bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE EFFECTS ON BIOLOGICAL MATERIALS OF FREEZING AND DRYING BY VACUUM SUBLIMATION
Authors: Greiff Donald , Blumenthal Herman , Chiga Masahiro , Pinkerton Henry 
Published: June 2004

The infectivity titre of influenza virus-infected allantoic fluid was determined after a variety of procedures involving cyclic slow freezing and thawing, freezing at various rates with subsequent storage at different temperatures freezing at various rates with subsequent dehydration at various temperatures, and different degrees of dehydration. All these factors were found to influence the survival rate of the virus particles.
Five freeze-thaw cycles resulted in a fall in titre from 10–8.6 to 10–0.8 cycles 2, 3, and 4 causing much greater losses than cycles 1 and 5. Rapid cooling to –40°C. or slow cooling to –80 or 190°C. did not cause significant titre loss, but rapid cooling to temperatures above –40° or slow cooling to temperatures above –80°C. caused definite titre loss. Loss of titre on storage occurred only at temperatures above –40deg;C.
The effect of lyophilization depends both on the preliminary treatment and on the dehydration temperature. Better conservation of titre was obtained after preliminary cooling to –190 or –80°C. than after preliminary cooling to higher temperatures. The most effective sublimation temperatures were 0 and –80°.; the least effective was +20°C. Titre losses in suspensions sublimated at –10, –30, and –60°C. were in general intermediate. No loss in titre occurred after preliminary cooling to –80 or –190°C. and subsequent dehydration at –80 or 0°C. The degree of dehydration definitely affects the survival of virus on storage at 0°C., but sublimation for 4 hours at 0°C. gave complete protection against titre loss on storage at this temperature.
Possible explanations of the observations made are suggested, based on known physiochemical phenomena such as supercooling, vitrification, variations in size and shape of ice crystals with different freezing speeds, differential enzyme inactivation, changes in salt concentration, and changes in energy levels.
SIGNIFICANCE OF THE HYDROXYL GROUPS OF STEROIDS IN PROMOTING GROWTH
Authors: Huggins Charles , Jensen Elwood V. 
Published: June 2004

The presence of a 17ß-hydroxyl group endows the simple androstane molecule with the ability to produce growth of the uterus, vagina, and prostate of the female hypophysectomized albino rat. It appears that hydrogen atoms at position 17 are of critical importance since related compounds with a ketone group at this site are inactive. Monofunctional steroids with a hydroxyl or a ketone group at position 3 likewise are devoid of activity.
If a phenolic A-ring is present in monofunctional steroids the 17ß-hydroxyl group is not obligatory for growth. Proliferation of the uterus and vagina were found to follow the administration of 17-desoxyestradiol.
STUDIES ON ENTRY AND EGRESS OF POLIOMYELITIC INFECTION
Authors: Faber Harold K. , Dong Luther 
Published: June 2004

At 56, 60, and 72 hours after simple feeding of poliomyelitis virus, typical, discrete lesions were found in the ganglia supplying the mouth and pharynx, which were most numerous and severe in the Gasserian ganglia. Lesions were also found in the nerve bundles adjacent to the infected ganglia.
The character, localizations, and time of appearance of lesions point to nerve-conducted entry of infection from the mucosa of the mouth and pharynx.
The possibility is suggested that under natural conditions of exposure, in which only small amounts of virus are involved, artificially induced immunity, active and probably passive, may block primary neural entry at the oropharyngeal portal by virtue of antibodies in the overlying mucus.
OSMOTIC ACTIVITY OF TISSUES DURING FETAL AND POSTNATAL GROWTH
Authors: Opie Eugene L. 
Published: June 2004

The osmotic pressure maintained by liver tissue of the white rat preceding birth is less than that of the maternal blood serum and shortly after birth approximates this level.
Following birth osmotic pressure of liver tissue, continuing to increase, reaches after about 60 to 90 days the level found in the liver of mature animals and is then isotonic with solutions of sodium chloride with concentration slightly more than twice that isotonic with blood serum.
Osmotic pressure maintained by kidney tissue pursues with growth a similar course but at a lower level and about 35 to 60 days after birth reaches that found in the mature animal being represented by isotonicity with a concentration of sodium chloride slightly less than twice that isotonic with blood serum.
The tissues of the whole fetus are isotonic with sodium chloride solutions less concentrated than that isotonic with the maternal blood serum.
GROWTH CHARACTERISTICS OF POLIOMYELITIS VIRUS IN HELA CELL CULTURES: LACK OF PARALLELISM IN CELLULAR INJURY AND VIRUS INCREASE
Authors: Ackermann W. Wilbur , Rabson Alan , Kurtz Hilda 
Published: June 2004

