bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vivo Uptake of Isotope-Tagged Tuberculin by Leukocytes
Authors: Ritts Roy E. , Favour Cutting B. 
Published: January 2023

Summary
PPD has been tagged with I131 without altering its biological potency. The fate of I131-tagged PPD given intravenously to normal rabbits has been followed by measuring radioactivity found in plasma and on the leukocytes and erythrocytes of these animals during the subsequent 24 hours. I131-tagged PPD is partially cleared from the plasma during the first 24 hours after injection. It is firmly absorbed to the leukocytes during the first 4 hours after injection. No tag is found on leukocytes after 4 hours. The significance of leukocyte uptake of a tagged bacterial protein is discussed.
In Vitro Production of Diphtheria Antitoxin by Tissues of Immunized Animals
Authors: Stavitsky Abram B. 
Published: January 2023

Summary
Lymph node and spleen fragments and slices from immunized animals appeared to produce diphtheria antitoxin when placed in a suitable medium. Disruption of the tissues or inclusion in the medium of various inhibitors of oxidative metabolism such as cyanide or dinitrophenol resulted in complete inhibition of antibody production. Moreover, the in vitro process of antibody formation appeared to parallel both the in vivo process and the passive transfer reaction whereby antitoxin appeared in the blood of normal rabbits following the injection of lymph node or splenic cells from immunized animals. In fact, the striking parallels between the in vitro and passive transfer reactions suggested that these two reactions might be fundamentally similar.
It appears that under the conditions employed the tissue fragments and slices continued in vitro the net synthesis of antitoxin initiated in vivo.
Susceptibility of the Pigeon (Columba Livia) to Infection with Western Equine Encephalomyelitis Virus
Authors: Kaplan William , Winn John F. , Palmer Dan F. 
Published: January 2023

Summary
Subcutaneous inoculation of pigeons with 160 chick LD50 and 1600 chick LD50 of WEE virus produced early viremias which persisted for at least 96 hours. Virus was recovered from 3 out of 15 pigeons inoculated with lesser amounts of virus, but in these cases virus was slower in appearance and is considered due to contact infection through handling. WEE infection, also apparently through contact, occurred in 1 of the 5 pigeons in the group which received no virus artificially.
Poliomyelitis and Other Antibody Patterns in Natives of Tahiti and Raiatea
Authors: Horstmann Dorothy M. , Kraft Lisbeth M. , Melnick Sarah , Mascola Anne 
Published: January 2023

Summary
In 1951, the island of Tahiti experienced its first recorded epidemic of poliomyelitis. An unusual feature of the outbreak was the age distribution of cases, the majority being in the 10-to 24-year age group, with relative sparing of young children. The present study is concerned with attempts to designate the type of virus responsible for the epidemic, and to determine if serological tests could shed any light on the problem of the age distribution of cases.
The evidence obtained by virus isolation, and by results of neutralizing and CF antibody studies of convalescent cases, points to a type 1 epidemic. The patterns of neutralizing and CF antibodies in normal individuals suggest that the population had not been exposed to this type of virus for a number of years, that a high proportion of those under 20 to 29 were infected during the outbreak, but the infection reached clinical levels chiefly in older children and young adults. Those over 30 were spared presumably because of previous infection, and the possession of low level neutralizing antibodies.
The presence of neutralizing antibodies to all three types of poliomyelitis viruses in all age groups indicates that these agents have been prevalent on the islands in the past, although no epidemic had been recorded previously.
Quantitative Studies on the Bactericidal Actions of Serum and Complement
Authors: Muschel Louis H. , Treffers Henry P. 
Published: January 2023

