Search PubMed⌕ Search

Biomedical subjects

V W Rahlfs

Publications and source records attributed to V W Rahlfs.

At least 19 recordsLinked to original sources
PubMed1990

Variations of skin sensitivity to intracutaneous histamine provocations with regard to provocation time.

Dermal provocation tests with histamine and other mediators of allergy are widely used as diagnostic tools and as clinical pharmacological models. Diurnal variations of skin reactivity e.g. flare reactions have been postulated earlier. Potential differences in skin reactivity using histamine provoked flare areas as model were investigated by means of five different placebo formulations (i.v. solution; p.o. solution; p.o. solid forms). Flare reactions have been provoked every 3rd hour within a time span of 29 h using a cross-over design with an H1-antagonist positive control. No provocation was provided between 0:00 and 7:00 a.m. There was no statistically significant variation of skin reactivity with respect to provocation times under placebo treatment conditions. No dependence on plasmacortisol levels was observed. Interindividual differences in skin reactivity are more pronounced than the intraindividual variations.

Adult↗
PubMed1989

[Proof of bioequivalence of two nifedipine preparations].

A crossover-study was performed with 20 volunteers in order to demonstrate the bioequivalence of two nifedipine preparations after single dose application. Methods for demonstrating bioequivalence were according to the APV (Arbeitsgemeinschaft für pharmazeutische Verfahrenstechnik)- and FDA-guidelines; in addition some new but less well-known biometric procedures were used. Bioequivalence could be proved for the criteria AUC, Cmax and tmax as stated in the nifedipine monograph of Zentrallaboratorium Deutscher Apotheker.

Adult↗
PubMed1986

Influence of different bisoprolol doses on hemodynamics, plasma catecholamines, platelet aggregation, and alpha 2- and beta-receptors in hypertensive patients.

This study was designed to evaluate the effects of the beta 1-selective adrenoceptor antagonist bisoprolol on blood pressure, heart rate, plasma catecholamines, platelet aggregation, and alpha 2- and beta-adrenoceptor density in 45 male hypertensive patients (WHO stages I-II). Following a two-week placebo phase, the patients received either 5, 10, or 20 mg bisoprolol in a double-blind randomized fashion, once daily for 12 weeks. On days - 14, 0, 1, 7, 28, 56, 84, and 1 and 2 weeks after discontinuation of treatment (administration of placebo), blood pressure and heart rate were measured in the supine and sitting position, as well as during and after a 15-min exercise period on a bicycle ergometer. Simultaneously with the hemodynamic measurements, blood samples were obtained for the determination of plasma catecholamines. Blood samples for the assessment of beta-receptor density on lymphocytes and alpha 2-receptor density on thrombocytes, as well as thrombocyte aggregation sensitivity, were collected before bicycle ergometry. Five, 10, and 20 mg bisoprolol caused dose-dependent reductions of blood pressure and heart rate at rest and at peak exercise. The responder rates (diastolic BP less than or equal to 90 mm Hg) were 33%, 67%, and 100% with 5, 10, and 20 mg bisoprolol, respectively. After discontinuation of active treatment, blood pressure and heart rate gradually returned to pretreatment values within 1-2 weeks. Plasma epinephrine and norepinephrine levels in patients in the supine position remained unchanged during the whole course of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1977

Spread of extradural analgesia following caudal injection in children. A statistical study.

Data on the segmental spread of analgesia from three independent studies of caudal extradural blocks in children with three different local anaesthetic agents were examined with multiple regression techniques to find the effects of age on dose requirements. All three studies confirmed the existence of a linear relationship between the spread of analgesia and age. As there were no significant differences between the three regression lines a common regression line was calculated. This may be used as a guideline for predicting dose requirements in the daily routine of anaesthesia. By injecting a mixture of a radio-opaque substance and 4% lignocaine it was shown by comparison of the radiological spread of the solution and the distribution of clinical analgesia that the latter always exceeded the former by four to six segments. This may indicate the occurrence of diffusion.

Age Factors↗
PubMed1977

[Effects of premedication, narcosis and surgery on the coagulation and fibrinolysis systems and the platelets. The influence of dextran and hydroxyethyl starch (hes) during and after operation (author's transl)].

Patients who had undergone orthopaedic surgery were investigated. The changes attributable to premedication and narcosis were characterized by a primary fibrinolysis which was accompanied by a slight hypercoagulability. This increased fibrinolytic activity was more pronounced immediately after the beginning of the operation. The post operative changes are characterized by increased ADP-induced aggregation, increased release of platelet factors 3 and 4 and hypercoagulability with reduced fibrinolysis. The reduction in platelets during the operation could be prevented due to the influence of dextran and hydroxyethyl starch (HES). It came further to a slight increase in the activity of factor VII, to an increased fibrinogen polymerization and also to an increased release of platelet factor 4.

Adenosine Diphosphate↗
PubMed1976

[Design and evaluation of the controlled clinical trial/demonstrated by an efficacy test of the combination pentosan polysulphate/nicotinic acid in disturbed cerebral circulation (author's transl)].

Design and evaluation of the controlled clinical trial are thoroughly discussed by giving an example for testing a sodium pentosan polysulphate/nicotinic acid combination (Compuron). 60 patients with cerebral vascular disorders were randomly allocated to the two treatments and received medication over a period of eight weeks. A detailed biostatistical analysis of the data led to the following conclusions: 1. Regarding the target symptoms headache, nausea, sleep disturbance, reduced alertness, reduced ability for contacts and moods significant differences in favor of the active medication beginning with the sixth treatment week. 2. Regarding the psychological tests substantial and statistically highly significant (P less than 0.001) therapeutic effects. 3. Statistically significant decrease of the cholesterol and triglycerides level, absolutely as well as relative to placeo medication. 4. No treatment related side effects during the entire trial period of eight weeks.

Attention↗
PubMed1976

[Treatment of irritable colon. A multicenter placebo-controlled double-blind study in general practice].

The effect of Asa foetida (0.1% alcoholic dilution) and a combination of Asa foetida and Nux vomica (0.01% alcoholic dilution) was tested in a multicenter placebo-controlled double-blind trial. Both groups with active medication differed trivially but showed a marked superiority to the placebo group. The differences, however, just miss the conventional 5%-level of statistical significance. For the interpretation of this result it must be considered that only about half of the total of patients could be reached who in the planning phase of the study had been regarded necessary for a statistical confirmation of a therapeutic effect. The diagnosis "Colon irritabile" is discussed in its historical context and the psychological structure of the patient sample is described by means of the scores of a standard personal inventory test (FPI). The trial shows that it is possible to obtain objective results on the basis of the patients' judgment (rating scales with low information content).

Clinical Trials as Topic↗