Immobilization of Plasminogen Activator, Urokinase, on Nylon

1978 ◽  
Vol 39 (02) ◽  
pp. 426-436 ◽  
Author(s):  
Akio Sugitachi ◽  
Kunihiko Taragi ◽  
Shingi Imaoka ◽  
Goroh Kosaki
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Thrombus Formation ◽  
Fibrinolytic Enzyme ◽  
Modified Method ◽  
Optimum Ph ◽  
Human Material ◽  
The Uk ◽  
Long Term Preservation

SummaryUrokinase (UK), a fibrinolytic enzyme activator purified from human material was immobilized on nylon using different procedures. One was a modified method of immobilization of antigen or antibody initially carried out by Edelman and others in 1971 (Procedure I). The other was our newly devised method (Procedure II) (Sugitachi et al. 1976).Major specificities of the immobilized UK are as follows:1. The UK revealed properties of a plasminogen activator and the optimum pH of the immobilized UK was between 7.2 and 7.4, these values being in good parallel with that of soluble UK. The immobilized UK maintained a stable fibrinolytic activity after long-term preservation and heat-treatment.2. As the fibrinolytic activity of immobilized UK was found to be inhibited by the antiplasmin in human plasma, an antiplasmin inhibitor was immobilized on the nylon together with the UK.The antiplasmin activity was to some extent prevented using this procedure.3. Nylon tubes immobilized with UK and antiplasmin inhibitor were used for thrombotic coagulation studies carried out according to the method of Chandler. Thrombus formation time (TFT) of UK-immobilized tubes was 30 min, while that of the non-treated tubes was no longer than 10 min.

Effect of muscular exercise in a hot environment on canine fibrinolytic activity

1965 ◽  
Vol 20 (6) ◽  
pp. 1307-1311 ◽  
Author(s):  
E. Bedrak
Keyword(s):  
Heat Stress ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Enzyme System ◽  
Fibrinolytic Enzyme ◽  
Plasma Fibrinogen ◽  
Muscular Exercise ◽  
Heat Acclimatization ◽  
Hot Environment ◽  
Fibrin Plate

The effect of muscular exercise, heat stress, and muscular exercise plus heat stress on the euglobulin fibrinolytic enzyme system was determined in 11 Alsatian dogs prior to and after acclimatization in a hot environment. All the physiological stresses employed, particularly muscular exercise in a hot environment, enhanced the fibrinolytic activity and lowered plasma fibrinogen levels in all animals, especially in the nonacclimatized. The increased fibrinolytic activity, as measured by fibrin plate methods, was primarily related to plasminogen activator and to a lesser degree to active plasmin. In acclimatized animals at rest, the activity of plasminogen activator is lower, that of plasmin is relatively unchanged, while the level of plasma fibrinogen tends to be higher than in nonacclimatized animals at rest. euglobulin fibrinolytic activity and heat acclimatization in dogs; heat stress; plasminogen activator; plasmin fibrinogen and heat acclimatization; nonacclimatized and heat-acclimatized dogs Submitted on November 23, 1964

scholarly journals The Maintenance of Archive Collections in Times of Constricting Budgets: Some Alternative Approaches under Development on the UK

Atlanti ◽  
2016 ◽  
Vol 26 (2) ◽  
pp. 105-112
Author(s):  
Jonathan Rhys-Lewis
Keyword(s):  
Professional Staff ◽  
Commercial Sector ◽  
Private Funding ◽  
Statutory Duty ◽  
The Status ◽  
Alternative Approaches ◽  
The Uk ◽  
Collections Care ◽  
Long Term Preservation

The paper will outline the key objectives for collections care and analyse the direct impacts on long-term preservation resulting from austerity measures. The particular focus will be on local government funded archive services that carry a statutory duty to preserve archive collections. What has been the effect on standards? The author considers how standards are developing and where he feels the emphasis has changed to reflect the change in funding. The availability and access to both government and private funding will also be assessed and how funding criteria are driving preservation decisions. What options are there for improving storage and managing collections? How can archive services reduce and manage risk when the status of archive services is constantly under review and resources are scarce? The need for robust collecting and preservation policies is becoming a key strand of the response from both archivists and conservator-restorers. Additionally, this paper will investigate the increased challenges of promoting preservation in the absence of experienced, professional staff, and how the use of volunteers is shaping policy. The presentation will then assess the capacity and efficacy of the commercial sector in assisting with the maintenance and development of collections. The author hopes that by outlining current approaches in the UK, other countries will feel more confident to consider and explore similar models.

