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Biomedical subjects

A J Winter

Publications and source records attributed to A J Winter.

At least 91 records · Page 5Linked to original sources
PubMed1975

Bovine veneral vibriosis: cure of genital infection in females by systemic immunization.

Cure of female cattle with venereal vibriosis by systemic immunization with killed Campylobacter fetus cells in incomplete Freund adjuvant was investigated. Heifers infected in the cervicovaginal area with a cloned population of C. fetus venerealis were vaccinated subcutaneously 14 and 24 days thereafter with the infecting strain in incomplete Freund adjuvant. Six of eight vaccinated heifers were free of infection 25 to 48 days postinfection. One of the cured animals had an intercurrent infection which precluded interpretation of a vaccine effect. All controls remained infected 48 to 51 days postinfection, when the experiment was terminated. In vaccinated animals, agglutination titers against whole cells of the infecting strain reached peaks varying from 1,280 to 20,480 in serum and from 20 to 5,120 in cervicovaginal mucus (CVM) within days 24 to 32 postinfection. No consistent relationship was noted between levels of whole cell antibodies in serum and those in CVM. Evidence for the occurrence of antigenic variation in the organism after vaccination was sought by comparing the agglutinability of the infecting strain and CVM isolates in serum and CVM extracts. Serum samples of most cured heifers agglutinated whole cells prepared from isolates of the respective heifers to the same extent as cells of the infecting strain. In the corresponding comparisons, those from noncured animals agglutinated isolates to lower titers. CVM extracts from one cured animals agglutinated isolates derived from the same or closely spaced CVM samples to titers comparable with those obtained with the infecting strain. In the remaining animals, CVM extracts which agglutinated the infecting strain produced lower or undetectable reactions with corresponding isolates. It is proposed that the elimination of infection is dependent upon opposing responses of host and parasite, of which the degree of antigenic alteration in the infecting strain and the rate of mobilization and the concentration of specific antibodies in the genital secretions are key factors.

Agglutination Tests↗
PubMed1975

Superficial antigens of Campylobacter (Vibrio) fetus: characterization of antiphagocytic component.

A glycoprotein responsible for the antiphagocytic properties of Campylobacter fetus has been identified by comparing cells of a wild-type strain with those of a mutant lacking this substance. The antiphagocytic component is demonstrable through electron microscopy as a discrete, negatively charged structure on the periphery of the cell. CLT is readily removed from the cell by mild extraction procedures and contributes to the inagglutinability in O antiserum normally displayed by C. fetus. Cells possessing this antigen are refractory to ingestion by macrophages except in the presence of specific antiserum. In its absence maximum phagocytosis occurs without a requirement for opsonins. It is concluded that the antiphagocytic component comprises a critical virulence factor of the bacterium.

Animals↗
PubMed1975

Flagellar ultrastructure and flagella-associated antigens of Campylobacter fetus.

Ultrastructural examinations of the flagellum of Compylobacter (Vibrio) fetus were performed throughout the growth cycle. Filament diameters, exceeding 17.6 nm during the exponential phase, were substantially greater than those reported for unsheathed flagella of other genera with the exception of Pseudomonas fluorescens. Filament diameters increased during growth, reaching a mean width of 21.2 nm in middle to late stationary phase. Internal flagellar structure, principally of the parallel lined variety, was observed during the later periods of growth but not during exponential or early stationary phase. Despite the unusually large filament sizes, no evidence of a flagellar sheath was observed after selected treatments (0.01 N HCl, 6 M urea, tris(hydroxymethyl) amino-methane-hydrochloride buffer, warm water) or examination of thin sections. To determine whether alterations in filament size and variable ability to demonstrate filament fine structure were correlated with progressive changes in serological activity, agglutination and immobilization tests were conducted with antisera directed against intact flagella, the principal flagellar antigen, the O antigen, and a superficial glycoprotein which has been found in association with the flagellum and the cell envelope. Significant differences in the serological activity of cells at different growth intervals were not noted with any of the sera employed.

Agglutination Tests↗
PubMed1975

Bovine venereal vibriosis. Ultrastructure of endometrial inflammatory lesions.

The inflammatory lesions in bovine venereal vibriosis have been examined by light and transmission electron microscopy in order to provide a better understanding of host defense of the uterus against bacterial invasion. Neutrophils and eosinophils were found mainly at the endometrial surface and in glandular lumina. Mononuclear cells within the endometrial tissue were identified ultrastructurally. Lymphocytes were most abundant, plasma cells were next in frequency, and mononuclear phagocytes were least often observed. An attempt was made to classify lymphocytes on the basis of presence or absence of a cytoplasmic network of filaments and other ultrastructural characteristics.

Animals↗
PubMed1975

Bovine venereal vibriosis: activity of inflammatory cells in protective immunity.

