Kinetic analysis of the cleavage of human protease-activated receptor-1/2/3 and 4 using quenched-fluorescent peptide substrates

Protease-activated receptors [PARs] are a family of G-protein-coupled seven-transmembrane domain receptors that are activated by proteolytic cleavage of their amino-terminal exodomain. To characterize the cleavage rate of human PAR-1 / 2 / 3 and 4 by trypsin and thrombin, four synthetic quenched-fluorescent peptide substrates have been synthesized. Each substrate consisted of a ten-residue peptide spanning the receptor activation cleavage site and using progress-curve kinetics, k(cat)/K-m values were determined.

Penetration of human skin by the cercariae of Schistosoma mansoni: an investigation of the effect of multiple cercarial applications.

It has previously been postulated that L-arginine emitted by penetrating Schistosoma mansoni cercariae serves as an intraspecific signal guiding other cercariae to the penetration site. It was suggested that penetrating in groups offers a selective advantage. If this hypothesis is correct and group penetration at one site on the host offers an advantage, it would follow that at such a site, successive groups of cercariae would be able to penetrate skin in either greater numbers or at a faster rate. This prediction was tested by the use of an in vitro model of cercarial penetration based on the Franz cell and using human skin. It was demonstrated that there was no increase in the percentage of cercariae able to penetrate the skin with subsequent exposures. Consequently, it seems unlikely that the release of L-arginine by cercariae during penetration could have evolved as a specific orientation system based on a selective advantage offered by group penetration.

ARTICLE: On the Curious Disappearance of Human Servitude from General International Law

The following study considers the fragmentation of law which occurred in 1956 with regard to the law on servitude. As States were unwilling to go as far as the Universal Declaration on Human in establishing that "no one shall be held in [...] servitude", the negotiators of the 1956 Supplementary Conventions moved to expunge the very term 'servitude' from the text and to replace it with the phrase 'institutions and practices similar to slavery' which could then be abolished 'progressively and as soon as possible'. The negotiation history of the 1956 Convention clear demonstrate that the Universal Declaration on Human was the elephant in the room and that it ultimately lead to a fragmentation of the law as between general international law manifest in the 1956 Supplementary Convention on the one hand and international human rights law on the other. It is for this reason that, for instance the 2001 UN and 2005 Council of Europe trafficking conventions mention both 'practices similar to slavery' and 'servitude' as types of human exploitation to be suppressed in their definition of 'trafficking in persons'.