INCREASED PLATELET AGGREGABILITY IN NATIVE WHOLE BLOOD IN THE ADULT RESPIRATORY DISTRESS SYNDROME (ARDS)

The measurement of aggregation in whole blood allows the study of platelets in their natural milieu, but may still have anticoagulant induced artifacts; citrate decreases extracellular (Ca++) and heparin activates platelets. A technique for measuring aggregation in unanticoagulated (native) whole blood (NWB) was developed; blood is diluted in prewarmed saline with and without platelet agonists and aggregation is monitored by electrical impedance. Spontaneous and collagen induced aggregation were measured and the effect of prostacyclin analogue ZK 36,374 studied. The time until response (lag), aggregation rate, and clotting time were measured. Normal blood gave a cv of <7% for the NWB parameters; collagen gave a shorter lag and higher rate than in citrated whole blood (CWB). The lag and rate were inhibited in a dose dependent manner by ZK 36,374. 6 patients were studied on admission with ARDS and followed for several days. All had increased aggregation to collagen, which was more pronounced in NWB than CWB. A shortened lag was seen in some patients, but none showed spontaneous aggregation. ARDS patients showed no inhibition to ZK 36,374, and the heightened aggregation was not influenced by 2mM ASA, or normal plasma, while 2.5mM EDTA abolished all responses. Serum thromboxane B2 was normal, and increased flux through the cyclo-oxygenase pathway therefore unlikely. A parallel study has shown very low levels of antithrombin III (ATIII) in these patients, which may mean an increased thrombin generation rate with more thrombin available for platelet activation. This partly explains the difference in degree of hyperaggregability seen with NWB and CWB. During recovery from ARDS, collagen aggregation and the response to ZK 36,374 normalises at the same time as AT-III increases.

Role Of Cyclic Amp In The Inhibition Of Human Platelet Functions By Quercetin, A Flav0N0Id That Potentiates PGI2 Effect

10.1055/s-0038-1652487 ◽

1981 ◽

Author(s):

J P Cazenave ◽

A Beretz ◽

A Stierlé ◽

R Anton

Keyword(s):

Maximum Level ◽

Inhibitory Effect ◽

Dependent Manner ◽

Pde Inhibitors ◽

Pde Inhibition ◽

Induced Aggregation ◽

Camp Levels ◽

Injury to the endothelium (END) and subsequent platelet (PLAT)interactions with the subEND are important steps in thrombosis and atherosclerosis. Thus,drugs that protect the END from injury and also inhibit PLAT function are of interest. It has been shown that some flavonoids(FLA), a group of compounds found in plants, prevent END desquamation in vivo, inhibit cyclic nucleotide phosphodiesterases(PDE)and inhibit PLAT function. We have studied the structure-activity relationships of 13 purified FLA on aggregation and secretion of 14c-5HT of prelabeled washed human PLAT induced by ADP, collagen(COLL) and thrombin(THR). All the FLA were inhibitors of the 3 agents tested. Quercetin(Q), was the second best after fisetin. It inhibited secretion and aggregation with I50 of 330µM against 0.1 U/ML.THR, 102µM against 5µM ADP and 40 µM against COLL. This inhibitory effect is in the range of that of other PDE inhibitors like dipyridamole or 3-isobutyl-l- methylxanthine. The aggregation induced by ADP, COLL and THR is at least mediated by 3 mechanisms that can be inhibited by increasing cAMP levels. We next investigated if Q, which is a PDE inhibitor of bovine aortic microsomes,raises PLAT cAMP levels. cAMP was measured by a protein-binding method. ADP- induced aggregation(5µM) was inhibited by PGI2 (0.1 and 0.5 nM) . Inhibition was further potentiated(l.7 and 3.3 times) by lOµM Q, which alone has no effect on aggregation. The basal level of cAMP(2.2 pmol/108PLAT) was not modified by Q (50 to 500µM). Using these concentrations of Q,the rise in cAMP caused by PGI2(0.1 and 0.5nM) was potentiated in a dose dependent manner. Q potentiated the effect of PGI2 on the maximum level of cAMP and retarded its breakdown. Thus Q and possibly other FLA could inhibit the interaction of PLAT with the components of the vessel wall by preventing END damage and by inhibiting PLAT function through a rise in cAMP secondary to PDE inhibition and potentiation of the effect of vascular PGI2 on PLAT adenylate cyclase.

