Influence of Gelatin–Agarose Composites and Mg on Hydrogel-Carbonate Aggregate Formation and Architecture

2019 ◽  
Vol 19 (10) ◽  
pp. 5696-5715 ◽  
Author(s):  
Xiaofei Yin ◽  
Erika Griesshaber ◽  
Lurdes Fernández-Díaz ◽  
Andreas Ziegler ◽  
F. Javier García-García ◽  
...  
Keyword(s):  
Aggregate Formation ◽  
Carbonate Aggregate

A Simple and Rapid Method to Determine GPIIb/IIIa-Receptor Inhibitor Activity in Whole Blood

1999 ◽  
Vol 19 (03) ◽  
pp. 134-138
Author(s):  
Gitta Kühnel ◽  
A. C. Matzdorff
Keyword(s):  
Flow Cytometry ◽  
Platelet Count ◽  
Blood Sample ◽  
Platelet Activation ◽  
Whole Blood ◽  
Receptor Occupancy ◽  
Aggregate Formation ◽  
Inhibitor Activity ◽  
Receptor Inhibitor

SummaryWe studied the effect of GPIIb/IIIa-inhibitors on platelet activation with flow cytometry in vitro. Citrated whole blood was incubated with increasing concentrations of three different GPIIb/IIIa-inhibitors (c7E3, DMP728, XJ757), then thrombin or ADP were added and after 1 min the sample was fixed. Samples without c7E3 but with 0.1 U/ml thrombin had a decrease in platelet count. Samples with increasing concentrations of c7E3 had a lesser or no decrease in platelet count. The two other inhibitors (DMP 725, XJ757) gave similar results. GPIIb/IIIa-inhibitors prevent aggregate formation and more single platelets remain in the blood sample. The agonist-induced decrease in platelet count correlates closely with the concentration of the GPIIb/IIIa inhibitor and receptor occupancy. This correlation may be used as a simple measure for inhibitor activity in whole blood.

Glycoproteins IIb and IIIa and Platelet Thrombospondin in a Liposome Model of Platelet Aggregation

1986 ◽  
Vol 55 (02) ◽  
pp. 240-245 ◽  
Author(s):  
M E Rybak
Keyword(s):  
Platelet Aggregation ◽  
Direct Evidence ◽  
Phospholipid Vesicles ◽  
Aggregate Formation ◽  
Membrane Glycoproteins ◽  
Protein Orientation ◽  
Phosphatidylcholine Liposomes ◽  
Calcium Dependent ◽  
Lentil Lectin ◽  
Complete Reversal

SummaryPlatelet membrane glycoproteins IIb and IIIa and platelet thrombospondin were incorporated onto phosphatidylcholine liposomes, by freeze thawing and sonication. Protein orientation on the liposomes was confirmed by susceptibility to neuraminidase cleavage and binding to lentil lectin-Sepharose (GPIIb-IIIa liposomes) and to heparin-Sepharose (thrombospondin liposomes). Glycoproteins Ilb-IIIa bound 125I-fibrinogen with Kd of 7.5 × 10™7M. Binding was reversible and calcium-dependent. Ilb-IIIa liposomes underwent fibrinogen-dependent aggregation in the presence of 10 mM CaCl2. Maximal aggregate formation was observed with a combination of IIb-IIIa liposomes and thrombospondin liposomes. This aggregation was partially inhibited by preincubation with monoclonal antibodies to the IIb-IIIa complex. Addition of EDTA caused complete reversal of aggregates. Thrombospondin liposomes also underwent fibrinogen and calcium dependent aggregation, however, this aggregation was less than that observed with the GPIIb-IIIa liposomes. Maximal aggregate formation was observed with a mixture of IIb-IIIa liposomes and thrombospondin liposomes. These studies demonstrate that GPIIb-IIIa and thrombospondin can be incorporated into phospholipid vesicles with preservation of function. Direct evidence is provided to demonstrate that glycoprotein lib and Ilia and fibrinogen are sufficient for platelet aggregation and to demonstrate that thrombospondin may also contribute to platelet aggregation.

