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Biomedical subjects

D A Vuitton

Publications and source records attributed to D A Vuitton.

At least 91 records · Page 5Linked to original sources

Alterations in polymeric immunoglobulin receptor expression and secretory component levels in bladder carcinoma.

To assess the capacity of transitional cells to synthesize the release polymeric immunoglobulin receptor (pIg-R) in bladder carcinoma, we studied the localization of pIg-R in normal and tumor tissues and measured the levels of secretory component (SC) either in the free form or bound to Ig (S-IgA, S-IgM) in the serum and urine of 56 patients with transitional-cell carcinoma (TCC) of the bladder. In the normal bladder mucosa, pIg-R was localized in the cytoplasm and plasma membranes of the superficial cells and on all epithelial cell membranes. In TCC cases, 65% of those studied expressed pIg-R. A marked heterogeneity in pIg-R staining was observed in some tumors. Although a better expression of pIg-R in tumors with a well-preserved epithelial architecture was observed, no correlation was found between pIg-R expression and the grade or stage of the tumors in the patients under study. Three groups were established: (1) in TCC with no complications, serum levels of free SC and S-IgA were significantly increased; (2) in TCC with urinary infections (UI), serum levels of free SC and S-IgA were significantly higher than control values but lay within the same range observed in TCC with no complications and rates of urinary excretion of SC were significantly higher than those in normal subjects; (3) in TCC without UI but with hepatic disorders [high gamma-glutamyl transferase (GGT) activity], there was a correlation between serum S-IgA levels and GGT activity (r = 0.5, P less than 0.005) and serum SC levels were significantly higher than those observed in the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers, Tumor↗

The phagocyte oxidative metabolism function in ankylosing spondylitis.

The phagocyte oxydative metabolism function was measured using chemiluminescence in microamounts of whole blood in 15 ankylosing spondylitis (AS) patients (10 were B27 positive), and in 17 controls. It was obtained from cells at rest, and following stimulation (latex, zymosan, fMLP), with luminol and lucigenin as amplifiers. The maximal light intensity was significantly higher (P less than 0.01) in AS compared to the controls in resting cells as well as in those after stimulation. There was no difference between HLA-B27 positive or negative AS patients. The increase in oxidative metabolism of the phagocyte system in AS was more evident in the luminol dependent assay, suggesting an activation of the myeloperoxydase system.

Adolescent↗

Serum and bile secretory immunoglobulins and secretory component during the early postoperative course after liver transplantation.

Secretory component was assayed in serum and bile from 34 patients within 40 days after a first or a second (three cases) liver transplantation. Levels of serum secretory IgA and IgM and of a serum component referred to as immunoreactive free secretory component, identified by its reactivity with monoclonal and polyclonal antibodies specific to secretory component, were significantly elevated in all posttransplant patients compared with 45 healthy subjects and 10 kidney transplant patients (p less than 0.0001). The highest serum levels of bound secretory component and of immunoreactive free secretory component were observed in patients with acute rejection. The elevation of immunoreactive free secretory component was significantly higher in patients with rejection as compared with patients with a graft ischemia (p = 0.002) or an uncomplicated postoperative evolution (p = 0.01). The highest levels of immunoreactive free secretory component and secretory IgM were observed in a transplant patient with selective IgA deficiency. No significant difference was seen between the levels of serum immunoreactive free secretory component observed in patients with rejection and those of patients with cytomegalovirus hepatitis or sepsis. Immunoreactive free secretory component, secretory IgA and secretory IgM levels measured in the serum of three patients with primary nonfunction were lower than those observed in the other groups. Immunoreactive free secretory component bile/serum ratios calculated from 16 patients were significantly higher in patients with acute rejection than in infected patients. This study provides new insight into the mechanisms of increase of serum immunoreactive free secretory component, secretory IgA and secretory IgM in various types of liver dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Orthotopic liver transplantation for incurable alveolar echinococcosis of the liver: report of 17 cases.

