University of Fribourg

About: University of Fribourg is a education organization based out in Fribourg, Freiburg, Switzerland. It is known for research contribution in the topics: Population & Context (language use). The organization has 6040 authors who have published 14975 publications receiving 542500 citations. The organization is also known as: UNIFR & Universität Freiburg.

Cell “vision”: complementary factor of protein corona in nanotoxicology

Abstract: Engineered nanoparticles are increasingly being considered for use as biosensors, imaging agents and drug delivery vehicles Their versatility in design and applications make them an attractive proposition for new biological and biomedical approaches Despite the remarkable speed of development in nanoscience, relatively little is known about the interaction of nanoscale objects with living systems In a biological fluid, proteins associate with nanoparticles, and the amount and the presentation of the proteins on their surface could lead to a different in vivo response than an uncoated particle Here, in addition to protein adsorption, we are going to introduce concept of cell “vision”, which would be recognized as another crucial factor that should be considered for the safe design of any type of nanoparticles that will be used in specific biomedical applications The impact of exactly the same nanoparticles on various cells is significantly different and could not be assumed for other cells; the possible mechanisms that justify this cellular response relate to the numerous detoxification strategies that any particular cell can utilize in response to nanoparticles The uptake and defence mechanism could be considerably different according to the cell type Thus, what the cell “sees”, when it is faced with nanoparticles, is most likely dependent on the cell type

The corticopontine system in the rat. II. The projection pattern.

Abstract: The projection from various cortical areas to the pontine nuclei (PN) of rats was investigated with anterograde tracing methods. As a general topological rule, a medial to lateral succession of the PN projection fields from the motor, somatosensory, and visual cortices was observed. Apart from the main "private" projections, each cortical area was found to send fibers also to disjunctive "extra-projection" territories which receive convergent inputs from two or more cortical areas. The sensorimotor and visual cortices provide the bulk of corticofugal fibers, but contributions from the following association areas were noted: frontal cortex, (dependent of the thalamic mediodorsal nucleus), rhinal sulcus region, and cingulate cortex.

Greenland – Norway separation: A geodynamic model for the North Atlantic

Abstract: The Norwegian North Atlantic rift system contains not only one of Europe’s largest offshore hydrocarbon provinces, but also one of Europe’s most investigated mountain belts, the Caledonian Orogen (Figs. 1 & 2). In this paper we combine data from both the onshore and offshore realms of this region and propose a conceptual model for the Scandinavian side of the North Atlantic rift system. The model takes into account a redefinition of the physical boundaries of the passive margin, a re-assessment of the crustal-scale structure of the conjugate Greenland-Norway margins, and a plate tectonic history that links rifting events and geometries from the Permian through to the Present. Changing the traditional boundaries of the passive margin necessarily affects calculations of the amount of extension an area has undergone, as well as interpretations of crustal structure in regional cross-sections that display both extended passive margin and unaffected craton. Our interpretation of the crustal-scale structure suggests predominantly asymmetric crustal extension and we discuss the implications of the margin structure and asymmetry on the regional evolution of the European North Atlantic passive margin.

Killer lymphocytes use granulysin, perforin and granzymes to kill intracellular parasites

Abstract: Protozoan infections are a serious global health problem. Natural killer (NK) cells and cytolytic T lymphocytes (CTLs) eliminate pathogen-infected cells by releasing cytolytic granule contents--granzyme (Gzm) proteases and the pore-forming perforin (PFN)--into the infected cell. However, these cytotoxic molecules do not kill intracellular parasites. CD8(+) CTLs protect against parasite infections in mice primarily by secreting interferon (IFN)-γ. However, human, but not rodent, cytotoxic granules contain the antimicrobial peptide granulysin (GNLY), which selectively destroys cholesterol-poor microbial membranes, and GNLY, PFN and Gzms rapidly kill intracellular bacteria. Here we show that GNLY delivers Gzms into three protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii and Leishmania major), in which the Gzms generate superoxide and inactivate oxidative defense enzymes to kill the parasite. PFN delivers GNLY and Gzms into infected cells, and GNLY then delivers Gzms to the intracellular parasites. Killer cell-mediated parasite death, which we term 'microbe-programmed cell death' or 'microptosis', is caspase independent but resembles mammalian apoptosis, causing mitochondrial swelling, transmembrane potential dissipation, membrane blebbing, phosphatidylserine exposure, DNA damage and chromatin condensation. GNLY-transgenic mice are protected against infection by T. cruzi and T. gondii, and survive infections that are lethal to wild-type mice. Thus, GNLY-, PFN- and Gzm-mediated elimination of intracellular protozoan parasites is an unappreciated immune defense mechanism.