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Biomedical subjects

P Herve

Publications and source records attributed to P Herve.

At least 37 records · Page 2Linked to original sources
PubMed1997

Production and consumption of the tetrapeptide AcSDKP, a negative regulator of hematopoietic stem cells, by hematopoietic microenvironmental cells.

This study was performed to evaluate the role of human microenvironmental cells in the metabolism of AcSDKP, a physiological inhibitor of hematopoietic stem cells. Using long-term marrow cultures (LTMCs), whose medium already contained a baseline value of AcSDKP, we found after 2 weeks a net output in the culture supernatant indicating that release by cells from the adherent layer was superior to consumption of the peptide. Since human microenvironmental cells consist of macrophages and vascular smooth-muscle-like stromal cells we generated pure populations of macrophages (by culturing cord blood cells in the presence of granulomonocytic colony-stimulating factor) and of stromal cells (generated by stromal colonies). We found in supernatants of macrophage cultures a significantly (p < 0.01) increased level of AcSDKP (compared with value in medium) while in supernatants of stromal cell cultures the level was decreased. Cell content of angiotensin-converting enzyme (ACE) in stromal cells was higher than in macrophages, which suggests a degradation of AcSDKP by stromal cells because of their higher amount of ACE. Finally, we analyzed the content of AcSDKP in adherent layers of LTMCs (with or without extracellular matrix [ECM] components), macrophages, and stromal cells. We found levels of AcSDKP of 1.5 pMol per 106 cells in extracts from macrophages or from stromal cells. On the contrary, extracts from primary layers of LTMCs contained 3 times more AcSDKP; however, after treatment of primary layers by collagenase, AcSDKP level fell to 1 pMol per 10(6) cells. Immunofluorescence using an anti-AcSDKP monoclonal antibody showed an extracellular network in certain areas of LTMCs. This study shows that 1) macrophages synthesize and release in the supernatant AcSDKP, 2) stromal cells probably degrade the peptide via ACE, and 3) components of the ECM from LTMCs serve as a reservoir for the peptide. These results are reminiscent of what has been described for growth factors, produced by microenvironmental cells, and stored in the ECM in close vicinity to hematopoietic precursors.

Adipose Tissue↗
PubMed1996

Evidence that a transient enhancement of endogenous hematopoiesis contributes significantly to the favorable outcome following interleukin 1 pretreatment and allogeneic bone marrow transplantation.

The administration of IL-1, a potent radioprotective cytokine, before allogeneic BMT is associated with an early transient increase of circulating granulocytes, successful engraftment, and accelerated multilineage hematopoietic recovery. We have examined the effects of IL-1 alpha pretreatment on the engraftment of an allogeneic BMT unable to sustain survival by itself after a lethal irradiation: (1) transplantation of a limited amount of marrow cells and (2) transplantation several days after irradiation. IL-1 was unable to allow the engraftment of an early quantitatively inadequate BMT. However, delayed BMT with limited amounts of marrow cells was associated with engraftment in IL-1 pretreated recipients. Engraftment of a late (day 12) BMT in these IL-1-pretreated mice was comparable to the engraftment of a similar day 12 allogeneic BMT in non-IL-1-pretreated mice rescued from the lethal irradiation by an early (day 1) syngeneic graft. These findings demonstrate that IL-1 pretreatment can result in a dissociation between BMT-induced survival and engraftment and suggest that the favorable effects of IL-1 pretreatment in an allogeneic BMT setting are mainly mediated through a transient enhancement of endogenous hematopoiesis and not through a direct effect on the allogeneic stem cells present in the marrow graft.

Animals↗
PubMed1996

Treatment of acute myelogenous leukaemia in patients aged 50-65: idarubicin is more effective than zorubicin for remission induction and prolonged disease-free survival can be obtained using a unique consolidation course. The Goelam Group.

