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The exchange interaction of a brominated Co-porphyrin molecule with the Cooper pair condensate of Pb(111) is modified by reducing the Co-surface separation. The stepwise dehalogenation and dephenylation change the Co adsorption height by a few picometers. Only the residual Co-porphine core exhibits a Yu-Shiba-Rusinov bound state with low binding energy in the Bardeen-Cooper-Schrieffer energy gap. Accompanying density functional calculations reveal that the Co dz2 orbital carries the molecular magnetic moment and is responsible for the intragap state. The calculated spatial evolution of the Yu-Shiba-Rusinov wave function is compatible with the experimentally observed oscillatory attenuation of the electron-hole asymmetry with increasing lateral distance from the magnetic porphine center.
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Recently, a multitude of conceptual architectures and theoretical foundations for fog computing have been proposed. Despite this, there is still a lack of concrete frameworks to setup real-world fog landscapes. In this work, we design and implement the fog computing framework FogFrame-a system able to manage and monitor edge and cloud resources in fog landscapes and to execute Internet of Things (IoT) applications. FogFrame provides communication and interaction as well as application management within a fog landscape, namely, decentralized service placement, deployment and execution. For service placement, we formalize a system model, define an objective function and constraints, and solve the problem implementing a greedy algorithm and a genetic algorithm. The framework is evaluated with regard to Quality of Service parameters of IoT applications and the utilization of fog resources using a real-world operational testbed. The evaluation shows that the service placement is adapted according to the demand and the available resources in the fog landscape. The greedy placement leads to the maximum utilization of edge devices keeping at the edge as many services as possible, while the placement based on the genetic algorithm keeps devices from overloads by balancing between the cloud and edge. When comparing edge and cloud deployment, the service deployment time at the edge takes 14% of the deployment time in the cloud. If fog resources are utilized at maximum capacity, and a new application request arrives with the need of certain sensor equipment, service deployment becomes impossible, and the application needs to be delegated to other fog resources. The genetic algorithm allows to better accommodate new applications and keep the utilization of edge devices at about 50% CPU. During the experiments, the framework successfully reacts to runtime events: (i) services are recovered when devices disappear from the fog landscape; (ii) cloud resources and highly utilized devices are released by migrating services to new devices; (iii) and in case of overloads, services are migrated in order to release resources.
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A novel mechanism for extending the circulatory half-life of coagulation factor VIII (FVIII) has been established and evaluated preclinically. The FVIII binding domain of von Willebrand factor (D'D3) fused to human albumin (rD'D3-FP) dose dependently improved pharmacokinetics parameters of coadministered FVIII in all animal species tested, from mouse to cynomolgus monkey, after IV injection. At higher doses, the half-life of recombinant FVIII (rVIII-SingleChain) was calculated to be increased 2.6-fold to fivefold compared with rVIII-SingleChain administered alone in rats, rabbits, and cynomolgus monkeys, and it was increased 3.1-fold to 9.1-fold in mice. Sustained pharmacodynamics effects were observed (ie, activated partial thromboplastin time and thrombin generation measured ex vivo). No increased risk of thrombosis was observed with coadministration of rVIII-SingleChain and rD'D3-FP compared with rVIII-SingleChain alone. At concentrations beyond the anticipated therapeutic range, rD'D3-FP reduced the hemostatic efficacy of coadministered rVIII-SingleChain. This finding might be due to scavenging of activated FVIII by the excessive amount of rD'D3-FP which, in turn, might result in a reduced probability of the formation of the tenase complex. This observation underlines the importance of a fine-tuned balance between FVIII and its binding partner, von Willebrand factor, for hemostasis in general.
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Hemofilia A , Hemostáticos , Albuminas , Animais , Fator VIII , Meia-Vida , Expectativa de Vida , Macaca fascicularis , Camundongos , Coelhos , RatosRESUMO
In the last decade, adverse outcome pathways have been introduced in the fields of toxicology and risk assessment of chemicals as pragmatic tools with broad application potential. While their use in the pharmaceutical and cosmetics sectors has been well documented, their application in the food area remains largely unexplored. In this respect, an expert group of the International Life Sciences Institute Europe has recently explored the use of adverse outcome pathways in the safety evaluation of food additives. A key activity was the organization of a workshop, gathering delegates from the regulatory, industrial and academic areas, to discuss the potentials and challenges related to the application of adverse outcome pathways in the safety assessment of food additives. The present paper describes the outcome of this workshop followed by a number of critical considerations and perspectives defined by the International Life Sciences Institute Europe expert group.
