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D Guyotat

Publications and source records attributed to D Guyotat.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Follow-up of allogenic bone marrow graft with DNA polymorphisms. Use of two minisatellite MS31 and MS43 probes. Comparison with data of chromosomal polymorphisms].

OBJECTIVES: Allogenic bone marrow transplantation is widely used to treat many diseases of the haemopoietic system as well as metabolic disorders. Follow-up is essential to assess acceptance, rejection or post-graft relapse. This study was undertaken to evaluate the usefulness of the minisatellite probes MS31 and MS43 used as a routine follow-up test after bone marrow transplantation. METHODS: Twenty receivers of allogenic bone marrow transplants were followed-up. Two monoclonal minisatellite probes, MS31 and MS43, were used for comparison with the classical polymorphism methods. RESULTS: Fourteen cases of total chimeras, 3 cases of rejections and 3 cases of mixed chimeras were observed with the molecular probe techniques. In 19 of the 20 cases, this technique gave results compatible with classical polymorphism results. CONCLUSIONS: The minisatellite probes MS31 and MS43 were found to be sensitive, effective tests for bone marrow transplants which can be used in routine follow-up.

Adolescent↗
PubMed1995

Definition of optimal conditions for collection and cryopreservation of umbilical cord hematopoietic cells.

Prior studies have shown that human umbilical cord blood cells can restore hematopoiesis and be used as a source of stem cells for hematopoietic transplantation. We have performed a study of the best conditions of collection and cryopreservation of blood from eight umbilical cords. We compared the influence of cell separation and of delay between collection and cryopreservation on the numbers of nucleated cells and of hematopoietic progenitors recovered before and after cryopreservation. Ficoll separation resulted in the loss of more than 50% of nucleated cells, but also of a significant number of progenitors before freezing. Unseparated cells could be kept at 25 degrees C as long as 24 h before freezing with minimal loss of progenitors before and after freezing and thawing. In contrast, there was a significant decrease in the number of viable cells and progenitors when cells were maintained at 4 degrees C before freezing. Our data show that cord blood banking is feasible with simple collection and cryopreservation procedures.

Blood Banks↗
PubMed1995

Allogeneic bone marrow transplantation remains an efficient consolidation for adults with acute myeloid leukemia even when performed very soon after diagnosis (< 100 days). The SFGM (Société Française de Greffe de Moelle.

Allogeneic BMT is presently recognized as one of the reference anti-leukemic treatments for AML patients. It could be a very useful therapy in CR1 AML if it is efficient as an early form of consolidation after induction therapy. Later procedures may be of lesser importance since they concern a population which may have already been cured by chemotherapy. Alternatively it is not solved if very early BMT gives patients sufficient therapy and provides lower toxicity. To answer this question we analyzed data from the Société Française de Greffe de Moelle (SFGM) on a sub-group of patients according to the following criteria: (1) Allogeneic BMT carried out on patients with AML in CR1; (2) after January 1985; (3) conditioning with CyTBI; (4) GVHD prophylaxis with MTX-CsA; (5) interval between diagnosis and BMT < 100 days. Forty-two fulfilled all criteria. Age was 31 +/- 8 years and M/F ratio was 19/23. WBC at diagnosis were 36 +/- 49 x 10(9)/l and four patients needed two induction courses to achieve CR1. Median follow-up is now 51 (24-116) months. Twenty-two patients developed a grade > or = 2 acute GVHD. Early transplant mortality at 1 year is no higher than 14%. Two patients died of secondary malignancies at 3.5 and 6.5 years after BMT. Finally 5-year (and 7-year) probabilities for relapse, survival, leukemia and event-free survival are respectively 17% (17%), 71% (62%), and 71% (71%) and 68% (59%). These data indicate the feasibility of such an approach with low mortality and low relapse rates providing a good long-term outcome. This should prompt an invitation to initiate the search for an HLA-identical sibling when AML is diagnosed in a young patient eligible for allo-BMT.

Adult↗
PubMed1994

Effects of BCL-2 antisense oligodeoxynucleotides on in vitro proliferation and survival of normal marrow progenitors and leukemic cells.

