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Biomedical subjects

B Kuhn

Publications and source records attributed to B Kuhn.

24 records · Page 2Linked to original sources
PubMed1983

[Antibiotic therapy in the compromised host--presented as a model for listeriosis in the mouse. II. Effect of tetracycline].

The effectiveness of tetracycline therapy on Listeria-infection in compromised host was evaluated in three different murine models. In normal adult mice infected with a tetracycline susceptible strain of Listeria monocytogenes, treatment with this antibiotic caused a reduced rate of multiplication of bacteria. That is, a low bacterial count was found in the spleen. When the macrophage system which in Listeria-infection represents a major defense mechanism was blocked through dextran sulfate 500, treatment with tetracycline was still very effective. In this case, bacterial multiplication has ceased. However, an elimination of the organisms could only be achieved after the macrophage system recovered from its temporary blockade. Secondly, nude athymic mice which are unable to develop cell mediated immunity were used to establish chronic infection with Listeria. Treatment with tetracycline in this instance only reduced bacterial counts moderately. Thirdly, five days old baby mice which are extremely susceptible to Listeria could at least partially be protected with tetracycline therapy against fatal infection.

Animals↗
PubMed1982

DNA synthesis at a fork in the presence of DNA helicases.

In a mixture of Escherichia coli DNA polymerase III holoenzyme, single-strand-binding protein, artificially forked lambda bacteriophage DNA with primer annealed to the leading side of the fork, dNTPs and ATP, DNA synthesis is enhanced by helicase II, less so by helicases, I, III or rep protein of E. coli or T4 phage helicase. The effect of helicase II depends on ATP, it is enhanced by helicase III, and it is not observed using DNA polymerase I or T4 DNA polymerase. In the absence of dNTPs helicase II is less active than helicase I or T4 helicase in unwinding the forked DNA. We believe that helicase II both shifts the forks and stimulates DNA polymerase III. The results support the conclusion derived from previous studies that helicase II is part of the DNA-synthesizing system of E. coli.

Adenosine Triphosphatases↗
PubMed1979

DNA helicases.

In summary, we postulate that DNA unwinding and ATP dephosphorylation are coupled in different ways, depending on whether the fibrous ATPase or one of the globular ATPases provides the catalytic agent. Unanswered is the question of whether there is stoichiometry of ATP utilization during the unwinding of a duplex, and unsolved is the role of the individual enzyme in the cell.

Adenosine Triphosphatases↗