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Rotas de Resultados Adversos , Aditivos Alimentares , Inocuidade dos Alimentos , Testes de Toxicidade/métodos , Animais , Cosméticos , Europa (Continente) , Alimentos , Humanos , Medição de RiscoRESUMO
There is considerable interest in adverse outcome pathways (AOPs) as a means of organizing biological and toxicological information to assist in data interpretation and method development. While several chemical sectors have shown considerable progress in applying this approach, this has not been the case in the food sector. In the present study, safety evaluation reports of food additives listed in Annex II of Regulation (EC) No 1333/2008 of the European Union were screened to qualitatively and quantitatively characterize toxicity induced in laboratory animals. The resulting database was used to identify the critical adverse effects used for risk assessment and to investigate whether food additives share common AOPs. Analysis of the database revealed that often such scrutiny of AOPs was not possible or necessary. For 69% of the food additives, the report did not document any adverse effects in studies based on which the safety evaluation was performed. For the remaining 31% of the 326 investigated food additives, critical adverse effects and related points of departure for establishing health-based guidance values could be identified. These mainly involved effects on the liver, kidney, cardiovascular system, lymphatic system, central nervous system and reproductive system. AOPs are available for many of these apical endpoints, albeit to different degrees of maturity. For other adverse outcomes pertinent to food additives, including gastrointestinal irritation and corrosion, AOPs are lacking. Efforts should focus on developing AOPs for these particular endpoints.
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Aditivos Alimentares/efeitos adversos , Inocuidade dos Alimentos , Humanos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Nível de Efeito Adverso não Observado , Medição de RiscoRESUMO
Haemostasis including blood coagulation is initiated upon vessel wall injury and indispensable to limit excessive blood loss. However, unregulated pathological coagulation may lead to vessel occlusion, causing thrombotic disorders, most notably myocardial infarction and stroke. Furthermore, blood exposure to foreign surfaces activates the intrinsic pathway of coagulation. Hence, various clinical scenarios, such as extracorporeal membrane oxygenation, require robust anticoagulation consequently leading to an increased bleeding risk. This study aimed to further assess the antithrombotic efficacy of the activated factor XII (FXIIa) inhibitor, rHA-Infestin-4, in several thrombosis models. In mice, rHA-Infestin-4 decreased occlusion rates in the mechanically-induced arterial (Folt's) and the FeCl3 -induced venous thrombosis model. rHA-Infestin-4 also protected from FeCl3 -induced arterial thrombosis and from stasis-prompted venous thrombosis in rabbits. Furthermore, rHA-Infestin-4 prevented occlusion in the arterio-venous shunt model in mice and rabbits where thrombosis was induced via a foreign surface. In contrast to heparin, the haemostatic capacity in rabbits was unaffected by rHA-Infestin-4. Using rodent and non-rodent species, our data demonstrate that the FXIIa inhibitor rHA-Infestin-4 decreased arterial, venous and foreign surface-induced thrombosis without affecting physiological haemostasis. Hence, we provide further evidence that targeting FXIIa represents a potent yet safe antithrombotic treatment approach, especially in foreign surface-triggered thrombosis.