Differential Role of Components of the Fibrinolytic System in the Formation and Removal of Thrombus Induced by Endothelial Injury

1999 ◽  
Vol 81 (04) ◽  
pp. 601-604 ◽  
Author(s):  
Hiroyuki Matsuno ◽  
Osamu Kozawa ◽  
Masayuki Niwa ◽  
Shigeru Ueshima ◽  
Osamu Matsuo ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Thrombus Formation ◽  
Endothelial Injury ◽  
Fibrinolytic System ◽  
Tissue Type ◽  
Clot Lysis ◽  
Wild Type ◽  
Type Plasminogen Activator ◽  
Pai 1

SummaryThe role of fibrinolytic system components in thrombus formation and removal in vivo was investigated in groups of six mice deficient in urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), or plasminogen activator inhibitor-1 (PAI-1) (u-PA-/-, t-PA-/- or PAI-1-/-, respectively) or of their wild type controls (u-PA+/+, t-PA+/+ or PAI-1+/+). Thrombus was induced in the murine carotid artery by endothelial injury using the photochemical reaction between rose bengal and green light (540 nm). Blood flow was continuously monitored for 90 min on day 0 and for 20 min on days 1, 2 and 3. The times to occlusion after the initiation of endothelial injury in u-PA+/+, t-PA+/+ or PAI-1+/+ mice were 9.4 ± 1.3, 9.8 ± 1.1 or 9.7 ± 1.6 min, respectively. u-PA-/- and t-PA-/- mice were indistinguishable from controls, whereas that of PAI-1-/- mice were significantly prolonged (18.4 ± 3.7 min). Occlusion persisted for the initial 90 min observation period in 10 of 18 wild type mice and was followed by cyclic reflow and reocclusion in the remaining 8 mice. At day 1, persistent occlusion was observed in 1 wild type mouse, 8 mice had cyclic reflow and reocclusion and 9 mice had persistent reflow. At day 2, all injured arteries had persistent reflow. Persistent occlusion for 90 min on day 0 was observed in 3 u-PA-/-, in all t-PA-/- mice at day 1 and in 2 of the t-PA-/-mice at day 2 (p <0.01 versus wild type mice). Persistent patency was observed in all PAI-1-/- mice at day 1 and in 5 of the 6 u-PA-/- mice at day 2 (both p <0.05 versus wild type mice). In conclusion, t-PA increases the rate of clot lysis after endothelial injury, PAI-1 reduces the time to occlusion and delays clot lysis, whereas u-PA has little effect on thrombus formation and spontaneous lysis.

Fibrinolysis in Normal Subjects - Comparison Between Plasminogen Activator Inhibitor and Other Components of the Fibrinolytic System

1988 ◽  
Vol 59 (02) ◽  
pp. 299-303 ◽  
Author(s):  
Grazia Nicoloso ◽  
Jacques Hauert ◽  
Egbert K O Kruithof ◽  
Guy Van Melle ◽  
Fedor Bachmann
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Plasminogen Activator Inhibitor ◽  
Venous Occlusion ◽  
Venous Stasis ◽  
Plasminogen Activator Inhibitor 1 ◽  
Plate Assay ◽  
Fibrin Plate ◽  
Activator Inhibitor ◽  
Pai 1

