139 research outputs found
Activity of human erythrocyte membrane-bound glycohydrolases is related to Plasmodium Falciparum products
Plasmatic soluble receptor for advanced glycation end products (SRAGE) as a new oxidative stress biomarker in patients with prosthetic-joint-associated infections
Plasmatic Soluble Receptor for Advanced Glycation End Products as a New Oxidative Stress Biomarker in Patients with Prosthetic-Joint-Associated Infections?
Prosthetic joint infection (PJI) is the most common cause of failure of total joint arthroplasty, but a gold standard for PJI diagnosis
is still lacking. Advanced glycation end products (AGEs) are proinflammatory molecules inducing intracellular oxidative stress
(OS) after binding to their cell membrane receptors (RAGE). The aim of this study was to evaluate plasmatic soluble receptor
for advanced glycation end products (sRAGE), as a new OS and infection marker correlating sRAGE to the level of OS and
antioxidant defenses, in PJI, in order to explore the possible application of this new biomarker in the early diagnosis of PJI.
Plasmatic sRAGE levels (by ELISA assay), plasma antioxidant total defenses (by lag time method), plasma reactive oxygen
species (ROS), and thiobarbituric acid reactive substance (TBARS) levels (by colorimetric assay) were evaluated in 11 PJI
patients and in 30 matched controls. ROS and TBARS were significantly higher (p < 0 001) while plasma total antioxidant
capacity and sRAGE were significantly lower (p < 0 01) in patients with PJI compared to controls. Our results confirm the OS in
PJI and show a strong negative correlation between the level of sRAGE and oxidative status, suggesting the plasmatic sRAGE as
a potential marker for improving PJI early diagnosis
The role of N-glycans of HIV-1 gp41 in virus infectivity and susceptibility to the suppressive effects of carbohydrate-binding agents
The Glycan Shield of HIV Is Predominantly Oligomannose Independently of Production System or Viral Clade
The N-linked oligomannose glycans of HIV gp120 are a target for both microbicide and vaccine design. The extent of cross-clade conservation of HIV oligomannose glycans is therefore a critical consideration for the development of HIV prophylaxes. We measured the oligomannose content of virion-associated gp120 from primary virus from PBMCs for a range of viral isolates and showed cross-clade elevation (62–79%) of these glycans relative to recombinant, monomeric gp120 (∼30%). We also confirmed that pseudoviral production systems can give rise to notably elevated gp120 oligomannose levels (∼98%), compared to gp120 derived from a single-plasmid viral system using the HIVLAI backbone (56%). This study highlights differences in glycosylation between virion-associated and recombinant gp120
Allosteric Modulation of the HIV-1 gp120-gp41 Association Site by Adjacent gp120 Variable Region 1 (V1) N-Glycans Linked to Neutralization Sensitivity
The HIV-1 gp120-gp41 complex, which mediates viral fusion and cellular entry, undergoes rapid evolution within its external glycan shield to enable escape from neutralizing antibody (NAb). Understanding how conserved protein determinants retain functionality in the context of such evolution is important for their evaluation and exploitation as potential drug and/ or vaccine targets. In this study, we examined how the conserved gp120-gp41 association site, formed by the N- and Cterminal segments of gp120 and the disulfide-bonded region (DSR) of gp41, adapts to glycan changes that are linked to neutralization sensitivity. To this end, a DSR mutant virus (K601D) with defective gp120-association was sequentially passaged in peripheral blood mononuclear cells to select suppressor mutations. We reasoned that the locations of suppressors point to structural elements that are functionally linked to the gp120-gp41 association site. In culture 1, gp120 association and viral replication was restored by loss of the conserved glycan at Asn136 in V1 (T138N mutation) inconjunction with the L494I substitution in C5 within the association site. In culture 2, replication was restored with deletion of the N139INN sequence, which ablates the overlapping Asn141-Asn142-Ser-Ser potential N-linked glycosylation sequons inV1, in conjunction with D601N in the DSR. The 136 and 142 glycan mutations appeared to exert their suppressive effects by altering the dependence of gp120-gp41 interactions on the DSR residues, Leu593, Trp596 and Lys601. The 136 and/or 142glycan mutations increased the sensitivity of HIV-1 pseudovirions to the glycan-dependent NAbs 2G12 and PG16, and also pooled IgG obtained from HIV-1-infected individuals. Thus adjacent V1 glycans allosterically modulate the distal gp120-gp41 association site. We propose that this represents a mechanism for functional adaptation of the gp120-gp41 association site to an evolving glycan shield in a setting of NAb selection
