Biomedical subjects

P Moreau

Publications and source records attributed to P Moreau.

At least 55 records · Page 3Linked to original sources

PubMed2001

Workshop: excess growth and apoptosis: is hypertension a case of accelerated aging of cardiovascular cells?

Several groups including ours have demonstrated cardiac hyperplasia in neonates from genetically hypertensive rat strains. We have shown that similar problems exist in the kidney as well. More recently, we found that excessive heart and kidney weight is neonatally related to inhibition of apoptosis. Using recombinant inbred strains derived from a reciprocal cross between Brown Norway and spontaneously hypertensive rat progenitor strains, we mapped the inhibition of neonatal apoptosis to 2 distinct loci on chromosomes 1 (Myl 2) and 18 (Abrb 2). Positional candidate genes at these loci are being explored. These studies have also demonstrated that the loci determining kidney and heart weights in neonates are distinct from those determining increased organ weight in adults. The impact of blood pressure per se is also divergent because adult kidney weight is negatively correlated whereas heart weight is positively correlated with it. Analyses by extremes of low and high percentiles from fetal life to adulthood identified a single locus determining heart weight at Acaa on chromosome 8 in newborn (P=0.0003) and adult (P=0.016) rats. The Acaa region contains a DNA mismatch repair gene (hMLH1). The kinetics of neonatal growth through adulthood by prelabeling DNA with [(3)H]thymidine in pregnant mares showed that although the growth process is complex and nonlinear in the kidney of hypertensive rats, there is an increased turnover of cells, that is, reduced half-life of DNA. This observation is supported by the presence of shorter telomere fragments in kidneys of spontaneously hypertensive rats. These studies suggest that cardiovascular cells from hypertensive animals are subject to accelerated turnover, potentially leading to their accelerated aging.

Animals↗

PubMed2001

An update on the status of endothelin receptor antagonists for hypertension.

Endothelin receptor antagonists (ETRA) are actively developed by the pharmaceutical industry for several cardiovascular indications. In the context of hypertension, preclinical studies are increasingly focused on prevention or regression of end-organ damage and drug combination than on control of arterial pressure in monotherapy, as most experimental models have already been studied. In general, the antihypertensive effect of ETRA is limited but the overwhelming efficacy of this class of drugs to prevent several end-organ damages warrants judicious combination. However, the few studies looking at regression of hypertension-induced cardiovascular alterations proved less successful, suggesting that ETRA should be used early in the treatment of hypertension to obtain full benefit. Judging from the progression of ongoing trials and the development of new trials patients suffering from pulmonary hypertension and heart failure may be the first to benefit from this new class of drugs. However, it is expected that once on the market, responsive subsets of hypertensive patients will be identified and will benefit from end-organ protection.

Animals↗

PubMed2001

[Autologous peripheral blood selected CD34+ cell transplantation in the treatment of multiple myeloma].

OBJECTIVE: To investigate the clinical impact of CD(34)(+) cell selected autologous peripheral blood stem cell transplantation (APBSCT) in multiple myeloma (MM). METHODS: The hematopoietic recovery time, treatment efficacy, survival rate, transplantation related morbidity and the cost were compared between 21 MM patients receiving CD(34)(+) APBSCT and 21 MM patients receiving unselected APBSCT. The age and beta(2) microglobulin level at diagnosis and disease status at the time of transplantation were similar in the two groups. The induction treatment and conditioning regimen were the same. RESULTS: Significantly lower CD(34)(+) cells were infused in the selected group as compared with the control group: 2.2 (0.5 - 14.3) x 10(6)/kg vs 9.4 (1.1 - 15.0) x 10(6)/kg, (P < 0.001). The median times to neutrophil >or= 0.5 x 10(9)/L and platelet >or= 20 x 10(9)/L were 10 and 9 days for the selected group, and 9.5 (P = 0.357) and 4.5 days (P = 0.005) for the control group, respectively. Response rates were similar in both groups (85.7% for the selected group vs 90.4% for the control group). Three year disease-free survival (32% for the selected group vs 39% for the control group) and overall survival rates (85% for the selected group vs 79% for the control group) were not significantly different. Furthermore, unselected APBSCT could reduce the cost for the transplantation. CONCLUSION: It shows that CD(34)(+) cell selected autologous transplantation is more expensive and does not improve the clinical outcome of patients with MM.