SummaryWe analyzed fibrinolytic parameters in 20 healthy men and 20 healthy women, aged from 25 to 59, before and after 10 and 20 min venous occlusion. The 10 min post-occlusion fibrinolytic activity measured directly in diluted unfractionated plasma by a highly sensitive 125I-fibrin plate assay correlated well with the activity of euglobulins determined by the classical fibrin plate assay (r = 0.729), but pre-stasis activities determined with these two methods did not correlate (r = 0.084). The enhancement of fibrinolytic activity after venous occlusion was mainly due to an increase of t-PA in the occluded vessels (4-fold increase t-PA antigen after 10 min and 8-fold after 20 min venous occlusion). Plasminogen activator inhibitor (PAI) activity and plasminogen activator inhibitor 1 (PAI-1)1 antigen levels at rest showed considerable dispersion ranging from 1.9 to 12.4 U/ml, respectively 6.9 to 77 ng/ml. A significant increase of PAI-1 antigen levels was observed after 10 and 20 min venous occlusion. At rest no correlation was found between PAI activity or PAI-1 antigen levels and the fibrinolytic activity measured by 125I-FPA. However, a high level of PAI-1 at rest was associated with a high prestasis antigen level of t-PA and a low fibrinolytic response after 10 min of venous stasis. Since the fibrinolytic response inversely correlated with PAI activity at rest, we conclude that its degree depends mainly on the presence of free PAI.

Coagulation and Fibrinolytic Activity in Behçet's Disease

1991 ◽  
Vol 66 (03) ◽  
pp. 292-294 ◽  
Author(s):  
K K Hampton ◽  
M A Chamberlain ◽  
D K Menon ◽  
J A Davies
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Behçet’S Disease ◽  
Fibrinolytic Activity ◽  
Behcet’S Disease ◽  
Behçet's Disease ◽  
Plasminogen Activator Inhibitor ◽  
Behcet's Disease ◽  
Tissue Plasminogen ◽  
Von Willebrand

SummaryCoagulation and fibrinolytic activities were studied in 18 subjects with Behçet's disease and compared with results from 14 matched control patients suffering from sero-negative arthritis. Significantly higher plasma concentrations (median and range) were found in Behçet's patients for the following variables: fibrinogen 3.7 (1.7-6.9) vs 3.0 (2.0-5.1) g/1, p <0.05; von Willebrand factor antigen, 115 (72-344) vs 74 (60-119)%, p <0.002; plasminogen activator activity (106/ECLT2) 219 (94-329) vs 137 (78-197) units, p <0.002; tissue plasminogen activator inhibitor (t-PA-I) activity, 9.1 (5.5-19.3) vs 5.1 (1.8-12.0) IU/ml, p <0.002; and PAI-1 antigen, 13.9 (4.5-20.9) vs 6.4 (2.4-11.1) ng/ml, p <0.002. Protein C antigen was significantly lower: 97 (70-183) vs 126 (96-220)%, p <0.02. No differences were observed in antithrombin III activity or antigen, factor VIII coagulant activity, fibrinopeptides A and Bβ15-42, plasminogen, α-2-antiplasmin, functional and immunological tissue-plasminogen activator, thrombin-antithrombin complexes and D-dimer. Levels of tissue plasminogen activator inhibitor (activity and antigen) correlated with disease activity while fibrinogen and von Willebrand factor concentrations did not. Seven of the 18 subjects with Behçet's disease had suffered thrombotic events but it was not possible to distinguish these from the 11 patients without thrombosis using the assays performed. The results suggest the abnormal fibrinolytic activity in Behçet's disease is due to increased inhibition of tissue plasminogen activator. No abnormality of coagulation or fibrinolytic activity specific to Behçet's disease was detected.

Influence of Moderate and Strenuous Daily Physical Activity on Fibrinolytic Activity of Blood: Possibility of Plasminogen Activator Stores Depletion

1979 ◽  
Vol 41 (04) ◽  
pp. 745-755 ◽  
Author(s):  
Dušan Keber ◽  
Mojca Stegnar ◽  
Irena Keber ◽  
Bojan Accetto
Keyword(s):  
Physical Activity ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Regular Physical Activity ◽  
Clot Lysis ◽  
Moderate Activity ◽  
Lysis Time ◽  
Strenuous Activity ◽  
Activity Measurements ◽  
Clot Lysis Time

