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Sample records for heparin binding mechanism

  1. Effects of heparin on insulin binding and biological activity

    International Nuclear Information System (INIS)

    Kriauciunas, K.M.; Grigorescu, F.; Kahn, C.R.

    1987-01-01

    The effect of heparin, a polyanionic glycosaminoglycan known to alter the function of many proteins, on insulin binding and bioactivity was studied. Cultured human lymphocytes (IM-9) were incubated with varying concentrations of heparin, then extensively washed, and 125 I-labeled insulin binding was measured. Heparin at concentrations used clinically for anticoagulation (1-50 U/ml) inhibited binding in a dose-dependent manner; 50% inhibition of binding occurred with 5-10 U/ml. Scatchard analysis indicated that the decrease in binding was due to a decrease in both the affinity and the apparent number of available insulin receptors. The effect occurred within 10 min at 22 degrees C and persisted even after the cells were extensively washed. Inhibition of insulin binding also occurred when cells were preincubated with heparinized plasma or heparinized serum but not when cells were incubated with normal serum or plasma from blood anticoagulated with EDTA. By contrast, other polyanions and polycations, e.g., poly-L-glutamic acid, poly-L-lysine, succinylated poly-L-lysine, and histone, did not inhibit binding. Heparin also inhibited insulin binding in Epstein-Barr (EB) virus-transformed lymphocytes but had no effect on insulin binding to isolated adipocytes, human erythrocytes, or intact hepatoma cells. When isolated adipocytes were incubated with heparin, there was a dose-dependent inhibition of insulin-stimulated glucose oxidation and, to a lesser extent, of basal glucose oxidation. Although heparin has no effect on insulin binding to intact hepatoma cells, heparin inhibited both insulin binding and insulin-stimulated autophosphorylation in receptors solubilized from these cells

  2. A Heparin Binding Motif Rich in Arginine and Lysine is the Functional Domain of YKL-40

    Directory of Open Access Journals (Sweden)

    Nipaporn Ngernyuang

    2018-02-01

    Full Text Available The heparin-binding glycoprotein YKL-40 (CHI3L1 is intimately associated with microvascularization in multiple human diseases including cancer and inflammation. However, the heparin-binding domain(s pertinent to the angiogenic activity have yet been identified. YKL-40 harbors a consensus heparin-binding motif that consists of positively charged arginine (R and lysine (K (RRDK; residues 144–147; but they don't bind to heparin. Intriguingly, we identified a separate KR-rich domain (residues 334–345 that does display strong heparin binding affinity. A short synthetic peptide spanning this KR-rich domain successfully competed with YKL-40 and blocked its ability to bind heparin. Three individual point mutations, where alanine (A substituted for K or R (K337A, K342A, R344A, led to remarkable decreases in heparin-binding ability and angiogenic activity. In addition, a neutralizing anti-YKL-40 antibody that targets these residues and prevents heparin binding impeded angiogenesis in vitro. MDA-MB-231 breast cancer cells engineered to express ectopic K337A, K342A or R344A mutants displayed reduced tumor development and compromised tumor vessel formation in mice relative to control cells expressing wild-type YKL-40. These data reveal that the KR-rich heparin-binding motif is the functional heparin-binding domain of YKL-40. Our findings shed light on novel molecular mechanisms underlying endothelial cell angiogenesis promoted by YKL-40 in a variety of diseases.

  3. Structural and binding studies of SAP-1 protein with heparin.

    Science.gov (United States)

    Yadav, Vikash K; Mandal, Rahul S; Puniya, Bhanwar L; Kumar, Rahul; Dey, Sharmistha; Singh, Sarman; Yadav, Savita

    2015-03-01

    SAP-1 is a low molecular weight cysteine protease inhibitor (CPI) which belongs to type-2 cystatins family. SAP-1 protein purified from human seminal plasma (HuSP) has been shown to inhibit cysteine and serine proteases and exhibit interesting biological properties, including high temperature and pH stability. Heparin is a naturally occurring glycosaminoglycan (with varied chain length) which interacts with a number of proteins and regulates multiple steps in different biological processes. As an anticoagulant, heparin enhances inhibition of thrombin by the serpin antithrombin III. Therefore, we have employed surface plasmon resonance (SPR) to improve our understanding of the binding interaction between heparin and SAP-1 (protease inhibitor). SPR data suggest that SAP-1 binds to heparin with a significant affinity (KD = 158 nm). SPR solution competition studies using heparin oligosaccharides showed that the binding of SAP-1 to heparin is dependent on chain length. Large oligosaccharides show strong binding affinity for SAP-1. Further to get insight into the structural aspect of interactions between SAP-1 and heparin, we used modelled structure of the SAP-1 and docked with heparin and heparin-derived polysaccharides. The results suggest that a positively charged residue lysine plays important role in these interactions. Such information should improve our understanding of how heparin, present in the reproductive tract, regulates cystatins activity. © 2014 John Wiley & Sons A/S.

  4. Heparin-associated thrombocytopenia: antibody binding specificity to platelet antigens.

    Science.gov (United States)

    Lynch, D M; Howe, S E

    1985-11-01

    Sera from four patients with heparin-associated thrombocytopenia (HAT) were evaluated by a quantitative enzyme-linked immunosorbent assay (ELISA) to detect heparin-dependent serum platelet-bindable immunoglobulin (S-PBIg) and by Western blotting and immunoprecipitation to investigate the specificity of the antibody binding. All HAT sera showed mildly increased S-PBIg (mean, 7.8 fg per platelet; normal, less than 6.0 fg per platelet) to intact target platelets in the ELISA, which was markedly increased in the presence of heparin (mean, 20.9 fg per platelet). This increase was 20-fold greater than normal control sera, which showed a mean differential increase of only 0.5 fg per platelet. Immunoglobulin binding specificity to platelet antigens was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis of platelet lysate with transfer of the platelet fractions onto nitrocellulose strips (Western blotting) and subsequent immunoassay using HAT and normal sera. In the presence of heparin, the four HAT patients demonstrated increased binding of immunoglobulin to platelet antigens of apparent molecular weights of 180, 124, and 82 kd. Radiolabeled heparin when incubated with HAT sera, normal sera, or albumin blanks bound to platelet proteins of the same apparent molecular weights. These observations are consistent with current hypotheses suggesting that HAT antibody is directed to heparin-platelet complexes or, alternatively, that heparin induces conformational change of antigenic sites on the platelet membrane.

  5. Improved assay for measuring heparin binding to bull sperm

    International Nuclear Information System (INIS)

    Miller, D.J.; Ax, R.L.

    1988-01-01

    The binding of heparin to sperm has been used to study capacitation and to rank relative fertility of bulls. Previous binding assays were laborious, used 10 7 sperm per assay point, and required large amounts of radiolabeled heparin. A modified heparin-binding assay is described that used only 5 x 10 4 cells per incubation well and required reduced amounts of [ 3 H] heparin. The assay was performed in 96-well Millititer plates, enabling easy incubation and filtering. Dissociation constants and concentrations of binding sites did not differ if analyzed by Scatchard plots, Woolf plots, or by log-logit transformed weighted nonlinear least squares regression, except in the case of outliers. In such cases, Scatchard analysis was more sensitive to outliers. Nonspecific binding was insignificant using nonlinear logistic fit regression and a proportion graph. The effects were tested of multiple free-thawing of sperm in either a commercial egg yolk extender, 40 mM Tris buffer with 8% glycerol, or 40 mM Tris buffer without glycerol. Freeze-thawing in extender did not affect the dissociation constant or the concentration of binding sites. However, freeze-thawing three times in 40 mM Tris reduced the concentration of binding sites and lowered the dissociation constant (raised the affinity). The inclusion of glycerol in the 40 mM Tris did not significantly affect the estimated dissociation constant or the concentration of binding sites as compared to 40 mM Tris without glycerol

  6. Endostatin competes with bFGF for binding to heparin-like glycosaminoglycans

    International Nuclear Information System (INIS)

    Reis, Renata C.M.; Schuppan, Detlef; Barreto, Aline C.; Bauer, Michael; Bork, Jens P.; Hassler, Gerda; Coelho-Sampaio, Tatiana

    2005-01-01

    Endostatin is a potent inhibitor of angiogenesis and tumor growth. Here, we used human endothelial cells from lung capillaries to investigate if endostatin competes with the proangiogenic growth factors, bFGF and VEGF, for binding to costimulatory heparan sulfate molecules. Endostatin inhibited 79% and 95% of the increase in proliferation induced by bFGF and VEGF 165 , respectively. The stimulatory effect of VEGF 165 was not affected by the presence of exogenous heparin, while that of bFGF was further enhanced in the presence of up to 0.1 μg/ml heparin. The heparin-binding protein protamine completely blocked bFGF-stimulated proliferation, while it did not affect the response to VEGF 165 . Simultaneous addition of endostatin and protamine led to additive effects both in inhibition of proliferation and induction of apoptosis. Although bFGF was found to bind more strongly to heparin-Sepharose than endostatin, the latter, but not the former, displaced protamine from heparin in solution, which supports the notion that endostatin can compete with bFGF for binding to heparan sulfate in vivo. Taken as a whole, our results demonstrate that there is a direct connection between the dependence of endostatin activity on heparin-like glycosaminoglycans and its ability to antagonize bFGF

  7. A mutation in the heparin-binding site of noggin as a novel mechanism of proximal symphalangism and conductive hearing loss.

    Science.gov (United States)

    Masuda, Sawako; Namba, Kazunori; Mutai, Hideki; Usui, Satoko; Miyanaga, Yuko; Kaneko, Hiroki; Matsunaga, Tatsuo

    2014-05-09

    The access of bone morphogenetic protein (BMP) to the BMP receptors on the cell surface is regulated by its antagonist noggin, which binds to heparan-sulfate proteoglycans on the cell surface. Noggin is encoded by NOG and mutations in the gene are associated with aberrant skeletal formation, such as in the autosomal dominant disorders proximal symphalangism (SYM1), multiple synostoses syndrome, Teunissen-Cremers syndrome, and tarsal-carpal coalition syndrome. NOG mutations affecting a specific function may produce a distinct phenotype. In this study, we investigated a Japanese pedigree with SYM1 and conductive hearing loss and found that it carried a novel heterozygous missense mutation of NOG (c.406C>T; p.R136C) affecting the heparin-binding site of noggin. As no mutations of the heparin-binding site of noggin have previously been reported, we investigated the crystal structure of wild-type noggin to investigate molecular mechanism of the p.R136C mutation. We found that the positively charged arginine at position 136 was predicted to be important for binding to the negatively charged heparan-sulfate proteoglycan (HSPG). An in silico docking analysis showed that one of the salt bridges between noggin and heparin disappeared following the replacement of the arginine with a non-charged cysteine. We propose that the decreased binding affinity of NOG with the p.R136C mutation to HSPG leads to an excess of BMP signaling and underlies the SYM1 and conductive hearing loss phenotype of carriers. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Dansyl (5-dimethylaminonaphthalene-1-sulphonyl)-heparin binds antithrombin III and platelet factor 4 at separate sites

    Science.gov (United States)

    Piepkorn, Michael W.

    1981-01-01

    Antithrombin III binds to, and thereby augments the fluorescence of, dansyl-(5-dimethylaminonaphthalene-1-sulphonyl)-heparin; platelet factor 4 binding to the fluorescent heparin has little of this effect. Competition studies in which antithrombin III competes with platelet factor 4 for heparin binding demonstrate that heparin can simultaneously bind both proteins. PMID:7317004

  9. Relationship of nonreturn rates of dairy bulls to binding affinity of heparin to sperm

    International Nuclear Information System (INIS)

    Marks, J.L.; Ax, R.L.

    1985-01-01

    The binding of the glycosaminoglycan [ 3 H] heparin to bull spermatozoa was compared with nonreturn rates of dairy bulls. Semen samples from five bulls above and five below an average 71% nonreturn rate were used. Samples consisted of first and second ejaculates on a single day collected 1 d/wk for up to 5 consecutive wk. Saturation binding assays using [ 3 H] heparin were performed to quantitate the binding characteristics of each sample. Scatchard plot analyses indicated a significant difference in the binding affinity for [ 3 H] heparin between bulls of high and low fertility. Dissociation constants were 69.0 and 119.3 pmol for bulls of high and low fertility, respectively. In contrast, the number of binding sites for [ 3 H] heparin did not differ significantly among bulls. Differences in binding affinity of [ 3 H] heparin to bull sperm might be used to predict relative fertility of dairy bulls

  10. Basic fibroblast growth factor binds to subendothelial extracellular matrix and is released by heparitinase and heparin-like molecules

    International Nuclear Information System (INIS)

    Bashkin, P.; Doctrow, S.; Klagsbrun, M.; Svahn, C.M.; Folkman, J.; Vlodavsky, I.

    1989-01-01

    Basic fibroblast growth factor (bFGF) exhibits specific binding to the extracellular matrix (ECM) produced by cultured endothelial cells. Binding was saturable as a function both of time and of concentration of 125 I-bFGF. Scatchard analysis of FGF binding revealed the presence of about 1.5 x 10 12 binding sites/mm 2 ECM with an apparent k D of 610 nM. FGF binds to heparan sulfate (HS) in ECM as evidenced by (i) inhibition of binding in the presence of heparin or HS at 0.1-1 μg/mL, but not by chondroitin sulfate, keratan sulfate, or hyaluronic acid at 10 μg/mL, (ii) lack of binding to ECM pretreated with heparitinase, but not with chondroitinase ABC, and (iii) rapid release of up to 90% of ECM-bound FGF by exposure to heparin, HS, or heparitinase, but not to chondroitin sulfate, keratan sulfate, hyaluronic acid, or chondroitinase ABC. Oligosaccharides derived from depolymerized heparin, and as small as the tetrasaccharide, released the ECM-bound FGF, but there was little or no release of FGF by modified nonanticoagulant heparins such as totally desulfated heparin, N-desulfated heparin, and N-acetylated heparin. FGF released from ECM was biologically active, as indicated by its stimulation of cell proliferation and DNA synthesis in vascular endothelial cells and 3T3 fibroblasts. Similar results were obtained in studies on release of endogenous FGF-like mitogenic activity from Descement's membranes of bovine corneas. It is suggested that ECM storage and release of bFGF provide a novel mechanism for regulation of capillary blood vessel growth. Whereas ECM-bound FGF may be prevented from acting on endothelial cells, its displacement by heparin-like molecules and/or HS-degrading enzymes may elicit a neovascular response

  11. Removal of glycosaminoglycans from bovine granulosa cells contributes to increased binding of hydrogen-3 heparin

    Energy Technology Data Exchange (ETDEWEB)

    Ax, R.L.; Stodd, C.M.; Boehm, S.K.; Bellin, M.E.

    1986-02-01

    Granulosa cells from small or large bovine follicles were pretreated with enzymes that hydrolyze various glycosaminoglycans, and binding of (/sup 3/H)-heparin to the granulosa was measured. Binding of (/sup 3/H) heparin increased significantly after enzymatic pretreatments with chondroitinase ABC and fungal hyaluronidase, and similar results were obtained with granulosa from small and large follicles. No changes in binding of (/sup 3/H) heparin were detected after hydrolyses with chondroitinase AC and heparinase in either follicle size. Heparitinase, which hydrolyzes heparan sulfate, led to a significant 50% increase in binding of (/sup 3/H) heparin to granulosa from large follicles but was without effect in small follicles. These results suggest that the lower binding of (/sup 3/H) heparin, which has been reported with follicular enlargement, may be due to heparan sulfate occupying or obstructing binding sites for heparin on granulosa from large follicles.

  12. Detection of growth factor binding to gelatin and heparin using a photonic crystal optical biosensor

    International Nuclear Information System (INIS)

    Morgan, Abby W.; Chan, Leo L.; Sendemir-Urkmez, Aylin; Cunningham, Brian T.; Jamison, Russell D.

    2010-01-01

    Drug-carrier interactions are important to protein controlled release systems to protect the protein from denaturation and ensure properly timed release. A novel photonic crystal biosensor was used to investigate a gelatin-protein controlled release system to determine the amount of protein bound to the carrier at physiological conditions. The Biomolecular Interaction Detection (BIND) system reflects a narrow band of wavelengths when white light is shone incident to the grating. As mass is deposited onto the surface, the peak wavelength value is shifted due to changes in the optical density of the biosensor. The BIND system was used to detect the binding of growth factors onto acidic gelatin, basic gelatin, and heparin on the sensor surface. Through a series of experiments, including functionalizing the sensor, adjusting the ionic strength of the solution, adjusting the substrate concentration, and minimizing non-specific signal, the adsorption of the gelatins and heparin on the sensor was enhanced. The binding interaction of recombinant human transforming growth factor (rhTGF)-β1 and bone morphogenetic protein (rhBMP)-2 with the two types of gelatin and heparin were investigated. The strength of the interaction between rhTGF-β1 and the substrates is in the following order: heparin > acidic gelatin > basic gelatin. RhBMP-2 bound to the substrates but with less intensity than TGF-β1: heparin > basic gelatin > acidic gelatin. This work provides support for the controlled release mechanism through degradation of the gelatin carrier.

  13. A sensitive competitive binding assay for exogenous and endogenous heparins

    International Nuclear Information System (INIS)

    Dawes, J.; Pepper, D.S.

    1982-01-01

    A new type of assay for heparins has been devised, in which the test material competes with 125 I-labelled heparin for binding to protamine-Sepharose. The assay is very sensitive and will measure heparin concentrations down to 10 ng ml-1. It responds to both the degree of sulphation and the molecular weight of acidic polysaccharides, but is independent of their biological activities. It can be used to quantitate heparins in biological fluids after pretreatment of the samples with protease. In this way endogenous heparins were measured in normal human serum, plasma and urine. The assay is extremely versatile and has great potential for the investigation of endogenous and exogenous heparins

  14. Analyses of Interactions Between Heparin and the Apical Surface Proteins of Plasmodium falciparum

    Science.gov (United States)

    Kobayashi, Kyousuke; Takano, Ryo; Takemae, Hitoshi; Sugi, Tatsuki; Ishiwa, Akiko; Gong, Haiyan; Recuenco, Frances C.; Iwanaga, Tatsuya; Horimoto, Taisuke; Akashi, Hiroomi; Kato, Kentaro

    2013-11-01

    Heparin, a sulfated glycoconjugate, reportedly inhibits the blood-stage growth of the malaria parasite Plasmodium falciparum. Elucidation of the inhibitory mechanism is valuable for developing novel invasion-blocking treatments based on heparin. Merozoite surface protein 1 has been reported as a candidate target of heparin; however, to better understand the molecular mechanisms involved, we characterized the molecules that bind to heparin during merozoite invasion. Here, we show that heparin binds only at the apical tip of the merozoite surface and that multiple heparin-binding proteins localize preferentially in the apical organelles. To identify heparin-binding proteins, parasite proteins were fractionated by means of heparin affinity chromatography and subjected to immunoblot analysis with ligand-specific antibodies. All tested members of the Duffy and reticulocyte binding-like families bound to heparin with diverse affinities. These findings suggest that heparin masks the apical surface of merozoites and blocks interaction with the erythrocyte membrane after initial attachment.

  15. Heparin binding domain of antithrombin III: Characterization using a synthetic peptide directed polyclonal antibody

    International Nuclear Information System (INIS)

    Smith, J.W.; Dey, B.; Knauer, D.J.

    1990-01-01

    Antithrombin III (ATIII) is a plasma-borne serine protease inhibitor that apparently forms covalent complexes with thrombin. The interaction between ATIII and thrombin is enhanced several thousandfold by the glycosaminoglycan, heparin. The authors have previously proposed that the heparin binding site of ATIII residues within a region extending from amino acid residues 114-156. Computer-assisted analysis of this region revealed the presence of a 22 amino acid domain (residues 124-145), part of which shows a strong potential for the formation of an amphipathic helix: hydrophobic on one face and highly positively charged on the other. In the presence studies, polyclonal antisera were generated against a synthetic peptide corresponding to residues 124-145 in native human ATIII. Affinity-purified IgG from these antisera, as well as monovalent Fab's derived from them, specifically blocked the binding of heparin to ATIII. Additionally, occupancy of the heparin binding site by these same monovalent and bivalent IgG's at least partially substituted for heparin, accelerating linkage formation between ATIII and thrombin. These results provide the first immunological evidence that region 124-145 is directly involved in the binding of heparin to ATIII and that an antibody-induced conformational change within this region can mediate ATIII activation

  16. The differences in heparin binding for the C-terminal basic-sequence-rich peptides of HPV-16 and HPV-18 capsid protein L1

    International Nuclear Information System (INIS)

    Sun Jian; Yu Jisheng; Yu Zhiwu; Zha Xiao; Wu Yuqing

    2012-01-01

    Graphial abstract: The differences in heparin binding for the C-terminal basic-sequence-rich peptides of HPV-16 and HPV-18 capsid protein L1. Highlights: ► Several driving forces contribute to the interaction between heparin and peptides. ► C-terminal of HPV L1 is a potential candidate for the attachment to host cells. ► The C-terminal peptides of HPV-16 and -18 L1 have different heparin-binding. ► The different heparin-binding provides an explanation for the distinct prevalences. - Abstract: The high-risk types of human papillomaviruses (HPV) HPV-16 and -18 are the predominant types associated with cervical cancer. HPV-16 and -18 account for about 50% and 20%, respectively, of cervical cancers worldwide. While the reason and molecular mechanism of the distinct prevalence and distributions between them remain poorly understood, the binding affinity of cell surface receptor with capsid proteins, especially L1, may be involved. We examined heparin binding with two synthetic peptides corresponding to the 14 amino acid C-terminal peptides of HPV-16 and -18 L1 with the goal of comparing the equivalent residues in different HPV types. Using isothermal titration calorimetry (ITC) and static right-angle light scattering (SLS), we determined the binding constant K, reaction enthalpy ΔH, and other thermodynamic parameters in the interaction. Especially, we assessed the role of specific residues in binding with heparin by comparing the NMR spectra of free and heparin-bound peptides.

  17. Layer-by-Layer Heparinization of the Cell Surface by Using Heparin-Binding Peptide Functionalized Human Serum Albumin.

    Science.gov (United States)

    Song, Guowei; Hu, Yaning; Liu, Yusheng; Jiang, Rui

    2018-05-20

    Layer-by-layer heparinization of therapeutic cells prior to transplantation is an effective way to inhibit the instant blood-mediated inflammatory reactions (IBMIRs), which are the major cause of early cell graft loss during post-transplantation. Here, a conjugate of heparin-binding peptide (HBP) and human serum albumin (HSA), HBP-HSA, was synthesized by using heterobifunctional crosslinker. After the first heparin layer was coated on human umbilical vein endothelial cells (HUVECs) by means of the HBP-polyethylene glycol-phospholipid conjugate, HBP-HSA and heparin were then applied to the cell surface sequentially to form multiple layers. The immobilization and retention of heparin were analyzed by confocal microscopy and flow cytometry, respectively, and the cytotoxity of HBP-HSA was further evaluated by cell viability assay. Results indicated that heparin was successfully introduced to the cell surface in a layer-by-layer way and retained for at least 24 h, while the cytotoxity of HBP-HSA was negligible at the working concentration. Accordingly, this conjugate provides a promising method for co-immobilization of heparin and HSA to the cell surface under physiological conditions with improved biocompatibility.

  18. Human IGF-I propeptide A promotes articular chondrocyte biosynthesis and employs glycosylation-dependent heparin binding.

    Science.gov (United States)

    Shi, Shuiliang; Kelly, Brian J; Wang, Congrong; Klingler, Ken; Chan, Albert; Eckert, George J; Trippel, Stephen B

    2018-03-01

    Insulin-like growth factor I (IGF-I) is a key regulator of chondrogenesis, but its therapeutic application to articular cartilage damage is limited by rapid elimination from the repair site. The human IGF-I gene gives rise to three IGF-I propeptides (proIGF-IA, proIGF-IB and proIGF-IC) that are cleaved to create mature IGF-I. In this study, we elucidate the processing of IGF-I precursors by articular chondrocytes, and test the hypotheses that proIGF-I isoforms bind to heparin and regulate articular chondrocyte biosynthesis. Human IGF-I propeptides and mutants were overexpressed in bovine articular chondrocytes. IGF-I products were characterized by ELISA, western blot and FPLC using a heparin column. The biosynthetic activity of IGF-I products on articular chondrocytes was assayed for DNA and glycosaminoglycan that the cells produced. Secreted IGF-I propeptides stimulated articular chondrocyte biosynthetic activity to the same degree as mature IGF-I. Of the three IGF-I propeptides, only one, proIGF-IA, strongly bound to heparin. Interestingly, heparin binding of proIGF-IA depended on N-glycosylation at Asn92 in the EA peptide. To our knowledge, this is the first demonstration that N-glycosylation determines the binding of a heparin-binding protein to heparin. The biosynthetic and heparin binding abilities of proIGF-IA, coupled with its generation of IGF-I, suggest that proIGF-IA may have therapeutic value for articular cartilage repair. These data identify human pro-insulin-like growth factor IA as a bifunctional protein. Its combined ability to bind heparin and augment chondrocyte biosynthesis makes it a promising therapeutic agent for cartilage damage due to trauma and osteoarthritis. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Furin proteolytically processes the heparin-binding region of extracellular superoxide dismutase

    DEFF Research Database (Denmark)

    Bowler, Russell P; Nicks, Mike; Olsen, Dorte Aa

    2002-01-01

    Extracellular superoxide dismutase (EC-SOD) is an antioxidant enzyme that attenuates brain and lung injury from oxidative stress. A polybasic region in the carboxyl terminus distinguishes EC-SOD from other superoxide dismutases and determines EC-SOD's tissue half-life and affinity for heparin....... There are two types of EC-SOD that differ based on the presence or absence of this heparin-binding region. It has recently been shown that proteolytic removal of the heparin-binding region is an intracellular event (Enghild, J. J., Thogersen, I. B., Oury, T. D., Valnickova, Z., Hojrup, P., and Crapo, J. D...... of intracellular proteases implicate furin as a processing protease. In vitro experiments using furin and purified EC-SOD suggest that furin proteolytically cleaves EC-SOD in the middle of the polybasic region and then requires an additional carboxypeptidase to remove the remaining lysines and arginines...

  20. Proteomic analysis of heparin-binding proteins from human seminal ...

    Indian Academy of Sciences (India)

    Prakash

    (MALDI TOF/MS) for protein analysis of human HBPs. We resolved 70 ... Thus, the combined effects of seminal plasma components support the survival of ...... The BBXB motif of RANTES is the principal site for heparin binding and controls ...

  1. Heparin-binding peptide amphiphile supramolecular architectures as platforms for angiogenesis and drug delivery

    Science.gov (United States)

    Chow, Lesleyann W.

    A fascinating phenomenon in nature is the self-assembly of molecules into a functional, hierarchical structure. In the past decade, the Stupp Laboratory has developed several classes of self-assembling biomaterials, one of which is the synthetic peptide amphiphile (PA). Self-assembling PAs are attractive and versatile biomolecules that can be customized for specific applications in regenerative medicine. In particular, a heparin-binding peptide amphiphile (HBPA) containing a specific heparin-binding peptide sequence was used here to induce angiogenesis and serve as a delivery vehicle for growth factors and small hydrophobic molecules. Throughout this dissertation, the HBPA/heparin system is used in different architectures for a variety of regenerative medicine applications. In one aspect of this work, hybrid scaffolds made from HBPA/heparin gelled on a poly(L-lactic acid) (PLLA) fiber mesh were used to promote angiogenesis to facilitate pancreatic islet transplantation for the treatment of type 1 diabetes. Delivery of growth factors with HBPA/PLLA scafflolds increased vessel density in vivo and correlated with improved transplant outcomes in a streptozotocin-induced diabetic mouse model. Soluble HBPA nanofiber architectures were also useful for islet transplantation applications. These nanofibers were used at concentrations below gelation to deliver growth factors into the dense islet cell aggregate, promoting cell survival and angiogenesis in vitro. The nanostructures infiltrated the islets and promoted the retention of heparin and growth factors within the islet. Another interesting growth factor release system discussed here is the HBPA membrane structure. HBPA was found to self-assemble with hyaluronic acid, a large biopolymer found in the body, into macroscopic, hierarchically-ordered membranes. Heparin was incorporated into these membranes and affected the membrane's mechanical properties and growth factor release. Human mesenchymal stem cells were also shown

  2. Heparin-independent, PF4-dependent binding of HIT antibodies to platelets: implications for HIT pathogenesis.

    Science.gov (United States)

    Padmanabhan, Anand; Jones, Curtis G; Bougie, Daniel W; Curtis, Brian R; McFarland, Janice G; Wang, Demin; Aster, Richard H

    2015-01-01

    Antibodies specific for platelet factor 4 (PF4)/heparin complexes are the hallmark of heparin-induced thrombocytopenia and thrombosis (HIT), but many antibody-positive patients have normal platelet counts. The basis for this is not fully understood, but it is believed that antibodies testing positive in the serotonin release assay (SRA) are the most likely to cause disease. We addressed this issue by characterizing PF4-dependent binding of HIT antibodies to intact platelets and found that most antibodies testing positive in the SRA, but none of those testing negative, bind to and activate platelets when PF4 is present without any requirement for heparin (P HIT antibodies recognize PF4 in a complex with heparin, only a subset of these antibodies recognize more subtle epitopes induced in PF4 when it binds to CS, the major platelet glycosaminoglycan. Antibodies having this property could explain "delayed HIT" seen in some individuals after discontinuation of heparin and the high risk for thrombosis that persists for weeks in patients recovered from HIT. © 2015 by The American Society of Hematology.

  3. The N-terminal of a heparin-binding sperm membrane mitogen possess lectin-like sequence

    International Nuclear Information System (INIS)

    Mor, Visesato; Chatterjee, Tapati

    2007-01-01

    Glycosaminoglycans like heparin and heparin sulfate in follicular fluid induce changes in the intracellular environment during the spermatozoal functional maturation. We previously reported the isolation, purification and partial characterization of a heparin binding sperm membrane protein (HBSM). In the present study, the amino acids analysis provided evidence of a single sequence, which suggest the homogeneity of the purified HBSM. Fourteen amino acids- 1 A D T I V A V E L D T Y P N 14 -correspond to the amino terminal sequence of Concanavalin A (Con A) and contain 45.2% carbohydrate by weight. HBSM possess mitogenic property on lymphocytes with comparable magnitude to the well-known mitogen; Con A, inducing 83% radiolabel thymidine incorporation in growing lymphocytes. Unlike Con A, there was no agglutination of cell by HBSM upto 5 ng/ml concentration. Interestingly, we found that heparin and chondroitin sulfate-conjugated HBSM inhibit the proliferative activity. Similar effect was also found with an in-house isolate sulfated glycans; G-I (28% sulfate). In contrast, there was no inhibition by the desulfated form; G-ID. Altogether, our data suggest that the mechanism of cell proliferative pathway may be different for HBSM and Con A

  4. Sequence similarity between the erythrocyte binding domain of the Plasmodium vivax Duffy binding protein and the V3 loop of HIV-1 strain MN reveals a functional heparin binding motif involved in binding to the Duffy antigen receptor for chemokines

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    Bolton Michael J

    2011-11-01

    Full Text Available Abstract Background The HIV surface glycoprotein gp120 (SU, gp120 and the Plasmodium vivax Duffy binding protein (PvDBP bind to chemokine receptors during infection and have a site of amino acid sequence similarity in their binding domains that often includes a heparin binding motif (HBM. Infection by either pathogen has been found to be inhibited by polyanions. Results Specific polyanions that inhibit HIV infection and bind to the V3 loop of X4 strains also inhibited DBP-mediated infection of erythrocytes and DBP binding to the Duffy Antigen Receptor for Chemokines (DARC. A peptide including the HBM of PvDBP had similar affinity for heparin as RANTES and V3 loop peptides, and could be specifically inhibited from heparin binding by the same polyanions that inhibit DBP binding to DARC. However, some V3 peptides can competitively inhibit RANTES binding to heparin, but not the PvDBP HBM peptide. Three other members of the DBP family have an HBM sequence that is necessary for erythrocyte binding, however only the protein which binds to DARC, the P. knowlesi alpha protein, is inhibited by heparin from binding to erythrocytes. Heparitinase digestion does not affect the binding of DBP to erythrocytes. Conclusion The HBMs of DBPs that bind to DARC have similar heparin binding affinities as some V3 loop peptides and chemokines, are responsible for specific sulfated polysaccharide inhibition of parasite binding and invasion of red blood cells, and are more likely to bind to negative charges on the receptor than cell surface glycosaminoglycans.

  5. The heparin-binding site in tetranectin is located in the N-terminal region and binding does not involve the carbohydrate recognition domain.

    Science.gov (United States)

    Lorentsen, R H; Graversen, J H; Caterer, N R; Thogersen, H C; Etzerodt, M

    2000-04-01

    Tetranectin is a homotrimeric plasma and extracellular-matrix protein that binds plasminogen and complex sulphated polysaccharides including heparin. In terms of primary and tertiary structure, tetranectin is related to the collectin family of Ca(2+)-binding C-type lectins. Tetranectin is encoded in three exons. Exon 3 encodes the carbohydrate recognition domain, which binds to kringle 4 in plasminogen at low levels of Ca(2+). Exon 2 encodes an alpha-helix, which is necessary and sufficient to govern the trimerization of tetranectin by assembling into a triple-helical coiled-coil structural element. Here we show that the heparin-binding site in tetranectin resides not in the carbohydrate recognition domain but within the N-terminal region, comprising the 16 amino acid residues encoded by exon 1. In particular, the lysine residues in the decapeptide segment KPKKIVNAKK (tetranectin residues 6-15) are shown to be of primary importance in heparin binding.

  6. Heparin-binding epidermal growth factor-like growth factor promotes neuroblastoma differentiation.

    Science.gov (United States)

    Gaviglio, Angela L; Knelson, Erik H; Blobe, Gerard C

    2017-05-01

    High-risk neuroblastoma is characterized by undifferentiated neuroblasts and low schwannian stroma content. The tumor stroma contributes to the suppression of tumor growth by releasing soluble factors that promote neuroblast differentiation. Here we identify heparin-binding epidermal growth factor-like growth factor (HBEGF) as a potent prodifferentiating factor in neuroblastoma. HBEGF mRNA expression is decreased in human neuroblastoma tumors compared with benign tumors, with loss correlating with decreased survival. HBEGF protein is expressed only in stromal compartments of human neuroblastoma specimens, with tissue from high-stage disease containing very little stroma or HBEGF expression. In 3 human neuroblastoma cell lines (SK-N-AS, SK-N-BE2, and SH-SY5Y), soluble HBEGF is sufficient to promote neuroblast differentiation and decrease proliferation. Heparan sulfate proteoglycans and heparin derivatives further enhance HBEGF-induced differentiation by forming a complex with the epidermal growth factor receptor, leading to activation of the ERK1/2 and STAT3 pathways and up-regulation of the inhibitor of DNA binding transcription factor. These data support a role for loss of HBEGF in the neuroblastoma tumor microenvironment in neuroblastoma pathogenesis.-Gaviglio, A. L., Knelson, E. H., Blobe, G. C. Heparin-binding epidermal growth factor-like growth factor promotes neuroblastoma differentiation. © FASEB.

  7. Endothelial cell capture of heparin-binding growth factors under flow.

    Directory of Open Access Journals (Sweden)

    Bing Zhao

    2010-10-01

    Full Text Available Circulation is an important delivery method for both natural and synthetic molecules, but microenvironment interactions, regulated by endothelial cells and critical to the molecule's fate, are difficult to interpret using traditional approaches. In this work, we analyzed and predicted growth factor capture under flow using computer modeling and a three-dimensional experimental approach that includes pertinent circulation characteristics such as pulsatile flow, competing binding interactions, and limited bioavailability. An understanding of the controlling features of this process was desired. The experimental module consisted of a bioreactor with synthetic endothelial-lined hollow fibers under flow. The physical design of the system was incorporated into the model parameters. The heparin-binding growth factor fibroblast growth factor-2 (FGF-2 was used for both the experiments and simulations. Our computational model was composed of three parts: (1 media flow equations, (2 mass transport equations and (3 cell surface reaction equations. The model is based on the flow and reactions within a single hollow fiber and was scaled linearly by the total number of fibers for comparison with experimental results. Our model predicted, and experiments confirmed, that removal of heparan sulfate (HS from the system would result in a dramatic loss of binding by heparin-binding proteins, but not by proteins that do not bind heparin. The model further predicted a significant loss of bound protein at flow rates only slightly higher than average capillary flow rates, corroborated experimentally, suggesting that the probability of capture in a single pass at high flow rates is extremely low. Several other key parameters were investigated with the coupling between receptors and proteoglycans shown to have a critical impact on successful capture. The combined system offers opportunities to examine circulation capture in a straightforward quantitative manner that

  8. In vivo studies on the binding of heparin and its fractions with platelet factor 4

    International Nuclear Information System (INIS)

    Walz, D.A.; Hung, G.L.

    1985-01-01

    PF4 has a half-life in plasma of less than 3 minutes, and its rapid clearance appears to be a function of binding to the vascular endothelium. Once bound to the endothelium, PF4 can be released by heparin in a time-dependent manner; recovery is greater the sooner heparin is administered following PF4 infusion. This heparin-induced release of PF4 can be abolished if the heparin is first complexed with hexadimethrine bromide. Likewise, this heparin-induced release of PF4 is dependent upon the type of heparin used; low molecular weight heparin fractions and fragments do not cause the PF4 rebound seen with intact heparin. Thus, it would appear that low molecular weight forms of heparin are advantageous in that their in vivo administration would not be mediated by such platelet modulators as PF4

  9. Heparin binding sites on Ross River virus revealed by electron cryo-microscopy

    International Nuclear Information System (INIS)

    Zhang Wei; Heil, Marintha; Kuhn, Richard J.; Baker, Timothy S.

    2005-01-01

    Cell surface glycosaminoglycans play important roles in cell adhesion and viral entry. Laboratory strains of two alphaviruses, Sindbis and Semliki Forest virus, have been shown to utilize heparan sulfate as an attachment receptor, whereas Ross River virus (RRV) does not significantly interact with it. However, a single amino acid substitution at residue 218 in the RRV E2 glycoprotein adapts the virus to heparan sulfate binding and expands the host range of the virus into chicken embryo fibroblasts. Structures of the RRV mutant, E2 N218R, and its complex with heparin were determined through the use of electron cryo-microscopy and image reconstruction methods. Heparin was found to bind at the distal end of the RRV spikes, in a region of the E2 glycoprotein that has been previously implicated in cell-receptor recognition and antibody binding

  10. Mapping the heparin-binding site of the BMP antagonist gremlin by site-directed mutagenesis based on predictive modelling.

    Science.gov (United States)

    Tatsinkam, Arnold Junior; Mulloy, Barbara; Rider, Christopher C

    2015-08-15

    Gremlin is a member of the CAN (cerberus and DAN) family of secreted BMP (bone morphogenetic protein) antagonists and also an agonist of VEGF (vascular endothelial growth factor) receptor-2. It is critical in limb skeleton and kidney development and is re-expressed during tissue fibrosis. Gremlin binds strongly to heparin and heparan sulfate and, in the present study, we sought to investigate its heparin-binding site. In order to explore a putative non-contiguous binding site predicted by computational molecular modelling, we substituted a total of 11 key arginines and lysines located in three basic residue sequence clusters with homologous sequences from cerberus and DAN (differential screening selected gene abberative in neuroblastoma), CAN proteins which lack basic residues in these positions. A panel of six Myc-tagged gremlin mutants, MGR-1-MGR-6 (MGR, mutant gremlin), each containing different combinations of targeted substitutions, all showed markedly reduced affinity for heparin as demonstrated by their NaCl elution on heparin affinity chromatography, thus verifying our predictions. Both MGR-5 and MGR-6 retained BMP-4-binding activity comparable to that of wild-type gremlin. Low-molecular-mass heparin neither promoted nor inhibited BMP-4 binding. Finally, glutaraldehyde cross-linking demonstrated that gremlin forms non-covalent dimers, similar behaviour to that of DAN and also PRDC (protein related to cerberus and DAN), another CAN protein. The resulting dimer would possess two heparin-binding sites, each running along an exposed surface on the second β-strand finger loop of one of the monomers. © 2015 Authors; published by Portland Press Limited.

  11. Thermodynamic parameters associated with the binding of adrenaline and norephedrine to heparin

    International Nuclear Information System (INIS)

    Ali-Ali, A.K.; Buchanan, J.D.; Power, D.M.; Butler, J.

    1983-01-01

    Pulse radiolysis was used to determine the thermodynamic parameters (ΔG', ΔH' and ΔS') governing the binding of adrenalin and norephedrine to heparin. The complexes were completely dissociated by increasing concentrations of inorganic salts. Lower concentrations of divalent cations (e.g. Ca 2+ ) were more necessary to affect dissociation than those of monovalent cations (e.g. Na + ). For each interaction, an increase in drug binding occurred as the temperature was increased from ambient. However, a transition temperature was observed (48 degC) above which the drug was progressively released as temperature was increased. These observations probably reflect conformational changes induced in the heparin below and above its melting temperature. (author)

  12. Heparin: The Silver Bullet of Aneurysmal Subarachnoid Hemorrhage?

    Directory of Open Access Journals (Sweden)

    Nicolas K. Khattar

    2018-03-01

    Full Text Available Various neurological diseases have recently been associated with neuroinflammation and worsening outcomes. Subarachnoid hemorrhage has been shown to generate a potent neuroinflammatory response. Heparin is a potential effective anti-inflammatory agent to prevent initial injury as well as delayed neurological decline. Different mechanisms of action for heparin have been proposed including, but not limited to the binding and neutralization of oxyhemoglobin, decreased transcription and signal transduction of endothelin-1, inhibition of binding to vessel wall selectins and vascular leakage into the subarachnoid space as well as direct binding and neutralization of inflammatory molecules. With a reasonably safe side-effect profile, heparin has shown significant promise in small series in human studies of aneurysmal subarachnoid hemorrhage in decreasing both initial and delayed neurological injury. Further studies are needed to validate various neuroprotective features of heparin in subarachnoid hemorrhage as well as other disease states.

  13. Simple and Efficient Purification of Recombinant Proteins Using the Heparin-Binding Affinity Tag.

    Science.gov (United States)

    Jayanthi, Srinivas; Gundampati, Ravi Kumar; Kumar, Thallapuranam Krishnaswamy Suresh

    2017-11-01

    Heparin, a member of the glycosaminoglycan family, is known to interact with more than 400 different types of proteins. For the past few decades, significant progress has been made to understand the molecular details involved in heparin-protein interactions. Based on the structural knowledge available from the FGF1-heparin interaction studies, we have designed a novel heparin-binding peptide (HBP) affinity tag that can be used for the simple, efficient, and cost-effective purification of recombinant proteins of interest. HBP-tagged fusion proteins can be purified by heparin Sepharose affinity chromatography using a simple sodium chloride gradient to elute the bound fusion protein. In addition, owing to the high density of positive charges on the HBP tag, recombinant target proteins are preferably expressed in their soluble forms. The purification of HBP-fusion proteins can also be achieved in the presence of chemical denaturants, including urea. Additionally, polyclonal antibodies raised against the affinity tag can be used to detect HBP-fused target proteins with high sensitivity. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  14. Interactions between nattokinase and heparin/GAGs.

    Science.gov (United States)

    Zhang, Fuming; Zhang, Jianhua; Linhardt, Robert J

    2015-12-01

    Nattokinase (NK) is a serine protease extracted from a traditional Japanese food called natto. Due to its strong fibrinolytic and thrombolytic activity, NK is regarded as a valuable dietary supplement or nutraceutical for the oral thrombolytic therapy. In addition, NK has been investigated for some other medical applications including treatment of hypertension, Alzheimer's disease, and vitreoretinal disorders. The most widely used clinical anticoagulants are heparin and low molecular weight heparins. The interactions between heparin and proteins modulate diverse patho-physiological processes and heparin modifies the activity of serine proteases. Indeed, heparin plays important roles in almost all of NK's potential therapeutically applications. The current report relies on surface plasmon resonance spectroscopy to examine NK interacting with heparin as well as other glycosaminoglycans (GAGs). These studies showed that NK is a heparin binding protein with an affinity of ~250 nM. Examination with differently sized heparin oligosaccharides indicated that the interaction between NK and heparin is chain-length dependent and the minimum size for heparin binding is a hexasaccharide. Studies using chemically modified heparin showed the 6-O-sulfo as well as the N-sulfo groups but not the 2-O-sulfo groups within heparin, are essential for heparin's interaction with NK. Other GAGs (including HS, DS, and CSE) displayed modest binding affinity to NK. NK also interfered with other heparin-protein interactions, including heparin's interaction with antithrombin and fibroblast growth factors.

  15. A triad of lys12, lys41, arg78 spatial domain, a novel identified heparin binding site on tat protein, facilitates tat-driven cell adhesion.

    Directory of Open Access Journals (Sweden)

    Jing Ai

    Full Text Available Tat protein, released by HIV-infected cells, has a battery of important biological effects leading to distinct AIDS-associated pathologies. Cell surface heparan sulfate protoglycans (HSPGs have been accepted as endogenous Tat receptors, and the Tat basic domain has been identified as the heparin binding site. However, findings that deletion or substitution of the basic domain inhibits but does not completely eliminate Tat-heparin interactions suggest that the basic domain is not the sole Tat heparin binding site. In the current study, an approach integrating computational modeling, mutagenesis, biophysical and cell-based assays was used to elucidate a novel, high affinity heparin-binding site: a Lys12, Lys41, Arg78 (KKR spatial domain. This domain was also found to facilitate Tat-driven β1 integrin activation, producing subsequent SLK cell adhesion in an HSPG-dependent manner, but was not involved in Tat internalization. The identification of this new heparin binding site may foster further insight into the nature of Tat-heparin interactions and subsequent biological functions, facilitating the rational design of new therapeutics against Tat-mediated pathological events.

  16. Heparin Interaction with the Primed Polymorphonuclear Leukocyte CD11b Induces Apoptosis and Prevents Cell Activation

    Directory of Open Access Journals (Sweden)

    Meital Cohen-Mazor

    2015-01-01

    Full Text Available Heparin is known to have anti-inflammatory effects, yet the mechanisms are not completely understood. In this study, we tested the hypothesis that heparin has a direct effect on activated polymorphonuclear leukocytes (PMNLs, changing their activation state, and can explain its anti-inflammatory effect. To test our hypothesis, we designed both in vitro and ex vivo studies to elucidate the mechanism by which heparin modulates PMNL functions and therefore the inflammatory response. We specifically tested the hypothesis that priming of PMNLs renders them more susceptible to heparin. Amplified levels of CD11b and increased rate of superoxide release manifested PMNL priming. Increase in cell priming resulted in a dose-dependent increase in heparin binding to PMNLs followed by augmented apoptosis. Blocking antibodies to CD11b inhibited heparin binding and abolished the apoptotic response. Moreover, heparin caused a significant dose-dependent decrease in the rate of superoxide release from PMNLs, which was blunted by blocking antibodies to CD11b. Altogether, this study shows that the interaction of heparin with the PMNL CD11b results in cell apoptosis and explains heparin’s anti-inflammatory effects.

  17. Profiling Heparin-Chemokine Interactions Using Synthetic Tools

    Science.gov (United States)

    de Paz, Jose L.; Moseman, E. Ashley; Noti, Christian; Polito, Laura; von Andrian, Ulrich H.; Seeberger, Peter H.

    2009-01-01

    Glycosaminoglycans (GAGs), such as heparin or heparan sulfate, are required for the in vivo function of chemokines. Chemokines play a crucial role in the recruitment of leukocyte subsets to sites of inflammation and lymphocytes trafficking. GAG-chemokine interactions mediate cell migration and determine which leukocyte subsets enter tissues. Identifying the exact GAC sequences that bind to particular chemokines is key to understand chemokine function at the molecular level and develop strategies to interfere with chemokine-mediated processes. Here, we characterize the heparin binding profiles of eight chemokines (CCL21, IL-8, CXCL12, CXCL13, CCL19, CCL25, CCL28, and CXCL16) by employing heparin microarrays containing a small library of synthetic heparin oligosaccharides. The chemokines differ significantly in their interactions with heparin oligosaccharides: While some chemokines, (e.g., CCL21) strongly bind to a hexasaccharide containing the GlcNSO3(6-OSO3)-IdoA(2-OSO3) repeating unit, CCL19 does not bind and CXCL12 binds only weakly. The carbohydrate microarray binding results were validated by surface plasmon resonance experiments. In vitro chemotaxis assays revealed that dendrimers coated with the fully sulfated heparin hexasaccharide inhibit lymphocyte migration toward CCL21. Migration toward CXCL12 or CCL19 was not affected. These in vitro homing assays indicate that multivalent synthetic heparin dendrimers inhibit the migration of lymphocytes toward certain chemokine gradients by blocking the formation of a chemokine concentration gradient on GAG endothelial chains. These findings are in agreement with preliminary in vivo measurements of circulating lymphocytes. The results presented here contribute to the understanding of GAG-chemokine interactions, a first step toward the design of novel drugs that modulate chemokine activity. PMID:18030990

  18. Evidence for a saturable mechanism of disappearance of standard heparin in rabbits

    International Nuclear Information System (INIS)

    Boneu, B.; Caranobe, C.; Gabaig, A.M.; Dupouy, D.; Sie, P.; Buchanan, M.R.; Hirsh, J.

    1987-01-01

    This work demonstrates that after bolus intravenous injection standard heparin (SH) disappearance results from the combination of a saturable and a non saturable mechanism. Pharmacokinetics and pharmacodynamics of SH were studied by measuring the disappearance of increasing doses (5 - 500 anti-factor Xa U/kg) of 125 I-heparin and of its biological effects. CPM curves allowed the determination of the half lives of heparin according to the dose injected. The half lives were clearly dose dependent and reached a plateau over 100 anti-factor Xa U/kg. The complex curve which describes the amount of heparin cleared per time unit after any given dose has been resolved into its two components reflecting a saturable and a non saturable mechanism of disappearance. For the doses less than 100 anti-factor Xa U/kg the saturable mechanism was preeminent and the anti-factor Xa activity disappearance followed an exponential pattern; for the doses less than 100 anti-factor Xa U/kg the contribution of the non saturable mechanism becomes more important and the anti-factor Xa activity disappearance followed a concave-convex pattern. Further experiments showed that the heparin half life shortened as the circulating anti-factor Xa activity decreased; this phenomenon may explain the concave-convex pattern of the curve of the anticoagulant effect observed after injection of large doses of SH

  19. Aggregated forms of bull seminal plasma proteins and their heparin-binding activity

    Czech Academy of Sciences Publication Activity Database

    Jelínková, Petra; Ryšlavá, H.; Liberda, J.; Jonáková, Věra; Tichá, M.

    2004-01-01

    Roč. 69, - (2004), s. 616-630 ISSN 0010-0765 R&D Projects: GA ČR GA303/02/0433; GA ČR GP303/02/P069; GA MZd NJ7463 Institutional research plan: CEZ:AV0Z5052915; CEZ:MSM 113100001 Keywords : bull seminal plasma proteins * heparin-binding proteins * aggregated forms of proteins Subject RIV: CE - Biochemistry Impact factor: 1.062, year: 2004

  20. Octasaccharide is the minimal length unit required for efficient binding of cyclophilin B to heparin and cell surface heparan sulphate.

    Science.gov (United States)

    Vanpouille, Christophe; Denys, Agnès; Carpentier, Mathieu; Pakula, Rachel; Mazurier, Joël; Allain, Fabrice

    2004-09-01

    Cyclophilin B (CyPB) is a heparin-binding protein first identified as a receptor for cyclosporin A. In previous studies, we reported that CyPB triggers chemotaxis and integrin-mediated adhesion of T-lymphocytes by way of interaction with two types of binding sites. The first site corresponds to a signalling receptor; the second site has been identified as heparan sulphate (HS) and appears crucial to induce cell adhesion. Characterization of the HS-binding unit is critical to understand the requirement of HS in pro-adhesive activity of CyPB. By using a strategy based on gel mobility shift assays with fluorophore-labelled oligosaccharides, we demonstrated that the minimal heparin unit required for efficient binding of CyPB is an octasaccharide. The mutants CyPB(KKK-) [where KKK- refers to the substitutions K3A(Lys3-->Ala)/K4A/K5A] and CyPB(DeltaYFD) (where Tyr14-Phe-Asp16 has been deleted) failed to interact with octasaccharides, confirming that the Y14FD16 and K3KK5 clusters are required for CyPB binding. Molecular modelling revealed that both clusters are spatially arranged so that they may act synergistically to form a binding site for the octasaccharide. We then demonstrated that heparin-derived octasaccharides and higher degree of polymerization oligosaccharides inhibited the interaction between CyPB and fluorophore-labelled HS chains purified from T-lymphocytes, and strongly reduced the HS-dependent pro-adhesive activity of CyPB. However, oligosaccharides or heparin were unable to restore adhesion of heparinase-treated T-lymphocytes, indicating that HS has to be present on the cell membrane to support the pro-adhesive activity of CyPB. Altogether, these results demonstrate that the octasaccharide is likely to be the minimal length unit required for efficient binding of CyPB to cell surface HS and consequent HS-dependent cell responses.

  1. Activation of M1 macrophages in sepsis-induced acute kidney injury in response to heparin-binding protein.

    Directory of Open Access Journals (Sweden)

    Li Xing

    Full Text Available In the early stage of sepsis, M1 macrophages result in the production of inflammatory mediators and AKI. Heparin-binding protein (HBP have been shown to play important roles in sepsis-induced AKI. In this study, we investigate the association of HBP with M1 macrophages in sepsis-induced AKI.Male C57BL6 mice were subjected to cecal ligation and puncture (CLP or sham surgery. Biochemical and histological renal damage was assessed. Macrophage infiltration was assessed by immunohistochemistry. RT-PCR was used to investigate the expression of heparin-binding protein (HBP, the inducible nitric oxide synthase (iNOS and arginase 1 (Arg-1 mRNAs. Western blots were performed to assay the tissue levels of HBP, tumor necrosis factor alpha (TNF-α and interleukin-6 (IL-6.High levels of HBP were obviously detected 24 h after sepsis-induced AKI. Heparin inhibited HBP expression during sepsis-induced AKI. The suppression of HBP expression by heparin injection after the establishment of sepsis-induced AKI resulted in a reduction in renal injury severity accompanied with a significant repression of M1 macrophage activation and expression of TNF-α and IL-6.HBP plays an important role in the initial inflammatory reaction associated with sepsis-induced AKI, presumably by activating M1 macrophages and suppressing TNF-α and IL-6 secretion.

  2. Enantiomeric and Diastereomeric Self-Assembled Multivalent (SAMul) Nanostructures - Understanding the Effects of Chirality on Binding to Polyanionic Heparin and DNA.

    Science.gov (United States)

    Thornalley, Kiri; Laurini, Erik; Pricl, Sabrina; Smith, David K

    2018-05-15

    A family of four self-assembling lipopeptides containing Ala-Lys peptides attached to a C16 aliphatic chain was synthesised. These compounds form two enantiomeric pairs that bear a diastereomeric relationship to one another (C16-L-Ala-L-Lys/C16-D-Ala-D-Lys) and (C16-D-Ala-L-Lys/C16-L-Ala-D-Lys). These diastereomeric pairs have very different critical micelle concentrations (CMCs), with LL/DD < DL/LD suggesting more effective assembly of the former. The self-assembled multivalent (SAMul) systems bind biological polyanions as result of the cationic lysine groups on their surfaces. Polyanion binding was investigated using dye displacement assays and isothermal calorimetry (ITC). On heparin binding, there was no significant enantioselectivity, but there was a binding preference for the diastereomeric assemblies with lower CMCs. Conversely, on binding DNA, there was a significant enantioselective preference for systems displaying D-lysine ligands, with a further slight preference for attachment to L-alanine, with the CMC being irrelevant. Binding to adaptive, ill-defined heparin has a large favourable entropic term, suggesting it depends primarily on the cationic SAMul nanostructure maximising surface contact with heparin, which can adapt, displacing solvent and other ions. Conversely, binding to well-defined, shape-persistent DNA has a larger favourable enthalpic term, and combined with the enantioselectivity, this allows us to suggest that its SAMul binding is based on optimised individual electrostatic interactions at the molecular level, with a preference for binding to D-lysine. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Quantitative description of thermodynamic and kinetic properties of the platelet factor 4/heparin bonds

    Science.gov (United States)

    Nguyen, Thi-Huong; Greinacher, Andreas; Delcea, Mihaela

    2015-05-01

    Heparin is the most important antithrombotic drug in hospitals. It binds to the endogenous tetrameric protein platelet factor 4 (PF4) forming PF4/heparin complexes which may cause a severe immune-mediated adverse drug reaction, so-called heparin-induced thrombocytopenia (HIT). Although new heparin drugs have been synthesized to reduce such a risk, detailed bond dynamics of the PF4/heparin complexes have not been clearly understood. In this study, single molecule force spectroscopy (SMFS) is utilized to characterize the interaction of PF4 with heparins of defined length (5-, 6-, 8-, 12-, and 16-mers). Analysis of the force-distance curves shows that PF4/heparin binding strength rises with increasing heparin length. In addition, two binding pathways in the PF4/short heparins (=8-mers) are identified. We provide a model for the PF4/heparin complexes in which short heparins bind to one PF4 tetramer, while long heparins bind to two PF4 tetramers. We propose that the interaction between long heparins and PF4s is not only due to charge differences as generally assumed, but also due to hydrophobic interaction between two PF4s which are brought close to each other by long heparin. This complicated interaction induces PF4/heparin complexes more stable than other ligand-receptor interactions. Our results also reveal that the boundary between antigenic and non-antigenic heparins is between 8- and 12-mers. These observations are particularly important to understand processes in which PF4-heparin interactions are involved and to develop new heparin-derived drugs.Heparin is the most important antithrombotic drug in hospitals. It binds to the endogenous tetrameric protein platelet factor 4 (PF4) forming PF4/heparin complexes which may cause a severe immune-mediated adverse drug reaction, so-called heparin-induced thrombocytopenia (HIT). Although new heparin drugs have been synthesized to reduce such a risk, detailed bond dynamics of the PF4/heparin complexes have not been clearly

  4. Investigation of a Potential Protective Mechanism Against Heparin-Induced Thrombocytopenia in Patients on Chronic Intermittent Hemodialysis

    Science.gov (United States)

    Tanhehco, Yvette C.; Cuker, Adam; Rudnick, Michael; Sachais, Bruce S.

    2015-01-01

    BACKGROUND Heparin-induced thrombocytopenia (HIT) develops as a result of platelet (PLT) activation by anti-platelet factor 4 (PF4)/heparin complex antibodies. Despite repeated exposure to heparin, patients undergoing chronic intermittent hemodialysis (HD) rarely develop HIT. We investigated the possibility that HD decreases/removes PF4 from PLT surfaces and/or plasma, thereby disfavoring immune complex formation as a mechanism of protection against HIT. MATERIALS AND METHODS We enrolled 20 patients undergoing chronic HD at the Penn Presbyterian Medical Center. Blood samples were drawn before, during and after treatment in the presence and absence of heparin. PF4, PF4/heparin antibody, heparin, and P-selectin levels were measured. RESULTS No patients demonstrated clinical symptoms of HIT. PLT surface PF4 levels decreased and plasma PF4 levels increased concurrently with increase in plasma heparin concentration. In the absence of heparin, PLT surface and plasma PF4 levels were unchanged. Anti-PF4/heparin antibodies, which were non-functional by the serotonin release assay, were detectable in 8 patients. PLT surface P-selectin levels did not change during treatment. CONCLUSIONS Removal of PLT surface and/or plasma PF4 as a mechanism of protection against HIT in patients undergoing HD is not supported by the results of our study, although the transient decrease in PLT surface PF4 in the presence of large amounts of heparin remains a candidate mechanism. The small sample size, single type of dialyzer membrane, and early sampling time points may have led to the inability to detect changes in PF4 levels. Future studies should explore other potential protective mechanisms. PMID:23305841

  5. Voltammetric determination of heparin based on its interaction with malachite green

    Directory of Open Access Journals (Sweden)

    Xueliang Niu

    2008-08-01

    Full Text Available In this paper malachite green (MG was used as a bioprobe to determine heparin concentration by linear sweep voltammetry on the dropping mercury working electrode (DME. In Britton-Robinson (B-R buffer solution of pH 1.5, MG had a well-defined second order derivative linear sweep voltammetric reductive peak at –0.618 V (vs. SCE. After the addition of heparin into the MG solution, the reductive peak current decreased apparently without the movement of peak potential. Based on the difference of the peak current, a new voltammetric method for the determination of heparin was established. The conditions for the binding reaction and the electrochemical detection were optimized. Under the selected experimental conditions the difference of peak current was directly proportional to the concentration of heparin in the range from 0.3 to 10.0 mg/L with the linear regression equation as ∆ip″ (nA = 360.19 C (mg/L + 178.88 (n = 15, γ = 0.998 and the detection limit as 0.28 mg/L (3σ. The effects of coexisting substances such as metal ions, amino acids on the determination of heparin were investigated and the results showed that this method had good selectivity. This method was further applied to determine the heparin content in heparin sodium injection samples with satisfactory results and good recovery. The stoichiometry of the biocomplex was calculated by the electrochemical method and the binding mechanism was further discussed.

  6. Thermodynamic parameters associated with the binding of adrenalin and norephedrine to heparin

    International Nuclear Information System (INIS)

    Al-Ali, A.K.; Buchanan, J.D.; Power, D.M.; Butler, J.

    1983-01-01

    Pulse radiolysis has been used to determine the thermodynamic parameters (ΔG', ΔH' and ΔS') governing the binding of adrenalin and norephedrine to heparin. These complexes were completely dissociated by increasing concentrations of inorganic salts. Lower concentrations of divalent cations (e.g. Ca 2+ ) than of monovalent cations (e.g. Na + ) were necessary to effect dissociation of the complex. For each interaction an increase in drug binding occurred as the temperature was increased from ambient. However, a transition temperature was observed (48 0 C) above which the drug was progressively released as the temperature was increased. These observations are discussed in terms of conformational changes induced in the polymer below and above its melting temperature. (author)

  7. Sequence similarity between the erythrocyte binding domain of the Plasmodium vivax Duffy binding protein and the V3 loop of HIV-1 strain MN reveals a functional heparin binding motif involved in binding to the Duffy antigen receptor for chemokines

    OpenAIRE

    Bolton, Michael J; Garry, Robert F

    2011-01-01

    Abstract Background The HIV surface glycoprotein gp120 (SU, gp120) and the Plasmodium vivax Duffy binding protein (PvDBP) bind to chemokine receptors during infection and have a site of amino acid sequence similarity in their binding domains that often includes a heparin binding motif (HBM). Infection by either pathogen has been found to be inhibited by polyanions. Results Specific polyanions that inhibit HIV infection and bind to the V3 loop of X4 strains also inhibited DBP-mediated infectio...

  8. The heparin-binding domain of HB-EGF mediates localization to sites of cell-cell contact and prevents HB-EGF proteolytic release

    Energy Technology Data Exchange (ETDEWEB)

    Prince, Robin N.; Schreiter, Eric R.; Zou, Peng; Wiley, H. S.; Ting, Alice Y.; Lee, Richard T.; Lauffenburger, Douglas A.

    2010-07-01

    Heparin-binding EGF-like growth factor (HB-EGF) is a ligand for EGF receptor (EGFR) and possesses the ability to signal in juxtacrine, autocrine and/or paracrine mode, with these alternatives being governed by the degree of proteolytic release of the ligand. Although the spatial range of diffusion of released HB-EGF is restricted by binding heparan-sulfate proteoglycans (HSPGs) in the extracellular matrix and/or cellular glycocalyx, ascertaining mechanisms governing non-released HB-EGF localization is also important for understanding its effects. We have employed a new method for independently tracking the localization of the extracellular EGFlike domain of HB-EGF and the cytoplasmic C-terminus. A striking observation was the absence of the HB-EGF transmembrane proform from the leading edge of COS-7 cells in a wound-closure assay; instead, this protein localized in regions of cell-cell contact. A battery of detailed experiments found that this localization derives from a trans interaction between extracellular HSPGs and the HBEGF heparin-binding domain, and that disruption of this interaction leads to increased release of soluble ligand and a switch in cell phenotype from juxtacrine-induced growth inhibition to autocrine-induced proliferation. Our results indicate that extracellular HSPGs serve to sequester the transmembrane pro-form of HB-EGF at the point of cell-cell contact, and that this plays a role in governing the balance between juxtacrine versus autocrine and paracrine signaling.

  9. Cell adhesion to fibrillin-1: identification of an Arg-Gly-Asp-dependent synergy region and a heparin-binding site that regulates focal adhesion formation

    DEFF Research Database (Denmark)

    Bax, Daniel V; Mahalingam, Yashithra; Cain, Stuart

    2007-01-01

    We have defined the molecular basis of cell adhesion to fibrillin-1, the major structural component of extracellular microfibrils that are associated with elastic fibres. Using human dermal fibroblasts, and recombinant domain swap fragments containing the Arg-Gly-Asp motif, we have demonstrated...... a requirement for upstream domains for integrin-alpha(5)beta(1)-mediated cell adhesion and migration. An adjacent heparin-binding site, which supports focal adhesion formation, was mapped to the fibrillin-1 TB5 motif. Site-directed mutagenesis revealed two arginine residues that are crucial for heparin binding...

  10. Targeting Heparin to Collagen within Extracellular Matrix Significantly Reduces Thrombogenicity and Improves Endothelialization of Decellularized Tissues.

    Science.gov (United States)

    Jiang, Bin; Suen, Rachel; Wertheim, Jason A; Ameer, Guillermo A

    2016-12-12

    Thrombosis within small-diameter vascular grafts limits the development of bioartificial, engineered vascular conduits, especially those derived from extracellular matrix (ECM). Here we describe an easy-to-implement strategy to chemically modify vascular ECM by covalently linking a collagen binding peptide (CBP) to heparin to form a heparin derivative (CBP-heparin) that selectively binds a subset of collagens. Modification of ECM with CBP-heparin leads to increased deposition of functional heparin (by ∼7.2-fold measured by glycosaminoglycan composition) and a corresponding reduction in platelet binding (>70%) and whole blood clotting (>80%) onto the ECM. Furthermore, addition of CBP-heparin to the ECM stabilizes long-term endothelial cell attachment to the lumen of ECM-derived vascular conduits, potentially through recruitment of heparin-binding growth factors that ultimately improve the durability of endothelialization in vitro. Overall, our findings provide a simple yet effective method to increase deposition of functional heparin on the surface of ECM-based vascular grafts and thereby minimize thrombogenicity of decellularized tissue, overcoming a significant challenge in tissue engineering of bioartificial vessels and vascularized organs.

  11. Selective interaction of heparin with the variable region 3 within surface glycoprotein of laboratory-adapted feline immunodeficiency virus.

    Directory of Open Access Journals (Sweden)

    Qiong-Ying Hu

    Full Text Available Heparan sulfate proteoglycans (HSPG can act as binding receptors for certain laboratory-adapted (TCA strains of feline immunodeficiency virus (FIV and human immunodeficiency virus (HIV. Heparin, a soluble heparin sulfate (HS, can inhibit TCA HIV and FIV entry mediated by HSPG interaction in vitro. In the present study, we further determined the selective interaction of heparin with the V3 loop of TCA of FIV. Our current results indicate that heparin selectively inhibits infection by TCA strains, but not for field isolates (FS. Heparin also specifically interferes with TCA surface glycoprotein (SU binding to CXCR4, by interactions with HSPG binding sites on the V3 loop of the FIV envelope protein. Peptides representing either the N- or C-terminal side of the V3 loop and containing HSPG binding sites were able to compete away the heparin block of TCA SU binding to CXCR4. Heparin does not interfere with the interaction of SU with anti-V3 antibodies that target the CXCR4 binding region or with the interaction between FS FIV and anti-V3 antibodies since FS SU has no HSPG binding sites within the HSPG binding region. Our data show that heparin blocks TCA FIV infection or entry not only through its competition of HSPG on the cell surface interaction with SU, but also by its interference with CXCR4 binding to SU. These studies aid in the design and development of heparin derivatives or analogues that can inhibit steps in virus infection and are informative regarding the HSPG/SU interaction.

  12. Influence of heparin on radioimmunological assay of ACTH

    International Nuclear Information System (INIS)

    Dupouy, J.P.; Godaut, M.; Chatelain, A.

    1986-01-01

    1 - Heparin traps plasma ACTH, promoting the formation of aggregates with apparent high molecular weight as shown by chromatography on Sephadex G 50 fine columns. The percentage of 125 I-ACTH which appeared in the void volume of the column, increased linearly with the log. dose of heparin. 2 - Heparin at concentrations of up to 100 IU/ml does not impair ACTH adsorption on either silicic acid or Quso G 32 as well as further elution by acetic acid/acetone/water (I: 40: 59; V/V) or HCl O.I N. Silicic acid traps selectively ACTH but not heparin. 3 - Heparin interferes with direct RIA-ACTH in the plasma by decreasing 125 I-ACTH binding to the antibodies and modifying the slope of the standard curve. Unsuitable artefacts induced by heparin, as overestimation or underestimation of plasma ACTH levels by RIA, can be avoid by previous hormone extraction from heparinized plasmas. Such results emphasized the importance of the sample preparation in order to obtain consistent results [fr

  13. N-terminal and C-terminal heparin-binding domain polypeptides derived from fibronectin reduce adhesion and invasion of liver cancer cells

    International Nuclear Information System (INIS)

    Tang, Nan-Hong; Chen, Yan-Lin; Wang, Xiao-Qian; Li, Xiu-Jin; Wu, Yong; Zou, Qi-Lian; Chen, Yuan-Zhong

    2010-01-01

    Fibronectin (FN) is known to be a large multifunction glycoprotein with binding sites for many substances, including N-terminal and C-terminal heparin-binding domains. We investigated the effects of highly purified rhFNHN29 and rhFNHC36 polypeptides originally cloned from the two heparin-binding domains on the adhesion and invasion of highly metastatic human hepatocellular carcinoma cells (MHCC97H) and analyzed the underlying mechanism involved. The MHCC97H cells that adhered to FN in the presence of various concentrations of rhFNHN29 and rhFNHC36 polypeptides were stained with crystal violet and measured, and the effects of rhFNHN29 and rhFNHC36 on the invasion of the MHCC97H cells were then detected using the Matrigel invasion assay as well as a lung-metastasis mouse model. The expression level of integrins and focal adhesion kinase (FAK) phosphotyrosyl protein was examined by Western blot, and the activity of matrix metalloproteinases (MMPs) and activator protein 1 (AP-1) was analyzed by gelatin zymography and the electrophoretic mobility band-shift assay (EMSA), respectively. Both of the polypeptides rhFNHN29 and rhFNHC36 inhibited adhesion and invasion of MHCC97H cells; however, rhFNHC36 exhibited inhibition at a lower dose than rhFNHN29. These inhibitory effects were mediated by integrin αvβ3 and reversed by a protein tyrosine phosphatase inhibitor. Polypeptides rhFNHN29 and rhFNHC36 abrogated the tyrosine phosphorylation of focal adhesion kinase (p-FAK) and activation of activator protein 1 (AP-1), resulting in the decrease of integrin αv, β3 and β1 expression as well as the reduction of MMP-9 activity. Polypeptides rhFNHN29 and rhFNHC36 could potentially be applicable to human liver cancer as anti-adhesive and anti-invasive agents

  14. Structural characterization of pharmaceutical heparins prepared from different animal tissues.

    Science.gov (United States)

    Fu, Li; Li, Guoyun; Yang, Bo; Onishi, Akihiro; Li, Lingyun; Sun, Peilong; Zhang, Fuming; Linhardt, Robert J

    2013-05-01

    Although most pharmaceutical heparin used today is obtained from porcine intestine, heparin has historically been prepared from bovine lung and ovine intestine. There is some regulatory concern about establishing the species origin of heparin. This concern began with the outbreak of mad cow disease in the 1990s and was exacerbated during the heparin shortage in the 2000s and the heparin contamination crisis of 2007-2008. Three heparins from porcine, ovine, and bovine were characterized through state-of-the-art carbohydrate analysis methods with a view profiling their physicochemical properties. Differences in molecular weight, monosaccharide and disaccharide composition, oligosaccharide sequence, and antithrombin III-binding affinity were observed. These data provide some insight into the variability of heparins obtained from these three species and suggest some analytical approaches that may be useful in confirming the species origin of a heparin active pharmaceutical ingredient. Copyright © 2013 Wiley Periodicals, Inc.

  15. Heparin conjugated quantum dots for in vitro imaging applications.

    Science.gov (United States)

    Maguire, Ciaran Manus; Mahfoud, Omar Kazem; Rakovich, Tatsiana; Gerard, Valerie Anne; Prina-Mello, Adriele; Gun'ko, Yurii; Volkov, Yuri

    2014-11-01

    In this work heparin-gelatine multi-layered cadmium telluride quantum dots (QDgel/hep) were synthesised using a novel 'one-pot' method. The QDs produced were characterised using various spectroscopic and physiochemical techniques. Suitable QDs were then selected and compared to thioglycolic acid stabilised quantum dots (QDTGA) and gelatine coated quantum dots (QDgel) for utilisation in in vitro imaging experiments on live and fixed permeabilised THP-1, A549 and Caco-2 cell lines. Exposure of live THP-1 cells to QDgel/hep resulted in localisation of the QDs to the nucleus of the cells. QDgel/hep show affinity for the nuclear compartment of fixed permeabilised THP-1 and A549 cells but remain confined to cytoplasm of fixed permeabilised Caco-2 cells. It is postulated that heparin binding to the CD11b receptor facilitates the internalisation of the QDs into the nucleus of THP-1 cells. In addition, the heparin layer may reduce the unfavourable thrombogenic nature of quantum dots observed in vivo. In this study, heparin conjugated quantum dots were found to have superior imaging properties compared to its native counterparts. The authors postulate that heparin binding to the CD11b receptor facilitates QD internalization to the nucleus, and the heparin layer may reduce the in vivo thrombogenic properties of quantum dots. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Alboserpin, a Factor Xa Inhibitor from the Mosquito Vector of Yellow Fever, Binds Heparin and Membrane Phospholipids and Exhibits Antithrombotic Activity

    Czech Academy of Sciences Publication Activity Database

    Calvo, E.; Mizurini, D.M.; Sa-Nunes, A.; Ribeiro, J.M.C.; Andersen, J. F.; Mans, B.J.; Monteiro, R.Q.; Kotsyfakis, Michalis; Francischetti, I.M.B.

    2011-01-01

    Roč. 286, č. 32 (2011), 27998-28010 ISSN 0021-9258 Institutional research plan: CEZ:AV0Z60220518 Keywords : serpin * mosquito * Aedes albopictus * phospholipids * Factor Xa * heparin * binding affinity * coagulation * thrombus * bleeding Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 4.773, year: 2011

  17. Identifying the functional part of heparin-binding protein (HBP) as a monocyte stimulator and the novel role of monocytes as HBP producers

    DEFF Research Database (Denmark)

    Schou, Morten; Djurup, René; Norris, Kjeld

    2011-01-01

    Heparin-binding protein (HBP), an evolutionary ancient and biologically highly important molecule in inflammation, is an inactive serine protease due to mutations in the catalytic triad. The histidine (position 41) in the conserved sequence TAAHC is mutated to serine and this sequence (TAASC) pla...

  18. A spectroscopic study of interaction of cationic dyes with heparin

    Directory of Open Access Journals (Sweden)

    R. Nandini

    2010-01-01

    Full Text Available The interaction of two cationic dyes namely, acridine orange and pinacyanol chloride with an anionic polyelectrolyte, heparin, has been investigated by spectrophotometric method.The polymer induced metachromasy in the dyes resulting in the shift of the absorption maxima of the dyes towards shorter wavelengths. The stability of the complexes formed between acridine orange and heparin was found to be lesser than that formed between pinacyanol chloride and heparin. This fact was further confirmed by reversal studies using alcohols, urea and surfactants. The interaction of acridine orange with heparin has also been investigated fluorimetrically.The interaction parameters revealed that binding between acridine orange and heparin arises due to electrostatic interaction while that between pinacyanol chloride and heparin is found to involve both electrostatic and hydrophobic forces. The effect of the structure of the dye in inducing metachromasy has also been discussed.

  19. Low-molecular weight heparin increases circulating sFlt-1 levels and enhances urinary elimination.

    Directory of Open Access Journals (Sweden)

    Henning Hagmann

    Full Text Available RATIONALE: Preeclampsia is a devastating medical complication of pregnancy which leads to maternal and fetal morbidity and mortality. While the etiology of preeclampsia is unclear, human and animal studies suggest that excessive circulating levels of soluble fms-like tyrosine-kinase-1 (sFlt-1, an alternatively spliced variant of VEGF-receptor1, contribute to the signs and symptoms of preeclampsia. Since sFlt-1 binds to heparin and heparan sulfate proteoglycans, we hypothesized that the anticoagulant heparin, which is often used in pregnancy, may interfere with the levels, distribution and elimination of sFlt-1 in vivo. OBJECTIVE: We systematically determined serum and urine levels of angiogenic factors in preeclamptic women before and after administration of low molecular weight heparin and further characterized the interaction with heparin in biochemical studies. METHODS AND RESULTS: Serum and urine samples were used to measure sFlt-1 levels before and after heparin administration. Serum levels of sFlt-1 increased by 25% after heparin administration in pregnant women. The magnitude of the increase in circulating sFlt-1 correlated with initial sFlt-1 serum levels. Urinary sFlt-1 levels were also elevated following heparin administration and levels of elimination were dependent on the underlying integrity of the glomerular filtration barrier. Biochemical binding studies employing cation exchange chromatography revealed that heparin bound sFlt-1 had decreased affinity to negatively charged surfaces when compared to sFlt-1 alone. CONCLUSION: Low molecular weight heparin administration increased circulating sFlt1 levels and enhanced renal elimination. We provide evidence that both effects may be due to heparin binding to sFlt1 and masking the positive charges on sFlt1 protein.

  20. Enhancement of trophoblast differentiation and survival by low molecular weight heparin requires heparin-binding EGF-like growth factor.

    Science.gov (United States)

    Bolnick, Alan D; Bolnick, Jay M; Kohan-Ghadr, Hamid-Reza; Kilburn, Brian A; Pasalodos, Omar J; Singhal, Pankaj K; Dai, Jing; Diamond, Michael P; Armant, D Randall; Drewlo, Sascha

    2017-06-01

    Does low molecular weight heparin (LMWH) require heparin-binding epidermal growth factor (EGF)-like growth factor (HBEGF) signaling to induce extravillous trophoblast differentiation and decrease apoptosis during oxidative stress? LMWH increased HBEGF expression and secretion, and HBEGF signaling was required to stimulate trophoblast extravillous differentiation, increase invasion in vitro and reduce trophoblast apoptosis during oxidative stress. Abnormal trophoblast differentiation and survival contribute to placental insufficiency syndromes, including preeclampsia and intrauterine growth restriction. Preeclampsia often manifests as a pro-thrombotic state, with unsuccessful transformation of the spiral arteries that reduces oxygen supply and can produce placental infarction. LMWH improves placental function by increasing blood flow. Recent data suggest that the actions of LMWH transcend its anti-coagulative properties, but the molecular mechanism is unknown. There is evidence that LMWH alters the expression of human HBEGF in trophoblast cells, which regulates human trophoblast pathophysiology. HBEGF, itself, is capable of increasing trophoblast survival and invasiveness. First-trimester placental explants and the HTR-8/SVneo cell line, established using extravillous trophoblast outgrowths from first-trimester villous explants, were treated in vitro with LMWH to examine the effects on HBEGF signaling and trophoblast function under normal physiological and pathological conditions. A highly specific antagonist of HBEGF and other inhibitors of HBEGF downstream signaling were used to determine the relationship between LMWH treatment and HBEGF. Placental tissues (n = 5) were obtained with IRB approval and patient consent from first-trimester terminations. Placental explants and HTR-8/SVneo cells were cultured on plastic or Matrigel™ and treated with a therapeutic dose of LMWH (Enoxaparin; 10 IU/ml), with or without CRM197, pan Erb-B2 Receptor Tyrosine Kinase (ERBB

  1. Metabolic engineering of Chinese hamster ovary cells: towards a bioengineered heparin.

    Science.gov (United States)

    Baik, Jong Youn; Gasimli, Leyla; Yang, Bo; Datta, Payel; Zhang, Fuming; Glass, Charles A; Esko, Jeffrey D; Linhardt, Robert J; Sharfstein, Susan T

    2012-03-01

    Heparin is the most widely used pharmaceutical to control blood coagulation in modern medicine. A health crisis that took place in 2008 led to a demand for production of heparin from non-animal sources. Chinese hamster ovary (CHO) cells, commonly used mammalian host cells for production of foreign pharmaceutical proteins in the biopharmaceutical industry, are capable of producing heparan sulfate (HS), a related polysaccharide naturally. Since heparin and HS share the same biosynthetic pathway, we hypothesized that heparin could be produced in CHO cells by metabolic engineering. Based on the expression of endogenous enzymes in the HS/heparin pathways of CHO-S cells, human N-deacetylase/N-sulfotransferase (NDST2) and mouse heparan sulfate 3-O-sulfotransferase 1 (Hs3st1) genes were transfected sequentially into CHO host cells growing in suspension culture. Transfectants were screened using quantitative RT-PCR and Western blotting. Out of 120 clones expressing NDST2 and Hs3st1, 2 clones, Dual-3 and Dual-29, were selected for further analysis. An antithrombin III (ATIII) binding assay using flow cytometry, designed to recognize a key sugar structure characteristic of heparin, indicated that Hs3st1 transfection was capable of increasing ATIII binding. An anti-factor Xa assay, which affords a measure of anticoagulant activity, showed a significant increase in activity in the dual-expressing cell lines. Disaccharide analysis of the engineered HS showed a substantial increase in N-sulfo groups, but did not show a pattern consistent with pharmacological heparin, suggesting that further balancing the expression of transgenes with the expression levels of endogenous enzymes involved in HS/heparin biosynthesis might be necessary. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Heparin-binding peptide as a novel affinity tag for purification of recombinant proteins.

