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F Faure

Publications and source records attributed to F Faure.

At least 55 records · Page 3Linked to original sources
PubMed1991

Placental transfer of glycosaminoglycans in the human perfused placental cotyledon model.

Placental transfer of unfractionated heparin (UH), of low molecular weight heparin CY 216 (LMWH) and of Dermatan sulphate (DS) was studied using the human perfused placental cotyledon model. Two different techniques were used to assess the transfer: labelled molecules and biological activities as measured by antifactor Xa or antifactor IIa activities. No biological activity was present in the fetal circulation, for any of the drugs used; however, very low fractions of the perfused radioactivity were recorded, 0.76% +/- 0.36%, 1.46% +/- 1.44% and 2.37% +/- 0.89% for DS, UH and LMWH, respectively.

Dermatan Sulfate↗
PubMed1991

Maternal and umbilical cord concentrations of fentanyl after epidural analgesia for cesarean section.

The maternal and umbilical concentrations of fentanyl were measured after epidural analgesia for cesarean section, using a highly sensitive radioimmunoassay method. Sixteen parturients were anesthetized with a single epidural injection of a mixture of 85 mg bupivacaine 0.5%, 60 mg etidocaine 1%, and 100 micrograms fentanyl with epinephrine 1:200,000. Apparent maternal individual maximum peak concentration (Cmax) of fentanyl was 0.38 +/- 0.16 ng/ml (mean +/- SD) (range 0.12-0.59 ng/ml) and the time to reach Cmax (Tmax) was 24 +/- 14 min (range 5-60 min). Infants were born 19 to 42 min after epidural administration of fentanyl (mean 27 min). Fentanyl concentrations in neonates was 0.13 +/- 0.04 ng/ml for the umbilical vein and 0.06 +/- 0.03 ng/ml for the artery. The fetus extraction ratio was 53 +/- 19% (range 20-83%). The large difference between arterial and venous concentrations of fentanyl may be due to a metabolization by the fetus and/or an uptake of the drug in the fetal tissues. Thus, even if fentanyl levels reaching the fetus after cesarean section under epidural anesthesia, using local anesthetics with 100 micrograms of fentanyl, are within safe range values, the likelihood of fentanyl uptake by fetal tissues calls for a cautious use of repeated fentanyl administration.

Analgesia, Epidural↗
PubMed1991

Molecular characterization of human T cell receptor alpha chains including a V delta 1-encoded variable segment.

Previously we have shown that a small fraction of human peripheral T cells expresses a surface receptor recognized both by the BMA031 mAb, specific for a TcR alpha/beta framework epitope, and by the A13 mAb, putatively specific for an epitope encoded by the V delta 1 gene segment. An interleukin 2-dependent polyclonal cell line (termed T2) was derived from such A13+BMA031+ circulating lymphocytes. The molecular characterization of the TcR chains expressed by T2 cells demonstrated indeed that the V delta 1 gene (one of the two major V delta genes) was transcribed with the C alpha gene segment. In the T2 polyclonal cell line, distinct V delta 1/C alpha transcripts were all found to include the same J alpha segment suggesting the existence of "hybrid" TcR alpha/delta chains encoded by unique V delta 1/J alpha rearrangements. The present study was designed to characterize further the V delta 1/J alpha rearranged genes expressed in A13+BMA031+ cells. Three additional cell lines were generated from peripheral blood of distinct adult healthy donors. Using the anchored polymerase chain reaction, it was found that 17 different J alpha segments were used in the 20 V delta 1J alpha C alpha transcripts which have been studied. Together, these data indicate that V delta 1 is a "mixed" (i.e. alpha/delta) TcR V segment which can join with most (if not all) J segments in the alpha/delta locus. In addition, it can be definitely concluded that the A13 mAb recognizes a V delta 1-encoded antigenic determinant and not a V delta 1J epitope (i.e. it can be defined and used as an anti-V delta 1 mAb, as opposed to reagents such as for example delta-TCS-1).

Adult↗
PubMed1991

[Femoral anteversion in upper femoral epiphysiolysis in adolescents. Apropos of 25 cases].

CT-scan examinations have been performed in 25 children with slipped capital femoral epiphysis (SCFE) and in 127 children in an out-patients orthopaedic consultation. A low femoral anteversion (FA) was present in SCFE. This morphological abnormality, in association with other factors, could explain the production of SCFE at the moment of the most important fragility of the upper femoral growth plate, which is puberty. A statistical analysis showed that the risk of SCFE was distinctly greater, even for the contralateral hip when FA was low.

