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Biomedical subjects

G C Faure

Publications and source records attributed to G C Faure.

At least 73 records · Page 4Linked to original sources
PubMed1994

Humoral immune responses of workers occupationally exposed to wheat flour.

Wheat flour is a complex organic dust likely to induce immune responses when inhaled in work environment conditions. We compared the humoral status of 159 exposed workers from 11 flour mills and one industrial bakery with that of 41 workers from a salt factory. IgG, IgA, and IgM levels of antibodies to whole flour and to gliadin were assayed using ELISA tests in serum and saliva samples. Serum levels of IgG and IgA to both antigens were significantly higher (p < 0.0001) in occupationally exposed workers. Exposed workers had significantly higher levels of salivary IgG (p = 0.005) and IgA (p < 0.0001) to whole flour and of salivary IgG (p = 0.0005) to gliadin. In both groups, similar levels of anti-gliadin salivary IgA antibodies were observed. These data suggest that occupational exposure to wheat flour triggers specific immune responses, most likely through stimulation of the mucosal immune system. The presence of significant levels of serum antibodies, however, indicates that a systemic immunologic response is also present among exposed individuals.

Antibody Formation↗
PubMed1994

Immunohistological analysis of macrophages, B-cells, and T-cells in the mouse lung.

BACKGROUND: Numerous studies have described the anatomy of the large lymphoid aggregates of bronchus-associated lymphoid tissue (BALT) in rabbits and rats. Less work has been performed on other immunocompetent areas of the respiratory tract, and available data again mostly describe rabbit or rat tissues. Little is known therefore of the microanatomy of the mouse lung immune system. METHODS: We report a study, devised in order to establish the immunohistological characteristics of normal healthy mice lungs, performed on whole lungs from 22 mice of various strains and/or ages. Snap frozen tissues were serially sectioned and analysed using histochemistry and immunohistological techniques. Scattered macrophages, IgA plasma cells, B and T cells were enumerated in each sample. RESULTS: The largest population was that of macrophages. B-cells were numerous in all mice but 3 adults. T-cells were always present, L3T4+ often more numerous than Lyt2+ cells. Small lymphoid aggregates, composed of B or T cells (L3T4+ and Lyt2+) were seen in all mice, in the vicinity of a bronchiole and a vein. In 12/22 mice, a peculiarly elongated para-esophageal lymph node with large peripheral B-cell nodules and medullary T-cells was observed. In the five strains of mice studied, large variations were noted, affecting all the cell types studied, and related either to age or strain. CONCLUSION: Besides providing a qualitative description and quantitative analysis of immunocompetent cells, this work reports age and strain-related variations in these cells' distribution. These data could be relevant for studies involving the analysis of mice respiratory immune responses to environmental antigens.

Aging↗
PubMed1994

Comparative immunohistochemical characteristics of human choroid plexus in vascular and Alzheimer's dementia.

Autoimmune alterations are indirectly supported in Alzheimer's disease by the demonstration of circulating antibodies directed to the epithelial basement membrane (BM) of the choroid plexus. We used immunohistochemical methods to compare the characteristics of choroid plexuses obtained postmortem from 15 patients. Six had a diagnosis of Alzheimer's disease, five had multi-infarct dementia (MID), and one suffered from mixed dementia. Similar tissue from three age-matched, non-demented controls was studied as well. Age-related psammoma bodies, lipofucsin, and flattened epithelial cells were present in all cases. Specific alterations were evident in Alzheimer's disease patients only. These were comprised of pseudolinear deposits of immunoglobulin (Ig)G and coarse deposits of C1q along the thickened and segmented epithelial BM, and were associated with IgM in five cases. Although no lymphoid infiltration was demonstrated, MHC Class II+ macrophages were observed in the plexus stroma, and numerous epithelial cells were class II+. These observations suggest that immune alterations, possibly of autoimmune origin, may be involved in Alzheimer's disease, leading to severe lesions of the choroid plexus. Such anomalies could be responsible for some of the alterations of cerebrospinal fluid (CSF) production or composition noted in this disease.