From December 1987 to June 1992, 251 patients aged 50-65 with de novo acute myelogenous leukaemia (AML) were recruited to a multi-institutional randomized clinical trial. Induction therapy consisted of Ara-C (200 mg/ m2, continuous infusion, days 1-7) with either zorubicin (ZRB) (200 mg/m2, i.v., days 1-4) or idarubicin (IDR) (8 mg/ m2, i.v., days 1-5). Consolidation therapy consisted of a single course of intensive chemotherapy with high-dose Ara-C (3 g/m2, 3 h infusion, q 12 h, days 1-4) and m-Amsa (100 mg/m2/d, i.v., days 5-7). The complete remission (CR) rate was (73%) with Ara-C/ IDR versus (60%) with Ara-C/ZRB (P = 0.033). In multivariate analysis, factors found to be significant in predicting CR were normal karyotype and treatment with IDR. With a median follow-up of 73 months, the median disease-free survival (DFS) duration of all CR patients and the probability of CR at 6 years were 17 months and 29%. In multivariate analysis the only factor associated with an increased DFS duration was a normal karyotype. The median event-free survival (EFS) duration for all evaluable patients and the median overall survival duration for all eligible patients were respectively 7 and 12 months without any difference between induction arms. The study shows that in patients aged 50-65 idarabicin is more effective than zorubicin for remission induction. However, the type of anthracycline did not influence overall survival duration. Using a unique consolidation course, we observed a prolonged DFS which compares favourably with results obtained with more prolonged consolidation therapy or maintenance treatment.

Aged↗
PubMed1996

The purification of CD34 cells from human cord blood: comparison of separation techniques and cytokine requirements for optimal growth of clonogenic progenitors.

This study was performed to assess the methods which gave maximal recovery of purified CD34/45+ cells from a cord blood specimen and optimal growth of progenitors cultured from the purified cells. Cord blood samples were separated using Percoll gradients (either one (1.080) or two successive (1.080 and 1.068) gradient(s)) and commercially available devices for CD34+ cell isolation (affinity columns as manufactured by CellPro Inc. or immunomagnetic separation procedure as devised by Baxter Inc.). "CellPro' or "Baxter' techniques gave similar results in terms of nucleated, CD34/45+ and progenitor cell concentration; however, the yield of CD34/45+ cells in the CD34+ enriched fraction was significantly higher when using the "CellPro' technique. We also found significantly higher numbers of CD34/45+ cells in the CD34+ enriched final fraction when using only one, 1.080, Percoll density gradient in the first separation step. Using one density separation step followed by the "CellPro' technique, we obtained an average of 3 x 10(6) purified CD34/45+ cells from samples containing 8.5 x 10(8) nucleated cells. Granulomonocytic progenitors (CFU-GM) and mixed progenitors (CFU-GEMM) cells from light-density and purified CD34/45+ cell fractions were evaluated. We found that 20-30% of the light-density cells and the purified CD34/45+ cells, yielded a granulomonocytic colony in serum free medium in the presence of interleukins 3 and 6, erythropoietin, granulomonocytic and granulocytic colony-stimulating factors and stem cell factor. The addition of tumour-necrosis factor alpha to the cocktail significantly improved the growth of CFU-GEMM allowing 10% of the purified CD34/45+ cells to yield a mixed colony, which confirms the role of this cytokine on CD34+ cells from cord blood. This study provides an improved method for recovery of CD34/45+ purified cells and their colony formation. These methods may serve as a basis for studies on CD34/45+ cell amplification and gene transfer.

Antigens, CD34↗
PubMed1996

Comparative preclinical study of three bone marrow purging methods using PCR evaluation of residual t(14;18) lymphoma cells.

The t(14;18) chromosomal translocation occurring in most follicular lymphomas can be exploited by a Bcl2/JH polymerase chain reaction (PCR) to detect residual disease and to monitor the effectiveness of ex-vivo tumor cell immunological purging. We first demonstrated the 10(-5) Bcl2/JH PCR sensitivity with serial dilutions of OCY-LY8 lymphoma cell lines in normal mononuclear cells; and then the specificity and reproductibility of this technique by analysing follicular and non follicular lymphoma samples. With the Bcl2/JH PCR, we tested the efficiency of three marrow purging protocols with an experimentally contaminated bone marrow either treated by three anti-B cell monoclonal antibodies (mAb) followed by three rounds of rabbit complement or two rounds of immunomagnetics beads. Samples obtained after each purging were amplified by Bcl2/JH PCR and hybridized with PFL3 probe. We were able to produce a 2 to 3 log tumor cell reduction after three rounds of complement and a 4 to 5 log reduction after two rounds of beads. This study showed that it is feasible to use the Bcl2/JH PCR technique for residual cell lymphoma detection in patients undergoing intensive chemotherapy or BM transplantation. These results indicate that ex-vivo immunomagnetic BM purging is probably superior to complement mediated lysis for the eradication of B lymphoma cells from the marrow of patients undergoing autologous transplantation.

