RELATION BETWEEN DEGREE OF IMMUNITY OF MICE FOLLOWING VACCINATION WITH ST. LOUIS ENCEPHALITIS VIRUS AND THE TITRE OF THE PROTECTIVE ANTIBODIES OF THE SERUM.

Vaccination of susceptible mice with St. Louis encephalitis virus induced an acquired immunity to intracerebral inoculation which appeared within 1 week. When first demonstrable this immunity was at a very high level and it remained so for about 6 weeks, after which time it declined and disappeared completely between the 12th and 20th week after vaccination.

FACTORS INFLUENCING THE PERSISTENCE OF CHORIOMENINGITIS VIRUS IN THE BLOOD OF MICE AFTER CLINICAL RECOVERY.

Mice infected in utero continued to carry choriomeningitis virus in the blood more regularly and in greater amount than suckling mice infected by contact. This result may be due to the difference in tissue maturity at the time of infection: the more immature the tissues are when infected, the longer the virus appears to persist in them after maturation. A similar result was obtained with mice of different ages infected either by contact or by intranasal instillation of virus, in that the carrier state lasted longer in the younger animals.

THE ISOLATION OF THE BLOOD GROUP A SPECIFIC SUBSTANCE FROM COMMERCIAL PEPTONE.

The isolation of the blood group A specific substance from commercial peptone has been described. The chemical and serological properties of the material from that source have been defined.

PRODUCTION OF EXPERIMENTAL OSTEOMYELITIS IN RABBITS BY INTRAVENOUS INJECTION OF STAPHYLOCOCCUS AUREUS.

1. The conditions under which a certain strain of staphylococcus (OH 172) causes in rabbits the development of bone inflammation have been described. 2.

INTRAPERITONEAL AND INTRACEREBRAL ROUTES IN SERUM PROTECTION TESTS WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS : I. A COMPARISON OF THE TWO ROUTES IN PROTECTION TESTS.

Young (12 to 15 day old) mice are approximately as susceptible to the virus of equine encephalomyelitis, Eastern or Western strain, when it is given intraperitoneally as are adult mice when the virus is injected intracerebrally. With this susceptibility by the intraperitoneal route as a basis, the injection of immune serum-virus mixtures intraperitoneally was found to result in protection in dilutions which give rise to infection after intracerebral inoculation. The difference of protective power by the two indicated routes was shown not to depend on the amount of inoculum nor on the age of the intracerebrally injected mice.

THE ACCUMULATION OF ELECTROLYTES : XII. ACCUMULATION OF HALIDE AND NITRATE BY VALONIA IN HYPERTONIC SOLUTIONS.

When cells of Valonia macrophysa were placed in hypertonic sea water, the concentration of halide and of nitrate increased, and the sum of halide + nitrate became 0.05 M greater inside than outside, which is about the same difference as is found in cells in normal sea water. In ordinary sea water the ratio of halide to nitrate is 80,000 to 1.

THE ACCUMULATION OF ELECTROLYTES : XI. ACCUMULATION OF NITRATE BY VALONIA AND HALICYSTIS.

The nitrate concentration in the sap of Valonia macrophysa, Kütz., is at least 2000 times that of the sea water, and in Halicystis Osterhoutii, Blinks and Blinks, at least 500 times that of the sea water.

CHANGES OF APPARENT IONIC MOBILITIES IN PROTOPLASM : III. SOME EFFECTS OF GUAIACOL ON HALICYSTIS.

Lowering the pH of sea water from 8.2 to 6.4 lowers the positive P.

IMMUNIZATION OF GUINEA PIGS AGAINST LYMPHOCYTIC CHORIOMENINGITIS WITH FORMOLIZED TISSUE VACCINES.

Guinea pigs can be immunized against lymphocytic choriomeningitis by 2 or 3 injections with formolized vaccines prepared from a variety of infected guinea pig tissues. Vaccines prepared from the consolidated areas of diseased lungs gave the best results. The immunity produced was partial in the majority of the cases, in that the vaccinated animals as a rule showed fever after the test of immunity and virus was present in the circulation during the febrile period.

VITAL STAINING OF THE CONNECTIVE TISSUES.

Trypan blue injected intravenously is bound almost at once by the intercellular connective tissue elements all over the body,-by collagen, reticulin, and elastic fibers. This union of dye and tissue elements is the factor responsible for the early macroscopic blue color and is antecedent to cellular colloidopexic action. Different examples of connective tissue differ among themselves in their ability to hold the dye.

FATE OF NASALLY INSTILLED POLIOMYELITIS VIRUS IN NORMAL AND CONVALESCENT MONKEYS WITH SPECIAL REFERENCE TO THE PROBLEM OF HOST TO HOST TRANSMISSION.

With a method of intranasal instillation of poliomyelitis virus that brings about infection of all M. rhesus monkeys subjected to it, a study was undertaken of the fate of nasally instilled virus in normal and convalescent, immune animals. Control experiments revealed that nasal mucosa of normal monkeys contained no observable antiviral factors and that when five or ten minimal cerebral infective doses were added to the mucosa, virus could be detected by the employed procedure.

IMMUNITY OF MICE FOLLOWING SUBCUTANEOUS VACCINATION WITH ST. LOUIS ENCEPHALITIS VIRUS.