Antigens, CD34↗

PubMed2000

A specific interferon (IFN)-stimulated response element of the distal HLA-G promoter binds IFN-regulatory factor 1 and mediates enhancement of this nonclassical class I gene by IFN-beta.

Type I interferons display a broad range of immunomodulatory functions. Interferon beta increases gene expression at the transcriptional level through binding of factors to the interferon-stimulated response element (ISRE) within the promoters of interferon-inducible genes, such as HLA class I. Despite mutation of the class I ISRE sequence within the nonclassical HLA-G class I gene promoter, we show that interferon beta enhances both transcription and cell surface expression of HLA-G in trophoblasts and amniotic and thymic epithelial cells that selectively express it in vivo. Deletion and mutagenesis analysis of a putative interferon-regulatory factor (IRF)-1 binding site within the HLA-G promoter show that HLA-G transactivation is mediated through an ISRE sequence 746 base pairs upstream from ATG, which is distinct from the interferon-responsive element described within proximal classical class I gene promoters. Electrophoretic mobility shift analysis and supershift analysis further demonstrate that interferon-responsive transcription factors, including IRF-1, specifically bind to the HLA-G ISRE. Our results provide evidence that IRF-1 binding to a functional ISRE within the HLA-G promoter mediates interferon beta-induced expression of the HLA-G gene. These observations are of general interest considering the implication of HLA-G in mechanisms of immune escape involved in fetal-maternal tolerance and other immune privilege situations.

Amnion↗

PubMed2000

Human herpesvirus 6 infection after autologous or allogeneic stem cell transplantation: a single-center prospective longitudinal study of 92 patients.

To determine the incidence and clinical relevance of active human herpesvirus 6 (HHV-6) infection, 92 consecutive unselected recipients of autologous or allogeneic stem cell grafts were investigated in a prospective longitudinal study. Active infection was assessed by the presence of viral deoxyribonucleic acid (DNA) in 846 peripheral blood mononuclear cell specimens and 115 plasma specimens, by means of a specially developed polymerase chain reaction designed to avoid detection of latent genome. The incidence of HHV-6 infection observed was 42.5%, irrespective of the type or source of graft, and infection was significantly associated with partial (P=.002) or total myelosuppression (P=.01) and fever (P<. 000001). Infusion of bone marrow as the source of graft, reactivation occurring before platelet or neutrophil engraftment, and presence of HHV-6 DNA in plasma were identified as risk factors for symptomatic HHV-6 infection (P<.002).

Adolescent↗

PubMed2000

Salvage extended-field irradiation in follicular non-Hodgkin's lymphoma after failure of chemotherapy.

PURPOSE: To evaluate the efficacy of total abdominopelvic (TAI) and total body irradiation (TBI) in heavily pretreated follicular non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: From 1983 to 1998, 34 patients received TAI (n = 22) or TBI (n = 12). All had Stage III or IV, Class B, C, D NHL in the working formulation and failed after receiving 1-5 regimens of chemotherapy. TAI was given at 20 Gy over a 3-week period. TBI was delivered in two successive half-body irradiations of 15 Gy over a 2-week period with a 4-week interval between each. RESULTS: Mean follow-up from TAI or TBI was 120 months (range, 6-180). Seventy-six percent of patients achieved complete response and 24% partial response. Median survival was 62 months, 5-year and 10-year overall survival was 59% and 41%, and disease-free survival was 56% and 30%, respectively. Grade III or IV toxicity was gastrointestinal in 38% of patients and hematologic in 30%. No toxic death or delayed complications were observed. CONCLUSION: Extended-field irradiation is feasible and efficient after failure of chemotherapy in follicular NHL.

Adult↗

PubMed2000

Limb salvage for proximal tibial tumours using a modular prosthesis.

We report early results after the resection of proximal tibial tumours followed by reconstruction using a modular prosthesis. The indication for wide resection was a malignant tumour in 13 patients, and a neglected giant cell tumour in 2. There were no mechanical failures during an average follow-up of 3.5 years. However, there were 5 peroneal nerve palsies, 1 complete sciatic nerve palsy, 1 vascular injury leading to an above knee amputation, and 2 deep prosthetic infections. There were 2 superficial skin necroses and 1 fracture proximal to the femoral prosthetic component. The mean post-operative Musculo-Skeletal Tumour Society (MSTS) score in 12 patients who still had their prosthesis in situ was 18.3 out of a possible total of 30 (range: 10-28). Limb salvage surgery in the proximal tibia has a high early complication rate even with the use of modern implants and improved techniques.

