Biomedical subjects

C Payen

Publications and source records attributed to C Payen.

At least 19 recordsLinked to original sources

PubMed2006

First-principles calculations within periodic boundary conditions of the NMR shielding tensor for a transition metal nucleus in a solid state system: The example of 51V in AlVO4.

We present the first density functional theory based calculations of NMR shielding parameters for a transition metal nucleus using periodic boundary conditions. These calculations employ the gauge-including projected augmented-wave pseudopotential approach. The quality of this method is discussed by comparing experimental and calculated chemical shift tensor eigenvalues for the quadrupolar 51V nucleus in the diamagnetic solid-state compound AlVO4. Furthermore, the combination of shielding tensor with fast and accurate projector augmented-wave electric field gradient tensor calculations allows us to determine the relative orientation of these two tensors.

Letter↗

PubMed2006

Neutron spin-echo investigation of slow spin dynamics in kagomé-bilayer frustrated magnets as evidence for phonon assisted relaxation in SrCr9xGa12-9xO19.

A neutron spin-echo investigation of the low temperature spin dynamics in two well-characterized kagomé bilayer compounds SrCr9xGa12-9xO19 (x=0.95, SCGO) and Ba2Sn2ZnCr7xGa10-7xO22 (x=0.97, BSZCGO) reveals two novel features. One is the slowing down of the relaxation rate without critical behavior at Tg, where a macroscopic spin-glass-like freezing occurs. The second is, in SCGO at 4 K (approximately Tg)<T<7 K, the relaxation rate activation energy Ea=7+/-0.4 meV, equal to the energy of a phonon mode, pointing out the role of spin-lattice coupling.

Journal Article↗

PubMed2005

[Preparation and administration of cytotoxic drugs: prickly innovation].

The requirement for safe and optimal administration of cytotoxic drugs led us to test a new product manufactured by Codan. The transfer set (CONNECT SET) and the administration set (CYTO-AD-SET) were assessed successively by pharmacist assistance within a centralized unit for cytotoxic drug preparation and by the nursing staff in an ambulatory unit. Transfer sets can be handled in the centralized units without using needles, but with an increased sterilization load and production cost. Assessment of the administration sets demonstrated time saving for the nursing staff. These materials require significant expenditures, careful training, and a change in treatment routine, but provide important time savings for the nursing staff and considerable improvement in the safety of handling cytotoxic drugs.

Antineoplastic Agents↗

PubMed2004

Delayed toxicity following acute ingestion of valpromide.

As valpromide is a prodrug of valproic acid (valproate), the clinical presentation of overdoses with either valpromide or valproate sodium is generally considered similar. Whereas plasma peak levels and signs of central nervous system depression occur within a few hours after the acute ingestion of regular-release forms of valproate sodium, delayed toxicity and time to peak levels following valpromide ingestion can be seen as shown by the three reported cases. They were initially considered as mild because patients presented with no or only moderate symptoms and serum valproate levels were below or at therapeutic levels on admission more than 3 hours post-ingestion in two of the three patients. Serum valproate levels were not monitored until marked deterioration more than 10 hours after ingestion. At the time of deterioration, serum valproate was at toxic level in the three reported cases. Therefore, large intake of valpromide should be closely monitored because no or moderate symptoms together with low plasma levels in the first few hours after ingestion do not exclude a subsequent severe intoxication. Despite the usual favourable outcome and the poor correlation between plasma levels and toxic symptoms, patients should not be discharged until plasma levels are documented to remain at low levels for at least 10 hours after the ingestion of valpromide and the patient asymptomatic.

Adult↗

PubMed2003

Prothrombin time prolongation in paracetamol poisoning: a relevant marker of hepatic failure?

The association between paracetamol overdose and prolonged prothrombin time due to hepatic failure is well recognized. However, little is known of the possibility that paracetamol overdose can prolong the prothrombin time without overt hepatic failure. The few data from the literature suggest this is either due to a reduction in the functional levels of the vitamin K-dependent clotting factors by elevated doses of paracetamol, or a consequence of the administration of the antidote N-acetylcystein. The three reported cases provide further evidence that paracetamol overdose can be associated with a prolongation in the prothrombin time without overt hepatic failure. Even though the prothrombin time provides useful prognosis information, decisions regarding the management of these patients should not solely be based on this endpoint to avoid misinterpretation of the accuracy and the severity of liver failure.

