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SummaryChick embryos killed by prolonged storage at room temperature or 4°C are capable of supporting the multiplication of influenza virus upon prolonged incubation at 35°C.

SummaryCross serological reactions indicated that egg strains of influenza B virus obtained in different years were dissimilar in antigenic composition. The extent of the differences in antigenic pattern was analyzed. All strains studied were antigenically different from the mouse adapted Lee strain. The implication of these findings on the problem of immunization in man was discussed.

Summary1. Adult mice, ordinarily insusceptible to Coxsackie virus infection, may be lethally infected if preliminarily administered cortisone. 2. Multiplication, serial passage, and specific neutralization of Coxsackie virus in adult mice have been demonstrated. 3. Recovery of Coxsackie virus from a human source has been accomplished in adult mice.

SummarySuspensions of mouse brain infected with the GDVII strain of mouse encephalomyelitis virus cause agglutination of human Group O RBC at 4°C. Anti-GDVII virus serum inhibits hemagglutination by the agent as also does anti-FA virus serum. GDVII virus is adsorbed by human RBC at 4°C and rapidly elutes from them at 37°C. Three strains of poliomyelitis virus failed to show any evidence of hemagglutination.

SummaryNormal human urine contains a highly active inhibitor of viral hemagglutination, effective against PR8, Lee, FM1, swine, mumps, NDV, and GDVII viruses but inactive against PVM. The inhibitor concentration may approach 2 mg%. Considerable amounts of purified material, active at 0.0001 μg/cc, can be obtained readily. The activity of the inhibitor as it occurs in urine is inversely related to the salt concentration; it should be emphasized that in NaCl solutions of moderate strength it precipitates.

In complement-fixation tests with sera from patients with primary atypical pneumonia of unknown etiology, it was found unexpectedly that the convalescent serum from a number of patients reacted positively in high dilution with various and apparently unrelated antigens. Since this peculiar and as yet unexplained property can lead to difficulty in the interpretation of the results of complement-fixation tests with sera obtained from patients with this clinical syndrome the phenomenon has been studied.Materials and Methods. Specimens of serum were obtained from patients acutely ill with primary atypical pneumonia in the Rockefeller Hospital. Additional specimens of serum were obtained from these patients throughout the course of the illness and during convalescence. The sera were stored at 4°C.Mouse lung antigens. Antigens were prepared from the lungs of normal albino Swiss mice and from the lungs of similar mice which had been infected with one or another of the following viruses: a. pneumonia virus of mice...

SummaryThe concentration of Lee, PR8, or mumps virus in the allantoic fluid of eggs injected with cortisone acetate is significantly greater than the concentration of these agents in the allantoic fluid of control eggs.

Julianelle and Reimann1 have described the purpura that develops in white mice following the intraabdominal injection of pneumococcal autolysates. This reaction is most evident in those portions of the skin on which hair is either scanty or absent. They concluded that some autolytic derivative of the bacterial cells damaged the endothelium of the capillaries in these areas.The experiments of Julianelle and Reimann have been largely repeated and extended. One of the most striking features of the reaction is that the purpura produced is seldom evenly distributed over the ears, feet, tail, snout, and genitalia. Even on the ears the distribution may be splotchy while along the tail the reaction is always most irregular, certain points showing a very intense reaction while others may be completely negative. These irregularities as well as the anatomical distribution of purpura suggested that some factor such as a mild trauma might be involved in the localization of the reaction. As a test of this hypothesis se...

A virus capable of inducing fatal pneumonia in Swiss mice has been isolated from normal mouse lungs, and its immunological characteristics are now being studied in detail.Twenty-one groups of normal Swiss mice were inoculated intra-nasally under ether anesthesia with 0.05 cc of lung-suspensions from uninoculated mice. Serial mouse-passage was carried on with each group, using 10% to 30% lung-suspensions. Passages were made at an average interval of 7 days; usually 6 mice were used in each group. The mice were obtained from 6 different breeders. Initially, passages were made without regard to the breeder from whom the mice had been obtained. Lately, however, passages have been made in mice from each individual breeder in order to determine the source of the virus. Definite areas of pulmonary consolidation were present in 43% of the groups in the third serial passage, and in 52% of the groups at the sixth passage. Death occurred as early as the fourth passage, and by the sixth passage deaths were recorded i...

Elford, Grabar and Fischer1 have reported that the “antibody activity” of antipneumococcal horse-serum is associated with the “larger complex protein in the serum.” Thus it was estimated by the method of optimal proportions that 75% of the antibody passed a 140mμ membrane, rather less than one percent passed an 80mμ membrane, while the filtrate from a 54mμ membrane showed no trace of antibody-activity.The membranes used in the present experiments were prepared by the method of Elford2 with certain modifications described by Bauer and Hughes.3 For filtration, Type I antipneumococcal horse-and rabbit-sera were diluted 1:5 in broth. Concentrated antipneumococcal horse-serum was diluted 1:10 in the same reagent. For evaluating the amount of antibody in the filtrate the quantitative precipitation method of Heidelberger, Sia, and Kendall4 was used. Because of the difficulties in securing large amounts of filtrates complete analyses over a wide range of amounts of polysaccharide were impossible. Therefore an arb...

Hardy and Gardiner's method1 for the removal of lipoids from sera is based upon the fact that extraction of protein solutions by alcohol or alcohol-ether at low temperatures does not cause denaturation. Using this method, Hartley2 has shown that the removal of lipoids from certain antisera apparently abolishes their in vitro reactivity. Felton3 has extracted antipneumococcus horse serum in a similar manner, and has demonstrated that the removal of lipoids does not diminish protective action.These findings have been confirmed for Type I antipneumococcus horse serum. Extracted sera fail to agglutinate homologous type pneumococci and to give a precipitate with the specific capsular polysaccharide. In vivo, however, they show the presence of protective antibody in unaltered concentration.Lipoid extraction was carried out in the following manner: The antiserum was introduced, with stirring, into 10 volumes of absolute alcohol at —10°C. After 6 hours′ extraction the precipitate was collected by centrifugation a...