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Biomedical subjects

B L Reynolds

Publications and source records attributed to B L Reynolds.

17 recordsLinked to original sources
PubMed1985

The correlation between serum IgA antibody levels and resistance to infection with Salmonella typhimurium after oral immunization with various salmonellae.

Subsequent to oral feeding of various Salmonella strains to mice, the IgA antibodies directed against the O-somatic antigens of the immunising strain were measured in both serum and intestinal juice, using the ELISA technique. 21 days after oral immunization the IgA antibody levels were relatively high only in those mice which were resistant to challenge with a virulent strain of Salmonella typhimurium. Because there was no correlation between protection and the specificity of the 'O' somatic antigens of the immunising and challenge strains, the IgA antibodies measured were not responsible for protection. Nevertheless, the level of these antibodies affords a good index of the resistance of mice or immune status of mice to Salmonella infection.

Administration, Oral↗
PubMed1984

The ability of IgA to inhibit complement consumption by complement-fixing antigens and antigen-antibody complexes.

The polymeric and monomeric (7S) forms of the nitrophenyl-specific MOPC-315 murine IgA myeloma protein were examined for their capacity to inhibit the consumption of guinea-pig complement (C) by the C-activating protein DNP46BSA and by antigen-antibody (Ag-Ab) complexes. On a molar basis, 13S IgA was slightly (2-3 fold) more efficient than 7S IgA in inhibiting C consumption by DNP-BSA. When mixed with IgG antibodies prior to incubation with a non-complement-fixing antigen (TNP-KLH), 13S IgA was considerably more effective than 7S IgA in preventing the formation of Ag-Ab complexes able to fix C. The degree of inhibition observed was related to the concentration of C used in the assay, being greater at lower C concentrations.

Animals↗
PubMed1981

Inhibition of cutaneous anaphylaxis and arthus reactions in the mouse by antigen-specific IgA.

The nitrophenyl-specific IgA myeloma protein secreted by the MOPC-315 mouse plasmacytoma was examined for its capacity to inhibit antibody-mediated hypersensitivity reactions in the mouse. Specific inhibition of both cutaneous anaphylactic and complement-dependent (Arthus) reactions was observed in sensitised mice when the eliciting antigen was mixed with IgA prior to injection or when the mice injected with plasmacytoma cells and possessed detectable amounts of MOPC-315 IgA in their serum at the time of challenge. The possibility that IgA antibodies have a role in suppressing hypersensitivity reactions at mucosal surfaces is discussed.

Animals↗
PubMed1979

Adenocarcinoma of the frontal sinus with extension to the brain in a horse.

A space-occupying intracranial mass was diagnosed in a horse. The clinical findings included blindness, circling to the right, apprehension, anorexia, weight loss, and leaning against the stall. On ophthalmoscopic examination, the most striking observation was complete bilateral devascularization of the retinas. The horse was euthanatized and necropsied. Necroscopy revealed the mass to occupy the olfactory and frontal areas of the left hemisphere of the brain and part of the left frontal sinus. Microscopically, the mass was an adenocarcinoma and probably arose from the lining epithelium of the sinus or from the subepithelial glands.

Adenocarcinoma↗
PubMed1975

Interaction of complement components with a serum-resistant strain of Salmonella typhimurium.

Salmonella typhimurium C5 is under normal conditions (physiological saline containing 0.002 M Mg2+) resistant to the action of antibody and complement (C). It becomes sensitive, however, when suspended in tris(hydroxymethyl)-aminomethane buffer (Reynolds and Pruul, 1971; Reynolds and Rowley, 1969). The interaction of complement components with this strain sensitized with specific antibody has been studied to identify the intermediate step at which inhibition occurs. The components C1 yields C2 react normally, as has been shown by lysis of complement-treated cells incubated with complement in ethylenediaminetetraacetic acid. Also, the reaction of C3 can be demonstrated by positive immune adherence and agglutination with anti-C3. The complement-treated cells do not, however, react with rabbit C6 to 9 or rabbit serum lacking C6 in tris(hydroxymethyl)aminomethan buffer. We conclude from these date that C5 can not react effectively under normal conditions. In contrast, if bacteria-antibody complexes are pretreated with rabbit serum lacking C6 in tris(hydroxymethyl)aminomethane buffer, they are readily lysed by incubation with C6 to 9. Thus, C5 can react with the bacterial surface in tris(hydroxymethyl)-aminomethane buffer.

