A Comparison of the in Vitro and in Vivo Thrombogenic Activity of Factor IX Concentrates Using Stasis (Wessler) and Non-Stasis Rabbit Models

1980 ◽  
Vol 44 (02) ◽  
pp. 081-086 ◽  
Author(s):  
C V Prowse ◽  
A E Williams
Keyword(s):  
Platelet Rich Plasma ◽  
Thrombus Formation ◽  
Factor Ix ◽  
Coagulation System ◽  
In Vitro Tests ◽  
Clinical Use ◽  
Low Activity

SummaryThe thrombogenic effects of selected factor IX concentrates were evaluated in two rabbit models; the Wessler stasis model and a novel non-stasis model. Concentrates active in either the NAPTT or TGt50 in vitro tests of potential thrombogenicity, or both, caused thrombus formation in the Wessler technique and activation of the coagulation system in the non-stasis model. A concentrate with low activity in both in vitro tests did not have thrombogenic effects in vivo, at the chosen dose. Results in the non-stasis model suggested that the thrombogenic effects of factor IX concentrates may occur by at least two mechanisms. A concentrate prepared from platelet-rich plasma and a pyrogenic concentrate were also tested and found to have no thrombogenic effect in vivo.These studies justify the use of the NAPTT and TGt50 in vitro tests for the screening of factor IX concentrates prior to clinical use.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

Inhibition of Fibrinolysis and Fibrinogenolysis in Man: Comparison of ε-Aminocaproic Acid and Kallikrein Inhibitor

1963 ◽  
Vol 10 (01) ◽  
pp. 106-119 ◽  
Author(s):  
E Beck ◽  
R Schmutzler ◽  
F Duckert ◽  
Keyword(s):  
Aminocaproic Acid ◽  
Side Reactions ◽  
In Vitro Tests ◽  
Factor V ◽  
Clinical Use ◽  
Strong Inhibitor ◽  
Kallikrein Inhibitor ◽  
Therapeutic Possibilities

SummaryInhibitor of kallikrein and trypsin (KI) extracted from bovine parotis was compared with ε-aminocaproic acid (EACA): both substances inhibit fibrinolysis induced with streptokinase. EACA is a strong inhibitor of fibrinolysis in concentrations higher than 0, 1 mg per ml plasma. The same amount and higher concentrations are not able to inhibit completely the proteolytic-side reactions of fibrinolysis (fibrinogenolysis, diminution of factor V, rise of fibrin-polymerization-inhibitors). KI inhibits well proteolysis of plasma components in concentrations higher than 2,5 units per ml plasma. Much higher amounts of KI are needed to inhibit fibrinolysis as demonstrated by our in vivo and in vitro tests.Combination of the two substances for clinical use is suggested. Therapeutic possibilities are discussed.

Measurement of Activated Factor IX in Factor IX Concentrates: Correlation with In Vivo Thrombogenicity

1995 ◽  
Vol 73 (04) ◽  
pp. 675-679 ◽  
Author(s):  
Elaine Gray ◽  
Jill Tubbs ◽  
S Thomas ◽  
A Oates ◽  
M Boisclair ◽  
...  
Keyword(s):  
Significant Positive Correlation ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Prothrombin Complex Concentrates ◽  
Thrombotic Risk ◽  
Chromogenic Assay ◽  
The Mean ◽  
Thrombogenic Potential

SummaryCurrent in vitro tests for thrombogenicity of FIX concentrates used for prothrombin complex concentrates (PCCs), are of little value when applied to high purity FIX (HP FIXs). In the present study, we have developed a chromogenic assay for activated FIX (FIXa) and evaluated its ability to predict in vivo thrombogenic potential of HP FIXs in a modified Wessler stasis model. Among the HP FIXs, only 1 out of 7 products had no detectable FIXa; this product also showed no in vivo thrombogenicity. In the other 6 products, FIXa content ranged from 0.15–1.2 U/1000 iu FIX, and all showed some evidence of in vivo thrombogenicity, with mean thrombus scores ranging from 0.25–4. There was a significant positive correlation (r = 0.55, p <0.02) between FIXa levels and in vivo thrombogenicity of HP FIXs. NAPTT data were not significantly correlated with the in vivo results and the TFCT also showed no direct correlation with the mean thrombus score. These results indicate that HP FIXs may still carry a small residual thrombotic risk and measurement of FIXa content of these products may be a better predictor of thrombogenicity than the current in vitro tests.

