The thrombelastogram (TEG) measures the viscoelastic properties of clotting blood, displaying a visual trace of all phases of coagulation and fibrinolysis. Thrombelastography can be performed on whole blood (WBTEG) or on citrated blood or plasma, citrated samples facilitating delayed analysis but requiring recalcification of the sample. The aim of this ...

The physiological variability of fibrinolytic response to 20 min upper arm venous occlusion was studied in 191 healthy women and men, 19-80 years old. It was observed that fibrinolytic response measured by the absolute amount of t-PA antigen after venous occlusion increased with increasing age (from 10.7 at 19-30 years ...

In 24 albino New-Zealand rabbits spasm of the basilar artery was produced by local application of autologous blood. The effects of blood and blood clot removal or topical nicardipine, each alone and in combination of both methods, were studied and compared to untreated controls. As well clot removal alone as ...

Fresh retracted clots are known to be poorly lysable by fibrinolytic agents. We have studied whether lysis of retracted clots could be enhanced by bulk transport in comparison to pure diffusion of plasma containing urokinase (400 IU/ml) into the clots. Cylindrical retracted blood clots were occlusively glued by a polyester ...

Clots were allowed to form in samples of whole blood taken from the American horseshoe crab, Limulus polyphemus, in the absence and presence of dansylcadaverine (16), and were analyzed for their contents of N epsilon(gamma-glutamyl)lysine and gamma-glutamyl-dansylcadaverine. Clots obtained without dansylcadaverine yielded significant amounts of N epsilon(gamma-glutamyl)lysine product. Clots formed ...

BACKGROUND: The efficacy of fibrinolytic therapy is limited by the small surface area of the clot that is available for the binding of the thrombolytic agent, such as tissue-type plasminogen activator (t-PA). We hypothesized that exposure of the clot to ultrasound during thrombolytic treatment could enhance lysis through perturbation of ...

The blood flow of portal vein thrombus was studied by pulsed Doppler ultrasonography in 21 patients with tumor thrombus and 14 with blood clot thrombus. Pulsatile waves were observed in 19 of the 21 with tumor thrombus, with backward continuous waves in 3, and forward/backward continuous waves in 2. In ...

The effectiveness of thrombolytic therapy is determined by accessibility of thrombus compartments to plasminogen activators and, therefore, depends on permeability of thrombus to blood born macromolecules. Accumulation of 125I labeled proteins with molecular massess ranging from 150 to 450 kD into partly contracted blood clot or plasma clot was consistent ...

A retrospective study was undertaken to see if screening ultrasounds and elective surgical revision could decrease access failure. Two hundred fifty-three accesses [177 gortex grafts, 76 arteriovenous (AV) fistulas] were studied with duplex imaging. Patients were subdivided by access type, flow, percent stenosis, and whether they were surgically revised. Data ...

1. A comparison between the biochemical properties of semicarbazide-sensitive amine oxidase (SSAO) activities has been made in sheep blood plasma and arterial wall. 2. The metabolism of benzylamine (BZ) by blood plasma was resolved into high affinity (Km 2.76 +/- 0.24 microM) and low affinity (Km 743 +/- 49 microM) ...

OBJECTIVES: The authors assessed the effects of varying one extracellular component (fibrinogen concentration) and one cellular component (hematocrit) on magnetic resonance (MR) T1 and T2 relaxation times of in vitro blood clots. METHODS: Blood from six male subjects was collected into sodium citrate anticoagulant (3.8%) and the whole blood was ...

OBJECTIVE: To summarize the literature describing the epidemiology, pharmacology, efficacy, and adverse effects associated with growth hormone (GH), caffeine, aerobic metabolism facilitator (AMF), and sympathomimetic use among athletes. DATA SOURCES: Relevant articles were identified from a MEDLINE search using the search terms "Doping in Sports," "Blood," "Caffeine," "Cocaine," "Erythropoietin," "Somatotropin," ...

