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Biomedical subjects

A Ganser

Publications and source records attributed to A Ganser.

At least 181 records · Page 10Linked to original sources
PubMed1994

Acute leukemia.

Within the past year substantial progress has been made in understanding the molecular changes underlying the development of acute leukemia. Development of molecular probes allowed substantial improvements in the detection of minimal residual disease. Pilot studies underlined the correlation between the expression of the multidrug resistance gene and the likelihood of response to chemotherapy. The expression of mdr-1 apparently correlates with the expression of certain surface antigens like CD34 and CD7, which by themselves are associated with the expression of bcl-2 and poor treatment response. The value of hematopoietic growth factors to overcome drug resistance has not yet been clearly demonstrated in clinical trials, but they seem to reduce early mortality in elderly patients with acute myeloid leukemia when given after chemotherapy. Substantial progress has been made in the understanding of molecular changes in acute promyelocytic leukemia. Combination of all-trans retinoic acid and chemotherapy is the treatment of choice in acute promyelocytic leukemia. Allogeneic bone marrow transplantation proved to be superior in certain high-risk groups of patients with acute leukemia, including those with acute lymphoblastic leukemia with the bcr-abl configuration. The value of allogeneic bone marrow transplantation from related and unrelated donors, as well as the value of autologous bone marrow transplantation, is increasingly defined in randomized trials.

Acute Disease↗
PubMed1993

Simultaneous administration of granulocyte colony-stimulating factor (Filgrastim) and induction chemotherapy in acute lymphoblastic leukemia. A pilot study.

The present study was designed to determine whether Filgrastim, a neutrophil-specific hematopoietic growth factor, could be administered simultaneously with intensive induction chemotherapy for adult acute lymphoblastic leukemia (ALL). The effect of Filgrastim on the severity of chemotherapy-induced neutropenia, fever, and infections was assessed in 15 patients treated according to the protocol of the German multicenter ALL (GMALL) trial 04/89. Filgrastim (5 micrograms/kg/day) was given concurrently with successive cycles of cyclophosphamide, cytosine-arabinoside (ara-C), 6-mercaptopurine (6MP), prednisone (PRD), intrathecal methotrexate, and prophylactic cranial irradiation. During the study period the median total duration of severe neutropenia (< 0.5 x 10(9)/l) in 13 evaluable patients was 8 days, individual periods of neutropenia typically were short. Infections occurred in six patients; seven patients remained fever-free during treatment with Filgrastim. We conclude that simultaneous treatment with Filgrastim and chemotherapy in this specific setting is feasible and well tolerated. The efficacy of this treatment approach in terms of overall treatment results requires further testing in a randomized trial.

Adolescent↗
PubMed1993

Aggressive chemotherapy combined with G-CSF and maintenance therapy with interleukin-2 for patients with advanced myelodysplastic syndrome, subacute or secondary acute myeloid leukemia--initial results.

Aggressive chemotherapy of advanced myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) evolving from MDS, subacute AML and secondary AML has usually been associated with low complete remission (CR) rates, a high incidence of early death, and low disease-free survival. We therefore have initiated a phase-III trial of aggressive chemotherapy consisting of idarubicin, cytosine arabinoside, and VP-16 to improve the CR rate. Each chemotherapy cycle is followed by G-CSF to accelerate neutrophil recovery and to reduce the incidence of infections. Until now, 19 patients with high-risk AML have been entered. The CR rate is 47%, with only one death during induction. Patients achieving CR are randomized to receive either high-dose or low-dose interleukin-2 to eliminate residual leukemic cells and to prolong the duration of remission.

Adult↗
PubMed1993

Analysis of lymphocyte subsets in patients with aplastic anemia before and during immunosuppressive therapy.