Acetaminophen↗

PubMed2001

Immunotherapy by non-myeloablative allogeneic stem cell transplantation in multiple myeloma: results of a pilot study as salvage therapy after autologous transplantation.

Non-myeloablative allogeneic stem cell transplantation has been reported to induce sustained complete remission even in advanced diseases (acute leukemia, lymphomas). The tolerance of this procedure allows treatment of poor candidates to conventional allogeneic transplantation with persisting or relapsing myeloma patients. Twelve patients previously treated with at least VAD regimen and autologous transplantation were included. All patients had a serum beta2 microglobuline >3 mg/l at diagnosis. The conditioning regimen consisted of fludarabine 25 mg/m/day x 5, antithymoglobulin 2.5 mg/kg/day x 5, busulphan 2 mg/kg/day x 2; the transplant was peripheral stem cells (except one) from an HLA-matched sibling and was followed by cyclosporin for 45 to 90 days. This treatment results in a well-tolerated procedure (no mucositis, duration of aplasia <7 days). A dramatic graft anti-myeloma effect is documented even in progressive disease (11/12 PR + CR, 4/12 CR). However, five patients underwent CMV disease, one died of CMV encephalitis (UPN 3) and delayed severe GVHD occurred in four patients. Our data suggest that a better survival could be achieved when patients are transplanted with a controlled disease. In high risk patients, we now propose a non-myeloablative transplantation in addition to the conventional and intensive chemotherapy as first-line of treatment.

Graft vs Host Disease↗

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

Randomized study of recombinant interleukin-2 after autologous bone marrow transplantation for acute leukemia in first complete remission.

Immunological control of acute leukemia may be achieved after allogeneic transplant. Despite promising preliminary results, the impact of immunotherapy with interleukin-2 (r-IL-2) on patients with acute leukemia (AL), in first complete remission (CR1) remains unclear. We conducted a prospective multicenter randomized trial to compare outcome in patients with AL in CR1, treated with autologous bone marrow transplantation (BMT) with or without postgraft r-IL-2. One hundred and thirty patients with AL in CR1 (myeloblastic (AML): N = 78; lymphoblastic (ALL): N = 52) were randomized at time of BMT to receive (N = 65) or not (N = 65) r-IL-2. r-IL-2 (RU 49637 from Roussel Uclaf) was started after hematological recovery, as a five cycle regimen (12 M IU/m2/day continuous infusion on day 1-5, 15-17, 29-31,43-45 and 57-59). The two groups were balanced for patient and transplant characteristics. Analysis was based on an intent to treat. Thirty-eight (59%) of the 65 patients randomized into the study group started r-IL-2 at a median of sixty-eight days (23-140) after transplant and received 77% (16-100) of the scheduled dosage. They received a median of 120 x 10(6) IU/m2 (25-156) over 10 (3-13) days during a total median period of 56 (3-78) days. With a median follow-up of 7 years (5.4-8.1 years), 79 patients relapsed (study group: 43 (66%); control group: 36 (55%): p = NS). Survival and leukemia-free survival estimates were 33% (23-45) versus 43% (22-52) and 29% (19-41) versus 36% (24-51) respectively for study and control groups (all p = NS). These results show that leukemic control after autologous BMT is not increased by r-IL-2 therapy. Further studies should investigate more appropriate r-IL-2 schedules and the possibilities offered by better antigen recognition and activated effector cells.

Adult↗

PubMed1999

Familial multiple myeloma: report of fifteen families.

To further define the frequency, clinical and biological features of familial multiple myeloma we performed a retrospective study of related patients who presented with multiple myeloma. Most cases of familial multiple myeloma were observed in siblings (10/15), in whom the mean age at diagnosis was similar to unrelated multiple myeloma. In successive generations the mean age at diagnosis was lower. Monoclonal component was identical (IgG kappa) in seven families. Familial history of monoclonal gammopathy of undetermined significance was observed in three families. Five other prospective studies of 1263 patients identified four affected families (3.2 per 1000 cases of multiple myeloma), and raise the question of a genetic background in multiple myeloma.

