformation of the protofibril per se promotes the assembly into fibers. These findings introduce a novel mechanism for fibrin assembly that may be relevant to other biopolymers. PMID:25419972

Influence of biological factors on lipid and fibrinogen measurements in young men. An epidemiological study in 2009 recruits.

PubMed

Pitsavos, C; Skoumas, J; Dernellis, J; Toutouza, M; Doulalas, A; Stefanadis, C; Toutouzas, P

1998-11-01

The aim of the present study was to detect significant relationships between lipid and fibrinogen measurements and several biological factors in young men. Medical history was obtained, and plasma lipids, lipoprotein (a) and fibrinogen levels were measured in 2009 male Greek army recruits (mean age 22.37+/-3.03 years) not taking any drugs. Plasma levels were as follows: total cholesterol, 171+/-34 mg x dl(-1), low density lipoprotein (LDL) cholesterol, 111+/-34 mg x dl(-1), high density lipoprotein (HDL) cholesterol, 45+/-10 mg x dl(1), and triglycerides, 74+/-32 mg x dl(-1). Lipoprotein (a) and fibrinogen were 18+/-13 and 278+/-67 mg x dl(-1). The atherosclerotic index, calculated as the ratio of total cholesterol/HDL, was 4+/-1. Analysis of multivariate models that included potentially confounding factors revealed the following: body mass index, season of year during which blood examinations were performed, alcohol consumption, and place of residence were found to be significantly associated with plasma levels of total cholesterol, LDL-cholesterol, fibrinogen and the atherosclerotic index in the pooled population. Season and physical activity were significantly associated with HDL-cholesterol, whereas season and family history of acute myocardial infarction were associated with triglycerides levels. Body mass index, family history of myocardial infarction and physical activity were associated with lipoprotein (a). Body mass index, season, alcohol consumption and place of residence are markers of plasma lipid profile and fibrinogen in young men. A family history of acute myocardial infarction and physical activity are related to lipoprotein (a).

The Phosphorylation of Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) by Engineered Surfaces with Electrostatically or Covalently Immobilized VEGF

PubMed Central

Anderson, Sean M.; Chen, Tom T.; Iruela-Arispe, M. Luisa; Segura, Tatiana

2010-01-01

Growth factors are a class of signaling proteins that direct cell fate through interaction with cell surface receptors. Although a myriad of possible cell fates stem from a growth factor binding to its receptor, the signaling cascades that result in one fate over another are still being elucidated. One possible mechanism by which nature modulates growth factor signaling is through the method of presentation of the growth factor – soluble or immobilized (matrix bound). Here we present the methodology to study signaling of soluble versus immobilized VEGF through VEGFR-2. We have designed a strategy to covalently immobilize VEGF using its heparin-binding domain to orient the molecule (bind) and a secondary functional group to mediate covalent binding (lock). This bind-and-lock approach aims to allow VEGF to assume a bioactive orientation before covalent immobilization. Surface plasmon resonance (SPR) demonstrated heparin and VEGF binding with surface densities of 60 ng/cm2 and 100 pg/cm2, respectively. ELISA experiments confirmed VEGF surface density and showed that electrostatically bound VEGF releases in cell medium and heparin solutions while covalently bound VEGF remains immobilized. Electrostatically bound VEGF and covalently bound VEGF phosphorylate VEGFR-2 in both VEGFR-2 transfected cells and VEGFR-2 endogenously producing cells. HUVECs plated on VEGF functionalized surfaces showed different morphologies between surface-bound VEGF and soluble VEGF. The surfaces synthesized in these studies allow for the study of VEGF/VEGFR-2 signaling induced by covalently bound, electrostatically bound, and soluble VEGF and may provide further insight into the design of materials for the generation of a mature and stable vasculature. PMID:19540581

Genetics Home Reference: congenital afibrinogenemia

MedlinePlus

... Neerman-Arbez M. FGB mutations leading to congenital quantitative fibrinogen deficiencies: an update and report of four ... R, Staeger P, Antonarakis SE, Morris MA. Molecular analysis of the fibrinogen gene cluster in 16 patients with congenital afibrinogenemia: novel truncating ... Support USA. ...

Subgap in the Surface Bound States Spectrum of Superfluid (3) 3 He-B with Rough Surface

NASA Astrophysics Data System (ADS)

Nagato, Y.; Higashitani, S.; Nagai, K.

2018-03-01

The subgap structure in the surface bound states spectrum of superfluid ^3He-B with rough surface is discussed. The subgap is formed by the level repulsion between the surface bound state and the continuum states in the course of multiple scattering by the surface roughness. We show that the level repulsion is originated from the nature of the wave function of the surface bound state that is now recognized as Majorana fermion. We study the superfluid ^3He-B with a rough surface and in a magnetic field perpendicular to the surface using the quasi-classical Green function together with a random S-matrix model. We calculate the self-consistent order parameters, the spin polarization density and the surface density of states. It is shown that the subgap is found also in a magnetic field perpendicular to the surface. The magnetic field dependence of the transverse acoustic impedance is also discussed.

Pickup Ion Mass Spectrometry for Surface Bounded Exospheres and Composition Mapping of Lunar and Planetary Surfaces

NASA Technical Reports Server (NTRS)

Keller, J. W.; Zurbuchen, T. H.; Baragiola, R. A.; Cassidy, T. A.; Chornay, D. J.; Collier, M. R.; Hartle, R. E.; Johnson, R. E.; Killen, R. M.; Koehn, P.

2005-01-01

Many of the small to medium sized objects in the solar system can be characterized as having surface bounded exospheres, or atmospheres so tenuous that scale lengths for inter-particle collisions are much larger than the dimensions of the objects. The atmospheres of these objects are the product of their surfaces, both the surface composition and the interactions that occur on them and also their interiors when gases escape from there. Thus by studying surface bounded exospheres it is possible to develop insight into the composition and processes that are taking place on the surface and interiors of these objects. The Moon and Mercury are two examples of planetary bodies with surface bounded exospheres that have been studied through spectroscopic observations of sodium, potassium, and, on the moon, mass spectrometric measurements of lunar gases such as argon and helium.

Cell Wall and Secreted Proteins of Candida albicans: Identification, Function, and Expression

PubMed Central

Chaffin, W. Lajean; López-Ribot, José Luis; Casanova, Manuel; Gozalbo, Daniel; Martínez, José P.

1998-01-01

The cell wall is essential to nearly every aspect of the biology and pathogenicity of Candida albicans. Although it was intially considered an almost inert cellular structure that protected the protoplast against osmotic offense, more recent studies have demonstrated that it is a dynamic organelle. The major components of the cell wall are glucan and chitin, which are associated with structural rigidity, and mannoproteins. The protein component, including both mannoprotein and nonmannoproteins, comprises some 40 or more moieties. Wall proteins may differ in their expression, secretion, or topological location within the wall structure. Proteins may be modified by glycosylation (primarily addition of mannose residues), phosphorylation, and ubiquitination. Among the secreted enzymes are those that are postulated to have substrates within the cell wall and those that find substrates in the extracellular environment. Cell wall proteins have been implicated in adhesion to host tissues and ligands. Fibrinogen, complement fragments, and several extracellular matrix components are among the host proteins bound by cell wall proteins. Proteins related to the hsp70 and hsp90 families of conserved stress proteins and some glycolytic enzyme proteins are also found in the cell wall, apparently as bona fide components. In addition, the expression of some proteins is associated with the morphological growth form of the fungus and may play a role in morphogenesis. Finally, surface mannoproteins are strong immunogens that trigger and modulate the host immune response during candidiasis. PMID:9529890

The relationship between blood viscosity and blood pressure in a random sample of the population aged 55 to 74 years.

PubMed

Fowkes, F G; Lowe, G D; Rumley, A; Lennie, S E; Smith, F B; Donnan, P T

1993-05-01

Blood viscosity is elevated in hypertensive subjects, but the association of viscosity with arterial blood pressure in the general population, and the influence of social, lifestyle and disease characteristics on this association, are not established. In the Edinburgh Artery Study, 1592 men and women aged 55-74 years selected randomly from the general population attended a university clinic. A fasting blood sample was taken for the measurement of blood viscosity and its major determinants (haematocrit, plasma viscosity and fibrinogen). Systolic pressure was related univariately to blood viscosity (P < 0.001), plasma viscosity (P < 0.001) and plasma fibrinogen (P < 0.01), but the association with fibrinogen did not persist after adjusting for body mass index. Diastolic pressure was related univariately to blood viscosity (P < 0.001) and plasma viscosity (P < 0.001) and haematocrit (P < 0.001) but not to fibrinogen. The only difference between the sexes was that the association between blood viscosity and systolic pressure was confined to males. Blood viscosity was associated equally with systolic and diastolic pressures in males, and remained independently related on multivariate analysis adjusting for age, sex, body mass index, social class, smoking, alcohol intake, exercise, angina, HDL and non-HDL cholesterol, diabetes mellitus, plasma viscosity, fibrinogen, and haematocrit.

Commentary on Reconstituting Fibrinogen Concentrate to Maintain Blinding in a Double-blind, Randomized Trial in an Emergency Setting.

PubMed

Bruynseels, Daniel; Solomon, Cristina; Hallam, Angela; Collins, Peter W; Collis, Rachel E; Hamlyn, Vincent; Hall, Judith E

2016-01-01

The gold standard of trial design is the double-blind, placebo-controlled, randomized trial. Intravenous medication, which needs reconstitution by the attending clinician in an emergency situation, can be challenging to incorporate into a suitably blinded study. We have developed a method of blindly reconstituting and administering fibrinogen concentrate (presented as a lyophilized powder), where the placebo is normal saline. Fibrinogen concentrate is increasingly being used early in the treatment of major hemorrhage. Our methodology was designed for a multicenter study investigating the role of fibrinogen concentrate in the treatment of the coagulopathy associated with major obstetric hemorrhage. The method has been verified by a stand-alone pharmaceutical manufacturing unit with an investigational medicinal products license, and to date has successfully been applied 45 times in four study centers. There have been no difficulties in reconstitution and no related adverse events reported. We feel our method is simple to perform and maintains blinding throughout, making it potentially suitable for use in other trials conducted in psychologically high-pressure environments. Although fibrinogen concentrate was the focus of our study, it is likely that the method is applicable to other lyophilized medication with limited shelf life (e.g., antibiotics). Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Cortical atrophy and hypofibrinogenemia due to FGG and TBCD mutations in a single family: a case report.

PubMed

Stephen, Joshi; Nampoothiri, Sheela; Vinayan, K P; Yesodharan, Dhanya; Remesh, Preetha; Gahl, William A; Malicdan, May Christine V

2018-05-16

Blended phenotypes or co-occurrence of independent phenotypically distinct conditions are extremely rare and are due to coincidence of multiple pathogenic mutations, especially due to consanguinity. Hereditary fibrinogen deficiencies result from mutations in the genes FGA, FGB, and FGG, encoding the three different polypeptide chains that comprise fibrinogen. Neurodevelopmental abnormalities have not been associated with fibrinogen deficiencies. In this study, we report an unusual patient with a combination of two independently inherited genetic conditions; fibrinogen deficiency and early onset cortical atrophy. The study describes a male child from consanguineous family presented with hypofibrinogenemia, diffuse cortical atrophy, microcephaly, hypertonia and axonal motor neuropathy. Through a combination of homozygosity mapping and exome sequencing, we identified bi-allelic pathogenic mutations in two genes: a homozygous novel truncating mutation in FGG (c.554del; p.Lys185Argfs*14) and a homozygous missense mutation in TBCD (c.1423G > A;p.Ala475Thr). Loss of function mutations in FGG have been associated with fibrinogen deficiency, while the c.1423G > A mutation in TBCD causes a novel syndrome of neurodegeneration and early onset encephalopathy. Our study highlights the importance of homozygosity mapping and exome sequencing in molecular prenatal diagnosis, especially when multiple gene mutations are responsible for the phenotype.

Post-authorization safety study of Clottafact® , a triply secured fibrinogen concentrate in congenital afibrinogenemia. A prospective observational study.

PubMed

Négrier, C; Rothschild, C; Borg, J-Y; Lambert, T; Claeyssens, S; Sanhes, L; Stieltjes, N; Bertrand, A; André, M-H; Sié, P; Gruel, Y; Tellier, Z

2016-11-01

A new fibrinogen concentrate Clottafact ® was developed according to European guidelines on plasma-derived products. A post-authorization safety study was set up in 2009 as part of the risk management plan. This was a non-interventional, prospective, non-comparative, multicenter study of the use of fibrinogen concentrate for congenital afibrinogenemia in real-life medical practice in France. The analysis was descriptive and performed on 3 subgroups: prophylaxis vs. on-demand treatment, age (<6, <12 and ≥12) and severity of the deficiency. Fourteen patients [1-78 years] were included in 7 centres and followed for 1 year. Twenty-one adverse drug reactions (ADRs) classically reported with fibrinogen (pallor, chills, cough, vomiting, headache, urticaria and erythematous rash) were reported in 5 of 14 patients. Two ADRs were serious: an anaphylactic shock and a subclavian venous thrombosis with a favourable outcome without sequelae. In the nine patients under prophylaxis, 365 of 367 infusions were considered as successful (99·5%) and 2 as failures. For the five patients treated on-demand, the efficacy was rated as excellent for 27 of 48 infusions and good for the 21 others. This study confirms that the benefit/risk balance for this fibrinogen concentrate is favourable. © 2016 International Society of Blood Transfusion.

Immobilization of proteins on glow discharge treated polymers

NASA Astrophysics Data System (ADS)

Kiaei, D.; Safranj, A.; Chen, J. P.; Johnston, A. B.; Zavala, F.; Deelder, A.; Castelino, J. B.; Markovic, V.; Hoffman, A. S.

Certain glow discharge-treated surfaces have been shown to enhance retention of adsorbed proteins. On the basis of this phenomenon, we have investigated the possibility of immobilizing (a) albumin for developing thromboresistant and non-fouling surfaces, (b) antibodies for immuno-diagnostic assays and (c) enzymes for various biosensors and industrial bioprocesses. Albumin retention was highest on surfaces treated with tetrafluoroethylene (TFE) compared to untreated surfaces or other glow discharge treatments studied. Preadsorption of albumin on TFE-treated surfaces resulted in low fibrinogen adsorption and platelet adhesion. IgG retention was also highest on TFE-treated surfaces. The lower detection limits of both malaria antigen and circulating anodic antigen of the schistosomiasis worm were enhanced following glow discharge treatment of the assay plates with TFE. Both TFE and tetrachloroethylene (TCE) glow discharge treated surfaces showed high retention of adsorbed horseradish peroxidase (HRP). However, the retained specific activity of HRP after adsorption on TCE-treated surfaces was remarkably higher than on TFE-treated surfaces.

FDP-E induces adipocyte inflammation and suppresses insulin-stimulated glucose disposal: effect of inflammation and obesity on fibrinogen Bβ mRNA.

PubMed

Kang, Minsung; Vaughan, Roger A; Paton, Chad M

2015-12-01

Obesity is associated with increased fibrinogen production and fibrin formation, which produces fibrin degradation products (FDP-E and FDP-D). Fibrin and FDPs both contribute to inflammation, which would be expected to suppress glucose uptake and insulin signaling in adipose tissue, yet the effect of FDP-E and FDP-D on adipocyte function and glucose disposal is completely unknown. We tested the effects of FDPs on inflammation in 3T3-L1 adipocytes and primary macrophages and adipocyte glucose uptake in vitro. High-fat-fed mice increased hepatic fibrinogen mRNA expression ninefold over chow-fed mice, with concomitant increases in plasma fibrinogen protein levels. Obese mice also displayed increased fibrinogen content of epididymal fat pads. We treated cultured 3T3-L1 adipocytes and primary macrophages with FDP-E, FDP-D, or fibrinogen degradation products (FgnDP-E). FDP-D and FgnDP-E had no effect on inflammation or glucose uptake. Cytokine mRNA expression in RAW264.7 macrophage-like cells and 3T3-L1 adipocytes treated with FDP-E induced inflammation with maximal effects at 100 nM and 6 h. Insulin-stimulated 2-deoxy-d-[(3)H]glucose uptake was reduced by 71% in adipocytes treated with FDP-E. FDP-E, but not FDP-D or FgnDP-E, induces inflammation in macrophages and adipocytes and decreases glucose uptake in vitro. FDP-E may contribute toward obesity-associated acute inflammation and glucose intolerance, although its chronic role in obesity remains to be elucidated. Copyright © 2015 the American Physiological Society.

Testosterone and acute stress are associated with fibrinogen and von Willebrand factor in African men: the SABPA study.

PubMed

Malan, Nicolaas T; von Känel, Roland; Schutte, Alta E; Huisman, Hugo W; Schutte, Rudolph; Smith, Wayne; Mels, Carina M; Kruger, Ruan; Meiring, Muriel; van Rooyen, Johannes M; Malan, Leoné

2013-10-12

Low testosterone, acute and chronic stress and hypercoagulation are all associated with hypertension and hypertension-related diseases. The interaction between these factors and future risk for coronary artery disease in Africans has not been fully elucidated. In this study, associations of testosterone, acute cardiovascular and coagulation stress responses with fibrinogen and von Willebrand factor in African and Caucasian men in a South African cohort were investigated. Cardiovascular variables were studied by means of beat-to-beat and ambulatory blood pressure monitoring. Fasting serum-, salivary testosterone and citrate coagulation markers were obtained from venous blood samples. Acute mental stress responses were evoked with the Stroop test. The African group demonstrated a higher cardiovascular risk compared to Caucasian men with elevated blood pressure, low-grade inflammation, chronic hyperglycemia (HbA1c), lower testosterone levels, and elevated von Willebrand factor (VWF) and fibrinogen levels. Blunted testosterone acute mental stress responses were demonstrated in African males. In multiple regression analyses, higher circulating levels of fibrinogen and VWF in Africans were associated with a low T environment (R(2) 0.24-0.28; p≤0.01), but only circulating fibrinogen in Caucasians. Regarding endothelial function, a low testosterone environment and a profile of augmented α-adrenergic acute mental stress responses (diastolic BP, D-dimer and testosterone) were associated with circulating VWF levels in Africans (Adj R(2) 0.24; p<0.05). An interdependence between acute mental stress, salivary testosterone, D-dimer and vascular responses existed in African males in their association with circulating VWF but no interdependence of the independent variables occurred with fibrinogen levels. © 2013.

Interactions of proteins in human plasma with modified polystyrene resins.

PubMed

Boisson-Vidal, C; Jozefonvicz, J; Brash, J L

1991-01-01

Investigations are reported on the composition of protein layers adsorbed from plasma to various modified polystyrene resins. As well as polystyrene itself, polystyrene bearing sulfonate groups in the benzene rings, and polystyrene sulfonate in which the sulfonate groups were converted to amino acid sulfamide, were investigated. Some of these resins were shown in previous work to have anticoagulant properties. To study the adsorption of proteins from plasma, the resins were exposed to citrate anticoagulated human plasma for 3 h. Adsorbed proteins were then eluted sequentially by 1M Tris buffer and 4% SDS solution, and examined by SDS-PAGE. The gel patterns were similar on all resins except polystyrene. From the MWs of the gel bands, the major protein component appeared to be fibrinogen. Smaller amounts of plasminogen, transferrin, albumin, and IgG were also present. In addition, Ouchterlony immunoassay of the eluates from one resin gave positive identification of complement C3, fibronectin, IgG, and IgM. Many other minor gel bands remain unidentified. A consistent finding for all resins was the presence of plasmin-type fibrinogen degradation products though the amounts varied with resin type. It is concluded from this (and from experiments showing FDP formation when fibrinogen was absorbed to the resins, from buffer containing a trace of plasminogen) that the functional groups in these materials promote the adsorption of plasminogen and its activation to a plasmin-like molecule. It appears from the substantial quantities of fibrinogen adsorbed to these materials after 3 h exposure to plasma that the Vroman effect (giving transient adsorption of fibrinogen) is not operative on these materials. It is hypothesized that specific interactions occur between fibrinogen and sulfonate groups.

Fibrin Accumulation Secondary to Loss of Plasmin-Mediated Fibrinolysis Drives Inflammatory Osteoporosis in Mice

PubMed Central

Cole, Heather A.; Ohba, Tetsuro; Nyman, Jeffry S.; Hirotaka, Haro; Cates, Justin M. M.; Flick, Matthew J.; Degen, Jay L.; Schoenecker, Jonathan G.

2015-01-01

Objective Osteoporosis is a skeletal disorder characterized by low bone mass and increased bone fragility associated with aging, menopause, smoking, obesity, or diabetes. Persistent inflammation has been identified as an instigating factor in progressive bone loss. In addition to the role of fibrin in coagulation, inordinate fibrin deposition within a tissue matrix results in increased local inflammation. Given that fibrin accumulation is a hallmark of osteoporosis-related co-morbidities, we undertook this study to test the hypothesis that persistent fibrin deposition causes inflammatory osteoporosis. Methods Multiple imaging modalities, bone integrity metrics, and histologic analyses were employed to evaluate skeletal derangements in relation to fibrin deposition, circulating fibrinogen levels, and systemic markers of inflammation in mice that were plasminogen deficient and in plasminogen-deficient mice that were concomitantly either fibrinogen deficient or carrying a mutant form of fibrinogen lacking the αMβ2 binding motif. Results Mice generated with a genetic deficit in the key fibrinolytic protease, plasmin, uniformly developed severe osteoporosis. Furthermore, the development of osteoporosis was fibrin(ogen) dependent, and the derangements in the bone remodeling unit were mechanistically tied to fibrin(ogen)-mediated activation of osteoclasts via activation of the leukocyte integrin receptor αMβ2 on monocytes and secondary stimulation of osteoblasts by RANKL. Notably, the genetic elimination of fibrin(ogen) or the expression of a mutant form of fibrinogen retaining clotting function but lacking the αMβ2 binding motif prevented the degenerative skeletal phenotypes, resulting in normal local and systemic cytokine levels. Conclusion Taken together, these data reveal for the first time that fibrin promotes inflammation-driven systemic osteoporosis, which suggests a novel association between hemostasis, inflammation, and bone biology. PMID:24664548

Homocysteine and other cardiovascular risk factors in patients with lichen planus.

PubMed

Saleh, N; Samir, N; Megahed, H; Farid, E

2014-11-01

Chronic inflammation was found to play an important role in the development of cardiovascular risk factors. Homocysteine (Hcy) and fibrinogen have been identified as a major independent risk factor for cardiovascular disease. Lichen planus is assumed to be closely related to dyslipidaemia. Several cytokines involved in lichen planus pathogenesis, could explain its association with dyslipidaemia. Also chronic inflammation with lichen planus has been suggested as a component of the metabolic syndrome. The aim of this study was to detect a panel of cardiovascular risk factors in patients of lichen planus. This study was done on 40 patients of lichen planus and 40 healthy controls. All patients and controls were subjected to clinical examination. Serum levels of homocysteine, fibrinogen and high-sensitive C-reactive protein (hs-CRP) were measured by enzyme-linked immunosorbent assay technique (ELISA). Metabolic syndrome parameters including anthropometric measures, lipid profiles, blood sugar and blood pressure were studied. Patients with lichen planus showed significant association with metabolic syndrome parameters than controls (P < 0.001). Serum homocysteine, fibrinogen and hs-CRP were significantly higher in lichen planus patients than controls (P < 0.001). Serum homocysteine correlated with both serum hs-CRP and serum fibrinogen. However, there was no correlation between serum levels of homocysteine and fibrinogen with any metabolic syndrome criteria and related disorders except for a negative correlation of fibrinogen with high-density lipoprotein (HDL). In the present work, patients with lichen planus were found to have higher makers of both metabolic and cardiovascular risk factors in relation to controls most probably due to long standing inflammation. © 2013 European Academy of Dermatology and Venereology.

Fibrin accumulation secondary to loss of plasmin-mediated fibrinolysis drives inflammatory osteoporosis in mice.

PubMed

Cole, Heather A; Ohba, Tetsuro; Nyman, Jeffry S; Hirotaka, Haro; Cates, Justin M M; Flick, Matthew J; Degen, Jay L; Schoenecker, Jonathan G

2014-08-01

Osteoporosis is a skeletal disorder characterized by low bone mass and increased bone fragility associated with aging, menopause, smoking, obesity, or diabetes. Persistent inflammation has been identified as an instigating factor in progressive bone loss. In addition to the role of fibrin in coagulation, inordinate fibrin deposition within a tissue matrix results in increased local inflammation. Given that fibrin accumulation is a hallmark of osteoporosis-related comorbidities, we undertook this study to test the hypothesis that persistent fibrin deposition causes inflammatory osteoporosis. Multiple imaging modalities, bone integrity metrics, and histologic analyses were employed to evaluate skeletal derangements in relation to fibrin deposition, circulating fibrinogen levels, and systemic markers of inflammation in mice that were plasminogen deficient and in plasminogen-deficient mice that were concomitantly either fibrinogen deficient or carrying a mutant form of fibrinogen lacking the αM β2 binding motif. Mice generated with a genetic deficit in the key fibrinolytic protease, plasmin, uniformly developed severe osteoporosis. Furthermore, the development of osteoporosis was fibrin(ogen) dependent, and the derangements in the bone remodeling unit were mechanistically tied to fibrin(ogen)-mediated activation of osteoclasts via activation of the leukocyte integrin receptor αM β2 on monocytes and secondary stimulation of osteoblasts by RANKL. Notably, the genetic elimination of fibrin(ogen) or the expression of a mutant form of fibrinogen retaining clotting function but lacking the αM β2 binding motif prevented the degenerative skeletal phenotypes, resulting in normal local and systemic cytokine levels. Taken together, these data reveal for the first time that fibrin promotes inflammation-driven systemic osteoporosis, which suggests a novel association between hemostasis, inflammation, and bone biology. Copyright © 2014 by the American College of Rheumatology.

21 CFR 864.8100 - Bothrops atrox reagent.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Identification. A Bothrops atrox reagent is a device made from snake venom and used to determine blood fibrinogen... the treatment of thrombosis) or as an aid in the classification of dysfibrinogenemia (presence in the plasma of functionally defective fibrinogen). (b) Classification. Class II (performance standards). [45...

21 CFR 864.8100 - Bothrops atrox reagent.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Identification. A Bothrops atrox reagent is a device made from snake venom and used to determine blood fibrinogen... the treatment of thrombosis) or as an aid in the classification of dysfibrinogenemia (presence in the plasma of functionally defective fibrinogen). (b) Classification. Class II (performance standards). [45...

Technetium-fibrinogen lung scanning in canine lung contusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geller, E.; Khaw, B.A.; Strauss, H.W.

1984-07-01

To detect experimentally induced acute lung contusion in anesthetized dogs, serial radionuclide images of the lung were recorded following intravenous infusion of 99mTc-labelled human fibrinogen (Tc-HF). The accumulation of Tc-HF in canine lungs was serially quantitated for up to 20 hours after lung contusion. A contusion (number1) was produced in one lung, Tc-HF was injected IV after 15 minutes, and 75 minutes later a contralateral lung contusion (number2) was produced in a series of 14 dogs. At autopsy the excised lungs were scanned, sectioned, and counted for radioactivity. Radiolabelled fibrinogen accumulated within 2-4 minutes of contusion number2 and remained stablemore » over the next 20 hours in 14 dogs; contusion number1 was barely visible in four dogs. Lung Tc-HF activity in the central region of contusion number2 remained sixfold higher than in normal lung tissue. These data suggest that following lung contusion, fibrinogen deposition occurs rapidly and remains stable over a 20-hour interval of observation.« less

Educational Status, Anger, and Inflammation in the MIDUS National Sample: Does Race Matter?

PubMed

Boylan, Jennifer Morozink; Lewis, Tené T; Coe, Christopher L; Ryff, Carol D

2015-08-01

Racial differences in anger frequency and expression styles have been found. Further, African Americans receive fewer health benefits from higher education than Whites. This study seeks to investigate racial differences in how anger moderates the association between education and inflammation. Midlife in the US participants (n = 1,200; 43.0 % male; 18.5 % African American) provided education and anger data via survey assessments. Interleukin-6 (IL-6) and fibrinogen were determined from a fasting blood sample following an overnight clinic visit. African Americans reported higher anger-out, IL-6, and fibrinogen and lower anger-control than Whites. Anger-out predicted higher IL-6 and fibrinogen among African Americans with higher education; whereas, trait anger and anger-out predicted lower fibrinogen among Whites with higher education. Anger-out marginally predicted higher IL-6 in less educated Whites. Findings underscore racial differences in the benefits and consequences of educational attainment, and how social inequities and anger are manifested in inflammatory physiology.

Educational Status, Anger, and Inflammation in the MIDUS National Sample: Does Race Matter?

PubMed Central

Boylan, Jennifer Morozink; Lewis, Tené T.; Coe, Christopher L.; Ryff, Carol D.

2015-01-01

Background Racial differences in anger frequency and expression styles have been found. Further, African Americans receive fewer health benefits from higher education than Whites. Purpose To investigate racial differences in how anger moderates the association between education and inflammation. Methods Midlife in the U.S. (MIDUS) participants (N = 1,200; 43.0% male; 18.5% African American) provided education and anger data via survey assessments. Interleukin-6 (IL-6) and fibrinogen were determined from a fasting blood sample following an overnight clinic visit. Results African Americans reported higher anger-out, IL-6, and fibrinogen and lower anger-control than Whites. Anger-out predicted higher IL-6 and fibrinogen among African Americans with higher education, whereas trait anger and anger-out predicted lower fibrinogen among Whites with higher education. Anger-out marginally predicted higher IL-6 in less educated Whites. Conclusions Findings underscore racial differences in the benefits and consequences of educational attainment, and how social inequities and anger are manifest in inflammatory physiology. PMID:25715901

Scaffold permeability as a means to determine fiber diameter and pore size of electrospun fibrinogen.

PubMed

Sell, Scott; Barnes, Catherine; Simpson, David; Bowlin, Gary

2008-04-01

The purpose of this study was to construct a flowmeter that could accurately measure the hydraulic permeability of electrospun fibrinogen scaffolds, providing insight into the transport properties of electrospun scaffolds while making the measurement of their topographical features (fiber diameter and pore size) more accurate. Three different concentrations of fibrinogen were used (100, 120, and 150 mg/mL) to create scaffolds with three different fiber diameters and pore sizes. The fiber diameters and pore sizes of the electrospun scaffolds were first analyzed with scanning electron microscopy and image analysis software. The permeability of each scaffold was measured with the flowmeter and used to calculate permeability-based fiber diameters and pore sizes, which were compared to values obtained through image analysis. Permeability measurement revealed scaffold permeability to increase with fibrinogen concentration, much like average fiber diameter and pore size. Comparison between the two measurement methods demonstrated the efficacy of the flowmeter as a way to measure scaffold features. Copyright 2007 Wiley Periodicals, Inc.

Extending the Diffuse Layer Model of Surface Acidity Behavior: III. Estimating Bound Site Activity Coefficients

EPA Science Inventory

Although detailed thermodynamic analyses of the 2-pK diffuse layer surface complexation model generally specify bound site activity coefficients for the purpose of accounting for those non-ideal excess free energies contributing to bound site electrochemical potentials, in applic...

Hemostatic findings of pleural fluid in dogs and the association between pleural effusions and primary hyperfibrino(geno)lysis: A cohort study of 99 dogs

PubMed Central

Drigo, Michele; Piek, Christine J.; Simioni, Paolo; Caldin, Marco

2018-01-01

The primary objective of this study was to determine if activation of coagulation and fibrinolysis occurs in canine pleural effusions. Thirty-three dogs with pleural effusions of different origin were studied. Pleural effusion fibrinogen concentrations were significantly lower, while pleural fibrin-fibrinogen degradation products (FDPs) and D-dimer concentrations were significantly higher than those in plasma (P < 0.001 for all comparisons). These results show that, in canine pleural fluids, there is evidence of coagulation activation and fibrinolysis. The secondary aims of the current study were to determine if primary hyperfibrinolysis ([PHF] i.e., elevated plasma FDPs with a normal D-dimer concentrations), occurs in dogs with pleural effusion, and whether the presence of a concurrent inflammatory process may have activated the hemostatic cascade, with its intrinsically linked secondary hyperfibrinolysis, masking the concurrent PHF. The previously 33 selected dogs with pleural effusion (group 1) were compared to two control groups of 33 healthy (group 2) and 33 sick dogs without pleural effusion (group 3). Serum fibrinogen, FDPs, D-dimer, C-reactive protein (CRP), fibrinogen/CRP ratio, and frequency of PHF were determined. Fibrinogen, FDPs, D-dimer and CRP concentrations in group 1 were significantly increased compared to group 2 (P < 0.001 for all comparisons). FDPs and CRP concentrations in group 1 were also significantly increased compared to group 3 (P = 0.001 and P < 0.001, respectively). The fibrinogen/CRP ratio was significantly decreased in group 1 compared to groups 2 and 3 (P < 0.001 for both comparison). The frequency of PHF was significantly higher in group 1 compared to groups 2 (P = 0.004), but not compared to group 3. These results support the hypothesis that PHF occurs significantly more often in dogs with pleural effusion compared to healthy dogs. Nevertheless, the decrease in the fibrinogen/CRP ratio in group 1 compared to group 3, considering the higher FDPs and similar D-dimer concentrations, would suggest that PHF is also more frequent in dogs with pleural effusion compared to sick control dogs, and that this phenomenon is hidden due to concurrent secondary hyperfibrinolysis. PMID:29462172

Hemostatic findings of pleural fluid in dogs and the association between pleural effusions and primary hyperfibrino(geno)lysis: A cohort study of 99 dogs.

PubMed

Zoia, Andrea; Drigo, Michele; Piek, Christine J; Simioni, Paolo; Caldin, Marco

2018-01-01

The primary objective of this study was to determine if activation of coagulation and fibrinolysis occurs in canine pleural effusions. Thirty-three dogs with pleural effusions of different origin were studied. Pleural effusion fibrinogen concentrations were significantly lower, while pleural fibrin-fibrinogen degradation products (FDPs) and D-dimer concentrations were significantly higher than those in plasma (P < 0.001 for all comparisons). These results show that, in canine pleural fluids, there is evidence of coagulation activation and fibrinolysis. The secondary aims of the current study were to determine if primary hyperfibrinolysis ([PHF] i.e., elevated plasma FDPs with a normal D-dimer concentrations), occurs in dogs with pleural effusion, and whether the presence of a concurrent inflammatory process may have activated the hemostatic cascade, with its intrinsically linked secondary hyperfibrinolysis, masking the concurrent PHF. The previously 33 selected dogs with pleural effusion (group 1) were compared to two control groups of 33 healthy (group 2) and 33 sick dogs without pleural effusion (group 3). Serum fibrinogen, FDPs, D-dimer, C-reactive protein (CRP), fibrinogen/CRP ratio, and frequency of PHF were determined. Fibrinogen, FDPs, D-dimer and CRP concentrations in group 1 were significantly increased compared to group 2 (P < 0.001 for all comparisons). FDPs and CRP concentrations in group 1 were also significantly increased compared to group 3 (P = 0.001 and P < 0.001, respectively). The fibrinogen/CRP ratio was significantly decreased in group 1 compared to groups 2 and 3 (P < 0.001 for both comparison). The frequency of PHF was significantly higher in group 1 compared to groups 2 (P = 0.004), but not compared to group 3. These results support the hypothesis that PHF occurs significantly more often in dogs with pleural effusion compared to healthy dogs. Nevertheless, the decrease in the fibrinogen/CRP ratio in group 1 compared to group 3, considering the higher FDPs and similar D-dimer concentrations, would suggest that PHF is also more frequent in dogs with pleural effusion compared to sick control dogs, and that this phenomenon is hidden due to concurrent secondary hyperfibrinolysis.

