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Biomedical subjects

O Hermine

Publications and source records attributed to O Hermine.

At least 19 recordsLinked to original sources
PubMed2006

Overexpression of the heat-shock protein 70 is associated to imatinib resistance in chronic myeloid leukemia.

Imatinib is an effective therapy for chronic myeloid leukemia (CML), a myeloproliferative disorder characterized by the expression of the recombinant oncoprotein Bcr-Abl. In this investigation, we studied an imatinib-resistant cell line (K562-r) generated from the K562 cell line in which none of the previously described mechanisms of resistance had been detected. A threefold increase in the expression of the heat-shock protein 70 (Hsp70) was detected in these cells. This increase was not associated to heat-shock transcription factor-1 (HSF-1) overexpression or activation. RNA silencing of Hsp70 decreased dramatically its expression (90%), and was accompanied by a 34% reduction in cell viability. Overexpression of Hsp70 in the imatinib-sensitive K562 line induced resistance to imatinib as detected by a large reduction in cell death in the presence of 1 muM of imatinib. Hsp70 level was also increased in blast cells of CML patients resistant to imatinib, whereas the level remained low in responding patients. Taken together, the results demonstrate that overexpression of Hsp70 can lead to both in vitro and in vivo resistance to imatinib in CML cells. Moreover, the overexpression of Hsp70 detected in imatinib-resistant CML patients supports this mechanism and identifies potentially a marker and a therapeutic target of CML evolution.

Biomarkers, Tumor↗
PubMed2006

Minimal change nephrotic syndrome and classical Hodgkin's lymphoma: report of 21 cases and review of the literature.

Minimal change nephrotic syndrome (MCNS) is described as a paraneoplastic manifestation of classical Hodgkin's lymphoma (cHL). We reassessed the pathophysiological and clinical significance of this association. A retrospective study was performed to evaluate a cohort of adult patients who developed MCNS and cHL. Twenty-one patients recruited in 15 French centers were analyzed. cHL was associated with inflammatory and general symptoms in most cases. The morphological subtype was predominantly nodular sclerosis (71.4%). MCNS appeared before the diagnosis of lymphoma in eight patients (38.1%) and in this case, it was characterized by a nephrotic syndrome (NS) frequently resistant (50%) or dependent (12.5%) to steroid treatment. Interestingly, diagnosis (3-120 months after MCNS) and effective treatment of the hemopathy were associated with the disappearance of the MCNS. cHL was diagnosed before MCNS in nine patients (42.9%), and in this case, glomerulopathy was associated with cHL relapse in 55.5% of cases. In four patients (19%), the two diseases occurred simultaneously. Extensive immunohistochemical study of lymph nodes was performed in eight patients and did not reveal particular features. In conclusion, MCNS associated with cHL is frequently dependent or resistant to steroid regimen, but remission of NS is obtained with the cure of lymphoma.

Adolescent↗
PubMed2006

The VAD chemotherapy regimen plus a G-CSF dose of 10 microg/kg is as effective and less toxic than high-dose cyclophosphamide plus a G-CSF dose of 5 microg/kg for progenitor cell mobilization: results from a monocentric study of 82 patients.

A study was conducted to compare the efficiency and toxicity of two peripheral blood stem cell (PBSC) mobilization procedures for newly diagnosed patients with multiple myeloma. Patients from group 1 (n=51) were treated by high-dose cyclophosphamide (HD-CY) plus G-CSF (5 microg/kg/day), and the second group (n=31) by VAD regimen plus G-CSF administration (10 microg/kg/day). Successful mobilization, defined by a minimal count of 2.5 x 10(6) CD34(+) cells/kg collected, was achieved in 96 and 90% of patients in groups 1 and 2, respectively (P=0.15). The mean peripheral blood CD34(+) cells concentration and the mean CD34(+) cells/kg collected were higher in group 2 than in the group 1 (P=0.05). The mean number of leukaphereses necessary to collect a count of 2.5 x 10(6) CD34(+) cells/kg was reduced in group 2 compared to group 1. Adverse events, blood products consumption and time spent in the hospital were significantly greater after HD-CY. In conclusion, VAD plus a G-CSF dose of 10 microg/kg administration seems preferential to HD-CY plus a G-CSF dose of 5 microg/kg for PBSC collection because of equivalent or better efficiency in stem cell mobilization, strong favorable toxicity profile and reduced cost.

Antigens, CD34↗
PubMed2006

Incidence and prognostic impact of c-Kit, FLT3, and Ras gene mutations in core binding factor acute myeloid leukemia (CBF-AML).

