Biomedical subjects

H Chart

Publications and source records attributed to H Chart.

114 records · Page 7Linked to original sources

PubMed1985

Naturally occurring antibodies in human sera that react with the iron-regulated outer membrane proteins of Escherichia coli.

Sera from normal healthy human adults and infants, as well as sera from mice, rabbits, and guinea pigs, were examined by immunoblotting for naturally occurring antibodies reacting with outer membrane proteins of two Escherichia coli strains, O111 and O18. Some individuals had antibodies reacting very strongly with the iron-regulated outer membrane proteins, including the ferric-enterochelin receptor protein (Mr, 81,000), as well as with ompA. However, sera from infants contained predominantly antibodies to ompA; antibodies recognizing the iron-regulated outer membrane proteins were either absent or barely detectable. In human serum the antibodies were mainly of the immunoglobulin G class. No serotype-specific antibodies to the lipopolysaccharide of E. coli O111 or O18 were found in the sera tested.

Antibodies, Bacterial↗

PubMed1984

Structural and immunochemical homogeneity of Aeromonas salmonicida lipopolysaccharide.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze the lipopolysaccharides of typical and atypical strains of the fish pathogen Aeromonas salmonicida. 32P intrinsically radiolabeled lipopolysaccharide in sarcosinate-extracted outer membrane preparations, lipopolysaccharide stained by silver in proteinase K-digested outer membrane preparations and whole cell lysates, as well as purified lipopolysaccharide, displayed O-polysaccharide chains which were unusually homogeneous with respect to chain length. Chemical analysis further revealed that the sugar composition of the smooth lipopolysaccharide purified from three typical strains was very similar. Immunoblotting and immunofluorescent staining with both polyclonal and monoclonal antibody showed that the O-polysaccharide chains were strongly immunogenic and were antigenically cross-reactive on typical and atypical strains from diverse origins. Immunofluorescence analysis and phage binding studies demonstrated that a number of these O-polysaccharide chains traversed the surface protein array of virulent strains of A. salmonicida and were exposed on the cell surface.

Aeromonas↗

PubMed1984

Characterization of the surface antigens of the marine fish pathogens Vibrio anguillarum and Vibrio ordalii.

The technique of immunoblotting was used to identify the surface antigens of the marine vibrios pathogenic for fish, Vibrio anguillarum and Vibrio ordalii. Polyclonal antisera raised in rabbits to strains representing the two most common serotypes causing Vibriosis in fish in North America were used. The results demonstrated that antigenic specificity was conferred by the lipopolysaccharides, with three serotypes being displayed among the strains examined. The lipopolysaccharides of strains chosen as type species for V. anguillarum and V. ordalii displayed antigenic cross-reactivity. The morphological heterogeneity of the Vibrio lipopolysaccharides was also analyzed in silver-stained polyacrylamide gels and by intrinsic 32P-radiolabelling. Two distinct lipopolysaccharide morphologies were exhibited, one with 0 polysaccharide chains of heterogeneous chain length, the other having 0 polysaccharide chains of more uniform chain length but displaying microheterogeneity. These lipopolysaccharide morphologies corresponded to different serogroups. Two minor proteins of apparent molecular weights 49000-51000 present in outer membrane preparations isolated by the sarcosinate extraction procedure were also strong antigens, and common to all strains of V. anguillarum tested and to several strains of V. ordalii. The major outer membrane protein was a weak antigen common to both species.

Animals↗

PubMed1983

Multiflagellate variants of Vibrio anguillarum.

An ultrastructural examination of six strains of Vibrio anguillarum of varying virulence for eels revealed an apparent correlation between pathogenicity and the possession of more than one flagellum. The relationship between V. anguillarum surface appendages and virulence is discussed.

Animals↗

PubMed1983

Acquisition of iron by Aeromonas salmonicida.

The ability of six typical and three atypical strains of Aeromonas salmonicida to sequester Fe3+ from the high-affinity iron chelators ethylenediaminedihydroxy-phenylacetic acid, lactoferrin, and transferrin was determined. Typical strains were readily able to sequester Fe3+ and used two different mechanisms. One mechanism was inducible and appeared to involve production of a low-molecular-weight soluble siderophore(s). Iron uptake by this mechanism was strongly inhibited by ferricyanide. One virulent strain displayed a second mechanism which was constitutive and required cell contact with Fe3+-lactoferrin or -transferrin. This strain did not produce a soluble siderophore(s) but could utilize the siderophore(s) produced by the other strain. Fe3+ uptake by this stripping mechanism was strongly inhibited by dinitrophenol. Atypical strains displayed a markedly reduced ability to sequester iron from high-affinity chelators, although one of them was able to utilize the siderophores produced by the typical strain. In all strains examined, Fe3+ limitation resulted in the increased synthesis of several high-molecular-weight outer membrane proteins.

Aeromonas↗

PubMed1980

Temperature-sensitive mutants of equine arteritis virus.

Seventeen temperature-sensitive mutants of equine arteritis virus, a nonarthropod-borne togavirus, have been isolated. 5-Fluorouracil, o-methylhydroxylamine and ethyl methanesulphonate were used as mutagens. The mutants were characterized by their ability to synthesize virus RNA and virus proteins at the permissive (35 degrees C) and restrictive temperature (40 degrees C) using autoradiography of cells labelled with 3H-uridine in the presence of actinomycin D and immunofluorescence respectively. Among the mutants, four were unable to synthesize virus RNA and virus proteins at 40 degrees C (RNA-/protein-). The other mutants were RNA-/protein+ (3); RNA +/-/protein- (2); RNA+/protein+ (6) and RNA+/protein- (1).

Equartevirus↗