Factor XII-Deficient Chicken Plasma as a Useful Target for Screening of Pro- and Anticoagulant Animal Venom Toxins

Toxins ◽

10.3390/toxins12020079 ◽

2020 ◽

Vol 12 (2) ◽

pp. 79

Author(s):

Benedito C. Prezoto ◽

Nancy Oguiura

Keyword(s):

High Sensitivity ◽

Factor Xii ◽

Dependent Manner ◽

Clotting Time ◽

Natural Factor ◽

Rotational Thromboelastometry ◽

Factor Xii Deficiency ◽

Dose Dependent ◽

Recalcification Time ◽

Coagulation Pathway

The sensitivity of vertebrate citrated plasma to pro- and anticoagulant venom or toxins occurs on a microscale level (micrograms). Although it improves responses to agonists, recalcification triggers a relatively fast thrombin formation process in mammalian plasma. As it has a natural factor XII deficiency, the recalcification time (RT) of chicken plasma (CP) is comparatively long [≥ 1800 seconds (s)]. Our objective was to compare the ability of bee venom phospholipase A2 (bvPLA2) to neutralize clot formation induced by an activator of coagulation (the aPTT clot) in recalcified human and chicken plasmas, through rotational thromboelastometry. The strategy used in this study was to find doses of bvPLA2 that were sufficient enough to prolong the clotting time (CT) of these activated plasmas to values within their normal RT range. The CT of CP was prolonged in a dose-dependent manner by bvPLA2, with 17 ± 2.8 ng (n = 6) being sufficient to displace the CT values of the activated samples to ≥ 1800 s. Only amounts up to 380 ± 41 ng (n = 6) of bvPLA2 induced the same effect in activated human plasma samples. In conclusion, the high sensitivity of CP to agonists and rotational thromboelastometry could be useful. For example, during screening procedures for assaying the effects of toxins in several stages of the coagulation pathway, such as clot initiation, formation, stability, strength, or dissolution.

Measurement of Tissue Factor Activity in Whole Blood

10.1055/s-0037-1613835 ◽

2000 ◽

Vol 83 (03) ◽

pp. 445-454 ◽

Cited By ~ 44

Author(s):

Richard Santucci ◽

Jonathan Erlich ◽

Joanne Labriola ◽

Mark Wilson ◽

K. Kao ◽

...

Keyword(s):

Unstable Angina ◽

Tissue Factor ◽

Whole Blood ◽

Healthy Population ◽

Dependent Manner ◽

Clotting Time ◽

Tissue Factor Activity ◽

Patients At Risk ◽

The Mean ◽

Circulating Levels

SummaryHigh circulating levels of the procoagulant molecule tissue factor (TF) are associated with thrombosis in a variety of diseases including unstable angina, cancer, and sepsis. Currently, there are no clinical assays to measure the level of TF activity in whole blood. We present an assay called Tissue Factor Clotting Time (“TiFaCT™”) that detects fibrin formation in human blood. The mean baseline clotting time in a healthy population was 472 ± 94 s (mean ± SD, n = 150). Bacterial lipopolysaccharide (LPS or endotoxin) shortened the clotting time in a time-dependent manner. Inhibitory anti-TF antibodies prolonged the clotting time of LPS-stimulated blood, indicating that the shortened clotting time was due to induction of TF expression. Patients with unstable angina had shortened mean baseline clotting time (284 ± 86, n = 13) compared with healthy volunteers (474 ± 98, n = 30), suggesting that these patients had elevated levels of circulating TF. The TiFaCT assay should prove clinically useful in quantifying the levels of circulating TF in patients at risk of thrombosis.