Bromelain and cardiovascular risk factors in diabetes: An exploratory randomized, placebo controlled, double blind clinical trial.

PubMed

Ley, Chit Moy; Ni, Qing; Liao, Xing; Gao, Huai-Lin; Robinson, Nicola

2016-10-01

To assess whether the dietary supplement (bromelain) has the potential to reduce plasma fibrinogen and other cardiovascular disease (CVD) risk factors in patients with diabetes. This randomized placebo controlled, double blind, parallel design, efficacy study was carried out in China and investigated the effect of 12 weeks of bromelain (1,050 mg/day) on plasma fibrinogen. This randomized controlled trial (RCT) recruited 68 Chinese diabetic patients [32 males and 36 females; Han origin, mean age of 61.26 years (standard deviation (SD), 12.62 years)] with at least one CVD risk factor. Patients were randomized into either bromelain or placebo group. While bromelain group received bromelain capsule, the placebo group received placebo capsule which consisted inert ingredient and has no treatment effect. Subjects were required to take 1,050 mg (3×350 mg) of either bromelain or starch-filled placebo capsules, two to be taken (2×350 mg) after breakfast and another (350 mg) after dinner, daily for 12 weeks. Plasma fibrinogen, CVD risk factors and anthropometric indicators were determined at baseline and at 12 weeks. The change in the fibrinogen level in the bromelain group at the end of the study showed a mean reduction of 0.13 g/L (standard deviation (SD) 0.86g/L) compared with the mean reduction of 0.36 g/L (SD 0.96 g/L) for the placebo group. However, there was no significant difference in the mean change in fibrinogen between the placebo and bromelain groups (mean difference=0.23g/L (SD 0.22 g/L), =0.291). Similarly, the difference in mean change in other CVD risk factors (blood lipids, blood pressure), blood glucose, C-reactive protein and anthropometric measures between the bromelain and placebo groups was also not statistically significant. Statistical differences in fibrinogen between bromelain and placebo groups before the trial despite randomization may have influenced the results of this study. This RCT failed to show a beneficial effect in reducing fibrinogen or influencing other selected CVD risk factors but suggests other avenues for subsequent research on bromelain.

Daily Profiles of Fibrinogen Metabolism for 5 Days Following Hemorrhage and Lactated Ringer’s Resuscitation in Pigs

DTIC Science & Technology

2012-01-01

Sterile stable isotope solutions of 1 13C phenylalanine (1 13C phe, 100 2mol/mL) and d5 phe (100 2mol/mL) were made in 0.45% saline and infused via the left...described by Stein et al. (15). The enrichments of phenylalanine from isolated fibrinogen were determined by gas chromatography mass spectrometry (GC MS...baseline of 5.5 T 0.3 to 4.3 T 0.3 g/ dL (P G 0.05) on day 1 but returned to baseline on day 2 and thereafter. Changes in plasma fibrinogen

PDGF Suppresses the Sulfation of CD44v and Potentiates CD44v-Mediated Binding of Colon Carcinoma Cells to Fibrin under Flow

PubMed Central

Alves, Christina S.; Konstantopoulos, Konstantinos

2012-01-01

Fibrin(ogen) mediates sustained tumor cell adhesion and survival in the pulmonary vasculature, thereby facilitating the metastatic dissemination of tumor cells. CD44 is the major functional fibrin receptor on colon carcinoma cells. Growth factors, such as platelet-derived growth factor (PDGF), induce post-translational protein modifications, which modulate ligand binding activity. In view of the roles of PDGF, fibrin(ogen) and CD44 in cancer metastasis, we aimed to delineate the effect of PDGF on CD44-fibrin recognition. By immunoprecipitating CD44 from PDGF-treated and untreated LS174T colon carcinoma cells, which express primarily CD44v, we demonstrate that PDGF enhances the adhesion of CD44v-coated beads to immobilized fibrin. Enzymatic inhibition studies coupled with flow-based adhesion assays and autoradiography reveal that PDGF augments the binding of CD44v to fibrin by significantly attenuating the extent of CD44 sulfation primarily on chondroitin and dermatan sulfate chains. Surface plasmon resonance assays confirm that PDGF enhances the affinity of CD44v-fibrin binding by markedly reducing its dissociation rate while modestly increasing the association rate. PDGF mildly reduces the affinity of CD44v-hyaluronan binding without affecting selectin-CD44v recognition. The latter is attributed to the fact that CD44v binds to selectins via sialofucosylated O-linked residues independent of heparan, dermatan and chondroitin sulfates. Interestingly, PDGF moderately reduces the sulfation of CD44s and CD44s-fibrin recognition. Collectively, these data offer a novel perspective into the mechanism by which PGDF regulates CD44-dependent binding of metastatic colon carcinoma cells to fibrin(ogen). PMID:23056168

NITROGEN BOUNDING STUDY: METHODS FOR ESTIMATING THE RELATIVE EFFECTS OF SULFUR AND NITROGEN DEPOSITION ON SURFACE WATER CHEMISTRY

EPA Science Inventory

The leaching of atmospherically deposited nitrogen from forested watersheds may acidify lakes and streams. he Nitrogen Bounding Study evaluates the potential range of such adverse effects. he study estimates bounds on changes in regional-scale surface water acidification that mig...

The Longitudinal Relation of Stress during the Menopausal Transition to Fibrinogen Concentrations: Results from the Study of Women's Health Across the Nation

PubMed Central

Falconi, April M.; Gold, Ellen B.; Janssen, Imke

2015-01-01

Objective Life course theory suggests that exposures during critical or sensitive periods have particularly profound effects on health. Most research on this subject has focused on the occurrence of such windows early in life. We investigated whether perimenopause, a period of dramatic neuroendocrine changes at midlife, represents a sensitive period for response to stress by evaluating the relation of perceived stress to fibrinogen, a biomarker for inflammation. Methods The study sample was comprised of participants in the Study of Women's Health Across the Nation, a longitudinal study on women's health during the menopausal transition (n=3,287). We fitted linear mixed effects models to estimate the longitudinal relationship between stress and menopausal stage and the association between stress and fibrinogen over the menopausal transition. Results Women in early and late perimenopause reported perceiving higher levels of stress than premenopausal women (p<0.05), adjusted for confounding variables. This increased perception of stress during perimenopause, however, was unrelated to changes in fibrinogen. Conclusions Although neuroendocrine changes during the menopausal transition may exacerbate the negative health effects of stress, the findings of this study do not suggest such interaction, as measured by changes in fibrinogen. The significant association observed between perceived stress and menopausal status may still have important implications, however, given prior literature linking perceived stress with numerous health outcomes. PMID:26886885

The conversion of fibrinogen to fibrin: A brief history of some key events.

PubMed

Doolittle, Russell F

2017-07-01

The conversion of fibrinogen to fibrin is a process that has long fascinated an army of researchers. In this brief review some early break-through observations are noted and a few later unexpected results described. Copyright © 2016 Elsevier B.V. All rights reserved.

The fibrinogen-binding M1 protein reduces pharyngeal cell adherence and colonization phenotypes of M1T1 group A Streptococcus.

PubMed

Anderson, Ericka L; Cole, Jason N; Olson, Joshua; Ryba, Bryan; Ghosh, Partho; Nizet, Victor

2014-02-07

Group A Streptococcus (GAS) is a leading human pathogen producing a diverse array of infections from simple pharyngitis ("strep throat") to invasive conditions, including necrotizing fasciitis and toxic shock syndrome. The surface-anchored GAS M1 protein is a classical virulence factor that promotes phagocyte resistance and exaggerated inflammation by binding host fibrinogen (Fg) to form supramolecular networks. In this study, we used a virulent WT M1T1 GAS strain and its isogenic M1-deficient mutant to examine the role of M1-Fg binding in a proximal step in GAS infection-interaction with the pharyngeal epithelium. Expression of the M1 protein reduced GAS adherence to human pharyngeal keratinocytes by 2-fold, and this difference was increased to 4-fold in the presence of Fg. In stationary phase, surface M1 protein cleavage by the GAS cysteine protease SpeB eliminated Fg binding and relieved its inhibitory effect on GAS pharyngeal cell adherence. In a mouse model of GAS colonization of nasal-associated lymphoid tissue, M1 protein expression was associated with an average 6-fold decreased GAS recovery in isogenic strain competition assays. Thus, GAS M1 protein-Fg binding reduces GAS pharyngeal cell adherence and colonization in a fashion that is counterbalanced by SpeB. Inactivation of SpeB during the shift to invasive GAS disease allows M1-Fg binding, increasing pathogen phagocyte resistance and proinflammatory activities.

Adhesion of Blood Plasma Proteins and Platelet-rich Plasma on l-Valine-Based Poly(ester urea).

PubMed

Childers, Erin P; Peterson, Gregory I; Ellenberger, Alex B; Domino, Karen; Seifert, Gabrielle V; Becker, Matthew L

2016-10-10

The competitive absorption of blood plasma components including fibrinogen (FG), bovine serum albumin (BSA), and platelet-rich plasma (PRP) on l-valine-based poly(ester urea) (PEU) surfaces were investigated. Using four different PEU polymers, possessing compositionally dependent trends in thermal, mechanical, and critical surface tension measurements, water uptake studies were carried out to determine in vitro behavior of the materials. Quartz crystal microbalance (QCM) measurements were used to quantify the adsorption characteristics of PRP onto PEU thin films by coating the surfaces initially with FG or BSA. Pretreatment of the PEU surfaces with FG inhibited the adsorption of PRP and BSA decreased the absorption 4-fold. In vitro studies demonstrated that cells cultured on l-valine-based PEU thin films allowed attachment and spreading of rat aortic cells. These measurements will be critical toward efforts to use this new class of materials in blood-contacting biomaterials applications.

Non-fouling surfaces produced by gas phase pulsed plasma polymerization of an ultra low molecular weight ethylene oxide containing monomer.

PubMed

Wu; Timmons; Jen; Molock

2000-10-01

The pulsed plasma polymerization of low molecular weight molecules containing only one (ethylene oxide vinyl ether) and two (diethylene oxide vinyl ether) ethylene oxide units were investigated. The surface density of EO units retained in the polymer films increases sharply with decreasing average power input during deposition, particularly at very low plasma duty cycles. The protein adsorption properties of these plasma synthesized polymer were investigated using 125I-labeled albumin and fibrinogen. Surprisingly effective, non-fouling surfaces were observed with films synthesized from the monomer containing two ethylene oxide units; however, the monomer containing only one EO unit gave surfaces that were not particularly effective in preventing protein adsorptions. The results obtained show that ultra short chain length PEO modified surfaces can be biologically non-fouling. This, in turn, has interesting consequences in terms of trying to identify the basic reason for the effectiveness of EO units in preventing biomolecule adsorptions on surfaces.

THE ROLE OF MICROVASCULAR THROMBOSIS IN PARTICULATE MATTER (PM) AND PM COMPONENT-INDUCED CARDIOVASCULAR EFFECTS: OXIDATIVE STRESS AS A MEDIATOR OF THROMBOSIS

EPA Science Inventory

Particulate matter (PM) exposure has been associated with increased plasma fibrinogen. We have found that Spontaneously hypertensive rats respond to PM by increasing fibrinogen and plasminogen activator inhibitor -1 at PM concentration that would cause minimal changes in healthy ...

CORRELATED PULMONARY AND SYSTEMIC EFFECTS IN SPONTANEOUSLY HYPERTENSIVE RATS FOLLOWING ACUTE EXPOSURES TO CONCENTRATED AMBIENT PARTICLES (CAPS)

EPA Science Inventory

The increase in plasma fibrinogen, a risk factor for cardiovascular disease (CVD), has recently been associated with exposures to particulate air pollution (PM) in humans. We have shown a similar pattern of fibrinogen increases in rats exposed to emission PM. The purpose of thi...

Analysis of Novel Prostate Cancer Biomarkers and their Predictive Utility in an Active Surveillance Protocol

DTIC Science & Technology

2014-05-01

Shock Protein, Annexin A3, Sorbitol Dehydrogenase, Fibrinogen Beta Chain Precursor, Creatine Kinase B-Type, Annexin A1, Cystatin B, and AZI. We have...Shock Protein, Annexin A3, Sorbitol Dehydrogenase, Fibrinogen Beta Chain Precursor, and Creatine Kinase B-Type. After testing these candidates with

Direct detection of fibrinogen in human plasma using electric-double-layer gated AlGaN/GaN high electron mobility transistors

NASA Astrophysics Data System (ADS)

Regmi, Abiral; Sarangadharan, Indu; Chen, Yen-Wen; Hsu, Chen-Pin; Lee, Geng-Yen; Chyi, Jen-Inn; Shiesh, Shu-Chu; Lee, Gwo-Bin; Wang, Yu-Lin

2017-08-01

Fibrinogen found in blood plasma is an important protein biomarker for potentially fatal diseases such as cardiovascular diseases. This study focuses on the development of an assay to detect plasmatic fibrinogen using electrical double layer gated AlGaN/GaN high electron mobility transistor biosensors without complex sample pre-treatment methods used in the traditional assays. The test results in buffer solution and clinical plasma samples show high sensitivity, specificity, and dynamic range. The sensor exhibits an ultra-low detection limit of 0.5 g/l and a detection range of 0.5-4.5 g/l in 1× PBS with 1% BSA. The concentration dependent sensor signal in human serum samples demonstrates the specificity to fibrinogen in a highly dense matrix of background proteins. The sensor does not require complicated automation, and quantitative results are obtained in 5 min with <5 μl sample volume. This sensing technique is ideal for speedy blood based diagnostics such as POC (point of care) tests, homecare tests, or personalized healthcare.

The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows

NASA Astrophysics Data System (ADS)

Brust, M.; Aouane, O.; Thiébaud, M.; Flormann, D.; Verdier, C.; Kaestner, L.; Laschke, M. W.; Selmi, H.; Benyoussef, A.; Podgorski, T.; Coupier, G.; Misbah, C.; Wagner, C.

2014-03-01

The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These persistent aggregates should strongly affect cell distribution and blood perfusion in the microvasculature, with putative implications for blood disorders even within apparently asymptomatic subjects.

Control of diabetes and fibrinogen levels as well as improvement in health care might delay low cognitive performance in societies aging progressively.

PubMed

Lopes, Daniele Almeida; Moraes, Suzana Alves de; Freitas, Isabel Cristina Martins de

2015-01-01

To know the prevalence and factors associated to low cognitive performance in a representative sample of the adult population in a society aging progressively. Cross-sectional population-based study carried out in a three-stage sampling: 81 census tracts (primary sampling unity) were randomly selected, followed by 1,672 households and 2,471 participants (weighted sample) corresponding to the second and third stages, respectively. The outcome prevalence was calculated according sociodemographic, behavioral and health related variables. Crude and adjusted prevalence ratios were estimated using Poisson regression. The prevalence of low cognitive performance was high, mainly among females, and indicated linear trends into categories of age, schooling, income, plasma fibrinogen and self-reported health status. In multivariate models, gender, diabetes, fibrinogen and self-reported health status presented positive associations, while schooling, employment and sitting time presented negative associations with the outcome. Interventions related to diabetes and fibrinogen levels control as well as improvement in health care might delay low cognitive performance in societies aging progressively as such the study population.

Two families of synthetic peptides that enhance fibrin turbidity and delay fibrinolysis by different mechanisms.

PubMed

Pandi, Leela; Kollman, Justin M; Lopez-Lira, Francisco; Burrows, Jason M; Riley, Marcia; Doolittle, Russell F

2009-08-04

When fibrin clots are formed in vitro in the presence of certain positively charged peptides, the turbidity is enhanced and fibrinolysis is delayed. Here we show that these two phenomena are not always linked and that different families of peptides bring about the delay of lysis in different ways. In the case of intrinsically adhesive peptides corresponding to certain regions of the fibrinogen gammaC and betaC domains, even though these peptides bind to fibrin(ogen) and enhance turbidity, the delay in lysis is mainly due to direct inhibition of plasminogen activation. In contrast, for certain pentapeptides patterned on fibrin B knobs, the delay in lysis is a consequence of how fibrin units assemble. On their own, these B knob surrogates can induce the gelation of fibrinogen molecules. The likely cause of enhanced clot turbidity and delay in fibrinolysis was revealed by a crystal structure of the D-dimer from human fibrinogen cocrystallized with GHRPYam, the packing of which showed the direct involvement of the ligand tyrosines in antiparallel betaC-betaC interactions.

The role of fibrinogen glycation in ATTR: evidence for chaperone activity loss in disease.

PubMed

Fonseca, Daniel; Gilberto, Samuel; Ribeiro-Silva, Cristina; Ribeiro, Raquel; Guinote, Inês Batista; Saraiva, Susana; Gomes, Ricardo A; Mateus, Élia; Viana, Ana; Barroso, Eduardo; Freire, Ana Ponces; Freire, Patrick; Cordeiro, Carlos; da Costa, Gonçalo

2016-07-15

Transthyretin amyloidosis (ATTR) belongs to a class of disorders caused by protein misfolding and aggregation. ATTR is a disabling disorder of autosomal dominant trait, where transthyretin (TTR) forms amyloid deposits in different organs, causing dysfunction of the peripheral nervous system. We previously discovered that amyloid fibrils from ATTR patients are glycated by methylglyoxal. Even though no consensus has been reached about the actual role of methylglyoxal-derived advanced glycation end-products in amyloid diseases, evidence collected so far points to a role for protein glycation in conformational abnormalities, being ubiquitously found in amyloid deposits in Alzheimer's disease, dialysis-related amyloidosis and Parkinson's diseases. Human fibrinogen, an extracellular chaperone, was reported to specifically interact with a wide spectrum of stressed proteins and suppress their aggregation, being an interacting protein with TTR. Fibrinogen is differentially glycated in ATTR, leading to its chaperone activity loss. Here we show the existence of a proteostasis imbalance in ATTR linked to fibrinogen glycation by methylglyoxal. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Backward propagating branch of surface waves in a semi-bounded streaming plasma system

NASA Astrophysics Data System (ADS)

Lim, Young Kyung; Lee, Myoung-Jae; Seo, Ki Wan; Jung, Young-Dae

2017-06-01

The influence of wake and magnetic field on the surface ion-cyclotron wave is kinetically investigated in a semi-bounded streaming dusty magnetoplasma in the presence of the ion wake-field. The analytic expressions of the frequency and the group velocity are derived by the plasma dielectric function with the spectral reflection condition. The result shows that the ion wake-field enhances the wave frequency and the group velocity of the surface ion-cyclotron wave in a semi-bounded dusty plasma. It is found that the frequency and the group velocity of the surface electrostatic-ion-cyclotron wave increase with an increase of the strength of the magnetic field. It is interesting to find out that the group velocity without the ion flow has the backward propagation mode in a semi-bounded dusty plasma. The variations due to the frequency and the group velocity of the surface ion-cyclotron wave are also discussed.

Correlating structure and function during the evolution of fibrinogen-related domains

PubMed Central

Doolittle, Russell F; McNamara, Kyle; Lin, Kevin

2012-01-01

Fibrinogen-related domains (FReDs) are found in a variety of animal proteins with widely different functions, ranging from non-self recognition to clot formation. All appear to have a common surface where binding of one sort or other occurs. An examination of 19 completed animal genomes—including a sponge and sea anemone, six protostomes, and 11 deuterostomes—has allowed phylogenies to be constructed that show where various types of FReP (proteins containing FReDs) first made their appearance. Comparisons of sequences and structures also reveal particular features that correlate with function, including the influence of neighbor-domains. A particular set of insertions in the carboxyl-terminal subdomain was involved in the transition from structures known to bind sugars to those known to bind amino-terminal peptides. Perhaps not unexpectedly, FReDs with different functions have changed at different rates, with ficolins by far the fastest changing group. Significantly, the greatest amount of change in ficolin FReDs occurs in the third subdomain (“P domain”), the very opposite of the situation in most other vertebrate FReDs. The unbalanced style of change was also observed in FReDs from non-chordates, many of which have been implicated in innate immunity. PMID:23076991

Visualization of Neutrophil Extracellular Traps and Fibrin Meshwork in Human Fibrinopurulent Inflammatory Lesions: II. Ultrastructural Study

PubMed Central

Onouchi, Takanori; Shiogama, Kazuya; Matsui, Takahiro; Mizutani, Yasuyoshi; Sakurai, Kouhei; Inada, Ken-ichi; Tsutsumi, Yutaka

2016-01-01

Neutrophil extracellular traps (NETs) represent an extracellular, spider’s web-like structure resulting from cell death of neutrophils. NETs play an important role in innate immunity against microbial infection, but their roles in human pathological processes remain largely unknown. NETs and fibrin meshwork both showing fibrillar structures are observed at the site of fibrinopurulent inflammation, as described in our sister paper [Acta Histochem. Cytochem. 49; 109–116, 2016]. In the present study, immunoelectron microscopic study was performed for visualizing NETs and fibrin fibrils (thick fibrils in our tongue) in formalin-fixed, paraffin-embedded sections of autopsied lung tissue of legionnaire’s pneumonia. Lactoferrin and fibrinogen gamma chain were utilized as markers of NETs and fibrin, respectively. Analysis of immuno-scanning electron microscopy indicated that NETs constructed thin fibrils and granular materials were attached onto the NETs fibrils. The smooth-surfaced fibrin fibrils were much thicker than the NETs fibrils. Pre-embedding immunoelectron microscopy demonstrated that lactoferrin immunoreactivities were visible as dots on the fibrils, whereas fibrinogen gamma chain immunoreactivities were homogeneously observed throughout the fibrils. Usefulness of immunoelectron microscopic analysis of NETs and fibrin fibrils should be emphasized. PMID:27682015

Group IV nanocrystals with ion-exchangeable surface ligands and methods of making the same

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wheeler, Lance M.; Nichols, Asa W.; Chernomordik, Boris D.

Methods are described that include reacting a starting nanocrystal that includes a starting nanocrystal core and a covalently bound surface species to create an ion-exchangeable (IE) nanocrystal that includes a surface charge and a first ion-exchangeable (IE) surface ligand ionically bound to the surface charge, where the starting nanocrystal core includes a group IV element.

Genetic associations between fibrinogen and cognitive performance in three Scottish cohorts.

PubMed

Marioni, Riccardo E; Deary, Ian J; Murray, Gordon D; Lowe, Gordon D O; Strachan, Mark W J; Luciano, Michelle; Houlihan, Lorna M; Gow, Alan J; Harris, Sarah E; Rumley, Ann; Stewart, Marlene C; Fowkes, F Gerry R; Price, Jackie F

2011-09-01

There is increasing evidence to suggest that elevated plasma levels of fibrinogen are associated with late-life cognitive performance. This study tested the association of single nucleotide polymorphisms in the fibrinogen α (FGA) and β (FGB) genes with cognitive performance. Data were analysed from three community-dwelling populations of older persons (>50 years) in central Scotland: the Aspirin for Asymptomatic Atherosclerosis (AAA) Trial (n = 2,091), the Edinburgh Type 2 Diabetes Study (ET2DS, n = 1,066), and the Lothian Birth Cohort 1936 (LBC1936, n = 1,091). Cognition was assessed using a battery of five, seven, and four psychometric tests, respectively. This information was used to derive a general cognitive factor. Weakly significant associations were found between the rs4220 (FGB), and rs2227412 (FGB) SNPs and a single test of cognitive performance in the AAA Trial (p < 0.05). These findings did not replicate in the LBC1936 or ET2DS cohorts, except for the rs2227412 SNP, which was significantly associated with the general cognitive factor in the ET2DS (p = 3.3 × 10(-4)). A summary term that combined results from all three studies suggested that the rs2227412 genotype associated with reduced cognitive ability also associated with higher plasma fibrinogen levels. These findings suggest a tentative role for fibrinogen as a determinant of late-life cognitive performance and justify further attempts at replication in older persons.

Interaction with extracellular matrix proteins influences Lsh/Ity/Bcg (candidate Nramp) gene regulation of macrophage priming/activation for tumour necrosis factor-alpha and nitrite release.

PubMed

Formica, S; Roach, T I; Blackwell, J M

1994-05-01

The murine resistance gene Lsh/Ity/Bcg regulates activation of macrophages for tumour necrosis factor-alpha (TNF-alpha)-dependent production of nitric oxide mediating antimicrobial activity against Leishmania, Salmonella and Mycobacterium. As Lsh is differentially expressed in macrophages from different tissue sites, experiments were performed to determine whether interaction with extracellular matrix (ECM) proteins would influence the macrophage TNF-alpha response. Plating of bone marrow-derived macrophages onto purified fibrinogen or fibronectin-rich L929 cell-derived matrices, but not onto mannan, was itself sufficient to stimulate TNF-alpha release, with significantly higher levels released from congenic B10.L-Lshr compared to C57BL/10ScSn (Lshs) macrophages. Only macrophages plated onto fibrinogen also released measurable levels of nitrites, again higher in Lshr compared to Lshs macrophages. Addition of interferon-gamma (IFN-gamma), but not bacterial lipopolysaccharide or mycobacterial lipoarabinomannan, as a second signal enhanced the TNF-alpha and nitrite responses of macrophages plated onto fibrinogen, particularly in the Lshr macrophages. Interaction with fibrinogen and fibronectin also primed macrophages for an enhanced TNF-alpha response to leishmanial parasites, but this was only translated into enhanced nitrite responses in the presence of IFN-gamma. In these experiments, Lshr macrophages remained superior in their TNF-alpha responses throughout, but to a degree which reflected the magnitude of the difference observed on ECM alone. Hence, the specificity for the enhanced TNF-alpha responses of Lshr macrophages lay in their interaction with fibrinogen and fibronectin ECM, while a differential nitrite response was only observed with fibrinogen and/or IFN-gamma. The results are discussed in relation to the possible function of the recently cloned candidate gene Nramp, which has structural identity to eukaryote transporters and an N-terminal cytoplasmic proline/serine-rich putative SH3 binding domain.

Relation of thromboelastography parameters to conventional coagulation tests used to evaluate the hypercoagulable state of aged fracture patients

PubMed Central

Liu, Chen; Guan, Zhao; Xu, Qinzhu; Zhao, Lei; Song, Ying; Wang, Hui

2016-01-01

Abstract Fractures are common among aged people, and rapid assessment of the coagulation status is important. The thromboelastography (TEG) test can give a series of coagulation parameters and has been widely used in clinics. In this research, we looked at fracture patients over 60 and compared their TEG results with those of healthy controls. Since there is a paucity of studies comparing TEG assessments with conventional coagulation tests, we aim to clarify the relationship between TEG values and the values given by conventional coagulation tests. Forty fracture patients (27 femur and 13 humerus) over 60 years old were included in the study. The change in their coagulation status was evaluated by TEG before surgery within 4 hours after the fracture. Changes in TEG parameters were analyzed compared with controls. Conventional coagulation test results for the patients, including activated partial thromboplastin time (APTT), international normalized ratio (INR), fibrinogen, and platelets, were also acquired, and correlation analysis was done with TEG parameters, measuring similar aspects of the coagulation cascade. In addition, the sensitivity and specificity of TEG parameters for detecting raised fibrinogen levels were also analyzed. The K (time to 20 mm clot amplitude) and R (reaction time) values of aged fracture patients were lower than controls. The values for angle, maximal amplitude (MA), and coagulation index (CI) were raised compared with controls, indicating a hypercoagulable state. Correlation analysis showed that there were significant positive correlations between fibrinogen and MA/angle, between platelets and MA, and between APTT and R as well. There was significant negative correlation between fibrinogen and K. In addition, K values have better sensitivity and specificity for detecting elevated fibrinogen concentration than angle and MA values. Aged fracture patients tend to be in a hypercoagulable state, and this could be effectively reflected by a TEG test. There were correlations between TEG parameters and corresponding conventional tests. K values can better predict elevated fibrinogen levels in aged fracture patients. PMID:27311005

Relation of thromboelastography parameters to conventional coagulation tests used to evaluate the hypercoagulable state of aged fracture patients.

PubMed

Liu, Chen; Guan, Zhao; Xu, Qinzhu; Zhao, Lei; Song, Ying; Wang, Hui

2016-06-01

Fractures are common among aged people, and rapid assessment of the coagulation status is important. The thromboelastography (TEG) test can give a series of coagulation parameters and has been widely used in clinics. In this research, we looked at fracture patients over 60 and compared their TEG results with those of healthy controls. Since there is a paucity of studies comparing TEG assessments with conventional coagulation tests, we aim to clarify the relationship between TEG values and the values given by conventional coagulation tests.Forty fracture patients (27 femur and 13 humerus) over 60 years old were included in the study. The change in their coagulation status was evaluated by TEG before surgery within 4 hours after the fracture. Changes in TEG parameters were analyzed compared with controls. Conventional coagulation test results for the patients, including activated partial thromboplastin time (APTT), international normalized ratio (INR), fibrinogen, and platelets, were also acquired, and correlation analysis was done with TEG parameters, measuring similar aspects of the coagulation cascade. In addition, the sensitivity and specificity of TEG parameters for detecting raised fibrinogen levels were also analyzed.The K (time to 20 mm clot amplitude) and R (reaction time) values of aged fracture patients were lower than controls. The values for angle, maximal amplitude (MA), and coagulation index (CI) were raised compared with controls, indicating a hypercoagulable state. Correlation analysis showed that there were significant positive correlations between fibrinogen and MA/angle, between platelets and MA, and between APTT and R as well. There was significant negative correlation between fibrinogen and K. In addition, K values have better sensitivity and specificity for detecting elevated fibrinogen concentration than angle and MA values.Aged fracture patients tend to be in a hypercoagulable state, and this could be effectively reflected by a TEG test. There were correlations between TEG parameters and corresponding conventional tests. K values can better predict elevated fibrinogen levels in aged fracture patients.

[Determinants of the elevated factor VIII activity in patients following venous thromboembolism].

PubMed

Lech, Monika; Kościelniak, Barbara; Bryk, Agata; Undas, Anetta

2016-01-01

Activity of factor VIII (FVIII) increased above 150% of reference range predisposes to venous thromboembolism (VTE). The aim of this study was to identify predictors of increased FVIII activity in patients following VTE. 241 (38% men) patients presented due to objectively documented VTE episode at least 3 months ago were included in this study. FVIII activity was measured using a clotting assay on the analyzer BCS XP. Among 241 patients with VTE, activity of FVIII above 150% (FVIII ≥ 150%) was observed in 96 (40%). These patients were older (p = 0.035) and their concentrations of fibrinogen and C-reactive protein (CRP) were higher by 12% and 88% (p < 0.001), respectively, compared with other patients. There was a positive correlation between FVIII and fibrinogen (r = 0.34; p < 0.001), FVIII and CRP (r = 0.30; p < 0.001). Type of treatment, time from the VTE episode and type of VTE were not associated with FVIII. Twenty patients (8%) had activity of FVIII increased above 200% (FVIII > 200%) and this group was also older (p = 0.015), more patients in that group had obesity (p = 0.015), idiopathic VTE (p = 0.043), less of them had positive family history (p = 0.010) and they were characterized by fibrinogen and CRP increased by 28% (p < 0.001) and 102% (p = 0.004), respectively, compared with patients with FVIII between 150-200%. Independent predictors of FVIII ≥ 150% were: fibrinogen (p < 0.001), bilirubin (p = 0.002), hemoglobin (p = 0.016), glucose (p = 0.040), CRP (p = 0.023), total homocysteine (p = 0.032). Fibrinogen was the only independent predictor of FVIII > 200% (p = 0.016). The activity of FVIII in patients after VTE episode is influenced by age, concentration of fibrinogen, bilirubin, hemoglobin, glucose, CRP and homocysteine. Our results suggest the role of environmental factors, mainly inflammatory response in maintaining elevated FVIII activity following VTE.

The effect of fibrinogen concentrate on perioperative bleeding in transurethral resection of the prostate: a double-blind placebo-controlled and randomized study.

PubMed

Soleimani, M; Masoumi, N; Nooraei, N; Lashay, A; Safarinejad, M R

2017-02-01

Essentials Perioperative bleeding during prostate surgery is still a common morbidity. Anticoagulant and antiplatelet medications contribute to the risk of hemorrhage and prolonged hospital stay. Multiple pharmacological agents have been proposed, but none of them have been widely accepted. It is crucial to find a safe and effective modality to reduce hemorrhage. Background Hemorrhage during transurethral resection of the prostate (TUR-P) has always been a concern. Several studies have shown preoperative administration of fibrinogen concentrate to have promising results in reducing hemorrhage in cardiac surgery. Objectives To investigate the hemostatic effect of fibrinogen concentrate administration on reducing the amount of bleeding during TUR-P in patients with benign prostatic hyperplasia. Methods Sixty men with benign prostatic hyperplasia, who were chosen to undergo TUR-P, entered this prospective randomized double-blind placebo-controlled study. The participants were randomly assigned to two groups: treatment (n = 31) and placebo (n = 29). They received an infusion of 2 g of fibrinogen concentrate (treatment group) or normal saline (placebo group) before surgery. Data regarding the amount of bleeding, the operation and complications were recorded and analyzed. Results No difference was observed in bleeding between the fibrinogen and placebo groups during (521 mL versus 557 mL, respectively) and after (291 mL versus 341 mL, respectively) surgery. This lack of difference was also seen in operation time (43 min versus 42 min), irrigating fluid volume used during (17 L versus 19 L) and after (29 L versus 28 L) surgery, and resected adenoma volume (19 g versus 19 g). The mean blood pressure was also similar in both groups as a confounding factor for the amount of bleeding. Conclusion Preoperative administration of fibrinogen concentrate had no significant influence on intraoperative and postoperative bleeding in TUR-P surgery. © 2016 International Society on Thrombosis and Haemostasis.

Evaluation of C-Reactive Protein and Fibrinogen in Patients with Chronic and Aggressive Periodontitis: A Clinico-Biochemical Study.

PubMed

Chandy, Swaroop; Joseph, Kiran; Sankaranarayanan, Anila; Issac, Annie; Babu, George; Wilson, Bobby; Joseph, Jumol

2017-03-01

Periodontal disease is characterised by chronic infection and inflammation in periodontal tissues leading to destruction of alveolar bone with subsequent tooth loss. Periodontal infections are the result of an interaction between tooth associated microbial biofilms and the host defences. Periodontal pathogens can affect local and systemic immune and inflammatory responses. The aim of the present study was to evaluate serum C-Reactive Protein (CRP), plasma fibrinogen and peripheral blood levels in healthy subjects, chronic and aggressive periodontitis patients. A total of 55 subjects, 27 males and 28 females were selected for the study. Blood samples were taken from healthy controls (n=20) and patients with chronic periodontitis (n=20) and aggressive periodontitis (n=15). The periodontal status of each patient was assessed by recording Oral Hygiene Index-Simplified (OHI-S), Bleeding Index (BI), Probing Pocket Depth (PPD) and Clinical Attachment Level (CAL). The levels of serum CRP were measured using high sensitivity Enzyme Linked Immunosorbent Assay (ELISA) and levels of plasma fibrinogen were measured using Quantitative Immunoturbidimetric assay. Data description was done in the form of mean and standard deviation and analysis of data was done using one way ANOVA (Analysis of Variance) and Students t-test to test the statistical significance between groups. The levels of serum CRP and plasma fibrinogen was increased in patients with chronic and aggressive periodontitis when compared to healthy controls (p<0.001). A positive correlation was found to exist between levels of clinical parameters like OHI-S, BI, PPD and CAL when compared with CRP and fibrinogen as well as with the study groups. The finding of the present study suggests the role of serum as a diagnostic marker in inflammatory conditions and indicates that levels of CRP and fibrinogen may serve as important biomarkers for evaluating the association between periodontitis and cardiovascular diseases.

