bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE STIMULATION OF DNA SYNTHESIS IN CULTURES OF RABBIT LYMPH NODE AND SPLEEN CELL SUSPENSIONS BY HOMOLOGOUS CELLS
Authors: Chapman Niles D. , Dutton Richard W. 
Published: June 2004

An early proliferative response follows the mixing of homologous spleen or lymph node suspensions obtained from two unrelated rabbits. The rate of incorporation of radioactive thymidine has been used as a quantitative measure of this response. Thymus cells do not respond to homologous cell suspensions but may on occasion serve to stimulate the response in homologous spleen or lymph node cells. Homologous erythrocytes or autologous tissues do not stimulate a response.
No response occurs if the two cell populations are separated by a Millipore membrane.
Autoradiographic studies have established that 1 to 2 per cent of the intial cell population is involved in the response and they are large undifferentiated cells by the time they can first be identified as responders. There was no morphological evidence of any cellular interaction and the viability of mixed suspensions was not measurably different from that observed in separate suspension.
Simultaneous additive responses could be obtained to homologous cells and to antigen when cell suspensions from immunized rabbits were used. The interaction of the cell populations from the two rabbits did not appear to suppress the response of each to antigen.
The speed and magnitude of the response were in everyway comparable with the secondary response of cell suspensions from immunized rabbits exposed to the immunizing antigen. No evidence was obtained of any enhancement of the response to homologous cells by prior immunization with homologous tissues, but the possibility that it had occurred was not rigidly excluded.
MUCUS IN INTESTINAL CONTENTS OF GERMFREE RATS
Authors: Lindstedt Göran , Lindstedt Sven , Gustafsson Bengt E. 
Published: June 2004

The fecal excretion of total nitrogen and of total hexosamines has been determined in germfree and conventional rats. Germfree rats excreted more hexosamines than the conventional rats, while no difference in the nitrogen excretion was found. Infection of the germfree rats with a normal flora resulted in a temporarily increased excretion of hexosamines and nitrogen over a period of 2 to 3 days after which they reached the level of the conventional animals.
The contents of the germfree cecum contained 65 to 137 mg of hexosamines and 57 to 127 mg of nitrogen as compared to 1.2 to 5.3 and 7.4 to 23 mg in conventional animals. The high figures for hexosamines were due to an increase in the total amount of contents in the cecum and to a fivefold increase in the concentration of hexosamine-containing material.
Studies on the distribution of hexosamine-containing cecal contents between sediment and supernatant after centrifugation at 20,000 g for 2 hours demonstrated that 5 to 10 per cent of the hexosamines occurred in the sediment in the germfree rats, while 75 to 85 per cent was found in this fraction in the conventional rats. The soluble part of the cecal contents in germfree as well as in the conventional rats contained 70 per cent of hexosamines in molecules with a molecular weight above approximatively 100,000 as found by gel filtration experiments on sephadex gels.
The higher weight of the germfree cecal wall was reflected in a high total amount of nitrogen and hexosamines.
Isolated strains of bacteria capable of reducing the cecal size in vivo did not show any capacity to degrade the mucus in vitro in a test system, where a full intestinal flora was highly active.
CORROBORATION OF RECENT MODELS OF THE γG IMMUNOGLOBULIN MOLECULE
Authors: Fougereau M. , Edelman G. M. 
Published: June 2004

The relationships between the polypeptide chains of γG immunoglobulin and fragments of the molecule produced by papain and pepsin have been investigated. Specific procedures were employed including peptide mapping of tryptic hydrolysates and analysis of molecules reconstituted from chains labeled with different iodine isotopes. By these means, the Fab fragment was shown unequivocally to consist of the light chain and a portion of the heavy chain, the Fd fragment. The Fc fragment was found to be comprised of the residual portions of the heavy chain. These findings support the gross arrangement of chains embodied in recent models of the γG immunoglobulin molecule.
The present studies have also provided additional information on the susceptibility of γG immunoglobulin to proteolytic cleavage. It was found that the portion of heavy chains corresponding to the Fd fragment was extensively cleaved by papain.
THE EFFECT OF HYPERGLYCEMIA ON HYPOTHALAMIC GOLD UPTAKE AND HYPERPHAGIA IN GOLDTHIOGLUCOSE-TREATED MICE
Authors: Edelman P. Michael , Schwartz Irving L. , Cronkite Eugene P. , Brecher George , Livingston Linda 
Published: June 2004