    Science.gov (United States)

    Morris, Jacqueline; Jayanthi, Srinivas; Langston, Rebekah; Daily, Anna; Kight, Alicia; McNabb, David S; Henry, Ralph; Kumar, Thallapuranam Krishnaswamy Suresh

    2016-10-01

    Purification of recombinant proteins constitutes a significant part of the downstream processing in biopharmaceutical industries. Major costs involved in the production of bio-therapeutics mainly depend on the number of purification steps used during the downstream process. Affinity chromatography is a widely used method for the purification of recombinant proteins expressed in different expression host platforms. Recombinant protein purification is achieved by fusing appropriate affinity tags to either N- or C- terminus of the target recombinant proteins. Currently available protein/peptide affinity tags have proved quite useful in the purification of recombinant proteins. However, these affinity tags suffer from specific limitations in their use under different conditions of purification. In this study, we have designed a novel 34-amino acid heparin-binding affinity tag (HB-tag) for the purification of recombinant proteins expressed in Escherichia coli (E. coli) cells. HB-tag fused recombinant proteins were overexpressed in E. coli in high yields. A one-step heparin-Sepharose-based affinity chromatography protocol was developed to purify HB-fused recombinant proteins to homogeneity using a simple sodium chloride step gradient elution. The HB-tag has also been shown to facilitate the purification of target recombinant proteins from their 8 M urea denatured state(s). The HB-tag has been demonstrated to be successfully released from the fusion protein by an appropriate protease treatment to obtain the recombinant target protein(s) in high yields. Results of the two-dimensional NMR spectroscopy experiments indicate that the purified recombinant target protein(s) exist in the native conformation. Polyclonal antibodies raised against the HB-peptide sequence, exhibited high binding specificity and sensitivity to the HB-fused recombinant proteins (∼10 ng) in different crude cell extracts obtained from diverse expression hosts. In our opinion, the HB-tag provides a

  3. Amperometric Sensor for Heparin: Sensing Mechanism and Application in Human Blood Plasma Analysis

    Czech Academy of Sciences Publication Activity Database

    Langmaier, Jan; Olšák, J.; Samcová, E.; Samec, Zdeněk; Trojánek, Antonín

    2006-01-01

    Roč. 18, 13-14 (2006), s. 1329-1338 ISSN 1040-0397 R&D Projects: GA ČR GA203/04/0424 Institutional research plan: CEZ:AV0Z40400503 Keywords : heparin * amperometry * PVC membrane electrode * sensing mechanism * human blood plasma Subject RIV: CG - Electrochemistry Impact factor: 2.444, year: 2006

  4. The ligand-binding profile of HARE: hyaluronan and chondroitin sulfates A, C, and D bind to overlapping sites distinct from the sites for heparin, acetylated low-density lipoprotein, dermatan sulfate, and CS-E.

    Science.gov (United States)

    Harris, Edward N; Weigel, Paul H

    2008-08-01

    The hyaluronic acid receptor for endocytosis (HARE)/ Stabilin-2 is the primary systemic scavenger receptor for hyaluronan (HA), the chondroitin sulfates (CS), dermatan sulfate (DS), and nonglycosaminoglycan (GAG) ligands such as acetylated low-density lipoprotein (AcLDL), pro-collagen propeptides, and advanced glycation end products. We recently discovered that HARE is also a systemic scavenger receptor for heparin (Hep) (Harris EN, Weigel JA, Weigel PH. 2008. The human hyaluronan receptor for endocytosis [HARE/Stabilin-2] is a systemic clearance receptor for heparin. J Biol Chem. 283:17341-17350). Our goal was to map the binding sites of eight different ligands within HARE. We used biotinylated GAGs and radio-iodinated streptavidin or AcLDL to assess the binding activities of ligands directly or indirectly (by competition with unlabeled ligands) in endocytosis assays using stable cell lines expressing the 315 or 190 kDa HA receptor for endocytosis (315- or 190-HARE) isoforms, and ELISA-like assays, with purified recombinant soluble 190-HARE ecto-domain. For example, Hep binding to HARE was competed by DS, CS-E, AcLDL, and dextran sulfate, but not by other CS types, HA, dextran, or heparosan. (125)I-AcLDL binding to HARE was partially competed by Hep and dextran sulfate, but not competed by HA. Two ligands, DS and CS-E, competed with both Hep and HA to some degree. Hep and HA binding or endocytosis is mutually inclusive; binding of these two GAGs occurs with functionally separate, noncompetitive, and apparently noninteracting domains. Thus, HARE binds to HA and Hep simultaneously. Although the domain(s) responsible for Hep binding remains unknown, the Link domain was required for HARE binding to HA, CS-A, CS-C, and CS-D. These results enable us to outline, for the first time, a binding activity map for multiple ligands of HARE.

  5. Isolation of non-heprin-binding and heparin-binding proteins of boar prostate

    Czech Academy of Sciences Publication Activity Database

    Maňásková, Pavla; Liberda, J.; Tichá, M.; Jonáková, Věra

    2002-01-01

    Roč. 770, - (2002), s. 137-143 ISSN 1570-0232. [International Symposium /2./ - Separation in the BioSciences. Praha, 17.09.2001-20.09.2001] R&D Projects: GA ČR GA303/99/0357; GA ČR GV524/96/K162 Institutional research plan: CEZ:AV0Z5052915 Keywords : isolation * prostatic proteins * heparin Subject RIV: CE - Biochemistry Impact factor: 1.913, year: 2002

  6. Degranulating mast cells in fibrotic regions of human tumors and evidence that mast cell heparin interferes with the growth of tumor cells through a mechanism involving fibroblasts

    International Nuclear Information System (INIS)

    Samoszuk, Michael; Kanakubo, Emi; Chan, John K

    2005-01-01

    The purpose of this study was to test the hypothesis that mast cells that are present in fibrotic regions of cancer can suppress the growth of tumor cells through an indirect mechanism involving peri-tumoral fibroblasts. We first immunostained a wide variety of human cancers for the presence of degranulated mast cells. In a subsequent series of controlled in vitro experiments, we then co-cultured UACC-812 human breast cancer cells with normal fibroblasts in the presence or absence of different combinations and doses of mast cell tryptase, mast cell heparin, a lysate of the human mast cell line HMC-1, and fibroblast growth factor-7 (FGF-7), a powerful, heparin-binding growth factor for breast epithelial cells. Degranulating mast cells were localized predominantly in the fibrous tissue of every case of breast cancer, head and neck cancer, lung cancer, ovarian cancer, non-Hodgkin's lymphoma, and Hodgkin's disease that we examined. Mast cell tryptase and HMC-1 lysate had no significant effect on the clonogenic growth of cancer cells co-cultured with fibroblasts. By contrast, mast cell heparin at multiple doses significantly reduced the size and number of colonies of tumor cells co-cultured with fibroblasts, especially in the presence of FGF-7. Neither heparin nor FGF-7, individually or in combination, produced any significant effect on the clonogenic growth of breast cancer cells cultured without fibroblasts. Degranulating mast cells are restricted to peri-tumoral fibrous tissue, and mast cell heparin is a powerful inhibitor of clonogenic growth of tumor cells co-cultured with fibroblasts. These results may help to explain the well-known ability of heparin to inhibit the growth of primary and metastatic tumors

  7. Degranulating mast cells in fibrotic regions of human tumors and evidence that mast cell heparin interferes with the growth of tumor cells through a mechanism involving fibroblasts

    Directory of Open Access Journals (Sweden)

    Kanakubo Emi

    2005-09-01

    Full Text Available Abstract Background The purpose of this study was to test the hypothesis that mast cells that are present in fibrotic regions of cancer can suppress the growth of tumor cells through an indirect mechanism involving peri-tumoral fibroblasts. Methods We first immunostained a wide variety of human cancers for the presence of degranulated mast cells. In a subsequent series of controlled in vitro experiments, we then co-cultured UACC-812 human breast cancer cells with normal fibroblasts in the presence or absence of different combinations and doses of mast cell tryptase, mast cell heparin, a lysate of the human mast cell line HMC-1, and fibroblast growth factor-7 (FGF-7, a powerful, heparin-binding growth factor for breast epithelial cells. Results Degranulating mast cells were localized predominantly in the fibrous tissue of every case of breast cancer, head and neck cancer, lung cancer, ovarian cancer, non-Hodgkin's lymphoma, and Hodgkin's disease that we examined. Mast cell tryptase and HMC-1 lysate had no significant effect on the clonogenic growth of cancer cells co-cultured with fibroblasts. By contrast, mast cell heparin at multiple doses significantly reduced the size and number of colonies of tumor cells co-cultured with fibroblasts, especially in the presence of FGF-7. Neither heparin nor FGF-7, individually or in combination, produced any significant effect on the clonogenic growth of breast cancer cells cultured without fibroblasts. Conclusion Degranulating mast cells are restricted to peri-tumoral fibrous tissue, and mast cell heparin is a powerful inhibitor of clonogenic growth of tumor cells co-cultured with fibroblasts. These results may help to explain the well-known ability of heparin to inhibit the growth of primary and metastatic tumors.

  8. Heparin kinetics

    International Nuclear Information System (INIS)

    Swart, C.A.M. de.

    1983-01-01

    The author has studied the kinetics of heparin and heparin fractions after intravenous administration in humans and in this thesis the results of this study are reported. Basic knowledge about the physico-chemical properties of heparin and its interactions with proteins resulting in anticoagulant and lipolytic effects are discussed in a review (chapter II), which also comprises some clinical aspects of heparin therapy. In chapter III the kinetics of the anticoagulant effect are described after intravenous administration of five commercial heparin preparations. A mathematical model is presented that fits best to these kinetics. The kinetics of the anticoagulant and lipolytic effects after intravenous injection of various 35 S-radiolabelled heparin fractions and their relationship with the disappearance of the radiolabel are described in chapter IV. Chapter V gives a description of the kinetics of two radiolabels after injection of in vitro formed complexes consisting of purified, 125 I-radiolabelled antithrombin III and various 35 S-radiolabelled heparin fractions. (Auth.)

  9. Hydrolysis and Sulfation Pattern Effects on Release of Bioactive Bone Morphogenetic Protein-2 from Heparin-Based Microparticles.

    Science.gov (United States)

    Tellier, Liane E; Miller, Tobias; McDevitt, Todd C; Temenoff, Johnna S

    2015-10-28

    Glycosaminoglycans (GAGs) such as heparin are promising materials for growth factor delivery due to their ability to efficiently bind positively charged growth factors including bone morphogenetic protein-2 (BMP-2) through their negatively charged sulfate groups. Therefore, the goal of this study was to examine BMP-2 release from heparin-based microparticles (MPs) after first, incorporating a hydrolytically degradable crosslinker and varying heparin content within MPs to alter MP degradation and second, altering the sulfation pattern of heparin within MPs to vary BMP-2 binding and release. Using varied MP formulations, it was found that the time course of MP degradation for 1 wt% heparin MPs was ~4 days slower than 10 wt% heparin MPs, indicating that MP degradation was dependent on heparin content. After incubating 100 ng BMP-2 with 0.1 mg MPs, most MP formulations loaded BMP-2 with ~50% efficiency and significantly more BMP-2 release (60% of loaded BMP-2) was observed from more sulfated heparin MPs (MPs with ~100% and 80% of native sulfation). Similarly, BMP-2 bioactivity in more sulfated heparin MP groups was at least four-fold higher than soluble BMP-2 and less sulfated heparin MP groups, as determined by an established C2C12 cell alkaline phosphatase (ALP) assay. Ultimately, the two most sulfated 10 wt% heparin MP formulations were able to efficiently load and release BMP-2 while enhancing BMP-2 bioactivity, making them promising candidates for future growth factor delivery applications.

  10. Allergic anaphylaxis due to subcutaneously injected heparin

    Directory of Open Access Journals (Sweden)

    Anders Diana

    2013-01-01

    Full Text Available Abstract Heparins are one of the most used class of anticoagulants in daily clinical practice. Despite their widespread application immune-mediated hypersensitivity reactions to heparins are rare. Among these, the delayed-type reactions to s.c. injected heparins are well-known usually presenting as circumscribed eczematous plaques at the injection sites. In contrast, potentially life-threatening systemic immediate-type anaphylactic reactions to heparins are extremely rare. Recently, some cases of non-allergic anaphylaxis could be attributed to undesirable heparin contaminants. A 43-year-old patient developed severe anaphylaxis symptoms within 5–10 minutes after s.c. injection of enoxaparin. Titrated skin prick testing with wheal and flare responses up to an enoxaparin dilution of 1:10.000 indicated a probable allergic mechanism of the enoxaparin-induced anaphylaxis. The basophil activation test as an additional in-vitro test method was negative. Furthermore, skin prick testing showed rather broad cross-reactivity among different heparin preparations tested. In the presented case, history, symptoms, and results of skin testing strongly suggested an IgE-mediated allergic hypersensitivity against different heparins. Therefore, as safe alternative anticoagulants the patient could receive beneath coumarins the hirudins or direct thrombin inhibitors. Because these compounds have a completely different molecular structure compared with the heparin-polysaccharides.

  11. Heparin-Functionalized chitosan/ κ-carrageenan complexes as potential scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    Dofeliz, Joni L.; Rojas, Nina Rosario L.

    2015-01-01

    Cell-based approaches to tissue regeneration are playing an increasingly important role in bone and cartilage repair. This is made possible through the use of growth factors, which are signaling molecules that induce a number of effects such as cell proliferation, migration and differentiation. But problems arise as these growth factors tend to be expensive, short-lived and slow moving through the extracellular matrix, making them very inefficient in their current form of introduction. One such growth factor is basic fibroblast growth factor (bFGF). The general objective of this study is to construct heparin-functionalized chitosan/κ-carrageenan scaffolds, which when bound to basic fibroblast growth factor (bFGF), may be used in the culture of mesenchymal stem cells for differentiation into cartilage. In this study, gels of semi-interpenetrating networks (semi-IPN) of chitosan and κ-carrageenan (2:4:1 blend ration) were prepared using calcium chloride as a cross-linker. The gels were then functionalized with heparin, which is known for its growth factor binding ability, using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) as cross-linker. The functionalized gels were then reshaped into scaffold on the wells of 48-well plates through freeze-dry method. The scaffolds were found to be realatively porous with pore sizes larger than 100 μm which satisfies the requirements for cell culture. Subsequent thermogravimetric analysis shows that the scaffolds were relatively stable with a degradation temperature of 277°C. Additionally, there was no observable separation of the individual degradation temperatures of chitosan and κ-carrageenan, confirming that a single miscible phase in the form of a semi-IPN structure was created. Results of scanning electron microscopy also showed that the scaffolds were stable under 2 hours of UV sterilization. The FTIR spectra of the heparinized PEC showed characteristic absorption bands (S=O asymetric stretch) in the area of 1160

  12. Structure-Activity Relationships of Bioengineered Heparin/Heparan Sulfates Produced in Different Bioreactors

    Directory of Open Access Journals (Sweden)

    Ha Na Kim

    2017-05-01

    Full Text Available Heparin and heparan sulfate are structurally-related carbohydrates with therapeutic applications in anticoagulation, drug delivery, and regenerative medicine. This study explored the effect of different bioreactor conditions on the production of heparin/heparan sulfate chains via the recombinant expression of serglycin in mammalian cells. Tissue culture flasks and continuously-stirred tank reactors promoted the production of serglycin decorated with heparin/heparan sulfate, as well as chondroitin sulfate, while the serglycin secreted by cells in the tissue culture flasks produced more highly-sulfated heparin/heparan sulfate chains. The serglycin produced in tissue culture flasks was effective in binding and signaling fibroblast growth factor 2, indicating the utility of this molecule in drug delivery and regenerative medicine applications in addition to its well-known anticoagulant activity.

  13. N-acetyl-heparin attenuates acute lung injury caused by acid aspiration mainly by antagonizing histones in mice.

    Science.gov (United States)

    Zhang, Yanlin; Zhao, Zanmei; Guan, Li; Mao, Lijun; Li, Shuqiang; Guan, Xiaoxu; Chen, Ming; Guo, Lixia; Ding, Lihua; Cong, Cuicui; Wen, Tao; Zhao, Jinyuan

    2014-01-01

    Acute lung injury (ALI) is the leading cause of death in intensive care units. Extracellular histones have recently been recognized to be pivotal inflammatory mediators. Heparin and its derivatives can bind histones through electrostatic interaction. The purpose of this study was to investigate 1) the role of extracellular histones in the pathogenesis of ALI caused by acid aspiration and 2) whether N-acetyl-heparin (NAH) provides more protection than heparin against histones at the high dose. ALI was induced in mice via intratracheal instillation of hydrochloric acid (HCl). Lethality rate, blood gas, myeloperoxidase (MPO) activity, lung edema and pathological changes were used to evaluate the degree of ALI. Heparin/NAH was administered intraperitoneally, twice a day, for 3 days or until death. Acid aspiration caused an obvious increase in extracellular histones. A significant correlation existed between the concentration of HCl aspirated and the circulating histones. Heparin/NAH (10 mg/kg) improved the lethality rate, blood gas, MPO activity, lung edema and pathological score. At a dose of 20 mg/kg, NAH still provided protection, however heparin tended to aggravate the injury due to hemorrhagic complications. The specific interaction between heparin and histones was verified by the binding assay. In summary, high levels of extracellular histones can be pathogenic in ALI caused by acid aspiration. By neutralizing extracellular histones, heparin/NAH can offer similar protection at the moderate doses. At the high dose, NAH provides better protection than heparin.

  14. Targeting hepatic heparin-binding EGF-like growth factor (HB-EGF) induces anti-hyperlipidemia leading to reduction of angiotensin II-induced aneurysm development.

    Science.gov (United States)

    Kim, Seonwook; Yang, Lihua; Kim, Seongu; Lee, Richard G; Graham, Mark J; Berliner, Judith A; Lusis, Aldons J; Cai, Lei; Temel, Ryan E; Rateri, Debra L; Lee, Sangderk

    2017-01-01

    The upregulated expression of heparin binding EGF-like growth factor (HB-EGF) in the vessel and circulation is associated with risk of cardiovascular disease. In this study, we tested the effects of HB-EGF targeting using HB-EGF-specific antisense oligonucleotide (ASO) on the development of aortic aneurysm in a mouse aneurysm model. Low-density lipoprotein receptor (LDLR) deficient mice (male, 16 weeks of age) were injected with control and HB-EGF ASOs for 10 weeks. To induce aneurysm, the mice were fed a high fat diet (22% fat, 0.2% cholesterol; w/w) at 5 week point of ASO administration and infused with angiotensin II (AngII, 1,000ng/kg/min) for the last 4 weeks of ASO administration. We confirmed that the HB-EGF ASO administration significantly downregulated HB-EGF expression in multiple tissues including the liver. Importantly, the HB-EGF ASO administration significantly suppressed development of aortic aneurysms including thoracic and abdominal types. Interestingly, the HB-EGF ASO administration induced a remarkable anti-hyperlipidemic effect by suppressing very low density lipoprotein (VLDL) level in the blood. Mechanistically, the HB-EGF targeting suppressed hepatic VLDL secretion rate without changing heparin-releasable plasma triglyceride (TG) hydrolytic activity or fecal neutral cholesterol excretion rate. This result suggested that the HB-EGF targeting induced protection against aneurysm development through anti-hyperlipidemic effects. Suppression of hepatic VLDL production process appears to be a key mechanism for the anti-hyperlipidemic effects by the HB-EGF targeting.

  15. Interaction of the amyloid precursor protein-like protein 1 (APLP1) E2 domain with heparan sulfate involves two distinct binding modes

    Energy Technology Data Exchange (ETDEWEB)

    Dahms, Sven O., E-mail: sdahms@fli-leibniz.de [Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena (Germany); Mayer, Magnus C. [Freie Universität Berlin, Thielallee 63, 14195 Berlin (Germany); Miltenyi Biotec GmbH, Robert-Koch-Strasse 1, 17166 Teterow (Germany); Roeser, Dirk [Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena (Germany); Multhaup, Gerd [McGill University Montreal, Montreal, Quebec H3G 1Y6 (Canada); Than, Manuel E., E-mail: sdahms@fli-leibniz.de [Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena (Germany)

    2015-03-01

    Two X-ray structures of APLP1 E2 with and without a heparin dodecasaccharide are presented, revealing two distinct binding modes of the protein to heparan sulfate. The data provide a mechanistic explanation of how APP-like proteins bind to heparan sulfates and how they specifically recognize nonreducing structures of heparan sulfates. Beyond the pathology of Alzheimer’s disease, the members of the amyloid precursor protein (APP) family are essential for neuronal development and cell homeostasis in mammals. APP and its paralogues APP-like protein 1 (APLP1) and APP-like protein 2 (APLP2) contain the highly conserved heparan sulfate (HS) binding domain E2, which effects various (patho)physiological functions. Here, two crystal structures of the E2 domain of APLP1 are presented in the apo form and in complex with a heparin dodecasaccharide at 2.5 Å resolution. The apo structure of APLP1 E2 revealed an unfolded and hence flexible N-terminal helix αA. The (APLP1 E2){sub 2}–(heparin){sub 2} complex structure revealed two distinct binding modes, with APLP1 E2 explicitly recognizing the heparin terminus but also interacting with a continuous heparin chain. The latter only requires a certain register of the sugar moieties that fits to a positively charged surface patch and contributes to the general heparin-binding capability of APP-family proteins. Terminal binding of APLP1 E2 to heparin specifically involves a structure of the nonreducing end that is very similar to heparanase-processed HS chains. These data reveal a conserved mechanism for the binding of APP-family proteins to HS and imply a specific regulatory role of HS modifications in the biology of APP and APP-like proteins.

  16. Parent heparin and daughter LMW heparin correlation analysis using LC-MS and NMR

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xinyue, E-mail: liux22@rpi.edu [National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong, 250100 (China); Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); St Ange, Kalib, E-mail: stangk2@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); Wang, Xiaohua, E-mail: wangx35@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); School of Computer and Information, Hefei University of Technology, Hefei (China); Lin, Lei, E-mail: Linl5@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); Zhang, Fuming, E-mail: zhangf2@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); and others

    2017-04-08

    Heparin is a structurally complex, polysaccharide anticoagulant derived from livestock, primarily porcine intestinal tissues. Low molecular weight (LMW) heparins are derived through the controlled partial depolymerization of heparin. Increased manufacturing and regulatory concerns have provided the motivation for the development of more sophisticated analytical methods for determining both their structure and pedigree. A strategy, for the comprehensive comparison of parent heparins and their LMW heparin daughters, is described that relies on the analysis of monosaccharide composition, disaccharide composition, and oligosaccharide composition. Liquid chromatography-mass spectrometry is rapid, robust, and amenable to automated processing and interpretation of both top-down and bottom-up analyses. Nuclear magnetic resonance spectroscopy provides complementary top-down information on the chirality of the uronic acid residues and glucosamine substitution. Principal component analysis (PCA) was applied to the normalized abundance of oligosaccharides, calculated in the bottom-up analysis, to show parent and daughter correlation in oligosaccharide composition. Using these approaches, six pairs of parent heparins and their daughter generic enoxaparins from two different manufacturers were comprehensively analyzed. Enoxaparin is the most widely used LMW heparin and is prepared through controlled chemical β-eliminative cleavage of porcine intestinal heparin. Lovenox{sup ®}, the innovator version of enoxaparin marketed in the US, was analyzed as a reference for the daughter LMW heparins. The results, show similarities between LMW heparins from two different manufacturers with Lovenox{sup ®}, excellent lot-to-lot consistency of products from each manufacturer, and detects a correlation between each parent heparin and daughter LMW heparin. - Highlights: • Low molecular weight heparins prepared from different heparin parents were analyzed. • An integrated analytical

  17. Parent heparin and daughter LMW heparin correlation analysis using LC-MS and NMR

    International Nuclear Information System (INIS)

    Liu, Xinyue; St Ange, Kalib; Wang, Xiaohua; Lin, Lei; Zhang, Fuming

    2017-01-01

    Heparin is a structurally complex, polysaccharide anticoagulant derived from livestock, primarily porcine intestinal tissues. Low molecular weight (LMW) heparins are derived through the controlled partial depolymerization of heparin. Increased manufacturing and regulatory concerns have provided the motivation for the development of more sophisticated analytical methods for determining both their structure and pedigree. A strategy, for the comprehensive comparison of parent heparins and their LMW heparin daughters, is described that relies on the analysis of monosaccharide composition, disaccharide composition, and oligosaccharide composition. Liquid chromatography-mass spectrometry is rapid, robust, and amenable to automated processing and interpretation of both top-down and bottom-up analyses. Nuclear magnetic resonance spectroscopy provides complementary top-down information on the chirality of the uronic acid residues and glucosamine substitution. Principal component analysis (PCA) was applied to the normalized abundance of oligosaccharides, calculated in the bottom-up analysis, to show parent and daughter correlation in oligosaccharide composition. Using these approaches, six pairs of parent heparins and their daughter generic enoxaparins from two different manufacturers were comprehensively analyzed. Enoxaparin is the most widely used LMW heparin and is prepared through controlled chemical β-eliminative cleavage of porcine intestinal heparin. Lovenox"®, the innovator version of enoxaparin marketed in the US, was analyzed as a reference for the daughter LMW heparins. The results, show similarities between LMW heparins from two different manufacturers with Lovenox"®, excellent lot-to-lot consistency of products from each manufacturer, and detects a correlation between each parent heparin and daughter LMW heparin. - Highlights: • Low molecular weight heparins prepared from different heparin parents were analyzed. • An integrated analytical approach relied

  18. Heparin binding chitosan derivatives for production of pro-angiogenic hydrogels for promoting tissue healing

    Energy Technology Data Exchange (ETDEWEB)

    Yar, Muhammad, E-mail: drmyar@ciitlahore.edu.pk [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Shahzad, Sohail [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Shahzadi, Lubna [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Shahzad, Sohail Anjum [Department of Chemistry, COMSATS Institute of Information Technology, Abbottabad 22060 (Pakistan); Mahmood, Nasir [Department of Allied Health Sciences and Chemical Pathology, University of Health Sciences, Lahore (Pakistan); Department of Human Genetics and Molecular Biology, University of Health Sciences, Lahore (Pakistan); Chaudhry, Aqif Anwar [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Rehman, Ihtesham ur [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Materials Science and Engineering, North Campus, University of Sheffield, Broad Lane, Sheffield S3 7HQ (United Kingdom); MacNeil, Sheila, E-mail: s.macneil@sheffield.ac.uk [Materials Science and Engineering, North Campus, University of Sheffield, Broad Lane, Sheffield S3 7HQ (United Kingdom)

    2017-05-01

    Our aim was to develop a biocompatible hydrogel that could be soaked in heparin and placed on wound beds to improve the vasculature of poorly vascularized wound beds. In the current study, a methodology was developed for the synthesis of a new chitosan derivative (CSD-1). Hydrogels were synthesized by blending CSD-1 for either 4 or 24 h with polyvinyl alcohol (PVA). The physical/chemical interactions and the presence of specific functional groups were confirmed by Fourier transform infrared (FT-IR) spectroscopy and proton nuclear magnetic resonance ({sup 1}H NMR). The porous nature of the hydrogels was confirmed by scanning electron microscopy (SEM). Thermal gravimetric analysis (TGA) showed that these hydrogels have good thermal stability which was slightly increased as the blending time was increased. Hydrogels produced with 24 h of blending supported cell attachment more and could be loaded with heparin to induce new blood vessel formation in a chick chorionic allantoic membrane assay. - Highlights: • Chitosan based hydrogels were designed to stimulate angiogenesis. • Two new derivatives of chitosan were produced using a Mannich type reaction. • Blending a chitosan derivative with PVA gave a porous biocompatible hydrogel. • Heparin bound to the hydrogel on immersion changing its morphology. • Heparin loaded hydrogel stimulated blood vessel formation in a chick model.

  19. Cutaneous reactions to heparin therapy: when are they caused by heparin allergy?

    Directory of Open Access Journals (Sweden)

    Giuliana Zisa

    2013-03-01

    Full Text Available Introduction: Little is known about the incidence and causes of heparin-induced skin lesions. The most commonly reported causes are delayed-type hypersensitivity reactions. We describe 3 patients who were referred to our staff between March and October 2009 for suspected heparin allergies. All were scheduled to undergo major surgery (cardiovascular or orthopedic. Materials and methods: All 3 patients reported the development of itchy, erythematous rashes a few days after the subcutaneous administration of heparin (nadroparin calcium in cases 1 and 2, unspecified in case 3. Each of them underwent a diagnostic work-up for heparin allergy, which included prick and intradermal tests with commonly used heparins and patch testing with undiluted heparins and disinfectants. Results: Patch tests with disinfectants were negative in all 3 cases. In case 2, all allergological tests were negative. In cases 1 and 3, delayed positivity emerged for nadroparin calcium and at least one other heparin tested. Intravenous and/or subcutaneous provocation testing was done with an alternative heparin which produced negative results in skin tests (heparin sodium in case 1, pentasaccharide fondaparinux in case 3. In both cases the alternative drug was tolerated. After our evaluation, all 3 patients underwent surgery with no heparin-related complications. Discussion: The presenting clinical features in these 3 cases provided no information on which reactions were likely to be allergic: all 3 patients presented with similar local delayed reaction. The allergic reactions were identified only after cutaneous testing.

  20. Interaction of the protein transduction domain of HIV-1 TAT with heparan sulfate: binding mechanism and thermodynamic parameters.

    Science.gov (United States)

    Ziegler, André; Seelig, Joachim

    2004-01-01

    The positively charged protein transduction domain of the HIV-1 TAT protein (TAT-PTD; residues 47-57 of TAT) rapidly translocates across the plasma membrane of living cells. This property is exploited for the delivery of proteins, drugs, and genes into cells. The mechanism of this translocation is, however, not yet understood. Recent theories for translocation suggest binding of the protein transduction domain (PTD) to extracellular glycosaminoglycans as a possible mechanism. We have studied the binding equilibrium between TAT-PTD and three different glycosaminoglycans with high sensitivity isothermal titration calorimetry and provide the first quantitative thermodynamic description. The polysulfonated macromolecules were found to exhibit multiple identical binding sites for TAT-PTD with only small differences between the three species as far as the thermodynamic parameters are concerned. Heparan sulfate (HS, molecular weight, 14.2 +/- 2 kDa) has 6.3 +/- 1.0 independent binding sites for TAT-PTD which are characterized by a binding constant K0 = (6.0 +/- 0.6) x 10(5) M(-1) and a reaction enthalpy deltaHpep0 = -4.6 +/- 1.0 kcal/mol at 28 degrees C. The binding affinity, deltaGpep0, is determined to equal extent by enthalpic and entropic contributions. The HS-TAT-PTD complex formation entails a positive heat capacity change of deltaCp0 = +135 cal/mol peptide, which is characteristic of a charge neutralization reaction. This is in contrast to hydrophobic binding reactions which display a large negative heat capacity change. The stoichiometry of 6-7 TAT-PTD molecules per HS corresponds to an electric charge neutralization. Light scattering data demonstrate a maximum scattering intensity at this stoichiometric ratio, the intensity of which depends on the order of mixing of the two components. The data suggest cross-linking and/or aggregation of HS-TAT-PTD complexes. Two other glycosaminoglycans, namely heparin and chondroitin sulfate B, were also studied with isothermal

  1. Sequence similarity between the erythrocyte binding domain 1 of the Plasmodium vivax Duffy binding protein and the V3 loop of HIV-1 strain MN reveals binding residues for the Duffy Antigen Receptor for Chemokines

    Directory of Open Access Journals (Sweden)

    Garry Robert F

    2011-01-01

    Full Text Available Abstract Background The surface glycoprotein (SU, gp120 of the human immunodeficiency virus (HIV must bind to a chemokine receptor, CCR5 or CXCR4, to invade CD4+ cells. Plasmodium vivax uses the Duffy Binding Protein (DBP to bind the Duffy Antigen Receptor for Chemokines (DARC and invade reticulocytes. Results Variable loop 3 (V3 of HIV-1 SU and domain 1 of the Plasmodium vivax DBP share a sequence similarity. The site of amino acid sequence similarity was necessary, but not sufficient, for DARC binding and contained a consensus heparin binding site essential for DARC binding. Both HIV-1 and P. vivax can be blocked from binding to their chemokine receptors by the chemokine, RANTES and its analog AOP-RANTES. Site directed mutagenesis of the heparin binding motif in members of the DBP family, the P. knowlesi alpha, beta and gamma proteins abrogated their binding to erythrocytes. Positively charged residues within domain 1 are required for binding of P. vivax and P. knowlesi erythrocyte binding proteins. Conclusion A heparin binding site motif in members of the DBP family may form part of a conserved erythrocyte receptor binding pocket.

  2. Surface biomimetic modification with laminin-loaded heparin/poly-L-lysine nanoparticles for improving the biocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tao, E-mail: 11140021@hyit.edu.cn [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai' an (China); Hu, Youdong [Department of Geriatrics, The Affiliated Huai' an Hospital of Xuzhou Medical College, Huai' an (China); Tan, Jianying [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); Liu, Shihui [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai' an (China); Chen, Junying [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); Guo, Xin; Pan, Changjiang [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai' an (China); Li, Xia, E-mail: xial_li@qq.com [Department of Geriatrics, The Affiliated Huai' an Hospital of Xuzhou Medical College, Huai' an (China)

    2017-02-01

    Late thrombus and restenosis caused by delayed endothelialization and insufficient biocompatibility of polymer coating continue to be the greatest limitations of drug-eluting stents. In this study, based on the specific structure of vascular basement membrane, a novel biomimetic nano-coating was constructed by incorporating laminin into electrostatic-assembled heparin/poly-L-lysine nanoparticles. Alteration of heparin and poly-L-lysine concentration ratio in a certain range has no significantly influence nanoparticle size, uniformity and stability, but may affect the chemical property and subsequently the binding efficiency to dopamine-coated titanium surface. By use of this feature, four different nanoparticles were synthesized and immobilized on titanium surface for creating gradient nanoparticle binding density. According to in vitro biocompatibility evaluation, the nanoparticle modified surfaces were found to effectively block coagulation pathway and reduce thrombosis formation. Moreover, NP10L and NP15L modified surface with relatively low heparin exposing density (4.9 to 7.1 μg/cm2) showed beneficial effect in selective promoting EPCs and ECs proliferation, as well as stimulating cell migration and NO synthesis. - Highlights: • A novel laminin-loaded anticoagulant nanoparticle was prepared and used for titanium surface modification. • The nanoparticle binding density was adjustable by alteration the concentration ratio of heparin and poly-L-lysine. • In a certain range of NPs density, the surface was found to selectively direct platelet and vascular cells behavior.

  3. Surface biomimetic modification with laminin-loaded heparin/poly-L-lysine nanoparticles for improving the biocompatibility

    International Nuclear Information System (INIS)

    Liu, Tao; Hu, Youdong; Tan, Jianying; Liu, Shihui; Chen, Junying; Guo, Xin; Pan, Changjiang; Li, Xia

    2017-01-01

    Late thrombus and restenosis caused by delayed endothelialization and insufficient biocompatibility of polymer coating continue to be the greatest limitations of drug-eluting stents. In this study, based on the specific structure of vascular basement membrane, a novel biomimetic nano-coating was constructed by incorporating laminin into electrostatic-assembled heparin/poly-L-lysine nanoparticles. Alteration of heparin and poly-L-lysine concentration ratio in a certain range has no significantly influence nanoparticle size, uniformity and stability, but may affect the chemical property and subsequently the binding efficiency to dopamine-coated titanium surface. By use of this feature, four different nanoparticles were synthesized and immobilized on titanium surface for creating gradient nanoparticle binding density. According to in vitro biocompatibility evaluation, the nanoparticle modified surfaces were found to effectively block coagulation pathway and reduce thrombosis formation. Moreover, NP10L and NP15L modified surface with relatively low heparin exposing density (4.9 to 7.1 μg/cm2) showed beneficial effect in selective promoting EPCs and ECs proliferation, as well as stimulating cell migration and NO synthesis. - Highlights: • A novel laminin-loaded anticoagulant nanoparticle was prepared and used for titanium surface modification. • The nanoparticle binding density was adjustable by alteration the concentration ratio of heparin and poly-L-lysine. • In a certain range of NPs density, the surface was found to selectively direct platelet and vascular cells behavior.

  4. Role of the A+ helix in heparin binding to protein C inhibitor

    NARCIS (Netherlands)

    Elisen, M. G.; Maseland, M. H.; Church, F. C.; Bouma, B. N.; Meijers, J. C.

    1996-01-01

    Interactions between proteins and heparin(-like) structures involve electrostatic forces and structural features. Based on charge distributions in the linear sequence of protein C inhibitor (PCI), two positively charged regions of PCI were proposed as possible candidates for this interaction. The

  5. Heparin modulates the endopeptidase activity of Leishmania mexicana cysteine protease cathepsin L-Like rCPB2.8.

    Directory of Open Access Journals (Sweden)

    Wagner A S Judice

    Full Text Available Cysteine protease B is considered crucial for the survival and infectivity of the Leishmania in its human host. Several microorganism pathogens bind to the heparin-like glycosaminoglycans chains of proteoglycans at host-cell surface to promote their attachment and internalization. Here, we have investigated the influence of heparin upon Leishmania mexicana cysteine protease rCPB2.8 activity.THE DATA ANALYSIS REVEALED THAT THE PRESENCE OF HEPARIN AFFECTS ALL STEPS OF THE ENZYME REACTION: (i it decreases 3.5-fold the k 1 and 4.0-fold the k -1, (ii it affects the acyl-enzyme accumulation with pronounced decrease in k 2 (2.7-fold, and also decrease in k 3 (3.5-fold. The large values of ΔG  =  12 kJ/mol for the association and dissociation steps indicate substantial structural strains linked to the formation/dissociation of the ES complex in the presence of heparin, which underscore a conformational change that prevents the diffusion of substrate in the rCPB2.8 active site. Binding to heparin also significantly decreases the α-helix content of the rCPB2.8 and perturbs the intrinsic fluorescence emission of the enzyme. The data strongly suggest that heparin is altering the ionization of catalytic (Cys(25-S(-/(His(163-Im(+ H ion pair of the rCPB2.8. Moreover, the interaction of heparin with the N-terminal pro-region of rCPB2.8 significantly decreased its inhibitory activity against the mature enzyme.Taken together, depending on their concentration, heparin-like glycosaminoglycans can either stimulate or antagonize the activity of cysteine protease B enzymes during parasite infection, suggesting that this glycoconjugate can anchor parasite cysteine protease at host cell surface.

  6. Heparin-based hydrogels with tunable sulfation & degradation for anti-inflammatory small molecule delivery.

    Science.gov (United States)

    Peng, Yifeng; Tellier, Liane E; Temenoff, Johnna S

    2016-08-16

    Sustained release of anti-inflammatory agents remains challenging for small molecule drugs due to their low molecular weight and hydrophobicity. Therefore, the goal of this study was to control the release of a small molecule anti-inflammatory agent, crystal violet (CV), from hydrogels fabricated with heparin, a highly sulfated glycosaminoglycan capable of binding positively-charged molecules such as CV. In this system, both electrostatic interactions between heparin and CV and hydrogel degradation were tuned simultaneously by varying the level of heparin sulfation and varying the amount of dithiothreitol within hydrogels, respectively. It was found that heparin sulfation significantly affected CV release, whereby more sulfated heparin hydrogels (Hep and Hep(-N)) released CV with near zero-order release kinetics (R-squared values between 0.96-0.99). Furthermore, CV was released more quickly from fast-degrading hydrogels than slow-degrading hydrogels, providing a method to tune total CV release between 5-15 days while maintaining linear release kinetics. In particular, N-desulfated heparin hydrogels exhibited efficient CV loading (∼90% of originally included CV), near zero-order CV release kinetics, and maintenance of CV bioactivity after release, making this hydrogel formulation a promising CV delivery vehicle for a wide range of inflammatory diseases.

  7. Heparin molecularly imprinted polymer thin flm on gold electrode by plasma-induced graft polymerization for label-free biosensor.

    Science.gov (United States)

    Orihara, Kouhei; Hikichi, Atsushi; Arita, Tomohiko; Muguruma, Hitoshi; Yoshimi, Yasuo

    2018-03-20

    Heparin, a highly sulfated glycosaminoglycan, is an important biomaterial having biological and therapeutic functionalities such as anticoagulation, regeneration, and protein stabilization. This study addresses a label-free quartz crystal microbalance (QCM) biosensor for heparin detection based on a macromolecularly imprinted polymer (MIP) as an artificial recognition element. We demonstrate the novel strategy for MIP in the form of thin film on a gold (Au) electrode with the plasma-induced graft polymerization (PIP) technique. The procedure of PIP is as follows: (i) Hexamethyldisiloxane plasma-polymerized thin film (PPF) as a pre-coating scaffold of active species for PIP (post-polymerization) is deposited on an Au electrode. (ii) The PPF/Au electrode is soaked in an water solution containing heparin (template), (2-(methacryloxy)-ethyl)trimethylammonium chloride acrylamide (functional monomer), acrylamide, and N,N-methylenebisacrylamide (crosslinker). Double bonds of monomer and crosslinker attacked by residually active species in pre-coating PPF cause radical chain reaction. Consequently, a growing polymer network of 20 nm thickness of PIP-MIP thin film is formed and grafted on the PPF/Au surface. (iii) The PIP-MIP/PPF/Au is washed by sodium chloride solution so as to remove the template. Non-imprinted polymer (NIP) is carried out like the same procedure without a template. The AFM, XPS, and QCM measurements show that the PIP process facilitates macromolecularly surface imprinting of template heparin where the template is easily removed and is rapidly rebound to PIP-MIP without a diffusional barrier. The heparin-PIP-MIP specifically binds to heparin compared with heparin analog chondroitin sulfate C (selective factor: 4.0) and a detectable range of heparin in the presence of CS (0.1 wt%) was 0.001-0.1 wt%. The PIP-NIP does not show selectivity between them. The evaluated binding kinetics are association (k a  = 350 ± 100 M -1  s -1

  8. Purification of foot-and-mouth disease virus by heparin as ligand for certain strains.

    Science.gov (United States)

    Du, Ping; Sun, Shiqi; Dong, Jinjie; Zhi, Xiaoying; Chang, Yanyan; Teng, Zhidong; Guo, Huichen; Liu, Zaixin

    2017-04-01

    The goal of this project was to develop an easily operable and scalable process for the recovery and purification of foot-and-mouth disease virus (FMDV) from cell culture. Heparin resins HipTrap Heparin HP and AF-Heparin HC-650 were utilized to purify FMDV O/HN/CHA/93. Results showed that the purity of AF-Heparin HC-650 was ideal. Then, the O/HN/CHA/93, O/Tibet/CHA/99, Asia I/HN/06, and A/CHA/HB/2009 strains were purified by AF-Heparin HC-650. Their affinity/virus recoveries were approximately 51.2%/45.8%, 71.5%/70.9%, 96.4%/73.5, and 59.5%/42.1%, respectively. During a stepwise elution strategy, the viral particles were mainly eluted at 300mM ionic strength peaks. The heparin affinity chromatography process removed more than 94% of cellular and medium proteins. Anion exchange resin Capto Q captured four FMD virus particles; 40% of binding proteins and 80%-90% of viral particles were eluted at 450mM NaCl. Moreover, ionic strength varied from 30 to 450mM had no effect on the immunity to FMDV. The results revealed that heparin sulfate may be the main receptor for CHA/99 strain attachment-susceptible cells. Heparin affinity chromatography can reach perfect results, especially when used as a ligand of the virus. Anion exchange is useful only as previous step for further purification. Copyright © 2016. Published by Elsevier B.V.

  9. D-fructose-binding proteins in bull seminal plasma: Isolation and characterization

    Czech Academy of Sciences Publication Activity Database

    Liberda, J.; Kraus, Marek; Ryšlavá, H.; Vlasáková, M.; Jonáková, Věra; Tichá, M.

    2001-01-01

    Roč. 47, č. 4 (2001), s. 113-119 ISSN 0015-5500 R&D Projects: GA ČR GA303/99/0357; GA ČR GV524/96/K162 Institutional research plan: CEZ:AV0Z5052915 Keywords : bull seminal plasma * non-heparin-binding and heparin-binding proteins * D-fructose-binding proteins Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.519, year: 2001

  10. Sterilization of heparinized cuprophan hemodialysis membranes

    OpenAIRE

    ten Hoopen, Hermina W.M.; Hinrichs, W.L.J.; Hinrichs, W.L.J.; Engbers, G.H.M.; Feijen, Jan

    1996-01-01

    The effects of sterilization of dry heparinized Cuprophan hemodialysis membranes by means of ethylene oxide (EtO) exposure, gamma irradiation, or steam on the anticoagulant activity and chemical characteristics of immobilized heparin and the permeability of the membrane were investigated. Sterilization did not result in a release of heparin or heparin fragments from heparinized Cuprophan. Sterilization of heparinized Cuprophan by means of EtO exposure and gamma irradiation induced a slight, i...

  11. Heparin and glutathione II: correlation between decondensation of bull sperm cells and its nucleons.

    Science.gov (United States)

    Delgado, N M; Flores-Alonso, J C; Rodríguez-Hernández, H M; Merchant-Larios, H; Reyes, R

    2001-01-01

    The correlation between the kinetics of bull sperm nuclear and nucleon decondensation induced by the action of physiological concentrations of heparin/GSH was studied. Sperm and nucleon suspensions were incubated at 37 degrees C in salt medium, at a constant concentration of either heparin or GSH and increasing concentrations of the other reagent. Even though nucleons are pretreated with DTT/CTAB, when they are incubated alone with GSH for 96 h, they remain intact, no matter which concentration is employed, and it was impossible to observe the slightest sign of nuclei decondensation. Therefore, rupture of disulfide bridges is not the main mechanism to induce nuclei decondensation and perhaps the GSH role resides in potentate the heparin effect by increasing its negative charge. Nevertheless, nucleons reach 95% of chromatin decondensation in the presence of heparin plus GSH or heparin alone. The fact that the correlation between heparin and GSH concentrations needed to induce sperm nuclei decondensation was 3- to 4-fold greater that in nucleons might be due to the complete lack of nucleon membranes. Heparin/GSH seem to induce nuclei decondensation by an ionic chromatin charge neutralization mechanism.

  12. Heparin pharmacovigilance in Brazil.

    Science.gov (United States)

    Junqueira, Daniela Rezende Garcia; Viana, Thércia Guedes; Peixoto, Eliane R de M; Barros, Fabiana C R de; Carvalho, Maria das Graças; Perini, Edson

    2011-01-01

    To investigate the biological origin of injectable unfractioned heparin available in Brazilian market by discussing the impact of the profile of commercial products and the changes in heparin monograph on the drug safety. The Anvisa data base for the Registered Products of Pharmaceutical Companies and the Dictionary of Pharmaceutical Specialties (DEF 2008/2009) were searched. A survey with industries having an active permission for marketing the drug in Brazil was conducted. Five companies were granted a permission to market unfractioned heparin in Brazil. Three of them are porcine in origin and two of them are bovine in origin, with only one explicitly showing this information in the package insert. The effectiveness and safety of heparin studied in non-Brazilian populations may not represent the Brazilian reality, since most countries no longer produce bovine heparin. The currently marketed heparin has approximately 10% less anticoagulant activity than that previously produced and this change may have clinical implications. Evidence about the lack of dose interchangeability between bovine and porcine heparins and the unique safety profile of these drugs indicates the need to follow the treatment and the patients' response. Events threatening the patient's safety must be reported to the pharmacovigilance system in each particular country.

  13. Covalent Binding of Heparin to Functionalized PET Materials for Improved Haemocompatibility

    Directory of Open Access Journals (Sweden)

    Metod Kolar

    2015-03-01

    Full Text Available The hemocompatibility of vascular grafts made from poly(ethylene terephthalate (PET is insufficient due to the rapid adhesion and activation of blood platelets that occur upon incubation with whole blood. PET polymer was treated with NHx radicals created by passing ammonia through gaseous plasma formed by a microwave discharge, which allowed for functionalization with amino groups. X-ray photoelectron spectroscopy characterization using derivatization with 4-chlorobenzaldehyde indicated that approximately 4% of the –NH2 groups were associated with the PET surface after treatment with the gaseous radicals. The functionalized polymers were coated with an ultra-thin layer of heparin and incubated with fresh blood. The free-hemoglobin technique, which is based on the haemolysis of erythrocytes, indicated improved hemocompatibility, which was confirmed by imaging the samples using confocal optical microscopy. A significant decrease in number of adhered platelets was observed on such samples. Proliferation of both human umbilical vein endothelial cells and human microvascular endothelial cells was enhanced on treated polymers, especially after a few hours of cell seeding. Thus, the technique represents a promising substitute for wet-chemical modification of PET materials prior to coating with heparin.

  14. Investigation of the heparin-thrombin interaction by dynamic force spectroscopy.

    Science.gov (United States)

    Wang, Congzhou; Jin, Yingzi; Desai, Umesh R; Yadavalli, Vamsi K

    2015-06-01

    The interaction between heparin and thrombin is a vital step in the blood (anti)coagulation process. Unraveling the molecular basis of the interactions is therefore extremely important in understanding the mechanisms of this complex biological process. In this study, we use a combination of an efficient thiolation chemistry of heparin, a self-assembled monolayer-based single molecule platform, and a dynamic force spectroscopy to provide new insights into the heparin-thrombin interaction from an energy viewpoint at the molecular scale. Well-separated single molecules of heparin covalently attached to mixed self-assembled monolayers are demonstrated, whereby interaction forces with thrombin can be measured via atomic force microscopy-based spectroscopy. Further these interactions are studied at different loading rates and salt concentrations to directly obtain kinetic parameters. An increase in the loading rate shows a higher interaction force between the heparin and thrombin, which can be directly linked to the kinetic dissociation rate constant (koff). The stability of the heparin/thrombin complex decreased with increasing NaCl concentration such that the off-rate was found to be driven primarily by non-ionic forces. These results contribute to understanding the role of specific and nonspecific forces that drive heparin-thrombin interactions under applied force or flow conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Unfractionated heparin versus low molecular weight heparins for avoiding heparin-induced thrombocytopenia in postoperative patients.

    Science.gov (United States)

    Junqueira, Daniela R; Zorzela, Liliane M; Perini, Edson

    2017-04-21

    Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction presenting as a prothrombotic disorder related to antibody-mediated platelet activation. It is a paradoxical immune reaction resulting in thrombin generation in vivo, which leads to a hypercoagulable state and the potential to initiate venous or arterial thrombosis. A number of factors are thought to influence the incidence of HIT including the type and preparation of heparin (unfractionated heparin (UFH) or low molecular weight heparin (LMWH)) and the heparin-exposed patient population, with the postoperative patient population at higher risk.Although LMWH has largely replaced UFH as a front-line therapy, there is evidence supporting a lack of superiority of LMWH compared with UFH regarding prevention of deep vein thrombosis and pulmonary embolism following surgery, and similar frequencies of bleeding have been described with LMWH and UFH. The decision as to which of these two preparations of heparin to use may thus be influenced by harmful effects such as HIT. We therefore sought to determine the relative impact of UFH and LMWH on HIT in postoperative patients receiving thromboembolism prophylaxis. This is an update of a review first published in 2012. The objective of this review was to compare the incidence of heparin-induced thrombocytopenia (HIT) and HIT complicated by venous thromboembolism in postoperative patients exposed to unfractionated heparin (UFH) versus low molecular weight heparin (LMWH). For this update, the Cochrane Vascular Information Specialist searched the Specialised Register (May 2016), CENTRAL (2016, Issue 4) and trials registries. The authors searched Lilacs (June 2016) and additional trials were sought from reference lists of relevant publications. We included randomised controlled trials (RCTs) in which participants were postoperative patients allocated to receive prophylaxis with UFH or LMWH, in a blinded or unblinded fashion. Studies were excluded if they did not use

  16. Oral heparin results in the appearance of heparin fragments in the plasma of rats

    International Nuclear Information System (INIS)

    Larsen, A.K.; Lund, D.P.; Langer, R.; Folkman, J.

    1986-01-01

    We have previously shown that angiogenesis inhibition and tumor regression can be accomplished by combinations of heparin or heparin fragments with cortisone. Oral heparin was also effective in combination with cortisone. We now show that a single oral dose of [ 35 S]heparin or [ 3 H]heparin (15,000 units/kg) results in continuous release of radioactive material into the bloodstream for at least 12 hr. This is associated with the presence of anti-factor Xa activity at a level of approximately equal to 0.1 unit/ml. The radioactive material is identified as oligo-, di-, and monosaccharides by its behavior in chromatographic systems, its possession of anti-factor Xa activity, and the effect of treatment with bacterial heparinase. The heparin fragments are extensively metabolized to fragments without anti-factor Xa activity that are readily subject to urinary excretion

  17. Heparin: Past, Present, and Future.

    Science.gov (United States)

    Oduah, Eziafa I; Linhardt, Robert J; Sharfstein, Susan T

    2016-07-04

    Heparin, the most widely used anticoagulant drug in the world today, remains an animal-derived product with the attendant risks of adulteration and contamination. A contamination crisis in 2007-2008 increased the impetus to provide non-animal-derived sources of heparin, produced under cGMP conditions. In addition, recent studies suggest that heparin may have significant antineoplastic activity, separate and distinct from its anticoagulant activity, while other studies indicate a role for heparin in treating inflammation, infertility, and infectious disease. A variety of strategies have been proposed to produce a bioengineered heparin. In this review, we discuss several of these strategies including microbial production, mammalian cell production, and chemoenzymatic modification. We also propose strategies for creating "designer" heparins and heparan-sulfates with various biochemical and physiological properties.

  18. Comparative study of heparin-binding proteins profile of Murrah buffalo (Bubalus bubalis semen

    Directory of Open Access Journals (Sweden)

    S. S. Ramteke

    2014-09-01

    Full Text Available Aim: The experiment was conducted to study the total seminal plasma protein (TSPP and heparin-binding proteins (HBPs in relation to initial semen quality of buffalo bull. Materials and Methods: Semen from two Murrah buffalo bulls (bull no. 605 and 790 with mass motility of ≥3+ were used for the study and categorized into three groups (Group I- Mass motility 3+, Group II- Mass motility 4+ and Group III- Mass motility 5+. Seminal plasma from semen was separated by centrifugation. HBPs was isolated and purified from heparin-agarose affinity column by modified elution buffer. TSPP and isolated HBPs concentration was estimated by Lowry’s method. The purified HBPs were resolved on Sodium dodecyl sulfate polyacrylamide gel electrophoresis to check the protein profile of two bulls. Results: The mean values of TSPP concentrations in bull no. 605 and 790 in Group I, II and III were 30.64±0.12, 31.66±0.09, 32.53±0.19 and 28.51±0.09, 29.49±0.15, 30.45±0.17 mg/mL, respectively. The mean values of HBPs concentrations in bull no. 605 and 790 in Group I, II and III were 3.11±0.07, 3.32±0.06, 3.46±0.08 and 2.51±0.08, 2.91±0.05, 3.10±0.03 mg/mL, respectively. Both the values of TSPP and HBPs were significantly higher (p<0.01 in bull no. 605 when compared to 790 in all the three groups. 31 kDa HBP was more intensely present in bull no. 605, thus may indicate its superiority over bull no. 790 in relation to fertility potential. Conclusion: TSPP and HBPs shows variation in concentration with respect to initial semen quality. Furthermore, presence of fertility related 31 kDa HBPs in one of the bull may be an indication of high fertility of a bull. In future, in-vivo and in-vitro correlative study on larger basis is needed for the establishment of fertility-related HBPs in semen which might establish criteria for selection of buffalo bull with high fertility potential.

  19. Disappearance of a low molecular weight heparin fraction (CY 216) differs from standard heparin in rabbits

    International Nuclear Information System (INIS)

    Boneu, B.; Buchanan, M.R.; Caranobe, C.; Gabaig, A.M.; Dupouy, D.; Sie, P.; Hirsh, J.

    1987-01-01

    In previous studies, we have reported that standard heparin (SH) was cleared by two mechanisms, a saturable mechanism which predominated at low doses (less than 100 anti-factor Xa U/kg) and a non-saturable mechanism which predominated at higher doses, when the first mechanism became saturated. In this study, we examined the importance of these two mechanisms in the disappearance of a low molecular weight heparin fraction (LMWH) (CY 216), by comparing the pharmacokinetics and the pharmacodynamics of a wide range of doses of SH and CY 216 (1.5 to 500 anti-factor Xa U/kg). Pharmacokinetics was measured as the disappearance of 125 I-radiolabelled SH or CY 216. Pharmacodynamics was measured as the disappearance of the anti-factor Xa activity of SH and CY 216. We found that the saturable mechanism contributed little to the disappearance of CY 216 and that it was cleared predominantly by the non-saturable mechanism at all doses tested. Thus, at low doses (less than 100 anti-factor Xa U/kg), SH was cleared more rapidly than CY 216, whereas at higher doses, CY 216 was cleared more rapidly than SH. We conclude that the mechanism of disappearance of LMWH's differ significantly from those of SH, and that this difference may explain the apparent prolonged anticoagulant activity of LMWH's within the therapeutic range doses

  20. Intracellular protein delivery activity of peptides derived from insulin-like growth factor binding proteins 3 and 5

    International Nuclear Information System (INIS)

    Goda, Natsuko; Tenno, Takeshi; Inomata, Kosuke; Shirakawa, Masahiro; Tanaka, Toshiki; Hiroaki, Hidekazu

    2008-01-01

    Insulin-like growth factor binding proteins (IGFBPs) have various IGF-independent cellular activities, including receptor-independent cellular uptake followed by transcriptional regulation, although mechanisms of cellular entry remain unclear. Herein, we focused on their receptor-independent cellular entry mechanism in terms of protein transduction domain (PTD) activity, which is an emerging technique useful for clinical applications. The peptides of 18 amino acid residues derived from IGFBP-3 and IGFBP-5, which involve heparin-binding regions, mediated cellular delivery of an exogenous protein into NIH3T3 and HeLa cells. Relative protein delivery activities of IGFBP-3/5-derived peptides were approximately 20-150% compared to that of the HIV-Tat peptide, a potent PTD. Heparin inhibited the uptake of the fusion proteins with IGFBP-3 and IGFBP-5, indicating that the delivery pathway is heparin-dependent endocytosis, similar to that of HIV-Tat. The delivery of GST fused to HIV-Tat was competed by either IGFBP-3 or IGFBP-5-derived synthetic peptides. Therefore, the entry pathways of the three PTDs are shared. Our data has shown a new approach for designing protein delivery systems using IGFBP-3/5 derived peptides based on the molecular mechanisms of IGF-independent activities of IGFBPs

  1. Low molecular weight heparin versus unfractionated heparin in the initial treatment of venous thromboembolism

    NARCIS (Netherlands)

    Hettiarachchi, R. J.; Prins, M. H.; Lensing, A. W.; Buller, H. R.

    1998-01-01

    In this review, we analyze data from randomized trials in which low molecular weight heparin was compared with unfractionated heparin, both to estimate the treatment effect of low molecular weight heparin in the initial treatment of venous thromboembolism and to evaluate the effect of the varied

  2. Collection of heparinized plasma by plasmapheresis

    NARCIS (Netherlands)

    van der Meer, P. F.; Vrielink, H.; Pietersz, R. N.; Dekker, W. J.; Reesink, H. W.

    1999-01-01

    BACKGROUND AND OBJECTIVES: Heparinized plasma can be used for exchange transfusions in neonates and is usually collected by drawing whole blood using heparin as anticoagulant. The heparinized red blood cells and buffy coat cannot be used and are therefore discarded. To collect heparinized plasma

  3. Preparation and characterization of chitosan-heparin composite matrices for blood contacting tissue engineering

    International Nuclear Information System (INIS)

    He Qing; Gong Kai; Gong Yandao; Zhang Xiufang; Ao Qiang; Zhang Lihai; Hu Min

    2010-01-01

    Chitosan has been widely used for biomaterial scaffolds in tissue engineering because of its good mechanical properties and cytocompatibility. However, the poor blood compatibility of chitosan has greatly limited its biomedical utilization, especially for blood contacting tissue engineering. In this study, we exploited a polymer blending procedure to heparinize the chitosan material under simple and mild conditions to improve its antithrombogenic property. By an optimized procedure, a macroscopically homogeneous chitosan-heparin (Chi-Hep) blended suspension was obtained, with which Chi-Hep composite films and porous scaffolds were fabricated. X-ray photoelectron spectroscopy and sulfur elemental analysis confirmed the successful immobilization of heparin in the composite matrices (i.e. films and porous scaffolds). Toluidine blue staining indicated that heparin was distributed homogeneously in the composite matrices. Only a small amount of heparin was released from the matrices during incubation in normal saline for 10 days. The composite matrices showed improved blood compatibility, as well as good mechanical properties and endothelial cell compatibility. These results suggest that the Chi-Hep composite matrices are promising candidates for blood contacting tissue engineering.

  4. Analysis and characterization of heparin impurities.

    Science.gov (United States)

    Beni, Szabolcs; Limtiaco, John F K; Larive, Cynthia K

    2011-01-01

    This review discusses recent developments in analytical methods available for the sensitive separation, detection and structural characterization of heparin contaminants. The adulteration of raw heparin with oversulfated chondroitin sulfate (OSCS) in 2007-2008 spawned a global crisis resulting in extensive revisions to the pharmacopeia monographs on heparin and prompting the FDA to recommend the development of additional physicochemical methods for the analysis of heparin purity. The analytical chemistry community quickly responded to this challenge, developing a wide variety of innovative approaches, several of which are reported in this special issue. This review provides an overview of methods of heparin isolation and digestion, discusses known heparin contaminants, including OSCS, and summarizes recent publications on heparin impurity analysis using sensors, near-IR, Raman, and NMR spectroscopy, as well as electrophoretic and chromatographic separations.

  5. Heparin-induced thrombocytopenia: real-world issues.

    Science.gov (United States)

    Linkins, Lori-Ann; Warkentin, Theodore E

    2011-09-01

    Heparin-induced thrombocytopenia (HIT) is a prothrombotic drug reaction caused by platelet-activating antibodies. HIT sera often activate platelets without needing heparin-such heparin-"independent" platelet activation can be associated with HIT beginning or worsening despite stopping heparin ("delayed-onset HIT"). We address important issues in HIT diagnosis and therapy, using a recent cohort of HIT patients to illustrate influences of heparin type; triggers for HIT investigation; serological features of heparin-independent platelet activation; and treatment. In our cohort of recent HIT cases ( N = 13), low-molecular-weight heparin (dalteparin) was a common causative agent ( N = 8, 62%); most patients were diagnosed after HIT-thrombosis had occurred; and danaparoid was the most frequently selected treatment. Heparin-independent platelet activation was common (7/13 [54%]) and predicted slower platelet count recovery (>1 week) among evaluable patients (5/5 vs 1/6; P = 0.015). In our experience with argatroban-treated patients, HIT-associated consumptive coagulopathy confounds anticoagulant monitoring. Our observations provide guidance on practical aspects of HIT diagnosis and management. Thieme Medical Publishers.

  6. The cell-penetrating peptide domain from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) has anti-inflammatory activity in vitro and in vivo

    International Nuclear Information System (INIS)

    Lee, Jue-Yeon; Seo, Yoo-Na; Park, Hyun-Jung; Park, Yoon-Jeong; Chung, Chong-Pyoung

    2012-01-01

    Highlights: ► HBP sequence identified from HB-EGF has cell penetration activity. ► HBP inhibits the NF-κB dependent inflammatory responses. ► HBP directly blocks phosphorylation and degradation of IκBα. ► HBP inhibits nuclear translocation of NF-κB p65 subunit. -- Abstract: A heparin-binding peptide (HBP) sequence from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) was identified and was shown to exhibit cell penetration activity. This cell penetration induced an anti-inflammatory reaction in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. HBP penetrated the cell membrane during the 10 min treatment and reduced the LPS-induced production of nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cytokines (TNF-α and IL-6) in a concentration-dependent manner. Additionally, HBP inhibited the LPS-induced upregulation of cytokines, including TNF-α and IL-6, and decreased the interstitial infiltration of polymorphonuclear leukocytes in a lung inflammation model. HBP inhibited NF-κB-dependent inflammatory responses by directly blocking the phosphorylation and degradation of IκBα and by subsequently inhibiting the nuclear translocation of the p65 subunit of NF-κB. Taken together, this novel HBP may be potentially useful candidate for anti-inflammatory treatments and can be combined with other drugs of interest to transport attached molecules into cells.

  7. Human trophoblast survival at low oxygen concentrations requires metalloproteinase-mediated shedding of heparin-binding EGF-like growth factor.

    Science.gov (United States)

    Armant, D Randall; Kilburn, Brian A; Petkova, Anelia; Edwin, Samuel S; Duniec-Dmuchowski, Zophia M; Edwards, Holly J; Romero, Roberto; Leach, Richard E

    2006-02-01

    Heparin-binding EGF-like growth factor (HBEGF), which is expressed in the placenta during normal pregnancy, is down regulated in pre-eclampsia, a human pregnancy disorder associated with poor trophoblast differentiation and survival. This growth factor protects against apoptosis during stress, suggesting a role in trophoblast survival in the relatively low O(2) ( approximately 2%) environment of the first trimester conceptus. Using a well-characterized human first trimester cytotrophoblast cell line, we found that a 4-hour exposure to 2% O(2) upregulates HBEGF synthesis and secretion independently of an increase in its mRNA. Five other expressed members of the EGF family are largely unaffected. At 2% O(2), signaling via HER1 or HER4, known HBEGF receptors, is required for both HBEGF upregulation and protection against apoptosis. This positive-feedback loop is dependent on metalloproteinase-mediated cleavage and shedding of the HBEGF ectodomain. The restoration of trophoblast survival by the addition of soluble HBEGF in cultures exposed to low O(2) and metalloproteinase inhibitor suggests that the effects of HBEGF are mediated by autocrine/paracrine, rather than juxtacrine, signaling. Our results provide evidence that a post-transcriptional mechanism induced in trophoblasts by low O(2) rapidly amplifies HBEGF signaling to inhibit apoptosis. These findings have a high clinical significance, as the downregulation of HBEGF in pre-eclampsia is likely to be a contributing factor leading to the demise of trophoblasts.

  8. 77 FR 7584 - Draft Guidance for Industry on Heparin for Drug and Medical Device Use; Monitoring Crude Heparin...

    Science.gov (United States)

    2012-02-13

    ... strategies to ensure that the heparin supply chain is not contaminated with OSCS or any non- porcine origin... device manufacturers of finished products, and others to the potential risk of crude heparin...) among patients injected with heparin sodium in 2008, FDA identified the contaminant OSCS in heparin API...

  9. 78 FR 38058 - Guidance for Industry on Heparin for Drug and Medical Device Use: Monitoring Crude Heparin for...

    Science.gov (United States)

    2013-06-25

    ... public health. FDA developed this guidance to alert manufacturers to the risks of crude heparin contaminants and to recommend strategies to ensure that the heparin supply chain is not contaminated with OSCS... heparin sodium in 2008, FDA identified the contaminant OSCS in crude heparin sourced from China. FDA is...

  10. Heparin-Binding EGF-like Growth Factor (HB-EGF) Therapy for Intestinal Injury: Application and Future Prospects

    Science.gov (United States)

    Yang, Jixin; Su, Yanwei; Zhou, Yu; Besner, Gail E.

    2014-01-01

    Throughout the past 20 years, we have been investigating the potential therapeutic roles of heparin-binding EGF-like growth factor (HB-EGF), a member of the epidermal growth factor family, in various models of intestinal injury including necrotizing enterocolitis (NEC), intestinal ischemia/reperfusion (I/R) injury, and hemorrhagic shock and resuscitation (HS/R). Our studies have demonstrated that HB-EGF acts as an effective mitogen, a restitution-inducing reagent, a cellular trophic factor, an anti-apoptotic protein and a vasodilator, via its effects on various cell types in the intestine. In the current paper, we have reviewed the application and therapeutic effects of HB-EGF in three classic animal models of intestinal injury, with particular emphasis on its protection of the intestines from NEC. Additionally, we have summarized the protective functions of HB-EGF on various target cells in the intestine. Lastly, we have provided a brief discussion focusing on the future development of HB-EGF clinical applications for the treatment of various forms of intestinal injury including NEC. PMID:24345808

  11. Sensitive detection of oversulfated chondroitin sulfate in heparin sodium or crude heparin with a colorimetric microplate based assay.

    Science.gov (United States)

    Sommers, Cynthia D; Mans, Daniel J; Mecker, Laura C; Keire, David A

    2011-05-01

    In this work we describe a 96-well microplate assay for oversulfated chondroitin sulfate A (OSCS) in heparin, based on a water-soluble cationic polythiophene polymer (3-(2-(N-(N'-methylimidazole))ethoxy)-4-methylthiophene (LPTP)) and heparinase digestion of heparin. The assay takes advantage of several unique properties of heparin, OSCS, and LPTP, including OSCS inhibition of heparinase I and II activity, the molecular weight dependence of heparin-LPTP spectral shifts, and the distinct association of heparin fragments and OSCS to LPTP. These factors combine to enable detection of the presence of 0.003% w/w spiked OSCS in 10 μg of heparin sodium active pharmaceutical ingredient (API) using a plate reader and with visual detection to 0.1% levels. The same detection limit for OSCS was observed in the presence of 10% levels of dermatan sulfate (DS) or chondroitin sulfate A (CSA) impurities. In addition, we surveyed a selection of crude heparin samples received by the agency in 2008 and 2009 to determine average and extreme DS, CSA, and galactosamine weight percent levels. In the presence of these impurities and the variable heparin content in the crude heparin samples, spiked OSCS was reliably detected to the 0.1% w/w level using a plate reader. Finally, authentically OSCS contaminated heparin sodium API and crude samples were distinguished visually by color from control samples using the LPTP/heparinase test.

  12. Heparin (GAG-hed) inhibits LCR activity of Human Papillomavirus type 18 by decreasing AP1 binding

    International Nuclear Information System (INIS)

    Villanueva, Rita; Morales-Peza, Néstor; Castelán-Sánchez, Irma; García-Villa, Enrique; Tapia, Rocio; Cid-Arregui, Ángel; García-Carrancá, Alejandro; López-Bayghen, Esther; Gariglio, Patricio

    2006-01-01

    High risk HPVs are causative agents of anogenital cancers. Viral E6 and E7 genes are continuously expressed and are largely responsible for the oncogenic activity of these viruses. Transcription of the E6 and E7 genes is controlled by the viral Long Control Region (LCR), plus several cellular transcription factors including AP1 and the viral protein E2. Within the LCR, the binding and activity of the transcription factor AP1 represents a key regulatory event in maintaining E6/E7 gene expression and uncontrolled cell proliferation. Glycosaminoglycans (GAGs), such as heparin, can inhibit tumour growth; they have also shown antiviral effects and inhibition of AP1 transcriptional activity. The purpose of this study was to test the heparinoid GAG-hed, as a possible antiviral and antitumoral agent in an HPV18 positive HeLa cell line. Using in vivo and in vitro approaches we tested GAG-hed effects on HeLa tumour cell growth, cell proliferation and on the expression of HPV18 E6/E7 oncogenes. GAG-hed effects on AP1 binding to HPV18-LCR-DNA were tested by EMSA. We were able to record the antitumoral effect of GAG-hed in vivo by using as a model tumours induced by injection of HeLa cells into athymic female mice. The antiviral effect of GAG-hed resulted in the inhibition of LCR activity and, consequently, the inhibition of E6 and E7 transcription. A specific diminishing of cell proliferation rates was observed in HeLa but not in HPV-free colorectal adenocarcinoma cells. Treated HeLa cells did not undergo apoptosis but the percentage of cells in G 2 /M phase of the cell cycle was increased. We also detected that GAG-hed prevents the binding of the transcription factor AP1 to the LCR. Direct interaction of GAG-hed with the components of the AP1 complex and subsequent interference with its ability to correctly bind specific sites within the viral LCR may contribute to the inhibition of E6/E7 transcription and cell proliferation. Our data suggest that GAG-hed could have

  13. Click-coated, heparinized, decellularized vascular grafts.

    Science.gov (United States)

    Dimitrievska, Sashka; Cai, Chao; Weyers, Amanda; Balestrini, Jenna L; Lin, Tylee; Sundaram, Sumati; Hatachi, Go; Spiegel, David A; Kyriakides, Themis R; Miao, Jianjun; Li, Guoyun; Niklason, Laura E; Linhardt, Robert J

    2015-02-01

    A novel method enabling the engineering of a dense and appropriately oriented heparin-containing layer on decellularized aortas has been developed. Amino groups of decellularized aortas were first modified to azido groups using 3-azidobenzoic acid. Azide-clickable dendrons were attached onto the azido groups through "alkyne-azide" click chemistry, affording a tenfold amplification of adhesions sites. Dendron end groups were finally decorated with end-on modified heparin chains. Heparin chains were oriented like heparan sulfate groups on native endothelial cells surface. X-ray photoelectron spectroscopy, nuclear magnetic resonance imaging, mass spectrometry and Fourier transform infrared FTIR spectroscopy were used to characterize the synthesis steps, building the final heparin layered coatings. The continuity of the heparin coating was verified using fluorescent microscopy and histological analysis. The efficacy of heparin linkage was demonstrated with factor Xa anti-thrombogenic assay and platelet adhesion studies. The results suggest that oriented heparin immobilization to decellularized aortas may improve the in vivo blood compatibility of decellularized aortas and vessels. Copyright © 2014 Acta Materialia Inc. All rights reserved.

  14. Cancer Cell Adhesion and Metastasis: Selectins, Integrins, and the Inhibitory Potential of Heparins

    Directory of Open Access Journals (Sweden)

    Gerd Bendas

    2012-01-01

    Full Text Available Cell adhesion molecules play a significant role in cancer progression and metastasis. Cell-cell interactions of cancer cells with endothelium determine the metastatic spread. In addition, direct tumor cell interactions with platelets, leukocytes, and soluble components significantly contribute to cancer cell adhesion, extravasation, and the establishment of metastatic lesions. Clinical evidence indicates that heparin, commonly used for treatment of thromboembolic events in cancer patients, is beneficial for their survival. Preclinical studies confirm that heparin possesses antimetastatic activities that lead to attenuation of metastasis in various animal models. Heparin contains several biological activities that may affect several steps in metastatic cascade. Here we focus on the role of cellular adhesion receptors in the metastatic cascade and discuss evidence for heparin as an inhibitor of cell adhesion. While P- and L-selectin facilitation of cellular contacts during hematogenous metastasis is being accepted as a potential target of heparin, here we propose that heparin may also interfere with integrin activity and thereby affect cancer progression. This review summarizes recent findings about potential mechanisms of tumor cell interactions in the vasculature and antimetastatic activities of heparin.

  15. Heparin for assisted reproduction.

    Science.gov (United States)

    Akhtar, Muhammad A; Sur, Shyamaly; Raine-Fenning, Nick; Jayaprakasan, Kannamannadiar; Thornton, Jim G; Quenby, Siobhan

    2013-08-17

    Heparin as an adjunct in assisted reproduction (peri-implantation heparin) is given at or after egg collection or at embryo transfer during assisted reproduction. Heparin has been advocated to improve embryo implantation and clinical outcomes.  It has been proposed that heparin enhances the intra-uterine environment by improving decidualisation with an associated activation of growth factors and a cytokine expression profile in the endometrium that is favourable to pregnancy. To investigate whether the administration of heparin around the time of implantation (peri-implantation heparin) improves clinical outcomes in subfertile women undergoing assisted reproduction. A comprehensive and exhaustive search strategy was developed in consultation with the Trials Search Co-ordinator of the Cochrane Menstrual Disorders and Subfertility Group (MDSG). The strategy was used in an attempt to identify all relevant studies regardless of language or publication status (published, unpublished, in press, and in progress). Relevant trials were identified from both electronic databases and other resources (last search 6 May 2013). All randomised controlled trials (RCTs) were included where peri-implantation heparin was given during assisted reproduction. Peri-implantation low molecular weight heparin (LMWH) during IVF/ICSI was given at or after egg collection or at embryo transfer in the included studies. Live birth rate was the primary outcome. Two review authors independently assessed the eligibility and quality of trials and extracted relevant data. The quality of the evidence was evaluated using GRADE methods. Three RCTs (involving 386 women) were included in the review.Peri-implantation LMWH administration during assisted reproduction was associated with a significant improvement in live birth rate compared with placebo or no LMWH (odds ratio (OR) 1.77, 95% confidence interval (CI) 1.07 to 2.90, three studies, 386 women, I(2) = 51%, very low quality evidence with high

  16. Mechanisms of Staphylococcus epidermidis adhesion to model biomaterial surfaces: Establising a link between thrombosis and infection

    Science.gov (United States)

    Higashi, Julie Miyo

    Infections involving Staphylococcus epidermidis remain a life threatening complication associated with the use of polymer based cardiovascular devices. One of the critical steps in infection pathogenesis is the adhesion of the bacteria to the device surface. Currently, mechanisms of S. epidermidis adhesion are incompletely understood, but are thought to involve interactions between bacteria, device surface, and host blood elements in the form of adsorbed plasma proteins and surface adherent platelets. Our central hypothesis is that elements participating in thrombosis also promote S. epidermidis adhesion by specifically binding to the bacterial surface. The adhesion kinetics of S. epidermidis RP62A to host modified model biomaterial surface octadecyltrichlorosilane (OTS) under hydrodynamic shear conditions were characterized. Steady state adhesion to adsorbed proteins and surface adherent platelets was achieved at 90-120 minutes and 60-90 minutes, respectively. A dose response curve of S. epidermidis adhesion in the concentration range of 10sp7{-}10sp9 bac/mL resembled a multilayer adsorption isotherm. Increasing shear stress was found to LTA, and other LTA blocking agents significantly decreased S. epidermidis adhesion to the fibrin-platelet clots, suggesting that this interaction between S. epidermidis and fibrin-platelet clots is specific. Studies evaluated the adhesion of S. epidermidis to polymer immobilized heparin report conflicting results. Paulsson et al., showed that coagulase negative staphylococci adhered in comparable numbers to both immobilized heparin and nonheparinized surfaces, while exhibiting significantly greater adhesion to both surfaces than S. aureus. Preadsorption of the surfaces with specific heparin binding plasma proteins vitronectin, fibronectin, laminin, and collagen significantly increased adhesion. It was postulated that immobilized heparin contained binding sites for the plasma proteins, exposing bacteria binding domains of the

  17. Effect of buffer at nanoscale molecular recognition interfaces - electrostatic binding of biological polyanions.

    Science.gov (United States)

    Rodrigo, Ana C; Laurini, Erik; Vieira, Vânia M P; Pricl, Sabrina; Smith, David K

    2017-10-19

    We investigate the impact of an over-looked component on molecular recognition in water-buffer. The binding of a cationic dye to biological polyanion heparin is shown by isothermal calorimetry to depend on buffer (Tris-HCl > HEPES > PBS). The heparin binding of self-assembled multivalent (SAMul) cationic micelles is even more buffer dependent. Multivalent electrostatic molecular recognition is buffer dependent as a result of competitive interactions between the cationic binding interface and anions present in the buffer.

  18. Heparin and heparin-induced thrombocytopenia

    African Journals Online (AJOL)

    2007-06-15

    Jun 15, 2007 ... Heparin is one of the most widely used drugs. It is used routinely for treatment and thromboprophylaxis in a broad spectrum of conditions including venous thromboembolism, atrial fibrillation, acute coronary syndromes, peripheral vascular disease and to maintain the patency of indwelling catheters and ...

  19. Results of the HepZero study comparing heparin-grafted membrane and standard care show that heparin-grafted dialyzer is safe and easy to use for heparin-free dialysis

    NARCIS (Netherlands)

    Laville, Maurice; Dorval, Marc; Ros, Joan Fort; Fay, Renaud; Cridlig, Joelle; Nortier, Joelle L.; Juillard, Laurent; Debska-Slizien, Alicja; Lorente, Loreto Fernandez; Thibaudin, Damien; Franssen, Casper; Schulz, Michael; Moureau, Frederique; Loughraieb, Nathalie; Rossignol, Patrick

    2014-01-01

    Heparin is used to prevent clotting during hemodialysis, but heparin-free hemodialysis is sometimes needed to decrease the risk of bleeding. The HepZero study is a randomized, multicenter international controlled open-label trial comparing no-heparin hemodialysis strategies designed to assess

  20. Serum Heparin-binding Epidermal Growth Factor-like Growth Factor (HB-EGF) as a Biomarker for Primary Ovarian Cancer.

    Science.gov (United States)

    Miyata, Kohei; Yotsumoto, Fusanori; Fukagawa, Satoshi; Kiyoshima, Chihiro; Ouk, Nam Sung; Urushiyama, Daichi; Ito, Tomohiro; Katsuda, Takahiro; Kurakazu, Masamitsu; Araki, Ryota; Sanui, Ayako; Miyahara, Daisuke; Murata, Masaharu; Shirota, Kyoko; Yagi, Hiroshi; Takono, Tadao; Kato, Kiyoko; Yaegashi, Nobuo; Akazawa, Kohei; Kuroki, Masahide; Yasunaga, Shin'ichiro; Miyamoto, Shingo

    2017-07-01

    Ovarian cancer is the most lethal malignancy among gynaecological cancers. Although many anticancer agents have been developed for the treatment of ovarian cancer, it continues to have an extremely poor prognosis. Heparin-binding epidermal growth factor-like grown factor (HB-EGF) has been reported to be a rational therapeutic target for ovarian cancer. Here, we evaluated the clinical significance of serum HB-EGF by examining the association between prognosis and serum HB-EGF levels in patients with primary ovarian cancer. We found that high serum HB-EGF concentrations were significantly associated with poor prognosis in a combined cohort of patients with all stages of ovarian cancer, as well as in a subset of patients with advanced disease. In addition, serum HB-EGF levels increased as the cancer advanced. These data suggest that serum HB-EGF may be a target for the design of novel therapies for ovarian cancer. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  1. Elevated urine levels of heparin-binding protein in children with urinary tract infection.