Adolescent↗

PubMed2000

Reactive plasmacytoses in multiple myeloma during hematopoietic recovery with G- or GM-CSF.

We report on three cases of reactive plasmacytoses (RP) in the course of multiple myeloma (MM). The three patients achieved complete remission following high dose melphalan and peripheral blood stem cell transplantation. These transient plasmacytoses had all the characteristics of RP, i.e. expansion of highly proliferative polyclonal plasma cells (PC) with a normal phenotype and genotype and corresponding to expansion of both PC progenitors (plasmablasts) and PC precursors (early plasma cells). These cells were easily distinguished from malignant PC of the corresponding patients evaluated at diagnosis, especially by their phenotypic and genotypic features.

Female↗

PubMed2000

HLA-G, -E, -F preworkshop: tools and protocols for analysis of non-classical class I genes transcription and protein expression.

Non-classical MHC class I HLA-E, -F, and -G molecules differ from classical class I histocompatibility antigens by specific patterns of transcription, protein expression, and immunological functions. Restriction of the expression pattern of these non-classical antigens may play a key role in modulation of immune responses during pregnancy and diseases but remains to be additionally defined. A specific component of the second International Conference on HLA-G and the 13th HLA-G Histocompatibility Workshop will be dedicated to the analysis of transcription and expression of non-classical class I genes in normal and pathological tissues. In a first step, referred to as the preworkshop, we here report the analysis and conclusions of a working group which was constituted to gather and validate optimal reagents and protocols allowing RT-PCR analysis of HLA-E, -F, -G transcript levels and flow cytometry and immunochemistry analysis of HLA-G expression in cells and tissues. As a result of this work, use of specific primers and probes detecting alternative transcripts of HLA-E, -F, and G have been validated in transfected cells expressing differential pattern of HLA class I antigens. Analysis of the specificity and affinity of collected antibodies has allowed definition of reagents to be proposed for immunochemistry and flow cytometry analysis of HLA-G expression in normal and pathological tissues during the workshop. This work has allowed constitution of an extended workshop group which is now initiating analysis of non-classical class I transcription and expression in various cells and tissues, a collective contribution that will additionally refine our view of the expression of these antigens in normal and pathological situations.

Antibodies, Monoclonal↗

PubMed2000

Modulation of HLA-G expression in human thymic and amniotic epithelial cells.

Expression of the nonclassical HLA class I antigen, HLA-G, is tightly regulated. HLA-G physiologic expression is mostly restricted to some placental and thymic cell types. Only few established cell lines express HLA-G in vitro. Cytokine-induced expression of HLA-G is hardly observed and also depends on the cell lineage. We assessed expression and cytokine regulation of HLA-G in primary cultures derived from human thymus and amnion epithelial cells, which also express HLA-G in vivo. We show that HLA-G cell surface expression is maintained, but decreases gradually, in primary cultures derived from human thymus and amnion epithelial cells. We also show that IFN-gamma re-induces HLA-G cell surface expression and upregulates classical class I gene expression in both primary cultures and in a thymus derived cell line. We further show that IFN-gamma also upregulates levels of HLA-G transcripts in TEC primary cultures. This study provides evidence that IFN-gamma induction of HLA-G expression occurs in the human amnion and the thymus, and is mediated at the transcriptional level in these tissues. These results also suggest a role for the microenvironment in regulating HLA-G in vivo gene expression in the thymus and amnion membrane.

Amnion↗

PubMed2000

Analysis of the role of HLA-G in preeclampsia.

Preeclampsia (PE) is a multisystem disorder of human pregnancy, occurring in 5%-10% of all population births and represents the leading cause of both fetal and maternal morbidity and mortality in pregnancy. Although the disorder only becomes clinically apparent late in pregnancy, the underlying pathology indicates that invasion of fetal trophoblasts into maternal spiral arteries during early pregnancy is shallow or absent in PE. A large number of epidemiologic studies have been carried out and they demonstrate that the disorder is highly heritable and occurs with a high incidence in all populations. Studies have shown that PE is largely under genetic control, but the mode of its inheritance remains unclear. Genetic studies have been carried out using both large scale linkage analysis and candidate gene approaches; however, the genetic mechanisms underlying the disorder have yet to be determined. We focus on the potential role of HLA-G, a nonclassical class I HLA located on chromosome 6, which appears to be a key component in trophoblast invasion. We examine the hypothesis that HLA-G may have a key role in both genetic susceptibility to, and pathogenesis of, PE.

