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Corsini E, Gelati M, Dufour A, Massa G, Nespolo A, Ciusani E, Milanese C, La Mantia L, Salmaggi A. Effects of beta-IFN-1b treatment in MS patients on adhesion between PBMNCs, HUVECs and MS-HBECs: an in vivo and in vitro study. J Neuroimmunol 1997; 79:76-83. [PMID: 9357450 DOI: 10.1016/s0165-5728(97)00114-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The in vivo effects on the expression of adhesion molecules and on the adhesion between mononuclear cells and multiple sclerosis human brain endothelial cells (MS-HBECs) were investigated at the beginning of beta-IFN-1b treatment of MS patients. MS-HBECs were isolated from a surgical specimen obtained from an MS patient undergoing brain surgery for vascular aneurysm. 48 h after the first single administration of beta-IFN-1b, PBMNCs of 10 MS patients were analyzed for HLA-DR, CD11a, CD18 and VLA-4 expression and the adhesion between PBMNCs and both stimulated and unstimulated MS-HBECs evaluated. sICAM-1 and sVCAM-1 dosage in the serum of the patients was checked as well. The experiments were repeated using HUVECs in order to detect possible endothelial organ-specific differences. The experiments were also performed after six months of beta-INF-1b treatment on HUVECs. No significant effects on mononuclear cells/endothelium adhesion were detected at 48 h, but adhesion of PBMNCs to HUVECs decreased at six months. An increase in HLA-DR and VLA-4 and a decrease of CD18 was detected in monocytes. The serum level of sVCAM-1 increased at T2 and was still higher than at T0 at six months. The effect of the beta-IFN-1b treatment on both MS-HBECs and HUVECs, was selectively studied in vitro by testing the expression of cytokine-induced adhesion molecules HLA-DR, ICAM-1 and VCAM-1. The in vitro experiments confirmed that beta-IFN-1b is able to antagonize gamma-IFN-induced HLA-DR expression on MS human brain endothelial cells without relevant effects on VCAM-1 and ICAM-1.
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Dufour A, Castet E. The Misperception of the Direction of a Feature Added on a Moving Line is Eliminated with Static Cues. Perception 1997. [DOI: 10.1068/v970163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
It has been reported earlier that a feature (a gap or a dot) added on an oblique line which is translating vertically behind a horizontal rectangular aperture (we call this the basic display), appears to slide along that line while the perceived direction of the line is horizontal. Castet and Wuerger observed that, when the aperture is a visible circular outline, the perceived ‘sliding’ of the dot is significantly reduced compared to the conditions where the aperture is invisible. They suggested that the misperceived direction of the dot in the invisible-aperture condition might be due to a lack of static cues. To investigate this hypothesis further we ran a similar experiment in which the aperture was a rectangle. Subjects had to report with an adjustable arrow the direction of the dot added on the line. Results showed that the sliding effect completely disappeared when the rectangular aperture was visible (white outline) compared to the condition where the aperture was invisible. We hypothesised that better performance is obtained when the outlined aperture is rectangular rather than circular because of additional vertical cues. Therefore, in a second experiment using the basic display mentioned above, we tested how a single static dot affects the ‘sliding’ effect. The static dot was either vertically aligned or not, with the dot placed on the moving line. Results showed that the sliding effect was significantly reduced but not eliminated when the static dot was aligned vertically with the moving dot, compared to the conditions where the static dot was not aligned vertically with the moving dot (or where there was no static dot at all). This suggests that static features providing alignment information are optimal for eliminating the misperception of the direction of a moving feature.
