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Biomedical subjects

C Ferrand

Publications and source records attributed to C Ferrand.

18 recordsLinked to original sources
PubMed2000

Ganciclovir-sensitive acute graft-versus-host disease in mice receiving herpes simplex virus-thymidine kinase-expressing donor T cells in a bone marrow transplantation setting.

BACKGROUND: The use of donor T cells expressing the herpes simplex thymidine kinase (HSV-TK) gene followed by ganciclovir (GCV) treatment could allow for specific modulation of the alloreactivity occurring after bone marrow transplantation. We are presently exploring such an approach in a phase I clinical trial. METHODS: To examine the beneficial effect of administrating HSV-TK-expressing donor T lymphocytes +/- GCV treatment on acute graft-versus-host disease (aGVHD) control, irradiated Balb/c or C57BL/6 mice underwent transplantation with allogeneic bone marrow cells in conjunction with CD3+ allogeneic splenocytes from transgenic mice expressing an HSV-TK transgene. GCV treatment was initiated upon the occurrence of severe aGVHD. RESULTS: GCV treatment resulted in a 40-60% long-term survival rate of GVHD-free recipients having received HSV-TK-expressing T cells, whereas only 0-6% of mice survived without GCV treatment. Lethal aGVHD occurred in all the control animals having received non-HSV-TK-expressing T cells, irrespective of GCV treatment. CONCLUSION: Our results demonstrate that the administration of donor HSV-TK-expressing T cells to hematopoietic stem cell graft recipients followed by GCV treatment at the onset of severe aGVHD significantly reduces aGVHD-induced mortality and results in GVHD-free surviving recipients.

Animals↗
PubMed2000

Extensive vitiligo after ganciclovir treatment of GvHD in a patient who had received donor T cells expressing herpes simplex virus thymidine kinase.

The use of donor T cells expressing a suicide gene for destruction of graft-versus-host effector cells provides a tool for alloreactivity modulation. We describe a case of extensive vitiligo that developed after ganciclovir treatment of cutaneous chronic graft-versus-host disease in a patient who had received donor T lymphocytes expressing herpes simplex virus thymidine kinase at the time of transplantation.

Adult↗
PubMed2000

The association of HLA-DM genes with rheumatoid arthritis in Eastern France.

In this study, the polymorphisms of the HLA DMA and DMB genes in patients with rheumatoid arthritis (RA) were examined.DMA and DMB typing was performed in 120 white RA patients from eastern France and 100 healthy controls, using PCR-SSO (sequence specific oligonucleotide probes) method for DMA determination and PCR-RFLP (restriction fragment length polymorphism) method for DMB typing. All patients and controls had been HLA DRB1* genotyped.DMA*0103 was found significantly increased in RA patients (RA vs. controls: 18.3% vs. 4%) (p(corr) = 0.004; OR: 5.39; CI: 1.67-19.23). A decreased frequency of DMA*0102 was also observed in the RA group (RA vs. controls: 18.3% vs. 31%), but not significantly. There were no differences in the prevalence of DMB alleles between RA and controls. The patients and the controls were then stratified according to the expression of the HLA DRB1* RA-linked alleles (DRB1*01 and *04) and this allowed us to find no linkage disequilibrium between DMA*0103 and DRB1*01 or *04 alleles. Finally, most DMA*0103 patients were positive for rheumatoid factors and had extraarticular involvement such as subcutaneous nodules. Thus, our results suggest that DMA*0103 could be an additional genetic factor for RA susceptibility in French whites.

Adolescent↗
PubMed1998

Retrovirus-mediated transfer of the herpes simplex type I thymidine kinase gene in alloreactive T lymphocytes.

