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Biomedical subjects

E Wenzel

Publications and source records attributed to E Wenzel.

At least 145 records · Page 8Linked to original sources
PubMed1984

[Treatment of von Willebrand-Jürgens syndrome with "hepatitis-free" factor VIII concentrates].

In five patients with von Willebrand's disease the haemostatic effect of heat-treated factor VIII concentrates was examined. For comparison, small-pool cryoprecipitate was used. All three preparations (Factor VIII-HT Hyland, Factor VIII HS Behringwerke, Kryobulin SP) were shown to improve abnormal laboratory findings, especially bleeding time, and at times even normalize them. It was possible to prevent bleedings during operative procedures, and effectively treat spontaneous bleedings. Factor VIII-HT and Factor VIII HS could be used in dosages comparable to cryoprecipitate (20-40 U/kg); in patients undergoing surgery a dose interval of eight hours is recommended. Two of four patients suffering of chronic liver disease had raised transaminase activities after receiving Factor VIII-HT. Although the risk of hepatitis cannot be conclusively assessed, the preparations used provide, owing to their good blood-clotting effect, an advance in the treatment and prevention of serious complications in patients with von Willebrand's disease.

Adult↗
PubMed1984

The subcutaneous administration of the vasopressin analogue 1-desamino-8-D-arginine vasopressin in patients with von Willebrand's disease and hemophilia.

Twenty-one patients suffering from mild von Willebrand's disease (vWd) and patients suffering from mild or moderate hemophilia A received 1-desamino-8-D-arginine vasopressin (DDAVP) (Minirin, Ferring AG) s.c. at a dose of 0.4 microgram/kg body weight. Additionally, two hemophiliacs and 22 patients with vWd received DDAVP i.v. Within the observation period of 3 h Factor (F) VIII:C levels increased 2.4 X baseline levels in hemophiliacs, and the maximal effect was observed 3 h post DDAVP s.c. In patients with vWd post DDAVP s.c. (i.v.) a 2.7 (3.4), 2.1 (1.9) and 2.2 (2.8) fold increase for F VIII: C, F VIIIR:Ag and F VIII:Rcof was observed. In eight patients suffering from vWd with additional F XII deficiency a small and transitory but significant increase of F XII levels was detected post DDAVP s.c. No local or systemic side effects were observed. In five patients with vWd tooth extractions were performed without bleeding complications under DDAVP s.c. treatment. Two patients practiced self-treatment by injecting the drug s.c. at home. We thus conclude that s.c. DDAVP is an effective, reliable, and cost-reducing form of treatment that does not bring with it the risk of transmitting infectious diseases in patients with vWd and hemophilia and that can be administered at home.

Arginine Vasopressin↗
PubMed1984

[Relevance of antithrombin III in thrombogenesis: the diagnosis and therapy of antithrombin III defects].

Pathological and inconspicuous AT III measuring values were compared with the clinical findings (arterial occlusive diseases, postthrombotic syndromes, acute profound thrombosis of the pelvic veins and the leg veins, acute heparin tolerance in several basic diseases). After calculatory elaboration of all rightly positive and falsely positive, rightly negative and falsely negative laboratory results becomes evident that the positive power of prognosis of the AT III determination is unsatisfactory for a certain basic disease and the negative evidence in these questionings rather well satisfy for the functional measuring method. - The sensitivity of the functional AT III test for the recognition of increased heparin tolerances is quite satisfactory, and the test for the answer of this questioning also suitable and more sensitive than the immunological proof method. - The high percentage of rightly positive and rightly negative findings of all tested results of apparently healthy persons and the groups of patients represented makes clear, which role plays the AT III as a physiologic inhibitor against coagulation-active serine proteases particularly in DIC and in profound thrombosis of the pelvic and leg veins. - For the observation of the course in profound thrombosis of the pelvic and led veins, features of postthrombotic condition and the DIC at least the functional determination of AT III is decisively important.

Antithrombin III↗
PubMed1984

In vitro characterization of commercial Factor VIII concentrates: long-term follow-up.

Fifty batches of Factor VIII concentrates from 12 producers were characterized in a long-term follow-up. The following parameters were measured: Factor VIII: C, Factor VIIIR: AG, Factor VIII: Rcof, specific activity (U Factor VIII: C/mg protein), fibrinogen, IgG, IgM, IgA, isoagglutinins, Hbs-AG, heparin-like activity, thrombin-like activity, antithrombin III, Factor VIII-stability at room temperature, and the rate of complete dissolution of the lyophilizate. In most preparations there was an unacceptable batch-to-batch variation of both Factor VIII complex and contaminating proteins, which exceeded the inter-assay coefficient of variation of the applied test systems. Nevertheless, different brands could be recognized by their typical protein pattern. The results obtained suggest that the standardization of Factor VIII concentrates of unknown composition is still accompanied by considerable risks.

