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Biomedical subjects

G Seipelt

Publications and source records attributed to G Seipelt.

At least 19 recordsLinked to original sources
PubMed2002

Prospective randomized trial to evaluate two delayed granulocyte colony stimulating factor administration schedules after high-dose cytarabine therapy in adult patients with acute lymphoblastic leukemia.

In acute lymphoblastic leukemia (ALL), treatment with granulocyte colony stimulating factor (G-CSF) during remission induction shortens granulocytopenia and may decrease morbidity due to infections. However, the optimal timing of G-CSF administration after chemotherapy is not known. In a prospective randomized multi-center study, adult ALL patients were treated with high-dose ARA-C [HDAC, 3 g/m(2) bid (1 g/m(2) bid for T-ALL) days 1-4] and mitoxantrone (MI 10 mg/m(2) days 3-5). They were randomized to receive recombinant human G-CSF (Lenograstim) 263 micro g/day SC starting either from day 12 (Group 1) or day 17 (Group 2). Fifty-five patients (41 male, 14 female) with a median age of 34 years (range: 18-55 years) were enrolled into the study; 50 patients were evaluable. The median duration of neutropenia <500/ micro l after HDAC/MI was 12 days (range: 7-22 days) in the early G-CSF Group 1 and also 12 days (range: 4-22 days) in the late G-CSF Group 2; this was shorter than in the historical control group (15 days, range: 4-43 days, n=46) where the patients received identical cytotoxic treatment without G-CSF. Seventeen infections were observed in 14 patients in Group 1 (47%) and 13 infections in 10 patients in Group 2 (50%) compared to 27 infections in 49 patients of the historical control (54%). In Group 1, the patients received a median of 11 injections with G-CSF (range: 7-22) compared to 7 injections (range: 4-19) in Group 2. The total administered dose of G-CSF in Group 2 was significantly reduced by 40% ( P<0.0001). The delayed start of G-CSF after HDAC/MI in ALL achieves the same clinical benefit compared to the earlier initiation of G-CSF. The reduction of treatment costs by reducing the total G-CSF dose may be important in future treatment with this hematopoietic growth factor.

Adolescent↗
PubMed2002

Bendamustine is effective in relapsed or refractory aggressive non-Hodgkin's lymphoma.

BACKGROUND: Bendamustine, an alkylating agent with a nitrogen mustard group and a purine-like benzimidazol group, has been shown to be effective in several solid tumors and indolent non-Hodgkin's lymphomas, but has not yet been studied for efficacy in aggressive lymphomas. PATIENTS AND METHODS: We conducted a phase II study in patients with relapsed or refractory high-grade non-Hodgkin's lymphomas, using bendamustine at a dose of 120 mg/m(2) on days 1 and 2, every 3 weeks for up to six cycles. Twenty-one patients were enrolled; 18 were evaluable for response and toxicity, 10 of whom were refractory to previous chemotherapy. RESULTS: With three patients achieving a complete response (at 6, >or=8 and >or=22 months) and five a partial response (three at 2 months, one at 3 months and one at 10 months), the total response rate of the evaluable patients was 44% (eight out of 18; 38% of all patients). Two complete and two partial responders were refractory to prior treatment. In 10 patients, treatment had to be stopped after one to three cycles due to progressive disease or hematological toxicity (n = 2). Non-hematological side effects were mild. Eight (13%) WHO grade 3 and no grade 4 events were observed in 60 evaluable treatment cycles. Hematologic toxicity was moderate (grade 3 and 4): anemia in five cycles (8%), leukopenia in seven (12%) and thrombocytopenia in eight (13%). CONCLUSIONS: Bendamustine as a single agent is effective against aggressive lymphoma, even in cases of refractory disease. Further studies are warranted to determine the significance of bendamustine in the treatment of aggressive lymphomas.

Adult↗
PubMed2001

Effective treatment with rituximab in a patient with refractory prolymphocytoid transformed B-chronic lymphocytic leukemia and Evans syndrome.

