: Flap necrosis remains a major complication of reconstructive surgery. To improve skin flap survival, various treatments with vasodilators, antiplatelet drugs, or the local administration of growth factors have been performed. However, the sufficient prevention of skin necrosis is not well established. Platelet-rich plasma has been used as an autologous ...

The innate immune system is the first line of host defense against invading organisms. Thus, pathogens have developed virulence mechanisms to evade the innate immune system. Here, we report a novel means for inhibition of neutrophil recruitment by Group A Streptococcus (GAS). Deletion of the secreted esterase gene (designated sse) ...

ABSTRACT: The objective of the study was to observe the effects of tissue-engineered skin in combination with platelet-rich plasma (PRP) and other preparations on the repair of large skin wound on nude mice.We first prepared PRP from venous blood by density-gradient centrifugation. Large skin wounds were created surgically on the ...

Introduction: In patients with chronic kidney disease (CKD) predisposition to bleeding is frequently seen due to disturbances in platelet adhesion and aggregation. Various tests have been utilized to evaluate the disturbance of hemostasis in end-stage renal disease patients. In this trial; we evaluated skin bleeding time in patients admitted to ...

Chromatophores show significant changes during healing of skin wounds in Labeo rohita (Common Name - Rohu). Wound area can be divided into regions I, II and III. After infliction of wound, skin colour becomes significantly dark by 2h that is gradually restored by 2d. In regions II and III at ...

BACKGROUND AND OBJECTIVES: Platelet-rich plasma (PRP) is an autologous concentration of human platelets contained in a small volume of plasma and has recently been shown to accelerate wound healing and rejuvenate aging skin. The current study was conducted to determine whether there are additional effects of PRP combined with fractional ...

Hemochromatosis is a common genetic disorder of iron metabolism. The increase in systemic iron associated with hemochromatosis can negatively affect every system in the body, with potentially fatal implications. Little is known about the effects of iron overload on hemostasis and platelet activation. While performing platelet aggregation studies on hemochromatotic ...

Recent data suggest that platelets not only control thrombosis and hemostasis but may also regulate inflammatory processes such as acute pancreatitis. However, the specific role of platelet-derived mediators in the pathophysiology of acute pancreatitis is not known. Herein, we examined the role of CD40 ligand (CD40L, CD154) in different models ...

Hepatitis B spliced protein (HBSP) encoded by a 2.2 kb singly spliced hepatitis B virus (HBV) pre-genomic RNA (spliced between positions 2447 and 489 nt) is involved in the pathogenesis of HBV infection, whereas the exact mechanism is far from being fully elucidated. In this study, a yeast two-hybrid system ...

Thymosin beta 4 (Tβ(4)) is a major actin sequestering peptide present in most mammalian cells. It also acts as an anti-inflammatory agent and promotes corneal wound healing. In the present study, we constructed a four channel cylindrical flow chambers out of polydimethylsiloxane (PDMS) on microscope coverslips. The platelet-binding proteins-fibrinogen and ...

Coagulation defects related to severe trauma, trauma-induced coagulopathy (TIC), have a number of causal factors including: major blood loss with consumption of clotting factors and platelets, and dilutional coagulopathy after administration of crystalloids and colloids to maintain blood pressure. In addition, activation of the fibrinolytic system or hyperfibrinolysis, hypothermia, acidosis, ...

Objective: We have recently reported that prophylactic fibrinogen infusion reduces bleeding after coronary artery bypass grafting (CABG) surgery. Because fibrinogen for the first time was administered to patients without hereditary fibrinogen deficiency or ongoing bleeding, a detailed analysis of the effects of fibrinogen concentrate on biomarkers of coagulation, fibrinolysis, and ...

Platelets bind to Candida albicans, the major cause of candidiasis. But in contrast to other microorganisms the fungus does not aggregate platelets. Gliotoxin (GT), which possesses immunosuppressive properties, is produced by various fungi, including the opportunistic pathogens Aspergillus fumigatus and C. albicans . Its mode of action involves the formation ...

