IDENTITY OF "INHIBITOR" AND ANTIBODY IN EXTRACTS OF VIRUS-INDUCED RABBIT PAPILLOMAS.

The "inhibitor" demonstrable in extracts of the virus-induced rabbit papillomas is identical with the antiviral antibody found in the blood of hosts bearing the growths. The conditions in these latter are frequently favorable to its extravasation in considerable amount into them. Its significance and its influence upon the recovery of virus from the papillomas are discussed.

CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA : II. PROPERTIES OF NUCLEIC ACID OBTAINED FROM VACCINE VIRUS.

It has been possible by means of classical chemical methods to isolate and to characterize to some extent the nucleic acid of elementary bodies of vaccinia. Determination by means of diphenylamine reagent revealed that the major part of the nucleic acid was of the thymus type. This was further substantiated by its stability in the presence of ribonuclease, less than 10 per cent undergoing depolymerization during prolonged incubation at 37 degrees C.

INFECTIOUS MYXOMATOSIS OF RABBITS : II. DEMONSTRATION OF A SECOND SOLUBLE ANTIGEN ASSOCIATED WITH THE DISEASE.

A second soluble antigen, separable from the virus, occurs in extracts of infected skin and in the serum of rabbits acutely ill with infectious myxomatosis. Like the first antigen (A), the second (B) is heat labile and has certain characteristics of a globulin. The two antigens precipitate in different concentrations of ammonium sulfate and can be separated by this method.

A TRANSMISSIBLE AGENT (THEILER'S VIRUS) IN THE INTESTINES OF NORMAL MICE.

Every experiment with the contents of one, or with those pooled from two to five of the normal stock of Rockefeller Institute strain of albino mice, 1 to 2 months of age, revealed the presence of a virus which, after intracerebral inoculation into normal mice, induced characteristic paralytic encephalomyelitis, indistinguishable from Theilerapos;s disease. No difference was seen in this effect of intestinal contents deriving from animals paralyzed during the course of spontaneous encephalomyelitis and from normal mice. The influence of age on carriage of virus, as well as on the persistence of the carrier state, is discussed.

EFFECTS OF GUAIACOL AND HEXYLRESORCINOL IN THE PRESENCE OF BARIUM AND CALCIUM.

Guaiacol was applied at two spots on the same cell of Nitella. At one spot it was dissolved in 0.01 M NaCl, at the other in 0.

ACTION CURVES WITH SINGLE PEAKS IN NITELLA IN RELATION TO THE MOVEMENT OF POTASSIUM.

In Nitella the action curve has two peaks, apparently because both protoplasmic surfaces (inner and outer) are sensitive to K(+). Leaching in distilled water makes the outer surface insensitive to K(+). We may therefore expect the action curve to have only one peak.

SEPARATION OF POTASSIUM ISOTOPES IN VALONIA AND NITELLA.

The ratio of K(39) / K(41) appears to be lower in the sap of Valonia and Nitella than in the environment, indicating that the living cell can separate these isotopes to some extent. Experiments with a mixture of guaiacol and p-cresol suggest that a similar separation may occur here but further experiments are needed.

SOLUBILITY STUDIES ON PURIFIED TOBACCO MOSAIC VIRUS.

Different samples of purified tobacco mosaic virus show a relatively wide variation in solubility in ammonium sulfate solution. This variation and the type of solubility curve obtained in the presence of varying amounts of solid phase show that the purified virus whether isolated by mild treatment with ammonium sulfate or by ultracentrifugation is not a homogeneous chemical substance but contains more soluble and less soluble virus fractions of comparable specific activities. Long contact with strong ammonium sulfate solutions or 0.

THE PURIFICATION OF CATHEPSIN.

1. One mg. of the purified cathepsin whose preparation is described is as active as the extract of 1.

STUDIES ON ANTIBACTERIAL IMMUNITY INDUCED BY ARTIFICIAL ANTIGENS : II. IMMUNITY TO EXPERIMENTAL PNEUMOCOCCAL INFECTION WITH ANTIGENS CONTAINING SACCHARIDES OF SYNTHETIC ORIGIN.

1. Azoproteins containing structurally isomeric aldobionic acids evoke in rabbits antibodies which are both serologically and immunologically specific. 2.

A DWARF MUTATION IN THE RABBIT : THE CONSTITUTIONAL INFLUENCE ON HOMOZYGOUS AND HETEROZYGOUS INDIVIDUALS.

An hereditary type of dwarfism in the rabbit has been described. In contrast to the dwarfs described in other animals, this type is evident at birth and conforms to the classification, nannosomia primordialis, as used in human pathology. In homozygous form the variation is lethal and produces a miniature individual approximately one-third the size of its normal sibs.

A TRANSPLANTABLE RABBIT CARCINOMA ORIGINATING IN A VIRUS-INDUCED PAPILLOMA AND CONTAINING THE VIRUS IN MASKED OR ALTERED FORM.

