bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on Tetanal Toxin
Authors: Friedemann Ulrich , Hollander Alvin 
Published: January 2023

Summary and Conclusions
The antitoxin-requirements for 20 lethal doses of 7 tetanal toxins have been investigated with the aid of the direct and indirect intraventricular tests in rabbits and guinea-pigs. These investigations have led to the unexpected result that in the direct test in guinea-pigs 20 lethal doses of toxins from various sources are neutralized by entirely different amounts of antitoxin. The antitoxin-requirements were found to be 100 times higher for toxins 641B and 1175H than for toxin 388. The indirect test, therefore, reveals spectacular qualitative differences between toxins derived from different strains of Cl. tetani. These differences are not apparent in the direct test in guinea-pigs. Contrary to the findings in guinea-pigs, in the rabbit the antitoxin-requirements in the indirect test are identical for 10 lethal doses of toxins derived from various strains of Cl. tetani. In the direct test in rabbits, however, the antitoxin-requirements are different for the individual toxins. The explanation of these findings calls for further investigations which will be reported in a subsequent paper.
Genic Control of Species-Specific Antigens of Serum
Authors: Cumley R. W. , Irwin M. R. , Cole L. J. 
Published: January 2023

Summary
Qualitative differences in serum antigens specific for Senegal were observed in the serums of backcross birds resulting from matings to Ring dove of species- and backcross-hybrids from the cross of Senegal/Ring dove. These antigens have been found to segregate within the backcross families in accordance with genetic expectation. There is evidence that the genes which control the serum antigens are on different chromosomes from those that control the Senegal specific corpuscular antigens. These findings are similar to those resulting from studies of other species crosses.
On the Occurrence of Forssman Antigen in Trichinella Spiralis
Authors: Rose Harry M. 
Published: January 2023

Summary and Conclusions
In seventeen cases of trichinosis the titers of agglutinins and hemolysins for sheep's erythrocytes were found to be within normal limits. Similar findings were obtained in two rabbits infected with Trichinella spiralis.
Rabbits immunized against sheep's erythrocytes and guinea-pig's kidney did not develop precipitins for trichinella-antigen.
The evidence available at present does not warrant the conclusion that Trichinella spiralis contains the Forssman antigen.
Detection of the Virus of Mouse Encephalomyelitis in the Intestines of Normal Kangaroo Rats
Authors: Melnick Joseph L. 
Published: January 2023

Summary
An infectious agent capable of producing encephalomyelitis in mice has been detected in the intestines of normal kangaroo rats. These rats had been quartered for over a year in a laboratory which had also been inhabited by normal and poliomyelitis-infected monkeys and by albino mice proven to be intestinal carriers of Theiler's mouse encephalomyelitis virus. By means of cross immunity tests and complement fixation reactions this virus has been shown to be immunologically related to the FA strain of mouse encephalomyelitis virus.
The Complement-Fixation Test with Human Sera against the Viruses of St. Louis Encephalitis and Equine Encephalomyelitis
Authors: Howitt Beatrice F. 
Published: January 2023

