bluuebunny/crossref_metadata_2025_split huggingface dataset:
EFFECT OF DIETARY PROTEINS AND AMINO ACIDS ON THE SUSCEPTIBILITY OF MICE TO BACTERIAL INFECTIONS
Authors: Dubos René J. , Schaedler Russell W. 
Published: June 2004

Groups of young albino mice were fed continuously four different types of diets and were compared with regard to (1) rate of weight gain; (2) resistance to experimental bacterial infections.
The protein content of the four diets was as follows: (a) pellets: a minimum of 21 per cent "crude" protein (according to the manufacturer); (b) diet 20 C: 20 per cent casein; (c) diet 8 C: 8 per cent casein; (d) diet 8 C + AA: 8 per cent casein supplemented with 12 per cent of a mixture of essential amino acids. All diets provided an adequate supply of minerals and vitamins. They were administered ad lib.
Three strains of pathogens virulent for mice were used for the infection tests, namely: Staphylococcus aureus, Mycobacterium fortuitum, and Mycobacterium tuberculosis bovis. The bacteria were injected by the intravenous route.
The experimental regimens were begun at different times before infection, and were continued until death of the animal, or until termination of the experiment.
It was found that mice on the 8 C diet exhibited much greater susceptibility to infection than did mice on the 20 C diet; mice receiving pellets were intermediate between these two groups. The infection-enhancing effect of the 8 C diet could be entirely corrected by amino acid supplementation (diet 8 C + AA). Indeed, mice fed diet 8 C + AA proved the most resistant to infection.
The fact that animals fed pellets (which contain a minimum of 21 per cent protein) consistently died faster following infection than did animals fed diets 20 C or 8 C + AA suggests that qualitative characteristics of the protein in the regimen are as important as the quantity of protein fed in determining susceptibility to infection.
The differences in susceptibility exhibited by the mice on the four experimental diets were the same whatever the species of bacterial pathogen used for the infection test, the size of the infective dose, and the duration of the disease.
There was no apparent relation between the effects of the diets on the weight curves of the animals, and on resistance to infection. Mice on diet 8 C (which were most susceptible) gained weight as rapidly as those on 20 C and more rapidly than those fed 8 C + AA (which were most resistant).
All the tests reported in the present paper were carried out with young mice, which were placed on experimental diets within 1 to 2 weeks after weaning. Preliminary experiments suggest that the relation between dietary factors and susceptibility to infection was more difficult to bring out in older animals. There was evidence also that this relation was most apparent during the first weeks that the animals were fed the experimental diets, and became less striking after several weeks.
INHIBITION OF TUBERCULIN SKIN HYPERSENSITIVITY IN GUINEA PIGS BY INJECTION OF TUBERCULIN AND INTACT TUBERCLE BACILLI DURING FETAL LIFE
Authors: Weiss David W. 
Published: June 2004

Female guinea pigs were subjected to laparotomy at different stages of pregnancy, and their fetuses injected through the uterine walls with one of the following preparations: Old Tuberculin, tubercle bacilli of the BCG strain killed by heat or exposure to phenol, and living BCG.
A large number of the animals injected in utero with Old Tuberculin failed to develop skin hypersensitivity to P.P.D. following vaccination with 200 or 800 γ phenol-killed tubercle bacilli (BCG) in early adulthood. Normal control animals were sensitized by vaccination with such quantities of phenolized BCG. The failure of animals which had been injected with Old Tuberculin in fetal life to respond hypersensitively to P.P.D. after adult vaccination with tubercle bacilli is ascribed to their acquisition of a state of immunological tolerance to tuberculoprotein (tuberculin tolerance).
Fetal injection with killed BCG conferred a state of tolerance on a few of the animals, and rendered others tuberculin-sensitive. Fetal injection with living BCG sensitized most of the animals to tuberculin, even when fetal exposure was as early as 46 days before birth, and induced tolerance in none.
Fetuses of the same litter, injected simultaneously with identical inocula, often responded differently, some becoming tolerant to tuberculin, others developing hypersensitivity, and still others remaining immunologically unaffected, becoming neither sensitive nor tolerant.
The state of tuberculin tolerance induced in these experiments was limited. When tolerant animals were revaccinated with living BCG several weeks after vaccination with phenol-killed bacilli, they developed as high a degree of tuberculin skin sensitivity as the originally non-tolerant animals.
ARTHROPOD TRANSMISSION OF RABBIT PAPILLOMATOSIS
Authors: Dalmat Herbert T. 
Published: June 2004