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Fator XIIa/antagonistas & inibidores , Proteínas de Insetos/farmacologia , Proteínas Recombinantes de Fusão/farmacologia , Albumina Sérica/farmacologia , Trombose/tratamento farmacológico , Animais , Arteriopatias Oclusivas/tratamento farmacológico , Arteriopatias Oclusivas/etiologia , Modelos Animais de Doenças , Fibrinolíticos/farmacologia , Hemostasia/efeitos dos fármacos , Proteínas de Insetos/uso terapêutico , Cinética , Camundongos , Coelhos , Proteínas Recombinantes de Fusão/uso terapêutico , Albumina Sérica/uso terapêutico , Albumina Sérica Humana , Trombose/etiologia , Resultado do Tratamento , Trombose Venosa/tratamento farmacológico , Trombose Venosa/etiologiaRESUMO
Astaxanthin, a naturally occurring pigment used to give the characteristic orange-pink colour to salmonid fish reared in aquaculture, is also marketed as a dietary supplement. Synthetic 3S, 3'S-Astaxanthin was tested for potential harmful effects on the in utero development of New Zealand white rabbits in a study according to international regulatory guidelines. There were two control groups, one being a placebo administration and three dose levels corresponding to 100, 200, and 400 mg of 3S, 3'S-Astaxanthin per kg body weight/day. The group sizes varied from 23 to 27 litters, providing approximately 200 fetuses per group for evaluation of developmental toxicity. There were no significant effects on the health of the does, nor on the size and viability of the litters. Malformations, both external and internal, were rare and occurred in all groups, including controls with no indication of a treatment relationship. Variations were much more common, being found in all litters. However, when examined by type and frequency, no pattern emerged indicating a relationship to administration of the test substance. It is concluded that administration of 3S, 3'S-Astaxanthin in a gelatin/carbohydrate powder formulation throughout pregnancy up to 400 mg/kg body weight/day is without harmful effects on reproduction or fetal development.
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Anormalidades Induzidas por Medicamentos/patologia , Animais , Relação Dose-Resposta a Droga , Feminino , Gravidez , Coelhos , Xantofilas/administração & dosagem , Xantofilas/toxicidadeRESUMO
rVIII-SingleChain is a novel recombinant single-chain factor VIII (FVIII) construct, comprising covalently bonded heavy and light chains. Post-translational modifications of FVIII affect physicochemical parameters, including hydrophobicity and charge. The most relevant post-translational modifications of FVIII products are N-glycosylation of asparagine residues and tyrosine sulphations. Here, the physicochemical properties, thrombin cleavage products and post-translational modifications of rVIII-SingleChain were investigated and compared against commercially available recombinant FVIII (rFVIII) products with a predominant two-chain structure (B-domain deleted rFVIII and full-length rFVIII). rVIII-SingleChain was expressed in Chinese hamster ovary (CHO) cells and purified by chromatographic methods. Physicochemical properties of rVIII-SingleChain or thrombin-derived cleavage products were assessed using size-exclusion chromatography, reversed-phase chromatography and sodium dodecyl sulphate polyacrylamide gel electrophoresis. Analysis of the respective carbohydrate structures was performed after release of N-glycans by PNGase F followed by fluorescence labelling and high-performance liquid chromatography. Proteolysis by trypsin generated the corresponding peptides, which were analysed for sulphated tyrosines by liquid chromatography-electrospray ionisation time of flight-mass spectrometry. rVIII-SingleChain was shown to be of high purity and homogeneity, and presented a well-defined single-chain molecule with predominant ß-sheet conformation. The coagulation-relevant thrombin-activation products of rVIII-SingleChain were comparable with those obtained by activation of commercially available rFVIII products. rVIII-SingleChain post-translational modifications were similar to other CHO cell-derived rFVIII products for N-glycopattern and tyrosine sulphation. In conclusion, rVIII-SingleChain is of high homogeneity and purity, and provides an expected cleavage pattern on activation, setting the basis for optimal efficacy in the patient.
