The rapid one-step gradient centrifugation procedure for simultaneous isolation of granulocytic and mononuclear leukocytes from human blood: Biological, physical and chemical bases

1983 ◽  
Vol 12 (2) ◽  
pp. 103-111 ◽  
Author(s):  
Y.H. Thong ◽  
J.M. Currell ◽  
R.L. Rodwell
Keyword(s):  
Human Blood ◽  
Gradient Centrifugation ◽  
Mononuclear Leukocytes ◽  
One Step ◽  
Physical And Chemical

scholarly journals Specification and Evaluation of Plasticizer Migration Simulants for Human Blood Products: A Delphi Study

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1081
Author(s):  
Aurélie Thelliez ◽  
Grégory Hénard ◽  
Bruno Delorme ◽  
Sonia Chatellier ◽  
Cécile Danel ◽  
...  
Keyword(s):  
Human Blood ◽  
Delphi Study ◽  
Clinical Situation ◽  
Blood Products ◽  
Laboratory Studies ◽  
Short Supply ◽  
Plasticizer Migration ◽  
Physical And Chemical ◽  
Form Stability ◽  
Qualitative Phase

Potentially toxic plasticizers are commonly added to polyvinyl chloride medical devices for transfusion in order to improve their flexibility and workability. As the plasticizers are not chemically bonded to the PVC, they can be released into labile blood products (LBPs) during storage. Ideally, LBPs would be used in laboratory studies of plasticizer migration from the medical device. However, short supply (i.e., limited stocks of human blood in collection centres) has prompted the development of specific simulants for each type of LBP in the evaluation of new transfusion devices. We performed a Delphi study with a multidisciplinary panel of 24 experts. In the first (qualitative) phase, the panel developed consensus definitions of the specification criteria to be met by each migration simulant. Next, we reviewed the literature on techniques for simulating the migration of plasticizers into LBPs. A questionnaire was elaborated and sent out to the experts, and the replies were synthesized in order to obtain a consensus. The qualitative study established specifications for each biological matrix (whole blood, red blood cell concentrate, plasma, and platelet concentrate) and defined the criteria required for a suitable LBP simulant. Ten criteria were suggested: physical and chemical characteristics, opacity, form, stability, composition, ability to mimic a particular clinical situation, ease and safety of use, a simulant–plastic interaction correlated with blood, and compatibility with analytical methods. The questionnaire data revealed a consensus on the use of natural products (such as pig’s blood) to mimic the four LBPs. Opinions diverged with regard to synthetic products. However, an isotonic solution and a rheological property modifier were considered to be of value in the design of synthetic simulants. Consensus reached by the Delphi group could be used as a database for the development of simulants used to assess the migration of plasticizers from PVC bags into LBPs.

Micro-Ribbons and Micro-Wires Silica Synthesis Using Bottom-Top Technique

2020 ◽  
Vol 1008 ◽  
pp. 33-38
Author(s):  
Marwa Nabil ◽  
Hussien A. Motaweh
Keyword(s):  
Selection Process ◽  
Chemical Properties ◽  
Industrial Applications ◽  
Preparation Process ◽  
Pure Silica ◽  
One Step ◽  
Materials Used ◽  
Sonication Technique ◽  
Silica Synthesis ◽  
Physical And Chemical

Silica is one of the most important materials used in many industries. The basic factor on which the selection process depends is the structural form, which is dependent on the various physical and chemical properties. One of the common methods in preparing pure silica is that it needs more than one stage to ensure the preparation process completion. The goal of this research is studying the nucleation technique (Bottom-top) for micro-wires and micro-ribbons silica synthesis. The silica nanoand microstructures are prepared using a duality (one step); a combination of alkali chemical etching process {potassium hydroxide (3 wt %) and n-propanol (30 Vol %)} and the ultra-sonication technique. In addition, the used materials in the preparation process are environmentally friendly materials that produce no harmful residues. The powder product is characterized using XRD, FTIR, Raman spectrum and SEM for determining the shape of architectures. The most significant factor of the nucleation mechanism is the sonication time of silica powder production during the dual technique. The product stages are as follows; silica nanoparticles (21-38 nm), nanoclusters silica (46 – 67 nm), micro-wires silica (1.17 – 6.29 μm), and micro-ribbons silica (19.4 – 54.1 μm). It's allowing for use in environmental applications (multiple wastewater purification, multiple uses in air filters, as well as many industrial applications).

Epinephrine induces Ca2+ uptake in human blood platelets

1980 ◽  
Vol 239 (4) ◽  
pp. H483-H483
Author(s):  
N. E. Owen ◽  
H. Feinberg ◽  
G. C. Le Breton
Keyword(s):  
Human Blood ◽  
Density Gradient Centrifugation ◽  
Blood Platelets ◽  
Gradient Centrifugation ◽  
Receptor Interaction ◽  
Induced Aggregation ◽  
Selective Increase ◽  
Dose Dependent ◽  
Primary Platelet ◽  
Human Blood Platelets

Human blood platelets isolated by albumin density gradient centrifugation take up Ca2+ during 10-6M epinephrine-induced primary aggregation but not during 10-6 M ADP-induced primary aggregation. Platelet uptake of Ca2+ is dose-dependent over a range of 10-7) to 10-5 M epinephrine. Antagonism of the platelet α-receptor by phentolamine (10-6 M) results in inhibition of both epinephrine-stimulated Ca2+ uptake and aggregation. The Ca2+ antagonist verapamil (50 μM) blocks Ca2+ uptake and epinephrine-induced aggregation, but not ADP-induced aggregation. The verapamil inhibition of aggregation is reduced on Ca2+ addition. These results suggest that epinephrine acts to stimulate primary platelet aggregation through a specific receptor interaction that results in a selective increase in platelet membrane permeability to Ca2+.

