A Bernard

University of Kentucky, Lexington, Kentucky, United States

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Publications (194)888.91 Total impact

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    ABSTRACT: We evaluated whether IGL-1, a graft preservation solution containing polyethylene glycol, improves the outcome of small bowel grafts in comparison to the University of Wisconsin (UW) solution in a pig allotransplantation model. Seventeen pigs were randomly allocated to group 1 (n = 10; intestinal allotransplantation with IGL-1) and group 2 (n = 7; allotransplantation with UW). Pigs received no immunosuppression and were sacrificed on postoperative d (POD) 8. Intestinal specimens were obtained from the animal immediately before cold flushing (T0), 2 h after graft reperfusion (T1), and at sacrifice (T2). Survival rate to POD 8 was 50% in group 1 compared with 16% in group 2 (P < 0.05); 62% of pigs in group 1 did not present any acute cellular rejection (ACR) compared to 16% in group 2 (P < 0.05). Severe ACR rate was 25% in group 1 and 66% in group 2 (P < 0.05). iNOS activity and intestinal caspase 3 levels increased significantly between T0 and T1 in group 1 compared to group 2 (P < 0.05). Cell necrosis increased significantly between TO and T1 in group 2 compared with group 1 (P < 0.05) whereas cell apoptosis was significantly higher at T1 compared with T0 in group 1 in comparison to group 2. Our results show that IGL-1 improves intestinal graft viability as compared to UW solution, possibly by reducing graft immunogenicity and by favoring intestinal epithelial repair.
    Journal of Surgical Research 11/2011; 176(2):621-8. · 2.02 Impact Factor
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    Critical Care 01/2011; · 4.93 Impact Factor
  • Human Immunology - HUM IMMUNOL. 01/2011; 72.
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    ABSTRACT: Ewing's sarcoma (EWS) is an aggressive tumor of children and young adults that requires intensive treatment. The search for new prognostic factors is very important to choose the most appropriate therapy and to better understand the biology of the disease for the development of new therapeutic tools. We found that Xg, a thus far poorly described molecule and member of the CD99 family, is expressed in EWS cell lines and EWS primary tumors. Immunohistochemical analysis confirmed the expression of Xg in 24% of patients. We found that Xg expression in EWS defines a subgroup of patients with worse prognosis compared with those with Xg-negative localized tumors, indicating a clinical relevance of Xg expression in EWS. Forced expression of Xg in an EWS cell line upregulated cell migration and invasion in vitro. Furthermore, knockdown of Xg expression with specific short hairpin RNA significantly reduced migration and invasion of EWS cells. Consistent with these data, in vivo xenotransplant studies in nude mice revealed that Xg expression increased the incidence and the number of metastases of EWS cells. Thus, Xg expression is associated with lower overall survival in EWS patients with localized tumors and is implicated in metastasis.
    Cancer Research 04/2010; 70(9):3730-8. · 9.28 Impact Factor
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    ABSTRACT: The phenotypic and functional characteristics of immune cells of osteoporotic women compared to healthy controls similar for age and estrogen level showed for the first time significant changes in several B lymphocytes populations in postmenopausal osteoporosis, related to bone mineral density (BMD) and fractures, and a significant lower basal secretion of interferon-gamma (IFN-gamma) by CD4(+). To investigate the interactions between bone and immune system, we studied the phenotypic and functional characteristics of immune cells of 26 postmenopausal women with osteoporotic (OP) fractures compared to 24 healthy controls. We analyzed surface markers of peripheral B, CD4(+) and CD8(+) lymphocytes and cytokine secretion in supernatants of these cells cultured with or without stimulation. Body composition was assessed by dual energy X-ray absorptiometry. The two groups were similar for age and estrogen level. OP women had a significantly lower body mass index, fat mass, and lean mass. The number of CD19(+), CD19(+)/CD27(+), CD19(+)/CD27(+)/CD5(-)/CD38(+) and CD19(+)/CD27(+)/RANK(+), CD4(+)/CD27(+)/CD45RA(-)/RANK(+), and CD4(+)/CD27(+)/CD45RA(-)/CD28(+) was lower in OP women and positively correlated to BMD. In OP women, under basal conditions, CD4(+) secreted less IFN-gamma and B lymphocytes more granulocyte macrophage colony-stimulating factor (GM-CSF). GM-CSF was positively correlated to fracture rate and negatively to BMD. Our results suggest that, regardless of age and estrogen status, postmenopausal OP is associated with immune changes, highlighting a possible role of IFN-gamma in the pathophysiology of OP and reporting, for the first time, changes in several B lymphocyte populations. These alterations may reflect the frailty observed after fracture, providing new insight into the mechanisms of morbidity and mortality associated with OP fractures.
