bluuebunny/crossref_metadata_2025_split huggingface dataset:
STUDIES ON PNEUMONIA VIRUS OF MICE (PVM) IN CELL CULTURE
Authors: Compans Richard W. , Harter Donald H. , Choppin Purnell W. 
Published: June 2004

Pneumonia virus of mice (PVM) particles are spheres 80–120 mµ in diameter, or filaments of similar diameter with lengths up to 3 µ. The particles possess an outer spike-covered envelope and helical internal component 120–150 A in diameter. Virus particles acquire their envelope by a budding process at the cell membrane; mature particles are seen only extracellularly.
Dense inclusions are prominent in the cytoplasm of PVM-infected BHK21 cells by 48 hr after inoculation. The inclusions appear to consist of aggregates of the internal component of PVM, and the helical component has been isolated in a cesium chloride gradient from extracts of osmotically shocked cells.
Murine erythrocytes, which are agglutinated by PVM, adsorb to the surface of infected cells and to budding and extracellular PVM particles.
On the basis of its structure and morphogenesis, PVM appears to be a myxovirus; however, it does not fit into either of the established subgroups of myxoviruses. The 120–150 A diameter of the PVM internal component differs from the diameters of the internal components of the two established subgroups of myxoviruses, and suggests that a third subgroup of these viruses may exist.
CELLS AS ANTIGEN CARRIERS AND AS IMMUNOGLOBULIN PRODUCERS
Authors: Chou Chi-Tao , Dubiski S. , Cinader Bernhard 
Published: June 2004

The injection into newborn rabbits of a small quantity of human albumin, associated with red blood corpuscles or nucleated rabbit cells, induces an antibody response in the majority of animals, whereas the same quantity of antigen in solution fails to stimulate antibody formation or induces tolerance. The promoting capacity of the cells depends on attachment of antigen to them.
The antibody produced after the injection of albumin, associated with nucleated cells, is of recipient origin. However, immunoglobulin carrying the marker of donor cells can be demonstrated in the recipient animals, and may reach serum concentrations similar to those normally present in animals which are heterozygous with respect to the marker. It appears that the antibody-promoting function and the synthetic capacity for allotype are quite distinct and that the period required for allotype formation is very short with mononuclear peritoneal exudate cells and is very much longer with cells from the thymus. The capacity of cells from lymph nodes for sustained allotype formation is less than that of thymus cells but greater than that of mononuclear peritoneal exudate cells.
IMMUNIZATION OF DISSOCIATED SPLEEN CELL CULTURES FROM NORMAL MICE
Authors: Mishell Robert I. , Dutton Richard W. 
Published: June 2004

A culture system for cell suspensions from mouse spleens has been described. The system provides adequate conditions for in vitro immunization on initial exposure to heterologous erythrocytes. The in vitro response closely parallels that observed in vivo with respect to size, early kinetics, antigen dose, and the inhibitory effect of passive antibody.
The response of cultured cells differs in two respects from that seen in vivo. There is an increase in the ability to discriminate between different varieties of homologous erythrocytes and the in vitro response does not appear to be limited by whatever mechanisms regulate the in vivo response.
CELL POPULATIONS AND CELL PROLIFERATION IN THE IN VITRO RESPONSE OF NORMAL MOUSE SPLEEN TO HETEROLOGOUS ERYTHROCYTES
Authors: Dutton Richard W. , Mishell Robert I. 
Published: June 2004

The role of proliferation in the development of 19S antibody-forming cells in the primary response has been investigated in an in vitro system.
Spleen cell suspensions from normal, unimmunized mice were cultured in vitro in the presence of mammalian erythrocytes and the number of 19S hemolytic plaque-forming cells that arose 4 days later was measured. The hot pulse technique for the selective irradiation of those cells which synthesize DNA during a defined period of time has been described.
The effect of such hot pulses administered at various times after the addition of antigen on the subsequent appearance of antibody-forming cells was determined.
The results established that: (a) the onset of DNA synthesis does not start for approximately 24–32 hr after the addition of antigen, (b) essentially all the antibody-forming cells arise by cell division, and (c) different cell populations are involved in the response to two non-cross-reacting antigens.
STREPTOCOCCAL NUCLEASES
Authors: Wannamaker Lewis W. , Hayes Barbara , Yasmineh Walid 
Published: June 2004

