bluuebunny/crossref_metadata_2025_split huggingface dataset:
Standardization of Cobra (Naja Flava) Venom Using the Graded Response Method
Authors: Christensen P. Agerholm , Finney D. J. 
Published: January 2023

Summary
The relationship between dosage of Naja flava venom and death-time of mice has been examined from experiments using intravenous injection. The observations were found to be well represented by the equation .
From this formula, a function of death-time can be constructed that has a linear regression on the logarithm of the dose over a wide range of doses, the function being . The logarithm of the time also is linearly related to the log dose over very nearly the same dose range. For both these response metameters, and over the same range of doses, the variance was found to be almost independent of the mean.
Hence the potency of a preparation of venom may be assayed against a standard, using either f(T) or log T as a response metameter, in a parallel line assay of familiar type. The function f(T) has the advantage of giving a linear regression over a slightly greater range of doses, but redetermination of the numerical values of its parameters should precede its use in any other laboratory. At the South African Institute for Medical Research, assays of the (2 + 2) dose design have been found satisfactory; five trial assays reported in this paper used five animals at each of the four doses and gave limits of error of ±20% or less for a probability of 0.95.
In Vitro Action of Sulfur Mustard and Chloroethylamine Derivatives upon Antigenicity of Influenza A (PR8) Virus
Authors: Fong Jacob , Bernal Enrique 
Published: January 2023

Summary
Immunization of mice with mustard-treated vaccines evoked the production of antibodies as demonstrated in vivo by their acquired resistance to intranasal administrations of active virus, by the in vitro neutralization of the infective and toxic components of virus and by the fixation of complement in the presence of specific antigen. There were no marked differences between the antigenicity of sulfur and cyclo mustardtreated virus, but these were definitely inferior to the immunizing quality of native virus, a condition particularly noticeable upon reduction of the viral concentration of the vaccines. The injection of mustard-virus suspensions into mice failed to cause any suppression of antibody production by the host.
Antibody Formation in Vitro by Haemopoietic Organs after Subcutaneous and Intravenous Immunization
Authors: Thorbecke G. J. , Keuning F. J. 
Published: January 2023

Summary
Fragments of spleen, bone marrow, liver, thymus and lymph nodes of rabbits immunized with paratyphoid B vaccine were cultivated in roller tubes for 24 hours.
Antibody production was demonstrated in the red and white pulp of the spleen, and in the bone marrow and lymph nodes, but in cultures of thymus and liver no antibody production was found.
With the technique used, the red pulp of the spleen was found to play the major part in antibody formation, both after subcutaneous and after intravenous immunization.
The Effect of Complement in Rabbit Serum on the Quantitative Precipitin Reaction. I.
Authors: Maurer Paul H. , Talmage David W. 
Published: January 2023

Summary and Conclusions
Normal rabbit serum and low titered antisera contain appreciable quantities of complement nitrogen even after 3 to 5 months of storage at 0 C. Significant differences in both the total nitrogen precipitated from antisera with low concentrations of antibody and the antibody N/antigen N ratios before and after decomplementation of the antisera have been demonstrated. The differences in immunochemical behavior of antisera diluted in normal rabbit serum and in 0.85% saline are markedly reduced after decomplementation of the diluting serum.
Cutaneous Hypersensitivity in Brucellosis
Authors: Benedict Albert A. , Elberg Sanford S. 
Published: January 2023

Summary
By the use of chromatography and differential solubility in butanol two brucella fractions were separated from the antigen soluble in Lorol, namely, fraction A which represented the skin test antigen and fraction B which was inactive as a skin test antigen. Acid hydrolysis yielded the same 11 ninhydrin-reactive components from both fractions. Antiserum to Br. suis precipitated fraction B according to chromatographic data and bioassay. The supernate from the precipitin tests contained the allergen. In terms of the amount of nitrogen needed for skin tests on experimentally infected animals, fraction A was nonantigenic when injected into rabbits intravenously whereas fraction B readily stimulated the production of agglutinins.
Serological Studies with Vibrio Metschnikovii
Authors: Wynne E. Staten , Gott Cora L. , Mehl Donald A. , Norman James O. 
Published: January 2023