Between 1986 and 1989, orthotopic liver transplantations were performed in our unit for 17 patients with incurable alveolar echinococcosis. Ten patients had hilar involvement (group I), and seven patients had posterior localization (five of them had chronic Budd-Chiari syndrome) (group II). The delay between diagnosis and the orthotopic liver transplantation was more than 48 mo in group Ia (six patients), less than 24 mo in group Ib (four patients) and less than 48 mo in group II. Previous operations were more common in group Ia than in group Ib and II. Five patients have died-four in group I and one in group II. The actuarial survival rate at 15 mo was 75%. Early reoperations were frequent (69%), mainly caused by rebleeding. Bacterial and fungal infections occurred only in group Ia (four cases) and group II (three cases). In eight patients (palliative group), residual foci of infected nonhepatic tissue occurred after surgery. The titer of specific antibodies decreased during the first 3 mo in all the patients but one. In patients with radical liver transplantation, the complete disappearance of specific antibodies occurred within 2 yr in four cases. In the remaining five patients, specific antibodies remained detectable, but no evidence of recurrence has been obtained up to now. In the palliative group, a peak of specific IgM occurred at 3 mo; an increase of specific IgG was observed later. The growth of residual parasitic foci was relatively slow, and all these patients remained asymptomatic with a mean follow-up of 19 mo. We conclude that orthotopic liver transplantation is feasible in incurable alveolar echinococcosis and could be proposed without delay to patients with parasitic Budd-Chiari syndrome or complicated secondary biliary cirrhosis. In the other cases, the best time to perform an orthotopic liver transplantation is more difficult to determine. Nevertheless, in the perspective of an orthotopic liver transplantation, the management of these patients has to change, and repetitive laparotomies for palliative surgical procedures have to be replaced by interventional radiology.

Adult↗

Cellular immunity in experimental Echinococcus multilocularis infection. I. Sequential and comparative study of specific in vivo delayed-type hypersensitivity against E. multilocularis antigens in resistant and sensitive mice.

Species- or strain-related differences in receptivity of intermediate hosts to E. multilocularis larvae could be related to differences in specific cellular immune response of the host. In order to test this hypothesis, we assessed the delayed-type hypersensitivity (DTH) to E. multilocularis antigens (EmAg) in mice of three strains differing by their sensitivity (AKR and C57BL.6) or resistance (C57BL.10) to E. multilocularis infection. DTH was determined by measuring in vivo the foot-pad response 24 h after an EmAg antigenic challenge. The level of positive response was evaluated in immunized mice; however, a typical DTH response was only observed by immunizing mice with a strong adjuvant schedule. Course of DTH in the immunized mice was shown to be somewhat different in sensitive and resistant mice. The differences were much more marked in mice infected with proliferative E. multilocularis larvae. The levels of the footpad response was significantly higher in resistant mice, although the peak of the reaction was obtained later than in sensitive mice. DTH, expressed by the foot-pad response against EmAg, remained significant for the entire period of observation in sensitive as well as in resistant mice. There was no correlation between receptivity of the murine hosts and levels of specific antibodies against EmAg. These results suggest a relationship between resistance to E. multilocularis infection and intensity and/or course of DTH in mice. The resistance could be mediated by some particularities of the in situ cellular immune response in the periparasitic granuloma.

Animals↗

Cellular immunity in experimental Echinococcus multilocularis infection. II. Sequential and comparative phenotypic study of the periparasitic mononuclear cells in resistant and sensitive mice.

Cellular immune responses have been shown to be associated with differential evolutions of E. multilocularis infection in intermediate hosts. A relationship between course of delayed-type hypersensitivity (DTH) against parasitic antigens and receptivity of murine strains has been demonstrated recently. The aim of this study was to correlate resistance and sensitivity to E. multilocularis infection with the phenotypic patterns of cells within the periparasitic granuloma. Evolution of the ratios, macrophages/T lymphocyte and Ly1/Ly2 T lymphocytes, was associated with the receptivity of the strains. Persistence of numerous L3T4 + T lymphocytes and low numbers of macrophages and Ly2 + T lymphocytes were observed in the 'resistant' C57BL.10 mice. Comparison of the results with course of the DTH against E. multilocularis antigens showed that the particular phenotypic pattern observed in resistant mice was associated with a particular profile of DTH after infection. These results and similar observations in human alveolar echinococcosis suggest that cell composition of the periparasitic granuloma might be of crucial importance in controlling the spontaneous development of E. multilocularis larvae in the intermediate host.

Animals↗

Cellular immune response in Echinococcus multilocularis infection in humans. I. Lymphocyte reactivity to Echinococcus antigens in patients with alveolar echinococcosis.