Preparations of streptococcal DNAse D with high specific activity and free of other streptococcal nucleases have been obtained by zone electrophoresis and column chromatography. Antisera prepared by injecting rabbits with such preparations specifically neutralize the activity of this enzyme.
As with DNAse B, preparations of DNAse D regularly exhibit ribonuclease activity. For both B and D enzymes, the order of substrate preference is thymus DNA, yeast RNA, bacterial RNA; but the specific activity of the D enzyme is higher than that of the B enzyme with respect to thymus DNA and lower with respect to bacterial RNA.
Both the deoxyribonuclease and the ribonuclease activities exhibited by preparations of both enzymes are inhibited by bacterial RNA, but approximately 100-fold greater concentrations of bacterial RNA are required to achieve inhibition of the deoxyribonuclease activity of the D enzyme equivalent to the inhibition of the B enzyme. The deoxyribonuclease activity of the D enzyme is also inhibited by yeast RNA, but even larger amounts are required.
These observations indicate that the D enzyme is immunologically distinct from the other streptococcal nucleases and that it differs quantitatively from the B enzyme with respect to relative specific activities on different substrates and behavior in the presence of the bacterial ribonucleic acid inhibitor.
HURLER'S SYNDROME: A GENETIC STUDY OF CLONES IN CELL CULTURE WITH PARTICULAR REFERENCE TO THE LYON HYPOTHESIS
Authors: Danes B. Shannon , Bearn Alexander G. 
Published: June 2004

Clones of skin fibroblasts from normal individuals, patients with different mucopolysaccharidoses, and certain of their relatives have been examined for cellular metachromasia and cellular uronic acid.
All the clones derived from affected individuals and heterozygous carriers in families with the autosomal forms of Hurler's syndrome showed marked metachromasia and increased cellular uronic acid. Since only one cell population was demonstrated in clones derived from heterozygous carriers, no evidence for autosomal inactivation was obtained.
Clones derived from affected individuals with the X-linked recessive form of Hurler's syndrome contained uniform populations of metachromatic staining cells which demonstrated increased cellular uronic acid. Clones derived from the noncarrier fathers showed no cellular metachromasia or increased cellular uronic acid. Clones derived from the heterozygous mothers and sisters showed two populations both qualitatively and quantitatively. On the average, 72% of these clones were metachromatic and demonstrated an increased uronic acid content; 28% of the clones showed no metachromasia and the uronic acid content was similar to that found in normal individuals.
The appearance of two distinct cell populations in clones derived from females heterozygous for the X-linked recessive form of Hurler's syndrome provides evidence in favor of the Lyon hypothesis.
EFFECTS OF CHRONIC EXCESS SALT INGESTION
Authors: Dahl Lewis K. , Knudsen Knud D. , Heine Martha , Leitl George 
Published: June 2004

Parabiosis has been found to modify the expected blood pressure response of rats from two strains with opposite genetic propensities for experimental hypertension. When a member from one strain was united in parabiosis with a member from the other and both were maintained on high NaCl diet, the rat from the strain ordinarily resistant to it rapidly developed hypertension, in contrast to appropriate controls from this strain. The development of hypertension in this resistant animal preceded that in its mate from the strain highly sensitive to hypertension. In the latter, both the level of hypertension and mortality were significantly less than in its control. It seems likely that the hypertension observed is the resistant parabiont was initiated in its partner from the sensitive strain. This modification in blood pressures was not observed in the absence of a high NaCl diet.
Parabiosis between animals from the same strain did not alter their response. Thus, as in earlier experiences (1–4) the interaction of a nongenetic factor (NaCl) with the appropriate genetic substrate appeared to be necessary for the development of hypertension.
The findings are interpreted as evidence that a transmittable humoral influence plays an important role in the pathogenesis of rat hypertension. The presence of this agent is genetically determined but, under the conditions of these experiments, it took the added stimulus of dietary NaCl to demonstrate its existence.
STUDIES ON THE MODE OF ACTION OF DIPHTHERIA TOXIN
Authors: Goor Ronald S. , Pappenheimer A. M. , Ames Elizabeth 
Published: June 2004