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Gygi D, Fraser G, Dufour A, Hughes C. A motile but non-swarming mutant of Proteus mirabilis lacks FlgN, a facilitator of flagella filament assembly. Mol Microbiol 1997; 25:597-604. [PMID: 9302021 DOI: 10.1046/j.1365-2958.1997.5021862.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A TnphoA mutant of Proteus mirabilis was isolated, which had lost the ability to swarm, yet was still motile. The transposon had inserted into flgN, a flagella gene encoding a 147-amino-acid protein of undefined function. Proteus flgN is arranged in an operon with the class III anti-sigma28 gene, flgM, flanked by the class II genes, flgA, flgBCD and flhBA, and a novel putative virulence-related gene. The flgN mutation caused a substantial reduction in cell surface-associated flagellin, particularly during differentiation to the normally hyperflagellated swarm cell. This was not due to an effect on flagella gene expression or a typical defect in the flagella export apparatus as there was no class III gene downregulation by FlgM feedback, or intracellular flagellin accumulation. Loss of FlgN nevertheless caused a severe reduction in the incorporation of pulse-labelled flagellin into the membrane/flagellum fraction of differentiating cells. Substantial amounts of both non-oligomeric flagellin and flagellin degradation products appeared in the extracellular medium, although the few mature filaments made by the mutant were no more sensitive to proteolysis than those of the wild type. FlgN appeared soluble and active in the cytosol. The data suggest that the function of FlgN is to facilitate the initiation of flagella filament assembly, a role that may be especially critical in attaining the much higher concentration of surface flagellin required for swarming. Proteus FlgN has leucine zipper-like motifs arranged on potential amphipathic helices, a feature conserved in cytosolic chaperones for the exported substrates of flagella-related type III virulence systems. While gel filtration of FlgN from the soluble cell fraction did not establish an interaction with flagellin, it indicated that FlgN may associate with an unknown component and/or form an oligomer.
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Gelati M, Lamperti E, Dufour A, Corsini E, Venegoni E, Milanese C, Nespolo A, Salmaggi A. IL-10 production in multiple sclerosis patients, SLE patients and healthy controls: preliminary findings. ITALIAN JOURNAL OF NEUROLOGICAL SCIENCES 1997; 18:191-4. [PMID: 9323512 DOI: 10.1007/bf02080463] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
IL-10 is a cytokine with suppressive effects on (auto) antigen presentation and T-cell-mediated immune reactions, but is also capable of stimulating polyclonal IgG synthesis. Recent evidence suggests its involvement in multiple sclerosis (MS) and systemic lupus erythematosus (SLE). We assessed PBMNC IL-10 release in MS and SLE patients before and after in vivo prednisone or methylprednisolone treatment. The SLE patients showed a high level of IL-10 release by unstimulated PBMNCs, whereas the PHA-stimulated PBMNCs from MS patients produced large amounts of the cytokine.
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Salmaggi A, Corsini E, La Mantia L, Dufour A, Eoli M, Milanese C, Nespolo A. Immunological monitoring of azathioprine treatment in multiple sclerosis patients. J Neurol 1997; 244:167-74. [PMID: 9050957 DOI: 10.1007/s004150050068] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Despite the longstanding clinical use of azathioprine as an immunosuppressive agent in multiple sclerosis, little is known about the action of this drug on a number of parameters of putative pathogenic relevance in the disease. Eleven patients with multiple sclerosis, treated with azathioprine 2.5-3 mg/kg per day, and six untreated patients were studied with serial blood sampling for 1 year. The following immunological parameters were investigated: peripheral blood lymphocyte subsets, natural killer activity, serum IgG, IgM, ICAM-1 and tumour necrosis factor alpha (TNF-alpha). The most relevant changes included a decrease in CD3- CD56+ cells, an increase in CD4+ CD45RA+ cells and a decrease in TNF-alpha levels only in treated patients, while no changes occurred in untreated patients over a 1-year period. The decrease in TNF-alpha levels and the increase in "suppressor-inducer" lymphocytes could reduce chronic inflammation in multiple sclerosis, and paralleled an overall favourable clinical response to azathioprine treatment in our patients.
