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Biomedical subjects

U Becker

Publications and source records attributed to U Becker.

At least 109 records · Page 6Linked to original sources
PubMed1989

The effect of astemizole on bronchial hyperresponsiveness and exercise-induced asthma in children.

The ability of the new generation H1-receptor antagonist, astemizole, to prevent histamine-induced airway obstruction and exercise-induced asthma (EIA) was studied in 20 children with asthma. The study was a randomised clinically controlled trial of oral astemizole versus placebo in a cross-over study. In each of the two treatment periods the children were tested at days 0, 6, 15 and 22 of therapy. The two treatment periods were separated by a washout period of 50 days, and at each visit a bronchial challenge with increasing concentrations of histamine followed by an exercise test was performed, and peak flow and asthmatic symptom score were recorded daily. The children tolerated significantly higher mean concentrations of histamine when treated with astemizole compared with placebo (P less than 0.001). Astemizole postponed the response to exercise, but no change in the maximal response was found. No differences between the treatment periods were found regarding frequency of asthmatic symptoms or the daily recording of peak flow.

Administration, Oral↗
PubMed1988

Determination of plasminogen activator inhibitor (PAI) capacity of human plasma in presence of oxidants: a novel principle.

A new functional assay of PAI-activity in human plasma is described. Hitherto known assays for fast acting PAI have some disadvantages: predilution and/or acidification steps of the sample to afford the required inactivation of alpha-2-antiplasmin (A2-PI). This approach in contrast implicates test performance in presence of chloramine T (CT), an oxidant that destroys plasma antiplasmin activity without impairing significantly the activity of urokinase (u-PA) or plasmin. The following reaction conditions were found optimal: 50 microliter of undiluted plasma, anticoagulated with citrate or EDTA, were first incubated with 1 IU u-PA in a Tris-buffer, pH 8.4 and then with Glu-plasminogen (0.85 mumol/l final), CT (2.5 mmol/l final), tranexamic acid (0.9 mmol/l final) for 5 min. at 37 degrees C. After addition of 0.3 mmol/l of the chromogenic plasmin substrate H-D-Nva-CHA-Lys-pNA (pNA = para nitroanilide) and of NaCl (250 mmol/l final) a linear kinetic with delta A405/t in the range of 0.2/min for normal plasma was recorded. In an endpoint version of the test the chromogenic substrate can be added together with plasminogen resulting an A/t2-kinetic. Dilution studies showed a linear calibration curve from 0 to 14 arbitrary u-PA inhibiting units (AU)/ml plasma. By means of PAI-standard plasmas PAI-capacity values of 20 healthy volunteers (10 males/10 females) (x = 26 years, sigma = 4.2) were determined. They ranged from 0.4 - 6.9 (x = 1.3, sigma = 0.9) AU/ml plasma. Plasma samples containing more than 14 AU/ml were prediluted with PAI-deficient plasma. Intra- and inter-assay coefficients of variation (CV) were determined to be 1.3 +/- 0.6 and 4.3 +/- 0.5%, respectively. The values of this assay correlate well with those obtained by acidification of the samples. However, the possibility of measuring plasma PAI (and PA) activities by means of a simple and direct approach can be considered as an important progress with regard to routine hospital practice. The presented oxidative inactivation of A2-PI mimics the leukocyte attack phase, suggesting that activated leukocytes create a microenvironment of uncontrolled plasmin activity.

Adult↗
PubMed1988

Effect of alcohol and glucose infusion on pituitary-gonadal hormones in normal females.

During 1 h, median 976 mmol ethanol in 5.5% glucose was administered i.v. to six healthy female volunteers (aged 26-37 years) in the luteal phase of the menstrual cycle. The median maximal blood ethanol concentration was median 33.5 mmol/l and serum ethanol concentrations of 2 mmol/l were reached after 8 h. Four of the women participated in a control experiment with infusion of an equal volume of glucose 5.5%. Venous blood samples were drawn 5 times during the 24-h follow up period. Serum concentrations of sex steroids and pituitary hormones decreased in both ethanol and control experiments and the results did not differ significantly. The lowest hormone concentrations were observed 1-5 h after the start of infusion. Oestradiol, oestrone and oestrone-sulphate concentrations decreased 24-46% compared to basal values. 5 alpha-dihydro-testosterone levels decreased 23-31%, androstenedione and dehydroepiandrosterone-sulphate levels decreased 6-48%, while testosterone levels did not change significantly. Prolactin concentrations were reduced by 41-51% of basal values and luteinizing hormone concentrations by 37-68% Follicle stimulating hormone levels did not change significantly. Stress factors or haemodilution are not likely explanations of the observed changes in hormone concentrations. A circadian rhythm could not explain changes in hormones of non-adrenal origin.

