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F Lemoine

Publications and source records attributed to F Lemoine.

At least 37 records · Page 2Linked to original sources
PubMed1992

The tetrapeptide AcSDKP, an inhibitor of the cell-cycle status for normal human hematopoietic progenitors, has no effect on leukemic cells.

The tetrapeptide acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) inhibits the entry into DNA synthesis of murine spleen colony-forming units (CFU-S) and protects these cells during chemotherapy. This synthetic peptide also inhibits the growth of normal human marrow progenitors granulocyte-macrophage colony-forming units (CFU-GM) and erythroid burst-forming units (BFU-E) and decreases their percentage in DNA synthesis at nanomolar concentration. In view of its clinical application as a marrow protector, we have investigated its effects on malignant cells. Studies were carried out on HL-60 cells and on fresh leukemic cells from patients with either chronic myeloid leukemia (CML) or acute myeloid leukemia (AML). Results showed that AcSDKP, whatever the doses used, did not modify the proliferation of both HL-60 cells and AML cells even when enhanced by stimulating factors such as interleukin 3 or granulocyte-macrophage colony-stimulating factor (GM-CSF). In addition, no change in the number and the percentage in S-phase of both HL-60 clonogenic cells and CML progenitors was observed. Our data clearly demonstrate that the tetrapeptide AcSDKP was ineffective on leukemic cells and therefore by acting selectively on normal progenitors represents a potent therapeutical agent for the protection of normal bone marrow progenitors during chemotherapy.

Adult↗
PubMed1990

Inhibition of human bone marrow progenitors by the synthetic tetrapeptide AcSDKP.

The purpose of this work was to study the effects of a tetrapeptide, acetyl-N-Ser-Asp-Lys-Pro (AcSDKP), an inhibitor of spleen colony-forming unit (CFU-S) entry into DNA synthesis, on human progenitor cells. Normal human mononuclear cells were incubated with concentrations of the synthetic tetrapeptide ranging from 10(-12) to 10(-7) M for 1.5 and 24 h and then plated in methylcellulose in the presence of human placenta-conditioned medium and recombinant human erythropoietin. The proportion of progenitors in DNA synthesis was determined by the thymidine suicide assay. Incubation with AcSDKP for 24 h leads to a significant inhibition of granulocyte-macrophage colony-forming unit (CFU-GM) and erythroid burst-forming unit (BFU-E) growth and in some cases of erythroid colony-forming unit (CFU-E) growth. The inhibition, which was never greater than 50%, was obtained with 10(-10)-10(-9) M AcSDKP, whereas no effect was seen at higher concentrations. The percentage of CFU-GM, BFU-E, and CFU-E in DNA synthesis was significantly reduced in five consecutive patients after incubation of cells for 24 h with inhibitory doses of the peptide, indicating that it is active on cycling cells. Therefore, these studies provide the first evidence that the tetrapeptide AcSDKP, originally obtained from bovine marrow and now chemically synthesized, is able to inhibit the in vitro growth of human progenitors and to decrease their proportion in cell cycle.

Amino Acid Sequence↗
PubMed1990

[Hemorrhagic rectocolitis and carcinoma of the colon. Contribution of flow cytometry. Report of 3 cases].

Carcinoma complicating ulcerative colitis, although an uncommon event, is well known but follow-up of patients to detect high-grade dysplasia as a potential indicator for colectomy is very difficult. Retrospective morphological and cytometrical analysis of three resected colons harboring carcinoma coming from patients with ulcerative colitis were performed. It allowed to confirm the value of this technique. Histogram patterns varied between narrow unimodal in quiescent mucosa to broad unimodal with high IP (proliferation index) in regenerative mucosa and aneuploid in high dysplasic mucosa and carcinoma. In addition to histopathology and in spite of a patchy distribution of aneuploidy, different degrees of dysplasia in mucosa and technical sensibility DNA (desoxyribonucleic acid) analysis in long-standing ulcerative colitis seems to be helpful in the detection of potential malignancy.