A detailed study of the cytological changes which are induced in HeLa cells by the Saukett strain of Type III poliomyelitis virus has been made. The observations were of cultures in which a single sequence of infection was induced. The cytological changes were examined in relation to the growth curve of the virus in the same type of culture. This curve showed a latent period of 4 to 5 hours, followed by a gradual release of virus over an interval of 6 to 7 hours. Changes in the staining character of the cells occurred before the major portion of the viral yield appeared. The infected cells exhibited a striking cytopathology with increased basophilia, nuclear pyknosis, and basophilic cytoplasmic granules. Individual cells showed characteristic differences in the rate at which the cytopathology progresses.
The multiplication of the virus in HeLa cells was inhibited by fluorophenylalanine. The inhibitory effectiveness of the antimetabolite was related to the age of the infection. It apparently inhibits only an early stage of viral development. The inhibition is completely reversed by phenylalanine if the amino acid is added within 6 hours, not later, after the induction of virostasis. The data are interpreted in terms of the rate at which the ability of the infected cell to support viral synthesis was lost. Flurophenylalanine also inhibited the multiplication of HeLa cells; however, the effect upon the uninfected cell was reversible after 3 days, as indicated by viability after such treatment.
While the fluoro derivative completely inhibited viral multiplication, it did not prevent the cytopathogenic effect of the virus. In the presence of fluorophenylalanine, the disintegration of an infected cell proceeded at what appeared to be the ordinary rate, without any increase of the infectious agent. Experimentally the processes leading to viral increase and to cellular injury have been shown to possess a significant degree of autonomy.
IMMUNOCHEMICAL STUDIES OF ANTITOXIN PRODUCED IN NORMAL AND ALLERGIC INDIVIDUALS HYPERIMMUNIZED WITH DIPHTHERIA TOXOID
Authors: Kuhns William J. 
Published: June 2004

The method of filter paper electrophoresis was used to study proteins and protein-bound polysaccharides in sera obtained from subjects before and after a single booster dose of diphtheria toxoid, and in sera from allergic subjects.
The electrophoretic patterns of precipitating antitoxic sera resembled those found in normal non-immune sera. However, skin-sensitizing antitoxic sera were distinguished by a relatively large beta globulin component and a small or indistinct alpha2 globulin. Fusion of both components was present in some sera containing this variety of antitoxin. Considerable amounts of serum-bound polysaccharides in these sera migrated relatively slowly in contrast to the behavior of polysaccharides of precipitating antitoxic sera which migrated faster when tested under similar conditions. Alterations in proteins and carbohydrates were most readily observed in specimens containing high titers of antitoxin.
There were no demonstrable differences between the electrophoretic behavior of sera obtained from subjects before or after immunization with toxoid.
Electrophoretic patterns of serum from allergic subjects who developed marked eosinophilia showed attenuation of the alphas globulin associated with a relative preponderance of slow migrating protein-bound polysaccharides. These alterations were not present in sera obtained from the same persons before and after the development of eosinophilia.
Changes in the proteins and polysaccharides could not be demonstrated with consistency in subjects with mild to moderate hay-fever symptoms. One person who developed severe acute hay-fever symptoms showed alterations in the beta and alpha2 globulins.
Rheumatic fever subjects showed no unusual changes in the distribution of serum components. However, transition from the acute process to convalescence is graphically demonstrated by the marked decreases in gamma and alpha globulins and in protein-bound carbohydrates.
I. ANTIGENICITY OF OXYPOLYGELATIN AND GELATIN IN MAN
Authors: Maurer Paul H. 
Published: June 2004