The efficacy of recombinant vampire bat salivary plasminogen activator (bat-PA) as a thrombolytic agent was compared with that of human tissue-type plasminogen activator (t-PA) in a canine model of arterial thrombosis. An occlusive thrombus was formed in the femoral artery by insertion of a thrombogenic copper coil; femoral arterial blood ...

A viscoelastometer, the SonoClot Coagulation Analyzer, has been proposed for use in the evaluation of platelet function. The purpose of this study was to evaluate systematically this instrument when used with whole blood. Under laboratory conditions, the coefficient of variation (cv) of determinations of whole blood activated clotting time (ACT) ...

From August 1988 to October 1989, 60 specimens of citrate-phosphate-dextrose-adenine anticoagulated blood were retrieved from the placental umbilical veins of newborns from three gestational age groups. The specimens were removed with a needle and syringe apparatus and placed directly into sterile transfusion packs. The specimens were evaluated for the volume ...

The influence of HDL, isolated from normolipidemic human blood and blood of normo- and hyperlipidemic rabbits, on in vitro 6-keto-PGF1 alpha synthesis by rabbit aorta and on TXB2 synthesis by platelets of clotting human and rabbit blood was tested. The HDL fraction from normolipidemic subjects, when incubated with blood from ...

International discussions concerning rhinomanometry have been held but no numerical comparisons have been reported. In an attempt to make international comparisons between different rhinomanometric results, nasal resistances were measured by active posterior rhinomanometry with a head-out body plethysmograph produced in Canada and by active posterior and anterior methods with a ...

The circulating monocyte exhibits the capacity to initiate and accelerate the coagulation cascade. We have devised a simple whole blood clotting assay which quantitates the monocyte's contribution of procoagulant (a marker of monocyte activation) to the clotting process and in addition, measures the in vivo activation of the cell. Citrated ...

Effects on blood coagulation and fibrinolytic activity during ovarian stimulation for in-vitro fertilization (IVF) were examined in 12 women. Blood samples were taken prior to hormonal stimulation (days 2-3 of the menstrual cycle, mean serum oestradiol concentration 0.16 nmol/l) and the day after ovulation induction with human chorionic gonadotrophin (HCG) ...

A comparison was made between several characteristics of tissue-type plasminogen activator (t-PA) and urokinase (UK), potentially useful in microsurgery to restore perfusion to ischemic free-tissue transfers. An intraarterial infusion of one of the drugs (or normal saline [NS] as a control) was performed in conjunction with a rat femoral vein ...

Complement activity has been linked to decompression sickness (DCS), but the effects of intravascular bubbles on complement activation are poorly understood. We have investigated intravascular complement activation by measuring red blood cell (RBC)-bound C3d after repetitive air diving in man. Subjects were exposed to a single, 20 min, 170 fsw ...

Whole blood re-calcification times were evaluated as a measure of endotoxin-associated coagulopathy in horses. First, the effects of endotoxin concentration and duration of in vitro incubation of citrated whole blood with endotoxin on the whole blood re-calcification time of blood collected from healthy horses were determined. Increasing concentrations or incubation ...

OBJECTIVE: To explore the risk of inducing a coagulation defect in cardiac surgery patients by the reinfusion of mediastinal blood. DESIGN: Ten patients who underwent coronary artery surgery were prospectively studied for the haematological effects of reinfusion of blood drained from the chest drain tubes after the operation by a ...

Viscoelastic, pseudoplastic, radiopaque injectable hylan gel for percutaneous embolization was developed and evaluated by in vitro and in vivo tests. The embolization gel is composed of cross-linked hylan (hyaluronan, hyaluronate), tantalum, microcrystalline cellulose, hexamethonium chloride, and thrombin. Upon delivery through small-lumen catheters to the appropriate vascular site, the gel induces ...