    Science.gov (United States)

    Kjölvmark, Charlott; Akesson, Per; Linder, Adam

    2012-08-01

    Urinary tract infection (UTI) is a common infection diagnosis in children, and efficient diagnosis and treatment are important to avoid serious complications. In this study we investigated whether urinary levels of neutrophil-derived heparin-binding protein (HBP) can be used as a marker of UTI in children. These results were compared to those of dipstick analysis, interleukin-6 (IL-6) analysis in urine, and bacterial culturing. Seventy-eight children aged 0-18 years with fever and/or symptoms indicating UTI were enrolled in a prospective consecutive study. Urine samples were cultured and analyzed with dipstick, and concentrations of HBP and IL-6 were measured. Fifteen patients were classified as having UTI, 30 patients had fever but were diagnosed with a non-urinary tract infection, and 33 patients had neither UTI nor fever. Using a urine HBP (U-HBP) cut-off level of 32 ng/mL, the sensitivity and specificity for detecting UTI were 93.3 and 90.3 %, respectively. Receiver operating characteristic curves demonstrated that U-HBP levels were a higher specificity indicator of UTI than urine white blood cell counts or urine IL-6 levels; they also showed a higher sensitivity than the results of the urine nitrite test. All patients with significant growth of clinically relevant bacteria had elevated U-HBP levels. The results indicate that rapid analysis of U-HBP can provide helpful guidance in the management of children with suspected UTI.

  2. The role of heparin in sepsis: much more than just an anticoagulant.

    Science.gov (United States)

    Li, Xu; Ma, Xiaochun

    2017-11-01

    Despite progress in antibiotic treatment, mechanical ventilation, fluid resuscitation and blood glucose maintenance, sepsis remains a cause of high mortality in the intensive care unit to date, there are no proven treatment strategies for the routine management of septic patients. The extensive interaction between inflammation and coagulation contributes to the basic pathophysiology of sepsis. Thus, the agents that attenuate the activation of both inflammation and coagulation may improve the outcome in sepsis. Apart from the well-known anticoagulant effects of heparin, it also possesses various immunomodulatory properties and protects glycocalyx from shedding. Hence, heparin seems to be such an agent. Immunothrombosis plays an important role in early host defence against bacterial dissemination, thus the proper timing for anticoagulant therapy should be determined. We review the available experimental and clinical data supporting the use of heparin in sepsis. At this time the use of heparin in the treatment of sepsis is conflicting. Future trials of heparin therapy for sepsis should concentrate on the very severely ill patients, in whom benefit is most likely to be demonstrated. © 2017 John Wiley & Sons Ltd.

  3. In vitro binding of 67Ga to Ehrlich ascites tumor cells

    International Nuclear Information System (INIS)

    Kojima, S.; Kubodera, A.

    1984-01-01

    The binding of 67 Ga to Ehrlich ascites tumor cells (ETC) was studied in vitro. Acid mucopolysaccharide (AMPS) present at the cell surface of ETC was identified as heparan sulfate (HS). The extent of 67 Ga binding to ETC reached a plateau (ca. 10% of the added dose) at 1-2 h after the start of incubation. The binding was higher under neutral or alkaline conditions than under acidic conditions. Heparin and heparitinase treatment both significantly decreased the extent of 67 Ga binding to ETC. Mild treatment with protease, including trypsin or papain, also decreased the binding. On the contrary, the treatment with trypsin under severe conditions markedly increased the extent of 67 Ga binding to ETC. These results support the hypothesis that HS plays an important role as a 67 Ga receptor in the mechanism of gallium binding to ETC. (orig.)

  4. M/sub r/ 25,000 heparin-binding protein from guinea pig brain is a high molecular weight form of basic fibroblast growth factor

    International Nuclear Information System (INIS)

    Moscatelli, D.; Joseph-Silverstein, J.; Manejias, R.; Rifkin, D.B.

    1987-01-01

    A M/sub r/ 25,000 form of basic fibroblast growth factor (bFGF) has been isolated from guinea pig grain along with the typical M/sub r/ 18,000 form. Both forms were purified to homogeneity by a combination of heparin-affinity chromatography and ion-exchange chromatography on an FPLC Mono S column. The M/sub r/ 25,000 form, like the M/sub r/ 18,000 form was not eluted from the heparin-affinity column with 0.95 M NaCl, but was eluted with 2 M NaCl. The M/sub r/ 25,000 guinea pig protein stimulated plasminogen activator production by cultured bovine capillary endothelial cells in a dose-dependent manner at concentration of 0.1-10 ngml, the same range that was effective for guinea pig and human M/sub r/ 18,000 bFGFs. The binding of human 125 I-labeled bFGF to baby hamster kidney cells is inhibited equally by the M/sub r/ 25,000 guinea pig protein and the M/sub r/ 18,000 guinea pig and human bFGFs. Polyclonal antibodies raised against human bFGF recognize both the M/sub r/ 25,000 and 18,000 guinea pig proteins in an immunoblot analysis. In a radioimmunoassay, both the M/sub r/ 25,000 and M/sub r/ 18,000 guinea pig proteins compete equally well with iodinated human bFGF for binding to the anti-human bFGF antibodies. When treated with low concentrations of trypsin, the M/sub r/ 25,000 guinea pig bFGF was converted to a M/sub r/ 18,000 protein. These results show that the two molecules are closely related and suggest that the M/sub r/ 25,000 protein shares substantial homology with the M/sub r/ 18,000 bFGF

  5. Role of Heparan Sulfate in Cellular Infection of Integrin-Binding Coxsackievirus A9 and Human Parechovirus 1 Isolates.

    Directory of Open Access Journals (Sweden)

    Pirjo Merilahti

    Full Text Available Heparan sulfate/heparin class of proteoglycans (HSPG have been shown to function in cellular attachment and infection of numerous viruses including picornaviruses. Coxsackievirus A9 (CV-A9 and human parechovirus 1 (HPeV-1 are integrin-binding members in the family Picornaviridae. CV-A9 Griggs and HPeV-1 Harris (prototype strains have been reported not to bind to heparin, but it was recently shown that some CV-A9 isolates interact with heparin in vitro via VP1 protein with a specific T132R/K mutation. We found that the infectivity of both CV-A9 Griggs and HPeV-1 Harris was reduced by sodium chlorate and heparinase suggestive of HSPG interactions. We analyzed the T132 site in fifty-four (54 CV-A9 clinical isolates and found that only one of them possessed T132/R mutation while the other nine (9 had T132K. We then treated CV-A9 Griggs and HPeV-1 Harris and eight CV-A9 and six HPeV-1 clinical isolates with heparin and protamine. Although infectivity of Griggs strain was slightly reduced (by 25%, heparin treatment did not affect the infectivity of the CV-A9 isolates that do not possess the T132R/K mutation, which is in line with the previous findings. Some of the HPeV-1 isolates were also affected by heparin treatment, which suggested that there may be a specific heparin binding site in HPeV-1. In contrast, protamine (a specific inhibitor of heparin completely inhibited the infection of both prototypes and clinical CV-A9 and HPeV-1 isolates. We conclude that T132R/K mutation has a role in heparin binding of CV-A9, but we also show data, which suggest that there are other HSPG binding sites in CV-A9. In all, we suggest that HSPGs play a general role in both CV-A9 and HPeV-1 infections.

  6. Functionalization of chitosan/poly(lactic acid-glycolic acid) sintered microsphere scaffolds via surface heparinization for bone tissue engineering.

    Science.gov (United States)

    Jiang, Tao; Khan, Yusuf; Nair, Lakshmi S; Abdel-Fattah, Wafa I; Laurencin, Cato T

    2010-06-01

    Scaffolds exhibiting biological recognition and specificity play an important role in tissue engineering and regenerative medicine. The bioactivity of scaffolds in turn influences, directs, or manipulates cellular responses. In this study, chitosan/poly(lactic acid-co-glycolic acid) (chitosan/PLAGA) sintered microsphere scaffolds were functionalized via heparin immobilization. Heparin was successfully immobilized on chitosan/PLAGA scaffolds with controllable loading efficiency. Mechanical testing showed that heparinization of chitosan/PLAGA scaffolds did not significantly alter the mechanical properties and porous structures. In addition, the heparinized chitosan/PLAGA scaffolds possessed a compressive modulus of 403.98 +/- 19.53 MPa and a compressive strength of 9.83 +/- 0.94 MPa, which are in the range of human trabecular bone. Furthermore, the heparinized chitosan/PLAGA scaffolds had an interconnected porous structure with a total pore volume of 30.93 +/- 0.90% and a median pore size of 172.33 +/- 5.89 mum. The effect of immobilized heparin on osteoblast-like MC3T3-E1 cell growth was investigated. MC3T3-E1 cells proliferated three dimensionally throughout the porous structure of the scaffolds. Heparinized chitosan/PLAGA scaffolds with low heparin loading (1.7 microg/scaffold) were shown to be capable of stimulating MC3T3-E1 cell proliferation by MTS assay and cell differentiation as evidenced by elevated osteocalcin expression when compared with nonheparinized chitosan/PLAGA scaffold and chitosan/PLAGA scaffold with high heparin loading (14.1 microg/scaffold). This study demonstrated the potential of functionalizing chitosan/PLAGA scaffolds via heparinization with improved cell functions for bone tissue engineering applications.

  7. Heparin/heparan sulfates bind to and modulate neuronal L-type (Cav1.2) voltage-dependent Ca2+ channels

    DEFF Research Database (Denmark)

    Garau, Gianpiero; Magotti, Paola; Heine, Martin

    2015-01-01

    Our previous studies revealed that L-type voltage-dependent Ca2+ channels (Cav1.2 L-VDCCs) are modulated by the neural extracellular matrix backbone, polyanionic glycan hyaluronic acid. Here we used isothermal titration calorimetry and screened a set of peptides derived from the extracellular......M), integrating their enthalpic and entropic binding contributions. Interaction between heparin and recombinant as well as native full-length neuronal Cav1.2α1 channels was confirmed using the heparin–agarose pull down assay. Whole cell patch clamp recordings in HEK293 cells transfected with neuronal Cav1.......2 channels revealed that enzymatic digestion of highly sulfated heparan sulfates with heparinase 1 affects neither voltage-dependence of channel activation nor the level of steady state inactivation, but did speed up channel inactivation. Treatment of hippocampal cultures with heparinase 1 reduced the firing...

  8. Severe heparin osteoporosis in pregnancy.

    OpenAIRE

    Griffiths, H. T.; Liu, D. T.

    1984-01-01

    A case of severe osteoporosis following administration of low dose subcutaneous heparin in pregnancy is reported. Possible reasons for the condition are suggested which caution against the indiscriminate use of subcutaneous heparin in pregnancy.

  9. Nuclear androgen receptors in human prostatic tissue. Extraction with heparin and estimation of the number of binding sites with different methods

    International Nuclear Information System (INIS)

    Foekens, J.A.; Bolt-de Vries, J.; Mulder, E.; Blankenstein, M.A.; Schroeder, F.H.; Molen, H.J. van der

    1981-01-01

    A procedure for the estimation of nuclear androgen receptors in benign prostatic hyperplastic tissue is described, which employs extraction of receptors from nuclei with buffers containing heparin. Extraction of a nuclear pellet with a heparin-containing (1 g/l) buffer appeared to have definite advantages over 0.4 mol/l KCl extraction. Heparin appeared to be twice as efficient in extracting androgen receptors. In addition aggregated receptor proteins, formed after storage at -80 0 C, were partly deaggregated by heparin. Specific isolation of the androgen receptor was performed using either agar gel electrophoresis, protamine sulphate precipitation or LH-20 gel filtration. A comparison was made between the amounts of estimated receptors with these different techniques. Protamine sulphate precipitation resulted in the highest estimates of receptor-bound 5α-[ 3 H]dihydrotestosterone ( 3 H-DHT). Treatment of the labelled nuclear extracts with a charcoal suspension prior to the receptor assay resulted in lower amounts of estimated androgen receptors. A method for routine evaluation of nuclear androgen receptors in prostatic tissue has been evaluated, which involves extraction of nuclear pellets with a heparin-containing (1 g/l) buffer, exchange labelling of the nuclear extracts for 20 h at 10 0 C and quantification of the receptors with protamine sulphate precipitation. (Auth.)

  10. Interference of heparin in carcinoembryonic antigen radioimmunoassays

    International Nuclear Information System (INIS)

    Wu, J.T.

    1983-01-01

    A false Roche carcinoembryonic antigen (CEA) activity could be detected in all commercial and noncommercial heparin preparations examined. The possibility of 'due to contamination' has been ruled out. Using the Roche procedure, heparin solutions, in the absence of CEA, gave positive CEA activity; on the other hand, no CEA activity was detected in solutions containing only heparin when the Abbott Kit was used. When heparin was present in specimens containing CEA, the Abbott Kit underestimated the CEA activity, whereas the Roche Kit gave false elevated values. However, the negative effect of heparin could be reduced by heat treatment in the presence of plasma proteins. (Auth.)

  11. Biomimetic synthesis and biocompatibility evaluation of carbonated apatites template-mediated by heparin

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yi [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Sun, Yuhua [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Chen, Xiaofang [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhu, Peizhi, E-mail: pzzhu@umich.edu [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Wei, Shicheng, E-mail: sc-wei@pku.edu.cn [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China)

    2013-07-01

    Biomimetic synthesis of carbonated apatites with good biocompatibility is a promising strategy for the broadening application of apatites for bone tissue engineering. Most researchers were interested in collagen or gelatin-based templates for synthesis of apatite minerals. Inspired by recent findings about the important role of polysaccharides in bone biomineralization, here we reported that heparin, a mucopolysaccharide, was used to synthesize carbonated apatites in vitro. The results indicated that the Ca/P ratio, carbon content, crystallinity and morphology of the apatites varied depending on the heparin concentration and the initial pH value. The morphology of apatite changed from flake-shaped to needle-shaped, and the degree of crystallinity decreased with the increasing of heparin concentration. Biocompatibility of the apatites was tested by proliferation and alkaline phosphatase activity of MC3T3-E1 cells. The results suggested that carbonated apatites synthesized in the presence of heparin were more favorable to the proliferation and differentiation of MC3T3-E1 cells compared with traditional method. In summary, the heparin concentration and the initial pH value play a key role in the chemical constitution and morphology, as well as biological properties of apatites. These biocompatible nano-apatite crystals hold great potential to be applied as bioactive materials for bone tissue engineering. - Highlights: • Heparin was used as a template to synthesize needle-shaped nano-apatite. • Changing the pH value and concentration led to different properties of apatite. • Apatite prepared by heparin was more favorable to the osteogenic differentiation. • Possible synthesis mechanism of apatite templated by heparin was described.

  12. The Effect of Low Molecular Weight Heparins on Fracture Healing.

    Science.gov (United States)

    Kapetanakis, Stylianos; Nastoulis, Evangelos; Demesticha, Theano; Demetriou, Thespis

    2015-01-01

    Venous Thromboembolism is a serious complication in the trauma patient. The most commonly studied and used anticoagulant treatment in prophylaxis of thrombosis is heparin. The prolonged use of unfractionated heparin has been connected with increased incidence of osteoporotic fractures. Low molecular-weight-heparins (LMWHs) have been the golden rule in antithrombotic therapy during the previous two decades as a way to overcome the major drawbacks of unfractioned heparin. However there are few studies reporting the effects of LMWHs on bone repair after fractures. This review presents the studies about the effects of LMWHs on bone biology (bone cells and bone metabolism) and underlying the mechanisms by which LMWHs may impair fracture healing process. The authors' research based on literature concluded that there are no facts and statistics for the role of LMWHs on fracture healing process in humans and the main body of evidence of their role comes from in vitro and animal studies. Further large clinical studies designed to compare different types of LMWHs, in different dosages and in different patient or animal models are needed for exploring the effects of LMWHs on fracture healing process.

  13. Changes in heparin dose response slope during cardiac surgery: possible result in inaccuracy in predicting heparin bolus dose requirement to achieve target ACT.

    Science.gov (United States)

    Ichikawa, Junko; Mori, Tetsu; Kodaka, Mitsuharu; Nishiyama, Keiko; Ozaki, Makoto; Komori, Makiko

    2017-09-01

    The substantial interpatient variability in heparin requirement has led to the use of a heparin dose response (HDR) technique. The accuracy of Hepcon-based heparin administration in achieving a target activated clotting time (ACT) using an HDR slope remains controversial. We prospectively studied 86 adult patients scheduled for cardiac surgery requiring cardiopulmonary bypass. The total dose of calculated heparin required for patient and pump priming was administered simultaneously to achieve a target ACT of 450 s for HDR on the Hepcon HMS system. Blood samples were obtained after the induction of anesthesia, at 3 min after heparin administration and after the initiation of CPB to measure kaolin ACT, HDR slope, whole-blood heparin concentration based on the HDR slope and anti-Xa heparin concentration, antithrombin and complete blood count. The target ACT of 450 s was not achieved in 68.6% of patients. Compared with patients who achieved the target ACT, those who failed to achieve their target ACT had a significantly higher platelet count at baseline. Correlation between the HDR slope and heparin sensitivity was poor. Projected heparin concentration and anti-Xa heparin concentration are not interchangeable based on the Bland-Altman analysis. It can be hypothesized that the wide discrepancy in HDR slope versus heparin sensitivity may be explained by an inaccurate prediction of the plasma heparin level and/or the change in HDR of individual patients, depending on in vivo factors such as extravascular sequestration of heparin, decreased intrinsic antithrombin activity level and platelet count and/or activity.

  14. Safety and Efficacy of Argatroban in the Management of Heparin-Induced Thrombocytopenia

    Directory of Open Access Journals (Sweden)

    Bernd Saugel

    2011-01-01

    Full Text Available Heparin-induced thrombocytopenia (HIT is a life-threatening adverse reaction to heparin therapy that is characterized by thrombocytopenia and an increased risk of venous and arterial thrombosis. According to guidelines, in patients with strongly suspected or confirmed HIT all sources of heparin have to be discontinued and an alternative, nonheparin anticoagulant for HIT treatment must immediately be started. For both the prophylaxis of thrombembolic events in HIT and the treatment of HIT with thrombosis the direct thrombin inhibitor argatroban is approved in the United States. The objective of this review is to describe the mechanism of action and the pharmacokinetic profile of argatroban, to characterize argatroban regarding its safety and therapeutic efficacy and to discuss its place in therapy in HIT.

  15. Pharmacological inhibition of heparin-binding EGF-like growth factor promotes peritoneal angiogenesis in a peritoneal dialysis rat model.

    Science.gov (United States)

    Li, Zhenyuan; Yan, Hao; Yuan, Jiangzi; Cao, Liou; Lin, Aiwu; Dai, Huili; Ni, Zhaohui; Qian, Jiaqi; Fang, Wei

    2018-04-01

    Molecular mechanisms of peritoneal dialysis (PD) ultrafiltration failure, peritoneal neo-angiogenesis, and fibrosis remain to be determined. We aimed to determine the role of heparin-binding EGF-like growth factor (HB-EGF) inhibition on angiogenesis of peritoneal membrane in a PD rat model. 32 male Wistar rats were assigned into (1) control group; (2) uremic non-PD group: subtotal nephrectomy-induced uremic rats without PD; (3) uremic rats subjected to PD: uremic rats that were dialyzed with Dianeal ® for 4 weeks; (4) CRM 197 group: dialyzed uremic rats were supplemented with CRM197, a specific HB-EGF inhibitor. Peritoneal transport function was examined by peritoneal equilibration test. Expression of HB-EGF and EGFR in peritoneal samples were examined by real-time PCR, immunohistochemical staining, and western blot. Progressive angiogenesis and fibrosis were observed in uremic PD rats, and there were associated with decreased net ultrafiltration (nUF), increased permeability of peritoneal membrane, and reduced expression of HB-EGF and EGFR protein and mRNA in uremic PD rats compared to uremic non-PD or control groups (both p CRM197 significantly induced peritoneal membrane permeability, decreased nUF, increased higher vessel density, and reduced pericyte count compared to that of uremic PD rats. The levels of HB-EGF and EGFR expression negatively correlated with vessel density in peritoneal membrane (both p < 0.001). PD therapy was associated with peritoneal angiogenesis, functional deterioration, and downregulation of HB-EGF/EGFR. Pharmacological inhibition of HB-EGF promoted PD-induced peritoneal angiogenesis and fibrosis and ultrafiltration decline, suggesting that HB-EGF downregulation contributes to peritoneal functional deterioration in the uremic PD rat model.

  16. Structural and functional characterization of the interaction between cyclophilin B and a heparin-derived oligosaccharide.

    Science.gov (United States)

    Hanoulle, Xavier; Melchior, Aurélie; Sibille, Nathalie; Parent, Benjamin; Denys, Agnès; Wieruszeski, Jean-Michel; Horvath, Dragos; Allain, Fabrice; Lippens, Guy; Landrieu, Isabelle

    2007-11-23

    The chemotaxis and integrin-mediated adhesion of T lymphocytes triggered by secreted cyclophilin B (CypB) depend on interactions with both cell surface heparan sulfate proteoglycans (HSPG) and the extracellular domain of the CD147 membrane receptor. Here, we use NMR spectroscopy to characterize the interaction of CypB with heparin-derived oligosaccharides. Chemical shift perturbation experiments allowed the precise definition of the heparan sulfate (HS) binding site of CypB. The N-terminal extremity of CypB, which contains a consensus sequence for heparin-binding proteins was modeled on the basis of our experimental NMR data. Because the HS binding site extends toward the CypB catalytic pocket, we measured its peptidyl-prolyl cis-trans isomerase (PPIase) activity in the absence or presence of a HS oligosaccharide toward a CD147-derived peptide. We report the first direct evidence that CypB is enzymatically active on CD147, as it is able to accelerate the cis/trans isomerization of the Asp(179)-Pro(180) bond in a CD147-derived peptide. However, HS binding has no significant influence on this PPIase activity. We thus conclude that the glycanic moiety of HSPG serves as anchor for CypB at the cell surface, and that the signal could be transduced by CypB via its PPIase activity toward CD147.

  17. Convective Leakage Makes Heparin Locking of Central Venous Catheters Ineffective Within Seconds: Experimental Measurements in a Model Superior Vena Cava.

    Science.gov (United States)

    Barbour, Michael C; McGah, Patrick M; Ng, Chin H; Clark, Alicia M; Gow, Kenneth W; Aliseda, Alberto

    2015-01-01

    Central venous catheters (CVCs), placed in the superior vena cava (SVC) for hemodialysis or chemotherapy, are routinely filled while not in use with heparin, an anticoagulant, to maintain patency and prevent thrombus formation at the catheter tip. The heparin-locking procedure, however, places the patient at risk for systemic bleeding, as heparin is known to leak from the catheter into the blood stream. We provide evidence from detailed in vitro experiments that shows the driving mechanism behind heparin leakage to be convective-diffusive transport due to the pulsatile flow surrounding the catheter. This novel mechanism is supported by experimental planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV) measurements of flow velocity and heparin transport from a CVC placed inside a model SVC inside a pulsatile flow loop. The results predict an initial, fast (<10 s), convection-dominated phase that rapidly depletes the concentration of heparin in the near-tip region, the region of the catheter with side holes. This is followed by a slow, diffusion-limited phase inside the catheter lumen, where the concentration is still high, that is insufficient at replenishing the lost heparin concentration in the near-tip region. The results presented here, which are consistent with previous in vivo estimates of 24 hour leakage rates, predict that the concentration of heparin in the near-tip region is essentially zero for the majority of the interdialytic phase, rendering the heparin locking procedure ineffective.

  18. Preparation and characterization of microspheres of albumin-heparin conjugates

    NARCIS (Netherlands)

    Kwon, Glen S.; Bae, You Han; Kim, Sung Wan; Cremers, Harry; Cremers, H.F.M.; Feijen, Jan

    1991-01-01

    Albumin-heparin microspheres have been prepared as a new drug carrier. A soluble albumin-heparin conjugate was synthesized by forming amide bonds between human serum albumin and heparin. After purification the albumin-heparin conjugate was crosslinked in a water-in-oil emulsion to form

  19. How to give a heparin shot

    Science.gov (United States)

    ... you put the injection. Storing Your Heparin and Supplies Ask your pharmacist how to store your heparin ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  20. Acid-citrate-dextrose compared with heparin in the preparation of in vivo/in vitro technetium-99m red blood cells

    International Nuclear Information System (INIS)

    Porter, W.C.; Dees, S.M.; Freitas, J.E.; Dworkin, H.J.

    1983-01-01

    Red blood cells labeled in vivo/in vitro with Tc-99m (Tc-99m RBC) were prepared in a series of 21 patients and two normal volunteers. In each subject both heparin and acid-citrate-dextrose (ACD) solutions were used to label tandem blood samples. The immediate preinjection binding efficiency (BE) was then determined. In each of the 23 studies, the ACD preparation yielded superior BE. The average BE was 93.47% (+/- 3.78) with ACD and 87.23% (+/- 4.29) with heparin. With the ACD method the effect of carrier Tc-99 may be as great as a 24% reduction in BE observed when initial eluates from long-ingrowth-time generators were used. Improved image quality with minimal renal and urinary-bladder activity results with ACD labeling. It is concluded that the use of ACD results in superior RBC labeling with less nontarget activity relative to heparin and is preferred over heparin for preparing in vivo/in vitro Tc-99m RBC

  1. Endogenous heparin levels in the controlled asthmatic patient ...

    African Journals Online (AJOL)

    Background. Since heparin possesses anti-inflammatory properties, it is hypothesised that asthmatic patients have decreased levels of circulating heparin compared with healthy individuals. Design. We compared endogenous heparin levels in controlled asthmatic patients (53 adults) from the Asthma Clinic at ...

  2. Heparin increases food intake through AgRP neurons

    Science.gov (United States)

    Although the widely used anticoagulant drug heparin has been shown to have many other biological functions independent of its anticoagulant role, its effects on energy homeostasis are unknown. Here, we demonstrate that heparin level is negatively associated with nutritional states and that heparin t...

  3. Proteolytic activation transforms heparin cofactor II into a host defense molecule.

    Science.gov (United States)

    Kalle, Martina; Papareddy, Praveen; Kasetty, Gopinath; Tollefsen, Douglas M; Malmsten, Martin; Mörgelin, Matthias; Schmidtchen, Artur

    2013-06-15

    The abundant serine proteinase inhibitor heparin cofactor II (HCII) has been proposed to inhibit extravascular thrombin. However, the exact physiological role of this plasma protein remains enigmatic. In this study, we demonstrate a previously unknown role for HCII in host defense. Proteolytic cleavage of the molecule induced a conformational change, thereby inducing endotoxin-binding and antimicrobial properties. Analyses employing representative peptide epitopes mapped these effects to helices A and D. Mice deficient in HCII showed increased susceptibility to invasive infection by Pseudomonas aeruginosa, along with a significantly increased cytokine response. Correspondingly, decreased levels of HCII were observed in wild-type animals challenged with bacteria or endotoxin. In humans, proteolytically cleaved HCII forms were detected during wounding and in association with bacteria. Thus, the protease-induced uncovering of cryptic epitopes in HCII, which transforms the molecule into a host defense factor, represents a previously unknown regulatory mechanism in HCII biology and innate immunity.

  4. Sterilization of heparinized cuprophan hemodialysis membranes

    NARCIS (Netherlands)

    ten Hoopen, Hermina W.M.; Hinrichs, W.L.J.; Hinrichs, W.L.J.; Engbers, G.H.M.; Feijen, Jan

    1996-01-01

    The effects of sterilization of dry heparinized Cuprophan hemodialysis membranes by means of ethylene oxide (EtO) exposure, gamma irradiation, or steam on the anticoagulant activity and chemical characteristics of immobilized heparin and the permeability of the membrane were investigated.

  5. Does ′heparin-induced thrombocytopenia′ hit our minds?

    Directory of Open Access Journals (Sweden)

    Arun R Thangavel

    2016-01-01

    Full Text Available Unfractionated heparin is a widely used drug to prevent deep vein thrombosis and pulmonary emboli in patients at risk. With the advent of newer anticoagulants having lesser side effects, its use has diminished but not out of service. Here, we report a case of deep venous thrombosis, in a patient on prophylactic dose of heparin, which was later found to be a manifestation of heparin-induced thrombocytopenia (HIT. Thrombosis in the presence of heparin prophylaxis should be considered as HIT rather than a failure of anticoagulation.

  6. Heparin octasaccharide decoy liposomes inhibit replication of multiple viruses

    Science.gov (United States)

    Hendricks, Gabriel L.; Velazquez, Lourdes; Pham, Serena; Qaisar, Natasha; Delaney, James C.; Viswanathan, Karthik; Albers, Leila; Comolli, James C.; Shriver, Zachary; Knipe, David M.; Kurt-Jones, Evelyn A.; Fygenson, Deborah K.; Trevejo, Jose M.

    2016-01-01

    Heparan sulfate (HS) is a ubiquitous glycosaminoglycan that serves as a cellular attachment site for a number of significant human pathogens, including respiratory syncytial virus (RSV), human parainfluenza virus 3 (hPIV3), and herpes simplex virus (HSV). Decoy receptors can target pathogens by binding to the receptor pocket on viral attachment proteins, acting as ‘molecular sinks’ and preventing the pathogen from binding to susceptible host cells. Decoy receptors functionalized with HS could bind to pathogens and prevent infection, so we generated decoy liposomes displaying HS-octasaccharide (HS-octa). These decoy liposomes significantly inhibited RSV, hPIV3, and HSV infectivity in vitro to a greater degree than the original HS-octa building block. The degree of inhibition correlated with the density of HS-octa displayed on the liposome surface. Decoy liposomes with HS-octa inhibited infection of viruses to a greater extent than either full-length heparin or HS-octa alone. Decoy liposomes were effective when added prior to infection or following the initial infection of cells in vitro. By targeting the well-conserved receptor-binding sites of HS-binding viruses, decoy liposomes functionalized with HS-octa are a promising therapeutic antiviral agent and illustrate the utility of the liposome delivery platform. PMID:25637710

  7. Heparin- induced thrombocytopenia (HIT: a case report of CABG patient

    Directory of Open Access Journals (Sweden)

    Alireza Jahangirifard

    2016-08-01

    Full Text Available Heparin- induced thrombocytopenia (HIT is an antibody mediated adverse effect of heparin therapy which is classified into two subtypes, HITI which is non-immune, spontaneously reversible thrombocytopenia and; HITII which is an autoimmune-mediated adverse effect of heparin therapy. In this case report, we described a 65-year old male patient with HITII after coronary artery bypass grafting.Key words: Heparin- induced thrombocytopenia, Heparin- induced thrombosis, coronary artery bypass grafting.

  8. Safety and potential anticoagulant effects of nebulised heparin in burns patients with inhalational injury at Singapore General Hospital Burns Centre.

    Science.gov (United States)

    Yip, Lian Yee; Lim, Yen Fang; Chan, Hong Ngee

    2011-11-01

    Nebulised heparin, N-acetylcysteine (NAC) and salbutamol were shown to decrease reintubation rates, incidence of atelectasis and mortality in paediatric patients and reduce lung injury scores in adult burns patients with inhalational lung injury (ILI). Nebulised heparin, NAC and salbutamol treatment protocol was introduced in Singapore General Hospital (SGH) Burns Centre in 2006. However, safety data on the use of nebulised heparin and NAC for burns patients with ILI is not well established. In this study, we investigated the safety and potential anticoagulant effects of nebulised heparin in burns patients with ILI. A retrospective study with historical control was conducted. The treatment group consisted of 52 mechanically ventilated adult patients, with a diagnosis of ILI as confirmed by bronchoscopy, admitted to burn intensive care unit (BICU) from the year 2006 to 2009. The group was treated with nebulised heparin, NAC and salbutamol. The control group consists of 11 mechanically ventilated BICU ILI patients treated from year 2001 to 2005 before protocol initiation. Blood coagulation indices (prothrombin time (PT), activated partial thromboplastin time (APTT) and platelet count) were monitored and bleeding incidences were assessed. Blood coagulation indices did not suggest an increase risk of bleeding with nebulised heparin. The APTT, PT and platelet count followed a similar trend for both groups over 7 days. No clinically significant increase in bleeding risk was found to be associated with nebulised heparin. Nebulised heparin was not found to potentiate the risk of bleeding in burns patients with ILI. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

  9. 21 CFR 864.7525 - Heparin assay.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Heparin assay. 864.7525 Section 864.7525 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7525 Heparin assay. (a) Identification. A...

  10. Advanced nanocarriers based on heparin and its derivatives for cancer management.

    Science.gov (United States)

    Yang, Xiaoye; Du, Hongliang; Liu, Jiyong; Zhai, Guangxi

    2015-02-09

    To obtain a satisfying anticancer effect, rationally designed nanocarriers are intensively studied. In this field, heparin and its derivatives have been widely attempted recently as potential component of nanocarriers due to their unique biological and physiochemical features, especially the anticancer activity. This review focuses on state-of-the-art nanocarriers with heparin/heparin derivatives as backbone or coating material. At the beginning, the unique advantages of heparin used in cancer nanotechnology are discussed. After that, different strategies of heparin chemical modification are reviewed, laying the foundation of developing various nanocarriers. Then a systematic summary of diverse nanoparticles with heparin as component is exhibited, involving heparin-drug conjugate, polymeric nanoparticles, nanogels, polyelectrolyte complex nanoparticles, and heparin-coated organic and inorganic nanoparticles. The application of these nanoparticles in various novel cancer therapy (containing targeted therapy, magnetic therapy, photodynamic therapy, and gene therapy) will be highlighted. Finally, future challenges and opportunities of heparin-based biomaterials in cancer nanotechnology are discussed.

  11. Characterization of heparin aerosols generated in jet and ultrasonic nebulizers

    DEFF Research Database (Denmark)

    Bendstrup, K.E.; Newhouse, M.T.; Pedersen, Ole Finn

    1999-01-01

    Inhaled heparin has been used for asthma treatment, but results have been inconsistent, probably due to highly varying lung doses. We determined the output per unit time and the particle size distributions of sodium heparin, calcium heparin, and low molecular weight (LMW) heparin formulations in ...... on the exhalation filter, and 15,000 IU was captured on the inhalation filter (inhaled mass). This corresponds to a respirable mass of 10,000 IU of heparin with a high probability of reaching the lower respiratory tract in normal healthy adults....

  12. Citrate Anticoagulation for CRRT in Children: Comparison with Heparin

    Directory of Open Access Journals (Sweden)

    Sara Nicole Fernández

    2014-01-01

    Full Text Available Regional anticoagulation with citrate is an alternative to heparin in continuous renal replacement therapies, which may prolong circuit lifetime and decrease hemorrhagic complications. A retrospective comparative cohort study based on a prospective observational registry was conducted including critically ill children undergoing CRRT. Efficacy, measured as circuit survival, and secondary effects of heparin and citrate were compared. 12 patients on CRRT with citrate anticoagulation and 24 patients with heparin anticoagulation were analyzed. Median citrate dose was 2.6 mmol/L. Median calcium dose was 0.16 mEq/kg/h. Median heparin dose was 15 UI/kg/h. Median circuit survival was 48 hours with citrate and 31 hours with heparin (P=0.028. 66.6% of patients treated with citrate developed mild metabolic alkalosis, which was directly related to citrate dose. There were no cases of citrate intoxication: median total calcium/ionic calcium index (CaT/I of 2.16 and a maximum CaT/I of 2.33, without metabolic acidosis. In the citrate group, 45.5% of patients developed hypochloremia and 27.3% hypomagnesemia. In the heparin group, 27.8% developed hypophosphatemia. Three patients were moved from heparin to citrate to control postoperatory bleeding. In conclusion citrate is a safe and effective anticoagulation method for CRRT in children and it achieves longer circuit survival than heparin.

  13. Electrophoresis for the analysis of heparin purity and quality.

    Science.gov (United States)

    Volpi, Nicola; Maccari, Francesca; Suwan, Jiraporn; Linhardt, Robert J

    2012-06-01

    The adulteration of raw heparin with oversulfated chondroitin sulfate (OSCS) in 2007-2008 produced a global crisis resulting in extensive revisions to the pharmacopeia monographs and prompting the FDA to recommend the development of additional methods for the analysis of heparin purity. As a consequence, a wide variety of innovative analytical approaches have been developed for the quality assurance and purity of unfractionated and low-molecular-weight heparins. This review discusses recent developments in electrophoresis techniques available for the sensitive separation, detection, and partial structural characterization of heparin contaminants. In particular, this review summarizes recent publications on heparin quality and related impurity analysis using electrophoretic separations such as capillary electrophoresis (CE) of intact polysaccharides and hexosamines derived from their acidic hydrolysis, and polyacrylamide gel electrophoresis (PAGE) for the separation of heparin samples without and in the presence of its relatively specific depolymerization process with nitrous acid treatment. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Biological distribution of 51Cr-heparin

    International Nuclear Information System (INIS)

    Almeida, M.A.T.M. de.

    1979-01-01

    The kinetics of heparin in normal Wistar rats using the radioactive tracer 51 Cr, has been studied. The labeled and purified 51 Cr-heparin was injected into rats intravenously and by intraperitoneal injection. In measuring the radioactivity of organs it was possible to conclude that the tissues rich in mast cells, liver and spleen, were found to take up the greater amounts of heparin. The curve that represents the logarithm of the concentration of heparin versus time is biexponential. The half-lives of the two exponential were determined. The volume of distribution, the rate constant and the renal clearance were determined by the values of the plasma levels and urinary excretions. The biological half-time, the turnover rate and the turnover time were determined by measuring the residual radioactivity of the total body and urinary excretions. With the data obtained from the mentioned experiments a compartmental model was performed in which the plasma is the central compartment for the distribution of the drug, exchanging with another extraplasmatic compartment and finally the drug being stored in reticulo endothelial system cells. (Author) [pt

  15. Immunomodulating effects of heparin on human B cell proliferation

    International Nuclear Information System (INIS)

    Wasik, Maria; Stepien-Sopniewska, Barbara; Gorski, Andrzej

    1993-01-01

    Recent data indicate that heparin may act as an immunomodulator. In this paper we have analyzed the effect of this agent on human B cell proliferation ''in vitro'' induced by ''S. aureus'' Cowan. The action of heparin is complex, but there was a trend for inhibition of B cell responses obtained from defibrinated but not heparinized blood samples. This suggest that heparin interacts with platelet products (growth factors, cytokines) and the results of such interactions determine the final effect. (author). 6 refs, 4 figs

  16. Influence of spacer length on heparin coupling efficiency and fibrinogen adsorption of modified titanium surfaces

    Directory of Open Access Journals (Sweden)

    Gbureck Uwe

    2007-07-01

    Full Text Available Abstract Background Chemical bonding of the drug onto surfaces by means of spacer molecules is accompanied with a reduction of the biological activity of the drug due to a constricted mobility since normally only short spacer molecule like aminopropyltrimethoxysilane (APMS are used for drug coupling. This work aimed to study covalent attachment of heparin to titanium(oxide surfaces by varying the length of the silane coupling agent, which should affect the biological potency of the drug due to a higher mobility with longer spacer chains. Methods Covalent attachment of heparin to titanium metal and TiO2 powder was carried out using the coupling agents 3-(Trimethoxysilyl-propylamine (APMS, N- [3-(Trimethoxysilylpropyl]ethylenediamine (Diamino-APMS and N1- [3-(Trimethoxy-silyl-propyl]diethylenetriamine (Triamino-APMS. The amount of bound coupling agent and heparin was quantified photometrically by the ninhydrin reaction and the tolidine-blue test. The biological potency of heparin was determined photometrically by the chromogenic substrate Chromozym TH and fibrinogen adsorption to the modified surfaces was researched using the QCM-D (Quartz Crystal Microbalance with Dissipation Monitoring technique. Results Zeta-potential measurements confirmed the successful coupling reaction; the potential of the unmodified anatase surface (approx. -26 mV shifted into the positive range (> + 40 mV after silanisation. Binding of heparin results in a strongly negatively charged surface with zeta-potentials of approx. -39 mV. The retaining biological activity of heparin was highest for the spacer molecule Triamino-APMS. QCM-D measurements showed a lower viscosity for adsorbed fibrinogen films on heparinised surfaces by means of Triamino-APMS. Conclusion The remaining activity of heparin was found to be highest for the covalent attachment with Triamino-APMS as coupling agent due to the long chain of this spacer molecule and therefore the highest mobility of the drug

  17. New Mechanisms of Mercury Binding to Peat

    Science.gov (United States)

    Nagy, K. L.; Manceau, A.; Gasper, J. D.; Ryan, J. N.; Aiken, G. R.

    2007-12-01

    Mercury can be immobilized in the aquatic environment by binding to peat, a solid form of natural organic matter. Binding mechanisms can vary in strength and reversibility, and therefore will control concentrations of bioreactive mercury, may explain rates of mercury methylation, and are important for designing approaches to improve water quality using natural wetlands or engineered phytoremediation schemes. In addition, strong binding between mercury and peat is likely to result in the fixation of mercury that ultimately resides in coal. The mechanisms by which aqueous mercury at low concentrations reacts with both dissolved and solid natural organic matter remain incompletely understood, despite recent efforts. We have identified three distinct binding mechanisms of divalent cationic mercury to solid peats from the Florida Everglades using EXAFS spectroscopic data (FAME beamline, European Synchrotron Radiation Facility (ESRF)) obtained on experimental samples as compared to relevant references including mercury-bearing solids and mercury bound to various organic molecules. The proportions of the three molecular configurations vary with Hg concentration, and two new configurations that involve sulfur ligands occur at Hg concentrations up to about 4000 ppm. The binding mechanism at the lowest experimental Hg concentration (60-80 ppm) elucidates published reports on the inhibition of metacinnabar formation in the presence of Hg-bearing solutions and dissolved natural organic matter, and also, the differences in extent of mercury methylation in distinct areas of the Florida Everglades.

  18. Heparin and Heparin-Derivatives in Post-Subarachnoid Hemorrhage Brain Injury: A Multimodal Therapy for a Multimodal Disease

    Directory of Open Access Journals (Sweden)

    Erik G. Hayman

    2017-05-01

    Full Text Available Pharmacologic efforts to improve outcomes following aneurysmal subarachnoid hemorrhage (aSAH remain disappointing, likely owing to the complex nature of post-hemorrhage brain injury. Previous work suggests that heparin, due to the multimodal nature of its actions, reduces the incidence of clinical vasospasm and delayed cerebral ischemia that accompany the disease. This narrative review examines how heparin may mitigate the non-vasospastic pathological aspects of aSAH, particularly those related to neuroinflammation. Following a brief review of early brain injury in aSAH and heparin’s general pharmacology, we discuss potential mechanistic roles of heparin therapy in treating post-aSAH inflammatory injury. These roles include reducing ischemia-reperfusion injury, preventing leukocyte extravasation, modulating phagocyte activation, countering oxidative stress, and correcting blood-brain barrier dysfunction. Following a discussion of evidence to support these mechanistic roles, we provide a brief discussion of potential complications of heparin usage in aSAH. Our review suggests that heparin’s use in aSAH is not only safe, but effectively addresses a number of pathologies initiated by aSAH.

  19. Mr 25,000 heparin-binding protein from guinea pig brain is a high molecular weight form of basic fibroblast growth factor.

    OpenAIRE

    Moscatelli, D; Joseph-Silverstein, J; Manejias, R; Rifkin, D B

    1987-01-01

    A Mr 25,000 form of basic fibroblast growth factor (bFGF) has been isolated from guinea pig brain along with the typical Mr 18,000 form. Both forms were purified to homogeneity by a combination of heparin-affinity chromatography and ion-exchange chromatography on an FPLC Mono S column. The Mr 25,000 form, like the Mr 18,000 form, was not eluted from the heparin-affinity column with 0.95 M NaCl, but was eluted with 2 M NaCl. The Mr 25,000 guinea pig protein stimulated plasminogen activator pro...

  20. Overexpression of Heparin-Binding Epidermal Growth Factor-Like Growth Factor Mediates Liver Fibrosis in Transgenic Mice.

    Science.gov (United States)

    Guo, Yongze; Ding, Qian; Chen, Lei; Ji, Chenguang; Hao, Huiyao; Wang, Jia; Qi, Wei; Xie, Xiaoli; Ma, Junji; Li, Aidi; Jiang, Xiaoyu; Li, Xiaotian; Jiang, Huiqing

    2017-08-01

    The role of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in liver fibrosis is not clear and is sometimes even contradictory. To clarify this role, a HB-EGF transgenic (Tg) mouse model was, for the first time, used to evaluate the functions of HB-EGF in liver fibrosis. For the in vivo study, carbon tetrachloride injection and bile duct ligation treatment were used to induce liver fibrosis in HB-EGF Tg mice and wild-type (WT) mice, respectively. Primary hepatic satellite cells (HSCs) were isolated from HB-EGF Tg and WT mice for the in vitro study. Compared with the WT mice, HB-EGF Tg mice were shown to develop more severe liver fibrosis when treated with carbon tetrachloride or bile duct ligation, with increased matrix metalloproteinases 13 activity and enhanced expression of fibrogenic genes including α-smooth muscle actin and collagen I. HB-EGF gene transfer led to an increase in proliferation and a decrease in apoptosis in primary HSCs. The ERK signaling pathway was more highly activated in primary HSCs from HB-EGF Tg mice than in those from WT mice. Our investigation confirmed the profibrotic effect of HB-EGF on the liver using a Tg mouse model. This result may contribute to the elucidation of HB-EGF as a therapeutic target in liver fibrosis. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  1. Heparin-Induced Thrombocytopenia

    Science.gov (United States)

    ... HIT information card. Early identification of HIT and avoidance of inappropriate heparin therapy can help promote a ... Heart Association is a qualified 501(c)(3) tax-exempt organization. *Red Dress™ DHHS, Go Red™ AHA; ...

  2. Increased synthesis of heparin affin regulatory peptide in the perforant path lesioned mouse hippocampal formation

    DEFF Research Database (Denmark)

    Poulsen, F R; Lagord, C; Courty, J

    2000-01-01

    Heparin affin regulatory peptide (HARP), also known as pleiotrophin or heparin-binding growth-associated molecule, is a developmentally regulated extracellular matrix protein that induces cell proliferation and promotes neurite outgrowth in vitro as well as pre- and postsynaptic developmental...... differentiation in vivo. Here we have investigated the expression of HARP mRNA and protein in the perforant path lesioned C57B1/6 mouse hippocampal formation from 1 to 35 days after surgery. This type of lesion induces a dense anterograde and terminal axonal degeneration, activation of glial cells, and reactive...... axonal sprouting within the perforant path zones of the fascia dentata and hippocampus as well as axotomy-induced retrograde neuronal degeneration in the entorhinal cortex. Analysis of sham- and unoperated control mice showed that HARP mRNA is expressed in neurons and white and gray matter glial cells...

  3. Identification of a novel structure in heparin generated by potassium permanganate oxidation

    Science.gov (United States)

    Beccati, Daniela; Roy, Sucharita; Yu, Fei; Gunay, Nur Sibel; Capila, Ishan; Lech, Miroslaw; Linhardt, Robert J.; Venkataraman, Ganesh

    2012-01-01

    The worldwide heparin contamination crisis in 2008 led health authorities to take fundamental steps to better control heparin manufacture, including implementing appropriate analytical and bio-analytical methods to ensure production and release of high quality heparin sodium product. Consequently, there is an increased interest in the identification and structural elucidation of unusually modified structures that may be present in heparin. Our study focuses on the structural elucidation of species that give rise to a signal observed at 2.10 ppm in the N-acetyl region of the 1H NMR spectrum of some pharmaceutical grade heparin preparations. Structural elucidation experiments were carried out using homonuclear (COSY, TOSCY and NOESY) and heteronuclear (HSQC, HSQC-DEPT, HMQC-COSY, HSQC-TOCSY, and HMBC) 2D NMR spectroscopy on both heparin as well as heparin-like model compounds. Our results identify a novel type of oxidative modification of the heparin chain that results from a specific step in the manufacturing process used to prepare heparin. PMID:25147414

  4. Construction of mussel-inspired coating via the direct reaction of catechol and polyethyleneimine for efficient heparin immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yujie [School of Material Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); The Institute of Biomaterials and Surface Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Luo, Rifang, E-mail: lrifang@126.com [School of Material Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); The Institute of Biomaterials and Surface Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Shen, Fangyu; Tang, Linlin [School of Material Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); The Institute of Biomaterials and Surface Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Wang, Jin, E-mail: jinxxwang@263.net [School of Material Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); The Institute of Biomaterials and Surface Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Huang, Nan [School of Material Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); The Institute of Biomaterials and Surface Engineering, Southwest Jiaotong University, Chengdu 610031 (China)

    2015-02-15

    Highlights: • Catechol (CA) and PEI copolymerization was a mimetic and dopamine-like coating method. • CA/PEI film provided amine groups and was effective in heparin immobilization. • CA/PEI coating could inhibit smooth muscle cell proliferation. • CA/PEI coating did not show any significant cytotoxicity to endothelial cell. - Abstract: Dopamine could self-polymerize to form the coating on various substrates and the co-existence of catechols and amines was crucial in performing such polymerization process. In this work, a mimetic approach of coating formation was carried out based on the co-polymerization of catechol (CA) and polyethyleneimine (PEI). Mussel-inspired CA/PEI coating was deposited on 316L stainless steel (SS). Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy (XPS) demonstrated the successful coating formation. QCM measurement showed good affinity of heparin immobilization on CA/PEI coating surface ascribed to the amine groups. Herein, vascular cell-material interactions like endothelial cells (ECs) and smooth muscle cells (SMCs) were also investigated. Interestingly, CA/PEI and heparin modified coatings presented no cytotoxicity to ECs, however to a certain extent, decreased SMCs proliferation. Moreover, heparin-binding surface presented significant anti-platelet adhesion and activation properties. These results effectively suggested that the mussel-inspired CA/PEI coating might be promising when served as a platform for biomolecule immobilization.

  5. The Use of Heparin during Endovascular Peripheral Arterial Interventions: A Synopsis

    Directory of Open Access Journals (Sweden)

    Arno M. Wiersema

    2016-01-01

    Full Text Available A large variety exists for many aspects of the use of heparin as periprocedural prophylactic antithrombotics (PPAT during peripheral arterial interventions (PAI. This variation is present, not only within countries, but also between them. Due to a lack of (robust data, no systematic review on the use of heparin during PAI could be justified. A synopsis of all available literature on heparin during PAI describes that heparin is used on technical equipment to reduce the thrombogenicity and in the flushing solution with saline. Heparin could have a cumulative anticoagulant effect when used in combination with ionic contrast medium. No level-1 evidence exists on the use of heparin. A measurement of actual anticoagulation status by means of an activated clotting time should be mandatory.

  6. Polyguluronate sulfate and its oligosaccharides but not heparin promotes FGF19/FGFR1c signaling

    Science.gov (United States)

    Lan, Ying; Zeng, Xuan; Guo, Zhihua; Zeng, Pengjiao; Hao, Cui; Zhao, Xia; Yu, Guangli; Zhang, Lijuan

    2017-06-01

    Fibroblast growth factor 19(FGF19) functions as a hormone by affecting glucose metabolism. FGF19 improves glucose tolerance when overexpressed in mice with impaired glucose tolerance or diabetes. A functional cellular FGF19 receptor consists of FGF receptor (FGFR) and glycosaminoglycan complexed with either α Klotho or β Klotho. Interestingly, in mice with diet-induced diabetes, a single injection of FGF1 is enough to restore blood sugar levels to a healthy range. FGF1 binds heparin with high affinity whereas FGF19 does not, indicating that polysaccharides other than heparin might enhance FGF19/FGFR signaling. Using a FGFs/FGFR1c signaling-dependent BaF3 cell proliferation assay, we discovered that polyguluronate sulfate (PGS) and its oligosaccharides, PGS12 and PGS25, but not polyguluronate (PG), a natural marine polysaccharide, enhanced FGF19/FGFR1c signaling better than that of heparin based on 3H-thymidine incorporation. Interestingly, PGS6, PGS8, PGS10, PGS12, PGS25, and PGS, but not PG, had comparable FGF1/FGFR1c signal-stimulating activity compared to that of heparin. These results indicated that PGS and its oligosaccharides were excellent FGF1/FGFR1c and FGF19/FGFR1c signaling enhancers at cellular level. Since the inexpensive PGS and PGS oligosaccharides can be absorbed through oral route, these seaweed-derived compounds merit further investigation as novel agents for the treatment of type 2 diabetes through enhancing FGF1/FGFR1c and FGF19/FGFR1c signaling in future.

  7. Use of heparin in the investigation of obscure gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Mernagh, J.R.; O'Donovan, N.; Somers, S.; Gill, G.; Sridhar, S.

    2001-01-01

    To determine if the administration of heparin improves the predictive value of angiography in the investigation of obscure gastrointestinal (GI) bleeding. 18 patients with a history of chronic GI bleeding were investigated with angiography. For 6 patients, the cause of GI bleeding was established with angiography; the 12 patients who had negative results were given heparin for 24 h and were reassessed with angiography. After heparin administration, the source of GI bleeding was determined with angiography for 6 of the remaining 12 patients. Thus, heparinization increased diagnostic yield from 33% (6 of 18) to 67% (12 of 18). No significant complications, such as uncontrolled GI bleeding, occurred. Heparinization improves the diagnostic yield of angiography when obscure GI bleeding is being investigated. (author)

  8. Neutralisation of the anti-coagulant effects of heparin by histones in blood plasma and purified systems.

    Science.gov (United States)

    Longstaff, Colin; Hogwood, John; Gray, Elaine; Komorowicz, Erzsebet; Varjú, Imre; Varga, Zoltán; Kolev, Krasimir

    2016-03-01

    Neutrophil extracellular traps (NETs) composed primarily of DNA and histones are a link between infection, inflammation and coagulation. NETs promote coagulation and approaches to destabilise NETs have been explored to reduce thrombosis and treat sepsis. Heparinoids bind histones and we report quantitative studies in plasma and purified systems to better understand physiological consequences. Unfractionated heparin (UFH) was investigated by activated partial thromboplastin time (APTT) and alongside low-molecular-weight heparins (LMWH) in purified systems with thrombin or factor Xa (FXa) and antithrombin (AT) to measure the sensitivity of UFH or LMWH to histones. A method was developed to assess the effectiveness of DNA and non-anticoagulant heparinoids as anti-histones. Histones effectively neutralised UFH, the IC50 value for neutralisation of 0.2 IU/ml UFH was 1.8 µg/ml histones in APTT and 4.6 µg/ml against 0.6 IU/ml UFH in a purified system. Histones also inhibited the activities of LMWHs with thrombin (IC50 6.1 and 11.0 µg/ml histones, for different LMWHs) or FXa (IC50 7.8 and 7.0 µg/ml histones). Direct interactions of UFH and LMWH with DNA and histones were explored by surface plasmon resonance, while rheology studies showed complex effects of histones, UFH and LMWH on clot resilience. A conclusion from these studies is that anticoagulation by UFH and LMWH will be compromised by high affinity binding to circulating histones even in the presence of DNA. A complete understanding of the effects of histones, DNA and heparins on the haemostatic system must include an appreciation of direct effects on fibrin and clot structure.

  9. A sequential binding mechanism in a PDZ domain

    DEFF Research Database (Denmark)

    Chi, Celestine N; Bach, Anders; Engström, Åke

    2009-01-01

    that ligand binding involves at least a two-step process. By using an ultrarapid continuous-flow mixer, we then detected a hyperbolic dependence of binding rate constants on peptide concentration, corroborating the two-step binding mechanism. Furthermore, we found a similar dependence of the rate constants...

  10. Qualitative and quantitative analysis of heparin and low molecular weight heparins using size exclusion chromatography with multiple angle laser scattering/refractive index and inductively coupled plasma/mass spectrometry detectors.

    Science.gov (United States)

    Ouyang, Yilan; Zeng, Yangyang; Yi, Lin; Tang, Hong; Li, Duxin; Linhardt, Robert J; Zhang, Zhenqing

    2017-11-03

    Heparin, a highly sulfated glycosaminoglycan, has been used as a clinical anticoagulant over 80 years. Low molecular weight heparins (LMWHs), heparins partially depolymerized using different processes, are widely used as clinical anticoagulants. Qualitative molecular weight (MW) and quantitative mass content analysis are two important factors that contribute to LMWH quality control. Size exclusion chromatography (SEC), relying on multiple angle laser scattering (MALS)/refractive index (RI) detectors, has been developed for accurate analysis of heparin MW in the absence of standards. However, the cations, which ion-pair with the anionic polysaccharide chains of heparin and LMWHs, had not been considered in previous reports. In this study, SEC with MALS/RI and inductively coupled plasma/mass spectrometry detectors were used in a comprehensive analytical approach taking both anionic polysaccharide and ion-paired cations heparin products. This approach was also applied to quantitative analysis of heparin and LMWHs. Full profiles of MWs and mass recoveries for three commercial heparin/LMWH products, heparin sodium, enoxaparin sodium and nadroparin calcium, were obtained and all showed higher MWs than previously reported. This important improvement more precisely characterized the MW properties of heparin/LMWHs and potentially many other anionic polysaccharides. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Current Trends in Heparin Use During Arterial Vascular Interventional Radiology

    International Nuclear Information System (INIS)

    Durran, Alexandra C.; Watts, Christopher

    2012-01-01

    Purpose: This study was designed to assess the current use of heparinized saline and bolus doses of heparin in non-neurological interventional radiology and to determine whether consensus could be reached to produce guidance for heparin use during arterial vascular intervention. Methods: An interactive electronic questionnaire was distributed to members of the British Society of Interventional Radiology regarding their current practice in the use, dosage, and timing of heparin boluses and heparinized flushing solutions.ResultsA total of 108 completed questionnaires were received. More than 80% of respondents used heparinized saline with varying concentrations; the most prevalent was 1,000 IU/l (international units of heparin per liter) and 5,000 IU/l. Fifty-one percent of interventionalists use 3,000 IU as their standard bolus dose; however, the respondents were split regarding the timing of bolus dose with ∼60% administering it after arterial access is obtained and 40% after crossing the lesion. There was no consensus on altering dose according to body weight, and only 4% monitored clotting parameters. Conclusions: There seems to be some coherence among practicing interventionalists regarding heparin administration. We hypothesize that heparinized saline should be used at a recognized standard concentration of 1,000 IU/l as a flushing concentration in all arterial vascular interventions and that 3,000 IU bolus is considered the standard dose for straightforward therapeutic procedures and 5000 IU for complex, crural, and endovascular aneurysm repair work. The bolus should be given after arterial access is obtained to allow time for optimal anticoagulation to be achieved by the time of active intervention and stenting. Further research into clotting abnormalities following such interventional procedures would be an interesting quantifiable follow-up to this initial survey of opinions and practice.

  12. The intracellular uptake and protracted release of exogenous heparins by cultured endothelial cells

    International Nuclear Information System (INIS)

    Hiebert, L.M.; McDuffie, N.M.

    1989-01-01

    Heparins from bovine or porcine sources were fed in media for 48 hrs to cultured porcine aortic and human umbilical vein endothelial cells. Heparin was found in pericellular and cellular fractions after extraction by chemical methods and 125 I radiolabelled heparins were recovered when radiolabelled heparin was included in the feed. Even after washing and media changes heparin was detected in media and cell fractions up to 6 days post feeding. Metachromatic vacuoles within cells were demonstrated histologically up to 7 days post feeding after staining with toluidine blue. This is the first report of protracted internalization of exogenous heparin by cultured endothelial cells with concurrent prolonged release of the heparin to the media. This clearly demonstrates that the endothelium plays an important role in the distribution and metabolism of heparin

  13. Comparison of established and novel purity tests for the quality control of heparin by means of a set of 177 heparin samples.

    Science.gov (United States)

    Alban, Susanne; Lühn, Susanne; Schiemann, Simone; Beyer, Tanja; Norwig, Jochen; Schilling, Claudia; Rädler, Oliver; Wolf, Bernhard; Matz, Magnus; Baumann, Knut; Holzgrabe, Ulrike

    2011-01-01

    The widespread occurrence of heparin contaminated with oversulfated chrondroitin sulfate (OSCS) in 2008 initiated a comprehensive revision process of the Pharmacopoeial heparin monographs and stimulated research in analytical techniques for the quality control of heparin. Here, a set of 177 heparin samples from the market in 2008 as well as pure heparin sodium spiked with defined amounts of OSCS and DS were used to evaluate established and novel methods for the quality control of heparin. Besides (1)H nuclear magnetic resonance spectroscopy (NMR), the assessment included two further spectroscopic methods, i.e., attenuated total reflection-infrared spectroscopy (ATR-IR) and Raman spectroscopy, three coagulation assays, i.e., activated partial thromboplastin time (aPTT) performed with both sheep and human plasma and the prothrombin time (PT), and finally two novel purity assays, each consisting of an incubation step with heparinase I followed by either a fluorescence measurement (Inc-PolyH-assay) or by a chromogenic aXa-assay (Inc-aXa-assay). NMR was shown to allow not only sensitive detection, but also quantification of OSCS by using the peak-height method and a response factor determined by calibration. Chemometric evaluation of the NMR, ATR-IR, and Raman spectra by statistical classification techniques turned out to be best with NMR spectra concerning the detection of OSCS. The validity of the aPTT, the current EP assay, could be considerably improved by replacing the sheep plasma by human plasma. In this way, most of the contaminated heparin samples did not meet the novel potency limit of 180 IU/mg. However, also more than 50% of the uncontaminated samples had interpretation of the results.

  14. Cellular adhesion responses to the heparin-binding (HepII) domain of fibronectin require heparan sulfate with specific properties

    DEFF Research Database (Denmark)

    Mahalingam, Yashithra; Gallagher, John T; Couchman, John R

    2006-01-01

    of fibronectin (HepII domain) through its HS chains. The fine structure of HS is critical to growth factor responses, and whether this extends to matrix ligands is unknown but is suggested from in vitro experiments. Cell attachment to HepII showed that heparin oligosaccharides of >or=14 sugar residues were...

  15. Mechanism of action and efficacy of RX-111, a thieno[2,3-c]pyridine derivative and small molecule inhibitor of protein interaction with glycosaminoglycans (SMIGs), in delayed-type hypersensitivity, TNBS-induced colitis and experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Harris, Nicholas; Koppel, Juraj; Zsila, Ferenc; Juhas, Stefan; Il'kova, Gabriela; Kogan, Faina Yurgenzon; Lahmy, Orly; Wildbaum, Gizi; Karin, Nathan; Zhuk, Regina; Gregor, Paul

    2016-04-01

    Elucidate the mechanism of action of the small molecule inhibitor of protein binding to glycosaminoglycans, RX-111 and assay its anti-inflammatory activity in animal models of inflammatory disease. The glycosaminoglycan, heparin, was used in the mechanism of action study of RX-111. Human T lymphocytes and umbilical vein endothelial cells were used to assay the in vitro activity of RX-111. Mouse and rat models of disease were used to assay the anti-inflammatory activity of RX-111 in vivo. Circular dichroism and UV/Vis absorption spectroscopy were used to study the binding of RX-111 to the glycosaminoglycan, heparin. T lymphocyte rolling on endothelial cells under shear flow was used to assay RX-111 activity in vitro. Delayed-type hypersensitivity (DTH) and tri-nitrobenzene sulfonic acid (TNBS)-induced colitis in mice and experimental autoimmune encephalomyelitis (EAE) in rats were used to assay anti-inflammatory activity of RX-111 in vivo. RX-111 was shown to bind directly to heparin. It inhibited leukocyte rolling on endothelial cells under shear flow and reduced inflammation in the mouse model of DTH. RX-111 was efficacious in the mouse model of inflammatory bowel disease, TNBS-induced colitis and the rat model of multiple sclerosis, EAE. RX-111 exercises its broad spectrum anti-inflammatory activity by a singular mechanism of action, inhibition of protein binding to the cell surface GAG, heparan sulfate. RX-111 and related thieno[2,3-c]pyridine derivatives are potential therapeutics for the treatment of inflammatory and autoimmune diseases.

  16. Community nurse resource implications for a change in heparin prophylaxis policy

    Directory of Open Access Journals (Sweden)

    Parker Martyn J.

    2015-01-01

    Full Text Available Introduction: A review was undertaken for a consecutive series of hip fracture patients for the year before and then after a change in low dose heparin prophylaxis policy. Patients and methods: For the first year heparin was administered in hospital for a maximum of 14 days only. Patients sent home before this time were not discharged taking heparin. For the second year heparin was administered as recommended by NICE guidelines for 28 days from admission regardless of whether the patient was discharged. Results: For the first year 486 patients were treated with a mean of 10.4 doses of heparin per patient. For the second year 465 patients were treated with a mean of 24.3 doses per patient. In total an extra 6,464 doses of heparin were administered. 33.8% of patients were unable to administer their heparin at home therefore a district nurse administered 2,284 of these doses of subcutaneous heparin at the patient’s home. The increased cost associated with the change in policy was estimated to be £161 per patient, with over 90% of this increase being incurred by the district nurse expense. If applied nationally for the England, using extended heparin prophylaxis for hip fracture patients would cost in excess of 12 million pounds each year. Conclusion: Whilst the necessity for and duration of thromboembolic prophylaxis for these patients remains undetermined, there is a need to re-evaluate the cost effectiveness of the current recommendations for hip fracture patients.

  17. Chitosan-capped gold nanoparticles for selective and colorimetric sensing of heparin

    International Nuclear Information System (INIS)

    Chen, Zhanguang; Wang, Zhen; Chen, Xi; Xu, Haixiong; Liu, Jinbin

    2013-01-01

    In this contribution, novel chitosan-stabilized gold nanoparticles (AuNPs) were prepared by mixing chitosan with citrate-reductive AuNPs under appropriate conditions. The as-prepared chitosan-stabilized AuNPs were positively charged and highly stably dispersed in aqueous solution. They exhibited weak resonance light scattering (RLS) intensity and a wine red color. In addition, the chitosan-stabilized AuNPs were successfully utilized as novel sensitive probes for the detection of heparin for the first time. It was found that the addition of heparin induced a strong increase of RLS intensity for AuNPs and the color change from red to blue. The increase in RLS intensity and the color change of chitosan-stabilized AuNPs caused by heparin allowed the sensitive detection of heparin in the range of 0.2–60 μM (∼6.7 U/mL). The detection limit for heparin is 0.8 μM at a signal-to-noise ratio of 3. The present sensor for heparin detection possessed a low detection limit and wide linear range. Additionally, the proposed method was also applied to the detection of heparin in biological media with satisfactory results

  18. Chitosan-capped gold nanoparticles for selective and colorimetric sensing of heparin

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhanguang, E-mail: kqlu@stu.edu.cn; Wang, Zhen; Chen, Xi [Shantou University, Department of Chemistry (China); Xu, Haixiong [Shantou Central Hospital, Affiliated Shantou Hospital of SUN YAT-SEN University (China); Liu, Jinbin [University of Texasat Dallas, Department of Chemistry (United States)

    2013-09-15

    In this contribution, novel chitosan-stabilized gold nanoparticles (AuNPs) were prepared by mixing chitosan with citrate-reductive AuNPs under appropriate conditions. The as-prepared chitosan-stabilized AuNPs were positively charged and highly stably dispersed in aqueous solution. They exhibited weak resonance light scattering (RLS) intensity and a wine red color. In addition, the chitosan-stabilized AuNPs were successfully utilized as novel sensitive probes for the detection of heparin for the first time. It was found that the addition of heparin induced a strong increase of RLS intensity for AuNPs and the color change from red to blue. The increase in RLS intensity and the color change of chitosan-stabilized AuNPs caused by heparin allowed the sensitive detection of heparin in the range of 0.2-60 {mu}M ({approx}6.7 U/mL). The detection limit for heparin is 0.8 {mu}M at a signal-to-noise ratio of 3. The present sensor for heparin detection possessed a low detection limit and wide linear range. Additionally, the proposed method was also applied to the detection of heparin in biological media with satisfactory results.

  19. Capillary electrophoresis of heparin and other glycosaminoglycans using a polyamine running electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Loegel, Thomas N.; Trombley, John D.; Taylor, Richard T. [Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056 (United States); Danielson, Neil D., E-mail: danielnd@muohio.edu [Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056 (United States)

    2012-11-13

    Highlights: Black-Right-Pointing-Pointer Ethylenediamine is likely acting as an ion-pairing agent. Black-Right-Pointing-Pointer Oversulfated chondroitin sulfate is last peak instead of first peak. Black-Right-Pointing-Pointer There is about a factor of five improved detectability with a 12.5 min analysis time. Black-Right-Pointing-Pointer Use of a 50 {mu}m ID capillary is possible. - Abstract: This study involves the use of polyamines as potential resolving agents for the capillary electrophoresis (CE) of glycosaminoglycans (GAGs), specifically heparin, dermatan sulfate, chondroitin sulfate, over-sulfated chondroitin sulfate (OSCS), and hyaluronan. All of the compounds can be separated from each other with the exception of chondroitin sulfate and hyaluronan. Using optimization software, the final run conditions are found to be 200 mM ethylenediamine and 45.5 mM phosphate as the electrolyte with -14 V applied across a 50 {mu}m ID Multiplication-Sign 24.5 cm fused silica capillary at 15 Degree-Sign C. The ion migration order, with OSCS as the last instead of the first peak, is in contrast to previous reports using either a high molarity TRIS or lithium phosphate run buffer with narrower bore capillaries. Total analysis time is 12. 5 min and the relative standard deviation of the heparin migration time is about 2.5% (n = 5). The interaction mechanism between selected polyamines and heparin is explored using conductivity measurements in addition to CE experiments to show that an ion-pairing mechanism is likely.

  20. Capillary electrophoresis of heparin and other glycosaminoglycans using a polyamine running electrolyte

    International Nuclear Information System (INIS)

    Loegel, Thomas N.; Trombley, John D.; Taylor, Richard T.; Danielson, Neil D.

    2012-01-01

    Highlights: ► Ethylenediamine is likely acting as an ion-pairing agent. ► Oversulfated chondroitin sulfate is last peak instead of first peak. ► There is about a factor of five improved detectability with a 12.5 min analysis time. ► Use of a 50 μm ID capillary is possible. - Abstract: This study involves the use of polyamines as potential resolving agents for the capillary electrophoresis (CE) of glycosaminoglycans (GAGs), specifically heparin, dermatan sulfate, chondroitin sulfate, over-sulfated chondroitin sulfate (OSCS), and hyaluronan. All of the compounds can be separated from each other with the exception of chondroitin sulfate and hyaluronan. Using optimization software, the final run conditions are found to be 200 mM ethylenediamine and 45.5 mM phosphate as the electrolyte with −14 V applied across a 50 μm ID × 24.5 cm fused silica capillary at 15 °C. The ion migration order, with OSCS as the last instead of the first peak, is in contrast to previous reports using either a high molarity TRIS or lithium phosphate run buffer with narrower bore capillaries. Total analysis time is 12. 5 min and the relative standard deviation of the heparin migration time is about 2.5% (n = 5). The interaction mechanism between selected polyamines and heparin is explored using conductivity measurements in addition to CE experiments to show that an ion-pairing mechanism is likely.

  1. Potentiation of C1-esterase inhibitor by heparin and interactions with C1s protease as assessed by surface plasmon resonance.

    Science.gov (United States)

    Rajabi, Mohsen; Struble, Evi; Zhou, Zhaohua; Karnaukhova, Elena

    2012-01-01

    Human C1-esterase inhibitor (C1-INH) is a multifunctional plasma protein with a wide range of inhibitory and non-inhibitory properties, mainly recognized as a key down-regulator of the complement and contact cascades. The potentiation of C1-INH by heparin and other glycosaminoglycans (GAGs) regulates a broad spectrum of C1-INH activities in vivo both in normal and disease states. SCOPE OF RESEARCH: We have studied the potentiation of human C1-INH by heparin using Surface Plasmon Resonance (SPR), circular dichroism (CD) and a functional assay. To advance a SPR for multiple-unit interaction studies of C1-INH we have developed a novel (consecutive double capture) approach exploring different immobilization and layout. Our SPR experiments conducted in three different design versions showed marked acceleration in C1-INH interactions with complement protease C1s as a result of potentiation of C1-INH by heparin (from 5- to 11-fold increase of the association rate). Far-UV CD studies suggested that heparin binding did not alter C1-INH secondary structure. Functional assay using chromogenic substrate confirmed that heparin does not affect the amidolytic activity of C1s, but does accelerate its consumption due to C1-INH potentiation. This is the first report that directly demonstrates a significant acceleration of the C1-INH interactions with C1s due to heparin by using a consecutive double capture SPR approach. The results of this study may be useful for further C-INH therapeutic development, ultimately for the enhancement of current C1-INH replacement therapies. Published by Elsevier B.V.

  2. Bioinspired Heparin Nanosponge Prepared by Photo-crosslinking for Controlled Release of Growth Factors

    DEFF Research Database (Denmark)

    Choi, Won Il; Sahu, Abhishek; Vilos, Cristian

    2017-01-01

    to overcome these limitations. Herein, we have developed a thermosensitive heparin nanosponge (Hep-NS) by a one step photopolymerization reaction between diacrylated pluronic and thiolated heparin molecules. The amount of heparin in Hep-NS was precisely controlled by varying the heparin amount in the reaction...

  3. Preparation and in vitro evaluation of heparin-loaded polymeric nanoparticles.

    Science.gov (United States)

    Jiao, Y Y; Ubrich, N; Marchand-Arvier, M; Vigneron, C; Hoffman, M; Maincent, P

    2001-01-01

    Nanoparticles of a highly soluble macromolecular drug, heparin, were formulated with two biodegradable polymers (poly-E-caprolactone [PCL] and poly (D, L-lactic-co-glycolic-acid) 50/50 [PLAGA]) and two nonbiodegradable positively charged polymers (Eudragit RS and RL) by the double emulsion and solvent evaporation method, using a high-pressure homogenization device. The encapsulation efficiency and heparin release profiles were studied as a function of the type of polymers employed (alone or in combination) and the concentration of heparin. Optimal encapsulation efficiency was observed when 5000 IU of heparin were incorporated in the first emulsion. High drug entrapment efficiency was observed in both Eudragit RS and RL nanoparticles (60% and 98%, respectively), compared with PLAGA and PCL nanoparticles (PLAGA increased the encapsulation efficiency compared with these two biodegradable polymers used alone; however, the in vitro drug release was not modified and remained low. On the other hand, the addition of esterase to the dissolution medium resulted in a significant increase in heparin release. The in vitro biological activity of released heparin, evaluated by measuring the anti-Xa activity by a colorimetric assay, was conserved after the encapsulation process.

  4. The regulatory role of heparin on c-Met signaling in hepatocellular carcinoma cells.

    Science.gov (United States)

    İşcan, Evin; Güneş, Aysim; Korhan, Peyda; Yılmaz, Yeliz; Erdal, Esra; Atabey, Neşe

    2017-06-01

    The role of heparin as an anticoagulant is well defined; however, its role in tumorigenesis and tumor progression is not clear yet. Some studies have shown that anticoagulant treatment in cancer patients improve overall survival, however, recent clinical trials have not shown a survival benefit in cancer patients receiving heparin treatment. In our previous studies we have shown the inhibitory effects of heparin on Hepatocyte Growth Factor (HGF)-induced invasion and migration in hepatocellular carcinoma (HCC) cells. In this study, we showed the differential effects of heparin on the behaviors of HCC cells based on the presence or absence of HGF. In the absence of HGF, heparin activated HGF/c-Met signaling and promoted motility and invasion in HCC cells. Heparin treatment led to c-Met receptor dimerization and activated c-Met signaling in an HGF independent manner. Heparin-induced c-Met activation increased migration and invasion through ERK1/2, early growth response factor 1 (EGR1) and Matrix Metalloproteinases (MMP) axis. Interestingly, heparin modestly decreased the proliferation of HCC cells by inhibiting activatory phosphorylation of Akt. The inhibition of c-Met signaling reversed heparin-induced increase in motility and invasion and, proliferation inhibition. Our study provides a new perspective into the role of heparin on c-Met signaling in HCC.

  5. Insights on Structural Characteristics and Ligand Binding Mechanisms of CDK2

    Directory of Open Access Journals (Sweden)

    Yan Li

    2015-04-01

    Full Text Available Cyclin-dependent kinase 2 (CDK2 is a crucial regulator of the eukaryotic cell cycle. However it is well established that monomeric CDK2 lacks regulatory activity, which needs to be aroused by its positive regulators, cyclins E and A, or be phosphorylated on the catalytic segment. Interestingly, these activation steps bring some dynamic changes on the 3D-structure of the kinase, especially the activation segment. Until now, in the monomeric CDK2 structure, three binding sites have been reported, including the adenosine triphosphate (ATP binding site (Site I and two non-competitive binding sites (Site II and III. In addition, when the kinase is subjected to the cyclin binding process, the resulting structural changes give rise to a variation of the ATP binding site, thus generating an allosteric binding site (Site IV. All the four sites are demonstrated as being targeted by corresponding inhibitors, as is illustrated by the allosteric binding one which is targeted by inhibitor ANS (fluorophore 8-anilino-1-naphthalene sulfonate. In the present work, the binding mechanisms and their fluctuations during the activation process attract our attention. Therefore, we carry out corresponding studies on the structural characterization of CDK2, which are expected to facilitate the understanding of the molecular mechanisms of kinase proteins. Besides, the binding mechanisms of CDK2 with its relevant inhibitors, as well as the changes of binding mechanisms following conformational variations of CDK2, are summarized and compared. The summary of the conformational characteristics and ligand binding mechanisms of CDK2 in the present work will improve our understanding of the molecular mechanisms regulating the bioactivities of CDK2.

  6. Sensitive and selective turn off-on fluorescence detection of heparin based on the energy transfer platform using the BSA-stabilized Au nanoclusters/amino-functionalized graphene oxide hybrids.

    Science.gov (United States)

    Lan, Jing; Zou, Hong Yan; Wang, Qiang; Zeng, Ping; Li, Yuan Fang; Huang, Cheng Zhi

    2016-12-01

    An ultra-sensitive and selective turn off-on fluorescence detection of heparin based on the energy transfer in the BSA-stabilized gold nanoclusters/amino-functionalized graphene oxide (BSA-AuNCs/NH 2 -GO) hybrids was successfully realized. The BSA-AuNCs containing amounts of carboxyl groups could be absorbed on the surface of NH 2 -GO through the electrostatic interaction, which resulted in the fluorescence quenching of BSA-AuNCs with high efficiency. However, heparin, possessing high density of negative charge, could compete with BSA-AuNCs to bind NH 2 -GO and block the energy transfer from BSA-AuNCs to NH 2 -GO. The fluorescence recovery of BSA-AuNCs was closely related to the amount of heparin and there was a good linear relationship between fluorescence recovery of BSA-AuNCs and heparin over the range of 100ng/mL to 30μg/mL with a detection limit of 40ng/mL. What's more, the fluorescence assay was successfully applied for heparin sensing in human serums and intracellular imaging. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Angiogenesis alteration by defibrotide: implications for its mechanism of action in severe hepatic veno-occlusive disease.

    Science.gov (United States)

    Benimetskaya, Luba; Wu, Sijian; Voskresenskiy, Anatoliy M; Echart, Cinara; Zhou, Jin-Feng; Shin, Joongho; Iacobelli, Massimo; Richardson, Paul; Ayyanar, Kanyalakshmi; Stein, C A

    2008-11-15

    Defibrotide (DF) is a mixture of porcine-derived single-stranded phosphodiester oligonucleotides (9-80-mer; average, 50-mer) that has been successfully used to treat severe hepatic veno-occlusive disease (sVOD) with multiorgan failure (MOF) in patients who have received cytotoxic chemotherapy in preparation for bone marrow transplantation. However, its mechanism of action is unknown. Herein, we show that DF and phosphodiester oligonucleotides can bind to heparin-binding proteins (eg, basic fibroblast growth factor [bFGF] but not vascular endothelial growth factor [VEGF] 165) with low nanomolar affinity. This binding occurred in a length- and concentration-dependent manner. DF can mobilize proangiogenic factors such as bFGF from their depot or storage sites on bovine corneal endothelial matrix. However, these molecules do not interfere with high-affinity binding of bFGF to FGFR1 IIIc but can replace heparin as a required cofactor for binding and hence cellular mitogenesis. DF also protects bFGF against digestion by trypsin and chymotrypsin and from air oxidation. In addition, DF binds to collagen I with low nanomolar affinity and can promote human microvascular endothelial cell-1 (HMEC-1) cell mitogenesis and tubular morphogenesis in three-dimensional collagen I gels. Thus, our data suggest that DF may provide a stimulus to the sinusoidal endothelium of a liver that has suffered a severe angiotoxic event, thus helping to ameliorate the clinical sVOD/MOF syndrome.

  8. DEGRADATION AND INTRAHEPATIC COMPATIBILITY OF ALBUMIN-HEPARIN CONJUGATE MICROSPHERES

    NARCIS (Netherlands)

    CREMERS, HFM; WOLF, RFE; BLAAUW, EH; SCHAKENRAAD, JM; LAM, KH; NIEUWENHUIS, P; VERRIJK, R; KWON, G; BAE, YH; KIM, SW; FEIJEN, J

    The in vitro degradation properties of glutaraldehyde cross-linked albumin and albumin-heparin conjugate microspheres (AMS and AHCMS respectively) were evaluated using light microscopy, turbidity measurements and heparin release determinations, showing that the microspheres are degraded by

  9. In vitro anticoagulation monitoring of low-molecular-weight heparin

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-qi; SHI Xu-bo; YANG Jin-gang; HU Da-yi

    2009-01-01

    Background Although low-molecular-weight heparin has replaced unfractionated heparin to become the primary anticoagulation drug for treatment of acute coronary syndrome, there is no convenient bedside monitoring method. We explored the best laboratory monitoring method of low-molecular-weight heparins (enoxapadn, dalteparin, and nadroparin) by use of the Sonoclot coagulation analyzer to monitor the activated clotting time.Methods Atotal of 20 healthy volunteers were selected and 15 ml of fasting venous blood samples were collected and incubated. Four coagulants, kaolin, diatomite, glass bead, and magnetic stick, were used to determine the activated clotting time of the low-molecular-weight heparins at different in vitro anti-Xa factor concentrations. A correlation analysis was made to obtain the regression equation. The activated clotting time of the different low-molecular-weight heparins with the same anti-Xa factor concentration was monitored when the coagulant glass beads were applied. Results The activated clotting time measured using the glass beads, diatomite, kaolin, and magnetic stick showed a linear correlation with the concentration of nadroparin (r= 0.964, 0.966, 0.970, and 0.947, respectively). The regression equation showed that the linear slopes of different coagulants were significantly different (glass beads 230.03 s/IU,diatomite 89.91 s/IU, kaolin 50.87 s/IU, magnetic stick could not be calculated). When the concentration of the anti-Xa factor was the same for different low-molecular-weight heparins, the measured activated clotting time was different after the application of the glass bead coagulant.Conclusions The glass bead coagulant is most feasible for monitoring the in vitro anticoagulation activity of nadroparin.The different effects of different low-molecular-weight heparins on the activated clotting time may be related to the different anti-Ila activities.

