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Biomedical subjects

G Menzel

Publications and source records attributed to G Menzel.

At least 37 records · Page 2Linked to original sources
PubMed1986

Effect of whole-body vibration with different frequencies and intensities on auditory evoked potentials and heart rate in man.

Auditory evoked brain potentials (AEP) and electrocardiogram (ECG) were recorded from 9 healthy male subjects during sinusoidal whole-body vibration exposure (WBV) in the longitudinal (+/- az) direction with four frequencies (1 Hz, 2 Hz, 4 Hz, and 8 Hz) and two intensities as well as under non-WBV conditions. The sequences of the different experimental conditions were arranged according to a 9 X 9 Latin Square design. The sound of the electrohydraulic vibrator was masked by a constant noise level. A subtraction technique was used to eliminate vibration-synchronous activity contaminating the electroencephalogram. The AEP amplitude N1-P2 revealed systematic effects of different WBV frequencies and intensities. The amplitude decreased along with an increase in intensity (16 dB) by about 10 per cent. It diminished increasingly with a monotonic trend in the order non-WBV, WBV 8 Hz, WBV 4 Hz, WBV 2 Hz, and WBV 1 Hz. The interbeat-interval histograms computed from the ECG exhibited the highest mean values at MBV of 1 Hz, high intensity, and the lowest ones at WBV of 4 Hz, high intensity. The AEPs are reaffirmed as an informative measure for studying the WBV effect on central nervous information processing, although the modes of action are not yet fully known. Efferent influences on the acoustic input, cross-modality interaction, sensory mismatch, and changes of central nervous activation level are discussed as potential mechanisms.

Adolescent↗
PubMed1986

Effect of root extract from Boerhaavia diffusa L., containing an antiviral principle upon plaque formation of RNA bacteriophages.

An extract obtained from the roots of Boerhaavia diffusa plants, which inhibits the infection of several plant viruses, was tested by the agar diffusion hole method for its action on RNA-containing bacterial viruses. Plaque formation of the phages was only partially and non-uniformly influenced by the extract so that a uniform principle of action was not realized for the RNA viruses of prokaryotic and eukaryotic host organisms.

Escherichia coli↗
PubMed1985

[Enhanced formation of plaque in RNA phages/bacteria systems under the effect of surface-active preparations].

The effect of 21 surfactants on the plaque formation was tested in three RNA-phages/Escherichia coli systems and in one RNA-phage/Pseudomonas aeruginosa system. Especially anionic detergents proved to be able to influence the plaque formation substantially. In high concentrations of Metaupon, Fekunil 602, Fekunil S-BA, Emulgator W 270, and Emulgator O-BA the plaque formation by the phages M 12 and f2 was inhibited and in low concentrations it was promoted. In the system Q beta/E. coli AB 301 the effect of the detergents mentioned was restricted to the prevention of the appearance of plaques. The detergent E 30 brought about only plaque inhibitions, too, in all used RNA-phages/E. coli systems. The treatment with effective detergents in the system PP7/P. aeruginosa, however, increased only the number of plaques. This phenomenon was evident in the formation of radiate plaque patterns in the lawn of bacteria. In the case of RNA-phages of E. coli the formation of such trains of lysis depends on the choice of the nutritive medium. The addition of the detergent Fekunil 602 at different times after the contact between phages and host bacteria affects the length of the beams of lysis. The ionogenity of surfactants seems to be of importance for the formation of radiate plaque patterns, since the tested cationic compound and the nonionic surfactants, contrary to anionic surfactants, did not cause any beams of lysis.

Coliphages↗
PubMed1980

The effect of triazole on RNA viruses.

The triazole derivative 4-(1-hydroxy-3-piperid-N-yl-prop-l-yl)-5-methyl-2-methyl-2-phenyl-triazole (HMPT) markedly reduced plaque formation by, RNA bacteriophages and delayed their liberation. Replication of tobacco mosaic virus in a systemic host was hardly affected by HMPT, but local lesion formation in a hypersensitive host was strongly reduced by the drug. The mechanism of action of HMPT was discussed.

Antiviral Agents↗
PubMed1979

[Effect of the detergent Metaupon on replication of various phages].