It has been demonstrated that there are normally occurring antibodies to gelatin in human sera. Immunization with gelatin can in many cases increase the antibody level. The presence of these antibodies does not result in cutaneous reactions of the wheal and erythema type after injection of antigen.
Many of the properties of the gelatin-antigelatin reaction and the precipitates formed are those of a truly specific antigen-antibody aggregate.
Explanations have been advanced both as to the possible sources of the gelatin antibody and its significance.
A NON-TRANSMISSIBLE CYTOPATHOGENIC EFFECT OF INFLUENZA VIRUS IN TISSUE CULTURE ACCOMPANIED BY FORMATION OF NON-INFECTIOUS HEMAGGLUTININS
Authors: Henle Gertrude , Girardi Anthony , Henle Werner 
Published: June 2004

Various strains of influenza virus produce a cytopathogenic effect in cultures of HeLa cells. The virus could not be passed in series. Virus partially or even completely inactivated with respect to infectivity by exposure to 37°C. or ultraviolet light retained some of its cytopathogenic effect.
No evidence has been obtained of an increase in infectious virus in HeLa cultures, but an increase in hemagglutinins and in both viral and soluble complement-fixing antigens became detectable during incubation. These virus materials apparently were not released from these cells prior to their destruction.
These results suggested that HeLa cells are capable of supporting an incomplete reproductive cycle of influenza virus. The fact that radioactive phosphorus was readily incorporated into the hemagglutinin supplies strong evidence for this interpretation.
IMMUNOLOGICAL RELATIONSHIPS AMONG THE MYELOMA PROTEINS
Authors: Slater R. J. , Ward S. M. , Kunkel H. G. 
Published: June 2004

An immunological study of 21 myeloma sera was carried out to determine their relationship to components of normal γ-globulin and to each other. Ten proteins were separated for detailed characterization.
Every one of the myeloma proteins studied was immunologically different, indicating individual specificity.
The γ-type myeloma proteins were all related to normal γ-globulin or a fraction thereof, and although each was distinct from the others, all were related.
The ß-type myeloma proteins likewise were related to one another, though individually specific.
Evidence was found favoring the view that some of the γ-type myeloma proteins are related to the ß-type myeloma proteins although most of them were completely unrelated. Likewise the results indicated a definite but distant relationship between the ß-myeloma proteins and normal γ-globulin.
Certain of the ß-myeloma proteins were more closely related to a fraction of normal serum of similar electrophoretic mobility.
It is suggested that most multiple myeloma proteins fall into two groups or families of cross-reacting abnormal proteins, one closely related to normal γ-globulin, the other distantly related to γ-globulin with marked individual specificities.
THE ROLE OF HOMOCYSTINE IN PROTECTING PROTEIN-DEPLETED DOGS EXPOSED TO FATAL DOSES OF CHLOROFORM
Authors: Vennart George P. , McKee Frank W. 
Published: June 2004

In dogs maintained on low protein diets and subjected to phlebotomy over a long period of time, the inhalation of chloroform, for 30 minutes, produced uniform fatality within 48 hours. The histological changes of massive hepato-cellular destruction were observed at autopsy.
Homocystine, in the amount of 2.0 gm., given orally 2 hours after or 2 hours prior to the administration of chloroform, protected dogs against the lethal action of the toxin.
Inconstant changes in fibrinogen and icteric indices were observed in the protected animals, indicating some mild liver damage, but this was not correlated with the length of the previous depletion period, the phase of the experiment, or any other factor.
No evidence was obtained that methyl groups are necessary for the protection of the liver by homocystine.
THE MATURATION OF WESTERN EQUINE ENCEPHALOMYELITIS VIRUS AND ITS RELEASE FROM CHICK EMBRYO CELLS IN SUSPENSION
Authors: Rubin Harry , Baluda Marcel , Hotchin John E. 
Published: June 2004

Experiments are presented in which the plaque assay technique was used to study the intracellular appearance and release of Western equine encephalomyelitis virus in suspensions of infected chick embryo fibroblasts.
No intracellular virus could be found during the 1st hour after adsorption in spite of the fact that more than 1014 cells per ml. proved to be infected. This is taken to indicate that the infecting particle loses its infectivity upon entering a susceptible cell.
The first progeny virus was detectable in the cells between 1 and 2 hours after infection, and it increased in amount exponentially during the following 3 hours. The released virus as measured in the supernatant fluid increased at the same rate as the intracellular virus but exceeded it in amount by a factor of about twenty at all times during the period of exponential increase. More than 100 particles were spontaneously released from each cell, by the end of the period of exponential increase, yet the maximum number of intracellular infective particles at any instant during this period was never more than an average of from 4 to 10 per cell. Calculations based on these findings indicate that, on the average, a virus particle is released from the cell within 1 minute after it gains the property of infectiousness.
THE EFFECT OF IONIZING RADIATION ON PHAGOCYTOSIS AND THE BACTERICIDAL POWER OF THE BLOOD
Authors: Fishman M. , Shechmeister I. L. 
Published: June 2004

