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D M Weir

Publications and source records attributed to D M Weir.

At least 109 records · Page 6Linked to original sources
PubMed1984

Absence of bactericidal antibodies against Group-I lipopolysaccharide determinants of Neisseria gonorrhoeae during human infection.

None of 34 sera from patients with gonorrhoea contained antibodies bactericidal for strains of Neisseria gonorrhoeae with Group-I lipopolysaccharide (LPS). All contained antibodies against a strain with Group-II LPS, as do sera from uninfected controls. The absence of Group I-LPS antibodies in infected humans contrasts with previous findings that mice immunised with strains from either of the LPS groups produced bactericidal antibody to Group I. Our hope that detection of antibodies to Group-I strains would provide a screening test for gonorrhoea was, therefore, not realised.

Antibodies, Bacterial↗
PubMed1984

ABO blood group and susceptibility to urinary tract infection: no evidence for involvement of isohaemagglutinins.

Investigations of the possible mechanisms underlying the increased susceptibility of women who are blood group B and non-secretors of water-soluble blood group antigen to recurrent urinary tract infection (UTI) revealed that isohaemagglutinins are not involved in bactericidal killing or agglutination of 8 serotypes (1,2) of Escherichia coli frequently associated with UTI. The implications of these results and possible areas for future studies are discussed.

ABO Blood-Group System↗
PubMed1984

Binding of Neisseria gonorrhoeae by lectin-like receptors on human phagocytes.

The adherence of gonococci to phagocytes was examined for the presence of "lectin-like" receptors capable of binding these bacteria. The data suggests such "lectin-like" receptors are present on PMN and monocytes that recognize sugars present in the gonococcal cell wall and that there are quantitative and qualitative differences in expression of these receptors. These findings may have importance in investigation of the interaction of gonococci with phagocytes and with the subsequent induction of immunity in the disease.

Binding Sites↗
PubMed1984

Host-parasite interactions influencing establishment of gonococcal infection--a paradox resolved?

This study indicates that the gonococcal strains of lipopolysaccharide group (II) most frequently isolated from localized infections have a growth advantage over strains of group I. Their increased association with neutrophil polymorphs and their susceptibility to lysis by normal human serum would seem to act to the disadvantage of the bacteria. Our findings taken together with the cytotoxic effect of gonococci on neutrophil polymorphs offer an explanation for this apparent paradox.

Cytotoxins↗
PubMed1983

Macrophage 'receptors' for bacterial cell-wall sugars and immune response genes: possible determinants of susceptibility to infection.

Recognition of bacteria, antigen presentation and regulation of the immune response by the class II antigens of the major histocompatibility complex (MHC) are among the many factors that influence a host's response to microbial infection. 'Lectin-like' receptors on the macrophage membrane recognize a variety of bacteria by interaction with their cell-wall sugars. These receptors are susceptible to environmental factors and appear to be associated with the I-A subregion of the mouse MHC. Possible effects of this recognition system on the pathogenesis of microbial infection and reactive arthritides are considered.

Animals↗
PubMed1983

Blood group, secretor status, and susceptibility to infection by Neisseria gonorrhoeae.

To determine whether the presence or absence of anti-B isohaemagglutinin in individuals of blood group B increases their susceptibility to gonococcal infections 567 new patients attending a sexually transmitted disease clinic were screened for blood group and secretor status. Of the patients with blood group B, 20.1% had gonorrhoea and 12% had not. A higher percentage (20.9%) of patients with no anti-B isohaemagglutinin had gonorrhoea compared with those without (12.1%). There was, however, no synergy between the absence of anti-B isohaemagglutin and nonsecretion of water-soluble blood group B antigen. Further research is needed to determine the underlying host-parasite interactions responsible for the increased susceptibility to gonorrhoea in these individuals.

ABO Blood-Group System↗
PubMed1983

ABO blood group and susceptibility to gonococcal infection. I. Factors affecting phagocytosis of Neisseria gonorrhoeae.

The effect of opsonization of Neisseria gonorrhoeae by isohaemagglutinins from normal serum on attachment to human polymorphonuclear leukocytes (PMN) was investigated. No significant differences between sera from blood groups O, A, B or AB were found. Differences in attachment of gonococci were related to differences in lipopolysaccharide detected by sensitivity to R-type pyocines of Pseudomonas aeruginosa. Non-pilate variants of each test strain markedly stimulated nitroblue tetrazolium (NBT) reduction in PMN, but their pilate variants were essentially inactive in the NBT test.

ABO Blood-Group System↗
PubMed1983

Membrane changes in murine macrophages after in-vivo stimulation and activation.

The expression of various receptors and other surface determinants on resident, glycogen-and Corynebacterium parvum- elicited mouse peritoneal macrophages has been described. Macrophage Fc (IgG2b) receptors and I-A antigens were slightly increased after stimulation and a more marked increase was shown after activation with C. parvum. Complement receptor expression was enhanced after stimulation but was markedly reduced after activation. C. parvum-elicited macrophages, and to a lesser extent glycogen-elicited macrophages, showed a reduction in lectin-like receptors which recognize bacterial cell-wall sugars. Surface mannosyl determinants of the macrophage membrane were apparently increased after activation. The environment thus can be seen to influence the expression of macrophage surface receptors and antigens. These alterations are likely to influence the role of the macrophage in the immune response.

Acid Phosphatase↗
PubMed1983

Inhibition of bacterial binding to mouse macrophages by Pseudomonas alginate.