Spontaneous aggregation of platelets is considerably enhanced in the acute period after burn. The changes in indices-induced aggregation of platelets are non-uniform and not significant statistically. Thermal trauma is accompanied by the development of hyperfibrinogenemia and an increase in the level of oxidised fibrinogen. We studied the influence of fibrinogen ...

Congenital abnormalities of fibrinogen are rare disorders classified as quantitative (afibrinogenemia and hypofibrinogenemia) or qualitative types (dysfibrinogenemia and hypodysfibrinogenemia). Fibrinogen is essential to haemostasis as the substrate for fibrin clot formation and also acts in primary haemostasis as a key ligand in platelet aggregation. Quantitative deficiency of fibrinogen can result ...

Platelet activation increases with age, although it is still controversial whether it derives from aging per se or from atherosclerosis concomitant with aging. The purpose of this study is to clarify the association between platelet activation and aging or atherosclerosis. We studied the ultrastructure of platelets in the elderly subjects ...

Identifying early changes in hemostatic clot function as a result of tissue injury and hypoperfusion may provide important information regarding the mechanisms of traumatic coagulopathy. A combat-relevant swine model was used to investigate the development of coagulopathy during trauma by monitoring hemostatic function during increasing severity of shock. Swine were ...

OBJECTIVE: The authors hypothesized that various hemostatic products may differently affect viscoelastic clot formation depending on their respective procoagulant activity and fibrinogen content. DESIGN: In vitro coagulopathy modeling using warfarin-treated plasma (international normalized ratio, 2.8-3.8) and fibrinogen-deficient plasma evaluated by rotational thromboelastometry (ROTEM; Pentapharm, Munich, Germany). SETTING: A university laboratory. ...

BACKGROUND: Human fibrinogen concentrates have been commercially available for decades for substitution therapy in hypofibrinogenemia, dysfibrinogenemia and afibrinogenemia. Accumulating new data suggest that fibrinogen plays a critical role in achieving and maintaining hemostasis, particularly in patients suffering from acquired fibrinogen deficiency during massive bleeding, where benefit from early intervention with ...

Increased liability for thrombosis has been suspected at high altitude. Platelet function and fibrinogen levels are known to play a major role in thrombogenic disorders. In order to investigate effect of chronic hypobaric hypoxia on platelet function and fibrinogen concentration, a study was conducted on 40 healthy men at sea ...

We have constructed liposomes with hemostatic activity as a platelet substitute using moderately thrombocytopenic rats. The liposomes were conjugated with the dodecapeptide (HHLGGAKQAGDV: H12), which is a fibrinogen gamma-chain C-terminal sequence (gamma 400-411). To visualize liposome accumulation at the site of vascular injury by in vivo computed tomography, a water-soluble ...

A fraction of fibrinogen contains a differently spliced gamma chain called gamma', which presents itself mainly as heterodimer with the common gammaA chain as gammaA/gamma' fibrinogen. The gamma' chain differs from the gammaA chain in its C-terminus and has important functional implications for fibrinogen. The presence of the gamma' chain ...

BACKGROUND: Although the lethal triad of hypothermia, acidosis, and coagulopathy has been recognized for a decade, the underlying mechanisms related to the development of coagulopathy are not fully understood. Consequently, current strategy in treating trauma patients with coagulopathy is limited to "staying out of the trouble" instead of "getting out ...

Fibrin is a substance formed through catalytic conversion of coagulation constituents: fibrinogen and thrombin. The kinetics of the two constituents determines the structural properties of the fibrin architecture. We have shown previously that changing the fibrinogen and thrombin concentrations in the final three-dimensional (3D) fibrin matrix influenced cell proliferation and ...

BACKGROUND: Staphylococcus epidermidis is a commensal of the human skin that has been implicated in infective endocarditis and infections involving implanted medical devices. S. epidermidis induces platelet aggregation by an unknown mechanism. The fibrinogen-binding protein serine-aspartate repeat protein G (SdrG) is present in 67-91% of clinical strains. OBJECTIVES: To determine ...