Rats irradiated with 600 r (total body) showed increased indices of both opsonophagic and surface phagocytosis 2, 12, and 24 hours after irradiation. The indices decreased 72 hours after exposure and returned to normal by the 4th to 5th postirradiation day.
Bactericidal power of the blood of irradiated animals was depressed when measured 3 and 6 days after exposure to x-rays.
Decomplemented serum from irradiated animals was more bactericidal against M. aureus than decomplemented serum from the control rats. This bactericidal substance was destroyed at 78°C. and was found not to require any complement or specific antibodies for action.
Extracts of leucocytes from animals 3 days after irradiation demonstrated no bactericidal activity against M. aureus, while extracts from the control animals or rats 1 day after irradiation were actively bactericidal. The extracts from leucocytes of non-irradiated animals were thermolabile, non-dialyzable, had a pH optimum of 7.5, and were capable of being precipitated by NH4SO4 and of calcium phosphate fractionation.
The observed increase in susceptibility of irradiated rats to infection with M. aureus was correlated not only with granulopenia but also with the alteration of the above indicated functions of the granulocytes of the irradiated animals.
STUDIES ON ENTRY AND EGRESS OF POLIOMYELITIC INFECTION
Authors: Faber Harold K. , Dong Luther 
Published: June 2004

1. The effects of viremia on the CNS of cynomolgus monkeys were studied by comprehensive histological examination following inoculations of approximately equal amounts of the same strain of poliomyelitis virus into the femoral vein, carotid artery, and vertebral artery, respectively, of four animals in each case.
2. The intravenous injections failed to produce lesions in the CNS, indicating that an effective mechanism exists for the removal of virus from the blood stream. While not absolute, the degree of protection of the CNS afforded by this mechanism appears to be of major importance.
3. Inoculations into the carotid artery failed to produce significant lesions in the CNS in two animals; only a few minor lesions in one; and bulbar paralysis in one. The neuronal areas supplied by the carotid artery are in general those of low susceptibility to poliomyelitis virus.
4. Inoculations into the vertebral artery, which supplies neuronal areas of high susceptibility, produced in all four animals severe symmetrical and widely distributed lesions in the brainstem, chiefly the motor centers of the pons, medulla, and cord, and maximal in the cord. Involvement of all of the various affected areas appeared to be simultaneous.
5. Viremic invasion of the CNS appears to occur at many points by direct passage of virus from capillary to neuron, and not at a single area of specialized vascular permeability.
6. Comparison of the two routes of arterial inoculation indicates that: (a) the localizations of CNS lesions from viremia depend largely upon the susceptibilities of exposed nerve cells in a given region; (b) in areas of high neuron susceptibility the blood-neuron "barrier" does not present an obstacle of importance to the passage of virus.
7. Invasion of the CNS from the blood results in a notable difference in the initial localization of lesions from that produced by invasion by way of the peripheral nerves, the latter tending to occur in isolated nuclear groups, usually in the lower brainstem, related to the regional supply.
STUDIES ON THE MECHANISM OF THE SHWARTZMAN PHENOMENON
Authors: Stetson Chandler A. 
Published: June 2004

The cutaneous, ophthalmic, and systemic reactions of normal rabbits to Gram-negative bacterial endotoxins have been compared with the classical reactions of bacterial hypersensitivity, and in each case certain similarities have been found. It has also been shown that the Shwartzman phenomenon can be reproduced with tuberculin, in BCG-vaccinated rabbits, and with suspensions or extracts of heat-killed Group A streptococci in rabbits previously sensitized to these bacteria.
These considerations suggest the hypothesis that the biologic activity of endotoxins may be based on the existence in "normal" animals of delayed or tuberculin-type hypersensitivity to these materials.
PHASE AND ELECTRON MICROSCOPE STUDIES OF THE INTERRELATIONSHIP OF CYTOCHONDRIA AND MYOFIBRILS IN PIGEON BREAST MUSCLE
Authors: Weinreb Stanley , Harman John W. 
Published: June 2004