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Fator VIII/química , Fragmentos Fc das Imunoglobulinas/química , Fragmentos de Peptídeos/química , Proteínas Recombinantes de Fusão/química , Tirosina/análogos & derivados , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células CHO , Cricetinae , Cricetulus , Fator VIII/genética , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Dados de Sequência Molecular , Peso Molecular , Ligação Proteica , Proteínas Recombinantes de Fusão/genética , Tirosina/químicaRESUMO
INTRODUCTION: A novel fusion protein linking coagulation factor VIIa with albumin (rVIIa-FP) is currently undergoing clinical investigations. OBJECTIVE: This study was conducted to examine the biodistribution of rVIIa-FP in comparison to recombinant factor VIIa (rFVIIa). MATERIALS AND METHODS: [(3)H]-rVIIa-FP (10mgkg(-1)) or [(3)H]-rFVIIa (1.6mgkg(-1)) were administered intravenously to rats, followed by quantitative whole-body and knee joint autoradiography for 24 ([(3)H]-rFVIIa) or 240 ([(3)H]-rVIIa-FP) hours post-dose. Pharmacokinetic and excretion balance analyses were performed. RESULTS: In contrast to [(3)H]-albumin, the tissue distributions of [(3)H]-rVIIa-FP and [(3)H]-rFVIIa were similar. Within the knee, both were rapidly present within synovial and mineralized regions. Importantly, rVIIa-FP- and albumin-derived radioactivity were detectable up to 72-120hours, whereas [(3)H]-rFVIIa signals were already close to detection limits at 24hours. The longest rVIIa-FP retention times were observed in bone marrow and endosteum, in which the retention times were up to 5 times longer for rVIIa-FP compared with rFVIIa. Up to 8hours post-dose, 100% of radioactivity was assigned to unchanged [(3)H]-rVIIa-FP. Elimination of both proteins occurred primarily via the urine. CONCLUSIONS: The data suggest that the FVIIa moiety is directing rVIIa-FP's tissue distribution while the albumin moiety is responsible for the prolonged tissue retention. Importantly, rVIIa-FP is highly concentrated and retained over a long period in the growth plate of the knee joint-a vulnerable site in haemophilia patients. Overall, these improved tissue distribution characteristics of rVIIa-FP may enhance compliance and allow a more convenient dosing frequency.
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Fator VIIa/farmacocinética , Proteínas Recombinantes de Fusão/farmacocinética , Albumina Sérica/farmacocinética , Animais , Fator VIIa/genética , Masculino , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacocinética , Albumina Sérica/genética , Distribuição TecidualRESUMO
INTRODUCTION: rVIII-SingleChain (CSL627), a novel recombinant coagulation factor VIII (FVIII), is under investigation in a phase I/III clinical programme (AFFINITY) for the treatment of haemophilia A. Non-clinical studies were conducted to investigate the pharmacokinetic/pharmacodynamic profile of rVIII-SingleChain in comparison with full-length recombinant FVIII. MATERIALS AND METHODS: Binding affinity of rVIII-SingleChain for von Willebrand factor was investigated by surface plasmon resonance analysis. The pharmacokinetic profile of rVIII-SingleChain was compared with a marketed full-length recombinant FVIII concentrate (Advate(®)) in haemophilia A mice, von Willebrand factor knock-out mice, Crl:CD (SD) rats, rabbits and cynomolgus monkeys. Systemic FVIII activity or antigen levels were recorded. Procoagulant activity was measured in an FeCl3-induced arterial occlusion model and by recording thrombin generation activity (ex vivo) after administration of 200-250 IU/kg rVIII-SingleChain or full-length FVIII to haemophilia A mice. RESULTS: rVIII-SingleChain displayed a high affinity for von Willebrand factor (KD=44 pM vs. 139 pM for full-length recombinant FVIII). In all animal species tested, rVIII-SingleChain had more favourable pharmacokinetic properties than full-length recombinant FVIII: clearance was decreased and area under the curve and terminal half-life were enhanced vs. full-length recombinant FVIII, while in vivo recovery and volume of distribution were equivalent. rVIII-SingleChain showed a prolonged thrombin generation potential and prolonged procoagulant activity vs. full-length recombinant FVIII in an FeCl3-induced arterial occlusion model. CONCLUSIONS: rVIII-SingleChain had a higher affinity for von Willebrand factor than full-length recombinant FVIII and displayed favourable pharmacokinetic/pharmacodynamic properties in non-clinical models.