The accumulation of gold in the hypothalamus and the development of hyperphagia and obesity were studied in mice given a single intravenous injection of goldthioglucose at various levels of blood glucose concentration. It was found that the glucose concentration prevailing at the time of goldthioglucose injection was correlated directly with the level of free and bound goldthioglucose in the blood 3 minutes later, with the hypothalamic uptake of gold, with the extent of the hypothalamic lesion, and with the severity of the subsequent hyperphagia and obesity.
Hyperglycemia was associated with an increased gold deposition throughout the brain.
A gold content of 88 ± 12 µg/mg wet tissue in the hypothalamus of fasted animals was associated with clearcut lesions in all animals studied, whereas a similar gold content in the control brain lobes of hyperglycemic animals was not associated with lesions in any animal. This finding indicates that some regions in the brain (e.g. the ventral hypothalamus) are more susceptible than others to damage by goldthioglucose.
DEMONSTRATION OF TUMOR-SPECIFIC ANTIGENS IN HUMAN COLONIC CARCINOMATA BY IMMUNOLOGICAL TOLERANCE AND ABSORPTION TECHNIQUES
Authors: Gold Phil , Freedman Samuel O. 
Published: June 2004

Two methods were used to demonstrate the presence of tumor-specific antigens in adenocarcinomata of the human colon: (a) rabbits were immunized with extracts of pooled colonic carcinomata, and the antitumor antisera thus produced were absorbed with a pooled extract of normal human colon and with human blood components; (b) newborn rabbits were made immunologically tolerant to normal colonic tissue at birth, and were then immunized with pooled tumor material in adult life. Normal and tumor tissues were obtained from the same human donors in order to avoid misinterpretation of results due to individual-specific antigenic differences.
The antisera prepared by both methods were tested against normal and tumor antigens by the techniques of agar gel diffusion, immunoelectrophoresis, hemagglutination, PCA, and immunofluorescence. Distinct antibody activity directed against at least two qualitatively tumor-specific antigens, or antigenic determinants, was detected in the antisera prepared by both methods and at least two additional tumor antigens were detected exclusively in antisera prepared by the tolerance technique. Whether these additional antigens were qualitatively different from normal tissue antigens, or merely present in tumor tissue in higher concentrations than in normal tissue has not as yet been determined. Furthermore, it was shown that the tumor-specific antibodies were not directed against bacterial contaminants or against the unusually high concentrations of fibrin found in many neoplastic tissues.
It was concluded from these results that the pooled tumor extracts contained tumor-specific antigens not present in normal colonic tissue. Identical tumor-specific antigens were also demonstrated in a number of individual colonic carcinomata obtained from different human donors.
STUDIES ON IMMUNOLOGIC RECONSTITUTION OF THYMECTOMIZED MICE
Authors: Yunis Edmond J. , Hilgard Henry R. , Martinez Carlos , Good Robert A. 
Published: June 2004

1. Immunologic function, growth, and longevity of neonatally thymectomized mice was restored by intraperitoneal administration of 100 to 400 million syngeneic, hemiallogeneic, or ailogeneic thymus cells from newborn or adult donors. Assays of the graft versus host capabilities of spleen cells from the animals restored with allogeneic cells showed that their immunologically competent cells are of donor histocompatibility characteristics. Such animals accepted skin grafts from mice of the cell donor strain, but rejected skin from a third strain.
2. Similar results were obtained when the neonatally thymectomized animals were treated with 10 to 100 million syngeneic, hemiallogeneic, or allogeneic cells from adult spleen.
3. In one strain combination, C3H recipients and A donors, injected thymus or spleen cells apparently attacked host tissues, since the animals died very early of wasting disease. When this combination was reversed, A strain recipients treated with C3H cells were reconstituted immunologically and physiologically.
4. Syngeneic or allogeneic adult spleen, grafted in the newborn period, reconstituted neonatally thymectomized mice, but all experiments involving grafting of newborn spleen failed. Immunogenetic analysis of the host spleen cells from two allogeneic spleen-grafted animals previously thymectomized showed that the reconstitution was entirely of donor histocompatibility characteristics.
5. Postthymectomy wasting disease was reversed by administration of 200 million adult syngeneic spleen or thymus cells. Immunologic recovery was confirmed by graft versus host assays of the spleens of the recovered animals and by application of allogeneic skin grafts. Some of the animals have been under observation for 42 weeks and appear to be normal.
6. The wasting syndrome in neonatally thymectomized mice was also reversed by injection of 200 million hemiallogeneic or allogeneic spleen cells.
7. Thymus grafts did not reverse wasting disease, whether the donors were adult or newborn, of the same strain or a different one.
8. Spleen, lymph node, and Peyer's patches from representative animals of the reconstituted groups were examined and compared with the tissues of untreated neonatally thymectomized mice and intact animals of the same strain. Tissues of normal cellularity and follicular organization were found in some of the reconstituted animals and also in mice with reversed wasting disease. Extreme deficit of the lymphoid tissues was rare in either group.
MODIFICATION OF HOST RESPONSES TO BACTERIAL ENDOTOXINS
Authors: Kim Yoon Berm , Watson Dennis W. 
Published: June 2004