The involvement of cellular immunity in alveolar echinococcosis (AE) due to E. multilocularis is strongly suggested by the intense granulomatous infiltration observed around the hepatic parasitic lesions, and a progressive decrease of specific cellular immunity has been described in murine AE. However, specific cellular immunity against E. multilocularis has never been documented in human AE. The reactivity to phytohaemagglutinin (PHA) and E. multilocularis antigens of peripheral blood mononuclear cells (PBMC) from 48 patients with AE and 35 control subjects was evaluated by incorporation of 3H-methylthymidine into DNA. A sequential measurement of the proliferative response of PBMC was performed in 20 patients 2 years later, and again in five of them 4 years after the first determination. After stimulation by PHA, the mean proliferation index (PI) of the patients with AE was somewhat higher than that observed in the uninfected controls, but the difference was not significant. The PI obtained with E. multilocularis antigens was higher than the threshold value in all the patients but one, and in five control subjects. The difference between the PI values in the patients with AE and those obtained in the control subjects was highly significant. There was no correlation between the lymphocyte proliferation indices and the specific antibodies assessed using the Em 2-ELISA, or the volume of the parasitic lesions. All the five 'positive' control subjects were living in areas endemic for AE. A previous contract of these subjects with E. multilocularis in the past, followed by a spontaneous elimination of the parasite is possible. The long-term persistence of lymphocyte reactivity to parasite antigens was emphasized by the results of the follow-up of 20 patients with AE: reactivity of PBMC decreased progressively but persisted more than 4 years after complete resection of the parasitic lesions in the patients who underwent a radical surgical procedure. Conversely, an increase in the PI was shown to be usually associated with a progression of the liver lesions.

Adult↗

Cellular immune response in Echinococcus multilocularis infection in humans. II. Natural killer cell activity and cell subpopulations in the blood and in the periparasitic granuloma of patients with alveolar echinococcosis.

In animal models, the development of Echinococcus multilocularis larvae has been shown to correlate with the immune status of the host, and particularly with cellular immunity. In humans, a defect in immune regulation may explain the persistence of cellular infiltration and fibrogenesis. We assessed natural killer (NK) activity in the peripheral blood mononuclear cells (PBMC) of patients with alveolar echinococcosis, and compared in 12 patients who underwent a surgical procedure the cell populations in the PBMC with those present in the periparasitic granuloma. The results indicated that (i) the NK cell activity of the PBMC was significantly altered at the lower NK cell: target cell ratios; (ii) the percentage of CD8+ cells was significantly decreased in the PBMC with an increased CD4:CD8 cell ratio; (iii) inversely, the CD8+ cells constituted the main population of T cells in the liver of most patients; and (iv) the periparasitic granuloma was mainly composed of macrophages, T cells and myofibroblasts in close association with the developing fibrosis. A relatively high number of CD4+ cells in the periparasitic granuloma of two patients with 'abortive' parasitic lesions suggested that, as it is observed in experimental E. multilocularis infection, differential evolution of the phenotypic pattern of the periparasitic granuloma could be related to resistance or sensitivity to infection by E. multilocularis in humans.

Adult↗

IgE-dependent humoral immune response in Echinococcus multilocularis infection: circulating and basophil-bound specific IgE against Echinococcus antigens in patients with alveolar echinococcosis.

Clinical symptoms of immediate-type hypersensitivity (ITH) and specific IgE against Echinococcus granulosus antigens are frequently present in patients with hydatid cysts. In alveolar echinococcosis (AE) due to E. multilocularis, clinical manifestations related to ITH have never been reported. The IgE-dependent humoral immune response was evaluated in 30 patients with AE. Circulating specific IgE (sIgE) were determined with two different methods of radio-allergo-sorbent test. Serum sIgE were determined sequentially in 18 patients over 15 months. Specific IgE bound to circulating basophils were assessed with two tests in vitro, measuring specific degranulation and histamine release. The respective abilities of E. granulosus and E. multilocularis antigens to reveal bound and circulating IgE antibodies were also assayed. Despite the absence of clinical symptoms of ITH and the frequent lack of circulating sIgE, an immunological response involving IgE was always present in human AE: basophil-bound sIgE were revealed in every patient by histamine release and degranulation tests; these tests were constantly negative in control subjects. Echinococcus granulosus extracts were more effective for detecting circulating sIgE; however E. multilocularis antigenic preparation induced a histamine release significantly higher than E. granulosus extracts. These results suggest that IgE-dependent humoral immune response could play a role in the host-parasite relationship in AE. Moreover, the sensitivity of the tests used to detect basophil-bound sIgE was higher than that of the usual serological tests, and the basophil degranulation test could be used to confirm diagnosis of AE in endemic countries.

Adult↗

Collagen immunotyping of the hepatic fibrosis in human alveolar echinococcosis.

