摘要:

Equimolar concentrations of Lys-plasminogen (Lys-PLG) and streptokinase (SK) were mixed with various concentrations of fibrin, fibrinogen, fragment D or E (potentiating agents). The activity of the mixture was measured by the hydrolysis of S-2251. Kinetic analyses indicated that catalytic rate constant (kcat) of the hydrolysis of S-2251 increased in the presence of increasing amounts of potentiating agents. Km D. It could be concluded that a complex of SK, Lys-PLG and potentiating agent is a better enzyme, thus activator, than a complex of SK and Lys-PLG. Since Lys-PLG does not change its conformation and its activation rate upon interaction with fibrin, the enhanced activator activity of complex of SK, Lys-PLG and potentiating agent may not be due to the conformational change of Lys-PLG.

ISSN:1424-8832    

DOI:10.1159/000215790

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Streptokinase was immobilized on the magnetic carrier at a concentration of 2,000–2,700 IU/ml of preparation. Thrombosis was induced in both canine carotid arteries by means of the vascular wall flap inverting into its lumen. The red, completely occluding thrombus was formed inside the vessel 4–5 h later. A samarium-cobalt magnet was secured externally to one of the arteries. After the clot formation the magnetically immobilized streptokinase was injected intravenously. The preparation concentrated in the region of the magnetic field action caused complete thrombus degradation and normal blood flow restoration; no effect on the clot in the control artery was obser

ISSN:1424-8832    

DOI:10.1159/000215791

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Kinetic analyses were made for the activation of Glu-plasminogen (Glu-Plg) by tissue plasminogen activator (t-PA) obtained from various sources. We compared kinetic parameters for three t-PA preparations. t-PA(M) was obtained from cultured melanoma cell line, and t-PA(W) and t-PA(TD) were obtained from cells with recombinant DNA. t-PA(W) had two chains whereas t-PA(TD) had one chain. Although values of kinetic parameters were different in the three t-PA preparations, there were following general tendencies. The presence of catalytic amounts of fibrin resulted in a decrease in Km, whereas the presence of larger amounts of fibrin resulted in an increase in kcat with a slight decrease in Km. The presence of fibrinogen also enhanced the activation of Glu-Plg by t-PA with an increase in kcat and without change in Km. When the effects of fragment D or E were compared, the presence of increasing amounts of E resulted in an increase in kcat, but the presence of increasing amounts of D resulted in an increase in kcat and a decrease in Km. The results suggest that roles of D and E domains of fibrin may be different in the enhanced activation of plasminogen by t-PA.

ISSN:1424-8832    

DOI:10.1159/000215792

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000317840

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

In order to detect even minimal fibrinolysis activation in liver cirrhosis, we measured fibrinopeptide Bβ 15–42 (Bβ 15–42), an indicator of plasmin activity in vivo and α2-antiplasmin (α2-AP) in a group of cirrhotic patients. The second goal of this study was to investigate whether an increased fibrinolytic activity is related to a chronic disseminated intravascular coagulation. For this purpose we concomitantly measured fibrinopeptide A (FPA), marker of thrombin activity in vivo. Results show significantly higher levels of Bβ 15–42 in cirrhotic patients than in control (p < 0.01). In patients with high FPA levels we found significantly higher values than in patients with normal FPA (p < 0.01). α2-AP was lower in patients with high FPA levels than in patients with normal FPA (p < 0.05). A significant negative correlation was found between FPA and α2-AP only in patients with high FPA (p < 0.05). There was no relationship between Bβ 15–42 and FPA nor between Bβ 15–42 and α2-AP when all patients were considered. These findings confirm that in liver cirrhosis fibrinolysis activation may occur. The primary pathogenetic role of DIC may be important in this respect. However the lack of correlation between FPA and Bβ 15–42 suggests that other pathogenetic factors may be involved in determining f

ISSN:1424-8832    

DOI:10.1159/000215793

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Fibrinolytic activity was studied in 51 patients subjected to major surgery (27 urological and 24 gynecological) without prophylaxis. Postoperative deep-vein thrombosis (DVT) was diagnosed by venography in 6 patients (11 %). Blood samples were obtained preoperatively and on days 1, 3 and 7 postoperatively. Reduced fibrinolytic activity, as determined by prolongation of euglobulin lysis time (ELT), decrease in plasminogen activators on fibrin plate and decrease in tissue-type plasminogen activator (t-PA) activity were present postoperatively. Moreover, a marked increase in short duration in fast-acting inhibitor (PA-inhibitor) levels was observed on postoperative day 1 (p < 0.001). Patients with DVT had higher fibrinogen degradation product (FDP) levels on postoperative days 3 and 7 (p < 0.02). Preoperative PA-inhibitor activity was higher (p < 0.02) in those patients who developed postoperative DVT. It is concluded that the decrease in t-PA and the increase in PA-inhibitor may contribute to the reduced postoperative fibrinolytic activity after major surgery. PA-inhibitor may represent a useful predictive marker of postoperative DVT.

ISSN:1424-8832    

DOI:10.1159/000215794

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000215795

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000317841

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000317842

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000317843

出版商:S. Karger AG    

年代:1988

数据来源: Karger