Effects of initial whole blood hematocrit on quantitative ultrasonic backscatter from blood clots in vitro

1989 ◽  
Vol 11 (2) ◽  
pp. 136-137
Author(s):  
J Mottley
Keyword(s):  
Whole Blood ◽  
Blood Clots ◽  
Ultrasonic Backscatter

Studies on Thrombolysis with Streptokinase

1971 ◽  
Vol 25 (02) ◽  
pp. 354-378 ◽  
Author(s):  
R Gottlob ◽  
L Stockinger ◽  
U Pötting ◽  
G Schattenmann
Keyword(s):  
Electron Microscopy ◽  
Cross Section ◽  
Whole Blood ◽  
Jugular Vein ◽  
Thin Sections ◽  
The Third ◽  
Morphological Findings ◽  
Blood Clots ◽  
Arteries And Veins

SummaryIn vitro whole blood clots of various ages, experimental thrombi produced in the jugular vein of rabbits and human thrombi from arteries and veins were examined in semi-thin sections and by means of electron microscopy.In all types of clots examined a typical course of retraction was found. Retraction starts with a dense excentrical focus which grows into a densification ring. After 24 hours the entire clot becomes almost homogeneously dense; later a secondary swelling sets in.Shortly after coagulation the erythrocytes on the rim of the clot are bi-concave discs. They then assume the shape of crenate spheres, turn into smooth spheres and finally become indented ghosts which have lost the largest part of their contents. In the inner zone, which makes up the bulk of the clot, we observed bi-concave discs prior to retraction. After retraction we see no crenations but irregularly shaped erythrocytes. Once the secondary swelling sets in, the cross-section becomes polygonal and later spherical. After extensive hemolysis we observe the “retiform thrombus” made up of ghosts.Experimental and clinical thrombi present the same morphology but are differentiated from in vitro clots by: earlier hemolysis, immigration of leukocytes, formation of a rim layer consisting of fibrin and thrombocytes, and the symptoms of organization. Such symptoms of organization which definitely will prevent lysis with streptokinase were found relatively late in experimental and clinical thrombi. Capillary buds and capillary loops were never found in clinical thrombi prior to the third month.The morphological findings agree with earlier physical and enzymatic investigations. The observation that phenomena of reorganization occur relatively late and frequently only in the rim areas of large thrombi explains why lytic therapy is possible in some of the chronic obliterations.

Effect of Progesterone and Synthetic Progestins on Whole Blood Clot Formation and Erythrocyte Structure

2017 ◽  
Vol 23 (3) ◽  
pp. 607-617 ◽  
Author(s):  
Albe C. Swanepoel ◽  
Odette Emmerson ◽  
Etheresia Pretorius
Keyword(s):  
Whole Blood ◽  
Blood Clot ◽  
Thrombotic Event ◽  
Clot Formation ◽  
Erythrocyte Aggregation ◽  
Erythrocyte Morphology ◽  
Increased Risk ◽  
Blood Clots ◽  
Membrane Ultrastructure

AbstractCombined oral contraceptive (COC) use is a risk factor for venous thrombosis (VT) and related to the specific type of progestin used. VT is accompanied by inflammation and pathophysiological clot formation, that includes aberrant erythrocytes and fibrin(ogen) interactions. In this paper, we aim to determine the influence of progesterone and different synthetic progestins found in COCs on the viscoelasticity of whole blood clots, as well as erythrocyte morphology and membrane ultrastructure, in an in vitro laboratory study. Thromboelastography (TEG), light microscopy, and scanning electron microscopy were our chosen methods. Our results point out that progestins influence the rate of whole blood clot formation. Alterations to erythrocyte morphology and membrane ultrastructure suggest the presence of eryptosis. We also note increased rouleaux formation, erythrocyte aggregation, and spontaneous fibrin formation in whole blood which may explain the increased risk of VT associated with COC use. Although not all COC users will experience a thrombotic event, individuals with a thrombotic predisposition, due to inflammatory or hematological illness, should be closely monitored to prevent pathological thrombosis.