Previous studies have shown that the BCL-2 protooncogene encodes a mitochondrial protein that promotes cell survival by blocking programmed cell death. Bcl-2 protein has been detected in normal immature myeloid cells and in acute myeloid leukemia (AML) cells. To assess its functional role in normal and leukemic hematopoiesis, we performed serum-free cultures of CD34+ normal marrow cells, of bcl-2-positive myeloid lines, and of AML cells in the presence of bcl-2 sense, nonsense, and antisense phosphorothioate oligodeoxynucleotides. In all antisense-treated cultures, we observed (1) an inhibition of bcl-2 protein expression by day 4 to 6 of culture; (2) a decrease in cell survival duration; and (3) a decrease in the number of clonogenic cells present in the culture. Moreover, exposure to chemotherapeutic drugs resulted in more effective killing of AML cells in the presence of antisense oligomers. We conclude that bcl-2 protein is necessary for the survival of myeloid cells in culture, and that it may be implicated in the resistance of AML cells to chemotherapy.

Base Sequence↗
PubMed1994

Pentosan polysulfate-induced thrombocytopenia and thrombosis.

Pentosan polysulfate is a low-molecular-weight sulfated polysaccharide used as an antithrombotic drug. We present two patients who developed thrombocytopenia and venous thrombosis during treatment with pentosan polysulfate. The relationship between pentosan polysulfate and thrombocytopenia is supported by platelet aggregation and serotonin release tests. In the light of the literature and our two cases, it appears that pentosan polysulfate alone as standard heparin and low-molecular-weight heparin can induce thrombocytopenia and thrombosis. Platelet counts should therefore be periodically monitored during pentosan polysulfate treatment. In the case of pentosan polysulfate-induced thrombocytopenia, it seems that heparin or low-molecular-weight heparin should not be instituted during the acute phase even if platelet aggregation studies are negative, because of their low sensitivity. After remission of thrombocytopenia, whether or not glycosaminoglycans can be reinstituted, at least temporarily, after antibody had disappeared is still an open question.

Aged↗
PubMed1994

Expression of adhesion molecules in endothelial cells during allogeneic bone marrow transplantation.

Endothelial cell activation during allogeneic bone marrow transplantation, mainly in acute graft-versus-host disease (aGvHD) was studied in 23 recipients and 5 controls using anti-von Willebrand factor (vWF) antibody, antibodies to endothelial leukocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), and anti-HLA-DQ antibody, by immunohistological staining of skin. vWF extravasation, ELAM-1 and VCAM-1 expression were present in most recipients with a cutaneous rash which was confirmed as an aGvHD by histological examination (documented aGvHD) (p = 0.005 for vWF extravasation and ELAM-1 expression and p = 0.03 for VCAM-1 expression in comparison with the controls). In recipients with a rash, the cases displaying vWF extravasation and ELAM-1 expression were significantly more numerous in those with a documented aGvHD than in those without histological features of aGvHD (p = 0.01). vWF extravasation and ELAM-1 occurred concomitantly (p < 0.01). This study demonstrates that, during the course of skin aGvHD following bone marrow transplantation, there is transient expression of ELAM-1 and VCAM-1 by endothelial cells and simultaneous vWF extravasation, indicating an intense inflammation with endothelial cell participation.

Acute Disease↗
PubMed1994

Prospective genetically randomized comparison between intensive postinduction chemotherapy and bone marrow transplantation in adults with newly diagnosed acute myeloid leukemia.

