Myeloid-related protein 8/14 complex is released by monocytes and granulocytes at the site of coronary occlusion: a novel, early, and sensitive marker of acute coronary syndromes

AIMS: We investigated whether myeloid-related protein 8/14 complex (MRP8/14) expressed by infiltrating monocytes and granulocytes may represent a mediator and early biomarker of acute coronary syndromes (ACS). METHODS AND RESULTS: Immunohistochemistry of coronary thrombi was done in 41 ACS patients. Subsequently, levels of MRP8/14 were assessed systemically in 75 patients with ACS and culprit lesions, with stable coronary artery disease (CAD), or with normal coronary arteries. In a subset of patients, MRP8/14 was measured systemically and at the site of coronary occlusion. Macrophages and granulocytes, but not platelets stained positive for MRP8/14 in 76% of 41 thrombi patients. In ACS, local MRP8/14 levels [22.0 (16.2-41.5) mg/L] were increased when compared with systemic levels [13.4 (8.1-14.7) mg/L, P = 0.03]. Systemic levels of MRP8/14 were markedly elevated [15.1 (12.1-21.8) mg/L, P = 0.001] in ACS when compared with stable CAD [4.6 (3.5-7.1) mg/L] or normals [4.8 (4.0-6.3) mg/L]. Using a cut-off level of 8 mg/L, MRP8/14 but not myoglobin or troponin, identified ACS presenting within 3 h from symptom onset. CONCLUSION: In ACS, MRP8/14 is markedly expressed at the site of coronary occlusion by invading phagocytes. The occurrence of elevated MRP8/14 in the systemic circulation prior to markers of myocardial necrosis makes it a prime candidate for the detection of unstable plaques and management of ACS.

Managing a World Heritage Site: Potentials and limitations of transdisciplinary approaches

Balancing the frequently conflicting priorities of conservation and economic development poses a challenge to management of the Swiss Alps Jungfrau- Aletsch World Heritage Site (WHS). This is a complex societal problem that calls for a knowledge-based solution. This in turn requires a transdisciplinary research framework in which problems are defined and solved cooperatively by actors from the scientific community and the life-world. In this article we re-examine studies carried out in the region of the Swiss Alps Jungfrau-Aletsch WHS, covering three key issues prevalent in transdisciplinary settings: integration of stakeholders into participatory processes; perceptions and positions; and negotiability and implementation. In the case of the Swiss Alps Jungfrau-Aletsch WHS the transdisciplinary setting created a situation of mutual learning among stakeholders from different levels and backgrounds. However, the studies showed that the benefits of such processes of mutual learning are continuously at risk of being diminished by the power play inherent in participatory approaches.

Mummies and skeletons from the Coptic monastery complex Deir el-Bachit in Thebes-west, Egypt

Deir el-Bachit is the largest known Coptic monastery complex in Thebes-West. It dates to the Late Antiquity period between the 6th and the beginning of the 10th century AD. So far, at least 26 individuals from the site were analysed anthropologically. 22 of them were excavated directly at the necropolis, the other 4 are special burials that were found at other locations nearby.Most individuals from the necropolis are male adults. There are two categories of human remains: “mummified” and “skeletonised”. The differences are probably due to social stratification. A substance similar to bitumen was found at the mummies. At that time, resin containing oils and bitumen were normally not used any more. One of the Special burials was an approximately three years old child which was found enclosed within a wall. Another special burial was a juvenile or young adult female who was found in the vault of an abandoned granary. The female was most likely pregnant and fell victim to a violent crime. This is indicated by the bones of a six months old foetus and an intravital skull fracture. She was no contemporary from the time the monastery was cultivated but was later deposited in this area.

Managing a World Heritage Site – Potentials and Limitations of Transdisciplinary Approaches

Management of the World Heritage Site Swiss Alps Jungfrau-Aletsch is challenged by the interplay of conservation and economic development. This is a situation where a knowledge-based solution is sought for a complex societal problem. This sets the frame for transdisciplinary research where the problem is defined and solved cooperatively by actors from science and the life-world. In this paper we re-examine studies carried out in the region of the WHS Jungfrau-Aletsch and reveal the issue of integration into participation, the issue of perceptions and positions as well as the issue of negotiability and implementation as key issues prevalent in transdisciplinary settings. The transdisciplinary setting in the case of the WHS Jungfrau-Aletsch constructs a situation of mutual learning among stakeholders from different levels and backgrounds. However, the positive effects of mutual learning are continuously challenged by the power play inherent in participatory approaches.

