The specific polysaccharide of Type III pneumococcus, with only 0.05 per cent of N and 0.01 per cent of P, still shows almost maximal precipitation of a Type III antipneumococcus rabbit serum and the expected antigenicity in man. There is therefore no evidence that a prosthetic group is involved in these characteristic activities. Footnotes Submitted: 15 June 1951

Browse All Journals

Related Journals:

Immunologic Research BMC Immunology

Issue 10 (May)

journal article

LitStream Collection

AN ELECTROPHORETIC STUDY OF A STREPTOCOCCAL PROTEINASE AND ITS PRECURSOR

Shedlovsky, Theodore; Elliott, S. D.

1951 The Journal of Experimental Medicine

doi: 10.1084/jem.94.5.363pmid: 14888818

An electrophoretic study of crystalline preparations of a streptococcal proteinase and its precursor established their isoelectric points at pH values of 8.42 and 7.35 respectively (ionic strength 0.10). Preparations of the proteinase appeared to be electrophoretically homogeneous over a pH range of 5 to 8.5. Precursor preparations contained a relatively low concentration of the active enzyme visible as a separate peak in electrophoretic patterns of sufficiently concentrated solutions. Autocatalytic conversion of precursor to active enzyme was complete and resulted in a corresponding change in the electrophoretic pattern. Treatment of precursor preparations with trypsin produced incomplete conversion to the active enzyme and resulted in the formation of a modified precursor protein. This differed from the parent substance in electrophoretic mobility and in susceptibility to trypsin, but resembled it in immunological specificity and, as previously shown, in susceptibility to conversion to active enzyme by autocatalysis. Serological reactions of precursor and active enzyme components withdrawn from the cell after electrophoresis are described. It appears that the precursor protein may have two antigenic groups, one specific, the other shared by the active enzyme which behaves as a single antigen. Footnotes Submitted: 28 June 1951

journal article

LitStream Collection

CYTOCHEMICAL STUDIES ON THE KIDNEY

Kurnick, N. B.

1951 The Journal of Experimental Medicine

doi: 10.1084/jem.94.5.373pmid: 14888819

Determinations of the desoxyribonucleic acid (DNA) content of the kidneys of growing rats were made on the whole tissues and on isolated nuclei. It was found that the DNA content per nucleus is constant in rats of different weights. The DNA content of the kidneys increased proportionately to their mass over the range studied. It is concluded that increase in mass is primarily due to cell multiplication. Footnotes Submitted: 11 July 1951

journal article

LitStream Collection

STUDIES ON ENDEMIC PNEUMONIA OF THE ALBINO RAT

Nelson, John B.

1951 The Journal of Experimental Medicine

doi: 10.1084/jem.94.5.377pmid: 14888820

A colony of albino rats was developed from three breeders (not germ-free) originally delivered by Cesarian section and artificially reared in the laboratories of Professor James A Reyniers. The colony has been maintained under quarantine since June, 1948, in the absence of any demonstrable involvement of the respiratory tract or of the middle ears. At autopsy pleuropneumonia-like organisms, Streptobacillus moniliformis , and the virus-like agent associated with endemic pneumonia were not recoverable from the lungs or the nasal passages of 81 young and adult rats. During the same time interval the morbidity rate of pneumonia in another rat colony known to be free from infectious catarrh was 51 per cent while the incidence of infection with the virus-like agent approached 100 per cent. Footnotes Submitted: 29 June 1951

journal article

LitStream Collection

THE EFFECT OF CHEMICAL AND PHYSICAL AGENTS ON THE PHAGE RECEPTOR OF PHASE II SHIGELLA SONNEI

Barry, Guy T.; Goebel, Walther F.

