Anticoagulant Properties of Rabbit Lungs in Tissue Thromboplastin-induced Intravascular Coagulation

1997 ◽  
Vol 77 (04) ◽  
pp. 679-684 ◽  
Author(s):  
Henrik Vad ◽  
Tove F Tvedskov ◽  
Knud B Hansen ◽  
Ole K Albrechtsen ◽  
Jørgen Jespersen ◽  
...  
Keyword(s):  
Prothrombin Time ◽  
Right Atrium ◽  
Blood Platelets ◽  
Rabbit Brain ◽  
Intravascular Coagulation ◽  
Common Trend ◽  
Blood Ph ◽  
First Pass ◽  
Tissue Thromboplastin ◽  
The Right

SummaryThis study was conducted in order to examine possible anticoagulant properties of the lungs during tissue thromboplastin-induced intravascular coagulation. Rabbit brain tissue thromboplastin (n = 17) or saline (n = 6 + 3) was infused above the right atrium (n = 11 + 3) of the heart or in the arcus aorta (n = 6) for a period of 120 min in non-pregnant New Zealand rabbits. Rabbits infused with tissue thromboplastin responded with significantly (p <0.05) more excessive changes in a number of haemodynamic variables (heart rate, paO2> paCO2, blood pH etc.) compared with rabbits infused with saline.Similarly, the prothrombin time (p <0.05) and the activated partial thromboplastin time (p <0.05) were significantly more prolonged in rabbits receiving tissue thromboplastin compared with control animals. Also the concentration of blood platelets (p<0.05), plasma fibrinogen (p <0.05), antithrombin (p <0.05), and protein C (p <0.05) decreased significantly in thromboplastin-treated animals compared with control animals. In all these haemostatic variables there was a common trend that animals infused with tissue thromboplastin in the arcus aorta responded more excessively than animals infused in the right atrium of the heart, and these deviations were statistically significant for fibrinogen (p <0.05) and prothrombin time (p <0.05). Similarly, animals infused with tissue thromboplastin in the arcus aorta had an increased number of microthrombi in the lungs and kidneys compared with animals receiving tissue thromboplastin above the right atrium.As the lungs are the first pass organ when you infuse above the right atrium the results from this study suggest that the lungs play a key role in protecting the organism against excessive tissue thromboplastin-induced activation of coagulation.

Thromboplastin as a Reagent

1970 ◽  
Vol 23 (03) ◽  
pp. 585-592 ◽  
Author(s):  
A .J Quick
Keyword(s):  
Prothrombin Time ◽  
Oral Anticoagulant Therapy ◽  
Quantitative Measure ◽  
Rabbit Brain ◽  
Bacterial Action ◽  
Normal Human ◽  
Tissue Thromboplastin ◽  
Time Test ◽  
The One ◽  
Evacuated Tube

SummaryTissue thromboplastin is the key reagent in the one-stage prothrombin time test. To obtain reliable results, a potent thromboplastin with constant activity and stability is required. This need is met by acetone-dehydrated rabbit brain. This reagent, when protected against oxidation by sealing in an evacuated tube, retains its full activity indefinitely. The basic prothrombin time serves as a screening test for depletion of prothrombin, factors V, VII and X. Thromboplastin is slowly inactivated by oxidation and also by bacterial action. Phenol prevents the latter reaction and therefore a phenolized extract of either human brain or acetone-dehydrated rabbit brain serves as a satisfactory reagent for the prothrombin time when employed to control oral anticoagulant therapy.The constant 12 sec prothrombin time of fresh normal human plasma is fixed by the concentration of active prothrombin. By modifying the basic prothrombin time by adding excess of factors V, VII or X, the test is made a specific quantitative measure of each of these factors.

scholarly journals Recombinant lipoprotein-associated coagulation inhibitor inhibits tissue thromboplastin-induced intravascular coagulation in the rabbit

