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C Chabannon

Publications and source records attributed to C Chabannon.

6 recordsLinked to original sources
PubMed1992

Expression of CD7 on normal human myeloid progenitors.

Existence of biphenotypic leukemias co-expressing CD7 and CD34 has prompted the question of whether a similar population of cells is present in normal human bone marrow. As CD7 is considered to be a T cell-restricted Ag, the co-expression of CD7 with the "human stem cell Ag" CD34 may identify a bipotent stage within hemopoietic differentiation. Cells with this phenotype have previously been isolated from human thymus. In this report we provide evidence that human marrow mononuclear cells also contain a minor subpopulation of cells co-expressing CD7 and CD34. The CD7+/CD34+ cells were found to contain committed myeloid progenitors assayed both as CFU in semi-solid media and by their ability to produce granulocytes in long term marrow cultures. Expression of CD7 on myeloid committed progenitors was further confirmed in a C-mediated cytotoxic assay. We conclude that CD7 expression is not restricted to T cells but is also expressed during early stages of myeloid differentiation.

Antigens, CD↗
PubMed1991

Role of splenectomy in incidence and severity of acute graft-versus-host disease: a multicenter study of 157 patients.

Allogeneic bone marrow transplantation is a therapeutic option for many hematological malignancies. Graft-versus-host disease (GVHD) remains one of the major complications and has a high mortality rate. The pathophysiological mechanisms involved are poorly understood and GVHD prevention regimens still give disappointing results. This study concerned 157 patients with diverse diagnoses from Bordeaux, Grenoble and Marseille who had undergone an HLA-matched transplantation without T cell depletion. Thirty-one patients (20%) had been splenectomized before transplantation. The role of splenectomy in the incidence and severity of acute GVHD was investigated using a univariate and multivariate analysis of 11 risk factors including splenectomy. Univariate analysis found three significant risk factors linked with GVHD incidence: splenectomy, age of recipient and GVHD prevention by monotherapy versus a combination of methotrexate plus cyclosporin. Multivariate analysis retained only the effects of age and GVHD prevention on GVHD incidence and showed that splenectomy was the most important factor in GVHD severity. One explanation for the role of splenectomy could be the spleen's possible function as a filter of activated T lymphocytes from the transplant. We therefore concluded that it would be preferable to abstain from splenectomizing patients before transplantation although splenectomy is still advisable in certain malignancies after transplantation.

Acute Disease↗
PubMed1990

Study of megakaryocytic progenitors (CFU-MK) in human long-term bone marrow cultures (LTBMC): adjuvant effect of plasma from aplastic patients.

Human long-term bone marrow cultures (LTBMC) provide a very interesting tool for studying the events that are involved in stem cell commitment. At the present time, megakaryocyte (MK) progenitor cells have never been demonstrated in this system. In an effort to detect this cell lineage, we modified the culture medium by substituting fetal calf serum (FCS) and horse serum (HS) mix with human plasma obtained from treated aplastic leukemic patients. This plasma was harvested between days 15 and 21 following induction chemotherapy or conditioning regimen for autograft or allogeneic bone marrow transplantation. Using LTBMC, 17 normal marrows were cultivated for 11 weeks in Iscove's modified Dulbecco's medium containing either 20% human aplastic plasma or control FCS/HS mixture. In this plasma medium we observed the development of an adherent layer morphologically comparable to that observed with standard medium. We demonstrated presence of MK cells at all stages of maturation for 10 weeks and MK colony-forming cells (CFU-MK) for 11 weeks in the culture supernatants. An increased production of nonadherent cells and granulocyte-macrophage progenitors (CFU-GM) was also observed. LTBMC in aplastic plasma medium provide a new method for studying megakaryocytopoiesis, especially in human hematological diseases.

Adolescent↗
PubMed1990

Clinical and hematological improvement in a patient receiving danazol therapy for myelofibrosis with myeloid metaplasia.

We report the positive effect of danazol on clinical and hematological data in a patient with myelofibrosis and myeloid metaplasia. Severe cytopenia was corrected within 2 months and was maintained for an additional 2-month period. Myeloid metaplasia (lymph nodes and skin lesions) was greatly reduced. The patient experienced no side effects. We propose further trials to confirm the utility of this agent in this disease.

Danazol↗