bluuebunny/crossref_metadata_2025_split huggingface dataset:
STUDIES ON A PROTEOLYTIC ENZYME IN HUMAN PLASMA
Authors: Ratnoff Oscar D. 
Published: June 2004

1. Some conditions for the optimal activation of plasma proteolytic enzyme by chloroform have been described. The activation proceeds slowly. The action of chloroform is probably to remove some substance which inhibits or inactivates the plasma proteolytic enzyme preparation, rather than a direct activation of the enzyme.
2. Plasma proteolytic enzyme is activated by filtrates of cultures of beta hemolytic streptococci. When streptococcal fibrinolysin is present in maximally effective amounts, the activation is almost instantaneous. When the globulin is prepared from heated serum or the globulin is treated with chloroform, the activation of enzyme by streptococcal fibrinolysin appears to be catalytic. If the globulin is not so treated, the reaction appears to involve a stoichiometric process.
3. The plasma proteolytic enzyme activated by chloroform or by streptococcal fibrinolysin digests casein in direct proportion to the concentration of enzyme and to the time of digestion, during the early period of incubation.
4. Fibrinolysin-activated enzyme deteriorates rapidly relative to chloroform-activated enzyme. This may be due to the removal by chloroform of some substance which inactivates plasma proteolytic enzyme.
PROTEIN METABOLISM AND EXCHANGE AS INFLUENCED BY CONSTRICTION OF THE VENA CAVA
Authors: McKee Frank W. , Schloerb Paul R. , Schilling John A. , Tishkoff Garson H. , Whipple George H. 
Published: June 2004

Constriction of inferior vena cava above the diaphragm is used to produce experimental ascites in the dog.
This type of experimental ascites drains the body protein reserves, reduces the level of circulating plasma proteins, and in effect is an internal plasmapheresis.
As the ascitic fluid is withdrawn and the proteins measured, we observe a production of ascitic protein (80–90 gm. per week) comparable to that removed by plasmapheresis (bleeding and replacement of red cells in saline).
High protein diet tends to decrease the ascites but the protein content of the ascitic fluid may increase.
Sodium chloride increases notably the volume of the ascites which accumulates and the total ascitic protein output increases. Sodium-free salt mixtures have a negative influence.
High protein diet low in sodium salts gives minimal ascitic accumulation under these conditions.
The question of circulation of the ascitic fluid is raised—how rapid is the absorption and the related accumulation?
VARIATION OCCURRING IN GROUP A STREPTOCOCCI DURING HUMAN INFECTION
Authors: Rothbard Sidney , Watson Robert F. 
Published: June 2004

A study was made of the variation occurring in group A streptococci during the natural course of infection in man. From 54 patients with 56 different group A streptococcal infections of the upper respiratory tract, 251 strains of streptococci, isolated at weekly intervals following infection, were tested for their capacity to resist the bacteriostatic action of normal human blood. In 52 of the infections the streptococci were of recognized serological types and were also tested for variation in their ability to produce the type-specific M protein antigen. Strains isolated in the 1st week of infection were uniformly highly resistant to bacteriostasis and elaborated large amounts of M substance. In 42 per cent of the 52 infections, strains isolated in the convalescent and carrier stages showed an increasing susceptibility to bacteriostasis correlated with a progressive loss of M substance; whereas in the remaining 58 per cent resistance to bacteriostasis and the capacity to produce M protein were maintained throughout the observation period.
In 3 different infections, the streptococci became so degraded that no M protein could be demonstrated in acid extracts of these variants. Concomitantly these strains became highly susceptible to bacteriostasis. Spontaneous reversion did not occur, but serial mouse passage reestablished these functions. These degraded variants had the same T antigen as their respective original strains.
No evidence was obtained that variation of group A streptococci in resistance to bacteriostasis or in the ability to produce the type-specific M antigen was associated (a) with the appearance of type-specific bacteriostatic antibodies; (b) with any particular serological type of streptococcus; (c) with the production of streptococcal proteinase which digests the M protein; (d) with the therapeutic administration of sulfadiazine; or (e) with the development of complications.
The possible relationship of these observations to the problem of the "dangerous carrier" of group A hemolytic streptococci is discussed.
THE OCCURRENCE OF NUCLEASES IN CULTURE FILTRATES OF GROUP A HEMOLYTIC STREPTOCOCCI
Authors: McCarty Maclyn 
Published: June 2004