Some Effects of Purified Autoprothrombin C in Blood Clotting

10.1055/s-0038-1655656 ◽

1966 ◽

Vol 16 (03/04) ◽

pp. 707-722 ◽

Cited By ~ 3

Author(s):

G Müller-Berghaus ◽

W. H Seegers

Keyword(s):

Prothrombin Time ◽

Partial Thromboplastin Time ◽

Blood Clotting ◽

Blood Stream ◽

Clotting Time ◽

Glass Tubes ◽

Low Levels ◽

The Difference ◽

Autoprothrombin C ◽

Stage Analysis

SummaryPurified autoprothrombin C was added to rabbit blood or recalcified plasma in order to measure the exact influence on clotting time. At a concentration of 10 u of autoprothrombin C per ml blood there was clotting in 13 sec. At that concentration recalcified plasma clotted in 7 to 8 sec. In the acceleration of the whole blood clotting time with autoprothrombin C, the effect was greater in glass tubes than in silicone coated tubes. The difference was probably due to lipids from platelets. With autoprothrombin C at a concentration of 10 u/ml reaction mixture, the prothrombin time and partial thromboplastin time of plasma was brought down to 3 to 4 sec. The partial thromboplastin time supplied the most sensitive conditions for detecting autoprothrombin C activity. Less than 2 × 10−5 micrograms of autoprothrombin C were detected. Rabbits that were treated with Coumadin had their prothrombin concentration reduced to 9 u/ml plasma, as measured by two-stage analysis. Such plasma yielded twice as much thrombin when purified autoprothrombin C and purified Ac-globulin were used in the assay to determine the thrombin potential. Even when the prothrombin concentration was brought to low levels with Coumadin a partial thromboplastin time or prothrombin time of 7 sec was easily obtained by using autoprothrombin C as procoagulant. The important effect of Coumadin or related drugs is the reduction of prothrombin concentration. This involves a lowering of the autoprothrombin C potential as well as the thrombin potential of plasma, and also the amount of inhibitor that can be obtained from prothrombin.Normal blood was found to contain prethrombin in small amounts as well as prothrombin. The synthesis of prothrombin was stopped with Coumadin and it is likely that the residual prothrombin was in part utilized by degradation to prethrombin, inhibitor and autoprothrombin III. At the height of the anticoagulant effect the prethrombin concentration was higher than the prothrombin concentration. With the resumption of prothrombin synthesis, when vitamin K was given, it may be that prethrombin, inhibitor, and autoprothrombin III was first produced in the liver and some of the latter entered the blood stream to compensate for substrate deficiency. Free autoprothrombin III would account for the short prothrombin time observed before prothrombin concentration rose.

Quantifying manganese in lymphocytes to assess manganese nutritional status.

Clinical Chemistry ◽

10.1093/clinchem/35.9.1939 ◽

1989 ◽

Vol 35 (9) ◽

pp. 1939-1941 ◽

Cited By ~ 6

Author(s):

A Matsuda ◽

M Kimura ◽

M Kataoka ◽

S Ohkuma ◽

M Sato ◽

...

Keyword(s):

Nutritional Status ◽

Intravenous Injection ◽

Whole Blood ◽

Manganese Concentration ◽

Dependent Manner ◽

Dose Dependent ◽

Better Than ◽

Manganese Concentrations

Abstract To clarify whether manganese nutritional status is better reflected by the manganese concentration in lymphocytes or in whole blood, we injected manganese solutions intravenously into manganese-deficient rats and determined manganese concentrations in lymphocytes, whole blood, and various tissues. The manganese concentrations in lymphocytes and tissues, but not in whole blood, were significantly less in manganese-deficient rats than in normal rats. These low values could be prevented by intravenous injection of manganese in a dose-dependent manner. These results suggest that, for assessment of manganese nutritional status, measurement of manganese in lymphocytes is better than that in whole blood.