As several other surfactants do, the detergent Metaupon acts on the multiplication of bacteriophages. We investigated the influence of Metaupon on the phages phi and lambda, the cyanophage LPP-1, and the RNA-phages f 2, M 12, and Q beta by means of the agar diffusion test, pour plate test, adsorption test, and one-step growth test. The action of Metaupon on the free phages was also tested. Metaupon inhibits the formation of plaques by the phages with exception of lambda. With the phages f 2 and M 12 the substance increases the amount of plaques depending on concentration. The main mode of action of Metaupon was found to be the inhibition of the adsorption of the phages to the host cells. Only in the case of phi 105 free phages were inactivated.

Bacillus subtilis↗
PubMed1979

[On the antiviral effect of a triazole compound (author's transl)].

4-[Hydroxy-3-piperid-N-yl-prop-1-yl]-5-methyl-2-phenyl-triazole (HMPT) reduced the plaque formation caused by M 12, f 2, and Q beta and retarded the liberation of phages. The concentration of tobacco mosaic virus in primarily infected tobacco leaves was decreased. HMPT inhibited the development of local lesions. Free phages and TMV particles werenot influenced by HMPT.

Adsorption↗
PubMed1978

[Effect of 1,3,5-triazines on various bacteriophages and their hosts].

In the agar diffusion test 24 triazines were investigated with regard to their action on the mulplication of DNA phages (lambda and LPP-1) and RNA phages (M12 and Qbeta). In several cases the amount of plaques was diminished or increased depending on the kind of triazine and virus. The investigations demonstrate the triazines to be able to interfere with the formation of plaques by virulent and temperate viruses of procaryotes.

Bacteriophages↗
PubMed1978

HLA system and Balkan endemic nephropathy (a collective study with the collaboration of all participants in the HLA workshop--Sofia 1976).

Balkan endemic nephropathy, a fatal family disease with unknown aetiology and pathogenesis is typical for three neighbouring regions in Bulgaria, Yugoslavia and Rumania. HLA typing of 180 patients from the endemic area in Bulgaria was done and the antigen frequencies were compared with 1264 healthy controls. An increased frequency (P less than 0.001) of the antigen HLA-B18 in the patients was demonstrated.

Bulgaria↗
PubMed1978

[On the effect of some morpholinium compounds on the multiplication of RNA viruses (author's transl)].

In the present paper the authors report about the effect of N,N-dimethylmorpholinium chloride (DMMC), N,N-dimethyl-2-oxomorpholinium chloride (DMOMC), and N,N-diethyl-2-oxomorpholinium chloride (DEOMC) on the multiplication of tobacco mosaic virus (TMV), potato virus X (PVX), and cucumber mosaic virus (CMV) as well as the plaque formation by the RNA phages M 12, f 2, and Qbeta. The used morpholinium compounds do not influence strikingly the multiplication of phytoviruses. The results found by serological procedure and by bio-assay are indicated concordantly by the two methods. The plaque formation by bacteriophages is not influenced by DMMC, but enhanced significantly by DMOMC and DEOMC. These effects might be caused by the different hydrolytical behaviour of the morpholinium compounds tested.

Bacteriophages↗
PubMed1977

[T-rosette and rosette inhibition test with antilymphocyte globulin following kidney transplantation].

263 examinations with the rosette-test with sheep erythrocytes and the rosette inhibition test with antilymphocyte globulin in 42 normal persons and 56 patients after transplantation of a kidney showed in 10 patients a significnat decrease of the rosette-forming T-lymphocytes in the peripheral blood under conditions of rejection. On the other hand the number of rosettes significantly increased in 4 patients. The valency of the rosette inhibition test for the rejection diagnostics is restricted by technical difficulties and wrong positive results (11%). The results are discussed on the basis of the receptor synthesis rates for sheep erythrocytes and of the electric superficial potentials of the T-lymphocytes and in relation to the HLA-A/B/C/D-system.

Antilymphocyte Serum↗
PubMed1975

[Effect of several plant growth regulators on various prokaryotes and their viruses].

26 plant growth regulators including herbicides were investigated in their effect on the multiplication of Escherichia coli, Bacillus subtilis, and the blue-green alga Plectonema boryanum as well as the RNA phages M 12 and Qbeta and the DNA phages lambda, phi 105, and LPP-1 employing the agar diffusion method. Nearly all of the compounds inhibited and/or stimulated one or some of the prokaryotes tested. The most frequent and strongest effects occurred in Pl. boryanum, the least effects in E. coli. The multiplication of phages was also influenced by plant growth regulators leading to increase, decrease or non-appearance of plaques. The investigations with the temperate phages lambda and phi 105 suggested part of the compounds to be able to interfere with the process of lysogenization. The results are discussed comparatively involving correspondent findings referred to in literature.

Bacillus subtilis↗