Ultrasound affects distribution of plasminogen and tissuetype plasminogen activator in whole blood clots in vitro

2004 ◽  
Vol 92 (11) ◽  
pp. 980-985 ◽  
Author(s):  
Lisa Gherardini ◽  
Christoph Mayer ◽  
Martin Gröschl ◽  
Christoph Kaun ◽  
Ewald Benes ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Weight Reduction ◽  
Whole Blood ◽  
Tissue Type ◽  
Fibrin Degradation Product ◽  
Acoustic Intensity ◽  
Type Plasminogen Activator ◽  
Blood Clots ◽  
D Dimer

SummaryUltrasound of 2 MHz frequency and 1.2 W/cm2 acoustic intensity was applied to examine the effect of sonication on recombinant tissue-type plasminogen activator (rt-PA)-induced thrombolysis as well as on the distribution of plasminogen and t-PA within whole blood clots in vitro. Thrombolysis was evaluated quantitatively by measuring clot weight reduction and the level of fibrin degradation product D-dimer (FDP-DD) in the supernatant. Weight reduction in the group of clots treated both with ultrasound and rt-PA was 35.2% ± 6.9% which is significantly higher (p<0.0001) than in the group of clots treated with rt-PA only (19.9% ± 4.3%). FDP-DD level in the supernatants of the group treated with ultrasound and rt-PA increased sevenfold compared to the group treated with rt-PA alone, (14895 ± 2513 ng/ml vs. 2364 ± 725 ng/ml). Localization of fibrinolytic components within the clots was accomplished by using gel-entrapping technique and immunohistochemistry. Spatial distributions of t-PA and plasminogen showed clearly that ultrasound promoted the penetration of rt-PA into thrombi significantly (p<0.0001), and broadened the zone of lysis from 8.9 ± 2.6 µm to 21.2 ± 7.2 µm. We speculate that ultrasound enhances thrombolysis by affecting the distribution of rt-PA within the clot.

Über den Nachweis der Plasminogenverarmung in retrahierten Vollblutgerinnseln und über deren Bedeutung für die Lysierbarkeit mit Streptokinase

1966 ◽  
Vol 15 (03/04) ◽  
pp. 570-590 ◽  
Author(s):  
R Gottlob ◽  
G Blümel
Keyword(s):  
Water Content ◽  
Calcium Ions ◽  
Whole Blood ◽  
Immunological Method ◽  
Blood Clots

Summary1. Blood clots are lysed by SK before the beginning of retraction. Retracted clots are only very little lysed.2. Recalcified citrated blood is easily lysed since the excess of added calcium ions inhibits the retraction.3. The determination of the water content of the clots gives information on their retraction state.4. The determination of water content made it possible to prove that thrombus retraction takes place in vivo. Already one day after thrombosis the water content is clearly lower than in fresh clots. Later the water content increases again slightly.5. Clots formed in vitro and in vivo are lysed by SK after retraction if they come into contact with fibrin or fibrinogen containing plasminogen.6. Heated fibrin plates or heated fibrin tubes both with SK, casein degradation and an immunological method allowed to prove that whole blood clots loose their activable plasminogen during retraction. One assumes that plasminogen is expressed during retraction.7. The possibility of a therapeutical fibrinolysis with SK is due to the fact that SK can penetrate into the clot and the SK containing thrombus continuously comes in contact with circulating blood rich in plasminogen. The importance of these results for thrombolysis with SK is discussed.

Studies on Thrombolysis with Streptokinase

1968 ◽  
Vol 19 (01/02) ◽  
pp. 094-098 ◽  
Author(s):  
R Gottlob ◽  
G Blümel
Keyword(s):  
Whole Blood ◽  
Ringer Solution ◽  
Clot Lysis ◽  
Blood Clots ◽  
Free Environment

SummaryIn vitro whole blood clots were incubated in SK, washed several times in Ringer-solution and then introduced into plasminogen solution. These clots showed marked signs of lysis surpassing those observed in clots that had only been incubated in SK. There was a correlation between the duration of the SK incubation and the clot lysis in the plasminogen solution. We deduce from these findings that SK enters the clots by diffusion and that this process lasts several hours.If SK-incubated clots are placed into an SK-free environment, the SK slowly diffuses out of the thrombi.Even in contact with very slight plasminogen concentrations, SK-incubated clots undergo distinct degrees of lysis.