We have demonstrated in previous studies that retrovirus-mediated transfer of the herpes simplex thymidine kinase (HS-tk) and neomycin phosphotransferase (neo) genes in CD3/IL-2 stimulated primary T lymphocytes followed by G418 selection resulted in T cells retaining both interleukin-2 (IL-2) and alloresponsiveness and specifically inhibited by ganciclovir (GCV). A clinical trial examining the therapeutic potential of such gene-modified donor T cells after allogeneic bone marrow transplantation is presently underway. In the present study, we have investigated the feasibility and consequences of replacing polyclonal stimulation of T cells by an allogeneic stimulation prior to retrovirus-mediated gene transfer. Exposure of allostimulated primary donor T lymphocytes to retrovirus-containing supernatant resulted in T cells resistant to G418 while maintaining a strong, GCV-sensitive, allogeneic response when subsequently restimulated with the initial allogeneic cells. Control nontransduced cells identically stimulated exhibited a weaker, GCV-insensitive, allogeneic proliferative response. The transduced T cells were also capable of GCV-sensitive alloreactivity when exposed to third-party cells with, however, a lower proliferative response than that seen with the allogeneic cells used for stimulation at the time of transduction. Importantly, this difference in the proliferative responses was not observed with control nontransduced cells identically stimulated. A similar response pattern was observed with respect to pre-cytotoxic T lymphocyte (CTL) frequencies. Overall, retrovirus-mediated gene transfer after an allogeneic stimulation can lead to efficient transduction and the pattern of alloreactivity of the HS-tk-expressing cells is consistent with the preferential transduction of alloantigen-specific dividing T cells. Such an approach could be used to generate cells both strongly alloreactive and GCV-sensitive for in vivo therapeutic use.

Antimetabolites↗
PubMed1998

A closed culture system for the ex vivo transduction and expansion of human T lymphocytes.

A phase I clinical trial is currently being performed at our institution, with the aim of evaluating the feasibility and toxicity related to the administration of herpes simplex thymidine kinase gene-expressing human primary T lymphocytes following allogeneic hematopoietic stem cell transplantation. The need for safe and standardized preparation conditions for gene-modified cells is crucial. We describe the closed culture system used in the current trial for ex vivo retroviral-mediated gene transfer and transduced cell selection. Cell handling is performed in closed systems using a sterile connection device that avoids opening the culture system. Cell numbers during the production process increased from 93 +/- 16 on day 0 to 440 +/- 92 x 10(6) on day 12 (7.2 +/- 1.4-fold increase) (n = 11). Transduction efficiency before and after G418 resistance-based selection was 13.5 +/- 3.8% and 90.0 +/- 1.4%, respectively. Safety and efficacy testing included a search for replication-competent retrovirus, endotoxins, Mycoplasma, and bacterial contamination (n = 0/9), PCR-DNA, % CD3+ cells (91 +/- 2%), and viability after thawing (82 +/- 3%). Effective working time from day 0 to day 12 is approximately 20 h. The closed system we developed allows for safe and reproducible ex vivo preparation of gene-modified primary T lymphocytes for clinical use.

Cell Culture Techniques↗
PubMed1996

Gene transfer applied to the modulation of alloreactivity.

Allogenic hematopoietic stem cell transplantation is associated with a severe complication induced by the T-cells present in the graft: graft-vs-host disease (GVHD). While effectively preventing GVHD, ex vivo T-lymphocyte depletion of the graft unfortunately increases graft rejection and reduces the graft-vs-leukemia (GVL) effect. The ex vivo transfer to the herpes simplex thymidine kinase (HS-tk) suicide gene into T-cells before their infusion with the hematopoietic stem cells should allow for selective in vivo depletion of these T-cells with ganciclovir (GCV) if subsequent GVHD was to occur. In patients not experiencing GVHD, and therefore at a higher risk of relapse, one could preserve the beneficial effects of the donor T-cells on tumor control. Lastly, the early presence of donor T-cells in all patients should contribute to successful engraftment. We have demonstrated that retroviral-mediated transfer of HS-tk and Neomycine resistance genes in T-lymphocytes, followed by G418 selection, results in T-cells specifically inhibited by GCV with no bystander effect. In a phase I study, escalating amounts of HS-tk expressing T-cells will be infused in conjunction with a T-cell depleted marrow graft to allogenic HLA identical recipients. Toxicity, survival, alloreactivity and GCV-sensitivity of the gene-modified cells will be monitored. If successful, such an approach could significantly contribute to expanding the use of alloreactivity as a treatment modality.

Gene Transfer Techniques↗
PubMed1996

Comparative preclinical study of three bone marrow purging methods using PCR evaluation of residual t(14;18) lymphoma cells.