Adult↗
PubMed1989

[Transient ischemic colitis. Diagnostic value of patchy epithelial atrophy].

Microscopic findings, observed in 58 colonic biopsies, have been described by the authors during transient ischemic colitis. One of these lesions, closely associated with the diagnosis and named patchy tubular atrophy, was considered as a marker for ischemia. Patchy tubular atrophy was observed at the beginning of the disease, and was regularly associated with normal and necrotic areas. Three morphological aspects characterized this condition: --non secretory glandular crypts covered with rudimentary basophilic epithelium, --crypts regularly distributed in a geometrical pattern with intact connective spaces, --absence of interstitial inflammatory infiltrate, and presence of fibrinous thrombosis with extravasation of erythrocytes. This morphologic pattern was specific enough to rule ou the other inflammatory or trophic bowel diseases. Therefore patchy tubular atrophy, observed during transient ischemic colitis, was considered by authors as a distinct entity.

Aged↗
PubMed1988

Activation of multiple hemopoietic growth factor genes in Abelson virus-transformed myeloid cells.

We have recently shown that Abelson murine leukemia (A-MuLV) virus can transform cells in large mixed colonies to give tumorigenic myeloid cell lines capable of autonomous growth in vitro. Initial studies revealed that granulocyte-macrophage colony-stimulating factor (GM-CSF) production was consistently activated in these cells. Using a sensitive S1 RNA mapping technique and additional bioassays, we have now obtained evidence of expression of other hemopoietic growth factor genes. Uniformly 32P-labeled, single-stranded DNA probes (greater than 4 x 10(8) cpm/micrograms) were generated for interleukin 3 (IL-3) and GM-CSF using pTZ based vectors. IL-3 mRNA was detected in four of four cloned transformants (from two different infections) at approximately 1% of the level seen in pokeweed mitogen (PWM)-stimulated spleen cells. GM-CSF mRNA was detected in the two clones that showed the highest IL-3 mRNA levels. Medium conditioned by these cells was able to stimulate IL-3-dependent 32D cells, and IL-3- and GM-CSF-dependent B6SUtA cells, and also supported the growth of a variety of single and multilineage colonies in assays of mouse marrow cells even in the presence of neutralizing antibodies to GM-CSF. Rearrangements of the IL-3 and GM-CSF genes were not apparent by Southern blot analysis. Additional bioassays revealed the presence of two other growth factors: IL-6 (hybridoma growth factor or Ifn-beta 2) assayed on B13.29 cells, a factor-dependent murine B-cell hybridoma; and a new pre-B-cell stimulatory factor different from any of the above. Elucidation of the mechanism underlying this phenomenon may provide important insights into the regulation of hemopoietic growth factor gene expression and the role such genes play in human leukemogenesis.

Abelson murine leukemia virus↗
PubMed1987

[Intestinal stenosis, sequelae of necrotizing enterocolitis. Analysis of 9 cases].

Intestinal necrosis was a complication of necrotizing enterocolitis of the newborn in 9 of 42 cases. In 6 neonates it followed medical treatment of the enterocolitis, presenting in this case as an occlusive syndrome. After surgical treatment (3 cases) the diagnosis was made from radiologic imaging prior to reestablishment of digestive continuity. Surgery was necessary in all cases, and procedures used are described (technic, date of operation). The prognosis of enterocolitis is worsened by this stenosis (1 death in the 9 cases).

Enterocolitis, Pseudomembranous↗
PubMed1986

[Acute colectasia in patients on artificial respiration. 10 cases].

Acute colectasia may occur in patients under mechanical ventilation. Causative factors include haemodynamic changes, potassium loss, underlying pathology (chronic respiratory failure, cirrhosis) and especially morphine-like compounds used for sedation. Analysis of the results obtained with various treatments suggests that surgery is not justified: caecal perforation is extremely rare in a previous healthy colon; any surgical procedure is hazardous in this type of patient, and colectasia frequently regresses under appropriate medical treatment, even though mechanical ventilation is pursued.

Acute Disease↗
PubMed1986

Phenotype of early erythroblastic leukemias.