The capability of bovine polymorphonuclear (PMN) and mononuclear phagocytes to kill Campylobacter (Vibrio) fetus venerealis was tested under various conditions in order to judge their roles in protective immunity. Bovine PMN killed C fetus in the presence of immunoglobulin G (IgG) but not immunoglobulin A (IgA) antibodies. Some phagocytosis occurred in the absence of antibody in glass-adherent cultures, but not in suspension cultures--indicating that surface phagocytosis by the neutrophils normally present during estrus could account for natural protection at this time. Mononuclear phagocytes also killed C fetus in the presence of opsonins, making this a likely factor in protection during the later stages of inflammation when mononuclear cells predominate. The presence of numerous lymphocytes in this mononuclear infiltration and the capability of C fetus antigens to induce delayed hypersensitivity (DH) are consistent with the possibility that cell-mediated immunity (CMI) also may be involved in protective immunity.

Animals↗
PubMed1974

Immunoglobulin classes and biological functions of Campylobacter (Vibrio) fetus antibodies in serum and cervicovaginal mucus.

Serum and cervicovaginal mucus (CVM) antibodies from heifers after genital infection or systemic immunization with Campylobacter (Vibrio) fetus were classified according to their immunoglobulin class, antigenic specificities, and biological functions. Only immunoglobulin (Ig) A antibodies, specific both for O and superficial, heat-labile, whole-cell (W) antigens, were detected in CVM of convalescent animals. After systemic immunization, antibodies in serum were directed principally to W antigens and were located in IgG(1), IgG(2), and IgM classes; CVM antibodies of the same specificity were detected only in the IgG subclasses. Functional tests revealed that antibodies of W specificity, whether of the IgA or IgG class, were capable of immobilizing the organism. However, IgG antibodies immobilized with clumping, whereas IgA antibodies immobilized single organisms within the 3-min period. None of the antibody preparations was bactericidal in the presence of homologous complement when the infecting strain was used as the target organism, but a bactericidal effect was observed when the target strain was rough and non-encapsulated. Both serum and CVM from systemically immunized animals opsonized C. fetus organisms, but CVM from locally immunized animals containing IgA antibodies was not opsonic. It is hypothesized that functions of immobilization for IgA and IgG and of opsonization for IgG are important features of protective immunity in venereal vibriosis.

Agglutination Tests↗
PubMed1974

Bovine venereal vibriosis: variations in immunoglobulin class of antibodies in genital secretions and serum.

The immunoglobulin classes of antibodies to Campylobacter (Vibrio) fetus in cervicovaginal mucus (CVM) were determined by the indirect fluorescent antibody test at sequential periods, since the order of class appearance has not been established for specific secretory immune responses. In the local immune response to C. fetus immunoglobulin M (IgM) antibodies appeared first, immunoglobulin A (IgA) antibodies next, and immunoglobulin G (IgG) last. IgM antibodies were quite transient, but IgG antibodies remained longer, and those of the IgA class persisted until the end of the experimental period (up to 10 months). Since differences appear to exist between immune mechanisms at cervicovaginal and uterine sites, as well as between immune responses induced by local and systemic immunizations, the immunoglobulin classes of antibodies in uterine secretions were compared with the classes in CVM and serum. Uterine antibodies arose coincidently with uterine lesions in heifers slaughtered after short periods of infection. In convalescent animals only IgA antibodies were found in CVM, whereas the predominant class of antibodies in the uterine secretions was IgG(1) in three of four animals studied. Only IgG antibodies were detected in CVM and uterine secretions of systemically immunized animals. These findings could account for faster clearance of C. fetus from the uterus than from the cervicovaginal area in locally infected animals and for failure of colonization in systemically immunized animals, because IgG antibodies are good opsonins and IgA antibodies are not. IgA antibodies do immobilize C. fetus, however, so they could prevent recolonization of the uterus in cervicovaginal carriers.

Journal Article↗
PubMed1972

Natural and immune antibodies for Vibrio fetus in serum and secretions of cattle.

Naturally occurring antibodies for Vibrio fetus with whole-cell and O antigen specificities were detected in sera of mature cattle by means of the agglutination and indirect immunofluorescence reactions. O antibodies occurred in each of 21 sera examined, and whole-cell antibodies, in lower concentrations, occurred in 15 of the 21 sera. Natural antibodies were detected in the immunoglobulin G, M, and A (IgG, IgM, IgA) classes. Parenteral immunization with whole cells in Freund's complete adjuvant caused an increase in antibodies, predominantly IgG, with both whole-cell and O specificities; genital infection produced minimal alterations in levels of serum antibody. O antibodies, predominantly of the IgA class, occurred in nasal secretions of most of these animals but only infrequently in saliva or tears. Nasal secretion titers of O antibodies fluctuated widely from week to week but appeared to be unaffected by parenteral immunization or experimental infection. It is hypothesized that the nasal passages serve as a site of antigenic stimulation and synthesis of naturally occurring V. fetus antibodies.

Animals↗