Chemical-Shift Perturbations Reflect Bile Acid Binding to Norovirus Coat Protein: Recognition Comes in Different Flavors

Bile acids have been reported as important cofactors promoting human and murine norovirus (NoV) infections in cell culture. The underlying mechanisms are not resolved. Through the use of chemical shift perturbation (CSP) NMR experiments, we identified a low-affinity bile acid binding site of a human GII.4 NoV strain. Long-timescale MD simulations reveal the formation of a ligand-accessible binding pocket of flexible shape, allowing the formation of stable viral coat protein–bile acid complexes in agreement with experimental CSP data. CSP NMR experiments also show that this mode of bile acid binding has a minor influence on the binding of histo-blood group antigens and vice versa. STD NMR experiments probing the binding of bile acids to virus-like particles of seven different strains suggest that low-affinity bile acid binding is a common feature of human NoV and should therefore be important for understanding the role of bile acids as cofactors in NoV infection.     

Results from the ORPHEUS dark matter detector

The ORPHEUS dark matter detector consists of 450 g superconducting tin granules with diameters of 28 and 36 μm. The detector has been operating in the shallow site of the underground laboratory in Bern (70 m.w.e). First preliminary results on WIMP detection sensitivity will be presented.     

Zur Fließfähigkeit von Schüttgütern – Definition und Meßverfahren

Flowability of Bulk Solids – Definition and Measuring Principles . The flowability of bulk solids has to be known for many practical applications. The present paper describes how the flowability is defined and on which physical properties it depends. Experimental determination of the flowability using a shear test is demonstrated. Conditions influencing measuremed results are described. Finally an overview of various methods used for characterization of the flowability of bulk solids is given.     

Na+ channel modulation and force-frequency relationship in human myocardium

Insect cell lines in culture are used for a variety of studies. In this laboratory imaginal disc cell lines have been established from primary cultures from third instar larvae, and used for a number of experiments. The effect of ageing on the morphology and physiology of Drosophila cell lines has received very little attention, although problems of genotypic or phenotypic changes in cell lines with age are recognized in other areas of animal cell culture. We tested our cell line Cl8+ for any difference in growth, morphology and response to 20-hydroxyecdysone (20HE) at different ages (passage numbers). The cells were found to multiply faster, adhere less firmly to the substrate and to lose the tendency to aggregate at higher passages. The response to 20HE in terms of cell numbers and induction of beta-galactosidase was similar at all passage numbers but morphological changes in hormone-treated cells were less obvious in the higher passages. Cell lines are likely to vary in the extent of ageing effects but workers are advised to be aware of the possibilities. We suggest the effects of age on cell lines should be established, and passage numbers noted in experimental reports.     

Isothermic growth of one spherulite around circular obstacles in a polypropylene foil

Growth of one spherulite within a thin foil of polypropylene around one circular obstacle or around combinations of circular obstacles is investigated. For each obstacle there exists a region of shadow, seen from the nucleus of the spherulite, which influences the growth of the spherulite. Within any region of shadow the growth fronts are evolvents of the obstacle's boundary, because the spherulite grows isotropically. When two growth fronts belonging to one spherulite meet each other inside the shadow, an intrinsic grain boundary is formed for each obstacle. Additionally, growth of one spherulite around a rectangular obstacle and a spherical obstacle is investigated.     

Localization of G-proteins in macrophages and E. coli during phagocytosis

Heterotrimeric GTP-binding proteins (G-proteins) have been shown to play an important role in cellular signalling. However, G-protein involvement in the intracellular spreading of bacterial pathogens is still poorly understood. In this study, antibodies, that recognize G-protein alpha-subunits (anti-G alpha), were used to investigate the localization of G-proteins in the macrophage-like cell line P388D1 and E. coli, also in their L-forms, during phagocytosis. In E. coli, anti-G alpha-binding sites were detected preferably in the cell wall and septa of the whole bacterial forms as well as in the cytoplasm of L-forms. Western blotting of bacterial lysates demonstrated protein bands with positive immunoreaction to antibodies against Gs alpha, Gi alpha, and Gcommon alpha with a higher affinity to the antibody against Gs alpha. Immunoreaction with the anti-Gs alpha-antibody was markedly higher in pathogenic strains of E. coli. Because of the conserved structure in all GTP-binding proteins which seem to derive from a single primordial protein involved in signal transduction mechanisms, it is reasonable to assume that some anti-Ga-positive proteins in E. coli might be related to G-proteins of higher organisms. A putative candidate for bacterial G-proteins seems to be a 36 kDa protein. Enhancement in G-protein immunostaining in the cytoplasm of macrophages around the internalized bacteria testifies to the involvement of G-proteins in mediation of endocytosis responses of phagocytes.     

“Technically Unavoidable” in Terms of Genetically Modified Organisms – an Approach for Food Control

In case of findings of authorized genetically modified (gm) plant ingredients below the 0.9 per cent threshold, exceptions from labelling requirements according to regulation (EC) No. 1829/2003 can only be made, “provided that this presence is adventitious or technically unavoidable”. The authors describe factors that should be considered regarding contaminations by gm plant ingredients as technically unavoidable or not. A practical approach for interpretation, taking into account quality control measures and documentation as well as present findings in comparable products is proposed. Received: February 23, 2007     

High‐Tech‐Cellulose‐Funktionspolymere nach dem ALCERU®‐Verfahren

Functional High‐Tech‐Cellulose materials by the ALCERU® process Cellulose is one of the eldest materials of mankind. While the use of cellulose in former times was focused on application as a more construction or as a more textile material at present time the application profile turns to a more functional material using the ALCERU® process. Shaping of pure cellulose dissolution in NMMNO permits the manufacturing of materials for upholstery, filtration or biodegradable film strips having an uniform cross section. Fibreds, which can be applied in several packaging materials, are available using different techniques for regeneration cellulose. A great field of innovative functional cellulose materials is opened up by addition of several functional additives to cellulose dissolution. In this way piezo‐electrical conductive cellulose fibres (PZT) or high‐temperature filtration membranes are to be generated if one adds special types of ceramic powders. Above all PZT green fibres are applied in more recent uses as sensors or actuators. Electrically conductive cellulose fibres or filaments, which can be also used in the textile chain, can be prepared adding conductive carbon black to a cellulose dope on the same way, too. Cellulose material having adapted conductivity to different application is available by adding an exact defined amount of carbon black to cellulose dissolution. Finally cellulose beads can be manufactured by means of varied shaping technique. The beads are showing variable particle sizes and narrow pore size distribution. These properties open up very interesting application in the field of human blood purification or chromatography.     

Minimally invasive osteosynthesis of fractures of the tibial head

The role of closed reduction techniques in tibial plateau fractures was evaluated retrospectively in a group of 33 patients. The patients had mainly B fractures (AO classification) and were treated by the arthroscopic reduction technique (n = 10) or by reduction under fluoroscopic control (n = 23) and transcutaneous screw fixation. The 21 patients with an average follow-up of 34 months (minimum 1 year) were reviewed. Using clinical and radiological criteria, 19 results were considered excellent to good. One patient with a residual deformity was revised with a total knee and 1 patient with an anatomical result had arthritic pain in the knee operated on. Arthroscopic reduction had no advantages over reduction under fluoroscopic control in this study. The specific value of the technically demanding endoscopic procedure should be questioned, as percutaneous reduction under fluoroscopic control may achieve comparable results in the majority of these cases.