Nine cases of early erythroblastic leukemia, unidentified by usual criteria, have been diagnosed using a panel of antibodies. Three cases arose in patients with Down's syndrome, one in a patient with therapy-related leukemia, and four patients were in blast crisis of chronic myeloid leukemia; only one case arose de novo. Blast cells could be assigned to two main stages of erythroid differentiation: presence of all erythroid-specific proteins in two patients, a phenotype corresponding to an immature erythroblast; absence of the erythroid markers such as glycophorin A and spectrin in the presence of carbonic anhydrase isoenzyme I, ABH group antigens, and the antigen defined by FA6 152 monoclonal antibody in six patients, a phenotype related to a late erythroid progenitor (CFU-E). One patient had an intermediate phenotype. All patients except one demonstrated a megakaryocytic component. In three patients, chromosomal abnormalities were present, detected both in blasts and in erythroid colonies. In conclusion, these findings indicate that most "cryptic erythroleukemias" are blocked at a "CFU-E-like" stage of differentiation, it may be a frequent event in Down's syndrome and chronic myeloid leukemia, and these erythroleukemias are phenotypically heterogeneous.

Acetylcholinesterase↗
PubMed1986

A prospective study of the value of bone marrow erythroid progenitor cultures in polycythemia.

The diagnostic value in polycythemia of the presence of endogenous erythroid colonies derived from bone marrow cells (EECs) was assessed in a prospective study on 108 patients referred for polycythemia (Hb greater than g/dL in men, greater than 16 g/dL in women) with normal plasma volume by comparison with the standard criteria, the bone marrow grade, and the serum erythropoietin (Epo) level. Total red cell volume (TRCV) was high (greater than 36 mL/kg in men, 32 mL/kg in women) in 87 cases (group A) and slightly increased in 21 cases (group B). Standard criteria were applicable in 63 of 108 cases (57%); 46 were PV and 17 were secondary polycythemia (SP). Standard criteria were nonapplicable in 45 cases. EECs were present in 65 cases (60%) with a ratio of EEC/Epo-stimulated colonies of 39.5% +/- 18% (extremes 10% to 80%). EECs were noted in 43 of 46 polycythemia vera (PV) and 0 of 17 SP. Among the 45 unclassified cases, EECs were noted in 22: 18 of 29 cases from group A (10 with 2 major and 1 minor criteria; 8 with 2 major criteria) and 4 of 16 cases from group B (with variable standard criteria, 2 belonging to a PV family). In group A, there was a positive significant correlation between EECs and the presence of two major and 1 minor criteria (P less than .0001). In group B, there was a positive significant correlation between EECs and the presence of at least 1 major criterion and 2 minor criteria or a family background (P less than .0001). The unclassified polycythemias with EECs in the bone marrow are characterized by a bone marrow grade and a mean serum Epo level not different from that of patients with PV and an active course of the disease. The unclassified polycythemias without EECs in the bone marrow are a heterogeneous group corresponding in some cases to SPs of unknown origin (slightly increased bone marrow grade and/or high serum Epo level), and in others cases to spurious polycythemias (normal bone marrow grade and/or normal Epo level). In conclusion, EECs were of great value in differentiating PV from SP (P less than .001), and in allowing the diagnosis of PV in the absence of all the standard criteria even when TRCV was slightly increased. In our study, EEC improved the classification of polycythemia by 22%. The recommended diagnostic steps for the evaluation of polycythemia must be reconsidered.

Adult↗
PubMed1985

Vindesine-prednisone in the treatment of blast crisis of chronic myeloid leukemia.

Eight patients with chronic myeloid leukemia in blast crisis were treated with a combination of vindesine and prednisone. Complete remission was achieved in three patients; partial remission was achieved in three. All six responders received maintenance treatment with hydroxyurea and 6-mercaptopurine. The median duration of survival was 9 months. Two patients had long-term survival: one survived 32 months and the other is alive after 30 months. These data suggest that vindesine-prednisone polychemotherapy might improve the prognosis of blast crisis in chronic myeloid leukemia.

Adult↗