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Biomedical subjects

E Wenzel

Publications and source records attributed to E Wenzel.

At least 109 records · Page 6Linked to original sources
PubMed1988

In vivo recovery and half-life time of a steam-treated factor IX concentrate in hemophilia B patients. The influence of reagents and standards.

Factor IX (FIX) recovery and half-life was measured in ten hemophilia B patients under standardized conditions. Each patient received a steam-treated high-purity factor IX concentrate at a dose of 19-39 U/kg body weight. FIX activity was determined using a one-stage assay, which was calibrated against the international concentrate standard (reagents from Immuno, Heidelberg). The in vivo recovery ranged from 24% to 53% (mean value 37.7%) and the half-disappearance time (HDT) from 8-30 h (mean 16.7 h). In four of the ten patients, the distribution and elimination half-lives were estimated and ranged from 0.3 h to 3.9 h (mean 1.4 h) and from 28.6 h to 39.7 h (mean 33.1 h), respectively. In six patients FIX was redetermined using a different FIX deficient plasma and a plasma standard (reagents from Merz & Dade, Munich, FRG). Recoveries and HDT based on the results obtained with this method were significantly higher (68.2% vs 39.7%; p less than 0.05), and longer (14.8 h vs 10.6 h; p less than 0.05), respectively. FIX activity was also measured by both assay systems in 100 healthy subjects (50 males, 50 females). The reagents from Immuno yielded a mean value of 0.77 U/ml, while the mean FIX activity utilizing standards and reagents from Merz & Dade was 1.11 U/ml (p less than 0.000001). The coefficient of correlation between the FIX activity measurements, as determined in 100 healthy subjects and 6 hemophilia B patients using the different test systems, was r = 0.9 (N = 159; y = 0.08 +/- 1.3* chi; p less than 0.001). Our data suggest that recovery and HDT of factor IX concentrate strongly depend on the assay and calibration conditions and that an international FIX activity plasma standard is urgently required.

Adolescent↗
PubMed1988

Plasminogen: a brief introduction into its biochemistry and function.

Human plasminogen is a beta-globulin (2% carbohydrate, molecular weight 90 KD), which in its native form has NH2-terminal glutamic acid (Glu-plasminogen) whose primary structure is known (31, 37, 38). From human plasma plasminogen can easily be isolated by affinity chromatography techniques (10, 25, and Table 1). Plasminogen is synthesized in many organs. The production site of the zymogen may be the liver (21), the eosinophiles (3) or the kidney (15). The plasma-plasminogen level is low in newborns (22) and even lower in the premature infant (2). In healthy adults it is found in plasma or serum in a concentration of 200 mg/l (= 2 microM, 22, 39). The half-life of the native (Glu-) plasminogen is 2.24 +/- 0.29 days (6). Two types of Glu-plasminogen occur in human plasma, which differ in their carbohydrate composition as well as in their content of sialic acid. Genetic variants (see Mayr, 3.1.); of plasminogen have been reported (16) after isoelectric focusing of human plasma in polyacrylamide gels. Three patterns were found, two completely different and the third most likely a mixture of the other two. Characteristical functional properties of plasminogen are related to its molecular structure, e.g. its in vivo specificity for fibrin in contrast to the fairly unspecific in vitro activity of plasmin. Glu-plasminogen is easily converted by limited plasmic digestion to modified forms with NH2-terminal lysine, valine or methionine, which are commonly designated "Lys-plasminogen" displaying a plasma half-life time of 0.8 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrate Conformation↗
PubMed1988

Reference values and variability of plasminogen in healthy blood donors and its relation to parameters of the fibrinolytic system.

During a survey of four month's duration the following parameters were determined in 43 healthy blood donors (22 males, 21 females; mean age 29 years/20-49/): plasminogen activity, plasminogen concentration, alpha 2-antiplasmin (alpha 2-AP) activity, alpha 2-AP concentration, tissue type plasminogen activator (t-PA) activity, t-PA concentration, plasminogen activator inhibitor--I (PAI-I) activity, AT III activity, AT III concentration and heparin cofactor II (HC II) activity. Normal values including standard deviation (x +/- 2s) were: plasminogen activity: 96.3% (65.9-126.8), plasminogen concentration: 12.2 mg/dl (7.7-16.8), alpha 2-AP activity: 99.9% (83.8-116), alpha 2-AP concentration: 108.1% (84.5-131.8), t-PA activity: 0.85 IU/l (0.0-1.92), t-PA concentration: 10.3 ng/ml (2.5-18.1), PAI-I activity: 15.2 AU/ml, AT III activity: 111.4% (87.8-134.9), AT III concentration: 31.6 mg/dl (24.2-39.1) and HC II activity: 110.7% (81.4-140.0). Concerning plasminogen values no sex related difference could be stated. Women who were smokers and used oral contraceptives tended to present elevated t-PA activity levels due to a lower activity of PAI-I, although this tendency was not significant. Determining concentration and activity of components in the fibrinolytic system plays an important part in the diagnosis, therapy and prognosis of thrombophilic disorders.

