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Biomedical subjects

P Colombat

Publications and source records attributed to P Colombat.

At least 91 records · Page 5Linked to original sources
PubMed1991

Induction of granulocytic maturation in acute myeloid leukemia by G-CSF and retinoic acid.

AML cells were cultured free of serum with G-CSF in combination with all-trans-retinoic acid (RA), prostaglandin E2 or 8-bromocyclic AMP to see whether the maturation blockade of these cells could be overcome. The combination G-CSF + RA was most effective in inducing morphologic maturation, i.e. in 7/10 cases. Morphological alterations in response to G-CSF + RA indicated progression of the cells along the granulocytic pathway towards metamyelocytes and granulocytes. However, morphologically mature AML cells remained negative for myeloperoxidase and Sudan black stainings, indicators of granulocytic maturation. Chloracetate esterase positivity and CD15 membrane antigens became expressed on cultured AML cells, i.e. on unstimulated and G-CSF/RA exposed blasts. Ingestion of latex beads and reduction of nitroblue tetrazolium salt occurred in cultured AML cells regardless of the presence of inducers. In almost all cases clonogenic cells persisted after exposure to G-CSF + RA suggesting that subpopulations of immature cells escaped the action of these inducers. Thus although G-CSF + RA were capable of inducing maturation of AML cells along the granulocytic lineage, maturation was incomplete and the effect was evident in a subfraction of the cells only.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1991

Primary human acute myeloblastic leukaemia: an analysis of in vitro granulocytic maturation following stimulation with retinoic acid and G-CSF.

Acute myeloid leukaemia (AML) is characterized by the inability of myeloid cells to reach terminal maturation. We examined to what degree granulocytic maturation could be achieved by stimulating AML blast cells in an in vitro serum-free system with a combination of granulocyte-colony stimulating factor (G-CSF) and all-trans-retinoic acid (RA). Specimens from 41 AML patients were cultured for 7 d and then examined for cytochemistry (myeloperoxidase, Sudan Black, naphthyl-ASD-chloracetate esterase, periodic acid Schiff) an nitroblue tetrazolium reduction. The expression of CD11a, CD11b, CD11c, CD15, CD18, CD10, CD24 and B13-3 membrane antigens was also evaluated. Morphological and cytochemical studies were also performed after AML colony culture and culture of normal bone marrow cells (NBM). The comparative analysis of the panel of parameters was indicative of granulocytic maturation although to different degrees. The cells from 25/41 cases showed morphologic maturation (May-Grünwald-Giemsa). A positive correlation was evident between morphological maturation and CD11b expression (11/22 patients) as well as that of CD11c and CD15 (6 patients). Napthyl ASD chloroacetate esterase and PAS stainings also correlated with morphology (in 10/22 and 10/24 patients respectively). Nevertheless, the pattern of granulocytic maturation was remarkably variable among the 41 cases examined. The cells from only a few patients acquired the full spectrum of granulocytic markers. The comparison with normal bone marrow blasts indicates that serum-free culture conditions can, per se, limit granulocytic maturation, but it also confirms the intrinsic inability of AML cells to attain complete maturation in response to two potent granulocytic inducers.

Adult↗
PubMed1991

A randomized trial of amsacrine and rubidazone in 39 patients with acute promyelocytic leukemia.

Thirty-nine patients with untreated acute promyelocytic leukemia (APL) were randomly allocated to receive rubidazone (zorubicin) 200 mg/m2/d, days 1 to 4 plus cytarabine (Ara C) 200 mg/m2/d, days 1 to 7 (arm A, 21 patients), or amsacrine (Amsa) 150 mg/m2/d, days 1 to 4 plus Ara C 200 mg/m2/d, days 1 to 7 (arm B, 18 patients). Prophylaxis of disseminated intravascular coagulation was made by platelet transfusions and heparin. In case of leukemic resistance, patients received a second course with 2 days of rubidazone (arm A) or Amsa (arm B) and 3 days of Ara C. Patients who achieved complete remission (CR) received three consolidation courses with the two drugs used for induction and maintenance therapy for 3 years. Two patients in arm A and one in arm B were allografted in first CR. Initial characteristics were similar in both arms. In arm A, 18 patients (86%) reached CR, two had hypoplastic death, and one had leukemic resistance after two courses. In arm B, 12 patients (66%) achieved CR, two had early death (CNS bleeding, one case; ventricular fibrillation, one case), and four had resistant leukemia after two courses. The difference in CR rate between the two arms was not significant. In arm A, disease-free survival (DFS) showed a plateau at 54.3% after 34 months (95% confidence interval [CI], 32.1% to 74.9%), with eight CRs longer than 34 months. In arm B, DFS was significantly shorter (P less than .03), showing a plateau at 16.7% after 38 months (95% confidence interval, 4.7% to 44.6%), and only two prolonged CRs were seen. The difference in DFS remained significant after censoring allografted patients and patients who died in CR (one in arm A, two in arm B). Our results suggest that Amsa-Ara C combinations may be inferior to anthracycline-Ara C combinations in the treatment of APL, because they seem to provide shorter DFS and, possibly, a higher incidence of initial leukemic resistance. However, studies with larger numbers of patients are required.

