In vivo testing of gold nanoparticles using the Caenorhabditis elegans model organism

Gold nanoparticles (AuNPs) are present in many man-made products and cosmetics, and are also used by the food and medical industries. Tight regulations regarding the use of mammalian animals for product testing can hamper the study of the specific interactions between engineered nanoparticles and biological systems. Invertebrate models, such as the nematode Caenorhabditis elegans (C. elegans), can offer alternative approaches during the early phases of nanoparticle discovery. Here, we thoroughly evaluated the biodistribution of 11-nm and 150-nm citrate-capped AuNPs in the model organism C. elegans at multiple scales, moving from micrometric to nanometric resolution and from the organismal to cellular level. We confirmed that the nanoparticles were not able to cross the intestinal and dermal barriers. We investigated the effect of AuNPs on the survival and reproductive performance of C. elegans, and correlated these effects with the uptake of AuNPs in terms of their number, surface area, and metal mass. In general, exposure to 11-nm AuNPs resulted in a higher toxicity than the larger 150-nm AuNPs. NP aggregation inside C. elegans was determined using absorbance microspectroscopy, which allowed the plasmonic properties of AuNPs to be correlated with their confinement inside the intestinal lumen, where anatomical traits, acidic pH and the presence of biomolecules play an essential role on NP aggregation. Finally, quantitative PCR of selected molecular markers indicated that exposure to AuNPs did not significantly affect endocytosis and intestinal barrier integrity. Statement of significance This work highlights how the simple, yet information-rich, animal model C. elegans is ideally suited for preliminary screening of nanoparticles or chemicals mitigating most of the difficulties associated with mammalian animal models, namely the ethical issues, the high cost, and time constraints. This is of particular relevance to the cosmetic, food, and pharmaceutical industries, which all have to justify the use of animals, especially during the discovery, development and initial screening phases. This work provides a detailed and thorough analysis of 11-nm and 150-nm AuNPs at multiple levels of organization (the whole organism, organs, tissues, cells and molecules).Peer ReviewedPostprint (author's final draft

Pre-competition cardiac screening in professional handball players - setting up at the EHF European Handball Championship 2010 in Austria

Zusammenfassung: In vielen Sportarten wird ein regelmäßiges, richtliniengetreues kardiales Screening zur Verhinderung des plötzlichen Herztods noch immer nicht gewährleistet. Wir nahmen die Handball Europameisterschaften, welche 2010 in Wien und weiteren Städten in Österreich stattfanden, zum Anlass, die aktuelle Situation bei Toplevel-Handballern zu untersuchen: Ein standardisierter Fragebogen wurde vor dem Turnier an alle qualifizierten Teams und Spieler versandt. Eine Rücklaufrate von 42,7 % kann zum Schluss führen, dass das Problem des plötzlichen Herztods bei den Spielern und Verantwortlichen unterschätzt wird. Die überwiegende Mehrzahl der Spieler (82 %) wurde gemäß der Auswertung der Fragebögen korrekt, entsprechend der aktuellen Screening-Richtlinien untersucht. In gut der Hälfte der Teams wurde das Screening jedoch "inhomogen" durchgeführt. 5 Spieler (4,1 %) wurden zumindest nicht innerhalb der letzten Jahre untersucht, bei 1 Spieler (0,8 %) wurde kein EKG durchgeführt. Während 69 % der Handballer ihr erstes Screening erst nach dem Alter von 18 Jahren durchliefen, wurden 16 Spieler (13,1 %) gar niemals zuvor einer kardialen Vorsorgeuntersuchung unterzogen. Schließlich identifizierten wir aufgrund der Fragebögen 17 Athleten (13,9 %) mit einer hoch suspekten Anamnese, wovon 2 Athleten (1,6 %) niemals zuvor kardiologisch abgeklärt wurde

Lipid apheresis: oxidative stress, rheology, and vasodilatation

In the treatment of homozygous and therapy-resistant hypercholesterolemia, lipid apheresis enables not only low density lipoprotein (LDL) cholesterol to be lowered by approximately 60%, but also oxidative stress factors to be influenced and adhesion molecules reduced. This was investigated in a group of 12 patients using the heparin-induced extracorporeal LDL precipitation (H.E.L.P.) procedure

Three-dimensional architecture and biogenesis of membrane structures associated with hepatitis C virus replication