    Osteoporosis International 10/2009; 21(5):805-14. · 4.04 Impact Factor
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    ABSTRACT: Leukocyte adhesion deficiency (LAD)-III is associated with homozygous stop codon mutations in Kindlin-3, the hematopoietic member of the Kindlin family of integrin coactivators. In addition, a subgroup of LAD-III patients has a homozygous splice junction mutation in and reduced expression of the Rap-1 guanine nucleotide exchange factor, CalDAG-GEFI (CDGI). In this study, we compared the adhesive properties of the leukocyte function-associated antigen-1 (LFA-1) and very late activation antigen-4 (VLA-4) integrins in both primary and activated leukocytes derived from these 2 LAD-III subgroups. Primary lymphocytes lacking both Kindlin-3 and CDGI lost all firm T-cell receptor-stimulated LFA-1 adhesiveness, in contrast to LAD-III lymphocytes deficient in Kindlin-3 alone. Effector T cells expanded from all tested LAD-III variants expressed normal CDGI, but lacked Kindlin-3. These Kindlin-3-null effector T cells exhibited total loss of inside-out LFA-1 activation by chemokine signals as well as abrogated intrinsic LFA-1 adhesiveness. Surprisingly, VLA-4 in Kindlin-3-null resting or effector lymphocytes retained intrinsic rolling adhesions to vascular cell adhesion molecule-1 and exhibited only partial defects in chemokine-stimulated adhesiveness to vascular cell adhesion molecule-1. Deletion of the putative beta(1) Kindlin-3 binding site also retained VLA-4 adhesiveness. Thus, our study provides the first evidence that Kindlin-3 is more critical to LFA-1 than to VLA-4-adhesive functions in human lymphocytes.
    Blood 08/2009; 114(11):2344-53. · 9.78 Impact Factor
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    ABSTRACT: T-cell apoptosis during septic shock (SS) has been associated with deleterious outcome, but the mechanisms of apoptosis are not well understood. As T-cells are not infected in bacterial infection, our hypothesis was that deleterious interactions between lymphocytes and monocytes could be involved. This is a cross-sectional study of 27 patients presenting with community-acquired SS, 23 infected patients without SS and 18 controls. Cytofluorometric techniques were used to study apoptosis, the costimulatory pathway and cytokine synthesis. Apoptosis was increased in SS compared to infected patients without SS and controls: the median values were 18, 2 and 3%, respectively, for CD4(+) T-cells (P < 0.001), and 12, 5 and 2%, respectively, for CD8(+) T-cells (P < 0.001). Patients with SS exhibited significant CD152 over-expression on T-cells, while CD86 expression was decreased on monocytes (P = 0.004). The synthesis of interleukin-2 was decreased in patients with SS compared to the other groups, while secretions of interferon-gamma and TNF-alpha were not altered. Ten surviving patients with SS showed a trend towards the normalisation of these parameters on day 7. In SS, T-cell apoptosis is related, at least in part, to the alteration of the costimulatory pathway, which, in turn, leads to significant modification of the cytokine network.
    European Journal of Clinical Microbiology 03/2009; 28(6):575-84. · 3.02 Impact Factor
  • Clinical Nutrition Supplements 01/2009; 4(2):20-20.
