ABSTRACT Recent studies have shown that platelets can adhere to adsorbed albumin (Alb) through a receptor-mediated mechanism, but only if the Alb undergoes more than a critical degree of adsorption-induced unfolding. The objectives of this research were to investigate whether Alb that was initially adsorbed in a manner that induced ...

Aneurysmal subarachnoid hemorrhage (SAH) is associated with numerous "delayed neurological deficits" (DNDs) that have been attributed to multiple pathophysiological mechanisms, including ischemia, microthrombosis, free radical damage, inflammation, and vascular remodeling. To date, effective prophylactic therapy for SAH-induced DNDs has been elusive, due perhaps to the multiplicity of mechanisms involved that ...

Low-molecular-weight heparins (LMWHs) and fondaparinux are antithrombin dependent anticoagulant drugs considered to need no laboratory monitoring because of their reputedly predictable anticoagulant effect. However it has been suggested in the literature the existence of an inter-individual variability in response to LMWHs that would be not fully attributable to pharmacokinetics causes. ...

Unfractionated heparin (UFH) is the anticoagulant of choice for most maintenance hemodialysis units in the United States. Low molecular weight heparin (LMWH) is the norm in Western Europe, but is not approved for this indication in the United States. UFH is likely to remain the agent of choice in the ...

The murine 10-residue neurohormone kisspeptin (YNWNSFGLRY) is an important regulator of reproductive behavior and gonadotrophin secretion. It is known to form a random coil in solution, but undergoes a structural change in the presence of membranes although the nature of this change is not fully determined. The peptide's conformational versatility ...

Coimmobilization as a versatile biomodification technique has been widely used in the development of biomimetic materials with superior mechanical and biological properties. In this study, a mixture of heparin and fibronectin (Hep/Fn) was tested for its hemocompatibility after either physisorption or covalent coimmobilization to a titanium (Ti) substrate. The process ...

Ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia (PTCP) is the phenomenon of a spurious low platelet count due to antiplatelet antibodies that cause platelet clumping in blood anticoagulated with EDTA. The aggregation of platelets in EDTA-dependent PTCP is usually prevented by other anticoagulants, such as sodium citrate or heparin. EDTA-dependent PTCP has never ...

The coagulation cascade is complex but well studied. Dialysis membranes and lines are inherently pro-coagulant and activate both the intrinsic and extrinsic pathways of coagulation, as well as platelets and other circulating cellular elements. To provide safe and effective dialysis, appropriate anticoagulant measures must be applied. Haemodialysis, including anticoagulation, is ...

A mannogalactan from Pleurotus ostreatoroseus (MgPr) was chemically sulfated to give MgPr-S1, which was evaluated for its anticoagulant and antithrombotic activities, bleeding tendency, and platelet aggregation. MgPr-S1 was partially characterized by HPSEC-MALLS, methylation analysis, and 13C NMR spectroscopy. Its anticoagulant activity was determined by assays of aPTT, TT, alpha-thrombin and ...

Algal fucoidans possess a wide variety of biological activities, including anticoagulation and antithrombosis, making them potential candidates for clinical use. We assessed the antiaggregant, anticoagulant and antithrombotic activities and the underlying mechanism of the low- and high-molecular weight fucoidans from the seaweed Laminaria japonica of Qingdao, China (F-Q and HMWF-Q). ...

While heparin has been used almost exclusively as a blood anticoagulant, important literature demonstrates that it also has broad anti-inflammatory activity. Herein, using low anti-coagulant 2-O,3-O-desulfated heparin (ODSH), we demonstrate that most of the anti-inflammatory pharmacology of heparin is unrelated to anticoagulant activity. ODSH has low affinity for anti-thrombin III, ...

Heparin induced thrombocytopenia (HIT) is a significant, potentially life-threatening immune-mediated adverse event that occurs several days after commencement of therapy with unfractionated or low-molecular weight heparin. We present a 51-year-old female treated with unfractionated heparin for acute deep venous thrombosis (DVT) and pulmonary embolism (PE). She developed extension of her ...