Adult↗
PubMed1988

Characterization of commercially available plasminogen preparations in vitro: purity and reactivity.

Three different commercially available plasminogen preparations (Immuno-, Kabi-, and Behring-plasminogens) were examined regarding purity and reactivity to different activators (high molecular weight [HMW] or low molecular weight [LMW] two-chain urokinase type plasminogen activator [tcu-PA], single chain urokinase type plasminogen activator [scu-PA], tissue type plasminogen activator [t-PA], and streptokinase [SK]). The Immuno-preparation was a Lys-plasminogen, commercially available for therapeutical use, whereas the research reagents for KabiVitrum and Behringwerke were Glu-plasminogen. Activity data provided by the manufacturers correlated well with our findings. Also a good correlation of reactivity to activators measured with a chromogenic substrate and on fibrin plates could be observed. The Immuno-plasminogen showed a minimum contamination with plasmin which has to be taken into consideration for the interpretation for its apparently higher activation by plasminogen activators compared to the plasmin-free plasminogens. Further in vitro and in vivo research has to be performed to find out criteria for a practicable scheme of administration of fibrinolytic agents for therapeutical thrombolysis.

Electrophoresis, Polyacrylamide Gel↗
PubMed1988

Platelet aggregation, rheological parameters and blood glucose profiles in diabetic children (type I) treated with human and porcine insulin.

In a three-year bicentric cross-sectional investigation on type I diabetic children between six and eighteen years of age, blood sugar profiles and spontaneous thrombocyte aggregation were assessed besides anamnestic and clinical data. In the children treated with human insulin raised spontaneous thrombocyte aggregation was significantly more frequent than in those treated with porcine insulin. At the same time blood sugar fluctuation from day to day measured between seven and nine a.m. tended to be raised in the children treated with human insulin; the fluctuation in the diurnal profile measured for fourteen days was indeed very much greater. Since the two groups were comparable as to sex distribution, age, duration of disease, quality of compensation, application and dose of insulin, the greater fluctuation of blood sugar in the children treated with human insulin appears to be the cause for the raised spontaneous thrombocyte aggregation.

Adolescent↗
PubMed1988

The clinical significance of different routes of desmopressin (DDAVP) administration in various bleeding disorders.

In our study, we wanted to evaluate the clinical effect of s.c. DDAVP on haemostasis in different kinds of bleeding disorders. A total of 109 patients was treated with DDAVP s.c. at a dose of 0.4 microgram/Kg body weight. An effect of DDAVP on F VIII modalities was found after s.c. injection in all patients, but in comparison to i.v. DDAVP, the effect seems to be somewhat less. From our data, the patients blood groups do not influence the amount of F VIII modalities. Furthermore, the s.c. injection of DDAVP was found to be effective in patients with disorders of primary haemostasis. A number of operations was performed under the use of s.c. DDAVP in 24 patients with different kinds of bleeding disorders, in none of them, bleeding complications occurred.

Administration, Intranasal↗
PubMed1988

[Hemorheologic, micro- and macrocirculatory effects of hypervolemic hemodilution with middle molecular weight hydroxyethyl starch (Haes 200/0.62; 6 percent)].

During a single blind study the influence of hypervolemic hemodilution (Infusion of 500 cc Elohäst 6%) on micro- and macrocirculation, transcutaneous pO2 and fluidity of blood of apparently healthy subjects was investigated. Blood pressure and heart rate remained unchanged during and after the infusion. One hour after the infusion there was a significant increase in the blood flow of the common carotid artery and the cutaneous circulation, and after 3 h a significant increase in conjunctival oxygen partial pressure was observed. The decrease in hematocrit was significant at all measuring points but most marked after 3 h (with 4.2 by volume). After 3 h and 6 h a significant increase in plasma viscosity and erythrocyte aggregation could be observed, whereas both parameters were unchanged during the early phase.