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    ABSTRACT: Le polymorphisme du système HLA est corrélé à la survenue de plusieurs types de tumeurs, du fait de son rôle clé dans la présentation des antigènes au système immunitaire. L’efficacité de cette présentation est définie par le type des molécules HLA impliquées ainsi que leur niveau d’expression à la surface cellulaire. Une combinaison des molécules HLA pourrait induire une bonne réponse ou un échappement de lȉantigène au système immunitaire, puisque ces molécules déclenchent la cytotoxicité spécifique, suite à la présentation des antigènes endogènes aux lymphocytes TCD8+. Dans la présente étude, nous nous proposons de rechercher d’éventuelles associations entre les allèles du gène HLA B et les paramètres histopronostiques du cancer du sein en Tunisie. Soixante-quatre femmes tunisiennes atteintes du cancer du sein et 74 femmes tunisiennes saines et non apparentées ont été typées par la technologie luminex pour le gène HLA B. La valeur de p et l’Odds Ratio (OR) ont été calculés pour définir les allèles de protection ou de risque à l’occurrence, l’évolution et la gravité du cancer du sein en Tunisie. Les résultats montrent un rôle protecteur de l’allèle B*40 contre l’occurrence du cancer du sein chez la femme tunisienne (OR = 0; IC 95 %: ]0–0,66[). Cette corrélation négative a été faiblement démontrée en relation avec la présentation la plus grave (EE III) et le stade le plus avancé de la pathologie (N+). Par ailleurs, une corrélation positive entre l’allèle B*18 et un bon pronostic EE I et II est démontrée (OR = 3,85; IC 95 %: ]1,09–13,82[). Cependant, l’association de cet allèle à l’envahissement ganglionnaire n’est pas confirmée. HLA polymorphism is correlated with many types of tumour because of its key role in antigen presentation to the immune system. The efficacy of this presentation may be related to the expressed HLA molecules and the level to which they are expressed on the cell surface. A given HLA combination might contribute to tumour destruction or might escape the immune system, since antigenic presentation to TCD8+ triggers specific cytotoxicity. In the present work, we aimed to find possible associations between HLA B alleles and histo-prognostic factors related to breast cancer in Tunisia. Sixty-four patients and 74 healthy, unrelated controls were genotyped for HLA B locus. The P value and Odds Ratio were calculated in order to define HLA B correlations with the occurrence, the evolution and the histological grading of breast tumours in Tunisian women. Results show a protective effect for B*40 against breast cancer occurrence (OR = 0; 95% CI: ]0–0,66[). This correlation is poorly demonstrated for EE grading and lymph node invasion, whereas a positive association is found for B*18 allele with good and medium prognoses (OR = 3,85; 95% CI: ]1,09–13,82[). The risk effect is not confirmed for lymph node attack.
    Journal africain du cancer / African Journal of Cancer 01/2009; 1(1):36-41.
  • Gastroenterology 01/2009; 136(5). · 12.82 Impact Factor
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    ABSTRACT: By presenting antigenic peptides on the cell surface, human leukocyte antigen (HLA) class I molecules are critical for immune defense. Their surface density determines, to a large extent, the level of CD8(+) T cell-dependent immune reactions; their loss is a major mechanism of immune escape. Therefore, powerful processes should regulate their surface expression. Here we document the mechanisms used by CD99 to mediate HLA class I modulation. Up-regulation of HLA class I by IFN-gamma requires CD99. In the trans Golgi network (TGN), and up to the cell surface, CD99 and HLA class I are physically associated via their transmembrane domain. CD99 also binds p230/golgin-245, a coiled-coil protein that recycles between the cytosol and buds/vesicles of the TGN and which plays a fundamental role in trafficking transport vesicles. p230/golgin-245 is anchored within TGN membranes via its Golgin-97, RanBP1, IMh1p, P230 (GRIP) domain and the overexpression of which leads to surface and intracellular down-modulation of HLA class I molecules.
