Polymorphonuclear Leukocytes Activation: In Vitro Modulation by 6-Methoxy-2-Naphthylacetic Acid, The Major Active Metabolite of Nabumetone

1993 ◽  
Vol 28 (2) ◽  
pp. 163-174 ◽  
Author(s):  
A. Allegrezza-Giulietti ◽  
R. Serretti ◽  
M. Peroni ◽  
C. Cervini
Keyword(s):  
Active Metabolite ◽  
Polymorphonuclear Leukocytes ◽  
Naphthylacetic Acid

Clopidogrel inhibits platelet-leukocyte adhesion and plateletdependent leukocyte activation

2005 ◽  
Vol 94 (09) ◽  
pp. 568-577 ◽  
Author(s):  
Stefano Manarini ◽  
Giuseppe Dell’Elba ◽  
Nicola Martelli ◽  
Emanuela Napoleone ◽  
Angelomaria Di Santo ◽  
...  
Keyword(s):  
Whole Blood ◽  
Active Metabolite ◽  
Polymorphonuclear Leukocytes ◽  
Ex Vivo ◽  
Leukocyte Adhesion ◽  
Human Platelets ◽  
Cell System ◽  
Anti Platelet Therapy ◽  
Acute Complications

SummaryClopidogrel is considered to be an important therapeutic advance in anti-platelet therapy. We investigated whether inhibition by clopidogrel results in a reduced capacity of platelets to adhere and stimulate pro-atherothrombotic and inflammatory functions in polymorphonuclear leukocytes (PMN) and in monocytes (MN). An eventual effect on these processes could further substantiate anti-atherothrombotic properties of this drug. The effects of clopidogrel or of its active metabolite were investigated on ADP or thrombin receptor-induced platelet activation and on platelet-leukocyte interactions ex vivo in the mouse or in vitro in isolated human cells or whole blood, respectively. Clopidogrel inhibited platelet aggregation, expression of P-selectin, platelet-PMN adhesion and platelet-dependent ROS production in mouse PMN. Similarly pretreatment of human platelets with the active metabolite of clopidogrel in vitro resulted in a profound inhibition of platelet P-selectin expression, platelet-PMN adhesion and production of ROS by PMN. Pretreatment with the active metabolite of clopidogrel significantly impaired the ability of platelets to up-regulate the expression of TF procoagulant activity in MN, in a washed cell system. Moreover, the active metabolite of clopidogrel inhibited rapidTF exposure on platelet as well as on leukocyte surfaces in whole blood. By reducing platelet-dependent up-regulation of inflammatory and pro-atherothrombotic functions in leukocytes, clopidogrel may reduce inflammation that underlies the chronic process of atherosclerosis and its acute complications.

Defibrotide Inhibits Platelet Activation by Cathepsin G Released From Stimulated Polymorphonuclear Leukocytes

1992 ◽  
Vol 67 (06) ◽  
pp. 660-664 ◽  
Author(s):  
Virgilio Evangelista ◽  
Paola Piccardoni ◽  
Giovanni de Gaetano ◽  
Chiara Cerletti
Keyword(s):  
Platelet Activation ◽  
Polymorphonuclear Leukocytes ◽  
Direct Interaction ◽  
Cathepsin G ◽  
In Vivo Test ◽  
Cell Functions ◽  
Test Models ◽  
Antithrombotic Effects

SummaryDefibrotide is a polydeoxyribonucleotide with antithrombotic effects in experimental animal models. Most of the actions of this drug have been observed in in vivo test models but no effects have been reported in in vitro systems. In this paper we demonstrate that defibrotide interferes with polymorphonuclear leukocyte-induced human platelet activation in vitro. This effect was not related to any direct interaction with polymorphonuclear leukocytes or platelets, but was due to the inhibition of cathepsin G, the main biochemical mediator of this cell-cell cooperation. Since cathepsin G not only induces platelet activation but also affects some endothelial cell functions, the anticathepsin G activity of defibrotide could help to explain the antithrombotic effect of this drug.

The Use of the Vitality and Chemotaxis of Human Polymorphonuclear Leukocytes for the In Vitro Estimation of the Acute Toxicity of the First Ten Chemicals from the MEIC List

1993 ◽  
Vol 21 (1) ◽  
pp. 73-80
Author(s):  
Matteo Valentino ◽  
Francesca Monaco ◽  
Maria Antonietta Pizzichini ◽  
Mario Governa
Keyword(s):  
Ethidium Bromide ◽  
Polymorphonuclear Leukocytes ◽  
Rank Correlation ◽  
Fluorescein Diacetate ◽  
Live Cells ◽  
In Vitro Toxicity ◽  
Ic50 Values ◽  
Acute Cytotoxicity ◽  
Human Polymorphonuclear Leukocytes

The acute cytotoxicity of the first ten MEIC chemicals has been estimated by others in various cell lines. In the present investigation, isolated human polymorphonuclear leukocytes (PMN) from ten healthy non-smoking laboratory personnel were used to assess in vitro toxicity of the same chemicals. The cells were treated with different concentrations of the respective chemicals for three hours and their vitality and chemotaxis were tested. Vitality was measured by fluorescence microscopy after the addition of fluorescein diacetate and ethidium bromide. Living cells which took up and hydrolysed fluorescein diacetate, and dead cells, stained by ethidium bromide, were counted and the percentage of live cells was calculated. Locomotion stimulated by the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (F-MLP), was measured in blind-well Boyden chambers and a chemotactic index was calculated. The results were mathematically transformed to produce a linear curve, and then fitted by the linear least squares procedure, from which LC50 and IC50 values were obtained by interpolation. All the chemicals decreased the vitality and inhibited the chemotaxis of the PMN. Obviously the chemotactic test was more sensitive than the vitality one. A correlation (r = 0.933) was found between vitality and chemotaxis inhibition. Spearman rank correlation analysis revealed significant correlations between our results and those from in vitro experiments conducted in other laboratories, as well as with data concerning mouse, rat and human lethal doses.