Blood ◽  
1990 ◽  
Vol 76 (8) ◽  
pp. 1538-1545 ◽  
Author(s):  
KC Day ◽  
LC Hoffman ◽  
MO Palmier ◽  
KK Kretzmer ◽  
MD Huang ◽  
...  
Keyword(s):  
Body Weight ◽  
Prothrombin Time ◽  
Partial Thromboplastin Time ◽  
Rabbit Model ◽  
Activated Partial Thromboplastin Time ◽  
High Dose ◽  
Intravascular Coagulation ◽  
Coagulation Inhibitor ◽  
Tissue Thromboplastin ◽  
Induced Radioactivity

Lipoprotein-associated coagulation inhibitor produces feed-back inhibition of tissue factor (tissue thromboplastin)-induced coagulation in the presence of factor Xa Recombinant lipoprotein-associated coagulation inhibitor (rLACI) was tested for its ability to modify thromboplastin-induced intravascular coagulation in a rabbit model that allows monitoring of iodine-125 fibrin accumulation/disappearance in the lung and sampling of blood for the measurement of coagulation parameters. Infusion of thromboplastin into the rabbit caused a rapid increase of radioactivity over the lungs, possibly due to the accumulation of 125I fibrin in the lungs, followed by a rapid decline of radioactivity, suggestive of removal of fibrin from the lungs. Thromboplastin also caused a rapid decrease of systemic fibrinogen that was accompanied by a lengthening of the activated partial thromboplastin time and prothrombin time. The effect of coinfusion of rLACI with thromboplastin or bolus injection of rLACI before thromboplastin infusion was studied. At a high dose of rLACI (800 micrograms/kg body weight), the thromboplastin-induced radioactivity increase in the lungs and the systemic fibrinogen decrease were completely suppressed. The activated partial thromboplastin time and prothrombin time of the plasma samples lengthened, possibly due to the presence of thromboplastin in circulation. The thromboplastin-induced radioactivity increase over the lungs was not completely suppressed by lower doses of rLACI (135 to 270 micrograms/kg body weight), but these doses of rLACI prevented systemic fibrinogen decrease. At a bolus dose of 23 micrograms/kg body weight, rLACI provided 50% protection of the fibrinogen consumption (fibrinogen decreased to 82% compared with 65% in rabbits treated with thromboplastin alone). These results show that rLACI is effective in the inhibition of thromboplastin-induced coagulation in vivo.

scholarly journals A Rare Case of Cerebral Venous Thrombosis and Disseminated Intravascular Coagulation Temporally Associated to the COVID-19 Vaccine Administration

2021 ◽  
Vol 11 (4) ◽  
pp. 285
Author(s):  
Vincenzo D’Agostino ◽  
Ferdinando Caranci ◽  
Alberto Negro ◽  
Valeria Piscitelli ◽  
Bernardino Tuccillo ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Disseminated Intravascular Coagulation ◽  
Cerebral Venous Thrombosis ◽  
Blood Platelets ◽  
Brain Magnetic Resonance Imaging ◽  
Genetic Alterations ◽  
Vaccine Administration ◽  
Intravascular Coagulation ◽  
Angio Ct ◽  
The Right

