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Biomedical subjects

S Brunet

Publications and source records attributed to S Brunet.

At least 19 recordsLinked to original sources
PubMed2007

Outcome of patients with acute promyelocytic leukemia failing to front-line treatment with all-trans retinoic acid and anthracycline-based chemotherapy (PETHEMA protocols LPA96 and LPA99): benefit of an early intervention.

To determine prognosis of acute promyelocytic leukemia (APL) failing to front-line therapy with all-trans retinoic acid (ATRA) and anthracyclines, outcome of 52 patients (32 M/20 F; age: 37, 3-72) included in PETHEMA trials LPA96 and LPA99 who presented with either molecular failure (MOLrel, n=16) or hematological relapse (HEMrel, n=36) was analyzed. Salvage therapy consisted of ATRA and high-dose ara-C-based chemotherapy (HDAC) in most cases (83%), followed by stem-cell transplantation (autologous, 18; allogeneic, 10; syngeneic, 1). Fourteen patients with MOLrel (88%) achieved second molecular complete response (molCR), whereas 81% HEMrel patients responded to second-line treatment, with 58% molCR. After median follow-up of 45 months, four MOLrel and 18 HEMrel patients, respectively, experienced a second relapse. Outcome after MOLrel compared favorably to HEMrel, with longer survival (5-year survival: 64+/-14 vs 24+/-8%, P=0.01) and lower relapse risk (5-year relapse risk: 30+/-13 vs 64+/-9%; P=0.044). Additionally, age <or=40 and male gender were favorable variables for survival, whereas molecular response predicted longer leukemia-free survival. In conclusion, early institution of salvage therapy at molecular failure, before onset of hematological relapse, is beneficial in APL. Moreover, given the poor outcome of HEMrel managed with ATRA and HDAC, use of alternative therapeutic strategies in this setting is warranted.

Adolescent↗
PubMed2006

A systems biology analysis of the Drosophila phagosome.

Phagocytes have a critical function in remodelling tissues during embryogenesis and thereafter are central effectors of immune defence. During phagocytosis, particles are internalized into 'phagosomes', organelles from which immune processes such as microbial destruction and antigen presentation are initiated. Certain pathogens have evolved mechanisms to evade the immune system and persist undetected within phagocytes, and it is therefore evident that a detailed knowledge of this process is essential to an understanding of many aspects of innate and adaptive immunity. However, despite the crucial role of phagosomes in immunity, their components and organization are not fully defined. Here we present a systems biology analysis of phagosomes isolated from cells derived from the genetically tractable model organism Drosophila melanogaster and address the complex dynamic interactions between proteins within this organelle and their involvement in particle engulfment. Proteomic analysis identified 617 proteins potentially associated with Drosophila phagosomes; these were organized by protein-protein interactions to generate the 'phagosome interactome', a detailed protein-protein interaction network of this subcellular compartment. These networks predicted both the architecture of the phagosome and putative biomodules. The contribution of each protein and complex to bacterial internalization was tested by RNA-mediated interference and identified known components of the phagocytic machinery. In addition, the prediction and validation of regulators of phagocytosis such as the 'exocyst', a macromolecular complex required for exocytosis but not previously implicated in phagocytosis, validates this strategy. In generating this 'systems-based model', we show the power of applying this approach to the study of complex cellular processes and organelles and expect that this detailed model of the phagosome will provide a new framework for studying host-pathogen interactions and innate immunity.

Animals↗
PubMed2006

Absence of veno-occlussive disease in a cohort of multiple myeloma patients undergoing autologous stem cell transplantation with targeted busulfan dosage.

BACKGROUND: Plasma concentrations of oral busulfan (BU) were measured in multiple myeloma (MM) patients undergoing autologous peripheral blood stem cell transplantation (ASCT) with a double alkylating conditioning protocol in order to individualise doses of BU based on individual pharmacokinetic parameters and to reduce toxicities related to BU exposure. PATIENTS AND METHODS: Forty-four consecutive patients with MM participating in the co-operative Spanish protocol were prospectively evaluated. Conditioning regimen prior to autologous infusion consisted of BU followed by melphalan. BU pharmacokinetic parameters were estimated for each patient after the first dose based on measured concentrations and subsequent doses were modified as necessary to achieve target exposure. RESULTS: Mean BU exposure (AUCss) (+/-DS) before dosage modification range from 3192 to 12 180 ng h/mL. Twenty-six out of 44 (59%) patients required dose adjustment. None of the patients developed hepatic veno-occlusive disease (VOD). Grade > or = II oropharyngeal mucositis was observed in the majority of patients (95%) and the severity of mucositis increased with increasing average steady-state BU plasma concentration. There were four treatment-related deaths: two patients died from multiorgan failure and two of respiratory infections. Of the remaining 40 patients, 15 were in complete remission with negative immunofixation, 21 in partial remission and four in stable disease 3 months after ASCT. CONCLUSIONS: The results of the present study show the variability in BU pharmacokinetic parameters and suggest the possible relationship between toxicities and BU exposure. Individualising BU dosage in MM patients undergoing ASCT we observed the absence of VOD.

