Analysis of fibrinogen concentrate pharmacokinetics and dosing for bleeds and surgery in adults, adolescents, and children with congenital afibrinogenaemia and hypofibrinogenaemia.

INTRODUCTION: Congenital afibrinogenaemia and hypofibrinogenaemia are rare coagulation disorders where clotting is impaired due to a lack of fibrinogen. Consequent bleeding episodes (BEs) are treated using human fibrinogen concentrate (HFC). AIM: This post-hoc analysis compared HFC pharmacokinetics (PK) and dosing between patient age groups and defined the in vivo recovery (IVR) for children with a- and hypofibrinogenaemia. METHODS: The analysis used data from the FORMA-01 (Phase 2), FORMA-02 and FORMA-04 (Phase 3) multinational, prospective, open-label studies in patients with a- and hypofibrinogenaemia. HFC PK in adults/adolescents (≥12 years; FORMA-01) and children (<12 years; FORMA-04) was examined. Haemostatic efficacy in BE treatment and perioperative prophylaxis was examined in FORMA-02 and FORMA-04 using an objective 4-point scale, with success defined as excellent/good. RESULTS: Median (range) age was 23 years for FORMA-01 (12-53; n = 22), 26.5 years for FORMA-02 (12-54; n = 25), and 6 years for FORMA-04 (1-10; n = 13). Mean PK parameters were lower for children (AUC, Cmax , IVR; p = .02), while clearance was higher. Median (range) total dose of HFC for all BEs was 59.41 mg/kg (32.12-273.80) in adults/adolescents and was 24% higher (ns) in children at 73.91 mg/kg (47.45-262.50). Treatment was successful in 98.9% of the 89 BEs in adults/adolescents and in 100% of the 10 BEs in children, with comparable results for perioperative prophylaxis. CONCLUSION: As expected, HFC PK differed between adults/adolescents and children. However, with the higher doses given to children, HFC showed similar efficacy across age groups. Dose adaptation based on age groups appears recommendable.

Recombinant Human HPS Protects Mice and Nonhuman Primates from Acute Liver Injury.

Acute liver injury shares a common feature of hepatocytes death, immune system disorders, and cellular stress. Hepassocin (HPS) is a hepatokine that has ability to promote hepatocytes proliferation and to protect rats from D-galactose (D-Gal)- or carbon tetrachloride (CCl4)-induced liver injury by stimulating hepatocytes proliferation and preventing the high mortality rate, hepatocyte death, and hepatic inflammation. In this paper, we generated a pharmaceutical-grade recombinant human HPS using mammalian cells expression system and evaluated the effects of HPS administration on the pathogenesis of acute liver injury in monkey and mice. In the model mice of D-galactosamine (D-GalN) plus lipopolysaccharide (LPS)-induced liver injury, HPS treatment significantly reduced hepatocyte death and inflammation response, and consequently attenuated the development of acute liver failure. In the model monkey of D-GalN-induced liver injury, HPS administration promoted hepatocytes proliferation, prevented hepatocyte apoptosis and oxidation stress, and resulted in amelioration of liver injury. Furthermore, the primary pharmacokinetic study showed natural HPS possesses favorable pharmacokinetics; the acute toxicity study indicated no significant changes in behavioral, clinical, or histopathological parameters of HPS-treated mice, implying the clinical potential of HPS. Our results suggest that exogenous HPS has protective effects on acute liver injury in both mice and monkeys. HPS or HPS analogues and mimetics may provide novel drugs for the treatment of acute liver injury.

Pharmacology, Efficacy and Safety of a Triple-Secured Fibrinogen Concentrate in Children Less than or Equal to 12 Years with Afibrinogenaemia.