Adolescent↗
PubMed1990

Further analysis of the T cell receptor gamma/delta+ peripheral lymphocyte subset. The V delta 1 gene segment is expressed with either C alpha or C delta.

In the present study, we have characterized the reactivity of two mAbs that are directed at the human TCR-gamma/delta. These reagents, designated anti-A13 and anti-TiV delta 2, were found to recognize antigenic determinants encoded by the TCR V delta 1 and V delta 2 gene segments, respectively. Immunofluorescence analyses performed with the antibodies confirmed that, in the TCR-gamma/delta+ cell subpopulation, the expression of V delta 2+ delta chains is largely predominant, as compared with the V delta 1+ counterparts. However, these experiments led to an apparently discrepant finding. Indeed, the total number of cells recognized by the anti-A13 plus the anti-TiV delta 2 antibodies was often greater than that detected with anti-TCR-delta 1, a reagent specific for a constant epitope of the human delta chain. Further investigation showed that the presence of a sizeable peripheral lymphocyte subset coexpressing the BMA031 and the A13 epitopes. Because the former antibody is known to recognize an invariant antigenic determinant of the TCR-alpha/beta dimer, these results suggested that the V delta 1 gene segment may be expressed with either C delta or C alpha. This hypothesis was confirmed using T2, an IL-2-dependent BMA031+ A13+ polyclonal cell line developed from peripheral blood of a healthy adult donor. Indeed, T2 cells were found to have productively rearranged the V delta 1 gene. Together, results of Northern blot analysis and cDNA cloning indicated that V delta 1 was expressed in these cells as part of a 1.6-kb full-length message including J alpha-C alpha segments.

Animals↗
PubMed1990

CD1c as a target recognition structure for human T lymphocytes: analysis with peripheral blood gamma/delta cells.

It has been shown recently that one gamma/delta cell line, termed IDP2, derived from a immunodeficient patient recognizes the CD1c molecule on the surface of target cells. In light of these data, we have tested 43 cloned and 11 polyclonal gamma/delta cell lines derived from peripheral blood of 19 donors following nonspecific mitogenic stimulation. In this panel, which included lymphocytes expressing various combinations of gamma and delta chains, only one clone, termed J2B7, was found to interact with target cells via a CD1c-dependent recognition pathway. These J2B7 lymphocytes have, like IDP2, a delta chain which results from the frequent V1/J1 rearrangement while they use a distinct V gamma gene segment. The data support the view that the CD1c major histocompatibility complex "class I-like" gene product does not have a pivotal contribution to the repertoire of peripheral blood gamma/delta cells in adult individuals.

Antibodies, Monoclonal↗
PubMed1990

Effects of pH on antipyrine transfer across the human placenta ex vivo.

The influence of pH variations on transplacental transfer of antipyrine was studied using a human placental cotyledon perfused ex vivo. The antipyrine transfer rate is positively correlated with the pH in the fetal circulation and negatively correlated with the pH in the maternal circulation. Thus, the transfer rate is negatively correlated with the difference between pH values in maternal and fetal circulations. The antipyrine transfer rate is also positively correlated with the flows in maternal and fetal circulations. The above parameters allowed to explain 50% of the variance on the transfer rates obtained in various experimental conditions. In a final series of experiments where these parameters for each placenta were fixed at identical values, a good reproducibility in the results was obtained, the variation coefficient being 17%. Thus, establishing the effect of variations in pH allowed a good standardization of the perfused cotyledon model. This effect cannot be explained by modifications in the ionized fraction of the antipyrine molecular and is probably due to physiological mechanisms.

Adult↗
PubMed1989

cDNA cloning of functional T cell receptor gamma/delta chains expressed in human peripheral blood lymphocytes.

We have identified in earlier studies two V delta rearrangements corresponding to a 4.5-kb Eco RI fragment detected with a V delta1 probe and to a 7-kb Eco RI band detected with a V delta2 probe. These rearrangements have been found in two human T cell clones, F6C7 and G6, displaying surface phenotypes unfrequent in human peripheral blood, namely Ti gamma A+ BB3- (F6C7) and Ti gamma A- BB3+ (G6). Herein, we report the sequences of the functional transcripts encoded by these rearranged genes and show that the 4.5- and the 7-kb Eco RI fragments correspond to V1/D3/J delta 3 and to V2/D3/J delta 3 recombinations, respectively. In addition, we have sequenced the V2/D3/J1/C delta transcripts expressed in two clones, AB12 and VTC, which have a Ti gamma A+ BB3+ surface phenotype corresponding to that of most gamma/delta peripheral lymphocytes. Analyses of the delta transcripts expressed by these four cells further strengthen the hypothesis that anti-BB3 and anti-delta-TCS-1 monoclonal antibodies recognize a V delta 2- and a V1/(D)/J delta 1-encoded epitope, respectively. Sequence of the gamma transcripts expressed by AB12 and F6C7 cells shows that they encode a V9/JP/C gamma 1 chain. Finally, we confirm that non-combinatorial diversity in the gamma and delta proteins is generated by both junctional flexibility and N-region addition without any somatic mutation.

