scholarly journals A Novel ELISA Assay for the Detection of Anti-Prothrombin Antibodies in Antiphospholipid Syndrome Patients at High Risk of Thrombosis

2021 ◽  
Vol 12 ◽  
Author(s):  
Mathivanan Chinnaraj ◽  
Vittorio Pengo ◽  
Nicola Pozzi
Keyword(s):  
High Risk ◽  
Antiphospholipid Syndrome ◽  
Linear Correlation ◽  
Elisa Assay ◽  
Plastic Plate ◽  
Site Specific ◽  
Terminal Fragment ◽  
C Terminus ◽  
Improve Stability

Autoantibodies targeting prothrombin (aPT) can be found in antiphospholipid syndrome (APS) patients. However, their detection has proven difficult to standardize. Here, we developed a new ELISA assay to improve the identification of aPT and compared its performance with currently available anti-phosphatidylserine/prothrombin antibodies (aPS/PT) and autoantibodies targeting prothrombin bound to the plastic plate (aPT-A) assays using a cohort of 27 APS patients at high risk of thrombosis. We generated a novel prothrombin variant, ProTS525A-Biot, carrying an artificial tag at the C-terminus suitable for site-specific biotinylation and added the mutation S525A to improve stability. ProTS525A-Biot was immobilized to neutravidin-coated plates at the desired density and with a defined orientation, i.e., pointing the N-terminal fragment-1 toward the solvent. Antibodies against ProTS525A-Biot (aPT-Bio) were found in 24 out of 27 triple-positive APS patients (88%). When compared to aPS/PT and aPT-A, aPT-Bio showed an excellent linear correlation with aPS/PT (R2 = 0.85) but not with aPT-A (R2 = 0.40). Since aPS/PT but not aPT-A are an emerging biomarker of thrombosis in APS, this method may find utility for detecting pathogenic aPT in APS but also other prothrombotic conditions such as COVID-19.

scholarly journals Comparative Preclinical Evaluation of HER2-Targeting ABD-Fused Affibody® Molecules 177Lu-ABY-271 and 177Lu-ABY-027: Impact of DOTA Position on ABD Domain

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 839
Author(s):  
Yongsheng Liu ◽  
Anzhelika Vorobyeva ◽  
Tianqi Xu ◽  
Anna Orlova ◽  
Annika Loftenius ◽  
...  
Keyword(s):  
A Priori ◽  
Albumin Binding ◽  
Tumor Uptake ◽  
Site Specific ◽  
Affibody Molecules ◽  
Preclinical Evaluation ◽  
Renal Uptake ◽  
C Terminus ◽  
Minimal Modification ◽  
Structure Properties

Radiolabeled Affibody-based targeting agent 177Lu-ABY-027, a fusion of an anti-HER2 Affibody molecule with albumin binding domain (ABD) site-specifically labeled at the C-terminus, has demonstrated a promising biodistribution profile in mice; binding of the construct to albumin prevents glomerular filtration and significantly reduces renal uptake. In this study, we tested the hypothesis that site-specific positioning of the chelator at helix 1 of ABD, at a maximum distance from the albumin binding site, would further increase the strength of binding to albumin and decrease the renal uptake. The new construct, ABY-271 with DOTA conjugated at the back of ABD, has been labelled with 177Lu. Targeting properties of 177Lu-ABY-271 and 177Lu-ABY-027 were compared directly. 177Lu-ABY-271 specifically accumulated in SKOV-3 xenografts in mice. The tumor uptake of 177Lu-ABY-271 exceeded uptake in any other organ 24 h and later after injection. However, the renal uptake of 177Lu-ABY-271 was two-fold higher than the uptake of 177Lu-ABY-027. Thus, the placement of chelator on helix 1 of ABD does not provide desirable reduction of renal uptake. To conclude, minimal modification of the design of Affibody molecules has a strong effect on biodistribution, which cannot be predicted a priori. This necessitates extensive structure-properties relationship studies to find an optimal design of Affibody-based targeting agents for therapy.