Adult↗
PubMed2006

Prognostic value of minimal residual disease (MRD) in acute myeloid leukemia (AML) with favorable cytogenetics [t(8;21) and inv(16)].

Most patients with acute myeloid leukemia (AML) and t(8;21) or inv(16) have a good prognosis with current anthracycline- and cytarabine-based protocols. Tandem analysis with flow cytometry (FC) and real-time RT-PCR (RQ-PCR) was applied to 55 patients, 28 harboring a t(8;21) and 27 an inv(16), including one case with a novel CBFbeta/MYH11 transcript. A total of 31% (n=17) of CR patients relapsed: seven with t(8;21) and 10 with inv(16). The mean amount of minimal residual disease (MRD) detected by FC in relapsed and nonrelapsed patients was markedly different: 0.3 vs 0.08% (P=0.002) at the end of treatment. The mean number of fusion transcript copies/ ABL x 10(4) also differed between relapsed and non-relapsed patients: 2385 vs 122 (P=0.001) after induction, 56 vs 7.6 after intensification (P=0.0001) and 75 vs 3.3 (P=0.0001) at the end of chemotherapy. Relapses were more common in patients with FC MRD level >0.1% at the end of treatment than in patients with < or = 0.1%: cumulative incidence of relapse (CIR) was 67 and 21% (P=0.03), respectively. Likewise, using RQ-PCR, a cutoff level of >10 copies at the end of treatment correlated with a high risk of relapse: CIR was 75% for patients with RQ-PCR >10 compared to 21% for patients with RQ-PCR levels < or = 10 (P=0.04). Combined use of FC and RQ-PCR may improve MRD detection, and provide useful clinical information on relapse kinetics in AML patients.

Acute Disease↗
PubMed2006

Therapy of paraneoplastic pemphigus with Rituximab: a case report and review of literature.

Paraneoplastic pemphigus (PNP) is an autoimmune blistering disease with poor prognosis when associated with malignant neoplasm. We report the case of a patient with PNP associated with a CD20+ non-Hodgkin follicular lymphoma who was treated with Rituximab plus corticosteroids and short courses of cyclosporin. One and a half years after Rituximab therapy, oral ulcerations had cleared and oral methylprednisolone was slowly tapered down without further recurrences. In the course of the disease, the patient developed sepsis due to Listeria monocytogenes and viral infections by human herpes virus 1 and 3. At the end-stage of the disease she developed a cutaneous infection from Mycobacterium chelonae. The patient died 2 years and 7 months after the onset of PNP. Rituximab may be useful for PNP therapy, but further studies are necessary to confirm this hypothesis.

Aged↗
PubMed2005

Toward a detailed characterization of feline immunodeficiency virus-specific T cell immune responses and mediated immune disorders.

Infection of domestic cats with feline immunodeficiency virus (FIV) is associated with the development of an acquired immunodeficiency syndrome (AIDS). The pathogenesis of FIV is not fully understood but it has been reported that the immune system is progressively impaired during disease progression. As a result, anti-FIV specific immune response will usually not clear the virus and the acute stage is followed by a chronic asymptomatic phase. The overall objective of this study was to characterized FIV-induced immune cellular responses and -mediated immune disorder following the first weeks post-infection. Using both cytokine ELISpot and intracellular staining assays, FIV-specific T cells were monitored at 6, 9 and 12 weeks post-infection. We demonstrated that both IFNgamma(+) and, CD4 and CD8 TNFalpha(+) T cells specifically respond to FIV antigens. These responses were found to reach a peak at 9 weeks post-infection. It was further shown that the TNFalpha(+)CD8(+) responding T cells were contained within a CD8beta(low)CD62L(-) T cell subpopulation, expanded in FIV-infected cats. This T cell subpopulation which present features of activated CD8 T cells was further shown to be susceptible to spontaneous apoptosis following a short-term in vitro culture. Moreover, it was observed that cell death by apoptosis of this T cell subset was increased following FIV antigen-recognition. Therefore, FIV might alter immune homeostasis in inducing chronic activation of TNFalpha(+)CD8(+) T cells which eventually will die following antigen contact while deleting CD4(+) T cells. Interestingly, this study confirmed the strong similarity between FIV and HIV pathogenesis.

