Chapter 6, Note 33. Microbes, Phages And Lipids

We have investigated the influence of various insaponifiable fractions upon the relationship between microbes and bacteriophages. Coli bacilli, of a strain which has shown considerable resistance to phage, were grown in broth to which insaponifiable fractions from different sourcesósuch as human placenta, eggs, butterówere added in colloidal suspensions. While in these media the microbes showed a higher susceptibility to being attacked by phage than the controls grown in simple broth, only very few microbes if any remained resistant. In another experiment, this same strain of coli resistant to phage was grown in successive passages in broth containing insaponifiable fractions. After several such passages, the microbe was grown in simple broth and its sensitivity to phage was tested in this medium. While the phage used appeared unable to attack the microbes of the untreated cultures, lysis was manifest in the treated coli. Thus, insaponifiable fractions increased the sensitivity of the microbes to bacteriophage, not only as an immediate effect, but also as a transmissible character.

Chapter 6, Note 34. Lipids And Survival Time Of Tetrahymena

Various fatty acids have shown a special influence on survival time of tetrahymena pyriformis. Survival time was determined by keeping a few drops of culture in a capillary closed at one end and by daily examination of the mobility of the tetrahymena. By adding progressive amounts of an agent and withdrawing such a capillary after each addition, we also were able to determine the influence exerted by different concentrations.

In general, addition of very small amounts of fatty acids was found to prolong survival. Similar effects were obtained with hydropersulfide, and even with a solution of saponines which are known to bound sterols in insoluble combinations. The most marked effect was obtained with a fatty acid having a relatively low number of carbons. The addition of heptanoic acid in progressive amounts greatly increased longevity. The longevity increased as the concentration increased up to a point, after which it declined rapidly when greater concentrations were used. Of all the substances studied, heptanoic acid appeared to be most effective in increasing the longevity of tetrahymena pyriformis.

Chapter 6, Note 35. Lipids, Temperature And Tetrahymena

We have investigated the influence exerted by different lipids upon the capacity of tetrahymena pyriformis to resist increased temperature. In general, exposure of a culture of tetrahymena pyriformis to increased temperature induces rapid death. Kept in capillaries so a temperature of 37°C could be quickly attained, tetrahymena died in about 15 minutes. By growing tetrahymena for several successive generations in a medium containing insaponifiable fractions, increased sensitivity to temperature was obtained. In some experiments, death occurred within five minutes after exposure to 37°C. On the other hand, growth in media to which fatty acids were added markedly increased resistance, and survival after more than1/2hour of exposure to 37°C was seen.

Chapter 6, Note 36. Pain Induced By Lipids

During treatment of cancer patients with lipids, especially in exceptionally large amounts, some who had been pain free before, experienced pain. Correlation could be established between the appearance of pain and the administration of lipids since pain increased with each new injection. Furthermore, a difference was seen to exist between the pain induced by the administration of fatty acids and insaponifiable fractions. While the former had an alkaline pattern, the second had an acid one. In several cases, pain subsided with discontinuation of the medication; in others, it persisted. The pain always was controlled by the administration of the opposite lipids, fatty acids for the acid type of pain and sterols for the alkaline.

Chapter 6, Note 37. Lipids And Wound Healing

The influence exerted by lipids upon wounds was followed by the changes induced in the healing processes. In order to compare the wounds, one square centimeter of the skin was excised down to the aponeurosis on the back of rats and rabbits after mechanical epilation of the skin, and the surface measured daily. We used transparent cellophane on which the exact dimensions of the wounds were drawn. The outlines which corresponded to the surface of the wounds were then passed on paper and cut out. The paper outlines were then weighed to give us a means of comparing the changes in the actual surfaces of these wounds during healing.

While lipid acids in general induce a retardation in the healing of the wound, the administration of lipoids with a positive character were seen to have an opposite effect. It is worthwhile noting that the naturally occurring sterolsócholesterol and insaponifiable fractionsóare much more active than the synthetic in inducing rapid wound healing.

We studied the histological and cytological changes in parallel incisions made on the back of rats and rabbits and excised at intervals. In animals treated with sterol preparations, a difference was seen between the healing of epithelial and connective tissue wounds. While healing of the former was enhanced, healing of the latter was not influenced. On the other hand, the higher alcohols, such as polyunsaturated alcohols or butanol, were more active in increasing healing of connective tissue wounds than of epithelial. It is interesting to note also that in the wounds treated with the sterol preparations, the scar showed an epithelium with many more layers than that of the normal surrounding skin. In rabbits, instead of two or three layers, there were more than ten.