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Biomedical subjects

R Mentel

Publications and source records attributed to R Mentel.

At least 37 records · Page 2Linked to original sources

Inhibition of cell adhesion to the virus by synthetic peptides of fiber knob of human adenovirus serotypes 2 and 3 and virus neutralisation by anti-peptide antibodies.

The fiber knob of adenovirus (Ad) causes the first step in the interaction of adenovirus with cell membrane receptors. To obtain information on the receptor binding site(s) several synthetic peptides derived from Ad2 and Ad3 fiber head sequences and their antisera were tested for interference with virus attachment to HeLa and FL cells and cell adhesion to viruses. The anti-peptide sera were also evaluated in ELISA and virus neutralisation test. Ad2 (of subgroup C) and Ad3 (of subgroup B) attachment was not significantly inhibited by peptides corresponding to the amino acid residues 535-554, 555-573, 562-582 of Ad2 fiber or 210-225, 267-283, 291-306 and 300-319 of Ad3 fiber. However, microplate pre-adsorbed Ad3 fiber residues 210-225 and 267-283 could bind FL and HeLa cells, and 1 mg/ml of Ad3 fiber residues 267-283 inhibited the cell adhesion to Ad3 virus to approximately 90%. This peptide may participate in the receptor binding site of Ad3 fiber. ELISA reactive anti-peptide antibodies against the homologous peptide and virus did not significantly reduce the cell adhesion to the immobilised virus or the virus attachment to cells, but in the neutralisation assay antibodies raised to Ad2 fiber residues 555-573 and 562-582 and Ad3 fiber residues 210-225 caused neutralisation of the homologous virus at serum dilutions of 1:500 and 1:32, respectively. The corresponding peptides and one further peptide of Ad2 fiber and two of Ad3 fiber seem to contain neutralisation epitopes.

Adenoviruses, Human↗

Quantification of adenovirus particles.

A physical method for quantification of the adenovirus was tested. It implies a centrifugation of the clarified or chloroform- (or freon-) treated crude virus suspension (0.5 ml) in a gentle sucrose gradient, following the analysis in a sensitive UV flow photometer and calculation of virus mass. The result (micrograms/ml) is obtained after about 1 h. The sensitivity of detection at wavelength 254 nm, 278 nm and 226 nm was compared. Virus yield of several serotypes from monolayer cultures of FL-cells was determined in a range of < 0.1 to 7 micrograms/ml. The ratio of infectious to physically complete virus (about the 770S component), the influence of freezing and thawing, storing at 4 degrees C and the effectiveness of concentration steps were also determined. There was no significant difference between the sucrose density gradient method (sedimentation rate) and the density equilibrium ultracentrifugation in a CsCl gradient.

Adenoviridae↗

[Suspected vaccination complications or atypical vaccination course. Diagnostic assessment of 58 vaccine recipients].

The "list of recommended vaccinations" of the regional Ministries of Health is the legal basis for routine vaccination programmes in each region of Germany; the recommendations of the Federal Commission on Vaccinations, "STIKO", are not legally binding. These programmes of the different regions provide legal grounds for determining claims for damage against a vaccinating doctor. In cases of damage, the Ministry of Health is liable for the damage to a patient caused by a recommended vaccination. Irrespective of these clear and comprehensive legal provisions, in case of an atypical course the patient is entitled to careful diagnosis of the complaint and appropriate medical treatment. However, later claims by the patient for damage can only be decided correctly if the necessary diagnostic data have been carefully collected at the acute stage of the disease. In our 58 patients suffering from atypical vaccination courses or suspected complications, we were able to show in each case that the symptoms are the result of interference by infectious diseases or that there was some other clear diagnosis; in no case did we find that the vaccination had caused disease or permanent damage.

Adolescent↗

Effects of norakin on respiratory syncytial virus in tissue culture and in mice.

Norakin at 1 microgram/ml inhibits the reproduction of respiratory syncytial virus (RSV) in Vero cells to 50% and at 5 micrograms/ml to 90%. The development of lung lesions in RSV-infected BALB/c mice was suppressed by 70% when the animals were treated with two doses (25 mg/kg each) of norakin, 30 min before and 4 hr post infection. (p.i.), respectively.

Animals↗

Role of genes 4 and 6 for the expression of some biological properties of influenza virus A/PR/8/34.

Genetic composition and biological properties of influenza virus recombinants A/PR/8/34 (H1N1) and A/Greifswald/6/74 (H3N2) were analysed. The haemagglutinin (HA) gene of the strain A/PR/8/34 was shown an important part of the gene complex determining the virulence for mice, the yield of HA and the plaque forming capacity. The exchange of the HA gene with that of an another strain led to a drastic reduction of these properties. On the other hand, the introduction of the HA gene of A/PR/8/34 strain into the genome of an another strain, did not render the latter virulent for mice. The production of H3 HA proceeded at an about 5-fold higher extent when the H3-gene was cooperating with the genes of A/PR/8/34 in contrast to the genes of A/Greifswald/6/74.

Animals↗

[Radial hemolysis in the diagnosis of influenza virus infections].

Some of the parameters of the radial haemolysis test were studied, and the test was used to determine antibody titres of sera obtained from patients involved in the epidemic outbreak of influenza-A/Port Chalmers, 1975. The sensitivity of the method was found to depend on the degree of erythrocyte sensitisation. An enlargement by 40 per cent of the haemolytic halo diameter should be considered and treated as antibody rise, if the reaction was to used in serological diagnosis under the conditions tested. The findings were in agreement with the complement fixation reaction in 48 per cent of all cases and with the haemagglutination inhibition test in 53.8 per cent.

Antibodies, Viral↗

The antiviral activity of dipyridamole.

Dipyridamole, a coronary vasodilatator, was found to possess antiviral activity against representatives of different families. The antiviral properties were studied in chick embryo, human diplid and FL cell cultures by the agar diffusion plaque inhibition and plaque reduction tests and one-step growth cycle experiments. The inhibition of the virus-induced cytopathic effect was estimated quantitatively. Dipyridamole significantly inhibited the yield of members of the viral families Picornaviridae, Togaviridae, Orthomyxoviridae, Paramyxoviridae, Herpetoviridae and Poxviridae, as well as of Chlamydiaceae (sheep abortion agent).

Antiviral Agents↗