To define the contribution of T-lymphocyte subsets in the development of aplastic anemia (AA), T-cell subpopulations including alpha beta T cells, gamma delta T cells, and delta TCS1-positive gamma delta T cells, were analyzed by cytophotometry in the peripheral blood (PB) and bone marrow (BM) of patients with AA before and after 6 weeks of therapy with anti-lymphocyte globulin (ALG), methylprednisolone, and cyclosporin A (CSA). In nine patients with AA a significant decrease of PB- and BM-derived T cells was observed after 6 weeks of therapy as compared with normal controls. At diagnosis, the CD4/CD8 ratio in PB and BM of the patients did not differ from the ratio in the control population; however, a reversed ratio (< 1) was present in PB as well as in BM after weeks of therapy. Interestingly, lymphocytes expressing the gamma delta T-cell receptor (TCR tau delta) were significantly decreased both before (PB 1.2 +/- 0.1%; BM 0.8 +/- 0.1%) and after 6 weeks of therapy (PB 0.7 +/- 0.1%; BM 0.7 +/- 0.1%) as compared with healthy controls (PB 2.4 +/- 0.2%; BM 2.3 +/- 0.2%). However, the proportion of the gamma delta-T-cell subpopulation expressing the delta TCS1 phenotype was markedly increased before (PB 42 +/- 3.5%; BM 31 +/- 3%) and especially after 42 days of therapy (PB 77 +/- 12%; BM 45 +/- 2%) as compared with that in normal subjects (PB 19 +/- 2%; BM 9.7 +/- 0.8%). At present, follow-up is under evaluation to correlate these findings with hematological response. The pathophysiological significance of the observed alterations within the T-cell subsets and especially the gamma delta T-cell populations will require further functional analyses, in particular since delta TCS1-positive gamma delta T cells exhibit autoimmunological capacity.

Anemia, Aplastic↗
PubMed1993

Induction of TNF-alpha in patients with myelodysplastic syndromes undergoing treatment with interleukin-3.

The study was undertaken to analyse whether the presence or the induction of TNF-alpha, a potent inhibitor of haemopoiesis, might affect the clinical response to treatment with interleukin-3 in patients with myelodysplastic syndromes. A total of 15 patients were treated with IL-3. Baseline serum TNF-alpha levels were elevated in MDS patients (14.2 +/- 2.4 pg/ml) compared to healthy controls (9.1 +/- 1.1 pg/ml). During IL-3 therapy TNF-alpha levels remained unchanged in 3/14 patients in whom platelet counts increased, while in non-responders TNF-alpha levels increased 1.9-fold (P < 0.025). These findings indicate that TNF-alpha not only is induced during IL-3 therapy in MDS patients but that this elevation might be associated with a poor platelet response to therapy.

Adult↗
PubMed1993

Restoration of impaired cytokine secretion from monocytes of patients with myelodysplastic syndromes after in vivo treatment with GM-CSF or IL-3.

Cytokine treatment in patients with myelodysplastic syndrome (MDS) aims to overcome the maturation defects of myeloid lineage cells associated with cytopenia and cellular dysfunction of mature cells. Since phagocytes play a major role in host defense against microbial infection, we investigated cytokine secretion and oxygen radical release (ORR) from peripheral blood monocytes (PBMC) in a total of 16 MDS patients, 12 patients with refractory anemia (RA) and four patients with RA and excess of blasts (RAEB). Interleukin (IL-6), tumour necrosis factor alpha (TNF alpha), IL-1 beta, and IL-8 secretion from monocytes in response to lipopolysaccharide (LPS) was significantly reduced in the 12 patients with RA compared to 12 healthy controls, whereas no difference was seen in ORR. We further assessed cytokine secretion from monocytes of 10 MDS patients before and after therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, or a combination therapy with GM-CSF and cytosine arabinoside (AraC). In all 10 patients, secretion of IL-1 beta, IL-6, and TNF alpha from PBMC increased after cytokine therapy, whereas IL-8 secretion increased only in five patients with GM-CSF or IL-3 therapy receiving a dosage > or = 250 micrograms/m2 per day but decreased in all other patients. ORR increased in all patients on either GM-CSF or IL-3 therapy. These data indicate that the ability of monocytes to secrete secondary cytokines is impaired in MDS patients but can be restored by in vivo administration of GM-CSF and IL-3.

Aged↗
PubMed1993

A new technical approach for the ultrastructural analysis of hematopoietic cells using cell monolayers adherent to electron-transparent melamine resins.