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Corsini E, Dufour A, Ciusani E, Gelati M, Frigerio S, Gritti A, Cajola L, Mancardi GL, Massa G, Salmaggi A. Human brain endothelial cells and astrocytes produce IL-1 beta but not IL-10. Scand J Immunol 1996; 44:506-11. [PMID: 8947603 DOI: 10.1046/j.1365-3083.1996.d01-343.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The ability of human brain endothelial cells to produce mRNA for interleukin-10, and release IL-10 in culture supernatants after in vitro stimulation with LPS, TNF-alpha and gamma-IFN was assessed and compared to that of astrocytes, peripheral blood mononuclear cells and human umbilical vein endothelial cells. IL-1 beta and beta 2-microglobulin release were also analysed. IL-10 and TNF-alpha mRNA presence was investigated in normal brain as well as in three plaques from two multiple sclerosis patients. While increased IL-1 beta and beta 2-microglobulin release in the supernatants of stimulated cells could be detected in all the studied cell lineages, IL-10 mRNA and protein release was only seen in LPS-stimulated PBMNCs. Similarly, mRNA for IL-10 was not detected in CNS tissues, while TNF-alpha was present in all plaques. The lack of production of significant amounts of IL-10 by astrocytes and human brain endothelial cells suggests that these cells may not be the primary source of in vivo IL-10-mediated down-regulation of immune reactions within the central nervous system.
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Dufour A, Corsini E, Giombini S, Nespolo A, Milanese C, Salmaggi A. Increased adhesion of CD4+ and CD14+ mononuclear cells to cultured multiple sclerosis brain endothelial cells. J Neurol 1996; 243:666-7. [PMID: 8892072 DOI: 10.1007/bf00878667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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83
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Bonnet C, Dufour A. Extracting Distributed Orientations in Different Contexts. Perception 1996. [DOI: 10.1068/v96l0511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
It has been shown that discriminating the orientations of a target is influenced by the spatial distribution of the orientations of similar elements in the background. However, this effect appears to be essentially decisional (Dufour and Bonnet, 1995 Spatial Vision9 307 – 324). In the present experiment, we explored the accuracy with which subjects can discriminate relative proportions of orientations distributed over a surface (background). Stimuli were textures made of 100 segments with regular spacing. Each of the segments had one of four possible orientations. For each display, one of the orientations was overrepresented (31%, 37%, 43% and 49%). The task of the subject was to discriminate, in a reaction-time paradigm, which of the four orientations was more frequent within a given display. Three spatial conditions were used. In condition 1, the different orientations were randomly distributed over the surface. In the two other conditions, nine elements of the same orientation formed a group within one region of the texture. In condition 2, these grouped elements had the over-represented orientation. In condition 3, they had one of the three under-represented orientations. Grouping of the oriented elements has a facilitating effect when it contains the over-represented orientation, and a negative effect when it contains one of the under-represented orientations. There are good reasons to think that these interferences are decisional rather than sensorial.
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Salmaggi A, Dufour A, Silvani A, Ciusani E, Nespolo A, Boiardi A. Intrathecal immunotherapy in CNS tumors disseminating via CSF: preliminary evaluation using different treatment schedules. ITALIAN JOURNAL OF NEUROLOGICAL SCIENCES 1996; 17:267-76. [PMID: 8915757 DOI: 10.1007/bf01997785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Eight patients affected by central nervous system tumours disseminating via cerebrospinal fluid received rIL-2 immunotherapy according to three different protocols involving intrathecal administration followed or not by systemic infusion. Immunological monitoring included serial evaluation of CSF leukocytes, CSF and peripheral blood CD3-CD56+ cells, and NK activity. The most marked rise in CSF leukocyte levels was induced by daily intrathecal rIL2 administration, which also induced increased PB NK activity. Systemic rIL2 infusion following intrathecal treatment maintained a high percentage of CSF CD3-CD56+ cells, but not CSF leukocytes at high levels. Clinical conditions improved after treatment in two patients, worsened in one and remained substantially unchanged in the remaining five. The side effects of intrathecal rIL2 treatment included fever, confusion, and seizures, and there were marked interindividual variations in the immunological response.