Serum from rabbits rendered tolerant or immune to 100 MPD-3/kg of endotoxin when passively transferred to normal rabbits gave partial tolerance to the standard dose of endotoxin. The same serum was fractionated by DEAE chromatography into 4 major fractions. Immunoelectrophoretic analysis indicated that the 7S γ2-and the 19S γ1-immunoglobulins were separated into two distinct fractions. Of the four fractions tested, only fraction IV containing 19S γ1-immunoglobulm conferred complete pyrogenic tolerance to 100 MPD-3/kg of endotoxin.
Additional fractionation of DEAE fraction IV by exclusion chromatography on sephadex G-200 gave 3 fractions. Of these only the first, containing 19S γ1-immunoglobulin conferred complete pyrogenic and lethal tolerance to normal rabbits. There was no correlation between the quantity of O-specific antibodies and the ability to transfer tolerance.
It is concluded that endotoxin tolerance involves a classical immune mechanism which includes both 19S γ1-immunoglobulin specific for toxophore groups common to many endotoxins and a normally functioning RES.
To avoid confusion with immunologic tolerance, it is suggested that the term endotoxin immunity be substituted for endotoxin tolerance.
THE LYSIS OF CELL WALLS OF GROUP A STREPTOCOCCI BY STREPTOMYCES ALBUS ENZYME TREATED WITH DIISOPROPYL FLUOROPHOSPHATE
Authors: Schmidt Willard C. 
Published: June 2004

Diisopropyl fluorophosphate (DFP) effectively inhibited proteolytic activity in preparations of partially purified Streptomyces albus enzyme used to lyse cell walls of Group A streptococci.
Lysis of non-trypsinized Group A cell walls with DFP-treated S. albus enzyme released a soluble protein fraction containing antigenic type-specific M protein, a carbohydrate fraction consisting of Group A and a small amount of A-variant polysaccharides, and a dialyzable fraction. The similarities of the products of DFP-treated S. albus enzyme lysis of streptococcal cell walls to those released by phage muralytic enzyme furnish additional evidence of the close relationship of these wall lysins.
In view of small differences in electrophoretic mobility, immunodiffusion, and chemical composition, it is suggested that Group A streptococcal cell wall polysaccharide dissolved by DFP-S. albus enzyme consists of a spectrum of molecules having the same immunological determinants but differing in content of conjugated mucopeptide.
THE IN VITRO DIFFERENTIATION OF MONONUCLEAR PHAGOCYTES
Authors: Cohn Zanvil A. , Benson Belinda 
Published: June 2004

The concentration of newborn calf serum in the medium has marked effects on the morphological and biochemical properties of mouse mononuclear phagocytes. At a low serum concentration, the cells developed small numbers of tiny cytoplasmic granules and little or no increase in acid phosphatase, cathepsin, and ß-glucuronidase. As the serum concentration was raised, granules were formed at a more rapid rate and were larger in size. The rate of production and total amount of three hydrolytic enzymes was increased at higher levels of serum.
Observations on living cells indicated that the phase-dense granules which accumulated in the perinuclear region were derived from pinocytic vesicles. These clear vesicles fused and migrated to the centrosphere where they underwent a gradual increase in phase density and reacted positively for acid phosphatase.
A microscopic technique was described for the evaluation of the pinocytic process. When this method was employed, the rate of pinocytosis increased curvilinearly with elevations in the calf serum concentration of the medium.
The comparative influence of bovine, horse, and rabbit serum on mouse cells was evaluated.
It is suggested that pinocytosis is a major regulator of granule formation and hydrolytic enzyme production by the mouse macrophage.
A STUDY OF THE ANTIGENS INVOLVED IN ADENOVIRUS 12 TUMORIGENESIS BY IMMUNODIFFUSION TECHNIQUES
Authors: Berman Leonard D. , Rowe Wallace P. 
Published: June 2004