THE EFFECT OF TEMPERATURE ON CHEMILUMINESCENCE BY POLYMORPHONUCLEAR LEUKOCYTES IN VITRO

1979 ◽  
pp. 725-736 ◽  
Author(s):  
John E. Repine ◽  
John R. Hoidal ◽  
Gregory D. Beall ◽  
Fred L. Rasp ◽  
Dennis P. Clifford ◽  
...  
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Effect Of Temperature

scholarly journals POLYMORPHONUCLEAR LEUKOCYTES IN IMMUNOLOGIC REACTIONS

1966 ◽  
Vol 124 (4) ◽  
pp. 733-752 ◽  
Author(s):  
Charles G. Cochrane ◽  
Barbara S. Aikin
Keyword(s):  
Basement Membrane ◽  
Polymorphonuclear Leukocytes ◽  
Electron Microscopic Observation ◽  
Severe Damage ◽  
Electron Microscopic ◽  
Cationic Proteins ◽  
Vascular Basement Membrane ◽  
Arthus Phenomenon ◽  
Immunologic Reactions

Vascular basement membrane was disrupted in the presence of polymorphonuclear leukocytes (PMN's) during two immunologic reactions: The Arthus phenomenon and the reaction to locally injected antibody to vascular basement membrane. This disruption was evidenced by (a) the inability of the basement membrane to retain circulating carbon, by (b) loss of antigenic constituents, and by (c) electron microscopic observation showing actual gaps in the structure of the vascular basement membrane. The factors within PMN's responsible for damage to isolated glomerular basement membrane in vitro were found by isolation procedures to be cathepsins D and E. Cationic proteins of PMN's were separable from the cathepsins. While inducing vascular permeability upon injection, these basic proteins failed to inflict the severe damage to the basement membrane observed in Arthus and antibasement membrane reactions. It is concluded that the full expression of these immunologic lesions requires destruction of the basement membrane possibly brought about by cathepsins D and E. Some of the physicochemical properties of these pathologically active leukocytic factors are given.

scholarly journals Assessment of the Drug Susceptibility of Plasmodium falciparum Clinical Isolates from Africa by Using a Plasmodium Lactate Dehydrogenase Immunodetection Assay and an Inhibitory Maximum Effect Model for Precise Measurement of the 50-Percent Inhibitory Concentration

2006 ◽  
Vol 50 (10) ◽  
pp. 3343-3349 ◽  
Author(s):  
Halima Kaddouri ◽  
Serge Nakache ◽  
Sandrine Houzé ◽  
France Mentré ◽  
Jacques Le Bras
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Lactate Dehydrogenase ◽  
Active Metabolite ◽  
Inhibitory Concentration ◽  
Drug Susceptibility ◽  
Maximum Effect ◽  
Malaria Parasites ◽  
Effect Model

ABSTRACT The extension of drug resistance among malaria-causing Plasmodium falciparum parasites in Africa necessitates implementation of new combined therapeutic strategies. Drug susceptibility phenotyping requires precise measurements. Until recently, schizont maturation and isotopic in vitro assays were the only methods available, but their use was limited by technical constraints. This explains the revived interest in the development of replacement methods, such as the Plasmodium lactate dehydrogenase (pLDH) immunodetection assay. We evaluated a commercially controlled pLDH enzyme-linked immunosorbent assay (ELISA; the ELISA-Malaria antigen test; DiaMed AG, Cressier s/Morat, Switzerland) to assess drug susceptibility in a standard in vitro assay using fairly basic laboratory equipment to study the in vitro resistance of malaria parasites to major antimalarials. Five Plasmodium falciparum clones and 121 clinical African isolates collected during 2003 and 2004 were studied by the pLDH ELISA and the [8-3H]hypoxanthine isotopic assay as a reference with four antimalarials. Nonlinear regression with a maximum effect model was used to estimate the 50% inhibitory concentration (IC50) and its confidence intervals. The two methods were observed to have similar reproducibilities, but the pLDH ELISA demonstrated a higher sensitivity. The high correlation (r = 0.98) and the high phenotypic agreement (κ = 0.88) between the two methods allowed comparison by determination of the IC50s. Recently collected Plasmodium falciparum African isolates were tested by pLDH ELISA and showed drug resistance or decreased susceptibilities of 62% to chloroquine and 11.5% to the active metabolite of amodiaquine. No decreased susceptibility to lumefantrine or the active metabolite of artemisinin was detected. The availability of this simple and highly sensitive pLDH immunodetection assay will provide an easier method for drug susceptibility testing of malaria parasites.

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