Association of preoperative plasma fibrinogen level with postoperative bleeding after on-pump coronary bypass surgery: does plasma fibrinogen level affect the amount of postoperative bleeding?

PubMed

Alagha, Sameh; Songur, Murat; Avci, Tugba; Vural, Kerem; Kaplan, Sadi

2018-05-15

Our primary aim was to investigate the association between the preoperative concentration of plasma fibrinogen and the volume of postoperative bleeding. Our secondary aim was to identify whether there is a possible correlation between the patients' different characteristics and haemostatic laboratory variables and the postoperative amount of bleeding after on-pump coronary artery bypass grafting procedures. A total of 550 adult patients undergoing isolated coronary artery bypass grafting on cardiopulmonary bypass in our hospital were enrolled and investigated retrospectively. The total amount of chest tube drainage within the first 24 postoperative hours or until the patient was re-explored for bleeding was assessed. Excessive bleeding was defined as more than 500 ml drainage in the first 24 h. The patients were divided into 2 groups: Group 1: the patients who bled ≤500 ml in the first 24 h and Group 2: the patients who bled >500 ml in the first 24 h. A preoperative fibrinogen threshold associated with excessive bleeding was investigated by receiver operating characteristic curve analyses, revealing a calculated cutoff value of 3.1 g/l. Risk factors for increased bleeding were analysed by a logistic regression model that revealed male gender (P < 0.001), body mass index ≤28.3 kg/m2 (P < 0.001), platelet count ≤233 × 103/µl (P < 0.001), estimated glomerular filtration rate ≤90.8 ml/min (P < 0.001) and fibrinogen ≤3.1 g/l (P = 0.01) as significant predictors. A preoperative plasma fibrinogen concentration <3.1 g/l was associated with increased risk of excessive bleeding in patients undergoing on-pump coronary artery bypass grafting. The amount of postoperative blood loss can be roughly predicted with simple preoperative blood tests.

Multilayer Choline Phosphate Molecule Modified Surface with Enhanced Cell Adhesion but Resistance to Protein Adsorption.

PubMed

Chen, Xingyu; Yang, Ming; Liu, Botao; Li, Zhiqiang; Tan, Hong; Li, Jianshu

2017-08-22

Choline phosphate (CP), which is a new zwitterionic molecule, and has the reverse order of phosphate choline (PC) and could bind to the cell membrane though the unique CP-PC interaction. Here we modified a glass surface with multilayer CP molecules using surface-initiated atom-transfer radical polymerization (SI-ATRP) and the ring-opening method. Polymeric brushes of (dimethylamino)ethyl methacrylate (DMAEMA) were synthesized by SI-ATRP from the glass surface. Then the grafted PDMAEMA brushes were used to introduce CP groups to fabricate the multilayer CP molecule modified surface. The protein adsorption experiment and cell culture test were used to evaluate the biocompatibility of the modified surfaces by using human umbilical veinendothelial cells (HUVECs). The protein adsorption results demonstrated that the multilayer CP molecule decorated surface could prevent the adsorption of fibrinogen and serum protein. The adhesion and proliferation of cells were improved significantly on the multilayer CP molecule modified surface. Therefore, the biocompatibility of the material surface could be improved by the modified multilayer CP molecule, which exhibits great potential for biomedical applications, e.g., scaffolds in tissue engineering.

Intravesical Bacillus Calmette-Guérin therapy for murine bladder tumors: initiation of the response by fibronectin-mediated attachment of Bacillus Calmette-Guérin.

PubMed

Ratliff, T L; Palmer, J O; McGarr, J A; Brown, E J

1987-04-01

Intravesical Bacillus Calmette-Guérin (BCG) is considered to be one of the most effective treatments for superficial bladder cancer. Although the mechanisms by which BCG inhibits tumor growth are not known, previous studies have shown that systemic immunization to BCG and the local expression of the immune response in the bladder are associated with a favorable response to BCG therapy. We have investigated the conditions required for the initiation of an immunological response after the intravesical instillation of BCG. Initial histological studies showed that BCG attached to the bladder wall only in areas where the urothelium was damaged by electrocautery and suggested that attachment was associated with the fibrin clot. Quantitative studies verified the histological observations. Minimal BCG attachment (mean less than 10(2) colony forming units) was observed in normal bladders in contrast with a mean of 1.42 X 10(4) colony forming units/bladder in bladders damaged by electrocautery (10 separate experiments). BCG attachment to the bladder wall was durable since organisms were observed in bladders 48 h after instillation. To investigate the proteins to which BCG attached, we tested the binding of BCG to extracellular matrix and inflammatory proteins which comprise a significant portion of the fibrin clot. BCG bound in vitro to coverslips coated in vivo with extracellular matrix proteins but did not bind to control albumin-coated coverslips. BCG also bound to coverslips coated with purified plasma fibronectin but not to coverslips coated with other purified extracellular matrix proteins including laminin, fibrinogen, and type IV collagen. BCG attachment to coverslips coated with either extracellular matrix proteins or purified fibronectin was inhibited by antibodies specific for fibronectin. Moreover, BCG attachment to cauterized bladders in vivo was inhibited by antifibronectin antibodies. These results demonstrate that fibronectin mediates the attachment of BCG to surfaces and suggest that it is the primary component mediating attachment within the bladder. Moreover, the data suggest that the BCG-fibronectin interaction may be a requisite first step for the initiation of the antitumor activity in intravesical BCG for bladder cancer.

Sequence of Fibrinogen Proteolysis and Platelet Release after Intrauterine Infusion of Hypertonic Saline

PubMed Central

Nossel, H. L.; Wasser, J.; Kaplan, K. L.; Lagamma, K. S.; Yudelman, I.; Canfield, R. E.

1979-01-01

Plasma fibrinopeptide B (Bβ1-14 or FPB) immunoreactivity was studied by radioimmunoassay in patients who received intrauterine infusion of hypertonic saline to terminate pregnancy. FPB immunoreactivity increased with thrombin treatment (TIFPB) suggesting the presence of a larger FPB-containing peptide, since purified FPB is not altered by thrombin, whereas thrombin increases the immunoreactivity of Bβ1-42 (which includes FPB) 10-fold. TIFPB immunoreactivity in plasma, drawn 4 h after hypertonic saline infusion eluted from Sephadex G-50 similarly to isolated Bβ1-42. Streptokinase, incubated with normal plasma progressively generated TIFPB immunoreactivity, which showed a major component which eluted from Sephadex G-50 similarly to Bβ1-42. Streptokinase generated TIFPB much more rapidly in reptilase-treated plasma that contains fibrin I, (which still includes FPB), indicating that fibrin I is preferred over fibrinogen as a substrate for plasmin cleavage of arginine (Bβ42)-alanine (Bβ43). Serial studies were then made in 10 patients receiving intrauterine hypertonic saline. Fibrinopeptide A (FPA) levels rose immediately, reached a peak between 1 and 2 h, were declining at 4 h, and were normal at 24 and 48 h. TIFPB levels rose slightly in the 1st h, reached a peak at 4 h, and had returned to base-line values at 24 h. Serum fibrinogen degradation product levels were unchanged at 1 h, reached their highest level at 4 h, and were still markedly elevated at 24 and 48 h. Fibrinogen levels dropped slightly being lowest at 4 and 24 h. Platelet counts declined in parallel with the fibrinogen levels over the first 4 h, but continued to decrease through 48 h. Beta thromboglobulin (βTG) levels generally paralleled FPA levels whereas platelet factor 4 (PF4) levels showed only slight changes. The data indicate that immediately after intrauterine hypertonic saline infusion thrombin is formed that cleaves FPA from fibrinogen to produce fibrin I and releases βTG and PF4 from platelets. Later plasmin cleaves Bβ1-42 from fibrin I to produce fragment X, which is further degraded to form serum fibrinogen degradation products. This sequence of proteolysis indicates that plasmin action on fibrin I serves as a mechanism that regulates fibrin II formation by removing the Bβ chain cleavage site, which is required for thrombin action in converting fibrin I to fibrin II. PMID:500818

Numerical Implementation of the Cohesive Soil Bounding Surface Plasticity Model. Volume I.

DTIC Science & Technology

1983-02-01

AD-R24 866 NUMERICAL IMPLEMENTATION OF THE COHESIVE SOIL BOUNDING 1/2 SURFACE PLASTICITY ..(U) CALIFORNIA UNIV DAVIS DEPT OF CIVIL ENGINEERING L R...a study of various numerical means for implementing the bounding surface plasticity model for cohesive soils is presented. A comparison is made of... Plasticity Models 17 3.4 Selection Of Methods For Comparison 17 3.5 Theory 20 3.5.1 Solution Methods 20 3.5.2 Reduction Of The Number Of Equation

Talin does not associate exclusively with alpha 2b beta 3 integrin in activated human platelets.

PubMed

Escolar, G; Diaz-Ricart, M; White, J G

1995-05-01

Talin is a high-molecular-weight protein that may stabilize connections between cytoplasmic actin and the submembrane portion of glycoprotein IIb-IIIa (GPIIb-IIIa) (alpha 2b beta 3 integrin) in thrombin-stimulated human platelets. Using morphologic and electrophoretic techniques, we have examined the association of talin with the cytoskeleton of platelets activated by thrombin in the presence of fibrinogen-coated gold particles (Fgn/Au). Ultrastructural studies confirmed the presence of Fgn/Au firmly bound to the outside membranes of detergent-extracted platelets. Immunoblots of protein bands showed GPIIIa, but not talin, associated with cytoskeletons of activated platelets. Immunogold cytochemical techniques were performed on ultrathin cryosections of whole platelets to localize talin at the ultrastructural level. Studies were performed on normal platelets and platelets defective in GPIIb-IIIa (Glanzmann's thrombasthenia) and GPIb (Bernard-Soulier syndrome). Talin was randomly distributed in the cytoplasm of resting platelets. Activation resulted in binding of Fgn/Au to the surface membrane and redistribution of talin to the submembrane region. However, no definitive colocalization between the two markers was noted. Activated thrombasthenic platelets failed to bind Fgn/Au, but talin was localized to the submembrane location. After activation, talin was confined to the submembrane zone of Bernard-Soulier syndrome platelets. No definitive colocalization was observed between large clusters of Fgn/Au-occupied receptors and talin distributed in the submembrane region. GPIb and GPIIb-IIIa are not necessary for talin to localize in the submembrane region of activated cells. Talin does not redistribute exclusively with GPIIb-IIIa, and it may stabilize connections with other glycoproteins.

An acidic microenvironment sets the humoral pattern recognition molecule PTX3 in a tissue repair mode

PubMed Central

Doni, Andrea; Musso, Tiziana; Morone, Diego; Bastone, Antonio; Zambelli, Vanessa; Sironi, Marina; Castagnoli, Carlotta; Cambieri, Irene; Stravalaci, Matteo; Pasqualini, Fabio; Laface, Ilaria; Valentino, Sonia; Tartari, Silvia; Ponzetta, Andrea; Maina, Virginia; Barbieri, Silvia S.; Tremoli, Elena; Catapano, Alberico L.; Norata, Giuseppe D.; Bottazzi, Barbara; Garlanda, Cecilia

2015-01-01

Pentraxin 3 (PTX3) is a fluid-phase pattern recognition molecule and a key component of the humoral arm of innate immunity. In four different models of tissue damage in mice, PTX3 deficiency was associated with increased fibrin deposition and persistence, and thicker clots, followed by increased collagen deposition, when compared with controls. Ptx3-deficient macrophages showed defective pericellular fibrinolysis in vitro. PTX3-bound fibrinogen/fibrin and plasminogen at acidic pH and increased plasmin-mediated fibrinolysis. The second exon-encoded N-terminal domain of PTX3 recapitulated the activity of the intact molecule. Thus, a prototypic component of humoral innate immunity, PTX3, plays a nonredundant role in the orchestration of tissue repair and remodeling. Tissue acidification resulting from metabolic adaptation during tissue repair sets PTX3 in a tissue remodeling and repair mode, suggesting that matrix and microbial recognition are common, ancestral features of the humoral arm of innate immunity. PMID:25964372

Energy efficient synthesis of boranes

DOEpatents

Thorn, David L [Los Alamos, NM; Tumas, William [Los Alamos, NM; Schwarz, Daniel E [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM

2012-01-24

The reaction of halo-boron compounds (B--X compounds, compounds having one or more boron-halogen bonds) with silanes provides boranes (B--H compounds, compounds having one or more B--H bonds) and halosilanes. Inorganic hydrides, such as surface-bound silane hydrides (Si--H) react with B--X compounds to form B--H compounds and surface-bound halosilanes. The surface bound halosilanes are converted back to surface-bound silanes electrochemically. Halo-boron compounds react with stannanes (tin compounds having a Sn--H bond) to form boranes and halostannanes (tin compounds having a Sn--X bond). The halostannanes are converted back to stannanes electrochemically or by the thermolysis of Sn-formate compounds. When the halo-boron compound is BCl.sub.3, the B--H compound is B.sub.2H.sub.6, and where the reducing potential is provided electrochemically or by the thermolysis of formate.

Energy efficient synthesis of boranes

DOEpatents

Thorn, David L.; Tumas, William; Schwarz, Daniel E.; Burrell, Anthony K.

2010-11-23

The reaction of halo-boron compounds (B--X compounds, compounds having one or more boron-halogen bonds) with silanes provides boranes (B--H compounds, compounds having one or more B--H bonds) and halosilanes. Inorganic hydrides, such as surface-bound silane hydrides (Si--H) react with B--X compounds to form B--H compounds and surface-bound halosilanes. The surface bound halosilanes are converted back to surface-bound silanes electrochemically. Halo-boron compounds react with stannanes (tin compounds having a Sn--H bond) to form boranes and halostannanes (tin compounds having a Sn--X bond). The halostannanes are converted back to stannanes electrochemically or by the thermolysis of Sn-formate compounds. When the halo-boron compound is BCl.sub.3, the B--H compound is B.sub.2H.sub.6, and where the reducing potential is provided electrochemically or by the thermolysis of formate.

Plamonics for Biomolecular Sensors and THz Metamaterial Waveguides (Near and Far-Field Interfaces to DNA. Guided Nanostructures from RF to Lightwave: Exploiting the Spectrum)

DTIC Science & Technology

2014-12-17

surface bound modes named spoofed surface plasmon polariton (SSPP) modes. Such modes mimic the common optical surface plasmon mode traveling at...Triangle Park, NC 27709-2211 Terahertz, Biosensing, Mach Zehnder Interferometer, Multiplexer and Spoof surface Plasmon Polariton REPORT DOCUMENTATION PAGE...frequencies, the textured surfaces on a subwavelength scale can support surface bound modes named spoofed surface plasmon polariton (SSPP) modes. Such modes

Surface-Bound Casein Modulates the Adsorption and Activity of Kinesin on SiO2 Surfaces

PubMed Central

Ozeki, Tomomitsu; Verma, Vivek; Uppalapati, Maruti; Suzuki, Yukiko; Nakamura, Mikihiko; Catchmark, Jeffrey M.; Hancock, William O.

2009-01-01

Abstract Conventional kinesin is routinely adsorbed to hydrophilic surfaces such as SiO2. Pretreatment of surfaces with casein has become the standard protocol for achieving optimal kinesin activity, but the mechanism by which casein enhances kinesin surface adsorption and function is poorly understood. We used quartz crystal microbalance measurements and microtubule gliding assays to uncover the role that casein plays in enhancing the activity of surface-adsorbed kinesin. On SiO2 surfaces, casein adsorbs as both a tightly bound monolayer and a reversibly bound second layer that has a dissociation constant of 500 nM and can be desorbed by washing with casein-free buffer. Experiments using truncated kinesins demonstrate that in the presence of soluble casein, kinesin tails bind well to the surface, whereas kinesin head binding is blocked. Removing soluble casein reverses these binding profiles. Surprisingly, reversibly bound casein plays only a moderate role during kinesin adsorption, but it significantly enhances kinesin activity when surface-adsorbed motors are interacting with microtubules. These results point to a model in which a dynamic casein bilayer prevents reversible association of the heads with the surface and enhances association of the kinesin tail with the surface. Understanding protein-surface interactions in this model system should provide a framework for engineering surfaces for functional adsorption of other motor proteins and surface-active enzymes. PMID:19383474

Enhancement of nitric oxide release and hemocompatibility by surface chirality of D-tartaric acid grafting

NASA Astrophysics Data System (ADS)

Han, Honghong; Wang, Ke; Fan, Yonghong; Pan, Xiaxin; Huang, Nan; Weng, Yajun

2017-12-01

Nitric Oxide (NO) generation from endogenous NO-donors catalyzed by diselenide modified biomaterials has been reported. Here we reported surface chirality by L-tartaric acid and D-tartaric acid grafting on the outermost showed a significant impact on diselenide modified biomaterials, which modulated protein adsorption, NO release and anti-platelet adhesion properties. D-tartaric acid grafted surface showed more blood protein adsorption than that of L-surfaces by QCM analysis, however, ELISA analysis disclosed less fibrinogen denatured on the D surfaces. Due to the surface ratio of selenium decreasing, NO release catalyzed by L-tartaric acid grafting on the outermost significantly decreased in comparison to that of only selenocystamine immobilized surfaces. While NO release catalyzed by D-tartaric acid grafting on the outermost didn't decrease and was similar with that of selenocystamine immobilized surfaces. Surface chirality combined with NO release had synergetic effects on platelet adhesion, and it showed the lowest number of platelets adhered on the D-tartaric acid grafted surfaces. Thus surface chirality from D-tartaric acid grafting enhanced hemocompatibility of the surface in this study. Our work provides new insights into engineering novel blood contacting biomaterials by taking into account surface chirality.

SFG analysis of surface bound proteins: a route towards structure determination.

PubMed

Weidner, Tobias; Castner, David G

2013-08-14

The surface of a material is rapidly covered with proteins once that material is placed in a biological environment. The structure and function of these bound proteins play a key role in the interactions and communications of the material with the biological environment. Thus, it is crucial to gain a molecular level understanding of surface bound protein structure. While X-ray diffraction and solution phase NMR methods are well established for determining the structure of proteins in the crystalline or solution phase, there is not a corresponding single technique that can provide the same level of structural detail about proteins at surfaces or interfaces. However, recent advances in sum frequency generation (SFG) vibrational spectroscopy have significantly increased our ability to obtain structural information about surface bound proteins and peptides. A multi-technique approach of combining SFG with (1) protein engineering methods to selectively introduce mutations and isotopic labels, (2) other experimental methods such as time-of-flight secondary ion mass spectrometry (ToF-SIMS) and near edge X-ray absorption fine structure (NEXAFS) to provide complementary information, and (3) molecular dynamic (MD) simulations to extend the molecular level experimental results is a particularly promising route for structural characterization of surface bound proteins and peptides. By using model peptides and small proteins with well-defined structures, methods have been developed to determine the orientation of both backbone and side chains to the surface.

SFG analysis of surface bound proteins: A route towards structure determination

PubMed Central

Weidner, Tobias; Castner, David G.

2013-01-01

The surface of a material is rapidly covered with proteins once that material is placed in a biological environment. The structure and function of these bound proteins play a key role in the interactions and communications of the material with the biological environment. Thus, it is crucial to gain a molecular level understanding of surface bound protein structure. While X-ray diffraction and solution phase NMR methods are well established for determining the structure of proteins in the crystalline or solution phase, there is not a corresponding single technique that can provide the same level of structural detail about proteins at surfaces or interfaces. However, recent advances in sum frequency generation (SFG) vibrational spectroscopy have significantly increased our ability to obtain structural information about surface bound proteins and peptides. A multi-technique approach of combining SFG with (1) protein engineering methods to selectively introduce mutations and isotopic labels, (2) other experimental methods such as time-of-flight secondary ion mass spectrometry (ToF-SIMS) and near edge x-ray absorption fine structure (NEXAFS) to provide complementary information, and (3) molecular dynamic (MD) simulations to extend the molecular level experimental results is a particularly promising route for structural characterization of surface bound proteins and peptides. By using model peptides and small proteins with well-defined structures, methods have been developed to determine the orientation of both backbone and side chains to the surface. PMID:23727992

Generalized surface tension bounds in vacuum decay

NASA Astrophysics Data System (ADS)

Masoumi, Ali; Paban, Sonia; Weinberg, Erick J.

2018-02-01

Coleman and De Luccia (CDL) showed that gravitational effects can prevent the decay by bubble nucleation of a Minkowski or AdS false vacuum. In their thin-wall approximation this happens whenever the surface tension in the bubble wall exceeds an upper bound proportional to the difference of the square roots of the true and false vacuum energy densities. Recently it was shown that there is another type of thin-wall regime that differs from that of CDL in that the radius of curvature grows substantially as one moves through the wall. Not only does the CDL derivation of the bound fail in this case, but also its very formulation becomes ambiguous because the surface tension is not well defined. We propose a definition of the surface tension and show that it obeys a bound similar in form to that of the CDL case. We then show that both thin-wall bounds are special cases of a more general bound that is satisfied for all bounce solutions with Minkowski or AdS false vacua. We discuss the limit where the parameters of the theory attain critical values and the bound is saturated. The bounce solution then disappears and a static planar domain wall solution appears in its stead. The scalar field potential then is of the form expected in supergravity, but this is only guaranteed along the trajectory in field space traced out by the bounce.

Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots

PubMed Central

Chung, Tze-Wen; Lin, Pei-Yi; Wang, Shoei-Shen; Chen, Yen-Fung

2014-01-01

Chitosan nanoparticles (NPs) decorated with adenosine diphosphate (ADP) (ANPs) or fibrinogen (FNPs) were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP) or FNP (clot/FNP) were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1±14.0, 251.0±9.8, and 326.5±14.5 nm and zeta potentials of 24.1±0.5, 20.6±1.9, and 15.3±1.5 mV (n=4), respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR) spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM) micrographs of the structure of the clot induced with “undecorated” chitosan NPs (clot/NP), clot/ANP, and clot/FNP (at 0.05 wt%) were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc) of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM), were significantly (P<0.05) (n=4) shorter than that of a clot induced by a phosphate-buffered solution (PBS) (clot/PBS) (63.6%±3.1%, 48.3%±6.2%, and 63.2%±4.7%, respectively). The ΔF2 values in the spectra of frequency shifts associated with the propagation of fibrin networks in the clot/ANPs and clot/FNPs were significantly lower than those of clot/PBS. Interestingly, texture profile analysis of the compressional properties showed significantly lower hardness and compressibility in clot/NPs and clot/ANPs (P<0.05 or better) (n=4) compared with clot/PBS and clot/FNPs. Accordingly, among the hemostatic NPs, ANP substantially reduced blood clotting times, ΔF2 values, and compression flow properties of the clot. Hence, ANPs have potential applications for preventing severe local hemorrhage. PMID:24729701

Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots.

PubMed

Chung, Tze-Wen; Lin, Pei-Yi; Wang, Shoei-Shen; Chen, Yen-Fung

2014-01-01

Chitosan nanoparticles (NPs) decorated with adenosine diphosphate (ADP) (ANPs) or fibrinogen (FNPs) were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP) or FNP (clot/FNP) were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1 ± 14.0, 251.0 ± 9.8, and 326.5 ± 14.5 nm and zeta potentials of 24.1 ± 0.5, 20.6 ± 1.9, and 15.3 ± 1.5 mV (n=4), respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR) spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM) micrographs of the structure of the clot induced with "undecorated" chitosan NPs (clot/NP), clot/ANP, and clot/FNP (at 0.05 wt%) were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc) of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM), were significantly (P<0.05) (n=4) shorter than that of a clot induced by a phosphate-buffered solution (PBS) (clot/PBS) (63.6% ± 3.1%, 48.3% ± 6.2%, and 63.2% ± 4.7%, respectively). The ΔF2 values in the spectra of frequency shifts associated with the propagation of fibrin networks in the clot/ANPs and clot/FNPs were significantly lower than those of clot/PBS. Interestingly, texture profile analysis of the compressional properties showed significantly lower hardness and compressibility in clot/NPs and clot/ANPs (P<0.05 or better) (n=4) compared with clot/PBS and clot/FNPs. Accordingly, among the hemostatic NPs, ANP substantially reduced blood clotting times, ΔF2 values, and compression flow properties of the clot. Hence, ANPs have potential applications for preventing severe local hemorrhage.

Fibrinogen-Related Proteins in Tissue Repair: How a Unique Domain with a Common Structure Controls Diverse Aspects of Wound Healing.

PubMed

Zuliani-Alvarez, Lorena; Midwood, Kim S

2015-05-01

Significance: Fibrinogen-related proteins (FRePs) comprise an intriguing collection of extracellular molecules, each containing a conserved fibrinogen-like globe (FBG). This group includes the eponymous fibrinogen as well as the tenascin, angiopoietin, and ficolin families. Many of these proteins are upregulated during tissue repair and exhibit diverse roles during wound healing. Recent Advances: An increasing body of evidence highlights the specific expression of a number of FRePs following tissue injury and infection. Upon induction, each FReP uses its FBG domain to mediate quite distinct effects that contribute to different stages of tissue repair, such as driving coagulation, pathogen detection, inflammation, angiogenesis, and tissue remodeling. Critical Issues: Despite a high degree of homology among FRePs, each contains unique sequences that enable their diversification of function. Comparative analysis of the structure and function of FRePs and precise mapping of regions that interact with a variety of ligands has started to reveal the underlying molecular mechanisms by which these proteins play very different roles using their common domain. Future Directions: Fibrinogen has long been used in the clinic as a synthetic matrix serving as a scaffold or a delivery system to aid tissue repair. Novel therapeutic strategies are now emerging that harness the use of other FRePs to improve wound healing outcomes. As we learn more about the underlying mechanisms by which each FReP contributes to the repair response, specific blockade, or indeed potentiation, of their function offers real potential to enable regulation of distinct processes during pathological wound healing.

Effects on fibrinogen, fibrin, and blood coagulation of proteolytic extracts from fruits of Pseudananas macrodontes, Bromelia balansae, and B. hieronymi (Bromeliaceae) in comparison with bromelain.

PubMed

Errasti, María E; Prospitti, Anabela; Viana, Carolina A; Gonzalez, Mariana M; Ramos, Márcio V; Rotelli, Alejandra E; Caffini, Néstor O

2016-06-01

Extracts rich in cysteine proteases obtained from fruits of Pseudananas macrodontes (Pm), Bromelia balansae (Bb), and B. hieronymi (Bh) have previously shown an anti-inflammatory effect on animal models. Given the close relationship between hemostasis and inflammation, it is attractive to investigate therapeutic agents capable of modulating both systems. The aim of this work was to study the effect of Pm, Bb, and Bh on fibrin(ogen) and blood coagulation compared with stem bromelain (Bro). Action on fibrinogen was electrophoretically and spectrophotometrically evaluated, fibrinolytic activity was measured both electrophoretically and by the fibrin plate assay, and the effect on blood coagulation was studied by conventional coagulation tests (PT and APPT). All extracts showed the same proteolytic preference for fibrinogen subunits, that is Aα > Bβ, whereas γ was partially hydrolyzed by 100-fold concentration increase. Unlike Bro, cysteine proteases of Pm, Bb, and Bh increased absorbance at 540 nm of fibrinogen solution, suggesting thrombin-like activity, which was time-dependent and reached maximum values at lower concentration. All extracts showed the same proteolytic preference for fibrin subunits; however Pm, Bb, and Bh showed lower fibrinolytic activity than Bro at the assayed concentrations. Although Bb acted only as anticoagulant, Pm, Bh, and unexpectedly Bro showed dual action on blood coagulation: at low concentration showed procoagulant effect and at high concentration anticoagulant effect. Results reveal new plant species as potential sources of pharmacological agents for the treatment of a wide range of hemostatic disorders as well as to wound healing.

Baseline repeated measures from controlled human exposure studies: associations between ambient air pollution exposure and the systemic inflammatory biomarkers IL-6 and fibrinogen.

PubMed

Thompson, Aaron M S; Zanobetti, Antonella; Silverman, Frances; Schwartz, Joel; Coull, Brent; Urch, Bruce; Speck, Mary; Brook, Jeffrey R; Manno, Michael; Gold, Diane R

2010-01-01

Systemic inflammation may be one of the mechanisms mediating the association between ambient air pollution and cardiovascular morbidity and mortality. Interleukin-6 (IL-6) and fibrinogen are biomarkers of systemic inflammation that are independent risk factors for cardio-vascular disease. We investigated the association between ambient air pollution and systemic inflammation using baseline measurements of IL-6 and fibrinogen from controlled human exposure studies. In this retrospective analysis we used repeated-measures data in 45 nonsmoking subjects. Hourly and daily moving averages were calculated for ozone, nitrogen dioxide, sulfur dioxide, and particulate matter

Fractalkine Signaling Attenuates Perivascular Clustering of Microglia and Fibrinogen Leakage during Systemic Inflammation in Mouse Models of Diabetic Retinopathy

PubMed Central

Mendiola, Andrew S.; Garza, Rolando; Cardona, Sandra M.; Mythen, Shannon A.; Lira, Sergio A.; Akassoglou, Katerina; Cardona, Astrid E.

2017-01-01

Fractalkine (FKN) is a chemokine expressed constitutively by healthy neurons and signals to microglia upon interaction with the FKN receptor, CX3CR1. Signaling between FKN and CX3CR1 transduces inhibitory signals that ameliorate microglial activation and proinflammatory cytokine release in neuroinflammatory conditions. The aim of this study is to determine the mechanisms associated with microglial activation and vascular leakage during diabetic retinopathy (DR) and under conditions of low-level endotoxemia, common in diabetic patients. Utilizing the Ins2Akita strain (Akita), a mouse model of type 1 diabetes, our results show that leakage of the blood-protein fibrin(ogen) into the retina occurs as a result of chronic (4 months) but not acute (1.5 months) hyperglycemia. Conversely, inducing endotoxin-mediated systemic inflammation during acute diabetes resulted in fibrinogen deposition in the retina, a phenotype that was exacerbated in mice lacking CX3CR1 signaling. Systemic inflammation in Cx3cr1−/− mice led to robust perivascular clustering of proliferating microglia in areas of fibrinogen extravasation, and induced IL-1β expression in microglia and astrocytes. Lastly, we determined a protective effect of modulating FKN/CX3CR1 signaling in the diabetic retina. We show that intravitreal (iv) administration of recombinant FKN into diabetic FKN-KO mice, reduced fibrinogen deposition and perivascular clustering of microglia in the retina during systemic inflammation. These data suggest that dysregulated microglial activation via loss of FKN/CX3CR1 signaling disrupts the vascular integrity in retina during systemic inflammation. PMID:28119571

Profound effects of cardiopulmonary bypass priming solutions on the fibrin part of clot formation: an ex vivo evaluation using rotation thromboelastometry.

PubMed

Brinkman, Arinda C M; Romijn, Johannes W A; van Barneveld, Lerau J M; Greuters, Sjoerd; Veerhoek, Dennis; Vonk, Alexander B A; Boer, Christa

2010-06-01

Dilutional coagulopathy as a consequence of cardiopulmonary bypass (CPB) system priming may also be affected by the composition of the priming solution. The direct effects of distinct priming solutions on fibrinogen, one of the foremost limiting factors during dilutional coagulopathy, have been minimally evaluated. Therefore, the authors investigated whether hemodilution with different priming solutions distinctly affects the fibrinogen-mediated step in whole blood clot formation. Prospective observational laboratory study. University hospital laboratory. Eight male healthy volunteers. Blood samples diluted with gelatin-, albumin-, or hydroxyethyl starch (HES)-based priming solutions were ex-vivo evaluated for clot formation by rotational thromboelastometry. The intrinsic pathway (INTEM) coagulation time increased from 186 +/- 19 seconds to 205 +/- 16, 220 +/- 17, and 223 +/- 18 seconds after dilution with gelatin-, albumin-, or HES-containing prime solutions (all p < 0.05 v baseline). The extrinsic pathway (EXTEM) coagulation time was only minimally affected by hemodilution. Moreover, all 3 priming solutions significantly reduced the INTEM and EXTEM maximum clot firmness. The HES-containing priming solution induced the largest decrease in the maximum clot firmness attributed to fibrinogen, from 13 +/- 1 mm (baseline) to 6 +/- 1 mm (p < 0.01 v baseline). All studied priming solutions prolonged coagulation time and decreased clot formation, but the fibrinogen-limiting effect was the most profound for the HES-containing priming solution. These results suggest that the composition of priming solutions may distinctly affect blood clot formation, in particular with respect to the fibrinogen component in hemostasis. Copyright 2010 Elsevier Inc. All rights reserved.

Neprilysin Inhibits Coagulation through Proteolytic Inactivation of Fibrinogen

PubMed Central

Burrell, Matthew; Henderson, Simon J.; Ravnefjord, Anna; Schweikart, Fritz; Fowler, Susan B.; Witt, Susanne; Hansson, Kenny M.; Webster, Carl I.

2016-01-01

Neprilysin (NEP) is an endogenous protease that degrades a wide range of peptides including amyloid beta (Aβ), the main pathological component of Alzheimer’s disease (AD). We have engineered NEP as a potential therapeutic for AD but found in pre-clinical safety testing that this variant increased prothrombin time (PT) and activated partial thromboplastin time (APTT). The objective of the current study was to investigate the effect of wild type NEP and the engineered variant on coagulation and define the mechanism by which this effect is mediated. PT and APTT were measured in cynomolgus monkeys and rats dosed with a human serum albumin fusion with an engineered variant of NEP (HSA-NEPv) as well as in control plasma spiked with wild type or variant enzyme. The coagulation factor targeted by NEP was determined using in vitro prothrombinase, calibrated automated thrombogram (CAT) and fibrin formation assays as well as N-terminal sequencing of fibrinogen treated with the enzyme. We demonstrate that HSA-NEP wild type and HSA-NEPv unexpectedly impaired coagulation, increasing PT and APTT in plasma samples and abolishing fibrin formation from fibrinogen. This effect was mediated through cleavage of the N-termini of the Aα- and Bβ-chains of fibrinogen thereby significantly impairing initiation of fibrin formation by thrombin. Fibrinogen has therefore been identified for the first time as a substrate for NEP wild type suggesting that the enzyme may have a role in regulating fibrin formation. Reductions in NEP levels observed in AD and cerebral amyloid angiopathy may contribute to neurovascular degeneration observed in these conditions. PMID:27437944

[The balance of markers of regulation vascular tone and fibrinogen in the prognosis of hemorrhagic transformation and fatal outcome in the acute period of ischemic stroke].

