Search results for "Heparin"

A novel in vivo inducible dendritic cell ablation model in mice

2010

Abstract Dendritic cells (DCs) are involved in T cell activation via their uptake and presentation of antigens. In vivo function of DCs was analyzed using transgenic mouse models that express diphtheria toxin receptor (DTR) or the diphtheria toxin-A subunit (DTA) under the control of the CD11c/Itgax promoter. However, CD11c+ cells are heterogeneous populations that contain several DC subsets. Thus, the in vivo function of each subset of DCs remains to be elucidated. Here, we describe a new inducible DC ablation model, in which DTR expression is induced under the CD11c/Itgax promoter after Cre-mediated excision of a stop cassette (CD11c-iDTR). Crossing of CD11c-iDTR mice with CAG-Cre transge…

Role of the Netrin-like Domain of Procollagen C-Proteinase Enhancer-1 in the Control of Metalloproteinase Activity

2010

The netrin-like (NTR) domain is a feature of several extracellular proteins, most notably the N-terminal domain of tissue inhibitors of metalloproteinases (TIMPs), where it functions as a strong inhibitor of matrix metalloproteinases and some other members of the metzincin superfamily. The presence of a C-terminal NTR domain in procollagen C-proteinase enhancers (PCPEs), proteins that stimulate the activity of astacin-like tolloid proteinases, raises the possibility that this might also have inhibitory activity. Here we show that both long and short forms of the PCPE-1 NTR domain, the latter beginning at the N-terminal cysteine known to be critical for TIMP activity, show no inhibition, at …

Pr�vention thromboembolischer Komplikationen in der Unfallchirurgie durch Dosisanpassung von niedermolekularem Heparin anhand TAT- und D-Dimer-Werten

2003

Bei unfallchirurgischen Patienten tritt in bis zu 40% eine tiefe Beinvenenthrombose auf. Das individuelle Risiko kann kaum kalkuliert werden. 518 unfallchirurgische Patienten mit Prophylaxe durch eine tagliche Einzeldosis eines niedermolekularen Heparins (NMH) wurden praoperativ und bis zu 10 Tage postoperativ in einer prospektiven Untersuchung beobachtet. Sie wurden in 2 Gruppen unterteilt: Gruppe I mit Huft- und Oberschenkeloperationen sowie Kniegelenkprothesen und Gruppe II mit Knie- und Unterschenkeloperationen. Bestimmt wurden Thrombin-Antithrombin-Komplex und D-Dimer. Eine 2. Dosis NMH wurde bei Uberschreiten des D-Dimer-Cut-off-Wertes verabreicht. Bei sonographischem Verdacht auf ein…

Ileus following spontaneous jejunum intramural hematoma: case report and review of the literature.

2013

Anticoagulant therapy may cause the onset of a spontaneous intramural hema- toma of the small bowel, in the jejunum, ileum or duodenum. A 53-year-old woman on therapy with heparin for previous pulmonary embolism was admitted for abdominal pain and vomit. Computed tomography scan visualized an intramural hematoma of the jejunum causing subtotal obstruction of the intestinal lumen. The patient underwent resection of a part of the jejunum, securing intestinal continuity by a mechanical side-to-side anastomosis. The postoperative course was regular, but the initial anticoagulant therapy was reduced to prevent recurrence. In conclusion, spontaneous hema- toma of small bowel can occur as a compli…

Prothrombinase-Induced Clotting Time Assay for Determination of the Anticoagulant Effects of Unfractionated and Low-Molecular-Weight Heparins, Fondap…

2008

The prothrombinase-induced clotting time assay (PiCT, Pentapharm, Basel, Switzerland) is a clotting assay sensitive to factor Xa and factor IIa inhibitors. It is based on the addition of factor Xa and snake venom RVV-V (Russell viper venom factor V activator) specifically activating factor V and phospholipids to platelet-poor plasma. Following an incubation time, the mixture is recalcified and the clotting time is determined. An almost linear dose-response and high sensitivity of the assay for unfractionated heparin (UFH), low-molecular-weight heparins (LMWHs), r-hirudin, and argatroban was found. Fondaparinux showed a nonlinear dose-response. By using ex vivo samples, the following Pearson…

Characterisation of disaccharide fragments from the enzymatic digestion of heparin by liquid secondary ion mass spectrometry

1988

Disaccharide fragments resulting from the enzymatic digestion of heparins with heparinase have been purified by gel filtration chromatography and directly analyzed by positive and negative ion liquid secondary ion mass spectrometry (LSIMS). Following the chromatographic purification from excess sodium salt, the mass spectra of di- and tetrasaccharide fragment mixtures enabled the identification of up to three covalently bound sulfate moieties per glycosaminoglycan-disaccharide unit, by means of their molecular ions, containing the corresponding alkali-counterions.

Human histidine-rich glycoprotein expressed in SF9 insect cells inhibits apatite formation

1997

Histidine-rich glycoprotein (HRG) is structurally related to the alpha2-HS glycoprotein/fetuin family of mammalian plasma proteins; both belong to the cystatin superfamily of proteins. We expressed recombinant human HRG and alpha2-HS in Sf9 insect cells for functional analysis. Recombinant HRG bound heparin and fibrinogen while alpha2-HS did not. Both proteins inhibited the formation of apatite, recombinant HRG (IC50 approximately 1 microM) with 2-fold lower molar activity than alpha2-HS (IC50 approximately 0.5 microM). The inhibition in vitro of apatite formation suggests a new function for plasma HRG protein, inhibition of phase separation in blood vessels.

Hyaluronic acid, elastin and heparin containing scaffolds for the treatment of skin chronic wounds

2014

Inhibition of Transfer to Secondary Receptors by Heparan Sulfate-Binding Drug or Antibody Induces Noninfectious Uptake of Human Papillomavirus

2007

ABSTRACT Infection with various human papillomaviruses (HPVs) induces cervical cancers. Cell surface heparan sulfates (HS) have been shown to serve as primary attachment receptors, and molecules with structural similarity to cell surface HS, like heparin, function as competitive inhibitors of HPV infection. Here we demonstrate that the N , N ′-bisheteryl derivative of dispirotripiperazine, DSTP27, efficiently blocks papillomavirus infection by binding to HS moieties, with 50% inhibitory doses of up to 0.4 μg/ml. In contrast to short-term inhibitory effects of heparin, pretreatment of cells with DSTP27 significantly reduced HPV infection for more than 30 h. Using DSTP27 and heparinase, we fu…

Human papillomavirus infection requires cell surface heparan sulfate.

2001

ABSTRACT Using pseudoinfection of cell lines, we demonstrate that cell surface heparan sulfate is required for infection by human papillomavirus type 16 (HPV-16) and HPV-33 pseudovirions. Pseudoinfection was inhibited by heparin but not dermatan or chondroitin sulfate, reduced by reducing the level of surface sulfation, and abolished by heparinase treatment. Carboxy-terminally deleted HPV-33 virus-like particles still bound efficiently to heparin. The kinetics of postattachment neutralization by antiserum or heparin indicated that pseudovirions were shifted on the cell surface from a heparin-sensitive into a heparin-resistant mode of binding, possibly involving a secondary receptor. Alpha-6…