Designed ankyrin repeat proteins: a new approach to mimic complex antigens for diagnostic purposes?

Inhibitory antibodies directed against coagulation factor VIII (FVIII) can be found in patients with acquired and congenital hemophilia A. Such FVIII-inhibiting antibodies are routinely detected by the functional Bethesda Assay. However, this assay has a low sensitivity and shows a high inter-laboratory variability. Another method to detect antibodies recognizing FVIII is ELISA, but this test does not allow the distinction between inhibitory and non-inhibitory antibodies. Therefore, we aimed at replacing the intricate antigen FVIII by Designed Ankyrin Repeat Proteins (DARPins) mimicking the epitopes of FVIII inhibitors. As a model we used the well-described inhibitory human monoclonal anti-FVIII antibody, Bo2C11, for the selection on DARPin libraries. Two DARPins were selected binding to the antigen-binding site of Bo2C11, which mimic thus a functional epitope on FVIII. These DARPins inhibited the binding of the antibody to its antigen and restored FVIII activity as determined in the Bethesda assay. Furthermore, the specific DARPins were able to recognize the target antibody in human plasma and could therefore be used to test for the presence of Bo2C11-like antibodies in a large set of hemophilia A patients. These data suggest, that our approach might be used to isolate epitopes from different sets of anti-FVIII antibodies in order to develop an ELISA-based screening assay allowing the distinction of inhibitory and non-inhibitory anti-FVIII antibodies according to their antibody signatures.

Dimerization of β-site β-amyloid precursor protein-cleaving enzyme

Cleavage of the beta-amyloid precursor protein (APP) by the aspartyl protease beta-site APP-cleaving enzyme (BACE) is the first step in the generation of the amyloid beta-peptide, which is deposited in the brain of Alzheimer's disease patients. Whereas the subsequent cleavage by gamma-secretase was shown to originate from the cooperation of a multicomponent complex, it is currently unknown whether in a cellular environment BACE is enzymatically active as a monomer or in concert with other proteins. Using blue native gel electrophoresis we found that endogenous and overexpressed BACE has a molecular mass of 140 kDa instead of the expected mass of 70 kDa under denaturing conditions. This suggests that under native conditions BACE exists as a homodimer. Homodimerization was confirmed by co-immunoprecipitation of full-length BACE carrying different epitope tags. In contrast, the soluble active BACE ectodomain was exclusively present as a monomer both under native and denaturing conditions. A domain analysis revealed that the BACE ectodomain dimerized as long as it was attached to the membrane, whereas the cytoplasmic domain and the transmembrane domain were dispensable for dimerization. By adding a KKXX-endoplasmic reticulum retention signal to BACE, we demonstrate that dimerization of BACE occurs already before full maturation and pro-peptide cleavage. Furthermore, kinetic analysis of the purified native BACE dimer revealed a higher affinity and turnover rate in comparison to the monomeric soluble BACE. Dimerization of BACE might, thus, facilitate binding and cleavage of physiological substrates.

Mutation of a single residue in the ba 3 oxidase specifically impairs protonation of the pump site

The ba3-type cytochrome c oxidase from Thermus thermophilus is a membrane-bound protein complex that couples electron transfer to O2 to proton translocation across the membrane. To elucidate the mechanism of the redox-driven proton pumping, we investigated the kinetics of electron and proton transfer in a structural variant of the ba3 oxidase where a putative "pump site" was modified by replacement of Asp372 by Ile. In this structural variant, proton pumping was uncoupled from internal electron transfer and O2 reduction. The results from our studies show that proton uptake to the pump site (time constant ∼65 μs in the wild-type cytochrome c oxidase) was impaired in the Asp372Ile variant. Furthermore, a reaction step that in the wild-type cytochrome c oxidase is linked to simultaneous proton uptake and release with a time constant of ∼1.2 ms was slowed to ∼8.4 ms, and in Asp372Ile was only associated with proton uptake to the catalytic site. These data identify reaction steps that are associated with protonation and deprotonation of the pump site, and point to the area around Asp372 as the location of this site in the ba3 cytochrome c oxidase.