A 65-year-old male who had been diagnosed as having chronic lymphocytic leukemia (CLL) stage Rai 0 three years previously presented in October 1998 with progressive disease (splenomegaly, increasing lymphocytosis: 30/nl) and 50% prolymphocytes in his peripheral blood. The patient was refractory to initial treatment with fludarabine and epirubicin, and 2-chlorodeoxyadenosine. Additionally, the patient developed Evans syndrome. Therapy with cyclophosphamide, vincristine, and prednisone lead to an improvement of hemolysis, but the patient remained thrombocytopenic. Subsequently, lymphocytes further increased to 135/nl, and cyclophosphamide 3 g/m2 was again given but without effect on the peripheral lymphocyte count. At this stage, therapy with rituximab 375 mg/m2 four times weekly was initiated. The platelet count normalized within 1 week after the first dose of rituximab, and the lymphocyte count dropped within 2 months to 1.1/nl. This case demonstrates that patients with prolymphocytoid transformed B-CLL refractory to purine analogs and alkylating agents and autoimmune-hemolytic disease can effectively and safely be treated with rituximab and indicates that an investigation of antibody therapy is warranted in this patient group.

Aged↗
PubMed2001

TGF beta-induced SMAD2 phosphorylation predicts inhibition of thymidine incorporation in CD34+ cells from healthy donors, but not from patients with AML after MDS.

Cells from patients with MDS-derived AML display heterogeneous proliferative responses to transforming growth factor beta (TGF beta). We analyzed growth inhibition and SMAD2 phosphorylation by TGF beta in CD34+ cells from nine patients, as compared to normal controls. While TGF beta consistently inhibited thymidine incorporation of normal cells (41% of control, P < 0.05), cells from patients with AML were growth-inhibited in only four of seven cases (40%), whereas TGF beta stimulated thymidine incorporation in the three other samples (166%). Remarkably, TPO reverted the stimulatory effect of TGF beta to profound growth inhibition. Upon exposure to TGF beta, SMAD2 protein was phosphorylated in normal CD34+ cells (n = 3), CD34+ leukemic blasts from all examined patients with AML (n = 4), and in the myeloid leukemic cell lines M-07e and HEL. TGF beta inhibited TPO-mediated thymidine incorporation, cell proliferation and survival in all samples analyzed. In M-07e cells and CD34+ cells from healthy donors, this inhibition was enhanced by an antagonist of JAK2 (AG490), but not a MEK-1 antagonist (PD098059). Conversely, in CD34+ cells from a patient with AML, both AG490 and PD098059 significantly enhanced TGF beta-mediated suppression of TPO-induced thymidine incorporation. Thus, in MDS-derived AML, altered responses to TGF beta may be due to defects downstream of SMAD2 and may involve MAPK activation.

Acute Disease↗
PubMed2001

[Involvement of the facial skull in Erdheim-Chester disease].

We report on a patient suffering from Erdheim-Chester-disease (ECD). ECD represents a very rare entity with lipogranulomatosis of mesenchymal origin. The most common radiological manifestation is the involvement of the long bones of the extremities. Here we find sclerosis of the spongiosa combined with a thinning of cortical structures. This often results in a small crack of hyperlucency between corticals and spongiosa. Our case demonstrates an involvement of the craniofacial part of the skull showing sclerosis of the upper jaw bone. This manifestation has not yet been reported in the literature.

Adult↗
PubMed2000

Intensive chemotherapy with idarubicin, ara-C, etoposide, and m-AMSA followed by immunotherapy with interleukin-2 for myelodysplastic syndromes and high-risk Acute Myeloid Leukemia (AML).

Intensive chemotherapy followed by treatment with interleukin-2 (IL-2) was evaluated in a prospective, randomized, multicenter trial including 18 patients with refractory anemia with excess of blasts in transformation (RAEB-T), 86 patients with acute myeloid leukemia (AML) evolving from myelodysplastic syndromes, and six patients with secondary AML after previous chemotherapy. Median age was 58 years (range: 18-76 years). Forty-nine patients (45%) achieved a complete remission (CR) after two induction cycles with idarubicin, ara-C, and etoposide, 52% of them aged </=60 years and 35% aged >60 years (p=0.06). After two consolidation courses, patients were randomized to four cycles of either high- or low-dose IL-2. Patients aged up to 55 years with an HLA-identical sibling donor were eligible for allogeneic bone marrow transplantation. The median relapse-free survival was 12.5 months, with a probability of ongoing CR at 6.5 years of 19%. Overall survival of all patients was 8 months, and 21 months for the CR patients. Median survival was significantly longer among patients aged </=60 years than among the older patients (16 vs 6 months, p<0.001). Median duration of survival and relapse-free survival were not statistically different in the two IL-2 treatment arms.

