Mechanical compression and biochemical influences, e.g. by various inflammatory cells and mediators, have been suggested to be involved in the pathophysiology of sciatica. In addition, it has been suggested, but so far not clearly demonstrated, that blood pooling in the venous blood vessels surrounding nerve roots may contribute to impaired ...

During the initial phase of lysis of an occlusive thrombus using lytic agents such as tissue plasminogen activator, blood flow through the centre of the clot is established (the process of recanalization). Following canalization, the clot remains on the vessel wall and further lysis is required. This paper develops a ...

The biological chemistry that underlies and regulates the blood coagulation cascade is not fully understood. To begin to understand this, we performed clotting assays under various redox conditions. By varying the amount of oxidant and/or antioxidant in these assays, we observed that both the intrinsic/tenase complex and the extrinsic pathways ...

The incidence of placenta accreta has increased 10-fold in the past 50 years and now occurs with a frequency of 1 per 2,500 deliveries. Women who have had two or more cesarean deliveries with anterior or central placenta previa have nearly a 40% risk of developing placenta accreta. If the ...

An 18-month-old, intact female German shepherd dog was presented for evaluation of severe, frank hemorrhage from the vulva. A complete blood count, serum biochemical analysis, and urinalysis supported acute hemorrhage. Abdominal radiographs were unremarkable. Abdominal ultrasound demonstrated that the uterine body and cranial vaginal lumen were fluid-filled and contained hyperechoic, ...

An assay based on free oscillating rheometry to measure the activity of coagulation factors is described. The method can be used in blood and plasma and is particularly suitable for screening and monitoring coagulation disturbances in point-of-care testing (POCT) in environments where quick analysis with minimal preanalytical work is needed. ...

The goal of bleeding scintigraphy is to localize the site of origin of a hemorrhage to within general regions of the large or small bowel. Activity is typically seen to extravasate from the blood pool into the lumen, and the collection of activity then moves on sequential images, as a ...

In cardiac surgical patients we investigated the effects of cardiopulmonary bypass (CPB) with a hollow fiber membrane oxygenator on blood clotting measured by thromboelastography (TEG). We found only a minimal change in the strength of blood clot described either by the TEG parameter MA (maximum amplitude) or by the shear ...

OBJECTIVE: To evaluate cyclooxygenase (COX) selectivity of several nonsteroidal anti-inflammatory drugs (NSAID) in canine blood in vitro. ANIMALS: 11 healthy adult male hound crosses. PROCEDURE: 9 NSAID were studied at 5 concentrations. Thromboxane B2 (TxB2) was assayed as a measure of COX-1 activity in clotted blood. Prostaglandin E2 (PGE2) was ...

12-O-Tetradecanoylphorbol-13-acetate (TPA) is a potent stimulator of differentiation in myelocytic leukemia cells, and it has been shown to have activity in patients with acute myelocytic leukemia. Because attempts to develop a suitable mass spectrometry assay for TPA were unsuccessful (because of the lack of sufficient sensitivity), we developed a novel ...

This review summarizes basic properties and mechanisms of activation and inhibition of main components of the fibrinolytic system that, acting in accord with the system of blood coagulation, provides temporal formation of fibrin clots at sites of vascular injury for the time required for the regeneration of vascular wall. Impairments ...

Success of stroke treatment with rt-PA depends on rapid vessel recanalization. Enzymatic thrombolysis may be enhanced by additional transcranial application of ultrasound (US). We investigated this novel technique using a 185-kHz probe and compared it to standard diagnostic US. In vitro studies were performed in a continuous pressure tubing system. ...

A functional animal model to measure in vivo the blood fibrinolytic activity and pharmacological-induced changes thereof are described. A (125)I-fibrin coated plastic loop is inserted in the rat aorta; the rate of label disappearance (sigmoid curve) is directly registered outside the animal with a gamma scintillation probe. The time needed ...

Aspirin depresses thrombin generation, probably through a mechanism independent of the cyclooxygenase inhibition, but rather related to acetylation of the platelet membrane macromolecules. This action of aspirin is blunted in hypercholesterolemia. In men with marked hypercholesterolemia, lowering serum cholesterol by a three-month simvastatin treatment is accompanied by a reduction of ...

Though numerous animal thrombosis models have been introduced, an easy, reliable, and reproducible arterial thrombosis model remains a continuing challenge prior to a thrombolytic study. In an effort to evaluate the efficiency of various recombinant thrombolytic agents with specific affinity to activated platelets in vivo, we developed a novel double-opposing ...

PURPOSE: Sustained hemostatic function of fibrin sealant (FS) is crucial when it is used in cardiovascular surgery. The purpose of this study was to develop a model that can determine the long-term hemostatic efficacy of tissue sealants in a vascular surgery. METHODS: To determine the ability of the model to ...

Accurate differentiation between stagnant blood and soft tissue or clotted and unclotted blood has potential value in managing trauma patients with internal hemorrhage. Determination by regular ultrasound (US) imaging is sometimes difficult because the sonographic appearance of blood, clots and soft tissue may be similar. A hematoma model was developed ...