Anti-thrombotic effects of selective estrogen receptor modulator tamoxifen

2011 ◽  
Vol 106 (10) ◽  
pp. 624-635 ◽  
Author(s):  
Manasa Nayak ◽  
Sunil Singh ◽  
Arnab Roy ◽  
Vivek Prakash ◽  
Anand Kumar ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Platelet Rich Plasma ◽  
Thrombus Formation ◽  
Present Report ◽  
Protein S ◽  
Collagen Matrix ◽  
Cancer Drug ◽  
Receptor Modulator

SummaryTamoxifen is a known anti-cancer drug and established estrogen receptor modulator. Few clinical studies have earlier implicated the drug in thrombotic complications attributable to lower anti-thrombin and protein S levels in plasma. However, action of tamoxifen on platelet signalling machinery has not been elucidated in detail. In the present report we show that tamoxifen is endowed with significant inhibitory property against human platelet aggregation. From a series of in vivo and in vitro studies tamoxifen was found to inhibit almost all platelet functions, prolong tail bleeding time in mouse and profoundly prevent thrombus formation at injured arterial wall in mice, as well as on collagen matrix perfused with platelet-rich plasma under arterial shear against the vehicle dimethylsulfoxide (DMSO). These findings strongly suggest that tamoxifen significantly downregulates platelet responses and holds potential as a promising anti-platelet / anti-thrombotic agent.

scholarly journals Platelet interaction with activated endothelium: mechanistic insights from microfluidics

Blood ◽  
2017 ◽  
Vol 130 (26) ◽  
pp. 2819-2828 ◽  
Author(s):  
Daniëlle M. Coenen ◽  
Tom G. Mastenbroek ◽  
Judith M. E. M. Cosemans
Keyword(s):  
Molecular Mechanisms ◽  
Thrombus Formation ◽  
Flow Chamber ◽  
Coagulation System ◽  
Intercellular Adhesion Molecule ◽  
Platelet Glycoprotein ◽  
Intercellular Adhesion Molecule 1 ◽  
Chamber Studies

Abstract Traditionally, in vitro flow chamber experiments and in vivo arterial thrombosis studies have been proved to be of vital importance to elucidate the mechanisms of platelet thrombus formation after vessel wall injury. In recent years, it has become clear that platelets also act as modulators of inflammatory processes, such as atherosclerosis. A key element herein is the complex cross talk between platelets, the coagulation system, leukocytes, and the activated endothelium. This review provides insight into the platelet-endothelial interface, based on in vitro flow chamber studies and cross referenced with in vivo thrombosis studies. The main mechanisms of platelet interaction with the activated endothelium encompass (1) platelet rolling via interaction of platelet glycoprotein Ib-IX-V with endothelial-released von Willebrand factor with a supporting role for the P-selectin/P-selectin glycoprotein ligand 1 axis, followed by (2) firm platelet adhesion to the endothelium via interaction of platelet αIIbβ3 with endothelial αvβ3 and intercellular adhesion molecule 1, and (3) a stimulatory role for thrombin, the thrombospondin-1/CD36 axis and cyclooxygenase 1 in subsequent platelet activation and stable thrombus formation. In addition, the molecular mechanisms underlying the stimulatory effect of platelets on leukocyte transendothelial migration, a key mediator of atheroprogression, are discussed. Throughout the review, emphasis is placed on recommendations for setting up, reporting, interpreting, and comparing endothelial-lined flow chamber studies and suggestions for future studies.

scholarly journals Effects of New NSAID-CAI Hybrid Compounds in Inflammation and Lung Fibrosis

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1307
Author(s):  
Laura Lucarini ◽  
Mariaconcetta Durante ◽  
Silvia Sgambellone ◽  
Cecilia Lanzi ◽  
Elisabetta Bigagli ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Lung Fibrosis ◽  
Platelet Rich Plasma ◽  
In Vitro Tests ◽  
Carbonic Anhydrases ◽  
Hybrid Compounds ◽  
Cox 2 ◽  
Anti Inflammatory

