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V Leblond

Publications and source records attributed to V Leblond.

At least 19 recordsLinked to original sources
PubMed2006

Bitumen morphologies by phase-detection atomic force microscopy.

Summary Bitumen is a complex mixture of hydrocarbons for which microstructural knowledge is incomplete. In an effort to detail this microstructure, 13 bitumens were analysed by phase-detection atomic force microscopy. Based on morphology, the bitumens could be classified into three distinct groups. One group showed fine domains down to 0.1 microm, another showed domains of about 1 microm, and a third group showed up to four different domains or phases of different sizes and shapes. No correlation was found between the atomic force microscopy morphology and the composition based on asphaltenes, polar aromatics, naphthene aromatics and saturates. A high correlation was found between the area of the 'bee-like' structures and the vanadium and nickel content in bitumen, and between the atomic force microscopy groups and the average size of molecular planes made of fused aromatics. The morphology and the molecular arrangements in bitumen thus appear to be partly governed by the molecular planes and the polarity defined by metallic cations.

Journal Article↗
PubMed2005

[MALT-type B-cell lymphoma masquerading as scleritis or posterior uveitis].

PURPOSE: Diagnostic and therapeutic management of masquerade syndromes associated with MALT-type lymphoma. PATIENTS AND METHOD: We report the cases of three patients referred for acute or chronic severe loss of visual acuity. All of them suffered from uveitis or scleritis resistant to corticoid treatment. Each one had posterior uveitis associated with retinochoroidal infiltration, anterior scleritis associated with uveal effusion syndrome, or bilateral pan-uveitis associated with serous retinal detachment. Two patients had medical records of systemic malignancies. They underwent an extensive work-up. Search for an infectious, immune or malignant disease was negative but orbital imaging showed a posterior scleral thickening in all cases. RESULTS: Diagnosis of mucosa-associated lymphoid tissue (MALT) ocular lymphoma was assessed in all cases after scleral biopsy. Immunohistochemical analysis showed CD20(+) and CD5(-) scleral lymphocyte infiltrates. The three patients underwent chemotherapy associated with radiotherapy. Lesions were stabilized in the first case, whereas six lines of visual acuity improvement was noted in the second one, and full recovery was achieved after treatment in the third case. DISCUSSION: Clinical manifestations of this ocular lesion seem to be multiple, masquerading as different types of posterior uveitis or scleritis. In the three cases, we did found other systemic locations of MALT-type lymphoma. Diagnosis was mainly based on pathological analysis. Fast visual recovery in two cases demonstrated the importance of an early diagnosis and a specific treatment. All cases of chronic and corticoid-resistant posterior uveitis require a specialized radiological evaluation followed, if necessary, by multiple orbital biopsies.

Adult↗
PubMed2005

Fludarabine plus cyclophosphamide in Waldenström's macroglobulinemia: results in 49 patients.

Fludarabine (FDR) therapy gives a response rate of about 30% in previously treated patients with Waldenström's macroglobulinemia (WM). The combination of FDR and cyclophosphamide (Cy) has been shown to be effective in chronic lymphoproliferative disorders. We administered the combination of FDR (30 mg/m2 i.v. D1-D3) and Cy (300 mg/m2 i.v. D1-D3) to 49 patients. Median age was 64 years. The median hemoglobin, albumin, beta 2 microglobulin and immunoglobulin M (IgM) levels were 9.9 g/100 ml, 39.6 g/l, 3 mg/l and 24.7 g/l, respectively. In all, 14 patients (29%) had not previously been treated. FDR/Cy was administered every 4 weeks for a median of four cycles. In all, 38 patients (77.6%) had partial responses, nine had stable disease and two had progressive disease. After a median of follow-up of 25 months, six patients relapsed and two patients developed large-cell lymphoma. The median time to treatment failure was 27 months. The main toxicity was hematological. In all, 12 patients died, four from progression, one from large-cell lymphoma, three from infection and four from a second malignancy. Two factors negatively influenced overall and event-free survival, age >65 years and IgM <40 g/l. The FDR/Cy combination, therefore, gives a high response rate in WM, even in previously treated patients with factors of poor prognosis.

Aged↗
PubMed2005

Aerosol delivery of chemotherapy in an orthotopic model of lung cancer.