Amino Acid Sequence↗
PubMed1988

Characterization of human peripheral lymphocytes expressing the CD3-gamma/delta complex with anti-receptor monoclonal antibodies.

Three mAb, anti-Ti gamma A, anti-TCR delta 1, and anti-delta TCS1, have been developed against the CD3-associated gamma/delta molecular complex. One of this antibody anti-Ti gamma A is specific for an epitope encoded by the V9 gamma-gene. The two others react with the delta-chain but their fine epitopic specificity has not been characterized previously. In the present study, we have compared the surface expression of these three antigenic determinants on 27 cloned and 5 polyclonal CD3+ TCR gamma/delta + cell lines derived from human peripheral blood of 13 distinct individuals. It was found that all CD3+ TCR alpha/beta- clones and polyclonal cell lines tested were recognized by anti-TCR delta 1. In contrast, only a fraction of both clones and cell lines reacted with either anti-Ti gamma A or anti-delta TCS1 mAb. In fact reactivity of the latter reagents was found to be mutually exclusive on the cell panel. Northern blot analysis of RNA extracted from a series representative clones showed a positive correlation between the surface expression of the delta TCS1 epitope and the transcription of the V-delta gene isolated from the IDP2 cell line. These data support the view that anti-TCR delta 1 can be used to positively define the entire TCR gamma/delta+ fraction. Moreover, the reciprocal reactivity of anti-delta TCS1 and anti-Ti gamma A on cultured cell lines suggests that these reagents should delineate in human peripheral blood distinct, essentially non-overlapping, subsets. Taken together, the present results indicate that the complementary use of these three antibodies will be helpful to further characterize the TCR gamma/delta + peripheral lymphocyte fraction.

Adult↗
PubMed1988

Identification of a CD2- CD3+ T cell receptor-gamma+ peripheral blood lymphocyte subpopulation.

We have identified, in a healthy individual, a sub-population of human peripheral lymphocytes which surface express a CD3-TCR-gamma complex recognized by anti-Ti gamma A mAb, while being unreactive with a phycoerythrin-conjugated anti-CD2 antibody with T11/1 specificity. Further immunofluorescence analyses performed on uncultured cells indicated that such a putative CD2-CD3+ phenotype was restricted to a fraction of those T lymphocytes which carry a surface receptor of the "second family" (gamma/delta). The actual lack of CD2 expression was confirmed by a subsequent series of cloning experiments which showed that none of the three well characterized CD2 epitopic clusters, namely T11/1, T11/2, and T11/3, were detectable on the surface of the relevant cells. The cultured CD2-, CD3+/TCR gamma + lymphocytes were found to display, as well as their CD2+ counterparts, both non-MHC-restricted cytotoxic function and proliferative responses induced via the gamma receptor complex. In contrast, the proliferative capacity of the CD2-, CD3+/TCR-gamma + cells observed in a culture system designed for in vitro expansion of lymphocytes with undefined specificity was extremely limited. This may relate to an impaired interaction of the CD2- cloned lymphocytes with lymphocyte function-associated (LFA)3+ irradiated cells present in the feeder layer. Further characterization of such minor CD2- T lymphocytes subsets may help to better understand the biologic relevance of the CD2/LFA3 pathway of cell-cell interaction.

Adult↗
PubMed1988

CD3/Ti gamma A: a functional gamma-receptor complex expressed on human peripheral lymphocytes.