Summary
Growth agglutination has been used as a quantitative serological phenomenon for measurement of response of humans to Vibrio metschnikovii.
V. metschnikovii is postulated to contain an antigen consisting of a haptene and a heat-labile protein moiety. Saline and growth agglutinins are thought to be directed toward the haptene, while antibodies in the Coombs' anti-globulin test appear to be directed toward the protein portion. The haptene is apparently easily separated from the cell by heat.
Quantitative Studies of Cross Reactions between Shigella Flexneri Types 1a, 1b, and 3
Authors: Formal Samuel B. , Baker Edgar E. 
Published: January 2023

Summary
By means of the quantitative agglutination technic, antibodies against the type-specific antigens in antisera prepared with Shigella flexneri Types 1a, 1b, and 3 have been determined. It has been demonstrated that, with the exception of group-specific 6 antibody present in Sh. flexneri Types 1b and 3 antisera, the minor group antibodies represent only a very small fraction of the total antibody present in the serum.
Some Effects of Formalin on the Serological Activity of Crustacean and Mammalian Sera
Authors: Leone Charles A. 
Published: January 2023

Summary
With antisera produced against the native sera of the blue crab Callinectis sapidus and the domestic cow Bos taurus, the influence of formalin (0.2 to 10%) on the serological activity was studied. Alteration of the serological characteristics of the antigens by formalin was a function of its concentration in the systems.
Relation of the Incubation Period and the Secondary Immune Response to Lasting Immunity to Infectious Diseases
Authors: Macleod Colin M. 
Published: January 2023

Abstract
Lasting immunity has in general been considered to be characteristic especially of certain viral diseases. To explain the persistence of immunity, which is in reality a very common phenomenon, commoner indeed than immunity which is merely temporary, it has been suggested that in some diseases the virus persists in the body and acts as a permanent antigenic stimulus, whereas in other diseases, immunity is maintained throughout life by repeated subclinical attacks of the disease.
Persistence of viruses in the recovered animal and in man is recognized in a number of diseases such as salivary gland disease of guinea pigs, psittacosis in birds, lymphocytic choriomeningitis in mice, infectious anemia of horses and herpes simplex in man. In diseases where antibodies persist long after recovery and where there is no possibility of renewed contact with the agent, it has been suggested that the virus persists in the body even though it cannot be recognized.
Bio-Assay of Four Tetanus Toxoids (Aluminum Precipitated) in Mice, Guinea Pigs and Humans
Authors: Ipsen Johannes 
Published: January 2023

Summary
A series of experiments are presented where the validity of an adequate bioassay of tetanus toxoids was tested by comparing the immunizing potency of the same four aluminum precipitated tetanus toxoids in mice, guinea pigs and humans.
The mouse test was carried out in six laboratories using the same material and method. A three dose assay was performed challenging the animals with toxin fourteen days after immunization. Results obtained in all six laboratories agreed within the intra-assay error. One hundred and twenty-eight young adults who had not previously received tetanus toxoid were subdivided in eight groups of sixteen. Each group received either one of the four toxoids, in either of two doses. Antitoxin titres after 28 days were compared, with analysis of the four two-dose regression lines. The same number of guinea pigs received the identical treatments as the humans. Pools of serum for subgroups of eight were titrated for antitoxin. The relative potencies of the four toxoids to produce primary immunity in the three animal species agreed within the experimental error. In the guinea pigs and humans the response fourteen days after a second injection was also observed, and the relative potencies of the four toxoids to provoke the secondary reaction were comparable to those computed on the basis of primary stimulus. The assays based on secondary reaction are less precise than assays based on primary stimulus. The precision of assays based on primary immunity reaction is the same per individual whether mice, men or guinea pigs are used. Hence, the mouse assay is by far the least expensive.
The Effect of the Presence of Complement in Rabbit Serum on the Quantitative Precipitin Reaction
Authors: Maurer Paul H. , Talmage David W. 
Published: January 2023