Drug Stability↗
PubMed1984

[Significance of disordered antithrombin III function in disseminated intravascular coagulation and deep venous thrombosis for anticoagulant therapy].

In patients with acute deep vein thrombosis of the pelvis and limbs and in patients with decompensating course of DICFS considerable defects in AT III function are regularly demonstrated by laboratory tests, while in groups including patients with old or less pronounced venous thrombosis or in patients with compensated or overcompensated consumption coagulopathy normal AT III values might frequently be expected. This seems to be of interest for the interpretation of laboratory data on AT III. However, from these findings AT III replacement cannot be deduced and they cannot be used as a criterion to assess the prognostic value of AT III deficiency for the course of the underlying disease. In acquired AT III defects the anticoagulant activity of heparin is not necessarily decreased. After continuous infusion of doses below 500 USP in patients with DICFS and after administration of heparin doses of 750 USP/h/70 kg in patients undergoing fibrinolytic therapy the AT III content rather increases continuously. After extremely high heparin doses during extracorporeal circulation in the heart-lung machine transitorily decreased AT III values return to normal. In certain risk situations, however, such as after bolus injection of comparatively high heparin doses in patients with greatly reduced AT III values, a lowered anticoagulant effect of high heparin doses must be expected. In these cases AT III replacement is indicated. However, when enhanced heparin resistance is suspected or diagnosed, treatment with AT III concentrates is justified only when the diagnosis is based on laboratory findings. Cortisone and protamine chloride were found to exert direct effects on AT III function and concentration independent of the AT III defects mentioned.

Antithrombin III↗
PubMed1983

Determination of factor XIII activity and of factor XIII inhibitors using an ammonium-sensitive electrode.

An assay for rapid factor XIII activity measurement has been developed based on the determination of the ammonium released during fibrin stabilization. Factor XIII was activated by thrombin and calcium. Ammonium was measured by an ammonium-sensitive electrode. It was demonstrated that the assay procedure yields accurate and precise results and that factor XIII-catalyzed fibrin stabilization can be measured kinetically. The amount of ammonium released during the first 90 min of fibrin stabilization was found to be 7.8 +/- 0.5 moles per mole fibrinogen, which is in agreement with the findings of other authors. In 15 normal subjects and in 15 patients suffering from diseases with suspected factor XIII deficiency there was a satisfactory correlation between the results obtained by the "ammonium-release-method', Bohn's method, and the immunological assay (r1 = 0.65; r2 = 0.70; p less than 0.01). In 3 of 5 patients with paraproteinemias the values of factor XIII activity determined by the ammonium-release-method were markedly lower than those estimated by the other methods. It could be shown that inhibitor mechanisms were responsible for these discrepancies.

Ammonium Chloride↗
PubMed1983

Detection of interaural differences of intensity in trains of high-frequency clicks as a function of interclick interval and number.

Listeners were asked to detect interaural differences of intensity in trains of 4000-Hz clicks as the interclick interval (ICI) was varied from 10 to 1 ms and the number of clicks in a train (n) was varied from 1 to 32. As has previously been shown for differences of time [Hafter and Dye, J. Acoust. Soc. Am. 73, 644-651 (1983)], plots of log interaural threshold versus log n produced slopes that decrease with ICI. These results are explained in terms of a saturation model which argues that as the click rate increases, the evoked neural activity changes from what is essentially a tonic response toward one that is more phasic.

Auditory Threshold↗
PubMed1983

Arterial and venous thrombosis and normal response to streptokinase treatment in a young patient with severe Hageman factor deficiency.

The case history of a patient with severe factor XII deficiency (factor XII activity and concentration below 1%) is described. The case reported gives further evidence that factor XII deficiency leads to a prolonged euglobulin lysis time. This might be a risk factor indicating a proneness to thromboembolic events. The young man suffered from arterial and venous thrombosis, and underwent lower extremity amputation without bleeding complications, as well as thrombolytic therapy to save the other leg. There was a normal response to streptokinase, heparin, and phenprocoumon treatment.

Adult↗
PubMed1982

Thrombin-induced platelet malondialdehyde (MDA) formation in normal subjects and in women taking oral contraceptives.

