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Biomedical subjects

J Wagner

Publications and source records attributed to J Wagner.

At least 451 records · Page 25Linked to original sources
PubMed1979

[The antibacterial efficacy of cefaclor in routine testing of clinical material from two Berlin hospitals (author's transl)].

The agar diffusion method was used to test the antibacterial efficacy of cefaclor against bacterial strains isolated routinely from patients in two hospitals in Berlin. A comparison was made with the efficacy of oxacillin, azlocillin, amikacin, gentamicin, ampicillin, co-trimoxazole, tetracycline, penicillin, cefazolin, nalidixic acid and nitrofurantoin. A total of 1235 strains of Staphylococcus aureus, enterococci, Escherichia coli, Klebsiella, Enterobacter, Proteus species, Citrobacter and Pseudomonas aeruginosa were tested. Cefaclor was superior to the other substances in its activity against E. coli, Klebsiellae, and Proteus mirabilis. Co-trimoxazole and tetracycline, on the other hand, proved more effective against indole-positive Proteus species and Citrobacter. Tetracycline was also more effective against Enterobacter. Ampicillin was the most effective agent against enterococci, and oxacillin the most effective against S. aureus. Cefaclor showed good antibacterial activity against strains which were resistant to the orally administrable agents ampicillin, tetracycline and co-trimoxazole.

Bacteria↗
PubMed1979

Influence of stimulation of myocardial alpha- as well as beta-adrenoceptors on the effect of digoxin in isolated electrically driven rabbit papillary muscles.

On isolated electrically driven rabbit papillary muscle the cardiac glycoside digoxin was infused at driving rates of 0.5, 1.0 and 2.0 Hz. Two effective concentrations of digoxin were determined: 1. that inducing the maximal inotropic effect (maximal inotropic concentration) and 2, that causing cardiac arrest (toxic concentration). The influence of the alpha-sympathomimetic drug phenylephrine and for comparison that of the beta-sympathomimetic drug isoprenaline on either concentration of digoxin was investigated. 1. Stimulation of alpha-adrenoceptors by phenylephrine at a rate of 0.5 Hz significantly decreased the maximal inotropic as well as the toxic concentration of digoxin by about 36%; this decrease was maximal under the influence of the EC25 of phenylephrine and could be blocked by phentolamine. Phenylephrine did not alter the maximal inotropic effect of digoxin. At a stimulus rate of 1.0 Hz the EC75 of phenylephrine still diminished significantly the effective concentrations of digoxin whereas under these conditions the EC25 was ineffective. At 2.0 Hz stimulation of myocardial alpha-adrenoceptors had no effect anymore on either the maximal inotropic or the toxic concentration of digoxin. 2. In contrast, stimulation of beta-adrenoceptors by isoprenaline at a driving rate of 2.0 Hz resulted in a pronounced decrease of maximal inotropic and toxic concentration of digoxin while the maximal positive inotropic effect exerted by digoxin was found to be not altered by isoprenaline. The decrease of the effective concentration of digoxin caused by isoprenaline was abolished by pindolol. At a driving rate of 1.0 Hz this effect was slightly attenuated but was completely absent at 0.5 Hz. 3. From these results it can be concluded that stimulation of either adrenoceptor, alpha- and beta-, increases the effectiveness of the cardiac glycoside digoxin, i.e. diminishes the maximal inotropic as well as its toxic concentration. While stimulation of alpha-adrenoceptors is effective only at low rates of stimulation that of beta-adrenoceptors is vice versa at higher ones, thus supporting the view of different mechanisms underlying stimulation of alpha- or beta-adrenoceptors.

Animals↗
PubMed1978

[Progression and regression of diet-induced arterial changes in the domestic pig].

Under atherogenic diet in the pig changes of the intima developed in predisposed places of the arteries which have close relations to the atherogenesis in man. 4 months after the end of a 4-month atherogenic diet no decisive regression of lipid infiltrates could be established in spontaneous thickenings of the intima, however, signs of a lipid mobilisation.

Animals↗
PubMed1978

Demonstration in human atrial preparations of alpha-adrenoceptors mediating positive inotropic effects.

