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Biomedical subjects

M S Artenstein

Publications and source records attributed to M S Artenstein.

At least 37 records · Page 2Linked to original sources
PubMed1974

Alterations in dihydropteroate synthetase in cell-free extracts of sulfanilamide-resistant Neisseria meningitidis and Neisseria gonorrhoeae.

Extracts from Neisseria meningitidis and N. gonorrhoeae with varying susceptibility to sulfanilamide have been investigated for dihydropteroate synthetase activity. Sulfanilamide was a competitive inhibitor of dihydropteroate synthetase with respect to p-aminobenzoate in extracts from both species. Though the K(m) for p-aminobenzoate was unaffected, the K(i) for sulfanilamide increased and the V(max) decreased as the strains' resistance to sulfanilamide increased. Temperature studies have revealed differences in the dihydropteroate synthetase from N. meningitidis and N. gonorrhoeae. A direct relationship was observed between the minimal inhibitory concentration of sulfanilamide determined in vitro and the ratio of K(i)/K(m). This ratio may be a molecular explanation of sulfanilamide resistance for both N. meningitidis and N. gonorrhoeae.

Cell-Free System↗
PubMed1974

Human antibody response to three meningococcal outer membrane antigens: comparison by specific hemagglutination assays.

Three cell surface antigens, protein, lipopolysaccharide, and polysaccharide, were purified from group B and group C strains of Neisseria meningitidis representing a variety of serotypes. Chemical analysis indicated that cross-contamination was on the order of 1%. Sensitization of sheep erythrocytes with these antigens resulted in highly specific passive hemagglutination assays for the three kinds of antigens. Paired human sera from several groups of individuals were tested by hemagglutination for antibody against each of the antigens. Patients with group B or C systemic meningococcal disease showed increases in antibody titer against all three kinds of antigens, but the antibody response to B polysaccharide was low compared with the response to C polysaccharide. Nasopharyngeal carriers of group B meningococci showed significant increases in titer only against the protein antigens, and noncarriers who received a C-polysaccharide vaccine had a specific response to the C polysaccharide. A given protein or lipopolysaccharide antigen reacted on the average equally well with either group B or C convalescent sera. These results suggest that all three antigens may play a role in the broad human immunity following natural infection.

Journal Article↗
PubMed1973

Antibody responses to meningococcal polysaccharide vaccines.

Over the past 4 years 19 lots of group C polysaccharide vaccine and five lots of group A polysaccharide vaccine have been tested for their immunogenicity in man. For each lot tested, groups of 18 to 50 men received 50 mug of vaccine subcutaneously. Sera were obtained prior to and 2 weeks after vaccination. The analytical and serological methods used in these studies were Sepharose 4B chromatography for the estimation of molecular size, the radioactive antigen binding assay, and the indirect hemagglutination (IHA) test for measuring the antibody response. Results have shown that the radioactive antigen binding assay is preferable to the IHA test as a measure of antibody response. Group C meningococcal vaccines have been highly stable when stored at 4 C in powdered form. All lots of group C vaccine tested to date have been of equal potency, with molecular weight varying from 520,000 to 2,000,000. Group A polysaccharides have been found to be unstable after 2 years of storage at 4 C. Optimal antibody response to the group A vaccines appears to be directly related to the molecular size of the preparation.

Adult↗
PubMed1972

Hemagglutination inhibition for serogrouping of Neisseria meningitidis.

A hemagglutination inhibition (HI) test has been studied as an alternative to bacterial agglutination (BA) for serogrouping strains of Neisseria meningitidis isolated from clinical specimens. The HI test consists of polysaccharide antigens adsorbed to sheep red blood cells which were then agglutinated by group-specific antisera. Supernatant fluids from suspensions of meningococci were used to inhibit the agglutination. Results of the two tests agreed for 381 (80%) carrier strains. Of the remaining 95 strains, 82 (86%) were identified by HI although they were nongroupable by BA. Thus, the HI test has been shown to be more highly specific and sensitive and to be more economical of reagents and time than the BA test.

Adsorption↗
PubMed1972

Latex agglutination test for measurement of antibodies to meningococcal polysaccharides.

A latex agglutination test employing serogroup-specific meningococcal polysaccharides as the antigen has been developed. The test has been used to measure serological responses in patients with meningococcal disease, in meningococcal carriers, and in volunteers who received meningococcal vaccines. It has been shown to be a sensitive and highly specific test for the detection of group-specific meningococcal antibody. The advantages of standardized particles and antigens which are simple to prepare and stable make this assay feasible for many nonspecialized or small laboratories.

Antibodies, Bacterial↗
PubMed1972

Isolation and characterization of a native cell wall complex from Neisseria meningitidis.

A cell wall complex has been isolated by gentle methods from both the medium supernatant fluid and whole organisms of Neissieria meningitidis cultures. The two types of preparations have been shown to be essentially identical on the basis of chemical composition, electron microscopy, and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). Four major components were identified in the complex: group-specific polysaccharide (4 to 10%), protein (45 to 65%), lipopolysaccharide (10 to 25%), and lipid (15 to 30%). The whole complex was found to be immunogenic in rabbits and to elicit production of antibody directed against the protein, the group-specific polysaccharide, and the lipopolysaccharide components. The isolated protein component was also found to be immunogenic in rabbits and to elicit production of serotype-specific antibody. The protein component was found to produce a band pattern in SDS-PAGE that is simple, reproducible, and strain dependent. The lipopolysaccharide component was found to have chemical and biological properties characteristic of bacterial endotoxin. We propose that this complex is representative of the outer trilaminar membrane of the meningococcal cell envelope in its native state.

Animals↗