Thrombin-induced platelet malondialdehyde (MDA) production and platelet count were studied in 82 male and 74 female healthy blood donors. 37 women on oral contraceptives (OC) had significantly lower values of MDA production than women who were not using the pill. There were no statistically significant differences of MDA production in women on a low dose estrogen, a medium dose, and a relatively high dose. Males had significantly higher values than females. In 15 further subjects (5 males, 5 OC-users, 5 OC-nonusers) the kinetics of MDA formation was determined by using increasing doses of thrombin. No significant differences could be found. Platelet count in women on OCs was lightly increased, but the difference was not significant.

Blood Platelets↗
PubMed1982

[The effect of biseptol and sodium salicylate administration on the concentration of serotonin and histamine and mono- and diamine oxidase activities in rat placenta].

It is known that two biogenic amines:serotonin and histamine, as well as the enzymes connected with their metabolism (mono- and diamine oxidase), play very important role in human and animal fetal development. We have investigated the effect of Biseptol and sodium salicylate administered to pregnant rats on the concentrations of serotonin and histamine and activities of the above mentioned enzymes in placenta. The obtained results showed that the administration of Biseptol has no influence on the serotonin concentration, whereas the administration of sodium salicylate caused slight increase of serotonin concentration in rat placenta. The activity of monoamine oxidase was elevated after administration of both drugs (Tabl. I, Fig. 1). The administration of Biseptol decreased the histamine concentration and caused the marked increase of DAO activity. The sodium salicylate administration to the pregnant rats didn't influence on the histamine concentration, whereas it caused parallel twofold increase of DAO activity (Tabl. II, Fig. 2).

Amine Oxidase (Copper-Containing)↗
PubMed1981

Blood trauma during extracorporeal circulation: a comparison between two bubble and two membrane oxygenators in a standardized dog model.

Determination of blood traumatization by extracorporeal circulation systems (ECC) in clinical trials may be interfered with by the underlying heart disease, by priming the circuit with blood or plasma expanders and by different operation techniques requiring a variable amount of coronary suction. Therefore, in this study a standardized animal model was used to compare blood traumatization in 2 bubble and 2 membrane oxygenators. After 2 hours of extracorporeal circulation, there was no advantage of the membrane over the bubble oxygenators concerning hemolysis, platelet preservation and induction of clotting factors. Red cells and platelets were traumatized in membrane oxygenators during the first 30 minutes without a significant further increase, whereas blood trauma in bubble oxygenators increased until bypass was disconnected. Therefore bubble oxygenators appear better suited for shorter perfusions, whereas membrane oxygenators are the superior choice in perfusions lasting longer than 2 hours.

Animals↗
PubMed1981

[Serotonin concentration in the placentas in experimental intrauterine growth retardation].

A number of investigators have shown that 5-hydroxytryptamine (5-HT) administration to pregnant animals produces changes in the placenta and leads to death of the fetuses. It has been well known that 5-HT is the most potent umbilical-placental vasoconstrictor and that its administration affects the nutritional function of the placenta. In view of these results it seemed desirable to determine 5-HT concentration in the placenta in experimental intrauterine growth retardation. IUGR was induced on the 17th day of gestation in pregnant rats by ligating the uterine artery of one horn as described by Wigglesworth with the opposite horn left untouched (control). On day 22, fetuses were delivered by C-section. 5-HT was determined by a fluorometric method. Statistical analysis employed the paired Student t-test. Average weight of IUGR fetuses was 3,05 g, whereas control fetuses 4,48. The mean concentration of 5-HT was 11% higher in IUGR fetal placentas. The mean placental concentration in IUGR was 247 micrograms/g of tissue, whereas in control the mean concentration was 222 micrograms/g of tissue. The difference between these placental concentrations was significant (p less than 0,01). We conclude that decreased blood supply to the pregnant rat uterus results in increased concentration in the placenta of 5-HT.

Animals↗
PubMed1980

[Computer-tomographic diagnosis of the traumatised pelvis (author's transl)].

Eighteen patients with fractures of the pelvis were examined by computer tomography. The results were compared with those of conventional radiological diagnosis. In each case the bone injuries were accurately diagnosed, in some patients additional information was obtained or the findings corrected. It was also possible to demonstrate injuries to pelvic, abdominal and retroperitoneal organs and injuries to other regions of the body, such as the skull and thorax. Haematomas could be directly demonstrated and additional information, useful for plannng surgery, was obtained.

Acetabulum↗