  10. The heparin-binding domain of HB-EGF as an efficient cell-penetrating peptide for drug delivery.

    Science.gov (United States)

    Luo, Zhao; Cao, Xue-Wei; Li, Chen; Wu, Miao-Dan; Yang, Xu-Zhong; Zhao, Jian; Wang, Fu-Jun

    2016-11-01

    Cell-penetrating peptides (CPPs) have been shown to be potential drug carriers for cancer therapy. The inherently low immunogenicity and cytotoxicity of human-derived CPPs make them more suitable for intracellular drug delivery compared to other delivery vehicles. In this work, the protein transduction ability of a novel CPP (termed HBP) derived from the heparin-binding domain of HB-EGF was evaluated. Our data shows, for the first time, that HBP possesses similar properties to typical CPPs and is a potent drug delivery vector for improving the antitumor activity of impermeable MAP30. The intrinsic bioactivities of recombinant MAP30-HBP were well preserved compared to those of free MAP30. Furthermore, HBP conjugated to the C-terminus of MAP30 promoted the cellular uptake of recombinant MAP30-HBP. Moreover, the fusion of HBP to MAP30 gave rise to significantly enhanced cytotoxic effects in all of the tumor cell lines tested. In HeLa cells, this cytotoxicity was mainly caused by the induction of cell apoptosis. Further investigation revealed that HBP enhanced MAP30-induced apoptosis through the activation of the mitochondrial- and death receptor-mediated signaling pathways. In addition, the MAP30-HBP fusion protein caused more HeLa cells to become arrested in S phase compared to MAP30 alone. These results highlight the MAP30-HBP fusion protein as a promising drug candidate for cancer therapy and demonstrate HBP, a novel CPP derived from human HB-EGF, as a new potential vector for antitumor drug delivery. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  11. Increased accuracy in heparin and protamine administration decreases bleeding

    DEFF Research Database (Denmark)

    Runge, Marx; Møller, Christian H; Steinbrüchel, Daniel A

    2009-01-01

    Three to 5 percent of the patients undergoing cardiac surgery are reoperated because of bleeding. When a surgical cause can be excluded, heparin/protamine mismatch may be considered. Insufficient reversal of heparin and overdosing of protamine may cause postoperative bleeding. The purpose......). A reduced number of patients needed blood transfusions in the RxDx group, although this was not statistically significant (19% vs. 38%, respectively; p = .13). Initial heparin dose was significantly reduced in the RxDx group (250 mg; range, 100-375 mg) compared with the control group (300 mg; range, 200...

  12. Prophylaxis of postoperative thromboembolism with low molecular weight heparins

    DEFF Research Database (Denmark)

    Jørgensen, L N; Wille-Jørgensen, P; Hauch, O

    1993-01-01

    To evaluate the thromboprophylactic use of low molecular weight heparins (LMWHs), publications from 27 orthopaedic trials and 35 studies of patients undergoing general or gynaecological surgery were scrutinized and subjected to a partial meta-analysis. In orthopaedic surgery, LMWHs were superior...... to placebo or dextran and at least as efficient as unfractionated heparin in the prevention of deep vein thrombosis (DVT). Compared with unfractionated heparin, one of the LMWH preparations significantly reduced the total incidence of DVT. The rate of non-fatal pulmonary embolism was 0.49 per cent...

  13. Blood interaction with a Bioline heparin coated HIA-VAD : A study on calves

    NARCIS (Netherlands)

    vanderKamp, KWHJ; Magielse, CPE; Elstrodt, JM; vanderMeer, J; vanOeveren, W; Rakhorst, G

    The blood compatibility of ventricular assist devices developed by the Helmholtz institute Aachen (HA-VAD's) was tested on calves. Seven calves received a non-coated HIA-VAD (control) and three a Bioline heparin coated device. The circulatory support of these HIA-VAD's lasted one week. Mechanical

  14. Heparin induced thrombocytopenia type ii and myocardial infarction: Two case reports

    Directory of Open Access Journals (Sweden)

    Antonijević Nebojša

    2004-01-01

    Full Text Available Heparin-induced thrombocytopenia (HIT type II is an acquired thrombophylic state and life-threatening immune complication of a heparin treatment mainly clinically manifested by marked thrombocytopenia, frequently by arterial and venous thrombosis, and sometimes by skin changes. Functional assay as heparin aggregation test and 14C-serotonin release assays are used in diagnostics as well as antigen assays of which detection tests for heparin-platelet factor 4 antibodies are most frequently used. Considering the fact that there is no single reliable assays for HIT II detection available, sometimes it is necessary to combine both of the above-mentioned types of assays. We present the case of a 57-year-old patient with an acute anterior myocardial infarction with cardiac insufficiency of III and IV degree according to Killip, recurrent ventricular fibrillation and diabetes mellitus type II developing thrombocytopenia to 37x10 9/l accompanied with typical skin changes. The diagnosis was confirmed by the heparin aggregation test. The second patient aged 70 undergoing the treatment for anteroseptal myocardial infarction and reinfarction of the inferior wall complicated by a cardiogenic shock and acute right bundle branch block developed thrombocytopenia 59x10 9/I on the third day of the heparin therapy, with the remark that he had received a heparin therapy during the first infarction as well. Antibodies against heparin-platelet factor 4 were detected by particle gel ID-HPF4 immunoassay. In both patients, the disease had a lethal outcome despite all then available therapeutic measures applied. Further on we discuss advantages of certain types of tests, a therapy doctrine, need for urgent therapeutic measures, inclusive of the administration of anitithrombins, avoidance of harmful procedures like low-molecular-weight heparins administration and prophylactic platelet transfusion as well as preventive measures.

  15. Anti-tumor activity of a novel HS-mimetic-vascular endothelial growth factor binding small molecule.

    Directory of Open Access Journals (Sweden)

    Kazuyuki Sugahara

    Full Text Available The angiogenic process is controlled by variety of factors of which the vascular endothelial growth factor (VEGF pathway plays a major role. A series of heparan sulfate mimetic small molecules targeting VEGF/VEGFR pathway has been synthesized. Among them, compound 8 (2-butyl-5-chloro-3-(4-nitro-benzyl-3H-imidazole-4-carbaldehyde was identified as a significant binding molecule for the heparin-binding domain of VEGF, determined by high-throughput-surface plasmon resonance assay. The data predicted strong binding of compound 8 with VEGF which may prevent the binding of VEGF to its receptor. We compared the structure of compound 8 with heparan sulfate (HS, which have in common the functional ionic groups such as sulfate, nitro and carbaldehyde that can be located in similar positions of the disaccharide structure of HS. Molecular docking studies predicted that compound 8 binds at the heparin binding domain of VEGF through strong hydrogen bonding with Lys-30 and Gln-20 amino acid residues, and consistent with the prediction, compound 8 inhibited binding of VEGF to immobilized heparin. In vitro studies showed that compound 8 inhibits the VEGF-induced proliferation migration and tube formation of mouse vascular endothelial cells, and finally the invasion of a murine osteosarcoma cell line (LM8G7 which secrets high levels of VEGF. In vivo, these effects produce significant decrease of tumor burden in an experimental model of liver metastasis. Collectively, these data indicate that compound 8 may prevent tumor growth through a direct effect on tumor cell proliferation and by inhibition of endothelial cell migration and angiogenesis mediated by VEGF. In conclusion, compound 8 may normalize the tumor vasculature and microenvironment in tumors probably by inhibiting the binding of VEGF to its receptor.

  16. Heparin release from thermosensitive polymer coatings: in vivo studies

    NARCIS (Netherlands)

    Gutowska, Anna; Bae, You Han; Jacobs, Harvey; Mohammad, Fazal; Mix, Donald; Feijen, Jan; Kim, Sung Wan

    1995-01-01

    Biomer/poly(N-isopropylacrylamide)/[poly(NiPAAm)] thermosensitive polymer blends were prepared and their application as heparin-releasing polymer coatings for the prevention of surface-induced thrombosis was examined. The advantage of using poly(NiPAAm)-based coatings as heparin-releasing polymers

  17. Poly(vinyl alcohol)-heparin hydrogels as sensor catheter membranes

    NARCIS (Netherlands)

    Brinkman, E.; van der Does, L.; Bantjes, A.

    1991-01-01

    Poly(vinyl alcohol)-heparin hydrogels with varying water content were synthesized for use as sensor catheter membranes. Films were cast from aqueous mixtures of poly(viny) alcohol) (PVA), a photosensitive cross-linker p-diazonium diphenyl amine polymer (PA), glutaraldehyde (GA) and heparin. After

  18. From Farm to Pharma: An Overview of Industrial Heparin Manufacturing Methods.

    Science.gov (United States)

    van der Meer, Jan-Ytzen; Kellenbach, Edwin; van den Bos, Leendert J

    2017-06-21

    The purification of heparin from offal is an old industrial process for which commercial recipes date back to 1922. Although chemical, chemoenzymatic, and biotechnological alternatives for this production method have been published in the academic literature, animal-tissue is still the sole source for commercial heparin production in industry. Heparin purification methods are closely guarded industrial secrets which are not available to the general (scientific) public. However by reviewing the academic and patent literature, we aim to provide a comprehensive overview of the general methods used in industry for the extraction of heparin from animal tissue.

  19. P-selectin- and heparanase-dependent antimetastatic activity of non-anticoagulant heparins.

    Science.gov (United States)

    Hostettler, Nina; Naggi, Annamaria; Torri, Giangiacomo; Ishai-Michaeli, Riva; Casu, Benito; Vlodavsky, Israel; Borsig, Lubor

    2007-11-01

    Vascular cell adhesion molecules, P- and L-selectins, facilitate metastasis of cancer cells in mice by mediating interactions with platelets, endothelium, and leukocytes. Heparanase is an endoglycosidase that degrades heparan sulfate of extracellular matrix, thereby promoting tumor invasion and metastasis. Heparin is known to efficiently attenuate metastasis in different tumor models. Here we identified modified, nonanticoagulant species of heparin that specifically inhibit selectin-mediated cell-cell interactions, heparanase enzymatic activity, or both. We show that selective inhibition of selectin interactions or heparanase with specific heparin derivatives in mouse models of MC-38 colon carcinoma and B16-BL6 melanoma attenuates metastasis. Selectin-specific heparin derivatives attenuated metastasis of MC-38 carcinoma, but heparanase-specific derivatives had no effect, in accordance with the virtual absence of heparanase activity in these cells. Heparin derivatives had no further effect on metastasis in mice deficient in P- and L-selectin, indicating that selectins are the primary targets of heparin antimetastatic activity. Selectin-specific and heparanase-specific derivatives attenuated metastasis of B16-BL6 melanomas to a similar extent. When mice were injected with a derivative containing both heparanase and selectin inhibitory activity, no additional attenuation of metastasis could be observed. Thus, selectin-specific heparin derivatives efficiently attenuated metastasis of both tumor cell types whereas inhibition of heparanase led to reduction of metastasis only in tumor cells producing heparanase.

  20. Heparin modulates human intestinal smooth muscle (HISM) cell proliferation and matrix production

    International Nuclear Information System (INIS)

    Graham, M.; Perr, H.; Drucker, D.E.; Diegelmann, R.F.

    1986-01-01

    (HISM) cell proliferation and collagen production may play a role in the pathogenesis of intestinal stricture in Crohn's disease. The present studies were performed to evaluate the effects of heparin, a known modulator of vascular smooth muscle cells, on HISM cell proliferation and collagen production. Heparin (100 μg/ml) was added daily to HISM cell cultures for cell proliferation studies and for 24 hours at various time points during culture for collagen synthesis studies. Collagen synthesis was determined by the uptake of 3 H proline into collagenase-sensitive protein. Heparin completely inhibited cell proliferation for 7 days, after which cell numbers increased but at a slower rate than controls. Cells released from heparin inhibition demonstrated catch-up growth to control levels. Collagen production was significantly inhibited by 24 hours exposure to heparin but only at those times during culture when collagen synthesis was maximal (8 to 12 days). Non-collagen protein synthesis was inhibited by heparin at all time points during culture. Heparin through its modulation of HISM cells may play an important role in the control of the extracellular matrix of the intestinal wall

  1. Heparin-Based Nanoparticles: An Overview of Their Applications

    Directory of Open Access Journals (Sweden)

    Maria del Pilar Rodriguez-Torres

    2018-01-01

    Full Text Available This review deals with nanoparticles synthesized using heparin. Such nanoparticles have been widely studied since a long time ago, obtaining satisfactory outcomes. An outstanding aspect of these nanoparticles is that they possess good biocompatible characteristics, and since heparin is produced in the human body within the mast cells, this makes these nanoparticles useful for future applications like imaging, disease and cancer treatment, and antibacterial activity. They can also be used for applications that are not oriented directly to the medical and biological areas such as in the case of analyte detection in aqueous solution, although such studies are very few. These nanoparticles synthesis is mainly through wet chemistry methods, using heparin that could have been modified or not.

  2. Anticoagulant effect of low molecular weight heparin on central ...

    African Journals Online (AJOL)

    Purpose: To analyse the effect of low molecular weight heparin on venous catheters in haemodialysis patients. Methods: This study included 140 eligible patients who were randomly and evenly divided into two groups, viz, a study group that received low molecular weight heparin and a control group that received ...

  3. Nerve growth factor loaded heparin/chitosan scaffolds for accelerating peripheral nerve regeneration.

    Science.gov (United States)

    Li, Guicai; Xiao, Qinzhi; Zhang, Luzhong; Zhao, Yahong; Yang, Yumin

    2017-09-01

    Artificial chitosan scaffolds have been widely investigated for peripheral nerve regeneration. However, the effect was not as good as that of autologous grafts and therefore could not meet the clinical requirement. In the present study, the nerve growth factor (NGF) loaded heparin/chitosan scaffolds were fabricated via electrostatic interaction for further improving nerve regeneration. The physicochemical properties including morphology, wettability and composition were measured. The heparin immobilization, NGF loading and release were quantitatively and qualitatively characterized, respectively. The effect of NGF loaded heparin/chitosan scaffolds on nerve regeneration was evaluated by Schwann cells culture for different periods. The results showed that the heparin immobilization and NGF loading did not cause the change of bulk properties of chitosan scaffolds except for morphology and wettability. The pre-immobilization of heparin in chitosan scaffolds could enhance the stability of subsequently loaded NGF. The NGF loaded heparin/chitosan scaffolds could obviously improve the attachment and proliferation of Schwann cells in vitro. More importantly, the NGF loaded heparin/chitosan scaffolds could effectively promote the morphology development of Schwann cells. The study may provide a useful experimental basis to design and develop artificial implants for peripheral nerve regeneration and other tissue regeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Naked eye detection of infertility based on sperm protamine-induced aggregation of heparin gold nanoparticles.

    Science.gov (United States)

    Vidya, Raj; Saji, Alex

    2018-05-01

    The development of an easy to use, one-pot, environmentally friendly, non-invasive and label-free colorimetric probe for the determination of semen protamines, the biochemical marker of male fertility, using heparin gold nanoparticles (HAuNPs) is presented. The affinity of HAuNPs for protamines was due to the electrostatic interactions between polycationic protamine and polyanionic heparin. The binding of HAuNPs to protamine was characterized by variation in the plasmon absorption spectra followed by a visibly observable colour change of the solution from red to blue. We observed a red shift in the plasmon peak and the method exhibited linearity in the range of 10-70 ng/mL with a detection limit of 5 ng/mL, which is much lower than that reported for colorimetric sensors of protamine. The colour change and the variation in the absorbance of HAuNPs were highly specific for protamines in the presence of different interfering compounds and the method was successfully applied for determining protamine in real samples of semen and serum. Rather than a quantitative estimation, it seems that the method provides a quick screening between a large array of positive and negative samples and, moreover, it maintains the privacy of the user. The method appears to be simple and would be very useful in third-world countries where high-tech diagnostic aids are inaccessible to the majority of the population. Graphical Abstract Heparin gold nanoparticles aided visual detection of infertility.

  5. [Thrombocytopenia induced by type II heparin and myocardial infarct: 2 case reports].

    Science.gov (United States)

    Antonijević, Nabojsa; Stanojević, Milica; Perunicić, Jovan; Djokić, Milan; Miković, Danijla; Kovac, Mirjana; Miljić, Predrag; Milosević, Rajko; Terzić, Branka; Vasiljević, Zorana

    2004-01-01

    Heparin-induced thrombocytopenia (HIT) type II is an acquired thrombophylic state and life-threatening immune complication of a heparin treatment mainly clinically manifested by marked thrombocytopenia, frequently by arterial and venous thrombosis, and sometimes by skin changes. Functional assay as heparin aggregation test and 14C-serotonin release assays are used in diagnostics as well as antigen assays of which detection tests for heparin-platelet factor 4 antibodies are most frequently used. Considering the fact that there is no single reliable assays for HIT II detection available, sometimes it is necessary to combine both of the above-mentioned types of assays. We present the case of a 57-year-old patient with an acute anterior myocardial infarction with cardiac insufficiency of III and IV degree according to Killip, recurrent ventricular fibrillation and diabetes mellitus type II developing thrombocytopenia to 37 x 10(9)/l accompanied with typical skin changes. The diagnosis was confirmed by the heparin aggregation test. The second patient aged 70 undergoing the treatment for anteroseptal myocardial infarction and reinfarction of the inferior wall complicated by a cardiogenic shock and acute right bundle branch block developed thrombocytopenia 59 x 10(9)/l on the third day of the heparin therapy, with the remark that he had received a heparin therapy during the first infarction as well. Antibodies against heparin-platelet factor 4 were detected by particle gel ID-HPF4 immuno-assay. In both patients, the disease had a lethal outcome despite all then available therapeutic measures applied. Further on we discuss advantages of certain types of tests, a therapy doctrine, need for urgent therapeutic measures, inclusive of the administration of antithrombins, avoidance of harmful procedures like low-molecular-weight heparins administration and prophylactic platelet transfusion as well as preventive measures.

  6. Species of /sup 67/Ga-binding acid mucopolysaccharide in liver

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A.; Ando, I.

    1985-01-01

    It was determined from measuring neutral saccharide in the structure that the principal /sup 67/Ga-binding acid mucopolysaccharide in liver was keratan sulfate and/or keratan polysulfate. On the other hand, it was clarified from the results of mucopolysaccharase treatment that the main /sup 67/Ga-binding acid mucopolysaccharide in liver was neither keratan sulfate, heparan sulfate, heparin, nor chondroitin sulfate A, B and C. Based on the present results, it was deduced that the main /sup 67/Ga-binding acid mucopolysaccharide in liver was keratan polysulfate.

  7. Distribution of heparin-/sup 67/Ga in tumor-bearing rats

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, T; Ando, A; Sanada, S [Kanazawa Univ. (Japan). School of Paramedicine; Ando, I; Hisada, K

    1976-06-01

    Heparin is a kind of acidic mucopolysaccharide. The distribution of heparin-/sup 67/Ga complex in tumor-bearing rats was investigated by administering it to rats into which Yoshida sarcoma had been transplanted subcutaneously. These rats were sacrificed at 10 minutes, 30 minutes, 1 hour and 3 hours after injection. Radioactivity of the tumor, blood, muscle, liver, kidney, spleen and urine were measured with a well-type scintillation counter. Retention values in these organs and excretion rates in the urine were calculated. Excretion rates (%/dose) of heparin-/sup 67/Ga in 10 min., 30 min., 1 hour, and 3 hours were 38.2%, 67.5%, 79.5% and 78.0%, respectively. From these facts, it was thought that heparin-/sup 67/Ga complex was not suitable for tumor scanning, but that this compound might be a suitable agent for the renal function test.

  8. Involvement of three meningococcal surface-exposed proteins, the heparin-binding protein NhbA, the α-peptide of IgA protease and the autotransporter protease NalP, in initiation of biofilm formation

    KAUST Repository

    Arenas, Jesús

    2012-12-04

    Neisseria meningitidis is a common and usually harmless inhabitant of the mucosa of the human nasopharynx, which, in rare cases, can cross the epithelial barrier and cause meningitis and sepsis. Biofilm formation favours the colonization of the host and the subsequent carrier state. Two different strategies of biofilm formation, either dependent or independent on extracellular DNA (eDNA), have been described for meningococcal strains. Here, we demonstrate that the autotransporter protease NalP, the expression of which is phase variable, affects eDNA-dependent biofilm formation in N.meningitidis. The effect of NalP was found in biofilm formation under static and flow conditions and was dependent on its protease activity. Cleavage of the heparin-binding antigen NhbA and the α-peptide of IgA protease, resulting in the release of positively charged polypeptides from the cell surface, was responsible for the reduction in biofilm formation when NalP is expressed. Both NhbA and the α-peptide of IgA protease were shown to bind DNA. We conclude that NhbA and the α-peptide of IgA protease are implicated in biofilm formation by binding eDNA and that NalP is an important regulator of this process through the proteolysis of these surface-exposed proteins. © 2012 Blackwell Publishing Ltd.

  9. Involvement of three meningococcal surface-exposed proteins, the heparin-binding protein NhbA, the α-peptide of IgA protease and the autotransporter protease NalP, in initiation of biofilm formation

    KAUST Repository

    Arenas, Jesú s; Nijland, Reindert; Rodriguez, Francisco J.; Bosma, Tom N. P.; Tommassen, Jan

    2012-01-01

    Neisseria meningitidis is a common and usually harmless inhabitant of the mucosa of the human nasopharynx, which, in rare cases, can cross the epithelial barrier and cause meningitis and sepsis. Biofilm formation favours the colonization of the host and the subsequent carrier state. Two different strategies of biofilm formation, either dependent or independent on extracellular DNA (eDNA), have been described for meningococcal strains. Here, we demonstrate that the autotransporter protease NalP, the expression of which is phase variable, affects eDNA-dependent biofilm formation in N.meningitidis. The effect of NalP was found in biofilm formation under static and flow conditions and was dependent on its protease activity. Cleavage of the heparin-binding antigen NhbA and the α-peptide of IgA protease, resulting in the release of positively charged polypeptides from the cell surface, was responsible for the reduction in biofilm formation when NalP is expressed. Both NhbA and the α-peptide of IgA protease were shown to bind DNA. We conclude that NhbA and the α-peptide of IgA protease are implicated in biofilm formation by binding eDNA and that NalP is an important regulator of this process through the proteolysis of these surface-exposed proteins. © 2012 Blackwell Publishing Ltd.

  10. Structure and function of A41, a vaccinia virus chemokine binding protein.

    Directory of Open Access Journals (Sweden)

    Mohammad W Bahar

    2008-01-01

    Full Text Available The vaccinia virus (VACV A41L gene encodes a secreted 30 kDa glycoprotein that is nonessential for virus replication but affects the host response to infection. The A41 protein shares sequence similarity with another VACV protein that binds CC chemokines (called vCKBP, or viral CC chemokine inhibitor, vCCI, and strains of VACV lacking the A41L gene induced stronger CD8+ T-cell responses than control viruses expressing A41. Using surface plasmon resonance, we screened 39 human and murine chemokines and identified CCL21, CCL25, CCL26 and CCL28 as A41 ligands, with Kds of between 8 nM and 118 nM. Nonetheless, A41 was ineffective at inhibiting chemotaxis induced by these chemokines, indicating it did not block the interaction of these chemokines with their receptors. However the interaction of A41 and chemokines was inhibited in a dose-dependent manner by heparin, suggesting that A41 and heparin bind to overlapping sites on these chemokines. To better understand the mechanism of action of A41 its crystal structure was solved to 1.9 A resolution. The protein has a globular beta sandwich structure similar to that of the poxvirus vCCI family of proteins, but there are notable structural differences, particularly in surface loops and electrostatic charge distribution. Structural modelling suggests that the binding paradigm as defined for the vCCI-chemokine interaction is likely to be conserved between A41 and its chemokine partners. Additionally, sequence analysis of chemokines binding to A41 identified a signature for A41 binding. The biological and structural data suggest that A41 functions by forming moderately strong (nM interactions with certain chemokines, sufficient to interfere with chemokine-glycosaminoglycan interactions at the cell surface (microM-nM and thereby to destroy the chemokine concentration gradient, but not strong enough to disrupt the (pM chemokine-chemokine receptor interactions.

  11. Cellular Responses Modulated by FGF-2 Adsorbed on Albumin/Heparin Layer-by-Layer Assemblies.

    Science.gov (United States)

    Kumorek, Marta; Kubies, Dana; Filová, Elena; Houska, Milan; Kasoju, Naresh; Mázl Chánová, Eliška; Matějka, Roman; Krýslová, Markéta; Bačáková, Lucie; Rypáček, František

    2015-01-01

    In a typical cell culture system, growth factors immobilized on the cell culture surfaces can serve as a reservoir of bio-signaling molecules, without the need to supplement them additionally into the culture medium. In this paper, we report on the fabrication of albumin/heparin (Alb/Hep) assemblies for controlled binding of basic fibroblast growth factor (FGF-2). The surfaces were constructed by layer-by-layer adsorption of polyelectrolytes albumin and heparin and were subsequently stabilized by covalent crosslinking with glutaraldehyde. An analysis of the surface morphology by atomic force microscopy showed that two Alb/Hep bilayers are required to cover the surface of substrate. The formation of the Alb/Hep assemblies was monitored by the surface plasmon resonance (SPR), the infrared multiinternal reflection spectroscopy (FTIR MIRS) and UV/VIS spectroscopy. The adsorption of FGF-2 on the cross-linked Alb/Hep was followed by SPR. The results revealed that FGF-2 binds to the Alb/Hep assembly in a dose and time-dependent manner up to the surface concentration of 120 ng/cm(2). The bioactivity of the adsorbed FGF-2 was assessed in experiments in vitro, using calf pulmonary arterial endothelial cells (CPAE). CPAE cells could attach and proliferate on Alb/Hep surfaces. The adsorbed FGF-2 was bioactive and stimulated both the proliferation and the differentiation of CPAE cells. The improvement was more pronounced at a lower FGF-2 surface concentration (30 ng/cm(2)) than on surfaces with a higher concentration of FGF-2 (120 ng/cm(2)).

  12. Quantitation of heparosan with heparin lyase III and spectrophotometry.

    Science.gov (United States)

    Huang, Haichan; Zhao, Yingying; Lv, Shencong; Zhong, Weihong; Zhang, Fuming; Linhardt, Robert J

    2014-02-15

    Heparosan is Escherichia coli K5 capsule polysaccharide, which is the key precursor for preparing bioengineered heparin. A rapid and effective quantitative method for detecting heparosan is important in the large-scale production of heparosan. Heparin lyase III (Hep III) effectively catalyzes the heparosan depolymerization, forming unsaturated disaccharides that are measurable using a spectrophotometer at 232 nm. We report a new method for the quantitative detection of heparosan with heparin lyase III and spectrophotometry that is safer and more specific than the traditional carbazole assay. In an optimized detection system, heparosan at a minimum concentration of 0.60 g/L in fermentation broth can be detected. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Quantitative determination of heparin levels in serum with microtiter plate-format optode

    International Nuclear Information System (INIS)

    Kim, Sung Bae; Kang, Tae Young; Cha, Geun Sig; Nam, Hakhyun

    2006-01-01

    A new assay method has been developed for the quantitative determination of heparin in serum using a microtiter plate-format optode (MPO). Heparin and proton in physiological sample are favorably co-extracted into the solvent polymeric optode membrane containing both cationic lipophilic additive, tridodecylmethyl ammonium chloride (TDMAC), and proton-selective ionophore, 3-hydroxy-4-(4-nitrophenylazo)-phenyloctadecanoate (ETH 2412), resulting in the absorbance change of the membrane to varying heparin levels. The optimized MPO composition contains low polymer-to-plasticizer ratio compared to those of conventional ion-selective optodes or electrodes, i.e., poly(vinyl chloride) (20.0)/dioctylsebacate (76.3)/ETH 2412 (1.7)/TDMAC (1.0) (wt.%): it resulted in a quantitative response to heparin from 0 to 15 unit/mL in serum with high sensitivity. The heparin-protamine titration on the MPO could provide rapid and precise determination of heparin. It was shown that the heparin levels in serum sample could be determined from the rate of absorbance change over time (ΔA/Δt); this method was more effective than the direct absorbance measurement in minimizing the interferences from color and turbidity of serum samples. MPO has been developed as a high throughput and convenient disposable sensing device, and may find a wide application in the determination of polyions and charged macromolecules

  14. 99m Tc-labeled heparin test in orthopaedic surgery

    International Nuclear Information System (INIS)

    Bouvier, J.F.; Lafon, J.C.; Colin, M.; Chatelut, J.; Beaubatie, F.

    1983-01-01

    99m Tc-labeled heparin test was performed for early detection of phlebitis or pulmonary embolism after orthopaedic prothesis. Heparinic treatment and surgery per se were demonstrated to have no effect on the results. If this test demonstrates a statistical difference for pathologic patients, it is of greater value to consider ratio between rates before and after intervention [fr

  15. Evidence-based algorithm for heparin dosing before cardiopulmonary bypass. Part 1: Development of the algorithm.

    Science.gov (United States)

    McKinney, Mark C; Riley, Jeffrey B

    2007-12-01

    The incidence of heparin resistance during adult cardiac surgery with cardiopulmonary bypass has been reported at 15%-20%. The consistent use of a clinical decision-making algorithm may increase the consistency of patient care and likely reduce the total required heparin dose and other problems associated with heparin dosing. After a directed survey of practicing perfusionists regarding treatment of heparin resistance and a literature search for high-level evidence regarding the diagnosis and treatment of heparin resistance, an evidence-based decision-making algorithm was constructed. The face validity of the algorithm decisive steps and logic was confirmed by a second survey of practicing perfusionists. The algorithm begins with review of the patient history to identify predictors for heparin resistance. The definition for heparin resistance contained in the algorithm is an activated clotting time 450 IU/kg heparin loading dose. Based on the literature, the treatment for heparin resistance used in the algorithm is anti-thrombin III supplement. The algorithm seems to be valid and is supported by high-level evidence and clinician opinion. The next step is a human randomized clinical trial to test the clinical procedure guideline algorithm vs. current standard clinical practice.

  16. Anti-Platelet Factor 4/Heparin Antibody Formation Occurs Endogenously and at Unexpected High Frequency in Polycythemia Vera

    Directory of Open Access Journals (Sweden)

    Sara C. Meyer

    2017-01-01

    Full Text Available Background. Myeloproliferative neoplasms (MPN encounter thromboses due to multiple known risk factors. Heparin-induced thrombocytopenia (HIT is a thrombotic syndrome mediated by anti-platelet factor 4 (PF4/heparin antibodies with undetermined significance for thrombosis in MPN. We hypothesized that anti-PF4/heparin Ab might occur in MPN and promote thrombosis. Methods. Anti-PF4/heparin antibodies were analyzed in 127 MPN patients including 76 PV and 51 ET. Screening, validation testing, and isotype testing of anti-PF4/heparin Ab were correlated with disease characteristics. Results. Anti-PF4/heparin antibodies were detected in 21% of PV and 12% of ET versus 0.3–3% in heparin-exposed patients. Validation testing confirmed anti-PF4/heparin immunoglobulins in 15% of PV and 10% of ET. Isotype testing detected 9.2% IgG and 5.3% IgM in PV and exclusively IgM in ET. IgG-positive PV patients encountered thromboses in 57.1% suggesting anti-PF4/heparin IgG may contribute to higher risk for thrombosis in MPN. Overall, 45% of PV patients experienced thromboses with 11.8% positive for anti-PF4/heparin IgG versus 7.1% in PV without thrombosis. Conclusion. Anti-PF4/heparin antibodies occur endogenously and more frequently in MPN than upon heparin exposure. Thrombotic risk increases in anti-PF4/heparin IgG-positive PV reflecting potential implications and calling for larger, confirmatory cohorts. Anti-PF4/heparin IgG should be assessed upon thrombosis in PV to facilitate avoidance of heparin in anti-PF4/heparin IgG-positive PV.

  17. Effects of the repeated administration of adenosine and heparin on myocardial perfusion in patients with chronic stable angina pectoris.

    Science.gov (United States)

    Barron, H V; Sciammarella, M G; Lenihan, K; Michaels, A D; Botvinick, E H

    2000-01-01

    The mechanism by which ischemia stimulates angiogenesis is unknown. Adenosine is released during myocardial ischemia and may be a mediator of this process. Experimental data suggest that heparin may enhance this effect. The purpose of this open-labeled, placebo-controlled trial was to determine whether repeated intravenous administration of adenosine and heparin could mimic physiologic angiogenesis and reduce the amount of exercise-induced myocardial ischemia in patients with coronary artery disease. Subjects with chronic stable angina refractory to conventional medical therapy and not suitable for revascularization received either adenosine (140 microg/kg/min for 6 minutes) and heparin (10,000 U bolus), (n = 14), or placebo, (n = 7) daily for 10 days. All patients underwent baseline and follow-up exercise testing with thallium-201 single-photon emission computed tomography myocardial perfusion imaging. A semiquantitative assessment of the extent and severity of the perfusion abnormalities was calculated by 2 blinded investigators. There was no significant change in exercise duration or in the peak heart rate systolic blood pressure product associated with adenosine and heparin compared with placebo treatment. There was, however, a 9% reduction in the extent (60.6 +/- 4.0 vs 54.9 +/- 4.1, p = 0.03) and a 14% improvement in severity (41.5 +/- 3.2 vs 35.7 +/- 2.9, p = 0.01) of the myocardial perfusion abnormalities seen in patients who received adenosine and heparin compared with placebo. Thus, in this pilot study, repeated administration of adenosine and heparin reduced the amount of exercise-induced ischemia in patients with chronic stable angina refractory to conventional treatment.

  18. Characterization of currently marketed heparin products: key tests for LMWH quality assurance.

    Science.gov (United States)

    Ye, Hongping; Toby, Timothy K; Sommers, Cynthia D; Ghasriani, Houman; Trehy, Michael L; Ye, Wei; Kolinski, Richard E; Buhse, Lucinda F; Al-Hakim, Ali; Keire, David A

    2013-11-01

    During the 2007-2008 heparin crisis it was found that the United States Pharmacopeia (USP) testing monograph for heparin sodium or low molecular weight heparins did not detect the presence of the contaminant, oversulfated chondroitin sulfate (OSCS). In response to this concern, new tests and specifications were developed by the Food and Drug Administration (FDA) and USP and put in place to detect not only the contaminant OSCS, but also to improve assurance of quality and purity of these drug products. The USP monographs for the low molecular weight heparins (LMWHs) approved for use in the United States (dalteparin, tinzaparin and enoxaparin) are also undergoing revision to include many of the same tests used for heparin sodium, including; one-dimensional (1D) 500 MHz (1)H NMR, SAX-HPLC, percent galactosamine in total hexosamine and anticoagulation time assays with purified Factor IIa or Factor Xa. These tests represent orthogonal approaches for heparin identification, measurement of bioactivity and for detection of process impurities or contaminants in these drug products. Here we describe results from a survey of multiple lots from three types of LMWHs in the US market which were collected after the 2009 heparin sodium monograph revision. In addition, innovator and generic versions of formulated enoxaparin products purchased in 2011 are compared using these tests and found to be highly similar within the discriminating power of the assays applied. Published by Elsevier B.V.

  19. DNA-cisplatin binding mechanism peculiarities studied with single molecule stretching experiments

    Science.gov (United States)

    Crisafuli, F. A. P.; Cesconetto, E. C.; Ramos, E. B.; Rocha, M. S.

    2012-02-01

    We propose a method to determine the DNA-cisplatin binding mechanism peculiarities by monitoring the mechanical properties of these complexes. To accomplish this task, we have performed single molecule stretching experiments by using optical tweezers, from which the persistence and contour lengths of the complexes can be promptly measured. The persistence length of the complexes as a function of the drug total concentration in the sample was used to deduce the binding data, from which we show that cisplatin binds cooperatively to the DNA molecule, a point which so far has not been stressed in binding equilibrium studies of this ligand.

  20. The US regulatory and pharmacopeia response to the global heparin contamination crisis.

    Science.gov (United States)

    Szajek, Anita Y; Chess, Edward; Johansen, Kristian; Gratzl, Gyöngyi; Gray, Elaine; Keire, David; Linhardt, Robert J; Liu, Jian; Morris, Tina; Mulloy, Barbara; Nasr, Moheb; Shriver, Zachary; Torralba, Pearle; Viskov, Christian; Williams, Roger; Woodcock, Janet; Workman, Wesley; Al-Hakim, Ali

    2016-06-09

    The contamination of the widely used lifesaving anticoagulant drug heparin in 2007 has drawn renewed attention to the challenges that are associated with the characterization, quality control and standardization of complex biological medicines from natural sources. Heparin is a linear, highly sulfated polysaccharide consisting of alternating glucosamine and uronic acid monosaccharide residues. Heparin has been used successfully as an injectable antithrombotic medicine since the 1930s, and its isolation from animal sources (primarily porcine intestine) as well as its manufacturing processes have not changed substantially since its introduction. The 2007 heparin contamination crisis resulted in several deaths in the United States and hundreds of adverse reactions worldwide, revealing the vulnerability of a complex global supply chain to sophisticated adulteration. This Perspective discusses how the US Food and Drug Administration (FDA), the United States Pharmacopeial Convention (USP) and international stakeholders collaborated to redefine quality expectations for heparin, thus making an important natural product better controlled and less susceptible to economically motivated adulteration.

  1. Interactions of oversulfated chondroitin sulfate (OSCS) from different sources with unfractionated heparin.

    Science.gov (United States)

    Gray, Angel; Litinas, Evangelos; Jeske, Walter; Fareed, Jawed; Hoppensteadt, Debra

    2012-01-01

    In 2008, oversulfated chondroitin sulfate (OSCS) was identified as the main contaminant in recalled heparin. Oversulfated chondroitin sulfate can be prepared from bovine (B), porcine (P), shark (Sh), or skate (S) origin and may produce changes in the antithrombotic, bleeding, and hemodynamic profile of heparins. This study examines the interactions of various OSCSs on heparin in animal models of thrombosis and bleeding, as well as on the anticoagulant and antiprotease effects in in vitro assays. Mixtures of 70% unfractionated heparin (UFH) with 30% OSCS from different sources were tested. In the in vitro activated partial thromboplastin time (aPTT) assay, all contaminant mixtures showed a decrease in clotting times. In addition, a significant increase in bleeding time compared to the control (UFH/saline) was observed. In the thrombosis model, no significant differences were observed. The OSCSs significantly increased anti-Xa activity in ex vivo blood samples. These results indicate that various sources of OSCS affect the hemostatic properties of heparin.

  2. A genome-wide association study of heparin-induced thrombocytopenia using an electronic medical record

    DEFF Research Database (Denmark)

    Karnes, Jason H; Cronin, Robert M; Rollin, Jerome

    2015-01-01

    Heparin-induced thrombocytopenia (HIT) is an unpredictable, potentially catastrophic adverse effect of heparin treatment resulting from an immune response to platelet factor 4 (PF4)/heparin complexes. No genome-wide evaluations have been performed to identify potential genetic influences on HIT. ...

  3. Veno-venous bypass without systemic heparinization using a centrifugal pump: a blind comparison of a heparin bonded circuit versus a non heparin bonded circuit

    NARCIS (Netherlands)

    van der Hulst, V. P.; Henny, C. P.; Moulijn, A. C.; Engbers, G.; ten Cate, H.; Gründeman, P. F.; Klopper, P. J.

    1989-01-01

    Veno-venous bypass without the use of systemic heparinization has recently become of increasing interest for application during liver transplantation and surgery on the large abdominal veins. However, possible adverse effects on blood components as demonstrated by means of hematologic and hemostatic

  4. Heparin concentration is critical for cell culture with human platelet lysate.

    Science.gov (United States)

    Hemeda, Hatim; Kalz, Jana; Walenda, Gudrun; Lohmann, Michael; Wagner, Wolfgang

    2013-09-01

    Culture media for mesenchymal stromal cells (MSCs) are generally supplemented with fetal bovine serum. Human platelet lysate (hPL) has been proven to be a very effective alternative without the risk of xenogeneic infections or immune reactions. In contrast to fetal bovine serum, hPL comprises plasma, and anticoagulants-usually unfractionated heparin (UFH)-need to be added to prevent gel formation. Cultures of MSCs in hPL media with various concentrations of UFH and enoxaparin, a low-molecular-weight heparin (LMWH), were systematically compared with regard to proliferation, fibroblastoid colony-forming unit frequency, immunophenotype and in vitro differentiation. At least 0.61 IU/mL UFH or 0.024 mg/mL LMWH was necessary for reliable prevention of coagulation of hPL pools used in this study. Higher concentrations impaired cellular proliferation in a dose-dependent manner even without benzyl alcohol, which is commonly added to heparins as a bacteriostatic agent. Colony-forming unit frequency was also reduced at higher heparin concentrations, particularly with LMWH, whereas no significant effect was observed on cellular morphology or immunophenotype. High concentrations of heparins reduced the in vitro differentiation toward adipogenic and osteogenic lineages. Heparin concentration is critical for culture of MSCs in hPL media; this is of particular relevance for cellular therapy where cell culture procedures need to be optimized and standardized. Copyright © 2013 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  5. Fragment-based quantum mechanical calculation of protein-protein binding affinities.

    Science.gov (United States)

    Wang, Yaqian; Liu, Jinfeng; Li, Jinjin; He, Xiao

    2018-04-29

    The electrostatically embedded generalized molecular fractionation with conjugate caps (EE-GMFCC) method has been successfully utilized for efficient linear-scaling quantum mechanical (QM) calculation of protein energies. In this work, we applied the EE-GMFCC method for calculation of binding affinity of Endonuclease colicin-immunity protein complex. The binding free energy changes between the wild-type and mutants of the complex calculated by EE-GMFCC are in good agreement with experimental results. The correlation coefficient (R) between the predicted binding energy changes and experimental values is 0.906 at the B3LYP/6-31G*-D level, based on the snapshot whose binding affinity is closest to the average result from the molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) calculation. The inclusion of the QM effects is important for accurate prediction of protein-protein binding affinities. Moreover, the self-consistent calculation of PB solvation energy is required for accurate calculations of protein-protein binding free energies. This study demonstrates that the EE-GMFCC method is capable of providing reliable prediction of relative binding affinities for protein-protein complexes. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  6. A unique bivalent binding and inhibition mechanism by the yatapoxvirus interleukin 18 binding protein.

    Directory of Open Access Journals (Sweden)

    Brian Krumm

    Full Text Available Interleukin 18 (IL18 is a cytokine that plays an important role in inflammation as well as host defense against microbes. Mammals encode a soluble inhibitor of IL18 termed IL18 binding protein (IL18BP that modulates IL18 activity through a negative feedback mechanism. Many poxviruses encode homologous IL18BPs, which contribute to virulence. Previous structural and functional studies on IL18 and IL18BPs revealed an essential binding hot spot involving a lysine on IL18 and two aromatic residues on IL18BPs. The aromatic residues are conserved among the very diverse mammalian and poxviruses IL18BPs with the notable exception of yatapoxvirus IL18BPs, which lack a critical phenylalanine residue. To understand the mechanism by which yatapoxvirus IL18BPs neutralize IL18, we solved the crystal structure of the Yaba-Like Disease Virus (YLDV IL18BP and IL18 complex at 1.75 Å resolution. YLDV-IL18BP forms a disulfide bonded homo-dimer engaging IL18 in a 2∶2 stoichiometry, in contrast to the 1∶1 complex of ectromelia virus (ECTV IL18BP and IL18. Disruption of the dimer interface resulted in a functional monomer, however with a 3-fold decrease in binding affinity. The overall architecture of the YLDV-IL18BP:IL18 complex is similar to that observed in the ECTV-IL18BP:IL18 complex, despite lacking the critical lysine-phenylalanine interaction. Through structural and mutagenesis studies, contact residues that are unique to the YLDV-IL18BP:IL18 binding interface were identified, including Q67, P116 of YLDV-IL18BP and Y1, S105 and D110 of IL18. Overall, our studies show that YLDV-IL18BP is unique among the diverse family of mammalian and poxvirus IL-18BPs in that it uses a bivalent binding mode and a unique set of interacting residues for binding IL18. However, despite this extensive divergence, YLDV-IL18BP binds to the same surface of IL18 used by other IL18BPs, suggesting that all IL18BPs use a conserved inhibitory mechanism by blocking a putative receptor-binding

  7. The effect of different forms of heparin on point-of-care blood gas ...

    African Journals Online (AJOL)

    and heparin vacutainers on blood gas and electrolyte analysis and ... This prospective, cross-sectional study took place in the ED of a ... the effect of two concentrations of liquid heparin and the use of heparin vacutainers on the reliability of blood gas ... Germany) and (iv) a 2 mL plastic syringe (BD) washed with 5 000 IU/.

  8. Prospective multicentre cohort study of heparin-induced thrombocytopenia in acute ischaemic stroke patients

    Science.gov (United States)

    Kawano, Hiroyuki; Yamamoto, Haruko; Miyata, Shigeki; Izumi, Manabu; Hirano, Teruyuki; Toratani, Naomi; Kakutani, Isami; Sheppard, Jo-Ann I; Warkentin, Theodore E; Kada, Akiko; Sato, Shoichiro; Okamoto, Sadahisa; Nagatsuka, Kazuyuki; Naritomi, Hiroaki; Toyoda, Kazunori; Uchino, Makoto; Minematsu, Kazuo

    2011-01-01

    Acute ischaemic stroke patients sometimes receive heparin for treatment and/or prophylaxis of thromboembolic complications. This study was designed to elucidate the incidence and clinical features of heparin-induced thrombocytopenia (HIT) in acute stroke patients treated with heparin. We conducted a prospective multicentre cohort study of 267 patients who were admitted to three stroke centres within 7 d after stroke onset. We examined clinical data until discharge and collected blood samples on days 1 and 14 of hospitalization to test anti-platelet factor 4/heparin antibodies (anti-PF4/H Abs) using an enzyme-linked immunosorbent assay (ELISA); platelet-activating antibodies were identified by serotonin-release assay (SRA). Patients with a 4Ts score ≥4 points, positive-ELISA, and positive-SRA were diagnosed as definite HIT. Heparin was administered to 172 patients (64·4%: heparin group). Anti-PF4/H Abs were detected by ELISA in 22 cases (12·8%) in the heparin group. Seven patients had 4Ts ≥ 4 points. Among them, three patients (1·7% overall) were also positive by both ELISA and SRA. National Institutes of Health Stroke Scale score on admission was high (range, 16–23) and in-hospital mortality was very high (66·7%) in definite HIT patients. In this study, the incidence of definite HIT in acute ischaemic stroke patients treated with heparin was 1·7% (95% confidence interval: 0·4–5·0). The clinical severity and outcome of definite HIT were unfavourable. PMID:21671895

  9. Nycthemeral variations of 99Tcsup(m)-labelled heparin pharmacokinetic parameters

    International Nuclear Information System (INIS)

    Decousus, M.; Gremillet, E.; Decousus, H.; Champailler, A.; Houzard, C.; Perpoint, B.; Jaubert, J.

    1985-01-01

    Six healthy volunteers received four i.v.boluses of 99 Tcsup(m)-heparin at 8.00, 14.00, 20.00 and 02.00 hours at seven-day intervals. Nine blood samples were taken covering a period of 2 h after administration. Simultaneously urine was collected and diuresis not noted. Plasma and urinary radioactivity were measured and standard pharmacokinetic parameters were calculated. Nycthemeral variations of these kinetic parameters were detected by means of distribution-free tests. Circadian rhythms were analysed by means of the cosinor method and the Gauss-Marquardt method. The mean raw value of the following parameters: apparent volume of distribution, plasmatic clearance and extra-renal metabolic clearance, increased significantly between 8.00 and 14.00 and decreased between 14.00 and 20.00. A circadian rhythm was found for the plasmatic clearance only. On the other hand the elimination half-lives and the renal clearance were unaffected by the time of the injections. These results obtained for low doses of 99 Tcsup(m)-heparin suggest a circadian rhythm of the bio-availability of heparin in man. This fact should be taken into account for the use of 99 Tcsup(m)-heparin in the diagnosis of deep-vein thrombosis and for the safe adjustment of the heparin dosages in the treatment of severe thromboembolism. (author)

  10. Highly sensitive ratiometric detection of heparin and its oversulfated chondroitin sulfate contaminant by fluorescent peptidyl probe.

    Science.gov (United States)

    Mehta, Pramod Kumar; Lee, Hyeri; Lee, Keun-Hyeung

    2017-05-15

    The selective and sensitive detection of heparin, an anticoagulant in clinics as well as its contaminant oversulfated chondroitin sulfate (OSCS) is of great importance. We first reported a ratiometric sensing method for heparin as well as OSCS contaminants in heparin using a fluorescent peptidyl probe (Pep1, pyrene-GSRKR) and heparin-digestive enzyme. Pep1 exhibited a highly sensitive ratiometric response to nanomolar concentration of heparin in aqueous solution over a wide pH range (2~11) and showed highly selective ratiometric response to heparin among biological competitors such as hyaluronic acid and chondroitin sulfate. Pep1 showed a linear ratiometric response to nanomolar concentrations of heparin in aqueous solutions and in human serum samples. The detection limit for heparin was calculated to be 2.46nM (R 2 =0.99) in aqueous solutions, 2.98nM (R 2 =0.98) in 1% serum samples, and 3.43nM (R 2 =0.99) in 5% serum samples. Pep1 was applied to detect the contaminated OSCS in heparin with heparinase I, II, and III, respectively. The ratiometric sensing method using Pep1 and heparinase II was highly sensitive, fast, and efficient for the detection of OSCS contaminant in heparin. Pep1 with heparinase II could detect as low as 0.0001% (w/w) of OSCS in heparin by a ratiometric response. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Heparin induced alterations in clearance and distribution of blood-borne microparticles following operative trauma.

    Science.gov (United States)

    Saba, T M; Antikatzides, T G

    1979-04-01

    The influence of systemic heparin administration on the vascular clearance and tissue distribution of blood-borne microparticles was evaluated in normal rats and rats after operation (laparotomy plus intestinal manipulation) utilizing an (131)I- colloid which is phagocytized by the reticuloendothelial system (RES). Intravenous heparin administration (100 USP/100g body weight) into normal animals three minutes prior to colloid injection (50 mg/lOOg) induced a significant increase in pulmonary localization of the microparticles as compared to nonheparinized control rats, while hepatic and splenic uptake were decreased. Surgical trauma decreased hepatic RE uptake and increased pulmonary localization of the microparticles when injected systemically at 60 minutes postsurgery. Heparin administration 60 minutes after surgery and three minutes prior to colloid injection, magnified the increased pulmonary localization response with an associated further depression of the RES. The ability of heparin to alter both RE clearance function and lung localization of microparticles was dose dependent and a function of the interval between heparin administration and systemic particulate infusion. Thus, low dose heparin administration was capable of stimulating RE activity while heparin in doses of excess of 50 USP units/lOOg body weight decreased RE function. These findings suggest that the functional state of the hepatic RE system can be greatly affected in a dose-dependent manner by systemic heparin administration which may influence distribution of blood-borne microparticles.

  12. Exploring the binding sites and binding mechanism for hydrotrope encapsulated griseofulvin drug on γ-tubulin protein.

    Directory of Open Access Journals (Sweden)

    Shubhadip Das

    Full Text Available The protein γ-tubulin plays an important role in centrosomal clustering and this makes it an attractive therapeutic target for treating cancers. Griseofulvin, an antifungal drug, has recently been used to inhibit proliferation of various types of cancer cells. It can also affect the microtubule dynamics by targeting the γ-tubulin protein. So far, the binding pockets of γ-tubulin protein are not properly identified and the exact mechanism by which the drug binds to it is an area of intense speculation and research. The aim of the present study is to investigate the binding mechanism and binding affinity of griseofulvin on γ-tubulin protein using classical molecular dynamics simulations. Since the drug griseofulvin is sparingly soluble in water, here we also present a promising approach for formulating and achieving delivery of hydrophobic griseofulvin drug via hydrotrope sodium cumene sulfonate (SCS cluster. We observe that the binding pockets of γ-tubulin protein are mainly formed by the H8, H9 helices and S7, S8, S14 strands and the hydrophobic interactions between the drug and γ-tubulin protein drive the binding process. The release of the drug griseofulvin from the SCS cluster is confirmed by the coordination number analysis. We also find hydrotrope-induced alteration of the binding sites of γ-tubulin protein and the weakening of the drug-protein interactions.

  13. 12500 E heparin and 12500 E of a semisynthetic heparin analogue (SSHA) in preventing thrombosis during radiotherapy of gynaecological carcinomas

    International Nuclear Information System (INIS)

    Hilscher, T.M.

    1983-01-01

    The effects of 12500 E calcium heparin given once daily were contrasted with those seen under daily treatment with 12500 E of a semisynthetic heparin analogue (SSHA) and evaluated using iodine-125-labelled fibrinogen. The study included 80 patients, who were randomly assigned to the two treatment groups on a 1:1 basis. The findings revealed here led to the conclusion that both drugs, administered once daily by the subcutaneous route, were effective in preventing the occurrence of thrombosis during radiation treatment of gynaecological tumours. (orig./MG) [de

  14. Cationization of heparin for film applications

    Czech Academy of Sciences Publication Activity Database

    Šimkovic, I.; Mendichi, R.; Kelnar, Ivan; Filip, J.; Hricovíni, M.

    2015-01-01

    Roč. 115, 22 January (2015), s. 551-558 ISSN 0144-8617 Institutional support: RVO:61389013 Keywords : heparin * cationization * NMR Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.219, year: 2015

  15. SPECIFIC ASPECTS OF INTERACTION OF PLATELETS WITH THE HEPARINIZED MATERIALS

    Directory of Open Access Journals (Sweden)

    E.A. Nemets

    2012-01-01

    Full Text Available Comparative analysis of anticoagulant nature on medical materials testing was done. It was found that change of citrate by heparin is accompanied by significant changes in platelet adhesion and activation. This results allowed us to arrive at a conclusion about reasonability of heparin usage as anticoagulant in in vitro testing. 

  16. Safety of low-molecular-weight heparin in pregnancy: a systematic review

    NARCIS (Netherlands)

    Sanson, B. J.; Lensing, A. W.; Prins, M. H.; Ginsberg, J. S.; Barkagan, Z. S.; Lavenne-Pardonge, E.; Brenner, B.; Dulitzky, M.; Nielsen, J. D.; Boda, Z.; Turi, S.; Mac Gillavry, M. R.; Hamulyák, K.; Theunissen, I. M.; Hunt, B. J.; Büller, H. R.

    1999-01-01

    Unfractionated heparin (UFH) remains the anticoagulant of choice during pregnancy. Low-molecular-weight heparins (LMWH) are an attractive alternative to UFH due to their logistic advantages and their association with a lower incidence of osteoporosis and HIT. We reviewed all published clinical

  17. Qualitative and Quantitative Analysis of Heparin during Precipitation by Near-Infrared Spectroscopy

    OpenAIRE

    Lian Li; Jinfeng Wang; Hengchang Zang; Hui Zhang; Wei Jiang; Shang Chen; Fengshan Wang

    2016-01-01

    Heparin is a glycosaminoglycan (GAG) that plays an important role in the blood coagulation system. Its quality is of great importance, so it is necessary to develop a fast analytical method during the manufacture process to analyse the quality of heparin produced. In this study, the heparin contents of 80 samples collected from five batches during the precipitation process were analysed using nearinfrared (NIR) spectroscopy and a chemometrics approach. This was done in order to improve the ef...

  18. Rat embryo fibroblasts require both the cell-binding and the heparin-binding domains of fibronectin for survival

    DEFF Research Database (Denmark)

    Jeong, J; Han, I; Lim, Y

    2001-01-01

    of the cell-binding domain of FN with integrin is sufficient to rescue rat embryo fibroblasts (REFs) from detachment-induced apoptosis. REFs attached and spread normally after plating on substrates coated with either intact FN or a FN fragment, FN120, that contains the cell-binding domain but lacks the C...

  19. Extracellular matrix inspired surface functionalization with heparin, fibronectin and VEGF provides an anticoagulant and endothelialization supporting microenvironment

    International Nuclear Information System (INIS)

    Wang, Xue; Liu, Tao; Chen, Yuan; Zhang, Kun; Maitz, Manfred F.; Pan, Changjiang; Chen, Junying; Huang, Nan

    2014-01-01

    Highlights: • Surface modification with fibronectin, heparin and VEGF could selectively anticoagulant and promote endothelialization. • The bioactivity of biomolecules was more efficiently maintained via specific intermolecular interaction. • Poly-l-lysine interlayer was more feasible and the degradation product had no harm to human body. - Abstract: The biocompatibility of currently used coronary artery stent is still far from perfect, which closely related to insufficient endothelialization and thrombus formation. In this study, heparin, fibronectin and VEGF were immobilized on Ti surface to construct a multifunctional microenvironment with favorable properties to inhibit thrombosis formation and promote endothelialization simultaneously. The microenvironment on Ti surface was characterized in detail and demonstrated that the Hep/Fn/VEGF biofunctional coating was constructed successfully on Ti surface. The influence of surface properties such as chemical composition, roughness, hydrophilicity, and binding density of biomolecules on the performances of hemocompatibility and cytocompatibility was evaluated and discussed. Modified surface significantly enhanced the AT III binding density and prolonged the clotting time. In vitro platelet adhesion and activation assays further proved that the modified surface presented favorable anti-coagulant property. In addition, the proliferation of endothelial progenitor cells (EPCs) and endothelial cells (ECs) on the Hep/Fn/VEGF biofunctional coating was significantly promoted. In conclusion, the Hep/Fn/VEGF biofunctional coating was successfully constructed with desirable anticoagulant and endothelialization supporting properties. This work may provide a promising approach for biofunctional surface modification of coronary artery stent to acquire a desired multifunctional microenvironment

  20. Update on the clinical use of the low-molecular-weight heparin, parnaparin

    Directory of Open Access Journals (Sweden)

    Giuseppe Camporese

    2009-09-01

    Full Text Available Giuseppe Camporese1, Enrico Bernardi2, Franco Noventa31Unit of Angiology and 3Department of Clinical and Experimental Medicine, Clinical Epidemiology Group, University Hospital of Padua, Italy; 2Department of Emergency and Accident Medicine, Hospital of Conegliano Veneto, ItalyAbstract: Parnaparin is a low-molecular-weight heparin that has widely shown its efficacy and safety in prevention of venous thromboembolism, in the treatment of chronic venous disorders, and in the treatment of venous and arterial (stable and unstable angina, acute ST-segment elevation myocardial infarction thrombosis. Parnaparin at the respective dosages of 3200, 4250, 6400, or 12800 IUaXa for a period ranging from 3 to 5 days to 6 months, is usually administered subcutaneously by means of once-daily regimen and is better tolerated than unfractionated heparin at the injection site. In the variety of commercially available low-molecular-weight heparins, parnaparin represents a useful therapeutic option, even though little evidence is available comparing the superiority or the equivalent efficacy and safety of parnaparin to that of the unfractionated heparin or placebo. This review summarizes the available literature on the use of parnaparin in different settings of cardiovascular diseases, including papers published during the past year and ongoing studies.Keywords: low-molecular-weight heparin, heparin, parnaparin, acute coronary syndromes, venous thromboembolism

  1. Covalently bound conjugates of albumin and heparin: Synthesis, fractionation and characterization

    NARCIS (Netherlands)

    Hennink, Wim E.; Feijen, Jan; Ebert, Charles D.; Kim, Sung Wan

    1983-01-01

    Covalently bound conjugates of human serum albumin and heparin were prepared as compounds which could improve the blood-compatibility of polymer surfaces either by preadsorption or by covalent coupling of the conjugates onto blood contacting surfaces. The conjugates (10–16 weight % of heparin) were

  2. Characterization of currently marketed heparin products: key tests for quality assurance.

    Science.gov (United States)

    Keire, David A; Ye, Hongping; Trehy, Michael L; Ye, Wei; Kolinski, Richard E; Westenberger, Benjamin J; Buhse, Lucinda F; Nasr, Moheb; Al-Hakim, Ali

    2011-01-01

    During the 2007-2008 heparin crisis, it was found that the United States Pharmacopeia (USP) testing monograph for unfractionated heparin sodium (UFH) did not detect the presence of the contaminant, oversulfated chondroitin sulfate (OSCS) in heparin. In response to this concern, new tests and specifications were developed by the Food and Drug Administration (FDA) and USP and put in place to not only detect the contaminant OSCS but also to improve assurance of quality and purity of the drug product. Additional tests were also developed to monitor the heparin supply chain for other possible economically motivated additives or impurities. In 2009, a new USP monograph was put in place that includes 500 MHz (1)H NMR, SAX-HPLC, %galactosamine in total hexosamine, and anticoagulation time assays with purified factor IIa or factor Xa. These tests represent orthogonal approaches for UFH identification, measurement of bioactivity, and for detection of process impurities or contaminants in UFH. The FDA has applied these analytical approaches to the study of UFH active pharmaceutical ingredients in the marketplace. Here, we describe results from a comprehensive survey of UFH collected from seven different sources after the 2009 monograph revision and compare these data with results obtained on other heparin samples collected during the 2007-2008 crisis.

  3. How Glycosaminoglycans Promote Fibrillation of Salmon Calcitonin*

    Science.gov (United States)

    Malmos, Kirsten Gade; Bjerring, Morten; Jessen, Christian Moestrup; Nielsen, Erik Holm Toustrup; Poulsen, Ebbe T.; Christiansen, Gunna; Vosegaard, Thomas; Skrydstrup, Troels; Enghild, Jan J.; Pedersen, Jan Skov; Otzen, Daniel E.

    2016-01-01

    Glycosaminoglycans (GAGs) bind all known amyloid plaques and help store protein hormones in (acidic) granular vesicles, but the molecular mechanisms underlying these important effects are unclear. Here we investigate GAG interactions with the peptide hormone salmon calcitonin (sCT). GAGs induce fast sCT fibrillation at acidic pH and only bind monomeric sCT at acidic pH, inducing sCT helicity. Increasing GAG sulfation expands the pH range for binding. Heparin, the most highly sulfated GAG, binds sCT in the pH interval 3–7. Small angle x-ray scattering indicates that sCT monomers densely decorate and pack single heparin chains, possibly via hydrophobic patches on helical sCT. sCT fibrillates without GAGs, but heparin binding accelerates the process by decreasing the otherwise long fibrillation lag times at low pH and accelerates fibril growth rates at neutral pH. sCT·heparin complexes form β-sheet-rich heparin-covered fibrils. Solid-state NMR reveals that heparin does not alter the sCT fibrillary core around Lys11 but makes changes to Val8 on the exterior side of the β-strand, possibly through contacts to Lys18. Thus GAGs significantly modulate sCT fibrillation in a pH-dependent manner by interacting with both monomeric and aggregated sCT. PMID:27281819

  4. Morbidity associated with heparin therapy in spinal surgery patients with cardiovascular diseases

    International Nuclear Information System (INIS)

    Sawakami, Kimihiko; Ishikawa, Seiichi; Ito, Takui

    2011-01-01

    The objectives of this study were to investigate morbidity associated with heparin therapy in spinal surgery patients. The management of patients on anticoagulant therapy who undergo spinal surgery is becoming a common clinical problem. Although guidelines for the management of gastrointestinal endoscopy patients on heparin therapy have been published, spinal surgery may lead to specific complications, especially because of heparin therapy. However, only few studies have examined the clinical significance of heparin therapy in spinal surgery patients. The subjects of this study were 116 consecutive patients who were on anticoagulant or antiplatelet therapy. This says that all of the patients were receiving heparin or another anticoagunt. The patients were divided into 2 groups: a group that received heparin therapy before and after surgery (H group, n=25) and a group that did not receive heparin therapy (NH group, n=91). The results of clinical examinations and magnetic resonance imaging (MRI) in the 2 groups were compared. There were no significant differences between the 2 groups in baseline data. Comorbidities in both groups included valvular heart disease, atrial fibrillation, angina pectoris/myocardial infarction, and cerebral infarction. Mean intraoperative and postoperative blood loss in the H group were 324 ml and 536 ml, respectively, and the corresponding values in the NH group were 431 ml and 449 ml, respectively. MRI of all patients was performed within 10 days after surgery and T2-weighted images in the axial plane were examined for evidence of an epidural hematoma. Although the proportion of patients with an epidural hematoma, detected by MRI was higher in the H group than in the NH group (71% vs. 64%), none of the patients in either group required revision surgery because of intolerable pain or muscle weakness. Thrombocytopenia and skin necrosis were observed as complications of the heparin therapy in 1 patient in the H group (4%). The rate of

  5. How much heparin do we really need to go on pump? A rethink of current practices.

    LENUS (Irish Health Repository)

    Shuhaibar, M N

    2012-02-03

    OBJECTIVES: Patients undergoing myocardial revascularisation using extracorporeal circulation require heparin anticoagulation. We aimed to evaluate the effect of reducing heparin dosage on target activated clotting time (ACT) and postoperative blood loss. METHODS: In a prospective randomised trial, 195 patients undergoing isolated primary CABG were randomised into four groups A, B, C, and D receiving an initial heparin dosage of 100, 200, 250 and 300 iu\\/kg, respectively. Extra incremental heparin (50 iu\\/kg) was added if required to achieve a target ACT of 480 s before initiating cardiopulmonary bypass. Postoperative blood loss was measured from the time of heparin reversal to drain removal 24h later. RESULTS: Target ACT was achieved in 0, 63, 68.3 and 82.4% of patients in groups A, B, C and D, respectively, after the initial dose of heparin. In group B, of those not achieving target act a single increment of heparin was sufficient to achieve target ACT in further 18.6%. The mean ACT after the initial dose in groups B, C and D was 482.9, 519 and 588 s, respectively (P<0.05). Postoperative blood loss in millilitre per kilogram was directly proportional to preoperative heparin dose. CONCLUSIONS: Patients receiving lower dose of heparin has lower postoperative blood loss. Of those achieving the target ACT, group B was significantly the closest to the target ACT. A starting dose of 200 iu\\/kg of heparin and if necessary one 50 iu\\/kg increment achieved target ACT in 81.5% of patients. The added benefit of significant drop in postoperative blood loss is evident.

  6. Heparin-Induced Cardiac Tamponade and Life-Threatening Hyperkalemia in a Patient with Chronic Hemodialysis

    Directory of Open Access Journals (Sweden)

    Ho-Ming Su

    2005-03-01

    Full Text Available Heparin, a commonly used anticoagulant agent, is frequently used in patients undergoing hemodialysis. As with most medications, heparin has a significant side effect profile. Two of its most important side effects, major bleeding and hyperkalemia, may be devastating without immediate diagnosis and treatment. Major bleeding such as gastrointestinal, genitourinary or intracranial bleeding is occasionally encountered and rarely neglected. However, heparin-induced cardiac tamponade is rarely encountered and may be easily overlooked. Another side effect, heparin-induced hyperkalemia, an unusual but well-described side effect, is frequently forgotten until life-threatening arrhythmia has occurred. We report a case involving a 40-year-old male patient with uremia, who had received heparin for 10 days for deep vein thrombosis in the left lower extremity. Hemopericardium with cardiac tamponade and life-threatening hyperkalemia were both noted in this patient.

  7. Heparinization of alimentation solutions administered through peripheral veins in premature infants: a controlled study.

    Science.gov (United States)

    Alpan, G; Eyal, F; Springer, C; Glick, B; Goder, K; Armon, J

    1984-09-01

    A randomized controlled study was done to determine whether the addition of heparin (1 U/mL) to peripheral intravenous alimentation solutions would affect the incidence of phlebitis and duration of patency of intravenous catheters in premature infants. Twenty-two-gauge Teflon catheters were uniformly used. One hundred five catheters infused with heparin were placed in 13 infants, and 122 catheters were placed in the control group of 13 infants. The time, nature, and incidence of complications were noted for each infusion site. Infusion of heparin was found to double the duration of patency of intravenous catheters and to reduce significantly the incidence of phlebitis. No complications related to the administration of heparin were noted. Heparinization of intravenous alimentation solutions should therefore be considered in premature infants as a means of reducing the work load and incidence of complications associated with peripheral lines.

  8. Effects of heparin on platelet aggregation and release and thromboxane A2 production

    International Nuclear Information System (INIS)

    Mohammad, S.F.; Anderson, W.H.; Smith, J.B.; Chuang, H.Y.; Mason, R.G.

    1981-01-01

    Heparin, when added to citrated platelet-rich plasma (PRP), caused potentiation of platelet aggregation and the release reaction induced by the aggregating agents adenosine diphosphate (ADP), arachidonic acid, collagen, and epinephrine. At low concentrations (4.7 x 10(-5) M) arachidonic acid failed to cause aggregation of platelets in citrated PRP. However, in the presence of heparin, the same concentration of arachidonic acid caused aggregation. Examination of PRP for the presence of thromboxane A2 (TxA2) by use of a bioassay revealed that heparin also stimulated release of TxA2. This finding indicated that platelets released more TxA2 when they were challenged by low concentrations of arachidonic acid in the presence of heparin than in its absence. Platelets were labeled with 3 H-arachidonic acid and 14 C-serotonin, and attempts were made to determine whether heparin stimulated the platelet release reaction first with subsequent increased production of TxA2, or alternatively, whether heparin stimulated TxA2 production first with subsequent enhancement of the release reaction. In view of the demonstrated simultaneous release of 14 C-serotonin and 3 H-arachidonic acid metabolites, it appeared that either release of 14 C and 3 H occurs concurrently or, even if one of these events is dependent on the other, both events take place in rapid succession. Timed sequential studies revealed that in the presence of arachidonic acid, the addition of heparin hastened the apparently simultaneous release of both 14 C and 3 H

  9. Increased accuracy in heparin and protamine administration decreases bleeding: a pilot study

    DEFF Research Database (Denmark)

    Runge, Marx; Møller, Christian H; Steinbrüchel, Daniel A

    2009-01-01

    Three to 5 percent of the patients undergoing cardiac surgery are reoperated because of bleeding. When a surgical cause can be excluded, heparin/protamine mismatch may be considered. Insufficient reversal of heparin and overdosing of protamine may cause postoperative bleeding. The purpose......). A reduced number of patients needed blood transfusions in the RxDx group, although this was not statistically significant (19% vs. 38%, respectively; p = .13). Initial heparin dose was significantly reduced in the RxDx group (250 mg; range, 100-375 mg) compared with the control group (300 mg; range, 200...

  10. Prevention of adverse events of interferon γ gene therapy by gene delivery of interferon γ-heparin-binding domain fusion protein in mice

    Directory of Open Access Journals (Sweden)

    Mitsuru Ando

    2014-01-01

    Full Text Available Sustained gene delivery of interferon (IFN γ can be an effective treatment, but our previous study showed high levels of IFNγ-induced adverse events, including the loss of body weight. These unwanted events could be reduced by target-specific delivery of IFNγ after in vivo gene transfer. To achieve this, we selected the heparin-binding domain (HBD of extracellular superoxide dismutase as a molecule to anchor IFNγ to the cell surface. We designed three IFNγ derivatives, IFNγ-HBD1, IFNγ-HBD2, and IFNγ-HBD3, each of which had 1, 2, or 3 HBDs, respectively. Each plasmid-encoding fusion proteins was delivered to the liver, a model target in this study, by hydrodynamic tail vein injection. The serum concentration of IFNγ-HBD2 and IFNγ-HBD3 after gene delivery was lower than that of IFNγ or IFNγ-HBD1. Gene delivery of IFNγ-HBD2, but not of IFNγ-HBD3, effectively increased the mRNA expression of IFNγ-inducible genes in the liver, suggesting liver-specific distribution of IFNγ-HBD2. Gene delivery of IFNγ-HBD2-suppressed tumor growth in the liver as efficiently as that of IFNγ with much less symptoms of adverse effects. These results indicate that the adverse events of IFNγ gene transfer can be prevented by gene delivery of IFNγ-HBD2, a fusion protein with high cell surface affinity.

  11. Elimination of heparin interference during microarray processing of fresh and biobank-archived blood samples.

    Science.gov (United States)

    Hebels, Dennie G A J; van Herwijnen, Marcel H M; Brauers, Karen J J; de Kok, Theo M C M; Chalkiadaki, Georgia; Kyrtopoulos, Soterios A; Kleinjans, Jos C S

    2014-07-01

    In the context of environmental health research, biobank blood samples have recently been identified as suitable for high-throughput omics analyses enabling the identification of new biomarkers of exposure and disease. However, blood samples containing the anti-coagulant heparin could complicate transcriptomic analysis because heparin may inhibit RNA polymerase causing inefficient cRNA synthesis and fluorophore labelling. We investigated the inhibitory effect of heparin and the influence of storage conditions (0 or 3 hr bench times, storage at room temperature or -80°C) on fluorophore labelling in heparinized fresh human buffy coat and whole blood biobank samples during the mRNA work-up protocol for microarray analysis. Subsequently, we removed heparin by lithium chloride (LiCl) treatment and performed a quality control analysis of LiCl-treated biobank sample microarrays to prove their suitability for downstream data analysis. Both fresh and biobank samples experienced varying degrees of heparin-induced inhibition of fluorophore labelling, making most samples unusable for microarray analysis. RNA derived from EDTA and citrate blood was not inhibited. No effect of bench time was observed but room temperature storage gave slightly better results. Strong correlations were observed between original blood sample RNA yield and the amount of synthesized cRNA. LiCl treatment restored sample quality to normal standards in both fresh and biobank samples and the previously identified correlations disappeared. Microarrays hybridized with LiCl-treated biobank samples were of excellent quality with no identifiable influence of heparin. We conclude that, to obtain high quality results, in most cases heparin removal is essential in blood-derived RNA samples intended for microarray analysis. Copyright © 2014 Wiley Periodicals, Inc.

  12. Conditional loss of heparin-binding EGF-like growth factor results in enhanced liver fibrosis after bile duct ligation in mice

    Energy Technology Data Exchange (ETDEWEB)

    Takemura, Takayo; Yoshida, Yuichi [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan); Kiso, Shinichi, E-mail: kiso@gh.med.osaka-u.ac.jp [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan); Kizu, Takashi; Furuta, Kunimaro; Ezaki, Hisao; Hamano, Mina; Egawa, Mayumi; Chatani, Norihiro; Kamada, Yoshihiro [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan); Imai, Yasuharu [Department of Gastroenterology, Ikeda Municipal Hospital, Ikeda, Osaka (Japan); Higashiyama, Shigeki [Department of Biochemistry and Molecular Genetics, Ehime University, Graduate School of Medicine and Department of Cell Growth and Tumor Regulation, Proteo-Medicine Research Center (ProMRes), Ehime University, Shitsukawa, Toon, Ehime (Japan); Iwamoto, Ryo; Mekada, Eisuke [Department of Cell Biology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka (Japan); Takehara, Tetsuo [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan)

    2013-07-26

    Highlights: •HB-EGF expression was increased during the development of liver fibrosis. •Conditional HB-EGF knockout mouse showed enhanced experimental liver fibrosis. •HB-EGF antagonized TGF-β-induced activation of hepatic stellate cells. •We report a possible protective role of HB-EGF in cholestatic liver fibrosis. -- Abstract: Our aims were to evaluate the involvement of heparin-binding EGF-like growth factor (HB-EGF) in liver fibrogenesis of humans and mice and to elucidate the effect of HB-EGF deficiency on cholestatic liver fibrosis using conditional HB-EGF knockout (KO) mice. We first demonstrated that gene expression of HB-EGF had a positive significant correlation with that of collagen in human fibrotic livers, and was increased in bile duct ligation (BDL)-induced fibrotic livers in mouse. We then generated conditional HB-EGF knockout (KO) mice using the interferon inducible Mx-1 promoter driven Cre recombinase transgene and wild type (WT) and KO mice were subjected to BDL. After BDL, KO mice exhibited enhanced liver fibrosis with increased expression of collagen, compared with WT mice. Finally, we used mouse hepatic stellate cells (HSCs) to examine the role of HB-EGF in the activation of these cells and showed that HB-EGF antagonized TGF-β-induced gene expression of collagen in mouse primary HSCs. Interestingly, HB-EGF did not prevent the TGF-β-induced nuclear accumulation of Smad3, but did lead to stabilization of the Smad transcriptional co-repressor TG-interacting factor. In conclusion, our data suggest a possible protective role of HB-EGF in cholestatic liver fibrosis.

  13. Conditional loss of heparin-binding EGF-like growth factor results in enhanced liver fibrosis after bile duct ligation in mice

    International Nuclear Information System (INIS)

    Takemura, Takayo; Yoshida, Yuichi; Kiso, Shinichi; Kizu, Takashi; Furuta, Kunimaro; Ezaki, Hisao; Hamano, Mina; Egawa, Mayumi; Chatani, Norihiro; Kamada, Yoshihiro; Imai, Yasuharu; Higashiyama, Shigeki; Iwamoto, Ryo; Mekada, Eisuke; Takehara, Tetsuo

    2013-01-01

    Highlights: •HB-EGF expression was increased during the development of liver fibrosis. •Conditional HB-EGF knockout mouse showed enhanced experimental liver fibrosis. •HB-EGF antagonized TGF-β-induced activation of hepatic stellate cells. •We report a possible protective role of HB-EGF in cholestatic liver fibrosis. -- Abstract: Our aims were to evaluate the involvement of heparin-binding EGF-like growth factor (HB-EGF) in liver fibrogenesis of humans and mice and to elucidate the effect of HB-EGF deficiency on cholestatic liver fibrosis using conditional HB-EGF knockout (KO) mice. We first demonstrated that gene expression of HB-EGF had a positive significant correlation with that of collagen in human fibrotic livers, and was increased in bile duct ligation (BDL)-induced fibrotic livers in mouse. We then generated conditional HB-EGF knockout (KO) mice using the interferon inducible Mx-1 promoter driven Cre recombinase transgene and wild type (WT) and KO mice were subjected to BDL. After BDL, KO mice exhibited enhanced liver fibrosis with increased expression of collagen, compared with WT mice. Finally, we used mouse hepatic stellate cells (HSCs) to examine the role of HB-EGF in the activation of these cells and showed that HB-EGF antagonized TGF-β-induced gene expression of collagen in mouse primary HSCs. Interestingly, HB-EGF did not prevent the TGF-β-induced nuclear accumulation of Smad3, but did lead to stabilization of the Smad transcriptional co-repressor TG-interacting factor. In conclusion, our data suggest a possible protective role of HB-EGF in cholestatic liver fibrosis

  14. Laboratory tests for identification or exclusion of heparin induced thrombocytopenia: HIT or miss?

    Science.gov (United States)

    Favaloro, Emmanuel J

    2018-02-01

    Heparin induced thrombocytopenia (HIT) is a potentially fatal condition that arises subsequent to formation of antibodies against complexes containing heparin, usually platelet-factor 4-heparin ("anti-PF4-heparin"). Assessment for HIT involves both clinical evaluation and, if indicated, laboratory testing for confirmation or exclusion, typically using an initial immunological assay ("screening"), and only if positive, a secondary functional assay for confirmation. Many different immunological and functional assays have been developed. The most common contemporary immunological assays comprise enzyme-linked immunosorbent assay [ELISA], chemiluminescence, lateral flow, and particle gel techniques. The most common functional assays measure platelet aggregation or platelet activation events (e.g., serotonin release assay; heparin-induced platelet activation (HIPA); flow cytometry). All assays have some sensitivity and specificity to HIT antibodies, but differ in terms of relative sensitivity and specificity for pathological HIT, as well as false negative and false positive error rate. This brief article overviews the different available laboratory methods, as well as providing a suggested approach to diagnosis or exclusion of HIT. © 2017 Wiley Periodicals, Inc.

  15. Heparin-Induced Thrombocytopenia in a Patient with Essential Thrombocythemia: A Case Based Update

    Directory of Open Access Journals (Sweden)

    Edva Noel

    2015-01-01

    Full Text Available Vascular thrombosis is a common clinical feature of both essential thrombocythemia (ET and heparin-induced thrombocytopenia (HIT. The development of HIT in a patient with ET is rare and underrecognized. We report the case of a 77-year-old woman with preexisting ET, who was admitted with acute coronary syndrome, and IV heparin was started. She was exposed to unfractionated heparin (UFH 5 days prior to this admission. Decrease in platelet count was noted, and HIT panel was sent. Heparin was discontinued. Patient developed atrial fibrillation, and Dabigatran was started. On day three, patient also developed multiple tiny cerebral infarctions and acute right popliteal DVT. On day ten of admission, HIT panel was positive, and Dabigatran was changed to Lepirudin. Two days later, Lepirudin was also discontinued because patient developed pseudoaneurysm on the right common femoral artery at the site of cardiac catheterization access. A progressive increase in the platelet count was noted after discontinuing heparin. Physicians should be aware of the coexistence of HIT and ET, accompanied challenges of the prompt diagnosis, and initiation of appropriate treatment.

  16. Covalent co-immobilization of heparin/laminin complex that with different concentration ratio on titanium surface for selectively direction of platelets and vascular cells behavior

    International Nuclear Information System (INIS)

    Wang, Jian; Chen, Yuan; Liu, Tao; Wang, Xue; Liu, Yang; Wang, Yuan; Chen, Junying; Huang, Nan

    2014-01-01

    Highlights: • Extracellular matrix inspired surface modification with fibronectin, heparin and VEGF to construct a favorable microenvironment for selectively anticoagulant and promote endothelialization. • Take the advantage of specific intermolecular interaction, the bioactivity of above biomolecules was more efficiently maintained in compared with the common used covalent immobilization method. • Poly-l-lysine was used as a novel interlayer for surface amination, and in comparison, PLL coating was more feasible and the degradation product had no harm to human body. - Abstract: Surface biofunctional modification of coronary artery stent to improve the hemocompatibility and selectively accelerate endothelium regeneration but prevent restenosis have been become a new hotspot. For this, a novel method was developed in this work by co-immobilization of Ln and heparin complex on poly-L-lysine modified Ti surface. Take the advantage of the specific interaction between Ln and heparin, Ln and heparin complexes with different concentration ratios were set up for creating different exposure density of these two types of biomolecules. According to biocompatibility evaluation results, the Hep/Ln complexes modified surface displayed less platelet adhesion and activation. Especially, on L(150)H and L(200)H surface, the AT III binding quantity, APTT value and anti-coagulation property of modified surface were significantly promoted. Furthermore, the adherent density and proliferation activity of ECs and EPCs were positively correlated with Ln concentration. Notably, the proliferation of both ECs and EPCs on L(100)H, L(150)H and L(200)H surface were greatly promoted. Another hand, the proliferation activity of SMCs was significantly inhibited on Hep/Ln modified surfaces, which was considered mainly due to the inhibitory effect of heparin to SMCs. According to the existing results, this study demonstrated that in a certain range of heparin and laminin concentration ratio

  17. Heparin interferes with the radioenzymatic and homogeneous enzyme immunoassays for aminoglycosides

    International Nuclear Information System (INIS)

    Krogstad, D.J.; Granich, G.G.; Murray, P.R.; Pfaller, M.A.; Valdes, R.