Adult↗

PubMed1998

[Hereditary xanthinuria, rare cause of hypo-uric acidemia. 2 cases].

BACKGROUND: Hypouricemia can be observed in uncommon situations as in our two patients with hereditary xanthinuria. CASE REPORTS: In the first case, hereditary xanthinuria was discovered in a 36-year-old man when routine tests revealed hypouricemia. In the second case, a 76-year-old woman, hypouricemia was also a fortuitous discovery. She had major xanthinuria and a radiotranslucid lithiasis in the right kidney. DISCUSSION: Hereditary xanthinuria is characterized by hypouricemia, low urinary urate excretion and increased concentration of xanthine and to a lesser extent hypoxanthine. The disease results from a defect in xanthine oxidase and is considered to be transmitted by autosomal recessive heredity. This rare metabolic disorder is more often asymptomatic and detected by routine chemistry. Development of xanthine lithiasis is directly related to the low solubility of xanthine and is the main complication of the disease, occurring in 30-40% of patients. There is no effective treatment and the only useful measure is to prevent xanthine urolithiasis by maintaining urinary output above 2 l/day.

Adult↗

PubMed1996

A prospective, randomized trial of autologous bone marrow transplantation and chemotherapy in multiple myeloma. Intergroupe Français du Myélome.

BACKGROUND: The median survival of patients with myeloma after conventional chemotherapy is three years or less. Promising results have been reported with high-dose therapy supported by autologous bone marrow transplantation. We conducted a randomized study comparing conventional chemotherapy and high-dose therapy. METHODS: Two hundred previously untreated patients under the age of 65 years who had myeloma were randomly assigned at the time of diagnosis to receive either conventional chemotherapy or high-dose therapy and autologous bone marrow transplantation. RESULTS: The response rate among the patients who received high-dose therapy was 81 percent (including complete responses in 22 percent and very good partial responses in 16 percent), whereas it was 57 percent (complete responses in 5 percent and very good partial responses in 9 percent) in the group treated with conventional chemotherapy (P < 0.001). The probability of event-free survival for five years was 28 percent in the high-dose group and 10 percent in the conventional-dose group (P = 0.01); the overall estimated rate of survival for five years was 52 percent in the high-dose group and 12 percent in the conventional-dose group (P = 0.03). Treatment-related mortality was similar in the two groups. CONCLUSIONS: High-dose therapy combined with transplantation improves the response rate, eventfree survival, and overall survival in patients with myeloma.

Adult↗

PubMed1996

Vincristine degradation by serum from leukemic patients: role of myeloperoxidase.

Myeloperoxidase (MPO) has been shown to catalyze the in vitro degradation of vincristine (VCR). Given that MPO is a lysosomal enzyme that can be released into the circulation by both normal activated and leukemic myeloid cells, we investigated the possibility that sera from patients with acute myeloblastic leukemia (AML) might exhibit an increased capacity to degrade VCR. 31 serum samples (23 from patients with acute myeloblastic leukemia and 8 from patients with other conditions) were analyzed after incubation with ((3)H)VCR by using HPLC. Sera from patients with AML demonstrated an increased ability to breakdown VCR when compared to either normal sera or to sera from patients with lymphoid leukemias. VCR degradation was significantly increased by adding hydrogen peroxide, an electron donor for MPO, to the sera and was almost completely inhibited by adding 1 mM acetaminophen, an inhibitor of MPO. VCR peroxidation in the presence of hydrogen peroxide correlated both with the number of leukemic blasts in the circulation at the time the sera were obtained and with serum MPO concentrations determined by an immunoassay. These data suggest that the inactivity of VCR in AML may be due in part to its rapid peroxidation to inactive species by the MPO of leukemic myeloblasts.

Acetaminophen↗

PubMed1996

[Experimental prevention of deep venous thrombosis with low-molecular-weight heparin using implantable infusion devices].