Inhibition of soluble transferase II activity in cell-free systems by diphtheria toxin and NAD can be prevented or reversed in the presence of a sufficient concentration of nicotinamide. Quantitative studies on inhibition of peptide bond formation in cell-free extracts by toxin and NAD have indicated that two successive reversible reactions are involved. First, toxin and NAD interact mole for mole to form a relatively dissociable complex. This toxin-NAD complex then reacts with transferase II to form an enzymatically inactive product that is but slightly dissociated. In the presence of sufficient nicotinamide, however, the latter complex can be broken down to yield active transferase II once more.
Based on the above model, an equation has been derived that accurately predicts the per cent inhibition of amino acid incorporation in cell-free systems at any given toxin and NAD level. The observed inhibition appears to be independent of the sensitivity to toxin of the cell species from which the extracts were derived, and depends only on the toxin and NAD concentrations.
Although the model satisfactorily explains inhibition of peptide bond formation by toxin in cell-free systems, further assumptions are needed to explain how still lower concentrations of toxin are able to arrest protein synthesis completely in the living cell.
A STUDY OF THE PASSIVE TRANSFER OF DELAYED HYPERSENSITIVITY TO DNP-POLY-L-LYSINE AND DNP-GL IN RESPONDER AND NONRESPONDER GUINEA PIGS
Authors: Green Ira , Paul William E. , Benacerraf Baruj 
Published: June 2004

A study of the passive transfer of delayed hypersensitivity to DNP-poly-L-lysine and to DNP-GL was performed in Hartley guinea pigs. Delayed hypersensitivity to DNP-PLL and DNP-GL could be transferred successfully only by means of sensitized cells from genetic responder guinea pigs and in most cases, only into those guinea pigs genetically capable of responding to PLL.
The inability to transfer delayed hypersensitivity to DNP-PLL or DNP-GL to genetic nonresponder guinea pigs is not the result of the early destruction of the transferred cells by an incompatible host, since it was shown that delayed hypersensitivity to ovalbumin could be successfully transferred from guinea pigs with the PLL gene into genetic nonresponder animals.
The requirement of active participation of specific and genetically controlled host mechanisms in the successful passive transfer of delayed sensitivity to DNP-PLL and DNP-GL has been demonstrated.
COMPLEMENT AS A MEDIATOR OF INFLAMMATION
Authors: da Silva W. Dias , Eisele John W. , Lepow Irwin H. 
Published: June 2004

Purified preparations of human C'1 esterase, C'4, C'2, C'3, and C'5 were labeled with 125I. Reaction mixtures were prepared containing a single labeled component and other unlabled components. After incubation at 37°C for 10 min at pH 7.4 in the presence of 5 x 10–4 M Mg2+, they were adjusted to pH 3.5 and subjected to sucrose density gradient ultracentrifugation and gel filtration at pH 3.5. In all cases, an activity capable of contracting guinea pig ileum with tachyphylaxis was obtained in low molecular weight fractions. However, these fractions were labeled only when 125I-C'3 was employed, indicating that biological activity was associated with a cleavage product of C'3. This fragment has been designated F(a)C'3 in a nomenclature consistent with that of immunoglobulin degradation products. The much larger, residual portion of the C'3 molecule has been designated F(b)C'3.
The biochemical characteristics of generation of F(a)C'3 were consistent with a mechanism involving action of C'1 esterase on C'4 and C'2, activation of C'2, and cleavage of C'3.
F(a)C'3 had a molecular weight by gel filtration techniques of 6800 or less. It was thermostable and susceptible to inactivation by endo- and exopeptidases. The isolated fragment possessed all of the biological properties of unfractionated mixtures of C'1 esterase, C'4, C'2, and C'3. In addition to contraction of guinea pig ileum, these included failure to contract rat uterus, enhancement of vascular permeability in guinea pig skin, degranulation of mast cells in guinea pig mesentery, and release of histamine from rat peritoneal mast cells. F(a)C'3 did not cross-desensitize guinea pig ileum to rat agar anaphylatoxin and vice versa.
The existence of different protein fragments with anaphylatoxin properties has been discussed. Distinctive characteristics of F(a)C'3 from classical anaphylatoxin generated by treatment of fresh rat serum with agar have been indicated.
IODINATION OF BACTERIA: A BACTERICIDAL MECHANISM
Authors: Klebanoff Seymour J. 
Published: June 2004