The use of the agar gel diffusion technique has established the presence of three distinct antigenic reactions in the sera of Ad. 12 tumor-bearing hamsters. Only one of these antigens is directly demonstrable in the tumor. This "tumor" antigen is also formed during early stages of the infectious cycle in tissue culture cells. Other antigens present in the tumor, but only demonstrable indirectly with the use of antibody-containing serum of tumored hamsters, are the classical type-specific C antigen, and a new antigen, termed D.
Of ninety-eight Ad. 12 tumored hamster sera, six reacted in gel diffusion with virus and tumor preparations, and thirty-one with tumor only.
Sera which reacted in gel diffusion with viral antigen uniformly bad neutralizing antibody and high titers of CF antibody against viral and tumor antigens; however, many sera with comparable antibody titers did not react with the virus in gel diffusion. Sera which reacted in gel diffusion only with tumor antigen also had high CF antibody titers, but there was no correlation with neutralizing antibody.
EFFECTS OF ANTICELLULAR SERUM ON PHAGOCYTOSIS AND THE UPTAKE OF TRITIATED THYMIDINE AND URIDINE BY HELA CELLS
Authors: Carey Francis J. , Kuhn Nobuko O. , Harford Carl G. 
Published: June 2004

Anticellular serum inhibited phagocytosis of colloidal gold and staphylococci by HeLa cells. This inhibition of phagocytosis was reversed by conditions which allowed the antibody to elute from the cell. Concentrations of antiserum that inhibited phagocytosis did not interfere with the transport of tritiated thymidine and uridine across the cell membrane, and their incorporation into cell nucleic acids was unaltered as evaluated by autoradiography. These results indicate that thymidine and uridine were taken into cells independently of phagocytosis.
Morphologic changes induced in the cells by antibody suggest that the antibody agglutinates adjacent portions of the cell membrane. This agglutination of the cell membrane by antibody would be expected to interfere with the continuous evagination and invagination of the cell membrane associated with phagocytosis.
The inhibition of virus infection by anticellular antibody may be a result of the effect of the antiserum upon phagocytosis.
THE DEVELOPMENT OF THE BACTERIAL FLORA IN THE GASTROINTESTINAL TRACT OF MICE
Authors: Schaedler Russell W. , Dubos René , Costello Richard 
Published: June 2004

Selective culture media, and equipment for anaerobic incubation of large numbers of specimens, have been developed to facilitate the quantitative enumeration of the various aerobic and anaerobic bacterial species present in the gastrointestinal tract.
The evolution of this flora has been followed in young mice from several colonies by cultivating homogenates of the different parts of the gastrointestinal tract at daily intervals from the time of birth to the time of weaning.
It has been found that the lactobacilli and anaerobic streptococci become established immediately after birth and persist in large numbers, not only in the large intestine but also in the stomach and in the small intestine. In contrast, the anaerobic bacilli of the bacteroides group become established only after the 16th day; they multiply only in the large intestine but persist in this organ in very large numbers. Other bacterial species become established at different periods of time after birth, exhibit characteristic anatomic localizations, and greatly fluctuate in numbers. In general, the populations of enterobacilli and enterococci decrease precipitously after having reached a maximum level shortly after the beginning of colonization.
ASSOCIATION OF GERMFREE MICE WITH BACTERIA ISOLATED FROM NORMAL MICE
Authors: Schaedler Russell W. , Dubos René , Costello Richard 
Published: June 2004