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Dufour A, Alary M, Poulin C, Allard F, Noël L, Trottier G, Lépine D, Hankins C. Prevalence and risk behaviours for HIV infection among inmates of a provincial prison in Quebec City. AIDS 1996; 10:1009-15. [PMID: 8853735 DOI: 10.1097/00002030-199610090-00012] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To assess HIV prevalence and related risk factors among inmates at the Quebec Detention Centre (QDC). DESIGN Cross-sectional prevalence study. METHODS Inmates incarcerated at the QDC in September 1994 were asked to participate in an anonymous survey concerning HIV infection. Volunteers answered a questionnaire and provided a saliva sample during a meeting with an interviewer. RESULTS The overall participation rate was 95% (618 out of 651). HIV prevalence was 2% (11 out of 499) in men. All HIV-infected men were injecting drug users (IDU) with an HIV prevalence of 9% (11 out of 129) in this group. HIV prevalence was 14% (9/63) among male IDU admitting previous needle-sharing and 3% (two out of 66) among the other IDU (odds ratio, 5.3; P = 0.028). Twelve male inmates admitted injecting drugs during imprisonment, of whom 11 shared needles and three were HIV-positive. HIV prevalence in men reporting sexual intercourse with men prior to incarceration was 10% (five out of 52). Nine of the 119 women were HIV-infected (8%), seven of whom were IDU (prevalence of 16% in female IDU). One of the two non-IDU had sexual contacts with male IDU, and the other with men who had sex with men. Tattooing was not associated with HIV infection in either men or women. CONCLUSIONS Prisoners constitute a group at high risk of HIV infection mainly because of the high proportion of them who are IDU. Imprisonment offers a good opportunity to provide education and preventive programs to this specific group that might otherwise be difficult to reach.
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Alper S, Dufour A, Garsin DA, Duncan L, Losick R. Role of adenosine nucleotides in the regulation of a stress-response transcription factor in Bacillus subtilis. J Mol Biol 1996; 260:165-77. [PMID: 8764398 DOI: 10.1006/jmbi.1996.0390] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The RNA polymerase sigma factor sigma B is a stress-response regulatory protein in Bacillus subtilis. The activity of sigma B is controlled in part by RsbW, a protein that inhibits sigma B, and RsbV, a protein that counteracts this inhibition. We now demonstrate that purified RsbW is capable of forming alternative complexes with either sigma B or RsbV. Sigma B in the RsbW. sigma B complex was transcriptionally inactive. RsbV reversed this inhibition by sequestering RsbW in a RsbW-RsbV complex, thereby allowing sigma B to remain free and active. In contrast to interactions among the components of the homologous regulatory system for the sporulation transcription factor sigma F, the binding of RsbW to RsbV and sigma B did not require adenosine nucleotides. Experiments involving the exchange of proteins between the two regulatory systems demonstrated that RsbW and its homolog in the sigma F system, SpoIIAB, exhibit strong preference in binding to RsbV and sigma B, and SpoIIAA and sigma F, respectively, and that the difference in nucleotide-dependence of binding between these two systems is attributable to a difference between RsbW and SpoIIAB. In confirmation and extension of previous results, we show that RsbW is also a protein kinase that uses ATP to phosphorylate RsbV, thereby blocking the capacity of RsbV to bind to RsbW and activate transcription. A close correlation was observed between the concentration of ATP required for efficient RsbW-mediated phosphorylation of RsbV, inhibition of RsbW.RsbV comlex formation, and inhibition of sigma B-directed transcription. These results are consistent with the hypothesis that activation of sigma B under certain stress condition is due to a decrease in cellular ATP levels.