Globally, at the time of writing (20 March 2021), 121.759.109 confirmed COVID-19 cases have been reported to the WHO, including 2.690.731 deaths. Globally, on 18 March 2021, a total of 364.184.603 vaccine doses have been administered. In Italy, 3.306.711 confirmed COVID-19 cases with 103.855 deaths have been reported to WHO. In Italy, on 9 March 2021, a total of 6.634.450 vaccine doses have been administered. On 15 March 2021, Italian Medicines Agency (AIFA) decided to temporarily suspend the use of the AstraZeneca COVID-19 vaccine throughout the country as a precaution, pending the rulings of the European Medicines Agency (EMA). This decision was taken in line with similar measures adopted by other European countries due to the death of vaccinated people. On 18 March 2021, EMA’s safety committee concluded its preliminary review about thromboembolic events in people vaccinated with COVID-19 Vaccine AstraZeneca at its extraordinary meeting, confirming the benefits of the vaccine continue to outweigh the risk of side effects, however, the vaccine may be associated with very rare cases of blood clots associated with thrombocytopenia, i.e., low levels of blood platelets with or without bleeding, including rare cases of cerebral venous thrombosis (CVT). We report the case of a 54-year-old woman who developed disseminated intravascular coagulation (DIC) with multi-district thrombosis 12 days after the AstraZeneca COVID-19 vaccine administration. A brain computed tomography (CT) scan showed multiple subacute intra-axial hemorrhages in atypical locations, including the right frontal and the temporal lobes. A plain old balloon angioplasty (POBA) of the right coronary artery was performed, without stent implantation, with restoration of distal flow, but with persistence of extensive thrombosis of the vessel. A successive thorax angio-CT added the findings of multiple contrast filling defects with multi-vessel involvement: at the level of the left upper lobe segmental branches, of left interlobar artery, of the right middle lobe segmental branches and of the right interlobar artery. A brain magnetic resonance imaging (MRI) in the same day showed the presence of an acute basilar thrombosis associated with the superior sagittal sinus thrombosis. An abdomen angio-CT showed filling defects at the level of left portal branch and at the level of right suprahepatic vein. Bilaterally, it was adrenal hemorrhage and blood in the pelvis. An evaluation of coagulation factors did not show genetic alterations so as the nasopharyngeal swab ruled out a COVID-19 infection. The patient died after 5 days of hospitalization in intensive care.

Recombinant lipoprotein-associated coagulation inhibitor inhibits tissue thromboplastin-induced intravascular coagulation in the rabbit

Blood ◽  
1990 ◽  
Vol 76 (8) ◽  
pp. 1538-1545 ◽  
Author(s):  
KC Day ◽  
LC Hoffman ◽  
MO Palmier ◽  
KK Kretzmer ◽  
MD Huang ◽  
...  
Keyword(s):  
Body Weight ◽  
Prothrombin Time ◽  
Partial Thromboplastin Time ◽  
Rabbit Model ◽  
Activated Partial Thromboplastin Time ◽  
High Dose ◽  
Intravascular Coagulation ◽  
Coagulation Inhibitor ◽  
Tissue Thromboplastin ◽  
Induced Radioactivity

Abstract Lipoprotein-associated coagulation inhibitor produces feed-back inhibition of tissue factor (tissue thromboplastin)-induced coagulation in the presence of factor Xa Recombinant lipoprotein-associated coagulation inhibitor (rLACI) was tested for its ability to modify thromboplastin-induced intravascular coagulation in a rabbit model that allows monitoring of iodine-125 fibrin accumulation/disappearance in the lung and sampling of blood for the measurement of coagulation parameters. Infusion of thromboplastin into the rabbit caused a rapid increase of radioactivity over the lungs, possibly due to the accumulation of 125I fibrin in the lungs, followed by a rapid decline of radioactivity, suggestive of removal of fibrin from the lungs. Thromboplastin also caused a rapid decrease of systemic fibrinogen that was accompanied by a lengthening of the activated partial thromboplastin time and prothrombin time. The effect of coinfusion of rLACI with thromboplastin or bolus injection of rLACI before thromboplastin infusion was studied. At a high dose of rLACI (800 micrograms/kg body weight), the thromboplastin-induced radioactivity increase in the lungs and the systemic fibrinogen decrease were completely suppressed. The activated partial thromboplastin time and prothrombin time of the plasma samples lengthened, possibly due to the presence of thromboplastin in circulation. The thromboplastin-induced radioactivity increase over the lungs was not completely suppressed by lower doses of rLACI (135 to 270 micrograms/kg body weight), but these doses of rLACI prevented systemic fibrinogen decrease. At a bolus dose of 23 micrograms/kg body weight, rLACI provided 50% protection of the fibrinogen consumption (fibrinogen decreased to 82% compared with 65% in rabbits treated with thromboplastin alone). These results show that rLACI is effective in the inhibition of thromboplastin-induced coagulation in vivo.

