bluuebunny/crossref_metadata_2025_split huggingface dataset:
STUDIES OF ANTIGENIC DIFFERENCES AMONG STRAINS OF INFLUENZA A BY MEANS OF RED CELL AGGLUTINATION
Authors: Hirst George K. 
Published: June 2004

A study of cross inhibition tests among strains of influenza A virus and their antisera showed that the results obtained were subject to a certain amount of variation due to the red cells, the virus suspensions, and the ferret antisera employed. Methods have been demonstrated for handling the data obtained from such tests, so that these variables were corrected or avoided, making it possible to use the agglutination technique for antigenic comparisons.
The antigenic pattern of eighteen strains of influenza A virus, obtained from the 1940–41 epidemic in the United States, has been compared by means of agglutination inhibition tests with ferret antisera. No significant antigenic differences were found among sixteen of these strains (all isolated from throat washings by the inoculation of chick embryos) although they were obtained from individuals in widely separated regions of the country. Two strains, from cases occurring early in the epidemic and isolated from throat washings by ferret and mouse passage, showed a slight but significant strain difference from the other strains and from each other. One of the 1940–41 strains on cross test resembled the PR8 strain more closely than any other stock strain tested.
LABORATORY TRANSMISSION OF WESTERN EQUINE ENCEPHALOMYELITIS VIRUS BY MOSQUITOES OF THE GENERA CULEX AND CULISETA
Authors: Hammon W. McD. , Reeves W. C. 
Published: June 2004

1. Western equine virus has been successfully transmitted in the laboratory by 3 species of mosquitoes from 2 genera not previously reported as laboratory vectors: Culex tarsalis, Culiseta inornata, and Culiseta incidens.
2. Though transmission was not demonstrated, survival of the virus for more than a few days was shown to occur in Culex stigmatosoma and Psorophora confinnis. Possibly transmission occurred by the former.
3. In experiments with Culex tarsalis, infection of the mosquitoes occurred from feeding on an inoculated guinea pig, a duck, and virus-blood suspensions. After an incubation period of 10 to 30 days at a temperature above 25°C. these mosquitoes infected chickens and a guinea pig by their bite and virus was in turn demonstrated in the blood of the chickens and in the brain of the guinea pig. A total of 12 transmissions occurred. The fact that mosquitoes can be infected from fowl and in turn transmit to fowl, together with much other supporting data from field and laboratory, is interpreted as strengthening evidence that fowl serve as reservoirs of virus in nature.
4. Since Culex tarsalis mosquitoes have been repeatedly found infected with Western equine virus and epidemiologic evidence supports their incrimination, the vector rôle of this species is now established, and it may be regarded as fully incriminated.
5. Culiseta inornata has also been found infected in nature and now proven a laboratory vector. This species does not fit the epidemiological picture in the Yakima Valley as well as C. tarsalis, but may play an important rôle elsewhere.
6. Anopheles maculipennis freeborni and Culex pipiens found naturally infected have not transmitted the virus under laboratory conditions.
FURTHER LABORATORY STUDIES ON THE CLASSIFICATION OF PSITTACOSIS-LIKE AGENTS
Authors: Beck M. Dorthy , Eaton Monroe D. , O'Donnell Rosemary 
Published: June 2004

1. It was demonstrated by pathogenicity and latency tests in mammals and birds that variations exist among a group of viruses, isolated from several sources and producing coccoid elementary bodies resembling those of psittacosis.
2. Active cross immunity tests emphasized these differences and confirmed their significance.
3. On the basis of the present experimental evidence the psittacosis-like viruses causing atypical pneumonia in man may be classified into three groups: psittacosis, ornithosis, and human pneumonitis (strain S-F) of undetermined origin.
STUDIES ON THE ANTIGENIC COMPOSITION OF GROUP A HEMOLYTIC STREPTOCOCCI
Authors: Lancefield Rebecca C. , Stewart Walter A. 
Published: June 2004

1. Group A hemolytic streptococci have been described which do not agglutinate in anti-T serum because they lack T antigen.
2. Other strains occur which contain T antigen yet do not agglutinate in anti-T serum because T agglutination is blocked by the presence of large amounts of M substance in the streptococci.
3. Strains belonging to a number of types have been analyzed to determine their antigenic composition with respect to M and T antigens.
STUDIES ON THE ANTIGENIC COMPOSITION OF GROUP A HEMOLYTIC STREPTOCOCCI
Authors: Watson Robert F. , Lancefield Rebecca C. 
Published: June 2004