The Fibrinogen γ Chain Dodecapeptide Inhibits Agonist-induced Aggregation of Rabbit Platelets and Fibrinogen Binding to Rabbit Glycoprotein IIb-IIIa

10.1055/s-0037-1614899 ◽

1999 ◽

Vol 82 (12) ◽

pp. 1680-1686 ◽

Cited By ~ 6

Author(s):

Marian Packham ◽

Desirée Taylor ◽

Erik Yeo ◽

Cynthia Gemmell ◽

Sonali Patil ◽

...

Keyword(s):

Direct Interaction ◽

Human Platelets ◽

Rabbit Platelet ◽

Dependent Manner ◽

Affinity Matrix ◽

Human Fibrinogen ◽

Fibrinogen Binding ◽

Rabbit Platelets ◽

Induced Aggregation ◽

SummaryThe HHLGGAKQAGDV (H12) sequence at the carboxyl termini of the γ chains and the RGD sequences in the Aα chains of human fibrinogen are potential recognition sites for the binding of soluble fibrinogen to glycoprotein IIb-IIIa (GPIIb-IIIa) on activated human platelets. Thus, addition of either H12 or RGD-containing peptides inhibits aggregation of and fibrinogen binding to human platelets. In contrast, we reported previously that RGDS had relatively little inhibitory effect on these functions of rabbit platelets. In the present study, we found that H12 inhibited ADP- and thrombin-induced aggregation of rabbit platelets in a dose-dependent manner. Specificity was demonstrated by the failure of the variant HHLGGAKQAGEV peptide to inhibit ADP-induced aggregation. Furthermore, flow cytometric analyses demonstrated that H12 inhibited the binding of FITC-fibrinogen to ADP-activated rabbit platelets in a dose-dependent manner. To examine the direct interaction of H12 with rabbit GPIIb-IIIa, we performed affinity chromatography by applying an octylglucoside extract of rabbit platelet proteins onto an affinity matrix containing the fibrinogen γ chain sequence. Proteins of ∼135 kDa and ∼95 kDa were specifically eluted by soluble H12, and the 95 kDa protein band was immunoblotted by anti-LIBS1, a monoclonal antibody against human GPIIIa. In control samples, no detectable protein from rabbit platelet lysates was eluted from an RGD affinity matrix by GRGDSP. Collectively, our results demonstrated that H12 inhibits aggregation of and fibrinogen binding to rabbit platelets by directly interacting with rabbit GPIIb-IIIa. These findings suggest that rabbit platelets would serve as a suitable thrombosis model for testing the efficacy of peptide mimetics derived from H12.

Epinephrine Promotes IL-8 Production in Human Leukocytes via an Effect on Platelets

10.1055/s-0037-1614431 ◽

1999 ◽

Vol 81 (01) ◽

pp. 139-145 ◽

Cited By ~ 20

Author(s):

Bjarne Østerud ◽

Charlotte Engstad ◽

Trine Lund

Keyword(s):

