The Diagnosis of Lupus Anticoagulants by the Activated Partial Thromboplastin Time - The Central Role of Phosphatidyl Serine

1984 ◽  
Vol 52 (02) ◽  
pp. 172-175 ◽  
Author(s):  
P R Kelsey ◽  
K J Stevenson ◽  
L Poller
Keyword(s):  
Screening Method ◽  
Coagulation Factors ◽  
Phosphatidyl Serine ◽  
Test System ◽  
Specific Factor ◽  
Marginal Effect ◽  
Constant Composition ◽  
Lupus Anticoagulants ◽  
Different Types

SummaryLiposomes of pure phospholipids were used in a modified APTT test system and the role of phosphatidyl serine (PS) in determining the sensitivity of the test system to the presence of lupus anticoagulants was assessed. Six consecutive patients with lupus anticoagulants and seven haemophiliacs with anticoagulants directed at specific coagulation factors, were studied. Increasing the concentration of phospholipid in the test system markedly reduced the sensitivity to lupus anticoagulants but had marginal effect on the specific factor inhibitors. The same effect was achieved when the content of PS alone was increased in a vehicle liposome of constant composition.The results suggest that the lupus anticoagulants can best be detected by a screening method using an APTT test with a reagent of low PS content. The use of a reagent rich in PS will largely abolish the lupus anticoagulant’s effect on the APTT. An approach using the two different types of reagent may facilitate differentiation of lupus inhibitors from other types of anticoagulant.

A GENERAL MECHANISM FOR LUPUS ANTICOAGULANTS

1987 ◽  
Author(s):  
V Pengo ◽  
M J Heine ◽  
P Thiagarajan ◽  
s s Shapiro
Keyword(s):  
Lupus Anticoagulant ◽  
Anticoagulant Activity ◽  
Protein A ◽  
Coagulation Factors ◽  
Phosphatidyl Serine ◽  
General Mechanism ◽  
Factor X ◽  
Lupus Anticoagulants ◽  
Calcium Dependent ◽  
Anionic Phospholipids

Although- a number of observations have implied that lupus anticoagulants have immunologic specificity towards anionic. phospholipids, thereby prolonging phospholipid-dependent coagulation tests, this assumption has been directly demonstrated in only one patient with a monoclonal IgM paraprotein. We have tested the generality of this hypothesis directly by isolating five IgG lupus anticoagulants from patients with lupus-like syndromes and/or thrombosis. IgG lupus anticoagulant fractions were isolated free of other plasma proteins and free of contaminating phospholipid by adsorption to and elution from cardiolipin-cholesterol-dicetylphosphate liposomes , followed by chromatography on protein A-Sepharose. Cardiolipin liposomes, but not phosphatidylcholine liposomes, were capable of removing all, or nearly all, lupus anticoagulant activity from patient plasma. Anticardiolipin and lupus anticoagulant activity were both present in acidic fractions on isoelectric focusing. F(ab’)2 fragments retained lupus anti coagulant activity and bound to cardiolipin in an ELISA assay. The affinity-purified IgG preparations reacted with cardiolipin, phosphatidyl serine , phosphatidylinositol and phosphatidic acid, but not with phosphatidylcholine or phosphatidyl ethanol amine, and inhibited calcium-dependent binding of prothrombin and of factor X to phosphatidy1serine-coated surfaces. These data demonstrate a general mechanism for the action of lupus anticoagulants: antibodies that have immunologic specificity towards anionic phospholipids, thereby blocking the calcium-mediated binding of vitamin K-dependent coagulation factors to coagulation-active phospholipid surfaces.

Lipid Class Composition and Heparin Sensitivity in the Activated Partial Thromboplastin Time

1983 ◽  
Vol 50 (02) ◽  
pp. 601-603 ◽  
Author(s):  
K J Stevenson ◽  
Ann C Easton ◽  
Jean M Thomson ◽  
L Poller
Keyword(s):  
Phosphatidyl Inositol ◽  
Phosphatidyl Serine ◽  
Test System ◽  
Procoagulant Activity ◽  
Lipid Class Composition ◽  
Class Composition ◽  
Wide Range ◽  
Aptt Reagent ◽  
Rate Limiting