OBJECTIVE: To date, the use of a fibrinogen concentrate (FC) administered in children with inherited fibrinogen deficiency is poorly documented. Treatment modalities may differ from those of adults. The aim of this study was to investigate the pharmacokinetics (PK), efficacy (bleeding/surgery) and safety of a triple-secured FC (FibCLOT, LFB, France) in young patients aged of 12 years or less. METHODS: This was a prospective, non-comparative, multicentre, phase 2-3 study. Estimated PK parameters were based on population PK modelling. Target fibrinogen levels were 1.2 and 1.0 g/L for major and minor events, respectively. In vivo recovery (IVR) was calculated at study entry to tailor the dose. RESULTS: Sixteen afibrinogenaemia patients were treated with FC: 12 included in the PK study (6 aged ≤ 6 years and 6 aged 7-12 years). IVR at 1 hour post-infusion (geometric mean [coefficient of variation]) was 1.91 [20%] mg/dL per mg/kg and results were similar between the two age groups (1.87 [14%]) and (1.96 [27%]) with no statistical differences. Estimated half-life (t 1/2) was 49.0 hours [12%] with no observed differences between groups (46.6 hours [10%] and 51.6 hours [12%]). Overall efficacy was rated as excellent/good in 96.9% of 32 bleeds and in 100% of 11 surgeries. Most of the events (39/43, 90.7%) were managed with one infusion. There was no serious adverse drug reaction. CONCLUSION: Individually tailored dosing was efficacious in children who exhibited a lower IVR and shorter t 1/2 than those previously reported in adolescent and adult patients emphasising the importance of individualised dose optimisation.

Fibrinogen concentrates in hereditary fibrinogen disorders: Past, present and future.

Hereditary fibrinogen disorders (HFD) are rare coagulation disorders. Even if the spectrum of symptoms is broad depending on the sub-type, bleeding is the most common complication. Of the available sources of fibrinogen replacement, fibrinogen concentrate provides a safer and more effective option to treat and prevent bleeding. Recent clinical trials on established and new fibrinogen concentrates have increased our knowledge on the clinical pharmacology of these products, pointing out possible age and weight differences for dose adjustment. The efficacy of fibrinogen infusions has been demonstrated, especially for the management of acute bleeding with an excellent response based on investigator rating. The target fibrinogen levels in the setting of both minor and major surgeries have been better specified. The safety has been confirmed with a low number of adverse events but there still remains concern over possible thrombotic risks. Pharmacological, clinical aspects and future perspectives on the utilization of fibrinogen concentrates in the treatment and prevention of bleeding in patients with HFD are reviewed.

Clinical pharmacology, efficacy and safety study of a triple-secured fibrinogen concentrate in adults and adolescent patients with congenital fibrinogen deficiency.

Essentials A novel fibrinogen concentrate was evaluated in patients with congenital fibrinogen deficiency. An open-label, phase 2-3 trial studied pharmacology, efficacy, and safety in patients >6 years. The product offers safe and effective therapy in the treatment and prophylaxis of bleeding. Data in recovery show the need of adjusted treatment and further investigation in children. SUMMARY: Background Single-factor replacement therapy is considered the most suitable treatment option for hereditary fibrinogen deficiency. A triple-secured plasma-derived human fibrinogen product was developed to increase the safety of the former fibrinogen concentrate. Objectives This non-randomized, open-label, prospective study investigated pharmacokinetics, efficacy, and safety of a novel fibrinogen concentrate (FibCLOT® /CLOTTAFACT® LFB, France) in inherited deficiency. Patients/Methods Fourteen patients ≥40 kg received fibrinogen concentrate for pharmacology and 16 ≥ 23 kg received treatment for bleeding or surgery. Each treatment was followed by a 3-week safety observation period. Key outcomes included number of infusions, dose, bleeding control, daily assessment, hemoglobin, blood loss, transfusions, and physicians' global assessment of response. Results Incremental recovery was 2.35 mg mL-1  per mg kg-1 and maximal concentration 1.41 g L-1 (geometric mean) after 0.060 g kg-1 infusion in 14 afibrinogenemic patients. Terminal half-life was 69.3 h (non-compartmental analysis). The maximum clot firmness was increased by a mean of 10.3 mm from baseline to maximal effect. Sixteen patients participated to the efficacy phase: 32 bleeding episodes were treated in 9 patients, and 15 patients underwent 38 surgical/invasive procedures. All patients achieved appropriate hemostasis: response to treatment was successful in all bleeds (95% CI, 0.89-1.00) and procedures (95% CI, 0.91-1.00). Most (94%) bleeds were controlled with a single infusion (median 0.050 g kg-1 ). Two patients experienced asymptomatic distal venous thromboses identified by systematic ultrasound. Conclusion FibCLOT® /CLOTTAFACT® showed a pharmacokinetic profile comparable to that of other fibrinogen concentrates and provides safe and clinically effective substitution therapy for fibrinogen-deficient patients.