Whole Blood ◽

Mononuclear Cells ◽

Inflammatory Diseases ◽

Blood Platelets ◽

Platelet Factor 4 ◽

Dependent Manner ◽

Platelet Factor ◽

Important Mediator ◽

First Time ◽

SummaryInterleukin-8 (IL-8) is generally accepted to be an important mediator of a number of acute and chronic inflammatory diseases and is produced by monocytes upon stimulation by lipopolysaccharide (LPS). Epinephrine has been reported by several groups to suppress activation of monocytes in response to LPS, and the aim of the present study was to examine the effect of epinephrine on LPS induced IL-8 production using whole blood as a model system. Epinephrine increased LPS induced IL-8 production in a dose-dependent manner in the whole concentration range (0.001–100 μM) and 1 μM epinephrine increased IL-8 levels with 125%. Epinephrine per se had no effect on IL-8 levels. The potentiating effect of epinephrine was mediated by blood platelets, since IL-8 levels in samples containing platelets and stimulated with LPS and epinephrine (1–100 μM) were significantly higher (p <0.05) than in control samples containing no platelets. This effect of platelets seemed to be due to platelet release products, since addition of 25 μl platelet lysate supernatant to whole blood increased LPS induced IL-8 production with 100% and a similar effect was observed in freshly isolated mononuclear cells resuspended in plasma. Upon addition of 50 μg/ml of the carboxyterminal peptide of platelet factor 4 (PF4(58-70)) to whole blood, LPS stimulated IL-8 levels were increased with 115%, whereas in mononuclear cells, 20 μg/ml PF4(58-70) enhanced IL-8 production with 40%. We demonstrate for the first time that epinephrine promotes LPS induced production of IL-8 in whole blood via an effect on blood platelets. This potentiating effect of platelets is shown to be due to platelet granule contents, and platelet factor 4 (PF4) is suggested to be one of several platelet granule proteins promoting LPS induced IL-8 production in whole blood.

Dose-Dependent Effects of theCimicifuga racemosaExtract Ze 450 in the Treatment of Climacteric Complaints: A Randomized, Placebo-Controlled Study

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2012/260301 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 14

Author(s):

Ruediger Schellenberg ◽

Reinhard Saller ◽

Lorenzo Hess ◽

Jörg Melzer ◽

Christian Zimmermann ◽

...

Keyword(s):

Clinical Laboratory ◽

Symptom Relief ◽

Hormone Treatment ◽

Menopausal Symptoms ◽

Controlled Study ◽

Dependent Manner ◽

Double Blind ◽

The Difference ◽

Climacteric Complaints ◽

Extracts fromCimicifuga racemosa(CR, synonymActaea racemosa) have shown efficacy in trials in women with menopausal symptoms. Yet, dose dependency remains unclear. Therefore, 180 female outpatients with climacteric complaints were treated for 12 weeks in a randomized, double-blind, placebo-controlled, 3-armed trial (CR extract Ze 450 in 6.5 mg or 13.0 mg, or placebo). Primary outcome was the difference in menopausal symptoms (vasomotor, psychological, and somatic), assessed by the Kupperman Menopausal Index between baseline and week 12. Secondary efficacy variables were patients’ self-assessments of general quality of life (QoL), responder rates, and safety. Compared to placebo, patients receiving Ze 450 showed a significant reduction in the severity of menopausal symptoms in a dose-dependent manner from baseline to endpoint (mean absolute differences 17.0 (95% CI 14.65–19.35) score points,P<0.0001for 13.0 mg; mean absolute differences 8.47 (95% CI 5.55–11.39) score points,P=0.0003for 6.5 mg). QoL and responder rates corresponded with the main endpoint. Changes in menopausal symptoms and QoL were inversely correlated. Reported adverse events and clinical laboratory testing did not raise safety concerns. The CR extract Ze 450 is an effective and well-tolerated nonhormonal alternative to hormone treatment for symptom relief in menopausal women.

NEMO-Binding Domain Peptide Ameliorates Alveolar Hypercoagulation and Fibrinolytic Inhibition in Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome via NF-κB Signaling Pathway in Mice

10.21203/rs.3.rs-38826/v1 ◽

2020 ◽

Author(s):

Yahui WANG ◽

Yanqi WU ◽

Bo LIU ◽

Huilin YANG ◽

Hong QIAN ◽

...