The melamine resin is a polymer of a hexamethylol melamine ether which can coat glass slides with an electron-transparent foil (approximately 80 nm thick) after polymerization by p-toluene sulphonic acid and warming. Provided that the cells had been resuspended in a serum-free medium, normal peripheral blood, or bone marrow cells, blasts of different acute leukemias, cells of B-cell chronic lymphocytic leukemia, and of the cell-lines K562, KG1a, and HL-60 became adherent to the melamine-resin-covered glass slides. The optimal sedimentation time and cell concentration was 45 min and 10(7) cells/ml, respectively. Moreover, in serum-free culture medium the cells could be maintained adherent for up to 96 h without a great loss in cell number and viability. For transmission electron microscopical (TEM) analysis, the monolayers could be embedded in situ in epon after routine fixation and staining procedures. Alternatively, the foils could be removed from the glass and mounted on grids for whole mount electron microscopic analysis (WMEM). Both methods could be combined with immunogold labelling for the detection of surface antigens. This technique permits ultrastructural in situ analysis of morphological and/or immunological changes of cells induced by in vitro stimulation.

Cell Adhesion↗
PubMed1993

Effect of long-term treatment with recombinant human interleukin-3 in patients with myelodysplastic syndromes.

In a phase II study, involving nine patients with refractory anemia or refractory anemia with ring sideroblasts, the effects of treatment with recombinant human interleukin-3 (IL-3) on hematopoietic function were assessed. Doses of IL-3 ranging from 60 micrograms/m2 during weeks 1-6 to 125 micrograms/m2 during weeks 7-12 were administered as subcutaneous bolus injections three times per week for 12 weeks. Platelet counts increased in six patients. Platelet increase correlated with stable or decreased serum tumour necrosis factor alpha (TNF-alpha) levels, while an increase of TNF-alpha levels during IL-3 therapy occurred in patients with no change or a decrease of platelet counts. Leukocyte counts increased in two patients and reticulocytes in three, without an effect on hemoglobin levels. Morphological analysis of the bone marrow revealed an expansion of the myeloid compartment in seven of eight evaluable patients, mainly due to stimulation of the precursor cells. No improvement of the in vitro growth of hematopoietic progenitor cells was observed. Sequential cytogenetic analyses indicate that IL-3 treatment does not act preferentially on either the cytogenetically abnormal or the normal clones. These results suggest that long-term treatment with low-dose IL-3 stimulates megakaryopoiesis with increase of platelet counts, but that additional later-acting cytokines probably will be required to augment neutrophil and erythrocyte counts.

Aged↗
PubMed1992

A switch toward demethylation is associated with the expression of myeloperoxidase in acute myeloblastic and promyelocytic leukemias.

Expression of numerous genes encoding myeloid-specific proteins is tightly regulated during normal myeloid differentiation. This heterogeneous group of genes thus offers a tool for dissection of different maturational steps of myelopoiesis. We have previously shown that the human myeloperoxidase (MPO) gene is modified at numerous CpG residues in normal myeloid cells and in myeloid cell lines in a development-specific and expression-associated manner. In the present work, we have applied this type of methylation analysis to primary leukemia myeloid cell samples. We found that expression of MPO messenger RNA (mRNA) is grossly limited to leukemias of late myeloblastic and promyelocytic stages; expression is thus associated with progressive demethylation in the 5' region of the MPO gene. This modification was not global. Low-level induction of MPO mRNA expression in very immature leukemic cells using phorbol ester was not accompanied by progressive demethylation. This type of methylation analysis of a myeloid-specific gene may yield a molecular indicator for different types of myeloid leukemias.

Blotting, Northern↗
PubMed1992

In vitro culture of common acute lymphoblastic leukemia blasts: effects of interleukin-3, interleukin-7, and accessory cells.

