CAPACITY OF PLEUROPNEUMONIA-LIKE MICROORGANISMS TO GROW ON CHORIOALLANTOIC MEMBRANES

1. Among eight strains or variants, included in four different immunological types of pleuropneumonia-like microorganisms, all grew on chorioallantoic membranes; those belonging to Klieneberger's Type L5 (Sabin Type A) grew very poorly; and those included in three other types grew with varying degrees of vigor. 2. In all instances, strains of pleuropneumonia-like microorganisms tested grew better on dead sterile chorioallantoic membranes than on living membranes. 3. None of the strains tested was in itself lethal for chick embryos. 4. No constant macroscopic lesion developed as a result of inoculating chorioallantoic membranes with pleuropneumonia-like microorganisms

THE ACTION OF SODIUM SALICYLATE UPON THE FORMATION OF IMMUNE BODIES

1. Rabbits treated with sodium salicylate in daily doses of from 0.16 to 0.2 gm. per kilo of body weight and at the same time immunized with intravenous injections of Streptococcus viridans, both living and in the form of vaccines, and also with washed sheep red blood cells, showed diminished complement-fixing antibodies, agglutinins, and hemolysins when compared with controls similarly immunized. 2. If the antigens were treated with sodium salicylate in vitro and subsequently injected intravenously into rabbits, the animals usually showed lower antibody curves than did rabbits that received the untreated antigen intravenously and sodium salicylate by stomach tube. 3. The beneficial effect of sodium salicylate in rheumatic fever patients probably cannot be attributed to an increased production of circulating immune bodies against the infectious agent. This is, however, no contraindication to the administration of salicylates to patients suffering from infectious diseases

THE PATHOGENESIS OF RHEUMATIC FEVER

It is evident that there are two distinct types of response on the part of the body to the infectious agent of rheumatic fever; viz., proliferative and exudative. The perivascular proliferative type of lesion, resembling an infectious granuloma, explains the subacute and chronic character of the clinical symptoms in many patients with this disease. Marked exudation of serum into the periarticular tissues and of serum and cells into the joint cavities are concomitants of the acute arthritis occurring with high fever and general intoxication; these acute exudations disappear following the administration of certain drugs. But their disappearance does not mean necessarily that all lesions of the proliferative type have resolved. In fact, we know that these last mentioned lesions, when present in the subcutaneous tissues, often continue for months; and from analogy we may conclude that they have a similar persistent character in other tissues of the body invaded by the causative agent of rheumatic fever

A STUDY OF SERUM SALVARSANIZED IN VITRO

1. Addition of salvarsan to serum in vitro produces a spirocheticidal mixture which is increased in potency by heating. 2. The heated serum of salvarsan-treated patients is more spirocheticidal if it has been in contact with the clot over night than if it has been separated immediately after coagulation. This is not true with the serum from blood which has been salvarsanized in vitro. 3. The addition of salvarsan directly to serum produces a more potent mixture than results from the serum from blood to which salvarsan has been added in equivalent amounts. 4. The increase in activity of salvarsanized serum produced by heating to 56°C. is due in part to the removal of inhibitory substances in the serum and in part to a direct increase in spirocheticidal power in the heated salvarsan. 5. Both salvarsanized and neosalvarsanized serum are rendered more spirocheticidal by heating. 6. A more active spirocheticidal mixture is produced by mixing small amounts of salvarsan with the serum of a salvarsan-treated patient than by mixing the same amount with normal serum

PRESERVATION OF STOCK CULTURES OF BACTERIA BY FREEZING AND DRYING

Attention is called to the fact that bacteria may be preserved for a long time by desiccation in the frozen state. It has been shown that it is necessary to maintain the frozen condition until desiccation is complete; if the fluid melts before the moisture is completely removed, the organisms are killed, probably because of the concentration of the salts upon the surface of the bacteria. By the simple expedient of immersing the tubes of organisms in glycerol contained in a desiccator and subsequently keeping the whole apparatus in a salt-ice mixture until drying is complete, the organisms are easily maintained in the frozen state, and dry properly. Bacteria preserved in this manner retain their cultural, biochemical, and immunological characters for prolonged periods

THE EFFECT OF IRRITATION ON THE PERMEABILITY OF THE MENINGES FOR SALVARSAN

The subdural injection of normal salt solution, normal serum, serum salvarsanized in vivo or weak solutions of cyanide of mercury does not demonstrably increase the permeability of the spinal cord or brain for salvarsan which is circulating in the blood at the time of the subdural injection

CUTANEOUS REACTIVITY OF IMMUNE AND HYPERSENSITIVE RABBITS TO INTRADERMAL INJECTIONS OF HOMOLOGOUS INDIFFERENT STREPTOCOCCUS AND ITS FRACTIONS