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Dufour A, Voelker U, Voelker A, Haldenwang WG. Relative levels and fractionation properties of Bacillus subtilis σ(B) and its regulators during balanced growth and stress. J Bacteriol 1996; 178:3701-9 sigma. [PMID: 8682769 PMCID: PMC232625 DOI: 10.1128/jb.178.13.3701-9sigma.1996] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
sigma B is a secondary sigma factor that controls the general stress response in Bacillus subtilis. sigma B-dependent genes are activated when sigma B is released from an inhibitory complex with an anti-sigma B protein (RsbW) and becomes free to associate with RNA polymerase. Two separate pathways, responding either to a drop in intracellular ATP levels or to environmental stress (e.g., heat, ethanol, or salt), cause the release of sigma B from RsbW. rsbR, rsbS, rsbT, and rsbU are four genes now recognized as the upstream half of an operon that includes sigB (sigma B) and its principal regulators. Using reporter gene assays, we find that none of these four genes are essential for stationary-phase (i.e., ATP-dependent) activation of sigma B, but rsbU and one or more of the genes contained within an rsbR,S,T deletion are needed for stress induction of sigma B. In other experiments, Western blot (immunoblot) analyses showed that the levels of RsbR, RsbS, Rsb, and RsbU, unlike those of the sigB operon's four downstream gene products (RsbV, RsbW, RsbX and sigma B), are not elevated during sigma B activation. Gel filtration and immunoprecipitation studies did not reveal the formation of complexes between any of the four upstream sigB operon products and the products of the downstream half of the operon. Much of the detectable RsbR, RsbS, RsbT, and RsbU did, however, fractionate as a large-molecular-mass (approximately 600-kDa) aggregate which was excluded from our gel filtration matrix. The downstream sigB operon products were not present in this excluded material. The unaggregated RsbR, RsbS, and RsbU, which were retarded by the gel matrix, elated from the column earlier than expected from their molecular weights. The RsbR and RsbS fractionation profile was consistent with homodimers (60 and 30 kDa, respectively), while the RsbU appeared larger, suggesting a protein complex of approximately 90 to 100 kDa.
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Salmaggi A, Dufour A, Eoli M, Corsini E, La Mantia L, Massa G, Nespolo A, Milanese C. Low serum interleukin-10 levels in multiple sclerosis: further evidence for decreased systemic immunosuppression? J Neurol 1996; 243:13-7. [PMID: 8869381 DOI: 10.1007/bf00878525] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Serum interleukin 10 (IL10) levels were assessed in patients with multiple sclerosis who were either in a stable or active clinical condition. The levels were compared with values in healthy controls. Lower IL10 levels than in controls were seen in multiple sclerosis patients, regardless of clinical disease activity. Low IL10 levels were also seen in patients with systemic lupus erythematosus. No clear-cut relationships emerged between IL10 levels and those of tumour necrosis factor alpha and transforming growth factor beta, or between IL10 and lymphocyte subsets in peripheral blood.
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Dufour A. Interactions between noise and signal segments at the decision level are task contingent. SPATIAL VISION 1996; 10:273-83. [PMID: 9061834 DOI: 10.1163/156856896x00169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The ways in which unattended line segments influence the discrimination of a single line segment on which attention is focused was studied in two experiments which differed only by the task to be performed. In the first experiment subjects had to determine whether a line segment viewed centrally was oriented to the right or to the left with respect to the vertical, and in the second experiment they had to judge its tilt amplitude (45 deg vs. 55 deg to vertical). It appears that line segments surrounding the target segment did not affect subjects' response times in the same way in the two experiments. Results are interpreted in terms of response competition at the decision level.
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Voelker U, Voelker A, Maul B, Hecker M, Dufour A, Haldenwang WG. Separate mechanisms activate sigma B of Bacillus subtilis in response to environmental and metabolic stresses. J Bacteriol 1995; 177:3771-80. [PMID: 7601843 PMCID: PMC177095 DOI: 10.1128/jb.177.13.3771-3780.1995] [Citation(s) in RCA: 171] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
sigma B is a secondary sigma factor that controls the general stress response of Bacillus subtilis. sigma B-dependent transcription is induced by the activation of sigma B itself, a process that involves release of sigma B from an inhibitory complex with its primary regulator, RsbW. sigma B becomes available to RNA polymerase when RsbW forms a complex with an additional regulatory protein (RsbV) and, because of this, fails to bind sigma B. Using Western blot (immunoblot) analyses, reporter gene fusion assays, and measurements of nucleotide pool sizes, we provide evidence for two independent processes that promote the binding of RsbW to RsbV. The first occurs during carbon limitation or entry into stationary phase. Activation of sigma B under these circumstances correlates with a drop in the intracellular levels of ATP and may be a direct consequence of ATP levels on RsbW's binding preference. The second activation process relies on the product of a third regulatory gene, rsbU. RsbU is dispensable for sigma B activation during carbon limitation or stationary phase but is needed for activation of sigma B in response to any of a number of different environmental insults (ethanol treatment, salt or acid shock, etc.). RsbU, or a process dependent on it, alters RsbW binding without regard for intracellular levels of ATP. In at least some instances, the effects of multiple inducing stimuli are additive. The data are consistent with RsbW being a regulator at which distinct signals from separate effectors can be integrated to modulate sigma B activity.