Acute Disease↗
PubMed2000

Effect of treatment with amifostine used as a single agent in patients with refractory anemia on clinical outcome and serum tumor necrosis factor alpha levels.

Amifostine increases in vitro burst-forming unit-erythroid and colony-forming unit-granulocyte/granulcoyte-macrophage cultured from bone-marrow cells from patients with myelodysplastic syndrome (MDS). Several small clinical studies give divergent informations about the potential of amifostine as single agent to improve hematopoiesis in MDS patients. In these studies, patients with refractory anemia (RA), RA with excess of blasts (RAEB), and RAEB in transformation (RAEB-T) were analyzed together, resulting in response rates varying from 8% to 30%. The present multi-center study evaluated whether treatment with amifostine is of clinical benefit in patients with RA who are transfusion dependent. The effect on transfusion frequency as well as on platelets and absolute neutrophil count (ANC) was examined in 14 patients with RA [median age 67 years (55-72 years), male:female 9:5]. Four treatment cycles were planned, each consisting of intravenous amifostine at 200 mg/m2/day three times per week followed by a 2-week interval. Since tumor necrosis factor (TNF) alpha is a main suppressive cytokine for hematopoiesis in RA patients, serum samples for analyzing endogenous levels of TNF alpha were collected prior to the study and after four treatment cycles. In three patients (21%), reduced transfusion requirement with prolongation of the transfusion interval from 4 weeks to 8 weeks (two patients) and 4 weeks to 6 weeks was seen. An increase in ANC from 400/microliter to 2600/microliter and 200/microliter to 3400/microliter was observed in two patients. Platelets increased from 129,000/microliter to 277,000/microliter in an additional patient. In one patient, disease progression from RA to RAEB was observed. Serum TNF alpha levels were increased in MDS patients compared with normal controls (18.8 pg/ml vs 9.1 pg/ml), and there was no change during the treatment with amifostine (17.5 pg/ml). In conclusion, treatment with amifostine as a single agent was of limited benefit in patients with RA. The serum TNF alpha levels were unchanged during treatment with amifostine in RA patients.

Aged↗
PubMed2000

Cytokine therapy for myelodysplastic syndrome.

The myelodysplastic syndromes are a heterogeneous family of hematologic disorders characterized by ineffective hematopoiesis. Because of the interpatient variability regarding prognosis and morbidity, management of myelodysplastic syndromes continues to be a challenge to clinical hematologists. Pancytopenia and defective function of neutrophils and platelets carry a high risk of infectious or hemorrhagic complications. Erythropoietin is perhaps the most commonly used therapeutic option, second only to transfusion; improvement of erythropoiesis is seen in approximately 20% of patients, mainly in those with relatively preserved erythroid function and no or low transfusion requirements. Coadministration of erythropoietin with either granulocyte colony-stimulating factor or granulocyte-macrophage colony-stimulating factor may increase the response rate up to 50%. Although prophylactic administration of granulocyte- or granulocyte-macrophage colony-stimulating factor cannot be recommended, treatment of febrile neutropenia might benefit from administration of granulocyte- or granulocyte-macrophage colony-stimulating factor in addition to antibiotics.

Apoptosis↗
PubMed2000

Defective megakaryocytic development in myelodysplastic syndromes.

Megakaryocytic proliferation and differentiation is typically abnormal in patients with myelodysplastic syndromes (MDS). The underlying mechanisms for this finding are not known, but may involve defects at the level of the thrombopoietin-receptor (c-mpl) or post-receptor signaling pathways in megakaryocyte progenitor cells. Premature apoptosis of the bone marrow cells and inhibitory effects of cytokines such as tumor necrosis factor alpha have been implicated as contributing to altered megakaryopoiesis in MDS, but their significance remains unclear. The availability of thrombopoietin (TPO) has facilitated more detailed analysis of megakaryocytic biology using several experimental in-vitro systems. However numerous studies have shown that the developmental abnormalities of MDS megakaryocytes could not be corrected by TPO. Increasing investigations are being extended to the evaluation of signal transduction pathways of c-mpl both in cell lines and human hematopoietic cells in order to identify the molecular mechanisms responsible for the defective megakaryocytic development in MDS.

Cell Differentiation↗
PubMed1999

Treatment of patients with low-risk myelodysplastic syndromes using a combination of all-trans retinoic acid, interferon alpha, and granulocyte colony-stimulating factor.

