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Biomedical subjects

H J Eggers

Publications and source records attributed to H J Eggers.

At least 19 recordsLinked to original sources
PubMed1990

Notes on the pathogenesis of enterovirus infections. Observations, experiments, and speculations.

Despite extensive investigations over the last decades, several aspects of the pathogenesis of enterovirus infections in humans and animals are only poorly understood, such as the molecular basis of virulence (in particular of neurovirulence), tissue tropisms (e.g. the precise site of initial virus replication in the human intestinal tract), and precipitating factors of paralytic disease ("disposition"). Studies on poliovirus myocarditis in man are reviewed. Unequivocal evidence on replication of poliovirus type 2 (strains MEF1 and Lansing) in newborn and suckling mice and on poliovirus myocarditis is presented. Our observations strengthen the thesis of similar pathogenic potentials of the enterovirus group.

Animals↗
PubMed1990

Experiments on antiviral activity of hand disinfectants. Some theoretical and practical considerations.

Various members of the picornavirus family, adenovirus 2, papovavirus SV40, as well as rotaviruses were tested for inactivation of infectivity by hand disinfectants formulated on the basis of ethanol. The inactivating effect of povidine-iodine (Betaisodona) on enteroviruses and rotaviruses was also investigated. The degree of inactivation by these disinfectants on the various non-enveloped viruses studied, however, was found unpredictable. In fact, striking differences with the very same disinfectant existed even for members of one virus family. Isopropanol was inactive against enteroviruses. These findings are discussed from a theoretical point of view and practical implications are considered. Disinfection of poliovirus 1-contaminated hands by 80% (v/v) ethanol proved not very effective, despite encouraging results obtained in the suspension test. The load of rotavirus-contaminated hands, however, was substantially reduced by treatment with Desderman. A practical regimen can be proposed.

Adenoviruses, Human↗
PubMed1990

On the structure of the epidemic spread of AIDS: the influence of an infectious coagent.

The reported AIDS cases in the USA and the Federal Republic of Germany are growing almost exponentially. Considering the epidemiological curves for different risk groups (homosexual men, i.v. drug abusers, heterosexual partners etc.) it is extremely surprising, that nearly exactly the same development occurs in all risk groups. One only has to consider a certain time shift for each group. The conformity of the development for all groups is evident by the fact, that the curves representing the reported AIDS cases for different risk groups are straight lines (in a logarithmic scale) running nearly exactly in parallel. This remarkable parallelism can be understood only if the spread of AIDS is independent of the sexual or drug risk in a certain sense. On the other hand, the drastic overrepresentation of the sexually highly active groups and drug abusers in the number of AIDS cases obviously requires that the transmission of AIDS unequivocally depends on the sexual and drug risk. We present a mathematical model that is suitable to reconcile this apparent contradiction in the interpretation of the epidemiological data: the observed parallel time series for the spread of AIDS in groups with different risk of infection can be realized by computer simulation, if one assumes that the outbreak of full-blown AIDS only occurs if HIV and a certain infectious coagent (cofactor) CO are present. Such a situation is not uncommon, see, e.g. the influenza virus--Staphylococcus aureus system. According to the mathematical model this cofactor would spread independently of the sexual and drug risk--in contrast to HIV. However, due to its analytical properties the simulated cofactor cannot be identified so far with any known infectious agent.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Neutral red-labeled influenza virus loses photosensitivity during absorption to host cells but not to erythrocytes.

Neutral red (NR)-labeled influenza virus is extremely photosensitive. Unlike NR-labeled picornaviruses which lose their photosensitivity only after penetrating the host cell, NR-labeled influenza virus loses most of its photosensitivity during adsorption at 4 degrees C. We demonstrate that the underlying reaction occurs within seconds of adsorption and that it is irreversible, i.e., NR virus eluted from chick embryo cells after adsorption is hardly photosensitive anymore. In contrast to this, NR virus adsorbed to and eluted from erythrocytes retains its original photosensitivity. We suggest that the loss of photosensitivity during adsorption of NR virus to host cells reflects a conformational change in the virion which is not elicited by adsorption to red blood cells.

Adsorption↗
PubMed1989

[Clinical relevance of nucleic acid detection of human papillomaviruses (HPV) in cells from smears of the cervix uteri].

Cervical smears from 516 women were investigated cytologically and for the presence of papilloma virus (HPV) type 16/18 DNA sequences. From the cytologically normal smears (Pap I, II, IIw) 57/424 (13%) 16/18 were found HPV positive and from the pathological ones (Pap III, IIID, IVa, IVb, V), 30/92 (33%). The age prevalence of the HPV infection--provided a cytologically normal smear--appears compatible with the period of sexual activity, but persistence of the HPV infection has to be considered as a complicating factor. Our investigations on successive smears nevertheless permit the hypothesis that an HPV infection may disappear. The use of biotin-labeled nucleic acid probes yields results at least as reliable as those obtained with radioactive probes. The test for HPV positivity appears at present to be of limited diagnostic and prognostic benefit, particularly for the individual case. Investigations on fundamental oncogenic mechanisms are a different matter.

Adult↗
PubMed1988

Biochemistry and pathogenicity of echovirus 9. III. Thermosensitive mutants of echovirus 9, strain Barty, with reduced pathogenicity for newborn mice.

Different clinical isolates of echovirus 9 are known to vary strikingly with regard to pathogenicity. Prototype strain Hill and strain Barty have previously been shown to differ not only in paralytogenic potency for newborn mice but also in a number of in vitro characteristics related to virus capsid structures. A series of mutants of strain Barty, thermosensitive for replication at 40 degrees C, was isolated after mutagenization with 5-fluorouracil. For all mutants the virus dose required to paralyze 50% of the infected animals was significantly higher than of the parent strain Barty. This reduced pathogenicity was observed at normal room temperature where the baby mice had a body temperature of 32.5 degrees C, which is even below the permissive temperature for growth of the mutants. The paralytogenic potencies did not further decrease when the mice where kept at elevated room temperature and had a body temperature of 35.1 degrees C. Thus, the reduced pathogenicity is apparently not a direct consequence of thermosensitivity of growth. Biochemical and biophysical characterization indicated that at least two of the eight mutants have an alteration in capsid protein.

Animals↗