This study investigated the efficacy and safety of delayed therapy with tissue-plasminogen activator (t-PA) in a rabbit model of thromboembolic stroke. The t-PA therapy was started 3, 4, or 5 hours after autologous clot embolization. New Zealand rabbits were randomized to receive a 2-hour intravenous infusion of either t-PA (6.3 ...

A driving diaphragm in the long-term working total artificial heart (TAH) is under serious mechanical stress, and the long steady contact with blood causes changes to the diaphragm's surface. These changes can be influenced either by local or systemic interventions. In our study, we tried to follow the development of ...

PURPOSE: To evaluate changes in blood coagulability after high-velocity intravascular fluid injections under conditions relevant to angiography. MATERIALS AND METHODS: In 101 rabbits, fluids were injected at 1,000 psi (6,890 kPa) via a multiple-side-hole catheter in the abdominal aorta, while blood was simultaneously aspirated via a second downstream catheter. The ...

Ultrasound accelerates fibrinolysis in vitro and in animal models of thrombosis. Since transport of fibrinolytic enzymes into clots by permeation may be an important determinant of the rate of fibrinolysis, we examined the effect of ultrasound on permeation through fibrin gels in vitro. Gels of purified fibrin were prepared in ...

Global haemostasis was assessed on blood from patients with established blood clotting abnormalities using a hollow fibre flow device. The instrument monitors pressure changes across a polyethylene fibre through which non-anticoagulated whole blood is perfused. This method of analysis is significant because it (1) minimizes or eliminates common problems associated ...

To elucidate the roles of the ABO blood group, von Willebrand factor (vWF), and clotting factor VIII in the process of deep-vein thrombosis we undertook a population-based patient-control study in which 301 consecutive patients younger than 70 with a first, objectively diagnosed episode of venous thrombosis and without an underlying ...

PURPOSE: To study the effect of intravitreally injected tissue plasminogen activator (tPA) in an experimental model of subretinal hemorrhage. METHODS: Autologous blood was transsclerally injected into the subretinal space in 34 albino rabbits. One day later tPA was injected into the posterior vitreous in 24 eyes and saline was injected ...

To determine the hydrodynamic parameters involved in thrombus formation on indwelling catheters, fibrin coagulation was investigated in an in vitro model and compared with the prevailing flow field. Computational analysis was used to simulate clot growth and identify the variables which determine its localization. The fibrin clot grew from the ...

An exposure of blood to tissue factor (TF) activates the coagulation system by the extrinsic pathway and may cause clot formation. Recombinant TF (r-TF) has been produced and subsequently reconstituted into phospholipid vesicles. The aim of these studies was to elucidate the in vitro procoagulant effects and the in vivo ...

Various matrices were reacted with four different activation reagents, in order to prepare immuno-adsorbents for the selective removal of low-density lipoproteins from blood plasma of patients affected by hypercholesterolaemia. The resulting immuno-adsorbents were compared to that obtained earlier with cyanogen bromide activation, in terms of coupling yield, adsorption capacity and ...

The relative importance of vessel wall tissue factor (TF) in initiating thrombogenesis is not well defined. In contrast, vessel wall collagens have been well documented as potent inducers of thrombus formation. We compared the potency of a human TF/phospholipid surface with that of a surface consisting of human type III ...

Blood fibrinolytic activity is mediated by plasma and cellular components. We have studied blood fibrinolytic activity in different species and investigated the distribution pattern in rats after modulation with PAF, dexamethasone, or retinoic acid. Whole blood and plasma activity were measured in an assay system using human or endogenous fibrin ...

Recently developed rodent models of acute subdural hematoma have shown an associated large area of infarction underlying the clot. Excitotoxic processes have been postulated to play an important role in the extensive cell death seen with these models. However, whether increased pressure, vasoactive effects, or toxicity of the blood itself ...

This article summarizes the main blood products that can be gathered from, treated, and returned to the trauma patient in the operating room. A brief description of the physiology of blood and clotting mechanisms is given. A focus on plasma pheresis is provided, as well as a suggested procedure for ...

To control the morphology of a clot formed on an artificial flow path in pulsatile blood flow, the hydrodynamic effect of periodically fluctuating shear rate on clot growth has been quantitatively investigated in vitro. Uniform shear rates were applied to a sample of beagle blood in the concave-convex cones system. ...

There are very few reports on the involvement of bacterial proteinases on the blood clotting system using both human plasma and purified clotting factors. We studied whether microbial proteinases from the opportunistic pathogens Candida albicans, Pseudomonas aeruginosa and Serratia marcescens activate the blood clotting cascade by using normal human plasma, ...

The bactericidal activity of 'Phoraid 6000' and 'Clearsol' disinfectants was evaluated using suspension and surface tests. In suspension tests, 2% 'Phoraid' achieved a > 5 log10 reduction of Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus in 1 min in the absence of blood, but negligible activity in 10 min in ...