PubMed

Liang, O V; Kochetov, A G; Arkhipkin, A A; Novozhenova, Iu V; Shamalov, N A; Ramazanov, G R; Chuĭko, M R; Ogurtsov, P P; Skvortsova, V I

2012-01-01

The markers of regulation vascular tone, such as rennin, endothelin-1, and C-type natriuretic peptide, are of great value for prognosis of hemorrhagic transformation and fatal outcome of ischemic stroke. A change in the vascular tone in case of hemorrhagic transformation at the affected site precedes activation of the coagulation component of hemostasis as a mechanism preventing blood loss and increasing fibrinogen level. This work was aimed to study the balance of the above markers and fibrinogen in the prognosis of hemorrhagic transformation and fatal outcome in the acute period of ischemic stroke. It included 62 patients receiving no thrombolytic therapy. It was shown that symptomatic hemorrhagic transformation was associated with elevated rennin levels without a marked fall in the level of C-type natriuretic peptide and asymptomatic hemorrhagic transformation with elevated endothelin-1 levels and decreased concentration of natriuretic peptide. Fibrinogen level on day 4 of the observation proved to be a reliable predictor of negative prognosis. Asymptomatic hemorrhagic transformation without fatal outcome was associated with systemic and local vasoconstriction and inhibition of local vasodilation. Symptomatic hemorrhagic transformation with the fatal outcome was accompanied by dysregulation of vascular tone in the form of activation of systemic and local vasoconstriction, insufficient inhibition of local vasodilation and compensatory reaction in the form of activation of hemostatic mechanisms manifest as elevated fibrinogen levels on day 4. The lethal outcome without hemorrhagic transformation was associated with systemic vasoconstriction, activation of local vasodilation and vasoconstriction leading to local "biochemical paralysis" of vascular tone regulation.

Periodontal therapy reduces plasma levels of interleukin-6, C-reactive protein, and fibrinogen in patients with severe periodontitis and refractory arterial hypertension.

PubMed

Vidal, Fábio; Figueredo, Carlos Marcelo S; Cordovil, Ivan; Fischer, Ricardo G

2009-05-01

Recent epidemiologic studies suggest that inflammation is the link between periodontal diseases and cardiovascular complications. This study aimed to evaluate the effects of non-surgical periodontal treatment on plasma levels of inflammatory markers (interleukin [IL]-6, C-reactive protein [CRP], and fibrinogen) in patients with severe periodontitis and refractory arterial hypertension. Twenty-two patients were examined and randomly divided into two groups. The test group was composed of 11 patients (mean age, 48.9 +/- 3.9 years) who received periodontal treatment, whereas the control group had 11 patients (mean age, 49.7 +/- 6.0 years) whose treatment was delayed for 3 months. Demographic and clinical periodontal data were collected, and blood tests were performed to measure the levels of IL-6, CRP, and fibrinogen at baseline and 3 months later. The clinical results showed that the mean percentages of sites with bleeding on probing, probing depth (PD) 4 to 5 mm, PD > or =6 mm, clinical attachment loss (CAL) 4 to 5 mm, and CAL > or =6 mm were significantly reduced in the test group 3 months after periodontal treatment. There were no significant differences between the data at baseline and 3 months in the control group. Periodontal treatment significantly reduced the blood levels of fibrinogen, CRP, and IL-6 in the test group. Non-surgical periodontal therapy was effective in improving periodontal clinical data and in reducing the plasma levels of IL-6, CRP, and fibrinogen in hypertensive patients with severe periodontitis.

Fibrin glue.

PubMed

Brennan, M

1991-12-01

Fibrin glue is a topical biological adhesive, the effect of which imitates the final stages of coagulation. The glue consists of a solution of concentrated human fibrinogen which is activated by the addition of bovine thrombin and calcium chloride. The resultant clot aids haemostasis and tissue sealing and is completely absorbed during wound healing without foreign body reaction or extensive fibrosis. The fibrinogen component of fibrin glue can be produced from fresh frozen plasma obtained from single unit donations thereby reducing the risks of transfusion transmitted infections encountered by exposure to pools from large numbers of donors. Methods involving precipitation of fibrinogen by cryoprecipitation, polyethylene glycol or ammonium sulphate have been described and evaluated. The risk of transmission of infection can be further reduced by using plasma from 'accredited donors' who are plasma donors regularly tested for ALT and markers of viral infection or by use of fibrinogen prepared in advance of surgery from autologous blood. The second component, a mixture of thrombin and CaCl2, is quantitatively and qualitatively well defined and commercially available (Armour Pharmaceutical Co., Thrombinar (bovine thrombin]. Thrombin is applied to the operation site simultaneously and in equal volume to the fibrinogen but from a separate syringe. In the UK a commercial heat treated fibrin glue prepared from pooled plasma is available on a doctor/named patient basis (Tisseel, Immuno, Vienna). The haemostatic and adhesive properties of fibrin glue can be employed in virtually every surgical specialty. The usefulness of the glue is particularly well documented in the fields of cardiovascular surgery, ENT and neurosurgery.(ABSTRACT TRUNCATED AT 250 WORDS)

The Staphylococcus aureus Global Regulator MgrA Modulates Clumping and Virulence by Controlling Surface Protein Expression

PubMed Central

Crosby, Heidi A.; Schlievert, Patrick M.; Merriman, Joseph A.; King, Jessica M.; Salgado-Pabón, Wilmara; Horswill, Alexander R.

2016-01-01

Staphylococcus aureus is a human commensal and opportunistic pathogen that causes devastating infections in a wide range of locations within the body. One of the defining characteristics of S. aureus is its ability to form clumps in the presence of soluble fibrinogen, which likely has a protective benefit and facilitates adhesion to host tissue. We have previously shown that the ArlRS two-component regulatory system controls clumping, in part by repressing production of the large surface protein Ebh. In this work we show that ArlRS does not directly regulate Ebh, but instead ArlRS activates expression of the global regulator MgrA. Strains lacking mgrA fail to clump in the presence of fibrinogen, and clumping can be restored to an arlRS mutant by overexpressing either arlRS or mgrA, indicating that ArlRS and MgrA constitute a regulatory pathway. We used RNA-seq to show that MgrA represses ebh, as well as seven cell wall-associated proteins (SraP, Spa, FnbB, SasG, SasC, FmtB, and SdrD). EMSA analysis showed that MgrA directly represses expression of ebh and sraP. Clumping can be restored to an mgrA mutant by deleting the genes for Ebh, SraP and SasG, suggesting that increased expression of these proteins blocks clumping by steric hindrance. We show that mgrA mutants are less virulent in a rabbit model of endocarditis, and virulence can be partially restored by deleting the genes for the surface proteins ebh, sraP, and sasG. While mgrA mutants are unable to clump, they are known to have enhanced biofilm capacity. We demonstrate that this increase in biofilm formation is partially due to up-regulation of SasG, a surface protein known to promote intercellular interactions. These results confirm that ArlRS and MgrA constitute a regulatory cascade, and that they control expression of a number of genes important for virulence, including those for eight large surface proteins. PMID:27144398

M1 macrophage infiltrations and histological changes in the liver after portal vein embolization using fibrinogen and OK432 in the rat.

PubMed

Sato, Tetsu; Marubashi, Shigeru; Kenjo, Akira; Tsuchiya, Takao; Kimura, Takashi; Sato, Naoya; Watanabe, Junichiro; Tasaki, Kazuhiro; Hashimoto, Yuko; Wada, Ikuo; Gotoh, Mitsukazu

2016-05-01

The mechanism of anti-tumor effect of transarterial Immuno-Embolization (TIE) using OK-432 has not been well elucidated. In this study, we aimed to investigate the tissue injury and immune response after portal venous embolization (PVE) with/without OK-432. Embolic materials (L group: lipiodol, LF group: lipiodol+fibrinogen, LO group: lipiodol+OK-432, LFO group: lipiodol+fibrinogen+OK-432) were administered via the right portal vein in Wistar rats. The histological findings in LFO group demonstrated liver damage with severe architectural changes. The concentrations of CD68(+) cells were observed in a time-dependent manner; it was significantly increased in the LO group on day 1 and in the LFO group on day 3. CD68(+)CD163(-) macrophages significantly increased in the LFO group on day 7 (P<0.05). In conclusion, PVE with fibrinogen and OK-432 markedly increased the CD68(+)CD163(-) infiltrating macrophages around the peri-portal area in the liver. This novel technique could be applied as immune-enhanced chemo-embolization of liver tumors. Copyright © 2016 Elsevier Inc. All rights reserved.

What Is the Biological and Clinical Relevance of Fibrin?

PubMed

Litvinov, Rustem I; Weisel, John W

2016-06-01

As our knowledge of the structure and functions of fibrinogen and fibrin has increased tremendously, several key findings have given some people a superficial impression that the biological and clinical significance of these clotting proteins may be less than earlier thought. Most strikingly, studies of fibrinogen knockout mice demonstrated that many of these mice survive to weaning and beyond, suggesting that fibrin(ogen) may not be entirely necessary. Humans with afibrinogenemia also survive. Furthermore, in recent years, the major emphasis in the treatment of arterial thrombosis has been on inhibition of platelets, rather than fibrin. In contrast to the initially apparent conclusions from these results, it has become increasingly clear that fibrin is essential for hemostasis; is a key factor in thrombosis; and plays an important biological role in infection, inflammation, immunology, and wound healing. In addition, fibrinogen replacement therapy has become a preferred, major treatment for severe bleeding in trauma and surgery. Finally, fibrin is a unique biomaterial and is used as a sealant or glue, a matrix for cells, a scaffold for tissue engineering, and a carrier and/or a vector for targeted drug delivery. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Laser-assisted fibrinogen bonding of umbilical vein grafts.

PubMed

Oz, M C; Williams, M R; Souza, J E; Dardik, H; Treat, M R; Bass, L S; Nowygrod, R

1993-06-01

Despite success with autologous tissue welding, laser welding of synthetic vascular prostheses has not been possible. The graft material appears inert and fails to allow the collagen breakdown and electrostatic bonding that results in tissue welding. To develop a laser welding system for graft material, we repaired glutaraldehyde-tanned human umbilical cord vein graft incisions using laser-assisted fibrinogen bonding (LAFB) technology. Modified umbilical vein graft was incised transversely (1.2 cm). Incisions were repaired using sutures, laser energy alone, or LAFB. For LAFB, indocyanine green dye was mixed with human fibrinogen and the compound applied with forceps onto the weld site prior to exposure to 808 nm diode laser energy (power density 4.8 W/cm 2). Bursting pressures for sutured repairs (126.6 +/- 23.4 mm Hg) were similar to LAFB anastomoses (111.6 +/- 55.0 mm Hg). No evidence of collateral thermal injury to the graft material was noted. In vivo evaluation of umbilical graft bonding with canine arteries demonstrates that LAFB can reliably reinforce sutured anastomoses. The described system for bonding graft material with laser exposed fibrinogen may allow creation or reinforcement of vascular anastomoses in procedures where use of autologous tissue is not feasible.

Fibrinogen inhibits fibroblast-mediated contraction of collagen

PubMed Central

Nien, Yih-Dar; Han, Yuan-Ping; Tawil, Bill; Chan, Linda S.; Tuan, Tai-Lan; Garner, Warren L.

2008-01-01

Extracellular matrix changes in composition and organization as it transitions from the provisional matrix of the fibrin/platelet plug to collagen scar in healed wounds. The manner in which individual matrix proteins affect these activities is not well established. In this article we describe the interactions of two important extracellular matrix components, fibrin and collagen, using an in vitro model of wound contraction, the fibroblast-populated collagen lattice. We utilized different fibrinogen sources and measured tissue reorganization in floating and tensioned collagen lattices. Our results showed that both fibrin and fibrinogen decreased the contraction of fibroblast populated collagen lattices in a dose-dependent manner. Polymerization of fibrinogen to fibrin using thrombin had no effect on this inhibition. Further, there was no effect due to changes in protein concentration, alternate components of the fibrin sealant, or the enzymatic action of thrombin. These results suggest that the initial stability of the fibrin provisional matrix is due to the fibrin, because this protein appears to inhibit contraction of the matrix. This may be important in the early phases of wound healing when clot stability is vital for hemostasis. Later, as fibrin is replaced by collagen, wound contraction can occur. PMID:12950643

A Langevin dynamics simulation study of the tribology of polymer loop brushes.

PubMed

Yin, Fang; Bedrov, Dmitry; Smith, Grant D; Kilbey, S Michael

2007-08-28

The tribology of surfaces modified with doubly bound polymer chains (loops) has been investigated in good solvent conditions using Langevin dynamics simulations. The density profiles, brush interpenetration, chain inclination, normal forces, and shear forces for two flat substrates modified by doubly bound bead-necklace polymers and equivalent singly bound polymers (twice as many polymer chains of 12 the molecular weight of the loop chains) were determined and compared as a function of surface separation, grafting density, and shear velocity. The doubly bound polymer layers showed less interpenetration with decreasing separation than the equivalent singly bound layers. Surprisingly, this difference in interpenetration between doubly bound polymer and singly bound polymer did not result in decreased friction at high shear velocity possibly due to the decreased ability of the doubly bound chains to deform in response to the applied shear. However, at lower shear velocity, where deformation of the chains in the flow direction is less pronounced and the difference in interpenetration is greater between the doubly bound and singly bound chains, some reduction in friction was observed.

Fibrinogen, Riboflavin, and UVA to Immobilize a Corneal Flap – Molecular Mechanisms

PubMed Central

Littlechild, Stacy L.; Zhang, Yuntao; Tomich, John M.; Conrad, Gary W.

2012-01-01

Purpose. Tissue glue containing fibrinogen (FIB) and riboflavin (RF), upon exposure to long wavelength ultraviolet light (UVA, 365 nM) has been proposed potentially to solve long-standing problems presented by corneal wound and epithelial ingrowth side-effects from laser-assisted in situ keratomileuis (LASIK). Data presented in a previous study demonstrated an ability of FIB + RF + UVA to adhere two stromal surfaces; however, to our knowledge no molecular mechanisms have been proposed to account for interactions occurring between corneal extracellular matrix (ECM) and tissue glue molecules. Here, we document several covalent and noncovalent interactions between these classes of macromolecules. Methods. SDS-PAGE and Western blot techniques were used to identify covalent interactions between tissue glue molecules and corneal ECM molecules in either the presence or absence of RF and UVA, in vitro and ex vivo. Surface plasmon resonance (SPR) was used to characterize noncovalent interactions, and obtain ka, kd, and KD binding affinity values. Results. SDS-PAGE and Western blot analyses indicated that covalent interactions occurred between neighboring FIB molecules, as well as between FIB and collagen type I (Coll-I) proteins (in vitro and ex vivo). These interactions occurred only in the presence of RF and UVA. SPR data demonstrated the ability of FIB to bind noncovalently to corneal stroma molecules, Coll-I, decorin, dermatan sulfate, and corneal basement membrane molecules, laminin and heparan sulfate – only in the presence of Zn2+. Conclusions. Covalent and (zinc-mediated) noncovalent mechanisms involving FIB and stromal ECM molecules contribute to the adhesion created by FIB + RF + UVA. PMID:22879413

Emergent gauge field for a chiral bound state on curved surface

NASA Astrophysics Data System (ADS)

Shi, Zhe-Yu; Zhai, Hui

2017-09-01

Emergent physics is one of the most important concepts in modern physics, and one of the most intriguing examples is the emergent gauge field. Here we show that a gauge field emerges for a chiral bound state formed by two attractively interacting particles on a curved surface. We demonstrate explicitly that the center-of-mass wave function of such a deeply bound state is monopole harmonic instead of spherical harmonic, which means that the bound state experiences a magnetic monopole at the center of the sphere. This emergent gauge field is due to the coupling between the center-of-mass and the relative motion on a curved surface, and our results can be generalized to an arbitrary curved surface. This result establishes an intriguing connection between the space curvature and gauge field, and paves an alternative way to engineer a topological state with space curvature, and may be observed in a cold atom system.

Index theorem for the flat Andreev bound states at a dirty surface of a nodal superconductor

NASA Astrophysics Data System (ADS)

Ikegaya, Satoshi; Asano, Yasuhiro

2018-03-01

We discuss the stability of at-band Andreev bound states appearing at a surface of a nodal unconventional superconductor. In the clean limit, the existence of the surface bound states is topologically characterized by a momentum-dependent topological invariant: one-dimensional winding number de ned in the restricted Brillouin zone. Thus, such topological invariant is ill-defined in the presence of potential disorder which is inevitable in experiments. By paying attention to chiral symmetry of the Hamiltonian, we provide an alternative topological index N ZES that predicts the number of Andreev bound states at a dirty surface of an unconventional superconductor. Moreover, we demonstrate that the zero-bias differential conductance in a normal metal/unconventional superconductor junction is quantized at (4e 2 /h)|N ZES | in the limit of strong impurity scattering in the normal metal.

Fibrin hydrogels to deliver dental stem cells of the apical papilla for regenerative medicine.

PubMed

Germain, Loïc; De Berdt, Pauline; Vanacker, Julie; Leprince, Julian; Diogenes, Anibal; Jacobs, Damien; Vandermeulen, Gaëlle; Bouzin, Caroline; Préat, Véronique; Dupont-Gillain, Christine; des Rieux, Anne

2015-01-01

Evaluation of survival, proliferation and neurodifferentiation of dental stem cells from the apical papilla (SCAP) in fibrin hydrogels. We hypothesized that fibrin composition will influence cell behavior. Modulus, pore and fiber size were measured. SCAP in vitro viability, proliferation and neural differentiation, as well as in vivo proliferation and angiogenesis were studied. Hydrogel moduli were influenced by fibrin formulation but not hydrogel morphology, SCAP in vitro viability and proliferation. In total 60% of SCAP expressed PanNeurofilament in vitro without induction in Fibrinogen50-Thrombin10. SCAP proliferated when implanted in vivo and stimulated host endothelial cell infiltration. Fibrinogen30-Thrombin10 or Thrombin50 would be more favorable to in vitro SCAP viability and in vivo proliferation, while Fibrinogen 50-Thrombin50 would be more adapted to neurodifferentiation.

Low capping group surface density on zinc oxide nanocrystals.

PubMed

Valdez, Carolyn N; Schimpf, Alina M; Gamelin, Daniel R; Mayer, James M

2014-09-23

The ligand shell of colloidal nanocrystals can dramatically affect their stability and reaction chemistry. We present a methodology to quantify the dodecylamine (DDA) capping shell of colloidal zinc oxide nanocrystals in a nonpolar solvent. Using NMR spectroscopy, three different binding regimes are observed: strongly bound, weakly associated, and free in solution. The surface density of bound DDA is constant over a range of nanocrystal sizes, and is low compared to both predictions of the number of surface cations and maximum coverages of self-assembled monolayers. The density of strongly bound DDA ligands on the as-prepared ZnO NCs is 25% of the most conservative estimate of the maximum surface DDA density. Thus, these NCs do not resemble the common picture of a densely capped surface ligand layer. Annealing the ZnO NCs in molten DDA for 12 h at 160 °C, which is thought to remove surface hydroxide groups, resulted in a decrease of the weakly associated DDA and an increase in the density of strongly bound DDA, to ca. 80% of the estimated density of a self-assembled monolayer on a flat ZnO surface. These findings suggest that as-prepared nanocrystal surfaces contain hydroxide groups (protons on the ZnO surfaces) that inhibit strong binding of DDA.

A SOF Damage Control Resuscitation Cocktail

DTIC Science & Technology

2015-05-01

include Hextend for volume resuscitation and tissue perfusion, fibrinogen concentrate for hemostasis, and tranexamic acid for hemostasis. These...for hemostasis, and tranexamic acid for hemostasis. These components are tested in a combat-relevant swine polytrauma model of hemorrhagic shock with...HexVasoCntl HexVasoAlb Ctrl 4 4 would not allow adequate blood loss from the aortic tear, preventing testing of fibrinogen and tranexamic acid as

Heart-type fatty acid binding protein levels in elderly diabetics without known cardiovascular disease.

PubMed

Beysel, Selvihan; Kizilgul, Muhammed; Ozbek, Mustafa; Caliskan, Mustafa; Kan, Seyfullah; Apaydin, Mahmut; Ozcelik, Ozgur; Cakal, Erman

2017-01-01

Cardiovascular disease (CVD) is reported to be higher in elderly diabetics. Serum heart-type fatty acid binding protein (H-FABP) is a serum marker of myocardial ischemia. We aimed to investigate the association between serum H-FABP level and conventional cardiovascular risk factors, inflammatory markers and subclinical atherosclerosis in elderly diabetics without overt CVD. A total of 50 elderly diabetic patients without overt CVD and 30 age-, sex- and body mass index (BMI)-matched healthy controls were enrolled. Anthropometric and biochemical parameters, serum H-FABP, high-sensitivity C-reactive protein (hs-CRP), fibrinogen and carotid intima-media thickness (CIMT) were measured. Logistic regression analyses (adjustments for age, sex, hypertension, smoking, diabetes, BMI, blood pressure, lipid, blood glucose, hemoglobin A1c, hs-CRP and fibrinogen) were performed to evaluate the association between H-FABP and cardiovascular risk factors and atherosclerosis indices. Serum fibrinogen (421.50±85.52 mg/dL vs 319.17±30.77 mg/dL, p =0.023), CIMT (0.70±0.12 mm vs 0.59±0.06 mm, p <0.001) and hs-CRP (5.72±4.50 mg/dL vs 1.60±0.72 mg/dL, p <0.001) were significantly higher in diabetic patients than controls. The mean serum H-FABP level did not differ between groups (1571.79±604.60 ng/mL vs 1500.25±463.35 ng/mL, p =0.905). H-FABP was positively correlated with fibrinogen ( r 2 =0.473, p <0.001), hs-CRP ( r 2 =0.323, p =0.003) and CIMT ( r 2 =0.467, p <0.001). After full adjustments, the serum H-FABP level was independently associated with an increase in the fibrinogen level (odds ratio [OR] =4.21, 95% confidence level [CI] =1.49-11.90). Serum H-FABP was similar in the elderly diabetic patients without known CVD when compared with the nondiabetic control group. H-FABP does not possess a high diagnostic value as a cardiovascular marker when used alone; however, it may add supplementary information in patients with a high fibrinogen level.

SPM of nonlinear surface plasmon waveguides

NASA Astrophysics Data System (ADS)

Li, Yuee; Zhang, Xiaoping

2008-10-01

Pulse propagation equation of nonlinear dispersion surface plasmon waveguide is educed strictly from wave equation. The nonlinear coefficient is defined and then used to assess and compare the nonlinear characteristic of three popular 1-D surface plasmon waveguides: the single metal-dielectric interface, the metal slab bounded by dielectric and the dielectric slab bounded by metal. SPM (self-phase modulation) of the typical surface plasmon waveguide is predicted and discussed.

Role of G protein signaling in the formation of the fibrin(ogen)-integrin αIIbβ3-actin cytoskeleton complex in platelets.

PubMed

Budnik, Ivan; Shenkman, Boris; Savion, Naphtali

2016-09-01

Effective platelet function requires formation of a physical link between fibrin(ogen), integrin αIIbβ3, and cytoplasmic actin filaments. We investigated the role of the Gαq, Gαi, and Gα12/13 families of heterotrimeric GTP-binding proteins (G proteins) in the assembly of a ligand-αIIbβ3-actin cytoskeleton complex. Selective and combined activation of the G proteins was achieved by using combinations of various platelet agonists and inhibitors. Formation and stability of fibrinogen-αIIbβ3 interaction were evaluated by the extent of platelet aggregation and the rate of eptifibatide-induced platelet disaggregation; association of αIIbβ3 with the cytoskeleton was analyzed by western blot. Formation of the fibrin-αIIbβ3-actin cytoskeleton complex was evaluated by rotational thromboelastometry assay in which clot formation was induced by the mixture of reptilase and factor XIIIa. We demonstrated that involvement of heterotrimeric G proteins in the formation of the ligand-αIIbβ3-cytoskeleton complex depends on whether fibrinogen or fibrin serves as the integrin ligand. Formation of the fibrinogen-αIIbβ3-cytoskeleton complex requires combined activation of at least two G protein pathways while the maximal αIIbβ3-cytoskeleton association and the strongest αIIbβ3-fibrinogen binding supporting irreversible platelet aggregation require combined activation of all three-Gαq, Gαi, and Gα12/13-G protein families. In contrast, formation of the fibrin-αIIbβ3-cytoskeleton complex mediating clot retraction is critically dependent on the activation of the Gαi family, especially on the activation of Gαz.

Superior integrin activating capacity and higher adhesion to fibrinogen matrix in buffy coat-derived platelet concentrates (PCs) compared to PRP-PCs.

PubMed

Beshkar, Pezhman; Hosseini, Ehteramolsadat; Ghasemzadeh, Mehran

2018-02-01

Regardless of different sources, methods or devices which are applied for preparation of therapeutic platelets, these products are generally isolated from whole blood by the sedimentation techniques which are based on PRP or buffy coat (BC) separation. As a general fact, platelet preparation and storage are also associated with some deleterious changes that known as platelet storage lesion (PSL). Although these alternations in platelet functional activity are aggravated during storage, whether technical issues within preparation can affect integrin activation and platelet adhesion to fibrinogen were investigated in this study. PRP- and BC-platelet concentrates (PCs) were subjected to flowcytometry analysis to examine the expression of platelet activation marker, P-selectin as well as active confirmation of the GPIIb/IIIa (α IIb β 3 ) on day 0, 1, 3 and 5 post-storage. Platelet adhesion to fibrinogen matrix was evaluated by fluorescence microscopy. Glucose concentration and LDH activity were also measured by colorimetric methods. The increasing P-selectin expression during storage was in a reverse correlation with PAC-1 binding (r = -0.67; p = .001). PRP-PCs showed the higher level of P-selectin expression than BC-PCs, whereas the levels of PAC-1 binding and platelet adhesion to fibrinogen matrix were significantly lower in PRP-PCs. Higher levels of active confirmation of the GPIIb/IIIa in BC-PCs were also associated with greater concentration of glucose in these products. We demonstrated the superior capacities of integrin activation and adhesion to fibrinogen for BC-PCs compared to those of PRP-PCs. These findings may provide more advantages for BC method of platelet preparation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Plasma circulating fibrinogen stability and moderate beer consumption.

PubMed

Gorinstein, Shela; Caspi, Abraham; Zemser, Marina; Libman, Imanuel; Goshev, Ivan; Trakhtenberg, Simon

2003-12-01

MODERATE BEER CONSUMPTION (MBC) IS CARDIOPROTECTIVE: it positively influences plasma lipid levels and plasma antioxidant activity in beer-consuming individuals. The connection between MBC and blood coagulation is not clearly defined. Forty-two volunteers were equally divided into experimental (EG) and control (CG) groups following coronary bypass surgery. For 30 consecutive days, only patients of the EG consumed 330 mL of beer per day (about 20 g of alcohol). A comprehensive clinical investigation of 42 patients was done. Blood samples were collected before and after the investigation for a wide range of laboratory tests. The plasma fibrinogen was denatured with 8 M urea and intrinsic fluorescence (IF), hydrophobicity and differential scanning calorimetry (DSC) were used to reveal possible qualitative changes. After 30 days of moderate beer consumption, positive changes in the plasma lipid levels, plasma anticoagulant and plasma antioxidant activities were registered in patients of the EG group. In 17 out of 21 patients of the same group, differences in plasma circulating fibrinogen's (PCF), secondary and tertiary structures were found. The stability of fibrinogen, expressed in thermodynamic parameters, has shown that the loosening of the structure takes place under ethanol and urea denaturation. Also fluorescence stability of PCF was decreased. No changes in the lipid levels, anticoagulant and antioxidant activity or changes in PCF were detected in patients of CG. In conclusion, for the first time after a short term of moderate beer consumption some qualitative changes in the plasma circulating fibrinogen were detected: differences in the emission peak response, fluorescence intensity and all thermodynamic data. Together, with the decrease in the PCF concentration it may lead to an elevation of the blood anticoagulant activity.

Rational and timely haemostatic interventions following cardiac surgery - coagulation factor concentrates or blood bank products.

PubMed

Tang, Mariann; Fenger-Eriksen, Christian; Wierup, Per; Greisen, Jacob; Ingerslev, Jørgen; Hjortdal, Vibeke; Sørensen, Benny

2017-06-01

Cardiac surgery may cause a serious coagulopathy leading to increased risk of bleeding and transfusion demands. Blood bank products are commonly first line haemostatic intervention, but has been associated with hazardous side effect. Coagulation factor concentrates may be a more efficient, predictable, and potentially a safer treatment, although prospective clinical trials are needed to further explore these hypotheses. This study investigated the haemostatic potential of ex vivo supplementation of coagulation factor concentrates versus blood bank products on blood samples drawn from patients undergoing cardiac surgery. 30 adults were prospectively enrolled (mean age=63.9, females=27%). Ex vivo haemostatic interventions (monotherapy or combinations) were performed in whole blood taken immediately after surgery and two hours postoperatively. Fresh-frozen plasma, platelets, cryoprecipitate, fibrinogen concentrate, prothrombin complex concentrate (PCC), and recombinant FVIIa (rFVIIa) were investigated. The haemostatic effect was evaluated using whole blood thromboelastometry parameters, as well as by thrombin generation. Immediately after surgery the compromised maximum clot firmness was corrected by monotherapy with fibrinogen or platelets or combination therapy with fibrinogen. At two hours postoperatively the coagulation profile was further deranged as illustrated by a prolonged clotting time, a reduced maximum velocity and further diminished maximum clot firmness. The thrombin lagtime was progressively prolonged and both peak thrombin and endogenous thrombin potential were compromised. No monotherapy effectively corrected all haemostatic abnormalities. The most effective combinations were: fibrinogen+rFVIIa or fibrinogen+PCC. Blood bank products were not as effective in the correction of the coagulopathy. Coagulation factor concentrates appear to provide a more optimal haemostasis profile following cardiac surgery compared to blood bank products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Skin closure with dye-enhanced laser welding and fibrinogen.

PubMed

Wider, T M; Libutti, S K; Greenwald, D P; Oz, M C; Yager, J S; Treat, M R; Hugo, N E

1991-12-01

The topical application of wavelength-specific dye and fibrinogen has been used to enhance laser closure of vascular anastomoses. We compared the closure of skin incisions by two different dye-enhanced, fibrinogen-based laser welding systems [argon laser (power density 4.78 W/cm2) with fluorescein isothiocyanate dye (n = 32) and diode laser (power density 9.55 W/cm2) with indocyanine green dye (n = 32)] with closure by interrupted 5-0 nylon suture (n = 64) and examined tensile strength, hydroxyproline production, histology, and cosmesis. Two 3-cm full-thickness incisions were made on the shaved backs of 64 rats. One incision was closed with suture, whereas the other, after treatment with the appropriate dye, was welded with either argon- or diode-lasered fibrinogen. At postoperative days 5, 10, 15, and 28, the closure sites were harvested and sectioned for analysis. Initially, wounds closed with argon-lasered fibrinogen showed less inflammatory response, greater collagen production (34.61 +/- 0.74 mg/gm), and greater mean peak stress at rupture (64.85 lbs/in2) than those closed with suture (16.42 +/- 3.20 mg/gm, 26.68 lbs/in2) (p less than 0.05). By 15 days, both argon and diode laser closures are superior in strength and collagen production to suture closure (p less than 0.05). At 28 days, diode laser closures (1315.60 lbs/in2) are stronger than suture closures (998.09 lbs/in2), whereas both are stronger than argon laser closures (813.16 lbs/in2) (p less than 0.05). Cosmetically, argon-welded wounds consistently appeared finer and lacked cross-hatched suture scars.(ABSTRACT TRUNCATED AT 250 WORDS)

PARTICIPATION OF THE COAGULATION MECHANISM IN TUMOR LOCALIZATION OF I$sup 131$-LABELLED FIBRINOGEN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaeffer, J.R.

A transplantable tumor of the rat, the Murphy-Sturm lymphosarcoma, was found to contain 15 to 25% of the adminlstered radioactive dose 18 hours after intravenous injection of I/sup 131/-labeled rat fibrinogen in a rat bearing a tumor in the 2 to 12 gm weight range. At this time the concentration of radioactivity per gm of tumor was found to be some 4 to 15 times that of such vascular organs as the liver and kidney, smaller tumors (2 to 5 gm) localizing much more of the injected radioactive dose per gm than larger tumors (8 to 12 gm). These tumorsmore » did not concentrate radioactivity after intravenous injection of either I/sup 131/ gamma -globulin or inorganic NaI/sup 131/. The administration of heparin or warfarin in dosages adequate to completely inhibit the blood coagulation mechanism throughout the 18-hour experimental period decreased this specific tumor localization of I/sup 131/ fibrinogen by 60 to 80%. It is concluded that the coagulation mechanism participates in the localization of I/ sup 131/ fibrinogen in the Murphy-Sturm lymphosarcoma. Physiological mechanisms of action other than the anticoagulative one which could possibly explain the effect of heparin and warfarin on tumor localization are discussed. No experimental evidence for an enhancement of fibrinolysis as the mechanism of tumor I/sup 131/ localization decrease by the drugs was found. In particular, these anticoagulants did not decrease whole--body radioactivity retention, and the radioactivity retained in the tumor-bearing rats receiving anticoagulant was highly clottable 18 hours after injection of I/sup 131/ fibrinogen. (auth)« less

Thrombin like activity of Asclepias curassavica L. latex: action of cysteine proteases.

PubMed

Shivaprasad, H V; Rajesh, R; Nanda, B L; Dharmappa, K K; Vishwanath, B S

2009-05-04

To validate the scientific basis of plant latex to stop bleeding on fresh cuts. Cysteine protease(s) from Asclepias curassavica (Asclepiadaceae) plant latex was assessed for pro-coagulant and thrombin like activities. A waxy material from the latex of Asclepias curassavica latex was removed by freezing and thawing. The resulted latex enzyme fraction was assayed for proteolytic activity using denatured casein as substrate. Its coagulant activity and thrombin like activity were determined using citrated plasma and pure fibrinogen, respectively. Inhibition studies were performed using specific protease inhibitors to know the type of protease. The latex enzyme fraction exhibited strong proteolytic activity when compared to trypsin and exerted pro-coagulant action by reducing plasma clotting time from 195 to 58 s whereas trypsin reduced clotting time marginally from 195 to 155 s. The pro-coagulant activity of this enzyme fraction was exerted by selectively hydrolyzing A alpha and B beta subunits of fibrinogen to form fibrin clot when pure fibrinogen was used as substrate as assessed by fibrinogen-agarose plate method and fibrinogen polymerization assay. Trypsin failed to induce any fibrin clot under similar conditions. The electrophoretic pattern of latex enzyme fraction-induced fibrin clot was very much similar to that of thrombin-induced fibrin clot and mimic thrombin like action. The proteolytic activity including thrombin like activity of Asclepias curassavica latex enzyme fraction was completely inhibited by iodoaceticacid (IAA). Cysteine proteases from Asclepias curassavica latex exhibited strong pro-coagulant action and were found to be specific in its action (Thrombin like). This could be the basis for the use of plant latex in pharmacological applications that justify their use as folk medicine.

Lipid contribution to the affinity of antigen association with specific antibodies conjugated to liposomes.