Pharmacokinetics, clot strength and safety of a new fibrinogen concentrate: randomized comparison with active control in congenital fibrinogen deficiency.

Essentials Congenital afibrinogenemia causes a potentially life-threatening bleeding and clotting tendency. Two human fibrinogen concentrates (HFCs) were compared in a randomized pharmacokinetic study. Bioequivalence was not shown for AUCnorm , which was significantly larger for the new HFC. Increases in clot strength were comparable, and no thromboses or deaths occurred in the study. SUMMARY: Background Human fibrinogen concentrate (HFC) corrects fibrinogen deficiency in congenital a-/hypofibrinogenemia. Objectives To assess pharmacokinetics (PK), effects on thromboelastometry maximum clot firmness (MCF), and safety of a new double virus-inactivated/eliminated, highly purified HFC vs. active control. Patients/Methods In this multinational, randomized, phase II, open-label, crossover study in 22 congenital afibrinogenemia patients aged ≥ 12 years, 70 mg kg-1 of new HFC (FIBRYGA, Octapharma AG) or control (Haemocomplettan® P/RiaSTAP™, CSL Behring GmbH) were administered, followed by crossover to the other concentrate. Fibrinogen activity, PK and MCF in plasma were assessed. Results The concentrates were not bioequivalent for the primary endpoint, AUCnorm (mean ratio, 1.196; 90% confidence interval [CI], 1.117, 1.281). Remaining PK parameters (Cmaxnorm , IVR, t1/2 , MRT) reflected bioequivalence between concentrates, except for clearance (mean ratio, 0.836; 90% CI, 0.781, 0.895) and Vss (mean ratio, 0.886; 90% CI, 0.791, 0.994). Mean AUCnorm was significantly larger for the new HFC (1.62 ± 0.45 vs. 1.38 ± 0.47 h kg g L-1  mg-1 , P = 0.0001) and mean clearance was significantly slower (0.665 ± 0.197 vs. 0.804 ± 0.255 mL h-1  kg-1 , P = 0.0002). Mean MCF increased from 0 mm to 9.68 mm (new HFC) and 10.00 mm (control) 1-hour post-infusion (mean difference, -0.32 mm; 95% CI, -1.70, 1.07, n.s.). No deaths, thromboses, viral seroconversions or serious related adverse events occurred. Conclusions Bioequivalence was not demonstrated for AUCnorm , clearance and Vss . Larger AUCnorm and slower clearance were observed for the new HFC. Remaining pharmacokinetic parameters reflected bioequivalence to control. Safety profiles and increases in clot strength were comparable between concentrates.

Direct quantification of dual protein adsorption dynamics in three dimensional systems in presence of cells.

