bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARISONS OF INFLUENZA VIRUS STRAINS FROM THREE EPIDEMICS
Authors: Hirst George K.
Published: June 2004

Some of the peculiarities of strains of influenza A and B virus from two epidemics have been described. The influenza B virus of 1945–46, when compared with influenza A virus, proved to be much more difficult to isolate from human sources by any known means. Its adaptation to the chick embryo (by any route) or to mice was much slower than that of A virus. It did not keep nearly as well on storage at –72°C. either in throat garglings or as passage material. Its adaptation to amniotic growth was usually much better than to allantoic growth even after repeated allantoic passages. It failed to show primary evidence of occurring in the O form, although many of the secondary O characteristics were present and persisted. Its titer in throat washings was not demonstrably high as compared with certain strains of A virus, which were demonstrated in garglings at dilutions of 10–5 and 10–6.

The antigenic patterns of influenza A strains from two epidemics were compared. No antigenic differences of significant degree were found among the strains of either epidemic and the difference between the strains of the two epidemics was very slight. A similar study was made of the influenza B strains of the epidemic of 1945–46. This also showed complete lack of significant strain differences. The implications of these findings for influenza prophylaxis are discussed.
THE EFFECT OF SULFHYDRYL GROUPS ON PNEUMONIA VIRUS OF MICE (PVM)
Authors: Volkert Mogens , Horsfall Frank L.
Published: June 2004

Evidence is presented which indicates that PVM is affected adversely in concentrated lung tissue suspensions or in the presence of glutathione. Because iodoacetamide inhibits or eliminates these effects in a similar manner, it is concluded that sulfhydryl groups are essential to their development.
THE DEMONSTRATION OF ONE-STEP GROWTH CURVES OF INFLUENZA VIRUSES THROUGH THE BLOCKING EFFECT OF IRRADIATED VIRUS ON FURTHER INFECTION
Authors: Henle Werner , Henle Gertrude , Rosenberg Evelyn B.
Published: June 2004

After allantoic injection of chick embryos with a known amount of influenza virus, the process of adsorption of the agent onto host cells and infection of them can be interrupted at a given time by the administration of large quantities of heterologous virus inactivated by irradiation. A sudden great increase in the amount of free virus in the allantoic fluid occurring after 6 hours in the case of the PR8 strain, and 9 hours in that of the Lee strain, indicates that the untreated virus associated with the host cells has multiplied. The length of the period preliminary to this increase remains the same even though the concentration of the original inoculum is varied over a wide range. Since administration of the irradiated virus leaves no susceptible host cells, because of the interference phenomenon, and further adsorption of active virus is minimized or entirely prevented, practically the entire new increment of virus can be found in the allantoic fluid and assayed; for every ID50 adsorbed about 50 ID50 are released. Homologous irradiated virus, on the other hand, when injected after infection of the allantoic sac, reduces the yield of virus to a more or less considerable extent. Some inhibitory effect can still be observed when the homologous irradiated virus is given several hours after infection. This effect is linked to the virus particle and destroyed by prolonged irradiation.
PREPARATION OF HEMOGLOBIN SOLUTIONS FOR INTRAVENOUS INFUSION
Authors: Hamilton Paul B. , Farr Lee E. , Hiller Alma , Van Slyke Donald D.
Published: June 2004

A procedure has been detailed for the preparation of sterile non-pyrogenic solutions of oxyhemoglobin which have the approximate protein content and electrolyte composition of plasma.

Large volumes of solution can be rapidly prepared, with 95 to 98 per cent of the hemoglobin in the active form capable of combining with oxygen. The solutions contain no particulate matter; 95 per cent of total blood lipids are removed.

Solutions stored at 4°C. showed no conversion of hemoglobin to methemoglobin over a period of 2½ months; over a 6 month period a small and variable amount of methemoglobin may be formed.
STUDIES ON ENDEMIC PNEUMONIA OF THE ALBINO RAT
Authors: Nelson John B.
Published: June 2004

An attempt was made to reestablish the virus-like agent associated with rat pneumonia by the nasal instillation of the infectious material into supposedly normal young rats from the selected Princeton colony. The incidence of the pneumonia in these animals after the injection of suspensions of pneumonic lungs from either rats or mice was not significantly greater than the incidence under natural conditions.

In attempting to account for the refractory state of the immature rats it was found that the agent was widely dispersed through the breeding colony at an early age. Detailed tests of many litters indicated that the agent was acquired shortly after birth by way of the upper air passages as the result of maternal contact. In most instances it was so well tolerated by young rats during the suckling period and for several months thereafter that its presence was recognized only by nasal transfer to mice.

