Search results for "Clotting"
showing 10 items of 30 documents
Protease‐activated receptor signaling in intestinal permeability regulation
2019
Protease-activated receptors (PARs) are a unique class of G-protein-coupled transmembrane receptors, which revolutionized the perception of proteases from degradative enzymes to context-specific signaling factors. Although PARs are traditionally known to affect several vascular responses, recent investigations have started to pinpoint the functional role of PAR signaling in the gastrointestinal (GI) tract. This organ is exposed to the highest number of proteases, either from the gut lumen or from the mucosa. Luminal proteases include the host's digestive enzymes and the proteases released by the commensal microbiota, while mucosal proteases entail extravascular clotting factors and the enzy…
Current concepts in the prevention of pathogen transmission via blood/plasma-derived products for bleeding disorders
2015
The pathogen safety of blood/plasma-derived products has historically been a subject of significant concern to the medical community, Measures such as donor selection and blood screening have contributed to increase the safety of these products, but pathogen transmission does still occur. Reasons for this include lack of sensitivity/specificity of current screening methods, lack of reliable screening tests for some pathogens (e.g. prions) and the fact that many potentially harmful infectious agents are not routinely screened for. Methods for the purification/inactivation of blood/plasma-derived products have been developed in order to further reduce the residual risk, but low concentrations…
The impact of two whole blood inline filters on markers of coagulation, complement and cell activation
2005
Background and Objectives There exists a current lack of information about the impact of different inline filters, used for the leucoreduction of whole blood (WB), on the levels of clotting factors and markers of coagulation, complement and cell activation in plasma. Only a few small comparisons of different types of WB inline filters have been published to date. Materials and Methods This study compared two plasma types of 200 units each. Both study groups were derived from WB, inline-filtered and held for 2 h at 20° between donation and filtration. Then, 200 units (Group A) were filtered using a positively charged polyester filter (Baxter RZ2000) and the other 200 units (Group B) were f…
The quality of plasma collected by automated apheresis and of recovered plasma from leukodepleted whole blood.
2005
Background There exists a current lack of information about the composition of the different types of plasma. No direct comparisons between apheresis plasma (AP) and recovered plasma (RP) derived from in-line-filtered whole blood (WB) have been published to date. Study design and methods Sixty AP units, 100 RP units from in-line-filtered WB held for 3 hours at 20 degrees C between donation and freezing, and an additional 100 RP units held for 15 hours at 20 degrees C before freezing were analyzed for coagulation factors and inhibitors, total protein, immunoglobulin G (IgG), and hemostasis and proteolysis activation markers. The influence of twice freezing and thawing on clotting factors V, …
Safety and Effectiveness of Progressive Moderate-to-Vigorous Intensity Elastic Resistance Training on Physical Function and Pain in People With Hemop…
2020
Abstract Objective Strength training is recommended for people with hemophilia; however, published data are anecdotal and have methodological limitations. The purpose of this study was to evaluate the safety and effectiveness of progressive moderate-to-vigorous intensity elastic resistance training on physical function and pain in this patient population. Methods A randomized controlled trial was conducted in a university laboratory setting where 20 patients (17 with severe, 1 with moderate, and 2 with mild hemophilia) aged 21 to 53 years received evaluations at baseline and 8-week follow-up. Participants were allocated to intervention (progressive strength training) or control (usual daily…
VITAMIN K-INDUCED MODIFICATION OF COAGULATION PHENOTYPE IN VKORC1 HOMOZYGOUS DEFICIENCY
2008
Summary. Background: Combined vitamin K-dependent clotting factor (VKCF) deficiency type 2 (VKCFD2) is a rare bleeding disorder caused by mutated vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) gene. Methods and results: An Italian patient with moderate to severe bleeding tendency was genotyped, and found to be homozygous for the unique VKORC1 mutation (Arg98Trp) so far detected in VKCFD2. The activity levels of VKCFs were differentially reduced, and inversely related to the previously estimated affinity of procoagulant factor propeptides for the γ-carboxylase. The normal (factor IX) or reduced antigen levels (other VKCFs) produced a gradient in specific activities. Vitamin K su…
Modeling in cardiovascular biomechanics
2010
In this review, we briefly summarize some of Professor K.R. Rajagopal's contributions to the field of cardiovascular mechanics and highlight some applications that have employed his theories and have expanded the ability to model the complex behaviors that characterize biological tissues. His contributions, spawning directly from the classical nonlinear theories of mechanics, have had general impact in diverse fields of engineering. Within biomechanics per se, Rajagopal's efforts have provided state-of-the-art modeling tools not only to characterize tissues, such as blood vessels, cerebral aneurysms, or blood, but also to characterize their evolution, i.e. vessel growth and remodeling or bl…
Hyperviscosity syndrome in patients with ovarian carcinoma
1998
BACKGROUND In patients with ovarian carcinoma, an hematocrit-independent hyperviscosity syndrome is often present. The syndrome is characterized by normal or low hematocrit and hemoglobin concentration, an elevated platelet count, and an increase in clotting factor turnover. Because deep vein thrombosis (DVT) often complicates the course of ovarian carcinoma, the aim of this study was to investigate the possible association of hyperviscosity syndrome with the development of DVT. METHODS Rheologic estimations of the blood included red blood cell (RBC) aggregation (stasis and low shear), plasma viscosity (pv), blood cell count, and fibrinogen, which were performed before primary surgery and t…
Evaluation of Clotting Factor Concentrates for Treatment of Thrombotic Thrombocytopenic Purpura.
2010
Abstract Abstract 3678 Introduction: Thrombotic thrombocytopenic purpura (TTP) is characterized by microthrombi, hemolytic anemia as well as thrombocytopenia. These symptoms are caused by a decreased activity of the protease ADAMTS13 which cleaves the von Willebrand Factor (VWF), due to mutation of the ADAMTS13-gene or autoantibodies. At the moment, the only available immediate therapy is plasmapheresis with Fresh Frozen Plasma (FFP) which may induce side effects. Therefore an alternative therapy might be the treatment with clotting factor concentrates. Methods: 40 plasma samples were tested, consisting of FFP and solvent/detergent treated plasma, four batches of each blood group; VWF/VIII …
Autoantibody Inhibitor Eradication In Acquired Hemophilia Associated with Cancer: a Retrospective Analysis
2010
Abstract Abstract 1418 Introduction: Acquired hemophilia (AH), a rare autoimmune disorder primarily of adults, is typically characterized by the presence of IgG oligoclonal antibodies to the clotting factor VIII protein (FVIII). About 10–15% of patients with AH have an underlying malignancy, but the etiologic relationship of cancer to formation of FVIII inhibitor is yet to be determined. To date, there have been no published, comprehensive reviews on the efficacy of various treatments for AH in the context of either solid tumor or hematologic malignancies. Therefore, we have systematically reviewed 86 patients with cancer-associated AH from our own cancer center and from the published liter…