Myeloperoxidase, iodide, and H2O2 have a bactericidal effect on Escherichia coli. Myeloperoxidase can be replaced in this system by lactoperoxidase or by a guinea pig leukocyte particulate preparation, H2O2 by an H2O2-generating system such as glucose and glucose oxidase, and iodide by thyroxine or triiodothyronine. The bactericidal effect was high at pH 5.0 and fell as the pH was increased.
Preincubation of myeloperoxidase, iodide, and H2O2 for 30 min before the addition of the bacteria largely prevented the bactericidal effect. Thus, the organisms must be present in the reaction mixture during iodide oxidation for maximum killing, which suggests the involvement of labile intermediates of iodide oxidation rather than the more stable end products of oxidation such as iodine.
Iodination of the bacteria by the myeloperoxidase-iodide-H2O2 system was demonstrated chemically and radioautographically. Iodination and the bactericidal effect were similarly affected by changes in experimental conditions in all the parameters tested (effect of preincubation, pH, and inhibitors).
Phagocytosis of bacteria by guinea pig leukocytes was associated with the conversion of iodide to a trichloroacetic acid-precipitable form. Iodide was localized radioautographically in the cytoplasm of human leukocytes which contained ingested bacteria. Iodide fixation was not observed in the absence of phagocytosis or in the presence of Tapazole.
FURTHER OBSERVATIONS ON THE MECHANISM OF RETICULOENDOTHELIAL BLOCKADE
Authors: Drutz David J. , Koenig M. Glenn , Rogers David E. 
Published: June 2004

The mechanism of the reticuloendothelial "blockade" which followed injection of large quantities of chromic phosphate without exogenous stabilizing material was investigated in Wistar rats.
The RE blockade observed for several hours after induction appeared related to the continuing circulation of the chromic phosphate-blockading dose, and a reduction in the size of the particles used enhanced blockade.
RE blockade appeared to be particles specific and was not related to a generalized depression of RE-phagocytic cell function.
Studies in isolated perfused rat livers appeared to eliminate saturation of particle-specific macrophage clones as a likely explanation of blockade, and blockade could not be explained on the basis of depletion of serum opsonins.
In the system employed, it is postulated that blockade occurs when large numbers of circulating particles saturate specific macrophage cell membrane-binding sites rather than from physical stuffing of RE-phagocytic cells.
STUDIES ON CIRCULATING IMMUNE COMPLEXES
Authors: Cochrane Charles G. , Hawkins David 
Published: June 2004

The relationship between certain physicochemical properties of circulating immune complexes and their ability to localize in vessel walls during a state of increased permeability was studied. The ability to become deposited was related to the large size of complexes, rather than to their net charge or to a specific affinity between complexes and structures of vessel walls.
Soluble complexes with sedimentation rates greater than 19S were capable of being entrapped along the vessel wall membranes, while complexes smaller than this were not. These large complexes were removed rapidly from the circulation, while smaller complexes persisted. Minimal levels of total complexes in the circulation necessary for detectable vascular localization were found to be as low as 15 µg antibody N/ml plasma.
In experimental serum sickness, a disease known to be induced by circulating immune complexes, the development of vascular and glomerular lesions occurred almost exclusively in rabbits having large (greater than 19S) circulating immune complexes. Animals with smaller complexes did not show deposition of complexes in glomeruli or development of glomerulonephritis. Their incidence of vasculitis was markedly reduced.
SUPPRESSION OF ADJUVANT DISEASE IN THE RAT BY HETEROLOGOUS ANTILYMPHOCYTE GLOBULIN
Authors: Currey H. L. F. , Ziff Morris 
Published: June 2004

The effect of antilymphocyte globulin (ALG) on adjuvant arthritis, an immunologically induced disease in the rat, was studied. ALG was prepared from the serum of rabbits immunized against rat lymphocytes.
Adjuvant arthritis was induced in rats by a single intracutaneous injection of Freund's complete adjuvant; after 9 to 12 days, all control rats developed polyarthritis. Administration of antilymphocyte globulin about the time of adjuvant injection produced marked inhibition of clinical disease. Some suppression was apparent even when ALG was started after the onset of arthritis. Rats receiving ALG remained conspicuously healthy compared to controls. Urinary findings and renal histology showed no evidence of nephritis. The results of serum corticosterone determinations made it unlikely that adrenal stimulation contributed to the actions of ALG.
Antilymphocyte preparations lowered peripheral lymphocyte counts and suppressed primary antibody responses to sheep erythrocytes, but had little effect on the skin reaction to PPD, even in rats protected from arthritis.
All rats given ALG developed antibodies to rabbit globulin; there was no evidence that ALG inhibited the appearance of antibodies to itself, and prior hyperimmunization of rats with rabbit globulin did not interfere with the biological activity of ALG subsequently injected.
Antisera produced separately against lymph node and thymus cells had identical properties with regard to agglutination of lymphocytes and thymus cells. Administered to rats, these preparations were equally potent in lowering lymphocyte counts and suppressing both adjuvant arthritis and the primary antibody response to sheep erythrocytes.
It is concluded that ALG, as used in these experiments, is a potent immunosuppressive agent without obvious toxic effects.
HEMOPOIETIC COLONY STUDIES
Authors: Wolf N. S. , Trentin J. J. 
Published: June 2004