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Fator VIII/farmacologia , Fator VIII/farmacocinética , Fator de von Willebrand/metabolismo , Animais , Modelos Animais de Doenças , Hemofilia A/metabolismo , Macaca fascicularis , Camundongos , Coelhos , Ratos , Ressonância de Plasmônio de SuperfícieRESUMO
INTRODUCTION: The recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) is undergoing clinical trials for prophylaxis and on-demand treatment of haemophilia B patients. The aim of this study was to investigate the pharmacokinetics, whole-body and knee joint distribution of rIX-FP following intravenous administration to rats, compared with a marketed, non-fused rFIX and recombinant human albumin. MATERIAL AND METHODS: [(3)H]-rIX-FP, [(3)H]-rFIX or [(3)H]-albumin were administered to rats followed by quantitative whole-body autoradiography over 24 or 240 hours, and the tissue distribution as well as elimination of radioactivity were measured. RESULTS: Elimination of all radioactivity derived from the three proteins was shown to occur primarily via the urine. The tissue distribution of [(3)H]-rIX-FP and [(3)H]-rFIX (but not of [(3)H]-albumin) was comparable, both penetrating predominantly into bone, and well-perfused tissues, suggesting that the rIX moiety determines the distribution pattern of rIX-FP, while the albumin moity is responsible for the prolonged plasma and tissue retention. Detailed knee-joint analysis indicated rapid presence of [(3)H]-rIX-FP and [(3)H]-rFIX in synovial and mineralised bone tissue, mostly localised to the zone of calcified cartilage. Longest retention times were observed in the bone marrow and the endosteum of long bones. Intriguingly, [(3)H]-rIX-FP- and [(3)H]-albumin-derived radioactive signals were detectable up to 240 hours, while [(3)H]-rFIX-derived radioactivity rapidly declined after 1hour post-dosing correlating to the extended plasma half-life of [(3)H]-rIX-FP. CONCLUSION: The prolonged plasma and tissue retention of rIX-FP achieved by albumin fusion may allow a reduction in dosing frequency leading to increased therapeutic compliance and convenience.
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Albuminas/farmacocinética , Fator IX/farmacocinética , Animais , Humanos , Articulação do Joelho/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes de Fusão/farmacocinética , Distribuição TecidualRESUMO
The development of new and improved therapeutic options for the management of haemophilia is a great challenge for both physicians and manufacturers. After factor VIII concentrates became widely available, progress in medicine and advances in biotechnology led to the development of virus-inactivated, plasma-derived products of high purity and recombinant products, which are currently further improved regarding an extended half-life, potentially allowing for effective prophylaxis with reduced dosing frequency and hopefully less immunogenicity. This article describes some of the challenges that were experienced by the manufacturer during the development of the high-purity, plasma-derived factor VIII concentrate, Beriate® P, which, after implementation of a nanofiltration step in its manufacture, is now designated as Beriate®; it also outlines the challenges and achievements to date with half-life extended products such as the recombinant fusion proteins linking coagulation factor VIIa (rVIIa-FP) and factor IX (rIX-FP) with albumin.
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Fator IX/uso terapêutico , Fator VIII/uso terapêutico , Fator VIIa/uso terapêutico , Hemofilia A/terapia , Proteínas Recombinantes de Fusão/uso terapêutico , Albumina Sérica/uso terapêutico , Animais , Indústria Farmacêutica , HumanosRESUMO
Modeling collaboration processes is a challenging task. Existing modeling approaches are not capable of expressing the unpredictable, non-routine nature of human collaboration, which is influenced by the social context of involved collaborators. We propose a modeling approach which considers collaboration processes as the evolution of a network of collaborative documents along with a social network of collaborators. Our modeling approach, accompanied by a graphical notation and formalization, allows to capture the influence of complex social structures formed by collaborators, and therefore facilitates such activities as the discovery of socially coherent teams, social hubs, or unbiased experts. We demonstrate the applicability and expressiveness of our approach and notation, and discuss their strengths and weaknesses.
