The effects of air ions of the living mammalian trachea

Studies on the effects of air ions on the functional efficiency of the extirpated tracheal strip have been extended to the trachea of the living rabbit, rat, and mouse. Animals exposed to high mobility (+) air ions administered via a tracheotomy aperture displayed: (a) Decreased ciliary activity. (b) Decline in mucus flow rate, sometimes reversed by prolonged exposure to (+) ions; a frequent drop in the volume of mucous secretion. (c) Contraction of the membranous posterior tracheal wall. (d) Increased vulnerability to trauma of cilia and mucosal blood vessels. Similar treatment with (-) air ions reversed (+) ion effects on ciliary activity, mucus flow, contraction of the tracheal smooth muscle. Continued (-) ion treatment raised the ciliary rate (invariably) and the mucus flow rate (often) above their initial levels. (+) Air ions administered to unoperated resting mice and rats increased the respiratory rate; (-) ions reversed this effect. Long exposure of unoperated ambulatory mice to (+) air ions produced: (a) Decreased ciliary activity. (b) No clear cut effect on mucus flow. (c) Contraction of the posterior tracheal wall. (d) Increased vulnerability of the mucosa to trauma. (-) Air ions increased ciliary activity but had no clear-cut effect on the mucus flow rate.     

Staphylococcal virolysin,a phage-induced lysin; its differentiation from the autolysis of normal cells

Virolysin is a lysin which appears in Staphylococcus aureus K₁ cells infected with phage P₁₄; together with phage, virolysin is released from phage-infected cells at the time of lysis. Autolysin is a lysin formed by uninfected cells of the K₁ strain; autolysin is released from uninfected cells by autolysis. They show the following similarities: Both agents act within the genus Micrococcus. They lyse cells only after the cell has been subjected to a damaging or "sensitizing" treatment, such as heat, bacteriophage, acetone, or ultraviolet irradiation. The course of lysis of heated cells by both lysins has been found to proceed in a similar manner. A constant percentage of cells is lysed, independent of the concentration of lysin; the residual cells remain resistant to either lysin. Lysis proceeds logarithmically with time, and the velocity constants K are proportional to the lysin concentration. K increases with increasing temperature. Both lysins are unaffected by antiserum to the phage. They are inhibited alike by a number of chemicals, including known enzyme inhibitors. Both agents are destroyed by proteolytic enzymes and are precipitated by 40 per cent saturation with (NH₄)₂SO₄. Both lysins are very thermolabile. The two lysins differ with respect to their pH optimum, antigenic relationship and specificity for Micrococcus lysodeikticus. These results suggest that (1) both lysins have many properties associated with enzymes, (2) the lysis of heated cells, which they produce, has some of the characteristics of a chemical reaction, (3) the lysin from the phage-infected cell is clearly different from the lysin of the uninfected cell.     

The B. mycoides N host-virus system. III. Release of phage from the lysogenic strain

Experiments were performed to determine the mechanism of release of phage from the lysogenic strain of B. mycoides N. The results suggest that qualitatively the same situation obtains as in the phage-carrying cultures of B. megatherium 899 and E. coli Li; i.e., the population consists of two kinds of cells: "lysogènes potentiels" and "producteurs." Quantitatively, however, there are more "producers" in a broth culture of the lysogenic B. mycoides N, at least curing the first 4 to 8 hours after cells have been suspended in fresh medium, suggesting that the interaction between host and parasite is one in which the balance is easily swung in favor of the virus. These conclusions are based upon the following lines of evidence: (1) the slow "growth rate" of the lysogenic culture, (2) the fact that the colony count falls far below the plaque count or the filament count (which correspond) for a well washed suspension, (3) the increase in phage output in a large number of tubes, each containing a small number of lysogenic cells, after a few hours' incubation in nutrient broth at 30°C.     

Lysis from without of S. aureus K1 by the combined action of phage and virolysin

Lysis from without (LFW) occurs in two steps: (1) sensitization of cells by phage, which renders the cells susceptible to (2) destruction of an essential cell structure by an extracellular lytic enzyme. Virolysin, from phage-infected cells, was used in these studies. Normal cell autolysin is also effective. Evidence is presented that: 1. Neither phage nor lysin alone causes LFW. 2. Sensitization requires phage adsorption. 3. It can be caused by non-infectious particles. This establishes a new biological activity of the particle. 4. Heat, U.V., detergents, penicillin, and other damaging agents also sensitize cells. 5. Sensitization involves a non-lethal, reversible reaction. 6. Sensitization by phage prevents virus synthesis. Following adsorption, a cell can undergo sensitization or infection but not simultaneously. When only a few particles are adsorbed, infection can occur; when sufficient particles are adsorbed, sensitization takes place. 7. Quantitative aspects of LFW are described. Lysis proceeds logarithmically. The lysis end-point depends upon the phage concentration but is independent of the enzyme concentration.