Adult↗
PubMed1988

Thyroid hormones and thyroxine-binding globulin in relation to liver function and serum testosterone in men with alcoholic cirrhosis.

In 73 euthyroid male patients with histologically verified alcoholic cirrhosis, thyroid hormones, thyroxine-binding globulin (TBG) and testosterone concentrations (total, non-protein- and non-SHBG-bound) were studied in relation to each other and to the degree of liver dysfunction. Serum concentrations of triiodothyronine (T3) decreased significantly (p less than 0.05) and thyroid-stimulating hormone (TSH) increased with progressing liver dysfunction. Serum concentrations of tetraiodothyronine (T4), TBG and T4/TBG ratio did not correlate significantly with liver function. Serum T3 concentrations correlated significantly (Kendall Tau-beta = -0.33, p = 0.001) with total serum testosterone concentrations, while there was a negative correlation (Kendall Tau-beta = -0.20, p = 0.025) between testosterone and TSH values. No correlation was found between testosterone concentrations and serum levels of TBG. It is proposed that the association between T3 and TSH on one hand and testosterone concentrations on the other reflects a covariation of these variables with liver function. The TBG level was normal in most patients and was not correlated to testosterone concentrations.

Adult↗
PubMed1988

Effect of the stable prostacyclin analogue iloprost on water and electrolyte transfer of the rat ileum and colon in vivo.

The effect of iloprost on water and ion transfer was measured simultaneously in tied-off loops of the rat ileum and colon in vivo. (1) In the ileal loops iloprost had no effect on water and ion transfer neither by intraluminal, nor intraaortal or intravenous application. (2) In the colonic loops only intraaortal bolus application of the high dose of 500 micrograms iloprost significantly decreased net water, sodium and chloride absorption, but did not induce net secretion. (3) Inhibition of endogenous prostaglandin synthesis by indomethacin did not change net water and electrolyte transfer in the ileum and colon. (4) Under this pretreatment i.v.-application of 100 micrograms iloprost, ineffective without indomethacin, induced a net secretion of water and sodium and inhibited absorption of chloride in the colon. (5) At the same time iloprost had no effect in the ileal loops of the same animals. (6) Potassium secretion was activated already by 100 micrograms iloprost administered intraluminally. We conclude from this study, that prostacyclin and iloprost have a specific secretory action in the colon. However this effect is masked under in-vivo conditions, either by interactions of ineffective prostaglandin metabolites with the concerned receptors or by counteracting prostaglandins, and becomes evident only after inhibition of the prostaglandin biosynthesis.

Animals↗
PubMed1988

The effect of oral testosterone on serum TBG levels in alcoholic cirrhotic men.

Seventy-three euthyroid male patients with alcoholic cirrhosis of the liver were randomly allocated to oral testosterone (200 mg t.i.d.) or placebo and followed for up to 36 months. Triiodothyronine (T3), tetraiodothyronine (T4), thyroxine binding globulin (TBG) and T4/TBG ratio were determined before entry and during follow-up. No significant differences were observed before entry or during follow-up between the two treatment groups. T3, T4 and T4/TBG ratio did not change significantly during follow-up, while TBG concentrations decreased (P less than 0.05). Using a multivariate test, it is demonstrated that testosterone treatment significantly reduced TBG concentrations in cirrhotic men with preserved liver function, like normal men, but not in patients with moderate liver dysfunction. The lack of effect of testosterone in patients with more advanced cirrhosis may be due to a decreased function of sex hormone receptors in their liver.

Administration, Oral↗
PubMed1988

New perspectives in diagnosis of hemostasis disorders.