In core binding factors (CBF) acute myeloid leukemia (AML), the disruption of CBFalpha/beta genes impairs normal hematopoietic differentiation and is supposed to cooperate with additional mutations promoting proliferation. The incidence and the prognosis of receptor tyrosine kinase (RTK) c-Kit and FLT3 mutations and Ras mutations were evaluated in 103 pediatric and adult patients with CBF-AML. c-Kit mutations were present in 17% patients. c-Kit exon 8 mutations were more frequent in inv(16) than in t(8;21) subset (20 versus 6%). Only one patient had FLT3-ITD but FLT3-D835 was as frequent as reported in AML population (7%). Ras mutations were significantly more frequent in inv(16) than in t(8;21) subset (36 versus 8%, P=0.001). RTK mutations were associated with a higher white blood cell count (WBC) (36 versus 21 G/L, P=0.05). FLT3 mutations were significantly associated with a shorter EFS and survival (P<0.0001 and P=0.0002) owing to an excess of early events. c-Kit mutations were associated with a shorter EFS and RFS (P=0.002 and P=0.003) in t(8;21) but not inv(16) patients. As previously observed, Ras mutations did not affect prognosis. Screening for RTK mutations may help to identify patients with a more adverse outcome and thus susceptible to benefit from intensified protocols or RTK inhibitors.

Acute Disease↗
PubMed2005

[Membranous glomerulonephritis during primary Gougerot-Sjögren syndrome].

INTRODUCTION: Glomerulonephritis, mainly membranoproliferative or membranous (MG), is observed much less often than interstitial involvement in Sjögren's syndrome (SS). CASE: We report a case of MG revealed by thrombosis of the inferior vena cava and of a renal vein in a 40-year-old woman with primary SS, which began with polyarthritis, immune-type lymphadenopathy, and Hashimoto thyroiditis and did not include obvious sicca syndrome. After failure of moderate-dose steroids and then azathioprine, each over separate 9-month periods, the MG responded well within a few weeks to monthly alternation of methylprednisolone and oral cyclophosphamide for 6 months. DISCUSSION: SS may be an underestimated cause of glomerulonephritis, especially membranoproliferative and membranous glomerulonephritis. They should be considered even in the absence of obvious sicca syndrome. Although the prognosis is usually good, renal insufficiency can occur. In cases of MG, if moderate-dose steroids fail, monthly alternation of methylprednisolone and cyclophosphamide for 6 months appears effective and well tolerated, with a low risk of carcinogenicity.

Administration, Oral↗
PubMed2005

[Systemic mastocytosis].

Systemic mastocytosis is characterized by abnormal mast cell proliferation in different organs. The 2001 consensus classification distinguishes in separate categories indolent systemic mastocytosis, systemic mastocytosis with concomitant blood disease, aggressive systemic mastocytosis and mast cell leukemia. Clinical manifestations are caused by tissue infiltration by proliferating mastocytes and by release of mediators. The principal organs affected are the skin, bones, digestive tract, liver, spleen and lymph nodes. Diagnosis of mastocytosis is based on appropriate stains (Giemsa, toluidine blue) and immunophenotype features (tryptase, CD117, also known as c-KIT and stem cell factor receptor). Serum tryptase levels reflect the total mast cell burden. Treatment must prevent release of mast cell mediators (histamine antagonists, cromolyn sodium, corticosteroids, or leukotriene-receptor inhibitors), limit bone involvement (bisphosphonates) and reduce the number of circulating mast cells (interferon, cladribine, or tyrosine kinase inhibitors). Enhanced understanding of the pathogenic mechanisms (mutation of c-kit and platelet-derived growth factor receptor alpha has led to the development of targeted treatments, including new inhibitors of tyrosine kinase and of nuclear factor Kappa B.

Benzamides↗
PubMed2005

Hematopoietic stem cell transplantation for Shwachman-Diamond syndrome: experience of the French neutropenia registry.

Our objective was to study the outcome of allogeneic hematopoietic stem cell transplantation (HSCT) for Shwachman-Diamond Syndrome (SDS). Among 71 SDS patients included in the French Severe Chronic Neutropenia Registry, 10 received HSCT between 1987 and 2004 in five institutions. The indications were bone marrow failure in five cases, and myelodysplastic syndrome (MDS) or leukemia in five cases. The median follow-up of patients who survived without relapse is 6.9 years (3.1-16.8 years). The conditioning regimen consisted of a busulfan-cyclophosphamide combination (n=6) or total body irradiation plus chemotherapy (n=4). Six patients received stem cells from unrelated donors and four from identical siblings. Engraftment was complete in eight patients and unassessable in two patients. These latter two patients died of infections 32 and 36 days after HSCT, with grade IV graft-versus-host disease and multiorgan dysfunction. A third patient died from an acute respiratory distress syndrome 17 months after HSCT with progressive granulocytic sarcoma. One patient had an MDS relapse 4 months after HSCT and died 10 months later. The overall 5-year event-free survival rate is 60+/-15%. We conclude that HSCT is feasible for patients with SDS who develop bone marrow failure or malignant transformation.

