NATURE OF THE ACTION CURRENT IN NITELLA : V. PARTIAL RESPONSE AND THE ALL-OR-NONE LAW.

When a stimulus arrives before recovery is complete there may be no response or only a partial response. A typical response appears to involve an immediate loss of potential at the inner protoplasmic surface but not at the outer surface. As long as recovery is incomplete only a part of the total potential is located at the inner protoplasmic surface and the loss of this part of the total potential can cause only a partial response; i.

VENEZUELAN EQUINE ENCEPHALOMYELITIS IN MAN.

A filterable agent was isolated from the blood and from washings of the upper respiratory passages of a young laboratory worker during a mild, acute, febrile illness. This agent was identified as a strain of Venezuelan equine encephalomyelitis virus. Circulating specific complement-fixing and neutralizing antibodies not present in sera withdrawn during the acute phase of illness were demonstrated in sera obtained during convalescence.

PACEMAKERS IN NITELLA : III. ELECTRICAL ALTERNANS.

An electrical impulse traveling along a Nitella cell may produce a complete or a partial response. The two kinds of response may occur in regular alternation. The partial response varies greatly and may be so far reduced as to appear as a local thickening in the upstroke of the action curve, usually accompanied by a more or less pronounced hump.

INDUCED RESISTANCE OF THE CENTRAL NERVOUS SYSTEM TO EXPERIMENTAL INFECTION WITH EQUINE ENCEPHALOMYELITIS VIRUS : II. SEROTHERAPY IN WESTERN VIRUS INFECTION.

Under none of the experimental conditions here described was treatment of the infection induced by the virus of Western equine encephalomyelitis in mice and guinea pigs with specific hyperimmune rabbit serum effective if begun after the onset of signs of encephalitis. In mice, after intracerebral inoculation of virus, serum was ineffective when given even before that stage. After peripheral introduction of virus in guinea pigs the disease was completely arrested in certain animals by single or multiple doses of antiserum if treatment was begun within 24 to 48 hours after virus inoculation.

ISOLATION OF CHROMATIN THREADS FROM THE RESTING NUCLEUS OF LEUKEMIC CELLS.

1. A method for the separation of chromatin threads from the resting nucleus of leukemic cells has been described. 2.

ORAL PAPILLOMATOSIS OF RABBITS: A VIRUS DISEASE.

Papillomas occur frequently on the oral mucosa of domestic rabbits procured in the metropolitan area of New York. They are small and benign, and are situated mostly on the under side of the tongue. A filtrable virus can be extracted from them with which growths can be reproduced in the oral mucosa of several species of rabbits and hares but which fails to cause lesions when inoculated into other rabbit tissues and into the oral mucosa of other species.

THE LS-ANTIGEN OF VACCINIA : IV. CHEMICAL ANALYSIS OF LS AND THE EFFECT OF CHYMOTRYPSIN ON LS.

Pure LS-antigen of vaccinia contains 15.8 per cent N and 50.6 per cent C.

THE ELECTRICAL CONDUCTIVITY OF SODIUM AND POTASSIUM GUAIACOLATES IN GUAIACOL.

The data of the author and Uhlig, and new data, on the conductivity of sodium and of potassium guaiacolates in guaiacol at 25 degrees have been computed with an improved conductance equation which is valid to somewhat higher concentrations than the equations formerly used. The new constants are, Lambda(0) = 9.0, K = 2.

A NATURAL ANTIBODY THAT REACTS IN VITRO WITH A SEDIMENTABLE CONSTITUENT OF NORMAL TISSUE CELLS : II. SPECIFICITY OF THE PHENOMENON: GENERAL DISCUSSION.

Continued serological investigations of the sedimentable constituents of normal and neoplastic tissues have shown that the blood serum of normal rabbits will fix complement in mixture with saline extracts of normal rabbit tissues. The phenomenon has proved referable, not to anticomplementary effects of serum or antigen nor to so called non-specific complement fixation, but to a naturally occurring serum principle, hitherto unrecognized, which reacts specifically in vitro with a sedimentable constituent of normal tissue cells. The principle exists in the blood of nearly all adult rabbits but is absent from that of rabbits less than 1 month old.

A NATURAL ANTIBODY THAT REACTS IN VITRO WITH A SEDIMENTABLE CONSTITUENT OF NORMAL TISSUE CELLS : I. DEMONSTRATION OF THE PHENOMENON.

The foregoing experiments have shown that complement fixation takes place when the blood serum of normal adult rabbits is mixed with fresh saline extracts of normal rabbit tissues under controlled conditions. A natural antibody, which reacts in vitro with a sedimentable constituent of normal tissue cells, is responsible for the phenomenon.

SEROLOGICAL REACTIONS OF PROTEIN FILMS AND DENATURED PROTEINS.

Films of several proteins, hen ovalbumin, horse and human serum albumins, and globulins were found to combine specifically with antibodies, showing that the reactions can take place independently of the structure which secures the compact shape of the protein molecule. Serum globulin films differed from ovalbumin in that they lost their reactivity when kept on the water surface. Species specific reactions were observed with films of serum albumin and suitably diluted antisera, and likewise in the customary precipitin tests in which immune sera for denatured hen ovalbumin were tested against ovalbumin of other species.