We studied the effect of a fractionated heparin, Dalteparine Sodium, on the prevention of thrombosis of veins of the superior vena cava system catheterized by implantable infusion devices. Forty-six patients with solid or lympho-proliferative tumors, whose clinical condition required installation of a such device, were successively included into the study in 1991. The anticoagulant was administered for one month following implantation at the dosage of 2,500 anti-Xa units per day. The development of deep vein thrombosis was investigated by systematic Doppler ultrasound before the first and third months and at 1 year. Three early (D9, D12 and D16) and asymptomatic thrombosis were diagnosed (6.5%). This rate, although clearly more favourable, was not significantly different (p = 0.254) from the rate of 15.2% previously reported in a group of 72 comparable patients, but who did not receive preventive treatment. These results demonstrate the necessity and feasibility of a randomized study on a larger number of patients testing several protocols, before concluding on the efficacy of this type of preventive treatment.

Adolescent↗

PubMed1995

Consolidation treatment of adult acute lymphoblastic leukemia: a prospective, randomized trial comparing allogeneic versus autologous bone marrow transplantation and testing the impact of recombinant interleukin-2 after autologous bone marrow transplantation. BGMT Group.

A prospective, randomized trial was initiated in adult acute lymphoblastic leukemia (ALL) to compare (1) disease-free survival (DFS) after allogeneic or autologous bone marrow transplantation (BMT) and (2) the relapse rate of patients treated with or without interleukin-2 (IL-2) after autologous BMT. A total of 135 previously untreated patients, aged under 55 years, received the Berlin-Frankfurt-Muster (BFM) induction regimen: 126 patients (93%), of which 120 were HLA-typed, achieved complete remission (CR). According to this genetic randomization, patients with (n = 43) or without an HLA-identical sibling (n = 77) were to receive allogeneic or autologous BMT, respectively. The 3-year post-CR probability of DFS was significantly higher in the HLA-identical sibling group than in the non-HLA-identical sibling group (68% v 26%; P < .001). Eligible patients were randomized to receive (n = 30) or not to receive (n = 30) IL-2 after autologous BMT: the 3-year post-BMT probability of continuous CR was similar in both groups (29% v 27%, respectively). We conclude that, in ALL, early allogeneic BMT after the BFM induction regimen is an effective consolidation treatment and that IL-2 does not decrease the high relapse rate observed after autologous BMT.

Adult↗

PubMed1995

Bone marrow involvement in anaplastic large cell lymphoma. Immunohistochemical detection of minimal disease and its prognostic significance.

Bone marrow involvement by anaplastic large cell anaplastic large cell (ALC) lymphoma can be difficult to detect on routine morphologic examination alone. In a series of 42 patients with ALC lymphoma, the authors analyzed: (1) the usefulness of a limited panel of monoclonal antibodies directed against CD30 (Ber-H2, HRS4) and epithelial marrow involvement on routinely processed biopsy specimens; and (2) the prognostic significance of bone marrow involvement as detected on both morphologic and immunohistochemical grounds. On conventional examination, 17% of the patients were found to have bone marrow involvement at diagnosis. However, after immunohistochemical analysis, occult malignant cells were detected in 23% of the patients with negative bone marrow biopsy on routine histology. The low percentage of positive cases on routine morphologic examination compared to immunohistochemical examination was related to: (1) the scarcity of neoplastic cells which were scattered among hematopoietic cells; (2) the difficulty of distinguishing malignant cells from immature hematopoietic elements; and (3) the absence of alteration of the reticulin network. The authors observed a significant association between marrow infiltration and the presence of hematologic abnormalities (mostly anemia or cytopenias) at diagnosis, both in children and adult patients. More importantly, a significant lower survival was seen in patients with bone marrow involvement compared to those without bone marrow involvement. Immunohistochemistry with anti-CD30 and anti-EMA antibodies should be performed systematically in bone marrow biopsies from patients with ALC lymphoma to reliably identify the presence of bone marrow involvement that appears to carry a poor prognosis.

Adolescent↗

PubMed1995

Prognostic significance of karyotype in de novo adult acute myeloid leukemia. The BGMT group.

