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H J SIMON

Publications and source records attributed to H J SIMON.

At least 19 recordsLinked to original sources
PubMed1963

EPIDEMIOLOGY AND PATHOGENESIS OF STAPHYLOCOCCAL INFECTION. I. AN EXPERIMENTALLY INDUCED ATTENUATED STAPHYLOCOCCAL INFECTION IN GUINEA PIGS AND ITS MODIFICATION BY TETRACYCLINE.

An aerosol-induced staphylococcal infection of previously non-infected guinea pigs is described. Investigations concerning the dynamics of this infection indicate that: 1. An infection ("carrier state") could be established predictably in every animal exposed to the aerosol inoculum. 2. Infection was limited to the upper respiratory tract and occurred without apparent systemic dissemination. 3. Cross-infection between infected and non-infected animals did not occur. 4. The initially established infection persisted in detectable form for 6 days or less in the majority of exposed animals. 5. Tetracycline administration prior to and following aerosol infection with tetracycline-resistant strains significantly prolonged the duration of the carrier state. 6. When tetracycline-resistant strains were employed, the infection could be recalled predictably by means of tetracycline administration. 7. Infection initiated with a tetracycline-susceptible strain could not be recalled by tetracycline administration. 8. The mechanism(s) of action of tetracycline in recalling the attenuated infection is (are) unknown. It (they) may not be wholly attributable to ecological changes alone, at least as these are usually considered. The indigenous microflora diminished and changed as a result of tetracycline administration, and no growth-enhancing effect of the antimicrobial of the infection strains was detectable in vitro. 9. The experimental model described lends itself well to the study of attenuated staphylococcal infection in guinea pigs, and to more general studies of staphylococcal epidemiology and pathogenesis.

Aerosols↗
PubMed1962

The newer penicillins.

The newer penicillins give high promise of overcoming some of the few disadvantages of penicillin-G. THEY FALL INTO THREE GROUPS: The alpha-phenoxy-penicillins; the penicillinase resistant penicillins; and the penicillins with enhanced activity against gram-negative bacteria. The newer alpha-phenoxy-penicillins offer little over alpha-phenoxy methyl penicillin (penicillin-V). As the length of the side chain is increased, absorption and attainable serum concentration is also increased, but these are questionable benefits and probably not significant for therapeusis. The penicillinase-resistant penicillins have once more brought almost all severe staphylococcal infections within therapeutic range. One of them, methicillin, must be administered parenterally. It is the agent of choice for the treatment of severe, penicillin-G resistant staphylococcal infections, and this is its only clinical indication. Another, oxacillin, which may be administered orally, is partially resistant to gastric acid degradation, but must be given on an empty stomach. It is most useful as prolonged therapy following methicillin, in the treatment of mixed hemolytic streptococcal-penicillin-G resistant staphylococcal infections, and as primary therapy for moderately severe penicillin-G resistant staphylococcal infections. The third group is still mostly in the experimental stage, but some strains of Proteus, E. coli, Salmonella and Shigella are highly vulnerable to their action. Toxic and allergic reactions to the newer penicillins, and crossed allergic reactions with penicillin-G, present unsolved problems.

Escherichia coli↗