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INTRODUCTION: The preclinical efficacy and safety of rVIII-SingleChain (CSL627), a novel recombinant single-chain factor VIII, was assessed in a series of animal studies. MATERIALS AND METHODS: In the tail-clip bleeding model, hemophilia A mice were injected with escalating doses (1-150 IU/kg) of rVIII-SingleChain, B-domain deleted (BDD) rFVIII (ReFacto AF(®)), or full-length rFVIII products (Advate(®), Helixate(®)). Total blood loss and the percentage of animals in which hemostasis occurred were assessed in this observer-blinded, randomized study. In a second non-randomized study in hemophilia A mice, thromboelastographic analysis, thrombin generation, and activated partial thromboplastin time assays were performed. General safety and toxicity were assessed in three animal species, including determination of the prothrombotic potential of rVIII-SingleChain in a rabbit venous thrombosis model. RESULTS: Under acute bleeding conditions, the effect of rVIII-SingleChain on total blood loss and hemostasis was indistinguishable from BDD and full-length rFVIII. rVIII-SingleChain and full-length rFVIII (both 20 IU/kg) corrected thromboelastographic parameters, activated partial thromboplastin time, and thrombin generation to a similar degree in hemophilia A mice. In a thrombosis model, the effect of rVIII-SingleChain on thrombus incidence was non-significant and comparable to BDD rFVIII at doses up to 500 IU/kg. Treatment with rVIII-SingleChain did not cause anaphylactic reaction or local intolerance in safety and toxicity studies, and demonstrated an excellent overall safety profile. CONCLUSIONS: rVIII-SingleChain showed convincing hemostatic efficacy and excellent tolerability in animal studies, warranting continued investigation in human Phase I/III trials (AFFINITY).
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Fator VIII/farmacologia , Hemofilia A/tratamento farmacológico , Animais , Fatores de Coagulação Sanguínea/metabolismo , Fator VIII/efeitos adversos , Feminino , Hemofilia A/sangue , Hemostasia , Humanos , Masculino , Camundongos , Camundongos Knockout , Coelhos , Distribuição Aleatória , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/farmacologiaRESUMO
Albumin fusion technology has been used to enhance the pharmacokinetic properties of recombinant coagulation factors. The goal of linking albumin to coagulation factors is to extend the half-life of the coagulation factor, thereby allowing for less frequent dosing for patients with bleeding disorders, such as hemophilia. The novel recombinant fusion proteins linking coagulation factors VIIa and IX with albumin (rVIIa-FP and rIX-FP, respectively) have a longer half-life and similar hemostatic efficacy compared with available recombinant coagulation factor products. Clinical evaluation of these fusion proteins is underway, and preliminary results with rIX-FP in patients with hemophilia B are encouraging. Other advances in coagulation factor therapy include a unique recombinant single-chain factor VIII (FVIII) protein, which has improved intrinsic stability and a higher affinity for von Willebrand factor (VWF), relative to other recombinant FVIIIs, and a recombinant VWF-albumin fusion protein (rVWF-FP), which has a significant longer half-life compared to available VWF products. Evaluation of these novel recombinant proteins continues and will help determine their potential to enhance the management of patients with bleeding disorders.
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Albuminas/uso terapêutico , Fatores de Coagulação Sanguínea/uso terapêutico , Hemofilia A/tratamento farmacológico , Hemofilia B/tratamento farmacológico , Proteínas Recombinantes de Fusão/uso terapêutico , Albuminas/química , Albuminas/farmacocinética , Animais , Fatores de Coagulação Sanguínea/química , Fatores de Coagulação Sanguínea/farmacocinética , Fator VIII/química , Fator VIII/farmacocinética , Fator VIII/uso terapêutico , Humanos , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/farmacocinéticaRESUMO
BACKGROUND: The morphological analysis prior to endovascular abdominal aneurysm repair (EVAR) plays an important role in long-term outcomes. Post-imaging analysis of computed tomographic angiography (CTA) by three-dimensional reconstruction with central lumen line detection (CLL 3D-CTA) enables measurements to be made in orthogonal slices. This might be more precise than equal post-imaging analysis in axial slices by two-dimensional computed tomographic angiography (2D-CTA). PURPOSE: To evaluate the intra- and interobserver variability of CLL 3D-CTA and 2D-CTA post-imaging analysis methods and the agreement between them in pre-EVAR suitability analysis of patients with abdominal aortic aneurysm (AAA). MATERIAL AND METHODS: Anonymized CTA data-sets from 70 patients with AAA were analyzed retrospectively. Length measurements included proximal and distal aortic neck lengths and total distance from the lower renal artery to the higher iliac bifurcation. Width measurements included proximal and distal neck diameters, maximum AAA diameter and common iliac diameters just above the iliac bifurcations. The measurements were performed in random order by two vascular surgeons, twice per method with 1-month interval between readings. In the CLL 3D-CTA method we used semi-automated CLL detection by software and manual measurements on CTA slices perpendicular to CLL. The equal measurements in 2D-CTA were performed manually on axial CTA slices using a DICOM viewer workstation. The intra- and interobserver variability, as well as the agreement between the two methods were assessed by Bland-Altman test and bivariate correlation analysis. RESULTS: The intraobserver variability was significantly higher in 2D-CTA measurements for both readers. The interobserver variability was significant in 2D-CTA measurements of proximal neck dimensions while the agreement in CLL 3D-CTA analysis between the two readers was excellent in all studied parameters. The agreement between the two suitability analysis techniques was poor for both readers, especially in measurements of proximal neck's dimensions and in total aortoiliac length (p = 0.001). CONCLUSION: In pre-EVAR morphological evaluation of AAAs the CLL-3D CTA post-imaging analysis has better intra- and interobserver correlation than 2D-CTA and might represent a useful tool for the proper selection of endograft's type and size.
