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E Roux

Publications and source records attributed to E Roux.

107 records · Page 6Linked to original sources

Modification of human platelet behaviour in diabetes.

Among the different factors which could be responsible for the retinal vascular disturbances in diabetic retinopathy, we have investigated platelet populations, sialic acid content of platelets and collagen-induced platelet aggregation. The following results were obtained: a) there was no modification of platelet population distribution except for population A; b) there was a modification of collagen-induced platelet aggregation; the lag time was increased in diabetics.

Adult↗

T-cell repertoire complexity after allogeneic bone marrow transplantation.

We analyzed the T-cell repertoire in patients transplanted with bone marrow from an HLA identical sibling by determining the TCR diversity through Vbeta-CDR3-size spectratyping with Vbeta/Cbeta- and Vbeta/Jbeta-specific primers. Using the Vbeta/Cbeta primers, we observed limited TCR diversity only in recipients of a T-cell-depleted graft, whereas the TCR diversity of patients transplanted with an unmanipulated graft seemed to be indistinguishable from the one of a normal individual. However, with Vbeta/Jbeta-specific primers, increase of the resolution by approximately 10-fold also allowed the detection of imbalances in the TCR repertoire of recipients of an unmanipulated graft. This demonstrates that when high numbers of T cells are cotransfused with marrow, the TCR repertoire is more complete but still not as complete as in normal individuals, thereby emphasizing the important role of coinfused mature T cells in the restoration of the T-cell compartment after bone marrow transplantation.

Base Sequence↗

Interaction of extracellular albumin and intravenous anaesthetics, etomidate and propofol, on calcium signalling in rat airway smooth muscle cells.

It has been shown in vitro that general anaesthetics modify airway responsiveness via, at least partially, a direct inhibitory effect on calcium signalling in airway smooth muscle cells. However, in vivo, these anaesthetic compounds bind serum proteins. We have investigated the effect of exposure to extracellular albumin of freshly isolated airway smooth muscle cells on the propofol- and etomidate-induced inhibitory effect on calcium signalling. [Ca2+]i was measured by microspectrofluorimetry in rat isolated tracheal smooth muscle cells using the fluorescent dye indo-1. Propofol (3 x 10(-4) M) and etomidate (10(-4) M) were the lowest 'effective' concentrations that altered the [Ca2+]i response. This alteration consisted of a decrease in both the amplitude of the [Ca2+]i peak (from 358 +/- 13 nM to 65 +/- 15 and 108 +/- 27 nM for propofol and etomidate, respectively) and the percentage of responding cells (from 80% to 37 and 25% respectively) in response to the low concentration of ACh and a decrease in the Ca2+ oscillation frequency (from 9.9 +/- 0.3 min(-1) to 4.7 +/- 0.4 and 6.9 +/- 0.4 min(-1), respectively) in response to the high concentration of ACh. Increasing the concentration of albumin reduced the inhibitory effect of etomidate and propofol on the [Ca2+]i response to ACh. When extracellular albumin concentration was kept constant (20 g/L), increasing the concentration of etomidate by one log restored its inhibitory effect on the calcium signal. This study indicates that increasing the concentration of extracellular albumin reduces the inhibitory effect of intravenous anaesthetics on calcium signalling in airway smooth muscle cells. This report suggests that, in extrapolating in vitro dose-response relationships to those from in vivo conditions, the effect of the concentration of extracellular protein can be estimated.

Acetylcholine↗

[Electrophysiology and calcium signalling in human bronchial smooth muscle].

Recently, cells isolated from airways have been used to characterize precisely the electrophysiological properties of this smooth muscle and to describe the changes in cytosolic calcium concentration ([Ca2+]i) occurring upon agonist stimulation. Although most studies have produced consistent results in terms of types of ion channel and pathways of calcium signalling implicated in the mechanical activity of airways, there are differences according to (i) the site along the bronchial tree (trachea vs. bronchi); (ii) the proliferating status of the cells (freshly isolated vs. cultured) and (iii) the species (human vs. animals). With regard to the electrophysiological properties of airway smooth muscle, the contribution to [Ca2+]i rise of Ca2+ influx through L-type voltage-dependent calcium channels depends on the balance between depolarization related to non-specific cation channel and/or chloride channel activation and hyperpolarization related to activation of a variety of potassium channels. Most of the above-mentioned channels appear to be controlled, directly or indirectly, by agonists in human bronchial smooth muscle. With regard to calcium signalling, the pattern of agonist-induced [Ca2+]i responses, the so-called [Ca2+]i oscillations, has been observed recently in freshly isolated airway smooth muscle cells. The role and the calcium sources involved in these oscillations in human bronchial smooth muscle are currently being investigated.

Animals↗

Influence of the oral administration of lactic acid bacteria on iga producing cells associated to bronchus.

Intestinal, respiratory and genitourinary mucosal surfaces are the most important routes of entry for microbial pathogens. The stimulus of the mucosal immunity is not easy because the trigger keys for the activation do not follow the ones of the systemic immune response. In previous works we have demonstrated that some Lactic Acid Bacteria (LAB), when orally administered, can induce an enhance of the gut immune response. Taking into account the concept of a common mucosal response, we studied the effect of orally administered mice with Lactobacillus casei, L. acidophilus, L. rhamnosus, L. delbrueckii subsp. bulgaricus, Streptococcus salivarius subsp. thermophilus and Lactococcus lactis on the IgA secreting cells associated to bronchus. As shown before, oral immunostimulation with LAB induced an increase of the IgA* cells at intestinal level by a dose depending effect. In this study it is also showed that the LAB assayed, with exception of L. acidophilus, were able to enhance IgA+ cells at bronchial level, being also this effect dose dependent. The increment induced by some LAB in the number of IgA+ cells on the mucosa surface of the lower respiratory tract may be very important to prevent bronchus diseases.

Journal Article↗