Animals↗
PubMed2005

Adverse prognostic impact of CD36 and CD2 expression in adult de novo acute myeloid leukemia patients.

BACKGROUND AND OBJECTIVES: A consecutive series of acute myeloid leukemias (AML) patients was analyzed in conditions which reduce the inter-assay variations (the same flow cytometer, the same observers and the same panel of monoclonal antibodies) in order to investigate the prognostic information provided by flow cytometry. DESIGN AND METHODS: Two hundred and sixty-six bone marrow (BM) samples from 326 patients enrolled in the LMA-99 protocol from the CETLAM group were studied by multiparametric flow cytometry. Immunophenotyping studies were performed on erythrocyte-lysed BM samples. Antigen expression of leukemic cells was analyzed using triple stainings with fluorochrome-conjugated combinations of monoclonal antibodies. RESULTS: CD2 was positive in 21 cases (8%); an associated inv(16) was detected in eight CD2+ cases (38%). Two-year overall survival (OS) rate for CD2+/inv(16)+ patients was 75%, whereas it was 0% for CD2+/inv(16)- patients and 47% for CD2- patients (p=0.0001). CD36 was expressed in 37% of patients (n=98). Two-year leukemia-free survival (LFS) rate was 34% for CD36+ patients and 55% for CD36- patients (p=0.001). In the multivariate analysis, CD2+ (RR=8.4; p=0.0001) and adverse karyotype (RR=10.2; p=0.0001) were associated with a lower CR rate, CD36+ (RR=1.5; p=0.03), CD2+ (RR=2; p=0.04) and adverse karyotype (RR=4; p=0.0001) were associated with a lower OS and CD36+ (RR=2; p=0.002) and adverse karyotype (RR=3.5; p=0.005) predicted a lower LFS. CONCLUSIONS: CD2+ patients had a very poor OS when CD2/inv(16)+ cases were excluded. CD36 and CD2 expression at diagnosis can provide prognostically important information in adult de novo AML.

Acute Disease↗
PubMed2005

[Normal mouth opening in the adult French population].

INTRODUCTION: Limitation of mouth opening is a frequent symptom in the pathologies of the temporomandibular joint. The aim of this study is to establish normative basis for this criterion in the French population. MATERIALS AND METHODS: Maximal mouth opening was measured by an electronic goniometric device. Measurements were taken in 228 people (110 men and 126 women) aged between 18 to 84 years, representative of the French population. RESULTS: The average mouth opening is 50.7 7 mm, but it was greater in the male population. It was also greater in tall patients and in younger patients (under 50 years). DISCUSSION: Our study is original because it is based on normal subjects and because our population sample age is the same as that of the French population. Men have a greater mouth opening than women, but this can be due to the fact that they are taller. Mouth opening is wider in young subjects, under 50, because they are younger and because they are taller. Mouth opening is wider in tall patients, whatever their sex or their age.

Adolescent↗
PubMed2005

Long-term outcome of allogeneic PBSC transplantation in pediatric patients with hematological malignancies: a report of the Spanish Working Party for Blood and Marrow Transplantation in Children (GETMON) and the Spanish Group for Allogeneic Peripheral Blood Transplantation (GETH).

We analyzed the clinical outcome in 90 children undergoing allogeneic PBSC transplantation from HLA-identical relative for leukemia. GvHD prophylaxis was CsA+ methotrexate in 50 and CsA+/-steroids in 40. Median CD34+ cells infused were 6 x 10(6)/kg (range, 1.4-32). Median follow-up was 60 months (range, 6-115). CI of transplant-related mortality (TRM) was 18.4+/-4%. On multivariate analysis, high Lansky score (>80) at transplantation was associated with lower TRM (HR, 0.9; P<0.0002). Relapse incidence (RI) was 33.6+/-6%. On multivariate analysis, high Lansky score at transplantation and cGvHD were associated with lower RI (HR, 0.04; P<0.0005 and HR, 0.23; P<0.03, respectively). Disease-free survival (DFS) was 57.8+/-5%. Disease status at transplantation (HR, 0.33; P<0.02), steroid treatment at day +90 (HR, 5.61; P<0.005) and cGvHD (HR, 0.23; P<0.005) had a significant impact on DFS in multivariate analysis. CI of cGvHD was 63.7+/-7%. Patients with cGvHD had better DFS (65+/-5%) because of lower RI (15.7+/-6%) and similar TRM (27.4+/-4%). These data suggest acceptable long-term outcomes after allogeneic PBSC transplantation in children despite the high incidence of cGvHD. These patients had a lower risk of relapse and a better DFS.

