Studies on Meningococcus Infection

Scherp, Henry W.; Rake, Geoffrey

doi:10.1084/jem.61.6.753

Cited by 31 publications

(9 citation statements)

References 7 publications

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“…The criteria used for demonstration of change in type are as follows. Type I and type IIa cells are identified by their production of a type-specific substance (7)(8)(9). The production of each type-specific substance can be identified by swelling of the capsule of the organism or by precipitation of the soluble substance in the presence of the type-specific antibody.…”

Section: Methodsmentioning

confidence: 99%

Transformation of Type Specificity of Meningococci

Alexander

Redman

1953

Journal of Experimental Medicine

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Heritable type-specific traits have been induced in meningococcus populations by exposure to desoxyribonucleic acid (DNA)-containing extracts derived from meningococcus cells of the type desired. The DNA has been shown to be an essential component of the transforming extract. As in the H. influenzae system, the reaction between the susceptible cell and the DNA responsible for the heritable change requires less than 15 minutes. Only a minute proportion of the total cells exposed to the DNA extracts for a short time are susceptible to the change; but in the growth and reproduction of bacteria susceptible cells appear with fairly predictable frequency. Type I specific traits have been induced in populations of RIIa and SIIa cells. Type IIa specificity has been induced in RIIa cells.

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Section: Methodsmentioning

confidence: 99%

Transformation of Type Specificity of Meningococci

Alexander

Redman

1953

Journal of Experimental Medicine

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“…Calculated to the ash-free basis, except where no ash determinations are gaven. Taken from(9). polysaccharide as compared with those of M6C, M8CF, and M9B2 indicate a polysaccharide content about 55 to 60 per cent.…”

mentioning

confidence: 93%

Preparation of the Type-Specific Polysaccharide of the Type I Meningococcus and a Study of Its Effectiveness as an Antigen in Human Beings

Kabat

Kaiser

Sikorski

1944

Journal of Experimental Medicine

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The demonstration by Francis and Tillett (1) and others (2-5) that the typespecific polysaccharides of pneumococci are antigenic in man and induce the production of antibodies in humans which protect mice against subsequent injection of virulent organisms, has led to numerous attempts to use these purified polysaccharides in active immunization (4, 6). Since the antipolysaccharide in Type I antimeningococcal sera has also been found to be effective in protecting mice, the capacity of several preparations of Type I meningococcal polysaccharide to induce precipitin formation in human volunteers was studied. Use was made of the colorimetric micro method for the estimation of antibody developed by Heidelberger and MacPherson (7) and applied in a study of the antibody response accompanying convalescence from pneumonia (8).Preparations of the specific polysaccharide of the Type I meningococcus have been made and characterized by Scherp and Rake (9). Their materials, however, were shown to contain at least 20 per cent of a second substance which reacted with antimeningococcal sera (10) but was found not to remove protective antibody (11). A sample of polysaccharide (preparation 18 (9)) was generously supplied by Dr. H. W. Scherp for use in this investigation. In addition, since both glacial acetic acid and barium hydroxide had been used in purifying their polysaccharide, several lots were prepared in which the use of these fairly drastic reagents was avoided. The chemical and immunological properties of these materials were studied and it was found that, unlike preparation 18, they showed only a slight zone in the quantitative precipitin reaction where both antigen and antibody could be detected in the supernatant. No evidence 6f precipitin formation in humans was obtained with preparation 18, but in a few instances a small but significant antibody response to injection of *

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“…It is weakly but definitely antigenic in man. Direct comparison with an earlier product obtained by Scherp & Rake (18) indicates that the avoidance of acid or alkali durinEr the preparation of the more recent material has resulted in a somewhat purer and more nearly natural antigenic substance.…”

Section: Complexity Of the Bacterial Cellmentioning

confidence: 82%