We investigated the effects of interleukin-3 (IL-3), IL-7, IL-1, and IL-6, of irradiated bone marrow-derived fibroblasts (Fb) and of in vitro matured peripheral blood macrophages (M phi), on the survival, proliferation, and maturation of purified blasts from nine common acute lymphoblastic leukemias (cALLs) in 7-day suspension culture. Exposure to IL-3, IL-7, IL-1, and IL-6 resulted in a mean 2.8-, 1.5-, 1.4-, and 1.6-fold stimulation of 3H-thymidine (3H-TdR) incorporation, respectively. Cocultures of cALL blasts with irradiated M phi, either allowing direct cell-cell contact or preventing it by membrane filters, or with irradiated Fb, resulted in a mean 31.7-, 4.1-, and 11.2-fold increase of 3H-TdR incorporation, respectively. Southern blot analysis of immunoglobulin and T-cell receptor (TCR) gene rearrangements before and after culture indicated exclusive proliferation of the leukemic clone in three of eight samples, whereas additional generation of nonleukemic cells was found in five samples. Polyclonal growth pattern corresponded to the detection of heterogeneous cell populations using FACS analysis. Survival of cALL blasts as defined by the detection of cells coexpressing both CD10 and CD19 after culture was supported by accessory cells in five of eight samples. No evidence of induced lymphoid maturation was found under any culture condition. Our data demonstrate supportive effects of stromal cells on cALL growth, which cannot be replaced by IL-3 or IL-7.

Blotting, Southern↗
PubMed1992

Sequential in vivo treatment with two recombinant human hematopoietic growth factors (interleukin-3 and granulocyte-macrophage colony-stimulating factor) as a new therapeutic modality to stimulate hematopoiesis: results of a phase I study.

In a phase I study, the sequentially administered combination of recombinant human interleukin-3 (rhIL-3) and rhGM-CSF was compared with treatment with rhIL-3 alone in 15 patients with advanced tumors but normal hematopoiesis. Patients were initially treated with rhIL-3 for 15 days. After a treatment-free interval, the patients received a second 5-day cycle of rhIL-3 at an identical dosage, immediately followed by a 10-day course of rhGM-CSF, to assess the toxicity and biologic effects of this sequential rhIL-3/rhGM-CSF combination. rhIL-3 doses tested were 125, and 250 micrograms/m2, whereas rhGM-CSF was administered at a daily dosage of 250 micrograms/m2. Both cytokines were administered by subcutaneous (SC) bolus injection. rhIL-3/rhGM-CSF treatment was more effective than rhIL-3 but equally effective to each other in increasing peripheral leukocyte counts, especially neutrophilic and eosinophilic granulocyte counts. In contrast, both modes of cytokine therapy raised the platelet counts to the same degree. rhIL-3/GM-CSF treatment was more effective than rhIL-3 in increasing the number of circulating hematopoietic progenitor cells BFU-E and CFU-GM. High-dose rhIL-3, but not low-dose rhIL-3, was as effective as the rhIL-3/rhGM-CSF combinations in increasing the number of circulating CFU-GEMM. The increase in absolute neutrophil counts correlated with the increase in the number of circulating CFU-GM. Side effects, mainly fever, headache, flushing, and sweating, were generally mild, but in two patients the occurrence of chills, rigor, and dyspnea after initiation of GM-CSF treatment necessitated dose reduction and discontinuation, respectively. These results indicate that sequential treatment with rhIL-3 and rhGM-CSF is as effective as single-factor treatment with rhIL-3 in stimulating platelet counts, whereas the effect of combination therapy on neutrophil counts and circulating progenitor cells is superior.

Antineoplastic Agents↗
PubMed1992

Treatment of relapsed or refractory adult acute lymphocytic leukemia.

Sixty-six adult patients were treated for relapsing or refractory acute lymphocytic leukemia (ALL). The induction treatment consisted in a (1) first phase with vindesine 3 mg/m2 intravenously (IV) on days 1, 8, and 15; daunorubicin 45 mg/m2 IV on days 1, 8, and 15; erwinia-asparaginase 10,000 U/m2 IV on days 7, 8, 14, and 15; and prednisone 60 mg/m2 orally on days 1 to 21 and a (2) second phase with cytarabine 3000 mg/m2 as a 3-hour infusion two times a day on days 1 to 4 (in patients greater than 50 years of age we used 1000 mg/m2), and etoposide 100 mg/m2 IV on days 1 to 5. Side effects of induction Phase I were predominantly hematologic with subsequent infections. In Phase II, some patients additionally had gastrointestinal, cutaneous, ocular, and hepatic toxicity. Five patients died during Phase I and another died during Phase II. Five of these patients had T-cell ALL. Thirty-four (64%) of 54 patients in their first relapse had a complete remission (CR) with a median disease-free survival (DFS) of 2.9 months. The median overall survival (OAS) was 6.6 months. Seven of 12 patients with primary refractory disease, a second relapse, or relapse after bone marrow transplantation (BMT) had a CR. The CR rate and survival after first relapse was significantly better in patients with a preceding CR of more than 18 months compared with those with a shorter preceding remission. The leukocyte count was a second significant but not independent risk factor. There was a negative correlation between the leukocyte count and the duration of the preceding CR. The duration of the preceding CR was the major prognostic factor for survival in multivariate analysis. Twenty-two patients received BMT. None of nine patients with autologous BMT is alive and disease-free; 5 of 13 who underwent allogeneic BMT are. It was concluded that this treatment efficiently induced remission with tolerable toxicity. The remission duration should be improved by optimized consolidation treatment.