The t(14;18) chromosomal translocation occurring in most follicular lymphomas can be exploited by a Bcl2/JH polymerase chain reaction (PCR) to detect residual disease and to monitor the effectiveness of ex-vivo tumor cell immunological purging. We first demonstrated the 10(-5) Bcl2/JH PCR sensitivity with serial dilutions of OCY-LY8 lymphoma cell lines in normal mononuclear cells; and then the specificity and reproductibility of this technique by analysing follicular and non follicular lymphoma samples. With the Bcl2/JH PCR, we tested the efficiency of three marrow purging protocols with an experimentally contaminated bone marrow either treated by three anti-B cell monoclonal antibodies (mAb) followed by three rounds of rabbit complement or two rounds of immunomagnetics beads. Samples obtained after each purging were amplified by Bcl2/JH PCR and hybridized with PFL3 probe. We were able to produce a 2 to 3 log tumor cell reduction after three rounds of complement and a 4 to 5 log reduction after two rounds of beads. This study showed that it is feasible to use the Bcl2/JH PCR technique for residual cell lymphoma detection in patients undergoing intensive chemotherapy or BM transplantation. These results indicate that ex-vivo immunomagnetic BM purging is probably superior to complement mediated lysis for the eradication of B lymphoma cells from the marrow of patients undergoing autologous transplantation.

Animals↗
PubMed1991

A continuous-flow model for phonatory reaction time.

The purpose of this study was to validate a proposed continuous-flow model of phonatory reaction time by investigating the temporal order of selected laryngeal and neurophysiological events involved in a phonatory reaction time task. Ten normal speakers participated in a phonatory reaction time task. Laryngeal positioning movements prior to vocal fold closure (laryngeal shift) and onset of vocal fold vibration (acoustic onset) were recorded with an electroglottograph. P300 brain potentials were collected simultaneously, and they served as an index of a central process underlying reaction time. The obtained temporal ordering of laryngeal shift, P300, and acoustic onset supported a continuous-flow model of phonatory reaction time. Use of this model might yield information that is more accurate in explaining physiological function and more precise in describing temporal patterning than the serial model.

Adult↗
PubMed1987

Comparison of the effects of elevated K+ ions and muscle-conditioned medium on the neurotransmitter phenotype of cultured sympathetic neurons.

Neuronal depolarization and culture media conditioned by certain nonneuronal cells (CM) are known to exert opposite effects on the expression of cholinergic and noradrenergic traits in cultured rat sympathetic neurons. We have compared their effects on the developments of choline acetyltransferase (CAT), tyrosine hydroxylase (TOH), dopa decarboxylase (AADC) and acetylcholinesterase (AcChE) in these cultures. A macromolecular factor which was partially purified from CM increased CAT development in a dose-dependent manner and depressed the development of TOH and AADC by 5- to 10-fold. In the presence of intermediate concentrations of this partially purified factor, both CAT and catecholamine synthesizing enzymes developed to high levels, whereas high concentrations caused a long-lasting, but not total, impairment of TOH development. The effects of CM on both CAT and AADC activities resulted from variations in the number of immunotitratable enzyme molecules. Conversely, K+ ions (30-40 mM) depressed the development of CAT by 90% and stimulated TOH development 2.5-fold. Cultures grown with CM in high K+ medium had similar CAT and TOH activities as compared to those cultures grown without CM in low K+ medium suggesting that CM and K+ ions had antagonistic effects on the expression of these enzymes. However, K+ ions did not affect the development of AADC in these cultures. CM suppressed in a reversible manner the development of the 16 S form of AcChE. In the presence of 40 mM K+, the rate of development of AcChE was reduced. In particular, the development of 16 S AcChE was strikingly impaired, although not totally suppressed. The effect of elevated K+ ions on the percentage of 16 S AcChE was rapidly reversible. It is concluded that CM and elevated K+ ions have antagonistic effects on CAT and TOH, but not on AADC development; AcChE, in particular its asymmetric 16 S form, is regulated independently of the cholinergic/noradrenergic status of sympathetic neurons.

Acetylcholinesterase↗
PubMed1986

Cellular localization of the molecular forms of acetylcholinesterase in primary cultures of rat sympathetic neurons and analysis of the secreted enzyme.