1. Susceptible mice injected subcutaneously or intraperitoneally with 15,000 intracerebral lethal doses of St. Louis encephalitis virus develop an immunity in 4 to 7 days to 1,000 to 1,000,000 lethal doses given either intracerebrally or intranasally.

THE FATE OF VACCINIA VIRUS ON CULTIVATION IN VITRO WITH KUPFFER CELLS (RETICULO-ENDOTHELIAL CELLS).

The pathogenic activity of vaccinia virus is in large part suppressed when it is mixed with living Kupffer cells or clasmatocytes in the test-tube and injected intradermally. Vaccinia increases in quantity when introduced into cultures of Kupffer cells in vitro, and survives in immediate association with these elements. No antiviral principle is elaborated by them under such conditions.

STUDIES ON AN UNCOMPLICATED CORYZA OF THE DOMESTIC FOWL : IX. THE COOPERATIVE ACTION OF HEMOPHILUS GALLINARUM AND THE COCCOBACILLIFORM BODIES IN THE CORYZA OF RAPID ONSET AND LONG DURATION.

Coccobacilliform bodies were regularly demonstrable, in addition to H. gallinarum, in exudate from birds infected with a passage strain of the coryza of rapid onset and long duration (type III). Both agents were present throughout the entire course of the disease.

THE ACCUMULATION OF ELECTROLYTES : X. ACCUMULATION OF IODINE BY HALICYSTIS AND VALONIA.

Analyses of the sap of Halicystis Osterhoutii and of Valonia macrophysa for iodide indicate accumulations of the order of 1000 to 10,000-fold in the first case, and 40 to 250-fold in the second case. The chemical potential of KI, NaI, HI, and CaI(2) is greater inside than outside.

THE ACCUMULATION OF ELECTROLYTES : IX. REPLACEMENT OF AMMONIA BY SODIUM AND POTASSIUM.

Experiments on Valonia were carried out as follows: Stage I.-Cells in dim light accumulated 0.08 M ammonia (NH(3) + NH(4)OH + NH(4) (+)) from sea water containing 0.

EFFECTS OF POTASSIUM ON THE POTENTIAL OF HALICYSTIS.

Sea water in which sodium has been replaced by potassium produces about the same degree of negativity in Halicystis and in Valonia. With increasing dilution of this sea water up to 1 / 16 the degree of negativity steadily falls off in Halicystis. This differs from the situation in Valonia where Damon finds that with increasing dilution the negativity passes through a minimum after which increasing dilution produces increasing negativity.

FORMATION OF TRYPSIN FROM TRYPSINOGEN BY AN ENZYME PRODUCED BY A MOLD OF THE GENUS PENICILLIUM.

1. A powerful kinase which changes trypsinogen to trypsin was found to be present in the synthetic liquid culture medium of a mold of the genus Penicillium. 2.

TRANSFORMATION OF SWINE PEPSINOGEN INTO SWINE PEPSIN BY CHICKEN PEPSIN.

Activation of swine pepsinogen with chicken pepsin results in the formation of swine pepsin. Activation of chicken pepsinogen with swine pepsin results in the formation of chicken pepsin. The structure responsible for the species specificity of the enzyme is therefore present in the inactive precursor.

IMMUNIZATION OF EXPERIMENTAL ANIMALS WITH A SOLUBLE ANTIGEN EXTRACTED FROM PNEUMOCOCCI.

Pneumococci killed by acetic acid at pH 4.2, then allowed to become Gram-negative at pH 7.0, under conditions such that no cellular disintegration takes place, release in solution small amounts of a substance which is precipitable by acetic acid, and soluble at neutral reaction.

THE EFFECT OF A TISSUE ENZYME UPON PNEUMOCOCCI.

Polymorphonuclear leucocytes contain an enzyme which destroys the basophilic character of beat-killed pneumococci (R and S variants) and inactivates the type specific polysaccharide antigen of encapsulated cells. The same enzyme, however, fails to cause a disintegration of the bacterial cells, or to decompose the capsular polysaccharide itself. The enzyme has been extracted from a number of animal tissues; it appears identical with a purified enzyme extracted from pancreatin and which decomposes yeast nucleic acid.

SEROLOGICAL EVIDENCE FOR THE OCCURRENCE OF INFECTION WITH HUMAN INFLUENZA VIRUS IN SWINE.

Antibodies capable of neutralizing human influenza virus were present in the sera of old swine on two New Jersey institution farms, but absent from the sera of young swine on the same farms. The old animals had lived through the winter of 1936-37 in which outbreaks of upper respiratory tract disease were prevalent among the human inmates of the two institutions, while the young swine studied were born long after these outbreaks. It is believed that the swine whose sera neutralized human influenza virus had undergone an unrecognized human influenza virus infection acquired from man.

ON CROSS REACTIONS OF IMMUNE SERA TO AZOPROTEINS : II. ANTIGENS WITH AZOCOMPONENTS CONTAINING TWO DETERMINANT GROUPS.

Azoproteins have been prepared with azocomponents possessing two serologically active groups. On immunization with such antigens immune sera were obtained containing two separate, unrelated antibodies, each specific for one of the two groups and separable by absorption. In other cases one of the two structures was dominant, in that antibodies were formed only towards this and not towards the other grouping.