The aim of this study was to evaluate the effect on tumour growth of gemcitabine delivered by aerosol in an orthotopic model of lung carcinoma. Large cell carcinoma (NCI-H460) cells were implanted intrabronchially in 24 male BALB/c nude mice on day (d) 0. Aerosols were delivered once a week from d1 to d29 using an endotracheal sprayer. Altogether, 16 animals received gemcitabine at 8 (n=8) and 12 mg.kg-1 (n=8), and eight received a vehicle aerosol. Animals were sacrificed on d36 for histological examination. All animals in the vehicle group developed a large infiltrating carcinoma. Comparatively, four of 13 (31%) animals treated with gemcitabine had no visible tumour and nine of 13 (69%) had a smaller carcinoma with a mean+/-sem largest tumour diameter of 2.05+/-0.7 versus 5+/-0.3 mm in the vehicle group. Gemcitabine was well tolerated at 8 mg.kg-1. At 12 mg.kg-1, three cases of fatal pulmonary oedema were observed, prompting a dose reduction to 8 mg.kg-1 in the remaining animals. A dose effect was observed, with more marked tumour growth inhibition in the animals treated at 12 mg.kg-1 on d1 and d8. In conclusion, in this study, an animal model of aerosolised chemotherapy in lung cancer was developed and demonstrated inhibition of orthotopic tumour growth by aerosol delivery of gemcitabine.

Administration, Inhalation↗
PubMed2004

[French training program for medical students in transfusion medicine. Transfusion Medicine Teachers' College].

In France, transfusion medicine training program has been updated. A national committee of professors in transfusion medicine propose a series of 13 items which represent the minimum knowledge that general practitioners should possess. This overview of transfusion medicine is far below the level that specialists should reach and they will need an additional specialized training. Several French universities have set up their own training program which is quite similar to the work of the committee of professors. The following recommendations are not strict guidelines but is a common basis which will be improved in 2005 according to new evidence based transfusion medicine.

Accidents, Occupational↗
PubMed2004

Waldenström's macroglobulinemia: prognostic factors and recent therapeutic advances.

Waldenström's macroglobulinemia is a rare B cell malignancy. All prognostic studies have identified the adverse prognostic effect of advanced age and low hemoglobin level for survival, whereas the prognostic value of a high level of monoclonal component remains controversial. Response to treatment is probably a favorable prognostic factor for overall survival. Conventional treatment is based on alkylating agents, and especially chlorambucil. Purine analogues, used initially for salvage treatment, are increasingly employed as front-line therapy. Purine analogues have not been compared with alkylating agents as first-line therapy in randomized trials, and it is unclear whether purine analogues extend survival. An anti-CD20 monoclonal antibody has given a response rate in about 30% of patients. Autologous and allogeneic stem cell transplantation may be considered for patients with refractory or relapsing disease.

Combined Modality Therapy↗
PubMed2003

Transplantation in Waldenstrom's macroglobulinemia--the French experience.

Published data on transplantation in Waldenstrom's macroglobulinemia (WM) are still limited. We present a retrospective multicentric study of 27 WM patients who underwent 19 autologous (median age, 54 years) and 10 allogeneic (median age, 46 years) transplantations. Median time between diagnosis and transplantation was 36 months; 66% of patients had received three or more treatment lines and 72 % had chemosensitive disease. High-dose therapy (HDT) and autologous transplantation induced a 95% response rate (RR), including 10 major responses. With a median follow-up of 18 months, 12 patients are alive at 10 to 81 months and eight are free of disease progression at 10 to 34 months. The toxic mortality rate (TRM) was 6%. Allogeneic transplantation was preceded by HDT in nine patients and by a nonmyeloablative regimen in one patient. The RR was 80%, including seven major responses. With a median follow-up of 20.5 months, six patients are alive and free of progression at 3 to 76 months. Four patients died, all from toxicity, resulting in a TRM of 40%. HDT followed by autologous transplantation is feasible in WM, even in heavily pretreated patients, with some prolonged responses but a high relapse rate. Conversely, allogeneic transplantation is more toxic, but likely induces a graft-versus-WM effect and may, for some patients, result in long-term disease control.

Adult↗
PubMed2003

Primary follicular lymphoma of the gastrointestinal tract: a study of 25 cases and a literature review.