Used as single agents, ATRA, G-CSF, and IFN-alpha have shown a moderate benefit in patients with low-risk MDS, with a response rate of 10%. The aim of the present study was to evaluate the efficacy of a combination of these agents. The effect on hemoglobin (Hb), platelets, and absolute neutrophil count (ANC), as well as on transfusion frequency, was examined in 25 patients with MDS (11 RA, four RARS, eight RAEB, two CMML). The median age was 61 years (range 44-81), and the male/female ratio was 14/11. Treatment consisted of ATRA at 25 mg/m2/day p.o. for months 1, 3, 5, 7, 9, and 11, IFN-alpha at 1.5 MIU twice a week s.c. for 52 weeks, and, in patients with initial ANC <500/microl, G-CSF at 100-480 microg daily s.c. according to the degree of ANC. The duration of therapy was scheduled for 12 months. Two patients achieved ongoing CR (+19 months; +16 months), one patient with RA after 3 months and one with CMML after 7 months of treatment. In all patients, the mean ANC increased significantly from 1400+/-200/microl before the start of therapy to 3500+/-600/microl at the end of treatment (p=0.025). In two patients an increase of Hb was observed, and one patient ceased to require transfusions. In an additional patient with RA and 5q-syndrome, the platelet count normalized following administration of ATRA/IFN-alpha, increasing from 89,000/microl to 293,000/microl. The eight RAEB patients were nonresponders. We conclude that therapy with ATRA, IFNalpha, and G-CSF is effective in approximately 35% of low-risk MDS patients (in this study: six of 17) and may induce complete remission in individual cases.

Adult↗
PubMed1999

Characterization of defective megakaryocytic development in patients with myelodysplastic syndromes.

Megakaryocytic differentiation of progenitor cells was investigated in nine patients with low-risk myelodysplastic syndromes (MDS) (eight refractor anemia [RA] and one RA with ringed sideroblasts [RARS] and five patients with high-risk MDS (two RA with excess of blasts [RAEB] and three RAEB in transformation [RAEB-T]). Bone marrow-derived CD34+ cells were enriched to a purity of 87% +/- 2% (mean +/- SEM) and assayed in short-term suspension cultures in the presence of 10 ng/mL of PEGylated recombinant human megakaryocyte (MK) growth and development factor (PEG-rHuMGDF) and in addition to 50 ng/mL stem cell factor and 10 ng/mL interleukin-3. Cells of the megakaryocytic lineage were identified by flow cytometric analysis of CD42b (GP1b) and mature MKs by morphologic criteria. Transcription of c-mpl receptor-specific mRNA in the CD34+ cells of these patients was investigated by full-length reverse transcriptase polymerase chain reaction of the p form of c-mpl as well as of the alternative splice product c-mpl k. CD34+ cells from seven healthy bone marrow donors served as controls. Differentiation along the MK pathway was stimulated in five patients with RA. C-mpl mRNA was expressed in the CD34+ cells in all cases. In three low-risk patients the capacity for in vitro MK growth was absent or minimal even though mRNA for c-mpl receptor was detected in the CD34+ cells of this group as well. In patients with high-risk MDS, PEG-rHuMGDF stimulated in vitro MK growth from CD34+ cells in only one of five cases. As in the patients with low-risk MDS, c-mpl mRNA for both c-mpl p and c-mpl k splicing products was detected. These results indicate that the in vitro response to stimulation with c-mpl ligand discriminates between two groups of patients with low-risk MDS and that the observed defect in megakaryocytic development is unrelated to the level of c-mpl expression in both low-risk and high-risk MDS.

Antigens, Differentiation↗
PubMed1999

Megakaryocytic growth in patients with refractory anemia is suppressed by treatment with interferon alpha.