Summary
The bactericidal reaction, as studied with a new photometric growth assay, has been shown to parallel the hemolytic reaction in a number of respects: a stimulation by, if not an absolute requirement for, Mg ion and antibody-complement relations which can be expressed by identical equations. In a typical experiment 700–860 molecules of antibody and 1.5 × 107 molecules of complement were necessary to kill one organism, Salmonella typhosa, at the 50% end point. This amount of antibody is calculated to cover 0.03–0.7% of the bacterial cell surface. Heating at 56°C for a few minutes has been shown to decrease the bactericidal activity, particularly of weak sera, by partial destruction of antibody. Rabbit serum has an activating effect on guinea pig complement, human serum a depressing effect in the bactericidal although not in the hemolytic reaction. The relative titer of two sera is shown to vary with heating, and the species of complement used. Additional observations are presented on the Neisser-Wechsberg inhibition, and the mechanism of the bactericidal effect.
Fractions of Pig Complement
Authors: Leon Myron A. , Plescia Otto J. , Heidelberger Michael 
Published: January 2023

Summary
An inhibitor of g.p. C′ activity has been found in two fractions isolated from pig serum. For extents of hemolysis ranging from 0.2 to 0.8 the inhibitor reacts with one or more components of g.p. C′ according to first order kinetics with respect to C′i, the inhibited components of C′, if the assumptions are valid. The reaction is accelerated by an increase in temperature from 25°C to 37°C, as well as by a decrease in the concentration of divalent cations. The inhibitor, like C′1, is heat labile and is fixed by immune precipitates formed with rabbit antibody but not by those formed with horse antibody. This suggests that the inhibitor is partially degraded or denatured C′1 which forms hemolytically inactive complexes with one or more components of g.p. C′.
Studies on Antigenicity of Inactivated Influenza Virus
Authors: Fong Jacob 
Published: January 2023

Summary
The level of neutralizing antibodies in the serum of mice was highest after immunization with live virus. No significant difference in antigenicity was noted for mustard-inactivated and formalin-inactivated vaccines. Virus inactivated with 5 × 10-4 M mustard possessed a much greater interfering capacity than virus treated with 5 × 10-3 M mustard, but this was not reflected by a higher level of antigenicity for the former.
The Production of Antibody by Partially Hepatectomized Rats
Authors: Havens W. Paul , Schlosser Mary Ellen , Klatchko Jean 
Published: January 2023

Summary
The amounts of sheep-cell hemolysin produced by partially hepatectomized rats, laparotomized rats, and normal controls 6 days following the intravenous injection of a suspension of sheep cells were determined. No observable difference was found in the responses of the two control groups; however, the partially hepatectomized rats produced antibody in amounts that were significantly greater statistically than the amounts produced by the controls. The augmented synthesis of antibody by the partially hepatectomized rats suggests the possibility that some specific stimulus associated with removal of a large portion of the liver or its subsequent regeneration might have been operative.
Pneumococcal Antigenic Polysaccharide Substances from Human Tissues
Authors: Felton Lloyd D. , Prescott Benjamin , Kauffmann Gladys , Ottinger Barbara , Bullard H. H. , Binford C. H. , Warner C. G. 
Published: January 2023

Summary and Conclusions
In view of the observations that, following a dose of pneumococcus polysaccharide sufficient to produce “immunological paralysis” and a hypersusceptible state, mice retained in their tissues polysaccharide substances which on isolation stimulated a high degree of immunity in other mice against pneumococcus infection, whereas similar polysaccharide fractions from normal animals were lacking in antigenicity, a study has been made of substances similarly isolated from human tissues obtained from 125 individuals at autopsy. This unselected group, ranging in age from newborn to 88 years, included 3 primary lobar pneumonia cases, 2 primary and 23 secondary bronchopneumonia cases, and a miscellaneous group of 97 non-pneumonic fatalities. Ninety per cent of the entire group contained in one or more tissues (liver, spleen, kidney) polysaccharide substances which on isolation stimulated some immunity in mice against pneumococcus infection, especially of types I and/or II. There was some indication that the polysaccharides from pneumonia cases more often stimulated a high degree of immunity than those from non-pneumonia cases; also it was indicated that those from older individuals were more often antigenic than those from younger. It is suggested that accumulation of polysaccharide antigen in human tissues may influence susceptibility to pneumococcus infection and hence perhaps be a contributing factor in the incidence of pneumonia.
Some Considerations of the Antigen Dose-Antibody Response Relationship
Authors: Stevens Kingsley M. 
Published: January 2023