Apheresis in high risk antiphospholipid syndrome pregnancy and autoimmune congenital heart block

2015 ◽  
Vol 53 (3) ◽  
pp. 269-278 ◽  
Author(s):  
Amelia Ruffatti ◽  
Maria Favaro ◽  
Antonio Brucato ◽  
Veronique Ramoni ◽  
Myriam Facchinetti ◽  
...  
Keyword(s):  
High Risk ◽  
Antiphospholipid Syndrome ◽  
Heart Block ◽  
Congenital Heart ◽  
Congenital Heart Block

Additional Treatments for High-Risk Obstetric Antiphospholipid Syndrome: a Comprehensive Review

2016 ◽  
Vol 53 (1) ◽  
pp. 28-39 ◽  
Author(s):  
Amelia Ruffatti ◽  
Ariela Hoxha ◽  
Maria Favaro ◽  
Marta Tonello ◽  
Anna Colpo ◽  
...  
Keyword(s):  
High Risk ◽  
Antiphospholipid Syndrome ◽  
Comprehensive Review ◽  
Obstetric Antiphospholipid Syndrome

scholarly journals Thrombocytopenia in high-risk patients with antiphospholipid syndrome

2018 ◽  
Vol 16 (3) ◽  
pp. 529-532 ◽  
Author(s):  
E. Pontara ◽  
A. Banzato ◽  
E. Bison ◽  
M. G. Cattini ◽  
G. Baroni ◽  
...  
Keyword(s):  
High Risk ◽  
Antiphospholipid Syndrome ◽  
High Risk Patients ◽  
Risk Patients

scholarly journals Proinflammatory cytokines induce accumulation of glypican-1-derived heparan sulfate and the C-terminal fragment of β-cleaved APP in autophagosomes of dividing neuronal cells

Glycobiology ◽  
2020 ◽  
Vol 30 (8) ◽  
pp. 539-549
Author(s):  
Fang Cheng ◽  
Lars-Åke Fransson ◽  
Katrin Mani
Keyword(s):  
Heparan Sulfate ◽  
Proinflammatory Cytokines ◽  
Polyacrylamide Gel Electrophoresis ◽  
Neuronal Cells ◽  
Sodium Dodecyl ◽  
Terminal Fragment ◽  
C Terminus ◽  
Tnf Α ◽  
Sds Page ◽  
N Terminus

Abstract Proinflammatory cytokines stimulate expression of β-secretase, which increases processing of amyloid precursor protein (APP), ultimately leading to the deposition of amyloid beta (Aβ). The N-terminal domain of β-cleaved APP supports Cu/NO-dependent release of heparan sulfate (HS) from the glypican-1 (Gpc-1) proteoglycan. HS is an inhibitor of β-secretase, thereby constituting a regulatory, negative feedback loop. Here, we have investigated the effect of the proinflammatory cytokines TNF-α, IL-1β and IL-6 on the interplay between APP processing and release of HS from Gpc-1 in neuronal cells. We have used deconvolution immunofluorescence microscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and a panel of monoclonal/polyclonal antibodies recognizing the released HS, the N-terminus of Aβ, Aβ, the C-terminus of APP and the autophagosome marker LC3 as well as the chemical lysosome marker LysoTrackerRed (LTR). We repeatedly found that N2a neuroblastoma cells and human neural stem cells grown in the presence of the cytokines developed large cytoplasmic clusters, which stained positive for HS, the N-terminus of Aβ, Aβ, the C-terminus of APP, LC3 and LTR, indicating accumulation of HS and APP/APP degradation products in enlarged autophagosomes/lysosomes. The SDS-PAGE of immunoisolates obtained from TNF-α-treated N2a cells by using anti-C-terminus of APP revealed the presence of SDS-stable complexes between HS and the C-terminal fragment of β-cleaved APP (βCTF) migrating in the range 10–18 kDa. Clustered accumulation of βCTF disappeared when HS release was prevented and slightly enhanced when HS release was increased. Hence, when proinflammatory cytokines induce increased processing of APP, inhibition of β-secretase by HS is insufficient, which may lead to the impaired autophagosomal degradation.

Thrombocytopenia in primary antiphospholipid syndrome, a marker of high-risk patients?

2020 ◽  
Vol 74 ◽  
pp. 106-107 ◽  
Author(s):  
Cécile M. Yelnik ◽  
Yann Nguyen ◽  
Véronique Le Guern ◽  
Eric Hachulla ◽  
Marc Lambert
Keyword(s):  
High Risk ◽  
Antiphospholipid Syndrome ◽  
Primary Antiphospholipid Syndrome ◽  
High Risk Patients ◽  
Risk Patients

scholarly journals Implications of Projected Hydroclimatic Change for Tularemia Outbreaks in High-Risk Areas across Sweden

2020 ◽  
Vol 17 (18) ◽  
pp. 6786
Author(s):  
Yan Ma ◽  
Guillaume Vigouroux ◽  
Zahra Kalantari ◽  
Romain Goldenberg ◽  
Georgia Destouni
Keyword(s):  
High Risk ◽  
Power Law ◽  
Radiative Forcing ◽  
Disease Outbreaks ◽  
Global Climate Models ◽  
Future Climate ◽  
Climate Projections ◽  
Site Specific ◽  
Risk Areas ◽  
Hydroclimatic Change