In Vitro Elucidation of the Folding Intermediates and Aggregate Formation of Hemoglobin Induced by Acetonitrile: A Multispectroscopic Approach

2016 ◽  
Vol 23 (10) ◽  
pp. 884-891 ◽  
Author(s):  
Mohammad Furkan ◽  
Asim Rizvi ◽  
Mohammad Afsar ◽  
Mohammad Rehan Ajmal ◽  
Rizwan H. Khan ◽  
...  
Keyword(s):  
Aggregate Formation ◽  
Folding Intermediates

Fibronectin regulates anoikis resistance via cell aggregate formation

2021 ◽  
Author(s):  
Hyeong-jun Han ◽  
Jee Young Sung ◽  
Su-Hyeon Kim ◽  
Un-Jung Yun ◽  
Hyeryeong Kim ◽  
...  
Keyword(s):  
Cell Aggregate ◽  
Aggregate Formation ◽  
Anoikis Resistance

scholarly journals Characterization of design grammar of peptides for regulating liquid droplets and aggregates of FUS

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kiyoto Kamagata ◽  
Rika Chiba ◽  
Ichiro Kawahata ◽  
Nanako Iwaki ◽  
Saori Kanbayashi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Electrostatic Interactions ◽  
Amyloid Fibrils ◽  
Droplet Formation ◽  
Liquid Droplets ◽  
Proof Of Concept ◽  
Aggregate Formation ◽  
Fused In Sarcoma ◽  
Dynamics Simulations

AbstractLiquid droplets of aggregation-prone proteins, which become hydrogels or form amyloid fibrils, are a potential target for drug discovery. In this study, we proposed an experiment-guided protocol for characterizing the design grammar of peptides that can regulate droplet formation and aggregation. The protocol essentially involves investigation of 19 amino acid additives and polymerization of the identified amino acids. As a proof of concept, we applied this protocol to fused in sarcoma (FUS). First, we evaluated 19 amino acid additives for an FUS solution and identified Arg and Tyr as suppressors of droplet formation. Molecular dynamics simulations suggested that the Arg additive interacts with specific residues of FUS, thereby inhibiting the cation–π and electrostatic interactions between the FUS molecules. Second, we observed that Arg polymers promote FUS droplet formation, unlike Arg monomers, by bridging the FUS molecules. Third, we found that the Arg additive suppressed solid aggregate formation of FUS, while Arg polymer enhanced it. Finally, we observed that amyloid-forming peptides induced the conversion of FUS droplets to solid aggregates of FUS. The developed protocol could be used for the primary design of peptides controlling liquid droplets and aggregates of proteins.

scholarly journals Platelet hyaluronidase 2 enrichment in acute coronary syndromes: a conceivable role in monocyte-platelet aggregate formation

2021 ◽  
Vol 36 (1) ◽  
pp. 785-789
Author(s):  
Ramona Vinci ◽  
Daniela Pedicino ◽  
Alessia D’Aiello ◽  
Pellegrino Ciampi ◽  
Myriana Ponzo ◽  
...  
Keyword(s):  
Acute Coronary Syndromes ◽  
Aggregate Formation ◽  
Platelet Aggregate ◽  
Coronary Syndromes ◽  
Hyaluronidase 2

Molecular structure analysis of ascending aorta aneurysm upon atherosclerosis

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
I Mamarelis ◽  
V Mamareli ◽  
M Kyriakidou ◽  
O Tanis ◽  
C Mamareli ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Raman Spectra ◽  
Molecular Level ◽  
Ascending Aorta ◽  
Ir And Raman Spectra ◽  
Aggregate Formation ◽  
Aorta Aneurysm ◽  
Ft Ir ◽  
Molecular Structure Analysis ◽  
Ir And Raman

