Agrin defines polarized distribution of orthogonal arrays of particles in astrocytes

Accumulating evidence indicates that agrin, a heparan sulphate proteoglycan of the extracellular matrix, plays a role in the organization and maintenance of the blood-brain barrier. This evidence is based on the differential effects of agrin isoforms on the expression and distribution of the water channel protein, aquaporin-4 (AQP4), on the swelling capacity of cultured astrocytes of neonatal mice and on freeze-fracture data revealing an agrin-dependent clustering of orthogonal arrays of particles (OAPs), the structural equivalent of AQP4. Here, we show that the OAP density in agrin-null mice is dramatically decreased in comparison with wild-types, by using quantitative freeze-fracture analysis of astrocytic membranes. In contrast, anti-AQP4 immunohistochemistry has revealed that the immunoreactivity of the superficial astrocytic endfeet of the agrin-null mouse is comparable with that in wild-type mice. Moreover, in vitro, wild-type and agrin-null astrocytes cultured from mouse embryos at embryonic day 19.5 differ neither in AQP4 immunoreactivity, nor in OAP density in freeze-fracture replicas. Analyses of brain tissue samples and cultured astrocytes by reverse transcription with the polymerase chain reaction have not demonstrated any difference in the level of AQP4 mRNA between wild-type astrocytes and astrocytes from agrin-null mice. Furthermore, we have been unable to detect any difference in the swelling capacity between wild-type and agrin-null astrocytes. These results clearly demonstrate, for the first time, that agrin plays a pivotal role for the clustering of OAPs in the endfoot membranes of astrocytes, whereas the mere presence of AQP4 is not sufficient for OAP clustering.

Property-Rights-Verträge im Rahmen des Risikomanagements von Elementarschäden

noch hinzufügen

GERMANY: Creating New Property Rights on the Basis of General Legal Concepts - Without Limits?

In two cases recently decided by two different senates of the German Federal Supreme Court (Bundesgerichtshof, BGH), the following issue was raised: To what extent can the filming of sports events organized by someone else, on the one hand, and the photographing of someone else’s physical property, on the other hand, be legally controlled by the organizer of the sports event and the owner of the property respectively? In its “Hartplatzhelden.de” decision, the first senate of the Federal Supreme Court concluded that the act of filming sports events does not constitute an act of unfair competition as such, and hence is allowed even without the consent of the organizer of the sports event in question. However, the fifth senate, in its “Prussian gardens and parks” decision, held that photographing someone else’s property is subject to the consent of the owner of the grounds, provided the photographs are taken from a spot situated on the owner’s property. In spite of their different outcomes, the two cases do not necessarily contradict each other. Rather, read together, they may well lead to an unwanted – and unjustified – extension of exclusive protection, thus creating a new “organizer’s” IP right.

Internet Intermediaries and the Law Applicable to Intellectual Property Infringements

The coordination between territoriality restricted intellectual property rights and the potential global reach of Internet activities has been the focus of significant attention in recent years. The liability of Internet intermediaries offering potentially global services that may facilitate infringements of intellectual property rights by others in multiple countries poses a particular challenge in that regard. At a substantive law level, significant differences remain between jurisdictions regarding secondary liability for intellectual property rights infringements and safe harbor provisions for Internet intermediaries. The present article discusses the conflict of laws aspects of the liability of Internet intermediaries in light of the recent international efforts to adopt soft law provisions on intellectual property and private international law.

Infringement and Exclusive Jurisdiction in Intellectual Property: a Comparison for the International Law Association

The following comparison was written for the first meeting of the International Law Association newly established (2010) Committee on Intellectual Property and Private International Law (Chair: Professor Toshiyuki Kono, Kyushu University; Co-Rapporteurs: Professors Pedro de Miguel Asensio, Madrid Complutense University, and Axel Metzger, Hannover University) (hereinafter: ILA Committee), which was hosted at the Faculty of Law of the University of Lisbon in March 16-17, 2012. The comparison at stake concerns the rules on infringement and exclusive (subject-mater) jurisdiction posed (or rejected, in case of exclusive jurisdiction) by four sets of academic principles. Notwithstanding the fact that the rules in question present several differences, those differences in the majority of cases could be overcome by further studies and work of the ILA Committee, as the following comparison explains.