The virus of rabbit papillomatosis, a neoplastic disease studied intensively in relation to cancer because of its tendency toward malignant transformation, has been successfully transmitted by Aedes aegypti, Rhodnius prolixus, and Triatoma infestans from papillomas induced in cottontail rabbits, and by the first species mentioned, from papillomas induced in domestic rabbits. This was accomplished by interrupted feeding, feeding after an interval of several days from the infective meal, or by application of a suspension of the mouthparts of the insects either immediately after their infective meal or several days later.
Insect transmission was also successful from the satellite growths resulting from subcutaneous extensions of the typical papillomas of infected cottontails, and from certain peculiar, subcutaneous nodules, arising rapidly after infection, and not heretofore described. Although the latter growths resembled rabbit fibromas, antibodies to fibroma virus could not be demonstrated by neutralization tests with the sera of the animals involved.
A COMPARISON OF THE EFFECTS ON THE SHWARTZMAN PHENOMENON OF LEUKOPENIA PRODUCED BY NITROGEN MUSTARD AND BY WHOLE BODY IRRADIATION
Authors: Johnstone Douglas E. , Howland Joe W. 
Published: June 2004

The effect of leukopenia on the susceptibility of rabbits to the localized Shwartzman reaction was studied in those receiving whole body irradiation and nitrogen mustard respectively. Of animals receiving nitrogen mustard in which the total polymorphonuclear leukocyte count was less than 100 cells/c.mm. only 17 per cent developed positive local Shwartzman reactions whereas 75 per cent of irradiated animals with total polymorphonuclear leukocyte counts less than 100 cells/c.mm. had positive reactions. A local Shwartzman reaction occurred in 60 of 71 control rabbits (85 per cent). Animals of both the treated groups showed positive Shwartzman reactions at a time when their total polymorphonuclear leukocyte counts were less than 500 cells/c.mm.
From the findings, it is concluded (a) that the presence of normal numbers of circulating polymorphonuclear leukocytes is not an obligatory prerequisite condition to the localized hemorrhagic necrosis of the Shwartzman phenomenon, and (b) the mechanisms of action of nitrogen mustard and whole body irradiation on body tissues differ in relation to the Shwartzman reaction.
STUDIES ON PERSISTENT INFECTIONS OF TISSUE CULTURES
Authors: Henle Gertrude , Deinhardt Friedrich , Bergs Victor V. , Henle Werner 
Published: June 2004

Inoculation of the MCN and Lung-To lines of human cells in continuous culture with Newcastle disease (NDV), mumps, or 6-6 viruses led to slight cytopathic effects (CPE) if the multiplicity of infection exceeded one. On second passage or with smaller initial inocula no CPE became apparent. The viruses multiplied, however, as determined by titrations in HeLa cultures or chick embryos. Indeed, persistently infected sublines of MCN and Lung-To were readily established without resort to special manipulations and some of these have been carried now for over 18 months on the same media and schedules as the uninfected parent strains.
The viruses were found to be associated mainly with the cells and only 1, or at most 10 per cent of it was detectable in the media. The titers obtained were always low in relation to the available cell population.
Reduction or even omission of the horse serum component in the media or ultraviolet irradiation of the cultures did not increase the yield of virus, and CPE became apparent only when similarly treated, uninfected cultures were, likewise, affected by the manipulations.
The persistently infected cultures differed from their uninfected counterparts in that they exhibited (a) decreased cellular growth rates and ultimate yields; (b) increased aerobic glycolysis; and (c) a high degree of resistance to cytopathogenic viruses, influenza A (PR8), herpes simplex and, especially vesicular stomatitis (VSV) viruses.
Prolonged treatment of persistently infected cultures by addition of specific antiviral immune sera to the media reduced significantly the amount of virus present and the degree of resistance to VSV. However, upon removal of the sera after as many as 187 days of treatment the viruses reappeared in all but one instance. The cured culture, on reinfection, became again persistently infected.
No evidence was obtained to indicate genetic inhomogeneity of the cell populations. Of 50 cloned MCN lines none was destroyed by NDV and all became persistently infected. None were initially resistant to VSV but all after establishment of persistent NBV infection. All 39 cloned lines derived from MCNNDV cultures in the presence of anti-NDV serum, were free of virus and susceptible to VSV, and all acquired persistent infections and with it resistance to VSV following inoculation of NDV.
NDV maintained in MCN cultures differed from the parent, chick embryo-adapted strain with respect to its plaque morphology. Whereas the former yielded only plaques on monolayers of chick embryo fibroblasts which were of pin-point size and hazy, those obtained with the latter were rarely of this type and mostly large and clear. This apparent selection of virus particles did not alter significantly their behavior with respect to cytopathogenicity for uninfected MCN cultures.
POLIOMYELITIS AS A COMPLEX INFECTION
Authors: Dalldorf Gilbert , Weigand Heribert 
Published: June 2004