Adolescent↗
PubMed2005

Conventional versus reduced-intensity conditioning regimen for allogeneic stem cell transplantation in patients with hematological malignancies.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (HSCT) from human leukocyte antigen (HLA)-compatible sibling donors is a potential curative treatment for hematological and non-hematological malignancies. Nevertheless, high mortality rates may be associated with this therapy, especially in older patients, those with other comorbidities or who receive a second HSCT. PATIENTS AND METHODS: We analyzed the factors associated with transplant-related mortality (TRM) and overall survival in 157 consecutive adult patients (104 males and 53 females) who received a HSCT [29 bone marrow (BM) transplantation and 128 peripheral blood (PB) transplantation] from a HLA-identical sibling between January 1995 and March 2002 in our institution. One hundred patients received a standard conditioning prior to HSCT (STAND) and 57 patients received a reduced-intensity conditioning (RIC) HSCT. Fifty-eight patients were in an early phase at transplant and 99 in a non-early phase. Median age was 46 yr (16-66), and 90 patients (57%) were >45 yr of age. RESULTS: Patients in the RIC group were older than those in the STAND group, and had a higher proportion of non-early disease phases including a prior autologous HSCT in 39%. Median follow-up for survivors was 28 and 15 months in the STAND and RIC groups (P < 0,001), respectively. Cumulative incidence of TRM at 2 yr was 30% [95% confidence interval (CI) 22-41%] for the STAND group and 22% (95% CI 13-37%) for the RIC group [non-significant (NS)]. Factors associated with a higher TRM in multivariate analysis were: STAND vs. RIC conditioning regimen [relative risk (RR) 5.4; 95% CI 2.3-12.8; P < 0.001]; age > or =45 yr vs. <45 yr (RR 5; 95% CI 2.4-10.8, P < 0.001); second vs. first HSCT (RR 2.8, 95% CI 1.3-6.3, P = 0.01) and non-T-cell-depleted vs. T-cell-depleted graft (RR 2.7, 95% CI 1.3-5.8, P = 0.009). Overall survival (OS) at 2 yr was 52.5 +/- 10.4% for STAND group and 59 +/- 16.8% in RIC group. Factors associated with poorer OS in multivariate analysis were: STAND vs. RIC conditioning regimen (RR 3.4, 95% CI 1.7-6.9, P = 0.001); age > or =45 vs <45 yr (RR 2.5, 95% CI 1.4-4.5, P = 0.002) and diagnosis [other than chronic myeloid leukemia (CML) vs. CML] (RR 2.6, 95% CI 1.2-5.7 P = 0.02). CONCLUSIONS: Our results indicate that the introduction of RIC allogeneic HSCT for patients at high risk for TRM (advanced age, prior HSCT and non-T-cell depletion) leads to a reduction in the TRM and improvement in the OS.

Adolescent↗
PubMed2005

Anti-endothelial cell antibodies in idiopathic and systemic sclerosis associated pulmonary arterial hypertension.

BACKGROUND: It has previously been shown that IgG antibodies from patients with limited cutaneous systemic sclerosis (SSc) bind to specific microvascular endothelial cell antigens. Since patients with limited cutaneous SSc are prone to develop pulmonary arterial hypertension (PAH), and since endothelial cell activation is involved in the pathogenesis of idiopathic PAH (IPAH), a study was undertaken to examine the presence of anti-endothelial cell antibodies in patients with idiopathic or SSc associated PAH. METHODS: PAH was confirmed by right heart catheterisation (mean pulmonary artery pressure at rest >25 mm Hg). Serum IgG and IgM reactivities were analysed by immunoblotting on human macrovascular and microvascular lung and dermal endothelial cells from patients with IPAH (n = 35), patients with PAH associated with SSc (n = 10), patients with diffuse (n = 10) or limited cutaneous (n = 10) SSc without PAH, and 65 age and sex matched healthy individuals. RESULTS: IgG antibodies from patients with IPAH bound to a 36 kDa band in macrovascular endothelial cell extracts with a higher intensity than IgG from other patient groups and controls. IgG antibodies from patients with IPAH bound more strongly to a 58 kDa band in microvascular dermal endothelial cells and to a 53 kDa band in microvascular lung endothelial cells than IgG antibodies from other patients and controls. IgG antibodies from patients with limited cutaneous SSc with or without PAH, but not from other groups or from healthy controls, bound to two major bands (75 kDa and 85 kDa) in microvascular endothelial cells. CONCLUSION: IgG antibodies from patients with idiopathic or SSc associated PAH express distinct reactivity profiles with macrovascular and microvascular endothelial cell antigens.