A COMPARISON BETWEEN FIBRINOLYSIS OF FRESH AND AGED CLOTS OR THROMBI BY rt-PA IN VIVO, EX VIVO AND IN VITRO

1987 ◽  
Author(s):  
U Nauland ◽  
W Haarmann ◽  
T H Müller ◽  
W G Eisert
Keyword(s):  
Carotid Artery ◽  
Whole Blood ◽  
Jugular Vein ◽  
Ex Vivo ◽  
Clot Retraction ◽  
Therapeutic Applications ◽  
Blood Clots ◽  
Better Than

In view of the therapeutic applications of rt-PA it is of interest to investigate whether there is any difference in the lysability between fresh and aged thrombi. The efficiency of fibrinolysis by rt-PA was studied in 3 different ways: In vivo, by measuring the thrombus weight of fresh (1 h) or aged (24 h) thrombi in the carotid artery of rabbits which had been treated with rt-PA (0.4 mg/kg) or saline for 1 h. Ex vivo, by measuring I125-release of in vivo fresh (1 h) and aged (24 h) thrombi (labelled with I125-fibrinogen) suspended in vitro in plasma containing rt-PA (1 μg/ml) ; the thrombi were formed in the jugular vein and the carotid artery of each rabbit. In vitro, by measuring I125-release of fresh (1 h) and aged (6 or 24 h) human native whole blood clots, PPP-clots, PRP-clots and squeezed PPP-clots which were formed and lysed in vitro with rt-PA (1 μg/ml) . In vivo as well as ex vivo rt-PA lysed fresh (1 h) thrombi much better than aged (24 h) thrombi. This difference was more pronounced immediately after the onset of fibrinolysis, but decreased with time. However, in vitro relatively little difference was observed in fibrinolysis efficiency between fresh (1 h) and aged (6 or 24 h) clots; fibrinolysis of these clots was decreased (PPP > whole blood > PRP) with increasing clot retraction, which was almost complete within 1 h. This result was also confirmed when PPP-clots were “retracted” by simply squeezing them just before lysis. Therefore we conclude that a considerable difference in lysis efficiency between fresh and aged thrombi was only observed when thrombi were formed and aged in vivo. This difference was less pronounced with increasing fibrinolysis time.

Turbulent axially directed flow of plasma containing rt-PA promotes thrombolysis of non-occlusive whole blood clots in vitro

2004 ◽  
Vol 91 (03) ◽  
pp. 487-496 ◽  
Author(s):  
Gregor Tratar ◽  
Mitja Štrukelj ◽  
Urša Mikac ◽  
Igor Serša ◽  
Aleš Blinc
Keyword(s):  
Whole Blood ◽  
Spin Echo ◽  
Slow Flow ◽  
Directed Flow ◽  
Specific Lysis ◽  
Magnetic Resonance Contrast ◽  
Blood Clots ◽  
Dynamical Spin ◽  
Fast Flow

SummaryThe rate of thrombolysis markedly decreases after a thrombosed vessel is partly recanalized and the remaining clot poses serious risk for rethrombosis. We studied in vitro how thrombolysis depends on penetration of plasma containing thrombolytic agents – 0.2 μg/ml rt-PA or 250 IU/ml streptokinase (SK) nd the magnetic resonance contrast agent Gd-DTPA (at 1 mmol/l) into non-occlusive clots under conditions of fast (turbulent) or slow (laminar) axially directed flow. Cylindrical non-retracted (fresh) or retracted (aged) whole blood clots were pierced lengthways and connected to a perfusion system. Dynamical spin-echo MRI was used for measuring the penetration of labeled plasma into clots and for assessing the remaining clot size. In both types of clots fast flow enhanced the penetration of Gd-DTPA-labeled plasma into clots in comparison to slow flow. In non-retracted clots, lysis with rt-PA and to a lesser extent also lysis with SK followed the path of plasma penetration into clots. After 40 minutes of fast axially directed flow rt-PA resulted in almost complete lysis and SK left only about a third of the clot undissolved, whereas with slow flow lysis was much slower (undissolved clot: 86 ± 5 % with rt-PA and 95 ± 1 % with SK). In retracted clots, substantial lysis was possible only with rt-PA and rapid flow (53 ± 28% of the clot undissolved after 60 min), whereas the use of SK or slow flow precluded meaningful lysis. We conclude that rapid (turbulent) axially directed flow of plasma along non-occlusive blood clots causes forceful exchange of serum inside the clot with outer plasma which enhances both fibrin-specific and non-fibrin-specific lysis of fresh clots. Dissolution of non-occlusive retracted (aged) clots occurs only under fibrin-specific conditions combined with adequate transport of rt-PA into clots.

scholarly journals Toward understanding thrombus fracture: Dissipative phenomena of whole blood clots

2020 ◽  
Author(s):  
Gabriella P. Sugerman ◽  
Sapun H. Parekh ◽  
Manuel K. Rausch
Keyword(s):  
Stress Relaxation ◽  
Whole Blood ◽  
Room Temperature ◽  
Uniaxial Extension ◽  
Future Studies ◽  
Intensive Care Patients ◽  
Nonlinear Stress ◽  
Blood Clots ◽  
Submerged Conditions