1. In this study a series of experiments showing the antigenic relationship of type 10 and type 12 group A hemolytic streptococci is reported. Agglutinin, precipitin, and passive protection tests with unabsorbed and reciprocally absorbed antisera were employed to show that representative type 10 and 12 strains contain serologically identical M antigens but unrelated type-specific T antigens.
2. Twenty-three other strains of group A hemolytic streptococci previously classified as either type 10 or type 12, collected from various sources, were shown to have an antigenic composition similar to one or the other of the two representative type strains.
3. The relationship of the two specific antigens, M and T, must be considered when any method employing the agglutinin reaction for the typing of group A hemolytic streptococci is used.
STUDIES ON THE CHEMICAL NATURE OF THE SUBSTANCE INDUCING TRANSFORMATION OF PNEUMOCOCCAL TYPES
Authors: Avery Oswald T. , MacLeod Colin M. , McCarty Maclyn 
Published: June 2004

1. From Type III pneumococci a biologically active fraction has been isolated in highly purified form which in exceedingly minute amounts is capable under appropriate cultural conditions of inducing the transformation of unencapsulated R variants of Pneumococcus Type II into fully encapsulated cells of the same specific type as that of the heat-killed microorganisms from which the inducing material was recovered.
2. Methods for the isolation and purification of the active transforming material are described.
3. The data obtained by chemical, enzymatic, and serological analyses together with the results of preliminary studies by electrophoresis, ultracentrifugation, and ultraviolet spectroscopy indicate that, within the limits of the methods, the active fraction contains no demonstrable protein, unbound lipid, or serologically reactive polysaccharide and consists principally, if not solely, of a highly polymerized, viscous form of desoxyribonucleic acid.
4. Evidence is presented that the chemically induced alterations in cellular structure and function are predictable, type-specific, and transmissible in series. The various hypotheses that have been advanced concerning the nature of these changes are reviewed.
A VIRUS CAUSING PNEUMONIA IN CATS AND PRODUCING ELEMENTARY BODIES
Authors: Baker James A. 
Published: June 2004

From a contagious respiratory disease of cats an agent has been transmitted to mice, rabbits, guinea pigs, hamsters, and embryonated eggs. When inoculated intranasally into cats, it produces a disease like that seen in the naturally infected animals. Parenteral injection causes only a mild fever. From cats killed during acute illness, the agent was demonstrated regularly in the discharges from the eyes and nose and in the pneumonic lung but not in other organs. The agent can be demonstrated in the nasal mucosa of cats 1 to 2 months after injection.
Cultures of egg yolk sac containing the agent showed no growth, and cultures of active lung suspensions were usually negative, such positive findings as were obtained being due to respiratory contaminants. Attempts to pass the agent through Berkefeld N filters were generally unsuccessful. Stained preparations of egg yolk sac membranes and of infected mouse or hamster lungs showed typical elementary bodies. Centrifuge experiments showed that the agent and the bodies sedimented at the same rate. Complement fixation experiments using a suspension of partially purified bodies as antigen were negative with control sera and positive with sera from recovered cats. It is concluded that the respiratory disease of cats is due to a virus that forms elementary bodies.
THE ACTION OF CRYSTALLINE PROTEOLYTIC ENZYMES ON ANGIOTONIN
Authors: Plentl Albert A. , Page Irvine H. 
Published: June 2004

Angiotonin was subjected to enzymatic digestion by crystalline carboxy-peptidase, chymotrypsin, trypsin, and pepsin. These enzymes were found to destroy it in vitro. Hydrogen ion optima and proteolytic coefficients for these reactions were determined and were found to be of approximately the expected magnitude for typical substrates.
Regarding the purified crystalline enzymes as reagents, the experimental findings were interpreted on the basis of Bergmann's specificity studies. We were thus directed to the conclusion that angiotonin contains (1) a free terminal amino group, (2) a free terminal carboxyl group, (3) one basic amino acid residue which may be terminal but its carboxyl must be united in a peptide linkage, (4) one central dibasic amino acid residue in combination with an aromatic amino acid residue, (5) an aromatic amino acid residue which may be part of (4) and, if not part of (4) must be terminal with its carboxyl group in peptide linkage. The simplest compound satisfying these conditions is tyrosyl-arginylglutamyl-phenylalanine or a combination of amino acids with similar general characteristics.
EXPERIMENTAL EPIDEMIOLOGY OF TUBERCULOSIS
Authors: Lurie Max B. ,   With the Collaboration of Helen Tomlinson and Samuel Abramson
Published: June 2004