WITHDRAWN: Enlargement of the Right Atrium – Diverticulum or Aneurysm?

2002 ◽  
Author(s):  
R KOBZA ◽  
E OECHSLIN ◽  
R PRETRE ◽  
D KURZ ◽  
R JENNI
Keyword(s):  
Right Atrium ◽  
The Right

Recombinant Tissue Factor as Substitute for Conventional Thromboplastin in the Prothrombin Time Test

1992 ◽  
Vol 67 (01) ◽  
pp. 042-045 ◽  
Author(s):  
Armando Tripodi ◽  
Arnaldo Arbini ◽  
Veena Chantarangkul ◽  
Pier Mannuccio Mannucci
Keyword(s):  
Prothrombin Time ◽  
Tissue Factor ◽  
Oral Anticoagulant Therapy ◽  
Clotting Factor ◽  
Rabbit Brain ◽  
Sensitivity Index ◽  
Clotting Factors ◽  
Wide Range ◽  
Reference Preparation ◽  
Time Test

SummaryRelipidated recombinant tissue factor (r-TF) has been assessed in comparison with conventional rabbit brain thromboplastin (Manchester Reagent) for its suitability for measurement of prothrombin time (PT). The International Sensitivity Index (ISI) of r-TF calibrated against the International Reference Preparation BCT/253 (human plain) was found to be 0.96 and 1.12 with instrumental and manual techniques. Our study of plasmas from patients with congenital deficiencies of clotting factors covering a wide range of severity demonstrates that r-TF is able to detect even minor deficiencies of factors involved in the extrinsic and common coagulation pathways. Patients with liver diseases were correctly diagnosed with a prevalence of abnormal results comparable for both reagents. Between-assay reproducibility expressed as coefficient of variation was 2.3 % and 3.9 % at normal and abnormal PT levels.In conclusion, our evaluation shows that relipidated r-TF possesses the necessary requisites of sensitivity, diagnostic accuracy and reproducibility which make it a suitable candidate for PT determination both for monitoring oral anticoagulant therapy and diagnosing congenital and acquired clotting factor deficiencies. Moreover, being a highly defined reagent it may constitute a step forward in the standardization of PT testing.

The Effect of Several Tissue Thromboplastins on the Activation of the Abnormal Factor X (Factor X Friuli)

1972 ◽  
Vol 27 (03) ◽  
pp. 535-542 ◽  
Author(s):  
A Girolami ◽  
M Lazzarin ◽  
G Molaro
Keyword(s):  
Prothrombin Time ◽  
Rabbit Brain ◽  
Factor X ◽  
Dilution Curve ◽  
Human Origin ◽  
Rabbit Lung ◽  
Normal Ratio

SummaryThe effect of several tissue thromboplastins on the abnormal factor X (factor X Friuli) has been investigated.The prothrombin time varied between 33.6 and 69 sec. The prothrombin time percentile values (saline dilution curve and Quick’s formula for citrated plasma) varied between 6.6 and 22% and between 10.9 and 32.8%, respectively. The prothrombin time patient/normal ratio varied between 2.24 and 4.43.The factor X level varied between 3.5 and 20% of normal.Significant correlations were found to exist between the percentile factor X level and the prothrombin time in seconds, the percentile prothrombin time values and the prothrombin time patient/normal ratio. Thromboplastins of human origin yielded the lowest factor X values namely 5% thereby appearing to be practically “inert” with regard to the abnormal factor X. Thromboplastins obtained from rabbit lung on the contrary yielded the highest values, namely 15.3%. Thromboplastins obtained from simian or rabbit brain gave values intermediate between these two extremes.