Rabbits were immunized intravenously with intact indifferent streptococci, with homologous P fraction, and with an emulsion of mechanically ground cocci; others were sensitized by intravenous injection of the intact microorganisms. Their serologic and dermal reactions to these materials and to the homologous S fraction were compared with those of normal animals. The dissociation, in certain instances, between circulating antibody and dermal reactivity was noteworthy. From the results the following conclusions were drawn. 1. Intradermal injection of a soluble streptococcal protein into a rabbit immunized intravenously with that protein leads to the immediate anaphylactic type of skin response; while similar dermal testing of a rabbit sensitized by intracutaneous inoculation of the intact microorganism induces the delayed (tuberculin) type of response. 2. The induction of the immediate type of dermal reaction to streptococcal protein requires more than the mere presence of a high serum precipitin titer to that protein. 3. Lesions of the immediate type can be induced by the intradermal injection of a streptococcal carbohydrate into rabbits immunized intravenously with intact cocci and showing a high serum precipitin titer to that carbohydrate. 4. Intravenous immunization of rabbits with an emulsion of mechanically ground indifferent streptococci leads to the production of only non-type-specific antibodies. 5. It is possible that carbohydrate as well as protein fractions of indifferent streptococci are capable of eliciting the delayed type of dermal response in rabbits intracutaneously sensitized with that microorganism

REACTIONS OF RABBITS TO NON-HEMOLYTIC STREPTOCOCCI : I. GENERAL TUBERCULIN-LIKE HYPERSENSITIVENESS, ALLERGY, OR HYPERERGY FOLLOWING THE SECONDARY REACTION.

1. Accompanying and following the evolution of a secondary reaction in the skin of rabbits after inoculation with suitable doses of certain non-hemolytic streptococci there quickly develops a general state of hypersensitiveness or allergy towards these streptococci. 2. This state is made evident by ophthalmic reactions following corneal inoculations, by much increased reactivity of the skin following intracutaneous reinoculations, and by lethal reactions, resembling tuberculin shock, following intravenous inoculations. 3. In a given hypersensitive rabbit there is a rough parallelism in the intensities of these different kinds of reactions. 4. This type of hypersensitiveness or bacterial allergy does not follow primary intravenous inoculation of rabbits with comparable doses of the streptococci employed. 5. As the development of this type of hypersensitiveness or bacterial allergy seems to accompany the production of focal lesions of a certain intensity, it is probable that in these foci are produced the substances or conditions which lead to this type of bacterial allergy

EXPERIMENTAL NEPHRITIS IN RATS INDUCED BY INJECTION OF ANTIKIDNEY SERUM : V. CHRONIC NEPHRITIS OF INSIDIOUS DEVELOPMENT FOLLOWING APPARENT RECOVERY FROM ACUTE NEPHROTOXIC NEPHRITIS

1. Three different inbred lines of rats were found to vary in their response to antikidney serum: rats of the Whelan strain were most susceptible to nephrotoxin and most prone to develop chronic glomerulonephritis immediately following the acute injury induced by this agent; animals of the Evans strain were almost as vulnerable to the acute effects of nephrotoxin; Wistar rats were the least affected. 2. Both Evans and Wistar rats usually recovered quickly from the acute injury, and between the 2nd and 5th months after injection they excreted normal or only slightly abnormal urines. During this period of absence of clinical signs of disease, histopathological examination of their kidneys revealed only minor scarring in the glomerular tufts. 3. Most of these apparently recovered rats subsequently developed a slowly progressing chronic glomerulonephritis irrespective of whether they were fed a basal or high protein diet. 4. Histopathologically similar renal lesions were present in all three strains of rats with active chronic nephritis regardless of whether the chronic disease followed immediately the acute nephrotoxic injury or was separated from it by an interval of months. These lesions were somewhat more severe, however, in Whelan rats. 5. Some intraglomerular scarring was present in the kidneys of all rats which survived acute nephrotoxic nephritis. It was especially prominent in those animals that remained clinically cured for as long as a year. 6. The permanent clinical recovery of certain animals, which were found to have moderate glomerular fibrosis on postmortem examination, suggests that factors other than this residual scarring contributed to the development of the recurrent nephritis observed in most of the Evans and Wistar rats. These unknown factors may produce varying degrees of renal functional trauma affecting both glomeruli and tubules

THE QUESTION OF SENSITIZATION OF JOINTS WITH NON-HEMOLYTIC STREPTOCOCCI

It was impossible to demonstrate a condition of specific joint sensitization to non-hemolytic streptococci by first injecting the joints of rabbits with small doses of killed non-hemolytic streptococci, or with extracts of these organisms, and subsequently inoculating the rabbits intravenously with homologous living bacteria. Joints so treated were no more liable to involvement than were other untreated joints of the same animals