Understanding the composition of the adsorbed protein layer on a biomaterial surface is of an extreme importance as it directs the primary biological response. Direct detection using labeled proteins and indirect detection based on enzymatic assays or changes to mass, refractive index or density of a surface have been so far established. Nevertheless, using current methodologies, detection of multiple proteins simultaneously and particularly in a three-dimensional (3D) substrates is challenging, with the exception of radiolabeling. Here using fluorescence molecular tomography (FMT), we present a non-destructive and versatile approach to quantify adsorption of multiple proteins within 3D environments and reveal the dynamics of adsorption of human serum albumin (HSA) and fibrinogen (Fib) on 3D polymeric scaffold. Furthermore, we show that serum starved human articular chondrocytes in 3D environment preferentially uptake HSA over Fib and to our knowledge this represents the first example of direct visualization and quantification of protein adsorption in a 3D cell culture system. STATEMENT OF SIGNIFICANCE: The biomaterial surface upon exposure to biological fluids is covered by a layer of proteins, which is modified over a period of time and dictates the fate of the biomaterial. In this study, we present and validate a new methodology for quantification of protein adsorption on to a three-dimensional polymer scaffold from unitary and binary systems, using fluorescence molecular tomography, an optical trans-illumination technique with picomolar sensitivity. In additional to being able to follow behavior of two proteins simultaneously, this methodology is also suitable for studying protein uptake in cells situated in a polymer environment. The ability to follow protein adsorption/uptake in a continuous manner opens up new possibilities to study the role of serum proteins in biomaterial compatibility.

Multi Drug Loaded Thermo-Responsive Fibrinogen-graft-Poly(N-vinyl Caprolactam) Nanogels for Breast Cancer Drug Delivery.

This study aims at the targeted delivery of 5-fluorouracil (5-FU) and Megestrol acetate (Meg) loaded fibrinogen-graft-poly(N-Vinyl caprolactam) nanogels (5-FU/Meg-fib-graft-PNVCL NGs) toward α5ß1-integrins receptors expressed on breast cancer cells to have enhanced anti-cancer effect in vitro. To achieve this aim, we developed biocompatible thermoresponsive fib-graft-PNVCL NGs using fibrinogen and carboxyl terminated PNVCL via EDC/NHS amidation reaction. The Lower Critical Solution Temperature (LCST) of fib-graft-PNVCL could be tuned according to PNVCL/fibrinogen compositions. The 100-120 nm sized nanogels of fib-graft-PNVCL (LCST = 35 ?1 'C) was prepared using CaCl2 cross-linker. The 5-FU/Meg-fib-graft-PNVCL NGs showed a particle size of 150-170 nm size. The drug loading efficiency with 5-FU was 62% while Meg showed 74%. The 5-FU and Meg release was prominent above LCST than below LCST. The multi drug loaded fib-graft-PNVCL NGs showed enhanced toxicity, apoptosis and uptake by breast cancer (MCF-7) cells compared to their individual doses above their LCST. The in vivo assessment in Swiss albino mice showed sustained release of Meg and 5-FU as early as 3 days, confirming the therapeutic efficiency of the formulation. These results demonstrate an enhanced platform for the future animal studies on breast tumor xenograft model.

Fibrinogen concentrate administration attributes to significant reductions of blood loss and transfusion requirements in thoracic aneurysm repair.

BACKGROUND: Repair of thoracic aortic aneurysm (TAA) is often associated with massive hemorrhage aggravated by dilutional coagulopathy with severe hypofibrinogenemia. Although only fresh frozen plasma (FFP) is available for acquired hypofibrinogenemia in Japan, the hemostatic effect of FFP has not been enough for dilutional coagulopathy in TAA surgery. There are increasing reports suggesting that fibrinogen concentrate may be effective in controlling perioperative bleeding and reducing transfusion requirements. METHODS: We retrospectively analyzed the hemostatic effect of fibrinogen concentrate compared with FFP in total 49 cases of elective TAA surgery. In 25 patients, fibrinogen concentrate was administered when the fibrinogen level was below 150 mg/dL at the cardiopulmonary bypass (CPB) termination. The recovery of fibrinogen level, blood loss, and transfused units during surgery were compared between cases of this agent and FFP (n = 24). RESULTS: We observed rapid increases in plasma fibrinogen level and subsequent improvement in hemostasis by administration of fibrinogen concentrate after CPB termination. The average volume of total blood loss decreased by 64% and the average number of transfused units was reduced by 58% in cases of fibrinogen concentrate given, in comparison with cases of only FFP transfused for fibrinogen supplementation. CONCLUSIONS: In patients showing severe hypofibrinogenemia during TAA surgery, timely administration of fibrinogen concentrate just after removal from CPB is effective for hemostasis, and therefore in reducing blood loss and transfused volumes.