OBJECTIVE: To determine the kinetics of blood clot resolution in human cerebrospinal fluid. METHODS: Computed tomographic scans of 17 adult patients with intraventricular hemorrhages were analyzed. Intraventricular clot volume was determined and analyzed over time to determine both a standardized percentage rate and an absolute rate of clot resolution. Results ...

OBJECTIVE: Ultrasound is emerging as a promising modality for recanalization of acutely thrombosed blood vessels, especially when associated with fibrinolytics. We assessed the efficacy of ultrasound combined with saline, heparin, eptifibatide, aspirin, and streptokinase in disruption of fresh as well as aged human blood clots, using an in vitro model. ...

Hirudin, the anticoagulatory polypeptide of the leech Hirudo medicinalis, strongly inhibits thrombus formation by specifically interacting with thrombin. For diagnostic purposes, hirudin should be superior to other anticlotting compounds because it only minimally alters the mineral, protein, and cellular blood constituents. To test this hypothesis, hirudinized and routinely processed venous ...

Gas chromatography was used to establish the presence of quantifiable residues of 14 persistent chlorinated hydrocarbon pollutants in whole blood, clotted blood, heart, kidney, liver and muscle samples obtained from individual African whitebacked (Pseudogyps africanus), Cape griffon (Gyps coprotheres) and Lappetfaced (Torgos tracheliotos) vultures from different localities in South Africa. ...

In acute myocardial infarction (AMI), monocyte procoagulant activity is increased and may contribute to the risk for recurrence and other thrombotic events. This study sought to investigate the role tissue factor (TF) and tissue factor pathway inhibitor-1 (TFPI-1) in the regulation of monocyte procoagulant activity in AMI. Serial venous blood ...

Emboli of central nervous tissue were detected in the jugular venous blood of two of 15 sheep stunned with a conventional cartridge-operated captive bolt gun and in two of 15 sheep stunned with a pneumatically activated gun. No emboli were detected in arterial blood from these sheep or in venous ...

BACKGROUND: Glycoprotein IIb/IIIa antagonists and heparin are increasingly used for treatment of acute coronary syndromes. There is no data on the effect of these drugs on clot dissolution when combined with low frequency high-intensity ultrasonic energy. We examined a possible additive effect of low frequency high-intensity ultrasound with an antithrombotic, ...

PURPOSE: To evaluate the local hemodynamics in the region of the Simon nitinol filter (SNF), used to prevent pulmonary emboli by capturing clot and promoting lysis. MATERIALS AND METHODS: The hemodynamics of the Simon nitinol inferior vena cava (IVC) filter were evaluated under steady flow (Re = 600) in a ...

Rabbit seminal plasma catalase is much higher than in the semen of other mammals, and differences appear to be inherited. Because of the scarcity of information on rabbit blood catalase and haematocrit in Dutch-belted rabbits, an investigation of possible effects of gender, age and genetics on these variables was undertaken. ...

BACKGROUND: Intravenous administration of recombinant activated human clotting factor VII (rFVIIa) has been used successfully to prevent bleeding in hemophilia patients undergoing elective surgery, but not in previously normal trauma patients. This study was conducted to determine whether rFVIIa was a useful adjunct to gauze packing for decreasing blood loss ...

The augmentation of ultrasound-induced clot disruption by echocardiographic contrast microbubbles may be a direct mechanical erosive effect of the clot by the microparticles. To further assess this hypothesis, we evaluated the rate and extent of clot disruption by using external ultrasound and nongas-filled microparticles (HAEMACCEL and HAES). Human blood clots ...

In patients with thrombotic stroke, the occluded artery often reopens over time. This results through a natural dissolution of the occluding material, and fragments of the material may move downstream to obstruct distal arteries. The current study was undertaken to investigate the patency of brain microvessels at varying time intervals ...

As the biochemical mechanisms of hypercoagulable states are revealed, the syndromes of venous thromboembolism have been increasingly associated with specific aberrations. Most of these changes involve an increase in procoagulant potential, for example, by activation of the coagulation cascade, or by a defect or decrease in natural inhibitors of clotting. ...

Acute subdural haematoma is a well-entrenched nosological entity implying subdural collection of blood following acute head injury. Pathologically, it is usually associated with or, for that matter, secondary to cerebral contusion and laceration. Based on cumulated experience, clinical and pathological studies it is proposed that, for too long the neurosurgeons ...

Obstruction of the episceral venous system can present with glaucoma. We present two patients who were referred to us for management of acute glaucoma with presumed episceral venous compression. The first patient had open-angle glaucoma with probable elevated episcleral venous pressure and blood in the Schlemm's canal, following a 360 ...

Intraventricular extension of hemorrhage after intraparenchymal hemorrhage is associated with significant morbidity and mortality. Clinical improvement is reported in a patient with thalamic hemorrhage with intraventricular extension after third and fourth ventricular blood clot resolution with instillation of urokinase intraventricularly. A 49-year-old man with hypertension collapsed while at work. A ...