In heavily irradiated mice, bone marrow regeneration of either endogenous or exogenous origin was shown to occur in discrete foci comparable to the more intensively studied spleen colonies. The number of endogenous bone marrow colonies was inversely related to dose of whole body X-irradiation. Endogenous marrow colonies were found after higher doses of irradiation than were endogenous spleen colonies. Most of them were granulocytic in nature.
Exogenous bone marrow colonies in lethally irradiated mice injected with bone marrow cells were proportional in number to the dose of cells injected, appeared at a time comparable to spleen colonies like which, at 7 or 8 days, they were of single differentiated cell line, either granuloid or erythroid or megakaryocytic, with a small percentage of "mixed" colonies.
Whereas erythroid colonies outnumber granuloid colonies in spleen, either in situ or subcutaneously transplanted (E:G colony ratio of about 3.5), granuloid colonies outnumber erythroid in bone marrow (E:G colony ratio of about 0.7). The characteristic E:G colony ratios of spleen and marrow appear more likely to be the result of a hemopoietic organ stromal influence on pluripotent colony forming units (CFU's) than of selective lodgment of committed (unipotent) granuloid and erythroid CFU's in bone marrow and spleen, respectively, as indicated by the following.
Bone marrow stem cells (CFU) which had reseeded the marrow cavity of irradiated primary recipients 18–24 hr earlier, were reharvested and retransplanted intravenously into irradiated secondary hosts. The E:G colony ratio of the colonies formed in the spleen of the secondary hosts was typical of primary spleen colonies (2.8), that of the colonies formed in the marrow cavity was typical of bone marrow colonies (0.6). Pieces of marrow stroma containing reseeded CPU's from the contralateral femur of these same primary recipients were implanted by trocar directly into the spleens of other irradiated secondary recipients. Those CPU's that developed in the intrasplenic-implanted marrow stroma yielded an. E:G colony ratio of 0.1. Those that migrated into the contiguous and remote portions of the spleen gave E:G colony ratios of 2.9 and 2.4, respectively.
Irradiated marrow stroma and normal spleen CPU's (a 1 mm cube of spleen) were loaded into the same trocar and implanted directly into the spleens of irradiated mice. The spleen CFU's that migrated into the implanted marrow stroma yielded five granuloid and two mixed colonies. The larger number that developed in the host spleen yielded an E:G colony ratio of 2.9 or higher.
Of those 19 mixed colonies that bridged the junction of spleen and implanted marrow stroma in each of the above two experiments, in every case, the erythroid portion of the colony was in the splenic stroma, the granuloid portion was in the marrow stroma.
SPECIFICITY OF CELLULAR IMMUNE RESPONSES
Authors: Paul William E. , Siskind Gregory W. , Benacerraf Baruj 
Published: June 2004

In vitro antigen stimulation of DNA synthesis in lymph node cultures from immunized guinea pigs can be obtained with very low (10–4 µg/ml) antigen concentrations in the culture fluid. Immunization with low doses of DNP-GPA leads to a cell population capable of being stimulated, on the average, by low concentration of antigen whereas immunization with large antigen doses results in a sensitive cell population requiring, on the average, high antigen concentrations for stimulation. These findings correlate well with the affinity for hapten of the serum antibodies produced by these guinea pigs.
Both delayed reactions in vivo and DNA synthesis in vitro can be stimulated by hapten conjugated to proteins different from that used in primary immunization. However the immunizing conjugate is much more effective in terms of antigen concentration required for a given response.
These results can be understood in terms of a thermodynamically driven interaction of antigen (or "processed" antigen) with cell-associated antibody.