Summary
Data derived from the literature are presented in support of the 1912 theory of Smith and St. John-Brooks that the antigen dose-antibody response follows the form: K1c1/nAb where K1 is a constant, c is the concentration of the antigen, n is a constant between 1.9 and 3.6 and Ab is the maximum concentration of antibody.
The value of n appears to depend upon the chemical composition of the antigen. For proteins, n is about 1.9, for lipopolysaccharides about 2.6, and for polysaccharides about 3.6. From limited data, this equation appears to hold only at intermediate concentrations of antigen. At low concentrations, n approaches 1, while at high concentrations n approaches infinity.
On the basis of the above equation, certain values for K1 could be calculated, and these are listed.
These findings are consistent with, but do not prove, the concept that the limiting step in antibody production involves an adsorption process.
A Quantitative Study of a Technique of Double Diffusion in Agar
Authors: Preer John R. 
Published: January 2023

Summary
A technique of double diffusion is described. Warm liquid agar is layered onto serum in tubes and after the agar has cooled and solidified antigen is added. Tubes approximately 1.7 mm inside diameter are used, making it possible to use quantities as small as 0.01 ml. Egg albumin in concentrations as low as approximately 0.0001% could be detected in this way. A theoretical treatment of double diffusion is given which predicts the relation between band position, antigen and antibody concentration, antigen and antibody diffusion coefficients, time, and agar length. Experimental results are compared with these predictions and found to agree in most respects. Zones of precipitation, however, failed to move as rapidly as predicted. In particular, it was shown that band position is linearly related to the logarithm of the ratio of the antigen to antibody concentrations. Bovine gamma globulin and azo-substituted bovine gamma globulin were used to show the interaction between immunologically related proteins in double diffusion. Non-specific effects and the identification of bands were considered.
The Toxic Action of Preparations Containing the Oxygen-Labile Hemolysin of Streptococcus Pyogenes
Authors: Rowen Robert , Bernheimer Alan W. 
Published: January 2023

Summary
A study has been made of normal mouse plasma and of plasma of mice rendered refractory to the lethal effect of preparations of streptolysin O. Both types of plasma are inhibitory to the in vitro hemolytic action of streptolysin O but the inhibitory capacity of normal mouse plasma is relatively weak. The presence in the blood of refractory mice of a relatively large amount of inhibitory activity accounts for the refractoriness of these mice. The inhibitor in the plasma of refractory mice is not antibody nor does that in the plasma of normal mice appear to be antibody. The properties of the inhibitors in both normal and refractory mouse plasma indicate that the inhibitors are lipoproteins, and that more than one species of lipoprotein appears to be involved in the inhibition.
Poliomyelitis Virus in the Central Nervous Systems of Mice during Prolonged Incubation Periods
Authors: Evans C. A. , Cundy K. R. 
Published: January 2023

Summary and Conclusions
In 3 experiments more than 600 mice were injected with an inoculum of Y-SK poliomyelitis virus sufficient to kill approximately three-fourths of the animals in 40 days. Deaths due to viral infection began to occur on the 3rd day and continued well beyond 1 month. Approximately 40% of animals living, and apparently well on the 21st day, succumbed to infection by the 40th day. In 1 experiment in which observations were continued through the 85th day, 1 animal died of viral infection on the 82nd day.
In 2 of the above experiments 20 and 31 mice, apparently normal on the 21st day, were killed at that time and their CNS tissue tested for virus. Of the 51 mice tested, 6 contained virus in a titer (LD50) higher than 10-1 and 11 had smaller amounts of virus. In 7 of these, virus was sufficient to kill only 1 of 5 or 6 test animals injected with a 10% suspension of CNS tissue.
It is concluded that the concentration of infective virus remained low in the CNS of mice undergoing prolonged incubation periods until a few days before death. Then active viral increase occurred. Once multiplication started, it progressed and paralysis and death followed within a few days, probably in much the same time sequence as in animals that died after a short incubation period.
In view of these findings, it appears that the incubation period in this infection encompasses at least 3 distinct phases: In the initial phase virus infects cells and spreads to an unknown extent without much increase of detectable infective virus. Presumably this involves a series of cycles of cellular infection and degeneration, with release of virus and spread of some of the released virus to other cells, the balance being disposed of by undefined mechanisms. Extensive spread of non-infective virus is also a possibility. In a 2nd phase, which may be short or very long, infection remains relatively quiescent with a low concentration of detectable virus in the CNS and no obvious signs of illness of the animal. Whether this is just a prolongation of the first phase or is basically different is uncertain. In the final phase, there is active multiplication of virus with destruction of tissue. Signs of illness appear and progress rapidly until death occurs. It is suggested that the duration of the second phase and the change from second to third phase may be conditioned by physiologic changes in the host.
Flocculation Tests for Brucellosis
Authors: Hunter Charles A. , Colbert Bernice 
Published: January 2023