Summary
Of 137 sera tested from cases of encephalitis, 34 or 24.8 per cent, showed both complement-fixing and neutralizing antibodies for the St. Louis virus alone, 23 or 16.7 per cent for the western equine strain alone and 17 or 12.4 per cent for both viruses. Of these 137 sera, therefore, 73 or 54.0 per cent showed complete correlation between the complement-fixation and the neutralization-tests.
With the other 64 sera, there was more tendency for the complement-fixation test to be positive for the St. Louis virus than for the equine, particularly if the neutralization-tests were positive for both the strains.
Eleven or 8.02 per cent of the sera gave positive complement fixation with the St. Louis antigen when the neutralization-tests were negative to both strains.
Of 42 sera obtained during the first 2 weeks after the onset of disease, 100 per cent neutralized one or the other of the viruses while only 73.8 per cent reacted to complement fixation.
Neutralizing antibodies for the western equine strain appeared earlier in the disease than those fixing complement, while the reverse was observed for the St. Louis virus. During the later periods there was not much difference between the presence of either antibody for the 2 strains, except that the complement-fixing reaction remained positive longer for the western equine virus than for the St. Louis.
Complement-fixing antibodies for the western equine strain as well as neutralizing substances were found in a serum at least 2 years after the onset of the disease, while those for the St. Louis strain were demonstrated after 10 to 14 months.
The complement-fixing ability of a serum may be attenuated after prolonged storage but if the specimen is not anticomplementary or bacterially contaminated, significant reactions may be obtained even after 2 years in the refrigerator. A negative one, however, may not be of value.
Of a total of 257 specimens examined by both methods, 120 or 46.7 per cent reacted negatively. 47 of the sera came from the non-endemic Bay Region and 73 from the endemic San Joaquin Valley. 66 of the latter were from cases of poliomyelitis.
Complement-fixing as well as neutralizing antibodies were found in sera from a small group of contacts to frank cases of encephalitis.
Of 70 sera in the Bay Region tested against the lymphocytic choriomeningitis virus 4 or 5.7 per cent gave a positive complement fixation and only 3 (4.2 per cent) of these a correspondingly positive neutralization-test.
Of 121 sera examined none showed complement-fixing antibodies against the eastern equine strain of encephalomyelitis, while 4 out of 86 (4.3 per cent) reacted to a normal mouse brain antigen. The latter sera were likewise positive with the other antigens used.
It would be of value to use both the complement-fixation and the neutralization-test for the most accurate differentiation of human cases of encephalitis.
Quantitative Determination of Antigen, Antibody and Complement in Precipitates
Authors: Haurowitz Felix , Yenson M. Mutahhar 
Published: January 2023

Summary
Immune sera to arsanil-azo-globulin were precipitated by small and by large amounts of antigen, in the presence of active and of inactivated guinea-pig serum. Gravimetric analysis of the precipitates demonstrated: The weight of the precipitate obtained with active guinea-pig serum is greater. Maximally 0.15 to 0.20 mg of complement-protein were fixed per ml of guinea-pig serum. The amount of complement protein in the precipitate was independent of the antigen-antibody ratio and equaled about 20 per cent of the weight of the precipitates. Neither the antigen-antibody ratio nor the absolute amount of antigen or antibody in the precipitate is altered by complement fixation. Hemolysis of a single red cell requires approximately 10−11g, i.e. more than 1010 molecules of saponin or of sodium oleate. The same effect is produced by 1.5 × 10−14g, i.e. 60000 molecules of complement-protein. The much higher efficiency of complement supports the enzyme theory of complementary action.
The Validity of the “Percentage Law” in Bactericidal Reactions
Authors: Morris Marion C. 
Published: January 2023

Abstract
In previous communications (1, 2) we have reported experiments showing the effect of dilution on mixtures of pneumococcus type 1 and its specific antibody. Our findings led us to conclude that dilution does not cause an appreciable dissociation of antibody, although similar findings of various others with virus-antiserum mixtures have led to the conclusion either that there is no “in vitro” union of virus and neutralizing antibody, or that the union is freely reversible (3). Because the pneumococcus, in contradistinction to viruses, can be grown on artificial media, we were able to interpret our results somewhat more accurately than can be done with viruses. The use of a bacterial-antibody system thus becomes a useful “tool” in attempting to reconcile the differences which appear to exist in the laws governing immune reactions with bacteria on the one hand, and viruses on the other.
Studies on Influenzal Infections in the Chick-Embryo
Authors: Sigurdsson Björn 
Published: January 2023