There is every indication that the rate of infection of rats in the breeding colony approaches 100 per cent by the time the animals are old enough to be used experimentally.
STUDIES ON PLANT HYPERTENSINASE
Authors: Gollan Frank , Richardson Evelyn , Goldblatt Harry
Published: June 2004

Many plants contain an enzyme similar in most biological properties to the hypertensinase obtained from blood and some animal tissues, notably kidney and intestinal mucosa.

Wheat bran is a rich source of the plant hypertensinase, and from it a potent, non-toxic preparation was made by the use of isoelectric and ammonium sulfate precipitation as the means of purification.

Hypertensinase derived from bran and administered intramuscularly was not absorbed, or was absorbed only very slowly, into the blood plasma.

Repeated intramuscular injection of large quantities of plant hypertensinase did not reduce the blood pressure of dogs with experimental renal hypertension.

The intravenous injection of large quantities of plant hypertensinase into dogs resulted in an immediate increase in the content of hypertensinase in the plasma.

Dogs with a high hypertensinase level in the plasma failed to react, or reacted much less markedly to the intravenous injection of amounts of renin or hypertensin which had previously proved effective.

The slow intravenous injection of plant hypertensinase into a dog with experimental renal hypertension reduced the blood pressure to the normal level for the period during which the concentration of plant hypertensinase in the blood was considerably elevated. After the return of the hypertensinase of the plasma to normal, the blood pressure rose again to its previously high level.

Inactivated plant hypertensinase did not increase the hypertensinase content of the plasma, did not interfere with the action of renin and hypertensin, and did not reduce the high blood pressure of dogs with experimental renal hypertension.

In a dog with an increased level of plasma hypertensinase, the pressor substance hypertensin could still be detected in the systemic blood immediately after the intravenous injection of renin in an amount to which the animal responded with only a slight rise in blood pressure.
STUDIES IN THE RELATION OF THE HEMOLYTIC STREPTOCOCCUS TO RHEUMATIC FEVER
Authors: Harris T. N.
Published: June 2004

After disintegration by sonic vibrations the contents of the hemolytic streptococcus can be separated by differential centrifugation into three fractions: an insoluble residue, cytoplasmic particles, and a solution of proteins of smaller unit size.

The residue (R) presumably comprises the cell walls of the bacteria and contains the type-specific M protein. The cytoplasmic particles (CP) contain some lipoid, the group-specific carbohydrate, and nucleoprotein of the ribose type. The supernate fraction (S) contains two components, presumably protein, at least one of which is part of a dissociable nucleoprotein of the desoxyribose type.

Both CP and S precipitate and fix complement with antistreptococcal sera. Both give rise to antibodies on injection into rabbits. Both are of broad reactivity. CP and S can be shown to be serologically distinct by several means, including cross-absorption tests.

On continued disintegration of the organism an inverse relation is noted between the yield of R and that of CP, whereas the yield of S is constant.

A theory as to the structure of the streptococcal cell is offered in terms of the data presented.
HEPARINEMIA (?)
Authors: Allen J. Garrott , Sanderson Margaret , Milham Mary , Kirschon Alice , Jacobson L. O.
Published: June 2004

When the entire body of dogs was exposed to 450 units of Roentgen irradiation a hemorrhagic syndrome developed which was characterized by thrombo-cytopenia, prolonged clotting and bleeding times, and neutropenia.

The prothrombin time remained normal until about 24 hours before death. The calcium, phosphorus, and magnesium levels were not altered. Fibrinogen was present but syneresis was poor.

Toluidine blue and protamine sulfate, substances which can inhibit the biologic action of heparin, restored the clotting time to normal.

The hemorrhagic state was not materially altered by transfusions, vitamin K, or vitamin C.

Toluidine blue and protamine sulfate were ineffective in the control of hemorrhage produced by dicumarol.

The defect responsible for bleeding after irradiation appeared to be the presence in the circulation of an anticoagulant whose properties, so far as tested, were indistinguishable from those of heparin.
STUDIES ON A PROTEOLYTIC ENZYME IN HUMAN PLASMA
Authors: Ratnoff Oscar D.
Published: June 2004

1. The experiments reported suggest that the plasma proteolytic enzyme activated by streptococcal fibrinolysin is identical with that activated by chloroform.