Adolescent↗
PubMed2005

[Erythropoiesis: a paradigm for the role of caspases in cell death and differentiation].

Erythroid differentiation involves the transcription factor GATA-1 that positively regulates promoters of erythroid genes (including haemoglobin, glycophorin, erythropoietin receptor) and of erythropoietin. Terminal erythroid differentiation is characterized by major morphological changes that include chromatin condensation and cell size reduction. The morphological changes are partially similar at least to those observed during apoptosis. The production of red cells depends on the apoptosis rate of erythroid progenitors and precursors. Upon erythropoietin starvation or engagement of the death receptor Fas, caspases are activated in erythroid precursors and cleave GATA-1, thus inducing maturation arrest and apoptosis of immature erythroblasts. We have recently demonstrated that, upon erythropoietin stimulation, caspase-3 was also activated, an event required for human terminal erythroblast maturation. Proteins cleaved by caspases in erythroid cells undergoing terminal differentiation include Lamin B and Acinus, which are involved in chromatin condensation. In contrast, despite caspase-3 activation neither GATA-1 degradation nor apoptosis was observed. Thus, the fate of erythroid precursors is determined downstream of caspase activation by the pattern of cleaved targets. Therefore, there are some mechanisms underlying the selective protection of caspase-3 targets during erythropoiesis. This model in which caspases activation is required for differentiation may apply to other haematopoietic or non haematopoietic cellular systems which are described in this review.

Animals↗
PubMed2005

Reversibility of pulmonary arterial hypertension in HIV/HHV8-associated Castleman's disease.

The present study describes a case of pulmonary arterial hypertension (PAH) associated with multicentric Castleman's disease in a patient infected with HIV type 1 and human herpes virus 8. Therapy included highly active antiretroviral therapy, warfarin, diuretics, continuous i.v. epoprostenol and 12-monthly pulses of cyclophosphamide. The patient's condition improved dramatically with complete reversibility of PAH, allowing weaning of continuous i.v. epoprostenol therapy. After 5 yrs, both Castleman's disease and PAH have not relapsed. This supports the hypothesis that control of inflammation and retroviral replication may be of interest in the context of PAH, complicating the course of an inflammatory condition associated with viral infection. In conclusion, further studies should help in characterising the best candidates for anti-inflammatory treatment in the setting of pulmonary arterial hypertension.

Adult↗
PubMed2004

Retinoic acid therapy in "degenerative-like" neuro-langerhans cell histiocytosis: a prospective pilot study.

BACKGROUND: Degenerative-like neuro-Langerhans cell histiocytosis (DN-LCH) is a rare complication of LCH marked by progressive cerebellar ataxia. No treatment has so far been shown to slow this progression. PROCEDURE: All-trans retinoic acid (ATRA) was administered orally at a dose of 45 mg/m(2) daily for 6 weeks and then 2 weeks every month for 1 year. The endpoints were clinical status at 1 year (assessed with rating scales for ataxia and disability), adverse effects, and changes in neurological abnormalities on MRI. RESULTS: Ten patients were studied. The treatment was well tolerated. All the patients were clinically stable at the end of the study. No MRI changes were noted. CONCLUSIONS: DN-LCH appeared to be stable during ATRA therapy, but further studies are required to appreciate the possible long-term benefits of ATRA.

Adolescent↗
PubMed2004

A new clinical score for disease activity in Langerhans cell histiocytosis.

OBJECTIVE: To develop an objective tool for assessing disease activity in patients with Langerhans cell histiocytosis (LCH). METHOD: Scoring system was developed and applied to a database containing information on 612 patients. RESULTS: At diagnosis, the score distribution was highly asymmetrical: the score was between 0 and 2 in 74% of cases, 3-6 in 16%, 7-10 in 3%, and more than 10 in 6%. The 5-year mortality rates were 1, 4.4, and 43.4%, respectively, among patients with initial scores of 0-2, 3-6, and >6. Stability or an increase of the score at 6 weeks was highly predictive of death among patients with initial scores above 6, while score stability had no significant impact on vital outcome among patients with low or moderate scores at diagnosis. CONCLUSIONS: This LCH disease activity score provides an objective tool for assessing disease severity, both at diagnosis and during follow-up and treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Interest of interferon alpha in systemic mastocytosis. The French experience and review of the literature.