Triggering receptor expressed on myeloid cells-like (TREM-like) transcript-1 (TLT-1), a type 1 single Ig domain orphan receptor specific to platelet and megakaryocyte alpha-granules, relocates to the platelet surface upon platelet stimulation. We found here that patients diagnosed with sepsis, in contrast to healthy individuals, had substantial levels of soluble TLT-1 ...

Noble metals are interesting biomaterials for a number of reasons, e.g., their chemical inertness and relative mechanical softness, silver's long known antimicrobial properties, and the low allergenic response shown by gold. Although important for the final outcome of biomaterials, little is reported about early events between pure noble metals and ...

BACKGROUND: The A subunit of factor XIII (FXIII-A) functions as an intracellular transglutaminase (TG) in the megakaryocyte/platelet lineage, where it probably participates in the cytoskeletal remodeling associated with cell activation. However, so far, the precise role of cellular FXIII (cFXIII) and the functional consequences of its absence in FXIII-A-deficient patients ...

BACKGROUND: The biochemical mechanisms causing dilutional coagulopathy following infusion of hydroxyethyl starch 130/0.4 (HES) are not known in detail. OBJECTIVES: To give a detailed biochemical description of the mechanism of coagulopathy following 30%in vivo dilution with HES, to present a systematic ex vivo test of various hemostatic agents, and to ...

OBJECTIVE: To investigate changes and establish reference values for coagulation variables during normal pregnancy and after delivery in Chinese women. METHODS: A prospective, sequential, longitudinal study with strict inclusion and exclusion criteria was performed with 232 Chinese women. RESULTS: Prothrombin time, international normalized ratio, activated partial thromboplastin time, and activated ...

The functions of platelets and fibrinogen in protecting tumor cells from natural killer cytotoxicity have been discussed for more than 20 years. However, their exact roles and relationships in the process are still not clear. In this study, we show that tumor cells prefer to adhere to fibrinogen than to ...

BACKGROUND: Air pollution has consistently been associated with increased morbidity and mortality due to respiratory and cardiovascular disease. Underlying biological mechanisms are not entirely clear, and hemostasis and inflammation are suggested to be involved. OBJECTIVES: Our aim was to study the association of the variation in local concentrations of airborne ...

Binding of receptor proteins on circulating platelets to fibrinogen adsorbed on a biomaterial surface is a critical event in the blood-material interactions and surface-induced thrombogenesis. In this work, the interactions between purified platelet membrane integrin GPIIbIIIa (alpha(IIb)beta(3)) and fibrinogen on model hydrophilic and hydrophobic surfaces were characterized by measuring ligand-receptor ...

An intraluminal thrombus (ILT) forms in the majority of abdominal aortic aneurysms (AAAs). While the ILT has traditionally been perceived as a byproduct of aneurysmal disease, the mechanical environment within the ILT may contribute to the degeneration of the aortic wall by affecting biological events of cells embedded within the ...

Fibrinogen concentration influences mechanical and functional properties of the clot. The purpose of the present study was to identify threshold concentrations of fibrinogen resulting in relevant changes in whole blood clot elastic modulus and platelet contractile force, as well as plasma prothrombin time and activated partial thromboplastin time. We measured ...

The alphaIIbbeta3 receptor, which is the most abundant receptor on the surface of platelets, can interact with a variety of adhesive proteins including fibrinogen, fibronectin and the von Willebrand factor. Fibrinogen binding on alphaIIbbeta3 is an event essential for platelet aggregation and thrombus formation. Mapping of the fibrinogen-binding domains on ...

BACKGROUND: Patients experiencing massive haemorrhage are at high risk of developing coagulopathy through loss, consumption, and dilution of coagulation factors and platelets. It has been reported that plasma fibrinogen concentrations may reach a critical low level relatively early during bleeding, calling for replacement fibrinogen therapy. Cryoprecipitate has been widely used ...

Elevated levels of circulating fibrinogen are associated with an increased risk of atherothrombotic diseases although a causative correlation between high levels of fibrinogen and cardiovascular complications has not been established. We hypothesized that a potential mechanism for an increased prothrombotic state is the post-translational modification of fibrinogen by tyrosine nitration. ...

