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W F Verwey

Publications and source records attributed to W F Verwey.

15 recordsLinked to original sources
PubMed1976

Distribution of cholera organisms in experimental Vibrio cholerae infections: proposed mechanisms of pathogenesis and antibacterial immunity.

This study was undertaken to determine the sequence of events in the microenvironment of the intestinal tract that culminate in the symptoms of cholera and to attempt to define more clearly the mechanisms involved in antibacterial immunity. The extent to which mucus occurs in the normal intestine of rabbits and the appearance of the intestinal villi in unfixed frozen sections was demonstrated. The villi and intervillous spaces were found to be normally covered by a layer of mucoid material that formed a mucous zone between the intestinal contents and the tips of the villi. The distribution of cholera organisms in normal and immunized animals was demonstrated by the staining of frozen-tissue sections with specific fluorescent antibody. Study of tissue sections from normal animals showed that the onset of fluid accumulation was concomitant with the establishment of large masses of organisms in the intervillous spaces and crypts of the intestine after the successful penetration of this mucous zone. Tissue sections from animals actively or passively immunized against a cell wall antigen of Vibrio cholerae showed clumping of vibrios in the lumen and restricted distribution in the lumen and luminal border of the mucous zone. Antibody was not lytic in vivo.

Animals↗
PubMed1973

Differential medium for Vibrio cholerae.

A differential medium designed for rapid presumptive identification of Vibrio cholerae was described and shown to be useful for enumeration of viable cholera vibrios in the presence of other intestinal bacteria.

Cholera↗
PubMed1970

Isolation and Characterization of a Protective Antigen-Containing Particle from Culture Supernatant Fluids of Erysipelothrix rhusiopathiae.

The mouse-protective activity of Erysipelothrix rhusiopathiae culture supernatant fluids exists in a polydisperse form, ranging in density from aggregates which sediment at 10,000 x g for 3 hr to soluble units which will not sediment at 198,000 x g for 12 hr. A partially purified protective antigen has been isolated from the aggregates sedimented from a concentrate of the culture supernatant fluid at 20,000 x g for 3 hr. These aggregates contained the major protective antigen or antigens of E. rhusiopathiae, since, in addition to inducing active immunity, they adsorbed essentially all of the passively protecting antibody from rabbit antiserum produced by immunization with whole culture. The protective activity in these aggregates was destroyed by trypsin and greatly diminished by muramidase and heating at 64 C, but was not affected by lipase or ribonuclease.

Journal Article↗
PubMed1970

Solubilization and Characterization of a Protective Antigen of Erysipelothrix rhusiopathiae.

A particulate fraction of Erysipelothrix rhusiopathiae cultures has been subjected to butanol extraction and treatment with surface-active agents in an attempt to solubilize a protective antigen. The particulate fraction was partitioned into the butanol layer but was not solubilized. Only sodium dodecyl sulfate solubilized the particles. The soluble protective activity was not sedimented by centrifugation at 198,000 x g for 12 hr but was excluded by Sephadex G-200. Immunodiffusion studies of the soluble fraction demonstrated eight antigens, five of horse serum origin and three of E. rhusiopathiae origin. Ultracentrifugation indicated that spontaneous reaggregation occurred after removal of the sodium dodecyl sulfate. Analytical ultracentrifugation showed that 90% of the sodium dodecyl sulfatetreated material migrated as a single homogeneous 3.5S component. The physical and biological characteristics of the protective activity suggest that the protective antigen is a glyco-lipoprotein.

Journal Article↗
PubMed1965

Protective antigens from El Tor vibrios. 1. The preparation and properties of a purified protective antigen from an El Tor vibrio (Ogawa subtype).

A biochemically and immunologically homogeneous antigenic fraction having the properties of a lipopolysaccharide has been isolated from the culture supernatant of an El Tor vibrio (Ogawa subtype). This antigen was very specifically protective for mice challenged with Ogawa strains of either El Tor vibrios or Vibrio cholerae. Rabbit antisera prepared against the antigen were passively protective for mice and highly vibriocidal but had little agglutinating activity. However, the antigen was able specifically to absorb agglutinins, as well as mouse-protective and vibriocidal antibody from serum prepared against whole bacterial cells. The specific protective activity of this lipopolysaccharide was much greater than that of vaccines made from whole bacterial cells, and its toxicity in animals was about equivalent to that of whole cells. The relationship of activity to toxicity therefore represented an improvement over the vaccines that were studied.

Animals↗
PubMed1965

Protective antigens from El Tor vibrios. 2. Responses in animals and man to a partially purified Ogawa lipopolysaccharide antigen.

A previous report described the extraction and purification of a mouse-protective lipopolysaccharide antigen from culture supernatants of an El Tor vibrio of the Ogawa subtype. The chemical procedures for complete purification were complex, and considerable antigen was lost. The present paper describes a simpler method of obtaining an antigen of only slightly less purity in considerably improved yield. The method appears to be feasible for the preparation of an antigen that might be suitable for extensive immunization studies in humans.The antigen has been compared with the purified lipopolysaccharide and the Ogawa reference vaccine supplied by the National Institutes of Health with respect to active protection in mice, toxicity in mice and rabbits, and ability to produce passive mouse-protective antibody and vibriocidal antibody in rabbits. It has also been administered to a small number of volunteers in whom it was studied for its reaction-producing properties and its ability to produce agglutinin, vibriocidin and passive mouse-protective antibody. Little toxicity was found at dosages that induced very significant antibody production, and antibody remained elevated for at least six months.

Animals↗