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Respiratory Distress Syndrome ◽

Signaling Pathway ◽

Distress Syndrome ◽

Dependent Manner ◽

Domain Peptide ◽

Nemo Binding Domain ◽

Dose Dependent ◽

Pai 1 ◽

Coagulation And Fibrinolysis

Abstract Background It was confirmed that alveolar hypercoagulation and fibrinolytic inhibition were associated with refractory hypoxemia in acute respiratory distress syndrome (ARDS), and NF-κB pathway was involved in this process. The purpose of the present study is to explore the effects and relevant mechanisms exerted by NEMO-binding domain peptide (NBDP) to alleviate alveolar hypercoagulation and fibrinolytic inhibition aroused by lipopolysaccharide in ARDS mice. Materials and Methods Adult male BALB/c mice inhaled lipopolysaccharide (LPS, mg/L) to induce ARDS. 30 minutes before LPS administration, we treated the mice with increasing concentrations of intratracheally inhaled NBDP or saline aerosol. Six hours after LPS treatment, bronchoalveolar lavage fluids (BALF) were collected and then all mice were executed. We checked coagulation and fibrinolysis associated factors in lung tissues and in BALF as well. We simultaneously observed the activation of NF-κB signaling pathway as well. Results NBDP pretreatment dose-dependently inhibited either the expressions of tissue factor (TF) and plasminogen activator inhibitor (PAI) 1 in lung tissues or the secretions of TF, PAI-1, thrombin-antithrombin complex (TAT) and promoted activated protein C (APC) secretion in BALF induced by LPS. LPS-induced high expression of pulmonary procollagen peptide type Ⅲ (PⅢP) was also declined by NBDP pretreatment in dose-dependent manner. Western blotting showed that NBDP pretreatment obviously attenuated LPS-induced IKKα/β, Iκα and NF-κB p65 activation. LPS-induced p65 DNA binding activity was inhibited by NBDP pretreatment either. We also noticed NBDP protected mice against LPS-induced lung injury in a dose-dependent manner.Conclusions Our experimental findings demonstrate that NBDP dose-dependently ameliorated LPS-induced alveolar hypercoagulation and fibrinolytic inhibition through inhibiting NF-κB signaling pathway. NBDP is expected to be a new therapeutic target to correct the abnormalities of alveolar coagulation and fibrinolysis in ARDS.

The Hemagglutinin Stem-Binding Monoclonal Antibody VIS410 Controls Influenza Virus-Induced Acute Respiratory Distress Syndrome

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02457-15 ◽

2016 ◽

Vol 60 (4) ◽

pp. 2118-2131 ◽

Cited By ~ 32

Author(s):

Tatiana Baranovich ◽

Jeremy C. Jones ◽

Marion Russier ◽

Peter Vogel ◽

Kristy J. Szretter ◽

...

Keyword(s):

Monoclonal Antibody ◽

Influenza Virus ◽

Acute Respiratory Distress Syndrome ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Distress Syndrome ◽

Pulmonary Complications ◽

Lung Injury Score ◽

Dependent Manner ◽

ABSTRACTMost cases of severe influenza are associated with pulmonary complications, such as acute respiratory distress syndrome (ARDS), and no antiviral drugs of proven value for treating such complications are currently available. The use of monoclonal antibodies targeting the stem of the influenza virus surface hemagglutinin (HA) is a rapidly developing strategy for the control of viruses of multiple HA subtypes. However, the mechanisms of action of these antibodies are not fully understood, and their ability to mitigate severe complications of influenza has been poorly studied. We evaluated the effect of treatment with VIS410, a human monoclonal antibody targeting the HA stem region, on the development of ARDS in BALB/c mice after infection with influenza A(H7N9) viruses. Prophylactic administration of VIS410 resulted in the complete protection of mice against lethal A(H7N9) virus challenge. A single therapeutic dose of VIS410 given 24 h after virus inoculation resulted in dose-dependent protection of up to 100% of mice inoculated with neuraminidase inhibitor-susceptible or -resistant A(H7N9) viruses. Compared to the outcomes in mock-treated controls, a single administration of VIS410 improved viral clearance from the lungs, reduced virus spread in lungs in a dose-dependent manner, resulting in a lower lung injury score, reduced the extent of the alteration in lung vascular permeability and protein accumulation in bronchoalveolar lavage fluid, and improved lung physiologic function. Thus, antibodies targeting the HA stem can reduce the severity of ARDS and show promise as agents for controlling pulmonary complications in influenza.