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Azimuthal correlations of high transverse momentum jets at next-to-leading order in the parton branching method
AbstractThe azimuthal correlation,
Δ
ϕ
12
, of high transverse momentum jets in pp collisions at
s
=
13
TeV is studied by applying PB-TMD distributions to NLO calculations via MCatNLO together with the PB-TMD parton shower. A very good description of the cross section as a function of
Δ
ϕ
12
is observed. In the back-to-back region of
Δ
ϕ
12
→
π
, a very good agreement is observed with the PB-TMD Set 2 distributions while significant deviations are obtained with the PB-TMD Set 1 distributions. Set 1 uses the evolution scale while Set 2 uses transverse momentum as an argument in
α
s
, and the above observation therefore confirms the importance of an appropriate soft-gluon coupling in angular ordered parton evolution. The total uncertainties of the predictions are dominated by the scale uncertainties of the matrix element, while the uncertainties coming from the PB-TMDs and the corresponding PB-TMD shower are very small. The
Δ
ϕ
12
measurements are also compared with predictions using MCatNLO together Pythia8, illustrating the importance of details of the parton shower evolution.</jats:p
Azimuthal correlations of high transverse momentum jets at next-to-leading order in the parton branching method
AbstractThe azimuthal correlation,
Δ
ϕ
12
, of high transverse momentum jets in pp collisions at
s
=
13
TeV is studied by applying PB-TMD distributions to NLO calculations via MCatNLO together with the PB-TMD parton shower. A very good description of the cross section as a function of
Δ
ϕ
12
is observed. In the back-to-back region of
Δ
ϕ
12
→
π
, a very good agreement is observed with the PB-TMD Set 2 distributions while significant deviations are obtained with the PB-TMD Set 1 distributions. Set 1 uses the evolution scale while Set 2 uses transverse momentum as an argument in
α
s
, and the above observation therefore confirms the importance of an appropriate soft-gluon coupling in angular ordered parton evolution. The total uncertainties of the predictions are dominated by the scale uncertainties of the matrix element, while the uncertainties coming from the PB-TMDs and the corresponding PB-TMD shower are very small. The
Δ
ϕ
12
measurements are also compared with predictions using MCatNLO together Pythia8, illustrating the importance of details of the parton shower evolution.</jats:p
Test beam performance of a CBC3-based mini-module for the Phase-2 CMS Outer Tracker before and after neutron irradiation
The Large Hadron Collider (LHC) at CERN will undergo major upgrades to increase the instantaneous luminosity up to 5–7.5×10 cms. This High Luminosity upgrade of the LHC (HL-LHC) will deliver a total of 3000–4000 fb-1 of proton-proton collisions at a center-of-mass energy of 13–14 TeV. To cope with these challenging environmental conditions, the strip tracker of the CMS experiment will be upgraded using modules with two closely-spaced silicon sensors to provide information to include tracking in the Level-1 trigger selection. This paper describes the performance, in a test beam experiment, of the first prototype module based on the final version of the CMS Binary Chip front-end ASIC before and after the module was irradiated with neutrons. Results demonstrate that the prototype module satisfies the requirements, providing efficient tracking information, after being irradiated with a total fluence comparable to the one expected through the lifetime of the experiment
Griffithsin tandemers: flexible and potent lectin inhibitors of the human immunodeficiency virus
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