Animals↗
PubMed1996

Biological assessment and MRI monitoring of the therapeutic efficacy of a monoclonal anti-T CD4 antibody in multiple sclerosis patients.

An initial group of 21 patients plus a second group of 14 patients with active multiple sclerosis (MS) (18 progressive and 17 relapsing-remitting forms) were treated with a murine monoclonal anti-T CD4/BF5 antibody as part of a phase I open trial. Tolerance was relatively good: minor general side-effects occurred in 22 patients only upon the first mAb infusion. One year later, functional disability was stabilised in only six of the 35 patients and after 2 years in two patients only (among 21). One year after treatment, nine of the 17 relapsing-remitting patients were relapse-free. CD4 counts decreased dramatically 2 h after treatment. These counts were back to baseline counts at 3 months. A transient increase was found in IL-6 and TNF alpha levels 2 h after treatment, which probably accounts for the observed side effects. Cell adhesion molecule levels were not modified. Serial MRI scans were performed in the second group of 14 patients. In all of these patients, lesion modifications were observed in the three scans performed prior to treatment. Yet, no changes in the lesions were noted on the MRI scans performed over the following 3 months. These findings demonstrate the feasibility of this treatment insofar as it induced a marked CD4 lymphocyte depletion. However, it did not seem to stabilise the evolution of the disease--although one must be careful in drawing such conclusions in a phase I trial--or to curb the evolution of MRI-documented lesions.

Antibodies, Monoclonal↗
PubMed1995

Inhaled nitric oxide as a screening vasodilator agent in primary pulmonary hypertension. A dose-response study and comparison with prostacyclin.

To investigate the capacity of the pulmonary vascular bed to acutely vasodilate, we examined in 35 consecutive patients with primary pulmonary hypertension (PPH), the hemodynamic effects of incremental inhalation periods of an air-NO mixture at different concentrations (10, 20, and 40 ppm), and compared them with those of an acute infusion of prostacyclin (PGI2). An individual pulmonary vasodilator response was defined by a fall in total pulmonary resistance (TPR) > or = 30% relative to mean TPR baseline value. Thirteen patients were responders and 22 were nonresponders to both drugs, and they did not significantly differ in overall baseline characteristics except for mean right atrial pressure (p < 0.03). In responders, both drugs produced similar individual vasodilator response. Changes in mean pulmonary arterial pressure and TPR observed during NO and PGI2 were closely correlated (r2 = 0.9, p < 0.001, and r2 = 0.7, p < 0.01, respectively). The vasodilator response to NO was not concentration-related with a maximal effect obtained at 10 ppm. Combination of both drugs did not lead to any additive vasodilator response. Unlike PGI2, NO did not induce any systemic effect, no adverse reaction, but a moderate increase in methemoglobin. Inhaled NO at low dose (10 ppm) appears to be an effective, safe, and reliable substitute for PGI2 in screening for acute pulmonary vasodilator responsiveness during therapeutic assessment of patients with PPH.

Adult↗
PubMed1995

Pilot clinical trial of an anti-TNF alpha monoclonal antibody for the treatment of septic shock.