2. The precursor of this plasma proteolytic enzyme is precipitated with the euglobulin fraction of plasma at pH 5.2.
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?
THE EFFECT OF NITROGEN MUSTARDS ON ENZYMES AND TISSUE METABOLISM
Authors: Barron E. S. Guzman , Bartlett Grant R. , Miller Zelma Baker
Published: June 2004

Nitrogen mustards are powerful inhibitors for choline oxidase, acetylcholine esterase, and choline acetylase, half-inhibition of the first enzyme being produced with concentrations around 1 x 10–6 M; i.e., ten times less than the LD50 values. Acetylcholine esterase and choline acetylase required higher concentrations. This inhibition seems to be due to the structural similarity of the ethylenimonium derivatives with choline and acetylcholine. A list of enzyme systems inhibited by nitrogen mustards is given.
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.
STUDIES ON ACUTE DISSEMINATED ENCEPHALOMYELITIS PRODUCED EXPERIMENTALLY IN RHESUS MONKEYS. III
Authors: Kabat Elvin A. , Wolf Abner , Bezer Ada E.
Published: June 2004

The factor in brain tissue which induces acute disseminated encephalomyelitis, when injected into rhesus monkeys as an emulsion with adjuvants, has been found in human, monkey, rabbit, and chicken brain but is absent from frog and fish brain. It is unaffected by fixation of the brain in formalin, by boiling, and by treatment with ultrasound. It is present in the spinal cord of 3 day old rabbits but does not appear in the rabbit cerebrum until about the 12th day of life; in this respect it parallels the laying down of myelin. Attempts to produce the encephalomyelitis passively with large quantities of serum or of cell exudates, and suspensions of cells from spleen and lymph node from monkeys with encephalomyelitis, were unsuccessful.
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.
RESPIRATION OF TYPHUS RICKETTSIAE
Authors: Bovarnick Marianna R. , Snyder John C.
Published: June 2004

Partially purified suspensions of typhus rickettsiae have been shown to exhibit metabolic activity as evidenced by consumption of oxygen and production of carbon dioxide in the presence of glutamate. Similar activity at a much lower rate occurs in the presence of pyruvate. The rate of oxygen uptake was directly proportional to the concentration of viable rickettsiae, as estimated by their toxicity for mice. Normal yolk sac suspensions prepared in the same manner showed only a very slight oxygen uptake under the same conditions. Glucose was not metabolized by the rickettsial suspensions.
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.
INDUCTION OF CARDIAC LESIONS, CLOSELY RESEMBLING THOSE OF RHEUMATIC FEVER, IN RABBITS FOLLOWING REPEATED SKIN INFECTIONS WITH GROUP A STREPTOCOCCI
Authors: Murphy George E. , Swift Homer F.
Published: June 2004

Cardiac lesions, closely resembling those found in rheumatic fever, have developed in rabbits that sickened following multiple, successive skin infections with several serological types of group A streptococci.
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.
A LABILE COMPONENT OF NORMAL SERUM WHICH COMBINES WITH VARIOUS VIRUSES. NEUTRALIZATION OF INFECTIVITY AND INHIBITION OF HEMAGGLUTINATION BY THE COMPONENT
Authors: Ginsberg Harold S. , Horsfall Frank L.
Published: June 2004

A labile component present in the serum of human beings, guinea pigs, and rabbits neutralizes the infectivity of mumps, Newcastle disease, influenza A and B viruses. The labile component of these sera and of mouse serum also inhibits hemagglutination of chicken RBC by these viruses. The component is inactivated by heating at 56°C. for 30 minutes and upon storage at 4°C. for periods longer than 2 weeks. The virus-neutralizing and hemagglutination-inhibiting properties result from serum component-virus combination in the presence of calcium. The combination is stable, and does not undergo spontaneous dissociation. Partial separation of virus can be brought about by heating mixtures held for 24 hours or by removal of calcium ions with sodium citrate. The labile serum component appears to be distinct from hemolytic complement.
LYMPHATIC CONTRACTILITY
Authors: Smith Ralph O.
Published: June 2004

The most peripheral lymphatic vessels of rats, mice, and guinea pigs were found to possess a spontaneous intermittent contractility. (a) The rate of contraction was shown to be directly proportional to the rate of formation of lymph and contractions were apparently initiated by an increase in intraluminal pressure. (b) Epinephrine and pituitrin caused an increased contractile rate, or lymphatic spasm, whereas novocaine caused cessation of movement and lymphatic dilatation. (c) Section or electric stimulation of femoral and sciatic nerves did not alter the contractile rate of popliteal lymphatics.

