Background: Characterization of circulating microparticles (MPs) is usually performed by flow cytometry. Annexin V, a protein that Ca(2+)-dependently binds to phosphatidylserine, has been used to define entire microparticle (MP) populations, but not all MPs bind AnxV. Recent reports have correlated AnxV negative MPs to clinical parameters in systemic diseases, which emphasize the importance of including characterization of AnxV-binding. An obstacle in flow cytometric analysis of AnxV-binding to MPs is that plasma may clot when adding the Ca(2+)-containing buffers. We here devise a simple method for comprehensive assessment of circulating MPs directly from platelet-poor plasma with characterization of AnxV-binding and of cellular origin of MPs.
Materials And Methods: With 49 samples (20 healthy controls and 29 SLE patients) a flow cytometric method analyzing MPs directly from platelet-poor plasma was developed and compared with an established, more laborious method. The method relies on using heparin to inhibit plasma coagulation induced by Ca(2+) and subsequent incubation with labeling reagents directly in platelet-poor plasma.
Results: In comparison with standard methods the new direct method showed low variability (1-12% in total MP measurement), had higher MP counts (i.e. prevents loss of MPs), was less time consuming (saved 2/3 of sample processing time) and results correlated well with an established method of analysis of washed MPs by flow cytometry (r>0.7; p<0.0001). Additionally heparin was shown not to impact MP counts, longtime storage did not alter MP concentrations, and distinct effects of freezing on MP characteristics were confirmed.
Conclusions: The direct method reduces variability due its simplicity and faster handling, and it saves sample material. It is a convenient, fast, and reproducible method for assessing the population of circulating MPs and correlates well with more cumbersome approaches. These benefits make the method well suited for large studies.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jim.2012.12.001 | DOI Listing |
Expert Rev Hematol
July 2024
Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran.
Background: Platelet storage is complicated by deleterious changes, among which reduction of ristocetin-induced platelet aggregation (RIPA) has a poorly understood mechanism. The study elucidates the mechanistic roles of all the possible players in this process.
Research Design And Methods: PRP-platelet concentrates were subjected to RIPA, collagen-induced platelet aggregation (CIPA), and flowcytometric analysis of GPIbα and PAC-1 binding from days 0 to 5 of storage.
Aesthetic Plast Surg
June 2024
Department of Dermatology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan.
Background: As the demand for non-invasive esthetic procedures to maintain a youthful appearance increases, there has been growing interest in the use of autologous platelet-rich plasma (PRP) and platelet-poor plasma (PPP) for the treatment of facial aging. However, there are few studies directly comparing the efficacy of PRP and PPP for facial rejuvenation.
Objectives: This study aimed to compare the efficacy of PRP and PPP for facial rejuvenation.
J Am Heart Assoc
September 2023
Division of Nephrology, Department of Medicine Duke University School of Medicine Durham NC.
Background Platelet-poor plasma serotonin levels are associated with adverse cardiovascular outcomes. Although plasma serotonin levels increase in chronic kidney disease, the cardiovascular implications remain unknown. Methods and Results In 1114 participants from the prospective CRIC (Chronic Renal Insufficiency Cohort) Study, we evaluated the association between plasma serotonin, categorized as undetectable, intermediate, and high (≥20 ng/mL) levels, and cross-sectional findings on echocardiography, including left ventricular hypertrophy, left ventricular ejection fraction, and pulmonary hypertension.
View Article and Find Full Text PDFSmall
February 2022
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Extracellular vesicles (EVs) are recognized as next generation diagnostic biomarkers due to their disease-specific biomolecular cargoes and importance in cell-cell communications. A major bottleneck in EV sample preparation is the inefficient and laborious isolation of nanoscale EVs (≈50-200 nm) from endogenous proteins in biological samples. Herein, a unique microfluidic platform is reported for EV-protein fractionation based on the principle of size exclusion chromatography (SEC).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!