    Blood 11/2008; 113(2):347-57. · 9.78 Impact Factor
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    ABSTRACT: B-chronic lymphocytic leukemia (B-CLL) cell is characterized by the accumulation of long-lived CD5+ B lymphocytes, whose survival in vivo is in part dependent on exogenous factors such as cytokines and/or extracellular matrix proteins. Homeostatic chemokines are critical mediators of lymphoid cell trafficking. However, how they function in cell signaling and survival remains ill-defined. In this study, we have investigated the role of the homeostatic chemokines, CXCL12, CCL21, CCL19 and CXCL13, in B-CLL cell survival. Using primary leukemic cells isolated from 26 patients, we observed that each chemokine enhances cell survival. Chemokines induced the phosphorylation of ERK1/2 and p90RSK, and of Akt and its effectors GSK3 and FOXO3a. Consistently, inhibitors against mitogen-activated protein kinase/extracellular signal-regulated kinase and phosphatidylinositol 3-kinase inhibited chemokine-induced survival. Moreover, using a constitutively active mutated form of FOXO3a or siRNAs against FOXO3a in transfection experiments performed in primary B-CLL cells, we directly demonstrated the critical role of FOXO3a in both spontaneous and chemokine-induced B-CLL cell survival. Overall, our data support the notion that homeostatic chemokines contribute to B-CLL resistance to cell death through inactivation of the transcription factor FOXO3a, which may represent a novel therapeutic target in this hematopoietic malignancy.
    Oncogene 12/2007; 26(50):7081-91. · 8.56 Impact Factor
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    ABSTRACT: CD99 gene encodes two distinct proteins, produced by alternative splicing of CD99 gene transcript. Full-length CD99 isoform (CD99wt) is formed by an extracellular domain, followed by a transmembrane domain and a 36 amino-acid intracytoplasmic domain, which is partially deleted in the truncated, short form (CD99sh). A differential expression of these two CD99 molecules can lead to distinct functional outcomes in lymphocytes. To investigate the functional effects of CD99 molecules on malignancy, forced overexpression of the two CD99 isoforms was induced in osteosarcoma and prostate cancer cells. The two isoforms exhibited opposite functions: the major form dramatically inhibits anchorage-independent growth, anoikis resistance, migration and metastasis, whereas the CD99sh remarkably favours the phenomena. A mechanistic analysis of CD99-transfected osteosarcoma cells points to involvement of c-Src family kinase activity in regulating CD99 functions in malignancy. Ser168 residue of CD99 plays a pivotal role in the reversion of the malignant phenotype. Our findings highlight the involvement of CD99 in crucial processes of cancer malignancy, serving as a curtain raiser for this, so far neglected molecule. In addition, a dualistic role for the two CD99 isoforms was shown in agreement with what was observed for other cell adhesion molecules.
    Oncogene 11/2007; 26(46):6604-18. · 8.56 Impact Factor
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    ABSTRACT: Combination of alpha 2-macroglobulin, haptoglobin, apolipoprotein-A1, gamma-glutamyl transpeptidase, total bilirubin and alanine aminotransferase measurements allows to determine the Fibrotest-Actitest score, an alternative to liver biopsy in hepatitis C virus infection. The aims of this study were to evaluate the analytical variability of the Fibrotest-Actitest proteins alpha 2-macroglobulin, haptoglobin and apolipoprotein-A1, and to assess their impact on the Fibrotest-Actitest scores. We compared 129 sera from hepatitis C virus infected patients for alpha 2-macroglobulin, haptoglobin and apolipoprotein-A1 levels obtained with the Immage (Beckman-Coulter) and the BNProspec (Dade-Berhing) automates. We evaluated Fibrotest-Actitest results obtained with the two nephelemeters. Optimal correlation was found for alpha 2-macroglobulin (Y=1.05X + 0.01, correlation coefficient: 0.98) and haptoglobin (Y=1.05X - 0.07, correlation coefficient: 0.98). Apolipoprotein-A1 levels, as determined by Immage, were slightly lower than those obtained by BNProspec (Y=0.86X - 0.02, CC=0.95). When Fibrotest-Actitest scores obtained with the two protein measurements were compared adjusting for apolipoprotein-A1 from Immage, the concordance rate was 0.903+/-0.096, with only 2/107 patients showing minimal discordance>0.10 for Fibrotest, and 1.00+/-0.06 for Actitest, with no discordance>0.10. Measurement of apolipoprotein-A1, included in the Fibrotest-Actitest score, depends on the equipment used. Such discordance is of little clinical consequence for liver fibrosis evaluation in hepatitis C virus patients.