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Voelker U, Dufour A, Haldenwang WG. The Bacillus subtilis rsbU gene product is necessary for RsbX-dependent regulation of sigma B. J Bacteriol 1995; 177:114-22. [PMID: 8002609 PMCID: PMC176563 DOI: 10.1128/jb.177.1.114-122.1995] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
sigma B is a secondary sigma factor of Bacillus subtilis. sigma B-dependent transcription is induced when B. subtilis enters the stationary phase of growth or is exposed to any of a number of different environmental stresses. Three genes (rsbV, rsbW, and rsbX), which are cotranscribed with the sigma B structural gene (sigB), encode regulators of sigma B-dependent gene expression. RsbW and RsbV have been shown to control sigma B activity, functioning as an inhibitory sigma B binding protein and its antagonist, respectively. Using the SPAC promoter (PSPAC) to control the expression of the sigB operon, a ctc::lacZ reporter system to monitor sigma B activity, and monoclonal antibodies to determine the levels of sigB operon products, we have now obtained evidence that RsbX is an indirect regulator of sigma B activity. Genetic data and in vivo measurements argue that RsbX negatively regulates an extension of the RsbV-RsbW pathway that requires the product of an additional regulatory gene (rsbU) which lies immediately upstream of the sigB operon. The results are consistent with RsbU, or a process dependent on RsbU, being able to facilitate the RsbV-dependent release of sigma B from RsbW but normally prevented from doing this by RsbX.
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Dufour A, Bonnet C. Influence of unattended features on the processing of a single line segment. SPATIAL VISION 1995; 9:307-24. [PMID: 8962838 DOI: 10.1163/156856895x00025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This work investigates the interference of unattended line segments (distractors) of different orientations on a single line segment (target) when observer attention is focused on it in order to determine its orientation. It appears that the presence of line segments of different orientations in the visual field strongly influences the observer's decision on the judgement of the target orientation, whereas sensitivity is not affected. Two experiments were carried out to investigate distractor influence as a function of their number (Experiment I) and as a function of their proximity to the target, that is, to the point on which attention is focused (Experiment II). It appeared that distractors close to the target interfered more intensely than distractors at greater distances from the target, even if the latter were far more numerous. The results suggest that the output of the decision system is a function of all the information transmitted by feature detectors which act separately and in parallel.
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Chapeau V, Moulin A, Caude M, Dufour A. High-performance liquid chromatographic determination of oxodipine enantiomers, a new 1,4-dihydropyridine, applied to stereoselectivity studies in man and dog. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1994; 660:341-6. [PMID: 7866524 DOI: 10.1016/0378-4347(94)00288-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A specific and reproducible HPLC method using a Chiral-AGP column and UV detection was developed for the evaluation of the pharmacokinetic profile of oxodipine enantiomers in dog and man. Each enantiomer was determined in plasma in the concentration range 1-400 ng/ml using the internal standard calibration method with linear regression analysis. After extraction of oxodipine and the internal standard at alkaline pH with diethyl ether-n-hexane (50:50, v/v), this method permitted the determination of each enantiomer at levels down to 10 ng/ml in dog plasma and 25 ng/ml in human plasma with sufficient accuracy (relative error < 11%, n = 6) and precision (coefficient of variation < 16%, n = 6). The extracted plasma volume was 500 microliters and after evaporation of the organic phase, the dry residue was dissolved in 100 microliters of water-2-propranol; an aliquot of 80 microliters was injected into the HPLC system.
