20 research outputs found
Optimization of project planning in the construction industry
I varje projekt finns det brister i kommunikation som kan leda till att kostnad, tid och kvalitét påverkas. Varje projekt är en tillfällig organisation med olika företag och olika personer med varierande erfarenheter inom projektering. Detta medför att varje projekt är i sig unikt och hur alla ska kommunicera med varandra kan vara stora frågetecken under projekteringens förlopp. Denna rapport tittar närmare på vilka brister och svårigheter som kan uppkomma i projekteringskedet
Commissioning status of the Frankfurt Neutron Source FRANZ LEBT and RFQ
The Frankfurt Neutron Source FRANZ will be a compact accelerator driven neutron source utilizing the 7Li(p,n)^7Be reaction with a 2 MeV proton beam. Recent comissioning efforts showed succesful proton beam operation at the targeted RFQ injection energy of 60 keV up until the point of RFQ injection. The RFQ was retrofitted with new electrodes for the injection energy of 60 keV. We report on the status of comissioning of the beamline and RFQ
Identification of Potent Ebola Virus Entry Inhibitors with Suitable Properties for in Vivo Studies
Previous
studies identified an adamantane dipeptide piperazine <b>3.47</b> that inhibits Ebola virus (EBOV) infection by targeting
the essential receptor Niemann–Pick C1 (NPC1). The physicochemical
properties of <b>3.47</b> limit its potential for testing in
vivo. Optimization by improving potency, reducing hydrophobicity,
and replacing labile moieties identified <b>3.47</b> derivatives
with improved in vitro ADME properties that are also highly active
against EBOV infection, including when tested in the presence of 50%
normal human serum (NHS). In addition, 3A4 was identified as the major
cytochrome P450 isoform that metabolizes these compounds, and accordingly,
mouse microsome stability was significantly improved when tested in
the presence of the CYP3A4 inhibitor ritonavir that is approved for
clinical use as a booster of anti-HIV drugs. Oral administration of
the EBOV inhibitors with ritonavir resulted in a pharmacokinetic profile
that supports a b.i.d. dosing regimen for efficacy studies in mice
Identification of Potent Ebola Virus Entry Inhibitors with Suitable Properties for in Vivo Studies
Previous
studies identified an adamantane dipeptide piperazine <b>3.47</b> that inhibits Ebola virus (EBOV) infection by targeting
the essential receptor Niemann–Pick C1 (NPC1). The physicochemical
properties of <b>3.47</b> limit its potential for testing in
vivo. Optimization by improving potency, reducing hydrophobicity,
and replacing labile moieties identified <b>3.47</b> derivatives
with improved in vitro ADME properties that are also highly active
against EBOV infection, including when tested in the presence of 50%
normal human serum (NHS). In addition, 3A4 was identified as the major
cytochrome P450 isoform that metabolizes these compounds, and accordingly,
mouse microsome stability was significantly improved when tested in
the presence of the CYP3A4 inhibitor ritonavir that is approved for
clinical use as a booster of anti-HIV drugs. Oral administration of
the EBOV inhibitors with ritonavir resulted in a pharmacokinetic profile
that supports a b.i.d. dosing regimen for efficacy studies in mice
Fucosylation and protein glycosylation create functional receptors for cholera toxin
Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors using its B subunit (CTB). The ganglioside (glycolipid) GM1 is thought to be the sole CT receptor; however, the mechanism by which CTB binding to GM1 mediates internalization of CT remains enigmatic. Here we report that CTB binds cell surface glycoproteins. Relative contributions of gangliosides and glycoproteins to CTB binding depend on cell type, and CTB binds primarily to glycoproteins in colonic epithelial cell lines. Using a metabolically incorporated photocrosslinking sugar, we identified one CTB-binding glycoprotein and demonstrated that the glycan portion of the molecule, not the protein, provides the CTB interaction motif. We further show that fucosylated structures promote CTB entry into a colonic epithelial cell line and subsequent host cell intoxication. CTB-binding fucosylated glycoproteins are present in normal human intestinal epithelia and could play a role in cholera. DOI: http://dx.doi.org/10.7554/eLife.09545.00
GM1 ganglioside-independent intoxication by Cholera toxin
<div><p>Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors via its B subunit (CTB). We have recently shown that in addition to the previously described binding partner ganglioside GM1, CTB binds to fucosylated proteins. Using flow cytometric analysis of primary human jejunal epithelial cells and granulocytes, we now show that CTB binding correlates with expression of the fucosylated Lewis X (Le<sup>X</sup>) glycan. This binding is competitively blocked by fucosylated oligosaccharides and fucose-binding lectins. CTB binds the Le<sup>X</sup> glycan <i>in vitro</i> when this moiety is linked to proteins but not to ceramides, and this binding can be blocked by mAb to Le<sup>X</sup>. Inhibition of glycosphingolipid synthesis or sialylation in GM1-deficient C6 rat glioma cells results in sensitization to CT-mediated intoxication. Finally, CT gavage produces an intact diarrheal response in knockout mice lacking GM1 even after additional reduction of glycosphingolipids. Hence our results show that CT can induce toxicity in the absence of GM1 and support a role for host glycoproteins in CT intoxication. These findings open up new avenues for therapies to block CT action and for design of detoxified enterotoxin-based adjuvants.</p></div
CTB binds to Le<sup>X</sup>-carrying proteins in HL-60 cells.
<p><b>(A)</b> Histogram from flow cytometry analysis of CTB-binding to HL-60 cells following pre-treatment of the cells with AAL (10 μg/ml) or pre-treatment of CTB with sugars (50 mM). <b>(B)</b> gMFI of CTB binding to HL-60 cells cultured with the indicated inhibitors (*** = p<0.001 and ** = p<0.01). <b>(C-D)</b> Western blot using anti-CTB of HL-60 cells co-cultured with <b>(C)</b> (NB-DGJ) or <b>(D)</b> (benzyl-α-GalNAc, kifunensine, or 2F-Fuc) and the precursor sugar Ac4ManNDAz to enable UV-crosslinking between CTB and glycosylated structures. Representative of two independent experiments. <b>(E)</b> Western blot using anti-Le<sup>X</sup> of HL-60 cells after incubation with CTB, lysis and immunoprecipitation with anti-CTB. One representative out of two independent experiments is shown.</p
CTB binds to Le<sup>X</sup> linked to proteins but not ceramide.
<p><b>(A)</b> GM1- or Le<sup>X</sup>-os (oligosaccharide) linked to ceramide and immobilized to wells were detected with <sup>125</sup>I labeled CTB. Relative binding is displayed as counts per minute (CPM). <b>(B-C)</b> ELISA with titrated amounts of os-linked to HSA, immobilized to wells and detected with <b>(B)</b> CTB-HRP and <b>(C)</b> G33D-HRP. Graph shows absorbance values from three independent experiments. <b>(D)</b> ELISA with os-linked to HSA, immobilized in wells and then blocked with indicated concentrations of anti-Le<sup>X</sup> antibody HI98 or isotype control (IgM), and detected with CTB-HRP. Graph shows absorbance values from one representative out of two independent experiments. <b>(E)</b> ELISA with os-linked to HSA, immobilized in wells and detected with CTB-HRP in the presence of increasing blocking concentrations of tri-Le<sup>X</sup>-os and GM1-os. Graphs show absorbance values from one representative out of two independent experiments.</p