Recovery of fibrinogen concentrate after intraosseous application is equivalent to the intravenous route in a porcine model of hemodilution.

BACKGROUND: Fibrinogen concentrate is increasingly considered as a hemostatic agent for trauma patients experiencing bleeding. Placing a venous access is sometimes challenging during severe hemorrhage. Intraosseous access may be considered instead. Studies of intraosseous infusion of coagulation factor concentrates are limited. We investigated in vivo recovery following intraosseous administration of fibrinogen concentrate and compared the results with intravenous administration. METHODS: This study was performed on 12 pigs (mean [SD] body weight, 34.1 [2.8] kg). Following controlled blood loss (35 mL/kg) and fluid replacement with balanced crystalloid solution, intraosseous (n = 6) administration of fibrinogen concentrate (80 mg per kilogram of bodyweight) in the proximal tibia was compared with intravenous (n = 6) administration of the same dose (fibrinogen infusion time approximately 5 minutes in both groups). The following laboratory parameters were assessed: blood cell count, prothrombin time index, activated partial thromboplastin time, and plasma fibrinogen concentration (Clauss assay). Coagulation status was also assessed by thromboelastometry. RESULTS: All tested laboratory parameters were comparable between the intraosseous and intravenous groups at baseline, hemodilution, and 30 minutes after fibrinogen concentrate administration. In vivo recovery of fibrinogen was also similar in the two groups (89% [23%] and 91% [22%], respectively). There were no significant between-group differences in any of the thromboelastometric parameters. Histologic examination indicated no adverse effects on the tissue surrounding the intraosseous administration site. CONCLUSION: This study suggests that intraosseous administration of fibrinogen concentrate results in a recovery of fibrinogen similar to that of intravenous administration. The intraosseous route of fibrinogen concentrate could be a valuable alternative in situations where intravenous access is not feasible or would be time consuming. LEVEL OF EVIDENCE: Prospective, randomized, therapeutic feasibility study in an animal model, level V.

Paclitaxel loaded fibrinogen coated CdTe/ZnTe core shell nanoparticles for targeted imaging and drug delivery to breast cancer cells.

The study aims at the targeted imaging using CdTe/ZnTe core shell QDs and delivery of paclitaxel (PTX) loaded fibrinogen coated yellow-QDs (PTX-fib-yellow-QDs) towards breast cancer cells via the alpha5Beta1-integrins. We developed fibrinogen coated different sized CdTe/ZnTe core shell quantum dots of 2-10 nm size, which have been prepared by one-pot aqueous-phase approach. The fib-coated-QDs (fib-coated-QDs) and PTX-fib-yellow-QDs were prepared by two-step coacervation technique using CaCl2 as cross-linker. Particle size of fib-coated-QDs was in between 60-220 nm while PTX-fib-yellow-QDs showed 180 +/- 40 nm. The MTT assay confirmed cytocompatibility of fib-coated-QDs on L929 and MCF-7 than bare QDs, whereas significant toxicity toward MCF-7 by PTX-fib-yellow-QDs was observed. The hemocompatible fib-coated-QDs showed enhanced localization and retention toward alpha5beta1-integrins +ve MCF-7 compared to alpha5beta1-integrins -ve L929 cells. The specific binding of fib-coated-yellow-QDs was further confirmed with alpha5beta1-integrins +ve HeLa and alpha5/beta1-integrins -ve HT29 cells. Cellular uptake studies revealed localization of PTX-fib-coated-yellow-QDs inside MCF-7 cells compared to the normal L929 cells. These results indicated that fib-coated-QDs could be used for targeted imaging and as a suitable "nanocarrier" aiming breast cancer cells.