Summary
The effect of the presence of complement in normal rabbit sera on both the antigen and antibody precipitation behavior in the region of antigen excess has been shown. It has been postulated that rabbit complement causes some of the soluble antigen-antibody complexes to become insoluble, thus shifting the equilibria existing in the region of antigen excess. Only 60% of the complement nitrogen was removed by 100 μgN of an Ea-anti Ea specific precipitate per ml of serum. The precipitin curves obtained in the presence of 0.85% saline and 5% serum albumin are similar. The degree of iodination of gamma globulin molecules and antibody molecules (anti BSA) is fairly similar.
Effects of X-Irradiation and Adrenalectomy on Phagocytic Activity
Authors: Esplin Don W. , Marcus Stanley , Donaldson David M. 
Published: January 2023

Summary
Following intravenous injection of Thorotrast into normal mice about 50% of the ThO2 is taken up by the liver and 17% by the spleen. While the liver is about 10 times as large as the spleen and shows a greater total uptake of ThO2, the ThO2 uptake of splenic tissue per unit dry weight is almost 4 times that of hepatic tissue. The splenic uptake of ThO2 in mice is linearly related to the amount of Thorotrast injected for doses up to 0.15 ml per mouse. With this dose each spleen contains about 6 mg of ThO2 which makes up 15% of the dry weight of the organ. With doses above 0.15 ml the phagocytic cells of the spleen tend to become saturated, while with smaller doses the ability of the cells to take up additional ThO2 does not appear to be influenced by the ThO2 already ingested. X-irradiation (350 r) caused a great reduction in splenic weight but did not influence the 72 hour splenic or hepatic uptake of ThO2 in mice. Doses from 100 r to 600 r were also without effect on the splenic uptake of ThO2. After intraperitoneal injection with Micrococcus pyogenes var. aureus, leukocytes from the peritoneal cavities of irradiated mice (350 r) contained more bacteria than leukocytes from normal animals. Adrenalectomy caused a reduction in the phagocytic activity of mouse leukocytes which was marked at two days after adrenalectomy. By the sixth day after adrenalectomy however, the control and adrenalectomized groups were not significantly different in this respect. No change in splenic or hepatic uptake of ThO2 was noted to follow adrenalectomy in mice. In rats, however, adrenalectomy caused a threefold reduction in the 24 hour splenic uptake of ThO2.
Bovine Erythrocyte Antigens
Authors: Royal George C. , Ferguson L. C. , Sutton T. S. 
Published: January 2023

Summary
The observations reported in the present study indicate that a nitrogen-containing polysaccharide can be isolated from bovine erythrocytes which is capable of reacting specifically with several of the typing sera for bovine cellular antigens. The antigens extracted are non-antigenic in rabbits and are best demonstrated by means of inhibition tests.
The Persistence of Antigen in the Mouse
Authors: Erickson John O. , Armen Dorothy M. , Libby Raymond L. 
Published: January 2023

Summary
The persistence of a single intravenous injection of TMV in the mouse has been investigated by two independent methods which are free of many ambiguities.
P32 labeled TMV has been isolated from liver extracts 9 days after intravenous injection by means of specific precipitation with rabbit antiserum to TMV.
Direct observation of liver extracts in the electron microscope has revealed the presence of particles strikingly similar in size and shape to TMV through 15 days after intravenous injection.
It is evident that the mouse cannot rapidly dispose of a 2 mg intravenous dose of TMV.
These results suggest that the presence of antigen is a prerequisite for antibody formation.
Production of Influenza A Virus in the Cells of the Allantois
Authors: Cairns H. J. F. , Mason P. J. 
Published: January 2023

Abstract
The first cycle of influenza virus multiplication in the allantois may broadly be divided into three phases—the uptake of inoculated virus by the cells, the multiplication of this virus within the cells, and finally the liberation of newly-formed virus into the allantoic fluid. During much of the period of intracellular multiplication, little if any of the multiplying virus can be detected in the cells (1, 2), and the first sign that multiplication has occurred is the re-appearance of virus in suspensions of the allantoic membrane (3, 4). Some time later, virus can be detected in the allantoic fluid.
If virus becomes detectable while still inside the cell, then this interval, between formation of detectable virus in the membrane and release of virus into the fluid, must comprise both the time required for detectable virus, once formed, to emerge on to the cell surface (the pre-emergence period) and the time required for emerged virus to elute from the cell surface into the fluid (the pre-elution period).
Inhibition by Lecithin and Cholesterol of Bacterial (Escherichia Coli) Hemagglutination and Hemolysis
Authors: Neter Erwin , Zalewski N. Joyce , Zak Dorothy A. 
Published: January 2023