This spontaneous lymphatic contractility was not observed in rabbits and dogs although the lymphatic vessels did contract when irritated. Epinephrine, pituitrin, and novocaine produced the same effects as observed in the smaller mammals. Dilatation of lymphatic vessels produced by intradermal injection of fluid, massage, or passive motion was followed by a rapid return of the vessel to normal caliber.

The frequency of valves in lymphatic vessels, the distensibility of the lymphatics, and their ability to return to normal caliber against an increased gradient of pressure are considered to be the essential elements of an intrinsic mechanism contributing to the transport of lymph.
THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES
Authors: Smith William E.
Published: June 2004

The lung tissue of mouse embryos of the C strain proliferates to some extent after implantation in adult hosts of the same breed and rapidly differentiates, forming a parenchyma remarkably like the normal. The grafts persist long. When methylcholanthrene dissolved in olive oil has been introduced with them much more growth of them occurs. The carcinogen induces a pronounced metaplasia of the epithelium of the bronchial tree, and the altered cells are often aggressive, multiplying, invading, and largely replacing the parenchyma about them. So closely do they resemble malignant elements in aspect and behavior that it is frequently difficult to tell whether carcinomatous change is not actually present. Genuine tumors soon arise, multiple benign adenomas sometimes appearing within 3 weeks, and indubitable carcinomas a few weeks later. Not a few of the cancers are of transitional cell type, that is to say are expressive of an intermediate stage in the metaplasia.

Under the influence of methylcholanthrene the cells lining the alveolar spaces of the graft sometimes undergo metaplasia also, with result in stratified squamous epithelium. It follows that there is reason to doubt the current assumption that all squamous cell carcinomas of the lung necessarily arise from the bronchial tree. The findings, taken with others previously reported, make it difficult to suppose, furthermore, that the generality of lung tumors can be due to neoplastic viruses entering the organism in postnatal life and having no broader scope than those thus far discovered.
RECEPTOR DESTRUCTION BY VIRUSES OF THE MUMPS-NDV-INFLUENZA GROUP
Authors: Hirst George K.
Published: June 2004

A strain each of mumps and Newcastle disease virus and five strains of influenza virus were found to be capable of removing all the receptors for this group of viruses from fowl red cells. Five virus strains were tested for their capacity to inactivate the virus hemagglutinin of human plasma and of egg white. In the case of egg white all strains including mumps and Newcastle disease virus inactivated the inhibitor completely, or nearly so. With plasma the influenza strains inactivated the inhibitor completely but mumps and NDV destroyed only that portion of the complex which effected mumps inhibition. The inhibitor for some strains was destroyed more rapidly than that for others and the sequence in which they were destroyed (inhibitor gradient) was similar, regardless of the strain employed. The inhibitor gradient for egg white was very different from that for plasma and these in turn differed significantly from the receptor gradient for fowl red cells.
THE EFFECT OF INJURY BY TOXIC AGENTS UPON OSMOTIC PRESSURE MAINTAINED BY CELLS OF LIVER AND OF KIDNEY
Authors: Opie Eugene L.
Published: June 2004

As shown in a previous paper the cells of the liver and of the kidney maintain an osmotic pressure approximately twice that of blood and of erythrocytes, exceeding this slightly in the case of liver and being slightly less in that of kidney.

When liver cells are injured by chloroform or by carbon tetrachloride the osmotic pressure they maintain falls to the level of the medium that surrounds them but is promptly restored when recovery from the injury, with some regeneration of liver cells, occurs.

When nephrosis is caused by potassium chromate or by chloroform the osmotic pressure maintained by parenchymatous cells of the renal cortex falls to that of the medium about them but returns to its normal level with recovery from the injury.
ASSOCIATION OF A SPECIAL STRAIN OF PLEUROPNEUMONIA-LIKE ORGANISMS WITH CONJUNCTIVITIS IN A MOUSE COLONY
Authors: Nelson John B.
Published: June 2004

An outbreak of conjunctivitis, unaccompanied by involvement of the respiratory tract, is reported in a colony of white mice.

A special strain of pleuropneumonia-like organisms was regularly isolated from the eyes and nasal passages of affected mice but not from the lungs or middle ears.

Ocular carriage of these organisms in the absence of an inflammatory reaction occurred in at least 50 per cent of the adult mice.

Transmission to the young was presumably initiated by parental contact, the organisms being recoverable after the eyes were open, and was continued after weaning by direct contact between cage mates.

These organisms were repeatedly established on the conjunctiva of normal Swiss mice by direct contact with infected animals and subsequently maintained there for ten successive passages.