scholarly journals One-Step Method for Endothelial Cell Isolation from Large Human Blood Vessels Using Fibrin Glue

2000 ◽  
Vol 80 (6) ◽  
pp. 987-989 ◽  
Author(s):  
Ellen B M van Leeuwen ◽  
Grietje Molema ◽  
Koert P de Jong ◽  
Marja J A van Luyn ◽  
Freark Dijk ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Blood Vessels ◽  
Fibrin Glue ◽  
Human Blood ◽  
Cell Isolation ◽  
Step Method ◽  
One Step

Use of image analysis to determine algal and bacterial biomass in a high rate algal pond following Percoll® fractionation

2003 ◽  
Vol 48 (2) ◽  
pp. 53-60 ◽  
Author(s):  
N.J. Cromar ◽  
H.J. Fallowfield
Keyword(s):  
Image Analysis ◽  
Gradient Centrifugation ◽  
Bacterial Biomass ◽  
Nutrient Status ◽  
High Rate ◽  
Carbon And Nitrogen ◽  
Chemical Treatments ◽  
Gravimetric Determination ◽  
Physical And Chemical

This paper reports the results of work to allow a more accurate enumeration, and gravimetric determination, of the relative proportions of algae and bacteria within the floccular matrix present in a High Rate Algal Pond (HRAP). Methodology involving a combination of physical and chemical treatments was used and the resulting material was separated using density gradient centrifugation. The “fractions” were analysed using microscopical image analysis. Each “fraction” was categorised as containing bacteria only, algae only or an association of bacteria and algae, the relative proportions of which were then determined by image analysis to enable a “true” gravimetric determination of the algal and bacterial components of HRAP biomass for the first time. The biomass from HRAPs operated both outdoors and in a glasshouse was examined over complete operational seasons to investigate environmental effects as well as possible effects of variation in COD loading rate and retention time on cell biovolumes and cell quotients. In this study, the accurate assessment of both algal and bacterial biomass, determined as cell volume or dry matter, in addition to measurement of carbon and nitrogen has enabled the calculation of cell quotients. This allows a direct comparison between these values obtained from a nutrient-rich system and those published values obtained from systems with various nutrient status. Conversion factors obtained may also be of value for deriving inputs for computer models for the design and operation of high rate algal ponds.

scholarly journals One-Step Direct Amination of Nanodiamond Surface and Facile Separation by Viscosity Gradient Centrifugation

2019 ◽  
Author(s):  
Nianshun Yang ◽  
Jean Felix Mukerabigwi ◽  
Xueying Huang ◽  
Yuyang Sun ◽  
Juanxiao Cai ◽  
...  
Keyword(s):  
Gradient Centrifugation ◽  
Mechanochemical Reaction ◽  
Distribution Analysis ◽  
One Pot ◽  
Direct Amination ◽  
Wide Range ◽  
One Step ◽  
Ft Ir ◽  
Synthesis Procedure ◽  
Mechanochemical Reactions

Abstract: The introduction of terminal amine functional group on nanodiamond (ND) surface has been proposed as the key strategy to enable further synthesis of various ND derivatives for a wide range of application including sensors and biomedicine. Nevertheless, it is still challenging to develop a successful synthesis procedure to achieve monodispersed ND-NH2 mostly due to the undesirable high agglomeration effect of ND particles and complex synthetic steps which dramatically limit their practical use. In this work, we demonstrate a facile approach to obtain the direct amination of the ND surface, through a one pot mechanochemical reaction using ball milling in the presence of NH4Cl. To obtain monodispersed ND-NH2, a straightforward process by virtue of viscosity gradient centrifugation is adopted using aqueous polyvinylpyrrolidone (PVP) and glycerol. The results show a successful synthesis of ND-NH2 as evidenced by FT-IR and ζ–potential analysis. Moreover, the aminated ND particles morphology and size distribution analysis by TEM and DLS, respectively, show that using viscosity gradient built from aqueous PVP can achieve a better separation of NDs by size. Therefore, the findings suggested that the application of mechanochemical reactions and viscosity gradient centrifugation can be used to achieve homogeneous and monodispersed functionalized NDs for further specific technical applications.

scholarly journals Myeloperoxidase--H2O2--halide system: cytotoxic effect on human blood leukocytes

Blood ◽  
1977 ◽  
Vol 50 (1) ◽  
pp. 65-70
Author(s):  
RA Clark ◽  
SJ Klebanoff
Keyword(s):  
Human Blood ◽  
Polymorphonuclear Leukocytes ◽  
Cytotoxic Effect ◽  
Enzyme System ◽  
Cell Damage ◽  
Mononuclear Leukocytes ◽  
51Cr Release ◽  
Blood Leukocytes ◽  
Halide System ◽  
Particle Ingestion

Myeloperoxidase, H2O2, and a halide form a potent antimicrobial and cytotoxic system of the polymorphonuclear leukocyte. A cytotoxic effect of this system on human blood leukocytes is demonstrated, employing 51Cr release and dye exclusion assays. Cytotoxicity is dependent on enzymatically active myeloperoxidase, H2O2, or a peroxide-generating enzyme system and either chloride or iodide. Cell damage is rapid, with maximal levels of 51Cr release occurring within 30--60 min. Approximately equal sensitivity to the peroxidase system is observed for polymorphonuclear leukocytes and mononuclear leukocytes. Since myeloperoxidase and H2O2 are released from polymorphonuclear leukocytes under certain conditions, such as during particle ingestion, it is suggested that peroxidase-mediated leukocyte injury may be an important feature of the inflammatory response.

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