Summary
A method of producing a cholesterol-lecithin-brucella extract antigen for a microscopic slide and macroscopic tube flocculation tests has been described. The sensitivity and specificity of the antigen emulsion can be adjusted to conform to the standard antigen emulsion. A method of standardizing the antigen emulsion is described. Data are presented showing that the antigen emulsion is specific. The tests are rapidly performed and the results are clear cut and very easily read. The tests give reproducible results. Heating the serum to 56°C for 30 min reduces the prezone reaction. The agglutination tests give a better pattern after heating the serums.
Experiments on Adsorption in Vitro of Type II Poliomyelitis Virus on Red Cells
Authors: Bautista Gonzalo , Jungeblut Claus W. , Kodza Helen 
Published: January 2023

Summary and Conclusions
Human red cells from individual donors, when combined with poliomyelitis virus Type II, differ in their ability to remove virus from the supernatant and to anchor infectious doses on the cellular surface. This virus-removing property shows some relationship with the levels of type-specific neutralizing antibodies in the serum of the donor. Red cells from normal animals do not remove virus from the supernatants of virus-red cell mixtures, but virus removal may be demonstrated with cells from the same animals after their hyperimmunization with the specific antigen. Red cells which do not possess virus-removing capacity, whether from man or animals, acquire the property to remove virus after trypsinization of the erythrocytes. The mechanism of the virus-removing reaction is discussed.
Interaction between Internally Labeled Complement and Specific Precipitates
Authors: Penn Nathan , Haurowitz Felix , Yenson Mutahhar 
Published: January 2023

Summary
The components of complement (C′) incorporate S35-amino acids in vivo. Small amounts of radioactive S35-protein (C′i) are adsorbed by antigen-antibody precipitates from the decomplemented guinea pig serum; much larger amounts (C′a) from active guinea pig serum. The difference C′a — C′i, denoted as C′d, varies from 0.4 to 0.7% of the total protein-bound radioactivity of the guinea pig sera, and is almost the same at 0 as at 37°C in precipitates washed with 0.15 M saline solution. Much larger amounts of S35-protein are found in precipitates washed with 0.04 M NaCl solution. The loss of adsorbed S35-protein in 0.15 M NaCl solution is prevented by diisopropyl-phosphofluoridate.
Studies of Antibodies Against Organ-Antigens
Authors: Boroff Daniel A. , Meier Rita M. , Heller John H. 
Published: January 2023

Summary
Antimouse spleen serum exerted a pronounced effect upon mice as evidenced by ruffled fur, apathy and splenomegaly with histologic changes in the spleen elements. The antiserum did not, however, significantly affect the uptake from the circulation of the colloidal carbon by the RES of the mouse. Substitution of CrP32O4 for the carbon revealed that the spleens of the mice treated with AMSS contained at least twice as much radioactive colloid as spleens of the control mice. The increased uptake might be due to either the preferential stimulation of the spleen RES by the AMSS or by the spleen hyperplasia or by both.
Concerning the Mechanism of Complement Action
Authors: Cushman William F. , Becker Elmer L. , Wirtz George 
Published: January 2023

