Intracellular localization of Crimean-Congo Hemorrhagic Fever (CCHF) virus glycoproteins

BACKGROUND: Crimean-Congo Hemorrhagic Fever virus (CCHFV), a member of the genus Nairovirus, family Bunyaviridae, is a tick-borne pathogen causing severe disease in humans. To better understand the CCHFV life cycle and explore potential intervention strategies, we studied the biosynthesis and intracellular targeting of the glycoproteins, which are encoded by the M genome segment. RESULTS: Following determination of the complete genome sequence of the CCHFV reference strain IbAr10200, we generated expression plasmids for the individual expression of the glycoproteins G(N )and G(C), using CMV- and chicken β-actin-driven promoters. The cellular localization of recombinantly expressed CCHFV glycoproteins was compared to authentic glycoproteins expressed during virus infection using indirect immunofluorescence assays, subcellular fractionation/western blot assays and confocal microscopy. To further elucidate potential intracellular targeting/retention signals of the two glycoproteins, GFP-fusion proteins containing different parts of the CCHFV glycoprotein were analyzed for their intracellular targeting. The N-terminal glycoprotein G(N )localized to the Golgi complex, a process mediated by retention/targeting signal(s) in the cytoplasmic domain and ectodomain of this protein. In contrast, the C-terminal glycoprotein G(C )remained in the endoplasmic reticulum but could be rescued into the Golgi complex by co-expression of G(N). CONCLUSION: The data are consistent with the intracellular targeting of most bunyavirus glycoproteins and support the general model for assembly and budding of bunyavirus particles in the Golgi compartment

Comparison of Selective Laser Melted Titanium and Magnesium Implants Coated with PCL

Degradable implant material for bone remodeling that corresponds to the physiological stability of bone has still not been developed. Promising degradable materials with good mechanical properties are magnesium and magnesium alloys. However, excessive gas production due to corrosion can lower the biocompatibility. In the present study we used the polymer coating polycaprolactone (PCL), intended to lower the corrosion rate of magnesium. Additionally, improvement of implant geometry can increase bone remodeling. Porous structures are known to support vessel ingrowth and thus increase osseointegration. With the selective laser melting (SLM) process, defined open porous structures can be created. Recently, highly reactive magnesium has also been processed by SLM. We performed studies with a flat magnesium layer and with porous magnesium implants coated with polymers. The SLM produced magnesium was compared with the titanium alloy TiAl6V4, as titanium is already established for the SLM-process. For testing the biocompatibility, we used primary murine osteoblasts. Results showed a reduced corrosion rate and good biocompatibility of the SLM produced magnesium with PCL coating.DFG/299/11-

Selektive Unkrautbekämpfung mittels Lasertechnik

In diesem Beitrag werden technische und wachstumsrelevante Aspekte des Einsatzes von Lasertechnik zur Unkrautbekämpfung vorgestellt. In der Erforschung thermischer Unkrautbekämpfung mittels Laser stand zunächst die Wechselwirkung zwischen Laserstrahl und Unkrautpflanze im Vordergrund. Nach Auswahl eines CO2-Lasers auf Basis erster Ergebnisse wurde für weitere Studien unter Berücksichtigung der Faktoren Laserenergie, Laserspotfläche, Abdeckung des Meristems, Unkrautart und Unkrautwuchsgröße die letale Schädigung modelliert. Dies wurde für die untersuchte Unkrautpflanze Amaranthus retroflexus dargestellt. Das Modell diente der Festlegung der online zu applizierenden Laserenergie. Darüber hinaus wurde die für eine wirksame Schädigung erforderliche Laserstrahlpositionierung untersucht sowie ein Testsystem entworfen. Mithilfe aktueller Bildverarbeitungssalgorithmen zur Unkrauterkennung und zur Bestimmung der Zielobjekte wurde eine Laser-Servomotor-Ansteuerung entwickelt. Das Projekt, in dessen Rahmen wesentliche Teile dieses Beitrages durchgeführt wurden, wird unter dem Titel „Untersuchungen zur Laserlichtwirkung auf der Basis von Bildanalysen auf juvenile Pflanzen zur Unkrautregulierung“ von der Deutschen Forschungsgemeinschaft gefördert.Stichwörter: Laser-Applikation, Schädigungsmodell, Unkrautbekämpfung, ZielfindungSelective weed control using laser techniquesThis contribution discusses technical and growth relevant aspects of using laser techniques for weed control. The research on thermal weed control via laser first focused on the interaction of laser beams and weed plants. Due to preliminary studies, a CO2-laser was selected for further studies with regard to the process factors laser energy, laser spot area, coverage of the weeds meristem, weed species (Amaranthus retroflexus), and weed growth stage. Thereby, the laser damage was modeled in order to control the necessary laser output power online. Furthermore, the beam positioning leading to an effective damaging of the weeds was investigated and a test device was designed. With the aid of contemporary image processing algorithms for weed recognition and meristem determination, a laser and servo-motor control was developed. Most of the studies presented in this paper were part of the project “Investigations on laser light affected weed control of juvenile plants with the aid of image processing” funded by the Deutsche Forschungsgemeinschaft.Keywords: Damage model, laser application, targeting, weed contro