Adult↗
PubMed1992

Interleukin-3 and granulocyte-macrophage colony-stimulating factor in combination: clinical implication.

The multilineage hematopoietic effects of IL-3 appear to be most important for its clinical use comprising especially leucocyte and platelet responses. This was demonstrated to be dose dependent characterising doses of 250 to 500 micrograms/m2/day subcutaneously as hematopoietic effective and well tolerable. Since preclinical data suggest synergism between IL-3 and GM-CSF hematopoietic effects of their sequential administration were evaluated in 15 patients with preserved hematopoietic function. An enhanced stimulation of megakaryopoiesis combined with more pronounced stimulation of granulopoiesis than IL-3 alone could be demonstrated. The cytokine combination of IL-3 and GM-CSF was thus used during chemotherapy induced myelosuppression. Data indicates beyond the known amelioration of myelosuppression by GM-CSF additional chances to enhance platelet recovery which can be of important clinical impact.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Presence of more than two rearranged immunoglobulin heavy-chain genes in adult precursor B-cell acute lymphoblastic leukemia.

We examined the configuration of the immunoglobulin genes in the leukemic blast cell DNA of 20 adults with precursor B-cell acute lymphoblastic leukemia (ALL), treated according to the BMFT protocol. Sixteen of 20 (80%) patients expressed HLA-DR antigens and lacked detectable T-cell antigens. Eleven of the 20 patients (55%) were positive for the CD10 antigen and therefore classified as common ALL. Six patients were classified by immunological phenotyping as null-ALL (30%). Three patients (15%) expressed both immature B-cell markers CD19, CD22, or CD24 and myelomonocytic markers CDw65 or CD15, suggesting precursor B-ALL with cross-lineage expression of myeloid markers. In 18 of the 20 patients (90%), rearrangements and/or deletions of the immunoglobulin heavy-chain (IgH) gene locus were found. In none of the patients was a light-chain gene rearrangement observed. Two patients (10%) had a rearrangement of one allele for the J beta 1 gene region of the TCR-beta gene. In four patients (20%) more than two hybridizing bands for the IgH genes were detected. Two of these four patients with multiple hybridizing bands for the IgH genes had a t (4;11) translocation. Two of five patients with the t (4;11) translocation co-expressed both B-cell antigens and the myeloid antigens CD15 or CDw65. No correlation was found between the immunophenotype of the ALL and the arrangement pattern of their IgH genes. Kaplan-Meier plot analysis revealed no significant difference between adult precursor B-ALL patients with monoclonal or oligoclonal IgH gene rearrangements and their disease-free survival rates.

Adult↗
PubMed1992

Interleukin-3 in the treatment of myelodysplastic syndromes.

Patients with myelodysplastic syndromes frequently present with anemia, leukopenia and thrombocytopenia due to defective maturation of bone marrow cells. Clinical studies with hematopoietic growth factors, including interleukin-3 (IL-3), have been undertaken to evaluate the possibility to reverse cytopenia. In initial phase I/II trials, treatment with IL-3 has resulted in an increase of neutrophil counts in 59%, of platelet counts in 34%, and in reticulocyte counts in 25% of the patients. Adverse effects were rather mild but in individual patients a reversible decrease in platelet counts and in the number of blast cells in blood and bone marrow were observed. Further clinical trials should concentrate on the combination of an early acting cytokine like IL-3 and later acting hemopoietic growth factors like erythropoietin and granulocyte colony-stimulating factor.

Drug Evaluation↗