Animals↗
PubMed1972

Interaction of complement and polymyxin with gram-negative bacteria.

The interaction of complement and polymyxin with gram-negative bacteria has been investigated by using three strains of Salmonella typhimurium in an attempt to determine the loci of complement action. It has been shown that the bactericidal activities of complement and polymyxin towards a smooth gram-negative organism are similarly affected by various components of the bactericidal test system. Further, complement and polymyxin have been shown to act synergistically in the bactericidal event. Evidence is presented which suggests that each agent produces lesions in the outer membrane of gram-negative bacteria, allowing lysozyme to interact with its glycopeptide substrate. An attack on the inner cytoplasmic membrane follows, since cell respiration is rapidly inhibited and this membrane becomes sufficiently disorganized to permit massive leakage of beta-galactosidase from the cytoplasm of the target cells.

Bacteria↗
PubMed1971

Sensitization of complement-resistant smooth gram-negative bacterial strains.

Many gram-negative bacteria are susceptible to the bactericidal action of complement in the presence of specific antibody. As a general rule, rough strains are readily killed, whereas smooth strains are relatively resistant. The results of this study show that the serum sensitivity of smooth gram-negative organisms can be controlled by the environmental conditions imposed by the test system. Smooth organisms which are completely resistant to the bactericidal action of immune serum plus complement in the presence of divalent cations become quite sensitive in a test system containing a relatively high concentration of certain univalent cations; this effect is potentiated by ethylenediaminetetraacetic acid. Since it is generally accepted that the serum resistance of smooth gram-negative organisms is associated with the protection afforded by their thick lipopolysaccharide layer, it is suggested that environmental conditions favoring serum sensitization cause some structural disorganization of the smooth lipopolysaccharide of these cells.

Journal Article↗
PubMed1971

Protective role of smooth lipopolysaccharide in the serum bactericidal reaction.

The mechanism by which smooth lipopolysaccharide (LPS) protects Salmonella typhimurium C5 from the lethal action of specific antibody and complement has been investigated. Tris(hydroxymethyl)aminomethane (Tris) and ethylenediaminetetraacetate (EDTA), which sensitize S. typhimurium C5 to the bactericidal action of immune serum, were shown to cause appreciable structural modification of the smooth LPS associated with these cells. Mg(2+) was shown to reverse the sensitization of C5 by Tris, but this divalent cation was unable to reverse the sensitizing effect of Tris plus EDTA, which, unlike Tris, caused relatively large amounts of O-antigenic components to be released from the C5 cell wall. The possibility that smooth LPS blocks the interaction of activated complement components with receptors on the cell wall is discussed.

Animals↗
PubMed1969

Kinetics of adsorption of colicin CA42-E2 and reversal of its bactericidal activity.

The kinetics of killing of Escherichia coli K-12 by colicin CA42-E2 have been studied, and the data were used to estimate the adsorption constant of this colicin under various environmental conditions. Evidence was obtained suggesting that the adsorption of colicin occurred in two stages; the earlier stage was reversible and did not lead to the death of the cell, the latter stage was irreversible and bactericidal. Cells which had adsorbed a lethal quantity of colicin could be rescued for a short time by inactivating the adsorbed colicin with trypsin. However, when the metabolic activity of the cells was totally arrested the lethal effect of adsorbed colicin was subject to trypsin reversal over long periods of time.

Adsorption↗
PubMed1966

Reconstituted collagen and chromic catgut suture for colon anastomoses in dogs.

Reconstituted collagen sutures demonstrate no advantages over catgut sutures in this study, which was designed to observe the physiochemical and morphological characteristics of reconstituted collagen after implantation in colon anastomoses in dogs. There are three distinct disadvantages of the collagen suture: (1) early separation and fragmentation of the suture fiber, (2) evidence of prolonged chemical irritation, and (3) hyper-fibrillosis about the suture wound in prolonged observations.

Anastomosis, Surgical↗