OBJECTIVE: To determine the safety and pharmacokinetics of an anti-tumour necrosis factor (TNF alpha) monoclonal antibody in the treatment of septic shock, and to evaluate the biological evolution of cytokine response. DESIGN: Open-label, prospective, pilot trial with escalating doses of a murine monoclonal antibody (B-C7) directed against TNF alpha. SETTING: University medical centre intensive care unit. PATIENTS: Nine patients with septic shock, who received standard supportive care and antimicrobial therapy in addition to the anti-TNF alpha antibody. INTERVENTIONS: Patients were treated intravenously with one of three escalating doses of B-C7 monoclonal antibody (MoAb): 0.4 mg/kg, 0.8 mg/kg, 1 mg/kg. RESULTS: MoAb was well tolerated despite the development of human anti-mouse antibodies (HAMA) for each patient; B-C7 plasma levels were dose-dependent. At study entry, TNF alpha and IL-6 levels were detected in six and seven patients respectively; IL-1 levels were low and interferon-gamma was undetectable. CONCLUSIONS: No side effects were noted during treatment regardless of the dose used; however, further studies are needed to determine the clinical efficacy of this agent in septic shock.

APACHE↗
PubMed1995

Sequential use of three monoclonal antibodies in corticosteroid-resistant acute GVHD: a multicentric pilot study including 15 patients.

We previously demonstrated the potential of anti-IL-2R and anti-TNF alpha moAbs in the treatment of acute graft-versus-host disease (GVHD). However, one major problem was the recurrence of acute GVHD on treatment discontinuation. To target the two main effectors of acute GVHD lesions, T and NK cells on the one hand and TNF alpha on the other, we combined anti-CD2 and anti-TNF alpha moAbs. Then to prevent acute GVHD recurrence, we administered anti-IL-2R moAbs known for their inhibitory effect on activated cells. We included 15 patients with steroid-resistant acute GVHD. Seven were grafted from a genotypically-identical sibling, 5 from HLA-matched unrelated donors and 3 from partially-matched related donor. Prophylaxis of acute GVHD consisted of cyclosporin A +/- methotrexate or corticosteroids. Before treatment 6 patients had grade II, 2 patients grade III and 7 patients grade IV acute GVHD. Anti-TNF alpha (B-C7) moAbs (10 mg/day/4 days) were combined with anti-CD2 (B-E2) moAbs (10 mg/day/10 days) on the fifth day (day 5), anti-IL-2 receptor (B-B10) moAbs were given at 10 mg/day/10 days followed by 5 mg every other day for another 50 days. On day 15, 5 patients achieved a complete remission, 4 a very good partial response (62% a good response), 2 had a partial response and 4 did not respond. GVHD recurred in 4 of the 9 responders, although anti-IL-2R moAb treatment was maintained. Three patients are long-term survivors without chronic GVHD.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1995

Nontransformed colony-derived stromal cell lines from normal human marrows. I. Growth requirement and myelopoiesis supportive ability.

We report a new method for generating nontransformed human stromal cell lines with a replicative potential of 20 to 25 doublings yielding 10(6) to 3 x 10(7) cells after 4 to 6 weeks. Cells from week-3 to -6 adherent layers of human long-term bone marrow cultures (LTBMC) were plated in methylcellulose in the presence of 20 U/mL interleukin-1 beta (IL-1 beta) and 200 U/mL tumor necrosis factor-alpha (TNF-alpha). After 2 to 3 weeks, we obtained 180 +/- 14 colonies per 10(5) cells seeded. These well-delineated colonies with a dense central core consisted of up to several hundred tightly packed, identical, large refractile cells. Colonies were determined to be clones by sequential examination of the cultures and the linear relationship between the number of colonies counted and cells seeded. Colony-derived cell lines (CDCL) were developed by seeding individual colonies in long-term culture medium (LTCM) supplemented with 20 ng/mL basic fibroblast growth factor (bFGF). The selection of colonies yielding lines with high proliferative capacity was due to the presence of IL-1 beta and TNF-alpha in the semisolid medium. The most effective concentrations for clonal selection were 200 U/mL TNF-alpha and 20 U/mL IL-1 beta. The growth of CDCL in liquid culture depended on the presence of bFGF, with the most effective concentration at 20 ng/mL. CDCL were able to maintain the output of colony-forming units granulocyte/macrophage and burst-forming unit-erythrocyte (CFU-GM and BFU-E) for several weeks from cocultured CD34+ marrow cells. The weekly CFU-GM and BFU-E output from weeks 2-5 was at least the same as observed when using passaged adherent layers. CDCL represent a progenitor cell population for stromal cells that may prove a suitable model for the study of the relationship between marrow stromal cells and hematopoiesis.