BACKGROUND: To describe better the clinical, biological, endoscopic and pathological presentations, as well as the outcome, of primary follicular lymphoma (FL) of the gastrointestinal (GI) tract. PATIENTS AND METHODS: From November 1983 to February 2001, 25 eligible patients with primary FL of the GI tract were retrieved from several French Departments of Pathology departments based on histological diagnosis and immunophenotype. Median age was 56 years (range 44-71) with a sex ratio female/male of 2 (17/8). RESULTS: Abdominal pain was the main presenting symptom followed by intestinal obstruction. The small intestine was the most common site of involvement. Lesions were unifocal in the majority of patients (15/25). A pattern similar to lymphomatous polyposis was observed in 50% (7/14) of patients. Twelve patients had stage I, 10 patients stage II and three patients stage IV disease, and there was minimal extra intestinal involvement. Lymphoma tissues were composed of neoplastic follicles, most of which were grade 1 according to the World Health Organization (WHO) classification. The immunophenotype of the lymphoma cells was CD20+, CD10+, bcl2+ and CD5-. In tissue samples, IgH/bcl2 rearrangement at the MBR locus was present in 11 of 14 patients tested. Seven patients did not receive any treatment; four of them progressed after a median follow-up of 37.5 months. Treatment was otherwise heterogeneous, and complete remission was obtained in 15 patients which lasted for a median of 31 months. Relapses were either in the GI tract (n = 3) or outside the GI tract (n = 3). After a median follow-up of 34 months (range 5-203), 22 patients were still alive (complete remission, 11; partial remission, three; stable disease, six; progressive disease, two). CONCLUSIONS: Primary FL of the GI tract is a predominantly female lymphoma that most frequently involves the small intestine. Since the endoscopic and clinical presentation may not be different from lymphomatous polyposis, which is often associated with mantle cell origin of tumor cells, it is mandatory to perform an immunohistological and, if possible, a molecular analysis of GI lymphoma. The course of the disease is indolent and does not differ from nodal FL. Thus, therapy may not be required unless significant clinical symptoms are present or until disease progression.

Adult↗
PubMed2002

Treatment of post-transplant lymphomas with anti-B-cell monoclonal antibodies.

The treatment of post-transplant lymphomas still needs major improvements in order to put the patient in remission and to retain graft function. Chemotherapy is far too toxic in these patients. A more specific treatment such as anti-B-cell monoclonal antibody is very promising. The cytotoxic effect of antibody relies mainly on complement-induced and antibody-dependent cellular cytotoxicity; apoptosis may also induce tumor cell death. B-cell antigens expressed on the cell surface are the targets of antibody attack; some specificities may be chosen because of their level of expression or because of signaling induced within the cell. Anti-B-cell antibodies can be produced by genetic engineering in order to be humanized or to carry bispecific Fabs. The efficacy and safety of anti-B-cell monoclonal antibodies (mAbs) in transplant patients have been proven with different antibodies such as anti-CD21/CD24 mAb, anti-CD38 mAb and anti-CD20 mAb. In a retrospective analysis of different centers in France, rituximab (anti-CD20 mAb, Roche Products) achieved an overall 69% remission rate in 34 organ and bone-marrow transplant patients. But the conditions of use of antibody must be better defined, particularly with regard to the immunosuppressive therapy, the type of tumor and the dose of antibody. We must also improve our understanding of the in vivo mechanisms of action of antibody to develop more efficient antibody constructs.

Antibodies, Monoclonal↗
PubMed2002

Waldenström's macroglobulinaemia.

Waldenström's macroglobulinaemia (WM) is most usefully defined as a distinct chronic lymphoproliferative disorder with characteristic marrow morphology and phenotype; although nodal morphology if available will reveal a lymphoplasmacytoid lymphoma, the presence of a significant IgM paraprotein defines the clinical features of the disease. The clonal cell is a B-cell expressing IgM, CD19, and CD20 but not IgD, CD5, CD10 or CD23 and has somatic hypermutation of immunoglobulin heavy chain variable regions consistent with a post-germinal centre origin. Treatment of WM has been dependent on alkylating agents with or without coriticosteroids for many years, supplemented by the use of therapeutic plasmapheresis in the initial stages for patients at risk from the clinical consequences of hyperviscosity. This approach to treatment results in response rates of approximately 60% with a median survival of about 60 months. There is increasing evidence to show that the purine analogues fludarabine and cladribine which are active in the treatment of patients who are resistant to alkylating agents such as chlorambucil may be able to achieve higher response rates when used as initial therapy. A prospective trial is being undertaken to compare fludarabine and chlorambucil as initial treatment; because of the effect of subsequent active treatment on patients who do not respond to the first treatment choice, the long-term outcome may be similar for both groups. Recent advances in therapy include the use of therapeutic monoclonal antibodies such as rituximab and the use of autologous or allogeneic transplant procedures for selected patients.

Antineoplastic Agents↗
PubMed2001

Multicenter, randomized comparative trial of fludarabine and the combination of cyclophosphamide-doxorubicin-prednisone in 92 patients with Waldenström macroglobulinemia in first relapse or with primary refractory disease.