In isolated, electrically driven right auricular strips of the human heart the inotropic effect of phenylephrine was studied. 1. First, the influence of the driving rate on the tension developed (i.e., the frequency-force relationship) was determined by stimulation of the preparations at 0.1, 0.5, 1, 2 and 3 HZ. The force of contraction was lowest at a stimulation rate of 0.1 HZ (36.9 g/g dry weight). The maximally developed force of contraction observed at frequencies of 0.5, 1 and 2 HZ amounted to about 200 g/g dry weight. The values did not significantly differ from each other. 2. The negative log of the EC50 (-log EC50) for the positive inotropic effect of phenylephrine determined at a frequency of 0.5 and 1.0 HZ amounted to 5.28 +/- 0.08 and 5.34 +/- 0.11, respectively. The alpha-adrenolytic drug phentolamine (3 x 10(-6) M) diminished significantly the -log EC50 to 5.01 +/- 0.04 and 4.89 +/- 0.10, respectively. 3. At a frequency of 1 HZ a shift of the concentration-response curve to the right was observed after treatment with the beta-adrenolytic drug pindolol (3 x 10(-8) M); the -log EC50 of phenylephrine decreased significantly to 4.08 +/- 0.07. 4. From these results it is concluded that alpha-adrenoceptors are present in human atria; they mediate positive inotropic effects and are stimulated by phenylephrine.

Heart↗
PubMed1978

[Mitral stenosis on conventional radiographs. II. The relationship between pulmonary venous and arterial hypertension, their haemodynamic parameters and calcified mitral valves (author's transl)].

In the second paper, the relationship between pulmonary venous and arterial hypertension and calcification in the mitral valve is analysed statistically and its patho-physiological significance discussed. In one hundred cases of mitral stenosis the left atrium, as seen on the lateral projection, was always enlarged, but its size was independant of atrial pressure or the pressure gradient across the mitral valve. Apart from pulmonary fibrosis and haemosiderosis, the abnormal findings increased with increasing mean atrial pressure. Pulmonary-arterial mean pressure of more than 30 mmHg was found particularly in the presence of mitral valve calcification (94%). Calcification of the valve is the most important and reliable indicator for evaluating the severity of the stenosis.

Adult↗
PubMed1978

Preleukaemia (haemopoietic dysplasia) developing in a patient with psoriasis treated with 8-methoxypsoralen and ultraviolet light (PUVA treatment).

A 73-year-old man who had suffered for many years from psoriasis was treated with systemic psoralen and longwave ultraviolet light. After 1 year he developed a preleukaemic condition characterized by a refractory anaemia, a slight thrombocytopenia and a normo- to hypercellular bone marrow with an excess of myeloblasts. Karyotyping revealed an abnormal chromosome (12p-) and agar cultures of bone marrow showed moderate growth with a high cluster/colony ratio. He died 1 year later of renal failure precipitated by an acute pancreatitis. Owing to the possible causal relationship we would like to advise increased attention to the haematopoietic system of patients treated with psoralen.

Aged↗
PubMed1978

X-Y translocation in a retarded phenotypic male. Clinical, cytogenetic, biochemical, and serogenetic studies.

Cytogenetic studies on a mentally retarded boy revealed an X-Y translocation, karyotype 46,X,t(X;Y)(p22;q11). Only 5 other such cases have been reported and these were all females. The unequivocal male phenotype suggested non-random inactivation of the normal maternally derived X chromosome, and that the non-inactivated X-Y translocation chromosome included the locus for male determination. Confirmation of this was provided by unassociated X and Y chromatin in interphase cells, as well as by reverse banding after BrdU incorporation and autoradiography of metaphase chromosomes. There was anomalous Xg blood group inheritance in the proband, indicating possible localisation of the Xg locus to the terminal portion of the X short arm. Linkage of Xg and a form of X-linked mental retardation is suggested. Close linkage of the Xg locus with the loci for alpha-galactosidase, phosphoglycerate kinase, G-6-PD, and MPS II was excluded.

Blood Group Antigens↗