Abstract Background The atherosclerotic ascending aorta could represent a potential source of emboli or could be an indicator of atherosclerosis in general with high mortality. The mechanism of aneurysm formation and atherosclerosis of the ascending aorta at the molecular level has not yet been clarified. To approach the mechanism of ascending aortic lesions and mineralization at a molecular level, we used the non-destructive FT-IR, Raman spectroscopy, SEM and Hypermicroscope. Methods Six ascending aorta biopsies were obtained from patients who underwent aortic valve replacement (AVR) cardiac surgery. CytoViva (einst inc) hyperspectral microscope was used to obtain the images of ascending aorta. The samples were dissolved in hexane on a microscope glass plate. The FT-IR and Raman spectra were recorded with Nicolet 6700 thermoshintific and micro-Raman Reinshaw (785nm, 145 mwatt), respectively. The architecture of ascending aorta biopsies was obtained by using scanning electron microscope (SEM of Fei Co) without any coating. Results FT-IR and Raman spectra showed changes arising from the increasing of lipophilic environment and aggregate formation (Fig. 1). The band at 1744 cm–1 is attributed to aldehyde CHO mode due to oxidation of lipids. The shifts of the bands of the amide I and amide II bands to lower are associated with protein damage, in agreement with SEM data. The bands at about 1170–1000 cm–1 resulted from the C-O-C of advanced glycation products as result of connecting tissues fragmentations and polymerization. The spectroscopic data were analogous with the lesions observed with SEM and hypermicroscopic images. Conclusions The present innovate molecular structure analysis showed that upon ascending aorta aneurysm development an excess of lipophilic aggregate formation and protein lesions, changing the elasticity of the aorta's wall. The released Ca2+ interacted mostly with carbonate-terminal of cellular protein chains accelerated the ascending aorta calcifications. Figure 1. FT-IR and Raman spectra Funding Acknowledgement Type of funding source: None

Cropping diversity with rice influences soil aggregate formation and nutrient storage under different tillage systems

2020 ◽  
Author(s):  
Mohammad M. R. Jahangir ◽  
Muhammad Jahiruddin ◽  
Hasina Akter ◽  
Rahana Pervin ◽  
Khandakar Rafiq Islam
Keyword(s):  
Soil Aggregate ◽  
Aggregate Formation ◽  
Nutrient Storage ◽  
Tillage Systems

scholarly journals Immobilization of Pt nanoparticles on hydrolyzed polyacrylonitrile-based nanofiber paper

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Soon Yeol Kwon ◽  
EunJu Ra ◽  
Dong Geon Jung ◽  
Seong Ho Kong
Keyword(s):  
Particle Size ◽  
Uniform Distribution ◽  
Pt Nanoparticles ◽  
Electrochemical Activity ◽  
Aggregate Formation ◽  
Free Standing ◽  
Pt Electrode ◽  
Catalytic Current ◽  
Nucleation Sites ◽  
Hydrolysis Of

AbstractThe electrochemical activity of catalysts strongly depends on the uniform distribution of monodisperse Pt nanoparticles without aggregates. Here, we propose a new hydrolysis-assisted smearing method for Pt loading on a free-standing paper-type electrode. Polyacrylonitrile (PAN)-based nanofiber paper was used as the electrode, and it acted as a Pt support. Hydrolysis of the electrode tripled the number of active nucleation sites for Pt adsorption on the PAN nanofibers, thereby significantly enhancing the wettability of the nanofibers. This facilitated the uniform distribution of Pt nanoparticles without aggregate formation up to 40 wt% (about 0.8 mg/cm2) with a particle size of about 3 nm. The catalytic current of the hydrolyzed Pt electrode in CH3OH/H2SO4 solution exceeded 213 mA/cm2 Pt mg, which was considerably greater than the current was 148 mA/cm2 Pt mg for an unhydrolyzed electrode.

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