Antibacterial systems of serum in relation to nonspecific immunity to infection

[The importance of serum components, particularly complement factors, properdin and transferrin, in inhibition of bacterial growth by human serum (author's transl)]

In this study human serum was broken down of column chromatography into its protein components, which were than examined singly and in comnination for antibacterial activity. The bactericidal effect of serum was retained to an apperciable extent in only one of six fractions. Antibacterial inhibitory activity could be restored fully by combining the fractions however. There was no correlation with the specific antibody titers. Complement had an essential part in this unspecific defence. In the absence of C'9 all other combinations of the remanining complement components exhibited no appreciable inhibitory effect. Not all complement componets are required, however, for unspcific bacterial growth inhibition. In contrast to this all complement components are necessary in the antigen-antibody reaction. Futhermore, properdin displays bactericidal activity which is related to the presence of complements. A great deal of the antibacterial activity of human serum thus arises only from the combined action of several components. These do not include proteins with a molecular weight between 100,000 and 70,000, whereby transferrin plays a part.

On the participation of antibodies and complement in the antibacterial activity of an extract from rabbit polymorphonuclear leucocytes

Antibacterial activity against Escherichia coli was found in the cytoplasmic extracts of rabbit polymorphonuclear leucocytes. The lack of antibody activity was determined by agglutination, passive haemagglutination, bactericidal reaction in the presence of complement, bactericidal plaque technique and immunoelectrophoresis. Thermostability of the extract, higher activity in a sodium citrate buffer than in veronal buffer containing Ca^{+ +} and Mg^{+ +} and negative haemolysis give evidence against the participation of complement in this type of antibacterial activity. Inhibition of the activity following absorption with different bacterial suspensions is interpreted as involving electrostatic bonds between active cationic substances and the negative charge of the bacterial surfaces. In addition, inhibition of the antibacterial activity was proved in the presence of both native and inactivated piglet and rabbit whole sera and albumin, which suggests that there is no independent action of these cytoplasmic substances in serum in vivo.

Lysozyme insensitivity of bacteria indigenous to the oral cavity of man

SYNOPSIS IN INTERLINGUA

INSENSIBILITATE A LYSOZYMA DEL PARTE DE BACTERIOS INDIGENE AL CAVITATE ORAL DEL HOMINE.-Esseva constatate que inter 112 culturas pur, representante 13 gruppos de bacterios oral, nulle esseva lysate per lysozyma a concentrationes de 5,50, o 500 μg per ml, secundo essayos turbidimetric. In plus, esseva trovate que le plus numerose bacterios cultivabile ab specimens de debris gingival, de placa dental, e de saliva cresceva in le presentia de 0,5, 5, o 50 μg per ml de lysozyma. Quando specimens de debris gingival esseva incubate con 50 μg per ml de lysozyma, nulle liberation de proteina solubile esseva detegite. Iste datos pare indicar que lysozyma per se exerce pauc effecto super bacterios indigene al cavitate oral del homine.

The isolation and selected properties of blood monocytes

A technique is described for the quantitative recovery of monocytes from horse blood by means of flotation on dense albumin solutions. Monocytes are concentrated in a surface pellicle along with a few lymphocytes which are then removed when the monocytes adhere to a glass surface. The in vitro cultivation of homogeneous populations of monocytes results in an increase in (a) cell size, (b) number of mitochondria, and (c) phase-dense granules of the centrosphere. The phase-dense granules are osmiophilic and acid phosphatase positive. Quantitative biochemical analysis during cultivation have revealed increased levels of cytochrome oxidase, acid phosphatase, arylsulfatase, and BPN hydrolase. In addition, glucose utilization and lactic acid production are stimulated under the same conditions. The uptake of both bacteria and colloidal gold is stimulated during in vitro cultivation. The phagocytic activity of cultured monocytes may be enhanced by a purified bacterial lipopolysaccharide. These data are consistant with the in vitro maturation of monocytes to macrophages, a cell with greater metabolic and functional potentional.

EFFECT OF A RETICULOENDOTHELIAL STIMULATING AGENT (RESTIM) ON RESISTANCE OF MICE

Ransom, John P. (New England Institute for Medical Research, Ridgefield, Conn.), Varsenig Z. Pasternak, and John H. Heller . Effect of a reticuloendothelial stimulating agent (restim) on resistance of mice. J. Bacteriol. 84: 466–472. 1962.—The effect of restim, a preparation of yeast cell walls, on resistance of mice to challenge by Salmonella typhimurium has been investigated. Although restim markedly increases the rate of phagocytosis and clearance of carbon particles, and presumably of viable bacterial cells, this activity has no significant effect on the course of events when restim-treated mice are challenged with S. typhimurium . However, when specific antibody derived from either active or passive immunization of the mice is present, restim significantly enhances resistance as judged by survival time and by 20-day survival.