Summary
The effects of lecithin and cholesterol on Escherichia coli O26 hemagglutination and hemolysis were studied and the following results obtained.
Both crude and purified lecithin preparations, after contact with the bacterial antigen, inhibited E. coli hemagglutination. As little as 0.5 mg (0.1 mg per ml) of the purified preparation E prevented this reaction completely. This preparation also inhibited E. coli hemolysis. Cholesterol in amount of 0.05 mg, after contact with the bacterial antigen, inhibited E. coli hemagglutination and 0.5 mg prevented hemolysis. The inhibitory effect of both lecithin and cholesterol depends, aside from their concentration, upon the amount of bacterial antigen used, the length of time of contact between inhibitor and antigen and the temperature at which the mixtures were kept. Purified lecithin preparation E and cholesterol, when allowed to act on red blood cells, did not inhibit hemagglutination, indicating that their major effect is upon the antigen. Red blood cells treated with inhibitor-antigen mixtures failed to adsorb homologous bacterial antibodies of human origin, as evidenced by failure to be agglutinated by anti-human globulin (rabbit) antiserum; the latter serum caused agglutination of erythrocytes which had been modified by antigen alone and then treated with the same bacterial antiserum. Cholesterol-antigen mixture was precipitated at least as well as the untreated antigen by homologous E. coli antiserum and lecithin-antigen mixtures but slightly less than the control antigen, indicating that the inhibitory effects of the lipids on E. coli hemagglutination is not due to destruction of the bacterial antigen. The phenomena of bacterial (Escherichia coli) hemagglutination and hemolysis and their inhibition by lecithin and cholesterol are discussed.
Influenza Virus in Allantoic Sac Tissue Culture
Authors: Womack C. Ray , Kass Edward H. , Kendrick Mary I. , Lundgren Marguerite M. 
Published: January 2023

Summary
The use of allantoic sacs in suspended cell tissue cultures for the growth of influenza viruses has been investigated. Influenza A and B viruses grow readily in such cultures, with either Hanks-Simms' solution or Tyrode's solution as diluents. In the presence of the former solution, viral titers (influenza A) in tissue cultures reach a maximum slightly more slowly and decline more slowly than in Tyrode's solution.
Step-wise curves of multiplication of virus are readily demonstrable without recourse to dilution or interference techniques. A complete cycle of multiplication of influenza A virus in this system requires approximately 18 hours, and increases the titer about 100-fold. Frequent changes of the nutrient fluid and the addition of embryo extracts do not increase the capacity of the tissue to support viral growth. The titer of hemagglutinin in such cultures is affected by the amount of tissue in the cultures and by the size of the inoculum.
Quantitative study of the pentose and desozy-pentose nucleic acids of the cultures showed a progressive decrease in the former during the incubation of a tissue culture and insignificant alterations in the latter. Viral growth in such cultures may have increased the rate of decline of PNA more rapidly than in uninfected cultures, but had no consistent effect on DNA. Tyrode's and Hanks-Simms' solutions exerted similar effects on nucleic acid concentrations.
The incorporation of radioactive phosphorus into nucleic acids of both types by the tissue cultures was rapid. There were no consistent effects on the pattern of uptake of phosphate by the tissue cultures as a consequence of viral multiplication in the cultures. The data indicate that multiplication of tissue cells was not prominent in these cultures, and that a net degradative effect predominated. Uptake of radioactive phosphorus offers a more reliable indication of sufficient viability of tissue cells to support viral growth in suspended cell cultures than do increases in nucleic acid concentration.
In the presence of cortisone, both infected and uninfected cultures were characterized by the appearance of numerous cystic blebs of tissue, arising from the culture fragments of allantoic sac. Such outpouchings were less common in control cultures. No consistent effect of cortisone on the concentrations of pentose nucleic acid (PNA) or of desoxypentose nucleic acid (DNA) in the cultured tissues was demonstrable. The rate of incorporation of radioactive phosphate into PNA was slightly accelerated both in infected and uninfected cultures, but incorporation of phosphate into DNA was not significantly altered by the hormone. Cortisone did not affect viral multiplication significantly.
A Capillary Agglutination Test for Bovine Q Fever
Authors: Luoto Lauri 
Published: January 2023