SummaryFibrinolysis was studied in 10 alpinists during regular physical activity of different intensity. Blood was sampled at rest and after exposure to submaximal workload on the treadmill on three occasions: before and after 6 months physical conditioning (moderate physical activity), and after 6 weeks of an alpinistic expedition (strenuous physical activity). Measurements included submaximal working capacity, fibrinogen, euglobulin clot lysis time (ELT), whole plasma clot lysis time, and estimations derived from ELT - percent increase in fibrinolytic activity after exercise (RFS), and absolute increase in fibrinolytic activity after exercise (PAR).Regular moderate activity increased the resting level of ELT, but strenuous activity decreased is. After each treadmill testing, a marked increase in fibrinolytic activity was observed. RFS was unaltered at all three testings. PAR increased after moderate activity, but decreased after strenuous activity.The results indicate that regular physical activity can lead from enhanced to decreased resting activity of plasminogen activator in blood. It is presumed that increased release of activator during prolonged stress causes partial depletion of endothelial stores with the consequence of decreased activator activity in the blood.

Impaired Fibrinolysis in Obstructive Jaundice - Evidence from Clinical and Experimental Studies

1988 ◽  
Vol 60 (01) ◽  
pp. 025-029 ◽  
Author(s):  
M Colucci ◽  
D F Altomare ◽  
G Chetta ◽  
R Triggiani ◽  
L G Cavallo ◽  
...  
Keyword(s):  
Renal Failure ◽  
Bile Duct ◽  
Obstructive Jaundice ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Experimental Studies ◽  
Plasminogen Activator Inhibitor ◽  
Venous Stasis ◽  
Microvascular Thrombosis ◽  
Duct Ligation

SummaryMicrovascular thrombosis is considered an important pathogenetic factor in renal failure associated with obstructive jaundice but the mechanisms leading to fibrin deposition are still unknown. The plasma levels of plasminogen activator inhibitor (PAI) in 29 patients with obstructive jaundice were found significantly increased as compared to 20 nonjaundiced patients. Fibrin autography of plasma supplemented with tissue plasminogen activator (t-PA) revealed that in icteric samples most of the added activator migrated with an apparent Mr of 100 kDa, corresponding to t-PA-PAI complex, whereas in control samples virtually all t-PA migrated as free enzyme. PAI activity detected in icteric samples is similar to the endothelial type PAI since it is neutralized by a monoclonal antibody against PAI-1.Venous stasis in jaundiced patients was neither associated with an increase in blood fibrinolytic activity nor with a decrease in PAI activity. Immunologic assay showed that t-PA release was impaired in 3 out of 4 patients. In controls, venous occlusion induced an increase in both fibrinolytic activity and t-PA antigen and a reduction in PAI activity. Bile duct recanalization in jaundiced patients subjected to surgery was accompanied by a decrease in plasma PAI activity which paralleled the decrease in serum bilirubin levels. In nonjaundiced patients, surgical treatment did not cause significant changes in either parameter. Rabbits made icteric by bile duct ligation showed an early and progressive increase in plasma PAI activity indicating that obstructive jaundice itself causes the elevation of circulating PAI. It is concluded that obstructive jaundice is associated with a severe impairment of fibrinolysis which might contribute to microvascular thrombosis and renal failure.

Binding of Tissue Plasminogen Activator to Vascular Grafts

1989 ◽  
Vol 61 (01) ◽  
pp. 131-136 ◽  
Author(s):  
Richard A Harvey ◽  
Hugh C Kim ◽  
Jonathan Pincus ◽  
Stanley Z Trooskin ◽  
Josiah N Wilcox ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Polymer Surface ◽  
Enzymic Activity ◽  
Vascular Prostheses ◽  
Chemically Modified ◽  
Insoluble Surfactant ◽  
Tissue Plasminogen