Systemic mastocytosis (SM) are defined by an abnormal growth and accumulation of mast cells in bone marrow and/or other extracutaneous organs. There is currently no cure for this disease. Because of similarities and/or association of mastocytosis with myeloproliferative disorders, interferon alpha has been tested but with contradictory reported results. A first prospective multicenter phase II trial was then started in France. From 1994 to 1997, 20 adult patients with confirmed bone marrow involvement received interferon alpha-2b for at least 6 months, (from 1 million U per day up to 5 million U/m(2)/day). Thirteen patients who presented systemic and/or specific cutaneous manifestations, demonstrated objective responses: seven (35%) were partial, six (30%) minor but no complete response could be observed at the time of analysis. The bone marrow remained unchanged in 12/13. Thus, interferon should be offered to patients with severe systemic manifestations, who have not responded to symptomatic therapies, even in case of non-aggressive mastocytosis, with or without corticosteroids the first weeks. Long-term therapy should be offered to patients with initial positive response. To control more aggressive SM or mastocytosis associated with clonal hematologic non-mast cell lineage or leukaemia mast cell, other chemotherapeutic regimens should be proposed like Cladribine (2-chlorodeoxyadenosine, 2-CDA) or polychemotherapies including interferon as it is being tested in France in a new multicentric protocol, coordinated by the association AFIRMM, with interferon and oral cytarabine.

Bone Marrow Cells↗
PubMed2004

Loss of the ex vivo but not the reinducible CD8+ T-cell response to Tax in human T-cell leukemia virus type 1-infected patients with adult T-cell leukemia/lymphoma.

Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy (HAM). In asymptomatic carriers and HAM patients, HTLV-1 infection leads to a vigorous cytotoxic T-cell (CTL) response mainly directed to the regulatory Tax protein. In contrast, initial studies showed that anti-HTLV-1 CTL activities were not reproductively detected in ATLL patients, neither ex vivo, nor after in vitro restimulation. To better understand this discrepancy, we explored the anti-HTLV-1 CD8+ T-cell response of eight ATLL patients by using in vitro restimulated or freshly isolated CD8+ T cells. In all the ATLL patients, we found that mitogenic activation allowed the induction of CD8+ T cells able to lyse autologous HTLV-1-infected cells and/or to produce IFNgamma in response to Tax peptides. In contrast, only a minority of the patients possessed CD8+ cells able to respond ex vivo to the same epitopes. These findings indicate that although a restimulatable anti-HTLV-1 CTL activity persists during ATLL, the specific ex vivo response is not constantly maintained. This provides definitive evidence that the CD8+ T-cell response to HTLV-1 is affected by ATLL development and reveals that a major defect concerns the generation and/or the functionality of CD8+ effectors.

CD8-Positive T-Lymphocytes↗
PubMed2004

N-(4-hydroxyphenyl)retinamide induces growth arrest and apoptosis in HTLV-I-transformed cells.

N-(4-hydroxyphenyl)retinamide (HPR) is a synthetic retinoid that inhibits growth and induces apoptosis in many human cell lines. We explored the effects of HPR on human T-cell lymphotropic virus type I (HTLV-I)-positive and HTLV-I-negative malignant T-cell lines, most of which are resistant to all-trans retinoic acid. Clinically achievable concentrations of HPR caused a dramatic inhibition of cell proliferation, G(0)/G(1) arrest, and massive apoptosis in all tested malignant T cells, while no effect was observed on resting or activated normal lymphocytes. Interestingly, HTLV-I-negative cell lines were significantly more sensitive to HPR compared to HTLV-I-positive and Tax-transfected cells. In HTLV-I-negative cells only, HPR-induced apoptosis was associated with ceramide accumulation, sharp decrease in mitochondrial membrane potential, and activation of caspases 8, 9 and 3, and could be partially reverted by the caspase inhibitor z-VAD suggesting that Tax protects infected cells from ceramide accumulation and caspase-mediated apoptosis. In HTLV-I-positive cells, HPR treatment rapidly induced proteasomal-mediated degradation of p21, downregulated cyclin D(1), and upregulated bax protein levels. These findings support a potential therapeutic role for HPR in both HTLV-I-associated adult T-cell leukemia/lymphoma (ATL) and HTLV-I-negative peripheral T-cell lymphomas.

Antineoplastic Agents↗