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Biomedical subjects

C Jasmin

Publications and source records attributed to C Jasmin.

305 records · Page 17Linked to original sources
PubMedDate not supplied

Recombinant interleukin-2 (rIL-2) after autologous bone marrow transplantation (BMT): a pilot study in 19 patients.

In vivo use of rIL-2 autologous BMT may be the means of reproducing a kind of "adoptive immunotherapy" from grafted cells after allogeneic BMT. This approach may enhance the spontaneous generation of cytotoxic T-cells and NK cells which are presumably involved in this immunotherapy. Potential risks of such an approach would be to increase the usual toxicity of rIL-2 and to jeopardize the hemopoietic reconstitution. To determine the feasibility of this approach we have treated 19 poor prognosis patients with a succession of autologous BMT followed 78 +/- 12 days later by a continuous infusion of rIL-2. Eighteen million international units (IU) per m2 per day of Proleukine (CETUS, Amsterdam, The Netherlands) were administrated over 6 or 12 days. No patient died of the procedure. Clinical toxicity related to rIL-2 was not increased. Hemopoietic toxicity, significant both for platelets and granulocytes, was transient. Immune stimulation was dramatic for lymphocytes and subpopulations (CD3+ and NK cells) and for cytolytic functions (NK and LAK activity). This trial establishes the feasibility of administration of high doses of rIL-2, 2 months after autologous BMT. In this setting a 6 day period of continuous infusion of 18 million per m2 per day of Proleukine appears to be a regularly tolerable dosage conducting to a major immune activation and invites further studies to determine the clinical impact of such an approach.

Adjuvants, Immunologic↗
PubMedDate not supplied

Organization of haematopoietic stem cells and their relationship to mastocytopoiesis.

Haematopoiesis is a dynamic process in which differentiated blood cells are regularly replaced by the proliferation and differentiation of stem cells. Two types of haematopoietic stem cells (HSC) can be distinguished: totiopotent HSC capable of giving rise to cells of all haematopoietic lineages, and pluripotent HSC capable of giving rise only to the myeloid lineages. HSC are characterized by their capacity for self-renewal and differentiation in committed stem cells determined towards one of the haematopoietic lineages. These committed stem cells, also named progenitor cells or colony-forming units (CFU), have the capacity to give rise, in semi-solid medium, to colonies composed of differentiated cells. It has recently been shown that mast cells originate from a pluripotent HSC and that CFU Baso/Masto can be detected from murine and human bone marrow and blood cells. The in vivo regulation of the proliferation and differentiation of HSC is not well known. Several studies have emphasized the role of the haematopoietic microenvironment and of long- and short-range factors in such regulation. The in vitro growth of HSC is strictly dependent on growth factors, also named CSF (colony-stimulating factors) and interleukin (IL), in particular IL3. IL3 is a glycoprotein which induces the proliferation and differentiation of pluripotent and committed HSC and which seems to have a preferential role in mast cell regulation.

Animals↗
PubMedDate not supplied

Treatment of lymphoid neoplasias with interferon. I. Human fibroblastic beta-interferon in malignant gammapathies. Phase II trial.

18 patients with malignant gammapathies (16 with myeloma and 2 with Waldenström's disease) were treated with human fibroblastic Interferon (beta IF). This was administered i.v. 6 X 10(6) units weekly (7 patients) or 3 X 10(6) units twice weekly (11 patients). during at least 3 months if tolerated. Treatment was discontinued because of side effects in three patients. Reduction of the M component, by at least 25% from the initial value, was obtained in 3 patients. In one case the disappearance of a urinary Bence Jones protein was observed. In 4 cases, there was a significant reduction of bone marrow infiltration by plasma cells. In 5 cases, major alleviation or disappearance of bone pain was observed. Duration of treatment seemed to be an important factor for activity. Immune monitoring with currently available tests, mainly natural cytoxicity, yielded no correlation with therapeutic effect in these patients. This preliminary study demonstrates the effect of fibroblastic Interferon in myeloma. However, further studies are necessary to determine the population of patients most likely to benefit from treatment, the best modalities, possible special indications, dose schedules and duration of treatment. As it is not myelosuppressive it could be indicated in the frequent situation of advanced myeloma with bone marrow failure, contra-indicating combination chemotherapy.