1. All of the thirty-six strains of group A hemolytic streptococci tested were found to elaborate ribonuclease and desoxyribonuclease during growth in liquid cultures. Both enzymes are released into the medium.
2. Desoxyribonuclease is consistently produced in greater amount than ribonuclease. The concentration of desoxyribonuclease in the culture increases logarithmically during active growth of the organisms.
3. Under the conditions employed, the presence of specific substrate or enzymatic split products of the substrate did not influence the production of either nuclease.
4. The failure of viscous desoxyribonucleic acid to serve as a source of the purine growth factor required by certain strains of group A streptococci was shown not to be referable to the inability of these strains to form desoxyribonuclease.
5. The determination of nuclease activity provides another criterion for evaluating purification procedures used in the attempted isolation of substances such as streptokinase and proteinase from the supernates of streptococcal cultures.
SPECIFIC SERUM AGGLUTINATION OF ERYTHROCYTES SENSITIZED WITH EXTRACTS OF TUBERCLE BACILLI
Authors: Middlebrook Gardner , Dubos René J. 
Published: June 2004

A hemagglutination reaction has been described between sheep erythrocytes treated with a component of a polysaccharide fraction of mammalian tubercle bacilli and the sera of experimental animals or of tuberculous patients.
Evidence has been presented for the specificity of this reaction. A modification of the test, involving an inhibition reaction, has been developed for the detection and quantitation of minute amounts of the material responsible for the hemagglutination reaction.
EXPERIMENTAL SERUM DISEASE
Authors: Ehrich W. E. , Seifter Joseph , Forman Carolyn 
Published: June 2004

The intravenous injection of one large dose of serum into rabbits caused a variety of changes of considerable complexity.
1. There was an immediate proliferation of mesenchymal cells, including plasma cells, particularly in heart, lungs, and spleen.
2. The signs of serum disease developed only at the time of abundant antibody formation, before significant quantities of antibody were laid down in the vascular connective tissue.
3. Allergic arteritis, marked glomerular nephritis, myocardial necrosis, and Aschoff body-like structures were seen only after hypersensitivity had developed. It appears that most, if not all, of these pathological alterations were true Arthus phenomena.
4. There were at least two distinct varieties of allergic arteritis and glomerular nephritis, namely a proliferative one, following the first injection, and a a necrotizing one, seen only after 2 injections. It appears that the first was a subacute Arthus phenomenon, while the latter was an acute Arthus phenomenon superimposed on a subacute one. The subacute experimental glomerular nephritis resembled the intracapillary glomerulonephritis in man, while the acute variety was like human extracapillary glomerular nephritis.
AN ELECTRON MICROSCOPE STUDY OF SALIVARY GLAND CHROMOSOMES BY THE REPLICA METHOD
Authors: Palay Sanford L. , Claude Albert 
Published: June 2004

A method for preparing replicas of salivary gland chromosomes for electron microscopy is described.
Electron micrographs of these replicas show that the giant chromosomes are composed of a series of small granules of approximately equal size arranged transversely across the chromosome.
In stretched preparations a linear network of filaments appears between the rows of granules. These fibers cannot be traced between corresponding granules of more than two consecutive rows. When the chromosomes are digested by desoxyribonuclease, these fibers disappear and only amorphous material remains between the bands. The characteristics of the strands suggest that they are artifacts produced when the chromosomes are stretched.
The small granules are composed of desoxyribonucleic acid and at least one other component, probably a protein. The nucleic acid seems to lie at least in part on the surface of each granule.
EFFECTS OF PROTEINURIA ON THE KIDNEY
Authors: Baxter James H. , Cotzias George C. 
Published: June 2004