Bone Marrow Cells↗
PubMed1994

In situ hybridization for the detection of cytomegalovirus in blood or bone marrow leucocytes after allogeneic bone marrow transplantation.

We report a study of CMV detection by a nonradioactive in situ hybridization (ISH) technique using a biotinylated CMV-DNA probe. The method was applied to blood and bone marrow cells and its results were compared with those of other currently used techniques. First, we analysed peripheral leucocytes on blood donors, and, after comparison with PCR, we obtained 75% sensitivity and 87% specificity rates. We then studied four BMT recipients during the first 105 d post-transplant. A positive signal was detected as a predominantly nuclear staining. The detection of an ISH-positive signal occurred at least 8 d before CMV isolation from viral culture. The number of positive cells was variable according to the patients' clinical evolution, showing a dramatic increase of labelled cells in viraemic patients and then a decrease until complete disappearance of labelled cells when an efficient anti-viral treatment was initiated. This study suggests that the detection of CMV-DNA by ISH performed on peripheral leucocytes is a valuable tool for the early diagnosis of CMV infection and could lead to the initiation of optimal ganciclovir treatment.

Bone Marrow↗
PubMed1994

Pulmonary hypertension in patients with human immunodeficiency virus infection. Comparison with primary pulmonary hypertension.

BACKGROUND: Previously reported cases of patients with pulmonary hypertension (PH) and human immunodeficiency virus (HIV) infection are poorly documented regarding baseline hemodynamics and potential for pulmonary vasodilatation. The purpose of this report was to compare HIV-infected patients who had PH with non-HIV-infected patients who had primary pulmonary hypertension (PPH) in terms of (1) clinical characteristics, (2) hemodynamics in baseline conditions and during a short-term vasodilator trial with epoprostenol, and (3) survival. METHODS AND RESULTS: Between April 1987 and August 1992, 20 HIV-infected patients with PH and 93 non-HIV-infected patients with PPH were referred to our department. At the time of referral, baseline right-side heart hemodynamics were obtained in addition to demographic variables and medical history. A short-term vasodilator trial with epoprostenol was performed in 19 of 20 HIV-infected and 86 of 93 non-HIV-infected patients. Outcome and survival were analyzed and compared for both groups (22 transplant recipients were excluded from the group of patients with PPH). At the time of diagnosis of PH, HIV-infected patients significantly differed from non-HIV-infected patients in age (32 +/- 5 versus 42 +/- 13 years; P < .05) and degree of disability (New York Heart Association functional class III or IV, 50% versus 75%; P < .01). The proportion of disease states known to be associated with PPH (Raynaud's phenomenon, migraine, collagen disease without overt symptoms and signs, or a positive family history of PPH) was similar in the two groups. HIV-infected patients had a severe but significantly lower level of PH than patients with PPH. The percentage of responders to epoprostenol and the level achieved in pulmonary vasodilatation were similar in the two groups. PH was the cause of death in 8 of the 10 HIV-infected patients who died within 1 year after the diagnosis of PH. Overall survival was poor and not significantly different between the two groups. Pathological findings in lung tissue obtained from 3 HIV-infected patients were close to those seen in most of the lung specimens available from 27 patients with PPH and resembled plexogenic pulmonary arteriopathy. CONCLUSIONS: These results support the view that HIV infection may now be regarded as another common disease state that can be associated with PPH development. The lower initial severity in HIV-infected patients may be due to the close medical attention usually devoted to such patients, who may account for an earlier diagnosis. However, the overall survival rate of HIV-infected patients with PH appeared to be as poor as in non-HIV-infected patients with PPH.

Adult↗
PubMed1994

Are patients with acute leukaemia, alive and well 2 years post bone marrow transplantation cured? A European survey. Acute Leukaemia Working Party of the European Group for Bone Marrow Transplantation (EBMT).