Adolescent↗
PubMed1991

The TAM regimen prior to allogeneic and autologous bone marrow transplantation for high-risk acute lymphoblastic leukemias: a cooperative study of 62 patients.

A total of 62 patients with high-risk acute lymphoblastic leukemia (ALL) were treated with fractionated total body irradiation, high-dose cytosine arabinoside and melphalan followed by bone marrow transplantation (BMT). Thirty-six patients received allogeneic and 26 autologous BMT. Eight patients were treated in CR1, 36 in CR2 (first relapse occurring on therapy for 32), seven in further CR, 10 in relapse (five early first relapse, four second relapse and one fourth relapse) and one with refractory ALL. Severe toxicity occurred in 26 of the 62 patients (42%) and 14 died (22.5%) from non-leukemic causes. The actuarial event-free survival at 3.6 years was 28% after autologous BMT and 52% after allogeneic BMT with actuarial relapse rates of 62% and 35%, respectively. The results of this pilot study seem promising for this group of poor risk ALL, but the relapse rate remains high after autologous BMT and needs to be improved.

Adolescent↗
PubMed1990

Cutaneous toxicity of autologous bone marrow transplantation in nonseminomatous germ cell tumors.

High doses of carboplatin or cisplatin combined with cyclophosphamide and etoposide followed by autologous bone marrow transplantation (ABMT) rescue have been used in the treatment of testicular tumors that have had a bad prognosis. Unusual cutaneous complications, evoking radiation-induced dermatitis, have been seen in two of eight patients with the same regimen. This new type of toxicity seems to be related to high-dose combination chemotherapies. Good results in the treatment of patients with testicular tumors on relapse who continue to respond to chemotherapy lead to the extension of this type of schedule and cutaneous toxicity will probably develop.

Adult↗
PubMed1990

The role of autologous bone marrow transplantation in 46 adult patients with non-Hodgkin's lymphomas.

Forty-six patients with non-Hodgkin's lymphoma (NHL) were treated with autologous bone marrow transplantation (ABMT) in two different institutions. All patients were pretreated with conventional chemotherapy. Three different conditioning regimens were used, and 20 patients underwent bone marrow purging. Twelve patients were treated in first complete remission (CR); eight are in unmaintained CR 8 to 104 months after ABMT. Five patients were grafted in first partial remission (PR) after conventional therapy; all achieved CR, and all remain in prolonged CR (first CR for four patients, second CR for one patient). Of 21 patients with chemosensitive relapses, 13 patients are in prolonged unmaintained CR 8 to 94 months after ABMT. Eight patients with resistant disease remained uncured by ABMT; all eight died, six from progressive illness and two from toxicity. The current 3-year disease-free probability is 60% for all patients, 0% for refractory disease; 82% for first PR or CR, and 60% for sensitive relapses (SRs). These results confirm the efficacy of ABMT in the treatment of chemosensitive NHL with bad prognosis.

Adolescent↗
PubMed1990

[Wilms' tumors in adults].

Two cases of Wilms' tumors in adults are reported according to the criteria defined by Kilton. The study of the literature allows defining the pathogenetic hypothesis for these embryonic tumors, as well as their peculiarities in comparison with those occurring in childhood. The prognosis seems to be improved by an aggressive treatment. A schedule of treatment including initial surgery, radiation therapy and chemotherapy varying according to the tumoral group (NWTS 2 staging) is proposed.