SLM produced porous titanium implant improvements for enhanced vascularization and osteoblast seeding

To improve well-known titanium implants, pores can be used for increasing bone formation and close bone-implant interface. Selective Laser Melting (SLM) enables the production of any geometry and was used for implant production with 250-microm pore size. The used pore size supports vessel ingrowth, as bone formation is strongly dependent on fast vascularization. Additionally, proangiogenic factors promote implant vascularization. To functionalize the titanium with proangiogenic factors, polycaprolactone (PCL) coating can be used. The following proangiogenic factors were examined: vascular endothelial growth factor (VEGF), high mobility group box 1 (HMGB1) and chemokine (C-X-C motif) ligand 12 (CXCL12). As different surfaces lead to different cell reactions, titanium and PCL coating were compared. The growing into the porous titanium structure of primary osteoblasts was examined by cross sections. Primary osteoblasts seeded on the different surfaces were compared using Live Cell Imaging (LCI). Cross sections showed cells had proliferated, but not migrated after seven days. Although the cell count was lower on titanium PCL implants in LCI, the cell count and cell spreading area development showed promising results for titanium PCL implants. HMGB1 showed the highest migration capacity for stimulating the endothelial cell line. Future perspective would be the incorporation of HMGB1 into PCL polymer for the realization of a slow factor release.DFG/299/11-

Microsporidia::Why Make Nucleotides if You Can Steal Them?

Microsporidia are strict obligate intracellular parasites that infect a wide range of eukaryotes including humans and economically important fish and insects. Surviving and flourishing inside another eukaryotic cell is a very specialised lifestyle that requires evolutionary innovation. Genome sequence analyses show that microsporidia have lost most of the genes needed for making primary metabolites, such as amino acids and nucleotides, and also that they have only a limited capacity for making adenosine triphosphate (ATP). Since microsporidia cannot grow and replicate without the enormous amounts of energy and nucleotide building blocks needed for protein, DNA, and RNA biosynthesis, they must have evolved ways of stealing these substrates from the infected host cell. Providing they can do this, genome analyses suggest that microsporidia have the enzyme repertoire needed to use and regenerate the imported nucleotides efficiently. Recent functional studies suggest that a critical innovation for adapting to intracellular life was the acquisition by lateral gene transfer of nucleotide transport (NTT) proteins that are now present in multiple copies in all microsporidian genomes. These proteins are expressed on the parasite surface and allow microsporidia to steal ATP and other purine nucleotides for energy and biosynthesis from their host. However, it remains unclear how other essential metabolites, such as pyrimidine nucleotides, are acquired. Transcriptomic and experimental studies suggest that microsporidia might manipulate host cell metabolism and cell biological processes to promote nucleotide synthesis and to maximise the potential for ATP and nucleotide import. In this review, we summarise recent genomic and functional data relating to how microsporidia exploit their hosts for energy and building blocks needed for growth and nucleic acid metabolism and we identify some remaining outstanding questions

Influence of foaming agents on laser based manufacturing of closed-cell Ti foam

Titanium offers a high specific strength, low density, and excellent corrosion resistance. It finds application in many fields like automotive, aerospace, drilling, and biomedical industries. To improve the adherence of bone cells on implants a rough surface can be of advantage. Such a surface is featured by a foamed stru cture. For achieving a foamed Ti structure, laser induced foami ng was used. In this case, Ti powder is pre mixed with foaming agents. The foaming agents are degraded by laser induced energy and produce gaseous products like carbon dioxide, while the Ti powder is molten by the laser. Due to the fast cooling rate carb on dioxide forms gaseous bubbles in the solidifying material. Mandatory for the foaming agents is that they are biocompatible. Previous studies using the foaming agents CaCO 3 , MgCO 3 , MgTiO 3 , and MgTiO 3 mixed to Ti powder resulted in a porosity of up to 0.3. By varying the content of the foaming agent por osity and pore diameter of the samples were adjusted. It is expected that an increased porosity could be achieved by mixing the foaming agents among each other. The influence of the specific foaming agents and their mixtures on the porosity is pres ented in this work. By mixing the foaming agents together and adding them to the powder, the porosity of the samples was increased compared to only adding one foaming agent to the powder