A group of 201 adult patients, 127 younger and 74 older than 55 years, with de novo acute myeloid leukemia were investigated to determine the prognostic significance of karyotype on early death (toxic or aplastic death occurring before hematopoietic recovery), drug resistance, continuous complete remission (CCR) and survival probabilities at 5 years. A good prognostic impact was found for t(8;21), t(15;17) and inv(16). The best factor proved to be t(8;21) (5-year survival probability: 50%), followed by t(15;17) (5-year survival probability: 39%) and by inv(16) (5-year survival probability: 43%). An intermediate outcome was found in patients with trisomy 8 (27% alive at 5 years) and in patients with numerical abnormalities other than -7 and +8 (33% in CCR and 62% alive at 5 years). Normal karyotypes had a different prognostic impact according to age: intermediate in young and good in older patients. A poor outcome was observed among patients with del(5q)/-5 (median survival: 1 month), with 11q23 rearrangements (median survival: 1.5 months) and with del(7q)/-7 (median survival: 10 months). The 'other structural change' group was also found to be a poor risk population (5-year survival probability: 5%) whereas complex karyotypes were predictive of short survivals only in older patients. Conversely, del(7q)/-7 and +8 as secondary changes, had no prognostic impact.

Acute Disease↗

PubMed1994

Epstein-Barr virus (EBV) replicative gene expression in tumour cells of AIDS-related non-Hodgkin's lymphoma in relation to CD4 cell number and antibody titres to EBV.

OBJECTIVE: To determine whether activation of Epstein-Barr virus (EBV) replication in tumour cells of AIDS-related non-Hodgkin's lymphoma (ARNHL) is correlated with CD4+ cell counts and influences antibody response to EBV [anti-Z Epstein-Barr replicative activator (ZEBRA), anti-early antigen (EA), anti-viral capsid antigen (VCA)]. DESIGN: Retrospective study based on immunohistochemistry and in situ hybridization to detect EBV replicative gene products in tissue samples from patients affected by ARNHL and correlation with CD4+ cell counts and results of EBV serology (including anti-ZEBRA activity) in sera from the same patients. METHODS: Seventeen out of 22 cases of ARNHL were selected for the presence of EBV [Epstein-Barr early region (EBER) RNA-positive]. Immunohistochemistry was performed with anti-ZEBRA, anti-EA-restricted, anti-VCA antibodies and in situ hybridization with BHLF1/NotI oligoprobes on tumour samples. Results were statistically correlated with those of CD4+ cell counts (17 out of 17) and with anti-EBV antibody titres (13 out of 17) assessed using standard immunofluorescence method and enzyme-linked immunosorbent assay procedure using recombinant ZEBRA protein and synthetic peptides as antigens. RESULTS: BZLF1 (ZEBRA) or early gene products (EA-R and EA-D/BHLF1/NotI) were detected in a small proportion (< 0.01-5%) of tumour cells in eight of these 17 cases by immunohistochemistry and in situ hybridization. Demonstration of replicative gene expression did not correlate with either low CD4+ cell counts (P > 0.05) or anti-EBV antibody titres (P > 0.05). Anti-ZEBRA activity was not significantly increased in patients affected with ARNHL, the cells of which expressed replicative gene products (P > 0.05). CONCLUSION: The degree of immunodeficiency does not clearly enhance replicative gene expression in tumour cells of ARNHL. EBV serology, including anti-ZEBRA activity, is not a reliable tool for predicting the occurrence of such proliferations.

Acquired Immunodeficiency Syndrome↗

PubMed1994

bcl-2 proto-oncogene and Epstein-Barr virus latent membrane protein-1 expression in AIDS-related lymphoma.

The expression of bcl-2 protein and Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) was investigated in 18 cases of lymphoma occurring in the acquired immunodeficiency syndrome (AIDS). EBV small RNAs were detectable in tumour cells in all cases by in situ hybridization with EBER oligonucleotides. LMP-1 expression was detected in 61% of the cases, and 55% were positive for bcl-2. Dual expression of LMP-1 and bcl-2 was found in 8/18 (44%) cases, while five cases (28%) expressed either LMP-1 or bcl-2 and five expressed neither. Thus, there was an inconsistent relationship between the presence of EBV and the expression of bcl-2. One LMP-1 negative case was found to express bcl-2 in reactive lymphocytes but not in lymphoma cells. No clinical features were found to correlate statistically with LMP-1 or bcl-2 expression in the tumour cells. However, CD4 counts at diagnosis were significantly lower in bcl-2 positive cases (P < 0.05). The respective roles of EBV LMP-1 and the expression of bcl-2 in lymphogenesis in AIDS patients remains complex and is not yet fully understood.

Adult↗