Repeated intraperitoneal injections twice daily of various proteins into young rats were regularly accompanied by an increase in the protein content of the urine, significant renal enlargement, and often some degree of renal pallor. The most marked changes were induced by gelatin, followed in order by human albumin and bovine globulin. Rat serum produced similar but less conclusive changes. Similar changes were not produced by equivalent amounts of urea or casein hydrolysate.
In sections from the kidneys of animals receiving gelatin, the cells of the convoluted tubules appeared enlarged, and they contained clear "spaces" throughout the cytoplasm. The tubular cells of the animals receiving the other solutions were not obviously altered in size or shape, and the cytoplasmic changes were slight or absent. There was little evidence of increased multiplication of cells or of tubular dilatation in the kidneys of any of the groups.
Changes in concentrations of plasma proteins and hemoglobin, and the results of preliminary studies of the injected proteins in urine and renal tissue following the injections, are described and their possible significance discussed.
It appears that the renal enlargement, as well as the increase in proteinuria and the tubular alterations which followed the protein injections, might have been caused in part by effects on the kidney of protein molecules per se, perhaps most likely by the effects on the tubular cells of an increased amount of protein filtered through the glomerular membranes, rather than entirely by effects of products of protein digestion and metabolism reaching the kidney through the blood stream.
In the majority of animals there was no evidence from the morphological or functional studies, that the prolonged and continuous proteinuria induced by the protein injections resulted in renal damage, unless the renal enlargement, and the cytoplasmic changes which occurred regularly with gelatin, are considered evidence of damage. Renal enlargement and proteinuria promptly regressed after injections were discontinued.
Lesions characterized by severe degrees of tubular damage, possibly as a result of tubular plugging, were observed in some of the animals of one group receiving gelatin solution of the usual concentration, and dilatation of renal tubules and glomerular capsules was present in some other gelatin-treated animals autopsied after relatively brief injection periods. A description is also presented of lesions of remarkable character which developed in the kidneys of all the animals of one small group receiving homologous serum obtained from severely anoxic donors.
The possible relationship between the renal changes in the protein-injected animals and certain alterations of the kidneys observed in diseases characterized by large amounts of protein in the urine, is considered.
THE STRUCTURE OF ELASTIC TISSUE AS STUDIED WITH THE ELECTRON MICROSCOPE
Authors: Gross Jerome 
Published: June 2004

Electron microscope examination of fragmented elastic tissue obtained from fish swim bladder, bovine ligamentum nuchae, and aortas of various mammals, including man, reveals characteristically formed fibers and much amorphous material. Boiling in dilute acid destroys the associated collagen but does not obviously alter the elastic tissue.
Digestion in crystalline trypsin of either boiled or unheated tissue from any of the above-mentioned sources causes the release of thin threads ranging in length from 0.1 µ to many microns. A large proportion of these threads are evenly and tightly coiled double helices formed from at least two interlacing filaments and measuring about 120 A in width. The distance between coils ranges from about 470 to 590 A. The individual smooth filaments, many of which are present in parallel pairs, measure approximately 70 A in width.
Raising the pH of a neutral suspension of threads from ligamentum nuchae lowers the ratio of helical threads to uncoiled filaments, whereas lowering the pH with acetic acid results in clumping of threads with complete loss of identity at about pH 3.6.
Threads and filaments obtained from all sources studied were destroyed in the temperature range 75–85°C. at pH 7.
It is concluded that the elastic fiber is a two component system composed of bundles of trypsin-resistant threads of characteristic form and size plus a trypsin-sensitive, heat-resistant "amorphous" binding matrix.
The possible relationship of this structure to the elastic properties of the tissue is discussed.
STUDIES ON HOST-VIRUS INTERACTIONS IN THE CHICK EMBRYO-INFLUENZA VIRUS SYSTEM
Authors: Henle Werner , Henle Gertrude 
Published: June 2004