Aged↗
PubMedDate not supplied

Treatment of lymphoid neoplasias with interferon. II. Human leucocyte alpha-interferon in chronic lymphatic leukemia (CLL). PHase I-II trial.

Nine patients with chronic lymphoid leukemia (CLL) were treated with subcutaneous human (leukocyte) interferon a (IF a). In the first part of the study, 7 patients received intermittent 10 day courses, with free intervals of 10 to 15 days and with dose escalation in the same patient from cycle to cycle from 1.5 to 6 X 10(6) units daily, if tolerated. As we observed a decrease of peripheral lymphocytosis with low doses, and as high doses gave more side-effect in the second part of the study, 4 patients (including two who has previously received intermittent courses) were treated for three months or more at a dose of 1.5 X 10 units daily. Tumor mass reduction was seen in only three patients. However, a significant decrease in peripheral lymphocytosis was seen in 7 patients who were sustained in the continuous treatment group; with relapse at treatment discontinuation in one patient and despite continuation in another. Immune monitoring with currently available T, B, NK and macrophage tests, showed a good correlation between NK cell activity and clinical response, in this group of patients. Further studies are warranted to determine the best modalities of treatment, the population of patients likely to benefit from such treatment, the possible special respective indications of IF, and also the other treatments of CLL. One can already consider as a reasonable indication CLL presentations with myeloid insufficiency as IF is not myelotoxic, contrary to chemotherapy.

Aged↗
PubMedDate not supplied

Induction of erythropoiesis with erythrocyte production in bone marrow cell culture "in vitro".

In the system of long-term bone-marrow culture described by Dexter et al., the differentiation of hematopoietic stem cells into erythropoietic cells is not observed. In this system, bone marrow are grown in a medium supplemented with horse serum. We describe here the induction of erythrocytic maturation in the bone-marrow culture by the addition of 5% fetal calf serum, one or two weeks after seeding the bone-marrow cells. We obtained the persistance up to 5 weeks of erythrocytic production. This phenomenon does not depend on the presence of erythropoietin in fetal calf serum.

Animals↗
PubMedDate not supplied

Are interleukin-2 and interleukin-15 tumor promoting factors for human non-hematopoietic cells?

Human normal non hematopoietic cells of mesenchymal and neuroectodermal origin may express functional IL-Rs. For instance, in these cell types, IL-2 can stimulate proliferation (endothelial, intestinal and nervous cells) or modify the expression of adhesion molecules (fibroblasts) or inhibit proliferation (bone marrow stromal cells). Therefore, some cytotoxic effects described during IL-2 biotherapy could be due to a direct interaction between IL-2 and non-hematopoietic tissues. The expression of functional IL-2-R has also been reported in several human cell lines derived from solid tumors. In some instances IL-2 inhibits cell growth (head and neck, gastric and renal carcinomas), but in other tumors, growth stimulation and increased expression of markers of tumor progression have been reported (intestinal, breast, and lung carcinomas, gliomas, fibrosarcomas and melanomas). Additionally, secretion of biologically active IL-2 has been reported in some melanoma and breast cancer cell lines. Transcripts for the novel cytokine IL-15, which utilizes the beta and gamma chains of the IL2-R, have been found in melanoma cells and anti-IL-15 mAbs inhibit HLA class I expression in these cells. Therefore these cytokines may modify, inside a tumor, the behavior of both stromal and neoplastic cells. All these data may have important implications in our understanding of tumor host interactions and in future strategies of immunotherapy.

Endothelium, Vascular↗