    1981-01-01

    Heparin interferes with measurement of aminoglycosides in serum by biological, radioenzymatic, and homogeneous enzyme immunoassay techniques, but not with radioimmunoassay. At concentrations greater than or equal to 10 5 and greater than or equal to 3 X 10 6 USP units/L, respectively, it interferes with the radioenzymatic assay by inhibiting the gentamicin 3-acetyltransferase and kanamycin 6'-acetyltransferase enzymes used in the assay. It interferes with the homogeneous enzyme immunoassays for gentamicin and tobramycin (at concentrations greater than or equal to 10 5 and greater than or equal to10 4 USP units/L, respectively), but not with the commercially available homogeneous enzyme immunoassays for other drugs. Heparin interference with the homogeneous enzyme immunoassay for aminoglycosides requires both the heparin polyanion and glucose-6-phosphate dehydrogenase bound to a cationic aminoglycoside. This interference can be reproduced with dextran sulfate (but not dextran), and does not occur with free enzyme (glucose-6-phosphate dehydrogenase) alone. Heparin interference with these two assays and at concentrations that may be present in intravenous infusions or in seriously underfilled blood-collection tubes is described

  18. Prevention of equine herpesvirus myeloencephalopathy - Is heparin a novel option? A case report.

    Science.gov (United States)

    Walter, Jasmin; Seeh, Christoph; Fey, Kerstin; Bleul, Ulrich; Osterrieder, Nikolaus

    2016-10-12

    Equine herpesvirus myeloencephalopathy (EHM) is a severe manifestation of equine herpesvirus 1 (EHV-1) infection. Prevention and treatment of EHM during EHV-1 outbreaks is critical, but no reliable and tested specific medication is available. Due to the thromboischemic nature of EHM and due to the fact that EHV-1 entry in cells is blocked by heparin, it was hypothesized that this compound may be useful in reduction of EHM incidence and severity. Therefore, during an acute EHV-1 outbreak with the neuropathogenic G 2254 /D 752 Pol variant, metaphylactic treatment with heparin to prevent EHM was initiated. Clinical signs were present in 61 horses (fever n = 55; EHM n = 8; abortion n = 6). Heparin (25000 IU subcutaneously twice daily for 3 days) was given to 31 febrile horses from day 10 of the outbreak, while the first 30 horses exhibiting fever remained untreated. Treatment outcome was analyzed retrospectively. Heparin-treated horses showed a lower EHM incidence (1/31; 3.2%) than untreated horses (7/30; 23.3%; p = 0.03). Results indicate that heparin may be useful for prevention of EHM during an EHV-1 outbreak. These promising data highlight the need for randomized and possibly blinded studies for the use of heparin in EHV-1 outbreaks.

  19. Preparation of Low Molecular Weight Heparin by Microwave Discharge Electrodeless Lamp/TiO2 Photo-Catalytic Reaction.

    Science.gov (United States)

    Lee, Do-Jin; Kim, Byung Hoon; Kim, Sun-Jae; Kim, Jung-Sik; Lee, Heon; Jung, Sang-Chul

    2015-01-01

    An MDEL/TiO2 photo-catalyst hybrid system was applied, for the first time, for the production of low molecular weight heparin. The molecular weight of produed heparin decreased with increasing microwave intensity and treatment time. The abscission of the chemical bonds between the constituents of heparin by photo-catalytic reaction did not alter the characteristics of heparin. Formation of by-products due to side reaction was not observed. It is suggested that heparin was depolymerized by active oxygen radicals produced during the MDEL/TiO2 photo-chemical reaction.

  20. Cost-utility of enoxaparin compared with unfractionated heparin in unstable coronary artery disease

    Directory of Open Access Journals (Sweden)

    Milne Ruairidh

    2001-10-01

    Full Text Available Abstract Background Low molecular weight heparins hold several advantages over unfractionated heparin including convenience of administration. Enoxaparin is one such heparin licensed in the UK for use in unstable coronary artery disease (unstable stable angina and non-Q wave myocardial infarction. In these patients, two large randomised controlled trials and their meta-analysis showed small benefits for enoxaparin over unfractionated heparin at 30–43 days and potentially at one year. We found no relevant published full economic evaluations, only cost studies, one of which was conducted in the UK. The other studies, from the US, Canada and France, are difficult to interpret since their resource use and costs may not reflect UK practice. Methods We aimed to compare the benefits and costs of short-term treatment (two to eight days with enoxaparin and unfractionated heparin in unstable coronary artery disease. We used published data sources to estimate the incremental cost per quality adjusted life year (QALY, adopting a NHS perspective and using 1998 prices. Results The base case was a 0.013 QALY gain and net cost saving of £317 per person treated with enoxaparin instead of unfractionated heparin. All but one sensitivity analysis showed net savings and QALY gains, the exception (the worst case being a cost per QALY of £3,305. Best cases were a £495 saving and 0.013 QALY gain, or a £317 saving and 0.014 QALY gain per person. Conclusions Enoxaparin appears cost saving compared with unfractionated heparin in patients with unstable coronary artery disease. However, cost implications depend on local revascularisation practice.

  1. Heparan sulfate C5-epimerase is essential for heparin biosynthesis in mast cells.

    Science.gov (United States)

    Feyerabend, Thorsten B; Li, Jin-Ping; Lindahl, Ulf; Rodewald, Hans-Reimer

    2006-04-01

    Biosynthesis of heparin, a mast cell-derived glycosaminoglycan with widespread importance in medicine, has not been fully elucidated. In biosynthesis of heparan sulfate (HS), a structurally related polysaccharide, HS glucuronyl C5-epimerase (Hsepi) converts D-glucuronic acid (GlcA) to L-iduronic acid (IdoA) residues. We have generated Hsepi-null mouse mutant mast cells, and we show that the same enzyme catalyzes the generation of IdoA in heparin and that 'heparin' lacking IdoA shows a distorted O-sulfation pattern.

  2. Heparin-induced increase in serum levels of aminotranferases. A controlled clinical trial.

    Science.gov (United States)

    Nielsen, H K; Husted, S E; Koopmann, H D; Fasting, H; Simonsen, O; Andersen, K; Husegaard, H C; Petersen, T K

    1984-01-01

    Sixty-four patients over the age of 40 years, undergoing elective surgery of at least one hour's duration, were randomized to treatment with either a thromboembolic deterrent ( TED ) stocking (Kendall Co.) or subcutaneous low-dose heparin 5 000 IU every 12 hours. Serum levels of alanine aminotransferase (S-ALAT), aspartate aminotransferase (S-ASAT), gamma-glutamyl transpeptidase (S-gamma-GT) and alkaline phosphatase (S-ALP) were measured. S-ALAT increased significantly on the 5th and 10th postoperative day, from 27 +/- 2 (x +/- SE) to 40 +/- 4 (p less than 0.01) and 55 +/- 7 U/l (p less than 0.001), respectively, in the heparin group and was significantly higher in the heparin than in the TED group both on the 5th (p less than 0.01) and 10th (p less than 0.05) postoperative day. S-ASAT and S-gamma-GT increased significantly during heparin treatment, but did not differ significantly from the values of the TED group. No change in S-ALP was registered in either group. It is concluded that prophylactic treatment with low-dose heparin induces a significant increase in S-aminotransferase levels, especially in S-ALAT. The phenomenon has profound differential diagnostic implications in conditions such as pulmonary embolism and acute myocardial infarction.

  3. [Heparin-induced thrombocytopenia developed during the acute phase after left upper lobectomy for lung cancer].

    Science.gov (United States)

    Mitomo, Hideki; Miyamoto, Akira; Tabata, Toshiharu; Sugawara, Takafumi; Yabuki, Hiroshi; Fujimura, Shigefumi

    2014-12-01

    Heparin-induced thrombocytopenia (HIT) is a serious adverse effect of heparin administration. This must not be rarely encountered but is not often reported in Japan compared to Western countries. A 68-year-old woman underwent left upper lobectomy for lung cancer. Low-dose unfractionated heparin was administrated to prevent thromboembolism after the operation. Two days later, sudden dyspnea appeared and ultracardiosonography showing an extensive thromboembolus from the main trunk to both main branches of pulmonary artery indicated pulmonary embolization. After the establishment of percutaneous cardiopulmonary support (PCPS) support, the embolus was removed by emergent open heart surgery. However, despite further unfractionated heparin administration following embolization surgery, other thrombus was identified in both the bi-lateral internal jagular veins and inferior vena cava by ultrasonography and contrast computed tomography( CT). Her platelet count was decreased gradually despite platelet transfusion. Plate factor 4( PF4) antibody against heparin in her blood examination was found, and HIT II was diagnosed. Discontinuation of unfractionated heparin and administration of antithrombin agent improved platelet count, and no additional embolization was identified.

  4. Enhanced effect of BCG vaccine against pulmonary Mycobacterium tuberculosis infection in mice with lung Th17 response to mycobacterial heparin-binding hemagglutinin adhesin antigen.

    Science.gov (United States)

    Fukui, Masayuki; Shinjo, Kikuko; Umemura, Masayuki; Shigeno, Satoko; Harakuni, Tetsuya; Arakawa, Takeshi; Matsuzaki, Goro

    2015-12-01

    Although the BCG vaccine can prevent tuberculosis (TB) in infants, its ability to prevent adult pulmonary TB is reportedly limited. Therefore, development of a novel effective vaccine against pulmonary TB has become an international research priority. We have previously reported that intranasal vaccination of mice with a mycobacterial heparin-binding hemagglutinin adhesin (HBHA) plus mucosal adjuvant cholera toxin (CT) enhances production of IFN-γ and anti-HBHA antibody and suppresses extrapulmonary bacterial dissemination after intranasal infection with BCG. In the present study, the effects of intranasal HBHA + CT vaccine on murine pulmonary Mycobacterium tuberculosis (Mtb) infection were examined. Intranasal HBHA + CT vaccination alone failed to reduce the bacterial burden in the infected lung. However, a combination vaccine consisting of s.c. BCG priming and an intranasal HBHA + CT booster significantly enhanced protective immunity against pulmonary Mtb infection on day 14 compared with BCG vaccine alone. Further, it was found that intranasal HBHA + CT vaccine enhanced not only IFN-γ but also IL-17A production by HBHA-specific T cells in the lung after pulmonary Mtb infection. Therefore, this combination vaccine may be a good candidate for a new vaccine strategy against pulmonary TB. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  5. Alternative method for determination of contaminated heparin using chiral recognition.

    Science.gov (United States)

    Szekely, J; Collins, M; Currie, C A

    2014-05-15

    Since 2008 a significant amount of work has focused on the development of methods to analyze contaminated heparin. This work focuses on utilizing heparin's ability to serve as a chiral selector as a means for determining contamination. Specifically, the effect of contamination on the separation of pheniramine and chloroquine enantiomers was explored. Separations were conducted using heparin contaminated with chondroitin sulfate at varying levels. For each pair of enantiomers, electrophoretic mobility and resolution were calculated. For pheniramine enantiomers, an increase in contamination leads to a decrease in the electrophoretic mobility and resolution. A linear relationship between contamination level and electrophoretic mobility of the pheniramine enantiomers was observed for the entire contamination range. A linear relationship was also found between contamination level and resolution of the enantiomers between 0 and 70 percent contamination. For the separation of chloroquine enantiomers, it was found that at low levels of contamination, the resolution of enantiomers was increased due to the secondary interaction between the chloroquine enantiomers and the chondroitin sulfate. Results of this study illustrate the potential of using chiral recognition as a means to determine heparin contamination as well as the improvement of the chiral resolution of chloroquine with the additional of low levels of chondroitin sulfate A. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Preparation of tin -heparin complex to be applied for myocardial infarct diagnosis

    International Nuclear Information System (INIS)

    Badi, J. M.; Al-Azzawi, H. A.; Resen, H. M.; Abed, I. G.; Owiad, H.; Manji, A. N.

    2012-12-01

    Tin-heparin complex has been prepared (liquid form) to be labeled with technetium-99 can be applied for diagnosis of myocardial infarcts vascular diseases and deep vein thrombosis. The preparation contents are 0.1mg tin chloride dehydrate and 1250 1.U of heparin. The results of the pH effect on the labeling yield indicated that high percentage of labeling yield (96.1%) was obtained in the optimal pH (5.50). The obtained results showed that the quantity of reducing agent (tin chloride dehydrate) and chelating agent (heparin) has no effect on the labeling yield. Results of radio analytical studies by paper chromatography technique wear confirmed by data obtained by Gel chromatography column scanning techniques. These techniques showed the high labeling yield of the tin-heparin complex. The persistence of high labeling yield for 8 hours is a good indication for its stability and efficiency for radio diagnosis examination in nuclear medicine centers. (Author)

  7. Biomedical Application of Low Molecular Weight Heparin/Protamine Nano/Micro Particles as Cell- and Growth Factor-Carriers and Coating Matrix

    Directory of Open Access Journals (Sweden)

    Masayuki Ishihara

    2015-05-01

    Full Text Available Low molecular weight heparin (LMWH/protamine (P nano/micro particles (N/MPs (LMWH/P N/MPs were applied as carriers for heparin-binding growth factors (GFs and for adhesive cells including adipose-derived stromal cells (ADSCs and bone marrow-derived mesenchymal stem cells (BMSCs. A mixture of LMWH and P yields a dispersion of N/MPs (100 nm–3 μm in diameter. LMWH/P N/MPs can be immobilized onto cell surfaces or extracellular matrix, control the release, activate GFs and protect various GFs. Furthermore, LMWH/P N/MPs can also bind to adhesive cell surfaces, inducing cells and LMWH/P N/MPs-aggregate formation. Those aggregates substantially promoted cellular viability, and induced vascularization and fibrous tissue formation in vivo. The LMWH/P N/MPs, in combination with ADSCs or BMSCs, are effective cell-carriers and are potential promising novel therapeutic agents for inducing vascularization and fibrous tissue formation in ischemic disease by transplantation of the ADSCs and LMWH/P N/MPs-aggregates. LMWH/P N/MPs can also bind to tissue culture plates and adsorb exogenous GFs or GFs from those cells. The LMWH/P N/MPs-coated matrix in the presence of GFs may provide novel biomaterials that can control cellular activity such as growth and differentiation. Furthermore, three-dimensional (3D cultures of cells including ADSCs and BMSCs using plasma-medium gel with LMWH/P N/MPs exhibited efficient cell proliferation. Thus, LMWH/P N/MPs are an adequate carrier both for GFs and for stromal cells such as ADSCs and BMSCs, and are a functional coating matrix for their cultures.

  8. Antioxidant mechanism of milk mineral-high-affinity iron binding.

    Science.gov (United States)

    Allen, K; Cornforth, D

    2007-01-01

    Milk mineral (MM), a by-product of whey processing, is an effective antioxidant in meat systems, but the antioxidant mechanism has not been established. MM has been postulated to chelate iron and prevent iron-catalysis of lipid oxidation. The objective of this research was to examine this putative mechanism. MM was compared to sodium tripolyphosphate (STPP), calcium phosphate monobasic (CPM), and calcium pyrophosphate (CPP) to determine iron-binding capacity, sample solubility, and eluate soluble phosphorus after treating samples with a ferrous chloride standard. Scanning electron microscopy with energy-dispersive X-ray analysis was used to localize minerals on iron-treated MM particle surfaces. Histochemical staining for calcium was performed on raw and cooked ground beef samples with added MM. MM bound more iron per gram (P compounds, and was much less soluble (P iron across the MM particle surface, directly demonstrating iron binding to MM particles. Unlike other common chelating agents, such as STPP and citrate, histochemical staining demonstrated that MM remained insoluble in ground beef, even after cooking. The ability of MM to bind iron and remain insoluble may enhance its antioxidant effect by removing iron ions from solution. However, MM particles must be small and well distributed in order to adequately bind iron throughout the food system.

  9. High-throughput differentiation of heparin from other glycosaminoglycans by pyrolysis mass spectrometry.

    Science.gov (United States)

    Nemes, Peter; Hoover, William J; Keire, David A

    2013-08-06

    Sensors with high chemical specificity and enhanced sample throughput are vital to screening food products and medical devices for chemical or biochemical contaminants that may pose a threat to public health. For example, the rapid detection of oversulfated chondroitin sulfate (OSCS) in heparin could prevent reoccurrence of heparin adulteration that caused hundreds of severe adverse events including deaths worldwide in 2007-2008. Here, rapid pyrolysis is integrated with direct analysis in real time (DART) mass spectrometry to rapidly screen major glycosaminoglycans, including heparin, chondroitin sulfate A, dermatan sulfate, and OSCS. The results demonstrate that, compared to traditional liquid chromatography-based analyses, pyrolysis mass spectrometry achieved at least 250-fold higher sample throughput and was compatible with samples volume-limited to about 300 nL. Pyrolysis yielded an abundance of fragment ions (e.g., 150 different m/z species), many of which were specific to the parent compound. Using multivariate and statistical data analysis models, these data enabled facile differentiation of the glycosaminoglycans with high throughput. After method development was completed, authentically contaminated samples obtained during the heparin crisis by the FDA were analyzed in a blinded manner for OSCS contamination. The lower limit of differentiation and detection were 0.1% (w/w) OSCS in heparin and 100 ng/μL (20 ng) OSCS in water, respectively. For quantitative purposes the linear dynamic range spanned approximately 3 orders of magnitude. Moreover, this chemical readout was successfully employed to find clues in the manufacturing history of the heparin samples that can be used for surveillance purposes. The presented technology and data analysis protocols are anticipated to be readily adaptable to other chemical and biochemical agents and volume-limited samples.

  10. Two Differential Binding Mechanisms of FG-Nucleoporins and Nuclear Transport Receptors

    Directory of Open Access Journals (Sweden)

    Piau Siong Tan

    2018-03-01

    Full Text Available Summary: Phenylalanine-glycine-rich nucleoporins (FG-Nups are intrinsically disordered proteins, constituting the selective barrier of the nuclear pore complex (NPC. Previous studies showed that nuclear transport receptors (NTRs were found to interact with FG-Nups by forming an “archetypal-fuzzy” complex through the rapid formation and breakage of interactions with many individual FG motifs. Here, we use single-molecule studies combined with atomistic simulations to show that, in sharp contrast, FG-Nup214 undergoes a coupled reconfiguration-binding mechanism when interacting with the export receptor CRM1. Association and dissociation rate constants are more than an order of magnitude lower than in the archetypal-fuzzy complex between FG-Nup153 and NTRs. Unexpectedly, this behavior appears not to be encoded selectively into CRM1 but rather into the FG-Nup214 sequence. The same distinct binding mechanisms are unperturbed in O-linked β-N-acetylglucosamine-modified FG-Nups. Our results have implications for differential roles of distinctly spatially distributed FG-Nup⋅NTR interactions in the cell. : Archetypal-fuzzy complexes found in most FG-Nucleoporin⋅nuclear transport receptor complexes allow fast yet specific nuclear transport. Tan et al. show that FG-Nup214, located at the periphery of the nuclear pore complex, binds to CRM1⋅RanGTP via a coupled reconfiguration-binding mechanism, which can enable different functionalities e.g., cargo release. Keywords: intrinsically disordered protein, glycosylation, FG-Nup, nuclear transport receptors, binding mechanism, single-molecule FRET, molecular dynamics simulations

  11. A Prevention of Pre-eclampsia with the Use of Acetylsalicylic Acid and Low-molecular Weight Heparin - Molecular Mechanisms.

    Science.gov (United States)

    Darmochwal-Kolarz, Dorota; Kolarz, Bogdan; Korzeniewski, Michal; Kimber-Trojnar, Zaneta; Patro-Malysza, Jolanta; Mierzynski, Radzisław; Przegalinska-Kałamucka, Monika; Oleszczuk, Jan

    Pre-eclampsia appears to be the main cause for the maternal and fetal morbidity and mortality. Pregnant women with pre-eclampsia are more likely to be threatened with conditions which potentially may be lethal, such as: disseminated intravascular coagulation, cerebral hemorrhage, liver and renal failure. Pregnancy complicated with pre-eclampsia is also associated with a greater risk for iatrogenic prematurity, intrauterine growth retardation, premature abruption of placenta, and even intrauterine fetal death. In the majority of cases the reasons for arterial hypertension among pregnant women remain obscure. For the past decades, there were many abortive attempts in the use of some microelements, vitamins or specific diets, such as polyunsaturated fatty acids, for the prophylaxis of pre-eclampsia. Recently, it has been shown that a prevention of pre-eclampsia with the use of a lowmolecular- weight heparins (LMWHs) and acetylsalicylic acid (ASA) could considerably reduce the frequency of preeclampsia. In this review, we present the studies concerning the applications of LMWHs and aspirin in the prophylaxis of pre-eclampsia and some important data about the mechanisms of anti-inflammatory actions of LMWHs and ASA.

  12. Coexistence of Antiphospholipid Syndrome and Heparin-Induced Thrombocytopenia in a Patient with Recurrent Venous Thromboembolism

    Directory of Open Access Journals (Sweden)

    Samuel Adediran

    2017-01-01

    Full Text Available Heparin-induced thrombocytopenia (HIT is a prothrombotic adverse drug reaction in which heparin forms complexes with platelet factor 4 forming neoantigens that are recognized by autoantibodies. Antiphospholipid syndrome (APS is similar to HIT in that it is mediated by autoantibodies that are also prothrombotic. We present a case of rare coexistence of antiphospholipid antibody syndrome and heparin-induced thrombocytopenia.

  13. In vitro effects of heparin and tissue factor pathway inhibitor on factor VII assays. possible implications for measurements in vivo after heparin therapy

    DEFF Research Database (Denmark)

    Bladbjerg, E-M; Larsen, L F; Ostergaard, P

    2000-01-01

    The coagulant activity of blood coagulation factor VII (FVII:C) can be lowered by changes in lifestyle and by therapeutic intervention, e.g. heparin infusion. The question is, however, whether FVII:C determined ex vivo is a valid measure of the FVII activity in vivo. We measured plasma FVII......:C, activated FVII (FVIIa), FVII protein (FVII:Ag), tissue factor pathway inhibitor (TFPI), triglycerides, and free fatty acids (FFA) before and 15 min after infusion of a bolus of unfractionated heparin (50 IU/kg body weight) in 12 healthy subjects. Additionally, we conducted in vitro experiments...

  14. The binding mechanism of a peptidic cyclic serine protease inhibitor

    DEFF Research Database (Denmark)

    Jiang, Longguang; Svane, Anna Sigrid P.; Sørensen, Hans Peter

    2011-01-01

    Serine proteases are classical objects for studies of catalytic and inhibitory mechanisms as well as interesting as therapeutic targets. Since small-molecule serine protease inhibitors generally suffer from specificity problems, peptidic inhibitors, isolated from phage-displayed peptide libraries......, have attracted considerable attention. Here, we have investigated the mechanism of binding of peptidic inhibitors to serine protease targets. Our model is upain-1 (CSWRGLENHRMC), a disulfide-bond-constrained competitive inhibitor of human urokinase-type plasminogen activator with a noncanonical...... inhibitory mechanism and an unusually high specificity. Using a number of modified variants of upain-1, we characterised the upain-1-urokinase-type plasminogen activator complex using X-ray crystal structure analysis, determined a model of the peptide in solution by NMR spectroscopy, and analysed binding...

  15. Analytical characterization of heparin by capillary zone electrophoresis with conductivity detection and polymeric buffer additives.

    Science.gov (United States)

    Mikus, Peter; Valásková, Iva; Havránek, Emil

    2004-11-15

    A capillary zone electrophoresis (CZE) method for the analytical characterization of intact (high-molecular-weight) heparin was developed. For the first time, a hydrodynamically closed CZE separation system with conductivity detector was used for the separation, detection and quantitation of this highly sulfated, linear polysaccharide. Glycine (25mM) adjusted to pH 9.0 by bis-Tris-propane served as the running electrolyte system. Polymeric additives, polyvinylpyrrolidone (PVP), dextran (DEX), were used to improve the separation selectivity as they strongly retarded the heparin macromolecule while they did not practically influence comigrating inorganic anions. The proposed electrophoretic method was successfully validated. It was convenient for the sensitive, simple, rapid and reproducible assay of heparin in raw materials and isotonic saline. Here, the use of the conductivity detector was advantageous as it allowed heparin to be analyzed without a sample pretreatment. The CZE method should be an alternative to the pharmacopoeial conventional gel electrophoresis having used in the quality control of heparin so far. In addition, it should be convenient to quantitative estimation of heparin present in a preparation used, e.g., as the chiral selector in CE separations.

  16. Heparin and insulin in the management of hypertriglyceridemia-associated pancreatitis: case series and literature review.

    Science.gov (United States)

    Kuchay, Mohammad Shafi; Farooqui, Khalid J; Bano, Tarannum; Khandelwal, Manoj; Gill, Harmandeep; Mithal, Ambrish

    2017-01-01

    Severe hypertriglyceridemia accounts for up to 7% of all cases of acute pancreatitis. Heparin and insulin activate lipoprotein lipase (LPL), thereby reducing plasma triglyceride levels. However, the safety and efficacy of heparin and insulin in the treatment of hypertriglyceridemia-associated acute pancreatitis have not been well established yet. We successfully used heparin and insulin as first-line therapy in four consecutive patients with acute pancreatitis secondary to hypertriglyceridemia. In a literature search, we revised almost all reports published to date of patients managed successfully with this combination. Heparin and insulin appear to be a safe, effective, and inexpensive first-line therapy for hypertriglyceridemia-associated acute pancreatitis.

  17. Prevention of fatal postoperative pulmonary embolism by low doses of heparin. An international multicentre trial.

    Science.gov (United States)

    1975-07-12

    The efficacy of low-dose heparin in preventing fatal postoperative pulmonary embolism has been investigated in a multicentre prospective randomised trial. 4121 patients over the age of forty years undergoing a variety of elective major surgical procedures were included in the trial; 2076 of these were in the control group and 2045 patients received heparin. The two groups were well matched for age, sex, weight, blood-group, and other factors which could predispose to the development of venous thromboembolism. 180 (4-4 %) patients died during the postoperative period, 100 in the control and 80 in the heparin group: 72% of deaths in the control and 66% in the heparin group had necropsy examination. 16 patients in the control group and 2 in the heparin group were found at necropsy to have died due to acute massive pulmonary embolism (P smaller than 0-005). In addition, emboli found at necropsy in 6 patients in the control group and 3 in the heparin group were considered either contributory to death or an incidental finding since death in these patients was attributed to other causes. Taking all pulmonary emboli together, the findings were again significant (P smaller than 0-005). Of 1292 patients in whom the 125-I-fibrinogen test was performed to detect deep-vein thrombosis (D.V.T.) 667 were in the control group and 625 in the heparin group. The frequency of isotopic D.V.T. was reduced from 24-6% in the control group 7-7% in the heparin group (P smaller 0-005). In 30 patients D.V.T. was detected at necropsy; 24 in the control and 6 in the heparin group (P smaller 0-005). 32 patients in the control group and 11 in the heparin group developed clinically diagnosed D.V.T. which was confirmed by venography (P smaller than 0-005). In addition, 24 patients in the control and 8 in the heparin group were treated for clinically suspected pulmonary emoblism. The difference in the number of patients requiring treatment for D.V.T. and/or pulmonary embolism in the two groups was

  18. Heparan sulfate regulates fibrillin-1 N- and C-terminal interactions

    DEFF Research Database (Denmark)

    Cain, Stuart A; Baldwin, Andrew K; Mahalingam, Yashithra

    2008-01-01

    Fibrillin-1 N- and C-terminal heparin binding sites have been characterized. An unprocessed monomeric N-terminal fragment (PF1) induced a very high heparin binding response, indicating heparin-mediated multimerization. Using PF1 deletion and short fragments, a heparin binding site was localized w......-terminal interactions with heparin/heparan sulfate directly influence cell behavior, whereas C-terminal interactions with heparin/heparan sulfate regulate elastin deposition. These data highlight how heparin/heparan sulfate controls fibrillin-1 interactions....

  19. Bilateral adrenal haemorrhage associated with heparin-induced thrombocytopaenia during treatment of Fournier gangrene.

    Science.gov (United States)

    Tattersall, Timothy Lee; Thangasamy, Isaac A; Reynolds, Jamie

    2014-10-14

    We present a case of bilateral adrenal haemorrhage (BAH) associated with heparin-induced thrombocytopaenia (HIT) in a 61-year-old man admitted to hospital for the treatment of Fournier's gangrene. He presented to hospital with scrotal swelling and fever, and developed spreading erythaema and a gangrenous scrotum. His scrotum was surgically debrided and intravenous broad-spectrum antibiotics were administered. Unfractionated heparin was given postoperatively for venous thromboembolism prophylaxis. The patient deteriorated clinically 8-11 days postoperatively with delirium, chest pain and severe hypertension followed by hypotension and thrombocytopaenia. Abdominal CT scan revealed bilateral adrenal haemorrhage. Antibodies to the heparin-platelet factor 4 complex were present. HIT-associated BAH was diagnosed and heparin was discontinued. Intravenous bivalirudin and hydrocortisone were started, with rapid improvement in clinical status. BAH is a rare complication of HIT and should be considered in the postoperative patient with unexplained clinical deterioration. 2014 BMJ Publishing Group Ltd.

  20. Subtle differences in commercial heparins can have serious consequences for cardiopulmonary bypass patients: A randomized controlled trial.

    Science.gov (United States)

    Arsenault, Kyle A; Paikin, Jeremy S; Hirsh, Jack; Dale, Brian; Whitlock, Richard P; Teoh, Kevin; Young, Ed; Ginsberg, Jeffrey S; Weitz, Jeffrey I; Eikelboom, John W

    2012-10-01

    To compare the potency, reversibility, and perioperative bleeding risk of Hepalean with those of PPC heparin. Because in vitro testing failed to detect differences in the potency or protamine reversibility of the 2 heparin preparations, we conducted a parallel group, single-center, double-blind, randomized, controlled trial to compare the anticoagulant effects of Hepalean to those of PPC heparin in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. From June 1, 2011, to June 30, 2011, we randomly assigned 11 patients to receive PPC heparin and 10 to receive Hepalean. Despite similar initial doses of heparin, the median initial activated clotting time was numerically lower in the PPC heparin group than in the Hepalean group (median, 516.0 seconds; interquartile range, 481.0-633.0; vs median, 584.0 seconds, interquartile range, 520.0-629.0; P = .418). Those given PPC heparin required a greater total heparin dose (median, 46,000.0 U; interquartile range, 39,500.0-60,000.0 vs median, 34,500.0 U; interquartile range, 32,250.0-37,000.0; P = .011) and a greater dose of heparin per kilogram than those given Hepalean (median, 572.9 U/kg; interquartile range, 443.0-659.7 vs median, 401.1 U/kg; interquartile range, 400.0-419.4; P = .003). The key secondary results included an increased median total protamine dose (median, 600.0 mg; interquartile range, 550.0-700.0; vs median, 500.0 mg; interquartile range, 425.0-542.5; P = .026) and a trend toward increased chest tube output within 24 hours (median, 830.0 mL; interquartile range, 425.0-1135.0; vs median, 702.5 mL; interquartile range, 550.0-742.5; P = .324). PPC heparin use was associated with greater heparin and protamine dose requirements than Hepalean. These findings indicate that heparin preparations are not interchangeable and suggest that a direct comparison of the potency with the brand in use is needed if a change is made to ensure that the agents exert similar anticoagulant

  1. Anticoagulation and endothelial cell behaviors of heparin-loaded graphene oxide coating on titanium surface

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Chang-Jiang, E-mail: panchangjiang@hyit.edu.cn [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai' an 223003 (China); Pang, Li-Qun [Department of General Surgery, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an 223300 (China); Gao, Fei [Zhejiang Zylox Medical Devices Co., Ltd., Hangzhou 310000 (China); Wang, Ya-Nan; Liu, Tao; Ye, Wei; Hou, Yan-Hua [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai' an 223003 (China)

    2016-06-01

    Owing to its unique physical and chemical properties, graphene oxide (GO) has attracted tremendous interest in many fields including biomaterials and biomedicine. The purpose of the present study is to investigate the endothelial cell behaviors and anticoagulation of heparin-loaded GO coating on the titanium surface. To this end, the titanium surface was firstly covered by the polydopamine coating followed by the deposition of the GO coating. Heparin was finally loaded on the GO coating to improve the blood compatibility. The results of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that the heparin-loaded GO coating was successfully created on the titanium surface. The scanning electron microscopy (SEM) images indicated that a relative uniform GO coating consisting of multilayer GO sheets was formed on the substrate. The hydrophilicity of the titanium surface was enhanced after the deposition of GO and further improved significantly by the loading heparin. The GO coating can enhance the endothelial cell adhesion and proliferation as compared with polydopamine coating and the blank titanium. Loading heparin on the GO coating can significantly reduce the platelet adhesion and prolong the activated partial thromboplastin time (APTT) while not influence the endothelial cell adhesion and proliferation. Therefore, the heparin-loaded GO coating can simultaneously enhance the cytocompatibility to endothelial cells and blood compatibility of biomaterials. Because the polydopamine coating can be easily prepared on most of biomaterials including polymer, ceramics and metal, thus the approach of the present study may open up a new window of promising an effective and efficient way to promote endothelialization and improve the blood compatibility of blood-contact biomedical devices such as intravascular stents. - Highlights: • Heparin-loaded graphene oxide coating was

  2. Design of a new type of coating for the controlled release of heparin

    NARCIS (Netherlands)

    Hinrichs, W.L.J.; Hinrichs, W.L.J.; ten Hoopen, Hermina W.M.; Wissink, M.J.B.; Engbers, G.H.M.; Feijen, Jan

    1997-01-01

    Thrombus formation at the surface of blood contacting devices can be prevented by local release of heparin. Preferably, the release rate should be constant for prolonged periods of time. The minimum heparin release rate to achieve thromboresistance will be different for various applications and

  3. Platelet count recovery and seroreversion in immune HIT despite continuation of heparin: further observations and literature review.

    Science.gov (United States)

    Shih, Andrew W; Sheppard, Jo-Ann I; Warkentin, Theodore E

    2017-10-05

    One of the standard distinctions between type 1 (non-immune) and type 2 (immune-mediated) heparin-induced thrombocytopenia (HIT) is the transience of thrombocytopenia: type 1 HIT is viewed as early-onset and transient thrombocytopenia, with platelet count recovery despite continuing heparin administration. In contrast, type 2 HIT is viewed as later-onset (i. e., 5 days or later) thrombocytopenia in which it is generally believed that platelet count recovery will not occur unless heparin is discontinued. However, older reports of type 2 HIT sometimes did include the unexpected observation that platelet counts could recover despite continued heparin administration, although without information provided regarding changes in HIT antibody levels in association with platelet count recovery. In recent years, some reports of type 2 HIT have confirmed the observation that platelet count recovery can occur despite continuing heparin administration, with serological evidence of waning levels of HIT antibodies ("seroreversion"). We now report two additional patient cases of type 2 HIT with platelet count recovery despite ongoing therapeutic-dose (1 case) or prophylactic-dose (1 case) heparin administration, in which we demonstrate concomitant waning of HIT antibody levels. We further review the literature describing this phenomenon of HIT antibody seroreversion and platelet count recovery despite continuing heparin administration. Our observations add to the concept that HIT represents a remarkably transient immune response, including sometimes even when heparin is continued.

  4. Assessment of Heparin Anticoagulation Measured Using i-STAT and Hemochron Activated Clotting Time.

    Science.gov (United States)

    Maslow, Andrew; Chambers, Alison; Cheves, Tracey; Sweeney, Joseph

    2018-01-31

    Adequate anticoagulation, measured using activated clotting time (ACT), is important during vascular and cardiac surgeries. Unfractionated heparin is the most common anticoagulant used. The purpose of this analysis was to compare the i-STAT ACT (iACT) to the Hemochron ACT (hACT), both of which were then compared to anti-factor Xa (anti-Xa) assay, a representation of heparin level and activity. Prospective study. Tertiary care cardiovascular center. Eleven consecutive elective adult cardiac surgical patients. Prior to cardiopulmonary bypass, ACTs were measured using i-STAT and Hemochron technologies and compared to each other and to anti-Xa assay prior to and during a cumulative administration of heparin. Data were compared using bias analyses. Heparin (300 U/kg) was administered in quarterly doses. Coagulation labs were collected prior to and 3 minutes after each quarterly dose of heparin. The baseline ACTs for i-STAT and Hemochron were 147 and 142 seconds, respectively. A significant association was found between iACT and hACT (p = 0.002). The iACT measurements underestimated hACT at ACT levels >180 seconds or anti-Xa levels >0.75 U/mL. No significant difference was found between ACT data at anti-Xa levels 0.75 U/mL. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Ultrasensitive colorimetric detection of heparin based on self-assembly of gold nanoparticles on graphene oxide.

    Science.gov (United States)

    Fu, Xiuli; Chen, Lingxin; Li, Jinhua

    2012-08-21

    A novel colorimetric method was developed for ultrasensitive detection of heparin based on self-assembly of gold nanoparticles (AuNPs) onto the surface of graphene oxide (GO). Polycationic protamine was used as a medium for inducing the self-assembly of citrate-capped AuNPs on GO through electrostatic interaction, resulting in a shift in the surface plasmon resonance (SPR) absorption of AuNPs and exhibiting a blue color. Addition of polyanionic heparin disturbed the self-assemble of AuNPs due to its strong affinity to protamine. With the increase of heparin concentration, the amounts of self-assembly AuNPs decreased and the color changed from blue to red in solution. Therefore, a "blue-to-red" colorimetric sensing strategy based on self-assembly of AuNPs could be established for heparin detection. Compared with the commonly reported aggregation-based methods ("red-to-blue"), the color change from blue to red was more eye-sensitive, especially in low concentration of target. Moreover, stronger interaction between protamine and heparin led to distinguish heparin from its analogues as well as various potentially coexistent physiological species. The strategy was simply achieved by the self-assembly nature of AuNPs and the application of two types of polyionic media, showing it to be label-free, simple, rapid and visual. This method could selectively detect heparin with a detection limit of 3.0 ng mL(-1) in standard aqueous solution and good linearity was obtained over the range 0.06-0.36 μg mL(-1) (R = 0.9936). It was successfully applied to determination of heparin in fetal bovine serum samples as low as 1.7 ng mL(-1) with a linear range of 0-0.8 μg mL(-1).

  6. Discriminating binding mechanisms of an intrinsically disordered protein via a multi-state coarse-grained model

    Energy Technology Data Exchange (ETDEWEB)

    Knott, Michael [Department of Chemistry, Cambridge University, Lensfield Road, Cambridge CB2 1EW (United Kingdom); Best, Robert B., E-mail: robertbe@helix.nih.gov [Department of Chemistry, Cambridge University, Lensfield Road, Cambridge CB2 1EW (United Kingdom); Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520 (United States)

    2014-05-07

    Many proteins undergo a conformational transition upon binding to their cognate binding partner, with intrinsically disordered proteins (IDPs) providing an extreme example in which a folding transition occurs. However, it is often not clear whether this occurs via an “induced fit” or “conformational selection” mechanism, or via some intermediate scenario. In the first case, transient encounters with the binding partner favour transitions to the bound structure before the two proteins dissociate, while in the second the bound structure must be selected from a subset of unbound structures which are in the correct state for binding, because transient encounters of the incorrect conformation with the binding partner are most likely to result in dissociation. A particularly interesting situation involves those intrinsically disordered proteins which can bind to different binding partners in different conformations. We have devised a multi-state coarse-grained simulation model which is able to capture the binding of IDPs in alternate conformations, and by applying it to the binding of nuclear coactivator binding domain (NCBD) to either ACTR or IRF-3 we are able to determine the binding mechanism. By all measures, the binding of NCBD to either binding partner appears to occur via an induced fit mechanism. Nonetheless, we also show how a scenario closer to conformational selection could arise by choosing an alternative non-binding structure for NCBD.

  7. Discriminating binding mechanisms of an intrinsically disordered protein via a multi-state coarse-grained model

    International Nuclear Information System (INIS)

    Knott, Michael; Best, Robert B.

    2014-01-01

    Many proteins undergo a conformational transition upon binding to their cognate binding partner, with intrinsically disordered proteins (IDPs) providing an extreme example in which a folding transition occurs. However, it is often not clear whether this occurs via an “induced fit” or “conformational selection” mechanism, or via some intermediate scenario. In the first case, transient encounters with the binding partner favour transitions to the bound structure before the two proteins dissociate, while in the second the bound structure must be selected from a subset of unbound structures which are in the correct state for binding, because transient encounters of the incorrect conformation with the binding partner are most likely to result in dissociation. A particularly interesting situation involves those intrinsically disordered proteins which can bind to different binding partners in different conformations. We have devised a multi-state coarse-grained simulation model which is able to capture the binding of IDPs in alternate conformations, and by applying it to the binding of nuclear coactivator binding domain (NCBD) to either ACTR or IRF-3 we are able to determine the binding mechanism. By all measures, the binding of NCBD to either binding partner appears to occur via an induced fit mechanism. Nonetheless, we also show how a scenario closer to conformational selection could arise by choosing an alternative non-binding structure for NCBD

  8. Antiproliferative heparin (glycosaminoglycans) isolated from giant ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... source of these sulfated polysaccharides (Nader and. Dietrich, 1989) and it often corresponds up to 90% of the total GAG content of these organisms. Heparin and heap- rin-like substances have a wide range of important biolo- gical activities including inhibition of pulmonary artery smooth muscle cell ...

  9. Statistical-mechanical lattice models for protein-DNA binding in chromatin

    International Nuclear Information System (INIS)

    Teif, Vladimir B; Rippe, Karsten

    2010-01-01

    Statistical-mechanical lattice models for protein-DNA binding are well established as a method to describe complex ligand binding equilibria measured in vitro with purified DNA and protein components. Recently, a new field of applications has opened up for this approach since it has become possible to experimentally quantify genome-wide protein occupancies in relation to the DNA sequence. In particular, the organization of the eukaryotic genome by histone proteins into a nucleoprotein complex termed chromatin has been recognized as a key parameter that controls the access of transcription factors to the DNA sequence. New approaches have to be developed to derive statistical-mechanical lattice descriptions of chromatin-associated protein-DNA interactions. Here, we present the theoretical framework for lattice models of histone-DNA interactions in chromatin and investigate the (competitive) DNA binding of other chromosomal proteins and transcription factors. The results have a number of applications for quantitative models for the regulation of gene expression.

  10. Indium-111-labeled platelets: effect of heparin on uptake by venous thrombi and relationship to the activated partial thromboplastin time

    International Nuclear Information System (INIS)

    Fedullo, P.F.; Moser, K.M.; Moser, K.S.; Konopka, R.; Hartman, M.T.

    1982-01-01

    The goal of heparin thepapy in deep vein thrombosis is to prevent thrombus extension. The relationship between thrombus extension and the results of coagulation tests used to monitor heparin thepapy is unclear. To expose this relationship, we studied the effect of several heparin regimens on the accretion of indium-111-labeled platelets on fresh venous thrombi, as detected by gamma imaging, and monitored the activated partial thromboplastin time (APTT). Six dogs were treated with a 300-U/kg bolus of heparin followed by a 90-U/kg/hour heparin infusion, a dose of heparin sufficient to increase the APTT to levels greater than eight times baseline (APTT ratio); platelet accretion (thrombus imaging) occurred only after the heparin effect was reversed with protamine sulfate. Nineteen dogs were treated with a 150-U/kg bolus of heparin followed by a 4-hour, 45-U/kg/hour heparin infusion; a thrombus was demonstrated only after protamine injection in 12 (mean APTT ratio 1.3 +/- 0.19) and before protamine injection in seven. In thirteen of these 19 dogs, 30 minutes separated the platelet injection from heparin therapy, while in six this duration was less than 30 minutes. In four of these six dogs, thrombi were demonstrated before protamine therapy and at APTT ratios greater than 3.0. Finally, 10 dogs were treated with a 100-U/kg bolus followed by a 3-hour, 50-U/kg/hour heparin infusion, after which the APTT was allowed to return to baseline values spontaneously. In all 10 dogs, a thrombus was demonstrated only after cessation of the heparin infusion, and at a mean APTT ratio of 1.4 +/- 0.15 times baseline. These results suggest that, except with very early platelet injection, platelet accretion by thrombi is consistently inhibited by heparin at APTT ratios greater than 2.5

  11. Molecular Weights of Bovine and Porcine Heparin Samples: Comparison of Chromatographic Methods and Results of a Collaborative Survey

    Directory of Open Access Journals (Sweden)

    Sabrina Bertini

    2017-07-01

    Full Text Available In a collaborative study involving six laboratories in the USA, Europe, and India the molecular weight distributions of a panel of heparin sodium samples were determined, in order to compare heparin sodium of bovine intestinal origin with that of bovine lung and porcine intestinal origin. Porcine samples met the current criteria as laid out in the USP Heparin Sodium monograph. Bovine lung heparin samples had consistently lower average molecular weights. Bovine intestinal heparin was variable in molecular weight; some samples fell below the USP limits, some fell within these limits and others fell above the upper limits. These data will inform the establishment of pharmacopeial acceptance criteria for heparin sodium derived from bovine intestinal mucosa. The method for MW determination as described in the USP monograph uses a single, broad standard calibrant to characterize the chromatographic profile of heparin sodium on high-resolution silica-based GPC columns. These columns may be short-lived in some laboratories. Using the panel of samples described above, methods based on the use of robust polymer-based columns have been developed. In addition to the use of the USP’s broad standard calibrant for heparin sodium with these columns, a set of conditions have been devised that allow light-scattering detected molecular weight characterization of heparin sodium, giving results that agree well with the monograph method. These findings may facilitate the validation of variant chromatographic methods with some practical advantages over the USP monograph method.

  12. Molecular Weights of Bovine and Porcine Heparin Samples: Comparison of Chromatographic Methods and Results of a Collaborative Survey.

    Science.gov (United States)

    Bertini, Sabrina; Risi, Giulia; Guerrini, Marco; Carrick, Kevin; Szajek, Anita Y; Mulloy, Barbara

    2017-07-19

    In a collaborative study involving six laboratories in the USA, Europe, and India the molecular weight distributions of a panel of heparin sodium samples were determined, in order to compare heparin sodium of bovine intestinal origin with that of bovine lung and porcine intestinal origin. Porcine samples met the current criteria as laid out in the USP Heparin Sodium monograph. Bovine lung heparin samples had consistently lower average molecular weights. Bovine intestinal heparin was variable in molecular weight; some samples fell below the USP limits, some fell within these limits and others fell above the upper limits. These data will inform the establishment of pharmacopeial acceptance criteria for heparin sodium derived from bovine intestinal mucosa. The method for MW determination as described in the USP monograph uses a single, broad standard calibrant to characterize the chromatographic profile of heparin sodium on high-resolution silica-based GPC columns. These columns may be short-lived in some laboratories. Using the panel of samples described above, methods based on the use of robust polymer-based columns have been developed. In addition to the use of the USP's broad standard calibrant for heparin sodium with these columns, a set of conditions have been devised that allow light-scattering detected molecular weight characterization of heparin sodium, giving results that agree well with the monograph method. These findings may facilitate the validation of variant chromatographic methods with some practical advantages over the USP monograph method.

  13. Study of the Efficacy, Safety and Tolerability of Low-Molecular-Weight Heparin vs. Unfractionated Heparin as Bridging Therapy in Patients with Embolic Stroke due to Atrial Fibrillation.

    Science.gov (United States)

    Feiz, Farnia; Sedghi, Reyhane; Salehi, Alireza; Hatam, Nahid; Bahmei, Jamshid; Borhani-Haghighi, Afshin

    2016-06-01

    Anticoagulation with adjusted dose warfarin is a well-accepted treatment for the prevention of recurrent stroke in patients with atrial fibrillation. Meanwhile, using bridging therapy with heparin or heparinoids before warfarin for initiation of anticoagulation is a matter of debate. We compared safety, efficacy, and tolerability of low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH) as a bridging method in patients with recent ischemic stroke due to atrial fibrillation. This study was a randomized single-blind controlled trial in patients with acute ischemic stroke due to atrial fibrillation who were eligible for receiving warfarin and were randomly treated with 60 milligrams (mg) of LMWH (enoxaparin) subcutaneously every 12 h, or 1000 units/h of continuous intravenous heparin. The primary efficacy endpoints were recurrence of new ischemic stroke, myocardial infarction and/or death. The primary safety endpoint was central nervous system and/or systemic bleeding. Seventy-four subjects were recruited. Baseline demographic and clinical characteristics of two groups were matched. Composite endpoint outcome of new ischemic stroke, myocardial infarction, and/or death in follow-up period was seen in 10 subjects (27.03%) in UFH group and in four subjects (10.81%) in LMWH group (p value: 0.136). All hemorrhages and symptomatic central nervous system (CNS) hemorrhages in follow-up period were in 7 (18.9%) and 4 (10.8%) patients in UFH group, in 5 (13.5%), and 3 (8.1%) patients in LMWH group (p values: 0.754 and 0.751), respectively. Drop out and major adverse-effects such as heparin-induced thrombocytopenia and drug hypersensitivity were not seen in any patient. Enoxaparin can be a safe and efficient alternative for UFH as bridging therapy.

  14. 111In-labeled platelets: effects of heparin on uptake by venous thrombi and relationship to the activated partial thromboplastin time

    International Nuclear Information System (INIS)

    Fedullo, P.F.; Moser, K.M.; Moser, K.S.; Konopka, R.; Hartman, M.T.

    1982-01-01

    The goal of heparin therapy in deep vein thrombosis is to prevent thrombus extension. The relationship between thrombus extension and the results of coagulation tests used to monitor heparin therapy is unclear. To explore this relationship, we studied the effect of several heparin regimens on the accretion of 111 In-labeled platelets on fresh venous thrombi, as detected by gamma imaging, and monitored the activated partial thromboplastin time (APTT). Six dogs were treated with a 300-U/kg bolus of heparin followed by a 90-U/kg/hour heparin infusion, a dose of heparin sufficient to increase the APTT to levels greater than eight times baseline (APTT ratio); platelet accretion (thrombus imaging) occurred only after the heparin effect was reversed with protamine sulfate. Nineteen dogs were treated with a 150-U/kg bolus of heparin followed by a 4-hour, 45-U/kg/hour heparin infusion; a thrombus was demonstrated only after protamine injection in 12 (mean APTT ratio 1.3 +/- 0.19) and before protamine injection in seven. In thirteen of these 19 dogs, 30 minutes separated the platelet injection from heparin therapy, while in six this duration was less than 30 minutes. In four of these six dogs, thrombi were demonstrated before protamine therapy and at APTT ratios greater than 3.0. Finally, 10 dogs were treated with a 100-U/kg bolus followed by a 3-hour, 50-U/kg/hour heparin infusion, after which the APTT was allowed to return to baseline values spontaneously. In all 10 dogs, a thrombus was demonstrated only after cessation of the heparin infusion, and at a mean APTT ratio of 1.4 +/- 0.15 times baseline. These results suggest that, except with very early platelet injection, platelet accretion by thrombi is consistently inhibited by heparin at APTT ratios greater than 2.5. Platelet accretion by venous thrombi occurs within narrow limits of heparin effect as reflected by the APTT

  15. Tannic acid and chromic chloride-induced binding of protein to red cells: a preliminary study of possible binding sites and reaction mechanisms.

    Science.gov (United States)

    Hunt, A F; Reed, M I

    1990-07-01

    The binding mechanisms and binding sites involved in the tannic acid and chromic chloride-induced binding of protein to red cells were investigated using the binding of IgA paraprotein to red cells as model systems. Inhibition studies of these model systems using amino acid homopolymers and compounds (common as red cell membrane constituents) suggest that the mechanisms involved are similar to those proposed for the conversion of hide or skin collagen to leather, as in commercial tanning. These studies also suggest that tannic acid-induced binding of IgA paraprotein to red cells involves the amino acid residues of L-arginine, L-lysine, L-histidine, and L-proline analogous to tanning with phenolic plant extracts. The amino acid residues of L-aspartate, L-glutamate and L-asparagine are involved in a similar manner in chronic chloride-induced binding of protein to red cells.

  16. Peptide p5 binds both heparinase-sensitive glycosaminoglycans and fibrils in patient-derived AL amyloid extracts

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Emily B.; Williams, Angela [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Heidel, Eric [Department of Surgery, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Macy, Sallie [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Kennel, Stephen J. [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Department of Radiology, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Wall, Jonathan S., E-mail: jwall@utmck.edu [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Department of Radiology, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States)

    2013-06-21

    Highlights: •Polybasic peptide p5 binds human light chain amyloid extracts. •The binding of p5 with amyloid involves both glycosaminoglycans and fibrils. •Heparinase treatment led to a correlation between p5 binding and fibril content. •p5 binding to AL amyloid requires electrostatic interactions. -- Abstract: In previously published work, we have described heparin-binding synthetic peptides that preferentially recognize amyloid deposits in a mouse model of reactive systemic (AA) amyloidosis and can be imaged by using positron and single photon emission tomographic imaging. We wanted to extend these findings to the most common form of visceral amyloidosis, namely light chain (AL); however, there are no robust experimental animal models of AL amyloidosis. To further define the binding of the lead peptide, p5, to AL amyloid, we characterized the reactivity in vitro of p5 with in situ and patient-derived AL amyloid extracts which contain both hypersulfated heparan sulfate proteoglycans as well as amyloid fibrils. Histochemical staining demonstrated that the peptide specifically localized with tissue-associated AL amyloid deposits. Although we anticipated that p5 would undergo electrostatic interactions with the amyloid-associated glycosaminoglycans expressing heparin-like side chains, no significant correlation between peptide binding and glycosaminoglycan content within amyloid extracts was observed. In contrast, following heparinase I treatment, although overall binding was reduced, a positive correlation between peptide binding and amyloid fibril content became evident. This interaction was further confirmed using synthetic light chain fibrils that contain no carbohydrates. These data suggest that p5 can bind to both the sulfated glycosaminoglycans and protein fibril components of AL amyloid. Understanding these complex electrostatic interactions will aid in the optimization of synthetic peptides for use as amyloid imaging agents and potentially as

  17. Hemocompatible ɛ-polylysine-heparin microparticles: A platform for detecting triglycerides in whole blood.

    Science.gov (United States)

    Xu, Tingting; Chi, Bo; Chu, Meilin; Zhang, Qicheng; Zhan, Shuyue; Shi, Rongjia; Xu, Hong; Mao, Chun

    2018-01-15

    Triglycerides are clinically important marker for atherosclerosis, heart disease and hypertension. Here, a platform for detecting triglycerides in whole blood directly was developed based on hemocompatible ɛ-polylysine-heparin microparticles. The obtained products of ɛ-polylysine-heparin microparticles were characterized by fourier transform infrared (FT-IR) spectra, transmission electron microscopy (TEM) and ζ-potential. Moreover, the blood compatibility of ɛ-polylysine-heparin microparticles was characterized by in vitro coagulation tests, hemolysis assay and whole blood adhesion tests. Considering of uniform particle size, good dispersibility and moderate long-term anticoagulation capability of the microparticles, a Lipase-(ɛ-polylysine-heparin)-glassy carbon electrode (GCE) was constructed to detect triglycerides. The proposed biosensor had good electrocatalytic activity towards triglycerides, in which case the sensitivity was 0.40μAmg -1 dLcm -2 and the detection limit was 4.67mgdL -1 (S/N = 3). Meanwhile, the Lipase-(ɛ-polylysine-heparin)-GCE electrode had strong anti-interference ability as well as a long shelf-life. Moreover, for the detection of triglycerides in whole blood directly, the detection limit was as low as 5.18mgdL -1 . The new constructed platform is suitable for detecting triglycerides in whole blood directly, which provides new analytical systems for clinical illness diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Printed microfluidic filter for heparinized blood.

    Science.gov (United States)

    Bilatto, Stanley E R; Adly, Nouran Y; Correa, Daniel S; Wolfrum, Bernhard; Offenhäusser, Andreas; Yakushenko, Alexey

    2017-05-01

    A simple lab-on-a-chip method for blood plasma separation was developed by combining stereolithographic 3D printing with inkjet printing, creating a completely sealed microfluidic device. In some approaches, one dilutes the blood sample before separation, reducing the concentration of a target analyte and increasing a contamination risk. In this work, a single drop (8  μ l) of heparinized whole blood could be efficiently filtered using a capillary effect without any external driving forces and without dilution. The blood storage in heparin tubes during 24 h at 4 °C initiated the formation of small crystals that formed auto-filtration structures in the sample upon entering the 3D-printed device, with pores smaller than the red blood cells, separating plasma from the cellular content. The total filtration process took less than 10 s. The presented printed plasma filtration microfluidics fabricated with a rapid prototyping approach is a miniaturized, fast and easy-to-operate device that can be integrated into healthcare/portable systems for point-of-care diagnostics.

  19. Effect of heparin calcium different concentrations on some physical properties and structure in polyacrylamide matrix

    International Nuclear Information System (INIS)

    Abdelrazek, E.M.; Ibrahim, Hosam S.

    2010-01-01

    Films of polyacrylamide (PAAm) doped with different concentrations of heparin calcium, from 0.0 to 8 wt%, have been prepared by casting method. Studies were carried out utilizing X-ray, FT-IR, UV/VIS, DSC and DC electrical conduction to characterize the structural, optical and thermal properties of the films. Results revealed that the structural and chemical characterizations of PAAm films are affected by the addition of heparin calcium content. XRD spectra revealed that the amorphous phases increase with increase in filling levels of heparin (FLs). FT-IR analysis revealed that incorporation of heparin calcium leads to a small modification in the spectra of films. The optical absorption spectra in the UV/VIS region revealed structural variation increases with increase in concentration, which is reflected in the form of decrease in the energy band gap E g . Significant changes of DSC curves of the films suggest that strong interaction established between heparin calcium and PAAm molecules. The DC electric conduction data were interpreted on the basis of an intrachain one-dimensional interpolaron hopping model of Kuivalainen.

  20. Interaction of complement-solubilized immune complexes with CR1 receptors on human erythrocytes. The binding reaction

    DEFF Research Database (Denmark)

    Jepsen, H H; Svehag, S E; Jarlbaek, L

    1986-01-01

    showed no binding. IC solubilized in 50% human serum in the presence of autologous RBC bound rapidly to RBC-CR1, with maximal binding within less than 1 min at 37 degrees C. Release of CR1-bound IC under these conditions occurred slowly, requiring more than 30 min. Only binding of 'partially' solubilized...... of an intact classical pathway in preparing the IC for binding to RBC-CR1. C-solubilized IC could be absorbed to solid-phase conglutinin or antibody to C3c and C4c, and these ligands were able to inhibit the binding of solubilized IC to RBC. Heparin also exerted a marked, dose-dependent inhibitory effect...

  1. Thrombolytic treatment for acute ischemic cerebral stroke: intraarterial urokinase infusion vs. intravenous heparin and urokinase infusion

    International Nuclear Information System (INIS)

    Ko, Gi Young; Suh, Dae Chul; Lee, Jae Hong; Kim, Jun Hyoung; Choi, Choong Gon; Lee, Ho Kyu; Lee, Myoung Chong

    1996-01-01

    To evaluate the efficacy and limitation of intra-arterial urokinase (IAUK) infusion for treatment of acute cerebral stroke. Twenty-seven acute cerebral stroke patients treated with IAUK infusion within six hours of stroke onset were reviewed. All patients showed normal initial brain findings on CT. In 21 patients, urokinase(5-15 x 10 5 IU) was administered through a microcatheter placed into or proximal to occluded segment. Mechanical disruption of thrombus by guidewire was performed in 17 patients. Angiographic and clinical responses and complications after IAUK infusion, were evaluated and the results were compared with those of intravenous heparin(N=19) and urokinase infusion(N=19). Complete or partial angiographic recanalization of occluded segment was found in 18 patients (67%), and neurologic improvement was followed in 14 patients(52%). The degree of improvement on the stroke scale score after IAUK infusion was statistically more significant(p<0.05) than that shown after intravenous heparin and urokinase infusion. Complications after IAUK infusion were large(15%) and small amount intracerebral hemorrhage(15%), contrast leakage into brain parenchyma(11%), and gastrointestinal bleeding(4%). Between the IAVK and the intravenous urokinase infusion group, differences in extent and types of complications were statistically insignificant, but were significantly higher in those two groups than in the intravenous heparin infusion group. IAUK infusion may be effective for the treatment of acute cerebral stroke

  2. A new approach for heparin standardization: combination of scanning UV spectroscopy, nuclear magnetic resonance and principal component analysis.

    Directory of Open Access Journals (Sweden)

    Marcelo A Lima

    Full Text Available The year 2007 was marked by widespread adverse clinical responses to heparin use, leading to a global recall of potentially affected heparin batches in 2008. Several analytical methods have since been developed to detect impurities in heparin preparations; however, many are costly and dependent on instrumentation with only limited accessibility. A method based on a simple UV-scanning assay, combined with principal component analysis (PCA, was developed to detect impurities, such as glycosaminoglycans, other complex polysaccharides and aromatic compounds, in heparin preparations. Results were confirmed by NMR spectroscopy. This approach provides an additional, sensitive tool to determine heparin purity and safety, even when NMR spectroscopy failed, requiring only standard laboratory equipment and computing facilities.

  3. Analysis of electric moments of RNA-binding proteins: implications for mechanism and prediction

    Directory of Open Access Journals (Sweden)

    Sarai Akinori

    2011-02-01

    Full Text Available Abstract Background Protein-RNA interactions play important role in many biological processes such as gene regulation, replication, protein synthesis and virus assembly. Although many structures of various types of protein-RNA complexes have been determined, the mechanism of protein-RNA recognition remains elusive. We have earlier shown that the simplest electrostatic properties viz. charge, dipole and quadrupole moments, calculated from backbone atomic coordinates of proteins are biased relative to other proteins, and these quantities can be used to identify DNA-binding proteins. Closely related, RNA-binding proteins are investigated in this study. In particular, discrimination between various types of RNA-binding proteins, evolutionary conservation of these bulk electrostatic features and effect of conformational changes by complex formation are investigated. Basic binding mechanism of a putative RNA-binding protein (HI1333 from Haemophilus influenza is suggested as a potential application of this study. Results We found that similar to DNA-binding proteins (DBPs, RNA-binding proteins (RBPs also show significantly higher values of electric moments. However, higher moments in RBPs are found to strongly depend on their functional class: proteins binding to ribosomal RNA (rRNA constitute the only class with all three of the properties (charge, dipole and quadrupole moments being higher than control proteins. Neural networks were trained using leave-one-out cross-validation to predict RBPs from control data as well as pair-wise classification capacity between proteins binding to various RNA types. RBPs and control proteins reached up to 78% accuracy measured by the area under the ROC curve. Proteins binding to rRNA are found to be best distinguished (AUC = 79%. Changes in dipole and quadrupole moments between unbound and bound structures were small and these properties are found to be robust under complex formation. Conclusions Bulk electric

  4. Assessment of HIT Antibody Complex in Hip Fracture Patients Receiving Enoxaparin or Unfractionated Heparin

    DEFF Research Database (Denmark)

    Griffin, Justin W; Hopkinson, William J; Rud-Lassen, Michael

    2011-01-01

    of antiheparin-PF4 antibodies and a greater prevalence of immunoglobulin G (IgG) subtype. Heparin and enoxaparin are capable of generating heparin-induced thrombocytopenia (HIT) antibodies in elderly patients undergoing orthopedic surgery but perhaps not to the same extent. When comparing low...

  5. Heparin defends against the toxicity of circulating histones in sepsis.

    Science.gov (United States)

    Wang, Feifei; Zhang, Naipu; Li, Biru; Liu, Lanbo; Ding, Lei; Wang, Ying; Zhu, Yimin; Mo, Xi; Cao, Qing

    2015-06-01

    Although circulating histones were demonstrated as major mediators of death in septic mice models, their roles in septic patients are not clarified. The present study sought to evaluate the clinical relevance of the circulating histone levels in septic children, and the antagonizing effects of heparin on circulating histones. Histone levels in the plasma of septic children were significantly higher than healthy controls, and positively correlated with disease severity. Histone treatment could activate NF-κB pathway of the endothelial cells and induce the secretion of large amount of cytokines that further amplify inflammation, subsequently leading to organ damage. Co-injection of low dose heparin with lethal dose histones could protect mouse from organ damage and death by antagonizing circulating histones, and similar effects were also observed in other septic models. Collectively, these findings indicated that circulating histones might serve as key factors in the pathogenesis of sepsis and their levels in plasma might be a marker for disease progression and prognosis. Furthermore, low dose heparin might be an effective therapy to hamper sepsis progression and reduce the mortality.

  6. The effect of heparin administration on the FT4-levels and on an unspecific peripheral thyroid parameter

    International Nuclear Information System (INIS)

    Eber, B.; Borkenstein, J.; Leb, G.

    1984-01-01

    Heparin produces changes in FT 4 -levels both in vivo and in vitro as determined by commercial kits. Methods utilising the principle of equilibrium dialysis show significant increases whereas methods using T 4 -tracer analogue techniques reveal marked decreases in FT 4 -values. Possible clinical side-effects of heparin administration such as heparin-induced hyperthyroidism and tachyarrhythmias are discussed. The present results confirm the FT 4 -decreasing effect of in vivo and in vitro administration of heparin with FT 4 -RIAs based on the tracer analogue technique; however, the unspecific peripheral thyroid parameter of systolic time-intervals did not reveal any tendency towards hyperthyroidism. Also the discrepant results dependent on the method used, indicate that, following heparin administration FT 4 -levels do not reflect that hormone concentration is relevant to the metabolism of the whole body. (orig.) [de

  7. Quantum mechanics/molecular mechanics modeling of photoelectron spectra: the carbon 1s core-electron binding energies of ethanol-water solutions.

    Science.gov (United States)

    Löytynoja, T; Niskanen, J; Jänkälä, K; Vahtras, O; Rinkevicius, Z; Ågren, H

    2014-11-20

    Using ethanol-water solutions as illustration, we demonstrate the capability of the hybrid quantum mechanics/molecular mechanics (QM/MM) paradigm to simulate core photoelectron spectroscopy: the binding energies and the chemical shifts. An integrated approach with QM/MM binding energy calculations coupled to preceding molecular dynamics sampling is adopted to generate binding energies averaged over the solute-solvent configurations available at a particular temperature and pressure and thus allowing for a statistical assessment with confidence levels for the final binding energies. The results are analyzed in terms of the contributions in the molecular mechanics model-electrostatic, polarization, and van der Waals-with atom or bond granulation of the corresponding MM charge and polarizability force-fields. The role of extramolecular charge transfer screening of the core-hole and explicit hydrogen bonding is studied by extending the QM core to cover the first solvation shell. The results are compared to those obtained from pure electrostatic and polarizable continuum models. Particularly, the dependence of the carbon 1s binding energies with respect to the ethanol concentration is studied. Our results indicate that QM/MM can be used as an all-encompassing model to study photoelectron binding energies and chemical shifts in solvent environments.

  8. Anticoagulant effects of inhaled unfractionated heparin in the dog as determined by partial thromboplastin time and factor Xa activity.

    Science.gov (United States)

    Manion, Jill S; Thomason, John M; Langston, Vernon C; Claude, Andrew K; Brooks, Marjory B; Mackin, Andrew J; Lunsford, Kari V

    2016-01-01

    To evaluate the anticoagulant effects of inhaled heparin in dogs. This study was conducted in 3 phases. In phase 1, bronchoalveolar lavage fluid (BALf) was collected to generate an in vitro calibration curve to relate heparin concentration to the activated partial thromboplastin time (aPTT). In phase 2, heparin was administered via nebulization to determine the threshold dose needed to prolong systemic aPTT. In phase 3, the local anticoagulant activity of inhaled heparin was determined by measurement of BALf anti-Xa activity and aPTT. University teaching hospital. Six healthy intact female Walker Hounds were used in this study. Two dogs were used for each phase. Inhaled unfractionated sodium heparin was administered in doses ranging from 50,000 to 200,000 IU. In vitro addition of heparin to BALf caused a prolongation in aPTT. Inhaled heparin at doses as high as 200,000 IU failed to prolong systemic aPTT, and a threshold dose could not be determined. No significant local anticoagulant effects were detected. Even at doses higher than those known to be effective in people, inhaled heparin appears to have no detectable local or systemic anticoagulant effects in dogs with the current delivery method. © Veterinary Emergency and Critical Care Society 2015.

  9. Heparin for prolonging peripheral intravenous catheter use in neonates: a randomized controlled trial.

    Science.gov (United States)

    Upadhyay, A; Verma, K K; Lal, P; Chawla, D; Sreenivas, V

    2015-04-01

    To determine the efficacy of heparinized saline administered as intermittent flush on functional duration of the peripheral intravenous catheter (PIVC) in neonates. Randomized, double-blind and placebo-controlled trial. Neonatal intensive care unit of a teaching hospital. Term and preterm neonates born at >32 weeks of gestation who required PIVC only for intermittent administration of antibiotics. Eligible neonates were randomized to receive 1 ml of either heparinized saline (10 U ml(-1)) (n=60) or normal saline (n=60) every 12 h before and after intravenous antibiotics. Functional duration of first peripheral intravenous catheter. A total of 120 neonates were randomized to two groups of 60 neonates each. The mean (s.d.) of age of babies in case and control group was 5.7 (2.5) days and 4.6 (3.1) days, respectively. The average weight of babies in both the groups was 2.1 kg. Mean functional duration of first catheter was more in heparinized saline group, mean (s.d.) of 71.68 h  (27.3) as compared with 57.7 h (23.6) in normal saline group (P<0.005). The mean (95% confidence interval) difference in functional duration in the two groups was 13.9 h (4.7-23.15). Mean duration of patency for any catheter was also significantly more in heparinized saline group than control group. Heparinized saline flush increases the functional duration of peripheral intravenous catheter.

  10. Prevention of after-cataract by application of heparin treatment of capsular tension ring in Marfan syndrome and subluxation of lens

    Directory of Open Access Journals (Sweden)

    Zhong-Qing Li

    2013-08-01

    Full Text Available AIM: To investigate the effect of heparin treatment on capsular tension ring(CTRin the prevention of after-cataract postoperative patients with Marfan syndrome and subluxation of lens.METHODS: Totally 34 cases(56 eyeswere divided randomly into experimental and control groups. Preoperative heparin 12500 units was added to 500mL Ringer's infusion, and CTR was dealt with heparin stock solution soak for 20 minutes in experimental group; there was no any drugs in the control group's solution, and CTR was not dealt with heparin. Postoperative IOP, anterior chamber reaction, corneal edema, IOL position, posterior capsular opacification were observed.RESULTS: There was statistically significant difference in the posterior capsular opacification between the heparin group(13.3%and the contral group no-heparin(69.2%(PCONCLUSION: The present results indicate that there is the preventive effect on posterior capsular opacification by CTR soaked in heparin in postoperative patients with Marfan syndrome and subluxation of lens, thus contributing to the recovery of visual function.

  11. Vascular access site complication in transfemoral coronary angiography between uninterrupted warfarin and heparin bridging.

    Science.gov (United States)

    Wongcharoen, Wanwarang; Pinyosamosorn, Kittipong; Gunaparn, Siriluck; Boonnayhun, Suchada; Thonghong, Tasalak; Suwannasom, Pannipa; Phrommintikul, Arintaya

    2017-08-01

    Warfarin discontinuation with heparin bridging is a common practice in patients receiving warfarin prior to elective coronary angiography (CAG). The uninterrupted warfarin strategy has been suggested to be alternative option for patients with high thromboembolic risk. Therefore, we aimed to assess the safety of elective transfemoral CAG during uninterrupted warfarin therapy compared to heparin bridging. This study was a randomized open-label design with blinded event evaluation. The 110 consecutive patients (age ≥ 18 years) receiving warfarin before the planned transfemoral CAG were randomly assigned to either heparin bridging or uninterrupted warfarin with targeted INR (2.0-3.0). The primary outcome was the incidence of major vascular access site complications. The baseline characteristics were comparable between two groups (mean age was 60.1 ± 7.8 years, 49 males). The mean INR on the day of CAG of heparin bridging and uninterrupted warfarin groups was 1.2 ± 0.3 and 2.2 ± 0.5 (P warfarin patients (P = 0.243). The total vascular access site complications occurred in 6 (10.9%) heparin-bridging and one (1.8%) uninterrupted warfarin patients (P = 0.113). No patient developed either other bleeding or thromboembolic events during 7 days after CAG. We demonstrated that an uninterrupted warfarin strategy did not increase vascular access site complications in patients undergoing transfemoral CAG compared to heparin bridging therapy. Due to the safety and the ease of uninterrupted warfarin strategy, this approach should be encouraged in patients receiving long-term warfarin who undergo elective transfemoral CAG. © 2017, Wiley Periodicals, Inc.

  12. 21 CFR 864.5680 - Automated heparin analyzer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated heparin analyzer. 864.5680 Section 864.5680 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology Devices § 864...

  13. Stat5 phosphorylation is responsible for the excessive potency of HB-EGF.

    Science.gov (United States)

    Heo, Jeongyeon; Kim, Jae Geun; Kim, Sunghwan; Kang, Hara

    2017-12-23

    Heparin-binding EGF-like growth factor (HB-EGF) is a potent growth factor involved in wound healing and tumorigenesis. Despite the sequence similarity between HB-EGF and EGF, HB-EGF induces cellular proliferation and migration more potently than EGF. However, the differential regulation by HB-EGF and EGF has not been thoroughly elucidated. In this study, we compared signaling pathways activated by HB-EGF and EGF to understand the details of the molecular mechanism of the high potency induced by HB-EGF. HB-EGF specifically induced the phosphorylation of EGFR-Y1045 and activated Stat5, which is responsible for promoting cell proliferation, and migration. The competition of phosphorylated EGFR-Y1045 inhibited Stat5 activation and consequently lowered the effect of HB-EGF on cell proliferation, suggesting that the phosphorylation of EGFR-Y1045 is essential for the activation of Stat5. The phosphorylation of EGFR-Y1045 and Stat5 induced by HB-EGF was prevented by sequestering the heparin-binding domain, suggesting that the heparin-binding domain is critical for HB-EGF-mediated signaling and cellular responses. In conclusion, the heparin-binding domain of HB-EGF was responsible for EGFR-mediated Stat5 activation, resulting in a more potent cellular proliferation, and migration than that mediated by EGF. This molecular mechanism is useful for understanding ligand-specific EGFR signaling and developing biomedicines for wound healing or cancer therapy. © 2017 Wiley Periodicals, Inc.

  14. Analysis of the complex formation of heparin with protamine by light scattering and analytical ultracentrifugation: implications for blood coagulation management.

    Science.gov (United States)

    Maurer, Jürgen; Haselbach, Stephanie; Klein, Oliver; Baykut, Doan; Vogel, Vitali; Mäntele, Werner

    2011-02-02

    Heparin, a linear glycosaminoglycan, is used in different forms in anticoagulation treatment. Protamine, a highly positive charged peptide containing about 32 amino acids, acts as an antagonist for heparin to restore normal blood coagulation. The complex formation of protamine with heparin was analyzed by a combination of analytical ultracentrifugation and light scattering. Titration of heparin with protamine in blood plasma preparations results in a drastic increase of turbidity, indicating the formation of nanoscale particles. A similar increase of turbidity was observed in physiological saline solution with or without human serum albumin (HSA). Particle size analysis by analytical ultracentrifugation revealed a particle radius of approximately 30 nm for unfractionated heparin and of approximately 60 nm for low molecular weight heparin upon complexation with excess protamine, in agreement with atomic force microscopy data. In the absence of HSA, larger and more heterogeneous particles were observed. The particles obtained were found to be stable for hours. The particle formation kinetics was analyzed by light scattering at different scattering angles and was found to be complete within several minutes. The time course of particle formation suggests a condensation reaction, with sigmoidal traces for low heparin concentrations and quasi-first-order reaction for high heparin concentrations. Under all conditions, the final scattering intensity reached after several minutes was found to be proportional to the amount of heparin in the blood plasma or buffer solution, provided that excess protamine was available and no multiple scattering occurred. On the basis of a direct relation between particle concentration and the heparin concentration present before protaminization, a light scattering assay was developed which permits the quantitative analysis of the heparin concentration in blood plasma and which could complement or even replace the activated clotting time test

  15. Lead inhibition of DNA-binding mechanism of Cys(2)His(2) zinc finger proteins.

    Science.gov (United States)

    Hanas, J S; Rodgers, J S; Bantle, J A; Cheng, Y G

    1999-11-01

    The association of lead with chromatin in cells suggests that deleterious metal effects may in part be mediated through alterations in gene function. To elucidate if and how lead may alter DNA binding of cysteine-rich zinc finger proteins, lead ions were analyzed for their ability to alter the DNA binding mechanism of the Cys(2)His(2) zinc finger protein transcription factor IIIA (TFIIIA). As assayed by DNase I protection, the interaction of TFIIIA with the 50-bp internal control region of the 5S ribosomal gene was partially inhibited by 5 microM lead ions and completely inhibited by 10 to 20 microM lead ions. Preincubation of free TFIIIA with lead resulted in DNA-binding inhibition, whereas preincubation of a TFIIIA/5S RNA complex with lead did not result in DNA-binding inhibition. Because 5S RNA binds TFIIIA zinc fingers, this result is consistent with an inhibition mechanism via lead binding to zinc fingers. The complete loss of DNase I protection on the 5S gene indicates the mechanism of inhibition minimally involves the N-terminal fingers of TFIIIA. Inhibition was not readily reversible and occurred in the presence of an excess of beta-mercaptoethanol. Inhibition kinetics were fast, progressing to completion in approximately 5 min. Millimolar concentrations of sulfhydryl-specific arsenic ions were not inhibitory for TFIIIA binding. Micromolar concentrations of lead inhibited DNA binding by Sp1, another Cys(2)His(2) finger protein, but not by the nonfinger protein AP2. Inhibition of Cys(2)His(2) zinc finger transcription factors by lead ions at concentrations near those known to have deleterious physiological effects points to new molecular mechanisms for lead toxicity in promoting disease.

  16. Backbone dynamics of a biologically active human FGF-1 monomer, complexed to a hexasaccharide heparin-analogue, by 15N NMR relaxation methods

    International Nuclear Information System (INIS)

    Canales-Mayordomo, Angeles; Fayos, Rosa; Angulo, Jesus; Ojeda, Rafael; Martin-Pastor, Manuel; Nieto, Pedro M.; Martin-Lomas, Manuel; Lozano, Rosa; Gimenez-Gallego, Guillermo; Jimenez-Barbero, Jesus

    2006-01-01

    The binding site and backbone dynamics of a bioactive complex formed by the acidic fibroblast growth factor (FGF-1) and a specifically designed heparin hexasaccharide has been investigated by HSQC and relaxation NMR methods. The comparison of the relaxation data for the free and bound states has allowed showing that the complex is monomeric, and still induces mutagenesis, and that the protein backbone presents reduced motion in different timescale in its bound state, except in certain points that are involved in the interaction with the fibroblast growth factor receptor (FGFR)

  17. Biosynthesis of heparin. Effects of n-butyrate on cultured mast cells

    International Nuclear Information System (INIS)

    Jacobsson, K.G.; Riesenfeld, J.; Lindahl, U.

    1985-01-01

    Murine mastocytoma cells were incubated in vitro with inorganic [ 35 S]sulfate, in the absence or presence of 2.5 mM n-butyrate, and labeled heparin was isolated. The polysaccharide produced in the presence of butyrate showed a lower charge density on anion exchange chromatography than did the control material and a 3-fold increased proportion of components with high affinity for antithrombin. Structural analysis of heparin labeled with [ 3 H] glucosamine in the presence of butyrate showed that approximately 35% of the glucosamine units were N-acetylated, as compared to approximately 10% in the control material; the nonacetylated glucosamine residues were N-sulfated. The presence of butyrate thus leads to an inhibition of the N-deacetylation/N-sulfation process in heparin biosynthesis, along with an augmented formation of molecules with high affinity for antithrombin. Preincubation of the mastocytoma cells with butyrate was required for manifestation of either effect; when the preincubation period was reduced from 24 to 10 h the effects of butyrate were no longer observed. A polysaccharide formed on incubating mastocytoma microsomal fraction with UDP-[ 3 H]glucuronic acid, UDP-N-acetylglucosamine, and 3'-phosphoadenylylsulfate in the presence of 5 mM butyrate showed the same N-acetyl/N-sulfate ratio as did the corresponding control polysaccharide, produced in the absence of butyrate. These findings suggest that the effect of butyrate on heparin biosynthesis depends on the integrity of the cell

  18. Association between Activated Partial Thromboplastin Time and the Amount of Infused Heparin at Bone Marrow Transplantation.