Discussion and Summary
Infections in the chick-embryo with two recently isolated human strains of influenzal virus and two strains of swine-virus have been studied with relation to the influence of the temperature of incubation and the age of the host. The findings indicate that the temperature is of considerable importance and that 35–36 C is more suitable than 39–40 C for titrational purposes, as titrations carried out at 39–40 C gave very low and irregular 50-percent-infectivity endpoints. The explanation seems to be that a larger dose of virus was needed to infect at the higher temperature, and further that in many infected eggs the concentration of virus was not high enough to give positive red-cell agglutination. Both these factors contributed to the low endpoints obtained in the titrations at 39–40 C. This would probably be less conspicuous with strains having a higher agglutinin/infectivity ratio. Whether some intermediate temperature might be more suitable than 35–36 C has not been tested. Incubation at 37 C as used by Hirst for purposes of titration and isolation is obviously satisfactory. How 37 C compares with 35–36 C as to susceptibility of the embryo and amount of virus produced would have to be clarified by direct comparison.
The strains tested killed the embryos regularly at the lower temperature and infections and deaths were prevented by immune sera. The swine-strains also killed at 39–40 C but a few survivors were found with the human strains at that temperature. The report (24) that H. influenzæ suis is necessary in addition to the swine-virus if high mortality is to result from the infection is probably to be explained by differences in the strains of virus used.
The 7- and 12-day embryos apparently did not differ markedly in their resistance although the 7-day eggs were probably slightly more susceptible.
The route of inoculation (on the chorioallantoic membrane or into the amnion) and the amount of virus used did not greatly affect the rate of increase of virus in the fluids with strains TW 772 and V 15 strain 2. Strain TW 771, on the other hand, seemed to depend more on the route of inoculation and the size of the inoculum, the concentration rising quicker after a large inoculum.
Finally, the effect of Na-sulfadiazine on the infection was tested. It was found that 20 mg of Na-sulfadiazine per embryo did not reduce the number of positive infections in critical virus-dilutions; or in other words, titrations in eggs containing this amount of the drug did not show a lower infectivity-endpoint than did titrations in normal control eggs. Should it be desired to use an antibacterial agent with inocula that are not completely free of bacteria, Na-sulfadiazine would seem to be suitable as far as the virus is concerned.
Antigenic Relationships of Shigella Paradysenteriae
Authors: Wheeler K. M. 
Published: January 2023

Summary
In a serological study of the mannitol fermenting, lactose negative paradysentery group of bacteria, type-specific antigens for types V, W, Z, 88, 103 and P119 in the Flexner group were identified by means of specific agglutinins of sufficient strength to provide a practical means of strain identification. Specific antigens also were readily identified in cultures of Boyd types 170, P288, P274, D1, D19, P143. In the case of X and Y types only weak specific agglutinins were obtained and it seems likely that these cultures are degraded types as Boyd has proposed. Strains of types 170 and P274 isolated in the U. S. appeared to be identical with the stock strains. Extension of serological identification to include the less common Boyd types, 170, P288, P274, D1, D19 and P143, will provide a means of studying the significance of these strains in dysenteric disease.
Major group-antigens were identified among types in the Flexner group which were of sufficient importance for use in strain identification. By adsorption, serums were obtained showing group-components common to V-Z-103, V-W-Y-88, W-Y, V-88, X-Z-P119-W1268, X-Z-W1268, V-P119 and V-W1268-X-Z-P119 cultures.
The same type-specific antigen was found in combination with more than one set of group-antigens, e.g. the stock strain of type 103 had the major groupantigen of V and Z cultures while other strains of 103 lacked this but shared an antigen with the W and Y types. Different group-antigens were combined with the same specific antigen in the case of W strains, one sharing a major group-antigen with V, Y and type 88 strains the other with X, Z, and P119 strains. One type P119 culture was found which had some of the antigen of W-Y strains in addition to the principal group-antigen of the stock P119 strains.
The classification of Flexner types as outlined by Boyd provides a practical method of classification which has the advantage of pointing out the close serological relationships among the Flexner types. Some modifications based on the distribution of group-components among the types are desirable. Many of the broad antigenic relationships are of no differential value. Although Boyd types 170, P288, P274, D1, D19 and P143 possess little or none of the “Flexner” group-antigen the scheme of classification can eventually be extended to include these types.
Studies on Virus Immunity
Authors: Friedemann Ulrich , Hollander Alvin , Bornstein Siegbert 
Published: January 2023