Pulmonary fibrosis is a severe lung disease with progressive worsening of dyspnea, characterized by chronic inflammation and remodeling of lung parenchyma. Carbonic anhydrases are a family of zinc-metallo-enzymes that catalyze the reversible interconversion of carbon-dioxide and water to bicarbonate and protons. Carbonic Anhydrase Inhibitor (CAI) exhibited anti-inflammatory effects in animals with permanent-middle-cerebral artery occlusion, arthritis and neuropathic pain. The pharmacological profile of a new class of hybrid compounds constituted by a CAI connected to a Nonsteroidal-Anti-Inflammatory Drug (NSAID) was studied in the modulation of inflammation and fibrosis. In-vitro tests were performed to assess their effects on cyclo-oxygenase enzyme (COX)-1 and COX-2, namely inhibition of platelet aggregation and thromboxane B2 production in the human-platelet-rich plasma, and reduction of Prostaglandin-E2 production in lipopolysaccharide-treated-RAW-264.7 macrophage cell line. The activity of compound 3, one of the most active, was studied in a model of bleomycin-induced lung fibrosis in C57BL/6 mice. The hybrid compounds showed a higher potency in inhibiting PGE2 production, but not in modifying the platelet aggregation and the TXB2 production in comparison to the reference molecules, indicating an increased activity in COX-2 inhibition. In the in-vivo murine model, the compound 3 was more effective in decreasing inflammation, lung stiffness and oxidative stress in comparison to the reference drugs given alone or in association. In conclusion, these CAI-NSAID hybrid compounds are promising new anti-inflammatory drugs for the treatment of lung chronic inflammatory diseases.

scholarly journals Contradictory functions of sulfatide in the blood coagulation system as coagulant and anticoagulant.

1998 ◽  
Vol 45 (2) ◽  
pp. 493-499 ◽  
Author(s):  
M Kyogashima ◽  
J Onaya ◽  
A Hara ◽  
T Taketomi
Keyword(s):  
Blood Coagulation ◽  
Thrombus Formation ◽  
Coagulation Factor ◽  
Coagulation System ◽  
Factor Xii ◽  
Blood Coagulation System ◽  
Coagulant Activity ◽  
J 13

Sulfatide (galactosylceramide I3 -sulfate) has been reported to activate blood coagulation factor XII (Hageman factor), which suggests that it exhibits coagulant activity (Fujikama et al., 1980 Biochemistry 19, 1322-1330) However, sulfatide administered into animals as a bolus shot without subsequent thrombus formation, prolonged conventional clotting times and bleeding time (Hara et al., 1996 Glycoconjugate J. 13, 187-194). These findings suggest that it may exhibit anticoagulant rather than coagulant activity. Following this suggestion we found in vitro that binding of sulfatide to fibrinogen resulted in disturbance of fibrin formation. To examine a possible pharmacological effect of sulfatide on blood coagulation in vivo we continuously infused sulfatide into rats through plastic cannulae and found formation of giant thrombi around the tips of the cannulae. These data suggest that sulfatide may exhibit contradictory functions in the blood coagulation system.

scholarly journals A Critical Overview of the Use of Platelet-Rich Plasma in Equine Medicine Over the Last Decade

2021 ◽  
Vol 8 ◽  
Author(s):  
Livia Camargo Garbin ◽  
Catalina Lopez ◽  
Jorge U. Carmona
Keyword(s):  
Platelet Rich Plasma ◽  
Individual Variability ◽  
Therapeutic Effects ◽  
Clinical Use ◽  
Preparation Methods ◽  
Quantitative Evidence ◽  
Main Research ◽  
Anti Inflammatory

In the 1990s, the role of platelets in inflammation and tissue healing was finally recognized. Since then, the clinical use of platelet-derived products (hemocomponents), such as, platelet-rich plasma (PRP), markedly increased. The promise of a more economical option of a disease-modifying treatment led to the intensive and continuous research of PRP products and to its widespread clinical use. A number of protocols and commercial kits have been developed with the intention of creating a more practical and reliable option for clinical use in equine patients. Still, the direct comparison between studies is particularly challenging due to the lack of standardization on the preparation methods and product composition. The incomplete reports on PRP cellular concentration and the poorly designed in vivo studies are additional matters that contest the clinical efficiency of this biomaterial. To overcome such challenges, several in vitro and in vivo studies have been proposed. Specifically, experiments have greatly focused in protocol optimization and its effect in different tissues. Additionally, in vivo studies have proposed different biological products envisioning the upgrade of the anti-inflammatory cytokines trusting to increase its anti-inflammatory effect. The individual variability and health status of the animal, type of tissue and condition treated, and protocol implemented are known to influence on the product's cell and cytokine composition. Such variability is a main clinical concern once it can potentially influence on PRP's therapeutic effects. Thus, lack of qualitative and quantitative evidence-based data supporting PRP's clinical use persists, despite of the numerous studies intended to accomplish this purpose. This narrative review aims to critically evaluate the main research published in the past decade and how it can potentially impact the clinical use of PRP.

scholarly journals Organometallic iron complexes as potential cancer therapeutics.