When thrombus fractures and breaks off it can occlude vital vessels such as those of the heart, lung, or brain. These thromboembolic conditions are responsible for 1 in 4 deaths world-wide. This problem is also of significant current interest as 1 in 3 COVID-19 intensive care patients exhibit thromboembolic complications. Thrombus resistance to fracture is driven by its intrinsic fracture toughness as well as other, non-surface-creating dissipative mechanisms. In our current work, we identify and quantify these latter mechanisms toward future studies that aim to delineate fracture from other forms of dissipation. To this end, we use an in vitro thrombus mimic system to produce whole blood clots and explore their dissipative mechanics under simple uniaxial extension, cyclic loading, and stress-relaxation. We found that whole blood clots exhibit Mullins effect, hysteresis, permanent set, strain-rate dependence, and nonlinear stress-relaxation. Interestingly, we found that performing these tests under dry or submerged conditions did not change our results. However, performing these tests under room temperature or body temperature conditions yielded differences. Overall, we have demonstrated that whole blood clots show several dissipative phenomena - similarly to hydrogels - that will be critical to our understanding of thrombus fracture.

Studies on Thrombolysis with Streptokinase

1968 ◽  
Vol 19 (03/04) ◽  
pp. 516-525 ◽  
Author(s):  
R Gottlob ◽  
G Blümel ◽  
F Piza ◽  
P Brücke ◽  
H. J Böhmig
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Water Content ◽  
Whole Blood ◽  
Marked Decrease ◽  
Blood Clots ◽  
Plasmin Inhibitors

Summary1. Human thrombi of various ages obtained by surgery were incubated in SK solution. Whereas thrombi up to 2 days old showed no considerable lysis, older thrombi, in some cases more than 1 month old, showed good lysibility in SK.2. The good lysibility of older thrombi was reproduced in in vitro whole blood clots.3. Similar to the findings obtained in experimental thrombi, we found that in in vitro whole blood clots retraction goes along with a marked decrease in the water content, whereas we find again a moderate rise with increasing age.4. If we add 131I-labelled human serum albumin to the supernatant of in-vitro clots, we see an increased absorption of albumin, particularly in the second and third day after clotting.5. Massive hemolysis sets in on the second and third day in whole blood clots incubated at 37 centigrades in their own serum.6. The following are discussed as possible causes for the improved lysibility of older thrombi and clots : renewed absorption of plasminogen from the milieu ; the release of ferments that may be activated by SK in the process of cytolysis, and a decrease in the content of plasmin inhibitors.7. Based on the findings the suggestion is advanced to attempt lytic therapy with SK even in the case of older clinical thrombi.

Influence of Factor Xllla Activity on Human Whole Blood Clot Lysis In Vitro

1987 ◽  
Vol 57 (02) ◽  
pp. 171-175 ◽  
Author(s):  
J W C M Jansen ◽  
F Haverkate ◽  
J Koopman ◽  
H K Nieuwenhuis ◽  
C Kluft ◽  
...  
Keyword(s):  
Whole Blood ◽  
Major Part ◽  
Blood Clot ◽  
Tissue Type ◽  
Clot Lysis ◽  
Type Plasminogen Activator ◽  
Blood Clots ◽  
Lysis Rate ◽  
Per Se

SummaryWe studied the influence of Factor XIII a (F XIII a) activity on the lysis rate of fresh whole human blood clots, without using anticoagulants. Clotting was induced by exogenous thrombin, lysis by tissue-type Plasminogen Activator (t-PA) added before clotting. After various periods of time, lysis rates were determined by measuring the radioactivity in the supernatant of the clot originating from 125I-Fibrinogen added before clotting.Lysis rates were determined in the presence of endogenous F XHIa and compared with those obtained after specific inhibition of F XIII a activity. We used an IgG fraction of an antiserum quenching the F XIII a activity. Addition of increasing amounts of the antibodies to normal blood resulted in a dramatic increase in clot lysis rate, concomitant with loss of F XIII activity. Lysis of blood clots from a patient with a congenital, homozygous, functional α2-Antiplasmin (α2-AP) deficiency (α2-AP-Enschede) was not or slightly increased by the anti F XIII antibodies indicating that fibrin-fibrin crosslinking per se does not contribute essentially to resistance of the blood clot against fibrinolysis. Both active α2-AP and F XIII a are required for the major part of the F XIII-dependent resistance of whole blood clots against lysis.

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