Aged↗
PubMed1994

Compartmentalization of specific B-cells in sheep mucosae associated lymphoid organs.

Numerous studies have shown that Peyer's patches (PP) contribute to the seeding of other lymphoid organs in sheep. This was demonstrated by perfusing labeled lymphocytes in PP, and later investigating their presence in drainage lymph nodes, spleen, peripheral blood or bone marrow. These data showed that PP export considerable numbers of cells every day, but provided no information as to their specificity. In this work, we used the enzyme-linked immunosorbent assay (ELISA) spot method to investigate, in the peripheral blood, mesenteric and cervical lymph nodes and tonsils from ten sheep, the numbers of specific B-cells, directed to four common bacteria of the oro-pharyngeal area of mammals: Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae or Klebsiella pneumoniae. The data were obtained from five sets of monozygous sheep, one animal of each pair being previously fed ribosomal preparations of these bacteria. Both prior to and after oral challenge, specific B-cells could be found in all the tissues tested. They were mostly IgG-producing cells and preferentially located in oro-pharyngeal drainage lymph nodes and tonsils. Their numbers increased in these lymph nodes after stimulation, while they decreased in mesenteric lymph nodes. These observations are consistent with the current hypothesis suggesting intestinal sensitization, proliferation and fast emigration of specific B-cells after oral challenge.

Animals↗
PubMed1994

Antibody-producing cells in peripheral blood and tonsils after oral treatment of children with bacterial ribosomes.

The efficacy of ribosomal preparations as mucosal immunostimulants was examined in the peripheral blood and tonsils of 14 children, before and after 28 days of oral treatment with D-53, a preparation of ribosomes from Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae and Streptococcus pyogenes. Tonsils from 10 untreated children were used as controls. Immunofluorescence and ELISAspot were performed to analyse variations in the numbers of immunoglobulin-containing and immunoglobulin-secreting B-cells. Both isotypic and antigenic specificities of these two types of cells were investigated. Significant differences were observed after treatment in the peripheral blood as well as between tonsils from treated and untreated children. In the peripheral blood a significant increase in immunoglobulin-secreting cells directed against antigenic specificities of D-53 was the major change. In tonsils, higher numbers of specific immunoglobulin-containing and secreting cells, and higher numbers of IgA-secreting cells were induced in treated children. These data support the efficacy of D-53 as an oral immunostimulant.

Administration, Oral↗
PubMed1994

Bacterial crude extracts or ribosomes are recognized similarly by peripheral and mucosal B cells.

Bacterial ribosomes have been shown to induce effective humoral and cellular immunological responses to whole microorganisms. In this study, the numbers of specific antibody producing cells directed towards Klebsiella pneumoniae, Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae ribosomes or whole bacteria sonicates were compared in the peripheral blood and tonsils of 7 children, and in the tonsils, mesenteric and cervical lymph nodes of 10 sheep. No significant difference was noted between the two types of antigens, confirming that ribosomal preparations are able to mimic the immunogenicity of whole bacteria in the mucosae-associated lymphoid tissue.

Animals↗
PubMed1993

Restricted expression of Ki-67 in cholesteatoma epithelium.

Proliferative sites within the overgrowing epithelium of cholesteatoma are still ill defined. In this study, we used the monoclonal antibody Ki-67 on frozen cut sections from 23 cholesteatoma samples obtained at surgery from 20 patients. This reagent has been reported to stain the nucleus of proliferating tumor cells and the cytoplasm of growing keratinocytes. In this series of samples, flat superficial layers of epithelium were consistently negative for Ki-67 or displayed a faint staining of the basal layer. By contrast, the deepest areas of epithelial recesses appeared brightly stained with Ki-67. The latter were often in the close vicinity of inflammatory cells present in the underlying mucosa. This observation suggests that cholesteatoma growth is initiated within the deep epithelial folds of overgrown tympanic skin, and that it might be triggered or sustained by inflammatory cytokines.