Summary
The mechanism of immunity was studied in the case of the viruses of equine encephalomyelitis and rabies. The antibody contents of the immune sera were determined by injecting a mixture of a constant dose of virus and varying doses of immune serum into the intraventricular space of guinea-pigs. These experiments were designated as direct tests and the minimal neutralizing doses of immune serum as Ad. The capacity of the immune sera to confer passive immunity was measured by injecting the same dose of virus into the intraventricular space and varying doses of immune serum intravenously. These experiments were designated as indirect tests and the minimal neutralizing doses of immune serum as Ai. The ratio Ai/Ad was found to be at least 1280 for the virus of rabies and approximately 10 for the virus of equine encephalomyelitis. In the case of the virus of equine encephalomyelitis Ad is the same for non-incubated mixtures and mixtures incubated for 20 hours at room-temperature. In the case of the virus of rabies Ad is considerably lower for incubated mixtures. The virus of equine encephalomyelitis and its antibody do not combine in vitro once the immune serum is diluted to more than 1:4. On the contrary, the virus of rabies and its antibody combine in vitro even if the immune serum is highly diluted.
The Production of Antibrain Antibodies in the Monkey
Authors: Kopeloff Lenore M. , Kopeloff Nicholas 
Published: January 2023

Summary
Antibrain antibodies have been produced in the serum of the rhesus monkey. The method employed for immunization with alcoholic organ extracts was an adaptation of the Freund adjuvant-technic.
Organ-specificity was demonstrated by complement-fixation, flocculation, and absorptive tests.
Cross-reactions with testicle, and to a lesser degree with kidney, were noted.
Influence of Temperature of Incubation of the Increase of Influenzal Virus B (Lee Strain) in the Chorio-Allantoic Fluid of Chick Embryos
Authors: McLean I. W. , Beard Dorothy , Taylor A. R. , Sharp D. G. , Beard J. W. , Feller A. E. , Dingle John H. 
Published: January 2023

Summary
Studies were made on the rate of increase of infectivity and hemagglutinative activity of the influenzal virus B (Lee strain) in the chorio-allantoic fluid of chick embryos incubated for various periods at 35, 37 and 39 C. The rate of virus increase in the first 24 hours of incubation at 35 C was essentially the same as that in the same period at 37 C. The maximal level of infectivity at 35 C, reached at the 48-hour period of incubation, was about six times that at 37 C attained at 36 to 48 hours' incubation. Hemagglutinative activity seemed definitely greater at 35 C than at 37 C. From the present experiments it is evident that the temperature 39 C was unsuitable for the cultivation of influenzal virus B. Not only was the ultimate level of the total amount of virus low, but the infectivity and hemagglutinative activity found in the earlier periods of incubation at this temperature were rapidly lost later.
Titration of Tetanal Toxins and Toxoids by Flocculation
Authors: Moloney P. J. , Hennessy Joan N. 
Published: January 2023

Abstract
In 1926 G. Ramon and P. Descombey (1) described the phenomenon of flocculation which takes place in mixtures of tetanal toxin and tetanal antitoxic serum. In the same communication Ramon and Descombey reported that with certain sera “abnormal” flocculations may occur. Other workers have also reported, in the case of tetanus, similar “abnormal” flocculations, that is flocculations which occur in zones which do not correspond to true toxin-antitoxin neutralization. In order to overcome the difficulty presented by false zones of flocculation a number of solutions have been proposed.
In 1937 Ramon (2) reported that he had prepared a serum which flocculated in a single zone. This was accomplished by rapidly immunizing horses with the filtrate from broth cultures of tetanus which had been incubated for only a few days.
Prévot (3) claimed that true and false flocculation could be distinguished by a method based on graphic representation.
Studies on Plague Immunity in Experimental Animals
Authors: Jawetz E. , Meyer K. F. 
Published: January 2023

Abstract
Introduction. Comparatively few and limited observations have been made concerning the immunity mechanism in bubonic plague. Exhaustive reviews of the earlier literature on the subject have been given by Dieudonné and Otto (1). Petrie (2) and Pollitzer (3). The earliest investigators, Kolle and his associates (4) and Markl (5), studied particularly the influence of normal and immune serum inoculated simultaneously with the infecting plague bacilli into experimental animals and found bacteriolysis or phagocytosis or both. While these workers investigated the mechanism of passive immunity, Rowland (6) compared the progress of plague infection in normal and vaccinated animals and observed that the essential factor in active plague immunity was one which affected the rate of multiplication of the bacillus. Virulent bacilli multiplied as slowly in immune rats as avirulent organisms in normal ones, while the virulent infection of normal animals progressed very rapidly.
Immunologic Studies in Rheumatic Fever
Authors: Taran Leo M. , Jablon James M. , Weyr Helen N. 
Published: January 2023