Female↗

PubMed2000

The X1 box of HLA-G promoter is a target site for RFX and Sp1 factors.

HLA-G gene regulation was investigated with regards to homologies among the pathways regulating both classical MHC class I and MHC class II gene expression. They include four conserved cis-acting regulatory elements located in the proximal promoter region referred to as the W/S/Z box, the X box that is comprised of the X1 and X2 halves, and the Y box with an inverted CCAAT site. The X1 box is the binding site for the ubiquitous RFX complex consisting of three subunits; the X2 box is bound by the X2BP/ATF/CREB family factors. The basic S-X-Y regulatory module interacts with CIITA, which is expressed constitutively in APCs, but may be inducible in others cell types by IFN-gamma. Within HLA-G gene promoter the only conserved motifs are S and X1 boxes. We thus investigated the binding capacity of the HLA-G X box in comparison to that of HLA-DRA and HLA-E. We demonstrate that X2 box mutations in HLA-G promoter affect the binding of ATF/CREB family factors and may privilege the X2 box to access by other shared factors. The X1 box is the target for RFX complex and an additional factor we identified as Sp1. We propose that the X region in the HLA-G gene promoter might participate to the combination of factors which play a role in HLA-G gene activation.

Cell Extracts↗

PubMed2000

Recognition and cleavage of DNA by rebeccamycin- or benzopyridoquinoxaline conjugated of triple helix-forming oligonucleotides.

Indolocarbazole and benzopyridoquinoxaline derivatives have been shown to have anti-tumor activity and to stimulate DNA topoisomerase I-mediated cleavage. Two indolocarbazole compounds (R-6 and R-95) and one benzopyridoquinoxaline derivative (BPQ(1256)) were covalently attached to the 3'-end of a 16mer triple helix-forming oligonucleotide (TFO). These conjugates bind to DNA with a higher affinity than the unsubstituted oligonucleotides. Furthermore, they induce topoisomerase I-mediated and triplex-directed DNA cleavage in a sequence-specific manner.

Aminoglycosides↗

PubMed2000

Lack of benefit of CD34+ cell selected over non-selected peripheral blood stem cell transplantation in multiple myeloma: results of a single center study.

In order to determine the clinical impact of CD34+ cell selected autologous transplantation in multiple myeloma (MM), we have performed a retrospective case-controlled analysis comparing 21 MM patients receiving high-dose melphalan and autologous transplantation with CD34+ peripheral blood stem cells (PBSC) as front-line therapy to 21 control patients receiving unselected products. Case matching was performed using the following criteria: age and beta2-microglobulin at diagnosis and disease status at the time of transplantation. Both cohorts were homogeneous in term of induction treatment and conditioning regimen. Patients were collected for CD34+ selection after priming with G-CSF alone. Significantly fewer CD34+ cells/kg were infused to patients in the selected group as compared to patients in the control group: 2.2 (range 0.5-14.3) vs 9.4 (range 1.1-15) (P < 0.001). The median time to neutrophil recovery > or =0.05 x 10(9)/l was 10 days for the CD34+ group and 9.5 days for the control group (P = 0.357). The median time to platelet recovery > or = 20 x 10(9)/l was 9 days for the CD34+ group and 4.5 days for the control group (P = 0.005). Response rates were comparable in both groups (85.7% in the CD34+ group vs 90.4% in the control group). At 3 years, event-free survival (32% in the CD34+ group vs 39% in the control group) and overall survival (85% in the CD34+ group vs 79% in the control group) were not significantly different. Finally, use of unselected products dramatically reduced the cost of the transplantation procedure. This study shows that CD34+ cell selected autologous transplantation is more expensive than transplantation with unselected products and does not improve the clinical outcome of patients with MM.

Antigens, CD34↗

PubMed2000

Thalidomide in patients with advanced multiple myeloma.