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Salmaggi A, Dufour A, Eoli M, Corsini E, La Mantia L, Milanese C, Nespolo A. Study of IL10 levels in MS patients in different phases of the disease. J Neuroimmunol 1994. [DOI: 10.1016/0165-5728(94)90510-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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95
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Staveris S, Houin G, Dufour A, Plusquellec Y, Grenier JF, Jung L, Koffel JC, Saivin S. Evidence for a second site of absorption of veralipride in the human small intestine. Use of a new drug delivery telemetric shuttle. ARZNEIMITTEL-FORSCHUNG 1994; 44:1068-72. [PMID: 7986246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A new telemetric shuttle was used to coadminister veralipride (CAS 66644-81-3) and veralipride-D3 in order to test the assumption that veralipride is absorbed at two sites of the small intestine. Two different pharmacokinetic approaches were used to interpret the obtained data. According to the results, the second site of absorption of veralipride is located at a distance corresponding to 2/3 of the total length of the small intestine.
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Salmaggi A, Dufour A, Silvani A, Ciusani E, Nespolo A, Boiardi A. Immunological fluctuations during intrathecal immunotherapy in three patients affected by CNS tumours disseminating via CSF. Int J Neurosci 1994; 77:117-25. [PMID: 7989157 DOI: 10.3109/00207459408986024] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The immunological therapy of cancer has been proposed in a number of neoplasms (Borden, Sondel, 1989; Foon, 1989; Rosenberg, 1992) and has recently been adopted in the treatment of Central Nervous System (CNS) tumors in combination with conventional surgical and radiotherapeutical approach. In this context, loco-regional administration of immunomodulating agents (for instance in post-surgical cavity) allows to achieve much higher in situ concentrations than by systemic route. Since these treatments have potential adverse effects, careful assessment of clinical and immunological parameters in phase I trials is needed. CNS tumors disseminating via Cerebrospinal Fluid (CSF) pathways offer a stimulating opportunity for intrathecal immunotherapy. In this context, alpha-IFN and IL2 (alone or in combination with LAK cells) have been employed either loco-regionally or intrathecally (Merchant, Mc Vicar, Merchant & Young, 1992; Schiller, Hank, Storer, Borchert, Moore, Albertini, Bechhofer, Wesley, Brown, Bastin & Sondel, 1993). The rationale for the use of both these substances includes the known anti-tumor action of alpha-IFN (Mahaley, Urso, Whaley, Blue, Williams, Guaspari & Selker, 1985; Nagai, 1988) and the ability of r-IL2 to generate activated cells effective in lysing tumor cell targets (Hayes, Moore, Pierz, Chen, Da Rosso, Nirenberg & Allen, 1993). We treated 3 patients (2 affected by disseminating cerebellar medulloblastoma, 1 by disseminating thalamic glioblastoma) by intrathecal r-IL2 via recervoir. In the first 2 patients, this treatment was preceded by alpha-IFN (also intrathecally). Monitoring of immunological effects of the treatment schedule involved kinetics of CSF and serum TNF-alpha, IL2s and IL2R during the first day of r-IL2 treatment, as well as on day +2 and +4 of both r-IL2 cycles, and assessment of CSF cells, protein and CSF and PB NK cell activity and CD3-CD56+ cells during the course of all treatment cycles. We also assessed clinical and neuroradiological effects of immunotherapy.
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Salmaggi A, Milanese C, Eoli M, La Mantia L, Nespolo A, Dufour A. Immunological monitoring and clinical evaluation in cyclophosphamide-treated progressive multiple sclerosis patients. Int J Neurosci 1994; 76:305-12. [PMID: 7960486 DOI: 10.3109/00207459408986012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
15 patients with progressive Multiple Sclerosis (MS) were treated by an induction Cyclophosphamide (CFX) schedule followed by bimonthly boosters over one year. Of the 14 patients who completed the trial, only two displayed worsening of neurological status. Cerebrospinal fluid (CSF) total protein, IgG/Alb ratio and IgG index decreased at 6 months and were still low at the end of the treatment. Pretreatment percentages of PB CD8+ and CD4+CD45RA+ lymphocytes were lower in MS patients in comparison with healthy controls. However, no significant shifts occurred in percentage of PB CD4+, CD4+CD45RA+, CD4+CD45RA-, CD8+ lymphocytes of MS patients during immunosuppressive treatment. The lack of changes in the investigated immunological parameters contrasts with the good clinical response and the low rate of serious side effects during this treatment schedule.