Summary
A capillary agglutination test, employing a stained antigen of Coxiella burnetii, for use in detecting the presence of antibody against Q fever in bovine serums is described. An evaluation of the new test was accomplished by comparison of the results obtained with the complement-fixation test on a large number of serums. Nonspecific reactions did not commonly occur. The sensitivity of the capillary agglutination test appears to be greater than that of the complement-fixation test. A high degree of reproducibility for both screening and titration purposes is an outstanding characteristic. The technique makes possible a very simple, economical, and rapid test that is adaptable to work in the field or in the laboratory.
The Requirement for a Hydrazine-Sensitive Serum Factor and Heat-Labile Serum Factors in the Inactivation of Human C′3 by Zymosan
Authors: Pillemer Louis , Lepow I. H. , Blum Livia 
Published: January 2023

Summary
Heat-labile factors, resembling C′1 and C′2, and a hydrazine-sensitive factor resembling C′4 are required for the inactivation of C′3 by zymosan.
Certain similarities exist between the interaction of C′ with zymosan and with sensitized and unsensitized red cells and bacteria.
Quantitative Method of Titrating Anti-Platelet Serum in Vitro
Authors: Cruz W. O. 
Published: January 2023

Summary
A method for testing the potency of anti-platelet serum, by determining its ability to lyse platelets in the presence of complement in vitro, is described. Details concerning the dynamics of platelet lysis, the effects of interfering substances, and the conditions required for performing the test correctly are given.
The error of the method is about 8%. Several determinations per hour can be made, in contrast with methods in the literature which are difficult to read and are time consuming. A definition of a platelet lytic unit is presented, based on the time required for a certain amount of lysis as measured by turbidimetry in a photoelectric apparatus.
Biological Properties and Variations of Reactions of the Encephalitogenic Agent in Nervous Tissues
Authors: Olitsky Peter K. , Lee Johanna M. 
Published: January 2023

Summary
The tests reported here relate to the disclosure not only of additional stocks of mice that were found to be resistant to the development of acute disseminated encephalomyelitis, such as the Webster BRVR and BRVS stocks, but also to other stocks that were partially susceptible, namely the Webster BSVR and C3H mice, and to still another breed, the Webster BSVS that was fully susceptible.
Of the proteolipide “A + B” fraction of mouse or cattle CNS tissues, the “A” moiety was active and the “B” inactive after their inoculation into mice and guinea pigs. The bovine proteolipide “C” component was found to be inactive in these animals.
Effective production of encephalomyelitis in the mouse followed only when a Freund-type adjuvant was mixed with central nervous system tissue materials and injected as a mixture.
In mice that have responded with development of encephalomyelitis and then remitted to a quiescent state, the injection into them of mouse brain alone brought out an immediate reaction of hypersensitivity.
A discussion is included on the variations occurring in experimental reactions to the materials, methods, and animals employed for the production of the encephalomyelitis, and the relation of hypersensitivity to its development.
Some Properties of Herpes Simplex Virus
Authors: Munk Klaus , Ackermann W. Wilbur , Kurtz Hilda 
Published: January 2023

Summary
A procedure has been described for the preparation of suspensions of herpes virus which are relatively pure and sufficiently stable to be quite suitable for certain types of experimentation. A 100-fold concentration of the original virus has been achieved along with a 30-fold purification. A high percentage of recovery was obtained and some preparations contained 109 ID50 per mg of nitrogen.
In ionic media the maintenance of activity was favored by alkaline conditions. However, the virus was far more stable in water or 0.25 M sucrose than in ionic media.
Suspensions in water were examined with the analytical centrifuge and the electron microscope. A sedimentation constant of 1175 S was obtained from which the particle size was estimated to be 96 mμ. In electron micrographs prepared from these suspensions a predominating particle was found which was round in shape and about 116 mμ in diameter. In unshadowed preparations the particles appeared inhomogeneous with regard to electron adsorption indicating the virus is composed of a central structure surrounded by an area of lower density.