Mitochondria in pigeon breast muscle are composed of two protein gels: a fibrous gel, in the form of a folded ribbon, enclosed within a non-fibrous matrix. An external limiting "membrane" is not demonstrated, and there is poor demarcation between the mitochondria and adjacent structures or sarcoplasm.
No internal structure has been determined for sarcosomes. These structures, however, are symplasmic with mitochondria and usually are located within mitochondrial depressions. They apparently have a high lipid content.
The myofibrils also have no external limiting "membranes" and the mitochondria and sarcosomes are symplasmic with them. The mitochondria normally lie in the intermyofibrillar sarcoplasm oriented with their longitudinal axes parallel to the myofibrils. Cross-sections show that the myofilaments are oriented into well defined sheets.
THE RELATIONSHIP OF TOXIC FRACTIONS OF A FILTRATE OF CLOSTRIDIUM PERFRINGENS TYPE A TO THE PATHOGENESIS OF CLOSTRIDIAL MYONECROSIS
Authors: Ganley Oswald H. , Merchant Donald J. , Bohr David F. 
Published: June 2004

A crude filtrate from a culture of Clostridium perfringens, type A, was fractionated by a heavy metal-alcohol technique, and some degree of concentration of biologically active factors was achieved. Both the crude material and the fractions obtained were characterized in terms of their alpha toxin, theta toxin, hyaluronidase, and collagenase activities.
The filtrate and fractions were tested for their effect on the peripheral circulation of the rat, using the epinephrine threshold technique. The crude material and several fractions caused a sharp increase in epinephrine sensitivity of the capillary bed of the meso-appendix of the rat; fraction R3B1 giving an 86-fold increase in sensitivity. This reaction could be inhibited by specific antitoxic serums but not by normal serum. The "circulation factor" was shown to be heat-labile and appears to be independent of either the alpha or theta toxins. Bilateral nephrectomy greatly reduced, but did not abolish, the effect of the toxin, while the threshold response to epinephrine was not materially changed following bilateral adrenalectomy.
The crude filtrate and several fractions were shown to inhibit the phagocytosis of heat-killed B. anthracis to the extent of 40 to 50 per cent. Fraction R3C2 was devoid of all biological properties studied here, except phagocytosis inhibition, suggesting that the factor responsible for this activity is distinct from the "classical" toxins and the "circulation factor." Moreover, a 1:5000 dilution of an antiserum prepared against this fraction would completely neutralize the phagocytosis inhibition factor but failed to inhibit any of the other toxic activities.
Since cardiovascular collapse and absence of phagocytosis are two significant clinical findings in gas gangrene, the possible roles of the "circulation" and "phagocytosis inhibition" factors in the pathogenesis of this disease are discussed.
ANTIGENIC VARIANTS OF INFLUENZA A VIRUS (PR8 STRAIN)
Authors: Gerber Paul , Loosli Clayton G. , Hamre Dorothy 
Published: June 2004

Antigenically different strains of mouse-adapted PR8 influenza A virus have been produced by 17 serial passages of the virus in the lungs of mice immunized with the homologous agent. Comparative serological tests show that the variant strains share antigenic components with the parent strain but the dominant antigen is different. By means of antibody absorption it was shown that the "new" antigenic component of the variant was already present in minor amounts up to the eighth passage and thereafter gained prominence with continued passage in vaccinated mice.
Groups of mice vaccinated with either the PR8-S or T21 virus and having comparable antibody titers showed no growth of virus in the lungs following aid-borne challenge with homologous strains. On the other hand, following heterologous air-borne challenge no deaths occurred, but virus grew in the lungs of both groups of vaccinated mice. Almost unrestricted virus multiplication took place in the lungs of mice vaccinated with the parent strain and challenged with the PR8-T21 virus which resulted in extensive consolidation. Less virus grew in the lungs of the mice vaccinated with the variant strains and challenged with the PR8-S virus. In these animals only microscopic evidence of changes due to virus growth in the lungs was observed.
The successful serial passage of PR8 influenza A virus in immunized animals was dependent on the initial selection of mice with uniformly low H.I. antibody titers as determined on tail blood, and the intranasal instillation of sufficient virus to favor the survival of those virus particles least related to the antibodies present. The epidemiological implications of these observations are discussed briefly.