To determine whether nonionic contrast media present a clotting hazard when plastic or glass injection syringes are contaminated with aspirated blood, we evaluated two nonionic (iohexol and iopamidol) and two ionic (ioxaglate and diatrizoate) contrast agents. We used a blood:contrast media ratio of 2 mL:5 mL and ten normal donors, ...

Subretinal blood within the macula may cause visual loss in a number of macular diseases. The clinical and histopathologic effects of experimental subretinal hemorrhage were evaluated in the cat. Subretinal hemorrhages were produced by creating a focal neurosensory retinal detachment with micropipette techniques, then inserting a needle tip transsclerally to ...

In the present study, we systematically investigated aprotinin, epsilon-aminocaproic acid (EACA) and tranexamic acid as inhibitors of fibrinogen breakdown and of the generation of fibrinogen degradation products (FgDP). The experimental setting very closely imitated the conditions in practice when collecting blood from patients receiving thrombolytic therapy with streptokinase or APSAC. ...

To determine if tissue plasminogen activator, a clot-specific fibrinolytic agent, could eventually be used to assist in the clearance or removal of subretinal hemorrhage, we studied the effect of subretinal injections of tissue plasminogen activator, autologous blood, balanced salt solution, and the combination of either tissue plasminogen activator or balanced ...

An investigation was carried out to evaluate possible interference by mucopolysaccharide galactosaminoglucuronoglycans on blood clotting processes. Results obtained have demonstrated, both in vivo and in vitro, that the biopolymer has no influence on the principal blood clotting parameters taken into consideration, as regards both a single administration and treatments repeated ...

The immediate postoperative bleeding and blood clot formation was observed in 26 human knee joints following a variety of arthroscopic surgical procedures. Observations were made following lavage with lactated Ringer's and normal saline solutions. Bleeding occurred from all incised vascular tissue. Blood clot accumulated after each solution within 5 min ...

Heterogeneous diffusion of some antibiotics into fibrin rich infectious processes is one explanation of the difficulty to cure infections such as endocarditis. Ceftriaxone is a beta lactam antibiotic, potentially useful due to a broad spectrum of activity and its long elimination half-life. We investigated by means of autoradiography the diffusion ...

The purpose of this study was to test the hypothesis that healing of a stable tear in the avascular region of the meniscus occurs when a horizontal conduit, extending from the periphery to the defect, is filled with an exogenous fibrin clot. In 6 sheep a full-thickness laceration was made ...

An increased incidence of fistula thrombosis has been reported in haemodialysis patients treated with recombinant human erythropoietin (rHuEpo). The present study sought to investigate this problem by measuring fistula blood flow, blood viscosity, and a variety of tests of coagulation and haemostasis in a group of ten haemodialysis patients treated ...

A perfusion circuit was designed to investigate in vitro some of the factors which may influence the success of thrombolytic treatment in vivo. The rate of lysis of clotted plasma and different types of artificial thrombi (fibrin thrombi or whole blood thrombi) was measured in citrated plasma or whole blood ...

The binding affinity; incorporation and adsorption, of human tissue plasminogen activator (t-PA) and urokinase plasminogen activator (u-PA) for blood clots was investigated in vitro. In order to study the incorporation, the blood clot formation was performed after mixing [125I]t-PA or [125I]u-PA with the blood obtained from human and several animal ...

We studied thrombolysis in an animal model of embolic stroke to determine the safety of tissue plasminogen activator and streptokinase. We occluded the middle cerebral arteries of 137 rabbits with radiolabeled blood clots and administered tissue plasminogen activator (n = 49), streptokinase (n = 40), or saline (n = 48) ...

The in vitro effects of two metabolites of inhalational anaesthetics, fluoride and bromide, on pseudocholinesterase (PCHE) and acetylcholinesterase (ACHE) activities in the blood samples of seven healthy patients were studied. The PCHE and ACHE activities were determined by kinetic spectrophotometric methods. Fluoride at the levels achieved with clinical concentrations of ...