SummaryIn an APTT reagent, prepared from purified lipids, the role of phosphatidyl serine (PS) in determining the sensitivity of the APTT test system to measurement of the effect of heparin in plasma has been evaluated. As the concentration of PS decreases sensitivity to heparin increases but procoagulant activity decreases. Dilution of the test liposome over a wide range (1 g/1 to 30 mg/1) had a minimal effect on the clotting time. At levels below 30 mg/1, however, the amount of total lipid appeared to be rate limiting; a loss of procoagulant activity being paralleled by an increase in heparin sensitivity. Phosphatidyl inositol (PI) was not a satisfactory substitute for PS in the APTT method studied. The degree of unsaturation of test liposomes appeared to have no effect on either procoagulant activity or sensitivity to heparin at the lipid concentration employed.In the light of these findings, a more critical appraisal of the phospholipid components of APTT reagents should facilitate the development of more reliable reagents for heparin control. A further benefit of this type of approach should be a reduction in the acknowledged wide variations in sensitivity to heparin which exist between available APTT reagents.

An integrated screening method for evaluating the pulmonary toxicity of inhaled particulates: Role of microscopic techniques in assessing pulmonary macrophage clearance functions

1990 ◽  
Vol 48 (3) ◽  
pp. 826-827
Author(s):  
David B. Warheit ◽  
Lena Achinko ◽  
Mark A. Hartsky
Keyword(s):  
Bronchoalveolar Lavage ◽  
Pulmonary Toxicity ◽  
Screening Method ◽  
Pulmonary Response ◽  
Inhaled Particles ◽  
Cytochemical Analysis ◽  
Pulmonary Macrophages ◽  
Integrated Screening

There is a great need for the development of a rapid and reliable bioassay to evaluate the pulmonary toxicity of inhaled particles. A number of methods have been proposed, including lung clearance studies, bronchoalveolar lavage analysis, and in vitro cytotoxicity tests. These methods are often limited in scope inasmuch as they measure only one dimension of the pulmonary response to inhaled, instilled or incubated dusts. Accordingly, a comprehensive approach to lung toxicity studies has been developed.To validate the method, rats were exposed for 6 hours or 3 days to various concentrations of either aerosolized alpha quartz silica (Si) or carbonyl iron (CI) particles. Cells and fluids from groups of sham and dust-exposed animals were recovered by bronchoalveolar lavage (BAL). Alkaline phosphatase, LDH and protein values were measured in BAL fluids at several time points postexposure. Cells were counted and evaluated for viability, as well as differential and cytochemical analysis. In addition, pulmonary macrophages (PM) were cultured and studied for morphology, chemotaxis, and phagocytosis by scanning electron microscopy.

Potential Uses of Vinegar as a Medicine and Related in vivo Mechanisms

2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Review Paper ◽  
Heart Diseases ◽  
Folk Medicine ◽  
Active Role ◽  
Current Review ◽  
Different Types ◽  
Positive Effect

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.

On The Mechanism Of Heparin-Induced Potentiation Of Platelet Aggregation

1981 ◽  
Author(s):  
M Yamamoto ◽  
K Watanabe ◽  
Y Ando ◽  
H Iri ◽  
N Fujiyama ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Coagulation Factors ◽  
Marked Enhancement ◽  
Matrix Bound ◽  
Induced Aggregation ◽  
Aggregation Of Platelets ◽  
Plasma Heparin

It has been suggested that heparin caused potentiation of aggregation induced by ADP or epinephrine. The exact mechanism of heparin-induced platelet activation, however, remained unknown. In this paper, we have investigated the role of anti-thrombin III ( AT ) in heparin-induced platelet activation using purified AT and AT depleted plasma. When ADP or epinephrine was added to citrated PRP one minute after addition of heparin ( 1 u/ml, porcine intestinal mucosal heparin, Sigma Co. USA ), marked enhancement of platelet aggregation was observed, compared with the degree of aggregation in the absence of heparin. However, in platelet suspensions prepared in modified Tyrode’s solution, heparin exhibited no potentiating effect on platelet aggregation induced by epinephrine or ADP. Potentiation of epinephrine- or ADP-induced platelet aggregation by heparin was demonstrated when purified AT was added to platelet suspensions at a concentration of 20 μg/ml. AT depleted plasma, which was prepared by immunosorption using matrix-bound antibodies to AT, retained no AT, while determination of α1-antitrypsinα2- macroglobulin and fibrinogen in AT depleted plasma produced values which corresponded to those of the original plasma when dilution factor was taken into account. The activities of coagulation factors were also comparable to those of the original plasma. Heparin exhibited potentiating effect on ADP- or epinephrine-induced aggregation of platelets in original plasma, but no effect in AT depleted plasma. When purified AT was added back to AT depleted plasma at a concentration of 20 μg/ml, potentiation of platelet aggregation by heparin was clearly demonstrated.Our results suggest that effect of heparin on platelet aggregation is also mediated by anti-thrombin III.