1. Ultraviolet irradiation of the air of a room exercises a protective influence against natural air-borne contagion of tuberculosis in rabbits.
2. When the radiant energy is of low intensity it reduces considerably the incidence of tuberculosis.
(a) It completely protects rabbits of high natural resistance from acquiring demonstrable disease though they become tuberculin sensitive.
(b) It fails to protect a small proportion of rabbits of low natural resistance from fatal tuberculosis.
3. When the radiant energy is of high intensity all rabbits, whether of high or of low natural resistance, are almost completely protected from a contagion so severe that it is fatal to the great majority of rabbits of the same genetic constitution not protected by these rays. The protected rabbits do not develop tuberculin sensitivity.
4. The contagion of tuberculosis in these studies is air-borne and the radiant energy exercises its protective influence by its bactericidal properties. It is probable that ultraviolet irradiation may control air-borne contagion of human tuberculosis.
THE RECOVERABILITY OF VIRUS FROM PAPILLOMAS PRODUCED THEREWITH IN DOMESTIC RABBITS
Authors: Friedewald William F. , Kidd John G. 
Published: June 2004

By preliminary preparation of the skin in ways that render it hyperplastic the presence of infective virus can be demonstrated in extracts of domestic rabbit papillomas which yield no growths when inoculated by the ordinary methods and which for this reason have been supposed to contain no virus. The amount of virus recovered by the method outlined in the present work, however, is small when compared with the yield obtained in most instances from comparable cottontail rabbit papillomas. The yield is greatly influenced not only by the virus strain used to produce the growths but by the individual rabbit host. Although virus has been obtained from papillomas produced in domestic rabbits by all of the virus strains tested, a total of 21 thus far, only about one-fourth of these strains are readily to be procured again from the growths they cause and the others are demonstrable only in hosts in which the conditions are favorable for reasons unknown.
An experimental comparison of the capacity of suspensions of papilloma tissue from domestic and cottontail rabbits to elicit specific antibodies has shown that the titers attained are approximately proportional to the amount of infective virus demonstrable in the suspensions. The findings as a whole indicate that far less virus exists in infective or antigenic form in the papillomas of domestic rabbits than in those of cottontail rabbits.
STUDIES ON THE ETIOLOGY OF PRIMARY ATYPICAL PNEUMONIA
Authors: Eaton Monroe D. , Meiklejohn Gordon , van Herick William 
Published: June 2004

1. A filterable virus from certain cases of primary atypical pneumonia was transmitted to chick embryos by inoculation into the amnion of suspensions of bacteriologically sterile lung tissue or filtered sputum, and three strains were adapted by passage.
2. After intranasal inoculation into cotton rats or hamsters, suspensions of the infected chick embryo tissues produced pulmonary lesions which were similar to those seen after instillation of infective human material.
3. The agent propagated in chick embryos was specifically neutralizable by serum from patients recovered from primary atypical pneumonia and was not neutralized by the acute-phase specimens.
4. Passages of the virus in cotton rats and hamsters gave confusing results because of contamination with latent respiratory agents already present in the animals.
THE CONSTITUTION OF MITOCHONDRIA AND MICROSOMES, AND THE DISTRIBUTION OF NUCLEIC ACID IN THE CYTOPLASM OF A LEUKEMIC CELL
Authors: Claude Albert 
Published: June 2004