We have recently developed a mAb designated anti-Ti gamma A, which was found to immunoprecipitate from the well characterized CD3+ TCR alpha/beta- F6C7 fetal clone a CD3-associated disulfide-linked gamma-glycoprotein. This antibody recognizes approximately 3% of adult peripheral lymphocytes and delineates a CD2+ CD3+ TCR alpha/beta- CD4- NKH1- subset where expression of CD8 appears to vary widely from one individual to another. In the present study, we have used anti-Ti gamma A mAb to assess whether gamma-chains expressed on these adult lymphocytes are used as functional R. The two activities which have been associated thus far with TCR gamma+ cells, that is, IL-2-dependent proliferation and non-MHC-restricted cytotoxicity, were investigated here by using either resting or activated Ti gamma A+ lymphocytes. On the resting state, these cells (which appear as a very homogeneous population of granular lymphocytes) mediate little if any NK activity that could not be augmented by anti-Ti gamma A mAb. In contrast, after initial stimulation by PHA plus rIL-2 and subsequent culture in the presence of IL-2, activated Ti gamma A+ lymphocytes were strongly lytic against a series of conventional NK target cell lines. This cytotoxic function was either blocked or enhanced by anti-Ti gamma A mAb, depending upon experimental conditions. With respect to proliferation, it was possible to induce responses of resting Ti gamma A+ lymphocytes with antibody-coated CNBr beads only in the presence of exogenous IL-2, whereas, in culture, the same cells proliferated directly and secreted IL-2 after treatment by anti-Ti gamma A beads. Taken together, these data demonstrate that a major subset of circulating CD3+ TCR alpha/beta- lymphocytes use protein products of T cell gamma rearranging genes as functional R structures.

Animals↗
PubMed1988

A unique V-J-C-rearranged gene encodes a gamma protein expressed on the majority of CD3+ T cell receptor-alpha/beta- circulating lymphocytes.

We have recently described an mAb, anti-Ti gamma A, that recognizes an antigenic determinant carried by a TCR gamma chain. This antibody binds to approximately 3% of human PBLs and delineates a CD2+, CD3+, TCR-alpha/beta-, CD4-, CD8+/-, CD5+, NKH1-, and HLA class II- subset. The present study was designed to identify the gene encoding the Ti gamma A epitope. A first analysis was carried out on a previously characterized TCR gamma + fetal-cloned cell line termed F6C7. It was found that F6C7 cells have one gamma rearrangement on each chromosome: one joins V gamma 3 to J gamma 1, and the second joins V gamma 9 to J gamma P. Because only the latter allele appeared to be transcribed in the F6C7 lymphocytes, these data strongly suggested that anti-Ti gamma A mAb is specific for either a V gamma 9 or a V gamma 9-J gamma P-encoded peptide. To confirm this point, we studied an additional series of 13 randomly selected Ti gamma A+ cloned cells derived from peripheral blood of three distinct adult individuals. Each one of these lymphocytes was shown to both possess and transcribe a V gamma 9-J gamma P-C gamma 1-rearranged gene. It is therefore concluded that a predominant subpopulation of CD3+ TCR-alpha/beta- human circulating T lymphocytes (namely, the subset defined by anti-Ti gamma A mAb) surface expresses a gamma protein with a limited potential of variability from one cell to another.

Adult↗
PubMed1988

Triggering of the phosphoinositide transduction pathway by a monoclonal antibody specific for the human gamma/delta T cell receptor.

We have developed a monoclonal antibody (mAb), termed anti-TigammaA, which recognizes an antigenic determinant carried by a variable segment of the T cell receptor (TcR) gamma chain. This determinant, encoded by the V gamma 9 gene, is expressed on approximately 3% of peripheral blood lymphocytes. In the present study, we have found that binding of anti-TigammaA mAb to its specific ligand results in the triggering of the phosphatidylinositol (PI) cycle-related metabolic process. Indeed, an increased labeling of both phosphatidic acid and PI, related to an enhanced turnover of PI cycle-dependent phospholipids, was observed following exposure of 32P orthophosphoric acid-labeled cells to anti-TigammaA mAb. In addition, there was a rapid rise in intracellular free calcium concentrations. Similar experiments have been performed previously on CD3+ TcR alpha/beta- -cells with an anti-CD3 mAB. They predicted that signals produced by the interaction between the second TcR and its ligand(s) would be transmitted via the PI cycle-linked intracellular second messengers. We confirm this hypothesis in an experimental system where stimulation occurs directly through the gamma/delta receptor structure.

Antibodies, Monoclonal↗
PubMed1988

Cloned CD3+ TcR alpha/beta- Ti gamma A- peripheral blood lymphocytes compared to the Ti gamma A+ counterparts: structural differences of the gamma/delta receptor and functional heterogeneity.