All positive strand RNA viruses are known to replicate their genomes in close association with intracellular membranes. In case of the hepatitis C virus (HCV), a member of the family Flaviviridae, infected cells contain accumulations of vesicles forming a membranous web (MW) that is thought to be the site of viral RNA replication. However, little is known about the biogenesis and three-dimensional structure of the MW. In this study we used a combination of immunofluorescence- and electron microscopy (EM)-based methods to analyze the membranous structures induced by HCV in infected cells. We found that the MW is derived primarily from the endoplasmic reticulum (ER) and contains markers of rough ER as well as markers of early and late endosomes, COP vesicles, mitochondria and lipid droplets (LDs). The main constituents of the MW are single and double membrane vesicles (DMVs). The latter predominate and the kinetic of their appearance correlates with kinetics of viral RNA replication. DMVs are induced primarily by NS5A whereas NS4B induces single membrane vesicles arguing that MW formation requires the concerted action of several HCV replicase proteins. Three-dimensional reconstructions identify DMVs as protrusions from the ER membrane into the cytosol, frequently connected to the ER membrane via a neck-like structure. In addition, late in infection multi-membrane vesicles become evident, presumably as a result of a stress-induced reaction. Thus, the morphology of the membranous rearrangements induced in HCV-infected cells resemble those of the unrelated picorna-, corona- and arteriviruses, but are clearly distinct from those of the closely related flaviviruses. These results reveal unexpected similarities between HCV and distantly related positive-strand RNA viruses presumably reflecting similarities in cellular pathways exploited by these viruses to establish their membranous replication factories

Evolution of the nucleus

Under a Creative Commons license.The nucleus represents a major evolutionary transition. As a consequence of separating translation from transcription many new functions arose, which likely contributed to the remarkable success of eukaryotic cells. Here we will consider what has recently emerged on the evolutionary histories of several key aspects of nuclear biology; the nuclear pore complex, the lamina, centrosomes and evidence for prokaryotic origins of relevant players.Work in our laboratories was supported by the following agencies, and which is gratefully acknowledged; MRC and Wellcome Trust (MR/K008749/1 and 090007/Z/09/Z respectively, to MCF), C2A Junta de Andalucia to DPD and DFG GR1642/4-1 to RG.Open Access funded by Wellcome Trust.Peer Reviewe

Pre-competition cardiac screening in professional handball players - setting up at the EHF European Handball Championship 2010 in Austria

In many sports, regular cardiac screening for exercise-associated sudden cardiac death is still not provided. To set up the current situation in top-skilled handball players qualified for the 2010 European Handball Championship in Austria, a standardised questionnaire was sent to every team. The fact that only 42.7% of the players returned the questionnaire may lead to the conclusion that the awareness of the problem is quite low. However, 82% of these players have been screened according to current recommendations. Half of the teams were screened inhomogeneously: 5 players (4.1%) have not been screened within the last years, 1 athlete (0.8%) was screened without an ECG. While 69% of the athletes got their first screening only after the age of 18, 16 players (13.1%) never went through a specific screening ever. We identified 17 athletes (13.9%) with a highly suspicious history, 2 of them (1.6%) never underwent a medical screening at all

Pre-assembled Nuclear Pores Insert into the Nuclear Envelope during Early Development

SummaryNuclear pore complexes (NPCs) span the nuclear envelope (NE) and mediate nucleocytoplasmic transport. In metazoan oocytes and early embryos, NPCs reside not only within the NE, but also at some endoplasmic reticulum (ER) membrane sheets, termed annulate lamellae (AL). Although a role for AL as NPC storage pools has been discussed, it remains controversial whether and how they contribute to the NPC density at the NE. Here, we show that AL insert into the NE as the ER feeds rapid nuclear expansion in Drosophila blastoderm embryos. We demonstrate that NPCs within AL resemble pore scaffolds that mature only upon insertion into the NE. We delineate a topological model in which NE openings are critical for AL uptake that nevertheless occurs without compromising the permeability barrier of the NE. We finally show that this unanticipated mode of pore insertion is developmentally regulated and operates prior to gastrulation

Building bridges between cellular and molecular structural biology

The integration of cellular and molecular structural data is key to understanding the function of macromolecular assemblies and complexes in their in vivo context. Here we report on the outcomes of a workshop that discussed how to integrate structural data from a range of public archives. The workshop identified two main priorities: the development of tools and file formats to support segmentation (that is, the decomposition of a three-dimensional volume into regions that can be associated with defined objects), and the development of tools to support the annotation of biological structures.Peer reviewe