1951 The Journal of Experimental Medicine

doi: 10.1084/jem.94.5.387pmid: 14888821

A study has been made of the effect of bactericidal agents on the phage adsorption properties of Phase II. Sh. sonnei . The ability of this microorganism to adsorb T 3 , T 4 , and T 7 phages can be altered by treating the bacteria with chemical and physical agents. Footnotes Submitted: 24 July 1951

journal article

LitStream Collection

STUDIES ON THE PSITTACOSIS-LYMPHOGRANULOMA GROUP

Sigel, M. Michael; Girardi, Anthony J.; Allen, Emma G.

1951 The Journal of Experimental Medicine

doi: 10.1084/jem.94.5.401pmid: 14888822

Because of the peculiar properties of the psittacosis-lymphogranuloma group of viruses, the pattern of multiplication in the allantois of the chick embryo of one of their number, meningopneumonitis virus, was studied. This was done by determination of the changes in its infectivity for mice and chick embryos. Titration of infectivity in embryos proved to be a more sensitive procedure than titration in mice; the latter procedure however, had the advantage of greater simplicity and gave more clear-cut results. The mouse titration method was used in most of the experiments. Following inoculation of virus into the allantois, there was a slow decrease in infectivity in the allantoic fluids followed by an increase due to appearance of new virus between 24 and 48 hours. The slope of declining infectivity in the allantoic fluids in ovo was similar if not identical with the slope of decreasing infectivity in allantoic fluids in vitro caused by thermal degradation of virus. Multiplication of the virus in allantoic membranes was characterized by the following pattern: ( a ) Increase in infectivity in the first few hours (exact duration of increase depended on concentration of virus in inoculum) due to adsorption of virus. ( b ) Decrease in infectivity up to about 20 to 24 hours. ( c ) Increase in infectivity due to appearance of the new generation of virus. The growth curve of meningopneumonitis is analyzed and the pattern of growth is discussed in the light of the present concepts of viral multiplication. Footnotes Submitted: 25 July 1951

journal article

LitStream Collection

THE EFFECT OF ADRENOCORTICOTROPIC HORMONE ON INFLAMMATION DUE TO TUBERCULIN HYPERSENSITIVITY AND TURPENTINE AND ON CIRCULATING ANTIBODY LEVELS

Osgood, Charles K.; Favour, Cutting B.

1951 The Journal of Experimental Medicine

doi: 10.1084/jem.94.5.415pmid: 14888823

The treatment with adrenocorticotropic hormone of guinea pigs sensitized with heat-killed tubercle bacilli caused suppression of their skin reactivity to tuberculin. Similar animals treated with saline did not show this change. Normal guinea pigs treated with adrenocorticotropic hormone showed suppression of inflammation, but not necrosis, produced by intracutaneous oil of turpentine. There was slight, but probably not significant, diminution of inflammation during saline administration. Tuberculin complement-fixing antibody titers were not altered by either adrenocorticotropic hormone or saline administration. Adrenocorticotropic hormone produced marked eosinopenia and lymphopenia in guinea pigs. Footnotes Submitted: 21 June 1951

journal article

LitStream Collection

THE DOMINANT ROLE OF THE LIVER IN PLASMA PROTEIN SYNTHESIS

Miller, L. L.; Bly, C. G.; Watson, M. L.; Bale, W. F.

1951 The Journal of Experimental Medicine

doi: 10.1084/jem.94.5.431pmid: 14888824

A direct study of the isolated rat liver perfused with oxygenated blood containing amino acids and lysine-ϵ-C 14 has yielded facts indicating that the liver synthesizes practically all the plasma fibrinogen, the albumin fraction, and probably more than 80 per cent of the plasma globulin fraction. The response of the isolated perfused liver in protein synthesis is qualitatively and quantitatively analogous to that of the intact animal, notably in ( a ) the ability to discriminate between natural L -lysine and D -lysine, ( b ) the per cent of isotopic amino acid converted to CO 2 , ( c ) the per cent utilized in liver and plasma protein synthesis. The results obtained with the perfused liver are compared and contrasted with those reported for tissue homogenates, minces, and slices. Footnotes Submitted: 18 July 1951

Showing 1 to 8 of 8 Articles

Articles per page