2014 ◽  
Vol 61 (4) ◽  
Author(s):  
Gabriela Mojžišová ◽  
Ján Mojžiš ◽  
Janka Vašková
Keyword(s):  
Anticancer Agents ◽  
Acquired Resistance ◽  
Cancer Therapeutics ◽  
Iron Complexes ◽  
Cytotoxic Agents ◽  
In Vitro Tests ◽  
Clinical Use ◽  
In Vivo Experiments

Metal-containing drugs have long been used for medicinal purposes in more or less empirical way. The potential of these anticancer agents has only been fully realised and explored since the discovery of the biological activity of cisplatin. Cisplatin and carboplatin have been two of the most successful anti-cancer agents ever developed, and are currently used to treat ovarian, lung and testicular cancers. They share certain side effects, so their clinical use is severely limited by dose-limiting toxicity. Inherent or acquired resistance is a second problem often associated with platinum-based drugs, with further limits of their clinical use. These problems have prompted chemists to employ different strategies in development of the new metal-based anticancer agents with different mechanisms of action. There are various metal complexes still under development and investigation for the future cancer treatment use. In the search for novel bio-organometallic molecules, iron containing anti-tumoral agents are enjoying an increasing interest and appear very promising as the potential drug candidates. Iron, as an essential cofactor in a number of enzymes and physiological processes, may be less toxic than non essential metals, such as platinum. Up to now, some of iron complexes have been tested as cytotoxic agents and found to be endowed with an antitumor activity in several in vitro tests (on cultured cancer cell lines) and few in vivo experiments (e. g. on Ehrlich's ascites carcinoma). Although the precise molecular mechanism is yet to be defined, a number of observations suggest that the reactive oxygen species can play important role in iron-induced cytotoxicty. This review covers some relevant examples of research on the novel iron complexes.

Akt2 Supports aIIbb3-Dependent Reorganization of the Actin Cytoskeleton in Platelets.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3565-3565
Author(s):  
Shelley August ◽  
Donna S. Woulfe
Keyword(s):  
Platelet Rich Plasma ◽  
Thrombus Formation ◽  
Active Form ◽  
Dense Granule ◽  
Clot Retraction ◽  
Akt Activation ◽  
Cytoskeletal Remodeling ◽  
Fibrinogen Binding

Abstract Akt is a serine-threonine kinase with well-described roles in growth and metabolism. Previous studies from our laboratory have shown that Akt also plays important roles in platelet function in vitro and in thrombus formation in vivo. Two isoforms are present in mouse platelets, Akt1 and Akt2, with Akt2 being the dominant isoform. Our previous studies have shown that platelets from Akt2−/− mice have marked defects in aggregation, a- and dense granule secretion, and fibrinogen binding. Each of these platelet functions depends in part on the function of the major platelet integrin, aIIbb3. However, whether Akt might regulate the function of aIIbb3 is still unknown. To determine whether Akt regulates aIIbb3-dependent signaling, first the rate of thrombin-initiated clot retraction was compared in platelet-rich plasma (PRP) from wild-type versus Akt2−/− mice. Akt2−/− platelets have a delay in the aIIbb3-dependent retraction of the fibrin clot compared to their wildtype counterparts. Akt2−/− platelets also have a delay in aIIbb3-dependent spreading on immobilized fibrinogen. However, adhesion to immobilized fibrinogen was normal in these platelets, suggesting that the spreading defect is due to a defect in outside-in signaling by the integrin, rather than in fibrinogen binding. Furthermore, unstimulated platelets expressing a constitutively active form of Akt spread more rapidly on fibrinogen-coated slides and generate more filopodial extensions than wildtype platelets, suggesting that Akt activation may be sufficient to induce outside-in signaling and /or cytoskeletal remodeling. Interestingly, integrin activation was not sufficient to induce Akt phoshorylation, suggesting that integrin activity is downstream rather than upstream of Akt activation. Taken together, these results suggest that integrin aIIbb3 is not necessary for Akt activation; however, Akt promotes outside-in signaling and cytoskeletal remodeling by aIIbb3.

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