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Angiografia/métodos , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/cirurgia , Prótese Vascular , Imageamento Tridimensional , Tomografia Computadorizada por Raios X/métodos , Implante de Prótese Vascular/métodos , Meios de Contraste , Feminino , Humanos , Masculino , Interpretação de Imagem Radiográfica Assistida por Computador , Reprodutibilidade dos Testes , Estudos Retrospectivos , Software , Resultado do TratamentoRESUMO
Coagulation factor replacement therapy has become an established part of the prevention and treatment of bleeding episodes in patients with bleeding disorders, such as hemophilia A, hemophilia B, and von Willebrand disease. Advances in recombinant DNA technology have made it possible to modify recombinant coagulation factor products to enhance their pharmacokinetic properties, biological activity, or other characteristics. CSL Behring has created two novel albumin fusion proteins with the goal of extending the half-life of activated recombinant factor VII (rFVIIa) and recombinant factor IX (rFIX) to allow for less frequent dosing. Preclinical evaluation indicates that the resulting recombinant albumin fusion proteins (rVIIa-FP and rIX-FP) have improved pharmacokinetic properties, including an extended half-life, with preservation of hemostatic efficacy. Clinical evaluation of rIX-FP is now underway in patients with hemophilia B. In addition, we have designed a unique recombinant single-chain factor VIII protein (CSL627) that has improved stability during the manufacturing process and a high affinity for von Willebrand factor, relative to other recombinant factor VIII products. Ongoing studies of rVIIa-FP, rIX-FP, and CSL627 will help further define the potential clinical utility of these novel recombinant proteins in the management of patients with bleeding disorders.
Assuntos
Fatores de Coagulação Sanguínea/química , Fatores de Coagulação Sanguínea/uso terapêutico , Desenho de Fármacos , Fator IX/química , Fator IX/uso terapêutico , Fator VIII/química , Fator VIII/uso terapêutico , Fator VIIa/química , Fator VIIa/uso terapêutico , Hemofilia A/tratamento farmacológico , Hemofilia B/tratamento farmacológico , Humanos , Proteínas Recombinantes/química , Proteínas Recombinantes/uso terapêutico , Doenças de von Willebrand/tratamento farmacológicoRESUMO
Titanium dioxide and zinc oxide nanomaterials, used as UV protecting agents in sunscreens, were investigated for their potential genotoxicity in in vitro and in vivo test systems. Since standard OECD test methods are designed for soluble materials and genotoxicity testing for nanomaterials is still under revision, a battery of standard tests was used, covering different endpoints. Additionally, a procedure to disperse the nanomaterials in the test media and careful characterization of the dispersed test item was added to the testing methods. No genotoxicity was observed in vitro (Ames' Salmonella gene mutation test and V79 micronucleus chromosome mutation test) or in vivo (mouse bone marrow micronucleus test and Comet DNA damage assay in lung cells from rats exposed by inhalation). These results add to the still limited data base on genotoxicity test results with nanomaterials and provide congruent results of a battery of standard OECD test methods applied to nanomaterials.