Adult↗
PubMed2004

Risk assessment and outcome of chronic graft-versus-host disease after allogeneic peripheral blood progenitor cell transplantation in pediatric patients.

We retrospectively evaluated the incidence, risk factors for chronic graft-versus-host disease (cGvHD) and outcome in 80 pediatric patients (36 male) (median age 13 years) who underwent allogeneic peripheral blood progenitor cell transplantation. Patients were grafted from an HLA-identical sibling after myeloablative conditioning (total body irradiation (TBI) based 52; non-TBI 28). GvHD prophylaxis used were: cyclosporin A (CsA)+ short methotrexate (MTX) in 52 and CsA+/-prednisone in 28. The median number of CD34+ cells infused were 5.8 x 10(6)/kg (range: 1.4-32.8). The median follow-up was 24 months (range: 3-94). In all, 28 patients had cGvHD (confidence interval (CI): 54.2+/-10%). Factors that were significant on univariate analysis were diagnosis (P=0.03) and GvHD prophylaxis administered (P=0.04). On multivariate analysis, only GvHD prophylaxis used was associated with a significant risk of cGvHD (hazard ratio (HR): 3.94; 95% CI: 1.41-10.91, P=0.009). The CI of cGvHD for patients receiving CsA+MTX was 40.9+/-12 vs 76.5+/-18% for patients who did not (P=0.03). The probability of relapse was 36+/-6% for all patients (12.5+/-8% for patients with cGvHD vs 47.9+/-8% without cGvHD). The probability of disease-free survival was better for patients with cGvHD (69.9+/-10 vs 37.9+/-7%; HR: 3.59, 95% CI: 1.47-5.56; P=0.001). Our data suggest that the GvHD prophylaxis used is the most relevant predictor of cGvHD. Patients with cGvHD had a lower risk of relapse and a better survival.

Adolescent↗
PubMed2004

Frequent severe liver iron overload after stem cell transplantation and its possible association with invasive aspergillosis.

Iron overload is associated with free radical generation and tissue damage. Our main objective was to ascertain the frequency and severity of iron overload in a group of 59 patients who died after conventional-intensity autologous (n=24) or allogeneic (n=35) haematopoietic stem cell transplantation (HSCT). A second objective was to investigate associations between liver-iron concentration and causes of transplant-related mortality. The median age was 41 years (range, 19-66), 41 were males and 18 females. In total, 26 patients had acute leukaemia or MDS, 10 CML, 17 lymphoma, four myeloma and two aplastic anaemia. The median hepatic iron concentration (HIC) was 138 micromol/g dry weight (7.7 mg/g; range 31-631 micromol/g). In total, 4/32 (12%) patients with HIC <150 micromol/g and 10/27 (37%) with hepatic iron > or =150 micromol/g showed invasive aspergillosis at autopsy (P=0.035). This was significant in multivariate analysis (RR 9.0; 95% CI 1.6-50.3, P=0.012). In conclusion, severe iron overload is frequent in patients who die following HSCT and is associated with invasive aspergillosis.

Adult↗
PubMed2004

MEIS 1 expression is downregulated through promoter hypermethylation in AML1-ETO acute myeloid leukemias.

Retroviral insertional mutagenesis in BXH2 mice commonly induces myeloid leukemias. One of the most frequently involved genes in experimental studies is Meis 1. In contrast to other genes in murine models, Meis 1 has not been affected by recurrent chromosomal translocations or point mutations in human leukemias. We found a constant downregulation of the Meis 1 gene mRNA in AML1-ETO acute myeloid leukemias and in those cases harboring in frame mutations in the bZIP domain of CEBPalpha. The absence of the Meis 1 mRNA was not caused by inactivating point mutations in the coding sequence. Promoter hypermethylation was present in more than half of the cases (9/14), including samples obtained from the widely employed Kasumi-1 cell line. Double treatment with 5-Aza-2'-deoxycytidine and trichostatin A of the Kasumi-1 cell line partially reverses Meis 1 inhibition. HoxA9 levels were also low. In a cell line model (U937 Tet AML1-ETO), AML1-ETO expression was not associated with Meis 1 suppression at 72 h. Nevertheless, Meis 1 repression is dependent on the AML1-ETO transcript levels in treated leukemic patients. Chimeric products that arise from chromosomal translocations may be associated with locus-specific epigenetic inactivation. It remains to be investigated when this methylation process is acquired and which are the basic mechanisms underlying these molecular events in AML1-ETO and CEBPalpha-mutated AML.

Acute Disease↗