In agreement with earlier observations the infectivity titer in the allantoic fluids of chick embryos injected with influenza A virus remains constant for 5 to 6 hours before an increase in this activity can be noted. In contrast, the titers of hemagglutinin and complement-fixing antigen (virus antigen) have already begun to rise after 3 hours. The origin of the hemagglutinating and complement-fixing but non-infectious material is still obscure.
In the allantoic membrane development of both the soluble and virus antigens can be demonstrated after the 2nd hour of incubation and 1 hour prior to an increase in hemagglutinins and 2 hours prior to a rise in infectivity. Thus there remain the first 2 hours during which no record of virus activity in the tissues can be obtained.
Similar relationships are noted on dilution of the seed both in the allantoic fluids and membranes as long as the various properties reach measurable levels during the experimental period of one infectious cycle.
Injection of high titered immune serum following infection with about 109 ID50 reduces the amount of demonstrable seed virus in the allantoic fluid and membrane without significantly affecting propagation of the agent in the tissues as measured by infectivity titrations. The production of hemagglutinins appears markedly reduced under these conditions whereas formation of complement-fixing antigen is only slightly delayed and decreased.
No definite explanations for the various discrepancies between the infectivity and hemagglutination can be given at present.
A MURINE VIRUS (JHM) CAUSING DISSEMINATED ENCEPHALOMYELITIS WITH EXTENSIVE DESTRUCTION OF MYELIN
Authors: Cheever F. Sargent , Daniels Joan B. , Pappenheimer Alwin M. , Bailey Orville T. 
Published: June 2004

The isolation of a murine virus causing disseminated encephalomyelitis accompanied by extensive destruction of myelin in the central nervous system, and focal necrosis of the liver has been described.
Young mice can be infected by a number of parenteral routes. Both encephalitic and paralytic signs can be observed. After intracerebral inoculation the virus has been isolated from brain, spinal cord, liver, lung, spleen, and kidney, but not from blood or from intestinal walls and contents.
Hamsters, cotton rats, and Hisaw rats can be infected by the intracerebral route. Guinea pigs and rabbits appear to be insusceptible. Attempts to infect chick embryos have so far met with failure.
Under proper conditions the agent can pass through the usual bacterial filters. No inclusion bodies have been seen. No serological relationship to other neurotropic viruses has been demonstrated as yet.
SEQUENCES IN THE FORMATION OF CLOTS FROM PURIFIED BOVINE FIBRINOGEN AND THROMBIN: A STUDY WITH THE ELECTRON MICROSCOPE
Authors: Porter Keith R. , Hawn Clinton Van Zandt 
Published: June 2004

The observed sequences in the formation of clots from purified bovine fibrinogen and thrombin are described. Under the conditions of these experiments, it appears that fibrinogen molecules are polymerized by the action of thrombin to form needle-shaped, crystal-like protofibrils which then become aligned into fiber strands by lateral association. The integrity of the unit fibrils is maintained within the strand.
A model of the fibrinogen molecule is proposed which may satisfy the reported physical constants, data from x-ray diffraction studies, and observations made upon electron micrographs.
AN ELECTRON MICROSCOPE ANALYSIS OF NERVES INFECTED WITH THE B VIRUS
Authors: De Robertis E. 
Published: June 2004

Rabbits were infected with B virus in the right gastrocnemius muscle and both sciatic nerves were fixed and analyzed under the electron microscope, after periods varying between 26 and 144 hours.
Starting at 72 hours, a few neurotubules of the right sciatic show the presence of spherical particles, ranging between 300 and 600 Å. The number and size of the particles increase with time and appear to reach a maximum at 144 hours when the paralysis starts. At this moment also the proximal part of the left sciatic nerve shows the presence of dense particles. The relation of the particles with the periodic structure of the neurotubules was studied both in preparations stained in phosphotungstic acid and those shadowed with chromium. The small and medium sized particles are located within the edges of the neurotubules, and the large particles appear to be attached to the neurotubules.
The possible significance of the dense particles is discussed.
HEMOGLOBIN LABELED BY RADIOACTIVE LYSINE
Authors: Bale W. F. , Yuile C. L. , DeLaVergne L. , Miller L. L. , Whipple G. H. 
Published: June 2004