    Gastroentérologie Clinique et Biologique 10/2007; 31(10):815-21. · 1.14 Impact Factor
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    ABSTRACT: CD47 on the surface of T cells was shown in vitro to mediate either T cell activation or, in the presence of high amounts of thrombospondin (TSP), T cell apoptosis. We report here that CD47-deficient mice, as well as TSP-1 or TSP-2-deficient mice, sustain oxazolone-induced inflammation for more than four days, whereas wild-type mice reduce the inflammation within 48 h. We observe that prolonged inflammation in CD47-, TSP-1-, or TSP-2-deficient mice is accompanied by a local deficiency of T cell apoptosis. Finally, we show that upon activation normal T cells increase the expression of the proapoptotic Bcl-2 family member BNIP3 (Bcl-2/adenovirus E1B 19-kDa interacting protein) and undergo CD47-mediated apoptosis. This finding is consistent with our previous demonstration of a physical interaction between BNIP3 and CD47 that inhibits BNIP3 degradation by the proteasome, sensitizing T cells to CD47-induced apoptosis. Overall, these results reveal an important role in vivo for this new CD47/BNIP3 pathway in limiting inflammation by controlling the number of activated T cells.
    The Journal of Immunology 06/2007; 178(9):5930-9. · 5.52 Impact Factor
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    ABSTRACT: ZAP-70, after being considered as a potential surrogate for VH mutational status, has seen its own prognostic value emerge. We aimed at standardizing a simple, fast, and reproducible flow cytometry method. AntiZAP-70 antibody 2F3.2 was used with indirect labeling and secondary anti-IgG2a antibody. The reference values for the expression of the results were determined on 45 normal blood samples. ZAP-70 protein expression was investigated in 192 CLL samples. The indirect technique was compared with FITC-conjugated 2F3.2 clone, and with clone 1E7.2-FITC, -PE or -AlexaFluor 488. Using FITC or PE-conjugated antibodies, 2F3.2 and 1E7.2 clones allowed a much less adequate discrimination between positive and negative cells and discordant cases were most likely true negative cases. Using the AlexaFluor 488 conjugated 1E7.2 clone, the discordant cases were mostly negative with the conjugated antibody and positive with the 2F3.2 clone but Western blotting or RNA microarray confirmed discordant cases were false negative with the conjugated antibody. Subsequently, recommendations were used by 13 centers participating in an interlaboratory quality control protocol. The use of MFI ratio appeared to be more reliable. Results suggested that slight differences in the procedure had little impact on the interpretation in characteristic cases; however, careful interpretation was required for values close to threshold.
    Cytometry Part B Clinical Cytometry 04/2007; 72(2):103-8. · 2.23 Impact Factor
  • Archives of Internal Medicine 10/2006; 166(16):1783-4. · 11.46 Impact Factor
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    ABSTRACT: CD99 was recently reported to be under control of the osteoblast-specific transcription factor Cbfa1 (RUNX2) in osteoblasts, suggesting a role in the phato-physiology of these cells. No extensive information is available on the role(s) of this molecule in malignant phenotype, and osteosarcoma, in particular, has never been studied. We report that in 11 different cell lines and 17 clinical samples CD99 expression is either undetectable or very low. Being expressed in the normal counterpart, we tested the hypothesis that CD99 down-regulation may have a role in osteosarcoma development and progression. CD99-forced expression in two osteosarcoma cell lines significantly reduced resistance to anoikis, inhibited growth in anchorage independence as well as cell migration, and led to abrogation of tumorigenic and metastatic ability. Therefore, the molecule acts as a potent suppressor of malignancy in osteosarcoma. CD99 gene transfection induces caveolin-1 up-regulation and the two molecules were found to colocalize on the cell surface. Treatment with antisense oligonucleotides to caveolin-1 abrogates the effects of CD99 on migration. The findings point to an antioncogenic role for CD99 in osteosarcoma, likely through the regulation of caveolin-1 and inhibition of c-Src kinase activity.