Young cynomolgus monkeys inoculated intracerebrally with an attenuated Type 1 polio virus and, after 5 days, with a monkey adapted Coxsackie A-14 virus frequently became paralyzed. Neither virus alone was capable of inducing paralysis.
Similar results were observed when the AB IV strain of Coxsackie A-7 was substituted for the A-14 virus. In this case the 2nd inoculation was made intramuscularly.
Paralytic poliomyelitis may at times represent the summation of two infections, the total of motor neuron destruction by two independent and noninterfering enteroviruses.
ENZYMATIC VARIANTS OF INFLUENZA VIRUS
Authors: Padgett Billie L. , Walker Duard L. 
Published: June 2004

The rate of elution of the variant virus from chicken RBC is progressively decreased as the temperature of incubation is increased above 25°C. The activity of the parent virus, on the other hand, is increased as the temperature is increased up to 40°C. The major cause of the decreased activity of the variant at temperatures above 2S°C. is an inhibition of the variant enzyme rather than its inactivation.
The activity of the variant enzyme is stimulated in the presence of strontium, calcium, and barium ions. Manganese has only a slight effect, and magnesium has no stimulatory effect on the elution of the variant virus.
Elution of the variant at 37°C. is progressively inhibited at pH values above 7, while the parent virus is still active at pH 8.
In the absence of calcium the variant enzyme, hemagglutinin, and infectivity are more heat labile than those of the parent virus. The addition of calcium increases the heat stability of all three properties of the variant, and in the presence of calcium the infectivity of the variant is as stable as that of the parent virus.
INACTIVATION OF ENDOTOXIN BY A HUMORAL COMPONENT
Authors: Rosen Fred S. , Skarnes Robert C. , Landy Maurice , Shear Murray J. 
Published: June 2004

The uniformly high potency of citrated plasma as compared with the limited capacity of serum to inactivate endotoxin in vitro was found to be a consequence of the anticoagulant employed in collecting the plasma.
Addition of calcium to plasma suppressed the activity of its endotoxm detoxifying component (EDC) whereas the addition of calcium-binding anticoagulants rendered serum comparable to plasma.
Dialysis of plasma resulted in a marked reduction of its EDC activity despite the concommittant elimination of calcium. EDC activity could then be fully restored upon the addition of calcium-binding anticoagulants.
Resin-treated plasma, without added anticoagulant, had EDC activity equal to plasma obtained with calcium-binding anticoagulants. Following dialysis, resin-treated plasma also sustained a marked reduction in EDC activity which could be fully restored by calcium-binding anticoagulants. Restoration was also obtained with the dialysate even after ashing.
These findings indicated that the suppression of EDC activity by calcium is not direct but is mediated through its effects on an anionic component of plasma which is required for inactivation of endotoxin by EDC.
CHARACTERIZATION OF A FACTOR FORMED IN THE COURSE OF ADENOVIRUS INFECTION OF TISSUE CULTURES CAUSING DETACHMENT OF CELLS FROM GLASS
Authors: Rowe Wallace P. , Hartley Janet W. , Roizman Bernard , Levy Hilton B. 
Published: June 2004

Infectious tissue culture fluids of the majority of serotypes of adenovirus at low dilutions detach HeLa or KB cells from glass surfaces within a few hours after inoculation. A reproducible method for testing cell detachment was devised.
The factor present in infectious tissue culture fluids and responsible for cell detachment is trypsin-sensitive and non-dialyzable; it is smaller and more resistant to the effect of heat or ultraviolet light than the infectious virus particle.
Cell detachment activity was found to be temperature-dependent, and the cell-detaching titer of infectious tissue culture fluids was not affected by repeated exposure to HeLa cells. Inhibition of cell detachment by human or rabbit sera was observed only when other antibodies to adenovirus antigens were also present, but the antibody inhibiting cell detachment could not be correlated quantitatively with complement-fixing or homologous neutralizing antibody.
ELICITATION OF ALLERGIC CONTACT DERMATITIS IN THE GUINEA PIG
Authors: Eisen Herman N. , Tabachnick Milton 
Published: June 2004