Pharmacokinetic study of adenosine diphosphate-encapsulated liposomes coated with fibrinogen γ-chain dodecapeptide as a synthetic platelet substitute in an anticancer drug-induced thrombocytopenia rat model.

A fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV, H12)-coated, adenosine diphosphate (ADP)-encapsulated liposome [H12-(ADP)-liposome] was designed to achieve optimal performance as a homeostatic agent and expected as a synthetic platelet alternative. For the purpose of efficient function as platelet substitute, H12-(ADP)-liposomes should potentially have both acceptable pharmacokinetic and biodegradable properties under conditions of an adaptation disease including thrombocytopenia induced by anticancer drugs. The aim of this study was to characterize the pharmacokinetics of H12-(ADP)-liposomes in busulphan-induced thrombocytopenic rats using (14) C, (3) H double radiolabeled H12-(ADP)-liposomes, in which the encapsulated ADP and liposomal membrane (cholesterol) were labeled with (14) C and (3) H, respectively. After the administration of H12-(ADP)-liposomes, they were determined to be mainly distributed to the liver and spleen and disappeared from organs within 7 days after injection. The encapsulated ADP was mainly eliminated in the urine, whereas the outer membrane (cholesterol) was mainly eliminated in feces. The successive dispositions of the H12-(ADP)-liposomes were similar in both normal and thrombocytopenic rats. However, the kinetics of H12-(ADP)-liposomes in thrombocytopenic rats was more rapid, compared with the corresponding values for normal rats. These findings, which well reflect the clinical features of patients with anticancer drug-induced thrombocytopenia, provide useful information for the development of the H12-(ADP)-liposomes for future clinical use.

Pharmacokinetic study of the structural components of adenosine diphosphate-encapsulated liposomes coated with fibrinogen γ-chain dodecapeptide as a synthetic platelet substitute.

Fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV, H12)-coated, ADP-encapsulated liposomes [H12-(ADP)-liposomes] were developed as a synthetic platelet alternative that specifically accumulates at bleeding sites as the result of interactions with activated platelets via glycoprotein IIb/IIIa and augments platelet aggregation by releasing ADP. The aim of this study is to characterize the pharmacokinetic properties of H12-(ADP)-liposomes and structural components in rats, and to predict the blood retention of H12-(ADP)-liposomes in humans. With use of H12-(ADP)-liposomes in which the encapsulated ADP and liposomal membrane cholesterol were radiolabeled with (14)C and (3)H, respectively, it was found that the time courses for the plasma concentration curves of (14)C and (3)H radioactivity showed that the H12-(ADP)-liposomes remained intact in the blood circulation for up to 24 hours after injection, and were mainly distributed to the liver and spleen. However, the (14)C and (3)H radioactivity of H12-(ADP)-liposomes disappeared from organs within 7 days after injection. The encapsulated ADP was metabolized to allantoin, which is the final metabolite of ADP in rodents, and was mainly eliminated in the urine, whereas the cholesterol was mainly eliminated in feces. In addition, the half-life of the H12-(ADP)-liposomes in humans was predicted to be approximately 96 hours from pharmacokinetic data obtained for mice, rats, and rabbits using an allometric equation. These results suggest that the H12-(ADP)-liposome has potential with proper pharmacokinetic and acceptable biodegradable properties as a synthetic platelet substitute.

Astrocytes specifically remove surface-adsorbed fibrinogen and locally express chondroitin sulfate proteoglycans.