We investigated the occurrence of late events (beyond 2 years) in patients with acute leukaemia who received an allogeneic (BMT) (n = 1059), or an autologous bone marrow transplantation (ABMT) (n = 656) in Europe during the period from January 1979 to December 1990. Patients with no recurrence of leukaemia at 2 years had overall 82% chance of being alive in complete remission at 9 years following transplantation regardless of the nature of the leukaemia, the status at transplant, and the type of transplant. The incidence of late relapses continuously decreased with time. The latest relapses in acute myelogenous leukaemia (AML) were observed following BMT at 6.6 years in a patient transplanted in first remission (CR1) and at 3.7 years in a patient transplanted in second remission (CR2), and following ABMT at 6 years and 5.1 years respectively. The latest relapses in acute lymphoblastic leukaemia (ALL) were observed following BMT at 4 years in a patient transplanted in first remission (CR1) and at 6.8 years in a patient transplanted in second remission (CR2), and following ABMT at 5.3 years and 4.5 years respectively. Several factors predictive for late relapse or death were identified. Patients allografted experienced a lower frequency of late relapse than patients autografted. Of the numerous other prognostic factors studied, female sex in AML, the use of total body irradiation (TBI) in ALL and status in CR1, rather than CR2-3, for both ALL and AML allografted were correlated with a lower relapse incidence. The use of TBI in ALL was also associated with a better LFS and survival. The absence of acute graft-versus-host disease (GVHD) in allografted AML correlated with better LFS and better survival, but had no influence on the relapse incidence. This study indicates that patients alive and well at 2 years post transplant have a very high probability of being cured, but the possibility of late relapse still remains.

Adolescent↗
PubMed1993

Role of stromal cells and macrophages in fibronectin biosynthesis and matrix assembly in human long-term marrow cultures.

Fibronectin is a major component of the extracellular matrix of adherent layers of human long-term marrow cultures where it may stabilize the extracellular matrix network and provide adhesion sites for primitive hemopoietic cells. This study was devised to analyze the role of adherent cell populations in fibronectin synthesis, matrix assembly, and degradation. In cultures performed under the conditions described by Gartner and Kaplan, immunoprecipitation after metabolic labeling showed that adherent cells synthesized a fibronectin variant comprising the EDa domain and lacking the EDb one. Vascular smooth muscle-like stromal cells were the cell subset responsible for this synthesis. Once synthesized by stromal cells, EDa+fibronectin was secreted into the supernatant and incorporated into the extracellular matrix. The cumulation in the extracellular matrix was predominant by weeks 5 and 6 of culture, when a decrease in the stromal cell intracytoplasmic content of fibronectin was observed. Stromal cells from a transformed cell line, L2Ori-, were also able to synthesize the EDa+fibronectin variant, although for these cells the assembly into the extracellular matrix was partly impaired. Besides stromal cells, other cell types participated in fibronectin synthesis: early-adhering granulomonocytic cells and macrophages appearing later in culture were able to synthesize an EDa-, EDb- fibronectin variant, clearly distinct from the EDa+ variant produced by stromal cells. Studies on cultures in which macrophage growth was stimulated at the expense of stromal cells by adding granulocyte-macrophage colony-stimulating factor (50 ng/mL) to the culture medium showed a striking decrease in amounts of fibronectin measured in the adherent layer. This decrease was caused by a lack of incorporation of fibronectin in the extracellular matrix, disclosing a major difference between stromal cells and macrophages in terms of matrix assembly. This study confirms the similarity between stromal cells and vascular smooth muscle cells, because in vivo subendothelial intimal aortic smooth muscle cells and cultured smooth muscle cells from the aortic media express the EDa+, EDb- fibronectin variant. Furthermore, our results suggest that the level of fibronectin in adherent layers is regulated by stromal cells and macrophages. The balance between these two cell populations may therefore be crucial for the local control of hemopoiesis by regulating the extracellular fibronectin available for the adhesion of hematopoietic cells. Our data indicate that it may be essential to study the adhesion of stem cells to EDa+, EDb- fibronectin instead of EDa-, EDb- soluble fibronectin, as found in human plasma.

Bone Marrow↗