The secretion and cellular localization of the molecular forms of acetylcholinesterase (AChE) were studied in primary cultures of rat sympathetic neurons. When cultured under conditions favoring a noradrenergic phenotype, these neurons synthesized and secreted large quantities of the tetrameric G4, and the dodecameric A12 forms, and minor amounts of the G1 and G2 forms. When these neurons adopted the cholinergic phenotype, i.e., in the presence of muscle-conditioned medium, the development of the cellular A12 form was completely inhibited. These neurons secreted only globular, mainly G4, AChE. Both cellular and secreted A12 AChE in adrenergic cultures aggregated at an ionic strength similar to that of the culture medium, raising the hypothesis that this form was associated with a polyanionic component of basal lamina. In noradrenergic neurons, 60-80% of the catalytic sites were exposed at the cell surface. In particular, 80% of G4 form, but only 60% of the A12 form, was external, demonstrating for the A12 form a sizeable intracellular pool. The hydrophobic character of the molecular forms was studied in relation to their cellular localization. As in muscle cells, most of the G4 form was membrane-bound. Whereas 76% of the cell surface A12 form was solubilized in the aqueous phase by high salt concentrations, only 50% of the intracellular A12 form was solubilized under these conditions. The rest of intracellular A12 could be solubilized by detergents and was thus either membrane-bound or entrapped in vesicles originating from, e.g., the Golgi apparatus.

Acetylcholinesterase↗
PubMed1985

Changes in plasma fibronectin levels after cardiac and pulmonary surgery: role of cardiopulmonary bypass.

The changes in immunoassayable plasma fibronectin were studied during seven days after cardiac surgery with cardiopulmonary bypass (group A, 19 patients) or lung surgery without bypass (group B, 11 patients). In group A the fibronectin showed a series of rapid changes during the 24 perioperative hours. Simultaneous assessment of other plasma proteins (albumin, fibrinogen and immunoglobulin G) suggested that these changes mainly reflected hemodilution and hemoconcentration processes following the cardiopulmonary bypass, being influenced by the necessarily large transfusions of plasma. The fibronectin level decreased after day 1, with maximum depletion (averaging -32% of preoperative value) on day 3. Despite subsequent progressive rise, full restoration had not been reached by day 7. Group B did not show the initial rapid changes, but progressive fall in fibronectin level to a nadir on day 2 (-20% of preoperative) was followed by gradual return to outset value on days 4-5. The study demonstrated 1) that cardiac or lung surgery induces transient fibronectin depletion on days 2 to 3 postoperatively, and 2) that in surgery with cardiopulmonary bypass the decrease is significantly greater and more prolonged. It is proposed that this supplementary decrease is due to the large amounts of particulates of various origin entering the blood during the bypass.

Blood Proteins↗
PubMed1985

The role of extracellular signals in the differentiation of cholinergic neurons from the CNS and PNS in culture.

Rat skeletal muscle cells release in culture a macromolecule which stimulates by 25-100 fold the development of choline acetyltransferase (CAT) in cultures of new-born rat sympathetic neurons. This "cholinergic factor" impaired the development of three norepinephrine synthesizing enzymes and of acetylcholinesterase (AChE) in these cultures. The 16S form of AChE failed to develop in cultures grown with the factor, but amounted to 30-40% in 3-week old cultures grown in its absence. Using the development of CAT activity in sympathetic neuron cultures as an assay, the cholinergic factor has been partially purified in 6 steps, and its hydrodynamic parameters determined. The effects of this factor on sympathetic neurotransmitter choice were qualitatively reproduced by 1-10 mM Na butyrate. The cholinergic factor increased CAT activity and decreased AChE in neuron cultures from new-born rat nodose ganglia. The factor also stimulated CAT activity in rat embryo (E14) spinal cord cultures, but stimulated the development of AChE in these cultures.

Animals↗
PubMedDate not supplied

Sorbic acid-amine function interactions.

Sorbic acid has a system of conjugated double bonds which makes it able to undergo nucleophilic addition reactions with certain functions. The interactions between sorbic acid and amine functions present in the endogenous constituents of food were quantified. The formation of new products was demonstrated and the underlying mechanisms studied using ethyl sorbate and various amines. HPLC, GC, GC-SM and NMR analyses of the reaction mixtures enabled the products to be isolated and identified. The addition reactions led, at 20 degrees C, to linear monoadducts and, at 50 degrees C and 80 degrees C, to cyclic derivatives resulting from double addition.

Amines↗