In order to specifically detect the localization of thrombus in vivo, we have recently developed two monoclonal antibodies (SZ-58, SZ-63) which can specifically bind to cross-linked fibrin. The binding rates of the two monoclonal antibodies (MoAbs) to human plasma clots in vitro were 46.4 +/- 2.3% for 125I-SZ-58, 50.1 +/- ...

To evaluate the effectiveness of bleach disinfection of injection equipment, we tested HIV-1 inactivation by household bleach in needles and syringes. We obtained blood from HIV-1 infected injecting drug users (IDUs), placed small aliquots in needles and syringes. Blood with and without anticoagulant was incubated at room temperature for 3, ...

AT techniques are becoming the standard of care in surgery. Some controversy exists regarding the use of washed versus unwashed salvaged blood, as discussed. The literature concerning this unresolved problem has been reviewed. Because blood collected intraoperatively has undergone clotting and lysis, no beneficial coagulation effects can be expected with ...

We have shown that ultrasound accelerates TPA-induced thrombolysis in vitro as assessed by release of labeled fibrinogen from radioactive labeled clots. Others have shown that ultrasound shortens the time to recanalization of TPA treated thrombi in animal models. The aim of this study was to test the hypothesis that ultrasound ...

Some of the effects on blood and contrast agents of a laser angioplasty device of the "hot tip" variety have been studied. This device liberates iodine from contrast agents both in the form of soluble free iodide and in the form of solid elemental iodine debris. Some of the solid ...

The presence of clots or of a great amount of blood in the specimen from curettage or endometrial aspiration may lead to considerable problems for the pathologist. The application of a lysis buffer/ethanol solution before applying conventional fixation techniques may solve this problem. This new technique was tested on a ...

Structure characteristics of titanium oxide layer on titanium matrix were investigated by Rutherford Backscattering Spectroscopy (RBS), Auger Electron Spectroscopy (AES) and X-ray diffraction. It has been identified that the titanium oxide layers had rutile structure. The blood compatibility of the titanium oxide layers of different thickness was studied by blood ...

The lysine analogues epsilon-aminocaproic acid (EACA) and trans-4-amino-methyl cyclohexane carboxylic acid (AMCA) are used to prevent excessive bleeding in patients with coagulopathies, such as hemophilia and thrombocytopenia, or in those who have received tissue plasminogen activator (t-PA). However, their relative efficacy in inhibiting lysis of clots that have been formed ...

Endobronchial streptokinase has been used previously to dissolve blood clots caused by massive spontaneous hemoptysis, in settings including sarcoidosis, cavitary histoplasmosis, and multiple myeloma. To our knowledge, however, the use of thrombolytic agents to dissolve clots following transbronchial biopsy has not been reported previously. We describe a patient in whom ...

In Armigeres subalbatus, 60% and 3% of the ingested Brugia pahangi microfilariae (mf) respectively migrated into the haemocoel and the thorax within 5 minutes post ingestion (p.i.). Most of the mf had migrated from the gut into the haemocoel within the first 10 minutes p.i. There was no correlation between ...

This study examines whether vitamin E deficiency has any role in the hypercoagulability of neonatal blood. Blood was collected from mothers and their full-term placental cords. Vitamin E was measured by high-pressure liquid chromatography and whole blood clotting time was measured by recalcification. Cord plasma had significantly lower vitamin E ...

PURPOSE: A relative deficiency of plasminogen within the thrombus may be the rate limiting factor in clot lysis. METHODS: To investigate this hypothesis, we used an in vitro perfusion system and expanded polytetrafluoroethylene graft segments filled with radiolabeled human thrombus. Three groups of five perfusions were compared: (1) urokinase infusion ...

Thrombolytic therapy depends on penetration of plasminogen activator into clots which occurs through diffusion and flow. An in vitro system has been developed to characterize the rate and pattern of fibrinolysis in relation to flow through occlusive clots exposed to a pressure gradient. Whole blood clots formed in plastic tubes ...

This article reports on the preliminary development of an instrument that is intended to monitor catheterized, post-TURP patients specifically to assist care-providers in the reduction of clot retention. The primary objective of the instrument is to detect conditions that indicate an alarm condition for which the probability of clot retention ...

The causes and characteristics of the brain edema which forms adjacent to an acute intracerebral hemorrhage (ICH) have not been explored thoroughly. This study was designed to examine the edema process in rat brain provoked by two different blood clot components. An intracerebral clot was produced by stereotactic injection of ...

The therapeutic effects of antithrombin III (AT-III) and unrefined equine antivenom in the treatment of coagulopathy induced by Malayan pit viper (Calloselasma rhodostoma) venom were assessed in 42 adult Wistar rats. Following intramuscular venom injection (2 micrograms/g body weight), serial blood samples were taken from the femoral vein for measurement ...

The basal lysis rates of ex-vivo prepared blood clots from rats, mice, hamsters, dogs, and humans and levels of alpha 2-antiplasmin (alpha 2-AP) cross-linked to fibrin have been studied in the presence and absence of factor XIII (FXIII) inhibitors using a blood clot lysis assay and an alpha 2-AP binding ...