    Science.gov (United States)

    Kusuda, Machiko; Kimura, Shun-Ichi; Misaki, Yukiko; Yoshimura, Kazuki; Gomyo, Ayumi; Hayakawa, Jin; Tamaki, Masaharu; Akahoshi, Yu; Ugai, Tomotaka; Kameda, Kazuaki; Wada, Hidenori; Ishihara, Yuko; Kawamura, Koji; Sakamoto, Kana; Sato, Miki; Terasako-Saito, Kiriko; Kikuchi, Misato; Nakasone, Hideki; Kako, Shinichi; Tanihara, Aki; Kanda, Yoshinobu

    2018-03-27

    The actual heparin concentration of harvested allogeneic bone marrow varies among harvest centers. We monitor the activated partial thromboplastin time (APTT) of the patient during bone marrow infusion and administer prophylactic protamine according to the APTT. We retrospectively reviewed the charts of consecutive patients who underwent bone marrow transplantation without bone marrow processing at our center between April 2007 and March 2016 (n = 94). APTT was monitored during marrow transfusion in 52 patients. We analyzed the relationship between the APTT ratio and several parameters related to heparin administration. As a result, the weight-based heparin administration rate (U/kg/hour) seemed to be more closely related to the APTT ratio (r = .38, P = .005) than to the total amount of heparin. There was no significant correlation between the APTT ratio and renal or liver function. Bleeding complications during and early after infusion were seen in 3 of 52 patients, and included intracranial, nasal, and punctured-skin bleeding. The APTT ratio during transfusion was over 5.88 in the former 2 patients and 2.14 in the latter. All of these patients recovered without sequelae. In conclusion, slow bone marrow infusion is recommended to decrease the weight-based heparin administration rate when the heparin concentration per patient body weight is high. Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  19. Taurolidine lock is superior to heparin lock in the prevention of catheter related bloodstream infections and occlusions.

    Directory of Open Access Journals (Sweden)

    Evelyn D Olthof

    Full Text Available Patients on home parenteral nutrition (HPN are at risk for catheter-related complications; mainly infections and occlusions. We have previously shown in HPN patients presenting with catheter sepsis that catheter locking with taurolidine dramatically reduced re-infections when compared with heparin. Our HPN population therefore switched from heparin to taurolidine in 2008. The aim of the present study was to compare long-term effects of this catheter lock strategy on the occurrence of catheter-related bloodstream infections and occlusions in HPN patients.Data of catheter-related complications were retrospectively collected from 212 patients who received HPN between January 2000 and November 2011, comprising 545 and 200 catheters during catheter lock therapy with heparin and taurolidine, respectively. We evaluated catheter-related bloodstream infection and occlusion incidence rates using Poisson-normal regression analysis. Incidence rate ratios were calculated by dividing incidence rates of heparin by those of taurolidine, adjusting for underlying disease, use of anticoagulants or immune suppressives, frequency of HPN/fluid administration, composition of infusion fluids, and duration of HPN/fluid use before catheter creation.Bloodstream infection incidence rates were 1.1/year for heparin and 0.2/year for taurolidine locked catheters. Occlusion incidence rates were 0.2/year for heparin and 0.1/year for taurolidine locked catheters. Adjusted incidence ratios of heparin compared to taurolidine were 5.9 (95% confidence interval, 3.9-8.7 for bloodstream infections and 1.9 (95% confidence interval, 1.1-3.1 for occlusions.Given that no other procedural changes than the catheter lock strategy were implemented during the observation period, these data strongly suggest that taurolidine decreases catheter-related bloodstream infections and occlusions in HPN patients compared with heparin.

  20. Different mechanisms are involved in the antibody mediated inhibition of ligand binding to the urokinase receptor

    DEFF Research Database (Denmark)

    List, K; Høyer-Hansen, G; Rønne, E

    1999-01-01

    Certain monoclonal antibodies are capable of inhibiting the biological binding reactions of their target proteins. At the molecular level, this type of effect may be brought about by completely different mechanisms, such as competition for common binding determinants, steric hindrance or interfer......Certain monoclonal antibodies are capable of inhibiting the biological binding reactions of their target proteins. At the molecular level, this type of effect may be brought about by completely different mechanisms, such as competition for common binding determinants, steric hindrance......) can be employed as a highly useful tool to characterize the inhibitory mechanism of specific antagonist antibodies. Two inhibitory antibodies against uPAR, mAb R3 and mAb R5, were shown to exhibit competitive and non-competitive inhibition, respectively, of ligand binding to the receptor. The former...

  1. Clinical effects of low-molecular-weight heparin combined with ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research August 2016; 15 (8): 1787-1792 ... Keywords: Acute pancreatitis, Low-molecular-weight heparin, Multiple organ function syndrome,. APACHE II score ... mediators by lowering the expression of.

  2. [Morphology research of the rat sciatic nerve bridged by collage-heparin sulfate scaffold].

    Science.gov (United States)

    Wang, Shu-sen; Hu, Yun-yu; Luo, Zhuo-jing; Chen, Liang-wei; Liu, Hui-ling; Meng, Guo-lin; Lü, Rong; Xu, Xin-zhi

    2005-04-15

    To observe the treating effect of collage-heparin sulfate after the 10 mm rat sciatic nerve defect was bridged by it. A new kind of nervous tissue engineering scaffold was produced by freeze-drying technique from collagen-heparin sulfate. Thirty-two SD rats were randomly divided into A, B, C and D groups. Sciatic nerve defect in group A was bridged by collagen-heparin sulfate. In group B, sciatic nerve was bridged by auto-nerve transplantation. Group C was the blank control group. Animals in group D were normal. And 10 mm sciatic nerve defect was bridged in the experiment. Thirty-six weeks after the operation, the experimental animals were detected by HRP labeled retrograde trace, HE staining, toluidine staining, silvering staining, S100, GAP-43 and NF immunohistological staining, MBP immunofluorescence staining and transmission electron microscope to observe the nerve regeneration inducing effect of this new scaffold. Nine months after operation, the collage-heparin sulfate scaffold was replaced by newly regenerated nerve. The number of HRP labeled spinal cord anterior horn cells and the area of sensation nerve fiber at the posterior horn were similar with that was repaired by auto-nerve. GAP-43, NF and S100 labeled regenerated nerve fiber had passed the total scaffold and entered the distal terminal. The regenerated nerve fibers were paralleled, lineage arranged, coincide with the prearranged regenerating "channel" in the collagen-heparin sulfate scaffold. MBP immunofluorescence staining also proved that the newly regenerated nerve fiber could be ensheathed. In the experimental group, the area of myelinated nerve fiber and the thickness of the myelin sheath had no obvious difference with that of the group repaired by auto-nerve, except that the density of the regenerated myelinated sheath fiber was lower than that of the control group. Nervous tissue engineering scaffold produced by collagen-heparin sulfate can guide the regeneration of nerve fibers. The nerve

  3. Prolonged Activated Clotting Time after Protamine Administration Does Not Indicate Residual Heparinization after Cardiopulmonary Bypass in Pediatric Open Heart Surgery.

    Science.gov (United States)

    Yamamoto, Tomohiro; Wolf, Hans-Gerd; Sinzobahamvya, Nicodème; Asfour, Boulos; Hraska, Victor; Schindler, Ehrenfried

    2015-08-01

    In open heart surgery, heparinization is commonly neutralized using an empirical heparin:protamine ratio ranging between 1:1 and 1:1.5. However, these ratios may result in protamine overdose that should be avoided for its negative side effects on the coagulation system. This study aimed to indicate the appropriate treatment for prolonged activated clotting time (ACT) after protamine administration following cardiopulmonary bypass (CPB) in pediatric open heart surgery by investigating the underlying reasons for it. Twenty-seven children (open heart surgery were included. Heparin was administered only before CPB (400 IU/kg) and in the pump priming volume for CPB (2,000 IU) and was neutralized by 1:1 protamine after CPB. The blood heparin concentration was measured using anti-Xa assay. ACT and blood concentrations of heparin, coagulation factors, thrombin-antithrombin complex, and prothrombin fragment 1 + 2 were assessed. A rotational thromboelastometry (ROTEM; Tem International GmbH, München, Bayern, Germany) was used to confirm the coagulation status and residual heparin after protamine administration. Anti-Xa assay showed that there is no residual heparin in the blood after 1:1 protamine administration. Nevertheless, ACT (128.89 ± 3.09 seconds before heparin administration) remained prolonged (177.14 ± 5.43 seconds at 10 minutes after protamine, 182.00 ± 5.90 seconds at 30 minutes after protamine). The blood concentrations of coagulation factors were significantly lower than those before heparin administration (p < 0.01). The low FIBTEM MCF of ROTEM (4.43 ± 0.32 mm) at 10 minutes after protamine indicated low fibrinogen concentration. Prolonged ACT after heparin neutralization by 1:1 protamine administration does not necessarily indicate residual heparin, but low blood concentrations of coagulation factors should be considered as a reason as well. Accordingly, supply of coagulation factors instead of additional protamine should be

  4. Farmacovigilância da heparina no Brasil Heparin pharmacovigilance in Brazil

    Directory of Open Access Journals (Sweden)

    Daniela Rezende Garcia Junqueira

    2011-06-01

    Full Text Available OBJETIVO: Investigar a origem das preparações de heparina, na forma farmacêutica injetável, disponíveis no mercado brasileiro, discutindo o impacto do perfil dos produtos comercializados e das alterações na monografia da heparina na segurança do fármaco. MÉTODOS: Pesquisou-se o banco de dados de Produtos Registrados das Empresas de Medicamentos da Anvisa e o Dicionário de Especialidades Farmacêuticas (DEF 2008/2009. Foi realizado inquérito com as indústrias com autorização ativa para o comércio do fármaco no Brasil. RESULTADOS: Cinco indústrias possuem autorização para o comércio de heparina não fracionada no Brasil. Três são de origem suína e duas de origem bovina, sendo que apenas uma possui essa informação explicitada na bula. A efetividade e a segurança da heparina, estudadas em populações estrangeiras, podem não representar a nossa realidade, já que a maioria dos países não produz a heparina bovina. A heparina atualmente comercializada tem, ainda, aproximadamente 10% menos atividade anticoagulante que a anteriormente produzida, e essa alteração pode ter implicações clínicas. CONCLUSÃO: Evidências acerca da ausência de intercambialidade de doses entre as heparinas de origem bovina e suína e o diferenciado perfil de segurança entre esses fármacos indicam necessidade de acompanhamento do tratamento e da resposta dos pacientes. Eventos que ameacem a segurança do paciente devem ser comunicados ao sistema da farmacovigilância do país.OBJECTIVE: To investigate the biological origin of injectable unfractioned heparin available in Brazilian market by discussing the impact of the profile of commercial products and the changes in heparin monograph on the drug safety. METHODS: The Anvisa data base for the Registered Products of Pharmaceutical Companies and the Dictionary of Pharmaceutical Specialties (DEF 2008/2009 were searched. A survey with industries having an active permission for marketing the drug

  5. Inversion of lithium heparin gel tubes after centrifugation is a significant source of bias in clinical chemistry testing.

    Science.gov (United States)

    Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Lima-Oliveira, Gabriel; Brocco, Giorgio; Guidi, Gian Cesare

    2014-09-25

    This study was planned to establish whether random orientation of gel tubes after centrifugation may impair sample quality. Eight gel tubes were collected from 17 volunteers: 2 Becton Dickinson (BD) serum tubes, 2 Terumo serum tubes, 2 BD lithium heparin tubes and 2 Terumo lithium heparin tubes. One patient's tube for each category was kept in a vertical, closure-up position for 90 min ("upright"), whereas paired tubes underwent bottom-up inversion every 15 min, for 90 min ("inverted"). Immediately after this period of time, 14 clinical chemistry analytes, serum indices and complete blood count were then assessed in all tubes. Significant increases were found for phosphate and lipaemic index in all inverted tubes, along with AST, calcium, cholesterol, LDH, potassium, hemolysis index, leukocytes, erythrocytes and platelets limited to lithium heparin tubes. The desirable quality specifications were exceeded for AST, LDH, and potassium in inverted lithium heparin tubes. Residual leukocytes, erythrocytes, platelets and cellular debris were also significantly increased in inverted lithium heparin tubes. Lithium heparin gel tubes should be maintained in a vertical, closure-up position after centrifugation. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Engineering the mechanical and biological properties of nanofibrous vascular grafts for in situ vascular tissue engineering.

    Science.gov (United States)

    Henry, Jeffrey J D; Yu, Jian; Wang, Aijun; Lee, Randall; Fang, Jun; Li, Song

    2017-08-17

    Synthetic small diameter vascular grafts have a high failure rate, and endothelialization is critical for preventing thrombosis and graft occlusion. A promising approach is in situ tissue engineering, whereby an acellular scaffold is implanted and provides stimulatory cues to guide the in situ remodeling into a functional blood vessel. An ideal scaffold should have sufficient binding sites for biomolecule immobilization and a mechanical property similar to native tissue. Here we developed a novel method to blend low molecular weight (LMW) elastic polymer during electrospinning process to increase conjugation sites and to improve the mechanical property of vascular grafts. LMW elastic polymer improved the elasticity of the scaffolds, and significantly increased the amount of heparin conjugated to the micro/nanofibrous scaffolds, which in turn increased the loading capacity of vascular endothelial growth factor (VEGF) and prolonged the release of VEGF. Vascular grafts were implanted into the carotid artery of rats to evaluate the in vivo performance. VEGF treatment significantly enhanced endothelium formation and the overall patency of vascular grafts. Heparin coating also increased cell infiltration into the electrospun grafts, thus increasing the production of collagen and elastin within the graft wall. This work demonstrates that LMW elastic polymer blending is an approach to engineer the mechanical and biological property of micro/nanofibrous vascular grafts for in situ vascular tissue engineering.

  7. Backbone dynamics of a biologically active human FGF-1 monomer, complexed to a hexasaccharide heparin-analogue, by {sup 15}N NMR relaxation methods

    Energy Technology Data Exchange (ETDEWEB)

    Canales-Mayordomo, Angeles; Fayos, Rosa [Centro de Investigaciones Biologicas, CSIC, Departamento de Estructura y Funcion de Proteinas (Spain); Angulo, Jesus; Ojeda, Rafael [Instituto de Investigaciones Quimicas, CSIC, Grupo de Carbohidratos (Spain); Martin-Pastor, Manuel [Unidad de RM y Unidad de RMN de Biomoleculas Asociada al CSIC, Laboratorio de Estructura e Estructura de Biomoleculas Jose Carracido (Spain); Nieto, Pedro M.; Martin-Lomas, Manuel [Instituto de Investigaciones Quimicas, CSIC, Grupo de Carbohidratos (Spain); Lozano, Rosa; Gimenez-Gallego, Guillermo; Jimenez-Barbero, Jesus [Centro de Investigaciones Biologicas, CSIC, Departamento de Estructura y Funcion de Proteinas (Spain)], E-mail: jjbarbero@cib.csic.es

    2006-08-15

    The binding site and backbone dynamics of a bioactive complex formed by the acidic fibroblast growth factor (FGF-1) and a specifically designed heparin hexasaccharide has been investigated by HSQC and relaxation NMR methods. The comparison of the relaxation data for the free and bound states has allowed showing that the complex is monomeric, and still induces mutagenesis, and that the protein backbone presents reduced motion in different timescale in its bound state, except in certain points that are involved in the interaction with the fibroblast growth factor receptor (FGFR)

  8. Binding mechanism and dynamic conformational change of C subunit of PKA with different pathways.

    Science.gov (United States)

    Chu, Wen-Ting; Chu, Xiakun; Wang, Jin

    2017-09-19

    The catalytic subunit of PKA (PKAc) exhibits three major conformational states (open, intermediate, and closed) during the biocatalysis process. Both ATP and substrate/inhibitor can effectively induce the conformational changes of PKAc from open to closed states. Aiming to explore the mechanism of this allosteric regulation, we developed a coarse-grained model and analyzed the dynamics of conformational changes of PKAc during binding by performing molecular dynamics simulations for apo PKAc, binary PKAc (PKAc with ATP, PKAc with PKI), and ternary PKAc (PKAc with ATP and PKI). Our results suggest a mixed binding mechanism of induced fit and conformational selection, with the induced fit dominant. The ligands can drive the movements of Gly-rich loop as well as some regions distal to the active site in PKAc and stabilize them at complex state. In addition, there are two parallel pathways (pathway with PKAc-ATP as an intermediate and pathway PKAc-PKI as an intermediate) during the transition from open to closed states. By molecular dynamics simulations and rate constant analyses, we find that the pathway through PKAc-ATP intermediate is the main binding route from open to closed state because of the fact that the bound PKI will hamper ATP from successful binding and significantly increase the barrier for the second binding subprocess. These findings will provide fundamental insights of the mechanisms of PKAc conformational change upon binding.

  9. Structural and mutational analyses of the receptor binding domain of botulinum D/C mosaic neurotoxin: Insight into the ganglioside binding mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Nuemket, Nipawan [Graduate School of Life Sciences, Hokkaido University, Sapporo 060-0810 (Japan); Tanaka, Yoshikazu [Creative Research Institution ' Sousei,' Hokkaido University, Sapporo 001-0021 (Japan); Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810 (Japan); Tsukamoto, Kentaro; Tsuji, Takao [Department of Microbiology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192 (Japan); Nakamura, Keiji; Kozaki, Shunji [Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 598-8531 (Japan); Yao, Min [Graduate School of Life Sciences, Hokkaido University, Sapporo 060-0810 (Japan); Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810 (Japan); Tanaka, Isao, E-mail: tanaka@castor.sci.hokudai.ac.jp [Graduate School of Life Sciences, Hokkaido University, Sapporo 060-0810 (Japan); Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810 (Japan)

    2011-07-29

    Highlights: {yields} We determined the crystal structure of the receptor binding domain of BoNT in complex with 3'-sialyllactose. {yields} An electron density derived from the 3'-sialyllactose was confirmed at the cleft in the C-terminal subdomain. {yields} Alanine site-directed mutagenesis showed that GBS and GBL are important for ganglioside binding. {yields} A cell binding mechanism, which involves cooperative contribution of two sites, was proposed. -- Abstract: Clostridium botulinum type D strain OFD05, which produces the D/C mosaic neurotoxin, was isolated from cattle killed by the recent botulism outbreak in Japan. The D/C mosaic neurotoxin is the most toxic of the botulinum neurotoxins (BoNT) characterized to date. Here, we determined the crystal structure of the receptor binding domain of BoNT from strain OFD05 in complex with 3'-sialyllactose at a resolution of 3.0 A. In the structure, an electron density derived from the 3'-sialyllactose was confirmed at the cleft in the C-terminal subdomain. Alanine site-directed mutagenesis showed the significant contribution of the residues surrounding the cleft to ganglioside recognition. In addition, a loop adjoining the cleft also plays an important role in ganglioside recognition. In contrast, little effect was observed when the residues located around the surface previously identified as the protein receptor binding site in other BoNTs were substituted. The results of cell binding analysis of the mutants were significantly correlated with the ganglioside binding properties. Based on these observations, a cell binding mechanism of BoNT from strain OFD05 is proposed, which involves cooperative contribution of two ganglioside binding sites.

  10. Immobilized enzymes to convert N-sulfo, N-acetyl heparosan to a critical intermediate in the production of bioengineered heparin.

    Science.gov (United States)

    Xiong, Jian; Bhaskar, Ujjwal; Li, Guoyun; Fu, Li; Li, Lingyun; Zhang, Fuming; Dordick, Jonathan S; Linhardt, Robert J

    2013-09-10

    Heparin is a critically important anticoagulant drug that is prepared from pig intestine. In 2007-2008, there was a crisis in the heparin market when the raw material was adulterated with the toxic polysaccharide, oversulfated chondroitin sulfate, which was associated with 100 deaths in the U.S. alone. As the result of this crisis, our laboratory and others have been actively pursuing alternative sources for this critical drug, including synthetic heparins and bioengineered heparin. In assessing the bioengineering processing costs it has become clear that the use of both enzyme-catalyzed cofactor recycling and enzyme immobilization will be needed for commercialization. In the current study, we examine the use of immobilization of C₅-epimerase and 2-O-sulfotransferase involved in the first enzymatic step in the bioengineered heparin process, as well as arylsulfotransferase-IV involved in cofactor recycling in all three enzymatic steps. We report the successful immobilization of all three enzymes and their use in converting N-sulfo, N-acetyl heparosan into N-sulfo, N-acetyl 2-O-sulfo heparin. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. A new biocompatible delivery scaffold containing heparin and bone morphogenetic protein 2

    Directory of Open Access Journals (Sweden)

    Thanyaphoo Suphannee

    2016-09-01

    Full Text Available Silicon-substituted calcium phosphate (Si-CaP was developed in our laboratory as a biomaterial for delivery in bone tissue engineering. It was fabricated as a 3D-construct of scaffolds using chitosan-trisodium polyphosphate (TPP cross-linked networks. In this study, heparin was covalently bonded to the residual -NH2 groups of chitosan on the scaffold applying carbodiimide chemistry. Bonded heparin was not leached away from scaffold surfaces upon vigorous washing or extended storage. Recombinant human bone morphogenetic protein 2 (rhBMP-2 was bound to conjugated scaffolds by ionic interactions between the negatively charged SO42- clusters of heparin and positively charged amino acids of rhBMP-2. The resulting scaffolds were inspected for bone regenerative capacity by subcutaneous implanting in rats. Histological observation and mineralization assay were performed after 4 weeks of implantation. Results from both in vitro and in vivo experiments suggest the potential of the developed scaffolds for bone tissue engineering applications in the future.

  12. Managing cancer-related venous thromboembolic disease: low-molecular-weight heparins and beyond.

    Science.gov (United States)

    O'Connell, Casey L; Liebman, Howard A

    2008-12-01

    Venous thromboembolism is a major contributor to the morbidity and mortality of patients with cancer. For patients undergoing cancer surgery, several trials support the safety and efficacy of unfractionated heparin and of low-molecular-weight heparin for the prevention of venous thromboembolism, while data regarding the efficacy and safety of these agents in the setting of medical hospitalization is less definitive and must be extracted from trials including noncancer patients with different thrombotic risk factors. Randomized clinical studies confirm that patients with cancer who develop venous thromboembolism have superior outcomes when treated with long-term low-molecular-weight heparin as compared with warfarin. Novel anticoagulants that are orally bioavailable and function by directly inhibiting factor Xa or thrombin are entering the market. To date, data regarding the efficacy and safety of these novel anticoagulants as venous thromboembolism prophylaxis and treatment in cancer patients are not available and must be extracted from larger trials with heterogeneous patient populations.

  13. Obstacles in the diagnostics and therapy of heparin-induced thrombocytopenia.

    Science.gov (United States)

    Antonijević, Nebojsa M; Radovanović, Nebojsa; Obradović, Slobodan; Vucelić, Dragica; Stojanović, Bojan; Miković, Danijela; Kovac, Mirjana; Kocica, Tina; Tadić, Svetlana; Antonijević, Irina; Drasković, Snezana; Djordjević, Valentina; Calija, Branko; Perunicić, Jovan; Vasiljević, Zorana

    2010-01-01

    An immune-mediated, severe, acquired prothrombotic disorder, heparin-induced thrombocytopenia type II (HIT II) occurs in 0.5-5% of patients exposed to unfractionated heparin longer than 5-7 days. Arterial and venous thromboses are induced by HIT II in about 35-50% of patients. Typical death rate for HIT is about 29%, while 21% of HIT patients result in amputation of a limb. The trend towards the occurrence of HIT due to the administration of low molecular weight heparins (LMWH) taking ever conspicuous place in the standard venous thromboembolism (VTE) prophylaxis has been more frequently observed recently. It is considered that LMWH may cause HIT II in about 0.25-1%. The need for further modification of HIPA assays with LMWH has been imposed in the HIT laboratory diagnostics, heretofore overburdened with complexity. There are several constantly opposing problems arising in HIT laboratory diagnostics, one of which is that in a certain number of patients immunologic assays detect nonpathogenic antibodies (mainly IgM or IgA heparin-PF4 antibodies) while, on the other hand, the occurrence of HIT pathogenetically mediated by minor antigens (neutrophil-activating peptide 2 or interleukin 8) may be neglected in certain cases. The following factors play an important role in the interpretation of each laboratory HIT assays performed: 1. correlation with HIT clinical probability test, the best known of which is 4T'score, 2. the interpretation of the laboratory findings dependent on the time of the thrombocytopenia onset, as well as 3. the sensitivity and specificity of each test respectively. The HIT diagnostics in the presence of other comorbid states which may also induce thrombocytopenia, more precisely known as pseudo HIT (cancer, sepsis, disseminated intravascular coagulation, pulmonary embolism, antiphospholipid syndrome, etc), represents a specific clinical problem.

  14. Synthesis of Heparan Sulfate with Cyclophilin B-binding Properties Is Determined by Cell Type-specific Expression of Sulfotransferases*

    Science.gov (United States)

    Deligny, Audrey; Denys, Agnès; Marcant, Adeline; Melchior, Aurélie; Mazurier, Joël; van Kuppevelt, Toin H.; Allain, Fabrice

    2010-01-01

    Cyclophilin B (CyPB) induces migration and adhesion of T lymphocytes via a mechanism that requires interaction with 3-O-sulfated heparan sulfate (HS). HS biosynthesis is a complex process with many sulfotransferases involved. N-Deacetylases/N-sulfotransferases are responsible for N-sulfation, which is essential for subsequent modification steps, whereas 3-O-sulfotransferases (3-OSTs) catalyze the least abundant modification. These enzymes are represented by several isoforms, which differ in term of distribution pattern, suggesting their involvement in making tissue-specific HS. To elucidate how the specificity of CyPB binding is determined, we explored the relationships between the expression of these sulfotransferases and the generation of HS motifs with CyPB-binding properties. We demonstrated that high N-sulfate density and the presence of 2-O- and 3-O-sulfates determine binding of CyPB, as evidenced by competitive experiments with heparin derivatives, soluble HS, and anti-HS antibodies. We then showed that target cells, i.e. CD4+ lymphocyte subsets, monocytes/macrophages, and related cell lines, specifically expressed high levels of NDST2 and 3-OST3 isoforms. Silencing the expression of NDST1, NDST2, 2-OST, and 3-OST3 by RNA interference efficiently decreased binding and activity of CyPB, thus confirming their involvement in the biosynthesis of binding sequences for CyPB. Moreover, we demonstrated that NDST1 was able to partially sulfate exogenous substrate in the absence of NDST2 but not vice versa, suggesting that both isoenzymes do not have redundant activities but do have rather complementary activities in making N-sulfated sequences with CyPB-binding properties. Altogether, these results suggest a regulatory mechanism in which cell type-specific expression of certain HS sulfotransferases determines the specific binding of CyPB to target cells. PMID:19940140

  15. Synthesis of heparan sulfate with cyclophilin B-binding properties is determined by cell type-specific expression of sulfotransferases.

    Science.gov (United States)

    Deligny, Audrey; Denys, Agnès; Marcant, Adeline; Melchior, Aurélie; Mazurier, Joël; van Kuppevelt, Toin H; Allain, Fabrice

    2010-01-15

    Cyclophilin B (CyPB) induces migration and adhesion of T lymphocytes via a mechanism that requires interaction with 3-O-sulfated heparan sulfate (HS). HS biosynthesis is a complex process with many sulfotransferases involved. N-Deacetylases/N-sulfotransferases are responsible for N-sulfation, which is essential for subsequent modification steps, whereas 3-O-sulfotransferases (3-OSTs) catalyze the least abundant modification. These enzymes are represented by several isoforms, which differ in term of distribution pattern, suggesting their involvement in making tissue-specific HS. To elucidate how the specificity of CyPB binding is determined, we explored the relationships between the expression of these sulfotransferases and the generation of HS motifs with CyPB-binding properties. We demonstrated that high N-sulfate density and the presence of 2-O- and 3-O-sulfates determine binding of CyPB, as evidenced by competitive experiments with heparin derivatives, soluble HS, and anti-HS antibodies. We then showed that target cells, i.e. CD4+ lymphocyte subsets, monocytes/macrophages, and related cell lines, specifically expressed high levels of NDST2 and 3-OST3 isoforms. Silencing the expression of NDST1, NDST2, 2-OST, and 3-OST3 by RNA interference efficiently decreased binding and activity of CyPB, thus confirming their involvement in the biosynthesis of binding sequences for CyPB. Moreover, we demonstrated that NDST1 was able to partially sulfate exogenous substrate in the absence of NDST2 but not vice versa, suggesting that both isoenzymes do not have redundant activities but do have rather complementary activities in making N-sulfated sequences with CyPB-binding properties. Altogether, these results suggest a regulatory mechanism in which cell type-specific expression of certain HS sulfotransferases determines the specific binding of CyPB to target cells.

  16. The physiologic and therapeutic role of heparin in implantation and placentation

    Directory of Open Access Journals (Sweden)

    Michela Quaranta

    2015-01-01

    Full Text Available Implantation, trophoblast development and placentation are crucial processes in the establishment and development of normal pregnancy. Abnormalities of these processes can lead to pregnancy complications known as the great obstetrical syndromes: preeclampsia, intrauterine growth restriction, fetal demise, premature prelabor rupture of membranes, preterm labor, and recurrent pregnancy loss. There is mounting evidence regarding the physiological and therapeutic role of heparins in the establishment of normal gestation and as a modality for treatment and prevention of pregnancy complications. In this review, we will summarize the properties and the physiological contributions of heparins to the success of implantation, placentation and normal pregnancy.

  17. Protein interactions with quaternized chitosan/heparin multilayers

    Czech Academy of Sciences Publication Activity Database

    Kumorek, Marta M.; Kubies, Dana; Riedel, Tomáš

    2016-01-01

    Roč. 65, Suppl. 2 (2016), S253-S261 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LQ1604 Institutional support: RVO:61389013 Keywords : heparin * chitosan * protein Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.461, year: 2016 http://www.biomed.cas.cz/physiolres/pdf/65%20Suppl%202/65_S253.pdf

  18. Glycosaminoglycans are interactants of Langerin: comparison with gp120 highlights an unexpected calcium-independent binding mode.

    Science.gov (United States)

    Chabrol, Eric; Nurisso, Alessandra; Daina, Antoine; Vassal-Stermann, Emilie; Thepaut, Michel; Girard, Eric; Vivès, Romain R; Fieschi, Franck

    2012-01-01

    Langerin is a C-type lectin specifically expressed in Langerhans cells. As recently shown for HIV, Langerin is thought to capture pathogens and mediate their internalisation into Birbeck Granules for elimination. However, the precise functions of Langerin remain elusive, mostly because of the lack of information on its binding properties and physiological ligands. Based on recent reports that Langerin binds to sulfated sugars, we conducted here a comparative analysis of Langerin interaction with mannose-rich HIV glycoprotein gp120 and glycosaminoglycan (GAGs), a family of sulfated polysaccharides expressed at the surface of most mammalian cells. Our results first revealed that Langerin bound to these different glycans through very distinct mechanisms and led to the identification of a novel, GAG-specific binding mode within Langerin. In contrast to the canonical lectin domain, this new binding site showed no Ca(2+)-dependency, and could only be detected in entire, trimeric extracellular domains of Langerin. Interestingly binding to GAGs, did not simply rely on a net charge effect, but rather on more discrete saccharide features, such as 6-O-sulfation, or iduronic acid content. Using molecular modelling simulations, we proposed a model of Langerin/heparin complex, which located the GAG binding site at the interface of two of the three Carbohydrate-recognition domains of the protein, at the edge of the a-helix coiled-coil. To our knowledge, the binding properties that we have highlighted here for Langerin, have never been reported for C-type lectins before. These findings provide new insights towards the understanding of Langerin biological functions.

  19. Glycosaminoglycans are interactants of Langerin: comparison with gp120 highlights an unexpected calcium-independent binding mode.

    Directory of Open Access Journals (Sweden)

    Eric Chabrol

    Full Text Available Langerin is a C-type lectin specifically expressed in Langerhans cells. As recently shown for HIV, Langerin is thought to capture pathogens and mediate their internalisation into Birbeck Granules for elimination. However, the precise functions of Langerin remain elusive, mostly because of the lack of information on its binding properties and physiological ligands. Based on recent reports that Langerin binds to sulfated sugars, we conducted here a comparative analysis of Langerin interaction with mannose-rich HIV glycoprotein gp120 and glycosaminoglycan (GAGs, a family of sulfated polysaccharides expressed at the surface of most mammalian cells. Our results first revealed that Langerin bound to these different glycans through very distinct mechanisms and led to the identification of a novel, GAG-specific binding mode within Langerin. In contrast to the canonical lectin domain, this new binding site showed no Ca(2+-dependency, and could only be detected in entire, trimeric extracellular domains of Langerin. Interestingly binding to GAGs, did not simply rely on a net charge effect, but rather on more discrete saccharide features, such as 6-O-sulfation, or iduronic acid content. Using molecular modelling simulations, we proposed a model of Langerin/heparin complex, which located the GAG binding site at the interface of two of the three Carbohydrate-recognition domains of the protein, at the edge of the a-helix coiled-coil. To our knowledge, the binding properties that we have highlighted here for Langerin, have never been reported for C-type lectins before. These findings provide new insights towards the understanding of Langerin biological functions.

  20. Structural and quantum mechanical computations to elucidate the altered binding mechanism of metal and drug with pyrazinamidase from Mycobacterium tuberculosis due to mutagenicity.

    Science.gov (United States)

    Rasool, Nouman; Iftikhar, Saima; Amir, Anam; Hussain, Waqar

    2018-03-01

    Pyrazinamide is known to be the most effective treatment against tuberculosis disease and is known to have bacteriostatic action. By targeting the bacterial spores, this drug reduces the chances for the progression of the infection in organisms. In recent years, increased instances of the drug resistance of bacterial strains are reported. Pyrazinamidase, activator for pyrazinamide, leads to resistance against the drug due to mutagenicity across the world. The present study aimed at the quantum mechanistic analysis of mutations in pyrazinamidase to gain insights into the mechanism of this enzyme. Quantum mechanical calculations were performed to analyse the effect of mutations at the metal coordination site using ORCA software program. Moreover, conformational changes in PZase binding cavity has also been analysed due to mutations of binding pocket residues using CASTp server. In order to elucidate the behaviour of the mutant pyrazinamidase, docking of PZA in the binding pocket of PZase was performed using AutoDock Vina. Analysis of results revealed that iron showed weak binding with the metal coordination site of the mutant proteins due to alteration in electron transfer mechanism. The binding cavity of the mutant PZase has undergone major conformational changes as the volume of pocket increased due to bulky R-chains of mutated amino acids. These conformational changes lead to weak binding of the drug at binding cavity of PZase and reduce the drug activation mechanism leading to increased drug resistance in the bacterial strains. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. ATP-Binding Cassette Proteins: Towards a Computational View of Mechanism

    Science.gov (United States)

    Liao, Jielou

    2004-03-01

    Many large machine proteins can generate mechanical force and undergo large-scale conformational changes (LSCC) to perform varying biological tasks in living cells by utilizing ATP. Important examples include ATP-binding cassette (ABC) transporters. They are membrane proteins that couple ATP binding and hydrolysis to the translocation of substrates across membranes [1]. To interpret how the mechanical force generated by ATP binding and hydrolysis is propagated, a coarse-grained ATP-dependent harmonic network model (HNM) [2,3] is applied to the ABC protein, BtuCD. This protein machine transports vitamin B12 across membranes. The analysis shows that subunits of the protein move against each other in a concerted manner. The lowest-frequency modes of the BtuCD protein are found to link the functionally critical domains, and are suggested to be responsible for large-scale ATP-coupled conformational changes. [1] K. P. Locher, A. T. Lee and D. C. Rees. Science 296, 1091-1098 (2002). [2] Atilgan, A. R., S. R. Durell, R. L. Jernigan, M. C. Demirel, O. Keskin, and I. Bahar. Biophys. J. 80, 505-515(2002); M. M Tirion, Phys. Rev. Lett. 77, 1905-1908 (1996). [3] J. -L. Liao and D. N. Beratan, 2003, to be published.

  2. Assessment of anti-factor Xa activity of heparin in binary parenteral nutrition admixtures for premature neonates.

    Science.gov (United States)

    Foinard, A; Perez, M; Barthélémy, C; Lannoy, D; Flamein, F; Storme, L; Tournoys, A; Décaudin, B; Odou, P

    2015-07-01

    An in vitro study was carried out to determine the anti-Xa activity of heparin in binary parenteral nutrition (BPN) admixtures for premature neonates in our neonatal intensive care unit (NICU) after a 24-hour infusion, as well as to assess drug interaction with a 50% glucose solution. Two types of bags were prepared: (1) BPN admixtures (composition defined in the NICU) including sodium heparin at 77 UI/mL and (2) bags containing only G50% with sodium heparin at 193 UI/mL. The anti-Xa activity of heparin was measured in bags at T0, after the 24-hour infusion and in eluates at the outlet of the infusion line after 24hours, using a validated chromogenic anti-Xa method. Comparisons of the mean concentration observed with the theoretical value for anti-Xa activity were performed with the Student t-test. Mean values of anti-Xa activity do not differ significantly from the values expected for all conditions. We found a slight variation in anti-Xa activity when infused over 24hours for both types of bags, with and without in-line filtration, showing that heparin remains stable during this infusion period in both BPN admixtures and G50%. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  3. Artemin Crystal Structure Reveals Insights into Heparan Sulfate Binding

    Energy Technology Data Exchange (ETDEWEB)

    Silvian,L.; Jin, P.; Carmillo, P.; Boriack-Sjodin, P.; Pelletier, C.; Rushe, M.; Gong, B.; Sah, D.; Pepinsky, B.; Rossomando, A.

    2006-01-01

    Artemin (ART) promotes the growth of developing peripheral neurons by signaling through a multicomponent receptor complex comprised of a transmembrane tyrosine kinase receptor (cRET) and a specific glycosylphosphatidylinositol-linked co-receptor (GFR{alpha}3). Glial cell line-derived neurotrophic factor (GDNF) signals through a similar ternary complex but requires heparan sulfate proteoglycans (HSPGs) for full activity. HSPG has not been demonstrated as a requirement for ART signaling. We crystallized ART in the presence of sulfate and solved its structure by isomorphous replacement. The structure reveals ordered sulfate anions bound to arginine residues in the pre-helix and amino-terminal regions that were organized in a triad arrangement characteristic of heparan sulfate. Three residues in the pre-helix were singly or triply substituted with glutamic acid, and the resulting proteins were shown to have reduced heparin-binding affinity that is partly reflected in their ability to activate cRET. This study suggests that ART binds HSPGs and identifies residues that may be involved in HSPG binding.

  4. The clinical significance and risk factors of anti-platelet factor 4/heparin antibody on maintenance hemodialysis patients: a two-year prospective follow-up.

    Directory of Open Access Journals (Sweden)

    Delong Zhao

    Full Text Available BACKGROUND: Heparin-induced thrombocytopenia is an immune response mediated by anti-PF4/heparin antibody, which is clinically characterized by thrombocytopenia and thromboembolic events. In this study, a prospective and multi-center clinical investigation 1 determined the positive rate of anti-PF4/heparin antibody in maintenance hemodialysis patients in China, 2 identified the related risk factors, and 3 further explored the effect of the anti-PF4/heparin antibody on bleeding, thromboembolic events, and risk of death in the patients. METHODS: The serum anti-PF4/heparin antibody was measured in 661 patients from nine hemodialysis centers, detected by IgG-specific ELISA and followed by confirmation with excess heparin. Risk factors of these patients were analyzed. Based on a two-year follow-up, the association between the anti-PF4/heparin antibody and bleeding, thromboembolic events, and risk of death in the patients was investigated. RESULTS: 1 The positivity rate of the anti-PF4/heparin antibody in maintenance hemodialysis patients was 5.6%. With diabetes as an independent risk factor, the positivity rate of the anti-PF4/heparin antibody decreased in the patients undergoing weekly dialyses ≥3 times. 2 The positivity rate of the anti-PF4/heparin antibody was not related to the occurrence of clinical thromboembolic events and was not a risk factor for death within two years in maintenance hemodialysis patients. 3 Negativity for the anti-PF4/heparin antibody combined with a reduction of the platelet count or combined with the administration of antiplatelet drugs yielded a significant increase in bleeding events. However, the composite determination of the anti-PF4/heparin antibody and thrombocytopenia, as well as the administration of antiplatelet drugs, was not predictive for the risk of thromboembolic events in the maintenance hemodialysis patients. CONCLUSIONS: A single detection of the anti-PF4/heparin antibody did not predict the occurrence

  5. Binding Mechanisms in Selective Laser Sintering and Selective Laser Melting

    NARCIS (Netherlands)

    Kruth, J.P.; Mercelis, P.; Van Vaerenbergh, J.; van Vaerenbergh, J.; Froyen, L.; Rombouts, M.

    2005-01-01

    Purpose – This paper provides an overview of the different binding mechanisms in selective laser sintering (SLS) and selective laser melting (SLM), thus improving the understanding of these processes. Design/methodology/approach – A classification of SLS/SLM processes was developed, based on the

  6. Platelet-derived growth factor inhibits platelet activation in heparinized whole blood.

    Science.gov (United States)

    Selheim, F; Holmsen, H; Vassbotn, F S

    1999-08-15

    We previously have demonstrated that human platelets have functionally active platelet-derived growth factor alpha-receptors. Studies with gel-filtered platelets showed that an autocrine inhibition pathway is transduced through this tyrosine kinase receptor during platelet activation. The physiological significance of this inhibitory effect of platelet-derived growth factor on gel-filtered platelets activation is, however, not known. In the present study, we investigated whether platelet-derived growth factor inhibits platelet activation under more physiological conditions in heparinized whole blood, which represents a more physiological condition than gel-filtered platelets. Using flow cytometric assays, we demonstrate here that platelet-derived growth factor inhibits thrombin-, thrombin receptor agonist peptide SFLLRN-, and collagen-induced platelet aggregation and shedding of platelet-derived microparticles from the platelet plasma membrane during platelet aggregation in stirred heparinized whole blood. The inhibitory effect of platelet-derived growth factor was dose dependent. However, under nonaggregating conditions (no stirring), we could not demonstrate any significant effect of platelet-derived growth factor on thrombin- and thrombin receptor agonist peptide-induced platelet surface expression of P-selectin. Our results demonstrate that platelet-derived growth factor appears to be a true antithrombotic agent only under aggregating conditions in heparinized whole blood.

  7. Influences of apolipoprotein E on soluble and heparin-immobilized hepatic lipase

    International Nuclear Information System (INIS)

    Landis, B.A.; Rotolo, F.S.; Meyers, W.C.; Clark, A.B.; Quarfordt, S.H.

    1987-01-01

    The effect of human apolipoprotein E (apoE), either alone or in combination with apoC, on the lipolysis of a radiolabeled triglyceride emulsion was studied with hepatic lipase in solution and immobilized on heparin-Sepharose. The soluble hepatic lipase was inhibited, whereas the heparin-immobilized lipase was stimulated by apoE. This stimulation was attenuated by combining apoE with either apoC-II or C-III. The heparin-immobilized lipase demonstrated much less lipolysis of the zwitterionic phosphatidylcholine-stabilized triglyceride emulsion than did the soluble enzyme. This difference was less when the emulsion was stabilized by a nonionic detergent. apoE inhibited lipase activity when assayed under conditions (0.4 M NaCl) of bound enzyme and unbound substrate. Increasing the emulsion apoE content beyond optimum inhibited lipolysis by the immobilized enzyme. Kinetic analysis of phosphatidylcholine-stabilized triglyceride emulsions revealed a significant decrease in immobilized enzyme K/sub m/ and an increase in V/sub max/ when the emulsion was supplemented with apoE. Distributing the immobilized lipase in clustered aggregates produced more lipolysis than when the same enzyme content was uniformly bound

  8. The effect of heparin on pregnancy associated plasma protein-A concentration in healthy, non-pregnant individuals

    DEFF Research Database (Denmark)

    Jespersen, Camilla H B; Vestergaard, Kirstine R.; Schou, Morten

    2015-01-01

    Objectives: The objective of this study was to determine the differences in pregnancy associated plasma protein-A (PAPP-A) concentrations in heparin naive and heparin treated healthy men and non-pregnant women, to find a possible difference in different age groups, and to determine the response...

  9. Vitamin K antagonists or low-molecular-weight heparin for the long term treatment of symptomatic venous thromboembolism

    NARCIS (Netherlands)

    van der Heijden, J. F.; Hutten, B. A.; Büller, H. R.; Prins, M. H.

    2002-01-01

    BACKGROUND: People with venous thromboembolism are generally treated for five days with intravenous unfractionated heparin or subcutaneous low-molecular-weight heparin followed by three months of vitamin K antagonists treatment. Treatment with vitamin K antagonists requires regular laboratory

  10. ADRIAMYCIN-LOADED ALBUMIN-HEPARIN CONJUGATE MICROSPHERES FOR INTRAPERITONEAL CHEMOTHERAPY

    NARCIS (Netherlands)

    CREMERS, HFM; SEYMOUR, LW; LAM, K; LOS, G; KWON, G; BAE, YH; KIM, SW; FEIJEN, J

    1994-01-01

    Adriamycin-loaded albumin-heparin conjugate microspheres (ADR-AHCMS) were evaluated as possible intraperitoneal (i.p.) delivery systems for site-specific cytotoxic action. The biocompatibility of the microspheres after intraperitoneal injection was tested first. 1 day after i.p. administration of

  11. DNA Damage: Quantum Mechanics/Molecular Mechanics Study on the Oxygen Binding and Substrate Hydroxylation Step in AlkB Repair Enzymes

    Science.gov (United States)

    Quesne, Matthew G; Latifi, Reza; Gonzalez-Ovalle, Luis E; Kumar, Devesh; de Visser, Sam P

    2014-01-01

    AlkB repair enzymes are important nonheme iron enzymes that catalyse the demethylation of alkylated DNA bases in humans, which is a vital reaction in the body that heals externally damaged DNA bases. Its mechanism is currently controversial and in order to resolve the catalytic mechanism of these enzymes, a quantum mechanics/molecular mechanics (QM/MM) study was performed on the demethylation of the N1-methyladenine fragment by AlkB repair enzymes. Firstly, the initial modelling identified the oxygen binding site of the enzyme. Secondly, the oxygen activation mechanism was investigated and a novel pathway was found, whereby the catalytically active iron(IV)–oxo intermediate in the catalytic cycle undergoes an initial isomerisation assisted by an Arg residue in the substrate binding pocket, which then brings the oxo group in close contact with the methyl group of the alkylated DNA base. This enables a subsequent rate-determining hydrogen-atom abstraction on competitive σ-and π-pathways on a quintet spin-state surface. These findings give evidence of different locations of the oxygen and substrate binding channels in the enzyme and the origin of the separation of the oxygen-bound intermediates in the catalytic cycle from substrate. Our studies are compared with small model complexes and the effect of protein and environment on the kinetics and mechanism is explained. PMID:24339041

  12. Cooperative control of blood compatibility and re-endothelialization by immobilized heparin and substrate topography.

    Science.gov (United States)

    Ding, Yonghui; Yang, Meng; Yang, Zhilu; Luo, Rifang; Lu, Xiong; Huang, Nan; Huang, Pingbo; Leng, Yang

    2015-03-01

    A wide variety of environmental cues provided by the extracellular matrix, including biophysical and biochemical cues, are responsible for vascular cell behavior and function. In particular, substrate topography and surface chemistry have been shown to regulate blood and vascular compatibility individually. The combined impact of chemical and topographic cues on blood and vascular compatibility, and the interplay between these two types of cues, are subjects that are currently being explored. In the present study, a facile polydopamine-mediated approach is introduced for immobilization of heparin on topographically patterned substrates, and the combined effects of these cues on blood compatibility and re-endothelialization are systematically investigated. The results show that immobilized heparin and substrate topography cooperatively modulate anti-coagulation activity, endothelial cell (EC) attachment, proliferation, focal adhesion formation and endothelial marker expression. Meanwhile, the substrate topography is the primary determinant of cell alignment and elongation, driving in vivo-like endothelial organization. Importantly, combining immobilized heparin with substrate topography empowers substantially greater competitive ability of ECs over smooth muscle cells than each cue individually. Moreover, a model is proposed to elucidate the cooperative interplay between immobilized heparin and substrate topography in regulating cell behavior. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  13. Heparin sodium compliance to USP monograph: structural elucidation of an atypical 2.18 ppm NMR signal.

    Science.gov (United States)

    Mourier, Pierre A J; Guichard, Olivier Y; Herman, Fréderic; Viskov, Christian

    2012-01-01

    The ¹H nuclear magnetic resonance (NMR) acceptance criteria in the new heparin US Pharmacopeia (USP) monograph do not take into account potential structural modifications responsible for any extra signals observed in ¹H NMR spectra, some purified heparins may be non-compliant under the proposed new USP guidelines and incorrectly classified as unsuitable for pharmaceutical use. Heparins from the "ES" source, containing an extra signal at 2.18 ppm, were depolymerized under controlled conditions using heparinases I, II, and III. The oligosaccharides responsible for the 2.18 ppm signal were enriched using orthogonal chromatographic techniques. After multiple purification steps, we obtained an oligosaccharide mixture containing a highly enriched octasaccharide bearing the structural modification responsible for the extra signal. Following heparinase I depolymerization, a pure tetrasaccharide containing the fingerprint structural modification was isolated for full structural determination. Using 1D and 2D ¹H NMR spectroscopy, the structural moiety responsible for the extra signal at 2.18 ppm was identified as an acetyl group on the heparin backbone, most likely resulting from a very minor manufacturing process side reaction that esterifies the uronic acid at position 3. Such analytical peculiarity has always been present in this heparin source and it was used safety over the years. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Performance improvements of the BNC tubes from unique double-silicone-tube bioreactors by introducing chitosan and heparin for application as small-diameter artificial blood vessels.

    Science.gov (United States)

    Li, Xue; Tang, Jingyu; Bao, Luhan; Chen, Lin; Hong, Feng F

    2017-12-15

    In order to improve property of bacterial nano-cellulose (BNC) to achieve the requirements of clinical application as small caliber vascular grafts, chitosan (CH) was deposited into the fibril network of the BNC tubes fabricated in unique Double-Silicone-Tube bioreactors. Heparin (Hep) was then chemically grafted into the BNC-based tubes using EDC/NHS crosslinking to improve performance of anticoagulation and endothelialization. Physicochemical and mechanical property, blood compatibility, and cytocompatibility were compared before and after compositing. The results indicated that strength at break was increased but burst pressure decreased slightly after compositing. Performance of the BNC tubes was improved remarkably after introducing chitosan and heparin. The EDC/NHS crosslinking catalyzed both amide bonds and ester bonds formation in the BNC/CH-Hep composites. Three-dimensional surface structure and roughness were firstly obtained and discussed in relation to the hemocompatibility of BNC-based tubes. This work demonstrates the heparinized BNC-based tubes have great potential in application as small-diameter vascular prosthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Histones Differentially Modulate the Anticoagulant and Profibrinolytic Activities of Heparin, Heparin Derivatives, and Dabigatran.

    Science.gov (United States)

    Ammollo, Concetta Tiziana; Semeraro, Nicola; Carratù, Maria Rosaria; Colucci, Mario; Semeraro, Fabrizio

    2016-02-01

    The antithrombin activity of unfractionated heparin (UFH) is offset by extracellular histones, which, along with DNA, represent a novel mediator of thrombosis and a structural component of thrombi. Here, we systematically evaluated the effect of histones, DNA, and histone-DNA complexes on the anticoagulant and profibrinolytic activities of UFH, its derivatives enoxaparin and fondaparinux, and the direct thrombin inhibitor dabigatran. Thrombin generation was assessed by calibrated automated thrombinography, inhibition of factor Xa and thrombin by synthetic substrates, tissue plasminogen activator-mediated clot lysis by turbidimetry, and thrombin-activatable fibrinolysis inhibitor (TAFI) activation by a functional assay. Histones alone delayed coagulation and slightly stimulated fibrinolysis. The anticoagulant activity of UFH and enoxaparin was markedly inhibited by histones, whereas that of fondaparinux was enhanced. Histones neutralized both the anti-Xa and anti-IIa activities of UFH and preferentially blocked the anti-IIa activity of enoxaparin. The anti-Xa activity of fondaparinux was not influenced by histones when analyzed by chromogenic substrates, but was potentiated in a plasma prothrombinase assay. Histones inhibited the profibrinolytic activity of UFH and enoxaparin and enhanced that of fondaparinux by acting on the modulation of TAFI activation by anticoagulants. Histone H1 was mainly responsible for these effects. Histone-DNA complexes, as well as intact neutrophil extracellular traps, impaired the activities of UFH, enoxaparin, and fondaparinux. Dabigatran was not noticeably affected by histones and/or DNA, whatever the assay performed. In conclusion, histones and DNA present in the forming clot may variably influence the antithrombotic activities of anticoagulants, suggesting a potential therapeutic advantage of dabigatran and fondaparinux over heparins. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  16. Spurious hypocalcemia in hemodialysis patients after heparinization. In-vitro formation of calcium soaps.

    Science.gov (United States)

    Godolphin, W; Cameron, E C; Frohlich, J; Price, J D

    1979-02-01

    Patients on long-term hemodialysis via arteriovenous fistula received heparin when the fistula needle was inserted, before a sample of blood was obtained for chemical analysis. The resultant release of lipoprotein lipase activity in vivo and continued lipolytic activity in vitro sometimes produced sufficient free fatty acid to precipitate calcium soaps. The consequent spurious hypocalcemia was most frequently observed when the patients had chylomicronemia. This cause of apparent hypocalcemia was eliminated either by immediate analyses of the blood samples or by obtaining samples before systemic heparinization.

  17. Vitamin K antagonists or low-molecular-weight heparin for the long term treatment of symptomatic venous thromboembolism

    NARCIS (Netherlands)

    van der Heijden, J. F.; Hutten, B. A.; Büller, H. R.; Prins, M. H.

    2000-01-01

    Patients who have had an episode of symptomatic venous thromboembolism are usually treated for at least five days with intravenous unfractionated heparin or subcutaneous low-molecular-weight heparin. Thereafter, they received a three month course of a vitamin K antagonist, with a dose adjusted to

  18. Accelerating the peroxidase-like activity of gold nanoclusters at neutral pH for colorimetric detection of heparin and heparinase activity.

    Science.gov (United States)

    Hu, Lianzhe; Liao, Hong; Feng, Lingyan; Wang, Min; Fu, Wensheng

    2018-04-26

    The peroxidase-like catalytic activity of gold nanoclusters (NCs) is quite low around physiological pH, which greatly limits their biological applications. Herein, we found heparin can greatly accelerate the peroxidase-like activity of Au-NCs at neutral pH. The catalytic activity of Au-NCs toward the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) oxidation by H2O2 was 25-fold increased in the presence of heparin at pH 7. The addition of heparin not only accelerated the initial catalytic rate of Au-NCs, but also prevented the Au-NCs from catalyst deactivation. This allows the sensitive colorimetric detection of heparin at neutral pH. In the presence of heparinase, heparin was hydrolyzed into small fragments, weakening the enhancement effect of catalytic activity. Based on this phenomenon, the sensitive colorimetric determination of heparinase in biological samples was also developed.

  19. Mechanisms of zinc binding to the solute-binding protein AztC and transfer from the metallochaperone AztD.

    Science.gov (United States)

    Neupane, Durga P; Avalos, Dante; Fullam, Stephanie; Roychowdhury, Hridindu; Yukl, Erik T

    2017-10-20

    Bacteria can acquire the essential metal zinc from extremely zinc-limited environments by using ATP-binding cassette (ABC) transporters. These transporters are critical virulence factors, relying on specific and high-affinity binding of zinc by a periplasmic solute-binding protein (SBP). As such, the mechanisms of zinc binding and release among bacterial SBPs are of considerable interest as antibacterial drug targets. Zinc SBPs are characterized by a flexible loop near the high-affinity zinc-binding site. The function of this structure is not always clear, and its flexibility has thus far prevented structural characterization by X-ray crystallography. Here, we present intact structures for the zinc-specific SBP AztC from the bacterium Paracoccus denitrificans in the zinc-bound and apo-states. A comparison of these structures revealed that zinc loss prompts significant structural rearrangements, mediated by the formation of a sodium-binding site in the apo-structure. We further show that the AztC flexible loop has no impact on zinc-binding affinity, stoichiometry, or protein structure, yet is essential for zinc transfer from the metallochaperone AztD. We also found that 3 His residues in the loop appear to temporarily coordinate zinc and then convey it to the high-affinity binding site. Thus, mutation of any of these residues to Ala abrogated zinc transfer from AztD. Our structural and mechanistic findings conclusively identify a role for the AztC flexible loop in zinc acquisition from the metallochaperone AztD, yielding critical insights into metal binding by AztC from both solution and AztD. These proteins are highly conserved in human pathogens, making this work potentially useful for the development of novel antibiotics. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Heparin-Induced Thrombocytopenia Associated with Massive Intracardiac Thrombosis: A Case Report

    Directory of Open Access Journals (Sweden)

    Atheer Ahmed

    2012-01-01

    Full Text Available A 60-years old patient was admitted to a community hospital with septic arthritis. He was treated with antibiotics and subcutaneous unfractionated heparin (UH was used for venous thromboprophylaxis. After three days, he developed leg deep venous thrombosis and was treated with IV heparin. One day later, the patient developed pulmonary emboli, which was found using ventilation/perfusion scan. He was transferred to the University Hospital for further management. Upon arrival, antibiotic and intravenous UH were continued. Trans-Esophageal Echocardiogram showed a thrombus in the right atrium, a small portion of which extended to the left atrium through a patent foramen ovale. Another large thrombus was noted in the right ventricle, which extended to the pulmonary artery. Review of the patient’s medical records revealed a halving of his platelet count three days following the heparin administration. Therefore, HIT seemed very likely. Intravenous UH was stopped and an emergency thrombectomy was performed. ELISA testing of HIT antibodies came negative. This made HIT diagnosis unlikely and the patient received dalteparin. A week later, as the platelet count declined again, HIT antibodies’ testing using ELISA and C-14 serotonin release was repeated, and both assays were positive. Argatroban was restarted and the platelet count normalized.

  1. [The Role of Membrane-Bound Heat Shock Proteins Hsp90 in Migration of Tumor Cells in vitro and Involvement of Cell Surface Heparan Sulfate Proteoglycans in Protein Binding to Plasma Membrane].

    Science.gov (United States)

    Snigireva, A V; Vrublevskaya, V V; Skarga, Y Y; Morenkov, O S

    2016-01-01

    Heat shock protein Hsp90, detected in the extracellular space and on the membrane of cells, plays an important role in cell motility, migration, invasion and metastasis of tumor cells. At present, the functional role and molecular mechanisms of Hsp90 binding to plasma membrane are not elucidated. Using isoform-specific antibodies against Hsp90, Hsp9α and Hsp90β, we showed that membrane-bound Hsp90α and Hsp90β play a significant role in migration of human fibrosarcoma (HT1080) and glioblastoma (A-172) cells in vitro. Disorders of sulfonation of cell heparan sulfates, cleavage of cell heparan. sulfates by heparinase I/III as well as treatment of cells with heparin lead to an abrupt reduction in the expression level of Hsp90 isoforms. Furthermore, heparin significantly inhibits tumor cell migration. The results obtained demonstrate that two isoforms of membrane-bound Hsp90 are involved in migration of tumor cells in vitro and that cell surface heparan sulfate proteoglycans play a pivotal role in the "anchoring" of Hsp90α and Hsp90β to the plasma membrane.

  2. Chronic intravascular coagulation associated with chronic myelocytic leukemia. Use of heparin in connection with a surgical procedure.

    Science.gov (United States)

    German, H J; Smith, J A; Lindenbaum, J

    1976-10-01

    A women with Philadelphia chromosome-positive chronic myelocytic leukemia lived nearly 12 years from the time of diagnosis. During most of this period she received no therapy, and marked cyclic oscillations in the white blood cell count were documented. The last two years of her illness were marked by a hemorrhagic disorder associated with hypofibrinogenemia, thrombocytopenia, increased plasma fibrinopeptide A concentration and markedly elevated serum levels of fibrin degradation products. The coagulation disorder was rapidly reversible on several occasions with heparin therapy. After treatment with heparin and platelet transfusions, the patient underwent successful resection of a large ovarian cyst with excellent hemostasis during the procedure. Postoperatively, the administration of heparin and platelets was discontinued and a large wound hematoma developed. After resumption of therapy with heparin and platelets, the remainder of her postoperative course was uneventful. The literature on the subject is reviewed and tentative guidelines are offered concerning the management of patients with intravascular coagulation who require diagnostic or therapeutic surgical procedures.

  3. Computational Study of the Binding Mechanism of Actin-Depolymerizing Factor 1 with Actin in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Juan Du

    Full Text Available Actin is a highly conserved protein. It plays important roles in cellular function and exists either in the monomeric (G-actin or polymeric form (F-actin. Members of the actin-depolymerizing factor (ADF/cofilin protein family bind to both G-actin and F-actin and play vital roles in actin dynamics by manipulating the rates of filament polymerization and depolymerization. It has been reported that the S6D and R98A/K100A mutants of actin-depolymerizing factor 1 (ADF1 in Arabidopsis thaliana decreased the binding affinity of ADF for the actin monomer. To investigate the binding mechanism and dynamic behavior of the ADF1-actin complex, we constructed a homology model of the AtADF1-actin complex based on the crystal structure of AtADF1 and the twinfilin C-terminal ADF-H domain in a complex with a mouse actin monomer. The model was then refined for subsequent molecular dynamics simulations. Increased binding energy of the mutated system was observed using the Molecular Mechanics Generalized Born Surface Area and Poisson-Boltzmann Surface Area (MM-GB/PBSA methods. To determine the residues that make decisive contributions to the ADF1 actin-binding affinity, per-residue decomposition and computational alanine scanning analyses were performed, which provided more detailed information on the binding mechanism. Root-mean-square fluctuation and principal component analyses confirmed that the S6D and R98A/K100A mutants induced an increased conformational flexibility. The comprehensive molecular insight gained from this study is of great importance for understanding the binding mechanism of ADF1 and G-actin.

  4. Mechanisms of pancreatic beta-cell growth and regeneration

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1989-01-01

    Information about the mechanism of beta-cell growth and regeneration may be obtained by studies of insulinoma cells. In the present study the growth and function of the rat insulinoma cell lines RINm5F and 5AH were evaluated by addition of serum, hormones, and growth factors. It was found...... of insulin mRNA content showed that the insulinoma cells only contained about 2% of that of normal rat beta-cells. These results are discussed in relation to the role of growth factors, oncogenes, and differentiation in the growth and regeneration of beta-cells....... that transferrin is the only obligatory factor whereas growth hormone, epidermal growth factor, fibroblast growth factor, and TRH had modulating effects. A heat-labile heparin binding serum factor which stimulated thymidine incorporation but not cell proliferation was demonstrated in human serum. Measurements...

  5. Comparison of hematologic values in blood samples with lithium heparin or dipotassium ethylenediaminetetraacetic acid anticoagulants in Hispaniolan Amazon parrots (Amazona ventralis).

    Science.gov (United States)

    Guzman, David Sanchez-Migallon; Mitchell, Mark A; Gaunt, Stephen D; Beaufrère, Hugues; Tully, Thomas N

    2008-06-01

    Blood samples were collected from 20 Hispaniolan Amazon parrots (Amazona ventralis) and were divided into tubes that contained dipotassium ethylenediaminetetraacetic acid (K2EDTA) and lithium heparin. Complete blood cell counts were determined in each sample within 2 hours of collection. The level of agreement in results was moderate for plasma protein, packed cell volume (PCV), and leukocyte, monocyte, and lymphocyte counts between the anticoagulants. Plasma protein and PCV values were significantly lower in samples with lithium heparin than in those with K2EDTA, whereas lymphocyte numbers were significantly higher in lithium heparin samples than in K2EDTA samples. The level of agreement was good for the other cell types (heterophils, eosinophils, and basophils) when comparing the different anticoagulants. The poor level of agreement between anticoagulants with the increase in thrombocyte clumping in lithium heparin samples indicates that the use of lithium heparin as anticoagulant may affect thrombocyte count. No negative effects on morphology and staining of blood cells were apparent in smears from heparin samples compared with K2EDTA samples. Within the different values compared, the limits of agreement are small enough to be confident that lithium heparin can be used for routine CBC counts in a clinical setting. The use of the same anticoagulant should be recommended to follow trends within the same patient, especially when considering plasma protein concentration, PCV, and lymphocyte count.

  6. Relationship between binding activity of sup 67 Ga and low sulfated acid glycosaminoglycans

    Energy Technology Data Exchange (ETDEWEB)

    Ohkubo, Yasuhito; Tsukada, Fumitake; Kohno, Hiroyuki (Tohoku Coll. of Pharmacy, Sendai (Japan)); Kubodera, Akiko (Science Univ. of Tokyo (Japan). School of Pharmaceutical Sciences)

    1989-01-01

    Sulfate content of acid glycosaminoglycan (AGAG) extracted from granuloma which had been produced by turpentine oil was inversely proportional to the amount of {sub 67}Ga accumulation in the granuloma. Additionally, the lowest sulfation occurred in granuloma at a peak of inflammation when the uptake of {sub 67}Ga had reached a maximum. On the basis of electrophoretic pattern, sulfate content, and specific optical rotation, it was concluded that acid glycosaminoglycans obtained from granuloma are mainly composed of chondroitin sulfate-A, -B, and desulfated heparin, while haparan sulfate was a minor component. From in vitro assays, desulfated acid glycosaminoglycans, especially desulfated-heparin and desulfated-heparan sulfate, were found to have a high affinity to {sub 67}Ga. These results suggest that low- or de-sulfation of AGAG is related to the accumulation of {sub 67}Ga in inflammatory lesions such as granuloma. Moreover, these results suggest that {sub 67}Ga does not bind to glycosaminoglycans via sulfuric acid residues. (author).

  7. Effect of combined topical heparin and steroid on corneal neovascularization in children.

    Science.gov (United States)

    Michels, Rike; Michels, Stephan; Kaminski, Stephan

    2012-01-01

    To demonstrate the effect of topical heparin combined with topical steroid on corneal neovascularization (CN) in children. Four children (5 eyes) with new-onset progressive CN in at least one eye received topical rimexolone or dexamethasone in combination with heparin until complete regression of CN was obtained. The regression of CN was documented by slit-lamp or anterior segment photography. All 5 eyes showed complete regression of CN within 5 months. An anti-angiogenic effect was found as early as 1 week after starting topical combination treatment. No ocular and systemic side effects were detected and treatment was well tolerated by all children. In the 3 eyes with involvement of the optical axis, symmetrical visual acuity was obtained by amblyopia treatment. Recurrence of the CN was detectable in 2 eyes at 1 and 6 months, respectively, after ending combination therapy. Both eyes responded favorably to re-treatment. Combination of topical heparin and steroid leads to rapid regression and complete inactivity of CN. This therapeutic approach is promising, especially in children with limited therapeutic alternatives and a high risk for amblyopia. Copyright 2012, SLACK Incorporated.

  8. Heparin-Binding EGF-like Growth Factor (HB-EGF) stimulates the proliferation of Müller glia-derived progenitor cells in avian and murine retinas

    Science.gov (United States)

    Todd, Levi; Volkov, Leo I.; Zelinka, Chris; Squires, Natalie; Fischer, Andy J.

    2015-01-01

    Müller glia can be stimulated to de-differentiate, proliferate and form Müller glia-derived progenitor cells (MGPCs) that regenerate retinal neurons. In the zebrafish retina, Heparin-Binding EGF-like Growth Factor (HB-EGF) may be one of the key factors that stimulate the formation of proliferating MGPCs. Currently nothing is known about the influence of HB-EGF on the proliferative potential of Müller glia in retinas of birds and rodents. In the chick retina, we found that levels of both hb-egf and egf-receptor are rapidly and transiently up-regulated following NMDA-induced damage. Although intraocular injections of HB-EGF failed to stimulate cell-signaling or proliferation of Müller glia in normal retinas, HB-EGF stimulated proliferation of MGPCs in damaged retinas. By comparison, inhibition of the EGF-receptor (EGFR) decreased the proliferation of MGPCs in damaged retinas. HB-EGF failed to act synergistically with FGF2 to stimulate the formation of MGPCs in the undamaged retina and inhibition of EGF-receptor did not suppress FGF2-mediated formation of MGPCs. In the mouse retina, HB-EGF stimulated the proliferation of Müller glia following NMDA-induced damage. Furthermore, HB-EGF stimulated not only MAPK-signaling in Müller glia/MGPCs, but also activated mTor- and Jak/Stat-signaling. We propose that levels of expression of EGFR are rate-limiting to the responses of Müller glia to HB-EGF and the expression of EGFR can be induced by retinal damage, but not by FGF2-treatment. We conclude that HB-EGF is mitogenic to Müller glia in both chick and mouse retinas, and HB-EGF is an important player in the formation of MGPCs in damaged retinas. PMID:26500021

  9. Clinical effects of low-molecular-weight heparin combined with ...

    African Journals Online (AJOL)

    Purpose: To explore the clinical effects of low-molecular-weight heparin (LMWH) combined with ulinastatin (UTI) in children with acute pancreatitis. Methods: In total, 560 patients with severe acute pancreatitis treated at Binzhou People's Hospital, Shandong, China, from April 2012 to June 2014 were enrolled in this study.

  10. Early Heparin Administration Reduces Risk for Left Atrial Thrombus Formation during Atrial Fibrillation Ablation Procedures

    Directory of Open Access Journals (Sweden)

    Stefan Asbach

    2011-01-01

    Full Text Available Objective. Despite the use of anticoagulation during left atrial (LA ablation procedures, ischemic cerebrovascular accidents (CVAs are recognized as a serious complication. Heparin is usually given after safe transseptal access has been obtained, resulting in a short unprotected dwell time of catheters within the LA, which may account for CVAs. We investigated the frequency of CVAs and LA thrombus formation as detected by intracardiac ultrasound (ICE depending on the timing of heparin administration. Methods and Results. Sixty LA ablation procedures with the use of ICE were performed in 55 patients. Patients were grouped by heparin administration after (Group I, =13 and before (Group II, =47 transseptal access. Group I patients were younger (56.6±13.7 versus 65.9±9.9 years, =.01; other clinical and echocardiographic characteristics did not differ between groups. Early thrombus formation was observed in 2 (15.4% of group I patients as compared to 0% of group II patients (=.04. One CVA (2.1% occurred in one group II patient without prior thrombus detection, and none occurred in group I patients (=ns. Conclusion. Early administration of heparin reduces the risk of early intracardiac thrombus formation during LA ablation procedures. This did not result in reduced rate of CVAs.

  11. A Binding-Site Barrier Affects Imaging Efficiency of High Affinity Amyloid-Reactive Peptide Radiotracers In Vivo

    OpenAIRE

    Wall, Jonathan S.; Williams, Angela; Richey, Tina; Stuckey, Alan; Huang, Ying; Wooliver, Craig; Macy, Sallie; Heidel, Eric; Gupta, Neil; Lee, Angela; Rader, Brianna; Martin, Emily B.; Kennel, Stephen J.

    2013-01-01

    Amyloid is a complex pathology associated with a growing number of diseases including Alzheimer's disease, type 2 diabetes, rheumatoid arthritis, and myeloma. The distribution and extent of amyloid deposition in body organs establishes the prognosis and can define treatment options; therefore, determining the amyloid load by using non-invasive molecular imaging is clinically important. We have identified a heparin-binding peptide designated p5 that, when radioiodinated, was capable of selecti...

  12. A coupled channel study on a binding mechanism of positronic alkali atoms

    International Nuclear Information System (INIS)

    Kubota, Yoshihiro; Kino, Yasushi

    2008-01-01

    In order to investigate the binding mechanism of weakly bound states of positronic alkali atoms, we calculate the energies and wavefunctions using the Gaussian expansion method (GEM) where a positronium (Ps)-alkali ion channel and a positron-alkali atom channel are explicitly introduced. The energies of the bound states are updated using a model potential that reproduces well the observed energy levels of alkali atoms. The binding mechanism of the positronic alkali atom is analyzed by the wavefunctions obtained. The structure of the positronic alkali atom has been regarded as a Ps cluster orbiting the alkali ion, which is described by the Ps-alkali ion channel. We point out that the fraction having the positron-alkali atom configuration is small but plays an indispensable role for the weakly bound system

  13. Gender-based outcomes of bivalirudin versus heparin in patients undergoing percutaneous coronary interventions: Meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Mina, George S; Firouzbakht, Tina; Modi, Kalgi; Dominic, Paari

    2017-11-01

    We aimed to perform a gender-based meta-analysis of the outcome of bivalirudin versus heparin in patients undergoing percutaneous coronary interventions (PCI). Bivalirudin has been shown to decrease major bleeding when compared to heparin ± glycoprotein IIb/IIIa inhibitors (GPI) in patients undergoing PCI. It is unclear, however, if those differences in outcomes are the same for men and women. We included randomized controlled trials (RCTs) that compared bivalirudin to heparin with or without GPI in patients undergoing PCI and reported outcome data that were stratified by gender. Random effect model was used to pool odds ratio (OR) and 95% confidence intervals (CI). We included 9 trials with 33,224 patients. Bivalirudin decreased major bleeding when compared to heparin plus routine GPI in both men (OR: 0.51, P < 0.001) and women (OR: 0.55, P < 0.001). However, when GPI were used selectively with heparin, the bleeding lowering effect of bivalirudin was statistically significant in men (OR: 0.69, P = 0.02) but not in women (OR: 0.71, P = 0.21). When compared to heparin ± GPI, there was a nonstatistically significant trend toward lower all-cause mortality with bivalirudin in both men (OR: 0.76, P = 0.055) and women (OR: 0.79, P = 0.21). There were no significant differences in major adverse cardiovascular events between heparin and bivalirudin in both men and women. Bivalirudin decreases major bleeding in both men and women when compared to heparin plus routine GPI. However, when compared to heparin alone, the bleeding lowering benefit of bivalirudin is less evident in women. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Biochemical and microscopic evidence for the internalization and degradation of heparin-containing mast cell granules by bovine endothelial cells

    International Nuclear Information System (INIS)

    Atkins, F.M.; Friedman, M.M.; Metcalfe, D.D.

    1985-01-01

    Incubation of [ 35 S]heparin-containing mast cell granules with cultured bovine endothelial cells was followed by the appearance of 35 S-granule-associated radioactivity within the endothelial cells and a decrease in radioactivity in the extracellular fluid. These changes occurred during the first 24 hours of incubation and suggested ingestion of the mast cell granules by the endothelial cells. Periodic electron microscopic examination of the monolayers confirmed this hypothesis by demonstrating apposition of the granules to the plasmalemma of endothelial cells, which was followed by the engulfment of the granules by cytoplasmic projections. Under light microscopic examination, mast cell granules within endothelial cells then appeared to undergo degradation. The degradation of [ 35 S]heparin in mast cell granules was demonstrated by a decrease in the amount of intracellular [ 35 S]heparin proteoglycan after 24 hours and the appearance of free [ 35 S]sulfate in the extracellular compartment. Intact endothelial cells were more efficient at degrading [ 35 S]heparin than were cell lysates or cell supernatants. These data provide evidence of the ability of endothelial cells to ingest mast cell granules and degrade native heparin that is presented as a part of the mast cell granule

  15. Heparin as a pharmacologic intervention to induce positive scintiscan in occult gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Chaudhuri, T.K.; Brantly, M.

    1984-01-01

    The value of using heparin as a pharmacologic intervention to induce a positive scintiscan was studied in a patient with chronic occult gastrointestinal bleeding. When all standard diagnostic tests (upper and lower gastrointestinal series, upper and lower endoscopy, and conventional noninterventional Tc-99m RBC imaging) fail to detect and localize gastrointestinal bleeding in a patient who has definite clinical evidence (guaiac positive stool and dropping hemoglobin, hematocrit) of chronic occult gastrointestinal oozing, heparin may be used (with proper precaution) as a last resort to aid in the scintigraphic detection and localization of chronic occult gastrointestinal bleeding

  16. Successful Implantation of a Left Ventricular Assist Device in a Patient with Heparin-Induced Thrombocytopenia and Thrombosis

    Science.gov (United States)

    Garland, Cassandra; Somogyi, David

    2014-01-01

    Abstract: We report the case of a 27-year-old woman with signs of heparin-induced thrombocytopenia and thrombosis (HITT) and left heart failure presenting for urgent implantation of a left ventricular assist device (LVAD). HITT can occur in 4.2–6.1% of patients with LVADs. If the patient remains hemodynamically stable, implantation can be delayed for several months until the heparin/PF-4 antibodies decline allowing the use of heparin on cardiopulmonary bypass, However, in most cases related to cardiogenic shock, surgery cannot be delayed. We present the case of a patient who underwent implantation of a HeartMate II LVAD and discuss management strategy using bivalirudin during cardiopulmonary bypass. PMID:25208434

  17. Intravitreal low molecular weight heparin in PVR surgery.

    Directory of Open Access Journals (Sweden)

    Kumar Atul

    2003-01-01

    Full Text Available Purpose: To evaluate the efficacy of low molecular weight heparin (LMWH in prevention of postoperative fibrin formation following vitreoretinal surgery with proliferative vitreoretinopathy (PVR. Material and Methods: Thirty consecutive patients of retinal detachment with advanced PVR were enrolled in the study. They were randomised to study and control groups (n = 15 each. Study group patients received vitreoretinal surgery with 5 IU/cc of LMWH in vitrectomy infusion fluid. The control group patients received vitroretinal surgery without heparin in the infusion fluid. Patients were followed up at 1 week, 1 month and 3 months after surgery. Postoperative bleeding, media clarity, best-corrected visual acuity and success of the surgery at the end of 3 months were compared between the two groups. Results: At each follow-up visit, the study group showed a better media clarity, which was statistically significant ( P = 0.0042. The study group had a 50% better chance of retinal reattachment compared to the control group. Five patients had intraoperative bleeding in the study group (33% compared to 3 patients in the control group (20%. Conclusion: Use of intravitreal LMWH prevents postoperative fibrin formation and is beneficial in repair of retinal detachments with PVR.

  18. Deciphering the Role of Sulfonated Unit in Heparin-Mimicking Polymer to Promote Neural Differentiation of Embryonic Stem Cells.

    Science.gov (United States)

    Lei, Jiehua; Yuan, Yuqi; Lyu, Zhonglin; Wang, Mengmeng; Liu, Qi; Wang, Hongwei; Yuan, Lin; Chen, Hong

    2017-08-30

    Glycosaminoglycans (GAGs), especially heparin and heparan sulfate (HS), hold great potential for inducing the neural differentiation of embryonic stem cells (ESCs) and have brought new hope for the treatment of neurological diseases. However, the disadvantages of natural heparin/HS, such as difficulty in isolating them with a sufficient amount, highly heterogeneous structure, and the risk of immune responses, have limited their further therapeutic applications. Thus, there is a great demand for stable, controllable, and well-defined synthetic alternatives of heparin/HS with more effective biological functions. In this study, based upon a previously proposed unit-recombination strategy, several heparin-mimicking polymers were synthesized by integrating glucosamine-like 2-methacrylamido glucopyranose monomers (MAG) with three sulfonated units in different structural forms, and their effects on cell proliferation, the pluripotency, and the differentiation of ESCs were carefully studied. The results showed that all the copolymers had good cytocompatibility and displayed much better bioactivity in promoting the neural differentiation of ESCs as compared to natural heparin; copolymers with different sulfonated units exhibited different levels of promoting ability; among them, copolymer with 3-sulfopropyl acrylate (SPA) as a sulfonated unit was the most potent in promoting the neural differentiation of ESCs; the promoting effect is dependent on the molecular weight and concentration of P(MAG-co-SPA), with the highest levels occurring at the intermediate molecular weight and concentration. These results clearly demonstrated that the sulfonated unit in the copolymers played an important role in determining the promoting effect on ESCs' neural differentiation; SPA was identified as the most potent sulfonated unit for copolymer with the strongest promoting ability. The possible reason for sulfonated unit structure as a vital factor influencing the ability of the copolymers

  19. Release of proteins via ion exchange from albumin-heparin microspheres

    NARCIS (Netherlands)

    Kwon, Glen S.; Bae, You Han; Cremers, H.F.M.; Cremers, Harry; Feijen, Jan; Kim, Sung Wan

    1992-01-01

    Albumin-heparin and albumin microspheres were prepared as ion exchange gels for the controlled release of positively charged polypeptides and proteins. The adsorption isotherms of chicken egg and human lysozyme, as model proteins, on microspheres were obtained. An adsorption isotherm of chicken egg

  20. A generalized allosteric mechanism for cis-regulated cyclic nucleotide binding domains.

    Directory of Open Access Journals (Sweden)

    Alexandr P Kornev

    2008-04-01

    Full Text Available Cyclic nucleotides (cAMP and cGMP regulate multiple intracellular processes and are thus of a great general interest for molecular and structural biologists. To study the allosteric mechanism of different cyclic nucleotide binding (CNB domains, we compared cAMP-bound and cAMP-free structures (PKA, Epac, and two ionic channels using a new bioinformatics method: local spatial pattern alignment. Our analysis highlights four major conserved structural motifs: 1 the phosphate binding cassette (PBC, which binds the cAMP ribose-phosphate, 2 the "hinge," a flexible helix, which contacts the PBC, 3 the beta(2,3 loop, which provides precise positioning of an invariant arginine from the PBC, and 4 a conserved structural element consisting of an N-terminal helix, an eight residue loop and the A-helix (N3A-motif. The PBC and the hinge were included in the previously reported allosteric model, whereas the definition of the beta(2,3 loop and the N3A-motif as conserved elements is novel. The N3A-motif is found in all cis-regulated CNB domains, and we present a model for an allosteric mechanism in these domains. Catabolite gene activator protein (CAP represents a trans-regulated CNB domain family: it does not contain the N3A-motif, and its long range allosteric interactions are substantially different from the cis-regulated CNB domains.

  1. Photochemically synthesized heparin-based silver nanoparticles: an antimicrobial activity study

    Science.gov (United States)

    Rodriguez-Torres, Maria del Pilar; Acosta-Torres, Laura Susana; Díaz-Torres, Luis Armando

    2017-08-01

    The antimicrobial activity of silver nanoparticles has been extensively studied in the last years. Such nanoparticles constitute a potential and promising approach for the development of new antimicrobial systems especially due to the fact that several microorganisms are developing resistance to some already existing antimicrobial agents, therefore making antibacterial and antimicrobial studies on alternative materials necessary to overcome this issue. Silver nanoparticle concentration and size are determining factors on the antimicrobial activity of these nano systems. Heparin is a polysaccharide that belongs to the glycosaminoglycans (GAGs) family, molecules formed by a base disaccharide whose components are joined by a glycosidic linkage that is a repeating unit along their structure. It is highly sulfated making it a negatively charged material that is also widely used as an anticoagulant in Medicine because its biocompatibility besides it is also produced within the human body, specifically in the mast cells. Heparin alone possesses antimicrobial activity although it has not been studied very much in detail, it only has been demonstrated that it inhibits E. coli, P. aeruginosa, S. aureus and S. epidermidis, so taking this into account, this study is dedicated to assess UV photochemically-synthesized (λ=254 nm) heparin-based silver nanoparticles antimicrobial activity using the agar disk diffusion method complemented by the broth microdilution method to estimate de minimum inhibitory concentration (MIC), that is the lowest concentration at which an antimicrobial will inhibit visible growth of a microorganism. The strains used were the ones aforementioned to assess the antimicrobial activity degree these heparinbased nanoparticles exhibit.