INDUCED RESISTANCE OF THE CENTRAL NERVOUS SYSTEM TO EXPERIMENTAL INFECTION WITH EQUINE ENCEPHALOMYELITIS VIRUS : I. NEUTRALIZING ANTIBODY IN THE CENTRAL NERVOUS SYSTEM IN RELATION TO CEREBRAL RESISTANCE.

1. Neutralizing antibody to equine encephalomyelitis virus was found in the spinal fluid of rabbits sufficiently vaccinated with active or formalin-inactivated virus. Antibody was specific for the Western or for the Eastern virus.

INCREASED IRRITABILITY IN NITELLA DUE TO GUANIDINE.

Guanidine applied to Nitella may lower the threshold of E.M.F.

A NON-VIRULENT, SINGLE-DOSE RABIES VACCINE FOR PROPHYLACTIC IMMUNIZATION OF DOGS.

Our studies on rabies vaccines thus far have led us to the view that in order to develop and test vaccines, quantitative methods are necessary, and that such quantitative methods may be exploited to greatest advantage by using mice, preferably W-Swiss, as the test animal. Dogs, due to their variability and susceptibility to intercurrent infections when kept under experimental conditions, are useful chiefly to check whether or not a vaccine produces a high grade of immunity; they remain of limited value in testing the comparative potencies of weak vaccines. A second point is that the Pasteur strain of virus has proved as potent as any tested for the preparation of vaccines.

DISTRIBUTION OF THE Rh FACTOR IN AMERICAN INDIANS.

Erythrocytes from 120 full blooded American Indians and 155 Indians of mixed ancestry were tested for the Rh agglutinogen. Only a single blood among the full blooded Indians appeared to lack this factor, and in the Indians known not to be full blooded, the distribution of this (and other) blood properties was found to be intermediate between that for whites and pure Indians according to expectation. A variant of Rh demonstrable by a special human serum was more than twice as frequent in full blooded Indians as in white individuals.

PURIFICATION OF THROMBIN.

1. Under certain conditions crude prothrombin changes to thrombin without the addition of extraneous activators and in the absence of ionic calcium. 2.

SOME PROPERTIES OF CRYSTALLINE GUINEA PIG HEMOGLOBIN.

1. Guinea pig hemoglobin crystals are shown to be readily permeable to ferricyanide and hydrosulfite, indicating the presence of interstices between the protein molecules of the crystal. 2.

AN ELECTROPHORETIC STUDY OF MIXTURES OF OVALBUMIN AND YEAST NUCLEIC ACID.

Electrophoretic patterns of mixtures of ovalbumin and yeast nucleic acid indicate that the constituents migrate independently of each other in buffer solutions of 0.1 ionic strength and at pH values somewhat higher than the isoelectric point of the protein. In the isoelectric region, however, the patterns from the two sides of the channel exhibit asymmetries that can be explained by assuming the existence in the mixture of appreciable concentrations of a reversibly dissociable complex between the components.

SYNTHESIS OF INOSITOL IN MICE.

It has been shown that mice are able to synthesize inositol. This synthesis was not observed when pantothenic acid was absent from the diet. Cultures from the intestinal tract of animals which exhibited spontaneous cure of alopecia yielded microorganisms which synthesized much more inositol than did organisms isolated in the same fashion from the tracts of mice that had become hairless.

SEROLOGICAL REACTIVITY OF HYDROLYTIC PRODUCTS FROM SILK.

The foregoing experiments show that products of the hydrolysis of silk that consist of peptides having, from amino nitrogen determinations, molecular weights from about 600 to 1000 were capable of inhibiting the reactions of precipitin sera for silk. From the results it may reasonably be inferred that silk fibroin contains determinant structures not larger than the peptides examined, which probably consist of not more than 8 to 12 amino acids. That similar relations may obtain with other proteins is not improbable in view of results previously reported with dialyzable split products.

CELL STATE AS AFFECTING SUSCEPTIBILITY TO A VIRUS : ENHANCED EFFECTIVENESS OF THE RABBIT PAPILLOMA VIRUS ON HYPERPLASTIC EPIDERMIS.

Rabbit skin can be rendered abnormally susceptible to papilloma virus infection by preliminary treatments with a variety of agents. The most effective agents thus far found are 0.3 per cent methylcholanthrene in benzene and a mixture in equal parts of turpentine and acetone, applied four or five times at 2 day intervals.

PURIFIED DIPHTHERIA ANTITOXIN IN THE ULTRACENTRIFUGE AND IN THE ELECTROPHORESIS APPARATUS.

ULTRACENTRIFUGATION STUDIES OF DIPHTHERIA ANTITOXIN SHOWED THAT: 1. Purified antitoxin of high activity obtained from horse plasma without enzymatic treatment has exactly the same sedimentation constant as the globulin fraction obtained in a similar way from normal horse plasma s(20) (water) = 6.9 x 10(-13).

PURIFICATION AND CRYSTALLIZATION OF DIPHTHERIA ANTITOXIN.

Purified preparations of diphtheria antitoxin have been obtained by digestion of the toxin-antitoxin complex with trypsin, followed by fractional precipitation with ammonium sulfate. The various fractions obtained in this way are all 90 per cent or more precipitated by diphtheria toxin but combine with different quantities of the toxin. The fraction precipitated between 0.

SOME FACTORS WHICH INFLUENCE THE OXIDATION OF SULFHYDRYL GROUPS.

1. Cyanide inhibits the oxidation of the SH groups of cysteine and denatured egg albumin by the uric acid reagent. 2.