PURPOSE: A physiologic in vitro model of the human inferior vena cava (IVC) was developed to evaluate the clot-trapping efficiency of various IVC filters. MATERIALS AND METHODS: The flow model closely simulates the physical parameters of the human IVC in fluid viscosity, specific gravity, temperature, and pulsatility; blood flow velocity, ...

The feasibility of percutaneous transluminal catheter-directed laser (Argon multiline 488/514 nm) atrial septostomy under echocardiographic guidance was studied in eight rabbits. In five animals the interatrial septum was exposed to laser energy for 30 s (n = 1) or for 10 s (n = 4) by using the continuous wave ...

RATIONALE AND OBJECTIVES: Current use of thrombolytic agents to lyse thrombus, though safe, is complicated by stroke, bleeding, and clot embolization. Therapy may be protracted, resulting in further ischemia and possible tissue loss. Peripheral arterial and graft occlusions often require several hours of thrombolytic therapy, which may occasionally exceed 48 ...

The effects of Poloxamer 188 (0-5 mg/ml) on the permeability, turbidity, compaction, and fibrinolysis of fibrin network developed in human plasma, and on the permeability and fibrinolysis of network developed in whole blood were examined. Poloxamer 188 was found to increase network permeability and compaction in plasma. In networks in ...

We have used magnetic resonance imaging to examine five patients treated with extradural blood patches for persistent post lumbar puncture headache. Images were obtained between 30 min and 18 h after patching. Extradural blood patch injection produced a focal haematoma mass around the injection site which initially compressed the thecal ...

PURPOSE: The clot-trapping efficiency of the Bird's Nest filter was studied in dogs with the stainless steel wires in a compacted versus fully elongated configuration. MATERIALS AND METHODS: Bird's Nest filters were placed infrarenally with the wires compacted in 10 dogs and with the wires elongated in an additional 10 ...

Effect of blood-air contact in the venous line air-trap chamber on blood clotting was studied. Fourteen chronic hemodialysis patients (six men, eight women; mean age, 49 years) with elevation of thrombin-antithrombin III were studied. To prevent blood-air contact, triglyceride (NOF-005) was floated over the blood in the chamber. Control hemodialysis ...

The study was performed to investigate the influence of lipoproteins (LP) on the thromboxane (TX) A2 formation capacity of platelets in clotting whole blood in vitro. The different lipoprotein fractions VLDL, LDL, HDL2 and HDL3 were isolated from blood of normo- or dyslipidemic volunteers by ultracentrifugation. These lipoproteins were incubated ...

We have characterized the effects of ultrasound on fibrinolysis in vitro to investigate the mechanism of ultrasonic potentiation of fibrinolysis and to identify potentially useful ultrasound parameters for therapeutic application. Radiolabeled clots in thin walled tubes were exposed to ultrasound fields in a water bath at 37 degrees C, and ...

A 67-year-old female developed an endocapsular hyphema after uncomplicated extracapsular cataract surgery. With a neodymium:YAG laser capsulotomy, we drained the blood into the vitreous and restored excellent visual acuity. We hypothesize that endocapsular hyphemas may fail to resorb because of sequestration of the clot from the fibrinolytic system of the ...

Ischemic venous thrombosis that led to necrosis of four toes developed in an 81-year-old man. Despite the extensive thrombosis, results of blood clotting tests showed an extremely low prothrombin time (20%). Plasma mixing studies demonstrated an inhibitor that may have features in common with the lupus anticoagulant. Lupus anticoagulant also ...

OBJECTIVES: The aims of this study were 1) to develop an in vitro flow system in which reperfusion mediated by ultrasound-accelerated thrombolysis could be studied, and 2) to test whether ultrasound-accelerated thrombolysis could hasten reperfusion in this system. BACKGROUND: Ultrasound has been shown to increase tissue plasminogen activator (t-PA)-induced thrombolysis ...

Complete thrombotic occlusion of the arterial blood flow in the upper extremity was produced after mixture of Isovue 370 (iopamidol) and papaverine hydrochloride during routine angiography. Bolus and then continuous infusion of urokinase failed to dissolve the thrombus. The patient required a surgical thrombectomy and recovered uneventfully. This case report ...

Ultrasonic energy may be used for dissolution of venous or arterial thrombi. However, its effects may depend on the mode of ultrasonic vibration and on the length of the probe. We investigated the in vitro effects of an ultrasonic angioplasty device coupled with a 130 cm-long flexible titanium probe, with ...

Fibrinolytic properties of four hybrids of u-PA and t-PA, all containing the u-PA growth factor domain and binding to recombinant human u-PA receptor expressed in CHO cells, were compared. Highest fibrin stimulation was observed with uK2tPA which when compared to t-PA in the rabbit system, had a considerably prolonged circulatory ...

A new method of measuring and analyzing the clinically significant structural characteristics of blood clots is described, using an oscillatory flow instrument (Vilastic-3 Viscoelasticity Analyzer). The development of the viscous and elastic properties of the clot are monitored continuously at known levels of stress and strain in a cylindrical tube ...