Biodistribution of the recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) in rats

AbstractIntroductionThe 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[3H]-rIX-FP, [3H]-rFIX or [3H]-albumin were administered to rats followed by quantitative whole-body autoradiography over 24 or 240hours, and the tissue distribution as well as elimination of radioactivity were measured.ResultsElimination of all radioactivity derived from the three proteins was shown to occur primarily via the urine. The tissue distribution of [3H]-rIX-FP and [3H]-rFIX (but not of [3H]-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 [3H]-rIX-FP and [3H]-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, [3H]-rIX-FP- and [3H]-albumin-derived radioactive signals were detectable up to 240hours, while [3H]-rFIX-derived radioactivity rapidly declined after 1hour post-dosing correlating to the extended plasma half-life of [3H]-rIX-FP.ConclusionThe 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

Unravelling the age of fine roots of temperate and boreal forests

Fine roots support the water and nutrient demands of plants and supply carbon to soils. Quantifying turnover times of fine roots is crucial for modeling soil organic matter dynamics and constraining carbon cycle–climate feedbacks. Here we challenge widely used isotopebased estimates suggesting the turnover of fine roots of trees to be as slow as a decade. By recording annual growth rings of roots from woody plant species, we show that mean chronological ages of fine roots vary from <1 to 12 years in temperate, boreal and sub-arctic forests. Radiocarbon dating reveals the same roots to be constructed from 10 ± 1 year (mean ± 1 SE) older carbon. This dramatic difference provides evidence for a time lag between plant carbon assimilation and production of fine roots, most likely due to internal carbon storage. The high root turnover documented here implies greater carbon inputs into soils than previously thought which has wide-ranging implications for quantifying ecosystem carbon allocation.Peer reviewe

Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases

Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises

Ein Polymorphismus im Intron 3 des p53-Gens und erhöhtes Risiko für Ovarialkarzinom

Jeder vierte gynäkologische Tumor ist ein Ovarialkarzinom. Das Ovarialkarzinom stellt die häufigste Todesursache bei Tumorerkrankungen des weiblichen Genitale dar. Frauen mit einem erhöhten Risiko für ein Ovarialkarzinom werden von der Diagnostik bisher nur in unzureichender Weise vor dem Ausbruch der Erkrankung erfaßt. In der hier vorgelegten Arbeit wurde der Zusammenhang zwischen dem polymorphen Auftreten eines sechzehn Basenpaare umfassenden Sequenzabschnittes im Intron 3 des Tumorsuppressorgens p53 und dem Risiko, an einem Ovarialkarzinom zu erkranken, untersucht. Dadurch sollte ein möglicher molekularer Marker für die Risikoabschätzung auf seine Aussagekraft getestet werden. Bei dem Vergleich der Häufigkeiten der beiden Allele des Polymorphismus p53PIN3, A1, dem Wildtypallel, und A2, dem Allel mit der Insertion von sechzehn Basenpaaren, bei 305 gesunden Blutspenderinnen und 155 Ovarialkarzinompatientinnen fand man folgende Ergebnisse: Das A2 Allel ist in der Gruppe der Ovarialkarzinompatientinnen signifikant häufiger vertreten als in der Kontrollgruppe (p: 0,016). Es ist das A2 Allel mit einer Erhöhung des Risikos, an dieser Krankheit zu erkranken, assoziiert (OR: 1,6; 95 Prozent KI: 1,0-2,5). Des weiteren hat sich gezeigt, daß das A2 Allel häufiger in den höheren Staging- und Gradingklassen zu finden ist. Hier im besonderen bei den großen T3 Tumoren (p: 0,002) und solchen niedrigen Differenzierungsgrades (G3 (p: 0,027)). Es könnte sich demnach der Polymorphismus p53PIN3 - nach einer weiteren Prüfung im Rahmen einer bevölkerungsbezogenen, prospektiv angelegten Studie - durchaus als ein sinnvoller Risikomarker für das Ovarialkarzinom erweisen

The Thioredoxin Boxes of Thyroglobulin: Possible Implications for Intermolecular Disulfide Bond Formation in the Follicle Lumen

Multimerization of thyroglobulin (TG) takes place extracellularly in the thyroid follicle lumen and is regarded as a mechanism to store TG at high concentrations. Human thyroglobulin (hTG) has been shown to multimerize mainly by intermolecular disulfide crosslinks. We recently noted that TG of various mammalian species contains three highly conserved thioredoxin boxes (CXXC). This sequence is known to underlie the enzymatic activity of protein disulfide isomerase (PDI). As hTG formed intermolecular disulfide bonds in the absence of other proteins depending on the redox conditions and hTG concentration, the CXXC-boxes of TG might provide the structural basis for self-assisted intermolecular cross-linking. To test this hypothesis we prepared a recombinant TG fragment containing the three thioredoxin boxes. This fragment exhibited a redox activity amounting to about 10 % of the activity of PDI at redox conditions supposed to be present in the extracellular space. This activity might be supplemented by the oxidizing system of the apical cell surfaces of thyrocytes facing the follicle lumen. Indeed, incubation of hTG with peroxidase and H 2 O 2 resulted in intermolecular disulfide bridge formation. Our results suggest a combined mechanism of selfassisted and peroxidase-mediated disulfide bond formation leading to the intermolecular cross-linking of lumenal hTG

Knowledge-based risk assessment for intelligent vehicles

Abstract — In order to set up assistance systems in intelligent vehicles or to control an autonomous vehicle a number of cognitive functions has to be realized in an integrated architecture. In this paper we propose a knowledge-based risk assessment procedure in order to identify objects which might be dangerous for the own vehicle. Having an advanced vision system with gaze control in mind a knowledge-based risk assessment can determine where to concentrate the attention. The approach is evaluated by simulating different traffic scenes. 1