BACKGROUND: To date, no study has tested the effect of different heparin dosages on the hemostatic changes during off-pump coronary artery bypass graft (OPCABG) surgery, and a wide variety of empirical anticoagulation protocols are being applied. We tested the effect of two different heparin dosages on the activation of the ...

A 56-year-old man developed mid-gut bowel ischaemia following an elective aortobiprofunda bypass for short-distance claudication. The bowel was resected and he was commenced on lifelong total parenteral nutrition. He was found to have developed heparin-induced thrombocytopenia and thrombosis, confirmed by high levels of heparin-platelet factor 4-antibody on enzyme-linked immunosorbent assay ...

Heparin and its improved version, low-molecular weight heparin (LMWH), are known to exert polypharmacological effects at various levels. Early studies focused on the plasma anti-Xa and anti-IIa pharmacodynamics of different LMWHs. Other important pharmacodynamic parameters for heparin and LMWH, including effects on vascular tissue factor pathway inhibitor (TFPI) release, inhibition ...

Glycosaminoglycans (GAGs), in particular as part of heparan sulfate proteoglycans, are associated with cerebral amyloid angiopathy (CAA). Similarly, GAGs are also associated with the severe CAA found in patients suffering from hereditary cerebral hemorrhage with amyloidosis of the Dutch type (HCHWA-D), where the amyloid beta (Abeta) peptide contains the Dutch ...

Mucopolysaccharide polysulfate (MPS) represents a mammalian-derived sulfated polysaccharide. Because the origin and structure of heparins is similar to MPS, this study was conducted to compare 2 ointment formulations containing MPS or heparin with a placebo ointment on tissue factor pathway inhibitor (TFPI) released in nonhuman primates (Macaca mulatta). A primate ...

Heparin may induce platelet activation and even heparin-induced thrombocytopenia. Lepirudin has been approved for HIT treatment. We speculated that lepirudin inhibits platelet function under high shear and the platelet thrombin receptor PAR-1 better than heparin. Thrombin-inducible platelet adherence under high shear conditions and the expression of PAR-1 were studied after ...

We report on a patient with coagulation abnormalities induced by a wasp sting anaphylaxis. First, we observed an unclottable activated partial thromboplastin time and a significant anti-Xa activity (equivalent to a therapeutic heparin range), whereas the patient had received no heparin. This phenomenon is probably due to activated mast cells ...

An assay for fondaparinux (Arixtra) is described based on a modified commercial assay for heparin. The assay is automated on a Dade Behring BCS XP (Siemens Healthcare Diagnostics, Deerfield, IL) and uses the inhibition of activated factor X to quantitate the drug. The assay was unaffected by platelet contamination or ...

BACKGROUND: Current guidelines state that platelet aggregation studies should be conducted within 4 h of venepuncture because of the decline in sensitivity to platelet agonists. This constrains studies of platelet activity in clinical situations where samples need to be transported or there are unavoidable delays prior to assessment. OBJECTIVES: The ...

Unfractionated heparin (UFH) enhances antithrombin (AT) inhibition of thrombin (IIa) and factor Xa (FXa). Low molecular weight heparins (LMWH) primarily enhance AT inhibition of FXa. M118 is a LMWH produced from UFH and retains its ability to promote both FXa and IIa inhibition. We tested the hypothesis that M118 has ...

Aims We examined the specific effects of unfractionated heparin and bivalirudin on thrombin-inducible platelet PAR-1 in patients undergoing percutaneous coronary intervention (PCI). Methods and results To simulate in vivo conditions that may precipitate a bleeding event, we added thrombin in vitro to blood samples from 89 patients who had been ...

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 (enoxaparin, dalteparin, and nadroparin) by use of the Sonoclot coagulation analyzer to monitor ...

OBJECTIVES: The administration of unfractionated heparin (UFH) prior to carotid clamping during carotid endarterectomy (CEA) transiently increases the platelet aggregation response to arachidonic acid (AA) despite the use of aspirin. We hypothesized that this phenomenon might be reduced by using low molecular weight heparin (LMWH) resulting in fewer emboli in ...

Continuous renal replacement therapy (CRRT) has emerged as the preferred dialysis modality for critically ill patients with acute kidney injury, particularly those with hemodynamic instability. Anticoagulation is necessary for effective delivery of CRRT, but this requirement can also present challenges, as many critically ill patients with sepsis and inflammation already ...