  2. Heparin-mimicking multilayer coating on polymeric membrane via LbL assembly of cyclodextrin-based supramolecules.

    Science.gov (United States)

    Deng, Jie; Liu, Xinyue; Ma, Lang; Cheng, Chong; Shi, Wenbin; Nie, Chuanxiong; Zhao, Changsheng

    2014-12-10

    In this study, multifunctional and heparin-mimicking star-shaped supramolecules-deposited 3D porous multilayer films with improved biocompatibility were fabricated via a layer-by-layer (LbL) self-assembly method on polymeric membrane substrates. Star-shaped heparin-mimicking polyanions (including poly(styrenesulfonate-co-sodium acrylate; Star-PSS-AANa) and poly(styrenesulfonate-co-poly(ethylene glycol)methyl ether methacrylate; Star-PSS-EGMA)) and polycations (poly(methyl chloride-quaternized 2-(dimethylamino)ethyl methacrylate; Star-PMeDMA) were first synthesized by atom transfer radical polymerization (ATRP) from β-cyclodextrin (β-CD) based cores. Then assembly of 3D porous multilayers onto polymeric membrane surfaces was carried out by alternating deposition of the polyanions and polycations via electrostatic interaction. The surface morphology and composition, water contact angle, blood activation, and thrombotic potential as well as cell viability for the coated heparin-mimicking films were systematically investigated. The results of surface ATR-FTIR spectra and XPS spectra verified successful deposition of the star-shaped supramolecules onto the biomedical membrane surfaces; scanning electron microscopy (SEM) and atomic force microscopy (AFM) observations revealed that the modified substrate had 3D porous surface morphology, which might have a great biological influence on the biointerface. Furthermore, systematic in vitro investigation of protein adsorption, platelet adhesion, human platelet factor 4 (PF4, indicates platelet activation), activate partial thromboplastin time (APTT), thrombin time (TT), coagulation activation (thrombin-antithrombin III complex (TAT, indicates blood coagulant)), and blood-related complement activation (C3a and C5a, indicates inflammation potential) confirmed that the heparin-mimicking multilayer coated membranes exhibited ultralow blood component activations and excellent hemocompatibility. Meanwhile, after surface coating

  3. Human recombinant interleukin-1 beta- and tumor necrosis factor alpha-mediated suppression of heparin-like compounds on cultured porcine aortic endothelial cells

    International Nuclear Information System (INIS)

    Kobayashi, M.; Shimada, K.; Ozawa, T.

    1990-01-01

    Cytokines are known to tip the balance of the coagulant-anticoagulant molecules on the endothelial cell surface toward intravascular coagulation. Their effects on endothelial cell surface-associated heparin-like compounds have not been examined yet. Incorporation of [35S]sulfate into heparan sulfate on cultured porcine aortic endothelial cells was suppressed by human recombinant interleukin-1 beta (rIL-1 beta) or tumor necrosis factor alpha (rTNF alpha) in a dose- and time-dependent manner with little effect on cell number, protein content, and [3H]leucine incorporation of cells. Maximal inhibition was achieved by incubation of cells with 100 ng/ml of rIL-1 beta or 5 ng/ml of rTNF alpha for 12-24 hours, resulting in a reduction of the synthesis of heparan sulfate on the cell surface by approximately 50%. The dose dependency was consistent with that seen in the stimulation of endothelial cell procoagulant activity by each cytokine. The suppression of heparan sulfate synthesis was sustained for at least 48 hours after pretreatment of cells with cytokines and was unchanged after the addition of indomethacin or polymyxin B. The rate of degradation of prelabeled 35S-heparan sulfate on the cell surface was not altered by cytokine treatments. Neither the size, the net negative charge, nor the proportion of the molecule with high affinity for antithrombin III of endothelial cell heparan sulfate was changed by cytokines. Furthermore, specific binding of 125I-labeled antithrombin III to the endothelial cell surface was reduced to 40-60% of control by cytokines. In parallel with reduction in binding, antithrombin III cofactor activity was partially diminished in cytokine-treated endothelial cells. Thus, cytokine-mediated suppression of heparin-like substance on endothelial cells appears to be another cytokine-inducible endothelial effects affecting coagulation

  4. CCN5 modulates the antiproliferative effect of heparin and regulates cell motility in vascular smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Castellot John J

    2003-11-01

    Full Text Available Abstract Background Vascular smooth muscle cell (VSMC hyperplasia plays an important role in both chronic and acute vascular pathologies including atherosclerosis and restenosis. Considerable work has focused on the mechanisms regulating VSMC proliferation and motility. Earlier work in our lab revealed a novel growth arrest-specific (gas gene induced in VSMC exposed to the antiproliferative agent heparin. This gene is a member of the CCN family and has been given the name CCN5. The objective of the present study is to elucidate the function of CCN5 protein and to explore its mechanism of action in VSMC. Results Using RNA interference (RNAi, we first demonstrate that CCN5 is required for the antiproliferative effect of heparin in VSMC. We also use this gene knockdown approach to show that CCN5 is an important negative regulator of motility. To explore the mechanism of action of CCN5 on VSMC motility, we use RNAi to demonstrate that knock down of CCN5 up regulates expression of matrix metalloproteinase-2 (MMP-2, an important stimulator of motility in VSMC. In addition, forced expression of CCN5 via adenovirus results in reduced MMP-2 activity, this also corroborates the gene knock down results. Finally, we show that loss of CCN5 expression in VSMC causes changes in VSMC morphology and cytoskeletal organization, including a reduction in the amount and macromolecular assembly of smooth muscle cell α-actin. Conclusions This work provides important new insights into the regulation of smooth muscle cell proliferation and motility by CCN5 and may aid the development of therapies for vascular diseases.

  5. Autocrine effect of DHT on FGF signaling and cell proliferation in LNCaP cells: role of heparin/heparan-degrading enzymes.

    Science.gov (United States)

    Kassen, A E; Sensibar, J A; Sintich, S M; Pruden, S J; Kozlowski, J M; Lee, C

    2000-07-01

    LNCaP cells are androgen-sensitive human prostate cancer cells. They are characterized by a bell-shaped growth curve in response to increasing doses of dihydrotestosterone (DHT) in culture. At a low concentration of DHT (0.1 nM), these cells show an increase in proliferation, but their growth is arrested at a high concentration (100 nM) of DHT. Results of our previous study demonstrated that the inhibitory effect of DHT at a high concentration was mediated through the action of TGF-beta1. The objective of the present study was to elucidate the mechanism of the proliferative effect of DHT in LNCaP cells. METHODS AND RESULTS DHT stimulated LNCaP proliferation only when cells were cultured in the presence of serum. In serum-free cultures, the characteristic DHT-induced proliferation was not observed. The addition of neutralizing antibody against FGF-2 (basic fibroblast growth factor) was able to inhibit this DHT-induced proliferation. These results suggest that the proliferative effect of DHT was mediated through the action of FGF-2. However, results of the reverse transcriptase polymerase chain reaction indicated that LNCaP cells did not express FGF-2 message. As a result, the source of FGF-2 in these cultures must be the serum supplemented in the culture media. FGF-2 can bind to heparin sulfate chains within the extracellular matrix (ECM). In cultures treated with exogenous heparin, the proliferative effect of DHT was abolished. These results led to the development of the hypothesis that DHT treatment mediates the release of FGF-2 entrapped in the ECM through increased heparinase activity. The addition of heparinase to cultures of LNCaP cells, in the absence of DHT, was able to stimulate cell proliferation. Moreover, 0.1 nM DHT caused a significant increase in heparinase activity. These results provide a possible mechanism for DHT action in LNCaP cells. In the absence of DHT, FGF-2 in culture was trapped in the extracellular matrix and was not available to interact

  6. Identification of heparin samples that contain impurities or contaminants by chemometric pattern recognition analysis of proton NMR spectral data

    Energy Technology Data Exchange (ETDEWEB)

    Zang, Qingda [University of Medicine and Dentistry of New Jersey, Department of Pharmacology, Robert Wood Johnson Medical School, Piscataway, NJ (United States); Snowdon, Inc., Monmouth Junction, NJ (United States); University of Medicine and Dentistry of New Jersey, Department of Health Informatics, School of Health Related Professions, Newark, NJ (United States); Keire, David A.; Buhse, Lucinda F.; Trehy, Michael L. [Food and Drug Administration, CDER, Division of Pharmaceutical Analysis, St. Louis, MO (United States); Wood, Richard D. [Snowdon, Inc., Monmouth Junction, NJ (United States); Mital, Dinesh P.; Haque, Syed; Srinivasan, Shankar [University of Medicine and Dentistry of New Jersey, Department of Health Informatics, School of Health Related Professions, Newark, NJ (United States); Moore, Christine M.V.; Nasr, Moheb; Al-Hakim, Ali [Food and Drug Administration, CDER, Office of New Drug Quality Assessment, Silver Spring, MD (United States); Welsh, William J. [University of Medicine and Dentistry of New Jersey, Department of Pharmacology, Robert Wood Johnson Medical School, Piscataway, NJ (United States)

    2011-08-15

    Chemometric analysis of a set of one-dimensional (1D) {sup 1}H nuclear magnetic resonance (NMR) spectral data for heparin sodium active pharmaceutical ingredient (API) samples was employed to distinguish USP-grade heparin samples from those containing oversulfated chondroitin sulfate (OSCS) contaminant and/or unacceptable levels of dermatan sulfate (DS) impurity. Three chemometric pattern recognition approaches were implemented: classification and regression tree (CART), artificial neural network (ANN), and support vector machine (SVM). Heparin sodium samples from various manufacturers were analyzed in 2008 and 2009 by 1D {sup 1}H NMR, strong anion-exchange high-performance liquid chromatography, and percent galactosamine in total hexosamine tests. Based on these data, the samples were divided into three groups: Heparin, DS {<=} 1.0% and OSCS = 0%; DS, DS > 1.0% and OSCS = 0%; and OSCS, OSCS > 0% with any content of DS. Three data sets corresponding to different chemical shift regions (1.95-2.20, 3.10-5.70, and 1.95-5.70 ppm) were evaluated. While all three chemometric approaches were able to effectively model the data in the 1.95-2.20 ppm region, SVM was found to substantially outperform CART and ANN for data in the 3.10-5.70 ppm region in terms of classification success rate. A 100% prediction rate was frequently achieved for discrimination between heparin and OSCS samples. The majority of classification errors between heparin and DS involved cases where the DS content was close to the 1.0% DS borderline between the two classes. When these borderline samples were removed, nearly perfect classification results were attained. Satisfactory results were achieved when the resulting models were challenged by test samples containing blends of heparin APIs spiked with non-, partially, or fully oversulfated chondroitin sulfate A, heparan sulfate, or DS at the 1.0%, 5.0%, and 10.0% (w/w) levels. This study demonstrated that the combination of 1D {sup 1}H NMR spectroscopy

  7. Decipher the mechanisms of protein conformational changes induced by nucleotide binding through free-energy landscape analysis: ATP binding to Hsp70.

    Directory of Open Access Journals (Sweden)

    Adrien Nicolaï

    Full Text Available ATP regulates the function of many proteins in the cell by transducing its binding and hydrolysis energies into protein conformational changes by mechanisms which are challenging to identify at the atomic scale. Based on molecular dynamics (MD simulations, a method is proposed to analyze the structural changes induced by ATP binding to a protein by computing the effective free-energy landscape (FEL of a subset of its coordinates along its amino-acid sequence. The method is applied to characterize the mechanism by which the binding of ATP to the nucleotide-binding domain (NBD of Hsp70 propagates a signal to its substrate-binding domain (SBD. Unbiased MD simulations were performed for Hsp70-DnaK chaperone in nucleotide-free, ADP-bound and ATP-bound states. The simulations revealed that the SBD does not interact with the NBD for DnaK in its nucleotide-free and ADP-bound states whereas the docking of the SBD was found in the ATP-bound state. The docked state induced by ATP binding found in MD is an intermediate state between the initial nucleotide-free and final ATP-bound states of Hsp70. The analysis of the FEL projected along the amino-acid sequence permitted to identify a subset of 27 protein internal coordinates corresponding to a network of 91 key residues involved in the conformational change induced by ATP binding. Among the 91 residues, 26 are identified for the first time, whereas the others were shown relevant for the allosteric communication of Hsp70 s in several experiments and bioinformatics analysis. The FEL analysis revealed also the origin of the ATP-induced structural modifications of the SBD recently measured by Electron Paramagnetic Resonance. The pathway between the nucleotide-free and the intermediate state of DnaK was extracted by applying principal component analysis to the subset of internal coordinates describing the transition. The methodology proposed is general and could be applied to analyze allosteric communication in

  8. Improved synthesis of polystyrene-poly(ethylene oxide)-heparin block copolymers

    NARCIS (Netherlands)

    Vulic, I.; Loman, A.J.B.; Feijen, Jan; Okano, T.; Kim, S.W.

    1990-01-01

    A novel procedure for the synthesis of block copolymers composed of a hydrophobic block of polystyrene, a hydrophilic block of poly(ethylene oxide) and a bioactive block of nitrous acid-degraded heparin was developed. Amino-semitelechelic polystyrene was prepared by anionic polymerization of styrene

  9. Role of Kallistatin Treatment in Aging and Cancer by Modulating miR-34a and miR-21 Expression

    Directory of Open Access Journals (Sweden)

    Julie Chao

    2017-01-01

    Full Text Available Kallistatin is an endogenous protein that regulates differential signaling pathways and a wide spectrum of biological activities via its two structural elements: an active site and a heparin-binding domain. Kallistatin via its heparin-binding site inhibits vascular inflammation and oxidative stress by antagonizing TNF-α-induced NADPH oxidase activity, NF-κB activation, and inflammatory gene expression in endothelial cells. Moreover, kallistatin via its active site inhibits microRNA-34a (miR-34a synthesis and stimulates eNOS and SIRT1 expression in endothelial progenitor cells, whereas its heparin-binding site is crucial for blocking TNF-α-induced miR-21 expression and oxidative stress, thus reducing cellular senescence. By downregulating miR-34a and miR-21 expression, kallistatin treatment attenuates oxidative damage and aortic senescence in streptozotocin-induced diabetic mice and extends Caenorhabditis elegans lifespan under stress conditions. Likewise, kallistatin through the heparin-binding site inhibits TGF-β-induced miR-21 synthesis and oxidative stress in endothelial cells, resulting in inhibition of endothelial-mesenchymal transition, a process contributing to fibrosis and cancer. Furthermore, kallistatin’s active site is essential for stimulating miR-34a and p53 expression and inhibiting the miR-21-Akt-Bcl-2 signaling pathway, thus inducing apoptosis in breast cancer cells. These findings reveal novel mechanisms of kallistatin in protection against senescence, aging, and cancer development by modulating miR-34a and miR-21 levels and inhibiting oxidative stress.

  10. Intra-articular TSG-6 delivery from heparin-based microparticles reduces cartilage damage in a rat model of osteoarthritis.

    Science.gov (United States)

    Tellier, Liane E; Treviño, Elda A; Brimeyer, Alexandra L; Reece, David S; Willett, Nick J; Guldberg, Robert E; Temenoff, Johnna S

    2018-05-01

    As a potential treatment for osteoarthritis (OA), we have developed injectable and hydrolytically degradable heparin-based biomaterials with tunable sulfation for the intra-articular delivery of tumor necrosis factor-alpha stimulated gene-6 (TSG-6), a protein known to inhibit plasmin which may degrade extracellular matrix within OA joints. We first assessed the effect of heparin sulfation on TSG-6 anti-plasmin activity and found that while fully sulfated (Hep) and heparin desulfated at only the N position (Hep-N) significantly enhanced TSG-6 bioactivity in vitro, fully desulfated heparin (Hep-) had no effect, indicating that heparin sulfation plays a significant role in modulating TSG-6 bioactivity. Next, TSG-6 loaded, degradable 10 wt% Hep-N microparticles (MPs) were delivered via intra-articular injection into the knee at 1, 7, and 15 days following medial meniscal transection (MMT) injury in a rat model. After 21 days, cartilage thickness, volume, and attenuation were significantly increased with soluble TSG-6, indicating degenerative changes. In contrast, no significant differences were observed with TSG-6 loaded MP treatment, demonstrating that TSG-6 loaded MPs reduced cartilage damage following MMT injury. Ultimately, our results indicate that Hep-N can enhance TSG-6 anti-plasmin activity and that Hep-N-based biomaterials may be an effective method for TSG-6 delivery to treat OA.

  11. Raman spectroscopy in investigations of mechanism of binding of human serum albumin to molecular probe fluorescein

    International Nuclear Information System (INIS)

    Vlasova, I M; Saletsky, A M

    2008-01-01

    The mechanism of binding of molecular probe fluorescein to molecules of human serum albumin was studied by the Raman spectroscopy method. The position of binding Center on human serum albumin molecule for fluorescein is determined. The amino acid residues of albumin molecule, participating in binding of fluorescein at different pH values of solution, are established. The conformation rearrangements of globules of human serum albumin, taking place at binding of fluorescein at different pH values of solution, are registered

  12. Heparin induces an accumulation of atherogenic lipoproteins during hemodialysis in normolipidemic end-stage renal disease patients.

    Science.gov (United States)

    Barbagallo, Carlo M; Noto, Davide; Cefalù, Angelo B; Ganci, Antonia; Giammarresi, Carlo; Panno, Donata; Cusumano, Gaspare; Greco, Massimiliano; Di Gaudio, Francesca; Averna, Maurizio R

    2015-07-01

    Dyslipidemias may account for the excess of cardiovascular mortality in end-stage renal disease (ESRD). Lipoprotein studies in ESRD patients are usually relative to prehemodialysis samples even if significative changes may occur after dialysis. In this study, we aimed to investigate the effects of ESRD on triglyceride-rich lipoproteins (TRL) subpopulations distribution and acute change following hemodialytic procedures, including the relative contribution of heparin administration. We selected a group of normolipidemic male middle-aged ESRD patients free of any concomitant disease affecting lipoprotein remnant metabolism compared with controls. We separated TRL subfractions according to density and apoE content and evaluated the changes of these particles after hemodialytic procedures with or without heparin. ESRD subjects had higher TRL subfractions, with the exception of apoE-rich particles, lower high-density lipoprotein (HDL) largest subclasses, and a smaller low-density lipoprotein peak particle size than controls. After a hemodialytic standard procedure with heparin, we demonstrated a significant reduction of triglyceride, an increase of HDL-cholesterol levels, and a raise of small very-low-density lipoprotein, intermediate-density lipoproteins (IDL), apoE-rich particles, and non-HDL-cholesterol levels. When hemodialysis was performed without heparin, no significant changes were observed. In the absence of concomitant hyperlipidemic triggers, ESRD patients show significant lipoprotein abnormalities before dialysis, but without any increased remnant particles concentrations. We speculate that hemodialysis, in particular heparin administration during this procedure, leads to a massive atherogenic TRLs production because of the acute stimulation of the dysfunctional lipolytic system not followed by an efficient removal, determining a recurrent lipoprotein remnant accumulation. © 2014 International Society for Hemodialysis.

  13. Heparin Assisted Photochemical Synthesis of Gold Nanoparticles and Their Performance as SERS Substrates

    Science.gov (United States)

    Rodríguez-Torres, Maria del Pilar; Díaz-Torres, Luis Armando; Romero-Servin, Sergio

    2014-01-01

    Reactive and pharmaceutical-grade heparins were used as biologically compatible reducing and stabilizing agents to photochemically synthesize colloidal gold nanoparticles. Aggregates and anisotropic shapes were obtained photochemically under UV black-light lamp irradiation (λ = 366 nm). Heparin-functionalized gold nanoparticles were characterized by Scanning Electron Microscopy and UV-Vis spectroscopy. The negatively charged colloids were used for the Surface Enhanced Raman Spectroscopy (SERS) analysis of differently charged analytes (dyes). Measurements of pH were taken to inspect how the acidity of the medium affects the colloid-analyte interaction. SERS spectra were taken by mixing the dyes and the colloidal solutions without further functionalization or addition of any aggregating agent. PMID:25342319

  14. Influence of Human Leukocyte Antigen (HLA) Alleles and Killer Cell Immunoglobulin-Like Receptors (KIR) Types on Heparin-Induced Thrombocytopenia (HIT).

    Science.gov (United States)

    Karnes, Jason H; Shaffer, Christian M; Cronin, Robert; Bastarache, Lisa; Gaudieri, Silvana; James, Ian; Pavlos, Rebecca; Steiner, Heidi E; Mosley, Jonathan D; Mallal, Simon; Denny, Joshua C; Phillips, Elizabeth J; Roden, Dan M

    2017-09-01

    Heparin-induced thrombocytopenia (HIT) is an unpredictable, life-threatening, immune-mediated reaction to heparin. Variation in human leukocyte antigen (HLA) genes is now used to prevent immune-mediated adverse drug reactions. Combinations of HLA alleles and killer cell immunoglobulin-like receptors (KIR) are associated with multiple autoimmune diseases and infections. The objective of this study is to evaluate the association of HLA alleles and KIR types, alone or in the presence of different HLA ligands, with HIT. HIT cases and heparin-exposed controls were identified in BioVU, an electronic health record coupled to a DNA biobank. HLA sequencing and KIR type imputation using Illumina OMNI-Quad data were performed. Odds ratios for HLA alleles and KIR types and HLA*KIR interactions using conditional logistic regressions were determined in the overall population and by race/ethnicity. Analysis was restricted to KIR types and HLA alleles with a frequency greater than 0.01. The p values for HLA and KIR association were corrected by using a false discovery rate qHIT cases and 350 matched controls were identified. No statistical differences in baseline characteristics were observed between cases and controls. The HLA-DRB3*01:01 allele was significantly associated with HIT in the overall population (odds ratio 2.81 [1.57-5.02], p=2.1×10 -4 , q=0.02) and in individuals with European ancestry, independent of other alleles. No KIR types were associated with HIT, although a significant interaction was observed between KIR2DS5 and the HLA-C1 KIR binding group (p=0.03). The HLA-DRB3*01:01 allele was identified as a potential risk factor for HIT. This class II HLA gene and allele represent biologically plausible candidates for influencing HIT pathogenesis. We found limited evidence of the role of KIR types in HIT pathogenesis. Replication and further study of the HLA-DRB3*01:01 association is necessary. © 2017 Pharmacotherapy Publications, Inc.

  15. Screening of Lactobacillus strains for their ability to bind benzo(a)pyrene and the mechanism of the process.

    Science.gov (United States)

    Zhao, Hongfei; Zhou, Fang; Qi, Yeqiong; Dziugan, Piotr; Bai, Fengling; Walczak, Piotr; Zhang, Bolin

    2013-09-01

    In order to investigate the binding ability of Lactobacillus strains to Benzo(a)pyrene (BaP), 15 strains were analysed. L. plantarum CICC 22135 and L. pentosus CICC 23163 exhibited high efficiency in removing BaP from aqueous medium; the binding rates were 66.76% and 64.31%, respectively. This process was affected by temperature, incubation time and pH, and cell viability was not necessary for the binding ability. Additionally, both strains, especially strain CICC 23163 showed high specificity in binding BaP. The cell-BaP complexes were stable in aqueous medium. The mechanism of binding was investigated by examining the binding ability of different components of the microorganism cells. The results revealed that peptidoglycans played an important role in binding BaP and its structural integrity was required. Consequently, we proposed that the mechanism of this process was a physisorption and peptidoglycan was the main binding site. These two strains may be used for dietary detoxification in human diet and animal feed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Cyclic Voltammetry of Biopolymer Heparin at PVC Plasticized Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Samec, Zdeněk; Trojánek, Antonín; Langmaier, Jan; Samcová, E.

    2003-01-01

    Roč. 5, - (2003), s. 867-870 ISSN 1388-2481 R&D Projects: GA ČR GA203/04/0424 Institutional research plan: CEZ:AV0Z4040901 Keywords : cyclic voltammetry * PVC plasticized liquit membrane * heparin Subject RIV: CG - Electrochemistry Impact factor: 2.300, year: 2003

  17. Heparin crisis 2008: a tipping point for increased FDA enforcement in the pharma sector?

    Science.gov (United States)

    Rosania, Larry

    2010-01-01

    Against a backdrop of steady deregulation, the pharmaceutical industry is increasingly outsourcing manufacturing, resulting in decentralized control of the global supply chain. Established products such as heparin have been held to outdated analytical standards. Ten million Americans receive heparin every year; Baxter International accounts for half of this market. In 2008, contamination of Baxter's heparin--sourced in China--resulted in about 350 adverse events and 150 deaths in the United States. In future, increasingly stringent FDA inspections and enforcement are expected for imported drugs and ingredients. More regional FDA offices will be set up overseas. FDA funding will likely be supplemented in future by user fees charged to importers. For newer products, companies will face pressure to adopt Quality by Design, with solid control of the global supply chain and a proactive focus on GMP. Older products will be held to modern standards. Long-term, imports of drugs and ingredients from developing markets will continue. This makes sense to companies from an economic standpoint, but protections will be essential to ensure that it is also justifiable from a public health perspective.

  18. Dynamics of Bovine Sperm Interaction with Epithelium Differ Between Oviductal Isthmus and Ampulla1

    Science.gov (United States)

    Ardon, Florencia; Markello, Ross D.; Hu, Lian; Deutsch, Zarah I.; Tung, Chih-Kuan; Wu, Mingming; Suarez, Susan S.

    2016-01-01

    In mammals, many sperm that reach the oviduct are held in a reservoir by binding to epithelium. To leave the reservoir, sperm detach from the epithelium; however, they may bind and detach again as they ascend into the ampulla toward oocytes. In order to elucidate the nature of binding interactions along the oviduct, we compared the effects of bursts of strong fluid flow (as would be caused by oviductal contractions), heparin, and hyperactivation on detachment of bovine sperm bound in vitro to epithelium on intact folds of isthmic and ampullar mucosa. Intact folds of oviductal mucosa were used to represent the strong attachments of epithelial cells to each other and to underlying connective tissue that exist in vivo. Effects of heparin on binding were tested because heparin binds to the Binder of SPerm (BSP) proteins that attach sperm to oviductal epithelium. Sperm bound by their heads to beating cilia on both isthmic and ampullar epithelia and could not be detached by strong bursts of fluid flow. Addition of heparin immediately detached sperm from isthmic epithelium but not ampullar epithelium. Addition of 4-aminopyridine immediately stimulated hyperactivation of sperm but did not detach them from isthmic or ampullar epithelium unless added with heparin. These observations indicate that the nature of binding of sperm to ampullar epithelium differs from that of binding to isthmic epithelium; specifically, sperm bound to isthmic epithelium can be detached by heparin alone, while sperm bound to ampullar epithelium requires both heparin and hyperactivation to detach from the epithelium. PMID:27605344

  19. A Turn-on Fluorescence Sensor for Heparin Detection Based on a Release of Taiwan Cobra Cardiotoxin from a DNA Aptamer or Adenosine-Based Molecular Beacon.

    Science.gov (United States)

    Shi, Yi-Jun; Wang, Liang-Jun; Lee, Yuan-Chin; Huang, Chia-Hui; Hu, Wan-Ping; Chang, Long-Sen

    2018-02-19

    This study presents two sensitive fluorescent assays for sensing heparin on the basis of the electrostatic interaction between heparin and Naja naja atra cardiotoxin 3 (CTX3). Owing to CTX3-induced folded structure of an adenosine-based molecular beacon (MB) or a DNA aptamer against CTX3, a reduction in the fluorescent signal of the aptamer or MB 5'-end labeled with carboxyfluorescein (FAM) and 3'-end labeled with 4-([4-(dimethylamino)phenyl]azo)-benzoic acid (DABCYL) was observed upon the addition of CTX3. The presence of heparin and formation of the CTX3-heparin complex caused CTX3 detachment from the MB or aptamer, and restoration of FAM fluorescence of the 5'-FAM-and-3'-DABCYL-labeled MB and aptamer was subsequently noted. Moreover, the detection of heparin with these CTX3-aptamer and CTX3-MB sensors showed high sensitivity and selectivity toward heparin over chondroitin sulfate and hyaluronic acid regardless of the presence of plasma. The limit of detection for heparin in plasma was determined to be 16 ng/mL and 15 ng/mL, respectively, at a signal-to-noise ratio of 3. This study validates the practical utility of the CTX3-aptamer and CTX3-MB systems for determining the concentration of heparin in a biological matrix.

  20. Cefotaxime-heparin lock prophylaxis against hemodialysis catheter-related sepsis among Staphylococcus aureus nasal carriers

    Directory of Open Access Journals (Sweden)

    Anil K Saxena

    2012-01-01

    Full Text Available Staphylococcus aureus nasal carriers undergoing hemodialysis (HD through tunneled cuffed catheters (TCCs form a high-risk group for the development of catheter-related bloodstream infections (CRBSI and ensuing morbidity. The efficacy of antibiotic-locks on the outcomes of TCCs among S. aureus nasal carriers has not been studied earlier. Persistent nasal carriage was defined by two or more positive cultures for methicillin-susceptible (MSSA or methicillin-resistant (MRSA S. aureus of five standardized nasal swabs taken from all the participants dialyzed at a large out-patient HD center affiliated to a tertiary care hospital. Of 218 participants, 82 S. aureus nasal carriers dialyzed through TCCs (n = 88 were identified through April 2005 to March 2006 and randomized to two groups. Group I comprised of 39 nasal carriers who had TCCs (n = 41 "locked" with cefotaxime/heparin while group II included 43 patients with TCCs (n = 47 filled with standard heparin. The CRBSI incidence and TCC survival at 365 days were statistically compared between the two groups. A significantly lower CRBSI incidence (1.47 vs. 3.44/1000 catheter-days, P <0.001 and higher infection-free TCC survival rates at 365 days (80.5 vs. 40.4%, P <0.0001 were observed in the cefotaxime group compared with the stan-dard heparin group. However, no significant difference in MRSA-associated CRBSI incidence was observed between the two groups. Cefotaxime-heparin "locks" effectively reduced CRBSI-incidence associated with gram-positive cocci, including MSSA, among S. aureus nasal carriers. There remains a compelling requirement for antibiotic-locks effective against MRSA.

  1. A binding-site barrier affects imaging efficiency of high affinity amyloid-reactive peptide radiotracers in vivo.

    Science.gov (United States)

    Wall, Jonathan S; Williams, Angela; Richey, Tina; Stuckey, Alan; Huang, Ying; Wooliver, Craig; Macy, Sallie; Heidel, Eric; Gupta, Neil; Lee, Angela; Rader, Brianna; Martin, Emily B; Kennel, Stephen J

    2013-01-01

    Amyloid is a complex pathology associated with a growing number of diseases including Alzheimer's disease, type 2 diabetes, rheumatoid arthritis, and myeloma. The distribution and extent of amyloid deposition in body organs establishes the prognosis and can define treatment options; therefore, determining the amyloid load by using non-invasive molecular imaging is clinically important. We have identified a heparin-binding peptide designated p5 that, when radioiodinated, was capable of selectively imaging systemic visceral AA amyloidosis in a murine model of the disease. The p5 peptide was posited to bind effectively to amyloid deposits, relative to similarly charged polybasic heparin-reactive peptides, because it adopted a polar α helix secondary structure. We have now synthesized a variant, p5R, in which the 8 lysine amino acids of p5 have been replaced with arginine residues predisposing the peptide toward the α helical conformation in an effort to enhance the reactivity of the peptide with the amyloid substrate. The p5R peptide had higher affinity for amyloid and visualized AA amyloid in mice by using SPECT/CT imaging; however, the microdistribution, as evidenced in micro-autoradiographs, was dramatically altered relative to the p5 peptide due to its increased affinity and a resultant "binding site barrier" effect. These data suggest that radioiodinated peptide p5R may be optimal for the in vivo detection of discreet, perivascular amyloid, as found in the brain and pancreatic vasculature, by using molecular imaging techniques; however, peptide p5, due to its increased penetration, may yield more quantitative imaging of expansive tissue amyloid deposits.

  2. RecO protein initiates DNA recombination and strand annealing through two alternative DNA binding mechanisms.

    Science.gov (United States)

    Ryzhikov, Mikhail; Gupta, Richa; Glickman, Michael; Korolev, Sergey

    2014-10-17

    Recombination mediator proteins (RMPs) are important for genome stability in all organisms. Several RMPs support two alternative reactions: initiation of homologous recombination and DNA annealing. We examined mechanisms of RMPs in both reactions with Mycobacterium smegmatis RecO (MsRecO) and demonstrated that MsRecO interacts with ssDNA by two distinct mechanisms. Zinc stimulates MsRecO binding to ssDNA during annealing, whereas the recombination function is zinc-independent and is regulated by interaction with MsRecR. Thus, different structural motifs or conformations of MsRecO are responsible for interaction with ssDNA during annealing and recombination. Neither annealing nor recombinase loading depends on MsRecO interaction with the conserved C-terminal tail of single-stranded (ss) DNA-binding protein (SSB), which is known to bind Escherichia coli RecO. However, similarly to E. coli proteins, MsRecO and MsRecOR do not dismiss SSB from ssDNA, suggesting that RMPs form a complex with SSB-ssDNA even in the absence of binding to the major protein interaction motif. We propose that alternative conformations of such complexes define the mechanism by which RMPs initiate the repair of stalled replication and support two different functions during recombinational repair of DNA breaks. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Voltammetric determination of heparin based on its interaction with ...

    African Journals Online (AJOL)

    ... with the linear regression equation as ∆ip″ (nA) = 360.19 C (mg/L) + 178.88 (n = 15, γ = 0.998) and the detection limit as 0.28 mg/L (3σ). The effects of coexisting substances such as metal ions, amino acids on the determination of heparin were investigated and the results showed that this method had good selectivity.

  4. How Robust Is the Mechanism of Folding-Upon-Binding for an Intrinsically Disordered Protein?

    Science.gov (United States)

    Bonetti, Daniela; Troilo, Francesca; Brunori, Maurizio; Longhi, Sonia; Gianni, Stefano

    2018-04-24

    The mechanism of interaction of an intrinsically disordered protein (IDP) with its physiological partner is characterized by a disorder-to-order transition in which a recognition and a binding step take place. Even if the mechanism is quite complex, IDPs tend to bind their partner in a cooperative manner such that it is generally possible to detect experimentally only the disordered unbound state and the structured complex. The interaction between the disordered C-terminal domain of the measles virus nucleoprotein (N TAIL ) and the X domain (XD) of the viral phosphoprotein allows us to detect and quantify the two distinct steps of the overall reaction. Here, we analyze the robustness of the folding of N TAIL upon binding to XD by measuring the effect on both the folding and binding steps of N TAIL when the structure of XD is modified. Because it has been shown that wild-type XD is structurally heterogeneous, populating an on-pathway intermediate under native conditions, we investigated the binding to 11 different site-directed variants of N TAIL of one particular variant of XD (I504A XD) that populates only the native state. Data reveal that the recognition and the folding steps are both affected by the structure of XD, indicating a highly malleable pathway. The experimental results are briefly discussed in the light of previous experiments on other IDPs. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  5. Binding of complement proteins C1q and C4bp to serum amyloid P component (SAP) in solid contra liquid phase

    DEFF Research Database (Denmark)

    Sørensen, Inge Juul; Nielsen, EH; Andersen, Ove

    1996-01-01

    Serum amyloid P component (SAP), a member of the conserved pentraxin family of plasma proteins, binds calcium dependently to its ligands. The authors investigated SAPs interaction with the complement proteins C4b binding protein (C4bp) and C1q by ELISA, immunoelectrophoresis and electron microscopy....... Binding of these proteins to SAP was demonstrated when SAP was immobilized using F(ab')2 anti-SAP, but not when SAP reacted with these proteins in liquid phase; thus the binding to human SAP was markedly phase state dependent. Presaturation of solid phase SAP with heparin, which binds SAP with high...... affinity, did not interfere with the subsequent binding of C4bp or C1q to SAP. In contrast, collagen I and IV showed partial competition with the binding of C1q to SAP. Using fresh serum, immobilized native SAP bound C4bp whereas binding of C1q/C1 could not be demonstrated. Altogether the results indicate...

  6. Determination of Oversulphated Chondroitin Sulphate and Dermatan Sulphate in unfractionated heparin by (1)H-NMR - Collaborative study for quantification and analytical determination of LoD.

    Science.gov (United States)

    McEwen, I; Mulloy, B; Hellwig, E; Kozerski, L; Beyer, T; Holzgrabe, U; Wanko, R; Spieser, J-M; Rodomonte, A

    2008-12-01

    Oversulphated Chondroitin Sulphate (OSCS) and Dermatan Sulphate (DS) in unfractionated heparins can be identified by nuclear magnetic resonance spectrometry (NMR). The limit of detection (LoD) of OSCS is 0.1% relative to the heparin content. This LoD is obtained at a signal-to-noise ratio (S/N) of 2000:1 of the heparin methyl signal. Quantification is best obtained by comparing peak heights of the OSCS and heparin methyl signals. Reproducibility of less than 10% relative standard deviation (RSD) has been obtained. The accuracy of quantification was good.

  7. Disparate effects of heparin on free thyroxine measured by two different radioimmunoassays

    International Nuclear Information System (INIS)

    McDougall, I.R.; Bayer, M.F.; Nierenberg, D.; Lewis, S.J.

    1983-01-01

    Heparin causes a rise in free thyroxine (FT4) measured by equilibrium dialysis (E.D.). With the introduction of at least 4 commercial radioimmunoassays (RIA) for FT4, FT4 measurements have become accepted as one of the best routine thyroid function tests. Investigators have indicated that FT4 levels determined by RIA may be of particular value in patients hospitalized for various severe nonthyroidal illnesses in whom conventional thyroid function tests tend to be abnormal. However, very little information is as yet available on possible effects of various drugs on FT4 levels measured by these new methods. A study was undertaken to evaluate the effect of heparin on FT4 measured by 2 different RIA procedures: RIA-I, GammaCoat FT4 by clinical Assays and RIA-II, Amerlex FT4 by Amersham

  8. Simultaneous estimation of vitamin K1 and heparin with low limit of detection using cascaded channels fiber optic surface plasmon resonance.

    Science.gov (United States)

    Tabassum, Rana; Gupta, Banshi D

    2016-12-15

    We report an approach for the simultaneous estimation of vitamin K1 (VK1) and heparin via cascaded channel multianalyte sensing probe employing fiber optic surface plasmon resonance technique. Cladding from two well separated portions of the fiber is removed and are respectively coated with thin films of silver (channel-1) and copper (channel-2). The nanohybrid of multiwalled carbon nanotube in chitosan is fabricated over silver layer for the sensing of VK1 whereas core shell nanostructure of polybrene@ZnO is coated over copper layer for the sensing of heparin. Spectral interrogation method is used for the characterization of the sensor. Analyte selectivity of both the channels is performed by carrying out experiments using independent solutions of VK1 and heparin. Experiments performed on the solution of the mixture of VK1 and heparin show red shifts in both the channels on changing the concentration of both the analytes in the mixture. The operating range of both VK1 and heparin is from 0 to 10(-3)g/l. The limit of detection of the sensor is 2.66×10(-4)µg/l and 2.88×10(-4)µg/l for VK1 and heparin respectively which are lower than the reported ones. The additional advantages of the present sensor are low cost, possibility of online monitoring and remote sensing. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. RNA binding specificity of Ebola virus transcription factor VP30.

    Science.gov (United States)

    Schlereth, Julia; Grünweller, Arnold; Biedenkopf, Nadine; Becker, Stephan; Hartmann, Roland K

    2016-09-01

    The transcription factor VP30 of the non-segmented RNA negative strand Ebola virus balances viral transcription and replication. Here, we comprehensively studied RNA binding by VP30. Using a novel VP30:RNA electrophoretic mobility shift assay, we tested truncated variants of 2 potential natural RNA substrates of VP30 - the genomic Ebola viral 3'-leader region and its complementary antigenomic counterpart (each ∼155 nt in length) - and a series of other non-viral RNAs. Based on oligonucleotide interference, the major VP30 binding region on the genomic 3'-leader substrate was assigned to the internal expanded single-stranded region (∼ nt 125-80). Best binding to VP30 was obtained with ssRNAs of optimally ∼ 40 nt and mixed base composition; underrepresentation of purines or pyrimidines was tolerated, but homopolymeric sequences impaired binding. A stem-loop structure, particularly at the 3'-end or positioned internally, supports stable binding to VP30. In contrast, dsRNA or RNAs exposing large internal loops flanked by entirely helical arms on both sides are not bound. Introduction of a 5´-Cap(0) structure impaired VP30 binding. Also, ssDNAs bind substantially weaker than isosequential ssRNAs and heparin competes with RNA for binding to VP30, indicating that ribose 2'-hydroxyls and electrostatic contacts of the phosphate groups contribute to the formation of VP30:RNA complexes. Our results indicate a rather relaxed RNA binding specificity of filoviral VP30, which largely differs from that of the functionally related transcription factor of the Paramyxoviridae which binds to ssRNAs as short as 13 nt with a preference for oligo(A) sequences.

  10. Multifunctional silk-heparin biomaterials for vascular tissue engineering applications

    Science.gov (United States)

    Seib, F. Philipp; Herklotz, Manuela; Burke, Kelly A.; Maitz, Manfred F.; Werner, Carsten; Kaplan, David L.

    2013-01-01

    Over the past 30 years, silk has been proposed for numerous biomedical applications that go beyond its traditional use as a suture material. Silk sutures are well tolerated in humans, but the use of silk for vascular engineering applications still requires extensive biocompatibility testing. Some studies have indicated a need to modify silk to yield a hemocompatible surface. This study examined the potential of low molecular weight heparin as a material for refining silk properties by acting as a carrier for vascular endothelial growth factor (VEGF) and improving silk hemocompatibility. Heparinized silk showed a controlled VEGF release over 6 days; the released VEGF was bioactive and supported the growth of human endothelial cells. Silk samples were then assessed using a humanized hemocompatibility system that employs whole blood and endothelial cells. The overall thrombogenic response for silk was very low and similar to the clinical reference material polytetrafluoroethylene. Despite an initial inflammatory response to silk, apparent as complement and leukocyte activation, the endothelium was maintained in a resting, anticoagulant state. The low thrombogenic response and the ability to control VEGF release support the further development of silk for vascular applications. PMID:24099708

  11. THE IMPACT OF HEPARIN IMPLEMENTER (GAG IN THE RABBIT INSEMINATION DOSE

    Directory of Open Access Journals (Sweden)

    Martin Fik

    2013-10-01

    Full Text Available The aim of this work was to evaluate the impact of implementer heparin in insemination dose in rabbits selected on reproductive parameters.The experiment was monitored reproductive parameters (conceptual relationship, the number of live-born pups per litter, the number of dead-born pups per litter, the number of live-born pups per inseminated does 156 does in the experimental group and 165 does in the control group. We used the ejaculate of synthetic broiler rabbit population with concentration of sperm 25-50 mil. / 0.5 ml / 1 ID. Heparin was added at a dose - 0.06 ml = 10 mg per 0.5 ml semen / 1 ID. Assessing selected reproductive parameters in does inseminated with insemination dose with the addition of heparin, we observed a higher conceptual proportion of 14.12 % in the experimental group compared to the control group. These differences did not show a statistically significant difference (χ 2 3.56-. The number of live-born pups per litter was 8.69 ± 4.10 pc in the experimental group and 8.41 ± 3.62 pc in the control group (P> 0.05. The number of dead-born pups was recorded 0.74 pc in the experimental group and 0.76 pc in the control group (P> 0.05. The number of live-born pups per litter per inseminated does we have seen improvement in favor of experimental group by 1.39 pc. This parameter was within each of experiments ranged from 0.91 to 1.66 pc live-born pups to inseminated does.

  12. Prediction of the oversulphated chondroitin sulphate contamination of unfractionated heparin by ATR-IR spectrophotometry.

    Science.gov (United States)

    Norwig, J; Beyer, T; Brinz, D; Holzgrabe, U; Diller, M; Manns, D

    2009-03-01

    The detection of a contamination of heparin with oversulphated chondroitin sulphate (OSCS) was first analysed in an unfractionated heparin batch supplied to the US API-market in April 2006. OSCS is a semi-synthetic derivative of the natural occuring glycosaminoglycan chondroitin sulphate. Moreover some spectroscopic characteristics of the substance overlap with those of heparin, so that the infrared (IR) spectra are visually difficult to distinguish whereas (1)H-NMR (Nuclear Magnetic Resonance) spectroscopy or capillary electrophoresis (CE) provides identification by a simple visual inspection of either the spectrum or the electropherogram respectively. However, applying special tools of Multivariate Data Analysis (MVA) to the IR spectra an identification of the contaminated samples is possible. In detail a rapid Attenuation Total Reflectance-Infrared (ATR-IR) measurement was selected, which does not require any sample preparation. The result (contaminated or not contaminated) is predicted within a few minutes. A method transfer to mobile ATR-IR spectrometers seems to be possible. The analysis is based on the fact that the fingerprint of the OSCS IR spectrum (1st derivative) complies with a theoretically calculated principal component in the MVA.

  13. Improved patency and reduced intimal hyperplasia in PTFE grafts with luminal immobilized heparin compared with standard PTFE grafts at six months in a sheep model.

    Science.gov (United States)

    Pedersen, G; Laxdal, E; Ellensen, V; Jonung, T; Mattsson, E

    2010-06-01

    The aim of this study was to compare the performance of polytetrafluoroethylene (PTFE) grafts with luminal coating of immobilized heparin to that of standard PTFE grafts at six months. Twenty-eight common carotid arteries in fourteen sheep were bypassed with heparin-coated PTFE grafts (6 mm diameter, 6 cm length) on one side and standard PTFE grafts on the other. The grafts were explanted after six months. The thickness of intimal hyperplasia (IH) in open grafts was measured with histomorphometrical methods. Two of 14 heparinized PTFE grafts and nine of 14 grafts in the control PTFE-group were occluded at explantation (P=0.006). Six-month patency rates for heparinized PTFE grafts and for standard PTFE grafts were 86% and 36%, respectively. Mean graft anastomotic IH thickness in open grafts were 0.074 mm for heparinized PTFE grafts and 0.259 mm for PTFE-grafts (P=0.006). PTFE grafts with luminal coating containing immobilized heparin had significantly better patency and recruited less intimal hyperplasia than standard PTFE grafts at six months.

  14. Mapping of low molecular weight heparins using reversed phase ion pair liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Li, Daoyuan; Chi, Lequan; Jin, Lan; Xu, Xiaohui; Du, Xuzhao; Ji, Shengli; Chi, Lianli

    2014-01-01

    Low molecular weight heparins (LMWHs) are structurally complex, highly sulfated and negatively charged, linear carbohydrate polymers prepared by chemical or enzymatic depolymerization of heparin. They are widely used as anticoagulant drugs possessing better bioavailability, longer half-life, and lower side effects than heparin. Comprehensive structure characterization of LMWHs is important for drug quality assurance, generic drug application, and new drug research and development. However, fully characterization of all oligosaccharide chains in LMWHs is not feasible for current available analytical technologies due to their structure complexity and heterogeneity. Fingerprinting profiling is an efficient way for LMWHs' characterization and comparison. In this work, we present a simple, sensitive, and powerful analytical approach for structural characterization of LMWHs. Two different LMWHs, enoxaparin and nadroparin, were analyzed using reversed phase ion pair electrospray ionization mass spectrometry (RPIP-ESI-MS). More than 200 components were identified, including major structures, minor structures, and process related impurities. This approach is robust for high resolution and complementary fingerprinting analysis of LMWHs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Cerebral venous thrombosis due to cryptogenic organising pneumopathy with antiphospholipid syndrome worsened by heparin-induced thrombocytopenia.

    Science.gov (United States)

    Hsieh, J; Kuzmanovic, I; Vargas, M I; Momjian-Mayor, I

    2013-07-09

    Cerebral venous thrombosis (CVT) has usually been ascribed to prothrombotic conditions, oral contraceptives, pregnancy, malignancy, infection, head injury or mechanical precipitants. The case reported here illustrates two rare causes of CVT observed in the same patient: the presence of antiphospholipid antibodies associated with an asymptomatic cryptogenic organising pneumopathy (COP) which were considered the origin of the venous cerebral thrombosis and heparin-induced thrombocytopenia (HIT) which was responsible for the worsening of the thrombosis observed a few days after the introduction of treatment. Moreover, we provide here additional positive experience in the treatment of both, CVT and HIT, by fondaparinux with bridging to warfarin given their successful evolution under this anticoagulant option.

  16. From simple receptors to complex multimodal percepts: a first global picture on the mechanisms involved in perceptual binding.

    Science.gov (United States)

    Velik, Rosemarie

    2012-01-01

    The binding problem in perception is concerned with answering the question how information from millions of sensory receptors, processed by millions of neurons working in parallel, can be merged into a unified percept. Binding in perception reaches from the lowest levels of feature binding up to the levels of multimodal binding of information coming from the different sensor modalities and also from other functional systems. The last 40 years of research have shown that the binding problem cannot be solved easily. Today, it is considered as one of the key questions to brain understanding. To date, various solutions have been suggested to the binding problem including: (1) combination coding, (2) binding by synchrony, (3) population coding, (4) binding by attention, (5) binding by knowledge, expectation, and memory, (6) hardwired vs. on-demand binding, (7) bundling and binding of features, (8) the feature-integration theory of attention, and (9) synchronization through top-down processes. Each of those hypotheses addresses important aspects of binding. However, each of them also suffers from certain weak points and can never give a complete explanation. This article gives a brief overview of the so far suggested solutions of perceptual binding and then shows that those are actually not mutually exclusive but can complement each other. A computationally verified model is presented which shows that, most likely, the different described mechanisms of binding act (1) at different hierarchical levels and (2) in different stages of "perceptual knowledge acquisition." The model furthermore considers and explains a number of inhibitory "filter mechanisms" that suppress the activation of inappropriate or currently irrelevant information.

  17. From simple receptors to complex multimodal percepts: A first global picture on the mechanisms involved in perceptual binding

    Directory of Open Access Journals (Sweden)

    Rosemarie eVelik

    2012-07-01

    Full Text Available The binding problem in perception is concerned with answering the question how information from millions of sensory receptors, processed by millions of neurons working in parallel, can be merged into a unified percept. Binding in perception reaches from the lowest levels of feature binding up to the levels of multimodal binding of information coming from the different sensor modalities and also from other functional systems. The last 40 years of research have shown that the binding problem cannot be solved easily. Today, it is considered as one of the key questions to brain understanding. To date, various solutions have been suggested to the binding problem including: (1 combination coding, (2 binding by synchrony, (3 population coding, (4 binding by attention, (5 binding by knowledge, expectation, and memory, (6 hardwired versus on-demand binding, (7 bundling and binding of features, (8 the feature-integration theory of attention, (9 synchronization through top-down processes. Each of those hypotheses addresses important aspects of binding. However, each of them also suffers from certain weak points and can never give a complete explanation. This article gives a brief overview of the so far suggested solutions of perceptual binding and then shows that those are actually not mutually exclusive but can complement each other. A computationally verified model is presented which shows that, most likely, the different described mechanisms of binding act (1 at different hierarchical levels and (2 in different stages of perceptual knowledge acquisition. The model furthermore considers and explains a number of inhibitory filter mechanisms that suppress the activation of inappropriate or currently irrelevant information.

  18. Comparison of two doses of heparin on outcome in off-pump coronary artery bypass surgery patients: A prospective randomized control study

    Directory of Open Access Journals (Sweden)

    Murali Chakravarthy

    2017-01-01

    Full Text Available Introduction: While off pump coronary artery bypass surgery is practiced with an intention to reduce the morbidity associated with cardiopulmonary bypass, the resultant ′hypercoagulability′ needs to be addressed. Complications such as cavitary thrombus possibly due to the hyper coagulability after off pump coronary artery bypass surgery have been described. Many clinicians use higher doses of heparin - up to 5 mg/kg in order to thwart this fear. Overall, there appears to be no consensus on the dose of heparin in off pump coronary artery bypass surgeries. Aim of the Study: The aim of the study was understand the differences in outcome of such as transfusion requirement, myocardial ischemia, and morbidity when two different doses were used for systemic heparinization. Methods: Elective patients scheduled for off pump coronary artery bypass surgery were included. Ongoing anti platelet medication was not an exclusion criteria, however, anti platelet medications were ceased about a week prior to surgery when possible. Thoracic epidural anesthesia was administered as an adjunct in patients who qualified for it. By computer generated randomization chart, patients were chosen to receive either 2 or 3 mg/kg of intravenous unfractioned heparin to achieve systemic heparinization with activated clotting time targeted at >240 secs. Intraoperative blood loss, postoperative blood loss, myocardial ischemic episodes, requirement of intraaortic balloon counter pulsation and transfusion requirement were analyzed. Results: Sixty two patients participated in the study. There was one conversion to cardiopulmonary bypass. The groups had comparable ACT at baseline (138.8 vs. 146.64 seconds, P = 0.12; 3 mg/kg group had significantly higher values after heparin, as expected. But after reversal with protamine, ACT and need for additional protamine was similar among the groups. Intraoperative (685.56 ± 241.42 ml vs. 675.15 ± 251.86 ml, P = 0.82 and postoperative

  19. Subcutis calcinosis caused by injection of calcium-containing heparin in a chronic kidney injury patient

    Directory of Open Access Journals (Sweden)

    Lilia Ben Fatma

    2014-01-01

    Full Text Available Subcutis calcinosis, characterized by abnormal calcium deposits in the skin, is a rare complication of using calcium-containing heparin occurring in patients with advanced renal failure. We report the case of an 83-year-old female, a known case of chronic kidney disease (CKD for four years with recent worsening of renal failure requiring hospitalization and hemodialysis. She developed subcutis calcinosis following injection of calcium-containing heparin. Biochemical tests showed serum parathormone level at 400 pg/dL, hypercalcemia, elevated calcium-phosphate product and monoclonal gammopathy related to multiple myeloma. She developed firm subcu-taneous nodules in the abdomen and the thighs, the injection sites of Calciparin ® (calcium nadroparin that was given as a preventive measure against deep vein thrombosis. The diagnosis of subcutis calcinosis was confirmed by the histological examination showing calcium deposit in the dermis and hypodermis. These lesions completely disappeared after discontinuing calcium nadro-parin injections. Subcutis calcinosis caused by injections of calcium-containing heparin is rare, and, to the best our knowledge, not more than 12 cases have been reported in the literature. Pathogenesis is not well established but is attributed to the calcium disorders usually seen in advanced renal failure. Diagnosis is confirmed by histological tests. Outcome is mostly favorable. The main differential diagnosis is calciphylaxis, which has a poor prognosis. Even though rarely reported, we should be aware that CKD patients with elevated calcium-phosphorus product can develop subcutis calcinosis induced by calcium-containing heparin. When it occurs, fortunately and unlike calci-phylaxis, outcome is favorable.

  20. Mechanism of the G-protein mimetic nanobody binding to a muscarinic G-protein-coupled receptor.

    Science.gov (United States)

    Miao, Yinglong; McCammon, J Andrew

    2018-03-20

    Protein-protein binding is key in cellular signaling processes. Molecular dynamics (MD) simulations of protein-protein binding, however, are challenging due to limited timescales. In particular, binding of the medically important G-protein-coupled receptors (GPCRs) with intracellular signaling proteins has not been simulated with MD to date. Here, we report a successful simulation of the binding of a G-protein mimetic nanobody to the M 2 muscarinic GPCR using the robust Gaussian accelerated MD (GaMD) method. Through long-timescale GaMD simulations over 4,500 ns, the nanobody was observed to bind the receptor intracellular G-protein-coupling site, with a minimum rmsd of 2.48 Å in the nanobody core domain compared with the X-ray structure. Binding of the nanobody allosterically closed the orthosteric ligand-binding pocket, being consistent with the recent experimental finding. In the absence of nanobody binding, the receptor orthosteric pocket sampled open and fully open conformations. The GaMD simulations revealed two low-energy intermediate states during nanobody binding to the M 2 receptor. The flexible receptor intracellular loops contribute remarkable electrostatic, polar, and hydrophobic residue interactions in recognition and binding of the nanobody. These simulations provided important insights into the mechanism of GPCR-nanobody binding and demonstrated the applicability of GaMD in modeling dynamic protein-protein interactions.

  1. Development and in vivo evaluation of an oral delivery system for low molecular weight heparin based on thiolated polycarbophil.

    Science.gov (United States)

    Kast, Constantia E; Guggi, Davide; Langoth, Nina; Bernkop-Schnürch, Andreas

    2003-06-01

    It was the purpose of this study to develop a new oral drug delivery system for low molecular weight heparin (LMWH) providing an improved bioavailability and a prolonged therapeutic effect. The permeation enhancing polycarbophil-cysteine conjugate (PCP-Cys) used in this study displayed 111.4 +/- 6.4 microM thiol groups per gram polymer. Permeation studies on freshly excised intestinal mucosa were performed in Ussing chambers demonstrating a 2-fold improved uptake of heparin as a result of the addition of 0.5% (w/v) PCP-Cys and the permeation mediator glutathione (GSH). Tablets containing PCP-Cys, GSH, and 279 IU of LMWH showed a sustained drug release over 4 h. To guarantee the swelling of the polymeric carrier matrix in the small intestine tablets were enteric coated. They were orally given to rats. For tablets being based on the thiomer/GSH system an absolute bioavailability of 19.9 +/- 9.3% (means +/- SD; n = 5) vs. intravenous injection could be achieved. whereas tablets comprising unmodified PCP did not lead to a significant (p < 0.01) heparin concentration in plasma. The permeation enhancing effect and subsequently a therapeutic heparin level was maintained for 24 h after a single dose. Because of the strong and prolonged lasting permeation enhancing effect of the thiomer/GSH system, the oral bioavailability of LMWH could be significantly improved. This new delivery system represents therefore a promising tool for the oral administration of heparin.

  2. Comparison on Anticoagulation and Antiplatelet Aggregation Effects of Puerarin with Heparin Sodium and Tirofiban Hydrochloride: An In Vitro Study.

    Science.gov (United States)

    Li, Si-Wei; Feng, Xue; Xu, Hao; Chen, Ke-Ji

    2018-02-01

    To detect the anticoagulation and antiplatelet effects of different concentrations of puerarin, heparin sodium and tirofiban hydrochloride on the blood samples of healthy volunteers by Sonoclot coagulation and platelet function analyzer. Peripheral blood samples were extracted from 20 healthy volunteers, followed by adding different concentrations of puerarin, heparin sodium and tirofiban hydrochloride. Samples were detected for activated clotting time (ACT), clot rate (CR) and platelet function (PF) by Sonoclot coagulation and platelet function analyzer instrument. For puerarin and heparin sodium, the values of ACT gradually increased, and the values of CR and PF gradually decreased with increasing in drug concentration. There was a linear (or log linear) relationship between ACT, CR, PF value and drug concentration (Phydrochloride, the values of ACT and CR had no significant changes, while PF values gradually decreased with concentration increasing. There was also a linear relationship between PF values and concentrations of tirofiban hydrochloride (Psodium. For high concentrations of puerarin (e.g. 3.8 mg/600 μL) and tirofiban hydrochloride (e.g. 0.8 μg/600 μL), PF values had no significant difference. However, PF values for high puerarin concentration had a larger variance. Puerarin has similar anticoagulant and antiplatelet effects with the heparin sodium, and may have a lower hemorrhage risk than heparin sodium when obtained the same anticoagulation effect in the concentration range of this experiment. In addition, for high concentration, puerarin had the same antiplatelet function as tirofiban hydrochloride but with a larger individual variability.

  3. Synthesis and characterization of polystyrene-poly(ethylene oxide)-heparin block copolymers

    NARCIS (Netherlands)

    Vulić, I.; Okano, T.; Kim, S.W.; Feijen, Jan

    1988-01-01

    A procedure for the preparation of new block copolymers composed of a hydrophobic block of polystyrene, a hydrophilic spacer-block of poly(ethylene oxide) and a bioactive block of heparin was investigated. Polystyrene with one amino group per chain was synthesized by free radical oligomerization of

  4. Heparin surface stent-graft for the treatment of a carotid pseudoaneurysm.

    Science.gov (United States)

    Tsolaki, Elpiniki; Elpiniki, Tsolaki; Salviato, Elisabetta; Rocca, Tiberio; Braccini, Lucia; Galeotti, Roberto; Mascoli, Francesco

    2010-10-01

    Carotid pseudoaneurysms are a rare consequence of carotid surgery, trauma, and infection. Historically, carotid aneurysms and pseudoaneurysms were treated surgically. However, endovascular techniques have recently become a valid alternative for the treatment of carotid pseudoaneurysms. The case of a 57-year-old male patient with a pseudoaneurysm of the right internal carotid artery is described. The patient came to our unit with a painless and pulsatile mass in the neck, which was growing slowly. Five years earlier, he had undergone surgery on a saccular aneurysm located on the distal extracranial segment of the right internal carotid artery. The pseudoaneurysm was successfully treated with a heparin surface Viabahn stent-graft system (Gore AL, Flagstaff, AZ). Heparin surface stent-grafts can be used for the treatment of carotid lesions and may offer protection against intimal hyperplasia and thrombosis. Further studies are needed to evaluate the long-term results. Copyright © 2010 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.

  5. An antimicrobial helix A-derived peptide of heparin cofactor II blocks endotoxin responses in vivo.

    Science.gov (United States)

    Papareddy, Praveen; Kalle, Martina; Singh, Shalini; Mörgelin, Matthias; Schmidtchen, Artur; Malmsten, Martin

    2014-05-01

    Host defense peptides are key components of the innate immune system, providing multi-facetted responses to invading pathogens. Here, we describe that the peptide GKS26 (GKSRIQRLNILNAKFAFNLYRVLKDQ), corresponding to the A domain of heparin cofactor II (HCII), ameliorates experimental septic shock. The peptide displays antimicrobial effects through direct membrane disruption, also at physiological salt concentration and in the presence of plasma and serum. Biophysical investigations of model lipid membranes showed the antimicrobial action of GKS26 to be mirrored by peptide incorporation into, and disordering of, bacterial lipid membranes. GKS26 furthermore binds extensively to bacterial lipopolysaccharide (LPS), as well as its endotoxic lipid A moiety, and displays potent anti-inflammatory effects, both in vitro and in vivo. Thus, for mice challenged with ip injection of LPS, GKS26 suppresses pro-inflammatory cytokines, reduces vascular leakage and infiltration in lung tissue, and normalizes coagulation. Together, these findings suggest that GKS26 may be of interest for further investigations as therapeutic against severe infections and septic shock. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Thermodynamics and binding mechanism of polyphenon-60 with human lysozyme elucidated by calorimetric and spectroscopic techniques

    International Nuclear Information System (INIS)

    Yasmeen, Shama; Riyazuddeen

    2017-01-01

    Highlights: • Thermodynamics of the binding of Lys with polypenone-60 were studied. • The binding was found to be exothermic. • Polyphenon-60 quenches the fluorescence of Lys through static quenching. • Polyphenon-60 binds to Lys through hydrogen binding. • Conformational changes of Lys were studied using circular dichorism. - Abstract: Protein-drug interaction offer information of the structural features that determine the therapeutic effectiveness of drug and have become an attractive research field in life science, chemistry, and clinical medicine. Interaction of pharmacologically important antioxidant drug polyphenon-60 with human lysozyme (Lys) at physiological pH 7.4 has been studied by using calorimetric and various spectroscopic techniques. UV–visible spectroscopy results indicate the complex formation between Lys and polyphenon-60. The binding constant, quenching mechanism and the number of binding sites were determined by the fluorescence quenching spectra of Lys in presence of polyphenon-60. Fluorescence data indicate that the polyphenon-60 interact with Lys through static quenching mechanism with binding affinity of 2.9 × 10 4 M −1 . The average binding distance between drug and Lys was found to be 2.89 nm on the basis of the theory of Förster's energy transfer. Isothermal titration calorimetry (ITC) data reveals the thermodynamic investigations which suggest that the interaction of Lys and polyphenon-60 through exothermic process and enthalpy driven and also explore that the polyphenon-60 binds in both sites of Lys with high and low affinity. Hydrogen bonding (high affinity) and hydrophobic interactions (low affinity) are the major forces in stabilizing the drug protein complex. Far-UV CD and FTIR results deciphere the conformational alterations in the secondary structure of Lys.

  7. Trans-Binding Mechanism of Ubiquitin-like Protein Activation Revealed by a UBA5-UFM1 Complex

    Directory of Open Access Journals (Sweden)

    Walaa Oweis

    2016-09-01

    Full Text Available Modification of proteins by ubiquitin or ubiquitin-like proteins (UBLs is a critical cellular process implicated in a variety of cellular states and outcomes. A prerequisite for target protein modification by a UBL is the activation of the latter by activating enzymes (E1s. Here, we present the crystal structure of the non-canonical homodimeric E1, UBA5, in complex with its cognate UBL, UFM1, and supporting biochemical experiments. We find that UBA5 binds to UFM1 via a trans-binding mechanism in which UFM1 interacts with distinct sites in both subunits of the UBA5 dimer. This binding mechanism requires a region C-terminal to the adenylation domain that brings UFM1 to the active site of the adjacent UBA5 subunit. We also find that transfer of UFM1 from UBA5 to the E2, UFC1, occurs via a trans mechanism, thereby requiring a homodimer of UBA5. These findings explicitly elucidate the role of UBA5 dimerization in UFM1 activation.

  8. Distinct mechanisms of a phosphotyrosyl peptide binding to two SH2 domains.

    Science.gov (United States)

    Pang, Xiaodong; Zhou, Huan-Xiang

    2014-05-01

    Protein phosphorylation is very common post-translational modification, catalyzed by kinases, for signaling and regulation. Phosphotyrosines frequently target SH2 domains. The spleen tyrosine kinase (Syk) is critical for tyrosine phosphorylation of multiple proteins and for regulation of important pathways. Phosphorylation of both Y342 and Y346 in Syk linker B is required for optimal signaling. The SH2 domains of Vav1 and PLC-γ both bind this doubly phosphorylated motif. Here we used a recently developed method to calculate the effects of Y342 and Y346 phosphorylation on the rate constants of a peptide from Syk linker B binding to the SH2 domains of Vav1 and PLC-γ. The predicted effects agree well with experimental observations. Moreover, we found that the same doubly phosphorylated peptide binds the two SH2 domains via distinct mechanisms, with apparent rigid docking for Vav1 SH2 and dock-and-coalesce for PLC-γ SH2.

  9. Comparison of heparinized saline and 0.9% sodium chloride for maintaining peripheral intravenous catheter patency in dogs.

    Science.gov (United States)

    Ueda, Yu; Odunayo, Adesola; Mann, F A

    2013-01-01

    To determine whether heparinized saline would be more effective in maintaining the patency of peripheral IV catheters in dogs compared to 0.9% sodium chloride. Prospective blinded randomized study. University Veterinary Teaching Hospital. Thirty healthy purpose bred dogs, intended for use in the junior surgery laboratory, were utilized. The dogs were randomized into 1 of 3 groups, 2 treatment groups and a control group. An 18-Ga cephalic catheter was placed in the cephalic vein of each dog. Each dog in the treatment group had their catheter flushed with either 10 IU/mL heparinized saline or 0.9% sodium chloride every 6 hours for 42 hours. The dogs in the control group did not have their catheters flushed until the end of the study period. Immediately prior to flushing catheters, each catheter was evaluated for patency by aspiration of blood and the catheter site was evaluated for phlebitis. All dogs in the heparinized saline and 0.9% sodium chloride group had catheters that flushed easily at each evaluation point. More dogs in the saline group had catheters from which blood could not be aspirated, but there was no significant difference between these groups. All dogs in the control group had catheters that flushed easily at the end of the assigned 6 hour interval except in 1 dog. Phlebitis was not detected in any dog. Flushes of 0.9% sodium chloride were found to be as effective as 10 IU/mL heparinized saline flushes in maintaining patency of 18-Ga peripheral venous catheters in dogs for up to 42 hours. For peripheral catheters placed with the intention of performing serial blood draws, heparinized flushes may be warranted. © Veterinary Emergency and Critical Care Society 2013.

  10. M2 macrophages induce ovarian cancer cell proliferation via a heparin binding epidermal growth factor/matrix metalloproteinase 9 intercellular feedback loop.

    Science.gov (United States)

    Carroll, Molly J; Kapur, Arvinder; Felder, Mildred; Patankar, Manish S; Kreeger, Pamela K

    2016-12-27

    In ovarian cancer, a high ratio of anti-inflammatory M2 to pro-inflammatory M1 macrophages correlates with poor patient prognosis. The mechanisms driving poor tumor outcome as a result of the presence of M2 macrophages in the tumor microenvironment remain unclear and are challenging to study with current techniques. Therefore, in this study we utilized a micro-culture device previously developed by our lab to model concentrated paracrine signaling in order to address our hypothesis that interactions between M2 macrophages and ovarian cancer cells induce tumor cell proliferation. Using the micro-culture device, we determined that co-culture with M2-differentiated primary macrophages or THP-1 increased OVCA433 proliferation by 10-12%. This effect was eliminated with epidermal growth factor receptor (EGFR) or heparin-bound epidermal growth factor (HB-EGF) neutralizing antibodies and HBEGF expression in peripheral blood mononuclear cells from ovarian cancer patients was 9-fold higher than healthy individuals, suggesting a role for HB-EGF in tumor progression. However, addition of HB-EGF at levels secreted by macrophages or macrophage-conditioned media did not induce proliferation to the same extent, indicating a role for other factors in this process. Matrix metalloproteinase-9, MMP-9, which cleaves membrane-bound HB-EGF, was elevated in co-culture and its inhibition decreased proliferation. Utilizing inhibitors and siRNA against MMP9 in each population, we determined that macrophage-secreted MMP-9 released HB-EGF from macrophages, which increased MMP9 in OVCA433, resulting in a positive feedback loop to drive HB-EGF release and increase proliferation in co-culture. Identification of multi-cellular interactions such as this may provide insight into how to most effectively control ovarian cancer progression.

  11. Low-thrombogenic fibrin-heparin coating promotes in vitro endothelialization

    Czech Academy of Sciences Publication Activity Database

    Kaplan, Ondřej; Hierlemann, T.; Krajewski, S.; Kurz, J.; Nevoralová, Martina; Houska, Milan; Riedel, Tomáš; Riedelová, Zuzana; Zárubová, Jana; Wendel, H. P.; Brynda, Eduard

    2017-01-01

    Roč. 105, č. 11 (2017), s. 2995-3005 ISSN 1549-3296 R&D Projects: GA MZd(CZ) NV15-29153A Institutional support: RVO:61389013 ; RVO:67985823 Keywords : fibrin-heparin coating * hemocompatibility * endothelialization Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery; FA - Cardiovascular Diseases incl. Cardiotharic Surgery (FGU-C) OBOR OECD: Cardiac and Cardiovascular systems; Cardiac and Cardiovascular systems (FGU-C) Impact factor: 3.076, year: 2016

  12. A binding-site barrier affects imaging efficiency of high affinity amyloid-reactive peptide radiotracers in vivo.

    Directory of Open Access Journals (Sweden)

    Jonathan S Wall

    Full Text Available Amyloid is a complex pathology associated with a growing number of diseases including Alzheimer's disease, type 2 diabetes, rheumatoid arthritis, and myeloma. The distribution and extent of amyloid deposition in body organs establishes the prognosis and can define treatment options; therefore, determining the amyloid load by using non-invasive molecular imaging is clinically important. We have identified a heparin-binding peptide designated p5 that, when radioiodinated, was capable of selectively imaging systemic visceral AA amyloidosis in a murine model of the disease. The p5 peptide was posited to bind effectively to amyloid deposits, relative to similarly charged polybasic heparin-reactive peptides, because it adopted a polar α helix secondary structure. We have now synthesized a variant, p5R, in which the 8 lysine amino acids of p5 have been replaced with arginine residues predisposing the peptide toward the α helical conformation in an effort to enhance the reactivity of the peptide with the amyloid substrate. The p5R peptide had higher affinity for amyloid and visualized AA amyloid in mice by using SPECT/CT imaging; however, the microdistribution, as evidenced in micro-autoradiographs, was dramatically altered relative to the p5 peptide due to its increased affinity and a resultant "binding site barrier" effect. These data suggest that radioiodinated peptide p5R may be optimal for the in vivo detection of discreet, perivascular amyloid, as found in the brain and pancreatic vasculature, by using molecular imaging techniques; however, peptide p5, due to its increased penetration, may yield more quantitative imaging of expansive tissue amyloid deposits.

  13. In vitro Heparin Precipitation in the Plasma of Euthyroid women with ...

    African Journals Online (AJOL)

    OBJECTIVE: Women with elevated Lp(a), who are susceptible to atherosclerosis, get to reduce, their cardiovascular disease by in-vivo administration of low dose heparin. And history of recurrent miscarriage associated with auto antibodies have had a high rate of life births in subsequent pregnancies when they were ...

  14. Graft patency after off-pump coronary artery bypass surgery is inferior even with identical heparinization protocols

    DEFF Research Database (Denmark)

    Houlind, Kim; Fenger-Grøn, Morten; Holme, Susanne J

    2014-01-01

    OBJECTIVE: To determine whether graft patency after on-pump and off-pump coronary artery bypass surgery is similar when performed using the same heparinization protocol. METHODS: In a randomized, controlled, multicenter trial, 900 patients more than 70 years of age received either on-pump or off......-pump coronary artery bypass surgery. Heparin was given to achieve an activated clotting time of 400 seconds before arteriotomy in both groups. After the procedure, protamine sulfate was given to revert the activated clotting time to less than 120 seconds. Coronary angiography was performed 6 months after...

  15. Venous thromboembolism in pregnancy: prophylaxis and treatment with low molecular weight heparin

    DEFF Research Database (Denmark)

    Andersen, Anita Sylvest; Berthelsen, Jørgen G; Bergholt, Thomas

    2010-01-01

    OBJECTIVE: To evaluate the safety of individually dosed low molecular weight heparin (LMWH) for prophylaxis and treatment of thromboembolic complications in pregnancy. DESIGN: Cohort study with a chronologic register-based control group. SETTING: Department of Obstetrics and Gynecology, Hillerød ...

  16. Comparison of a priori versus provisional heparin therapy on radial artery occlusion after transradial coronary angiography and patent hemostasis (from the PHARAOH Study).

    Science.gov (United States)

    Pancholy, Samir B; Bertrand, Olivier F; Patel, Tejas

    2012-07-15

    Systemic anticoagulation decreases the risk of radial artery occlusion (RAO) after transradial catheterization and standard occlusive hemostasis. We compared the efficacy and safety of provisional heparin use only when the technique of patent hemostasis was not achievable to standard a priori heparin administration after radial sheath introduction. Patients referred for coronary angiography were randomized in 2 groups. In the a priori group, 200 patients received intravenous heparin (50 IU/kg) immediately after sheath insertion. In the provisional group, 200 patients did not receive heparin during the procedure. After sheath removal, hemostasis was obtained using a TR band (Terumo corporation, Tokyo, Japan) with a plethysmography-guided patent hemostasis technique. In the provisional group, no heparin was given if radial artery patency could be obtained and maintained. If radial patency was not achieved, a bolus of heparin (50 IU/kg) was given. Radial artery patency was evaluated at 24 hours (early RAO) and 30 days after the procedure (late RAO) by plethysmography. Patent hemostasis was obtained in 67% in the a priori group and 74% in the provisional group (p = 0.10). Incidence of RAO remained similar in the 2 groups at the early (7.5% vs 7.0%, p = 0.84) and late (4.5% vs 5.0%, p = 0.83) evaluations. Women, patients with diabetes, patients having not received heparin, and patients without radial artery patency during hemostasis had more RAO. By multivariate analysis, patent radial artery during hemostasis (odds ratio [OR] 0.03, 95% confidence interval [CI] 0.004 to 0.28, p = 0.002) and diabetes (OR 11, 95% CI 3 to 38,p patent hemostasis is maintained. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Direct Pore Binding as a Mechanism for Isoflurane Inhibition of the Pentameric Ligand-gated Ion Channel ELIC.

    Science.gov (United States)

    Chen, Qiang; Kinde, Monica N; Arjunan, Palaniappa; Wells, Marta M; Cohen, Aina E; Xu, Yan; Tang, Pei

    2015-09-08

    Pentameric ligand-gated ion channels (pLGICs) are targets of general anesthetics, but molecular mechanisms underlying anesthetic action remain debatable. We found that ELIC, a pLGIC from Erwinia chrysanthemi, can be functionally inhibited by isoflurane and other anesthetics. Structures of ELIC co-crystallized with isoflurane in the absence or presence of an agonist revealed double isoflurane occupancies inside the pore near T237(6') and A244(13'). A pore-radius contraction near the extracellular entrance was observed upon isoflurane binding. Electrophysiology measurements with a single-point mutation at position 6' or 13' support the notion that binding at these sites renders isoflurane inhibition. Molecular dynamics simulations suggested that isoflurane binding was more stable in the resting than in a desensitized pore conformation. This study presents compelling evidence for a direct pore-binding mechanism of isoflurane inhibition, which has a general implication for inhibitory action of general anesthetics on pLGICs.

  18. Structure and function of ameloblastin as an extracellular matrix protein: adhesion, calcium binding, and CD63 interaction in human and mouse.

    Science.gov (United States)

    Zhang, Xu; Diekwisch, Thomas G H; Luan, Xianghong

    2011-12-01

    The functional significance of extracellular matrix proteins in the life of vertebrates is underscored by a high level of sequence variability in tandem with a substantial degree of conservation in terms of cell-cell and cell-matrix adhesion interactions. Many extracellular matrix proteins feature multiple adhesion domains for successful attachment to substrates, such as integrin, CD63, and heparin. Here we have used homology and ab initio modeling algorithms to compare mouse ameloblastin (mAMBN) and human ameloblastin (hABMN) isoforms and to analyze their potential for cell adhesion and interaction with other matrix molecules as well as calcium binding. Sequence comparison between mAMBN and hAMBN revealed a 26-amino-acid deletion in mAMBN, corresponding to a helix-loop-helix frameshift. The human AMBN domain (174Q-201G), homologous to the mAMBN 157E-178I helix-loop-helix region, formed a helix-loop motif with an extended loop, suggesting a higher degree of flexibility of hAMBN compared with mAMBN, as confirmed by molecular dynamics simulation. Heparin-binding domains, CD63-interaction domains, and calcium-binding sites in both hAMBN and mAMBN support the concept of AMBN as an extracellular matrix protein. The high level of conservation between AMBN functional domains related to adhesion and differentiation was remarkable when compared with only 61% amino acid sequence homology. © 2011 Eur J Oral Sci.

  19. Identification of chondroitin sulfate E proteoglycans and heparin proteoglycans in the secretory granules of human lung mast cells

    International Nuclear Information System (INIS)

    Stevens, R.L.; Austen, K.F.; Fox, C.C.; Lichtenstein, L.M.

    1988-01-01

    The predominant subclasses of mast cells in both the rat and the mouse can be distinguished from one another by their preferential synthesis of 35 S-labeled proteoglycans that contain either heparin or oversulfated chondroitin sulfate glycosaminoglycans. Although [ 35 S]heparin proteoglycans have been isolated from human lung mast cells of 40-70% purity and from a skin biopsy specimen of a patient with urticaria pigmentosa, no highly sulfated chondroitin sulfate proteoglycan has been isolated from any enriched or highly purified population of human mast cells. The authors demonstrate that human lung mast cells of 96% purity incorporate [ 35 S]sulfate into separate heparin and chondroitin sulfate proteoglycans in an ∼2:1 ratio. As assessed by HPLC of the chondroitinase ABC digests, the chondroitin [ 35 S]sulfate proteoglycans isolated from these human lung mast cells contain the same unusual chondroitin sulfate E disaccharide that is present in proteoglycans produced by interleukin 3-dependent mucosal-like mouse mast cells. Both the chondroitin [ 35 S]sulfate E proteoglycans and the [ 35 S]heparin proteoglycans were exocytosed from the [ 35 S]sulfate-labeled cells via perturbation of the IgE receptor, indicating that both types of 35 S-labeled proteoglycans reside in the secretory granules of these human lung mast cells

  20. Deep vein thrombosis, ecythyma gangrenosum and heparin-induced thrombocytopenia occurring in a man with a heterozygous Factor V Leiden mutation

    Directory of Open Access Journals (Sweden)

    Mariya Apostolova

    2012-11-01

    Full Text Available Skin necrosis and limb gangrene are occasional thrombotic manifestations of anticoagulation therapy. We report a man heterozygous for the Factor V Leiden (FVL mutation, and with a history of recurrent deep venous thrombosis, who initially presented with a necrotic skin lesion of the right flank while on warfarin therapy with a therapeutic international normalized ratio. Warfarin was discontinued and he received intravenous heparin. Thereafter he developed thrombocytopenia and pedal erythema and was diagnosed with heparin-induced thrombocytopenia (HIT. Heparin was replaced with argatroban. He ultimately underwent bilateral below-knee amputations for the thrombotic complications of the HIT. The initial necrotic lesion healed with antibiotics and wound care. Pathologic examination of multiple biopsy specimens revealed two separate lesions. One was necrotic tissue infiltrated with methicillin resistant Staphylococcus aureus having features of ecthyma gangrenosum. The second showed thrombotic changes consistent with HIT. The case illustrates the differential diagnosis of skin necrosis and limb gangrene in patients on warfarin and heparin, and also the clinical complexities that can occur in a FVL heterozygote.

  1. Combined quantum mechanics/molecular mechanics (QM/MM) simulations for protein-ligand complexes: free energies of binding of water molecules in influenza neuraminidase.