We have assessed the organization of T cell gamma rearranging genes (TRG) in circulating TcR gamma/delta+ lymphocytes which do not express V gamma 9-encoded Ti gamma A+ gamma chain. Following purification of the minor TcR gamma/delta+ Ti gamma A- fraction, cloned cell lines were developed from peripheral blood of 5 individuals. Out of the 26 clones studied, only 3 TcR gamma/delta+ Ti gamma A- cells were found to express a disulfide-linked C1-encoded gamma chain. The remaining 23 Ti gamma A- clones with a C2-encoded nondisulfide-linked receptor were found to display rearrangements of various V genes to J2 segments on both chromosomes; there was no predominance of a unique rearrangement even though the TRG-V3 and -V4 genes belonging to subgroup I were frequently employed. Together, these findings further strengthen the hypothesis that lymphocytes with a C gamma 1 encoded chain are produced earlier in T cell ontogeny than the C gamma 2 counterparts. The "non-major histocompatibility complex (MHC) requiring" (i.e., "natural killer-like") cytotoxicity mediated by many TcR gamma/delta+ Ti gamma A- cells appeared to be very low as compared to that of Ti gamma A+ clones. Yet, treatment by the OKT3 monoclonal antibody revealed a strong lytic potential in the Ti gamma A- lymphocytes with little, if any, natural killer-like activity. Thus, with respect to the latter function, a substantial heterogeneity is found in cells expressing distinct gamma chains. In an attempt to characterize undefined specificities of Ti gamma A- lymphocytes, they were screened against a panel of Epstein-Barr virus-transformed B cell lines homozygous for HLA-DR1 to DR10 determinants; one of the clones was found to recognize DR7. In light of reports from other groups describing class I-related specificities, it is apparent that TcR gamma/delta+ lymphocytes are able, like the TcR alpha/beta+, to recognize and kill target cells through either an MHC-dependent (with involvement of either class I or class II gene products) or a non-MHC-requiring pathway.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

A novel human V delta gene expressed predominantly in the Ti gamma A fraction of gamma/delta+ peripheral lymphocytes.

We have characterized a functional T cell receptor (TcR) delta transcript in a Ti gamma A+ human cloned cell line derived from peripheral blood. This cDNA includes a novel V gene (V-AB12), whose expression was initially studied in a series of TcR gamma/delta+ clones. Nine Ti gamma A+ clones derived independently from distinct donors have been tested: each of them was found to possess a unique V-AB12/J-IDP2 5.5-kb Eco RI rearrangement, which was constantly transcribed. Surface expression of the protein encoded by this unique rearranged gene was demonstrated by immunoprecipitations performed on three Ti gamma A+ polyclonal cell lines using a specific rabbit heteroantiserum. Further analysis strongly suggested that a monoclonal antibody (mAb), designated anti-BB3, detects a V-AB12-encoded antigenic determinant on the cell surface. Double-color immunofluorescence analysis of peripheral blood lymphocytes from ten donors indicated that most BB3+ cells are recognized by anti-Ti gamma A mAb. In previous studies, we have shown that a majority of TcR gamma/delta+ peripheral T cells expresses a gamma chain including V9 (Ti gamma A) and most frequently JP-encoded peptides. Given the present results on the delta chain, it can be concluded that, in many individuals, a predominant fraction (V gamma 9+/V-AB12+) of circulating CD3+ TcR alpha/beta- T lymphocytes expresses a receptor with little, if any, combinatorial diversity.

Amino Acid Sequence↗
PubMed1988

[Artificial urinary sphincter in the treatment of neurogenic bladder in children].

Over a two years period, the model AS 800 artificial urinary sphincter was implanted in 10 children (mean 14 years old) with incontinence due to a neurogenic bladder (7 spina bifida; 3 sacral agenesis). Goal of continence was achieved in 100% of 7 boys and 3 girls with a follow up between 6-32 months (mean 17 months). Patients selection was rigid and incontinence have failed to response at pharmaceutic manipulation (6) intermittent catheterisation (5) and previous classical surgery enterocystoplasty (2), Young-Dees procedure (1). Age minimum was 8 years. All sphincters were implanted around the bladder neck. Associated surgical techniques were performed in 4 cases: 2 detubularized enterocystoplasties, 1 Teflon injection for vesico ureteral reflux, 1 closure of previous cystostomy. Sphincterotomy was never done. 5 patients are submitted post implantation to intermittent catheterisation without any problem. 2 patients required one revision. Nocturnal desactivation is used in 2 cases. Authors focus on the necessity of correcting previously or at the time of implantation bladder compliance and vesico ureteral reflux.

Adolescent↗