1. Rat tumor extracts, containing chiefly the cytoplasmic constituents of leukemic cells, were fractionated into three main portions, the different components separating in the centrifuge according to size.
2. Mitochondria were isolated by centrifugation at relatively low speed. Elementary composition of purified mitochondria was found to correspond to about 11.5 per cent nitrogen, 1.6 per cent phosphorus, and 27 per cent lipids. Phosphorus and nitrogen content of the lipid portion suggests that as much as 75 to 80 per cent of the lipids of mitochondria is represented by phospholipids. Tests for ribose nucleic acid were positive.
3. Microsomes were separated by means of centrifugation at 18,000 x g. A relation between the high phosphorus content of the microsomes and the marked basophilia of the cytoplasm of leukemic cells is suggested.
4. Phosphorus distribution in the tumor extract, and light absorption analysis of the third fraction, seem to demonstrate that nucleic acid was not present either in a free condition, or in the form of nucleoprotein of relatively low molecular weight. The nature of the results suggests that ribose nucleic acid occurs in the cytoplasm of leukemic cells only in association with formed elements of relatively large size, namely microsomes, and mitochondria.
EXPERIMENTAL STREPTOBACILLUS MONILIFORMIS ARTHRITIS IN THE CHICK EMBRYO
Authors: Buddingh G. John 
Published: June 2004

1. A strain of Streptobacillus moniliformis isolated from a case of rat bite fever in man has been found to produce infection of the developing chick embryo following inoculation of the chorio-allantois.
2. The disease in embryos is characterized by invasion of the blood stream and an almost exclusive localization of the infectious process to the synovial lining of the joints.
3. In the early stages of the development of the joint lesions the Streptobacillus moniliformis behaves as a facultative intracellular parasite within the cytoplasm of the synovial lining cells. Conditions favorable for the growth of the microorganisms are maintained only temporarily. The infection appears to be self-limiting in nature.
THE HISTOPATHOLOGY OF PROGRESSIVE MUSCULAR DYSTROPHY AS REVEALED BY ULTRAVIOLET PHOTOMICROGRAPHY
Authors: Hoagland Charles L. , Shank Robert E. , Lavin George I. 
Published: June 2004

Results have been presented of the application of a simplified technique of ultraviolet photomicrography to a study of the specific lesions in muscle in subjects with progressive muscular dystrophy. An exact description of the histological changes occurring in this syndrome, as revealed by photomicrographs in ultraviolet light, is difficult at this time because of the lack of an adequate system of nomenclature. Attention has been drawn, however, to lesions of consistent character, found in sections of muscle removed at biopsy, which appear to be specific for the disease.
The method of simplified ultraviolet photomicrography possesses certain marked advantages over those classical methods of histology and pathology which depend on staining and examination of specimens in visible light. Not only is greater resolution achieved with ultraviolet light photomicrography but the image which is obtained in the ultraviolet may provide some idea of the chemical nature of the tissue as well, since it results chiefly from the selective absorption of light by proteins, nucleoproteins, and nucleic acids.
THE INITIATING AND PROMOTING ELEMENTS IN TUMOR PRODUCTION
Authors: Friedewald William F. , Rous Peyton 
Published: June 2004

Benzpyrene brings about neoplastic changes in rabbit epidermis much sooner than has been supposed. The long interval that elapses before visible growths appear is due in the main to the relatively slight power of the carcinogen to encourage multiplication of the cells it renders neoplastic. Yet some slight power of this sort it has. Methylcholanthrene has somewhat more but not nearly so much as tar. It may initiate neoplastic changes within less than 17 days, as compared with less than 10 days for tar, but tumors due to it do not ordinarily appear until months after those called forth by tarring. All three agents give rise to growths of essentially the same kinds, but most of those due to benzpyrene and methlycholanthrene remain for a long while small, dry, and indolent whereas many of the tar tumors are fleshy, vigorous, and rapidly enlarging,—differences wholly consequent on differences in the ability to promote growth. Such ability is an important element in the effectiveness of carcinogens.
Tar and the polycyclic hydrocarbons cause many more cells to become tumor cells than give rise to visible growths. Benzpyrene is as effective in initiating neoplastic changes when dissolved in mineral oil as when in benzene, yet no tumors result from it until months after the benzene solution has given rise to them, the reason being that when in oil it is almost devoid of influence to encourage cell proliferation. Benzene itself has a very slight influence of the sort. Solvents may determine not only whether carcinogens initiate neoplastic change but may condition to a crucial degree the influence of these agents to encourage tumor formation.
Rabbit epidermis is much more responsive to carcinogenic influences than that of the mouse, as measured in terms of time taken to elicit benign neoplasms. Even benzene will call forth these growths from rabbit skin. In appraising the relative responsiveness to carcinogens of various animal species it is essential to reckon in terms of cells of identical type.
PREPARATION OF THE TYPE-SPECIFIC POLYSACCHARIDE OF THE TYPE I MENINGOCOCCUS AND A STUDY OF ITS EFFECTIVENESS AS AN ANTIGEN IN HUMAN BEINGS
Authors: Kabat Elvin A. , Kaiser Hilda , Sikorski Helen 
Published: June 2004

