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Biomedical subjects

D E Stewart-Tull

Publications and source records attributed to D E Stewart-Tull.

11 recordsLinked to original sources
PubMed1992

Adjuvanted oral vaccines should not induce allergic responses to dietary antigens.

Oral vaccines may contain adjuvants which might elicit allergies against dietary proteins. Four antigens were used to measure such an effect--ovalbumin, soya bean protein, lactalbumin and gluten. Neither guinea pigs nor mice showed IgE responses after oral administration of adjuvanted vaccines containing lactalbumin and gluten. No IgE responses were detected in mice with any of these antigens after oral immunization, but, in the guinea pig, nine out of 18 animals reacted to either ovalbumin or soya bean protein and none reacted to lactalbumin and gluten. It is concluded that the risk of allergy induction against normal dietary proteins is low but such tests should be applied to potential adjuvanted oral vaccines to measure any possible contraindication, especially with atopic individuals.

Administration, Oral↗
PubMed1978

The binding of lipopolysaccharide from Escherichia coli to mammalian cell membranes and its effect on liposomes.

The kinetics of the absorption of 32P- or 14C-labelled lipopolysaccharide from Escherichia coli NCTC 8623, serotype 0 125, chemotype XII, to erythrocytes, leukocytes, peritoneal macrophages and peritoneal lymphocytes was examined. Under variable conditions maximal levels of binding were found due to saturation of receptor sites on the cell membrane or steric hindrance by bound lipopolysaccharide. During adsorption slight leakage of haemoglobin was found but complete lysis of erythrocytes was ruled out after noting the effect of lipopolysaccharide on artificial lipid bilayers. The affinit of lipopolysaccharide to cell membranes revealed a consistent pattern of cyclic fluctuation between adsorption and desorption. A model was proposed to explain this cyclic fluctuation in binding based on membrane reorganization. It was significant that the cycle of lipopolysaccharide adsorption-desorption proceeded to completion even if the process was interrupted. The indication was that, once triggered, membrane reorganization occurred independently without influence from the test environment.

Animals↗
PubMed1978

The binding of adjuvant-active mycobacterial peptidoglycolipids and glycopeptides to mammalian membranes and their effect on artificial lipid bilayers.

The nature of the binding of adjuvant-active amphiphilic mycobacterial peptidoglycolipids and glycopeptides to mammalian plasma membranes was investigated together with their effect on the stability of artificial lipid bilayers. The importance of these interactions between mycobacterial components and membranes is discussed in relation to immunopotentiation, mitogenicity and tuberculous infection.

Adjuvants, Immunologic↗
PubMed1976

The dissociation of adjuvant properties of mycobacterial components from mitogenicity, and from the ability to induce the release of mediators from macrophages.

Twelve preparations from mycobacterial cell walls and culture supernatant fluids were tested for their ability to activate lymphocytes from Balb/c or Nu/Nu mice, and to increase the release of mediators from macrophages in vitro. The peptidoglycolipids (wax D) were B-cell mitogens and induced plaque-forming cells. These properties were lost if the glycopeptide component was removed, leaving the pure lipid, mycolic acid. Neither the glycopeptide fractions, with well-documented adjuvant properties, nor mycobacterial polysacchardie II-activated B cells. Only intact peptidoglycolipid showed synergy with the mitogenic effect of phytohaemagglutinin (PHA) on thymocytes from Balb/c mice. The effect was much smaller than with E. coli lipopolysacharide (LPS) or dextran sulphate. The peptidoglycolipid also enhanced the release of factors from macrophages able to modify the response of Balb/c thymus cells to PHA. In this respect it resembled E. coli LPS. Adjuvant active glycopeptides did not share this property.

Adjuvants, Immunologic↗
PubMed1975

Procedures for large-scale antiserum production in sheep.

The increased cost of maintaining and purchasing small laboratory animals used in the production of large quantities of antiserum resulted in a search for a more suitable animal. This paper describes the procedures used to raise antisera in Scottish mountain sheep.

Ammonium Sulfate↗
PubMed1975

Antigenic analysis of yeast cell-walls.

Agglutination and complement fixation tests with yeast cell-walls revealed an extensive and complex pattern of cross-reactions amongst 26 species of 20 genera of yeasts. Common antigens were found in all yeast cell-walls. Ascosporogenous yeasts possessed antigens not found in the asporogenous yeasts and vice versa. Nuberical analyses of serological properties confirmed this distinction and also that little differentiation could be achieved at generic level with respect to Saccharomyces and Candida spp.

Agglutination Tests↗
PubMed1975

Immunoadjuvant activities of cell walls and their water-soluble fractions prepared from various gram-positive bacteria.

The cell walls from all 21 species of gram-positive bacteria examined, except lysozyme-susceptible Micrococcus lysodeikticus (NCTC 2665) and lysozyme-resistant Staphylococcus epidermidis (ATCC 155), were found to be definitely adjuvant-active in both stimulation of increased serum antibody levels and induction of delayed-type hypersensitivity to ovalbumin when administered to guinea-pigs as water-in-oil emulsions. Using various cell wall lytic enzymes, the immunoadjuvant principles were solubilized with full retention of the adjuvant activities from walls of Staphylococcus aureus (Copenhagen), Streptococcus pyogens (group A, type 6; S43/100), Streptococcus salivarius (IFO 3350), Streptococcus faecalis (IFO 12580), Streptococcus mutans (BHT), Lactobacillus plantarum (ATCC 8014), Bacillus megaterium (IFO 12068), Corynebacterium diphtheriae (Park-Williams No. 8), Mycobacterium smegmatis, and Actinomyces viscous (ATCC 15987). Evidence was obtained that the non-peptidoglycan portion of the cell walls is not essential for manifestation of immunoadjuvancy.

Adjuvants, Immunologic↗
PubMed1975

The adjuvant activity of a non-toxic, water-soluble glycopeptide present in large quantities in the culture filtrate of Mycobacterium tuberculosis strain DT.

A water-soluble mycobacterial glycopeptide was obtained in large quantities from the culture supernatant fluid of M. tuberculosis strain DT. This glycopeptide was strongly adjuvant-active when injected, in a water-in-oil emulsion contianing ovalbumin, into guinea-pigs. In addition, it was devoid of cord factor toxicity in mice, polyarthritogenic activity in rats and cavity stimulating activity in rabbit lungs.

Adjuvants, Immunologic↗