Germfree mice were given food contaminated with pure cultures of various bacterial species isolated from ordinary healthy mice. The cultures were given singly, or in association, or consecutively at weekly intervals.
Whatever the technique of administration, the lactobacilli and anaerobic streptococci immediately established themselves throughout the gastrointestinal tract, and became closely associated with the walls of the organs. In contrast, the organisms of the bacteroides group were found in large numbers only in the large intestine.
Within a week after exposure, the populations of these three bacterial species reached levels similar to those found in ordinary mice. They remained at these characteristic levels throughout the period of observation (several months). Their presence resulted in a progressive decrease in the size of the cecum which eventually became normal in gross appearance.
Coliform bacilli multiplied extensively and persisted at high levels in all parts of the gastrointestinal tract of germfree mice, even after these had become colonized with lactobacilli, anaerobic streptococci and bacteroides. However, the coliform population fell precipitously within a few days after the animals were fed the intestinal contents of healthy pathogen-free mice.
THE CELL WALLS OF GROUP D STREPTOCOCCI
Authors: Bleiweis Arnold S. , Krause Richard M. 
Published: June 2004

Group D Types 1 and 26 cell walls and the corresponding type-specific carbohydrates, extracted from the walls by various means, contain rhamnose, glucose, galactose, N-acetylglucosamine, and N-acetylgalactosamine. Mucopeptide elements are also present in the walls and in enzymatically-extracted carbohydrates. Types 1 and 26 carbohydrates extracted by formamide contain no mucopeptide, but the serologic reactivity of Type 1 antigen is destroyed by this procedure. The Type 1 antigen was successfully extracted, however, by a new technique involving autolysis of cell walls at pH 6.2. The type carbohydrate prepared by this procedure has chemical and serological similarities to the antigens prepared by the S. albus enzyme and the lysozyme methods.
Quantitative precipitin inhibition studies with Type 1 antigen and antibody indicate that D-glucose and N-acetylglucosamine may be components of the antigenic determinant. The terminal residue is probably bound by an ß-glycosidic bond to the subterminal sugar.
Similar studies with the Type 26 carbohydrate have not revealed any of the chemical features of the antigenic determinant.
STUDIES ON HUMAN ANTIBODIES
Authors: Bassett Emmett W. , Tanenbaum Stuart W. , Pryzwansky Katherine , Beiser Sam M. , Kabat Elvin A. 
Published: June 2004

Antilevan, antidextran, antiteichoic acid, anti-"A" and normal γG, all isolated from a single human, as well as pooled γG and γM, were analyzed for amino acid content. Differences ranging from 7 to 32 residues were found among these antibodies in glycine, valine, leucine, tyrosine, arginine, lysine, and threonine content. These conspicuous differences in amino acid composition were not correlated with the Gm type of these antibodies.
Hydroxylysine was found in two of the four antibodies, antidextran and antiteichoic acid, and in γM- immunoglobulin. No hydroxylysine was found in γG- globulins. These findings probably account for discrepancies in the literature concerning the occurrence of this residue in antibody protein.
PROLIFERATIVE RESPONSE OF THE SPLEEN AND LIVER TO HEMOLYSIS
Authors: Jandl James H. , Files Nancye M. , Barnett Susan Bell , MacDonald Richard A. 
Published: June 2004

Combined chemical and autoradiographic studies in rats injected with tritiated thymidine indicate that acute red cell sequestration stimulates reticuloendothelial (RE) proliferation. In the spleen DNA synthesis is most markedly stimulated in the marginal zone which is also the initial site of red cell sequestration. This proliferative response involves several division steps and eventuates in a colonization of the red pulp with increased numbers of all cell lines native to the spleen. In both spleen and liver there occurs also a generalized stimulation of division in the macrophages and littoral cells which involves only 1 or 2 division steps.
Chronic compensated hemolytic anemia achieved in rats by injections of phenylhydrazine caused functional overactivity of the RE system, including increased sequestering function and hypergammaglobulinemia. This splenic hyperplasia did not entirely regress after cessation of the injections. In man the splenomegaly of a chronic non-immunological hemolytic anemia, hereditary spherocytosis, was found to involve a marked (average: 8-fold) hyperplasia of all spleen cellular elements.
Neither the acute nor chronic proliferative reaction appears to arise from immunological or "toxic" stimuli and the findings support the view that the size of the RE system is a function of its particulate "work load." It is suggested that the cytoproliferative aspects of immune responses may depend upon non-specific, usually particulate stimulation. After prolonged stimulation, hyperplasia of the RES may become partly irreversible.