Syntheses, characterization and crystal structures of a new functionalised TTF derivative and its Ni(II) complex

The new ligand 4,5-bis (2-pyridylmethylsulfanyl)-4',5'-bis(cyanoethylthio)tetrathiafulvalene (BPM-BCET-TTF) and its nickel(II) complex have been prepared and crystallographically characterized. The Ni(II) complex shows octahedral geometry around the metal ion with the coordination site occupied by the pyridyl nitrogen atoms, the thioether sulfur atoms of the ligand and cis coordination of the halide ions.

Unique Sm core structure of U7 snRNPs: assembly by a specialized SMN complex and the role of a new component, Lsm11, in histone RNA processing.

A set of seven Sm proteins assemble on the Sm-binding site of spliceosomal U snRNAs to form the ring-shaped Sm core. The U7 snRNP involved in histone RNA 3' processing contains a structurally similar but biochemically unique Sm core in which two of these proteins, Sm D1 and D2, are replaced by Lsm10 and by another as yet unknown component. Here we characterize this factor, termed Lsm11, as a novel Sm-like protein with apparently two distinct functions. In vitro studies suggest that its long N-terminal part mediates an important step in histone mRNA 3'-end cleavage, most likely by recruiting a zinc finger protein previously identified as a processing factor. In contrast, the C-terminal part, which comprises two Sm motifs interrupted by an unusually long spacer, is sufficient to assemble with U7, but not U1, snRNA. Assembly of this U7-specific Sm core depends on the noncanonical Sm-binding site of U7 snRNA. Moreover, it is facilitated by a specialized SMN complex that contains Lsm10 and Lsm11 but lacks Sm D1/D2. Thus, the U7-specific Lsm11 protein not only specifies the assembly of the U7 Sm core but also fulfills an important role in U7 snRNP-mediated histone mRNA processing.

Transdisciplinarity – An Option for Applied Landscape Ecology in Complex and Uncertain Contexts.

Applied landscape ecology is considered to have a limited impact on decision-making. To improve the effectiveness of research, above all, closer cooperation between researchers and nonacademic actors is needed. We argue that a suitable research approach in this context is transdisciplinarity (td). We refer to td as interdisciplinary research that takes place in a complex environment-society context with a strong involvement of non-academic actors during the entire research process. A brief synthesis of a case study focusing on ‘Off-site Effects of Soil Erosion on the Swiss Plateau’ illustrates a promising application of a td approach.

First Staphylococcal Cassette Chromosome mec Containing a mecB-Carrying Gene Complex Independent of Transposon Tn6045 in a Macrococcus caseolyticus Isolate from a Canine Infection.

A methicillin-resistant mecB-positive Macrococcus caseolyticus (strain KM45013) was isolated from the nares of a dog with rhinitis. It contained a novel 39-kb transposon-defective complete mecB-carrying staphylococcal cassette chromosome mec element (SCCmecKM45013). SCCmecKM45013 contained 49 coding sequences (CDSs), was integrated at the 3' end of the chromosomal orfX gene, and was delimited at both ends by imperfect direct repeats functioning as integration site sequences (ISSs). SCCmecKM45013 presented two discontinuous regions of homology (SCCmec coverage of 35%) to the chromosomal and transposon Tn6045-associated SCCmec-like element of M. caseolyticus JCSC7096: (i) the mec gene complex (98.8% identity) and (ii) the ccr-carrying segment (91.8% identity). The mec gene complex, located at the right junction of the cassette, also carried the β-lactamase gene blaZm (mecRm-mecIm-mecB-blaZm). SCCmecKM45013 contained two cassette chromosome recombinase genes, ccrAm2 and ccrBm2, which shared 94.3% and 96.6% DNA identity with those of the SCCmec-like element of JCSC7096 but shared less than 52% DNA identity with the staphylococcal ccrAB and ccrC genes. Three distinct extrachromosomal circularized elements (the entire SCCmecKM45013, ΨSCCmecKM45013 lacking the ccr genes, and SCCKM45013 lacking mecB) flanked by one ISS copy, as well as the chromosomal regions remaining after excision, were detected. An unconventional circularized structure carrying the mecB gene complex was associated with two extensive direct repeat regions, which enclosed two open reading frames (ORFs) (ORF46 and ORF51) flanking the chromosomal mecB-carrying gene complex. This study revealed M. caseolyticus as a potential disease-associated bacterium in dogs and also unveiled an SCCmec element carrying mecB not associated with Tn6045 in the genus Macrococcus.