The magnetic resonance imaging (MRI) characteristics of hemorrhage and clotted blood change with age. The effects of methemoglobin and cell membrane lysis, factors which in part may underlie this evolution of imaging characteristics, were studied using clotted and heparinized dog blood at various methemoglobin concentrations. Cell lysis did not alter ...

Previous studies of hypothermia and blood coagulation have focused on alterations in the levels of blood clotting elements using coagulation tests performed under normothermic conditions. However, because of the enzymatic nature of activated clotting factors, hypothermia should also be expected to affect clotting factor activities. Multiple determinations of activated partial ...

Recurrent, bilateral, and severe conjunctival hemorrhages mandate the search for an underlying etiology, such as a blood dyscrasia, blood clotting disorder, or recurrent increased intrathoracic pressure caused by repetitive vomiting or coughing spells. Medical and ophthalmic management is discussed in a case of subconjunctival and external hemorrhage from the eye ...

The influence of invasive investigations on parameters of hemostasis and fibrinolysis is generally unknown, although this has consequences for the design of prospective studies on the association between those parameters and regression or progression of atherosclerosis. We therefore determined hemostatic and fibrinolytic factors in 12 patients who were admitted to ...

Fibrinolytic activity in the blood of rats during the development of Guerin epithelioma was studied. It was measured by means of radiometric method, based on the amount of plasmin degradation products released from 125I-fibrin, as well as by means of amidolytic technique with the use of Chromozym PL. During the ...

We studied in vitro the efficacy of ultrasound in human blood clot disruption, as well as the effects of clot age, wire probe length, and streptokinase on the outcome. The study included sizing the resulting particulate debris. Clot age (1 to 7 days) had no effect on the time required ...

In summary, it can be said that the improvement of blood fluidity and the simultaneous increase in fibrinolytic activity are an ideal complement. While the increase in fibrinolytic activity supports the physiological reparation process in the microcirculation, the improvement of blood fluidity produces an increase in capillary perfusion that has, ...

Since multiple ovarian punctures are performed during oocyte retrieval, the likelihood of blood contaminating the follicular fluid is high. The purpose of this study was to determine whether the presence of blood clots, which are frequently seen in the cumulus of oocytes retrieved under ultrasound guidance, has any effect on ...

Activation of plasma plasminogen to plasmin is the objective of current strategies for thrombolytic therapy. Although thrombolytic activity in blood involves a large cellular component as well as that in plasma, the contribution of this cellular phase to clinical thrombolysis has not been examined. Using a 125I-fibrin test tube assay, ...

Fibrinolytic therapy may be effective in the treatment of ischemic stroke, and clinical trials are under way. We evaluated two fibrinolytic agents, an analogue of tissue plasminogen activator (Fb-Fb-CF, the catalytic fragment of the tissue plasminogen activator molecule with a prolonged serum half-life, n = 10) and streptokinase (n = ...

The pharmacokinetics of 3 monospecific antivenoms were compared in patients envenomed by the Malayan pit viper, Calloselasma rhodostoma. There was a biphasic decline in serum concentrations following intravenous administration. The initial rapid decline was attributable to the formation of venom-antivenom complexes, as the fall in antivenom during this phase was ...

To investigate the relationship between clot formation and thromboembolism, canine blood was withdrawn into catheter-syringe or catheter-steerable wire systems containing either contrast medium or normal saline as used in debubbling techniques. The contrast media used were iohexol, iopamidol, ioxaglate, and diatrizoate. Without the use of heparin, after a 30-minute incubation, ...

This study investigated by interview, the initial syncopal episode of 103 blood/injury-related vasovagal fainters in order to examine two competing hypotheses concerning their origins. Graham (Circulation, 23, 901-906, 1961) postulated that the faint resulted when sympathetic nervous system (SNS) activity ceased on termination of a threat, leaving parasympathetic nervous system ...