The classical coagulation analyses are performed either by using manual methods or by means of various instruments with a different degree of automation. The introduction of chromogenic peptide substrates which can be split by thrombin has led to the development of photometric assays for PT and aPTT determination independent from the fibrinogen concentration and from its conversion to fibrin. After that, turbidimetric methods for the determination of fibrinogen, thrombin time and batroxobin time have been set up allowing the use of photometry for the determination of the most important hemostaseological parameters. For such purposes a new analytical system (ChromoTimeSystem, Behringwerke AG, Marburg/FRG) based on a special instrument and reagents for chromogenic and turbidimetric methods for coagulation and fibrinolysis has been developed. The ChromoTimeSystem allows to perform by photometry all important tests for coagulation and fibrinolysis. The analytical characteristics of this new system are presented.

Blood Coagulation Disorders↗
PubMed1988

Present status of standardization in coagulation assays for control of oral anticoagulation.

Recently, recommendations for the production of thromboplastins have been issued by International Committees (ICSH/ICTH) to achieve a standardization of prothrombin time assays. Following such recommendations we have standardized two new PT reagents based on coagulometric and photometric methods which rely on the same sensitive human placental thromboplastin. Both PT reagents have been optimized especially for use in oral anticoagulant therapy. They offer high sensitivity and reproducibility, accurate lot standardization and therefore internationally comparable values by the expression of the ISI value of each reagent batch.

Administration, Oral↗
PubMed1987

Effect of oral propranolol on splanchnic oxygen uptake and haemodynamics in patients with cirrhosis.

In order to elucidate the effect of beta-adrenergic blockade on liver metabolism and haemodynamics, splanchnic oxygen uptake, hepatic removal of indocyanine green (ICG) and splanchnic and systemic haemodynamics were studied in 13 patients with cirrhosis before and 1.5-2 h after an oral dose of 80 mg propranolol. All patients underwent hepatic vein catheterization and had a primed continuous intravenous infusion of ICG. Azygos vein catheterization was performed in six patients. Splanchnic (hepatic-intestinal) oxygen uptake (median control 68 ml/min vs. beta-blockade 56 ml/min, P less than 0.01), azygos venous oxygen saturation (76 vs. 67%, P less than 0.05), ICG clearance (263 vs. 226 ml/min, P less than 0.01), wedged-to-free hepatic vein pressure (16 vs. 13.5 mm Hg, P less than 0.01), hepatic blood flow (1.18 vs. 0.78 l/min, P less than 0.01), cardiac index (3.42 vs. 2.53 l/min . min 2, P less than 0.01), and heart rate (72 vs. 56 beats per min, P less than 0.01) decreased significantly after oral beta-blockade. The hepatic extraction ratio of ICG increased significantly (0.32 vs. 0.45, P less than 0.01), whereas estimated 'intrinsic' ICG clearance (289 vs. 300 ml/min, n.s.), arterial blood pressure, stroke volume, and systemic vascular resistance remained essentially unchanged. The results indicate that besides the well-known cardiovascular effects of propranolol, beta-adrenergic blockade may also reduce hepatic metabolic functions as evidenced by the significantly decreased splanchnic oxygen uptake. The raised hepatic extraction ratio of ICG may be caused by reduction in hepatic blood flow as well as in intrahepatic shunting.

Administration, Oral↗
PubMed1987

Antacid treatment of duodenal ulcer.

Sixty-seven consecutive outpatients with endoscopically verified duodenal ulcer were randomised to a double-blind treatment with either 10 ml of an antacid suspension (buffering capacity 85 mmol/10 ml, packed in single dosage pads) 1 and 3 h after each meal and at bedtime or cimetidine 400 mg b.i.d. The double-dummy technique was employed. Endoscopy was performed after 4 weeks treatment and, if the ulcer had not healed, after 8 weeks treatment. When ulcer healing had occurred, the patient entered a 1 year follow-up study. The cumulative healing rates after 4 and 8 weeks treatment were 83 and 97% vs. 69 and 94% in the antacid and cimetidine groups respectively. No significant differences were observed between the treatment groups regarding ulcer healing, symptom relief or compliance. Adverse reactions were few and only 3 (9%) patients in the antacid group had to discontinue the treatment due to diarrhoea. Of the cimetidine treated patients, 61% had symptomatic relapse during the 1 year follow-up compared to 71% of the antacid treated patients. There were no significant differences in recurrence rate or time to relapse. The moderate dose antacid treatment used here is efficient, well tolerated, safe, convenient and is a good alternative treatment of the duodenal ulcer patient.

Adult↗