During the period of November 2007 to January 2008, an increased prevalence of adverse reactions to heparin was noted. These adverse events have been attributed to the presence of purposeful contaminant, oversulfated chondroitin sulfate (OSCS) from April 2007 to May 2008. An analysis of dialysis patients' plasma obtained in 2006 ...

We have experienced 2 cases of heparin-induced thrombocytopenia during unfractionated heparin treatment for disseminated intravascular coagulation after surgery for an abdominal aortic aneurysm. In the first case, as a symptom of disseminated intravascular coagulation gradually improved with antithrombin concentrates and heparin treatment, mesenteric artery thrombosis suddenly occurred, associated with a ...

Low-molecular-weight heparins (LMWH) exert their anticoagulant effect by accelerating anti-thrombin (AT) inactivation of factor Xa (fXa) and thrombin. To address the hypothesis of a calcium-dependent template mechanism in LMWH activity, we compared the ability of the heparin neutralising agent Platelet Factor 4 (PF4) to inhibit various therapeutic LMWH in a ...

Pre- and intraoperative platelet function monitoring is increasingly recommended in order to detect risk factors for bleeding and to target coagulation management. The ideal anticoagulant for accurate platelet aggregometry remains controversial. The aim of this experimental trial was to compare platelet aggregability in whole blood stored in citrate, heparin and ...

PURPOSE: The aim of the study is the examination of effects of dipeptides containing S-hexyl-L-cysteine and glycine, on the prothrombin activation and the thrombin clotting time determined in the presence of heparin. MATERIAL AND METHODS: The activation of prothrombin was determined with the use of the thromboplastin test, the recalcification ...

Measurements of anti-FXa or anti-FIIa (thrombin) activities are conventional tests for biological monitoring of low molecular weight heparin (LMWH) or unfractionated heparin treatment. It was the aim of our study to assess the anticoagulant efficacy of the LMWHs nadroparin and enoxaparin and that of unfractionated heparin not by the above-mentioned ...

In a retrospective study among 35 severely septic patients treated with drotrecogin alfa (activated) (DrotAA) and renal replacement therapy (RRT), Camporota and colleagues demonstrated that the addition of heparin, epoprostenol, or both to DrotAA during RRT did not improve filter survival. Furthermore, in a multivariate logistic regression analysis, they identified ...

BACKGROUND: This study was designed to evaluate the effect of recombinant human thrombin (rThrombin) concentration on time to hemostasis (TTH), clot durability, and clot strength in settings that replicate the heparinization and platelet inhibition often found in surgical populations. METHODS: A modified, anticoagulated rabbit arteriovenous shunt preparation was selected to ...

Heparin-induced thrombocytopenia is a devastating, life-threatening, immune-mediated complication of therapy with unfractionated heparin, and less frequently, with low molecular weight heparin. Direct thrombin inhibitors are now standard therapy for the prevention of thrombosis in heparin-induced thrombocytopenia. Argatroban, a small synthetic molecule that inhibits thrombin at its active site, is increasingly ...

Although heparin-dependent antibodies (HDAs) typically manifest with thrombocytopenia as in heparin-induced thrombocytopenia (HIT), they may also manifest with preserved platelet counts. We describe a 35-year-old woman who developed severe thrombotic complications due to heparinization and unrecognized HDAs. She had received subcutaneous heparin as prophylaxis for deep vein thrombosis during a ...

Heparin-induced thrombocytopaenia (HIT) is an acquired, transient prothrombotic disorder caused by heparin. The predominant problem is the creation of a prothrombotic milieu, accompanied by a fall in the platelet count. This explains the apparent paradox of thrombosis in the face of thrombocytopaenia and why non-heparin antithrombotic agents are integral to ...

BACKGROUND: Treatment with Bevacizumab has been associated with arterial thromboembolism in colorectal cancer patients. However, the mechanism of this remains poorly understood, and preclinical testing in mice failed to predict thrombosis. OBJECTIVE: We investigated whether thrombosis might be the result of platelet activation mediated via the FcgammaRIIa (IgG) receptor - ...