Adult↗
PubMed1993

Immunologic alterations in patients with sensorineural hearing disorders.

The autoimmune etiology suspected for some forms of hearing loss, supported by the clinical efficacy of steroid therapy, is thought to involve immune complexes, autoantibodies directed to the inner ear and/or cellular effectors. We report a study performed in 57 individuals with sudden deafness (n = 17, group 1) or progressive sensorineural hearing impairment (n = 40, group 2). A severe depletion in CD3+ and CD4+ peripheral lymphocytes was observed in group 1 and a marked decrease of CD8+ cells levels was observed in both groups. Group 2 patients frequently had anti-nuclear and anti-thyroid antibodies, while anti-cochlear antibodies were found in both groups (respective incidences, 75 and 71%). Anti-cartilage antibodies, found with a similar frequency in both groups, were not correlated with anti-cochlear antibodies. These data suggest that different immune disorders are involved in the development of sudden and progressive deafness, while both types of sensorineural hearing impairment involve immune abnormalities.

Adult↗
PubMed1993

Bacterial lysates and ribosomes as inducers of specific immune responses: a comparative study.

A bacterial lysate (OM-85 BV), a preparation of purified bacterial ribosomes (D53) and a placebo were tested for ability to induce the local appearance of specific antibody-containing cells. The three compounds were given orally to 90 children who required tonsillectomy. Surgery was carried out after 1 month of therapy. Frozen-cut sections of each tonsil were tested in indirect immunofluorescence. Cells containing antibodies directed to Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae or Klebsiella pneumoniae were enumerated. Lowest values were noted in the placebo group. Slightly higher numbers were observed after treatment with OM-85 BV, but significant increases were noted only for the elevated numbers of specific antibody-containing cells observed after D53 therapy. Bacterial ribosomal preparations thus contribute efficient induction of specific local immune responses in man.

Adjuvants, Immunologic↗
PubMed1993

[Immunophenotyping of lymphoid cells].

The increasing availability of reagents and technologies has resulted in the widespread use of immunophenotyping to define and assess the course of pathologic disorders involving lymphoid cells. The diversity of markers and of the disorders concerned has complicated the application of the technique. This paper reviews lymphocyte differentiation antigens, the technologies available to study them and possible applications in immunopathology. Four major disease groups are discussed: spontaneous immunodeficiencies, iatrogenic immunodeficiencies, auto-immune disorders and lymphoproliferative diseases. The importance of sequential explorations is stressed, where the abnormalities observed are analysed in the dynamic context of the disease and its therapy.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1992

Peripheral B cells with intracytoplasmic mu chains in HIV infection.

Besides the major alteration of T lymphocytes, B-cell anomalies have been reported in HIV infection, related to late stages of B-cell maturation, and considered to result from the dysregulation of T/B interactions. Because T cells are also involved in the control of lymphopoiesis and/or because of specific alterations of the B lineage, anomalies of B-cell maturation could occur in HIV-infected patients. We investigated the presence of immature pre-B lymphocytes, characterized by cytoplasmic mu chains, in 35 peripheral blood samples from healthy controls, 82 from HIV-positive/non-AIDS patients, and 45 from AIDS patients. Significant numbers of such cells were observed in 48% of HIV-seropositive patients and in 40% of the patients with AIDS disease. The presence of pre-B cells correlated with higher numbers of CD8+ and/or CD57+ cells and of peripheral lymphocytes. These data suggest that B-cell dysregulation in HIV infection may lead to the abnormal release of immature B cells in the peripheral blood. This observation may be interpreted as a sign of bone marrow activity.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Antibodies to choroid plexus in senile dementia of Alzheimer's type.