1. Methods for preparing small amounts of Type I meningococcal polysaccharide which are electrophoretically homogeneous and contain only traces of other immunologically reactive material are given.
2. These polysaccharides are very poor antigens in man but in a small number of instances definite amounts of precipitin and protective antibody were formed.
3. The significance of these findings is discussed.
INFLUENCE OF pH AND OF CERTAIN OTHER CONDITIONS ON THE STABILITY OF THE INFECTIVITY AND RED CELL AGGLUTINATING ACTIVITY OF INFLUENZA VIRUS
Authors: Miller Gail Lorenz 
Published: June 2004

A study has been made of the pH stability of centrifugally purified strains of influenza virus with respect to the biological properties of mouse infectivity and chicken red blood cell agglutinating activity. Observations also were made on the importance of composition of buffer, temperature of storage, and concentration of virus protein to the stability of the virus.
When tested for stability at a protein concentration of 0.1 mg. per cc. in phosphate buffer, the infectivity of PR8 virus was found to be most stable at pH 6.5–7; the swine virus, at pH 7–7.9; and the Lee strain, at a pH of 7.9 or higher. The CCA activity of the PR8 virus in phosphate buffer was most stable at pH 7, that of the swine virus at pH 7–8, and that of the Lee virus at a pH greater than 9. Furthermore, the Lee virus was much less stable in dilute solution in phosphate buffer, even under optimum conditions of pH, than either the PR8 or swine strains.
The different strains of influenza virus were found to possess certain characteristics in common. They lost infectivity and CCA activity on the acid side of optimum pH conditions much more rapidly than on the alkaline side. Under suitable conditions of buffer and pH, the infectivity decreased while the CCA activity remained unchanged. In general, the rate of loss in infectivity was greater than the rate of loss in CCA activity.
When tests of stability were carried out at a protein concentration of 0.1 mg. per cc. in a composite phosphate-glycine-NaCl buffer, the virus strains showed less marked differences and possessed much higher stabilities of CCA activity and infectivity than when stored at the same concentration in phosphate buffer alone. Under the modified conditions, all three viruses possessed maximum stabilities of CCA activity and infectivity at pH 7–8 with the exception of the PR8 virus whose infectivity appeared more stable at pH 7 than at pH 8. In detailed experiments with the Lee virus, it was found that the infectivity and CCA activity of this strain at pH 7 and at a protein concentration of 0.1 mg. per cc. were maintained best in the composite phosphate-glycine-NaCl buffer, less well in a buffer containing glycine and NaCl, and least well in phosphate buffer alone.
In tests with PR8 virus, the activity was found to be much more stable at 4° C. than at 23° C.
When stored at a concentration of 2 mg. per cc. at 4° C. in phosphate buffer at pH 7, the PR8 and Lee strains were found to be much more stable than when stored at the concentration of 0.1 mg. per cc. At the higher concentration, no significant losses in either infectivity or CCA activity were observed over a period of 2 months.
IMMUNITY IN MUMPS
Authors: Kane Lewis W. , Enders John F. 
Published: June 2004

1. Fifty-one patients exhibiting signs and symptoms compatible with the clinical syndrome of acute aseptic meningoencephalitis have been studied by means of the complement fixation test for the demonstration of antibody reacting with the virus of mumps or its products.
2. In 17 of these individuals in whom the clinical diagnosis could be made with assurance because of an associated enlargement of the salivary glands, the test yielded evidence of recent infection with the virus.
3. In 16 patients without involvement of the salivary glands the results of the test likewise indicated recent infection with this virus.
4. In the remaining 18 patients the test gave no evidence of a recent infection with the virus.
5. Except for histories of recent exposure obtained from certain of the individuals in whom the complement fixation test was considered to be positive, the characteristics of the disease and the data afforded by the usual laboratory studies failed to distinguish the last 2 groups.
6. On the basis of these findings, it is concluded that the complement fixation test should be of value in the diagnosis of those cases of acute aseptic meningoencephalitis in which the virus of mumps is the etiologic agent and in which involvement of the salivary glands is slight or absent.