Surface-adsorbed fibrinogen (FBG) was recognized by adhering astrocytes, and was removed from the substrates in vitro by a two-phase removal process. The cells removed adsorbed FBG from binary proteins' surface patterns (FBG+laminin, or FBG+albumin) while leaving the other protein behind. Astrocytes preferentially expressed chondroitin sulfate proteoglycan (CSPG) at the loci of fibrinogen stimuli; however, no differences in overall CSPG production as a function of FBG surface coverage were identified. Removal of FBG by astrocytes was also found to be independent of transforming growth factor type ß (TGF-ß) receptor based signaling as cells maintained CSPG production in the presence of TGF-ß receptor kinase inhibitor, SB 431542. The inhibitor decreased CSPG expression, but did not abolish it entirely. Because blood contact and subsequent FBG adsorption are unavoidable in neural implantations, the results indicate that implant-adsorbed FBG may contribute to reactive astrogliosis around the implant as astrocytes specifically recognize adsorbed FBG.

Preliminary study on the effects of ageing cold oxygen plasma treated PET/PP with respect to protein adsorption.

Surfaces of polyethylene terephthalate (PET) and polypropylene (PP) have been modified by oxygen plasma. The surface hydrophilicity and changes in topography during up to 90 days storage in water and in dry air in a desiccator were analysed by dynamic contact angle test and atomic force microscopy (AFM). Clear ageing effects on the plasma treated surface were observed as increases in contact angle and changes in roughness as functions of increasing storage time. However, the effect of oxygen plasma treatment to increase the hydrophilicity of surface was still evident on the treated surfaces even after 90 days storage either in dry air or in water. In protein adsorption experiments, human serum albumin (HSA) and fibrinogen (Fg) were adsorbed on untreated and oxygen plasma treated PET and PP surfaces. The quantified ATR-FTIR results showed that both HSA and Fg adsorption on PET and PP surfaces decreased after oxygen plasma treatment, with the effect most evident for HSA. Although for both proteins adsorption increased with ageing, the amount of adsorbed proteins was still lower than untreated surface at 30 days. This suggests the shelf life of oxygen plasma treated samples could be as long as 30 days.

Activación de la coagulación y fibrinólisis inducida por un ejercicio de larga duración (carrera de maratón) / Coagulation and fibrinolysis activation induced by continued physical exercise (marathon race)

Introducción y objetivos. Durante el ejercicio físico aumentan tanto el potencial coagulante como el fibrinolítico. La realización de ejercicio físico regular y moderado está asociada a una disminución de los eventos trombóticos, por el contrario, el ejercicio físico extenuante parece ser un desencadenante de eventos trombóticos especialmente en sujetos no entrenados. El objetivo del estudio es valorar los efectos de una carrera de maratón sobre diferentes parámetros de la actividad coagulativa y de la actividad fibrinolítica en individuos entrenados. Material y métodos. Se han estudiado 31 deportistas amateurs que han seguido un programa de entrenamiento de 4 meses y a los que se ha tomado muestras de sangre preejercicio, postejercicio y a las 24 y 72 horas para analizar las variaciones de el tiempo de protrombina, actividad de protrombina, tiempo de tromboplastina parcial activada, fibrinógeno, antitrombina III y dímero D, en respuesta a una carrera de maratón. Resultados. Las muestras postejercicio muestran un aumento de la actividad coagulativa y un marcado incremento de los niveles de dímero D (marcador de actividad fibrinolítica) asociados a una disminución de los niveles de fibrinógeno, probablemente por consumo. Las muestras de 24h presentan una disminución de los niveles de antitrombina III, posiblemente como consecuencia de su consumo durante la fase de ejercicio. Conclusiones. Los resultados obtenidos sugieren que en sujetos que han seguido una preparación física se produce un equilibrio general de los mecanismos hemostáticos (activación de la coagulación y fibrinólisis) tras el ejercicio físico de larga duración (AU)