Exercise-Induced Fibrinolysis – Fact or Fiction?

1982 ◽  
Vol 48 (02) ◽  
pp. 201-203 ◽  
Author(s):  
N A Marsh ◽  
P J Gaffney
Keyword(s):  
Plasminogen Activator ◽  
Degradation Products ◽  
Coagulation Factors ◽  
Vascular Wall ◽  
Strenuous Exercise ◽  
Fibrin Degradation Products ◽  
Real Increase ◽  
Exercise Induced ◽  
Male Subjects

SummaryThe effect of strenuous exercise on the fibrinolytic and coagulation mechanisms was examined in six healthy male subjects. Five min bicycle exercise at a work-rate of 800 to 1200 kpm. min−1 produced an abrupt increase in plasma plasminogen activator levels which disappeared after 90 min. However, there was no change in early or late fibrin degradation products nor was there a change in fibrinopeptide A levels or βthromboglobulin levels after exercise although activated partial thromboplastin times were significantly shortened. It is concluded that strenuous exercise does not produce any real increase in fibrinogen-fibrin conversion nor any real increase in the breakdown of these proteins. The role of exercise-induced release of plasminogen activator remains unclear, but probably helps to maintain plasma levels in a discontinuous manner concurrently with the continuous low-level secretion from the vascular wall. The shortening of partial thromboplastin time may be due to the raised levels of plasminogen activator changing the activation state of other coagulation factors.

The Role of Evaluative Tools in the Creation of the Memorial Media Portrait of Jacques Chirac (1932—2019)

2020 ◽  
pp. 97-110
Author(s):  
E. N. Mikhailova ◽  
V. A. Telegina
Keyword(s):  
Print Media ◽  
Political Elite ◽  
Systematic Analysis ◽  
Research Material ◽  
Political Orientations ◽  
Different Types ◽  
The Media ◽  
The Creation ◽  
Entire Text

The article is devoted to the study of evaluative tools used in modern French media in order to form the media image of a representative of the political elite. The techniques used in the creation of a memorial media portrait of Jacques Chirac (1932—2019), President of France from 1995 to 2007 are considered. The research material was the most prestigious French print media of various political orientations, published in late September — early October 2019 in connection with the death of the ex-President of the French Republic. The relevance of the research topic is dictated by the close attention of modern linguistics to axiological phenomena, differently presented in different types of discursive practices. The novelty of the study is due to the appeal to the analysis of the complex of evaluation tools used in the French print media when characterizing the former leader of the state during the nation’s farewell period. The estimated potential of the title of the article and its influence on the formation of the estimated vector of the entire text of the publication are shown. A systematic analysis of the assessment expression means, reflected in the memorial media portrait of the politician, is given. The factors that influenced the peculiarities of their use in this type of media portrait are revealed.

The influence of information relevance on the continued influence effect of misinformation

2020 ◽  
Author(s):  
Hua Jin ◽  
Lina Jia ◽  
Xiaojuan Yin ◽  
Shilin Wei ◽  
Guiping Xu
Keyword(s):  
Experimental Study ◽  
Questionnaire Survey ◽  
Personal Involvement ◽  
Influence Effect ◽  
Information Relevance ◽  
Different Types ◽  
Role Of Information

Misinformation often continues to influence people’s cognition even after corrected (the ‘continued influence effect of misinformation’, the CIEM). This study investigated the role of information relevance in the CIEM by questionnaire survey and experimental study. The results showed that information with higher relevance to the individuals had a larger CIEM, indicating a role of information relevance in the CIEM. Personal involvement might explain the effects of information relevance on the CIEM. This study provides insightful clues for reducing the CIEM in different types of misinformation and misinformation with varying relevance.

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