Fibrinogen is an essential protein involved in several steps of hemostasis, being associated with the final steps of the blood coagulation mechanism. Herein, we describe the purification and characterization of a reptile fibrinogen, obtained from Bothrops jararaca plasma. Native B. jararaca fibrinogen showed a molecular mass of 372 kDa, and ...

The carboxyl terminal segment of the fibrinogen gamma chain from gamma408-411 plays a crucial role in platelet aggregation via interactions with the platelet receptor alpha(IIb)beta(3). We describe here the first naturally-occurring fibrinogen point mutation affecting this region and demonstrate its effects on platelet interactions. DNA sequencing was used to sequence ...

Plasma fibrinogen participates in several physiological and pathological events thus becoming a useful studying material in biomedical research. Here we report a new convenient method for fibrinogen purification based on the affinity of Staphylococcus aureus clumping factor A to fibrinogen. Clumping factor A (ClfA) is a cell wall-anchored surface protein ...

RGD (arginine-glycine-aspartic acid) is a known peptide sequence that binds platelet integrin GPIIbIIIa and disrupts platelet-fibrinogen binding and platelet cross-linking during thrombosis. RGD peptides are unsuitable for clinical applications due to their high 50% inhibitory concentration (IC50) and low in vivo residence times. We addressed these issues by conjugating RGD ...

BACKGROUND: The hemostatic system is the major target of snake venom serine proteinases (SVSPs) that act on substrates of the coagulation, fibrinolytic and kallikrein-kinin systems. Bothrops protease A (BPA), the most glycosylated SVSP, is a non-coagulant, thermostable enzyme. A cDNA encoding BPA showed that the protein has a calculated molecular ...

BACKGROUND: Although bradykinin is known to play a major role in the pathophysiology of hereditary and angiotensin-converting enzyme inhibitor (ACEi)-induced angioedema, other factors acting as triggers or enhancers are likely important as well. OBJECTIVE: We hypothesized that fibrinogen might contribute to ACEi-induced angioedema (eg, through direct actions on vascular tone). ...

Fibrinogen is a large plasma glycoprotein with a molecular mass of 340kDa that plays a critical role in the final stage of blood coagulation. Human plasma fibrinogen is a dimeric molecule comprising two sets of three different polypeptides (Aalpha, 66kDa; Bbeta, 55kDa; gamma, 48kDa). To express recombinant human fibrinogen in ...

BACKGROUND: Pathologic hemorheological parameters and increased platelet aggregation in association with other risk factors significantly increase the possibility of the development of ischemia. Acetylsalicylic acid (ASA) is an effective antithrombotic agent, which prevents a variety of cardiovascular diseases. OBJECTIVES: The aim of our present study was to compare the hemorheological ...

Small-molecule alphaIIbbeta3 antagonists competitively block ligand binding by spanning between the D224 in alphaIIb and the MIDAS metal ion in beta3. They variably induce conformational changes in the receptor, which may have undesirable consequences. To identify alphaIIbbeta3 antagonists with novel structures, we tested 33 264 small molecules for their ability ...

Sodium ascorbate and histidine were employed to protect fibrinogen against modifications followed by a gamma-irradiation process that could potentially inactivate the blood-borne viruses in plasma-derived products. Fibrinogen was irradiated (50 kGy total dose, on dry ice) using a 60Co source. Samples were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and ...

INTRODUCTION: Emerging lines of evidence have suggested that certain dysfibrinogens present a significant risk of thrombosis. PATIENT/METHODS: The thrombophilic nature of a new-type of dysfibrinogen Kagoshima identified in a 36-year-old female with deep vein thrombosis during the postpartum period was studied. RESULTS/DISCUSSION: Based on the analyses of the patient fibrinogen ...

Oxidatively-modified fibrinogen induces platelet aggregation and potentiates ADP-induced platelet aggregation and production of active oxygen forms in zymosan-stimulated leukocytes. Fibrinogen induces IL-8 production in primary culture of endothelial cells from human umbilical vein; the oxidized form of fibrinogen is more active, similarly as during induction of the expression cell adhesion ...