An extremely dense fibrosis is responsible for the main complications of alveolar echinococcosis (AE), a severe parasitic disease due to the development in the liver of a larval form of the cestode Echinococcus multilocularis. Immunotyping of collagens present in fibrous, granulomatous, and normal areas of the liver was performed in nine patients with AE. Immunofluorescent labelling of collagen types showed that dense fibrosis was entirely composed of thick bundles of type I and type III collagens, surrounding old parasitic vesicles with an autofluorescent laminated layer. In granulomatous areas, collagens were labelled as clusters consisting mainly of type III procollagen and collagen. Concentric bundles of type III collagen surrounded active parasitic vesicles. An enhancement of the normal labelling in portal spaces of the intact liver was present in all the patients. These results suggest that irreversible acellular keloid scar-like fibrosis observed in AE is the ultimate result of cytotoxic and fibrogenetic events related to the immune response of the host which are taking place initially in the granulomatous area surrounding the young parasite larvae.

Collagen↗

Gall bladder: the predominant source of bile IgA in man?

The sedimentation profiles of IgA and Secretory Component (SC) and the concentrations of IgA, IgG, IgM, SC and albumin were evaluated after an overnight fast in gall bladder bile of six adult subjects without hepatobiliary disease. The sedimentation profiles differed from those previously obtained in hepatic bile in three ways: gall bladder bile contained a greater percentage of free-SC, a greater percentage of polymeric-IgA (p-IgA), and a major peak of 14 to 19 S p-IgA associated to SC. In contrast to hepatic bile in which IgG is the predominant Ig, IgA clearly was the predominant Ig in gall-bladder bile, its concentration averaging 92 micrograms/ml. Relative-to-albumin coefficients of excretion of proteins in gall bladder bile averaged 0.99 for IgG, 8.6 for monomeric IgA, 196 for p-IgA and 31 for IgM, indicating that there was a selective excretion of IgA and IgM into gall bladder bile. As compared to hepatic bile, the enrichment of gall bladder bile with IgA and IgM was respectively 6.5 and 11.5 times greater than with IgG. These results suggest that quite a significant amount of p-IgA could have been added to bile during its storage in the gall bladder which should therefore be regarded as the predominant source of bile IgA in humans.

Bile↗

Humoral and cellular immunity in patients with hepatic alveolar echinococcosis. A 2 year follow-up with and without flubendazole treatment.

Parameters of humoral and cellular immunity were assessed in 12 patients with alveolar echinococcosis (AE) of the liver before, during and after discontinuation of treatment with flubendazole (FZ). In infected patients, before any medical treatment values of serum IgG, IgA, total haemolytic complement and C4 were significantly higher than those observed in control subjects; IgA levels were higher in jaundiced patients. Specific antibodies assayed by indirect haemagglutination and immunoelectrophoresis were present only in infected patients and were shown to decrease by the sixth month of treatment; however, similar fluctuations were observed without treatment. The percentage and absolute number of B lymphocytes, and total circulating lymphocytes, were significantly lower in patients with AE. An impairment of functional activity of T cells assayed by the leucocyte migration test, with PPD and Candidin as antigens, was demonstrated despite a normal percentage of SRBC rosettes. The 'score' of migration index still decreased during FZ treatment and returned to initial values after the year of follow-up without treatment. These results suggest that human AE is associated with important immunological disturbances. Changes in humoral immunity can be unequivocally considered to be a consequence of the parasite infection. The primary or secondary nature of the impairment of cellular immune responses and its mechanisms remain to be elucidated. Flubendazole could be responsible for an increase of cellular immune alterations in these patients.

Adult↗

Effect of an auditory stress on peritoneal and alveolar cells in C57 BL/6J mice of advanced age.

The aim of this study was to analyse the effects of auditory stress on peritoneal and alveolar macrophages in C57 BL/6J mice of advanced age, and to compare the results to those obtained in old mice submitted to a sham stress, and to those observed in young mice submitted to the same auditory stress. We used a chemiluminescence assay to measure the production of free oxygen radicals (FOR) by macrophages. Eight 22 month-old mice were exposed to a sound stress of 110 dB for three consecutive nights; nine were submitted to a sham stress. The results were compared to those obtained in young (8 week-old) mice, 21 submitted to noise stress, and 17 controls. The corticosterone level was not increased after stress in any group. FOR production in old mice was significantly higher than that in young mice. Stress did not induce significant changes in FOR production by alveolar cells in young mice; however, the FOR production by alveolar cells was significantly higher in the stressed group than in the control group of old mice. These results show that noise stress is associated with modifications of macrophage functions that are influenced by cell localization, the behaviour of alveolar and peritoneal macrophages of old mice being clearly different in our experimental model.

Acoustic Stimulation↗