PubMed

Klegerman, Melvin E; Huang, Shaoling; Parikh, Devang; Martinez, Janet; Demos, Sasha M; Onyuksel, Hayat A; McPherson, David D

2007-07-01

Immunoliposomes, directed to clinically relevant cell-surface molecules with antibodies, antibody fragments or peptides, are used for site-specific diagnostic evaluation or delivery of therapeutic agents. We have developed intrinsically echogenic liposomes (ELIP) covalently linked to fibrin(ogen)-specific antibodies and Fab fragments for ultrasonic imaging of atherosclerotic plaques. In order to determine the effect of liposomal conjugation on the molecular dynamics of fibrinogen binding, we studied the thermodynamic characteristics of unconjugated and ELIP-conjugated antibody molecules. Utilizing radioimmunoassay and enzyme-linked immunosorbent assay protocols, binding affinities were derived from data obtained at three temperatures. The thermodynamic functions DeltaH(o) , DeltaG(o) and DeltaS(o) were determined from van't Hoff plots and equations of state. The resultant functions indicated that both specific and nonspecific associations of antibody molecules with fibrinogen occurred through a variety of molecular interactions, including hydrophophic, ionic and hydrogen bonding mechanisms. ELIP conjugation of antibodies and Fab fragments introduced a characteristic change in both DeltaH(o) and DeltaS(o) of association, which corresponded to a variable contribution to binding by phospholipid gel-liquid crystal phase transitions. These observations suggest that a reciprocal energy transduction, affecting the strength of antibody-antigen binding, may be a singular characteristic of immunoliposomes, having utility for optimization and further development of the technology.

Lytic resistance of fibrin containing red blood cells

PubMed Central

Wohner, Nikolett; Sótonyi, Péter; Machovich, Raymund; Szabó, László; Tenekedjiev, Kiril; Silva, Marta M.C.G.; Longstaff, Colin; Kolev, Krasimir

2012-01-01

Objective Arterial thrombi contain variable amounts of red blood cell (RBC), which interact with fibrinogen through an eptifibatide-sensitive receptor and modify the structure of fibrin. Here we evaluate the modulator role of RBCs in the lytic susceptibility of fibrin. Methods and Results If fibrin is formed at increasing RBC counts, scanning electron microscopy evidenced a decrease in fiber diameter from 150 nm to 96 nm at 40 %(v/v) RBC, an effect susceptible to eptifibatide inhibition (restoring 140 nm diameter). RBC prolonged the lysis time in a homogeneous-phase fibrinolytic assay with tissue plasminogen activator (tPA) by up to 22.7±1.6 %, but not in the presence of eptifibatide. Confocal laser microscopy using green fluorescent protein (GFP)-labeled tPA and orange fluorescent fibrin showed that 20-40 %(v/v) RBC significantly slowed down the dissolution of the clots. tPA-GFP did not accumulate on the surface of fibrin containing RBC at any cell count above 10 %. The presence of RBC in the clot suppressed the tPA-induced plasminogen activation resulting in a 45 % less plasmin generated after 30 min activation at 40 %(v/v) RBC. Conclusion RBCs confer lytic resistance to fibrin resulting from modified fibrin structure and impaired plasminogen activation through a mechanism that involves eptifibatide-sensitive fibrinogen-RBC interactions. PMID:21737785

Osteoblast adhesion to orthopaedic implant alloys: Effects of cell adhesion molecules and diamond-like carbon coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kornu, R.; Kelly, M.A.; Smith, R.L.

1996-11-01

In total joint arthroplasty, long-term outcomes depend in part on the biocompatibility of implant alloys. This study analyzed effects of surface finish and diamond-like carbon coating on osteoblast cell adhesion to polished titanium-aluminum-vanadium and polished or grit-blasted cobalt-chromium-molybdenum alloys. Osteoblast binding was tested in the presence and absence of the cell adhesion proteins fibronectin, laminin, fibrinogen, and vitronectin and was quantified by measurement of DNA content. Although adherence occurred in serum-free medium, maximal osteoblast binding required serum and was similar for titanium and cobalt alloys at 2 and 12 hours. With the grit-blasted cobalt alloy, cell binding was reduced 48%more » (p < 0.05) by 24 hours. Coating the alloys with diamond-like carbon did not alter osteoblast adhesion, whereas fibronectin pretreatment increased cell binding 2.6-fold (p < 0.05). In contrast, fibrinogen, vitronectin, and laminin did not enhance cell adhesion. These results support the hypothesis that cell adhesion proteins can modify cell binding to orthopaedic alloys. Although osteoblast binding was not affected by the presence of diamond-like carbon, this coating substance may influence other longer term processes, such as bone formation, and deserves further study. 40 refs., 4 figs.« less

Multiple nitrogen isotope recorders for surface ocean nitrate utilization in the Subarctic North Pacific and the Bering Sea

NASA Astrophysics Data System (ADS)

Ren, H. A.; Anderson, R.; Sigman, D. M.; Studer, A.; Winckler, G.; Haugh, G.; Serno, S.; Gersonde, R.

2017-12-01

Sedimentary nitrogen isotopes have been developed as a proxy to reconstruct the degree of nitrate utilization in the polar surface oceans. But its application could be compromised by 1) uncertainties on the biological production, transport, and preservation of the organic material in the sediments, and 2) potential changes in the isotopic composition of the nitrate source, that is remotely controlled by processes in other regions. In this study, we map and compare spatial patterns of three d15N recorders (bulk sedimentary nitrogen, the organic nitrogen within cleaned diatom frustules or diatom-bound N, and within planktonic foraminifera tests or foraminifera-bound N) from multicore surface sediments across the Subarctic North Pacific (SNP) and the Bering Sea between 60°N and 35°N. Diatom-bound d15N varies between 3.5 and 8.5‰. Its spatial variation is reversely correlated with changes in the surface nitrate concentration, and is consistent with the expected d15N change of the export production in a simple nitrate assimilation model. Similar to previous findings, diatom-bound d15N is generally 2 4‰ higher than the modeled d15N value of the export production, likely reflecting a biomass to frustual-bound N difference. However, the greater d15N elevation observed in the eastern open SNP may be best explained by lateral transport of residual surface nitrate enriched in 15N from the western SNP. The d15N of Neogloboquadrina pachyderma (sinistral) is similar to the diatom-bound d15N within 1‰. Bulk sedimentary d15N generally agrees with diatom-bound d15N, but is more variable. It is higher than diatom-bound d15N in the eastern and western transect close to the shelf area, likely reflecting a terrigenous source, while exceptionally low d15N values were found on the Bering Sea shelf, possibly due to contamination by mineral-associated inorganic N.

Degradable Polymer with Protein Resistance in a Marine Environment.

PubMed

Ma, Jielin; Ma, Chunfeng; Zhang, Guangzhao

2015-06-16

Protein resistance is the central issue in marine antibiofouling. We have prepared poly(ε-caprolactone) (PCL)-based polyurethane with 2-(dimethylamino) ethyl methacrylate (DEM) as pendant groups by a combination of the thiol-ene click reaction and the condensation reaction. By the use of quartz crystal microbalance with dissipation (QCM-D) and surface plasmon resonance (SPR), we have investigated the adsorption of fibrinogen, bovine serum albumin (BSA), and lysozyme on the polymer surface. The polymer exhibits protein resistance in seawater but not in fresh water because DEM pendant groups carry net neutral charges in the former. The evaluation of antibacterial adhesion of the polymer by using Micrococcus luteus demonstrates that the polymer can effectively inhibit the settlement of marine bacteria. Our studies also show that the polymer is degradable in marine environments.

Hydrolysis-controlled protein adsorption and antifouling behaviors of mixed charged self-assembled monolayer: A molecular simulation study.

PubMed

Liu, Jie; Zhou, Jian

2016-08-01

Understanding the mechanism of the antimicrobial and antifouling properties of mixed charged materials is of great significance. The interactions between human gamma fibrinogen (γFg) and mixed carboxylic methyl ether-terminated (COOCH3-) and trimethylamino-terminated (N(CH3)3(+)-) SAMs and the influence of hydrolysis were studied by molecular simulations. After hydrolysis, the mixed SAMs exhibit behaviors from antimicrobial to antifouling, since the COOCH3-thiols were translated into carboxylic acid (COO(-)-) terminated thiols, which carried a net charge of -1 e. Simulation results showed that the main differences between COOCH3-/N(CH3)3(+)-SAM and COO(-)-/N(CH3)3(+)-SAM are the charged property and the hydration layer above the surface. γFg could stably adsorb on the positively-charged COOCH3-/N(CH3)3(+)-SAM. The adsorption behavior is mainly induced by the strong electrostatic attraction. There is a single hydration layer bound to the surface, which is related to the N(CH3)3(+) groups. The van der Waals repulsion between γFg and the single hydration layer are not strong enough to compensate the strong electrostatic attraction. After hydrolysis, the positively-charged SAM was transferred to a neutral mixed charged surface, the electrostatic attraction between γFg and the surface disappears. Meanwhile, the SAM surface is covered by double hydration layers, which is induced by the N(CH3)3(+) and COO(-) groups; water molecules around COO(-) groups are obviously denser than that around N(CH3)3(+) groups. With the combined contribution from double hydration layers and the vanishment of electrostatic attraction, γFg is forced to desorb from the surface. After hydrolysis, the internal structure of mixed SAM appears more ordered due to the electrostatic interactions between charged groups on the top of SAMs. The antimicrobial and antifouling materials are of great importance in many biological applications. The strong hydration property of surfaces and the interactions between proteins and surfaces play a key role in resisting protein adsorption. The mixed SAMs, constructed from a 1:1 combination of COOCH3- and N(CH3)3(+)-terminated thiols, can induce protein adsorption mainly through the electrostatic interaction. When the COOCH3-terminated thiols were hydrolyzed to negatively charged COO(-)-terminated thiols, the mixed-charged SAMs switched from antimicrobial to antifouling. Due to the strong hydration property of the mixed charged SAMs, the adsorbed γFg moved away from the surface. Understanding the interactions between protein and mixed-charged SAMs in the atomistic level is important for the practical design and development of new antimicrobial and antifouling materials. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Search for Chemically Bound Water in the Surface Layer of Mars Based on HEND/Mars Odyssey Data

NASA Technical Reports Server (NTRS)

Basilevsky, A. T.; Litvak, M. L.; Mitrofanov, I. G.; Boynton, W.; Saunders, R. S.

2003-01-01

This study is emphasized on search for signatures of chemically bound water in surface layer of Mars based on data acquired by High Energy Neutron Detector (HEND) which is part of the Mars Odyssey Gamma Ray Spectrometer (GRS). Fluxes of epithermal (probe the upper 1-2 m) and fast (the upper 20-30 cm) neutrons, considered in this work, were measured since mid February till mid June 2002. First analysis of this data set with emphasis of chemically bound water was made. Early publications of the GRS results reported low neutron flux at high latitudes, interpreted as signature of ground water ice, and in two low latitude areas: Arabia and SW of Olympus Mons (SWOM), interpreted as 'geographic variations in the amount of chemically and/or physically bound H2O and or OH...'. It is clear that surface materials of Mars do contain chemically bound water, but its amounts are poorly known and its geographic distribution was not analyzed.

Comparison of 10 Different Hemostatic Dressings in an Aortic Injury

DTIC Science & Technology

2003-02-01

lateral peritoneal recesses of the abdomen bilaterally. The rate of bleeding was quantified (grams accumulated every 10 sec- onds) in the suction...used frequently for hemostasis in dental procedures19 D5 TachoComb S Nycomed Amersham, Linz, Austria Collagen -based ( collagen from horse tendons...product with human fibrinogen and thrombin Collagen attracts and activates platelets to achieve hemostasis. D5 also had fibrinogen and thrombin, but at a

Fibroblast growth factor 23, iron and inflammation - are they related in early stages of chronic kidney disease?

PubMed

Lukaszyk, Ewelina; Lukaszyk, Mateusz; Koc-Zorawska, Ewa; Bodzenta-Lukaszyk, Anna; Malyszko, Jolanta

2017-06-01

Fibroblast growth factor 23 (FGF-23) levels are elevated in impaired renal function. Inflammation and iron are potential regulators of FGF-23. The aim of the study was to evaluate the association between FGF-23 concentration, novel iron status biomarkers and inflammatory parameters among patients with early stages of chronic kidney disease (CKD). The study population included 84 patients with CKD in the early stage. Serum hemoglobin, fibrinogen, creatinine, iron, transferrin saturation and ferritin levels were measured using standard laboratory methods. Commercially available kits were used to measure: intact FGF-23, hepcidin, soluble transferrin receptor (sTfR), interleukin 6 (IL-6) and high-sensitivity C-reactive protein (hsCRP). In patients with CKD no differences in FGF-23 concentration according to iron status were observed. Lower iron concentration was associated with higher concentrations of hsCRP, IL-6 and fibrinogen. In univariate and multivariate analysis FGF-23 correlated with fibrinogen ( r = -0.23, p < 0.05) and eGFR ( r = -0.36, p < 0.05). FGF-23 is affected by kidney function and fibrinogen but not iron status parameters in the early stages of CKD. Our data are paving the way for further studies on the role of FGF-23 in iron metabolism, especially in early stages of CKD.

Selective inhibition by a synthetic hirudin peptide of fibrin-dependent thrombosis in baboons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cadroy, Y.; Hanson, S.R.; Harker, L.A.

1991-02-15

To determine the importance of the thrombin substrate recognition exosite for fibrinogen binding in the formation of both arterial and venous thrombi the authors evaluated the antithrombotic effects of the tyrosine-sulfated dodecapeptide from residues 53-64 of hirudin (H peptide) in a nonhuman primate model. This peptide was studied because it inhibits thrombin cleavages of fibrinogen by simple competition without blocking enzyme catalytic-site function. When an exteriorized arteriovenous access shunt model was used in baboons (Papio anubis), thrombus formation was induced by placing a thrombogenic device made of (i) a segment of tubing coated covalently with type I collagen, which generatedmore » platelet-rich thrombi under arterial flow conditions, and (ii) two subsequent annular regions of flow expansion that produced fibrin-rich thrombi typically associated with venous valves and veins. Thrombus formation was quantified by measurements of {sup 111}In-labeled platelet and {sup 125}I-labeled fibrinogen deposition in both arterial-flow and venous-flow portions of the device. These finding suggest that, by competitive inhibition of fibrinogen binding to thrombin, fibrin-rich venous-type thrombus formation may be selectively prevented. This strategy may be therapeutically attractive for preserving normal platelet function when conventional anticoagulant therapy is contraindicated.« less

THE FLOCCULATION MAXIMUM (pH) OF FIBRINOGEN AND SOME OTHER BLOOD-CLOTTING REAGENTS. (RELATIVE TURBIDIMETRY WITH THE EVELYN PHOTOELECTRIC COLORIMETER).

PubMed

Ferguson, J H

1942-03-20

By means of a novel adaptation of the Evelyn photoelectric colorimeter to the measurement of relative turbidities, the question of the flocculation maximum (F.M.) in acetate buffer solutions of varying pH and salt content has been studied on (a) an exceptionally stable prothrombin-free fibrinogen and its solutions after incipient thermal denaturation and incomplete tryptic proteolysis, (b) plasma, similarly treated, (c) prothrombin, thrombin, and (brain) thromboplastin solutions. All the fibrinogens show a remarkable uniformity of the precipitation pattern, viz. F.M. =4.7 (+/-0.2) pH in salt-containing buffer solutions and pH = 5.3 (+/-0.2) in salt-poor buffer (N/100 acetate). The latter approximates the isoelectric point (5.4) obtained by cataphoresis (14). There is no evidence that denaturation or digestion can produce any "second maximum." The data support the view that fibrin formation (under the specific influence of thrombin) is intrinsically unrelated to denaturation and digestion phenomena, although all three can proceed simultaneously in crude materials. A criticism is offered, therefore, of Wöhlisch's blood clotting theory. Further applications of the photoelectric colorimeter to coagulation problems are suggested, including kinetic study of fibrin formation and the assay of fibrinogen, with a possible sensitivity of 7.5 mg. protein in 100 cc. solution.

Differential Dynamics of Platelet Contact and Spreading

PubMed Central

Lee, Dooyoung; Fong, Karen P.; King, Michael R.; Brass, Lawrence F.; Hammer, Daniel A.

2012-01-01

Platelet spreading is critical for hemostatic plug formation and thrombosis. However, the detailed dynamics of platelet spreading as a function of receptor-ligand adhesive interactions has not been thoroughly investigated. Using reflection interference contrast microscopy, we found that both adhesive interactions and PAR4 activation affect the dynamics of platelet membrane contact formation during spreading. The initial growth of close contact area during spreading was controlled by the combination of different immobilized ligands or PAR4 activation on fibrinogen, whereas the growth of the total area of spreading was independent of adhesion type and PAR4 signaling. We found that filopodia extend to their maximal length and then contract over time; and that filopodial protrusion and expansion were affected by PAR4 signaling. Upon PAR4 activation, the integrin αIIbβ3 mediated close contact to fibrinogen substrata and led to the formation of ringlike patterns in the platelet contact zone. A systematic study of platelet spreading of GPVI-, α2-, or β3-deficient platelets on collagen or fibrinogen suggests the integrin α2 is indispensable for spreading on collagen. The platelet collagen receptors GPVI and α2 regulate integrin αIIbβ3-mediated platelet spreading on fibrinogen. This work elucidates quantitatively how receptor-ligand adhesion and biochemical signals synergistically control platelet spreading. PMID:22325269

Fibrinogen gamma-A chain precursor in CSF: a candidate biomarker for Alzheimer's disease

PubMed Central

Lee, Joung Wook; Namkoong, Hong; Kim, Hyun Kee; Kim, Sanghee; Hwang, Dong Whi; Na, Hae Ri; Ha, Seon-Ah; Kim, Jae-Ryong; Kim, Jin Woo

2007-01-01

Background Cerebrospinal fluid (CSF) may be valuable for exploring protein markers for the diagnosis of Alzheimer's disease (AD). The prospect of early detection and treatment, to slow progression, holds hope for aging populations with increased average lifespan. The aim of the present study was to investigate candidate CSF biological markers in patients with mild cognitive impairment (MCI) and AD and compare them with age-matched normal control subjects. Methods We applied proteomics approaches to analyze CSF samples derived from 27 patients with AD, 3 subjects with MCI and 30 controls. The AD group was subdivided into three groups by clinical severity according to clinical dementia rating (CDR), a well known clinical scale for dementia. Results We demonstrated an elevated level of fibrinogen gamma-A chain precursor protein in CSF from patients with mild cognitive impairment and AD compared to the age-matched normal subjects. Moreover, its expression was more prominent in the AD group than in the MCI and correlated with disease severity and progression. In contrast, fibrinogen gamma-A chain precursor protein was detected very low in the age-matched normal group. Conclusion These findings suggest that the CSF level of fibrinogen gamma-A chain precursor may be a candidate biomarker for AD. PMID:17565664

Slope-aspect color shading for parametric surfaces

NASA Technical Reports Server (NTRS)

Moellering, Harold J. (Inventor); Kimerling, A. Jon (Inventor)

1991-01-01

The invention is a method for generating an image of a parametric surface, such as the compass direction toward which each surface element of terrain faces, commonly called the slope-aspect azimuth of the surface element. The method maximizes color contrast to permit easy discrimination of the magnitude, ranges, intervals or classes of a surface parameter while making it easy for the user to visualize the form of the surface, such as a landscape. The four pole colors of the opponent process color theory are utilized to represent intervals or classes at 90 degree angles. The color perceived as having maximum measured luminance is selected to portray the color having an azimuth of an assumed light source and the color showing minimum measured luminance portrays the diametrically opposite azimuth. The 90 degree intermediate azimuths are portrayed by unique colors of intermediate measured luminance, such as red and green. Colors between these four pole colors are used which are perceived as mixtures or combinations of their bounding colors and are arranged progressively between their bounding colors to have perceived proportional mixtures of the bounding colors which are proportional to the interval's angular distance from its bounding colors.

Kinetics of the Multistep Rupture of Fibrin ‘A-a’ Polymerization Interactions Measured Using Atomic Force Microscopy

PubMed Central

Averett, Laurel E.; Schoenfisch, Mark H.; Akhremitchev, Boris B.; Gorkun, Oleg V.

2009-01-01

Abstract Fibrin, the structural scaffold of blood clots, spontaneously polymerizes through the formation of ‘A-a’ knob-hole bonds. When subjected to external force, the dissociation of this bond is accompanied by two to four abrupt changes in molecular dimension observable as rupture events in a force curve. Herein, the configuration, molecular extension, and kinetic parameters of each rupture event are examined. The increases in contour length indicate that the D region of fibrinogen can lengthen by ∼50% of the length of a fibrin monomer before rupture of the ‘A-a’ interaction. The dependence of the dissociation rate on applied force was obtained using probability distributions of rupture forces collected at different pull-off velocities. These distributions were fit using a model in which the effects of the shape of the binding potential are used to quantify the kinetic parameters of forced dissociation. We found that the weak initial rupture (i.e., event 1) was not well approximated by these models. The ruptured bonds comprising the strongest ruptures, events 2 and 3, had kinetic parameters similar to those commonly found for the mechanical unfolding of globular proteins. The bonds ruptured in event 4 were well described by these analyses, but were more loosely bound than the bonds in events 2 and 3. We propose that the first event represents the rupture of an unknown interaction parallel to the ‘A-a’ bond, events 2 and 3 represent unfolding of structures in the D region of fibrinogen, and event 4 is the rupture of the ‘A-a’ knob-hole bond weakened by prior structural unfolding. Comparison of the activation energy obtained via force spectroscopy measurements with the thermodynamic free energy of ‘A-a’ bond dissociation indicates that the ‘A-a’ bond may be more resistant to rupture by applied force than to rupture by thermal dissociation. PMID:19917237

Topical application of recombinant activated factor VII during cesarean delivery for placenta previa.

PubMed

Schjoldager, Birgit T B G; Mikkelsen, Emmeli; Lykke, Malene R; Præst, Jørgen; Hvas, Anne-Mette; Heslet, Lars; Secher, Niels J; Salvig, Jannie D; Uldbjerg, Niels

2017-06-01

During cesarean delivery in patients with placenta previa, hemorrhaging after removal of the placenta is often challenging. In this condition, the extraordinarily high concentration of tissue factor at the placenta site may constitute a principle of treatment as it activates coagulation very effectively. The presumption, however, is that tissue factor is bound to activated factor VII. We hypothesized that topical application of recombinant activated factor VII at the placenta site reduces bleeding without affecting intravascular coagulation. We included 5 cases with planned cesarean delivery for placenta previa. After removal of the placenta, the surgeon applied a swab soaked in recombinant activated factor VII containing saline (1 mg in 246 mL) to the placenta site for 2 minutes; this treatment was repeated once if the bleeding did not decrease sufficiently. We documented the treatment on video recordings and measured blood loss. Furthermore, we determined hemoglobin concentration, platelet count, international normalized ratio, activated partial thrombin time, fibrinogen (functional), factor VII:clot, and thrombin generation in peripheral blood prior to and 15 minutes after removal of the placenta. We also tested these blood coagulation variables in 5 women with cesarean delivery planned for other reasons. Mann-Whitney test was used for unpaired data. In all 5 cases, the uterotomy was closed under practically dry conditions and the median blood loss was 490 (range 300-800) mL. There were no adverse effects of recombinant activated factor VII and we did not measure factor VII to enter the circulation. Neither did we observe changes in thrombin generation, fibrinogen, activated partial thrombin time, international normalized ratio, and platelet count in the peripheral circulation (all P values >.20). This study indicates that in patients with placenta previa, topical recombinant activated factor VII may diminish bleeding from the placenta site without initiation of systemic coagulation. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

The influence of dissolved and surface-bound humic acid on the toxicity of TiO₂ nanoparticles to Chlorella sp.

PubMed

Lin, Daohui; Ji, Jing; Long, Zhifeng; Yang, Kun; Wu, Fengchang

2012-09-15

NOM is likely to coat TiO₂ nanoparticles (nano-TiO₂) discharged into the aquatic environment and influence the nanotoxicity to aquatic organisms, which however has not been well investigated. This study explored the influence of nanoparticle surface-bound humic acid (HA, as a model NOM) as well as dissolved HA on the toxicity of nano-TiO₂ to Chlorella sp., with a specific focus on adhesion of the nanoparticles to the algae. Results showed that nano-TiO₂ and the dissolved HA could inhibit the algal growth with an IC₅₀ of 4.9 and 8.4 mg L⁻¹, respectively, while both dissolved and nanoparticle surface-bound HA could significantly alleviate the algal toxicity of nano-TiO₂. IC₅₀ of nano-TiO₂ increased to 18 mg L⁻¹ in the presence of 5 mg L⁻¹ of the dissolved HA and to 48 mg L⁻¹ as the result of surface-saturation by HA. Co-precipitation experiment and transmission electron microscopy observation revealed that both dissolved and nanoparticle surface-bound HA prevented the adhesion of nano-TiO₂ to the algal cells due to the increased electrosteric repulsion. The generation of intracellular reactive oxygen species (ROS) was significantly limited by the dissolved and nanoparticle surface-bound HA. The prevention of adhesion and inhibition of ROS generation could account for the HA-mitigated nanotoxicity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Reprogrammed streptokinases develop fibrin-targeting and dissolve blood clots with more potency than tissue plasminogen activator

PubMed Central

SAZONOVA, I. Y.; MCNAMEE, R. A.; HOUNG, A. K.; KING, S. M.; HEDSTROM, L.; REED, G. L.

2013-01-01

Summary Background: Given the worldwide epidemic of cardiovascular diseases, a more effective means of dissolving thrombi that cause heart attacks, could markedly reduce death, disability and healthcare costs. Plasminogen activators (PAs) such as streptokinase (SK) and tissue plasminogen activator (TPA) are currently used to dissolve fibrin thrombi. SK is cheaper and more widely available, but it appears less effective because it lacks TPA’s fibrin-targeted properties that focus plasminogen activation on the fibrin surface. Objective: We examined whether re-programming SK’s mechanism of action would create PAs with greater fibrin-targeting and potency than TPA. Methods and Results: When fibrinogen consumption was measured in human plasma, reprogrammed molecules SKΔ1 and SKΔ59 were 5-fold and > 119-fold more fibrin-dependent than SK (P < 0.0001), and 2-fold and > 50-fold more fibrin-dependent than TPA (P < 0.001). The marked fibrin-targeting of SKΔ59 was due to the fact that: (i) it did not generate plasmin in plasma, (ii) it was rapidly inhibited by α2-antiplasmin, and (iii) it only processed fibrin-bound plasminogen. To assess the fibrin-targeting and therapeutic potential of these PAs in vivo, a novel ‘humanized’ fibrinolysis model was created by reconstituting plasminogen-deficient mice with human plasminogen. When compared with TPA, SKΔ1 and SKΔ59 were 4-fold (P < 0.0001) and 2-fold (P < 0.003) more potent at dissolving blood clots in vivo, respectively, on a mass-dose basis and 2–3 logs more potent than TPA (P < 0.0001) when doses were calibrated by standard activity assays. Conclusion: These experiments suggest that reprogramming SK’s mechanism of action markedly enhances fibrin-targeting and creates, in comparison with TPA, activators with greater fibrinolytic potency. PMID:19566545

Reprogrammed streptokinases develop fibrin-targeting and dissolve blood clots with more potency than tissue plasminogen activator.

PubMed

Sazonova, I Y; McNamee, R A; Houng, A K; King, S M; Hedstrom, L; Reed, G L

2009-08-01

Given the worldwide epidemic of cardiovascular diseases, a more effective means of dissolving thrombi that cause heart attacks, could markedly reduce death, disability and healthcare costs. Plasminogen activators (PAs) such as streptokinase (SK) and tissue plasminogen activator (TPA) are currently used to dissolve fibrin thrombi. SK is cheaper and more widely available, but it appears less effective because it lacks TPA's fibrin-targeted properties that focus plasminogen activation on the fibrin surface. We examined whether re-programming SK's mechanism of action would create PAs with greater fibrin-targeting and potency than TPA. When fibrinogen consumption was measured in human plasma, reprogrammed molecules SKDelta1 and SKDelta59 were 5-fold and > 119-fold more fibrin-dependent than SK (P < 0.0001), and 2-fold and > 50-fold more fibrin-dependent than TPA (P < 0.001). The marked fibrin-targeting of SKDelta59 was due to the fact that: (i) it did not generate plasmin in plasma, (ii) it was rapidly inhibited by alpha2-antiplasmin, and (iii) it only processed fibrin-bound plasminogen. To assess the fibrin-targeting and therapeutic potential of these PAs in vivo, a novel 'humanized' fibrinolysis model was created by reconstituting plasminogen-deficient mice with human plasminogen. When compared with TPA, SKDelta1 and SKDelta59 were 4-fold (P < 0.0001) and 2-fold (P < 0.003) more potent at dissolving blood clots in vivo, respectively, on a mass-dose basis and 2-3 logs more potent than TPA (P < 0.0001) when doses were calibrated by standard activity assays. These experiments suggest that reprogramming SK's mechanism of action markedly enhances fibrin-targeting and creates, in comparison with TPA, activators with greater fibrinolytic potency.

Intravenous hemostats: challenges in translation to patients

NASA Astrophysics Data System (ADS)

Lashof-Sullivan, Margaret; Shoffstall, Andrew; Lavik, Erin

2013-10-01

Excessive bleeding and the resulting complications are a leading killer of young people globally. There are many successful methods to halt bleeding in the extremities, including compression, tourniquets, and dressings. However, current treatments for internal hemorrhage (including from head or truncal injuries), termed non-compressible bleeding, are inadequate. For these non-compressible injuries, blood transfusions are the current treatment standard. However, they must be refrigerated, may potentially transfer disease, and are of limited supply. In addition, time is of the essence for halting hemorrhage, since more than a third of civilian deaths due to hemorrhage from trauma occur before the patient even reaches the hospital. As a result, particles that can cross-link activated platelets through the glycoprotein IIb/IIIa receptor expressed on activated platelets are being investigated as an alternative treatment for non-compressible bleeding. Ideally, these particles would interact specifically with platelets to stabilize the platelet plug. Initial designs used biologically derived microparticles with red blood cell fragment or albumin cores decorated with RGD or fibrinogen, which bind to GPIIb/IIIa. More recently there has been research into the use of fully synthetic nanoparticles with liposomal or polymer cores that crosslink platelets through a targeting peptide bound to the surface. Some of the challenges for the development of these particles include appropriate sizing to prevent blocking the capillaries of the lungs, immune system evasion to prevent strong reactions and increase circulation time, and storage and resuspension so that first responders can easily use the particles. In addition, the effectiveness of the variety of animal bleeding models in predicting outcomes must be examined before test results can be fully understood. Progress has been made in the development of particles to combat hemorrhage, but issues of immune sensitivity and storage must be resolved before these types of particles can be translated for human use.

Influence of carbon source on cell surface topology of Thermomonospora curvata.

PubMed Central

Hostalka, F; Moultrie, A; Stutzenberger, F

1992-01-01

The appearance of cell surface protuberances in Thermomonospora curvata correlated with cell-bound exoenzymes which could be removed by brief sonication. Mycelia grown on cellulose or xylan had numerous protuberances and retained 20 to 25% of endoglucanase and endoxylanase at cell surfaces, while those grown on pectin or starch had few protuberances and negligible bound pectinase or amylase. Images PMID:1400256

Binding and orientation of fibronectin on polystyrene surfaces using immobilized bacterial adhesin-related peptides.

PubMed

Klueh, U; Bryers, J D; Kreutzer, D L

2003-10-01

Fibronectin (FN) is known to bind to bacteria via high affinity receptors on bacterial surfaces known as adhesins. The binding of bacteria to FN is thought to have a key role in foreign device associated infections. For example, previous studies have indicated that Staphylococcus aureus adhesins bind to the 29 kDa NH(3) terminus end of FN, and thereby promote bacteria adherence to surfaces. Recently, the peptide sequences within the S. aureus adhesin molecule that are responsible for FN binding have been identified. Based on these observations, we hypothesize that functional FN can be bound and specifically oriented on polystyrene surfaces using bacterial adhesin-related (BRP-A) peptide. We further hypothesize that monoclonal antibodies that react with specific epitopes on the FN can be used to quantify both FN binding and orientation on these surfaces. Based on this hypothesis, we initiated a systematic investigation of the binding and orientation of FN on polystyrene surfaces using BRP-A peptide. To test this hypothesis, the binding and orientation of the FN to immobilized BRP-A was quantified using (125)I-FN, and monoclonal antibodies. (125)I-FN was used to quantitate FN binding to peptide-coated polystyrene surfaces. The orientation of bound FN was demonstrated by the use of monoclonal antibodies, which are reactive with the amine (N) or carboxyl (C) termini of the FN. The results of our studies demonstrated that when the BRP-A peptide was used to bind FN to surfaces that: 1. functional FN was bound to the peptide; 2. anti-C terminus antibodies bound to the peptide FN; and 3. only limited binding of anti-N terminus antibodies to peptide-bound FN occurred. We believe that the data that indicate an enhanced binding of anti-C antibodies reactive to anti-N antibodies are a result of the FN binding in an oriented manner with the N termini of FN bound tightly to the BRP-A on the polystyrene surface. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 36-43, 2003

Fibrinogen Availability and Coagulation Function After Hemorrhage and Resuscitation in Pigs

DTIC Science & Technology

2011-08-01

Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to...that reduced clot formation rate and clot strength by ROTEM are indicative of transfusion re- quirements (14). The purpose of this study was to inves...administration and to reduce the usage of blood products (15,16). In this study, we observed a parallel changing pattern between fibrinogen concentration

Monoaminylation of Fibrinogen and Glia-Derived Proteins: Indication for Similar Mechanisms in Posttranslational Protein Modification in Blood and Brain.

PubMed

Hummerich, René; Costina, Victor; Findeisen, Peter; Schloss, Patrick

2015-07-15

Distinct proteins have been demonstrated to be posttranslationally modified by covalent transamidation of serotonin (5-hydropxytryptamin) to glutamine residues of the target proteins. This process is mediated by transglutaminase (TGase) and has been termed "serotonylation." It has also been shown that other biogenic amines, including the neurotransmitters dopamine and norepinephrine, can substitute for serotonin, implying a more general mechanism of "monoaminylation" for this kind of protein modification. Here we transamidated the autofluorescent monoamine monodansylcadaverine (MDC) to purified plasma fibrinogen and to proteins from a primary glia cell culture. Electrophoretic separation of MDC-conjugated proteins followed by mass spectrometry identified three fibrinogen subunits (Aα, Bβ, γ), a homomeric Aα2 dimer, and adducts of >250 kDa molecular weight, as well as several glial proteins. TGase-mediated MDC incorporation was strongly reduced by serotonin, underlining the general mechanism of monoaminylation.

Autotransfusion from experimental hemothorax: levels of coagulation factors.

PubMed

Napoli, V M; Symbas, P J; Vroon, D H; Symbas, P N

1987-03-01

The coagulation system was investigated in five dogs undergoing autotransfusion from experimental hemothorax. One fourth of the blood volume was bled into the pleural space, drained, and autotransfused. The hemothorax blood showed: very prolonged PT and PTT; very low platelets and fibrinogen; midly elevated FDP; very low coagulation factors VIII, and V; reduced XII, prothrombin, X, XI, and VII. Partial clotting, mild fibrinolysis, and fibrin deposition over the pulmonary pleura seemed to cause incoagulability of hemothorax blood. Post autotransfusion arterial blood showed: normal PT and PTT; 25% decrease in platelets, and 31% decrease in fibrinogen from baseline values. There was also an overall 20% reduction of fibrinogen from baseline values. There was also an overall 20% reduction of all clotting factors, but their levels remained above 50% activity. It was concluded that autotransfusion from a hemothorax of 25% the blood volume in dogs causes a mild loss of hemostatic components, but does not significantly compromise the clotting mechanism.