Hydroclimatic change may affect the range of some infectious diseases, including tularemia. Previous studies have investigated associations between tularemia incidence and climate variables, with some also establishing quantitative statistical disease models based on historical data, but studies considering future climate projections are scarce. This study has used and combined hydro-climatic projection outputs from multiple global climate models (GCMs) in phase six of the Coupled Model Intercomparison Project (CMIP6), and site-specific, parameterized statistical tularemia models, which all imply some type of power-law scaling with preceding-year tularemia cases, to assess possible future trends in disease outbreaks for six counties across Sweden, known to include tularemia high-risk areas. Three radiative forcing (emissions) scenarios are considered for climate change projection until year 2100, incuding low (2.6 Wm−2), medium (4.5 Wm−2), and high (8.5 Wm−2) forcing. The results show highly divergent changes in future disease outbreaks among Swedish counties, depending primarily on site-specific type of the best-fit disease power-law scaling characteristics of (mostly positive, in one case negative) sub- or super-linearity. Results also show that scenarios of steeper future climate warming do not necessarily lead to steeper increase of future disease outbreaks. Along a latitudinal gradient, the likely most realistic medium climate forcing scenario indicates future disease decreases (intermittent or overall) for the relatively southern Swedish counties Örebro and Gävleborg (Ockelbo), respectively, and disease increases of considerable or high degree for the intermediate (Dalarna, Gävleborg (Ljusdal)) and more northern (Jämtland, Norrbotten; along with the more southern Värmland exception) counties, respectively.

scholarly journals Comparing APLS and oranges: caution with the use of direct-acting oral anticoagulants (DOACs) instead of warfarin in the treatment of antiphospholipid syndrome (APLS)

2019 ◽  
Vol 12 (4) ◽  
pp. e227695
Author(s):  
Matthew Benger ◽  
Jasper Vink ◽  
Luke Blagdon Snell ◽  
Karen Breen
Keyword(s):  
High Risk ◽  
Secondary Prevention ◽  
Antiphospholipid Syndrome ◽  
Oral Anticoagulants ◽  
Multiorgan Dysfunction ◽  
Direct Acting ◽  
Direct Acting Oral Anticoagulants

A 63-year-old woman with known antiphospholipid syndrome (APLS) presented with catastrophic APLS and multiorgan dysfunction after a change in her anticoagulation from warfarin to rivaroxaban. Evidence suggests direct-acting oral anticoagulants (DOACs) like rivaroxaban may be less effective than warfarin in secondary prevention of thrombotic events in high-risk APLS patients.

scholarly journals Localization of Functional Domains of the Mitogenic Toxin of Pasteurella multocida

2001 ◽  
Vol 69 (12) ◽  
pp. 7839-7850 ◽  
Author(s):  
Gillian D. Pullinger ◽  
R. Sowdhamini ◽  
Alistair J. Lax
Keyword(s):  
Amino Acids ◽  
Fusion Proteins ◽  
Pasteurella Multocida ◽  
Transmembrane Domain ◽  
Polyclonal Antibodies ◽  
Full Length ◽  
Cell Binding ◽  
Terminal Fragment ◽  
C Terminus ◽  
N Terminus

ABSTRACT The locations of the catalytic and receptor-binding domains of thePasteurella multocida toxin (PMT) were investigated. N- and C-terminal fragments of PMT were cloned and expressed as fusion proteins with affinity tags. Purified fusion proteins were assessed in suitable assays for catalytic activity and cell-binding ability. A C-terminal fragment (amino acids 681 to 1285) was catalytically active. When microinjected into quiescent Swiss 3T3 cells, it induced changes in cell morphology typical of toxin-treated cells and stimulated DNA synthesis. An N-terminal fragment with a His tag at the C terminus (amino acids 1 to 506) competed with full-length toxin for binding to surface receptors and therefore contains the cell-binding domain. The inactive mutant containing a mutation near the C terminus (C1165S) also bound to cells in this assay. Polyclonal antibodies raised to the N-terminal PMT region bound efficiently to full-length native toxin, suggesting that the N terminus is surface located. Antibodies to the C terminus of PMT were microinjected into cells and inhibited the activity of toxin added subsequently to the medium, confirming that the C terminus contains the active site. Analysis of the PMT sequence predicted a putative transmembrane domain with predicted hydrophobic and amphipathic helices near the N terminus over the region of homology to the cytotoxic necrotizing factors. The C-terminal end of PMT was predicted to be a mixed α/β domain, a structure commonly found in catalytic domains. Homology to proteins of known structure and threading calculations supported these assignments.

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