    Science.gov (United States)

    Woods, Christopher J; Shaw, Katherine E; Mulholland, Adrian J

    2015-01-22

    The applicability of combined quantum mechanics/molecular mechanics (QM/MM) methods for the calculation of absolute binding free energies of conserved water molecules in protein/ligand complexes is demonstrated. Here, we apply QM/MM Monte Carlo simulations to investigate binding of water molecules to influenza neuraminidase. We investigate five different complexes, including those with the drugs oseltamivir and peramivir. We investigate water molecules in two different environments, one more hydrophobic and one hydrophilic. We calculate the free-energy change for perturbation of a QM to MM representation of the bound water molecule. The calculations are performed at the BLYP/aVDZ (QM) and TIP4P (MM) levels of theory, which we have previously demonstrated to be consistent with one another for QM/MM modeling. The results show that the QM to MM perturbation is significant in both environments (greater than 1 kcal mol(-1)) and larger in the more hydrophilic site. Comparison with the same perturbation in bulk water shows that this makes a contribution to binding. The results quantify how electronic polarization differences in different environments affect binding affinity and also demonstrate that extensive, converged QM/MM free-energy simulations, with good levels of QM theory, are now practical for protein/ligand complexes.

  2. Formation Mechanism and Binding Energy for Body-Centred Regular Icosahedral Structure of Li13 Cluster

    International Nuclear Information System (INIS)

    Liu Weina; Li Ping; Gou Qingquan; Zhao Yanping

    2008-01-01

    The formation mechanism for the body-centred regular icosahedral structure of Li 13 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes for this structure of Li 13 has been calculated by using the method of Gou's modified arrangement channel quantum mechanics (MACQM). The result shows that the curve has a minimal energy of -96.951 39 a.u. at R = 5.46a 0 . When R approaches to infinity, the total energy of thirteen lithium atoms has the value of -96.564 38 a.u. So the binding energy of Li 13 with respect to thirteen lithium atoms is 0.387 01 a.u. Therefore the binding energy per atom for Li 13 is 0.029 77 a.u. or 0.810 eV, which is greater than the binding energy per atom of 0.453 eV for Li 2 , 0.494 eV for Li 3 , 0.7878 eV for Li 4 , 0.632 eV for Li 5 , and 0.674 eV for Li 7 calculated by us previously. This means that the Li 13 cluster may be formed stably in a body-centred regular icosahedral structure with a greater binding energy

  3. Venous thromboembolism in pregnancy: prophylaxis and treatment with low molecular weight heparin

    DEFF Research Database (Denmark)

    Andersen, Anita Sylvest; Berthelsen, Jørgen G.; Bergholt, Thomas

    2010-01-01

    OBJECTIVE: To evaluate the safety of individually dosed low molecular weight heparin (LMWH) for prophylaxis and treatment of thromboembolic complications in pregnancy. DESIGN: Cohort study with a chronologic register-based control group. SETTING: Department of Obstetrics and Gynecology, Hillerød...

  4. Effects of inhaled nitric oxide on hemostasis in healthy adults treated with heparin: a randomized, controlled, blinded crossover study

    Directory of Open Access Journals (Sweden)

    Goldstein Brahm

    2012-01-01

    Full Text Available Abstract Background Effects of nitric oxide (NO on hemostasis have been studied in various investigational settings, but data regarding inhaled NO on bleeding and platelet function are conflicting. It is not known if inhaled NO has an effect when administered with drugs that influence hemostasis. This trial evaluated effects of inhaled NO on hemostasis in the presence of heparin using aspirin as a positive control. Patients/Methods Twelve healthy adult males were enrolled in a single-center, randomized, single-blind, four-way crossover trial. Subjects received 80 ppm NO or medical air (placebo inhalation for 30 min with simultaneous injection of placebo or heparin. Aspirin capsules were used as a positive control. Parameters of hemostasis were measured before treatment and at post-treatment intervals. Results Activated clotting time (ACT, prothrombin time (PT and activated partial thromboplastin time (aPTT increased only in groups that received heparin. Areas under the curve for ACT in heparin groups receiving inhaled NO were judged to be equivalent to those receiving medical air for both 0- to 4-h (ratio: 1.00; 90% CI, 0.90-1.11 and 0- to 24-h time intervals (ratio: 1.01; 90% CI, 0.92-1.12. Changes in bleeding time and platelet aggregation were observed only in aspirin groups. No clinically significant changes in hemoglobin, red blood cell counts or haematocrit were observed in any group. Conclusions Inhaled NO, when administered with heparin, exhibited no significant additive effects on ACT, PT, aPTT, bleeding time or platelet aggregation.

  5. Chitosan fibers with improved biological and mechanical properties for tissue engineering applications.

    Science.gov (United States)

    Albanna, Mohammad Z; Bou-Akl, Therese H; Blowytsky, Oksana; Walters, Henry L; Matthew, Howard W T

    2013-04-01

    The low mechanical properties of hydrogel materials such as chitosan hinder their broad utility for tissue engineering applications. Previous research efforts improved the mechanical properties of chitosan fiber through chemical and physical modifications; however, unfavorable toxicity effects on cells were reported. In this paper, we report the preparation of chitosan fibers with improved mechanical and biocompatibility properties. The structure-property relationships of extruded chitosan fibers were explored by varying acetic acid (AA) concentration, ammonia concentration, annealing temperature and degree of heparin crosslinking. Results showed that optimizing AA concentration to 2vol% improved fiber strength and stiffness by 2-fold. Extruding chitosan solution into 25wt% of ammonia solution reduced fiber diameters and improved fiber strength by 2-fold and stiffness by 3-fold, due to an increase in crystallinity as confirmed by XRD. Fiber annealing further reduced fiber diameter and improved fiber strength and stiffness as temperature increased. Chitosan fibers crosslinked with heparin had increased diameter but lower strength and stiffness properties and higher breaking strain values. When individual parameters were combined, further improvement in fiber mechanical properties was achieved. All mechanically improved fibers and heparin crosslinked fibers promoted valvular interstitial cells (VIC) attachment and growth over 10 day cultures. Our results demonstrate the ability to substantially improve the mechanical properties of chitosan fibers without adversely affecting their biological properties. The investigated treatments offer numerous advantages over previous physical/chemical modifications and thus are expected to expand the utility of chitosan fibers with tunable mechanical properties in various tissue engineering applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Heparin removal by ecteola-cellulose pre-treatment enables the use of plasma samples for accurate measurement of anti-Yellow fever virus neutralizing antibodies.

    Science.gov (United States)

    Campi-Azevedo, Ana Carolina; Peruhype-Magalhães, Vanessa; Coelho-Dos-Reis, Jordana Grazziela; Costa-Pereira, Christiane; Yamamura, Anna Yoshida; Lima, Sheila Maria Barbosa de; Simões, Marisol; Campos, Fernanda Magalhães Freire; de Castro Zacche Tonini, Aline; Lemos, Elenice Moreira; Brum, Ricardo Cristiano; de Noronha, Tatiana Guimarães; Freire, Marcos Silva; Maia, Maria de Lourdes Sousa; Camacho, Luiz Antônio Bastos; Rios, Maria; Chancey, Caren; Romano, Alessandro; Domingues, Carla Magda; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis

    2017-09-01

    Technological innovations in vaccinology have recently contributed to bring about novel insights for the vaccine-induced immune response. While the current protocols that use peripheral blood samples may provide abundant data, a range of distinct components of whole blood samples are required and the different anticoagulant systems employed may impair some properties of the biological sample and interfere with functional assays. Although the interference of heparin in functional assays for viral neutralizing antibodies such as the functional plaque-reduction neutralization test (PRNT), considered the gold-standard method to assess and monitor the protective immunity induced by the Yellow fever virus (YFV) vaccine, has been well characterized, the development of pre-analytical treatments is still required for the establishment of optimized protocols. The present study intended to optimize and evaluate the performance of pre-analytical treatment of heparin-collected blood samples with ecteola-cellulose (ECT) to provide accurate measurement of anti-YFV neutralizing antibodies, by PRNT. The study was designed in three steps, including: I. Problem statement; II. Pre-analytical steps; III. Analytical steps. Data confirmed the interference of heparin on PRNT reactivity in a dose-responsive fashion. Distinct sets of conditions for ECT pre-treatment were tested to optimize the heparin removal. The optimized protocol was pre-validated to determine the effectiveness of heparin plasma:ECT treatment to restore the PRNT titers as compared to serum samples. The validation and comparative performance was carried out by using a large range of serum vs heparin plasma:ECT 1:2 paired samples obtained from unvaccinated and 17DD-YFV primary vaccinated subjects. Altogether, the findings support the use of heparin plasma:ECT samples for accurate measurement of anti-YFV neutralizing antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Sustained Thromboresistant Bioactivity with Reduced Intimal Hyperplasia of Heparin-Bonded Polytetrafluoroethylene Propaten Graft in a Chronic Canine Femoral Artery Bypass Model.

    Science.gov (United States)

    Freeman, John; Chen, Aaron; Weinberg, Roy J; Okada, Tamuru; Chen, Changyi; Lin, Peter H

    2018-05-01

    Bypass graft thrombosis remains a significant mode of failure in prosthetic graft revascularization. The purpose of this investigation was to evaluate the long-term thromboresistant effect of heparin-bonded expanded polytetrafluoroethylene (ePTFE) graft using Carmeda BioActive Surface technology in a canine model. Bilateral femorofemoral artery bypass grafts with ePTFE grafts were performed in 25 adult grayhound dogs. In each animal, a heparin-bonded ePTFE graft (Propaten, WL Gore) was placed on one side, whereas a control nonheparin graft was placed on the contralateral side. The graft patency was assessed at 1, 6, 12, 18, and 24 months (n = 5 per group) following the bypass. Heparin bioactivity of the graft material was analyzed. The effect of intimal hyperplasia was also assessed. All bypass grafts were patent at 1 month. Significantly greater patency rates were noted in the Propaten group compared to the control group at 12, 18, and 24 months, which were 84%, 80%, and 80% vs. 55%, 35%, and 20%, respectively (P  0.05). Heparin-bonded ePTFE graft provides a thromboresistant surface and reduced anastomotic intimal hyperplasia at 2 years. The stable heparin bioactivity of the Propaten graft confers an advantage in long-term graft patency. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Transfer of heparin polyion across a polarized water/ionic liquid membrane interface

    Czech Academy of Sciences Publication Activity Database

    Langmaier, Jan; Samec, Zdeněk; Samcová, E.; Tůma, P.

    2012-01-01

    Roč. 24, OCT 2012 (2012), s. 25-27 ISSN 1388-2481 R&D Projects: GA ČR GAP206/11/0707 Institutional support: RVO:61388955 Keywords : heparin polyion * ionic liquid membrane * amperometric detection Subject RIV: CG - Electrochemistry Impact factor: 4.425, year: 2012

  9. Low-molecular-weight heparin in the treatment of patients with venous thromboembolism

    NARCIS (Netherlands)

    tenCate, JW; Buller, HR; Gent, M; Hirsh, J; Prins, MH; Baildon, R; Lensing, AWA; Anderson, DR; vanBeek, EJR; Fiesinger, JN; Tijssen, JGP; vanBarneveld, A; Eimers, LT; Graafsma, YP; Hettiarachchi, R; Hutten, B; Redekop, K; Haley, S; LIberale, L; Finch, T; Whittaker, S; Wilkinson, L; Prandoni, P; Villalta, S; Girolami, B; Bagatella, P; Rossi, L; Girolami, A; Piovella, F; Barone, M; Beltrametti, C; Serafini, S; Siragusa, S; Ascari, E; Kovacs, MJ; Morrow, B; Kovacs, J; Kuijer, PMM; Koopman, MMW; Jagt, H; Weitz, J; Kearon, C; Biagioni, L; Haas, S; Lossner, F; Spengel, FA; Berger, M; Demers, C; Poulin, J; vanderMeer, J; Que, GTH; Smid, WM; Robinson, KS; Boyle, E; Leclerc, [No Value; StJacques, B; Finkenbine, S; Gallus, AS; Cohlan, D; Rich, C; Brandjes, DPM; Hoefnagel, CA; deRijk, M; Turkstra, F; Desjardins, L; CoteDesjardins, J; Couture, L; Ruel, M; Villenueve, J; Geerts, WH; Jay, RM; Code, EKI; Turpie, AGG; Johnson, J; Nguyen, P; Cusson, [No Value; Roy, S; Wells, PS; Bormanis, J; Goudie, D; Cruickshank, M; vonLewinski, M; Monreal, M; Sahuquillo, JC; Lafoz, E; Simonneau, G; Parent, F; Jagot, J; Douketis, JD; Kinnon, K; Ginsberg, JS; BrillEdwards, P; Donovan, D; Ockelford, PA; Kassis, J; Bornais, S; Planchon, B; ElKouri, D; Pistorius, MA; Escribano, M; Garrido, G; Chesterman, CN; Chong, BH; Pritchard, S; Cade, JF; Bynon, T; Stanford, J; Brien, WM; Palmer, B; Faivre, R; Petiteau, B; Manucci, PM; Moia, M; Bucciarelli, P

    1997-01-01

    Background Low-molecular-weight heparin is known to be safe and effective for the initial Treatment of patients with proximal deep-vein thrombosis. However, its application to patients with pulmonary embolism or previous episodes of thromboembolism has not been studied. Methods We randomly assigned

  10. Post-heparin plasma lipoprotein lipase, but not hepatic lipase activity, is related to plasma adiponectin in type 2 diabetic patients and healthy subjects

    NARCIS (Netherlands)

    De Vries, R; Wolffenbuttel, BHR; Sluiter, WJ; Van Tol, A; Dullaart, RPF

    2005-01-01

    The aim of this study was to determine the relationships of plasma adiponectin with post-heparin plasma lipoprotein lipase (LPL) and hepatic lipase (HL) activities, and to evaluate whether plasma adiponectin contributes to diabetes-associated dyslipidaemia. Plasma adiponectin, post-heparin plasma

  11. Enhancement of antibacterial properties of polyurethanes by chitosan and heparin immobilization

    International Nuclear Information System (INIS)

    Kara, Filiz; Aksoy, E. Ayse; Yuksekdag, Zehranur; Aksoy, Serpil; Hasirci, Nesrin

    2015-01-01

    Graphical abstract: - Highlights: • Polyurethane elastomer was synthesized in medical purity. • Chitosan (CH) and heparin (Hep) were immobilized on polyurethane films. • Modification with CH and Hep increased hydrophilicity and surface free energy. • Immobilized films had high antibacterial activity against four bacteria. • Bacterial adhesion significantly decreased on the modified surfaces. - Abstract: Being antibacterial is a required property for the materials used in medical devices and instruments. Polyurethanes (PUs) are one class of polymers widely used in the production of devices that especially come in contact with blood (e.g. heart valves, blood vessels, vascular grafts and catheters). In this study, hexamethylene diisocyanate based polyurethanes (PUh) were synthesized and antibacterial and anti-adhesive properties were added by immobilizing chitosan (CH) and heparin (Hep) on the samples of PUh via a stepwise process. Chemistry and topography of the modified film samples (PUh-CH and PUh-CH-Hep) were examined by Fourier Transform Infrared Spectrophotometry-Attenuated Total Reflectance (FTIR-ATR), Electron Spectroscopy for Chemical Analysis (ESCA) and Atomic Force Microscopy (AFM), and surface free energy (SFE) values after each step were determined by goniometer. PUh-CH and PUh-CH-Hep samples were found to be antibacterial against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis) (both Gram positive) and Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) (both Gram negative) bacteria, and bacterial adhesion results showed a significant decrease in the number of viable bacteria on both modified samples where PUh-CH-Hep was the most effective. The findings of this study show that polymeric surfaces can be effectively modified and converted to be antibacterial by chitosan and heparin immobilization, and presence of both chemicals enhance efficacy against bacteria.

  12. Enhancement of antibacterial properties of polyurethanes by chitosan and heparin immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Kara, Filiz [Department of Chemistry, Faculty of Science, Gazi University, 06500 Ankara (Turkey); Aksoy, E. Ayse [Department of Basic Pharmaceutical Sciences, Faculty of Pharmacy, Hacettepe University, 06100 Ankara (Turkey); Yuksekdag, Zehranur [Biotechnology Laboratory, Department of Biology, Faculty of Science, Gazi University, 06500 Ankara (Turkey); Aksoy, Serpil [Department of Chemistry, Faculty of Science, Gazi University, 06500 Ankara (Turkey); Hasirci, Nesrin, E-mail: nhasirci@metu.edu.tr [BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering, Middle East Technical University, 06800 Ankara (Turkey); Department of Chemistry, Faculty of Arts and Sciences, Middle East Technical University, 06800 Ankara (Turkey)

    2015-12-01

    Graphical abstract: - Highlights: • Polyurethane elastomer was synthesized in medical purity. • Chitosan (CH) and heparin (Hep) were immobilized on polyurethane films. • Modification with CH and Hep increased hydrophilicity and surface free energy. • Immobilized films had high antibacterial activity against four bacteria. • Bacterial adhesion significantly decreased on the modified surfaces. - Abstract: Being antibacterial is a required property for the materials used in medical devices and instruments. Polyurethanes (PUs) are one class of polymers widely used in the production of devices that especially come in contact with blood (e.g. heart valves, blood vessels, vascular grafts and catheters). In this study, hexamethylene diisocyanate based polyurethanes (PUh) were synthesized and antibacterial and anti-adhesive properties were added by immobilizing chitosan (CH) and heparin (Hep) on the samples of PUh via a stepwise process. Chemistry and topography of the modified film samples (PUh-CH and PUh-CH-Hep) were examined by Fourier Transform Infrared Spectrophotometry-Attenuated Total Reflectance (FTIR-ATR), Electron Spectroscopy for Chemical Analysis (ESCA) and Atomic Force Microscopy (AFM), and surface free energy (SFE) values after each step were determined by goniometer. PUh-CH and PUh-CH-Hep samples were found to be antibacterial against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis) (both Gram positive) and Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) (both Gram negative) bacteria, and bacterial adhesion results showed a significant decrease in the number of viable bacteria on both modified samples where PUh-CH-Hep was the most effective. The findings of this study show that polymeric surfaces can be effectively modified and converted to be antibacterial by chitosan and heparin immobilization, and presence of both chemicals enhance efficacy against bacteria.

  13. Improved distribution and reduced toxicity of adriamycin bound to albumin-heparin microspheres

    NARCIS (Netherlands)

    Cremers, Harry; Cremers, H.F.M.; Bayon, L.G.; Verrijk, R.; Wesseling, M.M.; Wondergem, J.; Heuff, G.; Kwon, G.S.; Bae, Y.H.; Feijen, Jan; Kim, S.W.

    1995-01-01

    Adriamycin (ADR) was formulated in albumin-heparin conjugate microspheres (AHCMS) to improve site-specific delivery and to reduce the toxicity of the drug. The effect of formulating ADR in AHCMS was investigated upon intrahepatic administration to male Wag/Rij rats. After intraveno-portal (i.v.p.)

  14. Modulation of Correlated Segment Fluctuations in IDPs upon Complex Formation as an Allosteric Regulatory Mechanism.

    Science.gov (United States)

    Beier, Andreas; Schwarz, Thomas C; Kurzbach, Dennis; Platzer, Gerald; Tribuzio, Francesca; Konrat, Robert

    2018-05-05

    Molecular recognition of and by intrinsically disordered proteins (IDPs) is an intriguing and still largely elusive phenomenon. Typically, protein recognition involving IDPs requires either folding upon binding or, alternatively, the formation of "fuzzy complexes." Here we show via correlation analyses of paramagnetic relaxation enhancement data unprecedented and striking alterations of the concerted fluctuations within the conformational ensemble of IDPs upon ligand binding. We study the binding of α-synuclein to calmodulin, a ubiquitous calcium-binding protein, and the binding of the extracellular matrix IDP osteopontin to heparin, a mimic of the extracellular matrix ligand hyaluronic acid. In both cases, binding leads to reduction of correlated long-range motions in these two IDPs and thus indicates a loosening of structural compaction upon binding. Most importantly, however, the simultaneous presence of correlated and anti-correlated fluctuations in IDPs suggests the prevalence of "energetic frustration" and provides an explanation for the puzzling observation of disordered allostery in IDPs. Copyright © 2018. Published by Elsevier Ltd.

  15. Statistical Mechanics Analysis of ATP Binding to a Multisubunit Enzyme

    International Nuclear Information System (INIS)

    Zhang Yun-Xin

    2014-01-01

    Due to inter-subunit communication, multisubunit enzymes usually hydrolyze ATP in a concerted fashion. However, so far the principle of this process remains poorly understood. In this study, from the viewpoint of statistical mechanics, a simple model is presented. In this model, we assume that the binding of ATP will change the potential of the corresponding enzyme subunit, and the degree of this change depends on the state of its adjacent subunits. The probability of enzyme in a given state satisfies the Boltzmann's distribution. Although it looks much simple, this model can fit the recent experimental data of chaperonin TRiC/CCT well. From this model, the dominant state of TRiC/CCT can be obtained. This study provide a new way to understand biophysical processe by statistical mechanics analysis. (interdisciplinary physics and related areas of science and technology)

  16. Immobilization of heparin to EDC/NHS-crosslinked collagen. Characterization and in vitro evaluation

    NARCIS (Netherlands)

    Wissink, M.J.B.; Beernink, R.; Pieper, J.S.; Poot, Andreas A.; Engbers, G.H.M.; Beugeling, T.; Beugeling, T.; van Aken, W.G.; Feijen, Jan

    2001-01-01

    In the present study, heparin immobilization to a non-cytotoxic crosslinked collagen substrate for endothelial cell seeding was investigated. Crosslinking of collagen using N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (EDC) and N-hydroxysuccinimide (NHS) resulted in a material containing 14 free

  17. The impact of heparin-coated circuits on hemodynamics during and after cardiopulmonary bypass

    NARCIS (Netherlands)

    de Vroege, R; Huybregts, R; van Oeveren, W; van Klarenbosch, J; Linley, G; Mutlu, J; Jansen, E; Hack, E; Eijsman, L; Wildevuur, C

    This study was performed to investigate if heparin-coated extracorporeal circuits can reduce the systemic inflammatory reaction with the subsequent release of vasoactive substances during and after cardiopulmonary bypass. Fifty-one patients scheduled for coronary artery bypass grafting were perfused

  18. Angiogenic Factor Profiles in Pregnant Women With a History of Early-Onset Severe Preeclampsia Receiving Low-Molecular-Weight Heparin Prophylaxis.

    Science.gov (United States)

    Lecarpentier, Edouard; Gris, Jean Christophe; Cochery-Nouvellon, Eva; Mercier, Erick; Touboul, Cyril; Thadhani, Ravi; Karumanchi, S Ananth; Haddad, Bassam

    2018-01-01

    To evaluate whether daily low-molecular-weight (LMW) heparin prophylaxis during pregnancy alters profile of circulating angiogenic factors that have been linked with the pathogenesis of preeclampsia and fetal growth restriction. This is a planned ancillary study of the Heparin-Preeclampsia trial, a randomized trial in pregnant women with a history of severe early-onset preeclampsia (less than 34 weeks of gestation). In the parent study, all women were treated with aspirin and then randomized to receive LMW heparin or aspirin alone. In this study, we measured serum levels of circulating angiogenic factors (soluble fms-like tyrosine kinase-1, placental growth factor, and soluble endoglin by immunoassay) at the following gestational windows: 10-13 6/7 weeks, 14-17 6/7 weeks, 18-21 6/7 weeks, 22-25 6/7 weeks, 26-29 6/7 weeks, 30-33 6/7 weeks, and 34-37 6/7 weeks. Samples were available from 185 patients: LMW heparin+aspirin (n=92) and aspirin alone (n=93). The two groups had comparable baseline characteristics and had similar adverse composite outcomes (35/92 [38.0%] compared with 36/93 [38.7%]; P=.92). There were no significant differences in serum levels of soluble fms-like tyrosine kinase-1, placental growth factor, and soluble endoglin in the participants who received LMW heparin and aspirin compared with those who received aspirin alone regardless of gestational age period. Finally, women who developed an adverse composite outcome at less than 34 weeks of gestation demonstrated significant alterations in serum angiogenic profile as early as 10-13 6/7 weeks that was most dramatic 6-8 weeks preceding delivery. Prophylactic LMW heparin therapy when beginning from before 14 weeks of gestation with aspirin during pregnancy is not associated with an improved angiogenic profile. This may provide a molecular explanation for the lack of clinical benefit noted in recent trials. ClinicalTrials.gov, NCT00986765.

  19. Bivalirudin is superior to heparins alone with bailout GP IIb/IIIa inhibitors in patients with ST-segment elevation myocardial infarction transported emergently for primary percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Zeymer, Uwe; van 't Hof, Arnoud; Adgey, Jennifer

    2014-01-01

    was the composites of death or non-CABG-related major bleeding at 30 days. This pre-specified analysis compared patients receiving bivalirudin (n = 1089) with those receiving heparins with routine upstream GPI (n = 649) and those receiving heparins only with GPI use restricted to bailout (n = 460). The primary...... outcome death and major bleeding occurred in 5.1% with bivalirudin, 7.6% with heparin plus routine GPI (HR 0.67 and 95% CI 0.46-0.97, P = 0.034), and 9.8% with heparins plus bailout GPI (HR 0.52 and 95% CI 0.35-0.75, P = 0.006). Following adjustment by logistic regression, bivalirudin was still associated...

  20. Heparin sodium compliance to the new proposed USP monograph: elucidation of a minor structural modification responsible for a process dependent 2.10 ppm NMR signal.

    Science.gov (United States)

    Mourier, Pierre A J; Guichard, Olivier Y; Herman, Fréderic; Viskov, Christian

    2011-01-25

    Heparin is a highly sulfated hetero polysaccharide mixture found and extracted from mammalian tissues. It has been widely used as an anticoagulant drug during the past decades. In the new proposed USP heparin monograph, the ¹H NMR acceptance criteria to prevent contamination by over sulfated chondroitin sulfate (OSCS), or other persulfated glycosaminoglycans, specifies that no unidentified signals greater than 4% of the mean of signal height of 1 and 2 should be present in the following ranges: 0.10-2.00, 2.10-3.20, and 5.70-8.00 ppm. However, those criteria do not take into account the impact of potential structural modifications generated by the heparin manufacturing processes. In fact, starting from pig mucosa, heparin purification involves oxidizing reagents such as sodium peroxide, potassium permanganate and peracetic acid. In the present work, we demonstrate that potassium permanganate treated heparins show a small but characteristic extra signal at 2.10 ppm. Controlled heparinase I depolymerisation is used to target and excise the oligosaccharide responsible for this extra signal from the polysaccharide backbone. By using orthogonal chromatographic techniques, the fingerprint oligosaccharide was isolated and its structure elucidated. Without the identification of this structural moiety, such purified heparins may have been considered as non-compliant drug substance and not suitable for pharmaceutical use. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Comparison of digoxin concentration in plastic serum tubes with clot activator and heparinized plasma tubes.

    Science.gov (United States)

    Dukić, Lora; Simundić, Ana-Maria; Malogorski, Davorin

    2014-01-01

    Sample type recommended by the manufacturer for the digoxin Abbott assay is either serum collected in glass tubes or plasma (sodium heparin, lithium heparin, citrate, EDTA or oxalate as anticoagulant) collected in plastic tubes. In our hospital samples are collected in plastic tubes. Our hypothesis was that the serum sample collected in plastic serum tube can be used interchangeably with plasma sample for measurement of digoxin concentration. Our aim was verification of plastic serum tubes for determination of digoxin concentration. Concentration of digoxin was determined simultaneously in 26 venous blood plasma (plastic Vacuette, LH Lithium heparin) and serum (plastic Vacuette, Z Serum Clot activator; both Greiner Bio-One GmbH, Kremsmünster, Austria) samples, on Abbott AxSYM analyzer using the original Abbott Digoxin III assay (Abbott, Wiesbaden, Germany). Tube comparability was assessed using the Passing Bablok regression and Bland-Altman plot. Serum and plasma digoxin concentrations are comparable. Passing Bablok intercept (0.08 [95% CI = -0.10 to 0.20]) and slope (0.99 [95% CI = 0.92 to 1.11]) showed there is no constant or proportional error. Blood samples drawn in plastic serum tubes and plastic plasma tubes can be interchangeably used for determination of digoxin concentration.

  2. Multinuclear nuclear magnetic resonance spectroscopic study of cartilage proteoglycans

    Energy Technology Data Exchange (ETDEWEB)

    Lerner, L.

    1985-01-01

    Hyaline cartilage is a composite material whose major function is to withstand compression while retaining flexibility. Its mechanical properties are affected by tissue hydration and ionic composition. Models of the mechanical behavior of cartilage have incorporated certain assumptions about the interactions of the major components of cartilage: collagen, proteoglycans, water, and cations. To determine the validity of these assumption, the authors have used nuclear magnetic resonance spectroscopy (NMR). Two approaches have been used: (a) natural abundance carbon-13 NMR; and (b) NMR of sodium-23, potassium-39, magnesium-25, and calcium-43. Evidence from studies in intact tissues are reinforced by extensive measurements on solutions of proteoglycans and other relevant macromolecules. Based on the measurements of NMR relaxation rates and lineshapes reported here, it is concluded that neither sodium nor potassium interact strongly with bovine nasal proteoglycan aggregates or their substituent glycosaminoglycan chains in solution. Proteoglycans do bind magnesium and calcium. Therefore there is a qualitative difference between monovalent and divalent cations, which is not taken into account by polyelectrolyte models or models for the ionic dependence of mechanical properties. Cation binding to heparin, which has a higher charge density than cartilage proteoglycans, was also studied. The results presented here establish that heparin binds sodium, magnesium, and calcium.

  3. Ontogeny of basic fibroblast growth factor binding sites in mouse ocular tissues

    International Nuclear Information System (INIS)

    Fayein, N.A.; Courtois, Y.; Jeanny, J.C.

    1990-01-01

    Basic fibroblast growth factor (bFGF) binding to ocular tissues has been studied by autoradiographical and biochemical approaches directly performed on sections during mouse embryonic and postnatal development. Frozen sections of embryos (9 to 18 days), newborns, and adults (1 day to 6 months) were incubated with iodinated bFGF. One specific FGF binding site (KD = 2.5 nM) is colocalized with heparan sulfate proteoglycans of the basement membranes and is heparitinase sensitive. It first appears at Day 9 around the neural tube, the optic vesicles, and below the head ectoderm and by Day 14 of embryonic development is found in all basement membranes of the eye. At Day 16, very intensely labeled patches appear, corresponding to mast cells which have been characterized by metachromatic staining of their heparin-rich granulations with toluidine blue. In addition to the latter binding, we have also observed a general diffuse distribution of silver grains on all tissues and preferentially in the ecto- and neuroectodermic tissues. From Days 17-18, there is heterogeneous labeling inside the retina, localized in the pigmented epithelium and in three different layers colocalized with the inner and outer plexiform layers and with the inner segments of the photoreceptors. This binding is heparitinase resistant but N-glycanase sensitive and may represent a second specific binding site corresponding to cellular FGF receptors (KD = 280 pM). Both types of binding patterns observed suggest a significant role for bFGF in eye development and physiology

  4. Relationship between heparin anticoagulation and clinical outcomes in coronary stent intervention: observations from the ESPRIT trial.

    Science.gov (United States)

    Tolleson, Thaddeus R; O'Shea, J Conor; Bittl, John A; Hillegass, William B; Williams, Kathryn A; Levine, Glenn; Harrington, Robert A; Tcheng, James E

    2003-02-05

    We evaluated the relationship between the degree of heparin anticoagulation and clinical efficacy and bleeding in patients undergoing contemporary percutaneous coronary intervention (PCI) with stent implantation. Despite universal acceptance of heparin anticoagulation as a standard of care in PCI, considerable controversy still exists regarding the appropriate dosing of heparin. The study population (n = 2,064) comprised all patients enrolled in the Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial. The index activated clotting time (ACT) was defined as the ACT measured after the last heparin dose and before first device activation and was correlated with outcome and bleeding events. No association was observed between decreasing ACT levels and the rate of ischemic events in the treatment or placebo arms. The incidence of the primary composite end point (death, myocardial infarction, urgent target vessel revascularization, and thrombotic bailout glycoprotein IIb/IIIa inhibitor therapy at 48 h) was actually lowest in the lowest ACT tertile for both the placebo (10.0%) and treatment groups (6.1%). When analyzed by tertile, major bleeding rates did not increase in the lowest ACT tertile in patients given placebo (0.6%) versus those receiving eptifibatide (0.7%). Major bleeding rates increased as the ACT increased in the eptifibatide-treated patients. Ischemic end points in patients undergoing contemporary PCI with stent placement do not increase by decreasing ACT levels, at least to a level of 200 s. Bleeding events do increase with increasing ACT levels and are enhanced with eptifibatide treatment. An ACT of 200 to 250 s is reasonable in terms of efficacy and safety with the use of contemporary technology and pharmacotherapy.

  5. Two-step purification of His-tagged Nef protein in native condition using heparin and immobilized metal ion affinity chromatographies.

    Science.gov (United States)

    Finzi, Andrés; Cloutier, Jonathan; Cohen, Eric A

    2003-07-01

    The Nef protein encoded by human immunodeficiency virus type 1 (HIV-1) has been shown to be an important factor of progression of viral growth and pathogenesis in both in vitro and in vivo. The lack of a simple procedure to purify Nef in its native conformation has limited molecular studies on Nef function. A two-step procedure that includes heparin and immobilized metal ion affinity chromatographies (IMACs) was developed to purify His-tagged Nef (His(6)-Nef) expressed in bacteria in native condition. During the elaboration of this purification procedure, we identified two closely SDS-PAGE-migrating contaminating bacterial proteins, SlyD and GCHI, that co-eluted with His(6)-Nef in IMAC in denaturing condition and developed purification steps to eliminate these contaminants in native condition. Overall, this study describes a protocol that allows rapid purification of His(6)-Nef protein expressed in bacteria in native condition and that removes metal affinity resin-binding bacterial proteins that can contaminate recombinant His-tagged protein preparation.

  6. Eldecalcitol (ED-71), an analog of 1α,25(OH)2D3, inhibits the growth of squamous cell carcinoma (SCC) cells in vitro and in vivo by down-regulating expression of heparin-binding protein 17/fibroblast growth factor-binding protein-1 (HBp17/FGFBP-1) and FGF-2.

    Science.gov (United States)

    Shintani, T; Takatsu, F; Rosli, S N Z; Usui, E; Hamada, A; Sumi, K; Hayashido, Y; Toratani, S; Okamoto, Tetsuji

    2017-10-01

    Heparin-binding protein 17 (HBp17)/fibroblast growth factor-binding protein-1 (FGFBP-1) was first purified from medium conditioned by A431 cells for its capacity to bind to fibroblast growth factors 1 and 2 (FGF-1 and -2). Among FGF family members, FGF-2 is a potent mitogen for various cell types, including vascular endothelial cells, fibroblasts, and cancer cells such as oral squamous cell carcinoma (OSCC) cells. Besides being well known in bone metabolism, the active form of vitamin D 3 , i.e., 1α,25(OH) 2 D 3 (1,25D 3 ), was reported to have protective effects for heart disease and cancer. Previously, we reported that 1,25D 3 inhibited HBp17/FGFBP-1 expression in OSCC cell lines through NF-κB inhibition (IκBα activation) and resulted in the inactivation of FGF-2. In this study, we examined the potential anti-tumor effect of ED-71, an analog of 1α,25(OH) 2 D 3 , for squamous cell carcinoma cells in vitro and in vivo. The cell lines used were OSCC cell lines (NA-HO-1-n-1 and UE-HO-1-u-1), established from oral cancer patients in our laboratory, and an epidermoid carcinoma/SCC cell line (A431). The growth assay in serum-free culture revealed that ED-71 inhibited the growth of the cancer cell lines in a dose-dependent manner. In addition, ED-71 suppressed HBp17/FGFBP-1 expression by inhibiting the NF-κB pathway as did 1,25D 3 . Furthermore, a luciferase reporter assay revealed that the promoter activity of HBp17/FGFBP-1 (region between -217 and +61) was down-regulated by ED-71. Oral administration of ED-71 significantly inhibited the growth of A431-derived tumors in athymic nude mice. Immunohistochemical analysis revealed that the expression of HBp17/FGFBP-1, FGF-2, CD31, and Ki-67 in the tumors of ED71-treated group was down-regulated in comparison to control. These results suggest that ED-71 possesses potential anti-tumor activity for SCCs both in vitro and in vivo. This compound may act directly on the tumor cells or on endothelial cells by modulating the

  7. Influence of heparin on the assay of amitriptyline, clomipramine, and their metabolites

    NARCIS (Netherlands)

    Levering, S.C.M.; Oostelbos, M.C.J.M.; Toll, P.J.M.M.; Loonen, A.J.M.

    1996-01-01

    In this study the effect of the use of lithium heparin containers on the plasma levels of amitriptyline, clomipramine, and their metabolites was investigated. Twenty-five patients (10 men and 15 women, mean age 51.8 ± 14.9 years) taking either amitriptyline or clomipramine in a daily dosage varying

  8. Leveraging non-binding instruments for global health governance: reflections from the Global AIDS Reporting Mechanism for WHO reform.

    Science.gov (United States)

    Taylor, A L; Alfven, T; Hougendobler, D; Tanaka, S; Buse, K

    2014-02-01

    As countries contend with an increasingly complex global environment with direct implications for population health, the international community is seeking novel mechanisms to incentivize coordinated national and international action towards shared health goals. Binding legal instruments have garnered increasing attention since the World Health Organization adopted its first convention in 2003. This paper seeks to expand the discourse on future global health lawmaking by exploring the potential value of non-binding instruments in global health governance, drawing on the case of the 2001 United Nations General Assembly Special Session Declaration of Commitment on HIV/AIDS. In other realms of international concern ranging from the environment to human rights to arms control, non-binding instruments are increasingly used as effective instruments of international cooperation. The experience of the Global AIDS Reporting Mechanism, established pursuant to the Declaration, evidences that, at times, non-binding legal instruments can offer benefits over slower, more rigid binding legal approaches to governance. The global AIDS response has demonstrated that the use of a non-binding instrument can be remarkably effective in galvanizing increasingly deep commitments, action, reporting compliance and ultimately accountability for results. Based on this case, the authors argued that non-binding instruments deserve serious consideration by the international community for the future of global health governance, including in the context of WHO reform. Copyright © 2013 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  9. Effects of Sildenafil Citrate and Heparin Treatments on Placental Cell Morphology in a Murine Model of Pregnancy Loss.

    Science.gov (United States)

    Luna, Rayana Leal; Vasconcelos, Anne Gabrielle; Nunes, Ana Karolina Santana; de Oliveira, Wilma Helena; Barbosa, Karla Patricia de Sousa; Peixoto, Christina Alves

    2016-01-01

    Lipopolysaccharide (LPS) injections during pregnancy are well established as models for pregnancy complications, including fetal growth restriction (FGR), thrombophilia, preterm labor and abortion. Indeed, inflammation, as induced by LPS injection has been described as a pivotal factor in cases of miscarriage related to placental tissue damage. The phosphodiesterase-5 inhibitor sildenafil (Viagra®) is currently used to treat FGR cases in women, while low-molecular weight heparin (Fragmin®) is a standard treatment for recurrent miscarriage (RM). However, the pathways and cellular dynamics involved in RM are not completely understood. The aim of this study was to evaluate the protective effect of sildenafil and dalteparin in a mouse model of LPS-induced abortion. Histopathology, ultrastructural analysis and immunofluorescence for P-selectin were studied in two different placental cell types: trophoblast cells and labyrinth endothelial cells. Treatment with sildenafil either alone or in combination with heparin showed the best response against LPS-induced injury during pregnancy. In conclusion, our results support the use of these drugs as future therapeutic agents that may protect the placenta against inflammatory injury in RM events. Analyses of the ultrastructure and placental immunophysiology are important to understand the mechanism underlying RM. These findings may spark future studies and aid in the development of new therapies in cases of RM. © 2016 S. Karger AG, Basel.

  10. Developing a Highly Active Blood Anticoagulant—a Heparin Complex with Glutamic Acid—by Simulating Chemical Equilibria Based on pH-Metric Data

    Science.gov (United States)

    Nikolaeva, L. S.; Semenov, A. N.

    2018-02-01

    The anticoagulant activity of high-molecular-weight heparin is increased by developing a new highly active heparin complex with glutamate using the thermodynamic model of chemical equilibria based on pH-metric data. The anticoagulant activity of the developed complexes is estimated in the pH range of blood plasma according to the drop in the calculated equilibrium Ca2+ concentration associated with the formation of mixed ligand complexes of Ca2+ ions, heparin (Na4hep), and glutamate (H2Glu). A thermodynamic model is calculated by mathematically modelling chemical equilibria in the CaCl2-Na4hep-H2Glu-H2O-NaCl system in the pH range of 2.30 ≤ pH ≤ 10.50 in diluted saline that acts as a background electrolyte (0.154 M NaCl) at 37°C and initial concentrations of the main components of ν × 10-3 M, where n ≤ 4. The thermodynamic model is used to determine the main complex of the monomeric unit of heparin with glutamate (HhepGlu5-) and the most stable mixed ligand complex of Ca2+ with heparin and glutamate (Ca2hepGlu2-) in the pH range of blood plasma (6.80 ≤ pH ≤ 7.40). It is concluded that the Ca2hepGlu2- complex reduces the Ca2+ concentration 107 times more than the Ca2+ complex with pure heparin. The anticoagulant effect of the developed HhepGlu5- complex is confirmed in vitro and in vivo via coagulation tests on the blood plasma of laboratory rats. Additional antithrombotic properties of the developed complex are identified. The new highly active anticoagulant, HhepGlu5- complex with additional antithrombotic properties, is patented.

  11. Cell surface binding and uptake of arginine- and lysine-rich penetratin peptides in absence and presence of proteoglycans

    KAUST Repository

    Åmand, Helene L.

    2012-11-01

    Cell surface proteoglycans (PGs) appear to promote uptake of arginine-rich cell-penetrating peptides (CPPs), but their exact functions are unclear. To address if there is specificity in the interactions of arginines and PGs leading to improved internalization, we used flow cytometry to examine uptake in relation to cell surface binding for penetratin and two arginine/lysine substituted variants (PenArg and PenLys) in wildtype CHO-K1 and PG-deficient A745 cells. All peptides were more efficiently internalized into CHO-K1 than into A745, but their cell surface binding was independent of cell type. Thus, PGs promote internalization of cationic peptides, irrespective of the chemical nature of their positive charges. Uptake of each peptide was linearly dependent on its cell surface binding, and affinity is thus important for efficiency. However, the gradients of these linear dependencies varied significantly. Thus each peptide\\'s ability to stimulate uptake once bound to the cell surface is reliant on formation of specific uptake-promoting interactions. Heparin affinity chromatography and clustering experiments showed that penetratin and PenArg binding to sulfated sugars is stabilized by hydrophobic interactions and result in clustering, whereas PenLys only interacts through electrostatic attraction. This may have implications for the molecular mechanisms behind arginine-specific uptake stimulation as penetratin and PenArg are more efficiently internalized than PenLys upon interaction with PGs. However, PenArg is also least affected by removal of PGs. This indicates that an increased arginine content not only improve PG-dependent uptake but also that PenArg is more adaptable as it can use several portals of entry into the cell. © 2012 Elsevier B.V.

  12. Mechanism of sequence-specific template binding by the DNA primase of bacteriophage T7

    KAUST Repository

    Lee, Seung-Joo

    2010-03-28

    DNA primases catalyze the synthesis of the oligoribonucleotides required for the initiation of lagging strand DNA synthesis. Biochemical studies have elucidated the mechanism for the sequence-specific synthesis of primers. However, the physical interactions of the primase with the DNA template to explain the basis of specificity have not been demonstrated. Using a combination of surface plasmon resonance and biochemical assays, we show that T7 DNA primase has only a slightly higher affinity for DNA containing the primase recognition sequence (5\\'-TGGTC-3\\') than for DNA lacking the recognition site. However, this binding is drastically enhanced by the presence of the cognate Nucleoside triphosphates (NTPs), Adenosine triphosphate (ATP) and Cytosine triphosphate (CTP) that are incorporated into the primer, pppACCA. Formation of the dimer, pppAC, the initial step of sequence-specific primer synthesis, is not sufficient for the stable binding. Preformed primers exhibit significantly less selective binding than that observed with ATP and CTP. Alterations in subdomains of the primase result in loss of selective DNA binding. We present a model in which conformational changes induced during primer synthesis facilitate contact between the zinc-binding domain and the polymerase domain. The Author(s) 2010. Published by Oxford University Press.

  13. A randomised controlled trial of Heparin versus EthAnol Lock THerapY for the prevention of Catheter Associated infecTion in Haemodialysis patients – the HEALTHY-CATH trial

    Directory of Open Access Journals (Sweden)

    Broom Jennifer K

    2012-11-01

    Full Text Available Abstract Background Tunnelled central venous dialysis catheter use is significantly limited by the occurrence of catheter-related infections. This randomised controlled trial assessed the efficacy of a 48 hour 70% ethanol lock vs heparin locks in prolonging the time to the first episode of catheter related blood stream infection (CRBSI. Methods Patients undergoing haemodialysis (HD via a tunnelled catheter were randomised 1:1 to once per week ethanol locks (with two heparin locks between other dialysis sessions vs thrice per week heparin locks. Results Observed catheter days in the heparin (n=24 and ethanol (n=25 groups were 1814 and 3614 respectively. CRBSI occurred at a rate of 0.85 vs. 0.28 per 1000 catheter days in the heparin vs ethanol group by intention to treat analysis (incident rate ratio (IRR for ethanol vs. heparin 0.17; 95%CI 0.02-1.63; p=0.12. Flow issues requiring catheter removal occurred at a rate of 1.6 vs 1.4 per 1000 catheter days in the heparin and ethanol groups respectively (IRR 0.85; 95% CI 0.20-3.5 p =0.82 (for ethanol vs heparin. Conclusions Catheter survival and catheter-related blood stream infection were not significantly different but there was a trend towards a reduced rate of infection in the ethanol group. This study establishes proof of concept and will inform an adequately powered multicentre trial to definitively examine the efficacy and safety of ethanol locks as an alternative to current therapies used in the prevention of catheter-associated blood stream infections in patients dialysing with tunnelled catheters. Trial Registration Australian New Zealand Clinical Trials Registry ACTRN12609000493246

  14. Interactions of poly(amidoamine) dendrimers with human serum albumin: binding constants and mechanisms.

    Science.gov (United States)

    Giri, Jyotsnendu; Diallo, Mamadou S; Simpson, André J; Liu, Yi; Goddard, William A; Kumar, Rajeev; Woods, Gwen C

    2011-05-24

    The interactions of nanomaterials with plasma proteins have a significant impact on their in vivo transport and fate in biological fluids. This article discusses the binding of human serum albumin (HSA) to poly(amidoamine) [PAMAM] dendrimers. We use protein-coated silica particles to measure the HSA binding constants (K(b)) of a homologous series of 19 PAMAM dendrimers in aqueous solutions at physiological pH (7.4) as a function of dendrimer generation, terminal group, and core chemistry. To gain insight into the mechanisms of HSA binding to PAMAM dendrimers, we combined (1)H NMR, saturation transfer difference (STD) NMR, and NMR diffusion ordered spectroscopy (DOSY) of dendrimer-HSA complexes with atomistic molecular dynamics (MD) simulations of dendrimer conformation in aqueous solutions. The binding measurements show that the HSA binding constants (K(b)) of PAMAM dendrimers depend on dendrimer size and terminal group chemistry. The NMR (1)H and DOSY experiments indicate that the interactions between HSA and PAMAM dendrimers are relatively weak. The (1)H NMR STD experiments and MD simulations suggest that the inner shell protons of the dendrimers groups interact more strongly with HSA proteins. These interactions, which are consistently observed for different dendrimer generations (G0-NH(2)vs G4-NH(2)) and terminal groups (G4-NH(2)vs G4-OH with amidoethanol groups), suggest that PAMAM dendrimers adopt backfolded configurations as they form weak complexes with HSA proteins in aqueous solutions at physiological pH (7.4).

  15. Fondaparinux for intra and perioperative anticoagulation in patients with heparin-induced thrombocytopenia candidates for peripheral vascular surgery: Report of 4 cases.

    Science.gov (United States)

    Illuminati, Giulio; Calio', Francesco G; Pizzardi, Giulia; Amatucci, Chiara; Masci, Federica; Palumbo, Piergaspare

    2016-01-01

    Intra and perioperative anticoagulation in patients with heparin induced thrombocytopenia (HIT), candidates for peripheral vascular surgery remains a challenge, as the best alternative to heparin has not yet been established. We evaluated the off-label use of fondaparinux in four patients with HIT, undergoing peripheral vascular surgery procedures. Four patients of whom 3 men of a mean age of 66 years, with proven heparin induced thrombocytopenia (HIT) underwent two axillo-femoral bypasses, one femoro-popliteal bypass and one resection of a splenic artery aneurysm under fondaparinux. No intra or perioperative bleeding or thrombosis of new onset was observed. In the absence of a valid alternative to heparin for intra and perioperative anticoagulation in HIT, several other anticoagulants can be used in an off-label setting. However, no general consensus exist on which should be the one of choice. In this small series fondaparinux appeared to be both safe and effective. These preliminary results seem to justify the off-label use of fondaparinux for intra and perioperative anticoagulation in patients with HIT, candidates for peripheral vascular surgery interventions. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Revealing vilazodone's binding mechanism underlying its partial agonism to the 5-HT1A receptor in the treatment of major depressive disorder.

    Science.gov (United States)

    Zheng, Guoxun; Xue, Weiwei; Yang, Fengyuan; Zhang, Yang; Chen, Yuzong; Yao, Xiaojun; Zhu, Feng

    2017-11-01

    It has been estimated that major depressive disorder (MDD) will become the second largest global burden among all diseases by 2030. Various types of drugs, including selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and serotonin receptor partial agonist/reuptake inhibitors (SPARIs), have been approved and become the primary or first-line medications prescribed for MDD. SPARI was expected to demonstrate more enhanced drug efficacy and a rapid onset of action as compared to SSRI and SNRI. As one of the most famous SPARIs, vilazodone was approved by the FDA for the treatment of MDD. Because of the great clinical importance of vilazodone, its binding mechanism underlying its partial agonism to the 5-HT 1A receptor (5-HT 1A R) could provide valuable information to SPARIs' drug-like properties. However, this mechanism has not been reported to date; consequently, the rational design of new efficacious SPARI-based MDD drugs is severely hampered. To explore the molecular mechanism of vilazodone, an integrated computational strategy was adopted in this study to reveal its binding mechanism and prospective structural feature at the agonist binding site of 5-HT 1A R. As a result, 22 residues of this receptor were identified as hotspots, consistently favoring the binding of vilazodone and its analogues, and a common binding mechanism underlying their partial agonism to 5-HT 1A R was, therefore, discovered. Moreover, three main interaction features between vilazodone and 5-HT 1A R have been revealed and schematically summarized. In summary, this newly identified binding mechanism will provide valuable information for medicinal chemists working in the field of rational design of novel SPARIs for MDD treatment.

  17. Optical sensing of sulfate by polymethinium salt receptors: colorimetric sensor for heparin

    Czech Academy of Sciences Publication Activity Database

    Bříza, T.; Kejík, Z.; Císařová, I.; Králová, Jarmila; Martásek, P.; Král, V.

    2008-01-01

    Roč. 16, - (2008), s. 1901-1903 ISSN 1359-7345 R&D Projects: GA AV ČR KAN200200651; GA ČR(CZ) GA203/06/1038 Institutional research plan: CEZ:AV0Z50520514 Keywords : colorimetric sensor * heparin * polymethinium salt Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.340, year: 2008

  18. Low dose intravesical heparin as prophylaxis against recurrent noninvasive (stage Ta) bladder cancer

    DEFF Research Database (Denmark)

    Bitsch, M; Hermann, G G; Andersen, J P

    1990-01-01

    A controlled randomized clinical trial was conducted to examine the efficacy of topical low dose heparin (0.125 gm./l., 25,000 units per l.) as prophylaxis against recurrent noninvasive (stage Ta) transitional cell bladder cancer. Transurethral tumor resection was done with irrigation fluid conta...

  19. Carboxamide SIRT1 inhibitors block DBC1 binding via an acetylation-independent mechanism

    Science.gov (United States)

    Hubbard, Basil P; Loh, Christine; Gomes, Ana P; Li, Jun; Lu, Quinn; Doyle, Taylor LG; Disch, Jeremy S; Armour, Sean M; Ellis, James L; Vlasuk, George P; Sinclair, David A

    2013-01-01

    SIRT1 is an NAD+-dependent deacetylase that counteracts multiple disease states associated with aging and may underlie some of the health benefits of calorie restriction. Understanding how SIRT1 is regulated in vivo could therefore lead to new strategies to treat age-related diseases. SIRT1 forms a stable complex with DBC1, an endogenous inhibitor. Little is known regarding the biochemical nature of SIRT1-DBC1 complex formation, how it is regulated and whether or not it is possible to block this interaction pharmacologically. In this study, we show that critical residues within the catalytic core of SIRT1 mediate binding to DBC1 via its N-terminal region, and that several carboxamide SIRT1 inhibitors, including EX-527, can completely block this interaction. We identify two acetylation sites on DBC1 that regulate its ability to bind SIRT1 and suppress its activity. Furthermore, we show that DBC1 itself is a substrate for SIRT1. Surprisingly, the effect of EX-527 on SIRT1-DBC1 binding is independent of DBC1 acetylation. Together, these data show that protein acetylation serves as an endogenous regulatory mechanism for SIRT1-DBC1 binding and illuminate a new path to developing small-molecule modulators of SIRT1. PMID:23892437

  20. Effect of a solution containing citrate/Methylene Blue/parabens on Staphylococcus aureus bacteria and biofilm, and comparison with various heparin solutions.

    Science.gov (United States)

    Sauer, Karin; Steczko, Janusz; Ash, Stephen R

    2009-05-01

    Some antibiotic solutions increase bacterial resistance and may cause toxic side effects. Heparin, frequently used as an anticoagulant in catheter lock solutions, may cause bleeding and stimulate biofilm formation. The aim of this study was to investigate the effect of a new antibacterial/antithrombotic solution, citrate/Methylene Blue/parabens (C/MB/P), versus various heparin solutions on the viability and the structure of preformed mature biofilms of Staphylococcus aureus bacteria. The degree of eradication of both planktonic and sessile microorganisms was evaluated. The changes in the structure of biofilms after exposure to C/MB/P and several concentrations of heparin were analysed by means of confocal laser scanning microscopy. COMSTAT image analysis was utilized to compare biofilm biomass, average and maximum height, surface coverage and roughness coefficient. Viability studies were performed on both biofilms and supernatant solutions. C/MB/P, in contrast to heparin solutions, significantly reduced biofilm biomass and thickness and reduced viability by 5 log when compared with saline treatment. No viable planktonic bacteria were detected and the few remaining biofilm cells appeared to be lysed. In contrast, most heparin solutions only reduced viability up to 1.0 log and failed to eradicate planktonic bacteria. C/MB/P has a rapid bactericidal effect on the preformed, mature biofilm of S. aureus. The structural changes of biofilms treated with C/MB/P, together with the observed log reduction of viable biofilm cells, confirmed the high potential of this solution to eliminate sessile bacteria. Furthermore, the tested solution entirely eliminated planktonic bacteria detached from the biofilm.

  1. A heparin-functionalized carbon nanotube-based affinity biosensor for dengue virus.

    Science.gov (United States)

    Wasik, Daniel; Mulchandani, Ashok; Yates, Marylynn V

    2017-05-15

    Dengue virus is an arthropod-borne virus transmitted primarily by Aedes mosquitos and is major cause of disease in tropical and subtropical regions. Colloquially known as Dengue Fever, infection can cause hemorrhagic disorders and death in humans and non-human primates. We report a novel electronic biosensor based on a single-walled carbon nanotube network chemiresistive transducer that is functionalized with heparin for low-cost, label-free, ultra-sensitive, and rapid detection of whole dengue virus (DENV). Heparin, an analog of the heparan sulfate proteoglycans that are receptors for dengue virus during infection of Vero cells and hepatocytes, was used for the first time in a biosensor as a biorecognition element instead of traditional antibody. Detection of DENV in viral culture supernatant has similar sensitivity as the corresponding viral titer in phosphate buffer despite the presence of growth media and Vero cell lysate. The biosensor demonstrated sensitivity within the clinically relevant range for humans and infected Aedes aegypti. It has potential application in clinical diagnosis and can improve point-of-care diagnostics of dengue infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Successful Use of Alternative Anticoagulants in the Management of Heparin-induced Thrombocytopenia with Thrombotic Complications: Report of 5 cases and review of literature.

    LENUS (Irish Health Repository)

    Alkindi, Salam

    2011-08-01

    Heparin is one of the most frequently used anticoagulants. It is easy to use, but can be associated with life-threatening side effects. One of these is heparin-induced thrombocytopenia syndrome (HITS), which develops in about 3-5% of patients exposed to heparin and is associated with thrombosis in 1% of cases. We report here the successful treatment of five patients with HITS who were treated with alternative anticoagulants namely danaparoid or hirudin. The median time between their exposure to heparin and onset of symptoms and or signs was 10.2 days (range 7-14 days). Platelet counts decreased to a mean of 38.4 x 10(9) \\/l (12-82 x 10(9)\\/l). All five patients had evidence of thrombosis; four patients had clinical and radiological evidence of pulmonary emboli, one patient had confirmed deep vein thrombosis (DVT) and one patient had extensive skin necrosis of the thighs and abdomen. Platelet aggregation test were positive in two patients, inconclusive in one patient and negative in two patients. Two patients were anticoagulated with danaparoid and three with hirudin until their platelet counts returned to normal between 4 and 14 days (average 6 days) following the recognition of the syndrome. Our patients had significant morbidity, but no mortality. Immediate withdrawal of heparin is of paramount importance and introduction of alternative anticoagulant is necessary in the presence of thrombosis.

  3. Oscillatory mechanisms of process binding in memory.

    Science.gov (United States)

    Klimesch, Wolfgang; Freunberger, Roman; Sauseng, Paul

    2010-06-01

    A central topic in cognitive neuroscience is the question, which processes underlie large scale communication within and between different neural networks. The basic assumption is that oscillatory phase synchronization plays an important role for process binding--the transient linking of different cognitive processes--which may be considered a special type of large scale communication. We investigate this question for memory processes on the basis of different types of oscillatory synchronization mechanisms. The reviewed findings suggest that theta and alpha phase coupling (and phase reorganization) reflect control processes in two large memory systems, a working memory and a complex knowledge system that comprises semantic long-term memory. It is suggested that alpha phase synchronization may be interpreted in terms of processes that coordinate top-down control (a process guided by expectancy to focus on relevant search areas) and access to memory traces (a process leading to the activation of a memory trace). An analogous interpretation is suggested for theta oscillations and the controlled access to episodic memories. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  4. Mechanisms of Membrane Binding of Small GTPase K-Ras4B Farnesylated Hypervariable Region*

    Science.gov (United States)

    Jang, Hyunbum; Abraham, Sherwin J.; Chavan, Tanmay S.; Hitchinson, Ben; Khavrutskii, Lyuba; Tarasova, Nadya I.; Nussinov, Ruth; Gaponenko, Vadim

    2015-01-01

    K-Ras4B belongs to a family of small GTPases that regulates cell growth, differentiation and survival. K-ras is frequently mutated in cancer. K-Ras4B association with the plasma membrane through its farnesylated and positively charged C-terminal hypervariable region (HVR) is critical to its oncogenic function. However, the structural mechanisms of membrane association are not fully understood. Here, using confocal microscopy, surface plasmon resonance, and molecular dynamics simulations, we observed that K-Ras4B can be distributed in rigid and loosely packed membrane domains. Its membrane binding domain interaction with phospholipids is driven by membrane fluidity. The farnesyl group spontaneously inserts into the disordered lipid microdomains, whereas the rigid microdomains restrict the farnesyl group penetration. We speculate that the resulting farnesyl protrusion toward the cell interior allows oligomerization of the K-Ras4B membrane binding domain in rigid microdomains. Unlike other Ras isoforms, K-Ras4B HVR contains a single farnesyl modification and positively charged polylysine sequence. The high positive charge not only modulates specific HVR binding to anionic phospholipids but farnesyl membrane orientation. Phosphorylation of Ser-181 prohibits spontaneous farnesyl membrane insertion. The mechanism illuminates the roles of HVR modifications in K-Ras4B targeting microdomains of the plasma membrane and suggests an additional function for HVR in regulation of Ras signaling. PMID:25713064

  5. Dosagem da heparina em cirurgia cardíaca com circulação extracorpórea Measurement of heparin in cardiac surgery wilh extracorporea circulation

    Directory of Open Access Journals (Sweden)

    Fernando Moraes

    1996-09-01

    Full Text Available Com o objetivo de quantificar o nível sérico de heparina, sua atenuação em função do tempo e o valor residual após a neutralização com sulfato de protamina, foram coletadas amostras de sangue em tempos pré-estabelecidos em 27 pacientes submetidos a revascularização do miocárdio com circulação extracorpórea. Após a heparinização (400 Ul/kg as amostras de sangue foram coletadas nos tempos de 5, 10,30 e 60 minutos e subseqüentemente a cada 30 minutos, dependendo do tempo da circulação extracorpórea. A cada hora, após a heparinização, administrava-se nova dose de heparina (200 Ul/kg. As amostras eram armazenadas à temperatura de 4ºC antes do processo de extração da heparina que foi realizado por métodos físico-químicos. As dosagens mostraram que 5 minutos após a heparinização os pacientes apresentaram concentração sangüínea máxima de heparina e, ao tempo de 60 minutos, a sua concentração é de aproximadamente 68% da encontrada aos 5 minutos. Ao tempo de 90 minutos, ou seja, após a reheparinização a concentração de heparina é 96% da evidenciada aos cinco minutos e, após a neutralização com sulfato de protamina (1,5:1, ainda se encontra um valor residual de heparina que corresponde a 4% do observado inicialmente. Observou-se que os pacientes mais idosos têm uma tendência a manter um nível sérico mais prolongado e através da equação (Cone. de heparina = 104,7 + (- 12,85 x minutos (In + 0,25 x idade podemos estimar a concentração de heparina em determinado tempo.In order to quantify seric levels of heparin, its attenuation as a time function and its residual value after neutralization with protamine sulfate, blood samples were collected, at pre-set intervals, from 27 patients undergoing myocardial revascularization surgery under extracorporeal circulation. After heparinization (400 Ul/Kg, blood samples were collected at 5, 10, 30 and 60 minutes and subsequently every 30 minutes depending upon

  6. Extrapulmonary colony formation after intravenous injection of tumour cells into heparin treated animals

    NARCIS (Netherlands)

    Maat, B.

    1978-01-01

    Recent data on extrapulmonary colony formation after heparin administration are inconclusive. A systemic study of this topic was undertaken with 4 experimental tumour systems and 2 distinct periods of reduced clotting capacity in rats and mice. I.v. injection of various numbers of tumour cells into

  7. Heparin free coating on PLA membranes for enhanced hemocompatibility via iCVD

    Science.gov (United States)

    Wang, Hui; Shi, Xiao; Gao, Ailin; Lin, Haibo; Chen, Yongliang; Ye, Yumin; He, Jidong; Liu, Fu; Deng, Gang

    2018-03-01

    In the present work, we report one-step immobilization of nano-heparin coating on PLA membranes via initiated chemical vapor deposition (iCVD) for enhanced hemocompatibility. The nano-coating introduced onto the membrane surface via the crosslinking of P(MAA-EGDA) was confirmed by the FTIR, SEM and weight measurement respectively. The negative carboxyl groups could form the hydration interaction with the protein and platelets and electrostatic interaction with amide groups of thrombin by the mediation of antithrombin, which is similar but different with heparin. The P(MAA-EGDA) coated membranes showed suppressed platelet adhesion and prolonged clotting time (APTTs increased to 59 s, PTs increased to 20.4 s, TTs increased to 17.5 s, and the FIBs declined by 30 mg/dL). Moreover, the complement activation tests demonstrated the formation of C3a and C5a was inhibited. All results demonstrated that the nano-coating of P(MAA-EGDA) via iCVD significantly enhanced the hemocompatibility of PLA membranes, which is also applicable for various membranes.

  8. Comparison of Efficacy Compressive Stockings with Heparin in Prevention of Deep Vein Thrombosis in Stroke Patients

    Directory of Open Access Journals (Sweden)

    Nastaran Majdi-Nasab

    2013-04-01

    Full Text Available Background: The present study is carried out to make a comparison between two pharmacological (heparin and physical (compression stockings in the prevention of deep vein thrombosis in lower limb of the patients suffered from acute stroke. Materials and Methods: In this investigation as a clinical trial, the effectiveness of the above methods on 100 patients with the stroke was compared in two groups of 50 persons. Results: Three patients in physical group and two patients in pharmacological group got deep vein thrombosis that showed no significant difference between two groups.Conclusion: In spite of no significant relationship and due to less incurrence of thrombosis in heparin group, it is more reasonable to use pharmacological methods.

  9. [Obstetrical APS: Is there a place for additional treatment to aspirin-heparin combination?

    Science.gov (United States)

    Mekinian, A; Kayem, G; Cohen, J; Carbillon, L; Abisror, N; Josselin-Mahr, L; Bornes, M; Fain, O

    2017-01-01

    Obstetrical APS is defined by thrombosis and/or obstetrical morbidity associated with persistent antiphospholipid antibodies. The aspirin and low molecular weighted heparin combination dramatically improved obstetrical outcome in APS patients. Several factors could be associated with obstetrical prognosis, as previous history of thrombosis, associated SLE, the presence of lupus anticoagulant and triple positivity of antiphospholipid antibodies. Obstetrical APS with isolated recurrent miscarriages is mostly associated with isolated anticardiolipids antibodies and have better obstetrical outcome. The pregnancy loss despite aspirin and heparin combination define the refractory obstetrical APS, and the prevalence could be estimated to 20-39%. Several other treatments have been used in small and open labeled studies, as steroids, intravenous immunoglobulins, plasma exchanges and hydroxychloroquine to improve the obstetrical outcome. Some other drugs as eculizumab and statins could also have physiopathological rational, but studies are necessary to define the place of these various drugs. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Mechanism of selective VEGF-A binding by neuropilin-1 reveals a basis for specific ligand inhibition.

    Directory of Open Access Journals (Sweden)

    Matthew W Parker

    Full Text Available Neuropilin (Nrp receptors function as essential cell surface receptors for the Vascular Endothelial Growth Factor (VEGF family of proangiogenic cytokines and the semaphorin 3 (Sema3 family of axon guidance molecules. There are two Nrp homologues, Nrp1 and Nrp2, which bind to both overlapping and distinct members of the VEGF and Sema3 family of molecules. Nrp1 specifically binds the VEGF-A(164/5 isoform, which is essential for developmental angiogenesis. We demonstrate that VEGF-A specific binding is governed by Nrp1 residues in the b1 coagulation factor domain surrounding the invariant Nrp C-terminal arginine binding pocket. Further, we show that Sema3F does not display the Nrp-specific binding to the b1 domain seen with VEGF-A. Engineered soluble Nrp receptor fragments that selectively sequester ligands from the active signaling complex are an attractive modality for selectively blocking the angiogenic and chemorepulsive functions of Nrp ligands. Utilizing the information on Nrp ligand binding specificity, we demonstrate Nrp constructs that specifically sequester Sema3 in the presence of VEGF-A. This establishes that unique mechanisms are used by Nrp receptors to mediate specific ligand binding and that these differences can be exploited to engineer soluble Nrp receptors with specificity for Sema3.

  11. Quantitative ligand and receptor binding studies reveal the mechanism of interleukin-36 (IL-36) pathway activation.

    Science.gov (United States)

    Zhou, Li; Todorovic, Viktor; Kakavas, Steve; Sielaff, Bernhard; Medina, Limary; Wang, Leyu; Sadhukhan, Ramkrishna; Stockmann, Henning; Richardson, Paul L; DiGiammarino, Enrico; Sun, Chaohong; Scott, Victoria

    2018-01-12

    IL-36 cytokines signal through the IL-36 receptor (IL-36R) and a shared subunit, IL-1RAcP (IL-1 receptor accessory protein). The activation mechanism for the IL-36 pathway is proposed to be similar to that of IL-1 in that an IL-36R agonist (IL-36α, IL-36β, or IL-36γ) forms a binary complex with IL-36R, which then recruits IL-1RAcP. Recent studies have shown that IL-36R interacts with IL-1RAcP even in the absence of an agonist. To elucidate the IL-36 activation mechanism, we considered all possible binding events for IL-36 ligands/receptors and examined these events in direct binding assays. Our results indicated that the agonists bind the IL-36R extracellular domain with micromolar affinity but do not detectably bind IL-1RAcP. Using surface plasmon resonance (SPR), we found that IL-1RAcP also does not bind IL-36R when no agonist is present. In the presence of IL-36α, however, IL-1RAcP bound IL-36R strongly. These results suggested that the main pathway to the IL-36R·IL-36α·IL-1RAcP ternary complex is through the IL-36R·IL-36α binary complex, which recruits IL-1RAcP. We could not measure the binding affinity of IL-36R to IL-1RAcP directly, so we engineered a fragment crystallizable-linked construct to induce IL-36R·IL-1RAcP heterodimerization and predicted the binding affinity during a complete thermodynamic cycle to be 74 μm The SPR analysis also indicated that the IL-36R antagonist IL-36Ra binds IL-36R with higher affinity and a much slower off rate than the IL-36R agonists, shedding light on IL-36 pathway inhibition. Our results reveal the landscape of IL-36 ligand and receptor interactions, improving our understanding of IL-36 pathway activation and inhibition. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Importance of lipopolysaccharide aggregate disruption for the anti-endotoxic effects of heparin cofactor II peptides.

    Science.gov (United States)

    Singh, Shalini; Papareddy, Praveen; Kalle, Martina; Schmidtchen, Artur; Malmsten, Martin

    2013-11-01

    Lipid membrane and lipopolysaccharide (LPS) interactions were investigated for a series of amphiphilic and cationic peptides derived from human heparin cofactor II (HCII), using dual polarization interferometry, ellipsometry, circular dichroism (CD), cryoTEM, and z-potential measurements. Antimicrobial effects of these peptides were compared to their ability to disorder bacterial lipid membranes, while their capacity to block endotoxic effects of LPS was correlated to the binding of these peptides to LPS and its lipid A moiety, and to charge, secondary structure, and morphology of peptide/LPS complexes. While the peptide KYE28 (KYEITTIHNLFRKLTHRLFRRNFGYTLR) displayed potent antimicrobial and anti-endotoxic effects, its truncated variants KYE21 (KYEITTIHNLFRKLTHRLFRR) and NLF20 (NLFRKLTHRLFRRNFGYTLR) provide some clues on structure-activity relations, since KYE21 retains both the antimicrobial and anti-endotoxic effects of KYE28 (although both attenuated), while NLF20 retains the antimicrobial but only a fraction of the anti-endotoxic effect, hence locating the anti-endotoxic effects of KYE28 to its N-terminus. The antimicrobial effect, on the other hand, is primarily located at the C-terminus of KYE28. While displaying quite different endotoxic effects, these peptides bind to a similar extent to both LPS and lipid A, and also induce comparable LPS scavenging on model eukaryotic membranes. In contrast, fragmentation and densification of LPS aggregates, in turn dependent on the secondary structure in the peptide/LPS aggregates, correlate to the anti-endotoxic effect of these peptides, thus identifying peptide-induced packing transitions in LPS aggregates as key for anti-endotoxic functionality. This aspect therefore needs to be taken into account in the development of novel anti-endotoxic peptide therapeutics. Copyright © 2013. Published by Elsevier B.V.

  13. Structure and mechanism of calmodulin binding to a signaling sphingolipid reveal new aspects of lipid-protein interactions

    Science.gov (United States)

    Kovacs, Erika; Harmat, Veronika; Tóth, Judit; Vértessy, Beáta G.; Módos, Károly; Kardos, József; Liliom, Károly

    2010-01-01

    Lipid-protein interactions are rarely characterized at a structural molecular level due to technical difficulties; however, the biological significance of understanding the mechanism of these interactions is outstanding. In this report, we provide mechanistic insight into the inhibitory complex formation of the lipid mediator sphingosylphosphorylcholine with calmodulin, the most central and ubiquitous regulator protein in calcium signaling. We applied crystallographic, thermodynamic, kinetic, and spectroscopic approaches using purified bovine calmodulin and bovine cerebral microsomal fraction to arrive at our conclusions. Here we present 1) a 1.6-Å resolution crystal structure of their complex, in which the sphingolipid occupies the conventional hydrophobic binding site on calmodulin; 2) a peculiar stoichiometry-dependent binding process: at low or high protein-to-lipid ratio calmodulin binds lipid micelles or a few lipid molecules in a compact globular conformation, respectively, and 3) evidence that the sphingolipid displaces calmodulin from its targets on cerebral microsomes. We have ascertained the specificity of the interaction using structurally related lipids as controls. Our observations reveal the structural basis of selective calmodulin inhibition by the sphingolipid. On the basis of the crystallographic and biophysical characterization of the calmodulin–sphingosylphosphorylcholine interaction, we propose a novel lipid-protein binding model, which might be applicable to other interactions as well.—Kovacs, E., Harmat, V., Tóth, J., Vértessy, B. G., Módos, K., Kardos, J., Liliom, K. Structure and mechanism of calmodulin binding to a signaling sphingolipid reveal new aspects of lipid-protein interactions. PMID:20522785

  14. Gene expression of cyclin-dependent kinase inhibitors and effect of heparin on their expression in mice with hypoxia-induced pulmonary hypertension

    International Nuclear Information System (INIS)

    Yu Lunyin; Quinn, Deborah A.; Garg, Hari G.; Hales, Charles A.

    2006-01-01

    The balance between cell proliferation and cell quiescence is regulated delicately by a variety of mediators, in which cyclin-dependent kinases (CDK) and CDK inhibitors (CDKI) play a very important role. Heparin which inhibits pulmonary artery smooth muscle cell (PASMC) proliferation increases the levels of two CDKIs, p21 and p27, although only p27 is important in inhibition of PASMC growth in vitro and in vivo. In the present study we investigated the expression profile of all the cell cycle regulating genes, including all seven CDKIs (p21, p27, p57, p15, p16, p18, and p19), in the lungs of mice with hypoxia-induced pulmonary hypertension. A cell cycle pathway specific gene microarray was used to profile the 96 genes involved in cell cycle regulation. We also observed the effect of heparin on gene expression. We found that (a) hypoxic exposure for two weeks significantly inhibited p27 expression and stimulated p18 activity, showing a 98% decrease in p27 and 81% increase in p18; (b) other CDKIs, p21, p57, p15, p16, and p19 were not affected significantly in response to hypoxia; (c) heparin treatment restored p27 expression, but did not influence p18; (d) ERK1/2 and p38 were mediators in heparin upregulation of p27. This study provides an expression profile of cell cycle regulating genes under hypoxia in mice with hypoxia-induced pulmonary hypertension and strengthens the previous finding that p27 is the only CDKI involved in heparin regulation of PASMC proliferation and hypoxia-induced pulmonary hypertension

  15. Silver nanoparticles-loaded activated carbon fibers using chitosan as binding agent: Preparation, mechanism, and their antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chengli, E-mail: tcl-lily@mail.zjxu.edu.cn [College of Mechanical and Electrical Engineering, Jiaxing University, Jiaxing 314001 (China); Hu, Dongmei [College of Mechanical Science and Engineering, Jilin University, Changchun 130022 (China); Cao, Qianqian [College of Mechanical and Electrical Engineering, Jiaxing University, Jiaxing 314001 (China); Yan, Wei [Department of Environmental Science and Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Xing, Bo [College of Mechanical and Electrical Engineering, Jiaxing University, Jiaxing 314001 (China)

    2017-02-01

    Highlights: • Chitosan was firstly introduced as binding agent for AgNPs loading on ACF surface. • Molecular dynamics simulation was used to explore the AgNPs loading mechanism. • Loading mechanism was proposed based on the experimental and simulation results. • Antibacterial AgNPs-loaded ACF showed use potential for water disinfection. - Abstract: The effective and strong adherence of silver nanoparticles (AgNPs) to the substrate surface is pivotal to the practical application of those AgNPs-modified materials. In this work, AgNPs were synthesized through a green and facile hydrothermal method. Chitosan was introduced as the binding agent for the effective loading of AgNPs on activated carbon fibers (ACF) surface to fabricate the antibacterial material. Apart from conventional instrumental characterizations, i. e., scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), zeta potential and Brunauer-Emmett-Teller (BET) surface area measurement, molecular dynamics simulation method was also applied to explore the loading mechanism of AgNPs on the ACF surface. The AgNPs-loaded ACF material showed outstanding antibacterial activity for S. aureus and E. coli. The combination of experimental and theoretical calculation results proved chitosan to be a promising binding agent for the fabrication of AgNPs-loaded ACF material with excellent antibacterial activity.

  16. Low molecular weight heparins in the prevention of deep-vein thrombosis in general surgery.

    Science.gov (United States)

    Breddin, H K

    1999-01-01

    Unfractionated heparin (UFH) was the established treatment in the early 1980s for the prophylaxis of venous thromboembolic disease (VTED) in patients undergoing general surgery. This was one of the earliest indications in which low molecular weight heparins (LMWHs) were tested, and about 40 trials have revealed that these agents are at least as effective and safe as UFH with a tendency of superiority when higher dosages are used. In most trials, the fibrinogen uptake test has been used to assess the frequency of deep vein thrombosis. LMWHs exhibit a number of improved features over UFH, including ease of administration and convenient once daily dosing, facilitating outpatient management. A still open question is the ideal time and dose of the first one or two injections of a LMWH. To determine the clinical relevance of product differentiation further, clinical trials, directly comparing different LMWHs, are required.

  17. Insight into the binding mechanism of imipenem to human serum albumin by spectroscopic and computational approaches.

    Science.gov (United States)

    Rehman, Md Tabish; Shamsi, Hira; Khan, Asad U

    2014-06-02

    The mechanism of interaction between imipenem and HSA was investigated by various techniques like fluorescence, UV.vis absorbance, FRET, circular dichroism, urea denaturation, enzyme kinetics, ITC, and molecular docking. We found that imipenem binds to HSA at a high affinity site located in subdomain IIIA (Sudlow's site I) and a low affinity site located in subdomain IIA.IIB. Electrostatic interactions played a vital role along with hydrogen bonding and hydrophobic interactions in stabilizing the imipenem.HSA complex at subdomain IIIA, while only electrostatic and hydrophobic interactions were present at subdomain IIA.IIB. The binding and thermodynamic parameters obtained by ITC showed that the binding of imipenem to HSA was a spontaneous process (ΔGD⁰(D)= -32.31 kJ mol(-1) for high affinity site and ΔGD⁰(D) = -23.02 kJ mol(-1) for low affinity site) with binding constants in the range of 10(4)-10(5) M(-1). Spectroscopic investigation revealed only one binding site of imipenem on HSA (Ka∼10(4) M(-1)). FRET analysis showed that the binding distance between imipenem and HSA (Trp-214) was optimal (r = 4.32 nm) for quenching to occur. Decrease in esterase-like activity of HSA in the presence of imipenem showed that Arg-410 and Tyr-411 of subdomain IIIA (Sudlow's site II) were directly involved in the binding process. CD spectral analysis showed altered conformation of HSA upon imipenem binding. Moreover, the binding of imipenem to subdomain IIIA (Sudlow's site II) of HSA also affected its folding pathway as clear from urea-induced denaturation studies.

  18. Recommendations for the anticoagulation of pregnant patients with mechanical heart valves

    NARCIS (Netherlands)

    Schapkaitz, Elise; Jacobson, Barry Frank; Manga, Pravin; Chitsike, Rufaro Saeed; Benade, Estee; Haas, Sylvia; Buller, Harry R.

    2015-01-01

    The management of pregnant patients with mechanical heart valves remains challenging because there are no large randomised studies to provide guidelines for effective anticoagulant therapy. Both vitamin K antagonists and heparins may be associated with maternal and foetal adverse events. The

  19. Mechanisms of membrane binding of small GTPase K-Ras4B farnesylated hypervariable region.

    Science.gov (United States)

    Jang, Hyunbum; Abraham, Sherwin J; Chavan, Tanmay S; Hitchinson, Ben; Khavrutskii, Lyuba; Tarasova, Nadya I; Nussinov, Ruth; Gaponenko, Vadim

    2015-04-10

    K-Ras4B belongs to a family of small GTPases that regulates cell growth, differentiation and survival. K-ras is frequently mutated in cancer. K-Ras4B association with the plasma membrane through its farnesylated and positively charged C-terminal hypervariable region (HVR) is critical to its oncogenic function. However, the structural mechanisms of membrane association are not fully understood. Here, using confocal microscopy, surface plasmon resonance, and molecular dynamics simulations, we observed that K-Ras4B can be distributed in rigid and loosely packed membrane domains. Its membrane binding domain interaction with phospholipids is driven by membrane fluidity. The farnesyl group spontaneously inserts into the disordered lipid microdomains, whereas the rigid microdomains restrict the farnesyl group penetration. We speculate that the resulting farnesyl protrusion toward the cell interior allows oligomerization of the K-Ras4B membrane binding domain in rigid microdomains. Unlike other Ras isoforms, K-Ras4B HVR contains a single farnesyl modification and positively charged polylysine sequence. The high positive charge not only modulates specific HVR binding to anionic phospholipids but farnesyl membrane orientation. Phosphorylation of Ser-181 prohibits spontaneous farnesyl membrane insertion. The mechanism illuminates the roles of HVR modifications in K-Ras4B targeting microdomains of the plasma membrane and suggests an additional function for HVR in regulation of Ras signaling. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Mechanism of action and efficacy of RX-111, a thieno[2,3-c]pyridine derivative and small molecule inhibitor of protein interaction with glycosaminoglycans (SMIGs), in delayed-type hypersensitivity, TNBS-induced colitis and experimental autoimmune encephalomyelitis

    Czech Academy of Sciences Publication Activity Database

    Harris, N.; Koppel, J.; Zsila, F.; Juhás, Štefan; Ilková, G.; Kogan, F. Y.; Lahmy, O.; Wildbaum, G.; Karin, N.; Zhuk, R.; Gregor, P.

    2016-01-01

    Roč. 65, č. 4 (2016), s. 285-294 ISSN 1023-3830 Institutional support: RVO:67985904 Keywords : small molecule drug * glycosaminoglycan * heparin binding protein * heparan sulfate * inflammation * autoimmune disease Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.659, year: 2016