Adult↗
PubMed1988

[Isovolemic hemodilution in patients with coronary heart disease].

In the age of cellsavers patients suffering from coronary heart disease are diluted to a hematocrit of 20% or even less during a surgical intervention in the coronaries and they leave the operating room with a hematocrit of 30%. On the other hand, a hemodilution to a level of 30% in patients with coronary heart disease represents a contraindication due to the limited coronary reserve. On the occasion of the collection of autologue blood, before vascular surgery or for therapeutical hemodilution, the hematocrit was reduced from 45 to 35% by means of an isovolemic hemodilution with 500 ml of Haes 200/0.5 10% in 50 patients. In the load-ECG the pressure X frequency-product and the dyspnoe decreased significantly. The microcirculation in the nailfold and the systemical blood fluidity increased significantly. As in 22% of the patients a deterioration was stated, we propose to dilute all the patients who have to undergo a coronary vessel operation without exclusion criteria once isovolemically and to stress them before and afterwards. The patients having a clinical defict should be diluted intraoperatively only to 30% and postoperatively not under 35%.

Angina Pectoris↗
PubMed1987

[Use of streptokinase and urokinase in deep venous thrombosis and pulmonary embolism: indications and clinical experience].

The efficacy of fibrinolysis in DVT is dependent upon the age and organization of the thrombus as well as its localization. In consequence, selective evaluation prior to determining the indication for thrombolytic therapy is just as important for therapeutic success as choosing the appropriate fibrinolytic agent. To improve the results of fibrinolysis a team of angiologists, hemostaseologists, radiologists and surgeons are cooperating in a special "thromboembolic care unit". Phlebographic criteria were defined which allow differentiation of fibrinolytic indications depending upon the site of the thrombus. Selection of the fibrinolytic agent and careful monitoring of the thrombolysis should ensure a maximum therapeutic effect with a minimum of bleeding complications. The duration of thrombolysis was established through phlebographic verification and functional tests with venous occlusion plethysmography. The cause and results of 108 cases of thrombolysis shall be presented.

Humans↗
PubMed1987

High-dose systemic streptokinase and acylated streptokinase-plasminogen complex (BRL 26921) in acute myocardial infarction: alterations of the fibrinolytic system and clearance of fibrinolytic activity.

We report the results of two consecutive studies using intravenous bolus injections of streptokinase (SK) or acylated plasminogen-SK complex (BRL 26921) in patients with acute myocardial infarction (AMI). In the first study, 20 patients received either 750,000 units (U) SK (group IA, n = 10) or 1,500,000 U SK (group IB, n = 10) within 5-10 min intravenously. In the second study 10 consecutive patients received 750,000 U SK within 15 min (group IIA) intravenously. The following 10 consecutive patients received 30 mg BRL 26921 within 2 min (group IIB). Early reperfusion was found in 16 patients in the first study (8 in each group) and in 18 patients in the second study (9 in each group). The decrease of fibrinolytic activity was biphasic with a half-disappearance time of 112.5 min for BRL 26921 and 31 (IA) and 18 (IB) min for SK. alpha 2-Antiplasmin depletion and a decrease of fibrinogen was observed with no differences after bolus injections of SK and of BRL 26921.

Aged↗
PubMed1987

Measurement of factor VIII procoagulant antigen in normal subjects and in hemophilia A patients by an immunoradiometric assay and by an enzyme-linked immunosorbent assay.

Factor VIII coagulant antigen (FVIII:Ag) and FVIII coagulant activity (FVIII:C) were measured in 102 healthy individuals, in 5 hemophilia A carriers and in 21 hemophilia A patients before and after infusion of heat-treated high-purity FVIII concentrates. Factor VIII:Ag was determined by a solid-phase micro enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies and by a conventional solid-phase immunoradiometric assay (IRMA). Factor VIII:C was assessed using a one-stage assay. The micro ELISA was decidedly more precise than the IRMA. There was a close correlation between the results obtained by the three assays in the plasma of healthy subjects and in hemophilia A carriers. After transfusion of FVIII concentrates to hemophilia A patients, the FVIII:Ag recoveries were significantly lower than the FVIII:C recoveries and the biological half-life of FVIII:Ag was significantly shorter than for FVIII:C. The calculated half-life of FVIII:C was longer than in any previous study.

Adolescent↗