PURPOSE: To compare intensive chemotherapy and HLA-identical allogeneic bone marrow transplantation (BMT) as postinduction therapy in young adults with acute myeloid leukemia (AML). PATIENTS AND METHODS: Seventy-eight consecutive AML patients younger than 40 years of age were treated according to a prospective protocol in which every patient in complete remission (CR) with an HLA-identical sibling was scheduled to receive BMT rather than intensive chemotherapy consolidation. To minimize comparison biases, the availability or not of an HLA-identical sibling donor was considered to be the equivalent of genetic randomization to the BMT or chemotherapy arm, respectively. RESULTS: Fifty-eight patients (74%) achieved a CR. A donor was found for 27 patients (BMT arm), and 20 of these patients were actually transplanted in first CR. The 31 patients without a donor were allocated to the chemotherapy arm. Patients in the two arms had similar disease characteristics at diagnosis and previous responses to induction therapy. The cumulative risk of relapse was 43% +/- 24% in the BMT arm and 67% +/- 19% in the chemotherapy arm (P = .01). The 7-year leukemia-free survival (LFS) rate was 41% +/- 20% in the BMT arm and 27% +/- 16% in the chemotherapy arm, a difference that is not statistically significant between the two arms. The overall survival rates were 41% +/- 20% and 46% +/- 19%, respectively. CONCLUSION: In this study, the availability of an HLA-identical sibling donor was not associated with a better survival rate because of both the impossibility of some patients with a donor to receive BMT and the more efficient salvage treatment of patients who relapsed after intensive consolidation chemotherapy than of patients who relapsed after BMT.

Acute Disease↗
PubMed1993

High expression of bcl-2 protein in acute myeloid leukemia cells is associated with poor response to chemotherapy.

The BCL-2 proto-oncogene encodes a mitochondrial protein that blocks programmed cell death. High amounts of bcl-2 protein are found not only in lymphoid malignancies, but also in normal tissues characterized by apoptotic cell death, including bone marrow. Using a monoclonal antibody to bcl-2 protein, we analyzed 82 samples of newly diagnosed acute myeloid leukemia. The number of bcl-2+ cells in each sample was heterogeneous (range, 0% to 95%), with a mean of 23%. The percentage of bcl-2+ cells was higher in M4 and M5 types, according to French-American-British classification, and in cases with high white blood cell counts. bcl-2 expression was also correlated with that of the stem cell marker CD34. In vitro survival of leukemic cells maintained in liquid culture in the absence of growth factors was significantly longer in cases with a high percentage of bcl-2+ cells. High expression of bcl-2 was associated with a low complete remission rate after intensive chemotherapy (29% in cases with 20% or more positive cells v 85% in cases with less than 20% positive cells, P < 10(-5)) and with a significantly shorter survival. In multivariate analysis, the percentage of bcl-2+ cells (or the blast survival in culture), age, and the percentage of CD34+ cells were independently associated with poor survival.

Acute Disease↗
PubMed1993

S100 protein and neuron-specific enolase on monocytic leukemic CD1+ cells, probable precursors of Langerhans cells.

Langerhans cells are characterized by specific markers, such as Birbeck granules and CD1a antigen. S100 protein and neuron-specific enolase are less specific but are expressed only on Langerhans cells among the cells of the phagocytic mononuclear system. In this study, the expression of these two antigens on many monocytic leukemic cells is shown. These cells could be precursors of Langerhans cells which have been transformed into malignant cells.

Antigens, CD↗
PubMed1993

Allogeneic bone marrow transplantation for adult acute lymphoblastic leukemia in first complete remission: factors predictive of transplant-related mortality and influence of total body irradiation modalities.

In a retrospective multicentre study, we analyzed 184 consecutive patients who underwent bone marrow transplantation (BMT) from identical siblings for adult acute lymphoblastic leukemia in first complete remission between March 1980 and May 1989. The main causes of transplant-related mortality were GVHD and interstitial pneumonitis. Univariate and multivariate analyses identified the mode of total body irradiation (TBI) as the only independent predictive factor of transplant-related mortality. Ninety-one patients received single-dose TBI and 93 received fractionated-dose TBI as part of the conditioning regimen prior to BMT. Transplant-related mortality was more frequent in the single dose group (p = 0.017). The incidence of interstitial pneumonitis, acute and chronic GVHD and veno-occlusive disease of the liver was not statistically different between the two irradiation groups. However, fatal interstitial pneumonitis was significantly more frequent in the single dose irradiation group (p = 0.031). These results show that transplant-related mortality is closely associated with the mode of TBI administration. The increased relapse rate in the fractionated group explains why there was no difference between the two groups in terms of overall leukemia-free survival.

Adolescent↗
PubMed1993

Trisomy 12 in B-cell chronic lymphocytic leukemia: interphase study by in situ hybridization in 75 patients.