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Nanoestruturas/toxicidade , Protetores Solares/toxicidade , Titânio/toxicidade , Óxido de Zinco/toxicidade , Administração por Inalação , Animais , Peso Corporal/efeitos dos fármacos , Células da Medula Óssea/efeitos dos fármacos , Linhagem Celular , Cosméticos/química , Cosméticos/toxicidade , Cricetinae , Interpretação Estatística de Dados , Macrófagos Alveolares/efeitos dos fármacos , Masculino , Camundongos , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Testes de Mutagenicidade/métodos , Nanoestruturas/administração & dosagem , Nanoestruturas/química , Ratos , Ratos Wistar , Salmonella , Protetores Solares/administração & dosagem , Protetores Solares/química , Titânio/administração & dosagem , Titânio/química , Óxido de Zinco/administração & dosagem , Óxido de Zinco/químicaRESUMO
Based on the current weight of evidence of all available data, the risk for humans from the use of nano-structured titanium dioxide (TiO(2)) or zinc oxide (ZnO) currently used in cosmetic preparations or sunscreens is considered negligible. There is a large body of information that when viewed in its entirety is considered as sufficient to demonstrate that these nano-structured ultraviolet (UV) filters, irrespective of various treatments (coatings) or crystalline structure, can be regarded as safe for use at concentrations up to 25% in cosmetic products to protect the skin from harmful effects of solar UV radiation. "Nano" TiO(2) and ZnO formulated in topically applied sunscreen products exist as aggregates of primary particles ranging from 30-150 nm in size. These aggregates are bonded such that the force of sunscreen product application onto the skin would have no impact on their structure or result in the release of primary particles. Multiple studies have shown that under exaggerated test conditions neither nano-structured TiO(2) nor ZnO penetrates beyond the stratum corneum of skin. Further, the distribution and persistence of these nano-structured metal oxides is the same compared to larger pigment-grade (i.e., >100 nm) particles, demonstrating equivalence in the recognition and elimination of such material from the body. Finally, the in vitro genotoxic and photogenotoxic profiles of these nano-structured metal oxides are of no consequence to human health. Whereas the most logical, straightforward conclusion based on data from internationally-recognized guideline studies and current 20+ year history of human use is that nano-structured TiO(2) and ZnO are safe, there will continue to be questions as "nano" conjures images of technology gone awry. Despite this rather sober view, the public health benefits of sunscreens containing nano TiO(2) and/or ZnO outweigh human safety concerns for these UV filters.
Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Nanoestruturas/química , Nanoestruturas/toxicidade , Titânio/química , Titânio/toxicidade , Óxido de Zinco/química , Óxido de Zinco/toxicidade , Animais , Humanos , Absorção Cutânea , Titânio/metabolismo , Testes de Toxicidade , Óxido de Zinco/metabolismoRESUMO
Haemophilia B is a X-chromosome linked disease characterised by a deficiency of functionally active coagulation Factor IX (FIX). Patients with severe haemophilia B at risk of recurrent bleeding are treated approximately twice a week in a prophylactic setting by application of FIX concentrates. To increase convenience and compliance of the therapy it is desirable to reduce the dosing frequency by improving the pharmacokinetic properties of FIX. Here a concept of rFIX (recombinant factor IX) albumin fusion proteins (rIX-FPs) with cleavable linker peptides derived from the FIX activation sequence is presented. Constructs of the genetic fusion of FIX to albumin via cleavable linkers were expressed in mammalian cells and characterised after purification. In vitro activation studies with FXIa demonstrated that cleavage of the linker and the activation peptide proceeded comparably well. In a clotting assay the rIX-FPs with cleavable linker showed a 10- to 30-fold increase in the molar specific clotting activity compared to fusion proteins with non-cleavable linkers. Furthermore, in-vivo recovery, terminal half-life and the AUC of rIX-FPs in rats and rabbits as determined by FIX antigen measurements were significantly increased compared to rFIX (BeneFIX). In FIX deficient (FIX(-/-)) mice the in-vivo recovery and the AUC were also significantly increased. The efficacy in reducing bleeding time was shown in FIX(-/-) mice by a tail tip bleeding model. The results suggest that rIX-FPs with a cleavable linker between FIX and albumin are a promising concept that may support the use of the albumin fusion technology to extend the half-life of FIX.