Inhibiting platelets aggregation could aggravate the acute infection caused by Staphylococcus aureus.

PubMed

Zhang, Xin; Liu, Yu; Gao, Yaping; Dong, Jie; Mu, Chunhua; Lu, Qiang; Shao, Ningsheng; Yang, Guang

2011-01-01

Several fibrinogen binding proteins (Fibs) play important roles in the pathogenesis of Staphylococcus aureus (S. aureus). Most Fibs can promote the aggregation of platelets during infection, but the extracellular fibrinogen-binding protein (Efb) is an exception. It is reported that Efb can specifically bind fibrinogen and inhibit the aggregation of platelet with its N terminal. However, the biological significance of platelet aggregation inhibition in the infection caused by S. aureus is unclear until now. Here, we demonstrated that the persistence and aggregation of platelets were important for killing S. aureus in whole blood. It was found that the N terminal of Efb (EfbN) and platelets inhibitors could increase the survival of S. aureus in whole blood. The study in vivo also showed that EfbN and platelets inhibitors could reduce the killing of S. aureus and increase the lethality rate of S. aureus in the acute infection mouse model.

Crystal structures of Bbp from Staphylococcus aureus reveal the ligand binding mechanism with Fibrinogen α.

PubMed

Zhang, Xinyue; Wu, Meng; Zhuo, Wei; Gu, Jinke; Zhang, Sensen; Ge, Jingpeng; Yang, Maojun

2015-10-01

Bone sialoprotein-binding protein (Bbp), a MSCRAMMs (Microbial Surface Components Recognizing Adhesive Matrix Molecules) family protein expressed on the surface of Staphylococcus aureus (S. aureus), mediates adherence to fibrinogen α (Fg α), a component in the extracellular matrix of the host cell and is important for infection and pathogenesis. In this study, we solved the crystal structures of apo-Bbp(273-598) and Bbp(273-598)-Fg α(561-575) complex at a resolution of 2.03 Å and 1.45 Å, respectively. Apo-Bbp(273-598) contained the ligand binding region N2 and N3 domains, both of which followed a DE variant IgG fold characterized by an additional D1 strand in N2 domain and D1' and D2' strands in N3 domain. The peptide mapped to the Fg α(561-575) bond to Bbp(273-598) on the open groove between the N2 and N3 domains. Strikingly, the disordered C-terminus in the apo-form reorganized into a highly-ordered loop and a β-strand G'' covering the ligand upon ligand binding. Bbp(Ala298-Gly301) in the N2 domain of the Bbp(273-598)-Fg α(561-575) complex, which is a loop in the apo-form, formed a short α-helix to interact tightly with the peptide. In addition, Bbp(Ser547-Gln561) in the N3 domain moved toward the binding groove to make contact directly with the peptide, while Bbp(Asp338-Gly355) and Bbp(Thr365-Tyr387) in N2 domain shifted their configurations to stabilize the reorganized C-terminus mainly through strong hydrogen bonds. Altogether, our results revealed the molecular basis for Bbp-ligand interaction and advanced our understanding of S. aureus infection process.

High shear induces platelet dysfunction leading to enhanced thrombotic propensity and diminished hemostatic capacity.

PubMed

Chen, Zengsheng; Mondal, Nandan K; Zheng, Shirong; Koenig, Steven C; Slaughter, Mark S; Griffith, Bartley P; Wu, Zhongjun J

2017-11-28

Thrombosis and bleeding are devastating adverse events in patients supported with blood-contacting medical devices (BCMDs). In this study, we delineated that high non-physiological shear stress (NPSS) caused platelet dysfunction that may contribute to both thrombosis and bleeding. Human blood was subjected to NPSS with short exposure time. Levels of platelet surface GPIbα and GPVI receptors as well as activation level of GPIIb/IIIa in NPSS-sheared blood were examined with flow cytometry. Adhesion of sheared platelets on fibrinogen, von Willibrand factor (VWF), and collagen was quantified with fluorescent microscopy. Ristocetin- and collagen-induced platelet aggregation was characterized by aggregometry. NPSS activated platelets in a shear and exposure time-dependent manner. The number of activated platelets increased with increasing levels of NPSS and exposure time, which corresponded well with increased adhesion of sheared platelets on fibrinogen. Concurrently, NPSS caused shedding of GPIbα and GPVI in a manner dependent on shear and exposure time. The loss of intact GPIbα and GPVI increased with increasing levels of NPSS and exposure time. The number of platelets adhered on VWF and collagen decreased with increasing levels of NPSS and exposure time, respectively. The decrease in the number of platelets adhered on VWF and collagen corresponded well with the loss in GPIbα and GPVI on platelet surface. Both ristocetin- and collagen-induced platelet aggregation in sheared blood decreased with increasing levels of NPSS and exposure time. The study clearly demonstrated that high NPSS causes simultaneous platelet activation and receptor shedding, resulting in a paradoxical effect on platelet function via two distinct mechanisms. The results from the study suggested that the NPSS could induce the concurrent propensity for both thrombosis and bleeding in patients.

Synthesis and surface properties of polyurethane end-capped with hybrid hydrocarbon/fluorocarbon double-chain phospholipid.

PubMed

Li, Jiehua; Zhang, Yi; Yang, Jian; Tan, Hong; Li, Jianshu; Fu, Qiang

2013-05-01

To improve hemocompatibility of biomedical polyurethanes (PUs), a series of new fluorinated phospholipid end-capped polyurethanes (FPCPUs) as blending PU additives were designed and synthesized using diphenyl methane diisocyanate and 1,4-butanediol as hard segment, poly(tetramethylene glycol), polypropylene glycol, polycarbonate diols, and polyethylene glycol as soft segments, respectively, aminofunctionalized hybrid hydrocarbon/fluorocarbon double-chain phospholipid as end-capper. The bulk structures and surface properties of the obtained FPCPUs were fully characterized by (1)H NMR, Fourier transform infrared, gel permeation chromatography, X-ray photoelectron spectroscopy, differential scanning calorimetry, atomic force microscopy, and water contact angle measurement. It was found that the phosphatidylcholine groups could enrich on the surfaces and subsurfaces with the help of the fluorocarbon chains and self-assemble into mimic biomembrane on these polymer surfaces. These surfaces could effectively suppress fibrinogen adsorption, as evaluated by enzyme-linked immunosorbent assay method. Our work indicates that the FPCPUs should be one of the most potential modified additives for enhancing hemocompatibility of traditional medical PUs. Copyright © 2012 Wiley Periodicals, Inc.

Enhancing the protein resistance of silicone via surface-restructuring PEO-silane amphiphiles with variable PEO length

PubMed Central

Rufin, M. A.; Gruetzner, J. A.; Hurley, M. J.; Hawkins, M. L.; Raymond, E. S.; Raymond, J. E.

2015-01-01

Silicones with superior protein resistance were produced by bulk-modification with poly(ethylene oxide) (PEO)-silane amphiphiles that demonstrated a higher capacity to restructure to the surface-water interface versus conventional non-amphiphilic PEO-silanes. The PEO-silane amphiphiles were prepared with a single siloxane tether length but variable PEO segment lengths: α-(EtO)3Si(CH2)2-oligodimethylsiloxane13-block-poly(ethylene oxide)n-OCH3 (n = 3, 8, and 16). Conventional PEO-silane analogues (n = 3, 8 and 16) as well as a siloxane tether-silane (i.e. no PEO segment) were prepared as controls. When surface-grafted onto silicon wafer, PEO-silane amphiphiles produced surfaces that were more hydrophobic and thus more adherent towards fibrinogen versus the corresponding PEO-silane. However, when blended into a silicone, PEO-silane amphiphiles exhibited rapid restructuring to the surface-water interface and excellent protein resistance whereas the PEO-silanes did not. Silicones modified with PEO-silane amphiphiles of PEO segment lengths n = 8 and 16 achieved the highest protein resistance. PMID:26339488

Modulation of Protein Fouling and Interfacial Properties at Carbon Surfaces via Immobilization of Glycans Using Aryldiazonium Chemistry

PubMed Central

Zen, Federico; Angione, M. Daniela; Behan, James A.; Cullen, Ronan J.; Duff, Thomas; Vasconcelos, Joana M.; Scanlan, Eoin M.; Colavita, Paula E.

2016-01-01

Carbon materials and nanomaterials are of great interest for biological applications such as implantable devices and nanoparticle vectors, however, to realize their potential it is critical to control formation and composition of the protein corona in biological media. In this work, protein adsorption studies were carried out at carbon surfaces functionalized with aryldiazonium layers bearing mono- and di-saccharide glycosides. Surface IR reflectance absorption spectroscopy and quartz crystal microbalance were used to study adsorption of albumin, lysozyme and fibrinogen. Protein adsorption was found to decrease by 30–90% with respect to bare carbon surfaces; notably, enhanced rejection was observed in the case of the tested di-saccharide vs. simple mono-saccharides for near-physiological protein concentration values. ζ-potential measurements revealed that aryldiazonium chemistry results in the immobilization of phenylglycosides without a change in surface charge density, which is known to be important for protein adsorption. Multisolvent contact angle measurements were used to calculate surface free energy and acid-base polar components of bare and modified surfaces based on the van Oss-Chaudhury-Good model: results indicate that protein resistance in these phenylglycoside layers correlates positively with wetting behavior and Lewis basicity. PMID:27108562

Modulation of Protein Fouling and Interfacial Properties at Carbon Surfaces via Immobilization of Glycans Using Aryldiazonium Chemistry

NASA Astrophysics Data System (ADS)

Zen, Federico; Angione, M. Daniela; Behan, James A.; Cullen, Ronan J.; Duff, Thomas; Vasconcelos, Joana M.; Scanlan, Eoin M.; Colavita, Paula E.

2016-04-01

Carbon materials and nanomaterials are of great interest for biological applications such as implantable devices and nanoparticle vectors, however, to realize their potential it is critical to control formation and composition of the protein corona in biological media. In this work, protein adsorption studies were carried out at carbon surfaces functionalized with aryldiazonium layers bearing mono- and di-saccharide glycosides. Surface IR reflectance absorption spectroscopy and quartz crystal microbalance were used to study adsorption of albumin, lysozyme and fibrinogen. Protein adsorption was found to decrease by 30-90% with respect to bare carbon surfaces; notably, enhanced rejection was observed in the case of the tested di-saccharide vs. simple mono-saccharides for near-physiological protein concentration values. ζ-potential measurements revealed that aryldiazonium chemistry results in the immobilization of phenylglycosides without a change in surface charge density, which is known to be important for protein adsorption. Multisolvent contact angle measurements were used to calculate surface free energy and acid-base polar components of bare and modified surfaces based on the van Oss-Chaudhury-Good model: results indicate that protein resistance in these phenylglycoside layers correlates positively with wetting behavior and Lewis basicity.

Kaolin-activated thromboelastography and standard coagulation assays in cyanotic and acyanotic infants undergoing complex cardiac surgery: a prospective cohort study.

PubMed

Rizza, Alessandra; Ricci, Zaccaria; Pezzella, Chiara; Favia, Isabella; Di Felice, Giovina; Ranucci, Marco; Cogo, Paola

2017-02-01

Several studies report the use of thromboelatography (TEG) to monitor coagulation in pediatric cardiac surgery. The aim of this study was to compare baseline and intraoperative TEG, TEG-functional fibrinogen, and standard coagulation assays in children with cyanotic and acyanotic congenital heart disease (CHD) undergoing cardiac surgery. This is a prospective observational study of 63 children aged <24 months undergoing cardiac surgery with cardiopulmonary bypass (CPB). Exclusion criteria included preoperative anticoagulant therapy and hepatic failure. We collected blood at anesthesia induction (T1), at lowest temperature after CPB start (T2), and after heparin neutralization (T3). Coagulation was evaluated by TEG (reaction time [R]), k, alpha-angle, maximum amplitude (MA), MA-fibrinogen (MA-fib), and by standard coagulation assays (prothrombin time, activated partial thromboplastin time, fibrinogen level, platelet [PLT] count). Sixty-three patients were enrolled (38 cyanotic and 25 acyanotic). Median age was 4 [IQR 2-6] months and median weight was 5 [IQR 3.7-6.5] kg. Most common surgeries were: ventricular septal defect repair (n = 13), Fallot correction (n = 11), and arterial switch operation (n = 10). Cyanotic and acyanotic children were well matched: R, k, MA, and MA-fib at T1, T2, and T3 were not significantly different between cyanotic and acyanotic children. At T2, significant correlations were showed between MA and PLT count (r = 0.4; P = 0.0008) and k and plasma fibrinogen level (r = -0.54; P < 0.0001). At T3, significant correlations were showed between MA and PLT count (r = 0.5; P < 0.0001), G and PLT count (r = 0.6; P < 0.0001), and MA-fib and plasma fibrinogen level (r = 0.5; P = 0.002). According to our findings, cyanosis does not affect TEG parameters in children with CHD. PLT count and plasma fibrinogen significantly correlated (are significantly associated) with MA and MA-fib respectively, suggesting that use of TEG after protamine administration may be prompted for improved hemostatic monitoring in the perioperative phase. © 2016 John Wiley & Sons Ltd.

C-reactive protein, fibrinogen, and cardiovascular disease prediction.

PubMed

Kaptoge, Stephen; Di Angelantonio, Emanuele; Pennells, Lisa; Wood, Angela M; White, Ian R; Gao, Pei; Walker, Matthew; Thompson, Alexander; Sarwar, Nadeem; Caslake, Muriel; Butterworth, Adam S; Amouyel, Philippe; Assmann, Gerd; Bakker, Stephan J L; Barr, Elizabeth L M; Barrett-Connor, Elizabeth; Benjamin, Emelia J; Björkelund, Cecilia; Brenner, Hermann; Brunner, Eric; Clarke, Robert; Cooper, Jackie A; Cremer, Peter; Cushman, Mary; Dagenais, Gilles R; D'Agostino, Ralph B; Dankner, Rachel; Davey-Smith, George; Deeg, Dorly; Dekker, Jacqueline M; Engström, Gunnar; Folsom, Aaron R; Fowkes, F Gerry R; Gallacher, John; Gaziano, J Michael; Giampaoli, Simona; Gillum, Richard F; Hofman, Albert; Howard, Barbara V; Ingelsson, Erik; Iso, Hiroyasu; Jørgensen, Torben; Kiechl, Stefan; Kitamura, Akihiko; Kiyohara, Yutaka; Koenig, Wolfgang; Kromhout, Daan; Kuller, Lewis H; Lawlor, Debbie A; Meade, Tom W; Nissinen, Aulikki; Nordestgaard, Børge G; Onat, Altan; Panagiotakos, Demosthenes B; Psaty, Bruce M; Rodriguez, Beatriz; Rosengren, Annika; Salomaa, Veikko; Kauhanen, Jussi; Salonen, Jukka T; Shaffer, Jonathan A; Shea, Steven; Ford, Ian; Stehouwer, Coen D A; Strandberg, Timo E; Tipping, Robert W; Tosetto, Alberto; Wassertheil-Smoller, Sylvia; Wennberg, Patrik; Westendorp, Rudi G; Whincup, Peter H; Wilhelmsen, Lars; Woodward, Mark; Lowe, Gordon D O; Wareham, Nicholas J; Khaw, Kay-Tee; Sattar, Naveed; Packard, Chris J; Gudnason, Vilmundur; Ridker, Paul M; Pepys, Mark B; Thompson, Simon G; Danesh, John

2012-10-04

There is debate about the value of assessing levels of C-reactive protein (CRP) and other biomarkers of inflammation for the prediction of first cardiovascular events. We analyzed data from 52 prospective studies that included 246,669 participants without a history of cardiovascular disease to investigate the value of adding CRP or fibrinogen levels to conventional risk factors for the prediction of cardiovascular risk. We calculated measures of discrimination and reclassification during follow-up and modeled the clinical implications of initiation of statin therapy after the assessment of CRP or fibrinogen. The addition of information on high-density lipoprotein cholesterol to a prognostic model for cardiovascular disease that included age, sex, smoking status, blood pressure, history of diabetes, and total cholesterol level increased the C-index, a measure of risk discrimination, by 0.0050. The further addition to this model of information on CRP or fibrinogen increased the C-index by 0.0039 and 0.0027, respectively (P<0.001), and yielded a net reclassification improvement of 1.52% and 0.83%, respectively, for the predicted 10-year risk categories of "low" (<10%), "intermediate" (10% to <20%), and "high" (≥20%) (P<0.02 for both comparisons). We estimated that among 100,000 adults 40 years of age or older, 15,025 persons would initially be classified as being at intermediate risk for a cardiovascular event if conventional risk factors alone were used to calculate risk. Assuming that statin therapy would be initiated in accordance with Adult Treatment Panel III guidelines (i.e., for persons with a predicted risk of ≥20% and for those with certain other risk factors, such as diabetes, irrespective of their 10-year predicted risk), additional targeted assessment of CRP or fibrinogen levels in the 13,199 remaining participants at intermediate risk could help prevent approximately 30 additional cardiovascular events over the course of 10 years. In a study of people without known cardiovascular disease, we estimated that under current treatment guidelines, assessment of the CRP or fibrinogen level in people at intermediate risk for a cardiovascular event could help prevent one additional event over a period of 10 years for every 400 to 500 people screened. (Funded by the British Heart Foundation and others.).

Effect of Tranexamic Acid on Blood Loss, D-Dimer, and Fibrinogen Kinetics in Adult Spinal Deformity Surgery.

PubMed

Pong, Ryan P; Leveque, Jean-Christophe A; Edwards, Alicia; Yanamadala, Vijay; Wright, Anna K; Herodes, Megan; Sethi, Rajiv K

2018-05-02

Antifibrinolytics such as tranexamic acid reduce operative blood loss and blood product transfusion requirements in patients undergoing surgical correction of scoliosis. The factors involved in the unrelenting coagulopathy seen in scoliosis surgery are not well understood. One potential contributor is activation of the fibrinolytic system during a surgical procedure, likely related to clot dissolution and consumption of fibrinogen. The addition of tranexamic acid during a surgical procedure may mitigate the coagulopathy by impeding the derangement in D-dimer and fibrinogen kinetics. We retrospectively studied consecutive patients who had undergone surgical correction of adult spinal deformity between January 2010 and July 2016 at our institution. Intraoperative hemostatic data, surgical time, estimated blood loss, and transfusion records were analyzed for patients before and after the addition of tranexamic acid to our protocol. Each patient who received tranexamic acid and met inclusion criteria was cohort-matched with a patient who underwent a surgical procedure without tranexamic acid administration. There were 17 patients in the tranexamic acid cohort, with a mean age of 60.7 years, and 17 patients in the control cohort, with a mean age of 60.9 years. Estimated blood loss (932 ± 539 mL compared with 1,800 ± 1,029 mL; p = 0.005) and packed red blood-cell transfusions (1.5 ± 1.6 units compared with 4.0 ± 2.1 units; p = 0.001) were significantly lower in the tranexamic acid cohort. In all single-stage surgical procedures that met inclusion criteria, the rise of D-dimer was attenuated from 8.3 ± 5.0 μg/mL in the control cohort to 3.3 ± 3.2 μg/mL for the tranexamic acid cohort (p < 0.001). The consumption of fibrinogen was 98.4 ± 42.6 mg/dL in the control cohort but was reduced in the tranexamic acid cohort to 60.6 ± 35.1 mg/dL (p = 0.004). In patients undergoing spinal surgery, intravenous administration of tranexamic acid is effective at reducing intraoperative blood loss. Monitoring of D-dimer and fibrinogen during spinal surgery suggests that tranexamic acid impedes the fibrinolytic pathway by decreasing consumption of fibrinogen and clot dissolution as evidenced by the reduced formation of D-dimer. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Pre-polishing on a CNC platform with bound abrasive contour tools

NASA Astrophysics Data System (ADS)

Schoeffer, Adrienne E.

2003-05-01

Deterministic micorgrinding (DMG) of optical glasses and ceramics is the commercial manufacturing process of choice to shape glass surfaces prior to final finishing. This process employs rigid bound matrix diamond tooling resulting in surface roughness values of 3-51.tm peak to valley and 100-400nm rms, as well as mid-spatial frequency tool marks that require subsequent removal in secondary finishing steps. The ability to pre-polish optical surfaces within the grinding platform would reduce final finishing process times. Bound abrasive contour wheels containing cerium oxide, alumina or zirconia abrasives were constructed with an epoxy matrix. The effects of abrasive type, composition, and erosion promoters were examined for tool hardness (Shore D), and tested with commercial optical glasses in an OptiproTM CNC grinding platform. Metrology protocols were developed to examine tool wear and subsequent surface roughness. Work is directed to demonstrating effective material removal, improved surface roughness and cutter mark removal.

Prepolishing on a CNC platform with bound abrasive contour tools

NASA Astrophysics Data System (ADS)

Schoeffler, Adrienne E.; Gregg, Leslie L.; Schoen, John M.; Fess, Edward M.; Hakiel, Michael; Jacobs, Stephen D.

2003-05-01

Deterministic microgrinding (DMG) of optical glasses and ceramics is the commercial manufacturing process of choice to shape glass surfaces prior to final finishing. This process employs rigid bound matrix diamond tooling resulting in surface roughness values of 3-5μm peak to valley and 100-400nm rms, as well as mid-spatial frequency tool marks that require subsequent removal in secondary finishing steps. The ability to pre-polish optical surfaces within the grinding platform would reduce final finishing process times. Bound abrasive contour wheels containing cerium oxide, alumina or zirconia abrasives were constructed with an epoxy matrix. The effects of abrasive type, composition, and erosion promoters were examined for tool hardness (Shore D), and tested with commercial optical glasses in an Optipro CNC grinding platform. Metrology protocols were developed to examine tool wear and subsequent surface roughness. Work is directed to demonstrating effective material removal, improved surface roughness and cutter mark removal.

Determination of molecular configuration by debye length modulation.

PubMed

Vacic, Aleksandar; Criscione, Jason M; Rajan, Nitin K; Stern, Eric; Fahmy, Tarek M; Reed, Mark A

2011-09-07

Silicon nanowire field effect transistors (FETs) have emerged as ultrasensitive, label-free biodetectors that operate by sensing bound surface charge. However, the ionic strength of the environment (i.e., the Debye length of the solution) dictates the effective magnitude of the surface charge. Here, we show that control of the Debye length determines the spatial extent of sensed bound surface charge on the sensor. We apply this technique to different methods of antibody immobilization, demonstrating different effective distances of induced charge from the sensor surface.

Electron-Transfer Kinetics of Redox Centers Anchored to Metal Surfaces: Weak- versus Strong-Overlap Reaction Pathways.

DTIC Science & Technology

1983-11-01

constants ket are presented for the one-electron electroreduction of various Co1]:I(NH3)5X complexes bound to mercury, platinum, and gold surfaces...electroreduction of various Co^^(NH𔃽)𔃿X complexes bound to mercury, platinum, and gold surfaces via either small inorganic or extended organic ligands X. t...platinum, gold , and copper, to enable values of ke* to be obtained for the one-electron reduction of the surface-Douna_redox center.2.3 These

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oyola-Reynoso, S.; Tevis, I. D.; Chen, J.

Here, chemical grafting has been widely used to modify the surface properties of materials, especially surface energy for controlled wetting, because of the resilience of such coatings/modifications. Reagents with multiple reactive sites have been used with the expectation that a monolayer will form. The step-growth polymerization mechanism, however, suggests the possibility of gel formation for hydrolyzable moieties in the presence of physisorbed water. In this report, we demonstrated that using alkyltrichlorosilanes (trivalent [i.e., 3 reactive sites]) in the surface modification of a cellulosic material (paper) does not yield a monolayer but rather gives surface-bound particles. We infer that the presencemore » of physisorbed (surface-bound) water allows for polymerization (or oligomerization) of the silane prior to its attachment on the surface. Surface energy mismatch between the hydrophobic tails of the growing polymer and any unreacted bound water leads to the assembly of the polymerizing material into spherical particles to minimize surface tension. By varying paper grammage (16.2–201.4 g m –2), we varied the accessible surface area and thus the amount of surface-adsorbed water, allowing us to control the ratio of the silane to the bound water. Using this approach, polymeric particles were formed on the surface of cellulose fibers ranging from ~70 nm to a film. The hydrophobicity of the surface, as determined by water contact angles, correlates with particle sizes (p < 0.001, Student's t-test), and, hence, the hydrophobicity can be tuned (contact angle between 94° and 149°). Using a model structure of a house, we demonstrated that as a result of this modification, paper-based houses can be rendered self-cleaning or tolerant to surface running water. In another application, we demonstrated that the felicitous choice of architectural design allows for the hydrophobic paper to be used for water harvesting.« less

Engineering tunable bio-inspired polymeric coatings for amphiphobic fibrous materials

NASA Astrophysics Data System (ADS)

Oyola-Reynoso, Stephanie

Chemical grafting has been widely used to modify the surface properties of materials, especially surface energy for controlled wetting, because of the resilience of such coatings/modifications. Reagents with multiple reactive sites have been used with the expectation that a monolayer will form. The step-growth polymerization mechanism, however, suggests the possibility of gel formation for hydrolysable moieties in the presence of physisorbed water. In the following chapters, we demonstrate that using alkyltrichlorosilanes (trivalent [3 reactive sites]) in the surface modification of a cellulosic material (paper) does not yield a monolayer but rather gives surface-bound polymeric particles. We infer that the presence of physisorbed (surface-bound) water allows for polymerization (or oligomerization) of the silane, prior to its attachment on the surface. Surface energy mismatch between the hydrophobic tails of the growing polymer and any unreacted bound water leads to the assembly of the polymerizing material into spherical particles to minimize surface tension. By varying paper grammage (16.2-201.4 g/m2), we varied the accessible surface area and thus the amount of surface-adsorbed water, allowing us to control the ratio of the silane to the bound water. Using this approach, polymeric particles were formed on the surface of cellulose fibers ranging from 70 nm to a film. The hydrophobicity of the surface, as determined by water contact angles, correlates with particle sizes (p < 0.001, Student t-test), and, hence, the hydrophobicity can be tuned (contact angle between 94° and 149°). Using a model structure of a house, we demonstrated that as a result of this modification, cardboard houses can be rendered self-cleaning or tolerant to surface running water. Each of the chapters below supports the mechanism via a series of applications, material characterization, and/or, smart engineering.

Novel Osteoinductive Photo-cross-linkable Chitosan-lactide-fibrinogen Hydrogels Enhance Bone Regeneration in Critical Size Segmental Bone Defects

DTIC Science & Technology

2014-08-01

an absorbable collagen sponge (ACS) is the FDA-approved device for clinical applications including lumbar spine fusion, open tibial fractures, and...fibrinogen on the morphological change of the CL hydrogels was observed. The hydrogel samples were incubated into PBS (pH 7.4) at 37°C for 1 day and... morphology was observed qualitatively using a Zeiss Axiovert 200 microscope (Carl Zeiss Microimaging, Thornwood, NY). Photomicrographs of cells

Role of Fibrinogen in Trauma Induced Coagulopathy

DTIC Science & Technology

2010-01-01

phenylalanine was infused for 6 h and d5- phenylalanine was infused for 4 h. Blood samples were obtained hourly during the infusion and the isotopic...erature was stabilized at 328C, 1-13C- phenylalanine and d5- phenylalanine were infused to quantify fibrinogen meta- bolism.23 Hypothermia of 328C...cases. Vox Sang 1982; 42: 113–23 7 Martini WZ, Chinkes DL , Pusateri AE et al. Acute changes in fibri- nogen metabolism and coagulation after

Prognostic significance of pretreatment plasma fibrinogen level in patients with digestive system tumors: a meta-analysis.

PubMed

Ji, Rui; Ren, Qian; Bai, Suyang; Wang, Yuping; Zhou, Yongning

2018-06-01

High pretreatment levels of plasma fibrinogen have been widely reported to be a potential predictor of prognosis in digestive system tumors; however, the conclusions are not consistent. Therefore, we performed a meta-analysis to comprehensively assess the prognostic roles of high pretreatment plasma fibrinogen levels in digestive system tumors. We searched for eligible studies in the PubMed, Embase, and Web of Science electronic databases for publications from the database inception to 1 September 2017. The endpoints of interest included overall survival, disease-free survival, and recurrence-free survival. We investigated the relationship between fibrinogenemia and overall survival in colorectal cancer (10 studies), gastric cancer (6), pancreatic cancer (6), hepatocellular carcinoma (7), and esophageal squamous cell carcinoma (10); the pooled results indicated that fibrinogenemia was significantly related to a worse overall survival (hazard ratio (HR) 1.73; 95% confidence interval (CI) 1.52, 1.97; P <0.001; HR 1.71; 95% CI 1.28, 2.28; P <0.001; HR 1.57; 95% CI 1.13, 2.17; P = 0.007; HR 1.89; 95% CI 1.57, 2.27; P <0.001, and HR 1.67; 95% CI 1.35, 2.07; P <0.001). Taken together, an increased pretreatment plasma fibrinogen level was related to worse survival in digestive system tumors, indicating that it could be a useful prognostic marker in these types of tumors.

Determining the relationship between atherosclerosis and periodontopathogenic microorganisms in chronic periodontitis patients.

PubMed

Bozoglan, Alihan; Ertugrul, Abdullah Seckin; Taspınar, Mehmet; Yuzbasioglu, Betul

2017-05-01

The aim of this study is to determine the relationship between atherosclerosis and periodontopathogenic microorganisms in chronic periodontitis patients following periodontal treatment. A total of 40 patients were included in the study. 20 of these patients diagnosed with atherosclerosis and chronic periodontitis formed the test group. The remaining 20 patients were systemically healthy patients diagnosed with chronic periodontitis and formed the control group. All patients had nonsurgical periodontal treatment. The periodontopathogenic microorganism levels were determined at baseline and at 6 months in microbial dental plaque samples and WBC, LDL, HDL, PLT, fibrinogen, creatinine and hs-CRP levels were determined by blood samples. Statistically significant reduction has been achieved in clinical periodontal parameters following non-surgical periodontal treatment in test and control groups. Following periodontal treatment, WBC, LDL, PLT, fibrinogen, creatinine and hs-CRP levels significantly decreased and HDL levels significantly increased in both test and control groups. Similarly, the periodontopathogenic microorganism levels significantly decreased following periodontal treatment in the test and control groups. A statistically significant positive correlation has been determined between the periodontopathogenic microorganism levels and WBC, LDL, PLT, fibrinogen, creatinine, and hs-CRP levels in the test group. The association between hs-CRP, WBC, LDL, PLT, fibrinogen, creatinine, and the amount of periodontopathogenic microorganisms indicates the possibility that periodontal treatment could decrease the risk atherosclerosis. More studies must be conducted in order for these results to be supported.

The Non-catalytic B Subunit of Coagulation Factor XIII Accelerates Fibrin Cross-linking*

PubMed Central

Souri, Masayoshi; Osaki, Tsukasa; Ichinose, Akitada

2015-01-01

Covalent cross-linking of fibrin chains is required for stable blood clot formation, which is catalyzed by coagulation factor XIII (FXIII), a proenzyme of plasma transglutaminase consisting of catalytic A (FXIII-A) and non-catalytic B subunits (FXIII-B). Herein, we demonstrate that FXIII-B accelerates fibrin cross-linking. Depletion of FXIII-B from normal plasma supplemented with a physiological level of recombinant FXIII-A resulted in delayed fibrin cross-linking, reduced incorporation of FXIII-A into fibrin clots, and impaired activation peptide cleavage by thrombin; the addition of recombinant FXIII-B restored normal fibrin cross-linking, FXIII-A incorporation into fibrin clots, and activation peptide cleavage by thrombin. Immunoprecipitation with an anti-fibrinogen antibody revealed an interaction between the FXIII heterotetramer and fibrinogen mediated by FXIII-B and not FXIII-A. FXIII-B probably binds the γ-chain of fibrinogen with its D-domain, which is near the fibrin polymerization pockets, and dissociates from fibrin during or after cross-linking between γ-chains. Thus, FXIII-B plays important roles in the formation of a ternary complex between proenzyme FXIII, prosubstrate fibrinogen, and activator thrombin. Accordingly, congenital or acquired FXIII-B deficiency may result in increased bleeding tendency through impaired fibrin stabilization due to decreased FXIII-A activation by thrombin and secondary FXIII-A deficiency arising from enhanced circulatory clearance. PMID:25809477

THE FLOCCULATION MAXIMUM (pH) OF FIBRINOGEN AND SOME OTHER BLOOD-CLOTTING REAGENTS. (RELATIVE TURBIDIMETRY WITH THE EVELYN PHOTOELECTRIC COLORIMETER)

PubMed Central

Ferguson, John H.

1942-01-01

By means of a novel adaptation of the Evelyn photoelectric colorimeter to the measurement of relative turbidities, the question of the flocculation maximum (F.M.) in acetate buffer solutions of varying pH and salt content has been studied on (a) an exceptionally stable prothrombin-free fibrinogen and its solutions after incipient thermal denaturation and incomplete tryptic proteolysis, (b) plasma, similarly treated, (c) prothrombin, thrombin, and (brain) thromboplastin solutions. All the fibrinogens show a remarkable uniformity of the precipitation pattern, viz. F.M. =4.7 (±0.2) pH in salt-containing buffer solutions and pH = 5.3 (±0.2) in salt-poor buffer (N/100 acetate). The latter approximates the isoelectric point (5.4) obtained by cataphoresis (14). There is no evidence that denaturation or digestion can produce any "second maximum." The data support the view that fibrin formation (under the specific influence of thrombin) is intrinsically unrelated to denaturation and digestion phenomena, although all three can proceed simultaneously in crude materials. A criticism is offered, therefore, of Wöhlisch's blood clotting theory. Further applications of the photoelectric colorimeter to coagulation problems are suggested, including kinetic study of fibrin formation and the assay of fibrinogen, with a possible sensitivity of 7.5 mg. protein in 100 cc. solution. PMID:19873299

Postauthorization safety study of Clottafact® , a triply secured fibrinogen concentrate in acquired fibrinogen deficiency: a prospective observational study.

PubMed

Négrier, C; Ducloy-Bouthors, A-S; Piriou, V; De Maistre, E; Stieltjes, N; Borel-Derlon, A; Colson, P; Picard, J; Lambert, T; Claeyssens, S; Boileau, S; Bertrand, A; André, M-H; Fourrier, F; Ozier, Y; Sié, P; Gruel, Y; Tellier, Z

2018-02-01

A postauthorization safety study was performed between 2009 and 2012 to describe the use of Clottafact ® in acquired fibrinogen deficiency in real-life medical practice in France. One hundred and fifty patients were planned for 28 days of prospective follow-up after infusion. The analysis of this observational study was descriptive and performed according to the type of treatment (curative or preventive) and the origin of the bleed. One hundred and fifty-six patients (16-87 years) were included in 13 centres and treated in five different medical bleeding situations: postpartum (59), other gynaecological/obstetrical (6), trauma (34), liver (13), cardiovascular (23) and other various bleeding situations (21). The mean follow-up time was 18·9 ± 12·3 days. Two patients presented adverse drug reactions: one a pulmonary embolism and the other a four-site venous thromboembolic episode. All were serious with a dubious causal relationship with the study treatment. Efficacy data were collected as a secondary objective. In 150 patients receiving curative treatment, 117 of 159 infusions (73·6%) were considered as successful by the investigators, 35 as moderate (22%) and seven as no response (4·4%). The Clottafact ® safety profile observed during the study matched the known profile of fibrinogen during use. © 2017 International Society of Blood Transfusion.