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Rince A, Dufour A, Le Pogam S, Thuault D, Bourgeois CM, Le Pennec JP. Cloning, expression, and nucleotide sequence of genes involved in production of lactococcin DR, a bacteriocin from lactococcus lactis subsp. lactis. Appl Environ Microbiol 1994; 60:1652-7. [PMID: 8017945 PMCID: PMC201532 DOI: 10.1128/aem.60.5.1652-1657.1994] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The partial nucleotide sequence of a Lactococcus lactis subsp. lactis ADRIA 85LO30 bacteriocin-producing operon was determined. The first two open reading frames of the operon are necessary to get bacteriocin expression in L. lactis IL1403R.
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Dufour A, Haldenwang WG. Interactions between a Bacillus subtilis anti-sigma factor (RsbW) and its antagonist (RsbV). J Bacteriol 1994; 176:1813-20. [PMID: 8144446 PMCID: PMC205282 DOI: 10.1128/jb.176.7.1813-1820.1994] [Citation(s) in RCA: 158] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The activity of sigma B, a secondary sigma factor of Bacillus subtilis, is primarily controlled by an anti-sigma factor protein (RsbW) that binds to sigma B and blocks its ability to form an RNA polymerase holoenzyme (E-sigma B). Inhibition of sigma B by RsbW is counteracted by RsbV, a protein that is essential for the activation of sigma B-dependent transcription. When crude B. subtilis extracts were fractionated by gel filtration chromatography or electrophoresis through nondenaturing polyacrylamide gels, a complex composed of RsbW and RsbV that is distinct from the previously observed RsbW-sigma B complex was detected. In analogous experiments, RsbX, an additional regulator of sigma B-dependent transcription that is thought to act independently of RsbV-RsbW, was not found to associate with any of the other sigB operon products. Two forms of RsbV were visualized when crude cell extracts of B. subtilis were subjected to isoelectric focusing (IEF), with the more negatively charged RsbV species absent from extracts prepared from RsbW- strains. In vitro, RsbV became phosphorylated when incubated with ATP and RsbW but not with ATP alone. The phosphorylated RsbV species comigrated during IEF with the RsbW-dependent form of RsbV found in crude cell extracts. These results suggest that the modified RsbV, present in crude cell extracts, is phosphorylated. When gel filtration fractions containing RsbV-RsbW complexes or RsbV alone were subjected to IEF, only the unmodified form of RsbV was found associated with RsbW. The presumed phosphorylated variant of RsbV was present only in fractions that did not contain RsbW. The data support a model whereby RsbV binds directly to RsbW and blocks its ability to form the RsbW-sigma B complex. This activity of RsbV appears to be inhibited by RsbW-dependent phosphorylation.
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Dufour A, Salmaggi A, La Mantia L, Eoli M, Nespolo A, Milanese C. High-dose methylprednisolone treatment-induced changes in immunological parameters in progressive MS patients. Int J Neurosci 1994; 75:119-28. [PMID: 7914185 DOI: 10.3109/00207459408986295] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The effect of High-Dose Methylprednisolone (HD-MP) treatment on Peripheral Blood (PB) and Cerebrospinal Fluid (CSF) immune parameters was investigated in 9 patients with relapsing-progressive Multiple Sclerosis (MS). Short-time effects included reduction of the percentage of CD3+, CD4+ and CD4+CD45RA+ PB lymphocytes and increase in CD3-CD56+ cells. At the end of the treatment, only increase in PB CD19+ and in CSF CD8+, CD8+CD28+ and decrease of CSF CD4+CD45RA- and serum IL2R levels were observed. No changes in CD11a+CD4+, CD18+CD14+ PB cells were observed after treatment. The results further stress the complex and multifaceted action of HD-MP on immune parameters.
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