Eleanor Chaffee

Observations on the mechanism of action of penicillin

Summary Penicillin acts either as a bacteriostatic or bactericidal agent depending on the experimental conditions. The number of organisms decreases at a constant rate until 99% of the organisms have been destroyed. The rate of killing varies with different organisms. The action of penicillin on hemolytic streptococci is not accompanied by lysis of the organisms. No detectable amount of penicillin is destroyed or absorbed from solution by the organisms. It appears to be effective only when active multiplication takes place.

Activity of Penicillin in vitro

Summary The observations of Florey, et al. 3 on the antibacterial activity of penicillin against Gram positive organisms are confirmed and extended. Preparations have been obtained of such activity that 0.03 γ inhibits the growth of 2 to 4 million hemolytic streptococci. This represents an equivalent of 240-250 Oxford units per mg.

PENICILLIN AS A CHEMOTHERAPEUTIC AGENT

Excerpt In 1929, while examining plates seeded with staphylococci, Fleming1observed that colonies failed to grow in the neighborhood of a colony of a contaminating mold. Following up this chance ob...

Hyaluronic Acid in Pleura Fluid Associated with Malignant Tumor Involving Pleura and Peritoneum

Conclusion Hyaluronic acid in high concentration has been isolated from the chest fluid of a patient with a malignant tumor, probably an endothelioma. The polysaccharide acid in the original fluid migrates in an electric field at pH 7.8 at essentially the same speed as the isolated pure polysaccharide acid, indicating the existence in the fluid of the free acid and not of a protein complex.

Relationship between “Spreading Factor” and Hyaluronidase.

Summary Evidence is presented to show that hyaluronidase and “spreading factor” exhibit certain attributes in common. However, there is also considerable evidence that “spreading factor” does not owe its activity solely to the presence of hyaluronidase. It would seem probable that the phenomenon of “spreading” is a complex one and that several factors may be involved in its production. Further work is required to explain the mechanism of “spreading” in terms of known chemical and physico-chemical reactions.