Trisomy 12 is the most common cytogenetic abnormality in chronic lymphocytic leukaemia (CLL) and may be a prognostic indicator. In the present study, fluorescence in situ hybridization (FISH) is shown to be a method of choice for detection of trisomy 12 in interphase cells. Seventy-five cases of B-cell CLL were analysed with a chromosome 12 specific alpha satellite DNA probe and results compared with those from cytogenetic analysis. FISH showed the three hybridization spots characteristic of trisomy 12 in 32/75 patients (42.6%). Sixty-three patients were also studied by conventional cytogenetics: failure in 7 cases, normal karyotype in 28, trisomy 12 in 9 (14.3%) and in 19 cases abnormalities other than trisomy 12. In these same 63 patients, trisomy 12 was detected on 29 occasions by FISH (46%): in one case of failure by cytogenetic analysis, in 9 cases thought to have a normal karyotype, in 10 cases carrying abnormalities other than trisomy 12 and in all 9 cases showing trisomy 12 by conventional cytogenetic investigation. Correlation between trisomy 12 and the three stages of the Binet classification indicated an increasing proportion of trisomy 12 from stage A to stage C. It is concluded that fluorescence in situ hybridization is a powerful and sensitive technique for detection of trisomy 12 in CLL and although more cases will be required to confirm a correlation between the incidence of trisomy 12 and the stage of the disease, this link could be important from a prognostic point of view.

Adult↗
PubMed1992

Clinical significance of multidrug resistance P-glycoprotein expression on acute nonlymphoblastic leukemia cells at diagnosis.

To evaluate the clinical value of the expression of multidrug resistance P-glycoprotein (P-170) on the surface of acute nonlymphoblastic leukemia (ANLL) cells, we analyzed specimens from 150 newly diagnosed patients for staining with MRK16, a monoclonal antibody (MoAb) that binds to an external epitope of P-170. Other surface markers (CD13, CD14, CD15, and CD34) were studied by the same technique. A marker was considered positive when 20% or more cells were stained. Of 150 samples, 71 were P-170-positive. These cases did not differ from P-170-negative cases with regard to age, sex, initial white blood cell (WBC) counts, or French-American-British (FAB) type (except for M3 ANLL, which were more frequently negative). However, leukemias arising from previous myelodysplastic syndrome (MDS) and therapy-induced leukemias were more frequently P-170-positive. CD34 and P-170 expression were significantly associated. All patients were treated by intensive chemotherapy. Complete remission (CR) rates were significantly lower in P-170-positive (23/71, 32%) than in P-170-negative cases (64/79, 81%) (P less than 10(-5)). CD34 positivity was also associated with a low remission rate (P less than 10(-5)). Survival was shorter for P-170- and CD34-positive patients (P less than 10(-5)). The prognostic value of both markers was confirmed in multivariate analysis. CR duration was also shorter for P-170-positive cases, but the difference is less significant (P = .05). It is concluded that P-170 analysis may be an important tool for predicting the outcome of intensive chemotherapy in ANLL patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Maintenance with low-dose cytarabine for acute myeloid leukemia in complete remission.

Thirty-four patients with acute myeloid leukemia (AML) in complete remission (CR), 30 of them aged over 60, received maintenance therapy scheduling four courses of low-dose cytarabine (LDA) 20 mg/m2/day in two subcutaneous injections for 3 weeks every 6 weeks. Each course was stopped when hematologic toxicity occurred, and doses of LDA were subsequently reduced by 50% for the following courses. During the first course of LDA, 15 patients needed blood and four patients platelet transfusions. Overall, 28 patients received four courses of LDA: 11 did not require any dose reduction, while 14 required one dose reduction and three needed two successive dose reductions. Two patients were hospitalized during maintenance. Median disease-free survival (DFS) is 308 days, with 16% of patients surviving at 5 years. Seven patients relapsed during the 168 days of maintenance, while ten of the 27 patients remaining at risk on day 169 relapsed during the 168 days following maintenance. We conclude that in AML in CR, the maximal dose of LDA tolerated by ambulatory patients is 10 mg/m2/day for 3 weeks. LDA seemed to delay relapse; however, precise assessment of the efficacy of this approach would require a randomized trial.

Acute Disease↗