Few reports are available on the treatment of patients with Waldenström macroglobulinemia (WM) and primary or secondary resistance to alkylating-agent-based regimens. From December 1993 through December 1997, 92 patients with WM resistant to first-line therapy (42) or with first relapse (50) after alkylating-agent therapy were randomly assigned to receive fludarabine (25 mg/m(2) of body-surface area on days 1-5) or cyclophosphamide, doxorubicin (Adriamycin), and prednisone (CAP; 750 mg/m(2) cyclophosphamide and 25 mg/m(2) doxorubicin on day 1 and 40 mg/m(2) prednisone on days 1-5). The first end point evaluated was the response rate after 6 treatment courses. Forty-five patients received CAP and 45 received fludarabine. Two patients died before the first course of chemotherapy. No statistical differences were observed between the 2 treatment arms with respect to hematologic toxicity or infections. Mucositis and alopecia occurred significantly more often in patients treated with CAP. Partial responses were obtained in 14 patients (30%) treated with fludarabine and 5 patients (11%) treated with CAP (P =.019). Responses were more durable in patients treated with fludarabine (19 months versus 3 months), and the event-free survival rate was significantly higher in this group (P <.01). Forty-four patients died, 22 in the fludarabine group and 22 in the CAP group. There was no statistical difference in the median overall survival time in the 2 study arms. Fludarabine was thus more active than CAP in salvage therapy of WM and should be tested as first-line therapy in a randomized comparison with alkylating agents.

Adult↗
PubMed2001

Treatment of B-lymphoproliferative disorder with a monoclonal anti-interleukin-6 antibody in 12 patients: a multicenter phase 1-2 clinical trial.

Severe T-cell immunodeficiency after solid organ or bone marrow transplantation may result in the uncontrolled outgrowth of latently Epstein-Barr virus-infected B cells, leading to B-lymphoproliferative disorder (BLPD). Given the potentially important pathogenic role of IL-6 in BLPD, it was tested whether the in vivo neutralization of IL-6 by a monoclonal anti-IL-6 antibody could contribute to the control of BLPD. Safety and efficacy were assessed in 12 recipients of transplanted organs who had BLPD refractory to the reduction of immunosuppression over 8 days. Five patients received 0.4 mg/kg per day. The next 7 patients received 0.8 mg/kg per day. Treatment was scheduled to last 15 days. It was completed in 10 patients, and in the other 2 patients was discontinued early (days 10 and 13, respectively) because of disease progression. Treatment tolerance was good, and no major side effects were observed. High C-reactive protein levels were found in 9 patients before treatment but were normalized under treatment in all patients, demonstrating efficient IL-6 neutralization. Complete remission (CR) was observed in 5 patients and partial remission (PR) in 3 patients. Relapse was observed in 1 of these 8 patients in whom remission was observed. This relapse was unresponsive to treatment. Disease was stable in 1 patient, but it progressed in 3 patients. Seven patients are alive and well. Two patients died because of disease progression, and 3 patients died while in CR (chronic rejection in 2 patients and BLPD sequelae in 1 patient). These data suggest that the anti-IL-6 antibody is safe and should be further explored in the treatment of BLPD.

Adolescent↗
PubMed2001

Results of intensive chemotherapy followed by hematopoietic stem-cell rescue in 22 patients with refractory or recurrent primary CNS lymphoma or intraocular lymphoma.

PURPOSE: To assess the feasibility and efficacy of intensive chemotherapy with hematopoietic stem-cell rescue (IC + HCR) in patients with refractory or recurrent primary CNS lymphoma (PCNSL) or intraocular lymphoma (IOL). PATIENTS AND METHODS: IC consisted of thiotepa 250 mg/m(2)/d days -9 through -7, busulfan 10 mg/kg (total dose) days -6 through -4, and cyclophosphamide 60 mg/kg/d days -3 and -2. Intravenous clonazepam 2 mg/d was given prophylactically from the day before initiation of busulfan therapy to the day after completion of busulfan therapy. Patients with refractory or recurrent PCNSL underwent IC + HCR only if they were chemosensitive to two cycles of salvage treatment with cytarabine (2 g/m(2)/d days 2 through 5 and 50 mg/m(2)/d days 1 through 5 in a 12-hour infusion) and etoposide (VP-16; 200 mg/m(2)/d days 2 through 5) (CYVE). Patients with IOL refractory to high-dose methotrexate (MTX) and cytarabine entered the IC + HCR program directly. RESULTS: Twenty-two patients (10 with relapses, 12 with refractory disease) were enrolled. Twenty patients entered the IC + HCR program: twelve entered after CYVE treatment, seven entered directly, and one had previously been retreated with high-dose MTX. Before IC, eight patients were in complete remission (CR), four were in partial remission (PR), one had stable disease, and seven had refractory disease. After IC + HCR, 16 patients entered CR, two remained in PR, one had stable disease, and one had disease progression. Fourteen patients remained alive (median follow-up time, 41.5 months). The overall probability of survival at 3 years was 63.7%. After IC, that probability was 60% and the 3-year probability of event-free survival was 53%. Seven patients had neurologic adverse events during the entire procedure. CONCLUSION: IC + HCR proved feasible and effective in patients with refractory or recurrent PCNSL or IOL. The entire procedure seemed to be most toxic in patients > or = 60 years. A prospective multicenter study is ongoing.

Adult↗