Alginate, an acetylated polymer of D-mannuronic and L-guluronic acid obtained from a mucoid strain of Pseudomonas aeruginosa was shown to inhibit the binding of an isogenic non-mucoid revertant to mouse peritoneal and pulmonary macrophages. Inhibition of bacterial binding by the alginate was also demonstrated in tests with other non-mucoid P. aeruginosa strains and a strain of Staphylococcus albus. Since the mucoid form of P. aeruginosa eventually predominates in chronic P. aeruginosa infection in patients with cystic fibrosis, it is postulated that the alginate's inhibition of binding gives mucoid forms a selective advantage over non-mucoid forms against macrophage defence mechanisms in the lung.

Alginates↗
PubMed1983

Blood groups and susceptibility to gonococcal infection. II. The relationship of lipopolysaccharide type to gonococcal sensitivity to the bactericidal activity of normal human serum.

This study examines the bactericidal activity of normal human sera from individuals of blood groups A and B for gonococcal strains with simple and complex lipopolysaccharides (defined by pyocin-sensitivity) isolated from localised and disseminated infection. The bactericidal activity did not depend on A or B isohaemagglutinins. Resistance to normal human serum exhibited by strains from localised infections appeared to be due to lack of part of the lipopolysaccharide antigen, whereas resistance of strains from disseminated infection appeared to depend on a separate mechanism yet to be defined.

ABO Blood-Group System↗
PubMed1983

ABO blood groups and susceptibility to gonococcal infection. III. Role of isohemagglutinins in increased association of Neisseria gonorrhoeae to monocytes from blood group B individuals.

The association of human monocytes of different ABO blood groups with gonococci was examined under various conditions. Blood group B monocytes in the presence of autologous heat inactivated serum (HIS) showed increased association over monocytes of the other ABO groups with their autologous sera. No statistically significant trends in ABO monocyte association were noted for assays carried out in the absence of autologous HIS. Absorptions of isohemagglutinins from sera reduced the gonococcus-monocyte association level to that of controls.

ABO Blood-Group System↗
PubMed1982

Macrophage binding of Staphylococcus albus is blocked by anti I-region alloantibody.

Cell surface interactions involving carbohydrate may be important in immune recognition. Previous work from this laboratory has demonstrated the presence of 'lectin-like' receptors on mouse peritoneal macrophages that bind bacteria by means of their cell wall sugars. Others have shown that Ia molecules can bind antigen at specific sites which may be involved in presenting antigen to the immune system and recent work has shown that these molecules can carry carbohydrate determinants. It has also been found that human Ia molecules can bind to carbohydrates. As cell surface carbohydrate recognition mechanisms have been implicated in other immune interactions sugar-specific receptors may have a function in self--non-self recognition. We show here that the binding of the bacterium Staphylococcus albus to mouse peritoneal macrophages was inhibited by various conventional and monoclonal antibodies to Ia antigens suggesting that an I-region gene product may be associated with the binding of unopsonized bacteria.

Animals↗
PubMed1982

ABO blood group, secretor state, and susceptibility to recurrent urinary tract infection in women.

ABO blood group and secretor state was determined in 319 women with recurrent urinary tract infection and compared with those of a control group of 334 women of similar age ranges. Women of blood groups B and AB who are non-secretors of blood group substances showed a significant relative risk of recurrent urinary tract infection of 3.12 (95% confidence limits, 1.49 and 6.52) in comparison with other types. This appears to be a genuine example of synergy in which absence of anti-B isohaemagglutinin and secretor substances combines to give an increased risk of recurrent urinary tract infection. Determination of blood group and secretor state may provide additional information in identifying those at risk.

ABO Blood-Group System↗
PubMed1982

Phagocyte recognition by lectin receptors.

A "lectin-like" receptor for bacterial cell wall sugars, originally described in the membrane of mouse peritoneal macrophages, which facilitates binding of various bacteria to the macrophage surface, has now been shown to be present on most phagocytes from a variety of species. The role of such a receptor in the inflammatory response has been investigated by examining changes in its expression in response to chemoattractants. The chemoattractants, whilst enhancing or not altering expression of C3 and Fc receptors, respectively, appeared to decrease lectin receptor expression. The possibility of a relationship between I-region gene products of the major histocompatibility complex (MHC) and the bacterial binding lectin receptor was investigated. It was found that various conventional and monoclonal antibodies directed against I-region determinants inhibited binding of bacteria to mouse peritoneal macrophages. These findings suggest the need to examine the possibility that, in addition to phagocytosis and elimination of bacteria, the lectin receptor may also be involved in antigen presentation and macrophage-T-lymphocyte cooperative events leading to an immune response.

Animals↗
PubMed1982

Binding of type-III group-B streptococci to buccal epithelial cells.

A binding assay was used to study the attachment of type-III group-B streptococci (GBS) to buccal epithelial cells. Results indicate that an adhesin, with the characteristics of a protein, is the molecule at the streptococcal cell surface responsible for attachment to the buccal cells. The bacterial adhesin probably recognises a sugar on the surface of the mucosal cell, because periodate oxidation of the buccal cells caused a significant reduction in subsequent adherence of GBS. A sonicate to type-III GBS blocked the binding of the organism to buccal cells. The effects of physical and chemical modifications of the sonicate on its ability to prevent bacterial attachment are described; these corroborate the evidence gained from heat and periodate treatments of the buccal cells and GBS. Results suggest a lectin type of attachment mechanism for type-III BGS which can be blocked by N-acetyl-D-glucosamine, rather than attachment by means of a lipoteichoic acid as described for group-A streptococci.

Acetylglucosamine↗
PubMed1982

The regressed inpatient group in a graded group treatment program.

This article describes the progress of severely regressed inpatients as part of a graded group treatment program. Leaders must actively initiate structure, formulate goals, and emphasize the eventual "graduation" of patients to higher-level groups. Essential qualities of the group leaders and countertransference issues are discussed.

Countertransference↗