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Biomedical subjects

L B Corbeil

Publications and source records attributed to L B Corbeil.

107 records · Page 6Linked to original sources
PubMed1976

Immunoglobulin classes in genital secretions of mycoplasma-infected and normal heifers.

Immunoglobulin levels were studied in the genital secretions of seven heifers which had been bred to a bull infected with Mycoplasma agalactiae var. bovis and three heifers bred to a noninfected bull. The median immunoglobulin G (IgG)/IgA ratio ratio for vaginal secretions was 0.7, for cervical secretions 21.9, and for uterine secretions 13.0. This indicated that IgA was the mahor immunoglobilin class in the most superficial portion of the reproductive tract and that IgG was the major class in secretions of the deeper tract. The response to infection was studied by comparing animals infected with mycoplasma and noninfected controls. The IgG/IgA ratios were significantly lower in infected animals than in controls, apparently due to high IgA values in infected animals. Low mycoplasmal agglutinin titers were detected in secretions of three of the infected animals, but there appeared to be no relationship between agglutinin titers and histopathological lesions or between agglutinin titers and IgG/IgA ratios in this group of animals.

Albumins↗
PubMed1976

A rheumatoid-like arthritis in calves.

Arthritis characterized by lameness. Joint swelling and purulent synovial fluid was seen in a group of dairy replacement heifers. Mycoplasma was cultured from one joint aspirate, but all bacterial cultures were negative. Antiglobulins were demonstrated by double diffusion precipitin tests in the serum and synovial fluid. Due to the clinical and clinical pathological similarities to rheumatoid arthritis in man, the disease was called rheumatoid-like arthritis. The presence of antiglobulin may indicate antibody in the synovial fluid explaining the difficulty in culturing a causative agent.

Animals↗
PubMed1975

Bovine veneral vibriosis: antigenic variation of the bacterium during infection.

Host parasite relationships in the female genital tract were studied in bovine venereal vibriosis by investigating agglutinin production and alterations in superficial antigens of the bacterium during the course of infection in two heifers. Cervicovaginal mucus (CVM) steamed cell agglutinins were shown to appear earlier and remain at consistently higher levels than whole-cell agglutinins. Whole-cell agglutinin titers fluctuated much more than steamed cell titers, suggesting possible changes in whole-cell antigens. Marked antigenic variation was demonstrated in successive monthly CVM isolates from the two heifers by agglutination tests with rabbit antisera of various specificities. Some changes in CVM antibody specificity during the infection were noted also. Antigenic variation in the bacterium was proposed as a mechanism for maintenance of the asymptomatic cervicovaginal carrier state in the presence of antibody.

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

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↗
PubMed1975

Persistent papillomatosis associated with immunodeficiency.

A case report of a young bull with persistent papillomatosis associated with immunodeficiency is presented. Humoral immune responses were normal but cell mediated immunity was deficient. The possible significance of the findings to pathogenesis and therapy of the disease is discussed.

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↗
PubMedDate not supplied

Lethal Haemophilus influenzae type b infection in mice.

Previous animal models of invasive Haemophilus influenzae type b (HITB) infection are characterized by a low mortality rate. We produced a highly lethal infection in CF1 mice using mouse passage, mucin, and hemoglobin to enhance infectivity. Infection by the intraperitoneal route was followed by progressive peritonitis and bacteremia with subsequent HITB infection of the brain and meninges, and death. Death occurred between eight and 72 hours after infection and was associated with 10(6) to 10(9) HITB per ml of blood and with 10(2) to 10(5) HITB per g of brain. Mucin-hemoglobin did not augment HITB growth, but impaired macrophage adherence to glass in vitro, without decreasing cellular viability. In vivo, mucin-hemoglobin decreased the rate of disappearance of 51Cr-labelled HITB from the blood by impairment of hepatic clearance. This technically simple and inexpensive model is useful for the study of HITB infections in which bacterial multiplication, invasion and host lethality are desired features.

Animals↗