Adult↗
PubMed1990

[Primary non-Hodgkin's high grade malignant lymphoma of the digestive system. A prospective study of the combination of surgery-chemotherapy-radiotherapy].

We report a prospective study concerning the association of surgery-chemotherapy and radiotherapy in the treatment of primary high grade digestive non-Hodgkin's lymphomas in 19 patients. The analysis of 11 stages IE, 5 stages II1E and 3 stages II2E allowed us to evaluate the efficacy and the tolerance of this triple therapeutic association. Fifteen patients are alive and well with a median follow-up of 54 months. One of these patients relapsed, but after autologous bone marrow transplantation is in second unmaintained complete remission. Four patients died of intercurrent aetiology although one death was related to treatment morbidity. Our results and the analysis of literature data lead us to recommend the triple association in the treatment of stage II2E high grade primary digestive lymphomas (PDL) and for PDL without complete resection. However, surgery and chemotherapy appear to be sufficient in the treatment of stages IE and II1E with complete resection.

Adult↗
PubMed1990

High-dose etoposide and cisplatin in refractory or recurrent non-Hodgkin's lymphomas (NHL).

Thirty-one patients, 13 adults and 18 children, were included in a phase II study of combined treatment with CDDP 40 mg/m2 and VP16 100 or 200 mg/m2 for 5 days. Fourteen patients were primary refractory to front-line treatment and 17 were treated at relapse (9 on therapy, 8 off therapy). Four were low-grade follicular lymphomas, 7 intermediate grade lymphomas, and 20 high grade lymphomas. One of the 14 primary refractory cases responded (CR) whereas 3 PR and 10 CR were observed among the 17 relapses. Toxicity was acceptable. 9 patients are still alive after bone marrow transplantation (median survival, 16 months). This combination is an effective salvage regime before autologous bone marrow transplantation for relapsed NHL, but cannot be recommended for progression on front-line therapy.

Adolescent↗
PubMed1989

High dose chemotherapy including vepeside, cyclophosphamide and carboplatin with autologous bone marrow transplantation in one case of chemoresistant testicular cancer.

Non seminomatous germ cell testicular tumors (NSGCTT) is a very chemosensitive cancer; vepeside, cyclophosphamide or ifosfamide and cisplatin are the most effective drugs. Carboplatin is also active with a lack of nephrotoxicity, but there is probably a cross-resistance to cisplatin. High dose chemotherapy with autologous bone marrow transplantation is able to cure poor prognosis testicular cancers in first partial remission or in sensitive relapse. We report one case of non seminomatous testicular cancer which was progressive after chemotherapy with cisplatin and vepeside or teniposide, and which is in prolonged complete remission after conventional chemotherapy (vepeside, ifosfamide, carboplatin) and high dose chemotherapy (carboplatin, vepeside, cyclophosphamide) with autologous bone marrow transplantation.

Adult↗
PubMed1989

Bone marrow transplantation for adult poor prognosis lymphoblastic lymphoma in first complete remission.

Twenty-five adult patients, 19 males, six females, age 16-43 years (median 23), with lymphoblastic lymphoma received allogeneic or autologous bone marrow transplantation in first complete remission. Twelve patients were Murphy stage IV with bone marrow and/or CNS involvement and 13 were stage III of whom nine had thoracic involvement. Complete remission was achieved with an intensive anthracycline containing multiagent chemotherapy protocol. Twelve patients with an HLA identical sibling received an allogeneic marrow and 13 without a donor received their own marrow harvested a median of 2 months (0-4 months) after complete remission and purged in vitro with either mafosfamide (eight patients) or anti T-cell monoclonal antibodies and complement (three patients). Bone marrow transplantation was performed 1-7 months (median 3 months) after achieving first complete remission. The conditioning regimen consisted of cyclophosphamide or high dose melphalan and total body irradiation. The actuarial 4-year disease-free survival is 68% (+/- 9% SE). The actuarial probability of relapse was 26% (+/- 3% SE) with a median follow up to 22 months. There was no difference between allogeneic and autologous transplantation with eight out of 12 allo patients in first continuous complete remission 26-45 months after transplant and nine out of 13 auto in continuous complete remission 15-75 months after transplant. These results compare favourably with those achieved with the best chemotherapeutic regimen used for such patients.

Adolescent↗