Metabolism, survival, and gene expression of Pseudomonas putida to hematite nanoparticles mediated by surface-bound humic acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouyang, Kai; Walker, Sharon L.; Yu, Xiao-Ying

Natural organic matter (NOM) is likely to coat naturally occurring nanoparticles (NNPs) in the soil environment and poses distinct effects on the interaction between NPs and soil microorganisms, however such topic has not been well investigated. This study explored the influence of nanoparticle surface-bound humic acid (HA, as a model NOM) on the toxicity of hematite NPs (i.e., nano-Fe2O3) to Pseudomonas putida (P. putida). Results showed that nano-Fe2O3 could inhibit the bacterial growth with an IC50 of 23.58 mg L-1, while nanoparticle surface-bound HA could significantly alleviate the P. putida toxicity of nano-Fe2O3. IC50 of nano-Fe2O3 increased to 4774.23 mgmore » L-1 as a result of surface-saturation by HA. Co-precipitation experiment and transmission electron microscopy observation revealed that nanoparticle surface-bound HA prevented the adhesion of nano-Fe2O3 to the cells as well as limited cell internalization of nanoparticles due to the increased electrostatic repulsion. The generation of intracellular reactive oxygen species (ROS) was significantly limited by the nanoparticle surface-bound HA. The prevention of adhesion and inhibition of ROS generation could account for the HA-mitigated nanotoxicity. Interfacial interactions between hematite NPs and cell membrane were also evaluated on the basis of the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory, and the magnitude of interaction energy barrier correlated well with the 48 h LC50 data of hematite NPs to P. putida. This result implies that metal oxide NPs with strong association with the cell surface might induce more severe cytotoxicity in microorganisms.« less

Impact of hydrophilic and hydrophobic functionalization of flat TiO2/Ti surfaces on proteins adsorption

NASA Astrophysics Data System (ADS)

Fabre, Héloïse; Mercier, Dimitri; Galtayries, Anouk; Portet, David; Delorme, Nicolas; Bardeau, Jean-François

2018-02-01

Controlling adsorption of proteins onto medical devices is a key issue for implant-related infections. As self-assembled monolayers (SAMs) on titanium oxide represent a good model to study the surface-protein interactions, TiO2 surface properties were modified by grafting bisphosphonate molecules terminated with hydrophilic poly(ethylene glycol) groups and hydrophobic perfluoropolyether ones, respectively. Characterisation of the surface chemistry and surface topography of the modified surfaces was performed using XPS and atomic force microscopy (AFM). Quartz-crystal microbalance with dissipation (QCM-D) was used to determine the mass of adsorbed proteins as well as its kinetics. Poly(ethylene glycol)-terminated SAMs were the most effective surfaces to limit the adsorption of both BSA and fibrinogen in comparison to perfluorinated-terminated SAMs and non-modified TiO2 surfaces, as expected. The adsorption was not reversible in the case of BSA, while a partial reversibility was observed with Fg, most probably due to multilayers of proteins. The grafted surfaces adsorbed about the same quantity of proteins in terms of molecules per surface area, most probably in monolayer or island-like groups of adsorbed proteins. The adsorption on pristine TiO2 reveals a more important, non-specific adsorption of proteins.

Characterization of a gene coding for a type IIo bacterial IgG-binding protein.

PubMed

Boyle, M D; Weber-Heynemann, J; Raeder, R; Podbielski, A

1995-06-01

Two antigenic classes of non-immune IgG-binding proteins can be expressed by group A streptococci. One antigenic group of proteins is recognized by an antibody prepared against the product of a cloned fcrA gene (anti-FcRA). In this study, the immunogen used to prepare the antibody that defines the second antigenic class was shown to be the product of the emm-like (emmL) gene of M serotype 55 group A isolate, A928. The emmL55 gene expressed in E. coli produced an M(r) approximately 58,000 molecule which bound human IgG1, IgG2, IgG3 and IgG4, as well as horse, rabbit and pig IgG in a non-immune fashion. These properties are characteristic of the previously described type IIo IgG-binding protein isolated from this strain. In addition, the recombinant protein was reactive with human serum albumin and fibrinogen. The emmL 55 gene sequence was analysed and found to have the organization and sequence characteristics of a typical class I emm-like gene.

Cell-derived microparticles and complement activation in preeclampsia versus normal pregnancy.

PubMed

Biró, E; Lok, C A R; Hack, C E; van der Post, J A M; Schaap, M C L; Sturk, A; Nieuwland, R

2007-01-01

Inflammation plays a major role in the vascular dysfunction seen in preeclampsia, and several studies suggest involvement of the complement system. To investigate whether complement activation on the surface of microparticles is increased in plasma of preeclamptic patients versus healthy pregnant controls. Microparticles from plasma of preeclamptic (n=10), healthy pregnant (n=10) and healthy nonpregnant (n=10) women were analyzed by flow cytometry for bound complement components (C1q, C4, C3) and complement activator molecules (C-reactive protein [CRP], serum amyloid P component [SAP], immunoglobulin [Ig]M, IgG). Fluid phase complement activation products and activator molecules were also determined. Levels of microparticles with bound complement components showed no increase in complement activation on the microparticle surface in preeclamptic women, in line with levels of fluid phase complement activation products. In healthy nonpregnant and pregnant women, bound CRP was associated with classical pathway activation on the microparticle surface, and in healthy pregnant women IgM and IgG molecules also contributed. In preeclamptic women, microparticles with bound SAP and those with IgG seemed to contribute to C1q binding without a clear association to further classical pathway activation. Furthermore, significantly increased levels of microparticles with bound CRP were present in preeclamptic compared with healthy pregnant women (median 178x10(6)/L versus 47x10(6)/L, P<0.01), but without concomitant increases in complement activation. We found no evidence of increased complement activation on the microparticle surface in preeclamptic women. Microparticles with bound CRP were significantly increased, but in contrast to healthy pregnant and nonpregnant women, this was not associated with increased classical pathway activation on the surface of the microparticles.

Statistical inference in single molecule measurements of protein adsorption

NASA Astrophysics Data System (ADS)

Armstrong, Megan J.; Tsitkov, Stanislav; Hess, Henry

2018-02-01

Significant effort has been invested into understanding the dynamics of protein adsorption on surfaces, in particular to predict protein behavior at the specialized surfaces of biomedical technologies like hydrogels, nanoparticles, and biosensors. Recently, the application of fluorescent single molecule imaging to this field has permitted the tracking of individual proteins and their stochastic contribution to the aggregate dynamics of adsorption. However, the interpretation of these results is complicated by (1) the finite time available to observe effectively infinite adsorption timescales and (2) the contribution of photobleaching kinetics to adsorption kinetics. Here, we perform a protein adsorption simulation to introduce specific survival analysis methods that overcome the first complication. Additionally, we collect single molecule residence time data from the adsorption of fibrinogen to glass and use survival analysis to distinguish photobleaching kinetics from protein adsorption kinetics.

Crosslinking by ligands to surface immunoglobulin triggers mobilization of intracellular 45Ca2+ in B lymphocytes

PubMed Central

1979-01-01

Detailed studies of steady-state ion fluxes in murine lymphocytes were used to examine for possible ionic changes generated by surface Ig, the antigen receptor of B lymphocytes. When bound by ligands, surface Ig triggered the mobilization and release of 45Ca2+ from the cell interior by a transmembrane process requiring crosslinking of the bound receptors. This ionic event was unique for two reasons: (a) it did not occur when other common lymphocyte surface macromolecules were bound with rabbit anti-lymphocyte antibodies; and (b) it was not accompanied by a general perturbation of lymphocyte ionic properties such as a change in 42K+ fluxes nor did it depend on the presence of extracellular ions. Capping of surface Ig shares the same time sequence, dose response, requirement for crosslinking, and lack of dependence on extracellular ions. These correlations suggest that mobilization of intracellular Ca2+ may represent an early ionic signal for the contractile activation of lymphocytes that generates capping of surface Ig. PMID:315942

Continuous hierarchical slope-aspect color display for parametric surfaces

NASA Technical Reports Server (NTRS)

Moellering, Harold J. (Inventor); Kimerling, A. Jon (Inventor)

1994-01-01

A method for generating an image of a parametric surface, such as the aspect of terrain which maximizes color contrast to permit easy discrimination of the magnitude, ranges, intervals or classes of a surface parameter while making it easy for the user to visualize the form of the surface, such as a landscape. The four pole colors of the opponent process color theory are utilized to represent intervals or classes at 90 degree angles. The color perceived as having maximum measured luminance is selected to portray the color having an azimuth of an assumed light source and the color showing minimum measured luminance portrays the diametrically opposite azimuth. The 90 degree intermediate azimuths are portrayed by unique colors of intermediate measured luminance, such as red and green. Colors between these four pole colors are used which are perceived as mixtures or combinations of their bounding colors and are arranged progressively between their bounding colors to have perceived proportional mixtures of the bounding colors which are proportional to the interval's angular distance from its bounding colors.

Lipid, lipoproteins, C-reactive protein, and hemostatic factors at baseline in the diabetes prevention program.

PubMed

2005-10-01

Individuals with impaired glucose tolerance (IGT) appear to be at increased risk for cardiovascular disease (CVD) due at least in part to an increased prevalence of risk factors. We evaluated lipid, lipoprotein, C-reactive protein (CRP), fibrinogen, and tissue plasminogen activator (tPA) levels at study entry in the largest multiethnic cohort of participants with IGT described, namely in the Diabetes Prevention Program (DPP). Measurements were performed at the baseline visit of 3,819 randomized participants of the DPP. Among 3,622 participants who were not taking lipid-lowering medicines, cardiovascular risk factors were analyzed in relation to demographic, anthropometric, and metabolic measures. Major determinants of risk factors were assessed in multivariate analysis. Over 40% of participants had elevated triglyceride, LDL cholesterol, and CRP levels and reduced HDL cholesterol levels. Men had higher triglyceride and tPA and lower HDL cholesterol concentrations and smaller LDL particle size than women, whereas women had higher CRP and fibrinogen levels. African Americans had less dyslipidemia but higher fibrinogen levels, and Asian Americans had lower CRP and fibrinogen levels than Caucasians and Hispanics. The surrogate measure of insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]) had the strongest association with HDL cholesterol, triglyceride, and tPA levels and LDL particle size. BMI had the greatest influence on CRP and fibrinogen levels. Using median splits of indexes of insulin resistance and insulin secretion (insulin-to-glucose ratio), participants with greater insulin resistance had a more adverse CVD risk-factor profile, whereas insulin secretion had little influence on risk factors. The pattern of CVD risk factors in participants with IGT in the DPP exhibits substantial heterogeneity and is significantly influenced by race, sex, and age, as well as by obesity, glucose, and insulin measures. The degree of insulin resistance, as reflected by HOMA-IR, showed the greatest association with the cardiovascular risk factors.

Lipid, Lipoproteins, C-Reactive Protein, and Hemostatic Factors at Baseline in the Diabetes Prevention Program

PubMed Central

2005-01-01

OBJECTIVE — Individuals with impaired glucose tolerance (IGT) appear to be at increased risk for cardiovascular disease (CVD) due at least in part to an increased prevalence of risk factors. We evaluated lipid, lipoprotein, C-reactive protein (CRP), fibrinogen, and tissue plasminogen activator (tPA) levels at study entry in the largest multiethnic cohort of participants with IGT described, namely in the Diabetes Prevention Program (DPP). RESEARCH DESIGN AND METHODS — Measurements were performed at the baseline visit of 3,819 randomized participants of the DPP. Among 3,622 participants who were not taking lipid-lowering medicines, cardiovascular risk factors were analyzed in relation to demographic, anthropometric, and metabolic measures. Major determinants of risk factors were assessed in multivariate analysis. RESULTS — Over 40% of participants had elevated triglyceride, LDL cholesterol, and CRP levels and reduced HDL cholesterol levels. Men had higher triglyceride and tPA and lower HDL cholesterol concentrations and smaller LDL particle size than women, whereas women had higher CRP and fibrinogen levels. African Americans had less dyslipidemia but higher fibrinogen levels, and Asian Americans had lower CRP and fibrinogen levels than Caucasians and Hispanics. The surrogate measure of insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]) had the strongest association with HDL cholesterol, triglyceride, and tPA levels and LDL particle size. BMI had the greatest influence on CRP and fibrinogen levels. Using median splits of indexes of insulin resistance and insulin secretion (insulin-to-glucose ratio), participants with greater insulin resistance had a more adverse CVD risk-factor profile, whereas insulin secretion had little influence on risk factors. CONCLUSIONS — The pattern of CVD risk factors in participants with IGT in the DPP exhibits substantial heterogeneity and is significantly influenced by race, sex, and age, as well as by obesity, glucose, and insulin measures. The degree of insulin resistance, as reflected by HOMA-IR, showed the greatest association with the cardiovascular risk factors. PMID:16186282

Impact on hepatic estrogen-sensitive proteins by a 1-year contraceptive vaginal ring delivering Nestorone® and ethinyl estradiol.

PubMed

Archer, D F; Thomas, M A; Conard, J; Merkatz, R B; Creasy, G W; Roberts, K; Plagianos, M; Blithe, D; Sitruk-Ware, R

2016-01-01

Estrogen-sensitive hepatic proteins were assessed in women using a contraceptive vaginal ring (CVR) delivering 150mcg Nestorone® (NES) and 15mcg ethinyl estradiol (EE). A substudy of the Contraceptive Clinical Trials Network of the National Institute of Child Health and Human Development enrolled 129 participants, with assessments of factor VIII, fibrinogen, protein S (PS) and sex hormone binding globulin (SHBG). Thirty-six participants had used combined hormonal contraceptives (CHCs) in the cycle preceding first CVR use (recent users) and 70 had no history of recent use (nonusers). Mean values at baseline were within the normal range for all four proteins but were higher for factor VIII, fibrinogen and SHBG and significantly lower for PS in recent compared to nonusers. During NES/EE CVR use, factor VIII, fibrinogen and PS were within the normal range; however, SHBG levels were increased by nearly 100% at Cycle 13. The change from baseline to final evaluation was statistically significant for all proteins in nonusers. The change in recent users was significant for factor VIII at Cycle 6 and for SHBG at Cycles 6 and 13, but not for PS or fibrinogen. NES/EE CVR for up to 13cycles was associated with changes from baseline in plasma levels of factor VIII, fibrinogen and PS that were within the normal range, with SHBG levels above the normal range by Cycle 6. Nonusers of CHC before CVR showed wider changes in values versus recent users whose baseline values were increased by previous EE exposure. Recent use of CHCs demonstrated significant changes in all four measured hepatic proteins at baseline compared to nonusers. Use of the NES/EE CVR further changed these hepatic protein markers, but values remained within the normal range. Prebaseline exposure to estrogen can obscure interpretation of hepatic proteins changes associated with a second CHC. Copyright © 2016 Elsevier Inc. All rights reserved.

Haemostatic alterations in a group of canine cancer patients are associated with cancer type and disease progression

PubMed Central

2012-01-01

Background Haemostatic alterations are commonly detected in human and canine cancer patients. Previous studies have described haemostatic dysfunction in canine patients with haemangiosarcomas and carcinomas, and haemostasis has been assessed in dogs with various malignant and benign neoplasias. Few studies have addressed the effect of cancer type and progression of disease on the presence of haemostatic alterations in canine patients. The objective of the present study was to evaluate haemostatic variables of coagulation and fibrinolysis in a group of canine cancer patients, and to compare haemostatic changes to the cancer type and progression of disease. Methods The study population consisted of 71 dogs with malignant neoplasia presented to the University Hospital for Companion Animals, Faculty of Life Sciences, University of Copenhagen, Denmark. The study was designed as a prospective observational study evaluating the haemostatic function in canine cancer patients stratified according to type of cancer disease and disease progression. The coagulation response was evaluated by thromboelastrography (TEG), platelet count, activated partial thromboplastin time (aPTT), prothombin time (PT), fibrinogen and antithrombin (AT); and fibrinolysis by d-dimer and plasminogen. Results Hypercoagulability was the most common haemostatic dysfunction found. Non mammary carcinomas had increased clot strength (TEG G), aPTT and fibrinogen compared to the other groups. When stratifying the patients according to disease progression dogs with distant metastatic disease exhibited significantly increased fibrinogen, and d-dimer compared to dogs with local invasive and local non-invasive cancers. Conclusion Hypercoagulability was confirmed as the most common haemostatic abnormality in canine cancer patients and haemostatic dysfunction in canine cancer patients was found related to the cancer type and progression of disease. Increase in TEG G, aPTT and fibrinogen were observed in non-mammary carcinomas and were speculated to overall represent a proinflammatory response associated with the disease. Dogs with distant metastatic disease exhibited increased fibrinogen and d-dimer. Future studies are needed to elucidate the clinical importance of these results. PMID:22280938

Synergistic effect of signaling from receptors of soluble platelet agonists and outside-in signaling in formation of a stable fibrinogen-integrin αIIbβ3-actin cytoskeleton complex.

PubMed

Budnik, Ivan; Shenkman, Boris; Savion, Naphtali

2015-01-01

Thrombus formation in the injured vessel wall is a highly complex process involving various blood-born components that go through specific temporal and spatial changes as observed by intravital videomicroscopy. Platelets bind transiently to the developing thrombus and may either become stably incorporated into or disengage from the thrombus. The aim of the present study was to reveal the processes involved in the formation of a stable thrombus. Platelet-rich plasma and washed platelets were studied by the aggregometer. The aggregate stability was challenged by eptifibatide. Platelet Triton-insoluble fraction was prepared and the actin and αIIb content in the cytoskeleton was analyzed by western blot. Maximal actin polymerization is achieved 1min after platelet activation while maximal αIIbβ3-actin cytoskeleton association requires 5 to 10min of activation and fibrinogen-mediated platelet-to-platelet bridging. Thus, actin polymerization is dependent on platelet activation and requires neither αIIbβ3 integrin occupation nor platelet aggregation. Formation of a stable aggregate requires platelet activation for more than 1min, complete increase in actin cytoskeleton fraction and partial association of αIIbβ3 with the actin cytoskeleton. However, direct αIIbβ3 activation is not sufficient for cytoskeleton complex formation. Thus, stable αIIbβ3-fibrinogen interaction, representing stable aggregate, is achieved after more than 1min agonist activation, involving inside-out and outside-in signaling but not after direct integrin activation, involving only outside-in signaling. Formation of a stable fibrinogen-αIIbβ3-actin cytoskeleton complex is the result of the combined effect of platelet stimulation by soluble agonists, activation of αIIbβ3, fibrinogen binding and platelet-to-platelet bridging. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of intraoperative factor concentrates on blood product transfusions during orthotopic liver transplantation.

PubMed

Colavecchia, A Carmine; Cohen, David A; Harris, Jesse E; Thomas, Jeena M; Lindberg, Scott; Leveque, Christopher; Salazar, Eric

2017-12-01

Major bleeding in orthotopic liver transplantation is associated with significant morbidity and mortality. Limited literature exists regarding comparative effectiveness of prothrombin complex concentrate and fibrinogen concentrate during orthotopic liver transplantation on blood product utilization. This retrospective, single-institution study evaluated the impact of prothrombin complex concentrate and fibrinogen concentrate on blood product utilization during orthotopic liver transplantation from December 2013 to April 2016. This study included patients age 18 years or older and excluded patients who received simultaneous heart or lung transplantation or did not meet documentation criteria. A propensity score matching technique was used to match patients who were exposed to prothrombin complex concentrate with unexposed patients, at a 2 to 1 ratio, to control for selection bias. During this study, 212 patients received orthotopic liver transplantation with 39 prothrombin complex concentrate exposures. The matched study population included 39 patients who were exposed to prothrombin complex concentrate and 78 unexposed patients. Overall, 84.6% of patients who were exposed to prothrombin complex concentrate also received concomitant fibrinogen concentrate, whereas only 2% of patients in the control group received fibrinogen concentrate. After propensity score matching, no other factors that were included in the model differed significantly or had a standardized mean difference of 0.11 or greater. There was no statistical difference in the utilization of red blood cells or fresh frozen plasma for the exposed group versus the unexposed group after matching (mean ± standard deviation: red blood cell units, 12.4 ± 8.0 units vs. 9.7 ± 5.6 units [p = 0.058]; fresh-frozen plasma units, 10.0 ± 6.3 vs. 12.7 ± 9.7 units [p = 0.119], respectively). The intraoperative use of prothrombin complex concentrate and fibrinogen concentrate during orthotopic liver transplantation did not reduce intraoperative blood product requirements at a single institution. © 2017 AABB.

Clot formation is associated with fibrinogen and platelet forces in a cohort of severely-injured Emergency Department trauma patients

PubMed Central

White, Nathan J.; Newton, Jason C.; Martin, Erika J.; Mohammed, Bassem M.; Contaifer, Daniel; Bostic, Jessica L.; Brophy, Gretchen M.; Spiess, Bruce D.; Pusateri, Anthony E.; Ward, Kevin R.; Brophy, Donald F.

2015-01-01

Introduction Anticoagulation, fibrinogen consumption, fibrinolytic activation, and platelet dysfunction all interact to produce different clot formation responses after trauma. However, the relative contributions of these coagulation components to overall clot formation remains poorly defined. We examined for sources of heterogeneity in clot formation responses after trauma. Methods Blood was sampled in the Emergency Department from patients meeting trauma team activation criteria at an urban trauma center. Plasma prothrombin time (PT) ≥ 18 sec was used to define traumatic coagulopathy. Mean kaolin-activated thrombelastography (TEG) parameters were calculated and tested for heterogeneity using Analysis of Means (ANOM). Discriminant analysis and forward stepwise variable selection with linear regression were used to determine if PT, fibrinogen, platelet contractile force (PCF), and D-Dimer concentration, representing key mechanistic components of coagulopathy, each contribute to heterogeneous TEG responses after trauma. Results Of 95 subjects, 16% met criteria for coagulopathy. Coagulopathic subjects were more severely injured with greater shock, and received more blood products in the first 8 hours compared to non-coagulopathic subjects. Mean (SD) TEG maximal amplitude (MA) was significantly decreased in the coagulopathic group=57.5 (4.7) mm, vs. 62.7 (4.7), T test p<0.001. The MA also exceeded the ANOM predicted upper decision limit for the non-coagulopathic group and the lower decision limit for the coagulopathic group at alpha=0.05, suggesting significant heterogeneity from the overall cohort mean. Fibrinogen and PCF best discriminated TEG MA using discriminant analysis. Fibrinogen, PCF, and D-Dimer were primary covariates for TEG MA using regression analysis. Conclusion Heterogeneity in TEG-based clot formation in Emergency Department trauma patients was linked to changes in MA. Individual parameters representing fibrin polymerization, platelet contractile forces, and fibrinolysis were primarily associated with TEG MA after trauma and should be the focus of early hemostatic therapies. PMID:25643013

The Interaction of Integrin αIIbβ3 with Fibrin Occurs through Multiple Binding Sites in the αIIb β-Propeller Domain*

PubMed Central

Podolnikova, Nataly P.; Yakovlev, Sergiy; Yakubenko, Valentin P.; Wang, Xu; Gorkun, Oleg V.; Ugarova, Tatiana P.

2014-01-01

The currently available antithrombotic agents target the interaction of platelet integrin αIIbβ3 (GPIIb-IIIa) with fibrinogen during platelet aggregation. Platelets also bind fibrin formed early during thrombus growth. It was proposed that inhibition of platelet-fibrin interactions may be a necessary and important property of αIIbβ3 antagonists; however, the mechanisms by which αIIbβ3 binds fibrin are uncertain. We have previously identified the γ370–381 sequence (P3) in the γC domain of fibrinogen as the fibrin-specific binding site for αIIbβ3 involved in platelet adhesion and platelet-mediated fibrin clot retraction. In the present study, we have demonstrated that P3 can bind to several discontinuous segments within the αIIb β-propeller domain of αIIbβ3 enriched with negatively charged and aromatic residues. By screening peptide libraries spanning the sequence of the αIIb β-propeller, several sequences were identified as candidate contact sites for P3. Synthetic peptides duplicating these segments inhibited platelet adhesion and clot retraction but not platelet aggregation, supporting the role of these regions in fibrin recognition. Mutant αIIbβ3 receptors in which residues identified as critical for P3 binding were substituted for homologous residues in the I-less integrin αMβ2 exhibited reduced cell adhesion and clot retraction. These residues are different from those that are involved in the coordination of the fibrinogen γ404–411 sequence and from auxiliary sites implicated in binding of soluble fibrinogen. These results map the binding of fibrin to multiple sites in the αIIb β-propeller and further indicate that recognition specificity of αIIbβ3 for fibrin differs from that for soluble fibrinogen. PMID:24338009

Adhesion of normal erythrocytes at depressed venous shear rates to activated neutrophils, activated platelets, and fibrin polymerized from plasma.

PubMed

Goel, Mukul S; Diamond, Scott L

2002-11-15

Deep vein thrombosis (DVT) is a low flow pathology often prevented by vascular compression to increase blood movement. We report new heterotypic adhesive interactions of normal erythrocytes operative at low wall shear rates (gamma(w)) below 100 s(-1). Adhesion at gamma(w) = 50 s(-1) of washed red blood cells (RBCs) to fibrinogen-adherent platelets was 4-fold less (P <.005) than to collagen-adherent platelets (279 +/- 105 RBC/mm(2)). This glycoprotein VI (GPVI)-triggered adhesion was antagonized (> 80% reduction) by soluble fibrinogen (3 mg/mL) and ethylenediaminetetraacetic acid (EDTA). RBC-platelet adhesion was reduced in half by antibodies against CD36 or GPIb, but not by antibodies against GPIIb/IIIa, von Willebrand factor (VWF), thrombospondin (TSP), P-selectin, beta(1), alpha(v), or CD47. Adhesion of washed RBCs to fibrinogen-adherent neutrophils was increased 6-fold in the presence of 20 microM N-formyl-Met-Leu-Phe to a level of 67 RBCs per 100 neutrophils after 5 minutes at 50 s(-1). RBC-neutrophil adhesion was diminished by anti-CD11b (76%), anti-RBC Landsteiner-Wiener (LW) (ICAM4; 40%), or by EDTA (> 80%), but not by soluble fibrinogen or antibodies against CD11a, CD11c, CD36, TSP, beta(1), alpha(v), or CD47. RBC adhesion to activated platelets and activated neutrophils was prevented by wall shear stress above 1 dyne/cm(2) (at 100 s(-1)). Whereas washed RBCs did not adhere to fibrin formed from purified fibrinogen, adhesion was marked when pure fibrin was precoated with TSP or when RBCs were perfused over fibrin formed from recalcified plasma. Endothelial activation and unusually low flow may be a setting prone to receptor-mediated RBC adhesion to adherent neutrophils (or platelets/fibrin), all of which may contribute to DVT.

Biological risk factors for deep vein trombosis.

PubMed

Vayá, Amparo; Mira, Yolanda; Martínez, Marcial; Villa, Piedad; Ferrando, Fernando; Estellés, Amparo; Corella, Dolores; Aznar, Justo

2002-01-01

Hypercoagulable states due either to inherited or acquired thrombotic risk factors are only present in approximately half of cases of DVT, but the causes in the other half, remain unknown. The importance of biological risk factors such as hyperlipidemia, hypofibrinolysis and hemorheological alterations in the pathogenesis of DVT has not been well established. In order to ascertain whether the above mentioned biological factors are associated with DVT and could constitute independent risk factors, we carried out a case-control study in 109 first DVT patients in whom inherited or acquired thrombophilic risk factors had been ruled out and 121 healthy controls age (42+/-15 years) and sex matched. From all the biological variables analyzed (cholesterol, triglycerides, glucose, fibrinogen, erythrocyte aggregation, hematocrit, plasma viscosity and PAI-1) only fibrinogen concentration reached a statistically significant difference on the comparison of means (290+/-73 mg/dl in cases vs 268+/-58 mg/dl in controls, p<0.05). After this continuous variables were dichotomized according to our reference values, the percentage of cases with cholesterolemia >220 mg/dl, hematocrit >45% and fibrinogen >300 mg/dl was higher in cases than in controls: 38% vs 22%; p<0.01; 43% vs 27%; p<0.05; 36% vs 23%; p<0.05, respectively. The percentage of cases with PAI-1 values >30 ng/ml, 37% vs 25% was borderline significant; p=0.055. Multivariate logistic regression analysis showed that cholesterolemia >220 mg/dl and fibrinogen >300 mg/dl constitute independent predictors of venous thrombotic risk. The adjusted OR's were 2.03 (95% CI; 1.12-3.70) for cholesterolemia and 1.94 (95% CI; 1.07-3.55) for fibrinogen. When these two variables combined DVT risk rose about fourfold (3.96; p<0.05). Our results suggest that hypercholesterolemia and hyperfibrinogenemia should be added to the list of known DVT risk factors and we recommend adopting measures to decrease these variables in the population with a high risk of DVT.

High sensitivity C reactive protein, fibrinogen levels and the onset of major depressive disorder in post-acute coronary syndrome.

PubMed

Lafitte, Marianne; Tastet, Sandrine; Perez, Paul; Serisé, Marie-Aimée; Grandoulier, Anne-Sophie; Aouizerate, Bruno; Sibon, Igor; Capuron, Lucile; Couffinhal, Thierry

2015-03-18

Major depression disorder (MDD) is a common condition in patients suffering from acute coronary syndrome (ACS), and depression is a risk factor for mortality following an ACS. Growing evidence suggests that there is an intricate interplay between atherosclerosis, inflammation and depression. The aim of this study was to investigate the role of atherosclerosis-induced inflammation in the mediation of MDD. 87 patients without depression were recruited at the time of an ACS, evaluated at 3 and 7 days and followed at 1, 3 and 9 months for the occurrence of a MDD as assessed by structured interviews (MINI). At each time point, they were monitored for inflammatory markers (high sensitivity C Reactive Protein {hsCRP} and fibrinogen), cardiovascular risk factors and atherosclerosis burden. Association between possible predictive characteristics and depression was assessed using a multivariable logistic regression model. The overall incidence of MDD, in this population, was 28.7% [95% CI: 19.5 - 39.4] during the 9-month follow up period. Elevated hsCRP was not associated with depression onset after an ACS (adjusted OR: 1.07 [0.77 - 1.48]; p = 0.70), and similarly no association was found with fibrinogen. Furthermore, we found no association between hsCRP, fibrinogen or atherosclerosis burden at any time-point, and the occurrence of a MDD (or HDRS-17 and MADRS). The only factor associated with depression occurrence after an ACS was a previous personal history of depression (adjusted OR: 11.02 [2.74 to 44.34]; p = 0.0007). The present study shows that after an ACS, patients treated with optimal medications could have a MDD independent of elevated hsCRP or fibrinogen levels. Personal history of depression may be a good marker to select patients who should be screened for depression after an ACS.

Effect of losartan versus candesartan on uric acid, renal function, and fibrinogen in patients with hypertension and hyperuricemia associated with diuretics.

PubMed

Rayner, Brian L; Trinder, Yvonne A; Baines, Donette; Isaacs, Sedick; Opie, Lionel H

2006-02-01

Hyperuricemia may counter benefits of blood pressure (BP) reduction, although this is controversial. We examined the effects of candesartan and losartan on uric acid, creatinine, and fibrinogen. Patients with hypertension and serum uric acid > or = 0.42 mmol/L (7 mg/dL) associated with diuretics were randomized to receive losartan 50 to 100 mg or candesartan 8 to 16 mg for 24 weeks. At randomization and after 24 weeks, systolic and diastolic BP, serum uric acid, creatinine, and fibrinogen were measured. A total of 59 patients were entered into the study (30 in the losartan and 29 in the candesartan group). Mean systolic and diastolic BP were reduced in the candesartan group, from 156 mm Hg at baseline to 132 mm Hg at 24 weeks, and from 90.9 to 80.8 mm Hg respectively, P < .0001), and in the losartan group from 150.3 to 132 mm Hg and from 89.6 to 77.6 respectively, P < 0001). Overall mean values of fibrinogen levels were again reduced from 4.39 g/L at baseline to 4.01 g/L at 24 weeks (P < .02). Mean values of serum uric acid in the losartan and candesartan groups were similar at baseline (0.44 and 0.46 mmol/L, respectively), but they were lower in the losartan group after 24 weeks (0.39 and 0.48 mmol/L, P = .01). Twelve patients (44%) in the candesartan group had a 10% increase in serum creatinine compared with four patients (14.2%) in the losartan group (P < .02). Candesartan and losartan lowered BP, but only losartan reduced uric acid. The lowering of fibrinogen in both groups may explain the reduction in stroke with angiotensin receptor blockers. The effect of persistent hyperuricemia on renal function requires further study.

Maternal allergy is associated with surface-bound IgE on cord blood basophils.

PubMed

Matson, Adam P; Cloutier, Michelle M; Dhongade, Ashish; Puddington, Lynn; Rafti, Ektor

2013-09-01

The cell type(s) mediating the maternal influence on allergic disease in children remain unclear. We set out to define the relationship between maternal allergy and frequencies of cord blood (CB) basophils, and plasmacytoid dendritic cells (pDCs); to characterize surface-bound IgE and FcεRI expressions on these cells; and to investigate the association between maternal and CB serum IgE levels with surface-bound IgE and FcεRI expressions. One hundred and three mother/infant dyads were recruited prenatally, and maternal allergic history was recorded. Maternal blood was collected prior to delivery, and CB was collected after birth. Flow cytometry was used to identify CB basophils and pDCs and to determine surface-bound IgE and FcεRI expressions. Frequencies of CB basophils and pDCs were low and not related to maternal history of allergy. Percentages of CB basophils with surface-bound IgE were significantly higher in infants of allergic mothers compared with infants of non-allergic mothers (median, 59.60% vs. 19.70%, p = 0.01). IgE on CB basophils correlated with CB IgE levels (r = 0.72, p < 0.0001), but not with maternal IgE levels (r = 0.26, p = 0.06). IgE on CB pDCs was low and not significantly associated with maternal or CB IgE levels. Similarly, FcεRI expression by CB basophils and pDCs was not significantly associated with maternal or CB IgE levels. Frequencies of CB basophils and pDCs are not influenced by maternal allergy. CB basophils and pDCs have surface-bound IgE and express FcεRI; however, only IgE on CB basophils appears influenced by maternal allergy. © 2013 The Authors. Pediatric Allergy and Immunology published by John Wiley & Sons Ltd.