On the Early Detection of Intravascular Coagulation

1972 ◽  
Vol 27 (03) ◽  
pp. 365-376 ◽  
Author(s):  
G Fedder ◽  
Elisabeth M. Prakke ◽  
J Vreeken
Keyword(s):  
Early Detection ◽  
Clinical Medicine ◽  
Blood Platelets ◽  
Factor V ◽  
Intravascular Coagulation ◽  
Fibrin Monomer ◽  
Gelation Test

SummarySince the conception of intravascular coagulation has been introduced in clinical medicine, the interest of clinicians in the early detection of this syndrome is continuously increasing. Therefore small amounts of thrombin and thromboplastin were infused into rabbits and special parameters, such as presence of an activated form of factor V and occurrence of a positive fibrin monomer test, were checked. As it turned out, activation of factor V (proaccelerin, accelerator globulin or AcG) was an earlier sign of intravascular coagulation than the appearance of a positive gelation test, which may occur without changes in fibrinogen or the number of blood platelets. These experiments could be of value for the early detection of intravascular coagulation in man.

Increased Tissue Thromboplastin Activity in Monocytes of Patients with Meningococcal Infection: Related to an Unfavourable Prognosis

1983 ◽  
Vol 49 (01) ◽  
pp. 005-007 ◽  
Author(s):  
B Østerud ◽  
T Flægstad
Keyword(s):  
Disseminated Intravascular Coagulation ◽  
Fold Increase ◽  
Meningococcal Infection ◽  
High Concentration ◽  
Intravascular Coagulation ◽  
Tissue Thromboplastin ◽  
Unfavourable Prognosis

SummaryIn 16 patients, 13 with meningococcal infection and 3 suspected to have this infection, 8 patients were found to possess significant higher level of tissue thromboplastin activity of their monocytes isolated from the blood at the admission to the hospital than normal. Five of those 8 patients had an extremely high concentration, > 60-300 fold increase, and all these patients died. The exposed tissue thromboplastin activity on the surface of the endotoxin stimulated monocytes is probably the direct inducer of disseminated intravascular coagulation (DIC) in meningococcal infection.

Prothrombin Time Standardization: Report of the Expert Panel on Oral Anticoagulant Control

1979 ◽  
Vol 42 (04) ◽  
pp. 1073-1114 ◽  
Keyword(s):  
Prothrombin Time ◽  
Expert Panel ◽  
The Other ◽  
Rabbit Brain ◽  
Calibration Constant ◽  
Freeze Dried ◽  
The Mean ◽  
Point Of Intersection ◽  
And Control ◽  
Standardization Report

SummaryIn collaborative experiments in 199 laboratories, nine commercial thromboplastins, four thromboplastins held by the National Institute for Biological Standards and Control (NIBS & C), London and the British Comparative Thromboplastin were tested on fresh normal and coumarin plasmas, and on three series of freeze-dried plasmas. One of these was made from coumarin plasmas and the other two were prepared from normal plasmas; in each series, one plasma was normal and the other two represented different degrees of coumarin defect.Each thromboplastin was calibrated against NIBS&C rabbit brain 70/178, from the slope of the line joining the origin to the point of intersection of the mean ratios of coumarin/normal prothrombin times when the ratios obtained with the two thromboplastins on the same fresh plasmas were plotted against each other. From previous evidence, the slopes were calculated which would have been obtained against the NIBS&C “research standard” thromboplastin 67/40, and termed the “calibration constant” of each thromboplastin. Values obtained from the freeze-dried coumarin plasmas gave generally similar results to those from fresh plasmas for all thromboplastins, whereas values from the artificial plasmas agreed with those from fresh plasmas only when similar thromboplastins were being compared.Taking into account the slopes of the calibration lines and the variation between laboratories, precision in obtaining a patient’s prothrombin time was similar for all thromboplastins.

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