When one or two drops of a dilute, non-irritating solution of 2,4-dinitrochlorobenzene (DNCB) is applied to a small area of skin of the intact guinea pig, about 20 per cent of the applied material, or some derivative of it, is soon excreted in urine. In normal, as well as in specifically sensitized guinea pigs, DNCB at the site of local application becomes rapidly bound to skin protein through primary chemical bonds. Twenty-four hours after application roughly half of the material present at the local skin site is still extractable with organic solvents. Of the non-extractable dinitrophenyl groups, about 99 per cent are in epidermis, and about 85 per cent are substituted in ϵ-NH2 groups of lysine residues. Only traces of bound dinitrophenyl groups were observed in the corium. It is uncertain whether these are formed in situ, or are experimental contaminants, or are migratory epidermally formed conjugates. Even when DNCB is injected intradermally it combines predominantly with overlying epidermis and with epidermal components of hair follicles, but only slightly with corium.
The 2,4-dinitrophenyl conjugates which are localized in the deeper, viable half of the epidermis, close to the epidermal-dermal junction, are inferred to be the agents responsible for specifically evoking the allergic response in sensitized animals. Conjugates which are situated in the outer, cornified half of the epidermis are shown to be incapable of eliciting the allergic response. The results furnish a basis for interpreting a common pattern of lesions in allergic contact dermatitis as it occurs spontaneously in man.
THE ETIOLOGIC AGENTS OF VARICELLA AND HERPES ZOSTER
Authors: Weller Thomas H. , Witton Helen M. , Bell E. John 
Published: June 2004

Fourteen strains of virus derived from the cutaneous lesions of cases of varicella and eight from patients with herpes zoster were propagated serially in primary explant cultures of human preputial or embryonic skin-muscle tissue. Infectious material could not be demonstrated in the fluid phase of infected cultures and inocula for passage therefore consisted of suspensions of infected tissue. Such tissue suspensions when stored in the frozen state did not regularly retain infectivity.
The cytopathic process was focal and appeared to develop as the result of transfer of infectious material from cell to contiguous cell. Optimum development of the focal lesions in vitro related directly to conditions favoring optimum tissue growth and was further influenced by the spatial relationship of the tissue outgrowth.
A variety of types of cells of human origin and several of monkey origin were susceptible to infection and responded with the formation of intranuclear inclusion bodies. The cellular response otherwise was variable, ranging from simple rounding with little change in size to the formation of large multinucleated cytoplasmic syncytia.
Strains of virus recovered from patients with varicella and from patients with herpes zoster could not be distinguished on the basis of their cultural attributes.
BACTERICIDAL ACTION OF HISTONE
Authors: Hirsch James G. 
Published: June 2004

The arginine-rich fraction of calf thymus histone (histone B) exerts bactericidal activity on various coliform bacilli and micrococci under certain conditions in vitro. Final concentrations of less than 1 µg. histone per ml. kill susceptible microbes without detectable morphological alteration or lysis. Among the microorganisms highly susceptible to histone are Escherichia, Salmonella, Shigella, Pseudomonas, Klebsiella, and Micrococcus pyogenes var. albus. Less susceptible or completely resistant are Proteus, Serratia, Micrococcus pyogenes var. aureus, and various types of hemolytic streptococci.
Coliforms grown on solid media are much more resistant to the lethal effect of histone than are those cultured in liquid media. This difference is apparently related to the physiological state of the bacteria; agar grown microorganisms washed with water remain resistant to histone, whereas incubation in broth rapidly renders them more susceptible.
Histone is adsorbed onto heat-killed E. coli K-12 under conditions suitable for lethal action on this organism.
The bactericidal activity of histone is but little affected by pH of the test system, but ionic strength of the medium exerts a marked influence, the lethal action being reduced or blocked as the salt concentration reaches levels higher than that of 0.15–0.2 M NaCl. Relatively high concentrations of rabbit serum or of bovine plasma albumin reduce the bactericidal activity of histone in a medium at pH 7; these serum preparations are, however, essentially without effect in the test system at pH 5.6. The bactericidal effect of histone is antagonized by addition to the medium of small amounts of certain basic substances (protamine, spermine), or of various acid polysaccharides (heparin, nucleic acid, bacterial lipopolysaccharides).
The rate of killing of E. coli K-12 by histone increases as the temperature and the concentration of histone are raised. Within the limits studied, this rate also appears to be directly proportional to the concentration of bacteria in the system.
RAPID INDUCTION OF MAMMARY CARCINOMA IN THE RAT AND THE INFLUENCE OF HORMONES ON THE TUMORS
Authors: Huggins Charles , Briziarelli Giuliano , Sutton Harold 
Published: June 2004