Summary and Conclusions
The hypothesis has been advanced that several or all of the components of complement are proteolytic enzymes. It was further proposed that simple chemical substances related to the natural substrates of these supposed enzymes might competitively inhibit the immune hemolysis reaction. Based on these hypotheses over 60 compounds, amino acids, amino acid esters and peptides were tested for their inhibitory action on complement. Three classes of inhibitory compounds were found, sulfhydryl bearing compounds, (cysteine and thioglycollic acid), derivatives of basic amino acids (lysine ethyl ester, TAMe and canavanine) and peptides containing aromatic amino acids. These findings were considered to have supported the hypotheses, but the necessity for further work was stressed. It was further suggested that one of the components of complement might be a proteolytic enzyme either requiring the presence of aromatic amino acids in its substrate, or whose activity is enhanced by substrates containing such acids.
The Effect of Chemical and Physical Treatments of Sera on the Hemolytic Activities and Fixation of Complement Nitrogen by Antigen-Antibody Precipitates
Authors: Weigle William O. , Maurer Paul H. 
Published: January 2023

Summary
Little relationship was found between the amount of complement N contributed to specific precipitates and either the hemolytic activity of sera or the components of complement present. The complement component probably responsible for the contribution of complement N to immune precipitates was confirmed to be C′1.
Versene and cation exchange resin either decreased or inhibited the contribution of complement N to immune precipitates by guinea pig and human sera. However, these agents had little effect on either the contribution of complement N to immune precipitates or the precipitation of soluble antigen-antibody complexes by rabbit serum.
It was found that urea reversibly inactivated the components of complement. The hemolytic activity and contribution of complement N were either completely or partially inhibited. Almost complete restoration of complement activity of the sera occurred after removal of the urea by dialysis.
Studies on the Serologic Diagnosis of Murine Typhus and Rocky Mountain Spotted Fever
Authors: Hersey David F. , Colvin Mayme C. , Shepard Charles C. 
Published: January 2023

Summary
Guinea pigs and rabbits were used as experimental animals for a reinvestigation of the serologic diagnosis of murine typhus and RMSF, principally by means of the complement fixation test. In CF block titrations it was observed that method 1 antigens gave results significantly different with early sera than with late sera. With early convalescent or acute sera the antigen titer varied with the concentration of serum; it was uniformly the highest with the lowest dilution of serum tested (1:2) and decreased in a step-wise fashion when the serum was further diluted. With late convalescent sera the antigen titer did not vary in this manner but rather tended to be the same in both the lowest as well as in the highest serum dilution in which CF was observed. With early sera even the lowest dilution of sera did not give as great an antigen titer as the late convalescent sera. These differences in the results of block titrations of early and late specimens make it difficult to define a unit of antigen that will apply both to early and late serum specimens. Antibody was detected earlier in the course of the experimental disease in guinea pigs when increased amounts of method 1 antigen were employed. This was observed consistently in both murine typhus and RMSF.
The Submerged Culture of Mammalian Cells: The Spinner Culture
Authors: McLimans William F. , Davis Eldon V. , Glover Fletcher L. , Rake Geoffrey W. 
Published: January 2023

Summary
A spinner culture system for the growth of tissue cells in fluid suspension has been described. Actively proliferating mammalian cell suspensions, in volumes of 25 to 400 ml have been established utilizing the prototype “L” cell. Similar, although less extensive, investigations have been conducted with strain HeLa. A 300 to 400 ml “L” cell spinner culture has been continuously maintained for the last 5 months. It is suggested that the described submerged culture system provides a more quantitative tool for investigations relating to the response of the mammalian cell to infectious or pharmacologic agents.
The Effect of Feeding Simple Chemical Allergens to Pregnant Guinea Pigs upon Sensitizability of Their Offspring
Authors: Baer Rudolf L. , Rosenthal Stanley A. , Hagel Blanka 
Published: January 2023

Summary
Pregnant guinea pigs were fed solutions of picryl chloride (PC) or dinitrochlorobenzene (DNCB) during part of their gestation period. The offspring born to these animals had a slightly, though consistently, lower capacity to become sensitized to the homologous allergen than did the offspring born to mothers not fed the allergen. This slight effect appeared to be specific, since it did not extend to sensitizability to citraconic anhydride (CA), a chemically unrelated allergen.