A dog, doubly depleted of blood cells and plasma proteins, was fed dl-lysine labeled with C14 in the epsilon carbon position. In the first 8 hours 28 per cent of the administered C14 was excreted in the urine; in the first 72 hours, 35 per cent.
Twenty-four hours after feeding, 4.2 per cent of the fed C14 was circulating in the plasma, decreasing to 1 per cent at the end of 17 days. The C14 content of the blood cells increased from 1 per cent at 24 hours to 5.5 per cent in 5 days and 6.8 per cent in 22 days.
Evidence based on the rate of decrease of the C14 content of circulating blood cells is presented indicating an average life of 115 days for the erythrocyte protein as an entity not interchanging with extracellular constituents. This corresponds closely to the life span of the dog erythrocyte, 112 to 133 days according to the best evidence otherwise available and indicates that this experiment has actually measured the life span of the dog erythrocyte.
Following breakdown of blood erythrocytes the protein comprising them is not used preferentially for the formation of new erythrocytes.
THE PRODUCTION OF FEVER BY INFLUENZAL VIRUSES
Authors: Wagner Robert R. , Bennett Ivan L. , LeQuire Virgil S. 
Published: June 2004

The intravenous injection of the PR8 strain of influenza A virus, the Lee strain of influenza B, and the "B" strain of Newcastle disease virus produces fever in rabbits. This phenomenon has been studied in relation to certain in vitro properties of these viruses.
Saline suspensions of virus prepared by centrifugation or elution from chicken erythrocytes produced fever. Fluids from which most of the virus particles had been removed were non-pyrogenic.
Exposure to temperatures which destroyed the infectivity of the virus for chick embryos did not prevent fever. However, heating sufficient to destroy the hemagglutinin also rendered virus non-pyrogenic.
The injection of erythrocytes onto which virus had been adsorbed produced fever. Heated virus adsorbed onto erythrocytes, which failed to elute, produced no elevation of temperature, although heated virus alone was pyrogenic.
Neutralization of virus with specific immune serum prevented fever.
Antipyrine was capable of abolishing the febrile response to virus.
Certain differences between the febrile response in rabbits to the injection of viruses and that following bacterial pyrogens were noted. The period between injection and beginning of temperature rise is longer with virus than with bacterial pyrogens. Relatively low temperatures inactivate the fever-producing capacity of viruses, whereas bacterial pyrogens withstand prolonged autoclaving, and the neutralization of viral fever by specific immune serum contrasts sharply with the failure of antibody to affect the response to bacterial pyrogens.
Certain previous observations on the lymphopenia produced in rabbits by the injection of influenzal viruses were confirmed. The capacity of virus preparations to induce fever in rabbits closely parallels their capacity to induce lymphopenia.
It was concluded that the fever-producing property of influenzal viruses is closely associated with the capacity to agglutinate erythrocytes.
FORMATION OF A BACTERIAL TOXIN (STREPTOLYSIN S) BY RESTING CELLS
Authors: Bernheimer Alan W. 
Published: June 2004

The interaction of washed cocci, prepared under specified conditions, and a polynucleotide (AF) results in the formation of streptolysin S provided a fermentable carbohydrate is present. Maximum toxin formation requires, in addition, the presence of magnesium, potassium, and phosphate ions. Streptolysin S production proceeds anaerobically as well as aerobically but under the latter condition, apparently only if the system is sufficiently reducing. Temperature has a marked effect on the rate of appearance of toxin, the critical thermal increment having a value of approximately 36,000. The formation of streptolysin S is inhibited by mercuric ion, arsenite, iodoacetate, dinitrophenol, azide, and other enzyme poisons. The development of streptolysin S in resting cell systems depends neither upon autolysis nor upon physical extraction of preformed toxin but upon toxin synthesis.
From the supernatant fluid of the resting cell system, a product containing 20,000 to 30,000 units of streptolysin S per mg. dry weight can be isolated. Information concerning the pH stability of the product is presented. The product is free of streptokinase, hyaluronidase, and proteinase, but possesses appreciable desoxyribonuclease activity. Chemical analyses and other findings indicate that polynucleotide and carbohydrate are present in major amount, and that a small but undetermined quantity of protein is present. Inactivation of streptolysin S by chymotrypsin, ficin, papain, or cathepsin, and not by a variety of other enzymes, indicates that protein is essential for activity, but the precise chemical composition of the toxin remains to be established.