IFN alpha alone or in combination with retinoids or haematopoietic growth factors has been used to treat patients with early MDS because of its properties as a differentiation inducing agent. We investigated whether treatment of patients with refractory anemia (RA) with IFN alpha (1.5x10(6) IU twice a week) and intermittent all-trans retinoic acid (ATRA, 25 mg/m2/d) influences in-vitro megakaryocytic (MK) proliferation and differentiation stimulated by PEG-rHuMGDF. Low-density non-adherent bone marrow (BM) cells from 8 patients with RA were assayed prior to any treatment other than supportive and after a period of 6 months of treatment. MK development was assayed in suspension cultures in the presence of PEG-rHuMGDF and SCF for 7 d using morphological criteria and flow cytometric analysis of CD42b (GP1b) positive cells. BM-cells from 10 healthy individuals served as control. Following stimulation with PEG-rHuMGDF 23+/-7% and 16+/-4% of control cells were CD42b positive after 5 and 7 d of cultures, respectively. In cultures of cells from MDS patients prior to treatment 8+/-2% and 7+/-3% of cells were CD42b+ on days 5 and 7. In the course of IFN alpha treatment cultures of all BM samples from these MDS patients revealed a significant reduction of MK precursor cells (3+/-2%, CD42b+, p=0.03 and 0.04). In conclusion, treatment with TFN alpha and ATRA did not result in improved megakaryocytopoiesis as assessed by in-vitro cultures. On the contrary, low-dose IFN alpha appears to suppress cell proliferation as well as MK development.

Administration, Oral↗
PubMed1996

[Disseminated pneumoperitoneum during the therapy of lymphoma with methotrexate and cytosine arabinoside].

HISTORY AND CLINICAL FINDINGS: A 58-year-old man was treated for abdominal and inguinal recurrence of a centroblastic non-Hodgkin lymphoma with high doses of methotrexate and cytosine arabinoside. A chest radiogram, taken on the 18th day of chemotherapy to exclude pulmonary infiltration, revealed pneumoperitoneum. The patients's complaints were merely of abdominal fullness and persisting diarrhoea. His general state was hardly impaired, the abdomen soft on palpation with active peristalsis. INVESTIGATIONS: There was aplastic anaemia (haemoglobin 9.9 g/dl, erythrocytes 3.4 x 10(6)/microliters, white cells 1000/microliters, platelets 20,000/microliters. Plain film of the abdomen and abdominal computed tomography confirmed pneumoperitoneum. Intraluminal air had caused wall dissection in the ascending and transverse colon (pneumatosis coli as cause of the pneumoperitoneum). TREATMENT AND COURSE: There was complete absorption of the free abdominal air by the 29th day of chemotherapy under parenteral nutrition and metronidazole (3 x 500 mg daily).

Anemia, Aplastic↗
PubMed1996

Improved multilineage response of hematopoiesis in patients with myelodysplastic syndromes to a combination therapy with all-trans-retinoic acid, granulocyte colony-stimulating factor, erythropoietin and alpha-tocopherol.

Differentiation induction therapy is being tested in myelodysplastic syndromes to ameliorate maturation defects and to restore normal hematopoietic function. To this end, 17 patients (eight with refractory anemia, two with refractory anemia and ring sideroblasts, and seven with refractory anemia and excess of blast cells) were treated with a combination of all-trans-retinoic acid (ATRA), granulocyte colony-stimulating factor (G-CSF), erythropoietin (EPO), and alpha-tocopherol for durations of 8-16 weeks. Absolute neutrophil counts increased in all patients; platelet counts increased in five patients with discontinuation of transfusion needs in two of four transfusion-dependent patients. Stimulation of erythropoiesis was seen in eight patients with an increase in hemoglobin concentration in three, a discontinuation of transfusion requirements in another three, and a significant increase in reticulocyte counts as the only parameter in two patients. Clinically important multilineage responses with increases of hemoglobin levels or discontinuation of transfusion needs were thus seen in six patients (35.3%) with three patients having a trilineage response. Serum erythropoietin concentrations did not differ significantly between responders and nonresponders, but the erythroid response was accompanied by a rise in the serum transferrin receptor levels. In the bone marrow, the myeloid-to-erythroid ratio and the maturation index of myeloid cells increased during therapy, while the percentage of blast cells did not change. Cytogenetic analysis demonstrated the persistence of the abnormal clones. Prior to therapy, nonresponders had a significantly higher serum TNF level than responders. Serum concentrations of TNF-alpha and soluble TNF-alpha receptor significantly increased during therapy, but mainly in the patients without an erythroid and platelet response. Soluble IL-2 receptor and soluble ICAM-1 concentrations both increased. This pilot study demonstrates that treatment with ATRA/G-CSF/EPO/tocopherol is well tolerated, leading to normalization of neutrophil counts in most, and to improvement of platelets and red blood cells in a significant subgroup of patients.

Adult↗