Introduction and objectives. During physical exercise coagulation and fibrinolytic activities are increased. Moderate and regular exercise is associated with a decrease on thrombotic episodes. On the other hand exhausting physical exercise seems to be a trigger of thrombotic events, especially on non-trained subjects. The objective of this study is to investigate the effect of a marathon race on coagulation and fibrinolytic parameters on trained subjects. Material and methods. We studied 31 amateur athletes who had followed a training program for 4 months. Blood samples were collected before and after exercise and at 24hours and 72hours to test the effects of a marathon race on prothrombin time, prothrombin activity, activated partial thromboplastin time, fibrinogen, antithrombin III (AT3) and D dimer. Results. There was an increase in coagulation activity and a marked increase in D dimmer (marker of fibrinolytic activity) in post-exercise samples. There was also a decrease in fibrinogen levels, probably due to it has been used up during the exercise period. The 24 hour hours samples showed a decrease in AT3 levels, also as a result of AT3 consumption during the physical exercise. Conclusions. These data, suggests that in trained subjects, a general balance in haemostatic mechanisms is achieved (coagulation and fibrinolysis activation) with continued physical exercise (AU)

Pharmacokinetic study of minipooled solvent/detergent-filtered cryoprecipitate factor VIII.

Eighteen cryoprecipitate minipools, each made of 30 units of low volume, concentrated cryoprecipitate, have been treated by solvent-detergent and filtration (S/D-F) in a single-use CE-marked bag system. The S/D-F cryoprecipitate contained a mean of 10.5 IU mL⁻¹ factor VIII (FVIII), 17 mg mL⁻¹ clottable fibrinogen, and >10 IU mL⁻¹ von Willebrand factor ristocetin co-factor, and anti-A and anti-B isoagglutinins were undetectable. The products have been infused in 11 severe (FVIII <1%) haemophilia A patients (mean age: 17.4 years; mean weight: 57.6 kg) at a dose close to 40 IU kg⁻¹. Patients were hospitalized for at least 36 h to determine FVIII recovery, half-life and clearance. They were also closely monitored for possible adverse events. None of the infused patients demonstrated reactions or adverse events even though they did not receive anti-allergic drugs or corticosteroids prior to infusion. The mean recovery of FVIII 10 min postinfusion was 69.7%. Mean FVIII half-life was 14.2 h and clearance was 2.6 mL h⁻¹ kg⁻¹. All patients had a bleeding-free interval of 8-10 days postS/D-F cryoprecipitate infusion. The data show that S/D-F cryoprecipitate FVIII presents a normal pharmacokinetics profile, and support that it could be safely used for the control of acute and chronic bleeding episodes in haemophilia A patients.

Pharmacokinetics, tissue distribution and excretion of porcine fibrinogen after intraperitoneal injection of a porcine-derived fibrin glue to rats.

The aim of the present study was to characterize the preclinical pharmacokinetics, tissue distribution and excretion profiles of porcine fibrinogen in rats after intraperitoneal injection of a porcine-derived fibrin glue. A sensitive and rapid isotope-labeled assay method was developed and validated for quantitative analysis in biological analysis. Porcine fibrinogen, the major composition of the fibrin glue, was radioiodinated with Na(125)I using the Iodo-Gen method. Following the purification and identification of (125)I-porcine fibrinogen, the fibrin glue containing (125)I-porcine fibrinogen was intraperitoneally administered to rats at three single dosages (100, 200, 400mg/kg of porcine fibrinogen). The results showed that the (125)I-labeled assay method was suitable for the quantification of porcine fibrinogen in plasma samples, tissue samples and excreta samples with satisfactory linear (r(2)>0.998), precision (<13%), accuracy (95.9-104.2%) and recovery (>85%). After three single administrations, plasma concentration profiles showed a slow absorption phase with the mean t(max) of 1.83-5.67 h and a slow elimination proceeding with the terminal elimination half-life (T(1/2)) of 84.5-96.3h. Porcine fibrinogen was widely distributed to most of the tissues examined after a single intraperitoneal administration at 200mg/kg to rats. The radioactive porcine fibrinogen showed substantial disposition in liver, kidneys, stomach and intestine. Approximately 79.3% and 17.2% of administered radioactivity were recovered in urine and feces within 528 h post-dosing, which indicated the major elimination route was urinary excretion.

Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers.

In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.