ABSTRACT
Streptokinase, a 47-kDa protein isolated and secreted by most group A, C and G ß-hemolytic streptococci, interacts with and activates human protein plasminogen to form an active complex capable of converting other plasminogen molecules to plasmin. Our objective was to compare five streptokinase formulations commercially available in Brazil in terms of their activity in the in vitro tests of euglobulin clot formation and of the hydrolysis of the plasmin-specific substrate S-2251Õ. Euglobulin lysis time was determined using a 96-well microtiter plate. Initially, human thrombin (10 IU/ml) and streptokinase were placed in individual wells, clot formation was initiated by the addition of plasma euglobulin, and turbidity was measured at 340 nm every 30 s. In the second assay, plasminogen activation was measured using the plasmin-specific substrate S-2251Õ. StreptaseÕ was used as the reference formulation because it presented the strongest fibrinolytic activity in the euglobulin lysis test. The UnitinaseÕ and SolustrepÕ formulations were the weakest, showing about 50 percent activity compared to the reference formulation. All streptokinases tested activated plasminogen but significant differences were observed. In terms of total S-2251Õ activity per vial, StreptaseÕ (75.7 ± 5.0 units) and StreptonaseÕ (94.7 ± 4.6 units) had the highest activity, while UnitinaseÕ (31.0 ± 2.4 units) and StrekÕ (32.9 ± 3.3 units) had the weakest activity. SolustrepÕ (53.3 ± 2.7 units) presented intermediate activity. The variations among the different formulations for both euglobulin lysis test and chromogenic substrate hydrolysis correlated with the SDS-PAGE densitometric results for the amount of 47-kDa protein. These data show that the commercially available clinical streptokinase formulations vary significantly in their in vitro activity. Whether these differences have clinical implications needs to be investigated.
Subject(s)
Humans , Blood Coagulation Tests/methods , Plasminogen Activators/pharmacology , Plasminogen/drug effects , Serum Globulins/metabolism , Streptokinase/pharmacology , Chemistry, Pharmaceutical , Electrophoresis, Polyacrylamide Gel , Fibrinolysin , Plasminogen Activators/chemistry , Substrate Specificity , Streptokinase/chemistry , Time FactorsABSTRACT
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. The results showed clearly that there is decrease in euglobulin lysis time indicating increased plasminogen activator level, increased plasminogen level and decreased fibrinogen level after the operation. This suggests that there is significant increase in fibrinolytic activity of blood after prostatectomy leading to hypofibrinogenemia and clotting defects.
Subject(s)
Aged , Fibrinogen/metabolism , Humans , Male , Middle Aged , Plasminogen/metabolism , Postoperative Hemorrhage/blood , Prostatectomy/adverse effects , Serum Globulins/metabolismABSTRACT
The effect on protein and amino acid metabolism of combined oral contraceptives (OC) containing 150 micrograms of laevonorgestrel and 30 micrograms of ethinyl oestradiol was studied in a group of 34 healthy non-lactating women. This was compared to an identical study conducted in another group of 19 subjects who used IUCDs for contraception, and also in two other groups of subjects who were given an additional multivitamin preparation on a daily basis (29 subjects) and on the days when OC was not taken (29 subjects). Assessments were made prior to, and during the third week of the 4th, 7th, and the 13th cycles of OC treatment. Results indicated that the ceruloplasmin and retinol binding protein underwent significant increases with OC usage, while sex hormone binding globulin concentration, on the other hand, remained unaffected. At the same time, a significant reduction of several of the plasma amino acid and plasma albumin concentrations was observed, suggesting that the increase in the visceral and other types of protein concentrations previously noted was due to increased hepatic protein synthesis rather than increased breakdown or excretion as result of OC intake. Interesting biochemical alterations and metabolic effects previously observed may well be related to this altered synthesis and release of proteins and/or protein binders as well as induction of certain metabolic enzymes from the liver.
Subject(s)
Amino Acids/metabolism , Ceruloplasmin/metabolism , Contraceptives, Oral, Combined/pharmacology , Female , Humans , Proteins/metabolism , Retinol-Binding Proteins/metabolism , Retinol-Binding Proteins, Plasma , Serum Globulins/metabolism , Sex Hormone-Binding Globulin/metabolism , Vitamins/metabolismABSTRACT
Se estudió el sistema fibrinolítico en 20 pacientes con infarto agudo del miocardio. El estudio fibrinolítico se realizó en cinco etapas diferentes; etapa I, durante las primeiras 24 horas de iniciados los síntomas; etapa II, 24 horas después y las etapas III, IV y V, 48 horas, 72 horas y una semana después. Los resultados fueron: 3, 5, 8, 7 y 6 pacientes mostraron actividad fibrinolítica ligeramente aumentada, en las etapas I, II, III, IV y V respectivamente. La mayoría cursó con fibrinógeno aumentado en todas las etapas. Un mayor número mostró cifras de PDF normales en algunos casos de las etapas III y IV. En las etapas II, III y IV se obtuvo un número de casos con plasminógeno plasmático bajo. En las etapas II y IV un pequeño número de casos mostraron un aumento del tiempo de lisis de la euglobulina. Se comentan los resultados y se afirma la necesidad de interpretar los resultados de laboratorio con valoración integral clínica, inical y evolutiva