A study was made of the optimal conditions for the induction of mammary cancer in the rat. 3-Methylcholanthrene was administered via the gastrointestinal tract, and a simple technique was worked out for inducing mammary cancer regularly and rapidly. Under conducive conditions, which were readily reproduced, multiple mammary carcinomas and these tumors only were induced in every rat in repeated experiments in 60 days or less. In the strain of animal employed in the present experiments, the rapid induction of mammary cancer proved to be a function of (a) dosage, (b) the timing of administration of the aromatic hydrocarbon, and (c) a favoring hormonal status of the recipient.
Most of the established tumors were hormone-dependent because they diminished markedly in size after hormone withdrawal through ovariectomy or hypophysectomy. Similar regression of the tumors was frequently achieved by the administration of dihydrotestosterone. Shrinkage of the cancers was accompanied by atrophic changes. Experimental mammary tumors with these physiologic characteristics have not been recognized hitherto.
The minority of mammary cancers continued to grow after ovariectomy; these are hormone-independent tumors and tumors of this sort had a characteristic cytologic appearance following modification of the endocrine state.
The cell population of a single tumor was not always uniform in its response to appropriate hormonal modifications. In certain tumors in response to changes in the endocrine status of the host many of the cells underwent atrophy whilst other adjacent cells in the same tumor continued to grow so that the net result was a hormone-independent tumor.
Hypophysectomy was the most effective method found to induce regression of mammary cancer in the present experiments.
IDENTIFICATION OF A TOXIC CELLULAR COMPONENT OF GROUP A STREPTOCOCCI AS A COMPLEX OF GROUP-SPECIFIC C POLYSACCHARIDE AND A PROTEIN
Authors: Schwab John H. , Cromartie William J. , Roberson Bob S. 
Published: June 2004

The toxic cellular component of Group A streptococci, which produces a chronic multinodular lesion of the dermal connective tissue of rabbits, has been isolated by means of differential centrifugation and electrophoresis. The substance appeared to be a macromolecular complex of polysaccharide and protein, the polysaccharide having the serological and chemical characteristics of the group-specific C substance.
Evidence is presented indicating that the polysaccharide moiety is an essential part of the toxic complex. It is suggested that further studies of this material may help elucidate the mechanism of tissue damage in the non-suppurative sequelae of Group A streptococcal infections.
COMPARATIVE STUDIES ON THE PHYSICAL CHARACTERISTICS OF THE HERITABLE HAPTOGLOBIN GROUPS OF HUMAN SERUM
Authors: Bearn A. G. , Franklin E. C. 
Published: June 2004

Ultracentrifugal studies of the α2-proteins of normal human serum before and after the addition of hemoglobin have revealed three separate and clearly distinguishable patterns based on the three major serum haptoglobin groups. Isolation of the three haptoglobin hemoglobin complexes disclosed characteristic patterns for each group. The heterozygote was found to possess electrophoretic and ultracentrifugal components not seen in either homozygote.
Separation of normal human serum, to which hemoglobin had been added, by conventional starch zone electrophoresis resulted in three characteristic patterns which also permitted the ready identification of the serum haptoglobin group. The haptoglobin hemoglobin complex from Group 1-1 had the fastest mobility and that of Group 2-2 the slowest. The heterozygote Group 2-1 had an intermediate mobility. Immunologic differences between the haptoglobin hemoglobin complexes of the three groups could not be detected.
Some of the variations in the reported electrophoretic and ultracentrifugal patterns of normal human serum could be reasonably ascribed to the group variation of the haptoglobins in man. The physical studies imply that the proteins characteristic of the heterozygote differ in size and charge from those present in either of the two homozygotes and indicate that the genetic control of the synthesis of the serum haptoglobins is probably exceedingly complex.