BACKGROUND: Postoperative adhesion formation has been associated with a reduced capacity to degrade fibrin within the peritoneal cavity. Peritoneal fibrinolytic capacity has been shown to decrease during the course of a surgical operation. The aim of this study was to investigate whether tissue-type plasminogen activator (tPA), a key fibrinolytic enzyme, ...

OBJECTIVES: Placenta is a known source of some fibrinolytic components in pregnancy. The aim of the present study is to find out whether myometrium can be a parallel source. STUDY DESIGN: The study group consisted of 34 women (16 primaparas and 18 multiparas, 39.0 +/- 0.2 years) in the 36-40th ...

High-frequency ultrasound has been shown to accelerate enzymatic fibrinolysis. One of the supposed mechanisms of this effect is the enhancement of mass transport by acoustic streaming, i.e., ultrasound-induced macroscopic flow around the clot. In this study, which is aimed at further elucidating the mechanisms of the acceleration of fibrinolysis by ...

BACKGROUND: Because optimal use of combinations of antiplatelet and antithrombotic drugs requires improved methods for assessment of therapeutic efficacy, we developed an assay designed to increase sensitivity that is based on initiation of clotting by tissue factor in minimally altered whole blood. METHODS AND RESULTS: Blood samples were obtained from ...

After prostatectomy, hypofibrinogenemia and bleeding were reported earlier. The objective of present study is to find out, of blood, after prostatectomy. Blood samples of patients posted for operations were studied by following tests before and after operation along with controls. 1. Euglobulin lysis time. 2. Plasminogen assay. 3. Fibrinogen estimation. ...

RATIONALE AND OBJECTIVES: To test mechanical thrombectomy of extensive iliofemoral and iliocaval thrombi in an in vitro flow model with the use of 12F and 18F balloon sheaths. METHODS: Newly developed 12F and 18F sheaths were evaluated in four vessel models (simulation of femoral, iliofemoral, iliocaval, and caval thrombi by ...

Thrombolysis is an efficient therapy for hyperacute stroke within a limited time window. Neurological outcome depends on the recanalization time of the occluded vessel. Nonthermal effects of low-frequency ultrasound (US) accelerate enzymatic fibrinolysis in vitro. We examined the effects of transcranially applied US on recombinant tissue plasminogen activator (rt-PA)-mediated thrombolysis ...

BACKGROUND AND AIM OF THE STUDY: Thrombosis and thromboembolism remain the main problems associated with mechanical heart valves. We have devised a milk-based clotting technique to simulate in-vitro clinical incidence of thrombosis. Early results with the technique revealed good correlation between milk clot deposition and clinical thrombosis, but were limited ...

The rather impressive percentage of extraction sites undergoing clot loss and deranged healing results in significant morbidity for the patient and frequent visits to the surgeon to effect relief of discomfort, most often by the use of anodyne dressings. The amount of work lost by patients needing such palliative treatment, ...

Endodontic sealers that possess both optimum flow ability and antimicrobial properties may theoretically assist in the elimination of microorganisms located in confined areas of the root canal system. The antimicrobial effects and the flow rate of the following sealers were investigated and compared: Kerr Pulp Canal Sealer EWT, Grossman's Sealer, ...

The effects of intracarotid thrombolysis with recombinant tissue-plasminogen activator (rt-PA) on cerebral laser Doppler flow (LDF) and the degree of ischemic injury, as revealed by triphenyltetrazolium chloride (TTC) staining, were studied 24 h following cerebral thromboembolism in mice. Thromboembolization with fibrin-rich clot material (0.28-microl clot volume) led to an LDF ...

BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) is a highly morbid disease process. Perihematomal edema is reported to contribute to clinical deterioration and death. Recent experimental observations indicate that clotting of the intrahematomal blood is the essential prerequisite for hyperacute perihematomal edema formation rather than blood-brain barrier disruption. METHODS: We compared ...

High 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 ...

Fibrinolysis initially generates channels in an occluding thombus which results in blood flow through the thrombus. Since the impact of flow along the surface of a thrombus on thrombolysis has not been investigated in detail, we studied in vitro how such a flow affects lysis. Compacted and noncompacted plasma clots ...

The objective of this study was to determine if the thrombin inhibitors Argatroban and DUP 714 could anticoagulate whole blood without influencing the analyses of blood gases, electrolytes, ionized calcium or CO-oximetry. The anticoagulant potency of DUP 714 (0.5-68 micromol/l) and Argatroban (1.5-390 micromol/l) was evaluated using the activated partial ...

BACKGROUND: System clotting and the anticoagulation techniques employed to prevent it are important causes of morbidity in continuous renal replacement therapy (CRRT). Different means have been employed in attempts to prolong system lifespan while minimizing complications. SUBJECTS, MATERIALS AND METHODS: To determine whether augmenting blood flow and flush frequency could ...

Organophosphorus pesticide toxicology is normally evaluated in relation to inhibition of cholinesterases (acetyl and butyryl), neuropathy target esterase, and carboxylesterases, with less attention given to other physiologically important hydrolases. This study considers the relative organophosphate sensitivities of the aforementioned serine hydrolases compared with purified blood-clotting factors (thrombin, plasmin, and kallikrein) ...