    Molecular Biology of the Cell 05/2006; 17(4):1910-21. · 4.60 Impact Factor
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    ABSTRACT: CD99 is a 32kDa surface glycoprotein that is involved in the migration of leukocytes, cell-cell adhesion and apoptosis of T cells and Ewing's sarcoma (ES) cells, two cell types with a high level of CD99 expression. Engagement of the molecule induces a rapid death signal that appears to be related to the level of expression of this antigen. The rapid apoptosis induced by agonistic anti-CD99 monoclonal antibodies is of clinical interest in ES, a tumour for which no new drugs have been described as clearly effective in the last 10 years. In this study, we show that an anti-CD99 monoclonal antibody can be used to advantage in association with doxorubicin. Striking effectiveness was observed against local tumours and metastases. No remarkably toxic effects of anti-CD99 monoclonal antibody were found in bone marrow against blood precursors. These results provide the necessary rationale and support for a novel modality of therapeutic intervention, which may have application in the care of patients with ES.
    European Journal of Cancer 02/2006; 42(1):91-6. · 5.06 Impact Factor
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    ABSTRACT: Hepatitis C virus (HCV) infection leads to liver injury, which is thought to be immune-mediated. Apoptosis of hepatic T cells could influence histological damage. We quantified peripheral and intrahepatic T-cell apoptosis in 28 patients with chronic hepatitis C by using cytofluorometric techniques. METAVIR score and HCV plasma viral load were determined. Six liver biopsies, obtained from controls without chronic hepatitis during hepatobiliary surgery, served as controls. In patients, liver T-cell apoptosis was upregulated compared to peripheral T cells: 35 versus 7% for CD4+ and 56 versus 13% for CD8+ T cells (P < 0.001). Liver T-cell apoptosis levels from patients were increased compared to controls for both CD4+ (P = 0.041) and CD8+ T cells (P = 0.007). Nine patients exhibiting METAVIR scores A and F < or = 1 showed higher intrahepatic CD4+ T-cell apoptosis compared to the 19 patients with a higher METAVIR score (P = 0.001) and both histological activity and fibrosis were related to apoptosis level. There was also an inverse relationship between the level of intrahepatic CD8+ T-cell apoptosis and serum transaminase activity (P = 0.023). Our study shows immune compartmentalization, suggesting that the study of peripheral blood lymphocytes may not be fully relevant to the pathophysiology of HCV hepatitis, and that the severity of liver injury is inversely correlated with intrahepatic CD4+ T-cell apoptosis.
    Scandinavian Journal of Immunology 08/2005; 62(2):168-75. · 2.20 Impact Factor

Publication Stats

3k Citations
888.91 Total Impact Points

Institutions

  • 2011
    • University of Kentucky
      Lexington, Kentucky, United States
  • 1988–2010
    • French Institute of Health and Medical Research
      Lutetia Parisorum, Île-de-France, France
  • 2003–2009
    • Centre Hospitalier Universitaire de Nice
      Nice, Provence-Alpes-Côte d'Azur, France
  • 2000–2007
    • University of Nice-Sophia Antipolis
      Nice, Provence-Alpes-Côte d'Azur, France
  • 1994–2007
    • Unité Inserm U1077
      Caen, Lower Normandy, France
    • Hôpital Universitaire Robert Debré
      Lutetia Parisorum, Île-de-France, France
  • 2006
    • University of Bologna
      • Department of Experimental, Diagnostic and Specialty Medicine DIMES
      Bolonia, Emilia-Romagna, Italy
  • 1988–1998
    • French National Centre for Scientific Research
      Lutetia Parisorum, Île-de-France, France
  • 1994–1997
    • Institut de Recherche en Cancerologie de Montpellier
      Montpelhièr, Languedoc-Roussillon, France
  • 1978–1991
    • Institut de Cancérologie Gustave Roussy
      • • Department of Paediatrics
      • • Department of Radiotherapy
      Île-de-France, France
  • 1988–1990
    • Centre Léon Bérard
      Lyons, Rhône-Alpes, France
  • 1989
    • Centre Hospitalier Universitaire de Nancy
      • Laboratoire d’Immunologie
      Nancy, Lorraine, France
  • 1976–1987
    • Memorial Sloan-Kettering Cancer Center
      New York City, New York, United States
  • 1982
    • Centre Jean Perrin
      Clermont, Auvergne, France
  • 1975–1976
    • National Institutes of Health
      Maryland, United States