A squamous cell carcinoma derived from a virus-induced rabbit papilloma has been propagated in fourteen successive groups of animals. It grows rapidly now in most individuals to which it is transplanted, killing early and metastasizing frequently. The original cancer was the outcome of alterations in epidermal cells already rendered neoplastic by the virus, and the latter, or an agent nearly related to it, has persisted and increased in the malignant tissue, as a study of the blood of the first ten groups of cancerous animals has shown.

THE ACTIVATING, TRANSFORMING, AND CARCINOGENIC EFFECTS OF THE RABBIT PAPILLOMA VIRUS (SHOPE) UPON IMPLANTED TAR TUMORS.

The effects of the rabbit papilloma virus upon tar tumor tissue are widely various, as the present paper and previous ones attest. It enables some of the benign tar tumors of domestic rabbits (papillomas, carcinomatoids) to establish themselves after implantation,-which they are unable to do under ordinary circumstances, being dependent upon favoring factors; and it may drive them to active proliferation without altering their morphology. Some growths it fails to influence and some it converts into virus papillomas.

CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA : I. CERTAIN BASIC ANALYSES AND OBSERVATIONS ON LIPID COMPONENTS OF THE VIRUS.

The results of chemical analyses reveal that it is possible to secure preparations of elementary bodies of vaccinia that possess a considerable uniformity in their chemical constituents. Furthermore, the amounts of certain of these constituents, namely, nitrogen, alpha-amino nitrogen after hydrolysis, phosphorus, total fat, phospholipid, neutral fat, reducing sugar after hydrolysis, and cystine, in the purified virus are significantly different from those in the various materials discarded during the process of purification. The amounts of phospholipid and neutral fat in the virus preparations are not appreciably affected by extraction with ethyl ether or by digestion with lipase, procedures which do not inactivate the virus.

EFFECTS OF HEXYLRESORCINOL ON NITELLA.

In some ways the effects of hexylresorcinol on Nitella resemble those of guaiacol but in others they differ. Both substances depress the P.D.

A DOG TEST FOR MEASURING THE IMMUNIZING POTENCY OF ANTIRABIES VACCINES.

1. A quantitative method is described for testing the immunizing potency of antirabies vaccines in dogs. 2.

THE BEHAVIOR OF POX VIRUSES IN THE RESPIRATORY TRACT : III. THE SURVIVAL OF VARIOLA AND VACCINIA VIRUSES IN THE LUNGS OF MICE PREVIOUSLY INFECTED WITH VARIOLA.

Recovery from the transient pulmonary reaction which accompanies the nasal instillation of variola virus in mice was followed by a measurable protection against the homologous virus and also against vaccinia. Variola virus which regularly survived in the lung of normally susceptible mice through the 5th day was noticeably reduced in titer on the 3rd day in the lung of recovered animals, and usually eliminated by the 5th day. Vaccinia virus produced a less severe systemic reaction in recovered mice and its titer in the lung was significantly reduced on the 5th day.

PROPERTIES OF THE CAUSATIVE AGENT OF A CHICKEN TUMOR : XIV. RELATION BETWEEN A TUMOR NUCLEOPROTEIN AND THE ACTIVE PRINCIPLE.

1. The tumor-producing fraction, isolated from Chicken Tumor I by means of differential centrifugation at high speed, has been investigated as regards its power to absorb ultraviolet light. A characteristic absorption spectrum was found, with a maximum at lambda2575.

SOME PROPERTIES OF THE ENCEPHALOPATHIC AGENT IN PRIMATE BONE MARROW (THE GORDON AGENT).

The nature of the encephalopathic agent present in monkey bone marrow has been investigated. It is readily soluble at a pH of 7.4, as well as at the low pH of 2.

ON GROUP SPECIFIC A SUBSTANCES : IV. THE SUBSTANCE FROM HOG STOMACH.

An investigation is presented on the A substance contained in swine stomach. Preparations made by several procedures, and largely consisting of carbohydrates, were found by means of the ninhydrin method of Van Slyke and his colleagues to contain amino acids accounting for the bulk of the non-hexosamine nitrogen. As a working hypothesis the idea is advanced that amino acid structures can play a rôle in the serological specificity of haptens consisting predominantly of polysaccharides.

THE SIGNIFICANCE OF M AND T ANTIGENS IN THE CROSS REACTIONS BETWEEN CERTAIN TYPES OF GROUP A HEMOLYTIC STREPTOCOCCI.

In any one strain the occurrence of the previously recognized type-specific protein, M, is usually completely correlated with the presence of the recently recognized type-specific antigen, T. Strain C203 is exceptional in having the T substance of type 1 as well as the two type-specific antigens, M and T, characteristic of type 3. It does not have the M antigen of type 1.