INTRODUCTION: Recently, a report has suggested the efficacy and safety of thalidomide in refractory multiple myeloma. In an attempt to assess the efficacy and tolerance of thalidomide in advanced multiple myeloma (on behalf of the Intergroupe Franchophone dy Myelome (IFM)), we report the preliminary experience of the IFM with this drug. MATERIALS AND METHODS: Patients with advanced multiple myeloma (n=27) were treated with an oral dose of thalidomide (median 400 mg/day). At the start of treatment, all patients had active disease and 20 patients had received at least one autologous transplantation. RESULTS: Median follow-up was 105 days from the first administration. The serum and/or urine levels of the M-component were reduced by at least 75% in four patients including one patient with a >90% reduction, by at least 50% in five patients and by at least 25% in three patients, giving a total response rate of 45% (12 out of 27 patients). Nine patients had stable disease and six patients had progressed disease. Short-term side-effects of thalidomide were generally moderate. CONCLUSION: This study confirms that thalidomide is an effective agent in patients with advanced myeloma.

Agranulocytosis↗

PubMed2000

A combination of anti-interleukin 6 murine monoclonal antibody with dexamethasone and high-dose melphalan induces high complete response rates in advanced multiple myeloma.

To improve the complete response (CR) rate in advanced multiple myeloma (MM) without increasing the toxicity of high-dose therapy, we have used a new conditioning regimen. A combination of BE-8 [an anti-interleukin 6 (IL-6) murine monoclonal antibody] and dexamethasone followed by high-dose melphalan (220 mg/m2) and autologous stem cell transplantation was used to treat a series of 16 patients with advanced multiple myeloma. A strong inhibition of IL-6 activity evaluated by quantification of C-reactive protein was observed in all patients and was correlated with the high CR rate achieved with this combination therapy.

Adult↗

PubMed2000

Invasive aspergillosis as an opportunistic infection in nonallografted patients with multiple myeloma: a European Organization for Research and Treatment of Cancer/ Invasive Fungal Infections Cooperative Group and the Intergroupe Français du Myélome.

We report the occurrence of invasive aspergillosis (IA) in nonallografted patients with multiple myeloma (MM) who were treated at hematology or oncology centers in Europe during 1984-1996. Thirty-one cases met the criteria for definitive (21 [68%]) or probable (10 [32%]) IA. Of these cases, 23 (74%) were reported during 1992-1996. Twenty-nine cases (94%) occurred in patients with Durie-Salmon stage 3 MM, and 2 (6%) occurred in patients with Durie-Salmon stage 2 MM. The median time between MM and IA diagnoses was 8 months (range, 1-75 months). Sixteen patients (51%) had a neutrophil count </=500/mm3 for a median duration of 19 days (range, 10-37 days). Fourteen patients (45%) had recently received corticosteroid therapy, and 11 (36%), high doses of melphalan. Twenty-eight patients had primary pulmonary IA, and 3 had primary sinus IA. Forty-five percent of patients were considered to have died of IA. IA occurs as a potentially lethal opportunistic infection in intensively treated nonallografted patients with myeloma.

Adult↗

PubMed2000

Fluorescence in situ hybridization on peripheral-blood specimens is a reliable method to evaluate cytogenetic response in chronic myeloid leukemia.

PURPOSE: To evaluate the usefulness of fluorescence in situ hybridization (FISH) on peripheral-blood specimens to evaluate the cytogenetic response to treatment in patients with chronic myeloid leukemia (CML). PATIENTS AND METHODS: In a first attempt, we analyzed 62 bone marrow specimens using interphase FISH and compared the results with those of conventional cytogenetics. In a second step, we analyzed 60 paired sets of bone marrow and peripheral-blood specimens with interphase FISH. RESULTS: The results of interphase FISH agreed with conventional cytogenetics on bone marrow for most patients, and only minor differences were found (r =.98). The comparison of interphase FISH on bone marrow versus peripheral-blood specimens showed a strong correlation between these two specimen sources (r =.97). CONCLUSION: Our results confirmed that FISH is a sensitive technique for the evaluation of response to treatment in patients with CML. Moreover, our study suggests that follow-up of cytogenetic response to therapy can be evaluated on peripheral-blood specimens, thus enabling an easier and more frequent evaluation of patients. The next step will be to evaluate this technique in a large prospective trial to define the prognostic value of complete remissions evaluated by FISH.

Blood Cells↗