Biomedical subjects

C A Doroshow

Publications and source records attributed to C A Doroshow.

3 recordsLinked to original sources

PubMed1984

Antibacterial activity of beta-lactam antibiotics in experimental meningitis due to Streptococcus pneumoniae.

In order to define the characteristics of the antibacterial activity of beta-lactam antibiotics in the treatment of bacterial meningitis, the relationship between cerebrospinal fluid (CSF) drug concentrations and the rate of bacterial killing was investigated for penicillin G and four new cephalosporins in an animal model of meningitis due to Streptococcus pneumoniae. All five drugs showed a significant correlation between increasing drug concentrations in CSF and increasing bactericidal rates. Minimal activity was observed in CSF at drug concentrations of approximately the broth minimal bactericidal concentration (MBC). Maximal activity occurred with CSF concentrations 10-30 times higher. In vitro tests did not reproduce the unique correlation of increasing drug concentrations and killing activity found in vivo. When evaluating new beta-lactam antibiotics for the treatment of bacterial meningitis, it is reasonable to establish a minimum standard of CSF drug concentrations of greater than or equal to 30 times the MBC against the infecting organism.

Animals↗

PubMed1984

Plasmid-mediated resistance in multiply resistant Haemophilus influenzae type b causing meningitis: molecular characterization of one strain and review of the literature.

The increasing prevalence of infections due to ampicillin-resistant strains of Haemophilus influenzae type b requires that suspected H. influenzae meningitis in children be initially treated with both ampicillin and chloramphenicol. Previously, the recognition of strains resistant to chloramphenicol but susceptible to ampicillin supported combination chemotherapy. In this study one case of meningitis due to a strain of H. influenzae resistant to ampicillin, chloramphenicol, and tetracycline was analyzed. The patient involved received intravenous trimethoprim-sulfamethoxazole, but putative resistance to this combination prompted the additional administration of intravenous moxalactam. The resistance of this organism was mediated by a conjugative 43-megadalton R plasmid; the determinants of ampicillin and chloramphenicol resistance were transferred as a single unit. However, not all of the multiply resistant transconjugants contained a detectable plasmid; DNA homology studies with R plasmids of H. influenzae confirmed that these extrachromosomal DNA sequences were associated with chromosomal DNA and that an extrachromosomal location was rare.

Ampicillin↗

PubMed1974

Target structure and echo spectral discrimination by echolocating bats.

Echolocating bats can use sonar to discriminate among targets which reflect echoes differing in spectral distribution of energy but not in overall intensity. They can detect differences smaller than 1 millimeter in fine target structure. Bats may be capable of classifying targets from echo spectral signatures and might thus be able to distinguish among flying insect prey by sonar.

Animals↗