SummaryTissue plasminogen activator labeled with radioactive iodine (125I-tPA) was immobilized on vascular prostheses chemically modified with a thin coating of water-insoluble surfactant, tridodecylmethylammonium chloride (TDM AC). Surfactant- treated Dacron, polytetrafluoroethylene (PTFE), silastic, polyethylene and polyurethane bound appreciable amounts of 125I- tPA (5-30 μg 125I-tPA/cm2). Upon exposure to human plasma, the amount of 125I-tPA bound to the surface shows an initial drop during the first hour of incubation, followed by a slower, roughly exponential release with a t½ of appoximately 75 hours. Prostheses containing bound tPA show fibrinolytic activity as measured both by lysis of clots formed in vitro, and by hydrolysis of a synthetic polypeptide substrate. Prior to incubation in plasma, tPA bound to a polymer surface has an enzymic activity similar, if not identical to that of the native enzyme in buffered solution. However, exposure to plasma causes a decrease in the fibrinolytic activity of both bound tPA and enzyme released from the surface of the polymer. These data demonstrate that surfactant-treated prostheses can bind tPA, and that these chemically modified devices can act as a slow-release drug delivery system with the potential for reducing prosthesis-induced thromboembolism.

Plasma Fibrinolytic Activity Following Oral Anabolic Steroid Therapy

1975 ◽  
Vol 34 (01) ◽  
pp. 236-245 ◽  
Author(s):  
I. D Walker ◽  
J. F Davidson ◽  
P Young ◽  
J. A Conkie
Keyword(s):  
Heart Disease ◽  
Ischaemic Heart Disease ◽  
Anabolic Steroid ◽  
Fibrinolytic Activity ◽  
Anabolic Steroids ◽  
Long Term Effects ◽  
Lysis Time ◽  
Detailed Evaluation ◽  
Euglobulin Lysis Time

SummarySix anabolic steroids were assessed for their ability to enhance plasma fibrinolytic activity in males with ischaemic heart disease. Five 17α-alkylated steroids (Ethyloestrenol, Norethandrolone, Methandienone, Methylandrostenediol and Oxymetholone) were examined and all produced a significant increase in plasma plasminogen activator as measured by the euglobulin lysis time. The only non-17α-alkylated steroid studied (Methenolone acetate) failed to enhance fibrinolysis. The 17α-alkylated steroids studied all deserve more detailed evaluation of their long term effects on plasma fibrinolytic activity.

On the Fibrinolytic System in Aged Rats, and Its Reactivity to Endotoxin and Cytokines

1992 ◽  
Vol 67 (06) ◽  
pp. 697-701 ◽  
Author(s):  
J J Emeis ◽  
A Brouwer ◽  
R J Barelds ◽  
M A Horan ◽  
S K Durham ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Fibrinolytic System ◽  
Tissue Type ◽  
High Dose ◽  
Base Line ◽  
Aged Rats ◽  
Tissue Type Plasminogen Activator ◽  
Young Rats ◽  
Type Plasminogen Activator

SummaryAged rats are more susceptible to endotoxin-induced effects, including microthrombosis and platelet aggregation, than are young rats. To investigate whether changes in the fibrinolytic system might be involved, we investigated the fibrinolytic activity in plasma euglobulin fractions and tissues (lung and heart) of young (6-months old) and aged (24-months old) rats under baseline conditions and after challenge with endotoxin. Aged rats had lower plasma levels of tissue-type plasminogen activator (t-PA) and of urokinase-type PA (u-PA) activity. PA inhibitor (PAI) activity was higher in the plasma of aged rats, as was t-PA activity in lung and heart.Rats were treated with either a low dose (1 μg/kg) or a high dose (10 mg/kg) of endotoxin. Both treatments induced a transient phase of increased blood fibrinolytic activity, as evidenced by higher levels of tissue-type plasminogen activator (t-PA) activity and decreased levels of PA inhibitor (PAI) activity. Over time, the fibrinolytic activity decreased, probably due to increased levels of PA inhibitor.Both the early increase in t-PA activity, and the subsequent increase in PAI activity, were more pronounced in the aged rats, as compared with the younger rats, after the high dose of endotoxin. The aged rats also responded to an injection of interleukin-1β or tumor necrosis factor-α with a larger increase of PAI activity than did the younger rats.Together the data suggest that, compared to young rats, aged rats have a decreased base-line plasma fibrinolytic activity, while their fibrinolytic system is more responsive to challenge by endotoxin and cytokines.

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