Multiplication of the pleuropneumonia-like organisms, which was largely limited to the eye and its appendages, was accompanied by a low rate of conjunctivitis.

The multiple conjunctival instillation of ocular washings from infected mice was the only additional method of implantation of the organisms which was successful.
INFLUENZA
Authors: Greiff Donald , Blumenthal Herman T. , Pinkerton Henry
Published: June 2004

Allantoic fluid from embryonated eggs infected with influenza A virus contains a toxic agent which can be demonstrated and quantitatively measured by its rapid effect on oxygen consumption when it is introduced in new series of fertile eggs.

The effects were measured 90 minutes after the injection of the infected fluid, and were seen following both intra-allantoic injection and injection into the yolk sac.

This toxin, in concentrations resulting from the injection of 0.5 cc. or less of the infected fluid, has no effect on oxygen consumption. The injection of 0.75 to 2.0 cc. of the fluid strikingly increases the oxygen consumption of the fertile eggs, while the injection of 3.0 cc. markedly depresses respiration. A similar reversal and eventual loss of the effect of the toxin on respiration were noted when the concentration of toxin was progressively diminished by heat inactivation.

The toxic agent is slowly inactivated by heating at 56°C., but is effective long after infectivity and hemagglutinating ability have been destroyed. In this respect the agent differs from rickettsial and lymphogranuloma venereum virus toxins.

The method described may be of value in studying the physiological effects of other toxic agents.
FACTORS IN PLASMA CONCERNED IN NATURAL RESISTANCE TO AN AVIAN MALARIA PARASITE (PLASMODIUM LOPHURAE)
Authors: Trager William , McGhee R. Barclay
Published: June 2004

The plasma of adult chickens, when injected into young chicks or chick embryos infected with Plasmodium lophurae, lessened the parasitemia. The substances responsible for this effect were inactivated or removed by the heating of adult chicken plasma for ½ hour at 65°C., followed by centrifugation to remove the coagulated material; but they were not affected by heating for ½ hour at 56°C. The active materials were present in the euglobulin fraction of hen plasma.

In similar experiments with ducks, the plasma from each of a series of adult ducks was tested for its effect on the course of infection in young ducklings. The adult ducks were then inoculated with a large dose of parasites. There was a positive correlation between the effectiveness of a plasma in lessening the parasitemia of ducklings treated with it and the resistance on infection exhibited by the duck from which the plasma had been obtained. More than half of the adult female ducks with an active ovary which were tested, but only one of the males, had effective plasmas and also showed relative resistance to the infection.
STUDIES OF THE HEMOLYSIS OF RED BLOOD CELLS BY MUMPS VIRUS
Authors: Chu Liang-Wei , Morgan Herbert R.
Published: June 2004

The conditions for the production of extra-embryonic fluids with hemolytic activity from chick embryos infected with mumps virus have been investigated. Infected fluids with strong hemolytic activity can be obtained by harvesting the fluids of 6- to 8-day-old chick embryos inoculated by the amniotic route after 5 to 6 days' incubation at 35°C. Under such circumstances, the hemolytic capacity of amniotic fluids is usually much higher than that of the allantoic fluids.

The hemolytic activity and infectivity of the virus have been found to be reduced or destroyed by heat, formaldehyde, and ultraviolet irradiation under conditions which leave the hemagglutinating capacity practically unchanged. Ultraviolet irradiation appeared to have a greater deleterious effect on the infectivity of the virus than on its hemolytic capacity. The marked reduction or destruction of hemolytic activity of the virus produced by certain treatments with these various agencies was not accompanied by loss of the ability of the virus to elute following its adsorption on red blood cells during the process of hemagglutination. This test for hemolytic activity, which measures a more labile property of the virus than do determinations of virus hemagglutination or virus elution, may be useful in detecting changes which occur early during degradation of the virus.
CARBOHYDRATE HISTOCHEMISTRY STUDIED BY ACETYLATION TECHNIQUES
Authors: McManus J. F. A. , Cason Jane E.
Published: June 2004

An acetic anhydride pyridine mixture acetylates hydroxyl groups in tissue sections. The acetyl groups can be removed from tissue sections by weak alkali.

Sections acetylated by acetic anhydride pyridine no longer produce aldehydes after oxidation by periodic acid. Acetylated sections subjected to weak alkali regain the ability to produce aldehydes after oxidation by periodic acid. Acetylation of tissue sections and the removal of acetyl groups by weak alkali can be used as histochemical confirmation of the carbohydrate nature of materials coloring with Schiff's reagent after periodic acid.