AIMS: To investigate whether autoantibodies to choroid plexus are present in human senile dementia. METHODS: Serum samples from 40 elderly people presenting with characteristic, diagnostic criteria of senile dementia of Alzheimer's type and 20 age matched healthy controls were tested by indirect immunofluorescence for the presence of autoantibodies to choroid plexuses, using frozen sections of rat or human fetal brain tissue. RESULTS: Significant labelling of choroid plexus basement membrane was observed in 17 of the 40 samples from patients with senile dementia; in the control series one sample of rat but not human plexus labelled positively (p < 0.01). CONCLUSIONS: The antibodies identified in this series of patients with Alzheimer's disease suggest that autoimmune mechanisms might be responsible for some of the changes in cerebrospinal fluid production described in this disorder.

Aged↗
PubMed1992

Anti-ovary antibodies after attempts at human in vitro fertilization induced by follicular puncture rather than hormonal stimulation.

Anti-ovary antibodies (AOA) have been detected in serum samples of women undergoing in vitro fertilization (IVF). High concentrations of these antibodies have been found in women who have had several IVF attempts and they appear to correlate with reduced chances of pregnancy. In this paper, AOA were assayed sequentially in a series of 140 IVF candidates to investigate the respective roles of hormonal stimulation and follicular puncture in inducing the autoimmune response. Serum was obtained 8 days after the beginning of ovarian human menopausal gonadotrophin (hMG) stimulation, then 15 days after follicular puncture. Significantly higher concentrations of IgG (P < 0.0001) AOA were observed in the second series of samples than in the first, suggesting that ovarian trauma and not hormonal stimulation is responsible for triggering antibody production. In the whole group, there was a negative correlation between IgM levels after puncture and oocyte numbers (P < 0.05). Among 'immune-responder' women, the concentrations of IgA AOA (P = 0.01) in the first sample, and of IgG (P = 0.01) or IgA AOA (P < 0.05) in the second, correlated with fewer oocytes after stimulation. There was no variation in the mean concentrations of AOA in women who achieved pregnancy.

Autoantibodies↗
PubMed1992

Multiphenotypic acute leukemias: clinicopathologic correlations and response to therapy.

Multiphenotypic acute leukemias (MAL), defined by the coexpression on most blast cells of antigens classically attributed to different lineages, remain a rare event. We isolated a series of 26 such cases from a cohort of 1565 leukemic patients whose cells were immunophenotyped at diagnosis. Markers of B and myeloid lineage (BM) were associated in 16 cases (62%), 3 coexpressed B and T markers (BT), and T-cell and myeloid antigens (TM) were found in 7 (27%). A tumoral syndrome was observed in 69% of the patients, without significant differences between the immunophenotypic subgroups. Median event free survivals in the three immunophenotypic subgroups as defined were respectively 24 months for BM-MAL, 4 months for TM-MAL and 7 months for BT-MAL respectively. The poorer prognosis of TM-MAL was significantly different from that of BM-MAL (p < 0.001). This concurred with the poorer prognosis associated with CD7 expression or absence or CD10, both characteristic features of TM-MAL.

Acute Disease↗
PubMed1992

Expression of the T-cell receptor in HIV infection.

Expression of the T-cell receptor (TCR) was investigated on peripheral lymphocytes in 270 samples from HIV+ patients at different stages of infection. TCR is composed either of an alpha and a beta chain, or, in a smaller subset of T-cells, of a gamma and a delta chain, closely associated with CD3. The numbers and percentages of positive cells were established using monoclonals to the alpha and delta chains of TCR. The values of alpha-TCR positive cells were constantly lower than those observed for CD3, with a mean of 53% (+/- 19%) versus 66% (+/- 17) respectively for asymptomatic patients or patients with persistent generalized lymphadenopathy, and of 36% (+/- 19) versus 46% (+/- 21) for patients with AIDS disease. There was no compensatory increase in the number of cells expressing delta-TCR. These data demonstrate a new alteration of the immune system in HIV infection, which appears to occur early in this disease.

Acquired Immunodeficiency Syndrome↗