Polysaccharides extracted from brown marine algae represent a source of marine compounds with potential applications in medicine. Heparin-like compounds, fucoidans, have been proposed as alternatives to the anticoagulant heparin, which is prepared from mucous membrane of mammals. In this study, the activity of anticoagulant in activated partial thromboplastin time (APTT) ...

OBJECTIVES: Loading of biological matrices offers an opportunity to induce specific cell behaviour. We previously reported the use of growth factors to promote cell invasion and proliferation in tissue valve engineering. We investigated biological matrices preloaded with heparin as an ionically attractive template for the binding, activation and sustained release ...

Using the layer-by-layer technique, ELISA polystyrene plates were coated with multilayer assemblies of albumin with various heparins or with multilayer assemblies of albumin. The coatings containing heparin were tested for their ability to potentiate thrombin inhibition by antithrombin and its dependence on the layer arrangement. The order of activities of ...

PURPOSE OF REVIEW: This review addresses the clinical and biological strategy to be applied for the diagnosis of heparin-induced thrombocytopenia. RECENT FINDINGS: Heparin-induced thrombocytopenia is a severe prothrombotic disease caused by immunoglobulin G antibodies, which bind to platelet factor 4 and activate platelets with subsequent increased thrombin generation. Venous and ...

Indications for heparin during pregnancy are expanding. Heparin-induced thrombocytopenia caused by heparin-platelet factor 4 antibodies (HPF4-As), however, remains a serious concern. While up to 50% of cardiovascular surgical patients develop HPF4-As while receiving heparin, the rate of seroconversion is lower in medical patients, suggesting an impact of the patient population ...

The initiation and progression of acute pancreatitis is associated with disturbances in pancreatic microcirculatory. Microcirculatory disorders contribute to multiorgan dysfunction syndrome in the course of acute pancreatitis. The aim of this study was to determine the influence of heparin administration on the development and the course of ischemia/reperfusion-induced pancreatitis. Methods: ...

BACKGROUND: Quantum dots (QDs) have numerous possible applications for in vivo imaging. However, toxicity data are scarce. OBJECTIVES: To determine the acute in vivo toxicity of QDs with carboxyl surface coating (carboxyl-QDs) and QDs with amine surface coating (amine-QDs), we investigated the inflammatory properties, tissue distribution, and prothrombotic effects after ...

BACKGROUND: Antibodies against the "self" protein, platelet factor 4 (PF4), bound to heparin-the cause of immune heparin-induced thrombocytopenia-are believed invariably to be triggered by preceding heparin therapy. We describe a novel syndrome, spontaneous heparin-induced thrombocytopenia, in which clinical and serologic features characteristic of this adverse drug reaction develop in patients ...

Heparin induced thrombocytopaenia is an increasingly recognised prothrombotic disorder, where platelet activation by immunoglobulin G, heparin and platelet factor 4 complexes has been proposed to result in the activation of coagulation, and thrombus formation. However, this pathophysiological mechanism will not explain the predilection of patients, undergoing surgical procedures, especially orthopaedic ...

In this study, heparin was covalently coupled by glutaraldehyde to Poly(vinyl alcohol) [PVA] in solid-liquid two-phase reaction system by two-step synthesis method to prepare a LDL-selective adsorbent. The parameters (the material ratio, reaction time and dosage of catalyzer) were investigated to evaluate their effect upon the immobilized amount of heparin ...

Albumin liver dialysis using the Molecular Adsorbent Recirculating System (MARS) (Teraklin AG, Rostock, Germany) is used in severe acute liver failure (ALF). We hypothesized that intradialytic heparin worsens preexisting hemostatic defects without enhancing system longevity or therapeutic efficacy. This was a retrospective, single center study of 10 critically ill patients ...

We compared the effects of the low-molecular-weight heparin (LMWH), bemiparin, and dalteparin with unfractionated heparin (UFH) on the platelet subendothelium interaction under flow conditions. All three compounds decreased the percentage of subendothelial matrix covered by platelets, although the effect of LMWH was greater than that of UFH. Subendothelial matrix covered ...