Summary
Cutaneous reaction to the M fraction of 25 known Griffith types of hemolytic streptococcus was studied in rheumatic children, their normal siblings, and normal children. The incidence of positive cutaneous reaction in normal children is 65 per cent as compared with 83 per cent in rheumatic children.5 The incidence of positive cutaneous reaction in the normal siblings of these rheumatic children is the same as in rheumatic children. The cutaneous reactions of normal children are of a significantly milder degree than those of rheumatic children and their siblings; the highest degree of reactivity was found in the normal siblings of rheumatic children. The incidence and the degree of cutaneous reaction to the M fraction of the hemolytic streptococcus is not influenced by the age of the child, between the ages of 6 and 16, or by the rheumatic status: active cases do not show a higher incidence or degree of cutaneous reactivity. Cutaneous reactivity to specific M fraction in rheumatic children diminishes only slightly with the lapse of time following an acute rheumatic episode.
The Anticomplementary Activity of Serum Gamma Globulin
Authors: Davis Bernard D. , Kabat Elvin A. , Harris Ad , Moore Dan H. 
Published: January 2023

Summary
Electrophoretically separated gamma globulin from a number of normal human sera was highly anticomplementary, as little as 0.04 mg of protein giving complete inhibition of hemolysis under the conditions used. Purified Wassermann antibody, prepared by dissociation of the specific precipitate, was anticomplementary in similar amounts.
The anticomplementary action was decreased by heating at 56 C for ½ hour, and was abolished by addition of approximately equal amounts of albumin or beta globulin.
It is suggested that the data offer the first evidence of an easily dissociable compound between complement and antibody, postulated by Heidelberger, Weil, and Treffers in their theory of the mechanism of complement fixation.
Failure to Sensitize Guinea Pigs Passively with Equine Antisera That Fix Guinea-Pig Complement
Authors: Follensby Edna M. , Hooker Sanford B. 
Published: January 2023

Summary
Equine anti-ovalbumin and equine antihemocyanin, both capable of fixing guinea-pig complement, did not sensitize guinea pigs passively, or did so but feebly. Equine antihemocyanin did not confer passive anaphylaxis in the rabbit so that fatal shock occurred. Rabbits' blood was not passively sensitized in vitro by either equine or rabbit-antihemocyanin. An increase of histamine was not found in the blood of guinea pigs sensitized with equine antihemocyanin. An increase of histamine was found in the blood of some guinea pigs sensitized with rabbit-antihemocyanin. The blood of some guinea pigs sensitized with rabbit-antihemocyanin contained a skin-blanching substance. Guinea-pig antihemocyanin caused a positive Prausnitz-Küstner reaction in the guinea pig's skin but not in the human skin. Digested equine antihemocyanin evoked the Arthus reaction in rabbits that had been immunized with this material. The Arthus reaction to normal horse-serum was more marked than the reaction to digested material. The probable and actual mathematical relationships between the antibody in the sensitizing dose and the antigen in the shocking dose have been discussed, and, also, the bearing of such relationships upon the problem of passively sensitizing guinea pigs with equine antisera.
Studies on the Technic of Collodion Agglutination
Authors: Cavelti Philip A. 
Published: January 2023

Summary
Studies with regard to the influence of several factors on the sensitivity and specificity of serological reactions with collodion particles have been reported. The size and age of the particles, as well as the proportions of admixture of antigen and collodion to serum, have been found to be important for the optimal performance of the reactions.
Neutralization Tests with Certain Neurotropic Viruses
Authors: Lennette Edwin H. , Koprowski Hilary 
Published: January 2023

Abstract
The relative lack of sensitivity of intracerebral virus-neutralization tests in mice, and their consequent limitations when applied to the investigation of certain epidemiologic or immunologic problems, is generally recognized.
Inasmuch as the ability to detect or quantitate neutralizing antibodies in a serum is largely determined by the route by which the serum-virus mixtures are injected into the animal,3 it would appear that a more sensitive test might be achieved by inoculating the mixtures by a route other than the cerebral. In order to do so, however, mice of known age must be employed, as susceptibility to peripheral inoculation, unlike that to cerebral inoculation, usually diminishes markedly with increasing age.