Feasibility of Standardizing Automated Laboratory Analyzers On-Board U.S. Naval Ships

DTIC Science & Technology

1999-12-01

K), Chloride (Cl), Carbon Dioxide (C02) Fecal Leukocytes Feces for Ova, Cysts and Parasites Glucose Hematocrit Occult Blood Partial...Culture, Wound Culture, Throat Electrolytes (NA, K, Cl, C02) Fecal Leukocytes Feces for Ova, Cysts and Parasites Fibrinogen and FSP Gonorrhea...0.00 Drug screen, urine 0 0.00 0 0.00 Electrolytes 18 4.83 202 11.66 Fecal leukocytes 6 1.61 5 0.29 Fibrinogen/FSP 0 0.00 4 .023 GC

Studies of the Effects of Perfluorocarbon Emulsions on Platelet Number and Function in Models of Critical Battlefield Injury

DTIC Science & Technology

2014-01-01

br in og en Time Fibrinogen Assay after Intravenous  Perfluorocarbon  Infusion Oxygent Hespan Control 3. Fibrinogen measurement ...1 Award Number: W81XWH-13-1-0017 TITLE: Studies of the Effects of Perfluorocarbon Emulsions on Platelet Number and Function...of Perfluorocarbon Emulsions on Platelet 5b. GRANT NUMBER W81XWH-13-1-0017 Number and Function in Models of Critical Battlefield Injury 5c

Coagulopathy by Hypothermia and Acidosis: Mechanisms of Thrombin Generation and Fibrinogen Availability

DTIC Science & Technology

2009-07-01

lowered to 32°C and stabilized, stable iso- tope 1-13C- phenylalanine was infused for 6 hours and d5- phenylalanine was infused for 4 hours to investigate... phenylalanine (for 6 hours) and d5- phenylalanine (for 4 hours) was performed to inves- tigate changes in fibrinogen metabolism. Blood samples were...Sirchia G. Hemostasis testing during massive blood replacement. A study of 172 cases. Vox Sang. 1982;42: 113–123. 28. Martini WZ, Chinkes DL , Pusateri AE

Oxygen-implanted induced formation of oxide layer enhances blood compatibility on titanium for biomedical applications.

PubMed

Hung, Wei-Chiang; Chang, Fang-Mo; Yang, Tzu-Sen; Ou, Keng-Liang; Lin, Che-Tong; Peng, Pei-Wen

2016-11-01

Titanium dioxide (TiO2) layers were prepared on a Ti substrate by using oxygen plasma immersion ion implantation (oxygen PIII). The surface chemical states, structure, and morphology of the layers were studied using X-ray photoelectron spectroscopy, X-ray diffraction, Raman microscopy, atomic force microscopy and scanning electron microscope. The mechanical properties, such as the Young's modulus and hardness, of the layers were investigated using nanoindentation testing. The Ti(4+) chemical state was determined to be present on oxygen-PIII-treated surfaces, which consisted of nanocrystalline TiO2 with a rutile structure. Compared with Ti substrates, the oxygen-PIII-treated surfaces exhibited decreased Young's moduli and hardness. Parameters indicating the blood compatibility of the oxygen-PIII-treated surfaces, including the clotting time and platelet adhesion and activation, were studied in vitro. Clotting time assays indicated that the clotting time of oxygen-PIII-treated surfaces was longer than that of the Ti substrate, which was associated with decreased fibrinogen adsorption. In conclusion, the surface characteristics and the blood compatibility of Ti implants can be modified and improved using oxygen PIII. Copyright © 2016 Elsevier B.V. All rights reserved.

Cigarette smoke induces β2-integrin-dependent neutrophil migration across human endothelium

PubMed Central

2011-01-01

Background Cigarette smoking induces peripheral inflammatory responses in all smokers and is the major risk factor for neutrophilic lung disease such as chronic obstructive pulmonary disease. The aim of this study was to investigate the effect of cigarette smoke on neutrophil migration and on β2-integrin activation and function in neutrophilic transmigration through endothelium. Methods and results Utilizing freshly isolated human PMNs, the effect of cigarette smoke on migration and β2-integrin activation and function in neutrophilic transmigration was studied. In this report, we demonstrated that cigarette smoke extract (CSE) dose dependently induced migration of neutrophils in vitro. Moreover, CSE promoted neutrophil adherence to fibrinogen. Using functional blocking antibodies against CD11b and CD18, it was demonstrated that Mac-1 (CD11b/CD18) is responsible for the cigarette smoke-induced firm adhesion of neutrophils to fibrinogen. Furthermore, neutrophils transmigrated through endothelium by cigarette smoke due to the activation of β2-integrins, since pre-incubation of neutrophils with functional blocking antibodies against CD11b and CD18 attenuated this transmigration. Conclusion This is the first study to describe that cigarette smoke extract induces a direct migratory effect on neutrophils and that CSE is an activator of β2-integrins on the cell surface. Blocking this activation of β2-integrins might be an important target in cigarette smoke induced neutrophilic diseases. PMID:21651795

The construction, fouling and enzymatic cleaning of a textile dye surface.

PubMed

Onaizi, Sagheer A; He, Lizhong; Middelberg, Anton P J

2010-11-01

The enzymatic cleaning of a rubisco protein stain bound onto Surface Plasmon Resonance (SPR) biosensor chips having a dye-bound upper layer is investigated. This novel method allowed, for the first time, a detailed kinetic study of rubisco cleanability (defined as fraction of adsorbed protein removed from a surface) from dyed surfaces (mimicking fabrics) at different enzyme concentrations. Analysis of kinetic data using an established mathematical model able to decouple enzyme transfer and reaction processes [Onaizi, He, Middelberg, Chem. Eng. Sci. 64 (2008) 3868] revealed a striking effect of dyeing on enzymatic cleaning performance. Specifically, the absolute rate constants for enzyme transfer to and from a dye-bound rubisco stain were significantly higher than reported previously for un-dyed surfaces. These increased transfer rates resulted in higher surface cleanability. Higher enzyme mobility (i.e., higher enzyme adsorption and desorption rates) at the liquid-dye interface was observed, consistent with previous suggestions that enzyme surface mobility is likely correlated with overall enzyme cleaning performance. Our results show that reaction engineering models of enzymatic action at surfaces may provide insight able to guide the design of better stain-resistant surfaces, and may also guide efforts to improve cleaning formulations. Copyright 2010 Elsevier Inc. All rights reserved.

Architectural elements and bounding surfaces in fluvial deposits: anatomy of the Kayenta formation (lower jurassic), Southwest Colorado

NASA Astrophysics Data System (ADS)

Miall, Andrew D.

1988-03-01

Three well-exposed outcrops in the Kayenta Formation (Lower Jurassic), near Dove Creek in southwestern Colorado, were studied using lateral profiles, in order to test recent regarding architectural-element analysis and the classification and interpretation of internal bounding surfaces. Examination of bounding surfaces within and between elements in the Kayenta outcrops raises problems in applying the three-fold classification of Allen (1983). Enlarging this classification to a six-fold hierarchy permits the discrimination of surfaces intermediate between Allen's second- and third-order types, corresponding to the upper bounding surfaces of macroforms, and internal erosional "reactivation" surfaces within the macroforms. Examples of the first five types of surface occur in the Kayenta outcrops at Dove Creek. The new classifications is offered as a general solution to the problem of description of complex, three-dimensional fluvial sandstone bodies. The Kayenta Formation at Dove Creek consists of a multistorey sandstone body, including the deposits of lateral- and downstream-accreted macroforms. The storeys show no internal cyclicity, neither within individual elements nor through the overall vertical thickness of the formation. Low paleocurrent variance indicates low sinuosity flow, whereas macroform geometry and orientation suggest low to moderate sinuosity. The many internal minor erosion surfaces draped with mud and followed by intraclast breccias imply frequent rapid stage fluctuation, consistent with variable (seasonal? monsonal? ephemmeral?) flow. The results suggest a fluvial architecture similar to that of the South Saskatchewan River, through with a three-dimensional geometry unlike that interpreted from surface studies of that river.

An internal thioester in a pathogen surface protein mediates covalent host binding

PubMed Central

Walden, Miriam; Edwards, John M; Dziewulska, Aleksandra M; Bergmann, Rene; Saalbach, Gerhard; Kan, Su-Yin; Miller, Ona K; Weckener, Miriam; Jackson, Rosemary J; Shirran, Sally L; Botting, Catherine H; Florence, Gordon J; Rohde, Manfred; Banfield, Mark J; Schwarz-Linek, Ulrich

2015-01-01

To cause disease and persist in a host, pathogenic and commensal microbes must adhere to tissues. Colonization and infection depend on specific molecular interactions at the host-microbe interface that involve microbial surface proteins, or adhesins. To date, adhesins are only known to bind to host receptors non-covalently. Here we show that the streptococcal surface protein SfbI mediates covalent interaction with the host protein fibrinogen using an unusual internal thioester bond as a ‘chemical harpoon’. This cross-linking reaction allows bacterial attachment to fibrin and SfbI binding to human cells in a model of inflammation. Thioester-containing domains are unexpectedly prevalent in Gram-positive bacteria, including many clinically relevant pathogens. Our findings support bacterial-encoded covalent binding as a new molecular principle in host-microbe interactions. This represents an as yet unexploited target to treat bacterial infection and may also offer novel opportunities for engineering beneficial interactions. DOI: http://dx.doi.org/10.7554/eLife.06638.001 PMID:26032562

Two distinct forms of Factor VIII coagulant protein in human plasma. Cleavage by thrombin, and differences in coagulant activity and association with von Willebrand factor.

PubMed Central

Weinstein, M J; Chute, L E

1984-01-01

We have characterized Factor VIII coagulant protein, present in normal human plasma, that reacts with a specific human 125I-labeled anti-human VIII:C antigen Fab antibody fragment. Two major Factor VIII coagulant antigen populations were present. The first, approximately 85% of the total antigen, was bound to von Willebrand factor and when tested in a standard one-stage assay had Factor VIII coagulant activity. The second antigenic population, eluting near fibrinogen when plasma was gel filtered, was not bound to von Willebrand protein, did not have Factor VIII coagulant activity unless activated, but did block anti-VIII:C Fab neutralization of clotting activity. The two antigenic populations were separable by cryoprecipitation and agarose gel electrophoresis. Although the two antigenic populations differed in their Factor VIII coagulant activity and in their binding to von Willebrand factor, the principal member of both populations is of mol wt 2.4 X 10(5). Both antigens, when proteolyzed by thrombin, were quickly converted to a 1 X 10(5)-mol wt form in association with the appearance of VIII:C activity. The 1 X 10(5)-mol wt antigen was further slowly degraded to an 8 X 10(4)-mol wt form while Factor VIII coagulant activity declined. These results demonstrate the presence of an inactive Factor VIII coagulant protein in plasma, not associated with von Willebrand factor, that can react with thrombin to yield Factor VIII coagulant activity. Images PMID:6421875

Inhibition of neutrophil migration by aggregated immunoglobulin attached to micropore membranes.

PubMed Central

Kemp, A S; Brown, S

1980-01-01

The effect of substrate-bound immunoglobulin on neutrophil migration was examined. Immunoglobulin aggregates bound to micropore membranes inhibited the neutrophil response to a chemotactic stimulus. This inhibition was reversed by the presence of aggregates in suspension suggesting competition between substrate-bound and free aggregates for neutrophil surface binding sites. The immobilization of neutrophils by substrate-bound aggregated immunoglobulin suggests a mechanism for the accumulation of neutrophils at sites of immune complex deposition and tissue-bound antibodies in vivo. PMID:7380477

The effect of D-galactosamine on plasma protein synthesis by the perfused rat liver from turpentine-stimulated donors.

PubMed Central

Koj, A.; Dubin, A.

1978-01-01

D-galactosamine (100 mg) was added to the reconstituted blood during 4h perfusion of livers isolated either from control rats or those injected with turpentine 20 h or 5 h earlier. This dose of galactosamine administered 30 min before [3H]lysine significantly inhibited the incorporation of the label into liver proteins, and even more into plasma proteins, but albumin and acute-phase reactants (fibrinogen, seromucoid fraction, Concanavalin A-adsorbed glycoproteins) were all similarly affected. When galactosamine was administered in vivo simultaneously with turpentine, and the liver was isolated 5 h later, trauma-induced fibrinogen synthesis was selectively inhibited. This can be explained either by a differential control of synthesis of various acute-phase reactants, or by augmentation of catabolism of fibrinogen in galactosamine-treated rats. Crossed immunoelectrophoresis of the full perfusate or Concanavalin A-adsorbed glycoproteins did not reveal any significant effect of galactosamine on the protein pattern obtained from control or turpentine-stimulated liver donors. Images Fig. 1 PMID:718802

Cell and protein adhesion studies in glaucoma drainage device development

PubMed Central

The, A

1999-01-01

AIM—To examine in vitro whether phosphorylcholine coating of poly(methylmethacrylate) can reduce the adhesion of fibrinogen, fibrin, human scleral fibroblast and macrophage compared with current biomaterials used in the construction of glaucoma drainage devices.
METHODS—Sample discs (n=6) of poly(methylmethacrylate), silicone, polypropylene, PTFE, and phosphorylcholine coated poly(methylmethacrylate) were seeded with fibrinogen, fibrin, fibroblast, and macrophages and incubated for variable lengths of time. The quantification was performed using radioactivity, spectrophotometry, ATP dependent luminometry, and immunohistochemistry respectively.
RESULTS—Fibrinogen and fibrin adhesion to phosphorylcholine coated poly(methylmethacrylate) were significantly lower than PMMA (p=0.004). Phosphorylcholine coating of poly(methylmethacrylate) also significantly reduced the adhesion of human scleral fibroblast (p=0.002) and macrophage (p=0.01) compared with PMMA. All the other biomaterials showed either similar or insignificantly different levels of adhesion to all the proteins and cells tested compared with PMMA.
CONCLUSION—Phosphorylcholine coating is a new material technology that offers considerable promise in the field of glaucoma drainage device development.

 PMID:10502580

A Protocol for the Preparation of Cryoprecipitate and Cryo-depleted Plasma for Proteomic Studies.

PubMed

Sparrow, Rosemary L; Simpson, Richard J; Greening, David W

2017-01-01

Cryoprecipitate is a concentrate of high-molecular-weight plasma proteins that precipitate when frozen plasma is slowly thawed at 1-6 °C. The concentrate contains factor VIII (antihemophilic factor), von Willebrand factor (vWF), fibrinogen, factor XIII, fibronectin, and small amounts of other plasma proteins. Clinical grade preparations of cryoprecipitate are mainly used to treat fibrinogen deficiency caused by acute bleeding or functional abnormalities of the fibrinogen protein. In the past, cryoprecipitate was used to treat von Willebrand disease and hemophilia A (factor VIII deficiency), but the availability of more highly purified coagulation factor concentrates or recombinant protein preparations has superseded the use of cryoprecipitate for these coagulopathies. Cryo-depleted plasma ("cryosupernatant") is the plasma supernatant remaining following removal of the cryoprecipitate from frozen-thawed plasma. It contains all the other plasma proteins and clotting factors present in plasma that remain soluble during cold-temperature thawing of the plasma. This protocol describes the clinical-scale preparation of cryoprecipitate and cryo-depleted plasma for proteomic studies.

Aeroacoustic Duster

NASA Technical Reports Server (NTRS)

Wu, Jun-ru (Inventor); Hitt, Darren (Inventor); Vachon, Nicholas M. (Inventor); Chen, Di (Inventor); Marshall, Jeffrey S. (Inventor)

2016-01-01

The invention disclosed herein provides for high particle removal rate and/or heat transfer from surfaces. The device removes particulate matter from a surface using a bounded vortex generated over the surface, with suction in the vortex center and jets for blowing air along the periphery. The jets are tilted in the tangential direction to induce vortex motion within the suction region. The vortex is said to be bounded because streamlines originating in the downward jets are entrained back into the central vortex.

Analysis of nucleotides and oligonucleotides immobilized as self-assembled monolayers by static secondary ion mass spectrometry.

PubMed

Patrick, J S; Cooks, R G; Pachuta, S J

1994-11-01

Nucleic acid constituents can be bound to a metal surface in the form of self-assembled monolayers. Binding is achieved either through ionic interactions with a self-assembled 2-aminoethanethiol monolayer or by direct covalent binding of a dithiophosphate oligonucleotide to a metal surface through a sulfur-metal bond. Nucleotides, polynucleotides (both normal and a dithiophosphate analog) and double-stranded DNA have all been bound to surfaces. When the surfaces are interrogated using static secondary ion mass spectrometry (SIMS), the surface-bound nucleic acid constituents are observed in the form of the characteristic protonated nucleic acid base ions (BH2+). While a silver foil substrate was found to provide the highest absolute signal, vapor-deposited gold yields the best signal-to-noise ratio for ionically bound deoxyguanosine monophosphate. Under comparable conditions, a Cs+ projectile produces a 10-fold increase in the secondary ion signal relative to a Ga+ projectile. The experiment has been extended to a triple-quadrupole instrument where tandem mass spectrometric experiments on ionically immobilized dGMP showed the characteristic loss of ammonia from the released BH2+ ion. When a 'biomimetic' surface formed by ionically immobilizing double-stranded DNA is exposed to a solution containing ethidium bromide, ions corresponding to the non-covalent adduct are readily detectable using SIMS. This adduct and the nucleic acid constituents can be monitored at levels below 10 fmol.

Lecithin has no effect on serum lipoprotein, plasma fibrinogen and macro molecular protein complex levels in hyperlipidaemic men in a double-blind controlled study.

PubMed

Oosthuizen, W; Vorster, H H; Vermaak, W J; Smuts, C M; Jerling, J C; Veldman, F J; Burger, H M

1998-06-01

To examine the effects of lecithin on serum lipoprotein, plasma fibrinogen and macro molecular protein complex (MPC) levels. Twenty free living hyperlipidaemic men participated in this double-blind study which controlled for possible indirect effects. The subjects were randomly assigned to one of three treatments: frozen yoghurt or frozen yoghurt with 20 g soya bean lecithin or frozen yoghurt with 17 g sunflower oil. Sunflower oil was used to control for the increased energy and linoleic acid intake from lecithin. Yoghurt served as the 'vehicle' for the lecithin and sunflower oil and yoghurt alone was given to one group to control for possible effects due to the yoghurt 'vehicle', as well as other environmental influences. Variables were measured with standard methods twice at baseline and after 2 and 4 weeks of treatment. Plasma linoleic acid levels increased significantly with lecithin and sunflower oil treatments indicating that compliance to the treatments were obtained. Lecithin treatment did not have significant effects on serum total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol, apolipoprotein A, apolipoprotein B or lipoprotein (a) levels. Plasma fibrinogen and MPC levels were also not affected by lecithin therapy. Sunflower oil treatment resulted in significant increased body weight, serum TC and decreased MPC levels. Lecithin treatment had no independent effects on serum lipoprotein, plasma fibrinogen or MPC levels in hyperlipidaemic men.

Monthly haemostatic factor variability in women and men.

PubMed

Hill, Alison M; Stewart, Paul W; Fung, Mark K; Kris-Etherton, Penny M; Ginsberg, Henry N; Tracy, Russell P; Pearson, Thomas A; Lefevre, Michael; Reed, Roberta G; Elmer, Patricia J; Holleran, Stephen; Ershow, Abby G

2014-01-01

Hormonal status influences haemostatic factors including fibrinogen, factor VII and plasminogen activator inhibitor (PAI-1), and concentrations differ among men, premenopausal and postmenopausal women. This study examines how phases of the menstrual cycle influence variability of fibrinogen, factor VII and PAI-1. We studied 103 subjects (39 premenopausal women, 18 postmenopausal women and 46 men) during three, randomized, 8-week energy- and nutrient-controlled experimental diets in the Dietary Effects on Lipids and Thrombogenic Activity (DELTA) Study. Fasting blood samples were collected weekly during the last 4 weeks of each diet period, and haemostatic factors were quantified. Two linear mixed-effects models were used for fibrinogen, factor VII and PAI-1: one to estimate and compare group-specific components of variance, and the other to estimate additional fixed effects representing cyclical functions of day of menstrual cycle in premenopausal women. Systematic cyclical variation with day of menstrual cycle was observed for fibrinogen (P < 0.0001), factor VII (P = 0.0012) and PAI-1 (P = 0.0024) in premenopausal women. However, the amplitude of cycling was small relative to the total magnitude of intra-individual variability. In addition, the intra-individual variance and corresponding coefficient of variation observed in premenopausal women did not differ from postmenopausal women and men. The variability in haemostatic factors in premenopausal women is no greater than for postmenopausal women or men. Consequently, premenopausal women can be included in studies investigating haemostatic factor responses without controlling for stage of menstrual cycle. © 2014 Stichting European Society for Clinical Investigation Journal Foundation.

Effects of carprofen and meloxicam on C-reactive protein, ceruloplasmin, and fibrinogen concentrations in dogs undergoing ovariohysterectomy.

PubMed

Kum, Cavit; Voyvoda, Huseyin; Sekkin, Selim; Karademir, Umit; Tarimcilar, Tugrul

2013-10-01

To evaluate the effects of perioperative oral administration of carprofen and meloxicam on concentrations of 3 acute-phase proteins in dogs undergoing elective ovariohysterectomy (OVH). 18 healthy adult anestrous female dogs undergoing elective OVH. Dogs were allocated to 3 groups (6 dogs/group). A placebo treatment, carprofen (2.0 mg/kg), or meloxicam (0.2 mg/kg) was orally administered to the dogs of the respective groups. The initial doses were administered 30 minutes before premedication prior to OVH; additional doses were administered once daily for 4 days after surgery. Blood samples were collected 45 minutes before premedication and 4, 8, 12, 24, 36, 48, 72, 96, and 120 hours after the end of OVH; samples were used for measurement of total WBC and neutrophil counts and concentrations of C-reactive protein (CRP), ceruloplasmin, and fibrinogen. Values did not differ significantly among groups for WBC and neutrophil counts, serum concentrations of CRP and ceruloplasmin, and plasma concentrations of fibrinogen. Concentrations of all inflammatory markers, except serum ceruloplasmin, increased significantly following OVH, but in a similar manner for each group. No significant changes were detected in serum ceruloplasmin concentrations over time. Perioperative administration of both carprofen and meloxicam did not significantly affect the concentrations of CRP, ceruloplasmin, and fibrinogen in dogs undergoing OVH. Thus, use of carprofen or meloxicam should not affect clinical interpretation of results for these 3 acute-phase proteins.

Composition of fibrin glues significantly influences axial vascularization and degradation in isolation chamber model.

PubMed

Arkudas, Andreas; Pryymachuk, Galyna; Hoereth, Tobias; Beier, Justus P; Polykandriotis, Elias; Bleiziffer, Oliver; Gulle, Heinz; Horch, Raymund E; Kneser, Ulrich

2012-07-01

In this study, different fibrin sealants with varying concentrations of the fibrin components were evaluated in terms of matrix degradation and vascularization in the arteriovenous loop (AVL) model of the rat. An AVL was placed in a Teflon isolation chamber filled with 500 μl fibrin gel. The matrix was composed of commercially available fibrin gels, namely Beriplast (Behring GmbH, Marburg, Germany) (group A), Evicel (Omrix Biopharmaceuticals S.A., Somerville, New Jersey, USA) (group B), Tisseel VH S/D (Baxter, Vienna, Austria) with a thrombin concentration of 4 IU/ml and a fibrinogen concentration of 80 mg/ml [Tisseel S F80 (Baxter), group C] and with an fibrinogen concentration of 20 mg/ml [Tisseel S F20 (Baxter), group D]. After 2 and 4 weeks, five constructs per group and time point were investigated using micro-computed tomography, and histological and morphometrical analysis techniques. The aprotinin, factor XIII and thrombin concentration did not affect the degree of clot degradation. An inverse relationship was found between fibrin matrix degradation and sprouting of blood vessels. By reducing the fibrinogen concentration in group D, a significantly decreased construct weight and an increased generation of vascularized connective tissue were detected. There was an inverse relationship between matrix degradation and vascularization detectable. Fibrinogen as the major matrix component showed a significant impact on the matrix properties. Alteration of fibrin gel properties might optimize formation of blood vessels.

Blood transfusion and the anaesthetist: management of massive haemorrhage

PubMed Central

Thomas, D; Wee, M; Clyburn, P; Walker, I; Brohi, K; Collins, P; Doughty, H; Isaac, J; Mahoney, PF; Shewry, L

2010-01-01

Hospitals must have a major haemorrhage protocol in place and this should include clinical, laboratory and logistic responses. Immediate control of obvious bleeding is of paramount importance (pressure, tourniquet, haemostatic dressings). The major haemorrhage protocol must be mobilised immediately when a massive haemorrhage situation is declared. A fibrinogen < 1 g.l−1 or a prothrombin time (PT) and activated partial thromboplastin time (aPTT) of > 1.5 times normal represents established haemostatic failure and is predictive of microvascular bleeding. Early infusion of fresh frozen plasma (FFP; 15 ml.kg−1) should be used to prevent this occurring if a senior clinician anticipates a massive haemorrhage. Established coagulopathy will require more than 15 ml.kg−1 of FFP to correct. The most effective way to achieve fibrinogen replacement rapidly is by giving fibrinogen concentrate or cryoprecipitate if fibrinogen is unavailable. 1:1:1 red cell:FFP:platelet regimens, as used by the military, are reserved for the most severely traumatised patients. A minimum target platelet count of 75 × 109.l−1 is appropriate in this clinical situation. Group-specific blood can be issued without performing an antibody screen because patients will have minimal circulating antibodies. O negative blood should only be used if blood is needed immediately. In hospitals where the need to treat massive haemorrhage is frequent, the use of locally developed shock packs may be helpful. Standard venous thromboprophylaxis should be commenced as soon as possible after haemostasis has been secured as patients develop a prothrombotic state following massive haemorrhage. PMID:20963925

Metabolic factors, adipose tissue, and plasminogen activator inhibitor-1 levels in type 2 diabetes: findings from the look AHEAD study.

PubMed

Belalcazar, L Maria; Ballantyne, Christie M; Lang, Wei; Haffner, Steven M; Rushing, Julia; Schwenke, Dawn C; Pi-Sunyer, F Xavier; Tracy, Russell P

2011-07-01

Plasminogen activator inhibitor-1 (PAI-1) production by adipose tissue is increased in obesity, and its circulating levels are high in type 2 diabetes. PAI-1 increases cardiovascular risk by favoring clot stability, interfering with vascular remodeling, or both. We investigated in obese diabetic persons whether an intensive lifestyle intervention for weight loss (ILI) would decrease PAI-1 levels independently of weight loss and whether PAI-1 reduction would be associated with changes in fibrinogen, an acute phase reactant, or fibrin fragment D-dimer (D-dimer), a marker of ambient coagulation balance. We examined 1-year changes in PAI-1, D-dimer, and fibrinogen levels; adiposity; fitness; glucose; and lipid control with ILI in 1817 participants from Look AHEAD, a randomized trial investigating the effects of ILI, compared with usual care, on cardiovascular events in overweight or obese diabetic persons. Median PAI-1 levels decreased 29% with ILI and 2.5% with usual care (P < 0.0001). Improvements in fitness, glucose control, and high-density lipoprotein cholesterol were associated with decreased PAI-1, independently of weight loss (P = 0.03 for fitness, P < 0.0001 for others). Fibrinogen and D-dimer remained unchanged. Reductions in PAI-1 levels with ILI in obese diabetic individuals may reflect an improvement in adipose tissue health that could affect cardiovascular risk without changing fibrinogen or d-dimer levels. Clinical Trial Registration- URL: http://clinicaltrials.gov/ct2/show/NCT00017953. Unique identifier: NCT00017953.

Recruiting physisorbed water in surface polymerization for bio-inspired materials of tunable hydrophobicity

DOE PAGES

Oyola-Reynoso, S.; Tevis, I. D.; Chen, J.; ...

2016-08-18

Here, chemical grafting has been widely used to modify the surface properties of materials, especially surface energy for controlled wetting, because of the resilience of such coatings/modifications. Reagents with multiple reactive sites have been used with the expectation that a monolayer will form. The step-growth polymerization mechanism, however, suggests the possibility of gel formation for hydrolyzable moieties in the presence of physisorbed water. In this report, we demonstrated that using alkyltrichlorosilanes (trivalent [i.e., 3 reactive sites]) in the surface modification of a cellulosic material (paper) does not yield a monolayer but rather gives surface-bound particles. We infer that the presencemore » of physisorbed (surface-bound) water allows for polymerization (or oligomerization) of the silane prior to its attachment on the surface. Surface energy mismatch between the hydrophobic tails of the growing polymer and any unreacted bound water leads to the assembly of the polymerizing material into spherical particles to minimize surface tension. By varying paper grammage (16.2–201.4 g m –2), we varied the accessible surface area and thus the amount of surface-adsorbed water, allowing us to control the ratio of the silane to the bound water. Using this approach, polymeric particles were formed on the surface of cellulose fibers ranging from ~70 nm to a film. The hydrophobicity of the surface, as determined by water contact angles, correlates with particle sizes (p < 0.001, Student's t-test), and, hence, the hydrophobicity can be tuned (contact angle between 94° and 149°). Using a model structure of a house, we demonstrated that as a result of this modification, paper-based houses can be rendered self-cleaning or tolerant to surface running water. In another application, we demonstrated that the felicitous choice of architectural design allows for the hydrophobic paper to be used for water harvesting.« less

Integration of colloids into a semi-flexible network of fibrin.

PubMed

Bharadwaj, N Ashwin K; Kang, Jin Gu; Hatzell, Marta C; Schweizer, Kenneth S; Braun, Paul V; Ewoldt, Randy H

2017-02-15

Typical colloid-polymer composites have particle diameters much larger than the polymer mesh size, but successful integration of smaller colloids into a large-mesh network could allow for the realization of new colloidal states of spatial organization and faster colloid motion which can allow the possibility of switchable re-configuration of colloids or more dramatic stimuli-responsive property changes. Experimental realization of such composites requires solving non-trivial materials selection and fabrication challenges; key questions include composition regime maps of successful composites, the resulting structure and colloidal contact network, and the mechanical properties, in particular the ability to form a network and retain strain stiffening in the presence of colloids. Here, we study these fundamental questions by formulating composites with fluorescent (though not stimuli-responsive) carboxylate modified polystyrene/latex (CML) colloidal particles (diameters 200 nm and 1000 nm) in bovine fibrin networks (a semi-flexible biopolymer network with mesh size 1-5 μm). We describe and characterize two methods of composite preparation: adding colloids before fibrinogen polymerization (Method I), and electrophoretically driving colloids into a network already formed by fibrinogen polymerization (Method II). We directly image the morphology of colloidal and fibrous components with two-color fluorescent confocal microscopy under wet conditions and SEM of fixed dry samples. Mechanical properties are studied with shear and extensional rheology. Both fabrication methods are successful, though with trade-offs. Method I retains the nonlinear strain-stiffening and extensibility of the native fibrin network, but some colloid clustering is observed and fibrin network integrity is lost above a critical colloid concentration that depends on fibrinogen and thrombin concentration. Larger colloids can be included at higher volume fractions before massive aggregation occurs, indicating surface interactions as a limiting factor. Method II results in a loss of measurable strain-stiffening, but colloids are well dispersed and template along the fibrous scaffold. The results here, with insight into both structure and rheology, form a foundational understanding for the integration of other colloids, e.g. with stimuli-responsive functionalities, into semi-flexible networks.

Radiolabeled Cyclic RGD Peptides as Radiotracers for Imaging Tumors and Thrombosis by SPECT

PubMed Central

Zhou, Yang; Chakraborty, Sudipta; Liu, Shuang

2011-01-01

The integrin family is a group of transmembrane glycoprotein comprised of 19 α- and 8 β-subunits that are expressed in 25 different α/β heterodimeric combinations on the cell surface. Integrins play critical roles in many physiological processes, including cell attachment, proliferation, bone remodeling, and wound healing. Integrins also contribute to pathological events such as thrombosis, atherosclerosis, tumor invasion, angiogenesis and metastasis, infection by pathogenic microorganisms, and immune dysfunction. Among 25 members of the integrin family, the αvβ3 is studied most extensively for its role of tumor growth, progression and angiogenesis. In contrast, the αIIbβ3 is expressed exclusively on platelets, facilitates the intercellular bidirectional signaling (“inside-out” and “outside-in”) and allows the aggregation of platelets during vascular injury. The αIIbβ3 plays an important role in thrombosis by its activation and binding to fibrinogen especially in arterial thrombosis due to the high blood flow rate. In the resting state, the αIIbβ3 on platelets does not bind to fibrinogen; on activation, the conformation of platelet is altered and the binding sites of αIIbβ3 are exposed for fibrinogen to crosslink platelets. Over the last two decades, integrins have been proposed as the molecular targets for diagnosis and therapy of cancer, thrombosis and other diseases. Several excellent review articles have appeared recently to cover a broad range of topics related to the integrin-targeted radiotracers and their nuclear medicine applications in tumor imaging by single photon emission computed tomography (SPECT) or a positron-emitting radionuclide for positron emission tomography (PET). This review will focus on recent developments of αvβ3-targeted radiotracers for imaging tumors and the use of αIIbβ3-targeted radiotracers for thrombosis imaging, and discuss different approaches to maximize the targeting capability of cyclic RGD peptides and improve the radiotracer excretion kinetics from non-cancerous organs. Improvement of target uptake and target-to-background ratios is critically important for target-specific radiotracers. PMID:21547153

Ligand-modified metal clusters for gas separation and purification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okrut, Alexander; Ouyang, Xiaoying; Runnebaum, Ron

2017-02-21

Provided is an organic ligand-bound metal surface that selects one gaseous species over another. The species can be closely sized molecular species having less than 1 Angstrom difference in kinetic diameter. In one embodiment, the species comprise carbon monoxide and ethylene. Such organic ligand-bound metal surfaces can be successfully used in gas phase separations or purifications, sensing, and in catalysis.

The functional dissection of the plasma corona of SiO₂-NPs spots histidine rich glycoprotein as a major player able to hamper nanoparticle capture by macrophages.

PubMed

Fedeli, Chiara; Segat, Daniela; Tavano, Regina; Bubacco, Luigi; De Franceschi, Giorgia; de Laureto, Patrizia Polverino; Lubian, Elisa; Selvestrel, Francesco; Mancin, Fabrizio; Papini, Emanuele

2015-11-14

A coat of strongly-bound host proteins, or hard corona, may influence the biological and pharmacological features of nanotheranostics by altering their cell-interaction selectivity and macrophage clearance. With the goal of identifying specific corona-effectors, we investigated how the capture of amorphous silica nanoparticles (SiO2-NPs; Ø = 26 nm; zeta potential = -18.3 mV) by human lymphocytes, monocytes and macrophages is modulated by the prominent proteins of their plasma corona. LC MS/MS analysis, western blotting and quantitative SDS-PAGE densitometry show that Histidine Rich Glycoprotein (HRG) is the most abundant component of the SiO2-NP hard corona in excess plasma from humans (HP) and mice (MP), together with minor amounts of the homologous Kininogen-1 (Kin-1), while it is remarkably absent in their Foetal Calf Serum (FCS)-derived corona. HRG binds with high affinity to SiO2-NPs (HRG Kd ∼2 nM) and competes with other plasma proteins for the NP surface, so forming a stable and quite homogeneous corona inhibiting nanoparticles binding to the macrophage membrane and their subsequent uptake. Conversely, in the case of lymphocytes and monocytes not only HRG but also several common plasma proteins can interchange in this inhibitory activity. The depletion of HRG and Kin-1 from HP or their plasma exhaustion by increasing NP concentration (>40 μg ml(-1) in 10% HP) lead to a heterogeneous hard corona, mostly formed by fibrinogen (Fibr), HDLs, LDLs, IgGs, Kallikrein and several minor components, allowing nanoparticle binding to macrophages. Consistently, the FCS-derived SiO2-NP hard corona, mainly formed by hemoglobin, α2 macroglobulin and HDLs but lacking HRG, permits nanoparticle uptake by macrophages. Moreover, purified HRG competes with FCS proteins for the NP surface, inhibiting their recruitment in the corona and blocking NP macrophage capture. HRG, the main component of the plasma-derived SiO2-NPs' hard corona, has antiopsonin characteristics and uniquely confers to these particles the ability to evade macrophage capture.